Statistical Measurement [Domain] Statistical Measurement [Domain] Liability for Unpaid Losses and Loss Adjustment Expenses [Abstract] Liability for Unpaid Losses and Loss Adjustment Expenses [Abstract] Liability for Unpaid Losses and Loss Adjustment Expenses [Abstract] Operating lease liabilities due after year five Lessee, Operating Lease, Liability, to be Paid, after Year Five Schedule of Equity Securities and Other [Line Items] Debt and Equity Securities, FV-NI [Line Items] Debt Securities, Available-for-sale Debt Securities, Available-for-Sale [Table Text Block] Debt Securities, Available-for-sale, Allowance for Credit Loss, Writeoff Debt Securities, Available-for-Sale, Allowance for Credit Loss, Writeoff Prior periods Prior Year Claims and Claims Adjustment Expense Award Timing Predetermined Award Timing Predetermined [Flag] Operating lease right-of-use assets Increase (Decrease) Operating Lease Right-of-use Assets Increase (Decrease) Operating Lease Right-of-use Assets Entity File Number Entity File Number Additional Paid-in Capital Additional Paid-in Capital [Member] Investments, Net Realized Gains and Losses [Abstract] Investments, Net Realized Gains and Losses [Abstract] Investments, Net Realized Gains and Losses [Abstract] Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Reclassification adjustment for realized AFS investment losses in net income, net of tax benefit of $(0.5) and $(0.4) for the three months ended September 30, 2025 and 2024, respectively, and $(0.7) and $(1.3) for the nine months ended September 30, 2025 and 2024, respectively Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Tabular List, Table Tabular List [Table Text Block] Leases [Abstract] Leases [Abstract] Unearned premiums Unearned Premiums Purchases of short-term investments Payments to Acquire Short-Term Investments Debt Securities, Available-for-sale, Allowance for Credit Loss, Recovery Debt Securities, Available-for-Sale, Allowance for Credit Loss, Recovery Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Estimated fair value of financial instruments table Fair Value, by Balance Sheet Grouping [Table Text Block] Debt Securities [Member] Debt Securities [Member] Coverage provided under LPT Agreement Guarantor Obligations, Maximum Exposure, Undiscounted Non-cancellable obligations Non Cancellable Obligations Amount of non-cancellable obligations on the Balance Sheet of the Company. Debt securities, available-for-sale, gross unrealized loss Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Fair value investments entities that calculate net asset value per share liquidating investment original expected lives increments Fair value investments entities that calculate net asset value per share liquidating investment original expected lives increments Increments to average original expected period the underlying assets are expected to be liquidated by the investees for investments for which net asset value per share is calculated. Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Measurement Basis [Axis] Basic Earnings Per Share, Basic Other non-recurring expenses Other Expenses Adjustment to Compensation: Adjustment to Compensation [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Accounts payable, accrued expenses and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward] Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward] Finance lease expense Finance Lease Expense Total amount of finance lease expense. Excludes sublease income. OCI, Debt Securities, Available-for-Sale, Gain (Loss), before Adjustment, Tax OCI, Debt Securities, Available-for-Sale, Gain (Loss), before Adjustment, Tax Other comprehensive income, net of tax Change in net unrealized gains in investments, net of tax Other Comprehensive Income (Loss), Net of Tax Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] LPT Contingent Commission Adjustment [Abstract] LPT Contingent Commission Adjustment LPT Contingent Commission Adjustment Debt Securities, Available-for-sale, Allowance for Credit Loss, Securities Sold Debt Securities, Available-for-Sale, Allowance for Credit Loss, Securities Sold Investments at NAV [Abstract] Investments at NAV [Abstract] Investments at NAV [Abstract] Non-cancellable obligations Non Cancellable Obligations CF The change to cash flow during the reporting period in Non Cancellable Obligations. Adjustment to Compensation, Amount Adjustment to Compensation Amount Utilities operating expense, depreciation and amortization Utilities Operating Expense, Depreciation and Amortization Stock-based compensation Share-Based Payment Arrangement, Noncash Expense Finance lease liabilities due year three Finance Lease, Liability, to be Paid, Year Three Stock Option [Member] Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Other General and Administrative Expense Other General and Administrative Expense Property and Equipment [Table] Property, Plant and Equipment [Table] Cash and Cash Equivalents [Member] Cash and Cash Equivalents [Member] Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract] Effective Income Tax Rate Reconciliation, Percent [Abstract] Gain on Sale of Investments Gain on Sale of Investments Dividends declared, value Dividends, Common Stock, Cash Stockholders' Equity Attributable to Parent Stockholders' equity, value Stockholders' equity, value Stockholders’ equity Equity, Attributable to Parent Schedule of Available-for-sale Securities [Table] Debt Securities, Available-for-Sale [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Comprehensive income Other Comprehensive Income (Loss), Net of Tax [Abstract] Insider Trading Policies and Procedures [Line Items] NEW YORK NEW YORK Debt Securities, Available-for-sale, Allowance for Credit Loss Debt Securities, Available-for-Sale, Allowance for Credit Loss [Table Text Block] Property and Equipment Property, Plant and Equipment [Table Text Block] Common stock, shares authorized (in shares) Common Stock, Shares Authorized Total liabilities and stockholders’ equity Liabilities and Equity Fair Value, Recurring [Member] Fair Value, Recurring [Member] Deferred policy acquisition costs Deferred Policy Acquisition Cost Liabilities and stockholders’ equity Liabilities and stockholders' equity Liabilities and Equity [Abstract] Funds Held under Reinsurance Agreements, Asset Funds Held under Reinsurance Agreements, Asset Premiums receivable (less CECL allowance of $22.2 at September 30, 2025 and $19.2 at December 31, 2024) Premiums Receivable, Net Cover [Abstract] Cover [Abstract] Cash and cash equivalents, estimated fair value Cash and Cash Equivalents, Fair Value Disclosure Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Maximum [Member] Maximum [Member] Due after ten years, amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Table] Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Table] Complete disclosure pertaining to an entity's basic and diluted earnings per share. Policies In force Policies In force Policies In force Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] Purchases of other invested assets Payments to Acquire Other Investments Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease) Debt Securities, Available-for-Sale, Allowance for Credit Loss, Period Increase (Decrease) Cash transactions related to stock-based compensation Cash transactions related to stock based compensation Fair market value of stock withheld to satisfy minimum employee tax withholding Treasury Stock, Common Treasury Stock, Common [Member] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] US Government Agencies Debt Securities [Member] US Government Agencies Debt Securities [Member] Operating lease liability Operating Lease, Liability Unearned premiums Increase (Decrease) in Unearned Premiums Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Paid losses and LAE claims related to LPT Paid Losses and LAE Claims Related to LPT Paid Losses and LAE Claims Related to LPT. Net (loss) income before income taxes Net Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Vesting rights for RSUs awarded Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights Income Taxes [Abstract] Income Taxes [Abstract] Income Taxes [Abstract] Schedule of Revenue by Major Customers, by Reporting Segments [Table] Schedule of Revenue by Major Customers, by Reporting Segments [Table] Line of Credit Facility, Periodic Payment, Interest Line of Credit Facility, Periodic Payment, Interest Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Unpaid losses and loss adjustment expenses Increase (Decrease) in Liability for Claims and Claims Adjustment Expense Reserve Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Schedule of Cash Flow, Supplemental Disclosures Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Lessee, operating lease, remaining lease term Lessee, Operating Lease, Remaining Lease Term Stock-Based Compensation [Abstract] Stock-Based Compensation [Abstract] Stock-Based Compensation [Abstract] Company Selected Measure Amount Company Selected Measure Amount Operating lease liabilities due year three Lessee, Operating Lease, Liability, to be Paid, Year Three Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Line of Credit Facility [Table] Letters of Credit [Table] Line of Credit Facility [Table] Interest and financing expenses Interest and financing expenses Interest Expense, Operating Debt Issuance Costs, Gross Debt Issuance Costs, Gross Total Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Name Measure Name EAC Employers Assurance Company [Domain] Employers Assurance Company (EAC) Due in one year or less, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Line of Credit Facility [Abstract] Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract] Investments, Investment Income [Abstract] Investments, Investment Income [Abstract] Investments, Investment Income [Abstract] Proceeds from maturities and redemptions of fixed maturity securities Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Performance share awards, maximum payout Performane Share Awards, maximum payout Performane Share Awards, maximum payout based on certain performance targets. Document Fiscal Period Focus Document Fiscal Period Focus Award Timing Method Award Timing Method [Text Block] Unrealized gain (loss) on investments Unrealized Gain (Loss) on Investments [Table Text Block] Award Type [Axis] Award Type [Axis] Legal Entity [Axis] Legal Entity [Axis] Total assets Assets Reinsurance [Table] Reinsurance [Table] Reinsurance [Table] Trading Symbol Trading Symbol Operating lease liabilities due year four Lessee, Operating Lease, Liability, to be Paid, Year Four Geographical [Domain] Geographical [Domain] Proceeds from sales and maturities of short-term investments Proceeds from Sale, Maturity and Collection of Short-Term Investments Stock-based obligations, shares Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Entity Address, City or Town Entity Address, City or Town Short-term Debt, Type [Domain] Short-Term Debt, Type [Domain] Operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Adjusted Stockholder's Equity Adjusted Stockholder's Equity Total stockholders' equity plus Deferred reinsurance gain - LPT Agreement less Accumulated other comprehensive income (loss), net of tax. Restricted Stock Units (RSUs) [Member] Restricted Stock Units (RSUs) [Member] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Credit Losses Credit Loss, Financial Instrument [Text Block] Entity Emerging Growth Company Entity Emerging Growth Company Finance lease liabilities due next twelve months Finance Lease, Liability, to be Paid, Year One Cash dividends declared per common share and eligible equity plan awards Common Stock, Dividends, Per Share, Declared Other invested assets (cost $85.3 at September 30, 2025 and $90.9 at December 31, 2024) Total other invested assets Other Investments Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Components of Lease Expense [Abstract] Lease, Cost [Abstract] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Number of outstanding options or share units Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Repayments on line of credit advances Repayments of Lines of Credit Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Segment Net Income before taxes [Abstract] Segment Net Income before taxes [Abstract] Segment Net Income before taxes [Abstract] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Restricted cash and cash equivalents Restricted Cash and Cash Equivalent Final Audit Premium Accruals Final Audit Premium Accruals Final Audit Premium Accruals Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Deferred Tax Liabilities, Tax Deferred Income Deferred Tax Liabilities, Tax Deferred Income Federal Home Loan Bank, Advances, Option [Domain] Federal Home Loan Bank, Advances, Option [Domain] Lessee, operating lease liabilities due Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract] Less: inputed interest, finance lease Finance Lease, Liability, Undiscounted Excess Amount Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Allowance for expected credit losses Accounts Receivable, Credit Loss Expense (Reversal) PEO PEO [Member] Investments classified by contractual maturity date table Investments Classified by Contractual Maturity Date [Table Text Block] Investment income Investment Income, Interest New Accounting Standards [Abstract] New Accounting Standards [Abstract] New Accounting Standards [Abstract] Share-based compensation award, shares issued Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period Federal income taxes payable Accrued Income Taxes, Current UNITED STATES UNITED STATES Change in operating assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Loss on Sale of Investments Loss on Sale of Investments Retained Earnings Retained Earnings [Member] Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities Total net paid losses and LAE during the period Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Cash, cash equivalents, restricted cash and restricted cash equivalents at the beginning of the period Cash, cash equivalents, restricted cash and restricted cash equivalents at the end of the period Total cash, cash equivalents, restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income tax (benefit) expense Income Tax Expense (Benefit) Revenue, Major Customer [Line Items] Revenue, Major Customer [Line Items] Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Other assets Other Assets Proceeds from Sale and Maturity of Debt Securities, Available-for-Sale Proceeds from Sale and Maturity of Debt Securities, Available-for-Sale [Abstract] Balance at the beginning of the period Balance at end of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Total Investments at fair value, estimated fair value Investments, Fair Value Disclosure Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Net unrealized losses on AFS investments, before taxes Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities, Before Tax Accumulated appreciation or loss, pre-tax, in value of the total of available-for-sale securities at the end of an accounting period. Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Available for sale: Debt Securities, Available-for-Sale [Abstract] Property and equipment, gross Property, Plant and Equipment, Gross Total investments at fair value Investments Carried at Fair Value Sum of investments carried at fair value as of the balance sheet date. Losses and LAE, net of reinsurance, incurred during the period related to: Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract] Net investment income Net Investment Income Cloud computing arrangements Capitalized Cloud Computing Arrangements Cloud computing arrangements Amount related to Cloud Computing Arrangements. Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Equity Securities, FV-NI, Realized Loss Equity Securities, FV-NI, Realized Loss Organization, Consolidation and Presentation of Financial Statements [Abstract] Indemnification Agreement [Member] Indemnification Agreement [Member] Federal Home Loan Bank Branch [Domain] Federal Home Loan Bank Branch [Domain] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] City Area Code City Area Code Deposit Assets [Abstract] Deposit Assets [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Paid losses Reinsurance Recoverable for Paid Claims and Claims Adjustments All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Payments to develop software Payments to Develop Software Insurance Operations Insurance Operations [Member] Insurance Operations Reinsurance Recoverable, Allowance for Credit Loss, Period Increase (Decrease) Reinsurance Recoverable, Allowance for Credit Loss, Period Increase (Decrease) Equity Securities [Table] Debt Securities, Trading, and Equity Securities, FV-NI [Table] Supplemental Balance Sheet Information related to Leases Supplemental Balance Sheet Information related to Leases [Table Text Block] Tabular disclosure of supplemental balance sheet information related to leases. Investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Total AFS, gross unrealized gain Total Available for sale Debt Securities and Short-term investments, Unrealized Gain Available for sale Debt Securities and Short-term investments, Unrealized Gain Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Proceeds from sale of fixed maturity securities Proceeds from Sale of Debt Securities, Available-for-Sale Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Total lease expense Lease, Cost Automobiles Automobiles [Member] Other liabilities Other Liabilities Goodwill Goodwill Equity securities at fair value (cost $148.5 at September 30, 2025 and $145.0 at December 31, 2024) Equity Securities, FV-NI Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Current period Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year Lease, Cost Lease, Cost [Table Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Depreciation Depreciation Net realized and unrealized gains on investments Gain (Loss) on Investments Finance lease liabilities due year four Finance Lease, Liability, to be Paid, Year Four Total AFS investments Total Available for sale investments Total Available for sale investments Earnings Per Share, Basic and Diluted, by Common Class [Line Items] Earnings Per Share, Basic and Diluted, by Common Class [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Equity Components [Axis] Equity Components [Axis] Property and Equipment [Line Items] Property, Plant and Equipment [Line Items] Income Statement Parenthetical [Abstract] Income Statement Parenthetical [Abstract] Income Statement Parenthetical [Abstract] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Other comprehensive income (loss), reclassification adjustment for sale of securities included in net income, tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax LPT Agreement LPT Agreement [Text Block] LPT Agreement [Text Block] Debt securities, available-for-sale, amortized cost Debt Securities, Available-for-Sale, Amortized Cost Losses and loss adjustment expenses Policyholder Benefits and Claims Incurred, Net Other Performance Measure, Amount Other Performance Measure, Amount Entity Address, State or Province Entity Address, State or Province Payments on finance leases Payments on finance leases Finance Lease, Principal Payments Individual: Individual [Axis] Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization Distributions from other invested assets Proceeds from Limited Partnership Investments Dividends paid to stockholders Payments of Ordinary Dividends, Common Stock Additional paid-in capital Additional Paid in Capital, Common Stock Effect of Change in Accounting Estimate, Type [Axis] Effect of Change in Accounting Estimate, Type [Axis] Investments: Investments [Abstract] Entity [Domain] Entity [Domain] Net cash provided by (used in) investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Other Invest Assets [Abstract] Other Invest Assets [Abstract] Other Invest Assets [Abstract] Document Fiscal Year Focus Document Fiscal Year Focus Mortgage and asset-backed securities, amortized cost Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Amortized Cost Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Effective tax rate Effective Income Tax Rate Reconciliation, Percent Entity Interactive Data Current Entity Interactive Data Current Equity Securities, FV-NI, Realized Gain Equity Securities, FV-NI, Realized Gain Commissions and premium taxes payable Accrued Liabilities for Commissions, Expense and Taxes Operating Lease, Cost Operating Lease, Cost Leases, Supplement Balance Sheet Information [Abstract] Leases, Supplement Balance Sheet Information [Abstract] Leases, Supplement Balance Sheet Information [Abstract] Components of lease expense [Abstract] Components of lease expense [Abstract] Components of lease expense [Abstract] Share-based compensation arrangements by share-based payment award table Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block] Investment Owned, at Cost Investment Owned, Cost Segment Reporting Disclosure [Text Block] Segment Reporting Disclosure [Text Block] 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] US Treasury Securities [Member] US Treasury Securities [Member] Property and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Information Technology and Data Processing Information Technology and Data Processing Change in net unrealized gains (losses) Investments, Change in Net Unrealized Gains (Losses) The item represents the change in net unrealized gains (losses) for all fixed maturity and equity securities. Other Debt Obligations [Member] Other Debt Obligations [Member] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Accumulated Other Comprehensive Income, Net Comprehensive Income (Loss) Note [Text Block] Finance lease liabilities due year two Finance Lease, Liability, to be Paid, Year Two Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Finance Lease, Right-of-Use Asset, Accumulated Amortization Finance Lease, Right-of-Use Asset, Accumulated Amortization Deferred income tax asset, net Deferred Income Tax Assets, Net Schedule of accumulated other comprehensive income (loss) table Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Depreciation and amortization expenses Depreciation, Depletion and Amortization Entity Central Index Key Entity Central Index Key PEO Name PEO Name Premium Receivable, Allowance for Credit Loss Premium Receivable, Allowance for Credit Loss [Table Text Block] Segment Reporting, Disclosure of Major Customers Segment Reporting, Disclosure of Major Customers Total revenues Revenues Revenues Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Residential Mortgage Backed Securities [Member] Residential Mortgage-Backed Securities [Member] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Total net losses and LAE incurred during the period Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims Performance share awards, minimum payout Performance Share Awards, Minimum Payout Performane Share Awards, minimum payout based on certain performance targets. Letters of Credit [Abstract] Letters of Credit [Abstract] Letters of Credit [Abstract] Finance Lease, Liability, Total Finance lease, liability Finance Lease, Liability Arrangement Duration Trading Arrangement Duration Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Equity securities table Debt Securities, Trading, and Equity Securities, FV-NI [Table Text Block] Computer and software Computer Equipment [Member] Premiums Written, Net Premiums Written, Net Beginning balance of the allowance for CECL on premiums receivable Ending balance of the allowance for CECL on premiums receivable Premium Receivable, Allowance for Credit Loss Assets Held by Insurance Regulators Assets Held by Insurance Regulators Segments [Axis] Segments [Axis] Surcharges and Assigned Risk Premiums Surcharges and Assigned Risk Premiums Surcharges and Assigned Risk Premiums Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Local Phone Number Local Phone Number Other invested assets Other Invested Assets [Table Text Block] Other Invested Assets [Table Text Block] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Cloud computing arrangements Cloud Computing Arrangements CF The change to cash flow during the reporting period in Cloud Computing Arrangements. Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Stock-Based compensation Share-Based Payment Arrangement [Text Block] LPT Agreement [Abstract] LPT Agreement [Abstract] LPT Agreement [Abstract] Assets Assets [Abstract] AFS, Change in Unrealized Gains (Losses) on Fixed Maturity and Equity Securities reflected in AOCI OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, before Tax Underlying Security Market Price Change Underlying Security Market Price Change, Percent Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Stockholders' equity Equity, Attributable to Parent [Abstract] Investments, Held in Trust or on Deposit [Abstract] Investments, Held in Trust or on Deposit [Abstract] Investments, Held in Trust or on Deposit [Abstract] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Premiums Written, Gross Premiums Written, Gross (TTM) Premiums Written, Gross Entity Address, Address Line One Entity Address, Address Line One Reinsurance Agreement [Line Items] Reinsurance Agreement [Line Items] Reinsurance Agreement [Line Items] Acquisition of common stock, value Treasury Stock, Value, Acquired, Cost Method Debt and Equity Securities, Unrealized Gain (Loss) Debt and Equity Securities, Unrealized Gain (Loss) [Abstract] Accumulated Other Comprehensive Income, Net AOCI Attributable to Parent [Member] Commission expense Insurance Commissions Accounts Receivable, Allowance for Credit Loss, Current Accounts Receivable, Allowance for Credit Loss, Current Fair Value of Financial Instruments [Abstract] Fair Value of Financial Instruments [Abstract] Fair Value of Financial Instruments [Abstract] Investments [Domain] Investments [Domain] Allowance for Credit Loss Allowance for Credit Loss [Abstract] Short-duration Insurance Contracts, Accident Year [Domain] Short-Duration Insurance Contracts, Accident Year [Domain] Investments, Net (Increase)/Decrease in CECL Allowance Investments, Net (Increase)/Decrease in CECL Allowance Investments, Net (Increase)/Decrease in CECL Allowance Reinsurance recoverables on unpaid losses, allowance Beginning balance of the allowance for CECL on reinsurance recoverables Ending balance of the allowance for CECL on reinsurance recoverables Reinsurance Recoverables on Unpaid Losses, Allowance Contingent commission receivable—LPT Agreement Contingent Commission Receivable LPT Agreement The aggregate carrying amount, as of the balance sheet date, of contingent commission receivable related to the LPT Agreement, a retroactive 100% quota share reinsurance agreement. Fair Value as of Grant Date Award Grant Date Fair Value Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Equity Securities, FV-NI, Cost Equity Securities, FV-NI, Cost Entity Registrant Name Entity Registrant Name Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Policyholder Dividends, Expense Policyholder Dividends, Expense Labor and Related Expense Labor and Related Expense Depreciation [Abstract] Depreciation [Abstract] Amortization of cloud computing arrangements Capitalized Computer Software, Amortization Dilutive securities Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Short-Duration Insurance Contracts, Claim Duration [Domain] Short-Duration Insurance Contracts, Claim Duration [Domain] Title of Individual with Relationship to Entity [Domain] Title and Position [Domain] Unpaid losses (less CECL allowance of $0.8 at September 30, 2025 and $0.9 at December 31, 2024) Reinsurance Recoverable, Unpaid Losses, Less Allowance The known and estimated amount recoverable as of the balance sheet date from reinsurers for claims paid or incurred by the ceding insurer and associated claims settlement expenses, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance. Document Quarterly Report Document Quarterly Report Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Operating lease liabilities due year two Lessee, Operating Lease, Liability, to be Paid, Year Two Amortization of discounts and premiums on investments, net Accretion (Amortization) of Discounts and Premiums, Investments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Payments to Acquire Equity Securities, FV-NI Payments to Acquire Equity Securities, FV-NI Accrued investment income Accrued Investment Income Receivable Reinsurance Recoverable, Allowance for Credit Loss Reinsurance Recoverable, Allowance for Credit Loss [Table Text Block] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table Text Block] Schedule of Investment Income, Reported Amounts, by Category [Axis] Investment Type [Axis] Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Total investments Investments Investments Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Underwriting expenses Other Underwriting Expense Amortization of deferred gain Amortization of Deferred Gain The amount of Deferred reinsurance gain–LPT Agreement, related to the LPT Agreement, a retroactive 100% quota share reinsurance agreement, that is amortized into and reflected in earnings during the period. Restatement Determination Date: Restatement Determination Date [Axis] Non-PEO NEO Non-PEO NEO [Member] Financial Guarantee Insurance Contracts, Premium Received over Contract Period, Premium Receivable, Weighted Average Collection Period Financial Guarantee Insurance Contracts, Premium Received over Contract Period, Premium Receivable, Weighted Average Collection Period Debt Securities, Available-for-sale, Allowance for Credit Loss Debt Securities, Available-for-sale, Allowance for Credit Loss Beginning balance of CECL on AFS investments Ending balance of CECL on AFS investments Debt Securities, Available-for-Sale, Allowance for Credit Loss Bad debt expense Bad debt expense Bad debt expense Debt securities, available-for-sale, gross unrealized gain Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Name Trading Arrangement, Individual Name Award Type [Domain] Award Type [Domain] Operating lease liabilities due next twelve months Lessee, Operating Lease, Liability, to be Paid, Year One Equity Awards Adjustments Equity Awards Adjustments [Member] Leasehold improvements Leasehold Improvements [Member] Estimated remaining liabilities - LPT Agreement Estimated Remaining Liabilities - LPT Agreement Estimated remaining liabilities subject to the LPT agreement. Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Other (loss) income Other Income Compensation Amount Outstanding Recovery Compensation Amount Changes in the liability for unpaid losses and LAE table Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block] AllOtherStates [Member] AllOtherStates [Member] AllOtherStates [Member] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Estimate of Fair Value, Fair Value Disclosure [Member] Estimate of Fair Value Measurement [Member] Accumulated Other Comprehensive Income [Abstract] Accumulated Other Comprehensive Income [Abstract] Accumulated Other Comprehensive Income [Abstract] Involuntary Assigned Risk Business [Member] Related to Involuntary Assigned Risk Business [Member] Related to the Company's involuntary assigned risk business. MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Due after one year through five years, amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Name Awards Close in Time to MNPI Disclosures, Individual Name Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Revenues Revenues [Abstract] Foreign Government Debt Foreign Government Debt [Member] Credit Loss [Abstract] Credit Loss [Abstract] Other invested assets at NAV Alternative Investment Due after five years through ten years, amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Impact of the LPT Agreement Impact of the LPT Agreement Impact of the LPT Agreement (amortization of the deferred reinsurance gain—LPT Agreement, LPT Reserve Adjustments, and LPT Contingent Commission Adjustments) excluded from the total net losses and LAE. Debt Securities, number of issues in loss position, 12 months or greater Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions Stock-based obligations, value APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Treasury stock, at cost (35,565,657 shares at September 30, 2025 and 33,628,155 shares at December 31, 2024) Treasury Stock, Value Other comprehensive income (loss), unrealized holding gain (loss) on securities arising during period, tax OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax Accumulated other comprehensive loss, net of tax Total accumulated other comprehensive loss Accumulated other comprehensive loss, net of tax Accumulated Other Comprehensive Income (Loss), Net of Tax Financial Instruments [Domain] Financial Instruments [Domain] Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Segments [Domain] Segments [Domain] Deferred reinsurance gain—LPT Agreement Deferred Reinsurance Gain LPT Agreement Deferred Reinsurance Gain LPT Agreement Deferred reinsurance gain–LPT Agreement reflects the unamortized gain from our LPT Agreement, a retroactive 100% quota share reinsurance agreement. This gain is deferred and is being amortized using the recovery method. Amortization is determined by the proportion of actual reinsurance recoveries to total estimated recoveries over the life of the LPT Agreement, except for the gains associated with the contingent profit commission, which is amortized through June 30, 2024. The amortization is reflected in losses and LAE Performance Shares [Member] Performance Shares [Member] Investments Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Letters of credit collateral amount Letter of Credit Collateral Amount Represents the amount of investment securities at fair value pledged as collateral for the Letter of Credit. Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Schedule of Investment Income, Reported Amounts, by Category [Line Items] Net Investment Income [Line Items] Minimum [Member] Minimum [Member] Consolidated Statements of Cash Flows [Abstract] Consolidated Statements of Cash Flows [Abstract] Consolidated Statements of Cash Flows [Abstract] Maturities of Lease Liabilities [Abstract] Maturities of Lease Liabilities [Abstract] Maturities of Lease Liabilities [Abstract] Accumulated depreciation, depletion and amortization, property and equipment Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Expenses Cost of Revenue [Abstract] Company Selected Measure Name Company Selected Measure Name Premiums receivable Increase (Decrease) in Premiums Receivable Change in estimate of contingent commission receivable Change in estimate of contingent commission receivable Change in estimate of contingent commission receivable under the LPT agreement Fair Value, Disclosure Item Amounts [Domain] Fair Value Measurement [Domain] Purchases of fixed maturity securities Payments to Acquire Debt Securities, Available-for-Sale Debt Disclosure [Text Block] Debt Disclosure [Text Block] Net realized and unrealized gains on investments Gain (Loss) on Sale of Investments Aggregate Available Trading Arrangement, Securities Aggregate Available Amount US States and Political Subdivisions Debt Securities [Member] US States and Political Subdivisions Debt Securities [Member] Operating cash flows from operating leases Operating Lease, Payments Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Cash Equivalents Measured at Net Asset Value Cash Equivalents Measured at Net Asset Value Cash equivalents measured at net asset value. All Executive Categories All Executive Categories [Member] Current period Current Year Claims and Claims Adjustment Expense Common stock, $0.01 par value; 150,000,000 shares authorized; 58,275,261 and 58,184,861 shares issued and 22,709,604 and 24,556,706 shares outstanding at September 30, 2025 and December 31, 2024, respectively Common Stock, Value, Issued Finance Lease, Right-of-Use Asset, after Accumulated Amortization Finance Lease, Right-of-Use Asset, after Accumulated Amortization Net premiums earned Premiums Earned, Net Short-term investments at fair value (amortized cost $5.6 at September 30, 2025 and $0.1 at December 31, 2024) Short-term Investments Short-Term Investments Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Title of Individual [Axis] Title and Position [Axis] Weighted Average Number of Shares Outstanding, Diluted, Total Weighted Average Number of Shares Outstanding, Diluted Commitments and contingencies Commitments and Contingencies Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Entity Small Business Entity Small Business Revenue from External Customers by Geographic Areas Revenue from External Customers by Geographic Areas [Table Text Block] Total AFS, gross unrealized loss Total Available for sale Debt Securities and Short-term investments, Unrealized Loss Available for sale Debt Securities and Short-term investments, Unrealized Loss Line of Credit Facility, Commitment Fee Amount Line of Credit Facility, Commitment Fee Amount Document Transition Report Document Transition Report Investment income table Investment Income [Table Text Block] Due after one year through five years, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Short-term Investments [Member] Short-Term Investments [Member] New Accounting Standards Accounting Standards Update and Change in Accounting Principle [Text Block] Contingent commission receivable—LPT Agreement Contingent Commission Receivable LPT Agreement CFS The increase (decrease) during the reporting period of contingent commission receivable related to the LPT Agreement, a retroactive 100% quota share reinsurance agreement. Finance Lease, Liability, to be Paid, Total Finance Lease, Liability, to be Paid Premium Receivable, Allowance for Credit Loss [Roll Forward] Premium Receivable, Allowance for Credit Loss [Roll Forward] Preferred stock, $0.01 par value; 25,000,000 shares authorized; none issued Preferred Stock, Value, Outstanding Underlying Securities Award Underlying Securities Amount Debt Securities, Available-for-sale, Realized Gain Debt Securities, Available-for-Sale, Realized Gain Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Due after ten years, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Income Taxes Income Tax Disclosure [Text Block] Assets Held-in-trust [Abstract] Asset, Held-in-Trust [Abstract] Proceeds from Lines of Credit Proceeds from Lines of Credit Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Scenario [Axis] Scenario [Axis] Operating lease liabilities Increase (Decrease) in Operating Lease Liability Document Type Document Type Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Earnings Per Share Earnings Per Share [Text Block] Liability for Unpaid Losses and Loss Adjustment Expenses Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] Name Outstanding Recovery, Individual Name Investments, Continous Loss Position [Abstract] Investments, Continous Loss Position [Abstract] Investments, Continous Loss Position [Abstract] CALIFORNIA CALIFORNIA Furniture and equipment Office Equipment [Member] Federal Home Loan Bank Branch [Axis] Federal Home Loan Bank Branch [Axis] Debt Securities, Available-for-sale, Realized Loss Debt Securities, Available-for-Sale, Realized Loss Dilutive Securities by Type [Domain] Dilutive Securities by Type [Domain] Dilutive Securities by Type [Domain] All Individuals All Individuals [Member] Effect of Change in Accounting Estimate, Type [Domain] Effect of Change in Accounting Estimate, Type [Domain] ECIC Employers Compensation Insurance Company [Member] Employers Compensation Insurance Company is a subsidiary of the Parent. Name Forgone Recovery, Individual Name Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward] Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward] Schedule of Investment Income, Reported Amounts, by Category [Table] Investment Income [Table] Federal Home Loan Bank, Advances, Option [Axis] Federal Home Loan Bank, Advances, Option [Axis] Statistical Measurement [Axis] Statistical Measurement [Axis] Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Dilutive Securities [Axis] Dilutive Securities [Axis] Dilutive Securities [Axis] Share Repurchase Program, Authorized, Amount Share Repurchase Program, Authorized, Amount Letters of credit, unused capacity, commitment fee percentage Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Capital expenditures and other Payments to Acquire Other Property, Plant, and Equipment Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances Federal Home Loan Bank, Advance, Branch of FHLBank, Amount Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Equity securities: Debt Securities, Trading and Available-for-Sale [Abstract] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Proceeds from FHLBank Borrowings, Financing Activities Proceeds from FHLBank Borrowings, Financing Activities Available for sale, short-term investments, at amortized cost Other Short-Term Investments Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Line of Credit Facility [Line Items] Letters of Credit Facilities [Line Items] Line of Credit Facility [Line Items] Geographical [Axis] Geographical [Axis] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Investments, Gross Realized Losses Investments, Gross Realized Losses Total gross realized losses for all fixed maturity and equity securities. Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Other Increase (Decrease) in Other Operating Assets and Liabilities, Net Total expenses Operating Expenses Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Repayments of FHLBank Advance, Investing Activities Payments of FHLBank Borrowings, Financing Activities Deferred reinsurance gain—LPT Agreement Deferred reinsurance gain LPT Agreement CFS The increase (decrease) during the reporting period in Deferred reinsurance gain–LPT Agreement, which reflects the unamortized gain from our LPT Agreement, a retroactive 100% quota share reinsurance agreement. Federal Home Loan Bank [Member] Federal Home Loan Bank of San Francisco [Member] Diluted Earnings Per Share, Diluted Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Title of 12(b) Security Title of 12(b) Security Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Due after five years through ten years, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Share Repurchase Program, Excise Tax, Payable Share Repurchase Program, Excise Tax, Payable Performance share awards performance period Performance Share Awards Performance Period Performance Period for PSAs. Premium Receivable, Allowance for Credit Loss, Writeoff Premium Receivable, Allowance for Credit Loss, Writeoff Treasury stock, at cost (in shares) Treasury Stock, Common, Shares Officer [Member] Officer [Member] Earnings (loss) per common share (Note 13): Earnings Per Share [Abstract] Deduct payments for losses and LAE, net of reinsurance, related to: Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract] Operating lease liabilities due year five Lessee, Operating Lease, Liability, to be Paid, Year Five Other Investments and Securities, at Cost Other Investments and Securities, at Cost Business Description and Basis of Presentation Business Description and Basis of Presentation [Text Block] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Less reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE Reinsurance recoverable, excluding CECL allowance, on unpaid losses and LAE Reinsurance Recoverable, Unpaid Losses Excluding Allowance The known and estimated amount recoverable as of the balance sheet data from reinsurers for claims paid or incurred by the ceding insurer and associated claims settlement expenses, including estimated amounts for claims incurred but not reported and policy benefits, excluding any related valuation allowance. Short-term Debt, Type [Axis] Short-Term Debt, Type [Axis] Lessee, Operating Lease, Liability, Undiscounted Excess Amount Lessee, Operating Lease, Liability, Undiscounted Excess Amount Proceeds from Sale of Equity Securities, FV-NI Proceeds from Sale of Equity Securities, FV-NI Debt and Equity Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss Debt and Equity Securities, Gain (Loss), Excluding Other-than-temporary Impairment Loss Deferred tax benefit on net unrealized losses Accumulated Other Comprehensive Income, Deferred Tax on Net Unrealized Gains Accumulated Other Comprehensive Income, Deferred Tax on Net Unrealized Gains Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Finance lease liabilities due after year five Finance Lease, Liability, to be Paid, after Year Five Gain on redemption of notes payable Gain on redemption of notes payable Gain on redemption of notes payable Award Timing Disclosures [Line Items] Premiums Written, Gross excl. Adjustments Premiums Written, Gross excl. Adjustments Premiums Written, Gross excl. Adjustments Measurement Frequency [Domain] Measurement Frequency [Domain] Net unpaid losses and LAE at beginning of period Ending unpaid losses and LAE, net of reinsurance Liability for Unpaid Claims and Claims Adjustment Expense, Net Property, Plant and Equipment Disclosure [Text Block] Property, Plant and Equipment Disclosure [Text Block] Lessee, Operating Lease, Liability, to be Paid, Total Lessee, Operating Lease, Liability, to be Paid Lessee, operating lease, renewal term Lessee, Operating Lease, Renewal Term Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Unrealized AFS investment gains arising during the period, net of tax expense of $(3.9) and $(13.9) for the three months ended September 30, 2025 and 2024, respectively, and $(11.5) and $(9.5) for the nine months ended September 30, 2025 and 2024, respectively OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Finance Lease, Automobiles Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Line of Credit Facility, Current Borrowing Capacity Line of Credit Facility, Current Borrowing Capacity Reinsurance Quota Share, Percentage Reinsurance Quota Share, Percentage Agreement where the assuming company shares proportionally in the premiums and losses of the ceding company Net (loss) income Net income Net (loss) income available to stockholders - basic and diluted Net Income (Loss) Attributable to Parent Subsequent Event [Table] Subsequent Event [Table] Debt Instrument, Covenant Description Debt Instrument, Covenant Description Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Expiration Date Trading Arrangement Expiration Date Collateralized Loan Obligations [Member] Collateralized Loan Obligations [Member] Stockholders’ equity: Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Line of Credit Facility, Covenant Terms Line of Credit Facility, Covenant Terms Reinsurance recoverable for: Reinsurance Recoverable For [Abstract] -- None. No documentation exists for this element. -- Other Investments [Member] Other Investments [Member] Property and equipment, net Property and equipment, net Property, Plant and Equipment, Net Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Acquisition of common stock Payments for Repurchase of Common Stock Adoption Date Trading Arrangement Adoption Date Base Rate Base Rate [Member] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Total gross realized gains Investments, Gross Realized Gains Total gross realized gains for all fixed maturity and equity securities. Entity Current Reporting Status Entity Current Reporting Status Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] FLORIDA FLORIDA Due in one year or less, amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Retained earnings Retained Earnings (Accumulated Deficit) Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract] Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Number of Positions [Abstract] Vesting of RSUs and PSUs, net of shares withheld to satisfy minimum tax withholding, shares Restricted Stock, Shares Issued Net of Shares for Tax Withholdings Financial Instrument [Axis] Financial Instrument [Axis] 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] Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Loss Ratio Loss Ratio Net change in unsettled investment purchases and sales IncreaseDecreaseInUnsettledAccountsReceivablAndAccountsPayable The net change during the reporting period in accounts receivable on unsettled investment sales and accounts payable on unsettled investment purchases. Debt Securities, number of issues in loss position, less than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions Current Fiscal Year End Date Current Fiscal Year End Date AO and other expense allocations, other underwriting expense AO and other expense allocations, other underwriting expense AO and other expense allocations, other underwriting expense Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Investment income Investment Income, Dividend Notes Payable [Abstract] Notes Payable [Abstract] 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] Professional Fees Professional Fees Prior periods Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years Realized Investment Gains (Losses) Realized Investment Gains (Losses) [Abstract] Fair Value of Financial Instruments, Fair Value Measurements [Abstract] Fair Value of Financial Instruments, Fair Value Measurements [Abstract] Fair Value of Financial Instruments, Fair Value Measurements [Abstract] Statement [Table] Statement [Table] Equity securities at cost Federal Home Loan Bank Stock Deferred income tax expense Deferred Income Tax Expense (Benefit) Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Short-duration Insurance Contracts, Accident Year [Axis] Short-Duration Insurance Contracts, Accident Year [Axis] 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] Industrial and Miscellaneous [Member] Industrial, Miscellaneous, and All Others [Member] Variable Rate [Domain] Variable Rate [Domain] Capitalized Computer Software [Abstract] Capitalized Computer Software, Net [Abstract] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Fiscal Year Maturity [Abstract] Dividends declared, shares Common Stock Dividends, Shares Voluntary Risk Business [Member] Related to Voluntary Risk Business [Member] Related to Voluntary Risk Business Equity Securities, FV-NI Equity Securities, FV-NI, Current Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] All Adjustments to Compensation All Adjustments to Compensation [Member] Premium Receivable, Allowance for Credit Loss, Recovery Premium Receivable, Allowance for Credit Loss, Recovery Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Amendment Flag Amendment Flag Estimated Fair Value Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract] Short-Duration Insurance Contract, Accident Year 2025 [Member] Short-Duration Insurance Contract, Accident Year 2025 [Member] Unpaid losses and loss adjustment expenses Unpaid losses and LAE at beginning of period Unpaid losses and LAE at end of period Liability for Claims and Claims Adjustment Expense Investments, Amortized Cost and Estimated Fair Value [Abstract] Investments, Amortized Cost and Estimated Fair Value [Abstract] Investments, Amortized Cost and Estimated Fair Value [Abstract] Termination Date Trading Arrangement Termination Date Net cash 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] Excise Tax Rate, Percent Excise Tax Rate, Percent Excise Tax Rate, Percent Collateral against the Outstanding Letters of Credit Fair value of investments used as collateral against the outstanding letters of credit Fair value of investments used as collateral against the outstanding letters of credit Operating lease, weighted average discount rate, percent Operating Lease, Weighted Average Discount Rate, Percent Weighted average number of shares outstanding - basic Weighted Average Number of Shares Outstanding, Basic Property and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Debt Instrument, Description of Variable Rate Basis Debt Instrument, Description of Variable Rate Basis Net income and weighted average common shares outstanding used in earnings per share calculations table Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Director [Member] Director [Member] Premium taxes and assessments Premium taxes and assessments Premium taxes and assessments Subsequent Events [Abstract] Segment Reporting [Abstract] Segment Reporting [Abstract] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Investment expenses Investment Income, Investment Expense Entity Tax Identification Number Entity Tax Identification Number Scenario [Domain] Scenario [Domain] Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds Mortgage and asset-backed securities, fair value Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Fair Value 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) Stockholders' equity, shares Stockholders' equity, shares Common Stock, Shares, Issued Lessee, Operating and Finance Lease Liability Maturity Lessee Operating and Finance Lease Liability Maturity [Table Text Block] Tabular disclosure of undiscounted cash flows of finance lease liability and lessee's operating lease liability. Includes, but is not limited to, reconciliation of undiscounted cash flows to finance and operating lease liability recognized in statement of financial position. Operating lease, weighted average remaining lease term Operating Lease, Weighted Average Remaining Lease Term Commercial Mortgage Backed Securities [Member] Commercial Mortgage-Backed Securities [Member] Effect of dilutive securities: Dilutive Securities, Effect on Basic Earnings Per Share [Abstract] Line of Credit Facility, Fair Value of Amount Outstanding Line of Credit Facility, Fair Value of Amount Outstanding Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Premium Receivable, Allowance for Credit Loss, Period Increase (Decrease) Premium Receivable, Allowance for Credit Loss, Period Increase (Decrease) Trading Arrangement: Trading Arrangement [Axis] Current federal income taxes Increase (Decrease) in Income Taxes Payable Total Shareholder Return Amount Total Shareholder Return Amount Other [Member] Other Equities [Member] This item represents investments by the reporting entity in equity securities issued by any type of company in public utilities, banks, trusts, and insurance companies the investments in which are summarized elsewhere. Fair value, assets and liabilities measured on recurring basis table Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Subsequent Events Subsequent Events [Text Block] Insider Trading Arrangements [Line Items] Security Exchange Name Security Exchange Name Fair value of awards awarded on grant date Share-Based Compensation Arrangement by Share-Based Payment Award, Grants at Grant Date, Total Fair Value The total fair value of Share-based Award at grant date. Reinsurance recoverable on paid and unpaid losses Increase (Decrease) in Reinsurance Recoverable Equity Securities [Member] Equity Securities [Member] Total liabilities Liabilities Line of Credit Facility, Commitment Fee Percentage Line of Credit Facility, Commitment Fee Percentage Finance lease liabilities due year five Finance Lease, Liability, to be Paid, Year Five Net investment income Investment Income, Net Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] EPIC Employers Preferred Insurance Company [Member] Employers Preferred Insurance Company is a subsidiary of the Parent. Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Combined Ratio Combined Ratio 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 [Member] Asset-Backed Securities [Member] Variable Rate [Axis] Variable Rate [Axis] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalent Vesting of RSUs and PSUs, net of shares withheld to satisfy minimum tax withholding, value Restricted Stock, Value, Shares Issued Net of Tax Withholdings Subsequent Event [Line Items] Subsequent Event [Line Items] Gross investment income Gross Investment Income, Operating Total AFS, amortized cost Total Available for sale Debt Securities and Short-term investments, Cost Amortized cost of Available for sale Debt Securities and Short-term investments Common Stock Common Stock [Member] Fixed maturity securities at fair value (amortized cost $2,026.5 at September 30, 2025 and $2,203.1 at December 31, 2024, less CECL allowance of $0.6 at September 30, 2025 and $1.1 at December 31, 2024) Fixed maturity securities, fair value Total, fair value Debt Securities, Available-for-Sale Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Lessee, finance lease liabilities due Finance Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract] Corporate Debt Securities [Member] Corporate Debt Securities [Member] Net increase (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation