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Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Losses and loss settlement expenses Increase (Decrease) in Future Policy Benefit Reserves Performance Restricted Stock Unit Performance Restricted Stock Unit [Member] Performance Restricted Stock Unit Award Timing Disclosures [Line Items] Service cost Defined Benefit Plan, Service Cost Federal Home Loan Bank Advances Federal Home Loan Bank Advances [Member] Measurement Frequency [Domain] Measurement Frequency [Domain] Net liability for losses and loss settlement expenses at beginning of year Net liability for losses and loss settlement expenses at end of period Liability for Unpaid Claims and Claims Adjustment Expense, Net Lease extension option terms Lessee, Operating Lease, Renewal Term Total change in net unrealized investment gain (loss), net of tax Change in net unrealized gains and losses OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Carrying value Total mortgage loans at amortized cost Total Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss Mortgage loans (net of allowance for credit loss of $286 and $286) Mortgage loans, net Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss REINSURANCE Reinsurance [Text Block] Net Income (loss) Net Income (loss) Net income (loss) Net Income (Loss) Attributable to Parent Summary of Fixed Maturities Unrealized Loss Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Expiration Date Trading Arrangement Expiration Date Other, net Increase (Decrease) in Other Operating Liabilities Vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Property and equipment, at cost (less accumulated depreciation of $86,636 and $85,555) Property, Plant and Equipment, Net Commercial Mortgage Loans by Region Geographic Concentration Risk [Member] Adoption Date Trading Arrangement Adoption Date Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Entity Current Reporting Status Entity Current Reporting Status Net purchases and sales of property and equipment Payments for (Proceeds from) Productive Assets Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Due in one year or less Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Retained earnings Retained Earnings (Accumulated Deficit) Number of Issues Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Number of Positions [Abstract] Financial Instrument [Axis] Financial Instrument [Axis] Benefits, Losses and Expenses Benefits, Losses and Expenses [Abstract] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Executive Category: Executive Category [Axis] 12 months or longer Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Limited Liability Company Limited Liability Company [Member] Less than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions Interest expense Interest Expense, Operating and Nonoperating Current Fiscal Year End Date Current Fiscal Year End Date Less than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Number of shares available for issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Prior years Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years Net investment gains (losses): Realized Investment Gains (Losses) [Abstract] Statement [Table] Statement [Table] Deferred income tax expense (benefit) Deferred Income Tax Expense (Benefit) Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Cash Flows From Financing Activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] East North Central East North Central [Member] East North Central [Member] Total Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Fiscal Year Maturity [Abstract] Summary of Financial Instruments Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Anti-dilutive shares (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Weighted average common shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] All Adjustments to Compensation All Adjustments to Compensation [Member] Amendment Flag Amendment Flag Fair Value Fair Value Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract] Number of shares authorized (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Losses and loss settlement expenses Gross liability for losses and loss settlement expenses at beginning of year Gross liability for losses and loss settlement expenses at end of period Liability for Claims and Claims Adjustment Expense Mixed use/Other Other Property [Member] LEASE COMMITMENTS Lessee, Operating Leases [Text Block] Termination Date Trading Arrangement Termination Date Net cash provided by (used in) financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Measure: Measure [Axis] Allowance for mortgage loan losses Allowance for mortgage loan losses Beginning balance, January 1, 2026 Ending balance, March 31, 2026 Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Basic (in shares) Weighted-average common shares outstanding, basic (in shares) Weighted Average Number of Shares Outstanding, Basic Summary of Components of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Segment Reporting [Abstract] Total investment income Investment Income, Gross Investment Income, Gross Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Less investment expenses Investment Income, Investment Expense Entity Tax Identification Number Entity Tax Identification Number Income tax effect Reclassification from AOCI, Current Period, Tax Asset-backed securities Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Fair Value Available-for-sale Debt Securities, Available-for-Sale, Realized Gain (Loss) Change in net unrealized gain (loss) on investments OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares issued (in shares) Common Stock, Shares, Issued Commercial mortgage-backed Commercial mortgage-backed Commercial Mortgage-Backed Securities [Member] Use of Estimates Use of Estimates, Policy [Policy Text Block] Payment of cash dividends Payments of Dividends Trading Arrangement: Trading Arrangement [Axis] Income taxes payable Increase (Decrease) in Income Taxes Payable Total Shareholder Return Amount Total Shareholder Return Amount Less: lessor income Operating Lease, Lease Income Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Insider Trading Arrangements [Line Items] Security Exchange Name Security Exchange Name Reinsurance receivables Increase (Decrease) in Reinsurance Recoverable Reinsurance receivables, allowance for credit losses Beginning balance, January 1, 2026 Ending balance, March 31, 2026 Reinsurance Recoverable, Allowance for Credit Loss Allowance for Credit Losses Allowance for credit losses Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest Insurance Loss Reserves [Abstract] Insurance Loss Reserves [Abstract] Accrued expenses and other liabilities Accrued expenses and other liabilities Accrued expenses and other liabilities. Summary of Carrying Value of Commercial Mortgage Loans and Additional Information Schedule of Participating Mortgage Loans [Table Text Block] Total liabilities Liabilities Retail Retail Site [Member] Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Net investment income Investment Income, Net Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Amortization of deferred policy acquisition costs Deferred Policy Acquisition Cost, Amortization Expense and Amortization of Value of Business Acquired (VOBA) Deferred Policy Acquisition Cost, Amortization Expense and Amortization of Value of Business Acquired (VOBA) Granted fair value Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture Income on other long-term investments Other Long-Term Investments [Member] Statement [Line Items] Statement [Line Items] Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Asset-backed securities Asset-Backed Securities [Member] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalent East South Central East South Central [Member] East South Central [Member] Common stock Common Stock [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Corporate Corporate Corporate Debt Securities [Member] Net Change in Cash and Cash Equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation