Toggle SGML Header (+)


Section 1: 10-K (10-K)

unm-20191231
00000055132019FYFALSE--12-31TRUEnonononono104.0no0.62.3nonono0.20.20.20.2P5Yfive yearseight yearsP3YP3YP1YP3YP1YP3YnononoP5YP10YP5YP10YP1YP3YP1YP3YP5YP10YP5YP10YP1YP3YP1YP3Y00000055132019-01-012019-12-310000005513exch:XNYSus-gaap:CommonClassAMember2019-01-012019-12-310000005513exch:XNYSunm:A6250JuniorSubordinatedNotesDue2058Member2019-01-012019-12-31iso4217:USD00000055132019-12-31xbrli:shares00000055132020-02-140000005513us-gaap:AccidentAndHealthInsuranceSegmentMemberunm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513us-gaap:AccidentAndHealthInsuranceSegmentMemberunm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513us-gaap:AccidentAndHealthInsuranceSegmentMemberunm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:ColonialLifeMemberus-gaap:LifeInsuranceSegmentMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:ColonialLifeMemberus-gaap:LifeInsuranceSegmentMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:ColonialLifeMemberus-gaap:LifeInsuranceSegmentMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:CancerAndCriticalIllnessColonialMemberunm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:CancerAndCriticalIllnessColonialMemberunm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:CancerAndCriticalIllnessColonialMemberunm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:ColonialLifeMember2019-01-012019-12-310000005513unm:ColonialLifeMember2018-01-012018-12-310000005513unm:ColonialLifeMember2017-01-012017-12-3100000055132018-12-31iso4217:USDxbrli:shares00000055132018-01-012018-12-3100000055132017-01-012017-12-310000005513us-gaap:CommonStockMember2018-12-310000005513us-gaap:CommonStockMember2017-12-310000005513us-gaap:CommonStockMember2016-12-310000005513us-gaap:CommonStockMember2019-01-012019-12-310000005513us-gaap:CommonStockMember2018-01-012018-12-310000005513us-gaap:CommonStockMember2017-01-012017-12-310000005513us-gaap:CommonStockMember2019-12-310000005513us-gaap:AdditionalPaidInCapitalMember2018-12-310000005513us-gaap:AdditionalPaidInCapitalMember2017-12-310000005513us-gaap:AdditionalPaidInCapitalMember2016-12-310000005513us-gaap:AdditionalPaidInCapitalMember2019-01-012019-12-310000005513us-gaap:AdditionalPaidInCapitalMember2018-01-012018-12-310000005513us-gaap:AdditionalPaidInCapitalMember2017-01-012017-12-310000005513us-gaap:AdditionalPaidInCapitalMember2019-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2018-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2017-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2016-12-310000005513us-gaap:AccountingStandardsUpdate201602Memberus-gaap:AccumulatedOtherComprehensiveIncomeMember2018-12-310000005513us-gaap:AccountingStandardsUpdate201601Memberus-gaap:AccumulatedOtherComprehensiveIncomeMember2017-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMembersrt:RestatementAdjustmentMember2018-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMembersrt:RestatementAdjustmentMember2017-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMembersrt:RestatementAdjustmentMember2016-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2019-01-012019-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2018-01-012018-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2017-01-012017-12-310000005513us-gaap:AccumulatedOtherComprehensiveIncomeMember2019-12-310000005513us-gaap:RetainedEarningsMember2018-12-310000005513us-gaap:RetainedEarningsMember2017-12-310000005513us-gaap:RetainedEarningsMember2016-12-310000005513us-gaap:RetainedEarningsMemberus-gaap:AccountingStandardsUpdate201602Member2018-12-310000005513us-gaap:RetainedEarningsMemberus-gaap:AccountingStandardsUpdate201601Member2017-12-310000005513us-gaap:RetainedEarningsMembersrt:RestatementAdjustmentMember2018-12-310000005513us-gaap:RetainedEarningsMembersrt:RestatementAdjustmentMember2017-12-310000005513us-gaap:RetainedEarningsMembersrt:RestatementAdjustmentMember2016-12-310000005513us-gaap:RetainedEarningsMember2019-01-012019-12-310000005513us-gaap:RetainedEarningsMember2018-01-012018-12-310000005513us-gaap:RetainedEarningsMember2017-01-012017-12-310000005513us-gaap:RetainedEarningsMember2019-12-310000005513us-gaap:TreasuryStockMember2018-12-310000005513us-gaap:TreasuryStockMember2017-12-310000005513us-gaap:TreasuryStockMember2016-12-310000005513us-gaap:TreasuryStockMember2019-01-012019-12-310000005513us-gaap:TreasuryStockMember2018-01-012018-12-310000005513us-gaap:TreasuryStockMember2017-01-012017-12-310000005513us-gaap:TreasuryStockMember2019-12-3100000055132017-12-3100000055132016-12-31unm:Integer0000005513us-gaap:AccountingStandardsUpdate201602Member2018-12-310000005513us-gaap:AccountingStandardsUpdate201602Member2019-01-010000005513us-gaap:AccountingStandardsUpdate201602Membersrt:RestatementAdjustmentMember2019-01-01xbrli:pure0000005513us-gaap:FairValueInputsLevel1Member2019-12-310000005513unm:FairValueInputsOtherThanLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberunm:PricingServiceMember2019-12-310000005513unm:OtherObservableMarketDataMemberus-gaap:FairValueInputsLevel2Member2019-12-310000005513unm:FairValueInputsLevel2OrLevel3Member2019-12-310000005513unm:NotRedeemableMemberus-gaap:PrivateEquityFundsMemberunm:PrivateCreditMember2019-12-310000005513us-gaap:PrivateEquityFundsMemberunm:Quarterlyafter2yearlockwith90daysnoticeMemberunm:PrivateCreditMember2019-12-310000005513us-gaap:PrivateEquityFundsMemberunm:PrivateCreditMember2019-12-310000005513unm:NotRedeemableMemberus-gaap:PrivateEquityFundsMemberunm:PrivateEquityLimitedPartnershipMember2019-12-310000005513unm:NotRedeemableMemberus-gaap:PrivateEquityFundsMemberunm:RealAssetsMember2019-12-310000005513unm:QuarterlyMemberus-gaap:PrivateEquityFundsMemberunm:RealAssetsMember2019-12-310000005513us-gaap:PrivateEquityFundsMemberunm:RealAssetsMember2019-12-310000005513us-gaap:PrivateEquityFundsMember2019-12-310000005513unm:NotRedeemableMemberus-gaap:PrivateEquityFundsMemberunm:PrivateCreditMember2018-12-310000005513us-gaap:PrivateEquityFundsMemberunm:Quarterlyafter2yearlockwith90daysnoticeMemberunm:PrivateCreditMember2018-12-310000005513us-gaap:PrivateEquityFundsMemberunm:PrivateCreditMember2018-12-310000005513unm:NotRedeemableMemberus-gaap:PrivateEquityFundsMemberunm:PrivateEquityLimitedPartnershipMember2018-12-310000005513unm:NotRedeemableMemberus-gaap:PrivateEquityFundsMemberunm:RealAssetsMember2018-12-310000005513unm:QuarterlyMemberus-gaap:PrivateEquityFundsMemberunm:RealAssetsMember2018-12-310000005513us-gaap:PrivateEquityFundsMemberunm:RealAssetsMember2018-12-310000005513us-gaap:PrivateEquityFundsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel2Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:USTreasuryAndGovernmentMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:USStatesAndPoliticalSubdivisionsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PublicUtilityBondsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PublicUtilityBondsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:PublicUtilityBondsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:AssetBackedSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:AssetBackedSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:AssetBackedSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel2Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:RedeemablePreferredStockMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:RedeemablePreferredStockMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:RedeemablePreferredStockMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:RedeemablePreferredStockMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel2Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:CreditDefaultSwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PrivateEquityFundsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PrivateEquityFundsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:CurrencySwapMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel2Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel2Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:USTreasuryAndGovernmentMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:USStatesAndPoliticalSubdivisionsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:ForeignGovernmentDebtSecuritiesMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:ForeignGovernmentDebtSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PublicUtilityBondsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PublicUtilityBondsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PublicUtilityBondsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:PublicUtilityBondsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:AssetBackedSecuritiesMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:AssetBackedSecuritiesMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:AssetBackedSecuritiesMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel2Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:RedeemablePreferredStockMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:RedeemablePreferredStockMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:RedeemablePreferredStockMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:RedeemablePreferredStockMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:RedeemablePreferredStockMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:CurrencySwapMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:CurrencySwapMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:CurrencySwapMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel2Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CreditDefaultSwapMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:CreditDefaultSwapMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PrivateEquityFundsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PrivateEquityFundsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PrivateEquityFundsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:InterestRateSwapMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:InterestRateSwapMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:InterestRateSwapMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:CurrencySwapMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CurrencySwapMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:CurrencySwapMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel2Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsRecurringMemberus-gaap:DerivativeMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2018-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2019-01-012019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2018-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2019-01-012019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2019-12-310000005513us-gaap:PublicUtilityBondsMember2018-12-310000005513us-gaap:PublicUtilityBondsMember2019-01-012019-12-310000005513us-gaap:PublicUtilityBondsMember2019-12-310000005513us-gaap:AssetBackedSecuritiesMember2018-12-310000005513us-gaap:AssetBackedSecuritiesMember2019-01-012019-12-310000005513us-gaap:AssetBackedSecuritiesMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMember2019-01-012019-12-310000005513us-gaap:CorporateDebtSecuritiesMember2019-12-310000005513us-gaap:RedeemablePreferredStockMember2018-12-310000005513us-gaap:RedeemablePreferredStockMember2019-01-012019-12-310000005513us-gaap:RedeemablePreferredStockMember2019-12-310000005513us-gaap:DebtSecuritiesMember2018-12-310000005513us-gaap:DebtSecuritiesMember2019-01-012019-12-310000005513us-gaap:DebtSecuritiesMember2019-12-310000005513us-gaap:EquitySecuritiesMember2018-12-310000005513us-gaap:EquitySecuritiesMember2019-01-012019-12-310000005513us-gaap:EquitySecuritiesMember2019-12-310000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-01-012019-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2017-12-310000005513us-gaap:ForeignGovernmentDebtSecuritiesMember2018-01-012018-12-310000005513us-gaap:PublicUtilityBondsMember2017-12-310000005513us-gaap:PublicUtilityBondsMember2018-01-012018-12-310000005513us-gaap:CorporateDebtSecuritiesMember2017-12-310000005513us-gaap:CorporateDebtSecuritiesMember2018-01-012018-12-310000005513us-gaap:RedeemablePreferredStockMember2017-12-310000005513us-gaap:RedeemablePreferredStockMember2018-01-012018-12-310000005513us-gaap:DebtSecuritiesMember2017-12-310000005513us-gaap:DebtSecuritiesMember2018-01-012018-12-310000005513us-gaap:EquitySecuritiesMember2017-12-310000005513us-gaap:EquitySecuritiesMember2018-01-012018-12-310000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2017-12-310000005513us-gaap:EmbeddedDerivativeFinancialInstrumentsMember2018-01-012018-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMember2019-12-31utr:Rate0000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MarketApproachValuationTechniqueMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:MarketApproachValuationTechniqueMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMembersrt:WeightedAverageMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputEntityCreditRiskMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MarketApproachValuationTechniqueMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputEntityCreditRiskMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:MarketApproachValuationTechniqueMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputEntityCreditRiskMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMembersrt:WeightedAverageMember2019-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMemberus-gaap:EquitySecuritiesMember2019-12-310000005513us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DerivativeFinancialInstrumentsLiabilitiesMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MarketApproachValuationTechniqueMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:MarketApproachValuationTechniqueMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputDiscountForLackOfMarketabilityMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMembersrt:WeightedAverageMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputEntityCreditRiskMemberus-gaap:FairValueInputsLevel3Membersrt:MinimumMemberus-gaap:MarketApproachValuationTechniqueMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputEntityCreditRiskMemberus-gaap:FairValueInputsLevel3Membersrt:MaximumMemberus-gaap:MarketApproachValuationTechniqueMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:MeasurementInputEntityCreditRiskMemberus-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMembersrt:WeightedAverageMember2018-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:MarketApproachValuationTechniqueMemberus-gaap:EquitySecuritiesMember2018-12-310000005513us-gaap:ValuationTechniqueDiscountedCashFlowMemberus-gaap:FairValueInputsLevel3Memberus-gaap:DerivativeFinancialInstrumentsLiabilitiesMember2018-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsNonrecurringMember2019-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel3Member2019-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMember2019-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsNonrecurringMember2018-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMemberus-gaap:FairValueInputsLevel3Member2018-12-310000005513us-gaap:FairValueMeasurementsNonrecurringMember2018-12-310000005513us-gaap:AllOtherCorporateBondsMember2019-12-310000005513us-gaap:DebtSecuritiesMember2019-12-310000005513us-gaap:AllOtherCorporateBondsMember2018-12-310000005513us-gaap:DebtSecuritiesMember2018-12-310000005513unm:AvailableForSaleSecuritiesUnrealizedGainPositionFairValueMember2019-12-310000005513unm:AvailableForSaleSecuritiesUnrealizedLossPositionFairValueMember2019-12-310000005513unm:AvailableForSaleSecuritiesUnrealizedGainPositionFairValueMember2018-12-310000005513unm:AvailableForSaleSecuritiesUnrealizedLossPositionFairValueMember2018-12-310000005513us-gaap:ExternalCreditRatingInvestmentGradeMember2019-12-310000005513us-gaap:ExternalCreditRatingNonInvestmentGradeMember2019-12-310000005513unm:PartnershipInterestsInTaxCreditInvestmentsMember2019-12-310000005513us-gaap:EquityMethodInvestmentsMember2019-12-310000005513unm:PartnershipInterestsInTaxCreditInvestmentsMember2018-12-310000005513us-gaap:EquityMethodInvestmentsMember2018-12-310000005513us-gaap:BondsMemberunm:SpecialPurposeEntityMember2018-12-310000005513srt:ApartmentBuildingMember2019-12-310000005513srt:ApartmentBuildingMember2018-12-310000005513srt:IndustrialPropertyMember2019-12-310000005513srt:IndustrialPropertyMember2018-12-310000005513srt:OfficeBuildingMember2019-12-310000005513srt:OfficeBuildingMember2018-12-310000005513srt:RetailSiteMember2019-12-310000005513srt:RetailSiteMember2018-12-310000005513srt:OtherPropertyMember2019-12-310000005513srt:OtherPropertyMember2018-12-310000005513unm:NewEnglandMember2019-12-310000005513unm:NewEnglandMember2018-12-310000005513unm:MiddleAtlanticMember2019-12-310000005513unm:MiddleAtlanticMember2018-12-310000005513unm:EastNorthCentralMember2019-12-310000005513unm:EastNorthCentralMember2018-12-310000005513unm:WestNorthCentralMember2019-12-310000005513unm:WestNorthCentralMember2018-12-310000005513unm:SouthAtlanticMember2019-12-310000005513unm:SouthAtlanticMember2018-12-310000005513unm:EastSouthCentralMember2019-12-310000005513unm:EastSouthCentralMember2018-12-310000005513unm:WestSouthCentralMember2019-12-310000005513unm:WestSouthCentralMember2018-12-310000005513unm:MountainMember2019-12-310000005513unm:MountainMember2018-12-310000005513unm:PacificMember2019-12-310000005513unm:PacificMember2018-12-310000005513unm:CreditRatingMember2019-12-310000005513unm:CreditRatingMember2018-12-310000005513unm:BaaCreditRatingMember2019-12-310000005513unm:BaaCreditRatingMember2018-12-310000005513unm:BBCreditRatingMember2019-12-310000005513unm:BBCreditRatingMember2018-12-310000005513unm:LoanToValueRatioBelowOrEqualTo65PercentMember2019-12-310000005513unm:LoanToValueRatioBelowOrEqualTo65PercentMember2018-12-310000005513unm:LoanToValueRatioAbove65To75PercentMember2019-12-310000005513unm:LoanToValueRatioAbove65To75PercentMember2018-12-310000005513unm:LoanToValueRatioAbove75To85PercentMember2019-12-310000005513unm:LoanToValueRatioAbove75To85PercentMember2018-12-310000005513unm:LoanToValueRatioAbove85PercentMember2019-12-310000005513unm:LoanToValueRatioAbove85PercentMember2018-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2019-01-012019-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2017-01-012017-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2018-01-012018-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2018-09-300000005513us-gaap:CommercialRealEstateMember2018-01-012018-12-310000005513unm:OffBalanceSheetAmountMember2019-12-310000005513unm:OffBalanceSheetAmountMember2018-12-310000005513us-gaap:CorporateBondSecuritiesMemberus-gaap:MaturityOvernightMember2019-12-310000005513us-gaap:CorporateBondSecuritiesMemberus-gaap:MaturityOvernightMember2018-12-310000005513us-gaap:MaturityOvernightMember2019-12-310000005513us-gaap:MaturityOvernightMember2018-12-310000005513us-gaap:MortgageBackedSecuritiesMember2019-12-310000005513us-gaap:MortgageBackedSecuritiesMember2018-12-310000005513us-gaap:OverTheCounterMember2019-12-310000005513us-gaap:OverTheCounterMember2018-12-310000005513us-gaap:DebtSecuritiesMember2019-01-012019-12-310000005513us-gaap:DebtSecuritiesMember2018-01-012018-12-310000005513us-gaap:DebtSecuritiesMember2017-01-012017-12-310000005513us-gaap:DerivativeMember2019-01-012019-12-310000005513us-gaap:DerivativeMember2018-01-012018-12-310000005513us-gaap:DerivativeMember2017-01-012017-12-310000005513us-gaap:MortgageReceivablesMember2019-01-012019-12-310000005513us-gaap:MortgageReceivablesMember2018-01-012018-12-310000005513us-gaap:MortgageReceivablesMember2017-01-012017-12-310000005513us-gaap:PolicyLoansMember2019-01-012019-12-310000005513us-gaap:PolicyLoansMember2018-01-012018-12-310000005513us-gaap:PolicyLoansMember2017-01-012017-12-310000005513us-gaap:EquitySecuritiesMember2019-01-012019-12-310000005513us-gaap:EquitySecuritiesMember2018-01-012018-12-310000005513us-gaap:EquitySecuritiesMember2017-01-012017-12-310000005513srt:PartnershipInterestMember2019-01-012019-12-310000005513srt:PartnershipInterestMember2018-01-012018-12-310000005513srt:PartnershipInterestMember2017-01-012017-12-310000005513us-gaap:OtherLongTermInvestmentsMember2019-01-012019-12-310000005513us-gaap:OtherLongTermInvestmentsMember2018-01-012018-12-310000005513us-gaap:OtherLongTermInvestmentsMember2017-01-012017-12-310000005513us-gaap:ShortTermInvestmentsMember2019-01-012019-12-310000005513us-gaap:ShortTermInvestmentsMember2018-01-012018-12-310000005513us-gaap:ShortTermInvestmentsMember2017-01-012017-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2018-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2019-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2017-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2019-01-012019-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2018-01-012018-12-310000005513us-gaap:CommercialRealEstatePortfolioSegmentMember2017-01-012017-12-310000005513unm:CreditExposureMember2019-12-310000005513unm:CreditExposureMember2018-12-310000005513us-gaap:CashMember2019-12-310000005513us-gaap:CashMember2018-12-310000005513us-gaap:AvailableforsaleSecuritiesMember2019-12-310000005513us-gaap:AvailableforsaleSecuritiesMember2018-12-310000005513unm:DerivativeFinancialInstrumentsReceiveVariablePayFixedMemberus-gaap:InterestRateSwapMember2016-12-310000005513us-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMember2016-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2016-12-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2016-12-310000005513us-gaap:ForwardContractsMember2016-12-310000005513unm:DerivativeFinancialInstrumentsReceiveVariablePayFixedMemberus-gaap:InterestRateSwapMember2017-01-012017-12-310000005513us-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMember2017-01-012017-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2017-01-012017-12-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2017-01-012017-12-310000005513us-gaap:ForwardContractsMember2017-01-012017-12-310000005513unm:DerivativeFinancialInstrumentsReceiveVariablePayFixedMemberus-gaap:InterestRateSwapMember2017-12-310000005513us-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMember2017-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2017-12-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2017-12-310000005513us-gaap:ForwardContractsMember2017-12-310000005513unm:DerivativeFinancialInstrumentsReceiveVariablePayFixedMemberus-gaap:InterestRateSwapMember2018-01-012018-12-310000005513us-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMember2018-01-012018-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2018-01-012018-12-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2018-01-012018-12-310000005513us-gaap:ForwardContractsMember2018-01-012018-12-310000005513unm:DerivativeFinancialInstrumentsReceiveVariablePayFixedMemberus-gaap:InterestRateSwapMember2018-12-310000005513us-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMember2018-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2018-12-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2018-12-310000005513us-gaap:ForwardContractsMember2018-12-310000005513unm:DerivativeFinancialInstrumentsReceiveVariablePayFixedMemberus-gaap:InterestRateSwapMember2019-01-012019-12-310000005513us-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMember2019-01-012019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2019-01-012019-12-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2019-01-012019-12-310000005513us-gaap:ForwardContractsMember2019-01-012019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveVariablePayFixedMemberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2019-12-310000005513us-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2019-12-310000005513us-gaap:ForwardContractsMember2019-12-310000005513us-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:ForwardContractsMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:AvailableforsaleSecuritiesMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:LongTermDebtMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:LongTermDebtMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayFixedMember2018-12-310000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMemberus-gaap:CreditRiskContractMember2018-12-310000005513us-gaap:NondesignatedMemberus-gaap:ForwardContractsMember2019-12-310000005513unm:DerivativeFinancialInstrumentsReceiveVariablePayFixedMemberus-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2016-12-310000005513unm:DerivativeFinancialInstrumentsReceiveVariablePayFixedMemberus-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2017-01-012017-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLongTermInvestmentsMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:OtherLongTermInvestmentsMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:FairValueHedgingMemberus-gaap:OtherLongTermInvestmentsMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:OtherLongTermInvestmentsMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:OtherLongTermInvestmentsMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:CreditRiskContractMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:OtherLiabilitiesMemberus-gaap:CreditRiskContractMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMemberus-gaap:OtherLiabilitiesMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:OtherLiabilitiesMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:NondesignatedMemberus-gaap:OtherLiabilitiesMember2019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLongTermInvestmentsMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:FairValueHedgingMemberus-gaap:OtherLongTermInvestmentsMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:OtherLiabilitiesMemberus-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:OtherLongTermInvestmentsMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:OtherLongTermInvestmentsMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:OtherLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-12-310000005513us-gaap:NondesignatedMemberus-gaap:CreditRiskContractMemberus-gaap:OtherLongTermInvestmentsMember2018-12-310000005513us-gaap:NondesignatedMemberus-gaap:OtherLiabilitiesMemberus-gaap:CreditRiskContractMember2018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMemberus-gaap:OtherLongTermInvestmentsMember2018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMemberus-gaap:OtherLiabilitiesMember2018-12-310000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMemberus-gaap:OtherLongTermInvestmentsMember2018-12-310000005513us-gaap:NondesignatedMemberus-gaap:OtherLiabilitiesMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2018-12-310000005513us-gaap:NondesignatedMemberus-gaap:OtherLongTermInvestmentsMember2018-12-310000005513us-gaap:NondesignatedMemberus-gaap:OtherLiabilitiesMember2018-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2019-01-012019-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2019-01-012019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2019-01-012019-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2019-01-012019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:FairValueHedgingMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2018-01-012018-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2018-01-012018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2018-01-012018-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:FairValueHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2018-01-012018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:FairValueHedgingMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:FairValueHedgingMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2017-01-012017-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2017-01-012017-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2017-01-012017-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2017-01-012017-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2017-01-012017-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2017-01-012017-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:InvestmentIncomeMember2017-01-012017-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:GainLossOnInvestmentsMember1us-gaap:DesignatedAsHedgingInstrumentMember2017-01-012017-12-310000005513us-gaap:FairValueHedgingMemberus-gaap:InterestRateSwapMemberus-gaap:InterestExpenseMemberus-gaap:DesignatedAsHedgingInstrumentMember2017-01-012017-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2017-01-012017-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2017-01-012017-12-310000005513us-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2019-01-012019-12-310000005513us-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2018-01-012018-12-310000005513us-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2017-01-012017-12-310000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMember2019-01-012019-12-310000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMember2018-01-012018-12-310000005513us-gaap:NondesignatedMemberus-gaap:CreditDefaultSwapMember2017-01-012017-12-310000005513us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2019-01-012019-12-310000005513us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2018-01-012018-12-310000005513us-gaap:NondesignatedMemberus-gaap:InterestRateSwapMember2017-01-012017-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2019-01-012019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2018-01-012018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:NondesignatedMember2017-01-012017-12-310000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2019-01-012019-12-310000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2018-01-012018-12-310000005513us-gaap:NondesignatedMemberus-gaap:EmbeddedDerivativeFinancialInstrumentsMember2017-01-012017-12-310000005513us-gaap:NondesignatedMember2019-01-012019-12-310000005513us-gaap:NondesignatedMember2018-01-012018-12-310000005513us-gaap:NondesignatedMember2017-01-012017-12-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2016-12-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2016-12-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2016-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2016-12-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2017-01-012017-12-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2017-01-012017-12-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2017-01-012017-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2017-01-012017-12-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2017-12-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2017-12-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2017-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2017-12-310000005513us-gaap:AccountingStandardsUpdate201601Memberus-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2018-01-010000005513us-gaap:AccountingStandardsUpdate201601Memberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2018-01-010000005513us-gaap:AccumulatedTranslationAdjustmentMemberus-gaap:AccountingStandardsUpdate201601Member2018-01-010000005513us-gaap:AccountingStandardsUpdate201601Memberus-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2018-01-010000005513us-gaap:AccountingStandardsUpdate201601Member2018-01-010000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2018-01-012018-12-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2018-01-012018-12-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2018-01-012018-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2018-01-012018-12-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2018-12-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2018-12-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2018-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2018-12-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-01-012019-12-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-01-012019-12-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2019-01-012019-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2019-01-012019-12-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-12-310000005513us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-12-310000005513us-gaap:AccumulatedTranslationAdjustmentMember2019-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2019-12-310000005513us-gaap:DebtSecuritiesMember2019-12-310000005513us-gaap:DebtSecuritiesMember2018-12-310000005513us-gaap:DebtSecuritiesMember2018-01-010000005513us-gaap:DebtSecuritiesMember2017-12-310000005513us-gaap:DebtSecuritiesMember2016-12-310000005513us-gaap:DebtSecuritiesMember2019-01-012019-12-310000005513us-gaap:DebtSecuritiesMember2018-01-012018-12-310000005513us-gaap:DebtSecuritiesMember2017-01-012017-12-310000005513us-gaap:OtherInvestmentsMember2019-12-310000005513us-gaap:OtherInvestmentsMember2018-12-310000005513us-gaap:OtherInvestmentsMember2018-01-010000005513us-gaap:OtherInvestmentsMember2017-12-310000005513us-gaap:OtherInvestmentsMember2016-12-310000005513us-gaap:OtherInvestmentsMember2019-01-012019-12-310000005513us-gaap:OtherInvestmentsMember2018-01-012018-12-310000005513us-gaap:OtherInvestmentsMember2017-01-012017-12-310000005513unm:DeferredAcquisitionCostsMember2019-12-310000005513unm:DeferredAcquisitionCostsMember2018-12-310000005513unm:DeferredAcquisitionCostsMember2018-01-010000005513unm:DeferredAcquisitionCostsMember2017-12-310000005513unm:DeferredAcquisitionCostsMember2016-12-310000005513unm:DeferredAcquisitionCostsMember2019-01-012019-12-310000005513unm:DeferredAcquisitionCostsMember2018-01-012018-12-310000005513unm:DeferredAcquisitionCostsMember2017-01-012017-12-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2019-12-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2018-12-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2018-01-010000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2017-12-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2016-12-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2019-01-012019-12-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2018-01-012018-12-310000005513unm:ReserveForFuturePolicyAndContractBenefitsMember2017-01-012017-12-310000005513us-gaap:ReinsuranceRecoverableMember2019-12-310000005513us-gaap:ReinsuranceRecoverableMember2018-12-310000005513us-gaap:ReinsuranceRecoverableMember2018-01-010000005513us-gaap:ReinsuranceRecoverableMember2017-12-310000005513us-gaap:ReinsuranceRecoverableMember2016-12-310000005513us-gaap:ReinsuranceRecoverableMember2019-01-012019-12-310000005513us-gaap:ReinsuranceRecoverableMember2018-01-012018-12-310000005513us-gaap:ReinsuranceRecoverableMember2017-01-012017-12-310000005513us-gaap:DeferredIncomeTaxChargesMember2019-12-310000005513us-gaap:DeferredIncomeTaxChargesMember2018-12-310000005513us-gaap:DeferredIncomeTaxChargesMember2018-01-010000005513us-gaap:DeferredIncomeTaxChargesMember2017-12-310000005513us-gaap:DeferredIncomeTaxChargesMember2016-12-310000005513us-gaap:DeferredIncomeTaxChargesMember2019-01-012019-12-310000005513us-gaap:DeferredIncomeTaxChargesMember2018-01-012018-12-310000005513us-gaap:DeferredIncomeTaxChargesMember2017-01-012017-12-310000005513us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2018-01-010000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2019-01-012019-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2018-01-012018-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2017-01-012017-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-01-012019-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2018-01-012018-12-310000005513us-gaap:InterestRateSwapMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2017-01-012017-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-01-012019-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2018-01-012018-12-310000005513us-gaap:ForeignExchangeContractMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2017-01-012017-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2019-01-012019-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2018-01-012018-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2017-01-012017-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember2019-01-012019-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember2018-01-012018-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember2017-01-012017-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2019-01-012019-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2018-01-012018-12-310000005513us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMemberus-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember2017-01-012017-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2019-01-012019-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2018-01-012018-12-310000005513us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMemberus-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember2017-01-012017-12-310000005513unm:AmountRelatedtoInterestMember2019-01-012019-12-310000005513unm:AmountRelatedtoInterestMember2018-01-012018-12-310000005513unm:AmountRelatedtoInterestMember2017-01-012017-12-310000005513unm:IncurredClaimsMember2019-01-012019-12-310000005513unm:IncurredClaimsMember2018-01-012018-12-310000005513unm:IncurredClaimsMember2017-01-012017-12-310000005513unm:ForeignCurrencyMember2019-01-012019-12-310000005513unm:ForeignCurrencyMember2018-01-012018-12-310000005513unm:ForeignCurrencyMember2017-01-012017-12-310000005513us-gaap:OperatingExpenseMember2019-01-012019-12-310000005513us-gaap:OperatingExpenseMember2018-01-012018-12-310000005513us-gaap:OperatingExpenseMember2017-01-012017-12-310000005513unm:ClaimReserveMember2019-01-012019-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMemberunm:GroupLifeMember2017-01-012017-12-310000005513unm:VoluntaryBenefitsMemberunm:UnumUsMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513us-gaap:TaxYear2017Member2018-01-012018-12-310000005513us-gaap:DomesticCountryMember2019-12-310000005513us-gaap:DomesticCountryMember2018-12-310000005513us-gaap:DomesticCountryMemberunm:SubsidiaryReturnMember2018-12-310000005513us-gaap:DomesticCountryMemberunm:SubsidiaryReturnMember2019-12-310000005513us-gaap:StateAndLocalJurisdictionMember2019-12-310000005513unm:SecuredNotesIssuedin2007Memberus-gaap:SeniorNotesMember2019-12-310000005513unm:SecuredNotesIssuedin2007Memberus-gaap:SeniorNotesMember2018-12-310000005513unm:NotesIssuedin1998with2028MaturityDateMemberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesIssuedin1998with2028MaturityDateMemberus-gaap:SeniorNotesMember2018-12-310000005513unm:NotesIssuedin2002Memberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesIssuedin2002Memberus-gaap:SeniorNotesMember2018-12-310000005513unm:NotesIssuedin2010Memberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesIssuedin2010Memberus-gaap:SeniorNotesMember2018-12-310000005513unm:NotesPayabledue2042Memberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesPayabledue2042Memberus-gaap:SeniorNotesMember2018-12-310000005513us-gaap:SeniorNotesMemberunm:NotesIssuedin2014Member2019-12-310000005513us-gaap:SeniorNotesMemberunm:NotesIssuedin2014Member2018-12-310000005513unm:NotesIssuedin2015Memberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesIssuedin2015Memberus-gaap:SeniorNotesMember2018-12-310000005513unm:NotesIssuedin2016Memberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesIssuedin2016Memberus-gaap:SeniorNotesMember2018-12-310000005513unm:NotesIssuedIn2019Memberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesIssuedIn2019Memberus-gaap:SeniorNotesMember2018-12-310000005513unm:NotesIssuedIn2019Due2049Memberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesIssuedIn2019Due2049Memberus-gaap:SeniorNotesMember2018-12-310000005513unm:NotesIssued1990to1996Memberus-gaap:MediumTermNotesMember2019-12-310000005513unm:NotesIssued1990to1996Memberus-gaap:MediumTermNotesMember2018-12-310000005513unm:NotesIssuedin1998with2038MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2019-12-310000005513unm:NotesIssuedin1998with2038MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2018-12-310000005513unm:NotesIssuedin2018witha2058MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2019-12-310000005513unm:NotesIssuedin2018witha2058MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2018-12-310000005513unm:FairValueHedgeAdjustmentLtDebtMember2019-12-310000005513unm:FairValueHedgeAdjustmentLtDebtMember2018-12-310000005513us-gaap:SeniorNotesMemberunm:NotesIssuedin2010Member2018-12-310000005513srt:ParentCompanyMember2019-12-310000005513unm:NorthwindHoldingsLlcMember2007-01-012007-12-310000005513unm:NorthwindHoldingsLlcMember2019-12-310000005513unm:NorthwindHoldingsLlcMember2017-01-012017-12-310000005513unm:NorthwindHoldingsLlcMember2019-01-012019-12-310000005513unm:NorthwindHoldingsLlcMember2018-01-012018-12-310000005513unm:SecuredNotesacquired2016Memberus-gaap:LongTermDebtMember2017-01-012017-12-310000005513unm:MediumTermNotesPayableDue2028Memberus-gaap:MediumTermNotesMember2019-01-012019-12-310000005513unm:MediumTermNotesPayableDue2028Memberus-gaap:MediumTermNotesMember2019-12-310000005513unm:NotesIssuedin1998with2028MaturityDateMemberus-gaap:SeniorNotesMember2019-01-012019-12-310000005513unm:NotesIssuedin1998with2028MaturityDateMemberus-gaap:SeniorNotesMember2019-12-310000005513us-gaap:SeniorNotesMemberunm:SeniorNotesPayableDue2021Member2019-01-012019-12-310000005513us-gaap:SeniorNotesMemberunm:SeniorNotesPayableDue2021Member2019-12-310000005513unm:NotesIssuedIn2019Due2049Memberus-gaap:SeniorNotesMember2019-01-012019-12-310000005513unm:NotesIssuedIn2019Memberus-gaap:SeniorNotesMember2019-01-012019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin1998with2018MaturityDateMember2018-12-310000005513unm:NotesIssuedin2018witha2058MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2018-01-012018-12-310000005513unm:NotesIssuedin1998with2038MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember1998-01-011998-12-310000005513us-gaap:JuniorSubordinatedDebtMemberunm:JuniorSubordinatedNotesPayableDue2038Member2019-12-310000005513unm:CapitalSecuritiesNotesPayableDue2038Member2019-01-012019-12-310000005513us-gaap:JuniorSubordinatedDebtMemberunm:JuniorSubordinatedNotesPayableDue2038Member2019-01-012019-12-310000005513unm:CapitalSecuritiesNotesPayableDue2038Member2019-12-310000005513unm:FiveYearUnsecuredRevolvingCreditFacilityMember2019-12-310000005513unm:ThreeYearUnsecuredRevolvingCreditFacilityMember2019-12-310000005513country:USus-gaap:PensionPlansDefinedBenefitMember2017-01-012017-12-310000005513unm:GroupAnnuityContactMembercountry:USus-gaap:PensionPlansDefinedBenefitMember2019-01-012019-12-310000005513unm:GroupAnnuityContactMembercountry:USus-gaap:PensionPlansDefinedBenefitMemberus-gaap:SubsequentEventMember2020-01-022020-01-020000005513country:USus-gaap:PensionPlansDefinedBenefitMember2019-01-012019-12-310000005513country:GBus-gaap:PensionPlansDefinedBenefitMember2019-01-012019-12-310000005513country:USus-gaap:PensionPlansDefinedBenefitMember2018-12-310000005513country:USus-gaap:PensionPlansDefinedBenefitMember2017-12-310000005513country:GBus-gaap:PensionPlansDefinedBenefitMember2018-12-310000005513country:GBus-gaap:PensionPlansDefinedBenefitMember2017-12-310000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2018-12-310000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2017-12-310000005513country:USus-gaap:PensionPlansDefinedBenefitMember2018-01-012018-12-310000005513country:GBus-gaap:PensionPlansDefinedBenefitMember2018-01-012018-12-310000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-01-012019-12-310000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2018-01-012018-12-310000005513country:USus-gaap:PensionPlansDefinedBenefitMember2019-12-310000005513country:GBus-gaap:PensionPlansDefinedBenefitMember2019-12-310000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-12-310000005513us-gaap:EquitySecuritiesMembercountry:USus-gaap:PensionPlansDefinedBenefitMember2019-12-310000005513us-gaap:DebtSecuritiesMembercountry:USus-gaap:PensionPlansDefinedBenefitMember2019-12-310000005513unm:AlternativeInvestmentsMembercountry:USus-gaap:PensionPlansDefinedBenefitMember2019-12-310000005513country:GBus-gaap:PensionPlansDefinedBenefitMemberunm:DiversifiedGrowthAssetsMember2019-12-310000005513country:GBus-gaap:PensionPlansDefinedBenefitMemberus-gaap:InterestRateContractMember2019-12-310000005513us-gaap:PensionPlansDefinedBenefitMember2019-01-012019-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMembercountry:US2019-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMemberus-gaap:FairValueInputsLevel3Membercountry:US2019-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMembercountry:US2019-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:US2019-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:US2019-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:US2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMemberus-gaap:FairValueInputsLevel2Membercountry:US2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMemberus-gaap:FairValueInputsLevel3Membercountry:US2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMembercountry:US2019-12-310000005513country:USus-gaap:FairValueInputsLevel1Memberunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2019-12-310000005513us-gaap:FairValueInputsLevel2Membercountry:USunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2019-12-310000005513us-gaap:FairValueInputsLevel3Membercountry:USunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2019-12-310000005513country:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2019-12-310000005513country:USunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMemberus-gaap:FairValueInputsLevel2Membercountry:US2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMemberus-gaap:FairValueInputsLevel3Membercountry:US2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMembercountry:US2019-12-310000005513us-gaap:USTreasuryAndGovernmentMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel2Membercountry:US2019-12-310000005513us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel3Membercountry:US2019-12-310000005513us-gaap:USTreasuryAndGovernmentMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:USTreasuryAndGovernmentMembercountry:US2019-12-310000005513us-gaap:CorporateDebtSecuritiesMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:CorporateDebtSecuritiesMembercountry:US2019-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Membercountry:US2019-12-310000005513us-gaap:CorporateDebtSecuritiesMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:CorporateDebtSecuritiesMembercountry:US2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel2Membercountry:US2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel3Membercountry:US2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMembercountry:US2019-12-310000005513unm:OpportunisticCreditsMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513unm:OpportunisticCreditsMemberus-gaap:FairValueInputsLevel2Membercountry:US2019-12-310000005513unm:OpportunisticCreditsMemberus-gaap:FairValueInputsLevel3Membercountry:US2019-12-310000005513unm:OpportunisticCreditsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513unm:OpportunisticCreditsMembercountry:US2019-12-310000005513us-gaap:DefinedBenefitPlanRealEstateMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanRealEstateMembercountry:US2019-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:DefinedBenefitPlanRealEstateMembercountry:US2019-12-310000005513us-gaap:DefinedBenefitPlanRealEstateMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:DefinedBenefitPlanRealEstateMembercountry:US2019-12-310000005513unm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberunm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:US2019-12-310000005513us-gaap:FairValueInputsLevel3Memberunm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:US2019-12-310000005513unm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513unm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:US2019-12-310000005513us-gaap:PrivateEquityFundsMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:PrivateEquityFundsMembercountry:US2019-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:PrivateEquityFundsMembercountry:US2019-12-310000005513us-gaap:PrivateEquityFundsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:PrivateEquityFundsMembercountry:US2019-12-310000005513us-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:US2019-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:US2019-12-310000005513us-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513us-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:US2019-12-310000005513country:USus-gaap:FairValueInputsLevel1Member2019-12-310000005513us-gaap:FairValueInputsLevel2Membercountry:US2019-12-310000005513us-gaap:FairValueInputsLevel3Membercountry:US2019-12-310000005513country:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513country:US2019-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMembercountry:US2018-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMemberus-gaap:FairValueInputsLevel3Membercountry:US2018-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesUsLargeCapMembercountry:US2018-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:US2018-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:US2018-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:DefinedBenefitPlanEquitySecuritiesSmallCapMembercountry:US2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMemberus-gaap:FairValueInputsLevel2Membercountry:US2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMemberus-gaap:FairValueInputsLevel3Membercountry:US2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesGlobalMembercountry:US2018-12-310000005513country:USus-gaap:FairValueInputsLevel1Memberunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2018-12-310000005513us-gaap:FairValueInputsLevel2Membercountry:USunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2018-12-310000005513us-gaap:FairValueInputsLevel3Membercountry:USunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2018-12-310000005513country:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2018-12-310000005513country:USunm:DefinedBenefitPlanEquitySecuritiesInternationalMember2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMemberus-gaap:FairValueInputsLevel2Membercountry:US2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMemberus-gaap:FairValueInputsLevel3Membercountry:US2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513unm:DefinedBenefitPlanEquitySecuritiesEmergingMarketsMembercountry:US2018-12-310000005513us-gaap:USTreasuryAndGovernmentMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel2Membercountry:US2018-12-310000005513us-gaap:USTreasuryAndGovernmentMemberus-gaap:FairValueInputsLevel3Membercountry:US2018-12-310000005513us-gaap:USTreasuryAndGovernmentMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:USTreasuryAndGovernmentMembercountry:US2018-12-310000005513us-gaap:CorporateDebtSecuritiesMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:CorporateDebtSecuritiesMembercountry:US2018-12-310000005513us-gaap:CorporateDebtSecuritiesMemberus-gaap:FairValueInputsLevel3Membercountry:US2018-12-310000005513us-gaap:CorporateDebtSecuritiesMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:CorporateDebtSecuritiesMembercountry:US2018-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel2Membercountry:US2018-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:FairValueInputsLevel3Membercountry:US2018-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMembercountry:US2018-12-310000005513unm:OpportunisticCreditsMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513unm:OpportunisticCreditsMemberus-gaap:FairValueInputsLevel2Membercountry:US2018-12-310000005513unm:OpportunisticCreditsMemberus-gaap:FairValueInputsLevel3Membercountry:US2018-12-310000005513unm:OpportunisticCreditsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513unm:OpportunisticCreditsMembercountry:US2018-12-310000005513us-gaap:DefinedBenefitPlanRealEstateMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanRealEstateMembercountry:US2018-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:DefinedBenefitPlanRealEstateMembercountry:US2018-12-310000005513us-gaap:DefinedBenefitPlanRealEstateMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:DefinedBenefitPlanRealEstateMembercountry:US2018-12-310000005513unm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Memberunm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:US2018-12-310000005513us-gaap:FairValueInputsLevel3Memberunm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:US2018-12-310000005513unm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513unm:PrivateEquityFundsPrivateEquityDirectInvestmentsMembercountry:US2018-12-310000005513us-gaap:PrivateEquityFundsMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:PrivateEquityFundsMembercountry:US2018-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:PrivateEquityFundsMembercountry:US2018-12-310000005513us-gaap:PrivateEquityFundsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:PrivateEquityFundsMembercountry:US2018-12-310000005513us-gaap:HedgeFundsMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:HedgeFundsMembercountry:US2018-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:HedgeFundsMembercountry:US2018-12-310000005513us-gaap:HedgeFundsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:HedgeFundsMembercountry:US2018-12-310000005513us-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:US2018-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:US2018-12-310000005513us-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513us-gaap:DefinedBenefitPlanCashAndCashEquivalentsMembercountry:US2018-12-310000005513country:USus-gaap:FairValueInputsLevel1Member2018-12-310000005513us-gaap:FairValueInputsLevel2Membercountry:US2018-12-310000005513us-gaap:FairValueInputsLevel3Membercountry:US2018-12-310000005513country:USus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513country:US2018-12-310000005513us-gaap:PrivateEquityFundsMembersrt:MinimumMembercountry:USus-gaap:PensionPlansDefinedBenefitMember2019-01-012019-12-310000005513us-gaap:PrivateEquityFundsMembersrt:MaximumMembercountry:USus-gaap:PensionPlansDefinedBenefitMember2019-01-012019-12-310000005513country:GBus-gaap:FairValueInputsLevel1Memberunm:DiversifiedGrowthAssetsMember2019-12-310000005513country:GBus-gaap:FairValueInputsLevel2Memberunm:DiversifiedGrowthAssetsMember2019-12-310000005513country:GBus-gaap:FairValueInputsLevel3Memberunm:DiversifiedGrowthAssetsMember2019-12-310000005513country:GBunm:DiversifiedGrowthAssetsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513country:GBunm:DiversifiedGrowthAssetsMember2019-12-310000005513country:GBus-gaap:FairValueInputsLevel1Memberunm:FixedInterestandIndexlinkedSecuritiesMember2019-12-310000005513country:GBus-gaap:FairValueInputsLevel2Memberunm:FixedInterestandIndexlinkedSecuritiesMember2019-12-310000005513country:GBus-gaap:FairValueInputsLevel3Memberunm:FixedInterestandIndexlinkedSecuritiesMember2019-12-310000005513country:GBunm:FixedInterestandIndexlinkedSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513country:GBunm:FixedInterestandIndexlinkedSecuritiesMember2019-12-310000005513country:GBus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMemberus-gaap:FairValueInputsLevel1Member2019-12-310000005513country:GBus-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMember2019-12-310000005513country:GBus-gaap:FairValueInputsLevel3Memberus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMember2019-12-310000005513country:GBus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513country:GBus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMember2019-12-310000005513country:GBus-gaap:FairValueInputsLevel1Member2019-12-310000005513country:GBus-gaap:FairValueInputsLevel2Member2019-12-310000005513country:GBus-gaap:FairValueInputsLevel3Member2019-12-310000005513country:GBus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2019-12-310000005513country:GB2019-12-310000005513country:GBus-gaap:FairValueInputsLevel1Memberunm:DiversifiedGrowthAssetsMember2018-12-310000005513country:GBus-gaap:FairValueInputsLevel2Memberunm:DiversifiedGrowthAssetsMember2018-12-310000005513country:GBus-gaap:FairValueInputsLevel3Memberunm:DiversifiedGrowthAssetsMember2018-12-310000005513country:GBunm:DiversifiedGrowthAssetsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513country:GBunm:DiversifiedGrowthAssetsMember2018-12-310000005513country:GBus-gaap:FairValueInputsLevel1Memberunm:FixedInterestandIndexlinkedSecuritiesMember2018-12-310000005513country:GBus-gaap:FairValueInputsLevel2Memberunm:FixedInterestandIndexlinkedSecuritiesMember2018-12-310000005513country:GBus-gaap:FairValueInputsLevel3Memberunm:FixedInterestandIndexlinkedSecuritiesMember2018-12-310000005513country:GBunm:FixedInterestandIndexlinkedSecuritiesMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513country:GBunm:FixedInterestandIndexlinkedSecuritiesMember2018-12-310000005513country:GBus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMemberus-gaap:FairValueInputsLevel1Member2018-12-310000005513country:GBus-gaap:FairValueInputsLevel2Memberus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMember2018-12-310000005513country:GBus-gaap:FairValueInputsLevel3Memberus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMember2018-12-310000005513country:GBus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513country:GBus-gaap:DefinedBenefitPlanCashAndCashEquivalentsMember2018-12-310000005513country:GBus-gaap:FairValueInputsLevel1Member2018-12-310000005513country:GBus-gaap:FairValueInputsLevel2Member2018-12-310000005513country:GBus-gaap:FairValueInputsLevel3Member2018-12-310000005513country:GBus-gaap:FairValueMeasuredAtNetAssetValuePerShareMember2018-12-310000005513country:GB2018-12-310000005513us-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-12-310000005513us-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2018-12-310000005513us-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2018-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2018-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-01-012019-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2017-12-310000005513us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2018-01-012018-12-310000005513country:GBus-gaap:PensionPlansDefinedBenefitMember2017-01-012017-12-310000005513us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2017-01-012017-12-310000005513country:USus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-01-012019-12-31iso4217:GBP0000005513country:GBus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2019-01-012019-12-310000005513country:USus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2018-01-012018-12-310000005513country:USus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2017-01-012017-12-310000005513country:GBus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2017-01-012017-12-310000005513country:GBus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2018-01-012018-12-310000005513unm:RepurchaseProgramAuthorizedInMay2019Member2019-12-310000005513unm:RepurchaseProgramAuthorizedinMay2018Member2019-12-310000005513unm:RepurchaseProgramAuthorizedinMay2017Member2019-12-310000005513unm:OpenMarketRepurchaseMember2019-01-012019-12-310000005513unm:OpenMarketRepurchaseMember2018-01-012018-12-310000005513unm:OpenMarketRepurchaseMember2017-01-012017-12-310000005513unm:StockIncentivePlan2017Domain2019-12-310000005513unm:StockIncentivePlan2017Domain2019-01-012019-12-310000005513unm:StockIncentivePlan2012Domain2019-12-310000005513unm:StockIncentivePlan2012Domain2019-01-012019-12-310000005513unm:StockIncentivePlan2007Member2019-12-310000005513unm:StockIncentivePlan2007Member2019-01-012019-12-310000005513us-gaap:PerformanceSharesMember2019-01-012019-12-310000005513us-gaap:PerformanceSharesMember2018-12-310000005513us-gaap:PerformanceSharesMember2019-12-310000005513us-gaap:PerformanceSharesMember2018-01-012018-12-310000005513us-gaap:PerformanceSharesMember2017-01-012017-12-310000005513us-gaap:PerformanceSharesMembersrt:MinimumMember2019-12-310000005513us-gaap:PerformanceSharesMembersrt:MaximumMember2019-12-310000005513us-gaap:RestrictedStockUnitsRSUMember2019-01-012019-12-310000005513us-gaap:RestrictedStockUnitsRSUMember2018-12-310000005513us-gaap:RestrictedStockUnitsRSUMember2019-12-310000005513us-gaap:RestrictedStockUnitsRSUMember2018-01-012018-12-310000005513us-gaap:RestrictedStockUnitsRSUMember2017-01-012017-12-310000005513srt:MinimumMemberus-gaap:RestrictedStockUnitsRSUMember2019-01-012019-12-310000005513srt:MaximumMemberus-gaap:RestrictedStockUnitsRSUMember2019-01-012019-12-310000005513us-gaap:EmployeeStockOptionMember2019-01-012019-12-310000005513us-gaap:EmployeeStockOptionMember2018-12-310000005513us-gaap:EmployeeStockOptionMember2019-12-310000005513us-gaap:EmployeeStockOptionMembersrt:MinimumMember2019-01-012019-12-310000005513us-gaap:EmployeeStockOptionMembersrt:MaximumMember2019-01-012019-12-310000005513unm:RestrictedstockunitsandcashsettledawardsDomain2019-01-012019-12-310000005513unm:RestrictedstockunitsandcashsettledawardsDomain2018-01-012018-12-310000005513unm:RestrictedstockunitsandcashsettledawardsDomain2017-01-012017-12-310000005513us-gaap:EmployeeStockOwnershipPlanESOPPlanDomain2019-01-012019-12-310000005513us-gaap:EmployeeStockOwnershipPlanESOPPlanDomain2018-01-012018-12-310000005513us-gaap:EmployeeStockOwnershipPlanESOPPlanDomain2017-01-012017-12-310000005513us-gaap:EmployeeStockOptionMember2017-01-012017-12-310000005513us-gaap:EmployeeStockOptionMember2018-01-012018-12-310000005513us-gaap:ReinsurerConcentrationRiskMemberus-gaap:ReinsuranceRecoverableMembersrt:AMBestARatingMemberunm:Top13ReinsurersMember2019-01-012019-12-310000005513us-gaap:ReinsurerConcentrationRiskMemberunm:OtherReinsurersMembersrt:AMBestAMinusRatingMemberus-gaap:ReinsuranceRecoverableMember2019-01-012019-12-310000005513us-gaap:ReinsurerConcentrationRiskMemberunm:OtherReinsurersMemberus-gaap:ReinsuranceRecoverableMemberunm:AMBestBelowAorNotRatedMember2019-01-012019-12-310000005513unm:JaiminiHealthInc.Member2019-12-310000005513unm:JaiminiHealthInc.Member2019-01-012019-12-310000005513unm:UnumPolandMember2019-12-310000005513unm:UnumPolandMember2019-01-012019-12-310000005513unm:LeavelogicInc.Member2019-12-310000005513unm:LeavelogicInc.Member2019-01-012019-12-310000005513us-gaap:SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember2017-01-012017-12-310000005513us-gaap:SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember2018-12-310000005513us-gaap:SeriesOfIndividuallyImmaterialBusinessAcquisitionsMember2018-01-012018-12-310000005513unm:GroupLongTermDisabilityMemberunm:UnumUsMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:GroupLongTermDisabilityMemberunm:UnumUsMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:GroupLongTermDisabilityMemberunm:UnumUsMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:UnumUsMemberunm:GroupShortTermDisabilityMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:UnumUsMemberunm:GroupShortTermDisabilityMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:UnumUsMemberunm:GroupShortTermDisabilityMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMemberunm:GroupLifeMember2019-01-012019-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMemberunm:GroupLifeMember2018-01-012018-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMemberunm:AccidentalDeathDismembermentMember2019-01-012019-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMemberunm:AccidentalDeathDismembermentMember2018-01-012018-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMemberunm:AccidentalDeathDismembermentMember2017-01-012017-12-310000005513unm:IndividualDisabilityInsuranceMemberunm:UnumUsMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:IndividualDisabilityInsuranceMemberunm:UnumUsMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:IndividualDisabilityInsuranceMemberunm:UnumUsMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:VoluntaryBenefitsMemberunm:UnumUsMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:VoluntaryBenefitsMemberunm:UnumUsMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:UnumUsMemberunm:DentalandVisionMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:UnumUsMemberunm:DentalandVisionMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:UnumUsMemberunm:DentalandVisionMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:GroupLongTermDisabilityMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:GroupLongTermDisabilityMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:GroupLongTermDisabilityMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMemberunm:GroupLifeMember2019-01-012019-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMemberunm:GroupLifeMember2018-01-012018-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMemberunm:GroupLifeMember2017-01-012017-12-310000005513unm:SupplementalandVoluntaryInsuranceMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:SupplementalandVoluntaryInsuranceMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:SupplementalandVoluntaryInsuranceMemberunm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMemberunm:UnumPolandMember2019-01-012019-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMemberunm:UnumPolandMember2018-01-012018-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMemberunm:UnumPolandMember2017-01-012017-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:ClosedBlockMemberunm:LongTermCareMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:ClosedBlockMemberunm:LongTermCareMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:ClosedBlockMemberunm:LongTermCareMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:IndividualDisabilityInsuranceMemberunm:ClosedBlockMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:IndividualDisabilityInsuranceMemberunm:ClosedBlockMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:IndividualDisabilityInsuranceMemberunm:ClosedBlockMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513unm:ClosedBlockMemberus-gaap:OperatingSegmentsMemberus-gaap:OtherInsuranceProductLineMember2019-01-012019-12-310000005513unm:ClosedBlockMemberus-gaap:OperatingSegmentsMemberus-gaap:OtherInsuranceProductLineMember2018-01-012018-12-310000005513unm:ClosedBlockMemberus-gaap:OperatingSegmentsMemberus-gaap:OtherInsuranceProductLineMember2017-01-012017-12-310000005513unm:ClosedBlockMemberus-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513unm:ClosedBlockMemberus-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513unm:ClosedBlockMemberus-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513us-gaap:OperatingSegmentsMember2019-01-012019-12-310000005513us-gaap:OperatingSegmentsMember2018-01-012018-12-310000005513us-gaap:OperatingSegmentsMember2017-01-012017-12-310000005513us-gaap:OperatingSegmentsMemberus-gaap:CorporateAndOtherMember2019-01-012019-12-310000005513us-gaap:OperatingSegmentsMemberus-gaap:CorporateAndOtherMember2018-01-012018-12-310000005513us-gaap:OperatingSegmentsMemberus-gaap:CorporateAndOtherMember2017-01-012017-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMember2018-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2018-12-310000005513unm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2018-12-310000005513us-gaap:OperatingSegmentsMember2018-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMember2019-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2019-12-310000005513unm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2019-12-310000005513us-gaap:OperatingSegmentsMember2019-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMember2017-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2017-12-310000005513unm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2017-12-310000005513us-gaap:OperatingSegmentsMember2017-12-310000005513unm:UnumUsMemberus-gaap:OperatingSegmentsMember2016-12-310000005513unm:UnumInternationalMemberus-gaap:OperatingSegmentsMember2016-12-310000005513unm:ColonialLifeMemberus-gaap:OperatingSegmentsMember2016-12-310000005513us-gaap:OperatingSegmentsMember2016-12-310000005513unm:ClosedBlockMemberus-gaap:OperatingSegmentsMember2019-12-310000005513unm:ClosedBlockMemberus-gaap:OperatingSegmentsMember2018-12-310000005513us-gaap:OperatingSegmentsMemberus-gaap:CorporateAndOtherMember2019-12-310000005513us-gaap:OperatingSegmentsMemberus-gaap:CorporateAndOtherMember2018-12-310000005513unm:UnumUsMember2018-12-310000005513unm:UnumUsMember2019-12-310000005513unm:UnumInternationalMember2019-12-310000005513unm:UnumInternationalMember2018-12-310000005513unm:ColonialLifeMember2018-12-310000005513unm:ColonialLifeMember2019-12-310000005513us-gaap:LandAndBuildingMembersrt:MinimumMember2019-12-310000005513us-gaap:LandAndBuildingMembersrt:MaximumMember2019-12-310000005513us-gaap:MachineryAndEquipmentMembersrt:MinimumMember2019-12-310000005513us-gaap:MachineryAndEquipmentMembersrt:MaximumMember2019-12-310000005513unm:FairwindInsuranceCompanyMember2019-01-012019-12-310000005513unm:FairwindInsuranceCompanyMember2018-01-012018-12-310000005513unm:UnitedStatesTraditionalInsuranceSubsidiariesMember2019-01-012019-12-310000005513unm:UnitedStatesTraditionalInsuranceSubsidiariesMember2018-01-012018-12-310000005513unm:UnitedStatesTraditionalInsuranceSubsidiariesMember2017-01-012017-12-310000005513unm:CaptiveReinsurersMember2019-01-012019-12-310000005513unm:CaptiveReinsurersMember2018-01-012018-12-310000005513unm:CaptiveReinsurersMember2017-01-012017-12-310000005513unm:UnitedStatesTraditionalInsuranceSubsidiariesMember2019-12-310000005513unm:UnitedStatesTraditionalInsuranceSubsidiariesMember2018-12-310000005513unm:CaptiveReinsurersMember2019-12-310000005513unm:CaptiveReinsurersMember2018-12-310000005513unm:UnumLimitedMember2018-01-012018-12-310000005513unm:UnumLimitedMember2018-12-310000005513unm:UnumLimitedMember2019-12-3100000055132019-10-012019-12-3100000055132019-07-012019-09-3000000055132019-04-012019-06-3000000055132019-01-012019-03-3100000055132018-10-012018-12-3100000055132018-07-012018-09-3000000055132018-04-012018-06-3000000055132018-01-012018-03-310000005513us-gaap:USTreasuryAndGovernmentMember2019-12-310000005513us-gaap:USStatesAndPoliticalSubdivisionsMember2019-12-310000005513us-gaap:ForeignGovernmentDebtMember2019-12-310000005513us-gaap:PublicUtilityBondsMember2019-12-310000005513us-gaap:AssetBackedSecuritiesMember2019-12-310000005513us-gaap:AllOtherCorporateBondsMember2019-12-310000005513us-gaap:MandatorilyRedeemablePreferredStockMember2019-12-310000005513us-gaap:FixedMaturitiesMember2019-12-310000005513us-gaap:MortgagesMember2019-12-310000005513us-gaap:PolicyLoansMember2019-12-310000005513us-gaap:DerivativeMember2019-12-310000005513us-gaap:EquitySecuritiesInvestmentSummaryMember2019-12-310000005513us-gaap:OtherLongTermInvestmentsMember2019-12-310000005513us-gaap:ShortTermInvestmentsMember2019-12-310000005513srt:ParentCompanyMember2019-01-012019-12-310000005513srt:ParentCompanyMember2018-12-310000005513srt:ParentCompanyMember2018-01-012018-12-310000005513srt:ParentCompanyMember2017-01-012017-12-310000005513unm:NotesIssuedin1998with2028MaturityDateMembersrt:ParentCompanyMemberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesIssuedin1998with2028MaturityDateMembersrt:ParentCompanyMemberus-gaap:SeniorNotesMember2018-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2002Memberus-gaap:SeniorNotesMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2002Memberus-gaap:SeniorNotesMember2018-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2010Memberus-gaap:SeniorNotesMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2010Memberus-gaap:SeniorNotesMember2018-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2012and2016Memberus-gaap:SeniorNotesMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2012and2016Memberus-gaap:SeniorNotesMember2018-12-310000005513srt:ParentCompanyMemberus-gaap:SeniorNotesMemberunm:NotesIssuedin2014Member2019-12-310000005513srt:ParentCompanyMemberus-gaap:SeniorNotesMemberunm:NotesIssuedin2014Member2018-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2015Memberus-gaap:SeniorNotesMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2015Memberus-gaap:SeniorNotesMember2018-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2016Memberus-gaap:SeniorNotesMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2016Memberus-gaap:SeniorNotesMember2018-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedIn2019Memberus-gaap:SeniorNotesMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedIn2019Memberus-gaap:SeniorNotesMember2018-12-310000005513unm:NotesIssuedIn2019Due2049Membersrt:ParentCompanyMemberus-gaap:SeniorNotesMember2019-12-310000005513unm:NotesIssuedIn2019Due2049Membersrt:ParentCompanyMemberus-gaap:SeniorNotesMember2018-12-310000005513srt:ParentCompanyMemberunm:NotesIssued1990to1996Memberus-gaap:MediumTermNotesMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssued1990to1996Memberus-gaap:MediumTermNotesMember2018-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin1998with2038MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin1998with2038MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2018-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2018witha2058MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2018witha2058MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2018-12-310000005513srt:ParentCompanyMemberunm:FairValueHedgeAdjustmentLtDebtMember2019-12-310000005513srt:ParentCompanyMemberunm:FairValueHedgeAdjustmentLtDebtMember2018-12-310000005513srt:ParentCompanyMemberus-gaap:SeniorNotesMemberunm:NotesIssuedin2010Member2019-12-310000005513srt:ParentCompanyMemberus-gaap:SeniorNotesMemberunm:NotesIssuedin2010Member2018-12-310000005513unm:MediumTermNotesPayableDue2028Membersrt:ParentCompanyMemberus-gaap:MediumTermNotesMember2019-01-012019-12-310000005513unm:MediumTermNotesPayableDue2028Membersrt:ParentCompanyMemberus-gaap:MediumTermNotesMember2019-12-310000005513unm:NotesIssuedin1998with2028MaturityDateMembersrt:ParentCompanyMemberus-gaap:SeniorNotesMember2019-01-012019-12-310000005513unm:NotesIssuedin1998with2028MaturityDateMembersrt:ParentCompanyMemberus-gaap:SeniorNotesMember2019-12-310000005513srt:ParentCompanyMemberus-gaap:SeniorNotesMemberunm:SeniorNotesPayableDue2021Member2019-01-012019-12-310000005513srt:ParentCompanyMemberus-gaap:SeniorNotesMemberunm:SeniorNotesPayableDue2021Member2019-12-310000005513unm:NotesIssuedIn2019Due2049Membersrt:ParentCompanyMemberus-gaap:SeniorNotesMember2019-01-012019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedIn2019Memberus-gaap:SeniorNotesMember2019-01-012019-12-310000005513srt:ParentCompanyMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2018-12-310000005513srt:ParentCompanyMemberunm:DerivativeFinancialInstrumentsReceiveFixedPayVariableMemberus-gaap:InterestRateSwapMember2019-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin2018witha2058MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember2018-01-012018-12-310000005513srt:ParentCompanyMemberunm:NotesIssuedin1998with2038MaturityDateMemberus-gaap:JuniorSubordinatedDebtMember1998-01-011998-12-310000005513us-gaap:JuniorSubordinatedDebtMembersrt:ParentCompanyMemberunm:JuniorSubordinatedNotesPayableDue2038Member2019-12-310000005513us-gaap:JuniorSubordinatedDebtMembersrt:ParentCompanyMemberunm:JuniorSubordinatedNotesPayableDue2038Member2019-01-012019-12-310000005513srt:ParentCompanyMemberunm:CapitalSecuritiesNotesPayableDue2038Member2019-01-012019-12-310000005513srt:ParentCompanyMemberunm:FiveYearUnsecuredRevolvingCreditFacilityMember2019-12-310000005513srt:ParentCompanyMemberunm:ThreeYearUnsecuredRevolvingCreditFacilityMember2019-12-310000005513unm:ClosedBlockMember2019-12-310000005513unm:ClosedBlockMember2018-12-310000005513unm:UnumUsMember2019-01-012019-12-310000005513unm:UnumInternationalMember2019-01-012019-12-310000005513unm:ClosedBlockMember2019-01-012019-12-310000005513us-gaap:CorporateAndOtherMember2019-01-012019-12-310000005513unm:UnumUsMember2018-01-012018-12-310000005513unm:UnumInternationalMember2018-01-012018-12-310000005513unm:ClosedBlockMember2018-01-012018-12-310000005513us-gaap:CorporateAndOtherMember2018-01-012018-12-310000005513unm:UnumUsMember2017-01-012017-12-310000005513unm:UnumInternationalMember2017-01-012017-12-310000005513unm:ClosedBlockMember2017-01-012017-12-310000005513us-gaap:CorporateAndOtherMember2017-01-012017-12-310000005513us-gaap:LifeInsuranceSegmentMember2019-01-012019-12-310000005513us-gaap:AccidentAndHealthInsuranceSegmentMember2019-01-012019-12-310000005513us-gaap:LifeInsuranceSegmentMember2018-01-012018-12-310000005513us-gaap:AccidentAndHealthInsuranceSegmentMember2018-01-012018-12-310000005513us-gaap:LifeInsuranceSegmentMember2017-01-012017-12-310000005513us-gaap:AccidentAndHealthInsuranceSegmentMember2017-01-012017-12-310000005513us-gaap:AllowanceForLoanAndLeaseLossesRealEstateMember2018-12-310000005513us-gaap:AllowanceForLoanAndLeaseLossesRealEstateMember2019-01-012019-12-310000005513us-gaap:AllowanceForLoanAndLeaseLossesRealEstateMember2019-12-310000005513us-gaap:AllowanceForCreditLossMember2018-12-310000005513us-gaap:AllowanceForCreditLossMember2019-01-012019-12-310000005513us-gaap:AllowanceForCreditLossMember2019-12-310000005513us-gaap:AllowanceForLoanAndLeaseLossesRealEstateMember2017-12-310000005513us-gaap:AllowanceForLoanAndLeaseLossesRealEstateMember2018-01-012018-12-310000005513us-gaap:AllowanceForCreditLossMember2017-12-310000005513us-gaap:AllowanceForCreditLossMember2018-01-012018-12-310000005513us-gaap:AllowanceForLoanAndLeaseLossesRealEstateMember2016-12-310000005513us-gaap:AllowanceForLoanAndLeaseLossesRealEstateMember2017-01-012017-12-310000005513us-gaap:AllowanceForCreditLossMember2016-12-310000005513us-gaap:AllowanceForCreditLossMember2017-01-012017-12-31


UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D. C. 20549

FORM 10-K

(Mark One)

Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
For the fiscal year ended December 31, 2019

Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
For the transition period from to

Commission file number 001-11294

Unum Group
(Exact name of registrant as specified in its charter)
Delaware
62-1598430
(State or other jurisdiction of incorporation or organization)(I.R.S. Employer Identification No.)
1 Fountain Square
Chattanooga, Tennessee
37402
(Address of principal executive offices)(Zip Code)
(423)294-1011
(Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading SymbolName of each exchange on which registered
Common stock, $0.10 par value
UNM
New York Stock Exchange
6.250% Junior Subordinated Notes due 2058
UNMA
New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer as defined in Rule 405 of the Securities Act. Yes [X] No [ ]

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes [ ] No [X]

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes [X] No [ ]

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes [X] No [ ]





Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and "emerging growth company" in Rule 12b-2 of the Exchange Act.
(Check one):
Large Accelerated Filer
xAccelerated filer
Non-accelerated filer¨ Smaller reporting company 
Emerging growth company
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes No ☒

The aggregate market value of the shares of the registrant's common stock held by non-affiliates (based upon the closing price of these shares on the New York Stock Exchange) as of the last business day of the registrant's most recently completed second fiscal quarter was $7.0 billion. As of February 14, 2020, there were 202,971,077 shares of the registrant's common stock outstanding.





DOCUMENTS INCORPORATED BY REFERENCE

Portions of the information required by Part III of this Form 10-K are incorporated herein by reference from the registrant's definitive proxy statement for its 2020 Annual Meeting of Stockholders which will be filed with the Securities and Exchange Commission pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended, within 120 days after the end of the registrant's fiscal year ended December 31, 2019.





 TABLE OF CONTENTS

Page  




Cautionary Statement Regarding Forward-Looking Statements
The Private Securities Litigation Reform Act of 1995 (the Act) provides a "safe harbor" to encourage companies to provide prospective information, as long as those statements are identified as forward-looking and are accompanied by meaningful cautionary statements identifying important factors that could cause actual results to differ materially from those included in the forward-looking statements. Certain information contained in this Annual Report on Form 10-K (including certain statements in the business description in Item 1, Management's Discussion and Analysis in Item 7, and the consolidated financial statements and related notes in Item 8), or in any other written or oral statements made by us in communications with the financial community or contained in documents filed with the Securities and Exchange Commission (SEC), may be considered forward-looking statements within the meaning of the Act. Forward-looking statements are those not based on historical information, but rather relate to our outlook, future operations, strategies, financial results, or other developments. Forward-looking statements speak only as of the date made. We undertake no obligation to update these statements, even if made available on our website or otherwise. These statements may be made directly in this document or may be made part of this document by reference to other documents filed by us with the SEC, a practice which is known as "incorporation by reference." You can find many of these statements by looking for words such as "will," "may," "should," "could," "believes," "expects," "anticipates," "estimates," "plans," "assumes," "intends," "projects," "goals,” "objectives," or similar expressions in this document or in documents incorporated herein.

These forward-looking statements are subject to numerous assumptions, risks, and uncertainties, many of which are beyond our control. We caution readers that the following factors, in addition to other factors mentioned from time to time, may cause actual results to differ materially from those contemplated by the forward-looking statements:

Sustained periods of low interest rates.
Fluctuation in insurance reserve liabilities and claim payments due to changes in claim incidence, recovery rates, mortality and morbidity rates, and policy benefit offsets due to, among other factors, the rate of unemployment and consumer confidence, the emergence of new diseases, epidemics, or pandemics, new trends and developments in medical treatments, the effectiveness of our claims operational processes, and changes in governmental programs.
Unfavorable economic or business conditions, both domestic and foreign, that may result in decreases in sales, premiums, or persistency, as well as unfavorable claims activity.
Changes in, or interpretations or enforcement of, laws and regulations.
A cyber attack or other security breach could result in the unauthorized acquisition of confidential data.
The failure of our business recovery and incident management processes to resume our business operations in the event of a natural catastrophe, cyber attack, or other event.
Investment results, including, but not limited to, changes in interest rates, defaults, changes in credit spreads, impairments, and the lack of appropriate investments in the market which can be acquired to match our liabilities.
Increased competition from other insurers and financial services companies due to industry consolidation, new entrants to our markets, or other factors.
Changes in our financial strength and credit ratings.
Our ability to develop digital capabilities or execute on our technology systems upgrades or replacements.
Actual experience in the broad array of our products that deviates from our assumptions used in pricing, underwriting, and reserving.
Availability of reinsurance in the market and the ability of our reinsurers to meet their obligations to us.
Ability to generate sufficient internal liquidity and/or obtain external financing.
Damage to our reputation due to, among other factors, regulatory investigations, legal proceedings, external events, and/or inadequate or failed internal controls and procedures.
Effectiveness of our risk management program.
Contingencies and the level and results of litigation.
Ineffectiveness of our derivatives hedging programs due to changes in the economic environment, counterparty risk, ratings downgrades, capital market volatility, changes in interest rates, and/or regulation.
Fluctuation in foreign currency exchange rates.
Recoverability and/or realization of the carrying value of our intangible assets, long-lived assets, and deferred tax assets.

All subsequent written and oral forward-looking statements attributable to us or any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section.
1


PART I

ITEM 1. BUSINESS

General

Unum Group, a Delaware general business corporation, and its insurance and non-insurance subsidiaries, which collectively with Unum Group we refer to as the Company, operate in the United States, the United Kingdom, Poland, and, to a limited extent, in certain other countries. The principal operating subsidiaries in the United States are Unum Life Insurance Company of America (Unum America), Provident Life and Accident Insurance Company (Provident), The Paul Revere Life Insurance Company (Paul Revere Life), Colonial Life & Accident Insurance Company, Starmount Life Insurance Company (Starmount Life), in the United Kingdom, Unum Limited, and in Poland, Unum Zycie TUiR S.A. (Unum Poland). We are a leading provider of financial protection benefits in the United States and the United Kingdom. Our products include disability, life, accident, critical illness, dental and vision, and other related services. We market our products primarily through the workplace.

We have three principal operating business segments: Unum US, Unum International, and Colonial Life. Our other segments are the Closed Block and Corporate segments. These segments are discussed more fully under "Reporting Segments" included herein in this Item 1.

Business Strategies

The benefits we provide help the working world thrive throughout life's moments and protect people from the financial hardship of illness, injury, or loss of life by providing support when it is needed most. As a leading provider of employee benefits, we offer a broad portfolio of products and services through the workplace.

Specifically, we offer group, individual, voluntary, and dental and vision products as well as provide certain fee-based services. These products and services, which can be sold stand-alone or combined with other coverages, help employers of all sizes attract and retain a stronger workforce while protecting the incomes and livelihood of their employees. We believe employer-sponsored benefits are the most effective way to provide workers with access to information and options to protect their financial stability. Working people and their families, particularly those at lower and middle incomes, are perhaps the most vulnerable in today's economy yet are often overlooked by many providers of financial services and products. For many of these people, employer-sponsored benefits are the primary defense against the potentially catastrophic fallout of death, illness, or injury.
 
We have established a corporate culture consistent with the social values our products provide. Because we see important links between the obligations we have to all of our stakeholders, we place a strong emphasis on contributing to positive change in our communities. Accordingly, we are committed not only to meeting the needs of our customers who depend on us, but also to operating with integrity and being accountable for our actions through sound and consistent business practices, a strong internal compliance program, and a comprehensive risk management strategy.
 
We believe our disciplined approach to providing financial protection products at the workplace puts us in a position of strength as we seek to capitalize on the growing and largely unfilled need for our products and services. We believe the need for our products and services remains strong, and we intend to continue protecting our solid margins and returns through our pricing and risk management actions. Our strategy is centered on growing our existing business, expanding our reach, and investing in our operations and technology to anticipate and respond to new market demands to meet the changing needs of our customers.

Although the low interest rate environment continues to place pressure on our profit margins, we continue to analyze and employ strategies that we believe will help us navigate this environment and allow us to maintain solid operating margins and significant financial flexibility to support the needs of our businesses, while also continuing to return capital to our shareholders and exploring merger and acquisition opportunities to enhance our business lines. The continued strong labor market in the U.S. and the high level of consumer confidence will have positive impacts on our business. We have substantial leverage to rising interest rates and an improving economy which generates payroll growth and wage inflation. We believe that consistent operating results, combined with the implementation of strategic initiatives and the effective deployment of capital, will allow us to meet our long-term financial objectives.

2


Reporting Segments

Our reporting segments are comprised of the following: Unum US, Unum International, Colonial Life, Closed Block, and Corporate. The percentage of consolidated premium income generated by each reporting segment for the year ended December 31, 2019 is as follows:

Unum US64.0 %
Unum International7.0  
Colonial Life18.0  
Closed Block11.0  
Total100.0 %

Financial information is provided in "Management's Discussion and Analysis of Financial Condition and Results of Operations" contained herein in Item 7 and Note 13 of the "Notes to Consolidated Financial Statements" contained herein in Item 8.

Unum US Segment

Our Unum US segment includes group long-term and short-term disability products, group life and accidental death and dismemberment products, and supplemental and voluntary lines of business, which include individual disability, voluntary benefits, and dental and vision products. Our Unum US segment also includes fee-based leave management services and administrative services only (ASO) business. Unum US products are issued primarily by Unum America, Provident, and Starmount Life. Paul Revere Life previously issued products reported in our Unum US segment and continues to service the in-force policies, but Paul Revere Life no longer actively markets new business. These products are marketed through our field sales personnel who work in conjunction with independent brokers and consultants. Our market strategy for Unum US is to effectively deliver an integrated offering of employee benefit products in the group core market segment, which we define for Unum US as employee groups with fewer than 2,000 employees, the group large case market segment, and the supplemental and voluntary market segment.

The percentage of Unum US segment premium income generated by each product line during 2019 is as follows:

Group Disability43.1 %
Group Life and Accidental Death & Dismemberment30.4  
Individual Disability7.3  
Voluntary Benefits15.1  
Dental and Vision4.1  
Total100.0 %

Group Long-term and Short-term Disability

We sell group long-term and short-term disability products to employers for the benefit of employees.

Group long-term disability provides employees with insurance coverage for loss of income in the event of extended work absences due to sickness or injury. We offer services to employers and insureds to encourage and facilitate rehabilitation, retraining, and re-employment. Most policies begin providing benefits following 90 or 180 day waiting periods and continue providing benefits until the employee reaches a certain age, generally between 65 and 70, or recovers from the disability. The benefits are limited to specified maximums as a percentage of income. Also included in our long-term disability product line is our medical stop-loss product, which is designed to protect self-insured employers if their employees' medical claims exceed certain agreed upon thresholds.

Group short-term disability insurance generally provides coverage from loss of income due to injury or sickness for up to 26 weeks, and is limited to specified maximums as a percentage of income. Benefits are effective immediately for accidents and after one week for sickness.

Our leave management services provide administrative services on behalf of employers to ensure the protected leave eligibility and status for employees are in accordance with applicable laws and regulations. ASO products provide administrative services
3


regarding claims processing and billing for self-insured customers for which the responsibility for funding claim payments remain with the customer.

Premiums for group long-term and short-term disability are generally based on expected claims of a pool of similar risks plus provisions for administrative expenses, investment income, and profit. In some cases, coverage for large employers will include retrospective experience rating provisions or will be underwritten on an experience-rated basis. Premiums for experience-rated group long-term and short-term disability business are based on the expected experience of the client given its demographics, industry group, and location, adjusted for the credibility of the specific claim experience of the client. Both group long-term and short-term disability are sold primarily on a basis permitting periodic repricing to address the underlying claims experience. Fees for our leave management services and ASO business are generally based on the number of covered employees and an agreed-upon per-employee, per-month rate. Premiums for our medical stop-loss product are generally based on the number of covered employees in self-insured employer groups and their estimated overall health risk plus provisions for administrative expenses, and profit.

We have defined underwriting practices and procedures. If the coverage amount for our disability policies exceeds certain prescribed age and amount limits, we may require a prospective insured to submit evidence of insurability. Our disability policies are typically issued, both at inception and renewal, with rate guarantees. For new group policyholders, the usual rate guarantee is one to three years. For group policies being renewed, the rate guarantee is generally one year, but may be longer. The profitability of the policy depends on the adequacy of the rate during the rate guarantee period. The contracts provide for certain circumstances in which the rate guarantees can be overridden. Our medical stop loss contracts are renewable on an annual basis and rates are not guaranteed beyond one year. There is no requirement for prospective insureds to submit evidence of insurability because coverage levels are determined for the group as a whole.

Profitability of group long-term and short-term disability insurance and our medical stop-loss product is affected by sales, persistency, investment returns, claims experience, and the level of administrative expenses. Morbidity is an important factor in disability claims experience, and many economic and societal factors can affect claim incidence for disability insurance. We routinely make pricing adjustments on our group long-term and short-term disability insurance products, when contractually permitted, which take into account emerging experience and external factors.

Group Life and Accidental Death and Dismemberment

Group life and accidental death and dismemberment products are sold to employers as employee benefit products. Group life consists primarily of renewable term life insurance with the coverages frequently linked to employees' wages and includes a provision for waiver of premium, if disabled. Accidental death and dismemberment consists primarily of an additional benefit amount payable if death or severe injury is attributable to an accident.

Premiums are generally based on expected claims of a pool of similar risks plus provisions for administrative expenses, investment income, and profit. Underwriting practices and rate guarantees are similar to those used for group disability products, and evidence of insurability is required for benefits in excess of a specified limit.

Profitability of group life and accidental death and dismemberment insurance is affected by persistency, investment returns, claims experience, and the level of administrative expenses.

Individual Disability

Individual disability products are offered primarily to multi-life employer groups to supplement their group disability plans and may be funded by the employer, but the policy is owned by the employee and is portable. Individual disability insurance provides the insured with a portion of earned income lost as a result of sickness or injury. The benefits, including the underlying group disability coverage, typically range from 30 percent to 75 percent of the insured's monthly earned income. We provide various options with respect to length of benefit periods, product features, and waiting periods before benefit payments begin, which permit tailoring of the multi-life plan to a specific employer's needs. We also market individual disability policies which include payments for the transfer of business ownership between partners and payments for business overhead expenses, also on a multi-life basis. Individual disability products do not provide for the accumulation of cash values.

Premium rates for individual disability products vary by age, product features, and occupation based on assumptions concerning morbidity, mortality, persistency, administrative expenses, investment income, and profit. We develop our assumptions based on our own experience. Our underwriting rules, issue limits, and plan designs reflect risk and the financial circumstances of prospective insureds. Individuals in multi-life groups may be subject to limited medical underwriting. The majority of our
4


individual disability policies are written on a noncancelable basis. Under a noncancelable policy, as long as the insured continues to pay the fixed annual premium for the policy's duration, we cannot cancel the policy or change the premium.

Profitability of individual disability insurance is affected by persistency, investment returns, claims experience, and the level of administrative expenses.
 
Voluntary Benefits

Voluntary benefits products are primarily sold to groups of employees through payroll deduction at the workplace and include life, disability, accident, hospital indemnity, cancer, and critical illness offered on both a group and individual basis.

Premium rates for voluntary benefits products are based on assumptions concerning morbidity, mortality, persistency, administrative expenses, investment income, and profit. We develop our assumptions based on our own claims and persistency experience and published industry tables. Our underwriters evaluate the medical condition of prospective policyholders prior to the issuance of a policy on a simplified basis. Underwriting requirements may be waived for cases that meet certain criteria, including participation levels. Individual voluntary benefits products other than life insurance are offered on a guaranteed renewable basis which allows us to re-price in-force policies, subject to regulatory approval. Group voluntary benefits products are offered primarily on an optionally renewable basis which allows us to re-price or terminate in-force policies.

Profitability of voluntary benefits products is affected by the level of employee participation, persistency, investment returns, claims experience, and the level of administrative expenses.

Dental and Vision

Group dental and vision products are sold to employers as employee benefit products. Our group dental products include a variety of insured and self-insured dental care plans including preferred provider organizations and scheduled reimbursement plans. Our group vision products provide coverage that includes a range of both in-network and out-of-network benefits for routine vision services offered either in conjunction with our dental product offerings or as stand-alone coverage.

Premiums for small case group dental and vision products are generally based on expected claims of a pool of similar risks plus a provision for administrative expenses, investment income, and profit. Premiums for large employer groups are underwritten on an experience-rated basis.

Profitability of our dental and vision products is affected by persistency, claims experience, the level of administrative expenses, and to a lesser extent, investment returns.

Unum International Segment

The Unum International segment includes our operations in the United Kingdom and Poland. Unum UK's business includes insurance for group long-term disability, group life, and supplemental lines of business which include dental, individual disability, and critical illness products. Unum Poland's business primarily includes insurance for individual and group life with accident and health riders. Both Unum UK's and Unum Poland's products are sold primarily through field sales personnel and independent brokers and consultants. The market strategy for the segment is to offer benefits to employers and employees through the workplace, with a focus on the expansion of the number of employers and employees covered in our Unum UK core market segment, which we define as employee groups with fewer than 500 employees, and the growth of the existing Unum Poland business through the incorporation of our benefits and distribution expertise.

The percentage of Unum International segment premium income generated by each product line during 2019 is as follows:

Unum UK
Group Long-term Disability56.0 %
Group Life18.4  
Supplemental14.2  
Unum Poland11.4  
Total100.0 %

5


Unum UK Group Long-term Disability

Group long-term disability products are sold to employers for the benefit of employees. Group long-term disability provides employees with insurance coverage for loss of income in the event of extended work absences due to sickness or injury. Services are offered to employers and insureds to encourage and facilitate rehabilitation, retraining, and re-employment. Most policies begin providing benefits following 90 or 180 day waiting periods and continue providing benefits until the employee reaches a certain age or reaches the end of the limited period specified in the policy terms. The benefits are limited to specified maximums as a percentage of income.

Premiums for group long-term disability are generally based on expected claims of a pool of similar risks plus provisions for administrative expenses, investment income, and profit. Some cases carry experience rating provisions. Premiums for experience-rated group long-term disability business are based on the expected experience of the client given its demographics, industry group, and location, adjusted for the credibility of the specific claim experience of the client. Policies are sold primarily on a basis permitting periodic repricing to address the underlying claims experience.

We have defined underwriting practices and procedures.  If the coverage amount exceeds certain prescribed age and amount limits, we may require a prospective insured to submit evidence of insurability. Policies are typically issued, both at inception and renewal, with rate guarantees. The usual rate guarantee is two years but may vary depending on circumstances.  The profitability of the policy is dependent upon the adequacy of the rate during the rate guarantee period. The contracts provide for certain circumstances in which the rate guarantees can be overridden.

Profitability of group long-term disability insurance is affected by persistency, investment returns, claims experience, and the level of administrative expenses. Morbidity is an important factor in disability claims experience. We routinely make pricing adjustments on our group insurance products, when contractually permitted, which take into account emerging experience and external factors.

Unum UK Group Life

Group life products are sold to employers as employee benefit products. Group life consists of two types of products, a renewable term life insurance product and a group dependent life product. The renewable term life product provides a lump sum benefit to the beneficiary on death of an employee. The group dependent life product, which we discontinued offering to new customers in 2012, provides an annuity to the beneficiary upon the death of an employee. Both coverages are frequently linked to employees' wages. Premiums for group life are generally based on expected claims of a pool of similar risks plus provisions for administrative expenses, investment income, and profit. Underwriting and rate guarantees are similar to those utilized for group long-term disability products.

Profitability of group life is affected by persistency, investment returns, claims experience, and the level of administrative expenses. 

Unum UK Supplemental

Supplemental products are sold to individual retail customers as well as groups of employees and include individual disability, group and individual critical illness, and group dental. Individual disability products provide the insured with a portion of earned income lost as a result of sickness or injury. Critical illness products provide a lump-sum benefit on the occurrence of a covered critical illness event. Group dental products generally provide fixed benefits based on specified treatments or a portion of the cost of the treatment.

Premiums for our individual products vary by age and are based on assumptions concerning morbidity, mortality, persistency, administrative expenses, investment income, and profit. We develop our assumptions based on our own claims and persistency experience and published industry tables. Approximately one half of our individual disability policies are written on a noncancelable basis. The remainder of our individual disability policies and all of our individual critical illness products are offered on a guaranteed renewable basis which allows us to re-price in-force policies. Our underwriters evaluate the medical and financial condition of prospective policyholders prior to the issuance of a policy.

Premiums for group critical illness products are generally based on expected claims of a pool of similar risks plus provisions for administrative expenses, investment income, and profit. Underwriting and rate guarantees are similar to those utilized for group long-term disability products. Premiums for group dental products are generally based on standard industry rates that vary by age, with minor pricing variation based on the number of covered employees in the group.
6


Profitability of our supplemental products is affected by persistency, investment returns, claims experience, and the level of administrative expenses.

Unum Poland

Unum Poland products, which include both individual and group life products, provide renewable term and whole life insurance with accident and health riders. Premiums are based on expected claims of a pool of similar risks plus provisions for administrative expenses, investment income, and profit. Profitability of our Unum Poland products is affected by persistency, investment returns, claims experience, and the level of administrative expenses.

Colonial Life Segment

Our Colonial Life segment includes accident, sickness, and disability products, which includes our dental and vision products, life products, and cancer and critical illness products. These products are issued primarily by Colonial Life & Accident Insurance Company and marketed to employees, on both a group and an individual basis, at the workplace through an independent contractor agency sales force and brokers. Our market strategy for Colonial Life is to effectively deliver a broad set of voluntary products and services in the public sector market and in the commercial market, with a particular focus on the core commercial market segment, which we define for Colonial Life as accounts with fewer than 1,000 employees.

We have defined underwriting practices and procedures for each of our products. Most policies are issued on a simplified issue basis, based on answers to simple health and employment questions. If the amount applied for exceeds certain levels, the applicant may be asked to answer additional health questions or submit to additional medical examinations.

The percentage of Colonial Life segment premium income generated by each product line during 2019 is as follows:

Accident, Sickness, and Disability58.5 %
Life20.5  
Cancer and Critical Illness21.0  
Total100.0 %

Accident, Sickness, and Disability

The accident, sickness, and disability product line consists of short-term disability plans, accident-only plans providing benefits for injuries on a specified loss basis, and our dental and vision products. It also includes accident and health plans covering hospital admissions, confinement, and surgeries.

Premiums for accident, sickness, and disability products are generally based on assumptions for morbidity, mortality, persistency, administrative expenses, investment income, and profit. We develop our assumptions based on our own experience. Premiums are primarily individual guaranteed renewable for which we have the ability to change premiums on a state by state basis. A small percentage of the policies are written on a group basis for which we retain the right to change premiums at the individual account level. Premiums for our dental and vision products are generally guaranteed issue with standard industry rates that vary by age and region.
Profitability is affected by the level of employee participation, persistency, investment returns, claims experience, and the level of administrative expenses.

Life

Life products are primarily comprised of universal life, whole life, and term life policies.

Premium rates vary by age and are based on assumptions concerning mortality, persistency, administrative expenses, investment income, and profit. We develop our assumptions based on our own experience and published industry tables. Premiums for the whole life and level term products are guaranteed for the life of the contract. Premiums for the universal life products are flexible and may vary at the individual policyholder level. For the group term life products, we retain the right to change premiums at the account level based on the experience of the account.

7


Profitability is affected by the level of employee participation, persistency, investment returns, claims experience, and the level of administrative expenses.

Cancer and Critical Illness

Cancer policies provide various benefits for the treatment of cancer including hospitalization, surgery, radiation, and chemotherapy. Critical illness policies provide a lump-sum benefit and/or fixed payments on the occurrence of a covered critical illness event.

Premiums are generally based on assumptions for morbidity, mortality, persistency, administrative expenses, investment income, and profit. We develop our assumptions based on our own experience. Premiums are primarily individual guaranteed renewable wherein we have the ability to change premiums on a state by state basis.

Profitability of these products is affected by the level of employee participation, persistency, investment returns, claims experience, and the level of administrative expenses.

Closed Block Segment

Our Closed Block segment consists of group and individual long-term care, individual disability, and other insurance products no longer actively marketed. Closed Block segment premium income for 2019 was comprised of approximately 64 percent group and individual long-term care and 36 percent individual disability.

Group and Individual Long-term Care

We discontinued offering individual long-term care in 2009 and group long-term care in 2012. Group long-term care was previously offered to employers for the benefit of employees. Individual long-term care was previously marketed on a single-life customer basis.

Long-term care insurance pays a benefit upon the loss of two or more activities of daily living and the insured's requirement of standby assistance or cognitive impairment. Payment is generally made on an indemnity basis, regardless of expenses incurred, up to a lifetime maximum. Benefits begin after a waiting period, usually 90 days or less, and are generally paid for a period of three years, six years, or lifetime.

Our long-term care insurance was sold on a guaranteed renewable basis which allows us to re-price in-force policies, subject to regulatory approval. Premium rates for long-term care vary by age and are based on assumptions concerning morbidity, mortality, persistency, administrative expenses, investment income, and profit. Premium rate increases continue to be implemented where needed and where approved by state regulators. We develop our assumptions based on our own claims and persistency experience and published industry tables.

Profitability is affected by premium rate increases, persistency, investment returns, claims experience, and the level of administrative expenses.

Individual Disability

We began limiting sales of the types of individual disability policies reported in our Closed Block segment subsequent to the mid-1990s after substantial changes in product design were implemented to improve the overall risk profile of our offerings of individual disability products. We entirely discontinued issuing new policies in this closed block of business in 2004. The majority of the policies were written on a noncancelable basis and were marketed on a single-life customer basis. Profitability is affected by persistency, investment returns, claims experience, and the level of administrative expenses.

Other

Other insurance products not actively marketed include group pension, individual life and corporate-owned life insurance, reinsurance pools and management operations, and other miscellaneous product lines. The majority of these products have been reinsured, with approximately 80 percent of reserves at December 31, 2019 ceded to other insurance companies.

8


Corporate Segment

Our Corporate segment includes investment income on corporate assets not specifically allocated to a line of business, interest expense on corporate debt other than non-recourse debt, and certain other corporate income and expenses not allocated to a line of business.

Reinsurance

In the normal course of business, we assume reinsurance from and cede reinsurance to other insurance companies. In a reinsurance transaction, a reinsurer agrees to indemnify another insurer for part or all of its liability under a policy or policies it has issued for an agreed upon premium or fee. We undertake reinsurance transactions for both risk management and capital management. If the assuming reinsurer in a reinsurance agreement is unable to meet its obligations, we remain contingently liable. In the event that reinsurers do not meet their obligations under the terms of the reinsurance agreement, reinsurance recoverable balances could become uncollectible. We evaluate the financial condition of reinsurers to whom we cede business and monitor concentration of credit risk to minimize our exposure. We may also require assets to be held in trust, letters of credit, or other acceptable collateral to support reinsurance recoverable balances. The collectibility of our reinsurance recoverable is primarily a function of the solvency of the individual reinsurers. Although we have controls to minimize our exposure, the insolvency of a reinsurer or the inability or unwillingness of a reinsurer to comply with the terms of a reinsurance contract could have a material adverse effect on our results of operations.

In general, the maximum amount of life insurance risk retained by our U.S. insurance subsidiaries under group or individual life or group or individual accidental death and dismemberment policies during 2019 was $1 million per covered life per policy. The retention amount remains at $1 million for 2020. For Unum Limited life insurance risk, during 2019 we had reinsurance agreements which provided 75 percent coverage up to £500 thousand per covered life for group dependent life benefits and 25 percent coverage for group lump sum benefits, as well as 100 percent coverage per covered life above that amount. The same structures will be maintained for coverage during 2020 for Unum Limited. 

We have reinsurance agreements on approximately 76 percent of our Closed Block individual disability business. As of December 31, 2019, this reinsurance covers approximately 67 percent of that portion of the consolidated risk above a $3.9 billion retention limit.  The risk limit for the reinsurer grows over time to a maximum of $2.2 billion, after which any further losses will revert to us.

We have global catastrophic reinsurance coverage which covers all Unum Group insurance companies and includes four layers of coverage to limit our exposure under life, accidental death and dismemberment, long-term care, and disability policies in regard to a catastrophic event. Each layer provides coverage for all catastrophic events, including acts of war and any type of terrorism, up to $1 million of coverage per person per policy for each U.S. and non-U.K. line of covered business, and up to £2 million of coverage for each U.K. covered line of business. We have the following coverage for 2020, after a $100 million deductible:

Layer
Coverage (in millions)
Percent Coverage
First  $50.0  50.0 %
Second55.0  55.0  
Third  90.0  60.0  
Fourth180.0  60.0  
Total Catastrophic Coverage  $375.0  

9


In addition to the global catastrophic reinsurance coverage noted above, Unum Limited has additional catastrophic coverage via an arms-length, inter-company reinsurance agreement with Unum America, under similar terms as the global catastrophic treaties. Unum Limited has the following additional coverage for 2020, after a £75 million deductible:

Layer
Coverage (in millions)
Percent Coverage
First£15.0  20.0 %
Second9.0  22.5  
Total Catastrophic Coverage£24.0  

Unum Poland has additional global catastrophic reinsurance coverage of up to 70 million with a maximum retention limit of 0.8 million in 2019. Insurable events include passive war, as well as nuclear, chemical, biological and other forms of terrorism. This agreement was renewed with the same conditions for 2020.

Events may occur which limit or eliminate the availability of catastrophic reinsurance coverage in future years.

We have a quota share reinsurance agreement under which we cede certain blocks of Unum US group long-term disability claims. The agreement is on a combination coinsurance with funds withheld and modified coinsurance basis and provides 90 percent quota share reinsurance on the ceded claims. We also have four reinsurance agreements that collectively cede approximately 55 percent of Unum US group life risk up to our per person retention limit for our U.S. insurance subsidiaries. These reinsurance agreements for Unum US group disability and group life allow us to more effectively manage capital in conformity with statutory accounting principles but do not meet insurance risk transfer in accordance with applicable U.S. generally accepted accounting principles (GAAP) and therefore are not accounted for as reinsurance in our consolidated GAAP financial statements.

We also cede 30 percent of the risk for certain blocks of recently issued Unum US individual disability policies, as well as some related claims development risk for a limited period of time. The agreement is on a non-proportional modified coinsurance basis with a provision for experience refunds.

Certain of our domestic insurance subsidiaries cede blocks of business to Northwind Reinsurance Company (Northwind Re) and Fairwind Insurance Company (Fairwind), both of which are affiliated captive reinsurance subsidiaries (captive reinsurers) domiciled in the United States, with Unum Group as the ultimate parent. These captive reinsurers were established for the limited purpose of reinsuring risks attributable to specified policies issued or reinsured by our insurance subsidiaries in order to effectively manage risks in connection with certain blocks of our business as well as to enhance our capital efficiency. On a consolidated reporting basis for Unum Group, financial statement impacts of our reinsurance arrangements with affiliates are eliminated in accordance with GAAP.

For further discussion of our reinsurance activities, refer to "Risk Factors" contained herein in Item 1A; "Consolidated Operating Results," "Segment Results," and "Liquidity and Capital Resources - Cash Available from Subsidiaries" contained herein in Item 7, and Notes 1, 12, and 16 of the "Notes to Consolidated Financial Statements" contained herein in Item 8.

Reserves for Policy and Contract Benefits

The applicable insurance laws under which insurance companies operate require that they report, as liabilities, policy reserves to meet future obligations on their outstanding policies. These reserves are the amounts which, with the additional premiums to be received and interest thereon compounded annually at certain assumed rates, are calculated to be sufficient to meet the various policy and contract obligations as they mature. These laws specify that the reserves shall not be less than reserves calculated using certain specified mortality and morbidity tables, interest rates, and methods of valuation required for statutory accounting.

The reserves reported in our financial statements contained herein are calculated in conformity with GAAP and differ from those specified by the laws of the various states and reported in the statutory financial statements of our life insurance subsidiaries. These differences result from the use of mortality and morbidity tables and interest assumptions which we believe are more representative of the expected experience for these policies than those required for statutory accounting purposes and also result from differences in actuarial reserving methods.

10


The assumptions we use to calculate our reserves are intended to represent an estimate of experience for the period that policy benefits are payable. If actual experience is equal, or favorable, to our reserve assumptions, then reserves should be adequate to provide for future benefits and expenses. If experience is less favorable than the reserve assumptions, additional reserves may be required. The key experience assumptions include claim incidence rates, claim resolution rates, mortality and morbidity rates, policy persistency, interest rates, premium rate increases, and any applicable policy benefit offsets, including those for social security and other government-based welfare benefits. We periodically review our experience and update our policy reserves for new issues and reserves for all claims incurred, as we believe appropriate.

The consolidated statements of income include the annual change in reserves for future policy and contract benefits. The change reflects a normal accretion for premium payments and interest buildup and decreases for policy terminations such as lapses, deaths, and benefit payments. If policy reserves using best estimate assumptions as of the date of a test for loss recognition are higher than existing policy reserves net of any deferred acquisition costs, the increase in reserves necessary to recognize the deficiency is also included in the change in reserves for future policy and contract benefits.

For further discussion of reserves, refer to "Risk Factors" contained herein in Item 1A, "Critical Accounting Estimates" and the discussion of segment operating results included in "Management's Discussion and Analysis of Financial Condition and Results of Operations" contained herein in Item 7, and Notes 1 and 6 of the "Notes to Consolidated Financial Statements" contained herein in Item 8.

Investments

Investment activities are an integral part of our business, and profitability is significantly affected by investment results. We segment our invested assets into portfolios that support our various product lines. Generally, our investment strategy for our portfolios is to match the effective asset cash flows and durations with related expected liability cash flows and durations to consistently meet the liability funding requirements of our businesses. We seek to earn investment income while assuming credit risk in a prudent and selective manner, subject to constraints of quality, liquidity, diversification, and regulatory considerations. Our overall investment philosophy is to invest in a portfolio of high quality assets that provide investment returns consistent with that assumed in the pricing of our insurance products. Assets are invested predominately in fixed maturity securities. Changes in interest rates may affect the amount and timing of cash flows.

We actively manage our asset and liability cash flow match and our asset and liability duration match to limit interest rate risk. We may redistribute investments among our different lines of business, when necessary, to adjust the cash flow and/or duration of the asset portfolios to better match the cash flow and duration of the liability portfolios. Asset and liability portfolio modeling is updated on a quarterly basis and is used as part of the overall interest rate risk management strategy. Cash flows from the in-force asset and liability portfolios are projected at current interest rate levels and at levels reflecting an increase and a decrease in interest rates to obtain a range of projected cash flows under the different interest rate scenarios. These results enable us to assess the impact of projected changes in cash flows and duration resulting from potential changes in interest rates. Testing the asset and liability portfolios under various interest rate scenarios enables us to choose what we believe to be the most appropriate investment strategy, as well as to limit the risk of disadvantageous outcomes. Although we test the asset and liability portfolios under various interest rate scenarios as part of our modeling, the majority of our liabilities related to insurance contracts are not interest rate sensitive, and we therefore have minimal exposure to policy withdrawal risk. Our determination of investment strategy relies on long-term measures such as reserve adequacy analysis and the relationship between the portfolio yields supporting our various product lines and the aggregate discount rate assumptions embedded in the reserves. We also use this analysis in determining hedging strategies and utilizing derivative financial instruments for managing interest rate risk and the risk related to matching duration for our assets and liabilities. We do not use derivative financial instruments for speculative purposes.

Refer to "Risk Factors" contained herein in Item 1A; "Critical Accounting Estimates" and the discussion of investments in "Management's Discussion and Analysis of Financial Condition and Results of Operations" contained herein in Item 7; "Quantitative and Qualitative Disclosures About Market Risk" herein in Item 7A; and Notes 1, 2, 3, and 4 of the "Notes to Consolidated Financial Statements" contained herein in Item 8 for information on our investments and derivative financial instruments.

Ratings

AM Best, Fitch Ratings (Fitch), Moody's Investors Service (Moody's), and Standard & Poor's Ratings Services (S&P) are among the third parties that assign issuer credit ratings to Unum Group and financial strength ratings to our insurance subsidiaries. Issuer credit ratings reflect an agency's opinion of the overall financial capacity of a company to meet its senior
11


debt obligations. Financial strength ratings are specific to each individual insurance subsidiary and reflect each rating agency's view of the overall financial strength (capital levels, earnings, growth, investments, business mix, operating performance, and market position) of the insuring entity and its ability to meet its obligations to policyholders. Both the issuer credit ratings and financial strength ratings incorporate quantitative and qualitative analyses by rating agencies and are routinely reviewed and updated on an ongoing basis.
 
Rating agencies assign an outlook statement of "positive," "negative," or "developing" to indicate an intermediate-term trend in credit fundamentals which could lead to a rating change. "Positive" means that a rating may be raised, "negative" means that a rating may be lowered, and "developing" means that a rating may be raised or lowered with equal probability. Alternatively, a rating may have a "stable" outlook to indicate that the rating is not expected to change.

"Credit watch" or "under review" highlights the potential direction of a short-term or long-term rating. It focuses on identifiable events and short-term trends that cause a rating to be placed under heightened surveillance by a rating agency. Events that may trigger this action include mergers, acquisitions, recapitalizations, regulatory actions, criteria changes, or operating developments. Ratings may be placed on credit watch or under review when an event or a change in an expected trend occurs and additional information is needed to evaluate the current rating level. This status does not mean that a rating change is inevitable, and ratings may change without first being placed on a watch list. A rating is not a recommendation to buy, sell, or hold securities and may be subject to revision or withdrawal at any time by the rating agency. Each rating should be evaluated independently of any other rating.
 
See "Management's Discussion and Analysis of Financial Condition and Results of Operations - Ratings" contained herein in Item 7 for our current outlook, issuer credit, and financial strength ratings. See also further discussion in "Risk Factors" contained herein in Item 1A.

Competition

There is significant competition among insurance companies for the types of products we sell, particularly in the voluntary benefits market. We are operating in a dynamic competitive environment of both traditional and non-traditional competitors, with changes in product offerings, enrollment services, and technology solutions. We believe that the principal competitive factors affecting our business are price, quality of the customer experience regarding service and claims management, integrated product choices, enrollment capabilities, financial strength ratings, claims-paying ratings, and a solution to allow our customers to comply with the changing laws and regulations related to family medical leave benefits.

In the individual and group disability markets, we compete in the United States with a number of major companies and regionally with other companies offering specialty products. Our principal competitors for our other products, including group life and the product offerings sold to groups of employees through payroll deduction, include the largest insurance companies in the United States. Some of these companies have more competitive pricing or have higher claims-paying ratings. Some may also have greater financial resources with which to compete.

In the United Kingdom and Poland, where we sell both individual and group products, we compete with a mix of large internationally recognized providers and strong local carriers. 

All areas of the employee benefits markets are highly competitive due to the yearly renewable term nature of our products and the large number of insurance companies offering products in this market. There is a risk that our customers may be able to obtain more favorable terms or improved technology solutions from competitors in lieu of renewing coverage with us. The effect of competition may, as a result, adversely affect the persistency of these and other products, as well as our ability to sell products in the future.

We must attract and retain independent agents and brokers to actively market our products. Strong competition exists among insurers for agents and brokers. We compete with other insurers for sales agents and brokers primarily on the basis of our product offerings, financial strength, support services, and compensation. Sales of our products could be materially adversely affected if we are unsuccessful in attracting and retaining agents and brokers.

For further discussion, refer to "Risk Factors" contained herein in Item 1A.

12


Regulation

We and our subsidiaries are subject to extensive and comprehensive supervision and regulation in the United States, the United Kingdom, and Poland. The laws and regulations with which we must comply are complex and subject to change. New or existing laws and regulations may become more restrictive or otherwise adversely affect our operations.

Insurance Regulation and Oversight

Our U.S. insurance subsidiaries are subject to regulation and oversight by insurance regulatory authorities in the jurisdictions in which they do business and by the U.S. Department of Labor (DOL) on a national basis, primarily for the protection of policyholders. State insurance regulators in the U.S. generally have broad powers with respect to all aspects of the insurance business, including the power to: license and examine insurance companies; regulate and supervise sales practices and market conduct; license agents and brokers; approve policy forms; approve premium rates and subsequent increases thereon for certain insurance products; establish reserve requirements and solvency standards; place limitations on shareholder dividends; prescribe the form and content of required financial statements and reports; regulate the types and amounts of permitted investments; and regulate reinsurance transactions. Our U.S. insurance subsidiaries are examined periodically by their states of domicile and by other states in which they are licensed to conduct business. The domestic examinations have traditionally emphasized financial matters from the perspective of protection of policyholders, but they can and have covered other subjects that an examining state may be interested in reviewing, such as market conduct issues and reserve adequacy. Examinations in other states more typically focus on market conduct, such as a review of sales practices, including the content and use of advertising materials and the licensing and appointing of agents and brokers, as well as underwriting, claims, and customer service practices, and identification and handling of unclaimed property to determine compliance with state laws. Our U.S. insurance subsidiaries are also subject to assessments by state insurance guaranty associations to cover the proportional cost of insolvent or failed insurers. The DOL enforces a comprehensive federal statute which regulates claims paying fiduciary responsibilities and reporting and disclosure requirements for most employee benefit plans.

Our U.K. insurance subsidiary, Unum Limited, is subject to dual regulation by the Prudential Regulation Authority (PRA) and the Financial Conduct Authority (FCA). The PRA oversees the financial health and stability of financial services firms and is responsible for the prudential regulation and day-to-day supervision of insurance companies. The FCA seeks to protect consumers and oversees financial services products and practices, including those governing insurance companies in the U.K.

On January 31, 2020, an official bill was passed formalizing the withdrawal of the U.K. from the European Union (EU). The bill gives approval to an 11-month transition period, until December 31, 2020, to allow for further negotiations regarding the details of the future relationship. The U.K.'s decision to leave the EU may add cost and complexity to our compliance efforts if new laws and regulations are established that significantly diverge from those currently in place, however, we are not aware of any indications of such changes in the short-term and do not expect significant changes over the longer term. Additionally, the insurance policies issued by our U.K. insurance subsidiary cover businesses and policyholders based in the U.K. We do not expect these policies to be affected by the U.K.'s exit nor do we anticipate the need to obtain additional insurance permissions to be able to continue writing these policies. For the small amount of contracts and coverages provided to companies and individuals outside of the U.K., we have developed contingency plans that could be invoked following the U.K.'s exit. The employees that support our U.K. business reside in the U.K. and will not need to change residence status.

Our Polish insurance subsidiary, Unum Zycie TUiR, is subject to regulation by the Komisja Nadzoru Finansowego (KNF) of the Financial Supervision Authority (FSA) in Poland. The KNF oversees the financial health and stability of financial services firms and is responsible for the prudential regulation and day-to-day supervision of insurance companies and other financial institutions.
13


Capital Requirements

Risk-based capital (RBC) standards for U.S. life insurance companies are prescribed by the National Association of Insurance Commissioners (NAIC). The domiciliary states of our U.S. insurance subsidiaries have all adopted a version of the NAIC RBC Model Act, which prescribes a system for assessing the adequacy of statutory capital and surplus for all life and health insurers. The basis of the system is a risk-based formula that applies prescribed factors to the various risk elements in a life and health insurer's business to report a minimum capital requirement proportional to the amount of risk assumed by the insurer. The life and health RBC formula is designed to measure annually (i) the risk of loss from asset defaults and asset value fluctuations, (ii) the risk of loss from adverse mortality and morbidity experience, (iii) the risk of loss from mismatching of asset and liability cash flow due to changing interest rates, and (iv) business risks. The formula is used as an early warning tool to identify companies that are potentially inadequately capitalized. The formula is intended to be used as a regulatory tool only and is not intended as a means to rank insurers generally. The NAIC has also issued a proposal to implement a new and more granular RBC structure for fixed income asset capital charges. The proposed structure will expand the fixed income asset designations from six to 20 categories and will revise factor values. We will continue to monitor the NAIC's activities on this issue.

The NAIC continues to review the state-based solvency regulation framework to identify opportunities to respond to national and international insurance regulatory and solvency developments. The topics of its review include capital requirements, governance and risk management, statutory accounting and financial reporting, and reinsurance. This ongoing review will likely result in significant changes to U.S. insurance regulation and solvency standards, including those for our U.S. insurance subsidiaries. One of the outcomes of the NAIC's review was the adoption of the NAIC Risk Management and Own Risk and Solvency Assessment (ORSA) Model Act which, following enactment at the state level, requires insurers to provide, at least annually, a group-level perspective on the risks of the current and future business plans and the sufficiency of capital to support those risks. All states where our traditional U.S. insurance subsidiaries are domiciled have enacted ORSA requirements, and we file an ORSA summary report annually with the applicable insurance regulators.

The NAIC has established a working group charged with developing a group capital calculation that can be used by regulators as a baseline quantitative measure in assessing the risks and financial position of insurance groups. The working group completed its work on the U.S. group capital calculation and conducted field testing during the second half of 2019. The calculation and related instructions are being revised to incorporate findings and observations from the field testing and are expected to be adopted by the NAIC in late 2020. We are also monitoring developments around the implementation of reforms adopted by the International Association of Insurance Supervisors (IAIS) in November 2019 that established similar group capital requirements. We are not subject to the reforms adopted by the IAIS, however, the requirements could influence the reforms that will be adopted by the NAIC. We will continue to monitor the NAIC's activities on this issue but it is still too early to determine what, if any, impact these developments will have on our capital requirements.

The NAIC has adopted a valuation manual containing a principles-based approach to life insurance company reserves for new business. The earliest effective date was January 2017 with a three-year optional period before mandatory adoption by January 2020. The Company elected a staged approach to the implementation of the new requirements, with no material impact on our statutory reserves.

In 2012, the NAIC established a subgroup to study the insurance industry's use of captive reinsurers and special purpose vehicles to transfer insurance risk and is considering ways to promote uniformity in both the approval and supervision of such reinsurers. More recently, the NAIC adopted a proposal to subject certain captive reinsurers and special purpose vehicles to the same capital requirements as traditional insurers. As the NAIC and state insurance regulators continue to examine the use of captive insurance companies to finance reserves required under current regulations, we cannot predict the ultimate outcome of their work, or how long or extensively they will continue to focus on this issue. Although we believe it to be unlikely, a potential outcome of future NAIC decisions from its various committees, task forces, and working groups is that companies could be prohibited from using captive reinsurers. No changes in the use or regulation of captive reinsurers have been proposed by the NAIC, and we are unable to predict the extent of any changes that might be made. Accordingly, we expect to continue our strategy of using captive reinsurers to manage risks and enhance capital efficiency while monitoring the NAIC's study and proposed changes in regulations. See "Reinsurance" contained herein in this Item 1 for further discussion.

The PRA has statutory requirements, including capital adequacy and liquidity requirements and minimum solvency margins, to which Unum Limited must adhere as part of the provisions of Solvency II, an EU directive that prescribes capital requirements and risk management standards for the European insurance industry.  Our European holding company is also subject to the Solvency II requirements relevant to insurance holding companies, while its subsidiaries, which includes Unum Limited, are subject to group supervision under Solvency II.  The Unum European Economic Area (EEA) Group, which is comprised of the European holding company and its subsidiaries, received approval from the PRA to use its own internal model for calculating regulatory capital and also received approval for certain associated regulatory permissions including transitional relief as the
14


Solvency II capital regime is implemented.  Although there are currently no indications that the regulatory capital regime for our U.K. operations will change due to the U.K.'s decision to leave the EU, it remains too early to predict what, if any, impact this may have on existing capital requirements for our U.K. entities, but economic conditions may cause volatility in our solvency ratios.

See further discussion in "Risk Factors" contained herein in Item 1A and "Liquidity and Capital Resources" contained herein in Item 7 and Note 16 of the "Notes to Consolidated Financial Statements" contained herein in Item 8.  

Insurance Holding Company Regulation

We and our U.S. insurance subsidiaries (excluding captive reinsurers) are subject to regulation under the insurance holding company laws in the states in which our insurance subsidiaries are domiciled, which currently include Maine, Massachusetts, New York, South Carolina, and Tennessee. These laws generally require each insurance company that is domiciled in the state and a member of an insurance holding company system to register with the insurance department of that state and to furnish at least annually financial and other information about the operations of companies within the holding company system, including information concerning capital structure, ownership, management, financial condition, and certain intercompany transactions. Transactions between an insurer and affiliates in the holding company system generally must be fair and reasonable and, if material, require prior notice and approval by the domiciliary insurance regulator.

In addition, such laws and regulations restrict the amount of dividends that may be paid by our insurance subsidiaries to their respective shareholders, including our Company and certain of our intermediate holding company subsidiaries. See further discussion in "Risk Factors" contained herein in Item 1A and "Liquidity and Capital Resources - Cash Available from Subsidiaries" contained herein in Item 7.