Document and Entity Information [Abstract] Document and Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Shell Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Activity in Stock Award Plans Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Recognition of Stock-Based Compensation Expense Schedule of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block] Analysis of Award Activity Share-based Compensation, Stock Options, Activity [Table Text Block] Schedule of Restricted Stock Award Activity Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Weighted-average Grant-Date Fair Value Assumptions Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Summary of Stock Options Outstanding and Exercisable Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block] Equity [Abstract] ACCUMULATED OTHER COMPREHENSIVE INCOME Comprehensive Income (Loss) Note [Text Block] Income Tax Disclosure [Abstract] Valuation Allowance [Table] Valuation Allowance [Table] Valuation Allowance by Deferred Tax Asset [Axis] Valuation Allowance by Deferred Tax Asset [Axis] Deferred Tax Asset [Domain] Deferred Tax Asset [Domain] Valuation Allowance, Operating Loss Carryforwards SEC Schedule, 12-09, Valuation Allowance, Operating Loss Carryforward [Member] Operating Activities [Axis] Operating Activities [Axis] Operating Activities [Domain] Operating Activities [Domain] Continuing and Discontinuing Operations Continuing and Discontinuing Operations [Member] Continuing and Discontinuing Operations [Member] Valuation Allowance [Line Items] Valuation Allowance [Line Items] Valuation allowance Deferred Tax Assets, Valuation Allowance Reduction in valuation allowance Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Realization of NOLs Operating Loss Carryforwards, Amount Utilized Operating Loss Carryforwards, Amount Utilized Alternative minimum tax credit carryforward Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] Tranche one Share-based Compensation Award, Tranche One [Member] Tranche two Share-based Compensation Award, Tranche Two [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Employee Stock Award Plan-2008 Employee Stock Award Plan-2008 [Member] Employee Stock Award Plan (the "2008 Stock Plan") [Member] Director Plan - 2005 Director Plan - 2005 [Member] the 2005 Non-qualified Non-employee Director Stock Option and Restricted Stock Plan (the "Director Plan" [Member] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Stock Options Employee Stock Option [Member] Unrestricted Stock Awards Unrestricted Stock Awards [Member] Unrestricted Stock Awards [Member] Restricted Stock Awards Restricted Stock [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Percentage of option awards vest and exercisable in installments Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Award expiration term Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Vesting period of restricted stock awards Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Share-based Compensation Arrangement by Share-based Payment Award Available for Grant [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award Available for Grant [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award Available for Grant [Roll Forward] Beginning balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Additional shares authorized (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Number of awards granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Grants in Period, Gross Share-based Compensation Arrangement by Share-based Payment Award, Grants in Period, Gross Number of awards forfeited or expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Forfeitures and Expiration in Period Number of share-based compensation awards forfeited or expired in Period Ending balance (in shares) Number of option awards exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Number of restricted stock awards vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Retirement Benefits [Abstract] EMPLOYEE BENEFITS Pension and Other Postretirement Benefits Disclosure [Text Block] Reinsurance Disclosures [Abstract] Reinsurance [Table] Reinsurance [Table] Reinsurance [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Continuing Operations - Property and Casualty Insurance Property, Liability and Casualty Insurance Product Line [Member] Reinsurance [Line Items] Reinsurance [Line Items] [Line Items] for Reinsurance [Table] Ceded premiums written Ceded Premiums Written Ceded premiums earned Ceded Premiums Earned Loss and loss settlement expenses ceded Policyholder Benefits and Claims Incurred, Assumed and Ceded Assumed premiums written Assumed Premiums Written Assumed premiums earned Assumed Premiums Earned Loss and loss settlement expenses assumed Policyholder Benefits and Claims Incurred, Assumed Schedule of Employee Stock Ownership Plan (ESOP) Disclosures [Table] Schedule of Employee Stock Ownership Plan (ESOP) Disclosures [Table] Deferred Bonus and Profit Sharing Plan, Type of Deferred Compensation [Axis] Deferred Bonus and Profit Sharing Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain] Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain] Profit-Sharing Plan Deferred Profit Sharing [Member] Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] Employee Stock Ownership Plan (ESOP) Disclosures [Line Items] Employer contribution to the profit-sharing plan Deferred Compensation Arrangement with Individual, Contributions by Employer Statutory Insurance Financial Information [Abstract] Statutory Insurance Financial Information [Abstract] Schedule of Statutory Capital and Surplus Statutory Accounting Practices Disclosure [Table Text Block] Segment Reporting [Abstract] Premiums Earned by Segments Reconciliation of Revenue from Segments to Consolidated [Table Text Block] Investments, Debt and Equity Securities [Abstract] Schedule of Investments [Table] Schedule of Investments [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Fixed maturities Debt Securities [Member] U.S. Treasury US Treasury Securities [Member] U.S. government agency US Government Agencies Debt Securities [Member] General obligations General Obligations [Member] General Obligations [Member] Special revenue Special Revenue [Member] Special Revenue [Member] Foreign bonds Debt Security, Government, Non-US [Member] Public utilities Public Utility, Bonds [Member] Corporate bonds Corporate Debt Securities [Member] Mortgage-backed securities Collateralized Mortgage Backed Securities [Member] Collateralized mortgage obligations Collateralized Mortgage Obligations [Member] Asset-backed securities Asset-backed Securities [Member] Equity securities Equity Securities [Member] Common stock Common Stock [Member] Nonredeemable preferred stocks Nonredeemable Preferred Stock [Member] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Midwest Midwest [Member] Midwest [Member] Northeast Northeast [Member] Northeast [Member] South South [Member] South [Member] West West [Member] West [Member] Investment Sector [Axis] Investment Sector [Axis] Investment Sector [Domain] Investment Sector [Domain] Financial services Financial Services [Member] Financial Services [Member] Public utilities Public Utilities [Member] Energy Energy [Member] Energy [Member] Industrials Industrial [Member] Industrial [Member] Consumer goods and services Consumer Goods and Service [Member] Consumer Goods and Service [Member] Health care Health Care [Member] Technology, media and telecommunications Technology, Media and Telecommunications [Member] Technology, Media and Telecommunications [Member] Loans Insured or Guaranteed by Government Authorities [Axis] Loans Insured or Guaranteed by Government Authorities [Axis] Loans Insured or Guaranteed by Government Authorities [Domain] Loans Insured or Guaranteed by Government Authorities [Domain] Government national mortgage association Government National Mortgage Association (GNMA) Insured Loans [Member] Federal home loan mortgage corporation Federal Home Loan Mortgage Corporation (FHLMC) Insured Loans [Member] Federal national mortgage association Federal National Mortgage Association (FNMA) Insured Loans [Member] Discontinued Operations Discontinued Operations [Member] Schedule of Investments [Line Items] Schedule of Investments [Line Items] AVAILABLE-FOR-SALE Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] Number of Issues Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract] Fixed maturities, less than 12 months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions Fixed maturities, 12 months or longer Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions Fixed maturities, less than 12 months Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year Fixed maturities, 12 months or longer Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year Fair Value Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract] Fixed maturities, less than 12 months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months Fixed maturities, 12 months or longer Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Fixed maturities, total Debt Securities, Available-for-sale, Unrealized Loss Position Fixed maturities, less than 12 months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Fixed maturities, 12 months or longer Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Total Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Gross Unrealized Depreciation Debt Securities, Available-for-sale, Transfer to Trading, Gain (Loss) [Abstract] Fixed maturities, less than 12 months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Fixed maturities, 12 months or longer Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Fixed maturities, total Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Fixed maturities, less than 12 months Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Fixed maturities, 12 months or longer Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Total Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Abstract] SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Table] SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Table] Discontinued Operations - Life Insurance Life Insurance Product Line [Member] SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items] SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items] Deferred Policy Acquisition Costs SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Deferred Policy Acquisition Cost Future Policy Benefits, Losses, Claims and Loss Expenses SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Liability for Future Policy Benefit, Loss, Claim and Loss Expense Unearned Premiums SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Unearned Premium Earned Premium Revenue SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Premium Revenue Investment Income, Net SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Net Investment Income Benefits, Claims, Losses and Settlement Expenses SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Benefit, Claim, Loss and Settlement Expenses Amortization of Deferred Policy Acquisition Costs SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Amortization of Deferred Policy Acquisition Cost Other Underwriting Expenses SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Operating Expense Interest on Policyholders' Accounts Interest Credited to Policyholders Account Balances Premiums Written SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Premium Written Quarterly Financial Data [Abstract] Continuing Operations [Abstract] Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent [Abstract] Total revenues Revenues Income (loss) before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Net income (loss) Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Basic earnings per share (in dollars per share) Income (Loss) from Continuing Operations, Per Basic Share Diluted earnings per share (in dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Discontinued Operations [Abstract] Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent [Abstract] Total revenues Disposal Group, Including Discontinued Operation, Revenue Income (loss) before income taxes Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax Net income (loss) Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Basic earnings per share (in dollars per share) Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share Diluted earnings per share (in dollars per share) Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Pension Benefits Pension Plan [Member] Post-retirement Benefits Other Postretirement Benefits Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Unrecognized prior service cost Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax Unrecognized actuarial (gain) loss Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax Total amounts recognized in AOCI Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax Anticipated amortization of net actuarial losses in next fiscal year Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year Components of Deferred Tax Assets and Liabilities [Table] Components of Deferred Tax Assets and Liabilities [Table] Components of Deferred Tax Assets and Liabilities [Table] All other securities Components of Deferred Tax Assets and Liabilities [Line Items] Components of Deferred Tax Assets and Liabilities [Line Items] [Line Items] for Components of Deferred Tax Assets and Liabilities [Table] Deferred tax liabilities Deferred Tax Liabilities, Gross [Abstract] Net unrealized appreciation on investment securities Deferred Tax Liabilities, Net Unrealized Appreciation on Investment Securities Deferred Tax Liabilities, Net Unrealized Appreciation on Investment Securities Deferred policy acquisition costs Deferred Tax Liabilities, Deferred Expense, Deferred Policy Acquisition Cost Investments in partnerships Deferred Tax Liabilities, Investment in Noncontrolled Affiliates Prepaid pension cost Deferred Tax Liabilities, Prepaid Expenses Net bond discount accretion Deferred Tax Liabilities, Amortization of Net Bond Discount (Premium) Deferred Tax Liabilities, Amortization of Net Bond Discount (Premium) Depreciation Deferred Tax Liabilities, Property, Plant and Equipment Revaluation of investment basis Deferred Tax Liabilities, Investments Identifiable intangible assets Deferred Tax Liabilities, Intangible Assets Other Deferred Tax Liabilities, Other Gross deferred tax liability Deferred Tax Liabilities, Gross Deferred tax assets Deferred Tax Assets, Gross [Abstract] Financial statement reserves in excess of income tax reserves Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Reserves Unearned premium adjustment Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Unearned Premiums Reserve Net operating loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards Underfunded benefit plan obligation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Pensions Post-retirement benefits other than pensions Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Postretirement Benefits Other-than-temporary impairment of investments Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Impairment Losses Contingent ceding commission accrual Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Alternative minimum tax credit carryforward Compensation expense related to stock options Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Other Deferred Tax Assets, Other Gross deferred tax asset Deferred Tax Assets, Gross Valuation allowance Deferred tax asset Deferred Tax Assets, Net of Valuation Allowance Net deferred tax asset Deferred Tax Assets, Net Net deferred tax liability (asset) Deferred Tax Liabilities, Net Fair Value Disclosures [Abstract] Carrying Value and Estimated Fair Value of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Financial Instruments Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Summary of Changes in Fair Value of Level 3 Securities Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Schedule of Commercial Mortgage Loans Schedule of Participating Mortgage Loans [Table Text Block] Pension Benefits Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Fixed maturity securities - corporate bonds Redeemable preferred stock Redeemable Preferred Stock [Member] Equity securities Defined Benefit Plan, Equity Securities [Member] Core plus bond separate account fund Core Plus Bond Separate Account Fund [Member] Core Plus Bond Separate Account Fund [Member] U.S. property separate account fund U.S. Property Separate Account Fund [Member] U.S. Property Separate Account Fund [Member] Arbitrage fund Mutual Fund [Member] United Life annuity United Life Annuity [Member] United Life Annuity [Member] Pension Plan Assets, Cash and cash equivalents Defined Benefit Plan, Cash and Cash Equivalents [Member] Plan assets Defined Benefit Plan, Plan Assets, Amount Actual % of total Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage Target allocation Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Insurance Loss Reserves [Abstract] Short-duration Insurance Contracts, Historical Claims Duration [Table] Short-duration Insurance Contracts, Historical Claims Duration [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Commercial other liability Commercial other liability [Member] Commercial other liability [Member] Commercial fire and allied Commercial Fire & Allied [Member] Commercial Fire & Allied [Member] Commercial automobile Commercial Automobile [Member] Commercial Automobile [Member] Commercial workers' compensation Workers' Compensation Insurance [Member] Workers' Compensation Insurance [Member] Personal Personal [Member] Personal [Member] Short-duration Insurance Contracts, Historical Claims Duration [Line Items] Short-duration Insurance Contracts, Historical Claims Duration [Line Items] Year 1 Short-duration Insurance Contracts, Historical Claims Duration, Year One Year 2 Short-duration Insurance Contracts, Historical Claims Duration, Year Two Year 3 Short-duration Insurance Contracts, Historical Claims Duration, Year Three Year 4 Short-duration Insurance Contracts, Historical Claims Duration, Year Four Year 5 Short-duration Insurance Contracts, Historical Claims Duration, Year Five Year 6 Short-duration Insurance Contracts, Historical Claims Duration, Year Six Year 7 Short-duration Insurance Contracts, Historical Claims Duration, Year Seven Year 8 Short-duration Insurance Contracts, Historical Claims Duration, Year Eight Year 9 Short-duration Insurance Contracts, Historical Claims Duration, Year Nine Year 10 Short-duration Insurance Contracts, Historical Claims Duration, Year Ten STATUTORY REPORTING, CAPITAL REQUIREMENTS AND DIVIDENDS AND RETAINED EARNINGS RESTRICTIONS Statutory Reporting, Capital Requirements and Dividends and Retained Earnings Restrictions [Text Block] Statutory Reporting, Capital Requirements and Dividends and Retained Earnings Restrictions [Text Block] Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding at beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Exercised (in shares) Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares Expired (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Outstanding at end of period (in shares) Exercisable at end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted-Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Outstanding at beginning of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Expired (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Outstanding at end of period (in dollars per share) Exercisable at end of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Outstanding at end of period, weighted-average remaining life Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Exercisable at end of period, weighted-average remaining life Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Outstanding at end of period, aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Exercisable at end of period, aggregate intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Intrinsic value of options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Discontinued Operations and Disposal Groups [Abstract] DISCONTINUED OPERATIONS Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] INTANGIBLE ASSETS Goodwill and Intangible Assets Disclosure [Text Block] Earnings Per Share [Abstract] Components of Basic and Diluted Earnings per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 3 Fair Value, Inputs, Level 3 [Member] Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Fair value of plan assets at beginning of year Unrealized gains Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held Company contribution Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase for Purchase Fair value of plan assets at end of year Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Carrying Value Reported Value Measurement [Member] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Fixed Maturities Fixed Maturities [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Assets Assets [Abstract] Investments Investments [Abstract] Held-to-maturity securities Debt Securities, Held-to-maturity, Fair Value Available-for-sale securities Available-for-sale Securities Trading securities Debt Securities, Trading, and Equity Securities, FV-NI Equity securities Equity Securities, FV-NI Mortgage loans Mortgage Loans on Real Estate, Commercial and Consumer, Net Policy loans Policy Loan, Fair Value Disclosure Policy Loan, Fair Value Disclosure Other long-term investments Other Long-term Investments, Fair Value Disclosure Other Long-term Investments, Fair Value Disclosure Short-term investments Short-term Investments, Fair Value Disclosure Short-term Investments, Fair Value Disclosure Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Corporate-owned life insurance Cash Surrender Value, Fair Value Disclosure Liabilities Liabilities [Abstract] Policy reserves Liability for Future Policy Benefits [Abstract] Annuity (accumulations) Liability For Annuity Accumulations, Fair Value Disclosure Liability For Annuity Accumulations, Fair Value Disclosure Annuity (benefit payments) Liability for Annuity Benefit Payments, Fair Value Disclosure Liability for Annuity Benefit Payments, Fair Value Disclosure Disposal Groups, Including Discontinued Operations Disposal Groups, Including Discontinued Operations [Table Text Block] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] United Life Insurance Company United Life Insurance Company [Member] United Life Insurance Company [Member] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Discontinued Operations, Disposed of by Sale Discontinued Operations, Disposed of by Sale [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Revenues Disposal Group, Including Discontinued Operation, Revenues [Abstract] Disposal Group, Including Discontinued Operation, Revenues [Abstract] Net premiums earned Disposal Group, Including Discontinued Operation, Premiums Earned, Net Disposal Group, Including Discontinued Operation, Premiums Earned, Net Investment income, net of investment expenses Disposal Group, Including Discontinued Operation, Net Investment Income Disposal Group, Including Discontinued Operation, Net Investment Income Net realized investment gains (losses) Disposal Group, Including Discontinued Operation, Realized Investment Gains (Losses) [Abstract] Disposal Group, Including Discontinued Operation, Realized Investment Gains (Losses) [Abstract] Total net realized investment gains (losses) Disposal Group, Including Discontinued Operation, Realized Investment Gains (Losses) Disposal Group, Including Discontinued Operation, Realized Investment Gains (Losses) Other income Disposal Group, Including Discontinued Operation, Other Income Total revenues Benefits, Losses and Expenses Disposal Group, Including Discontinued Operation, Benefits, Losses and Expenses [Abstract] Disposal Group, Including Discontinued Operation, Benefits, Losses and Expenses [Abstract] Losses and loss settlement expenses Disposal Group, Including Discontinued Operation, Policyholder Benefits and Claims Incurred, Net Disposal Group, Including Discontinued Operation, Policyholder Benefits and Claims Incurred, Net Increase in liability for future policy benefits Disposal Group, Including Discontinued Operation, Liability for Future Policy Benefits, Period Expense (Income) Disposal Group, Including Discontinued Operation, Liability for Future Policy Benefits, Period Expense (Income) Amortization of deferred policy acquisition costs Disposal Group, Including Discontinued Operation, Deferred Policy Acquisition Cost, Amortization Expense and Amortization of Value of Business Acquired (VOBA) Disposal Group, Including Discontinued Operation, Deferred Policy Acquisition Cost, Amortization Expense and Amortization of Value of Business Acquired (VOBA) Other underwriting expenses Disposal Group, Including Discontinued Operation, Other Underwriting Expense Disposal Group, Including Discontinued Operation, Other Underwriting Expense Interest on policyholders’ accounts Disposal Group, Including Discontinued Operation, Interest Credited to Policyholders Account Balances Disposal Group, Including Discontinued Operation, Interest Credited to Policyholders Account Balances Total benefits, losses and expenses Disposal Group, Including Discontinued Operation, Benefits, Losses and Expenses Disposal Group, Including Discontinued Operation, Benefits, Losses and Expenses Income (loss) from discontinued operations before income taxes Federal income tax expense Discontinued Operation, Tax Effect of Discontinued Operation Net income (loss) from discontinued operations Earnings per common share from discontinued operations: Earnings Per Share, Basic And Diluted, Discontinued Operations [Abstract] Earnings Per Share, Basic And Diluted, Discontinued Operations [Abstract] Basic (in dollars per share) Diluted (in dollars per share) SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Abstract] Schedule VI. Supplemental Information Concerning Property and Casualty Insurance Operations SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Allocated share-based compensation expense Allocated Share-based Compensation Expense 2019 Future Share-based Compensation Expense, Year One Future Share-based Compensation Expense, Year One 2020 Future Share-based Compensation Expense, Year Two Future Share-based Compensation Expense, Year Two 2021 Future Share-based Compensation Expense, Year Three Future Share-based Compensation Expense, Year Three 2022 Future Share-based Compensation Expense, Year Four Future Share-based Compensation Expense, Year Four 2023 Future Share-based Compensation Expense, Year Five Future Share-based Compensation Expense, Year Five Total Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Statement of Financial Position [Abstract] Assets Investments Fixed maturities Debt Securities [Abstract] Held-to-maturity, at amortized cost (fair value $0 in 2018 and $150 in 2017) Debt Securities, Held-to-maturity Available-for-sale, at fair value (amortized cost $1,761,289 in 2018 and $1,516,610 in 2017) Debt Securities, Available-for-sale Trading securities, at fair value (amortized cost $11,277 in 2018 and $14,582 in 2017) Debt Securities, Trading Equity securities, at fair value (cost $64,819 in 2018 and $63,275 in 2017) Other long-term investments Other Long-term Investments Short-term investments Other Short-term Investments Total Investments Investments Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accrued investment income Accrued Investment Income Receivable Premiums receivable (net of allowance for doubtful accounts of $785 in 2018 and $1,255 in 2017) Premiums Receivable, Net Deferred policy acquisition costs Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Net Property and equipment (primarily land and buildings, at cost, less accumulated depreciation of $39,894 in 2018 and $51,603 in 2017) Property, Plant and Equipment, Net Reinsurance receivables and recoverables Reinsurance Recoverables, Including Reinsurance Premium Paid Prepaid reinsurance premiums Prepaid Reinsurance Premiums Deferred tax asset Deferred Income Tax Assets, Net Income taxes receivable Income Taxes Receivable Goodwill and net intangible assets Goodwill and intangible assets Goodwill and intangible assets Other assets Other Assets Assets held for sale Disposal Group, Including Discontinued Operation, Assets Total assets Assets Liabilities and stockholders' equity Liabilities and Equity [Abstract] Losses and loss settlement expenses Liability for Claims and Claims Adjustment Expense Unearned premiums Unearned Premiums Accrued expenses and other liabilities Accrued expenses and other liabilities Accrued expenses and other liabilities. Deferred income taxes Deferred Income Tax Liabilities, Net Liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities Total liabilities Liabilities Stockholders' equity Stockholders' Equity Attributable to Parent [Abstract] Common stock, $0.001 par value; authorized 75,000,000 shares; 25,097,408 and 24,916,806 shares issued and outstanding in 2018 and 2017, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income, net of tax Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders' equity Stockholders' Equity Attributable to Parent Total liabilities and stockholders' equity Liabilities and Equity Eligibility, minimum required service period Defined Benefit Plan, Eligibility, Requisite Service Period Defined Benefit Plan, Eligibility, Requisite Service Period Eligibility, minimum age Defined Benefit Plan, Participant Eligibility, Minimum Age Defined Benefit Plan, Participant Eligibility, Minimum Age Estimated employer contribution in next fiscal year Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Number of programs offered under health and dental benefit plan Employee Benefit Plan, Number of Programs Offered Employee Benefit Plan, Number of Programs Offered Retirement plan, employee deductible Defined Benefit Plans, Employee Plan Deductible Defined Benefit Plans, Employee Plan Deductible Percentage of retirement plan owed by employees 65 or older Defined Benefit Plans, Cost to Employee Older Than 65, Percentage of Plan Defined Benefit Plans, Cost to Employee Older Than 65, Percentage of Plan Percentage of retirement plan owed by employees less 65 Defined Benefit Plans, Cost to Employee Less Than 65, Percentage of Plan Defined Benefit Plans, Cost to Employee Less Than 65, Percentage of Plan Number of external investment managers Defined Benefit Plan, Plan Assets, Number of External Investment Managers Defined Benefit Plan, Plan Assets, Number of External Investment Managers Income Statement [Abstract] Reclassifications for unrealized net gains on available-for-sale securities Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Reclassifications for employee benefit costs Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax Reclassifications adjustments tax Reclassification from AOCI, Current Period, Tax Assets Disposal Group, Including Discontinued Operation, Assets [Abstract] Investments Disposal Group, Including Discontinued Operation, Investments [Abstract] Disposal Group, Including Discontinued Operation, Investments [Abstract] Fixed maturities Disposal Group, Including Discontinued Operation, Marketable Securities, Fixed [Abstract] Disposal Group, Including Discontinued Operation, Marketable Securities, Fixed [Abstract] Held-to-maturity, at amortized cost (fair value $0 in 2018 and $34 in 2017) Disposal Group, Including Discontinued Operation, Held-to-maturity Securities Disposal Group, Including Discontinued Operation, Held-to-maturity Securities Fixed maturities, held-to-maturity securities, fair value Disposal Group, Including Discontinued Operations, Held-to-maturity Securities, Fair Value Disposal Group, Including Discontinued Operations, Held-to-maturity Securities, Fair Value Available-for-sale, at fair value (amortized cost $0 in 2018 and $1,412,291 in 2017) Disposal Group, Including Discontinued Operation, Available-for-sale Securities, Debt Securities Disposal Group, Including Discontinued Operation, Available-for-sale Securities, Debt Securities Fixed maturities, available-for-sale securities, amortized cost Disposal Group, Including Discontinued Operations, Available-for-sale Debt Securities, Amortized Cost Basis Disposal Group, Including Discontinued Operations, Available-for-sale Debt Securities, Amortized Cost Basis Equity Securities available-for-sale, at fair value (cost $0 in 2018 and $5,099 in 2017) Disposal Group, Including Discontinued Operation, Available-for-sale Securities, Equity Securities Disposal Group, Including Discontinued Operation, Available-for-sale Securities, Equity Securities Equity securities available-for-sale, amortized cost Disposal Group, Including Discontinued Operations, Available-for-sale Equity Securities, Amortized Cost Basis Disposal Group, Including Discontinued Operations, Available-for-sale Equity Securities, Amortized Cost Basis Mortgage loans Disposal Group, Including Discontinued Operation, Mortgage Loans on Real Estate, Commercial and Consumer, Net Disposal Group, Including Discontinued Operation, Mortgage Loans on Real Estate, Commercial and Consumer, Net Policy loans Disposal Group, Including Discontinued Operation, Loans, Gross, Insurance Policy Disposal Group, Including Discontinued Operation, Loans, Gross, Insurance Policy Other long-term investments Disposal Group, Including Discontinued Operation, Other Long-term Investments Disposal Group, Including Discontinued Operation, Other Long-term Investments Total Investments Disposal Group, Including Discontinued Operation, Investments Disposal Group, Including Discontinued Operation, Investments Cash and cash equivalents Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents Deferred policy acquisition costs Disposal Group, Including Discontinued Operation, Deferred Policy Acquisition Costs Disposal Group, Including Discontinued Operation, Deferred Policy Acquisition Costs Other assets Disposal Group, Including Discontinued Operation, Other Assets Total assets held for sale Liabilities Disposal Group, Including Discontinued Operation, Liabilities [Abstract] Future policy benefits and losses Disposal Group, Including Discontinued Operation, Liability for Future Policy Benefits, Life Disposal Group, Including Discontinued Operation, Liability for Future Policy Benefits, Life Deferred income taxes Disposal Group, Including Discontinued Operation, Deferred Tax Liabilities Accrued expenses and other liabilities Disposal Group, Including Discontinued Operation, Accrued Expenses and Other Liabilities Disposal Group, Including Discontinued Operation, Accrued Expenses and Other Liabilities Total liabilities held for sale Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Subsegments [Axis] Subsegments [Axis] Subsegments [Domain] Subsegments [Domain] Commercial Lines Property and Casualty, Commercial Insurance Product Line [Member] Personal Lines Property and Casualty, Personal Insurance Product Line [Member] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Product Concentration Risk Product Concentration Risk [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Sales Revenue, Segment Sales Revenue, Segment [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of reportable business segments Number of Operating Segments Number of domestic business locations Number of Business Locations Number of Business Locations Percentage of insurance in force Concentration Risk, Percentage SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Table] SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Table] SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Affiliation with Registrant [Axis] SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Affiliation with Registrant [Axis] SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Affiliation with Registrant [Domain] SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Affiliation with Registrant [Domain] Consolidated Property and Casualty Insurance Entity SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Consolidated Property and Casualty Insurance Entity [Member] SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Line Items] SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Line Items] Deferred Policy Acquisition Costs SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Deferred Policy Acquisition Cost Reserves for Unpaid Claims and Claim Adjustment Expenses SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Reserve for Unpaid Claim and Claim Adjustment Expense Unearned Premiums SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Unearned Premium Earned Premiums SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Earned Premium Net realized investment gains Realized Investment Gains (Losses) Net Investment Income SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Net Investment Income Claims and Claim Adjustment Expenses Incurred Related to: Current Year Current Year Claims and Claims Adjustment Expense Claims and Claim Adjustment Expenses Incurred Related to: Prior Years Prior Year Claims and Claims Adjustment Expense Amortization of Deferred Policy Acquisition Costs SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Amortization of Deferred Policy Acquisition Cost Paid Claims and Claim Adjustment Expenses SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Paid Claim and Claim Adjustment Expense Premiums Written SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Premium Written Fair Value Disclosure [Abstract] Fair Value Disclosure [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Loan to Value [Axis] Loan to Value [Axis] Loan to Value [Domain] Loan to Value [Domain] LTV Less Than 65 Percent Ltv Less Than 65 Percent [Member] Ltv Less Than 65 Percent [Member] East North Central East North Central [Member] East North Central [Member] Southern Atlantic Southern Atlantic [Member] Southern Atlantic [Member] East South Central East South Central [Member] East South Central [Member] New England New England [Member] New England [Member] Middle Atlantic Middle Atlantic [Member] Middle Atlantic [Member] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Multifamily Multifamily [Member] Office Office Building [Member] Mixed use/Other Other Property [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Commercial mortgage loans, gross Loans Receivable, Gross, Commercial, Mortgage Commercial mortgage loans, allowance Allowance for Loan and Lease Losses, Real Estate Commercial mortgage loans, amortized cost Commercial mortgage loans, percent of total Percentage Of Commercial Mortgage Loans To Total Commercial Mortgage Loans Percentage Of Commercial Mortgage Loans To Total Commercial Mortgage Loans Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Restricted Stock Awards Restricted Stock And Restricted Stock Unit Awards [Member] Restricted Stock And Restricted Stock Unit Awards [Member] Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Non-vested at beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested (in shares) Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Non-vested at end of period (in shares) Weighted-Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Non-vested at beginning of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Non-vested at end of period (in dollars per share) Total compensation expense that has yet to be recognized Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Intrinsic value of the unvested restricted stock awards outstanding Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested Components of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Leases [Abstract] LEASE COMMITMENTS Commitments Disclosure [Text Block] Statutory Accounting Practices [Table] Statutory Accounting Practices [Table] Jurisdiction [Axis] Jurisdiction [Axis] Statutory Accounting Practices, Jurisdiction [Domain] Statutory Accounting Practices, Jurisdiction [Domain] State of Iowa Insurance Department State of Iowa Insurance Department [Member] State of Iowa Insurance Department [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] United Fire & Casualty Company United Fire & Casualty Company [Member] United Fire & Casualty Company [Member] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Subsidiaries Subsidiaries [Member] Statutory Accounting Practices [Line Items] Statutory Accounting Practices [Line Items] Statutory amount available for dividend payments Statutory Accounting Practices, Statutory Amount Available for Dividend Payments Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Payment of cash dividends Payments of Dividends Intercompany dividend payments that are eliminated in Consolidated Financial Statements SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Subsidiaries and Equity Method Investees Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Computer equipment and software Computer Equipment and Software [Member] Computer Equipment and Software [Member] Furniture and fixtures Furniture and Fixtures [Member] Real estate Land, Buildings and Improvements [Member] Airplane Airplane [Member] Airplane [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Useful Life Property, Plant and Equipment, Useful Life Condensed Financial Information Disclosure [Abstract] Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] United Fire Group, Inc. Parent Company [Member] Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Cash flows from operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss) Attributable to Parent Adjustments to reconcile net income to net cash provided by operating activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Equity in net income of subsidiary Income (Loss) from Equity Method Investments Dividends received from subsidiary Proceeds from Dividends Received Other, net Increase (Decrease) in Other Operating Liabilities Total adjustments Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Proceeds from maturity of held-to-maturity investments Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities Purchase of held-to-maturity investments Payments to Acquire Held-to-maturity Securities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Payment of cash dividends Payments of Ordinary Dividends, Common Stock Repurchase of common stock Payments for Repurchase of Common Stock Issuance of common stock Proceeds from Issuance of Common Stock Tax impact from issuance of common stock Payments Related to Tax Withholding for Share-based Compensation Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Net Change in Cash and Cash Equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and Cash Equivalents at Beginning of Year - Continuing Operations Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and Cash Equivalents at End of Year - Continuing Operations Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected option life Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Expected dividends (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Weighted-average grant-date fair value of options granted during the year (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Agency relationships Customer Relationships [Member] Software Computer Software, Intangible Asset [Member] Trade names Trade Names [Member] Favorable contract Contractual Rights [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Useful Life Finite-Lived Intangible Asset, Useful Life Schedule of Deferred Policy Acquisition Costs [Table] Schedule of Deferred Policy Acquisition Costs [Table] Schedule of Deferred Policy Acquisition Costs [Table] Deferred Policy Acquisition Costs Disclosure [Line Items] Deferred Policy Acquisition Costs Disclosure [Line Items] Deferred Policy Acquisition Costs Disclosure [Line Items] Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward] Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward] Recorded asset at beginning of year Underwriting costs deferred Deferred Policy Acquisition Costs, Additions Amortization of deferred policy acquisition costs Deferred Policy Acquisition Costs, Amortization Expense Ending unamortized deferred policy acquisition costs Deferred Policy Acquisition Costs Change in shadow deferred policy acquisition costs Deferred Policy Acquisition Cost, Unrealized Investment Gain (Loss) Sale of discontinued operations Deferred Policy Acquisition Costs, Disposition Recorded asset at end of year Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] Fixed maturities, Available-for-sale securities, amortized cost Debt Securities, Available-for-sale, Amortized Cost Common stock, par value per share (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Additional paid-in capital Additional Paid-in Capital [Member] Retained earnings Retained Earnings [Member] Accumulated other comprehensive income, net of tax AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance, beginning of year Shares repurchased Stock Repurchased During Period, Value Compensation expense and related tax benefit for stock-based award grants Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Shares issued for stock-based awards Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Cumulative effect of change in accounting principle Cumulative Effect of New Accounting Principle in Period of Adoption Accumulated effect of change in enacted tax rate Tax Cuts And Jobs Act Of 2017, Reclassification From AOCI To Retained Earnings Tax Cuts And Jobs Act Of 2017, Reclassification From AOCI To Retained Earnings Change in net unrealized investment appreciation Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Portion Attributable to Parent Dividends on common stock ($4.21 per share in 2018; $1.09 per share in 2017; $0.97 per share in 2016) Dividends, Common Stock Change in liability for underfunded employee benefit plans Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent All other changes in stockholders' equity accounts Changes In Stockholders Equity Accounts Excluding Net Income Loss Total changes in stockholders' equity accounts excluding net income loss. Balance, end of year Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value, Measurements, Recurring [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] States, municipalities and political subdivisions US States and Political Subdivisions Debt Securities [Member] Redeemable preferred stocks Available-for-sale Securities Trading and Equity Securities Short-Term Investments Money Market Accounts Corporate-Owned Life Insurance Total Assets Measured at Fair Value Assets, Fair Value Disclosure Land Land [Member] Buildings Building [Member] Total property and equipment Money market funds Money Market Funds [Member] Assets measured at fair value Schedule of Gain (Loss) on Securities [Table] Schedule of Gain (Loss) on Securities [Table] Investment [Axis] Investment [Axis] Investment [Domain] Investment [Domain] Fixed maturities Mortgage loans Mortgages [Member] Cash equivalents Cash Equivalents [Member] Real Estate Real Estate [Member] Debt Security Category [Axis] Debt Security Category [Axis] Other than Temporary Impairment, Credit Losses Recognized in Earnings, Categories of Investments [Domain] Other than Temporary Impairment, Credit Losses Recognized in Earnings, Categories of Investments [Domain] Available-for-sale Available-for-sale Securities [Member] Change in fair value Trading Account Assets, Change in Fair Value [Member] Trading Account Assets, Change in Fair Value [Member] Sales Trading Account Assets, Sales [Member] Trading Account Assets, Sales [Member] Gain (Loss) on Securities [Line Items] Gain (Loss) on Securities [Line Items] Net realized investment gains (losses) from continuing operations AVAILABLE-FOR-SALE Debt Securities, Available-for-sale [Abstract] Proceeds from sales Proceeds from Sale of Debt Securities, Available-for-sale Proceeds from sales Proceeds from Sale of Available-for-sale Securities Gross realized gains Debt Securities, Available-for-sale, Realized Gain Gross realized losses Debt Securities, Available-for-sale, Realized Loss Summary of Actual and Target Asset Allocation of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] Categories of Pension Plan Assets at Fair Value on Recurring Basis Schedule of Defined Benefit Plans Disclosures [Table Text Block] Summary of Changes in Fair Value of Pension Plan Securities Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets [Table Text Block] Schedule of Actuarial Assumptions Used Schedule of Assumptions Used [Table Text Block] Schedule of Health Care Cost Trend Rates Schedule of Health Care Cost Trend Rates [Table Text Block] Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block] Reconciliation of Benefit Obligations, Plan Assets, and Funded Status Schedule of Net Funded Status [Table Text Block] Schedule of Amounts Recognized in AOCI Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Components of Net Periodic Benefit Cost Schedule of Net Benefit Costs [Table Text Block] Summary of Expected Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Ceded insurance in-force SEC Schedule, 12-17, Insurance Companies, Reinsurance, Life Insurance in Force, Ceded Ceded premiums earned Loss and loss settlement expenses ceded Policyholder Benefits and Claims Incurred, Ceded Shares repurchased (in shares) Stock Repurchased During Period, Shares Shares issued for stock-based awards (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Dividends on common stock (in dollars per share) Common Stock, Dividends, Per Share, Declared Debt Disclosure [Abstract] CREDIT FACILITY Debt Disclosure [Text Block] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Assets Other Assets [Member] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Domain] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Domain] Rabbi Trust Rabbi Trust [Member] Rabbi Trust [Member] Loans and Leases Receivable, Allowance Sale of held-to-maturity securities Sale of Held-to-maturity Securities Sale of Held-to-maturity Securities Remaining potential off-balance sheet contractual obligation (up to) Remaining Potential Off-Balance Sheet Contractual Obligation Remaining Potential Off-Balance Sheet Contractual Obligation RESERVES FOR LOSSES AND LOSS SETTLEMENT EXPENSES Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] Expected Future Benefit Payments Defined Benefit Plan, Expected Future Benefit Payment [Abstract] 2019 Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months 2020 Defined Benefit Plan, Expected Future Benefit Payment, Year Two 2021 Defined Benefit Plan, Expected Future Benefit Payment, Year Three 2022 Defined Benefit Plan, Expected Future Benefit Payment, Year Four 2023 Defined Benefit Plan, Expected Future Benefit Payment, Year Five 2024 - 2028 Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter Reconciliation of Amortized Cost to Fair Value Marketable Securities [Table Text Block] Contractual Maturity of Investments Investments Classified by Contractual Maturity Date [Table Text Block] Summary of Net Realized Investment Gains (Losses) Realized Gain (Loss) on Investments [Table Text Block] Schedule of Proceeds and Gross Realized Gains (Losses) Schedule of Realized Gain (Loss) [Table Text Block] Schedule of Net Investment Income Investment Income [Table Text Block] Summary of Changes in Net Unrealized Investment Appreciation Unrealized Gain (Loss) on Investments [Table Text Block] Summary of Investments in Unrealized Loss Position Schedule of Unrealized Loss on Investments [Table Text Block] Schedule of Major Classes of Intangible Assets Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Table Text Block] Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Table Text Block] Schedule of Estimated Useful Lives of Amortizable Intangible Assets Schedule Of Finite Lived Intangible Assets Useful Lives By Major Class [Table Text Block] Schedule Of Finite Lived Intangible Assets Useful Lives By Major Class [Table Text Block] Schedule of Estimated Aggregate Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract] Schedule IV. Reinsurance SEC Schedule, 12-17, Insurance Companies, Reinsurance [Text Block] Line of Credit Facility [Table] Line of Credit Facility [Table] Credit Facility Letter of Credit Subfacility Letter of Credit [Member] Swingline Subfacility Swing Line of Credit [Member] Swing Line of Credit [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Debt instrument, term Debt Instrument, Term Debt covenant, maximum debt to total capitalization ratio Debt Covenant, Maximum Debt to Total Capitalization Ratio Debt Covenant, Maximum Debt to Total Capitalization Ratio Outstanding balance Long-term Line of Credit Interest expense incurred Interest Expense Components of Deferred Acquisition Costs Schedule of Deferred Policy Acquisition Costs [Table Text Block] Schedule of Deferred Policy Acquisition Costs [Table Text Block] Schedule of Property and Equipment Property, Plant and Equipment [Table Text Block] Reconciliation Of Consolidated Federal Income Tax Expense (Benefit) [Table] Reconciliation Of Consolidated Federal Income Tax Expense (Benefit) [Table] Reconciliation Of Consolidated Federal Income Tax Expense (Benefit) [Table] Reconciliation Of Consolidated Federal Income Tax Expense (Benefit) [Line Items] Reconciliation Of Consolidated Federal Income Tax Expense (Benefit) [Line Items] [Line Items] for Reconciliation Of Consolidated Federal Income Tax Expense (Benefit) [Table] Current Current Federal Tax Expense (Benefit) Deferred Deferred Federal Income Tax Expense (Benefit) Consolidated federal income tax expense (benefit) Income Tax Expense (Benefit) Schedule III. Supplementary Insurance Information SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Disclosure [Text Block] Ceded and Assumed Reinsurance Ceded and Assumed Reinsurance [Table Text Block] Ceded and Assumed Reinsurance [Table Text Block] Reinsurance Programs and Retentions Reinsurance Programs and Retentions [Table Text Block] Reinsurance Programs and Retentions [Table Text Block] SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] Allowance for bad debts SEC Schedule, 12-09, Allowance, Credit Loss [Member] Deferred tax asset valuation allowance SEC Schedule, 12-09, Valuation Allowance, Deferred Tax Asset [Member] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] Balance at beginning of period SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount Charged to costs and expenses SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense Deductions SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction Balance at end of period Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Exercise Price Range [Axis] Exercise Price Range [Axis] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Exercise Price $15.01 to $21.00 Exercise Price $15.01 to $21.00 [Member] Exercise Price $15.01 to $21.00 [Member] Exercise Price $21.01 to $28.00 Exercise Price $21.01 to $28.00 [Member] Exercise Price $21.01 to $28.00 [Member] Exercise Price $28.01 to $35.00 Exercise Price $28.01 to $35.00 [Member] Exercise Price $28.01 to $35.00 [Member] Exercise Price $35.01 to $43.00 Exercise Price $35.01 to $43.00 [Member] Exercise Price $35.01 to $43.00 [Member] Exercise Price $44.80 to $44.80 Exercise Price Range $44.80 to $44.80 [Member] Exercise Price Range $44.80 to $44.80 [Member] Exercise Price $52.16 to $52.16 Exercise Price $52.16 to $52.16 [Member] Exercise Price $52.16 to $52.16 [Member] Exercise Price $15.01 to $52.16 Exercise Price $15.01 to $52.16 [Member] Exercise Price $15.01 to $52.16 [Member] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Range of Exercise Prices, Lower Range (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit Range of Exercise Prices, Upper Range (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit Number Outstanding (in shares) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options Weighted-Average Remaining Contractual Life Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term Weighted-Average Exercise Price (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price Number Exercisable (in shares) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options Weighted-Average Exercise Price (in dollars per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price Cash proceeds Disposal Group, Including Discontinued Operation, Consideration