0000101199 2017-01-01 2017-12-31 0000101199 2017-06-30 0000101199 2018-02-26 0000101199 2016-12-31 0000101199 2017-12-31 0000101199 2015-01-01 2015-12-31 0000101199 2016-01-01 2016-12-31 0000101199 us-gaap:RetainedEarningsMember 2015-01-01 2015-12-31 0000101199 us-gaap:AdditionalPaidInCapitalMember 2015-01-01 2015-12-31 0000101199 us-gaap:RetainedEarningsMember 2016-01-01 2016-12-31 0000101199 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2015-01-01 2015-12-31 0000101199 us-gaap:AdditionalPaidInCapitalMember 2016-12-31 0000101199 us-gaap:AdditionalPaidInCapitalMember 2016-01-01 2016-12-31 0000101199 2015-12-31 0000101199 us-gaap:AdditionalPaidInCapitalMember 2014-12-31 0000101199 2014-12-31 0000101199 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2016-12-31 0000101199 us-gaap:RetainedEarningsMember 2015-12-31 0000101199 us-gaap:AdditionalPaidInCapitalMember 2017-01-01 2017-12-31 0000101199 us-gaap:CommonStockMember 2015-01-01 2015-12-31 0000101199 us-gaap:CommonStockMember 2015-12-31 0000101199 us-gaap:RetainedEarningsMember 2017-01-01 2017-12-31 0000101199 us-gaap:AdditionalPaidInCapitalMember 2015-12-31 0000101199 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2014-12-31 0000101199 us-gaap:CommonStockMember 2016-01-01 2016-12-31 0000101199 us-gaap:CommonStockMember 2016-12-31 0000101199 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-01-01 2017-12-31 0000101199 us-gaap:RetainedEarningsMember 2016-12-31 0000101199 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2016-01-01 2016-12-31 0000101199 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2015-12-31 0000101199 us-gaap:RetainedEarningsMember 2017-12-31 0000101199 us-gaap:RetainedEarningsMember 2014-12-31 0000101199 us-gaap:AdditionalPaidInCapitalMember 2017-12-31 0000101199 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-12-31 0000101199 us-gaap:CommonStockMember 2017-01-01 2017-12-31 0000101199 us-gaap:CommonStockMember 2017-12-31 0000101199 us-gaap:CommonStockMember 2014-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2014-12-31 0000101199 us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 ufcs:ContinuingandDiscontinuingOperationsMember 2017-01-01 2017-12-31 0000101199 us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-12-31 0000101199 us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2016-01-01 2016-12-31 0000101199 ufcs:ContinuingandDiscontinuingOperationsMember 2015-01-01 2015-12-31 0000101199 ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ContinuingandDiscontinuingOperationsMember 2015-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2015-12-31 0000101199 ufcs:ContinuingandDiscontinuingOperationsMember 2014-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2015-01-01 2015-12-31 0000101199 us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2015-12-31 0000101199 ufcs:ContinuingandDiscontinuingOperationsMember 2016-01-01 2016-12-31 0000101199 us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2015-01-01 2015-12-31 0000101199 ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2017-01-01 2017-12-31 0000101199 us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2014-12-31 0000101199 us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:ComputerEquipmentandSoftwareMember 2017-01-01 2017-12-31 0000101199 ufcs:AirplaneMember 2017-01-01 2017-12-31 0000101199 us-gaap:FurnitureAndFixturesMember 2017-01-01 2017-12-31 0000101199 us-gaap:FurnitureAndFixturesMember 2016-12-31 0000101199 ufcs:ComputerEquipmentandSoftwareMember 2016-12-31 0000101199 ufcs:ComputerEquipmentandSoftwareMember 2017-12-31 0000101199 ufcs:AirplaneMember 2017-12-31 0000101199 us-gaap:LandMember 2017-12-31 0000101199 us-gaap:BuildingMember 2017-12-31 0000101199 us-gaap:FurnitureAndFixturesMember 2017-12-31 0000101199 us-gaap:BuildingMember 2016-12-31 0000101199 us-gaap:LandMember 2016-12-31 0000101199 ufcs:AirplaneMember 2016-12-31 0000101199 2017-01-01 2017-09-17 0000101199 2017-09-18 2017-12-31 0000101199 us-gaap:MinimumMember 2017-01-01 2017-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember us-gaap:MinimumMember 2017-12-31 0000101199 2017-10-01 2017-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember us-gaap:MaximumMember 2017-12-31 0000101199 us-gaap:LifeInsuranceSegmentMember 2017-12-31 0000101199 us-gaap:MaximumMember 2017-01-01 2017-12-31 0000101199 us-gaap:AccountingStandardsUpdate201601Member us-gaap:ProFormaMember 2017-12-31 0000101199 us-gaap:LandBuildingsAndImprovementsMember us-gaap:MinimumMember 2017-01-01 2017-12-31 0000101199 us-gaap:LandBuildingsAndImprovementsMember us-gaap:MaximumMember 2017-01-01 2017-12-31 0000101199 us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:DebtSecuritiesMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:AssetBackedSecuritiesMember 2017-12-31 0000101199 us-gaap:DebtSecuritiesMember 2017-12-31 0000101199 us-gaap:MortgageBackedSecuritiesMember 2017-12-31 0000101199 us-gaap:CollateralizedMortgageObligationsMember 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember 2017-12-31 0000101199 us-gaap:SegmentDiscontinuedOperationsMember 2015-01-01 2015-12-31 0000101199 us-gaap:SegmentDiscontinuedOperationsMember 2016-01-01 2016-12-31 0000101199 us-gaap:SegmentDiscontinuedOperationsMember 2017-01-01 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:MaximumMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:MaximumMember 2017-12-31 0000101199 us-gaap:FixedMaturitiesMember 2015-01-01 2015-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:MaximumMember 2015-12-31 0000101199 us-gaap:EquitySecuritiesMember 2017-01-01 2017-12-31 0000101199 us-gaap:ShortTermInvestmentsMember 2015-01-01 2015-12-31 0000101199 us-gaap:ShortTermInvestmentsMember 2016-01-01 2016-12-31 0000101199 us-gaap:ShortTermInvestmentsMember 2017-01-01 2017-12-31 0000101199 us-gaap:OtherLongTermInvestmentsMember 2015-01-01 2015-12-31 0000101199 us-gaap:CashAndCashEquivalentsMember 2016-01-01 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember 2017-01-01 2017-12-31 0000101199 ufcs:ChangeinValueMember us-gaap:OtherLongTermInvestmentsMember 2015-01-01 2015-12-31 0000101199 us-gaap:FixedMaturitiesMember 2016-01-01 2016-12-31 0000101199 ufcs:ChangeinValueMember us-gaap:OtherLongTermInvestmentsMember 2017-01-01 2017-12-31 0000101199 us-gaap:FixedMaturitiesMember 2017-01-01 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember 2016-01-01 2016-12-31 0000101199 us-gaap:FixedMaturitiesMember 2015-01-01 2015-12-31 0000101199 us-gaap:OtherLongTermInvestmentsMember 2016-01-01 2016-12-31 0000101199 ufcs:ChangeinValueMember us-gaap:OtherLongTermInvestmentsMember 2016-01-01 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember 2015-01-01 2015-12-31 0000101199 us-gaap:CashAndCashEquivalentsMember 2017-01-01 2017-12-31 0000101199 us-gaap:OtherLongTermInvestmentsMember 2017-01-01 2017-12-31 0000101199 us-gaap:CashAndCashEquivalentsMember 2015-01-01 2015-12-31 0000101199 ufcs:IndustrialMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:CollateralizedMortgageObligationsMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:AssetBackedSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:MortgageBackedSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember ufcs:TradingAccountAssetsSalesMember 2016-01-01 2016-12-31 0000101199 us-gaap:FixedMaturitiesMember ufcs:TradingAccountAssetsSalesMember 2015-01-01 2015-12-31 0000101199 us-gaap:FixedMaturitiesMember us-gaap:AvailableforsaleSecuritiesMember 2016-01-01 2016-12-31 0000101199 us-gaap:RealEstateMember 2016-01-01 2016-12-31 0000101199 us-gaap:FixedMaturitiesMember ufcs:TradingAccountAssetsSalesMember 2016-01-01 2016-12-31 0000101199 us-gaap:FixedMaturitiesMember ufcs:TradingAccountAssetsChangeInFairValueMember 2016-01-01 2016-12-31 0000101199 us-gaap:FixedMaturitiesMember ufcs:OtherthantemporaryimpairmentChargesMember 2017-01-01 2017-12-31 0000101199 us-gaap:FixedMaturitiesMember ufcs:TradingAccountAssetsSalesMember 2017-01-01 2017-12-31 0000101199 us-gaap:FixedMaturitiesMember us-gaap:AvailableforsaleSecuritiesMember 2017-01-01 2017-12-31 0000101199 us-gaap:RealEstateMember 2015-01-01 2015-12-31 0000101199 us-gaap:EquitySecuritiesMember ufcs:TradingAccountAssetsSalesMember 2017-01-01 2017-12-31 0000101199 ufcs:CategoriesOfInvestmentsMarketableSecuritiesOtherLongTermInvestmentsMember 2016-01-01 2016-12-31 0000101199 us-gaap:CashEquivalentsMember 2017-01-01 2017-12-31 0000101199 us-gaap:FixedMaturitiesMember ufcs:TradingAccountAssetsChangeInFairValueMember 2017-01-01 2017-12-31 0000101199 us-gaap:FixedMaturitiesMember ufcs:TradingAccountAssetsChangeInFairValueMember 2015-01-01 2015-12-31 0000101199 us-gaap:EquitySecuritiesMember ufcs:TradingAccountAssetsChangeInFairValueMember 2016-01-01 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember ufcs:TradingAccountAssetsSalesMember 2015-01-01 2015-12-31 0000101199 us-gaap:FixedMaturitiesMember us-gaap:AvailableforsaleSecuritiesMember 2015-01-01 2015-12-31 0000101199 us-gaap:EquitySecuritiesMember ufcs:TradingAccountAssetsChangeInFairValueMember 2015-01-01 2015-12-31 0000101199 us-gaap:CashEquivalentsMember 2015-01-01 2015-12-31 0000101199 us-gaap:FixedMaturitiesMember ufcs:OtherthantemporaryimpairmentChargesMember 2015-01-01 2015-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:AvailableforsaleSecuritiesMember 2017-01-01 2017-12-31 0000101199 ufcs:CategoriesOfInvestmentsMarketableSecuritiesOtherLongTermInvestmentsMember 2015-01-01 2015-12-31 0000101199 us-gaap:RealEstateMember 2017-01-01 2017-12-31 0000101199 us-gaap:CashEquivalentsMember 2016-01-01 2016-12-31 0000101199 ufcs:CategoriesOfInvestmentsMarketableSecuritiesOtherLongTermInvestmentsMember 2017-01-01 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:AvailableforsaleSecuritiesMember 2015-01-01 2015-12-31 0000101199 us-gaap:FixedMaturitiesMember ufcs:OtherthantemporaryimpairmentChargesMember 2016-01-01 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember ufcs:TradingAccountAssetsChangeInFairValueMember 2017-01-01 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:AvailableforsaleSecuritiesMember 2016-01-01 2016-12-31 0000101199 us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember 2015-01-01 2015-12-31 0000101199 us-gaap:FixedMaturitiesMember 2017-01-01 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember 2016-01-01 2016-12-31 0000101199 us-gaap:FixedMaturitiesMember 2016-01-01 2016-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FixedMaturitiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FixedMaturitiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FixedMaturitiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FixedMaturitiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:ContinuingandDiscontinuingOperationsMember 2015-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-01-01 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-01-01 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-01-01 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-01-01 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2015-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-01-01 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2015-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2015-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2015-12-31 0000101199 us-gaap:OtherAssetsMember ufcs:RabbiTrustMember us-gaap:FairValueInputsLevel2Member 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:RedeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:RedeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:RedeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:RedeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-01-01 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-01-01 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-01-01 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-01-01 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-01-01 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2017-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:EquitySecuritiesMember 2017-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2017-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FixedMaturitiesMember 2017-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2017-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FixedMaturitiesMember 2016-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:EquitySecuritiesMember 2016-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FixedMaturitiesMember 2017-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2016-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FixedMaturitiesMember 2016-12-31 0000101199 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2016-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:EquitySecuritiesMember 2016-12-31 0000101199 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:EquitySecuritiesMember 2017-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:RedeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:RedeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:RedeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalHomeLoanMortgageCorporationFhlmcInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:IndustrialMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:MidwestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CorporateDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:NonredeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:EnergyMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:TechnologyMediaAndTelecommunicationsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:PublicUtilitiesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:RedeemablePreferredStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:HealthCareMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:SouthMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:NortheastMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:GovernmentNationalMortgageAssociationGnmaInsuredLoansMember us-gaap:CollateralizedMortgageObligationsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommonStockMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:SpecialRevenueMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:FinancialServicesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PublicUtilityBondsMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:ForeignGovernmentDebtSecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:ConsumerGoodsAndServiceMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 ufcs:GeneralObligationsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember ufcs:WestMember ufcs:ContinuingandDiscontinuingOperationsMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember us-gaap:SegmentDiscontinuedOperationsMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DebtSecuritiesMember 2016-12-31 0000101199 ufcs:PropertyCatastropheMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:CasualtyMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:PropertyMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:SuretyMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:BoilerAndMachineryMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:CasualtyMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 ufcs:PropertyCatastropheMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 ufcs:BoilerAndMachineryMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 ufcs:SuretyMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 ufcs:PropertyMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 ufcs:CasualtyMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2015-01-01 2015-12-31 0000101199 ufcs:BoilerAndMachineryMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2015-01-01 2015-12-31 0000101199 ufcs:PropertyCatastropheMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2015-01-01 2015-12-31 0000101199 ufcs:SuretyMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2015-01-01 2015-12-31 0000101199 ufcs:PropertyMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2015-01-01 2015-12-31 0000101199 ufcs:PropertyCatastropheTwoMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2015-01-01 2015-12-31 0000101199 us-gaap:IndividualPoliciesMember us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2017-01-01 2017-12-31 0000101199 ufcs:CasualtyExcessandPropertyExcessMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2015-01-01 2015-12-31 0000101199 ufcs:CasualtyExcessandPropertyExcessMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 us-gaap:GroupPoliciesMember us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2017-01-01 2017-12-31 0000101199 ufcs:CatastropheInsuranceMember us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2017-01-01 2017-12-31 0000101199 ufcs:CasualtyExcessandPropertyExcessMember us-gaap:MaximumMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:CasualtyExcessandPropertyExcessMember us-gaap:MaximumMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-12-31 0000101199 ufcs:TopFiveReinsurersMember us-gaap:LifeInsuranceSegmentMember us-gaap:SegmentDiscontinuedOperationsMember 2017-01-01 2017-12-31 0000101199 ufcs:CasualtyExcessandPropertyExcessMember us-gaap:MaximumMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-12-31 0000101199 ufcs:CasualtyExcessandPropertyExcessMember us-gaap:MaximumMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 ufcs:CasualtyExcessandPropertyExcessMember us-gaap:MinimumMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 ufcs:CasualtyExcessandPropertyExcessMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:CasualtyExcessandPropertyExcessMember us-gaap:MinimumMember us-gaap:PropertyLiabilityAndCasualtyInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2014-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2015-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2014-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2012-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2015-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2012-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2015-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2009-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2014-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2015-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2013-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2010-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2012-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2013-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2015-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2011-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortDurationInsuranceContractsAccidentYear2017Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2015-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2014-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2015-12-31 0000101199 ufcs:CommercialotherliabilityMember 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2012-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2013-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2014-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2013-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2013-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2010-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2010-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2014-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2013-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2015-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2011-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2011-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2012-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2008-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2016-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2011-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2014-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2017-12-31 0000101199 ufcs:CommercialotherliabilityMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2009-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2016-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2013-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2016-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2014-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2011-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2016-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2010-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2016-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2015-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortDurationInsuranceContractsAccidentYear2017Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2014-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2016-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2017-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2014-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2013-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2013-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2016-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2011-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2012-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2014-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2014-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2012-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2015-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2012-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2014-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2010-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2012-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2009-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2015-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2015-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2009-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2015-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2015-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2014-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2010-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2012-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2016-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2011-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2013-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2013-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2016-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2008-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2016-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2011-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2015-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2015-12-31 0000101199 ufcs:CommercialAutomobileMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2013-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2010-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2013-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2016-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2016-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2009-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2010-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2009-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2016-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2015-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2015-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2014-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2013-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2013-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2016-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2010-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2014-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2014-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2016-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2014-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2016-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2016-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2011-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2011-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2016-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2015-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2015-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2008-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2015-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2012-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2012-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2011-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2012-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2014-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2015-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2012-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2011-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2013-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2014-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2016-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2015-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortDurationInsuranceContractsAccidentYear2017Member 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2013-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2012-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2015-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2017-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2013-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2014-12-31 0000101199 ufcs:WorkersCompensationInsuranceMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2009-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2012-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2015-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2013-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2014-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2008-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2011-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortDurationInsuranceContractsAccidentYear2017Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2016-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2016-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2015-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2015-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2016-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2013-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2016-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2012-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2011-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2014-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2016-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2014-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2013-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2015-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2015-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2014-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2013-12-31 0000101199 ufcs:PersonalMember 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2011-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2012-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2010-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2016-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2014-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2010-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2013-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2012-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2017-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2009-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2013-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2015-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2015-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2016-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2016-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2015-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2014-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2014-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2012-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2011-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2016-12-31 0000101199 ufcs:PersonalMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2010-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2011-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2015-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2016-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2015-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2010-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2014-12-31 0000101199 ufcs:CommercialFireAlliedMember 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2016-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2010-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2015-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2011-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2014-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2010-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortDurationInsuranceContractsAccidentYear2017Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2008-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2009-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2015-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2015-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2011-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2013-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2013-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2017-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2012-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2013-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2015-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2014-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2014-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2012-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2016-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2011-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2010Member 2014-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2013-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2015Member 2016-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2014-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2009-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2016-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2016-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2011Member 2015-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2009Member 2012-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2012-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2012-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2014Member 2016-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2016Member 2016-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2016-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2008Member 2014-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2015-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2013Member 2013-12-31 0000101199 ufcs:CommercialFireAlliedMember us-gaap:ShortdurationInsuranceContractsAccidentYear2012Member 2013-12-31 0000101199 us-gaap:OtherShortdurationInsuranceProductLineMember 2017-12-31 0000101199 ufcs:LifeAccidentAndHealthInsuranceSegmentMember 2017-12-31 0000101199 ufcs:LifeAccidentAndHealthInsuranceSegmentMember 2016-12-31 0000101199 ufcs:LifeAccidentAndHealthInsuranceSegmentMember 2017-01-01 2017-12-31 0000101199 ufcs:LifeAccidentAndHealthInsuranceSegmentMember 2015-01-01 2015-12-31 0000101199 ufcs:LifeAccidentAndHealthInsuranceSegmentMember 2016-01-01 2016-12-31 0000101199 ufcs:LifeAccidentAndHealthInsuranceSegmentMember 2015-12-31 0000101199 ufcs:UnitedFireCasualtyCompanyMember 2017-01-01 2017-12-31 0000101199 ufcs:StateOfIowaInsuranceDepartmentMember 2017-12-31 0000101199 ufcs:UnitedLifeMember 2017-12-31 0000101199 us-gaap:RevolvingCreditFacilityMember 2017-12-31 0000101199 ufcs:UnitedFireCasualtyCompanyMember 2015-01-01 2015-12-31 0000101199 ufcs:UnitedFireCasualtyCompanyMember 2016-01-01 2016-12-31 0000101199 us-gaap:SubsidiariesMember 2016-01-01 2016-12-31 0000101199 us-gaap:SubsidiariesMember 2017-01-01 2017-12-31 0000101199 us-gaap:SubsidiariesMember 2015-01-01 2015-12-31 0000101199 us-gaap:ValuationAllowanceOperatingLossCarryforwardsMember 2017-01-01 2017-12-31 0000101199 us-gaap:ValuationAllowanceOperatingLossCarryforwardsMember 2016-01-01 2016-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MutualFundMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MoneyMarketFundsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MutualFundMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MutualFundMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MutualFundMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2016-01-01 2016-12-31 0000101199 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2015-01-01 2015-12-31 0000101199 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-01-01 2017-12-31 0000101199 us-gaap:PensionPlansDefinedBenefitMember 2015-01-01 2015-12-31 0000101199 us-gaap:PensionPlansDefinedBenefitMember 2016-01-01 2016-12-31 0000101199 us-gaap:PensionPlansDefinedBenefitMember 2017-01-01 2017-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2016-01-01 2016-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2015-12-31 0000101199 ufcs:PostretirementDentalBenefitsMember 2017-12-31 0000101199 ufcs:PostretirementDentalBenefitsMember 2016-12-31 0000101199 us-gaap:DefinedBenefitPostretirementHealthCoverageMember 2017-12-31 0000101199 us-gaap:DefinedBenefitPostretirementHealthCoverageMember 2016-12-31 0000101199 us-gaap:PensionPlansDefinedBenefitMember 2015-12-31 0000101199 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2015-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:MoneyMarketFundsMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:MutualFundMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:MutualFundMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:MutualFundMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:MutualFundMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:PensionPlansDefinedBenefitMember 2017-01-01 0000101199 us-gaap:DeferredProfitSharingMember 2016-01-01 2016-12-31 0000101199 us-gaap:DeferredProfitSharingMember 2017-01-01 2017-12-31 0000101199 us-gaap:DeferredProfitSharingMember 2015-01-01 2015-12-31 0000101199 us-gaap:PensionPlansDefinedBenefitMember 2017-01-01 2017-01-01 0000101199 ufcs:UnitedLifeAnnuityMember us-gaap:MaximumMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:CashAndCashEquivalentsMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:MinimumMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MutualFundMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:MaximumMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:UnitedLifeAnnuityMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:CashAndCashEquivalentsMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MutualFundMember us-gaap:MinimumMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:MaximumMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:MinimumMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 ufcs:CorePlusBondSeparateAccountFundMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:CorporateDebtSecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:RedeemablePreferredStockMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MutualFundMember us-gaap:MaximumMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:MutualFundMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:UnitedLifeAnnuityMember us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000101199 us-gaap:EquitySecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 ufcs:U.S.PropertySeparateAccountFundMember us-gaap:MaximumMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199 us-gaap:CashAndCashEquivalentsMember us-gaap:MaximumMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000101199