Bank loan participations: Bank Loan Participations [Abstract] Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities: Adjustments to reconcile net (loss) income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Net investment income SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Net Investment Income Other Related Party Transactions Related Party Transactions Disclosure [Text Block] Reserve For Losses And Loss Adjustment Expenses [Table] Reserve For Losses And Loss Adjustment Expenses [Table] A table or schedule providing information pertaining to reserve for losses and Loss adjustment expenses. Federal income tax expense (benefit) at applicable statutory rates Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Other income Other Nonoperating Income Cover [Abstract] Cover [Abstract] Thereafter Lessee, Operating Lease, Liability, to be Paid, after Year Five Change in cash, cash equivalents, and restricted cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect 2016 Short-Duration Insurance Contracts, Accident Year 2016 [Member] Summary of Lease Maturities Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Percentage of outstanding shares acquired Business Acquisition, Percentage of Voting Interests Acquired Condensed Income Statements, Captions [Line Items] Condensed Income Statements, Captions [Line Items] Trading Symbol Trading Symbol Ownership percentage Equity Method Investment, Ownership Percentage Non-NEOs Non-NEOs [Member] U.S. tax benefit on share based compensation expense Share-Based Payment Arrangement, Expense, Tax Benefit Dividend declared per common share (in dollars per share) Dividend declared per share (in dollars per share) Common Stock, Dividends, Per Share, Declared Goodwill Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Disposal Group Name [Domain] Disposal Group Name [Domain] Preferred stock, convertible, conversion price (in dollars per share) Preferred Stock, Convertible, Conversion Price Line of Credit Facility [Table] Line of Credit Facility [Table] Short-term investments Short-Term Investments [Member] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Purchases Payments to Acquire Equity Securities, FV-NI Reinsurance and Adjustable Features of Insurance and Reinsurance Contracts and Retroactive Reinsurance Accounting Reinsurance Accounting Policy [Policy Text Block] Equity securities Net realized and unrealized (losses) gains on investments in equity securities Equity Securities, FV-NI, Gain (Loss) Other operating expenses: Operating Costs and Expenses [Abstract] Earnings (Loss) Per Share Earnings Per Share, Policy [Policy Text Block] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Vesting of RSUs (in shares) Vesting of RSU awards (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Outstanding losses and loss adjustment expenses assumed from involuntary workers’ compensation pools Outstanding Losses And Loss Adjustment Expenses Assumed From Involuntary Workers Compensation Pools This element represents amount of outstanding losses and loss adjustment expenses assumed from involuntary workers compensation pools. Change in net unearned premiums Disposal Group, Including Discontinued Operation, (Increase) Decrease in Unearned Premiums, Net Disposal Group, Including Discontinued Operation, (Increase) Decrease in Unearned Premiums, Net Fair Value Measurements Fair Value Disclosures [Text Block] Unrealized (losses) gains arising during the period, net of U.S. income taxes OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Award Timing Disclosures [Line Items] Financial Asset, Period Past Due [Axis] Financial Asset, Aging [Axis] Short-duration Insurance Contracts, Accident Year [Domain] Short-Duration Insurance Contracts, Accident Year [Domain] Investment, Name [Domain] Investment, Name [Domain] Allowance for credit losses on reinsurance recoverables Reinsurance Recoverables on Unpaid Losses, Allowance Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] E&S Top Up ADC E&S Top Up ADC [Member] E&S Top Up ADC Contribution to subsidiary Payments Of Contributions To Affiliates Payments Of Contributions To Affiliates Financing activities Financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Jrg Re Jrg Re [Member] Represents information about JRG Re. SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] Plan Name [Domain] Plan Name [Domain] Per share price (in dollars per share) Shares issued at a public offering price (in dollars per share) Sale of Stock, Price Per Share United States United States UNITED STATES Ceded written premiums Disposal Group, Including Discontinued Operation, Ceded Premiums Written Disposal Group, Including Discontinued Operation, Ceded Premiums Written Cash and cash equivalents Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents Dilutive potential common shares (in shares) Weighted Average Number of Shares Outstanding, Diluted, Adjustment Leases [Abstract] Leases [Abstract] Series A redeemable preferred shares, issued (in shares) Temporary Equity, Shares Issued Bank Holding Company Bank Holding Company [Member] Represents information about Bank Holding Company. Gross Carrying Amount Finite-Lived Intangible Assets, Gross Fronting and Programs Fronting and Programs [Member] Represents information of Fronting and Programs. Short-duration Insurance Contracts, Claims Development [Table] Short-Duration Insurance Contracts, Claims Development [Table] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Preferred stock, dividend term Preferred Stock, Dividend Term Preferred Stock, Dividend Term Operating Segments Operating Segments [Member] Net cash (used in) provided by operating activities Net Cash Provided by (Used in) Operating Activities Adjustments to additional paid in capital, deemed contribution Adjustments to Additional Paid in Capital, Deemed Contribution Adjustments to Additional Paid in Capital, Deemed Contribution Secured Secured Debt [Member] Preferred stock, discount rate, percentage Preferred Stock, Discount Rate, Percentage Preferred Stock, Discount Rate, Percentage Non-employee directors Non-employee Directors [Member] Non-employee Directors [Member] Preferred stock, dividend payment rate, variable spread Preferred Stock, Dividend Payment Rate, Variable Spread Preferred Stock, Dividend Payment Rate, Variable Spread Award Timing Method Award Timing Method [Text Block] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Total outstanding losses and loss adjustment expenses, net of reinsurance Short-Duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net Measurement Frequency [Axis] Measurement Frequency [Axis] Required collateral percentage Required Collateral Percentage Required Collateral Percentage Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Energy Energy [Member] Name of underwriting division. Insider Trading Policies and Procedures [Line Items] State and municipal US States and Political Subdivisions Debt Securities [Member] Sale of JRG Re Cash payment Proceeds from Divestiture of Businesses Estimates and Assumptions Use of Estimates, Policy [Policy Text Block] Adjustment to Compensation, Amount Adjustment to Compensation Amount Compensation Amount Outstanding Recovery Compensation Amount Disposal Group Classification [Axis] Disposal Group Classification [Axis] 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] Entity Small Business Entity Small Business Company Selected Measure Amount Company Selected Measure Amount Payment of debt issuance costs Payments of Debt Issuance Costs Tabular List, Table Tabular List [Table Text Block] Bank loan participations, at fair value Bank loan participations Fair Value, Option, Loans Held as Assets, Aggregate Fair Value Fair Value, Option, Loans Held as Assets, Aggregate Fair Value Significant Unobservable Inputs Level 3 Fair Value, Inputs, Level 3 [Member] Deductions Amounts Written Off or Disposals SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Excess tax expense (benefits) on share based compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-Based Payment Arrangement, Amount Schedule of Incurred and Cumulative Paid Losses and Loss Adjustment Expenses, Net of Reinsurance Short-Duration Insurance Contracts, Claims Development [Table Text Block] Underwriting and other issue expenses Deferred Policy Acquisition Costs Underwriting And Other Issue Expenses Represents deferred policy acquisition costs underwriting and other issue expenses. Number of securities excluded from the calculations of diluted (loss) earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Carried reserve percentage Carried Reserve Percentage Carried Reserve Percentage Purchases Payment To Acquire Bank Loan Participations Represents payment to acquire Bank loan participations. Convertible preferred stock, shares reserved for future issuance (in shares) Preferred Stock, Convertible, Shares Issuable Impairment of Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Credit Facility [Domain] Credit Facility [Domain] Deferred reinsurance gain Disposal Group, Including Discontinued Operation, Deferred Reinsurance Gain Disposal Group, Including Discontinued Operation, Deferred Reinsurance Gain Individual Risk Workers' Compensation Individual Risk Workers Compensation [Member] Represents information about individual risk workers compensation. Reserve for losses and loss adjustment expenses Reserve for losses and loss adjustment expenses gross of reinsurance recoverables on unpaid losses and loss adjustment expenses at end of period Gross reserve for losses and loss adjustment expenses Liability for Claims and Claims Adjustment Expense 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] Goodwill Segment goodwill Goodwill Hurricane Hurricane [Member] Allowance for credit losses Accounts Receivable, Allowance for Credit Loss Largest reinsurer three Credit Risk Reinsurer Three [Member] Represents information about Credit Risk Reinsurer three. Payroll taxes withheld and remitted on net settlement of RSUs Payroll taxes withheld and remitted on net settlement of RSUs Payment, Tax Withholding, Share-Based Payment Arrangement Other comprehensive (loss) income: Other comprehensive (loss) income: Other Comprehensive Income (Loss), Net of Tax [Abstract] Schedule of Reserve for Losses and Loss Adjustment Expenses Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Table Text Block] Options Share-based Payment Arrangement, Option [Member] Share-Based Payment Arrangement, Option [Member] IBNR net of E&S ADC Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Net, Amount Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Net, Amount Debt Securities, Available-for-Sale [Table] Debt Securities, Available-for-Sale [Table] Acquired Intangible Assets [Line Items] Acquired Intangible Assets [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. Statutory Matters [Abstract] Statutory Matters [Abstract] Statutory Matters 2025 Lessee, Operating Lease, Liability, to be Paid, Year One State National State National [Member] State National Other expenses Other expenses Other expenses Other Expenses Total comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Schedule of Summary of Available-for-Sale Investments by Contractual Maturity Investments Classified by Contractual Maturity Date [Table Text Block] Award Type [Axis] Award Type [Axis] Corporate Corporate Debt Securities [Member] Statutory Matters Statutory Matters [Text Block] The entire disclosure represents information regarding insurance statutory matters. Credit Rating, AM Best [Domain] Credit Rating, AM Best [Domain] Basic Earnings Per Share, Basic [Abstract] Liabilities Disposal Group, Including Discontinued Operation, Liabilities [Abstract] Restricted Cash Equivalents Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Ceded Credit Risk [Line Items] Ceded Credit Risk [Line Items] Cash equivalent collateral returned to trust Cash Equivalent Collateral Returned to Trust Cash Equivalent Collateral Returned to Trust Gain for change in estimated loss on sale Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax Amortization of policy acquisition costs SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Amortization of Deferred Policy Acquisition Cost Property and equipment, net Property, Plant and Equipment, Net ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Total liabilities Liabilities Exercisable, end of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Expiration Date Trading Arrangement Expiration Date Liability for catastrophe claims, losses Liability For Catastrophe Claims, Losses Liability For Catastrophe Claims, Losses Underwriting (loss) profit Underwriting (loss) profit Underwriting Profit (Loss) Represents the amount related to underwriting profit (loss) during the period. Ceded Credit Risk, Reinsurer [Axis] Reinsurer, Name [Axis] Residential mortgage-backed Residential Mortgage Backed Fair Value Represents fair value of residential mortgage backed. Total Shareholder Return Amount Total Shareholder Return Amount Effective Income Tax Rate Reconciliation, Amount [Abstract] Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract] Reinsure percentage Reinsurance, Reinsured Risk, Percentage Junior subordinated debt Junior subordinated debt Junior Subordinated Debenture Owed to Unconsolidated Subsidiary Trust 2020 Short-Duration Insurance Contract, Accident Year 2020 [Member] After ten years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Short-term investments Short-term investments Other Short-Term Investments Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Transfers out of Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Percentage of dividend withholding tax Percentage Of Dividend Withholding Tax Represents percentage of dividend withholding tax. Financial Asset, Period Past Due [Domain] Financial Asset, Aging [Domain] Statutory Accounting Practices, Statutory Amount Available for Dividend Payments [Abstract] Statutory Accounting Practices, Statutory Amount Available for Dividend Payments [Abstract] Fixed maturity securities, gross realized gains Debt Securities, Available-for-Sale, Realized Gain Subsequent Event [Line Items] Subsequent Event [Line Items] Reserve for losses and loss adjustment expenses Increase (Decrease) in Liability for Claims and Claims Adjustment Expense Reserve Property and equipment, cost basis Property, Plant and Equipment, Gross Options exercised (in shares) Exercised (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Debt Instrument [Line Items] Debt Instrument [Line Items] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Weighted- Average Exercise Price Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] James River Group Senior Debt James River Group Senior Debt [Member] James River Group Senior Debt [Member] Other assets Other assets Other Assets Claims outstanding Short-Duration Insurance Contract, Cumulative Number of Reported Claims Basis of Presentation and Principles of Consolidation Basis of Accounting, Policy [Policy Text Block] Diluted (in shares) Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Statutory Accounting Practice, Jurisdiction [Axis] Statutory Accounting Practice, Jurisdiction [Axis] Statutory Accounting Practices [Line Items] Statutory Accounting Practices [Line Items] Write down of JRG Re to fair value less cost to sell Disposal Group, Including Discontinued Operation, Write Down Disposal Group, Including Discontinued Operation, Write Down MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Total shareholders’ equity Balance Balance Equity, Attributable to Parent Total deferred tax assets Deferred Tax Assets, Gross One year or less Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Total revenues Disposal Group, Including Discontinued Operation, Revenue Investing activities Investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Loss on fixed maturity securities Debt Securities, Available-for-Sale, Gain (Loss) Investment Income Investment Income, Net Amount of letters of credit issued Letters of Credit Outstanding, Amount Expense associated with Savings Plans Defined Contribution Plan, Cost Total principal balance received Proceeds from Sale and Maturity of Other Investments SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Line Items] Maximum number of shares available for issuance (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Sale of Stock [Domain] Sale of Stock [Domain] Dividends on Series A preferred shares Less: Dividends on Series A preferred shares Temporary Equity, Dividends, Adjustment Reinsure excess amount Reinsure Excess Amount Reinsure Excess Amount Document Fiscal Period Focus Document Fiscal Period Focus Year 6 Short-Duration Insurance Contracts, Historical Claims Duration, Year Six All Executive Categories All Executive Categories [Member] Schedule of Average Annual Percentage Payouts of Incurred Claims by Age, Net of Reinsurance Short-Duration Insurance Contracts, Schedule of Historical Claims Duration [Table Text Block] Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Table] Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Table] Equity securities Equity Securities [Member] 2026 Finite-Lived Intangible Asset, Expected Amortization, Year Two Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Assets Assets Assets [Abstract] Equity in other comprehensive (losses) earnings of subsidiaries Other Comprehensive Income (Loss), Net of Tax Net investment income Disposal Group, Including Discontinued Operation, Net Investment Income Disposal Group, Including Discontinued Operation, Net Investment Income Document Type Document Type Schedule of Summary of Company's Segment Results Schedule of Segment Reporting Information, by Segment [Table Text Block] Contingent Liabilities [Line Items] Contingent Liabilities [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. Carrying amount of Junior Subordinated Debt net of repurchases Junior Subordinated Notes Small Business Small Business [Member] Name of underwriting division. Number of agencies Number of Agencies Number of Agencies Downward adjustment Disposal Group, Including Discontinued Operation, Consideration Downward Adjustment Disposal Group, Including Discontinued Operation, Consideration Downward Adjustment Largest reinsurer two Credit Risk Reinsurer Two [Member] Represents information about Credit Risk Reinsurer two. Other Income and Expenses [Abstract] Reserve for losses and loss adjustment expenses net of reinsurance recoverables at beginning of period Reserve for losses and loss adjustment expenses net of reinsurance recoverables at end of period Net reserve for losses and loss adjustment expenses Liability for Unpaid Claims and Claims Adjustment Expense, Net Fixed maturity securities, available-for-sale, at amortized cost Cost or Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost Net cash provided by (used in) discontinued operations Net Cash Provided by (Used in) Discontinued Operations Funds held Disposal Group, Including Discontinued Operation, Funds Held under Reinsurance Agreements, Liability Disposal Group, Including Discontinued Operation, Funds Held under Reinsurance Agreements, Liability Income tax expense recognized over next six years Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense Provision for depreciation and amortization Depreciation, Amortization and Accretion, Net Schedule of Future Estimated Amortization Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Year 4 Short-Duration Insurance Contracts, Historical Claims Duration, Year Four Subsequent Event [Table] Subsequent Event [Table] Parent Company Parent Company [Member] Bank loan participations Net (losses) gains in bank loan participations Bank Loan Participations, Net Gain (Loss) Bank Loan Participations, Net Gain (Loss) Maximum Maximum [Member] Fixed maturity securities: Debt Securities, Available-for-Sale [Abstract] Preferred Shares – 2024 and 2023: $0.00125 par value; 19,835,000 shares authorized; no shares issued and outstanding Preferred Stock, Value, Outstanding Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Accumulated goodwill impairment losses Goodwill, Impaired, Accumulated Impairment Loss Furniture and equipment Furniture and Fixtures [Member] Total Finite-Lived Intangible Assets, Net Schedule of Reconciliation of Beginning and Ending Reserve Balances for Losses and Loss Adjustment Expenses Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Investment Type [Axis] Investment Type [Axis] Deferred Policy Acquisition Costs Deferred Policy Acquisition Costs [Text Block] Reinsurance Reinsurance [Text Block] LPT Trust And Loss Fund Trust LPT Trust And Loss Fund Trust [Member] LPT Trust And Loss Fund Trust Commercial Auto LPT Commercial Auto Business [Member] Commercial Auto Business Franklin Holdings II (Bermuda) Capital Trust I Franklin Holdings Ii Bermuda Capital Trust I [Member] Represents information about Franklin Holdings II Bermuda Capital Trust I. Accrued investment income Accrued Investment Income Receivable Statistical Measurement [Axis] Statistical Measurement [Axis] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] (Loss) income from continuing operations before income taxes Reduction in pre-tax income Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Associated Trust Agreement [Domain] Associated Trust Agreement [Domain] Associated Trust Agreement [Domain] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Deferred Policy Acquisition Costs Deferred Policy Acquisition Costs, Policy [Policy Text Block] Provision to return and amended tax returns Effective Income Tax Rate Reconciliation, Provision to Return And Amended Tax Returns, Amount Effective Income Tax Rate Reconciliation, Provision to Return And Amended Tax Returns, Amount Name Outstanding Recovery, Individual Name Allied Health Allied Health [Member] Name of underwriting division. Schedule of Disposal Groups, JRG Re's Assets and Liabilities and Operating Results Disposal Groups, Including Discontinued Operations [Table Text Block] Goodwill impairment Goodwill, Impairment Loss Stock Options, Restricted Stock Units and Convertible Preferred Stock Stock Options, Restricted Stock Units And Convertible Preferred Stock [Member] Stock options and share instrument which is convertible to stock or an equivalent amount of cash, after a specified period of time or when specified performance conditions are met. Series A redeemable preferred shares, authorized (in shares) Temporary Equity, Shares Authorized Title and Position [Axis] Title and Position [Axis] Deduct: Loss and loss adjustment expense payments net of reinsurance: Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract] Losses and loss adjustment expenses Disposal Group, Including Discontinued Operation, Losses And Loss Adjustment Expenses Disposal Group, Including Discontinued Operation, Losses And Loss Adjustment Expenses Number of insurance companies Number Of Insurance Companies This element represents number of insurance companies owned by the entity. Award Timing Predetermined Award Timing Predetermined [Flag] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Cash dividend declared (in dollars per share) Common Stock, Dividend Per Share, Cash Payments, Threshold Common Stock, Dividend Per Share, Cash Payments, Threshold Assumed Assumed Premiums Earned Dividends on common shares Payments of Ordinary Dividends, Common Stock Percentage of then-applicable conversion price threshold Preferred Stock, Convertible, Mandatory Conversion, Percentage Preferred Stock, Convertible, Mandatory Conversion, Percentage Investment, Name [Axis] Investment, Name [Axis] Limited partnerships Partnership Interest [Member] Debt redemption percentage Debt Instrument, Redemption Price, Percentage Diluted (in dollars per share) Earnings Per Share, Diluted Payout for achievement, maximum Share-Based Compensation Arrangement by Share-Based Payment Award, Payout For Achievement, Maximum Share-Based Compensation Arrangement by Share-Based Payment Award, Payout For Achievement, Maximum Counterparty Name [Domain] Counterparty Name [Domain] U.S. income (loss) before Federal income taxes Income (Loss) from Continuing Operations before Income Taxes, Domestic Current Current Income Tax Expense (Benefit) Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Deduct: Change in deferred reinsurance gain - retroactive reinsurance Increase (Decrease) In Deferred Reinsurance Gain Increase (Decrease) In Deferred Reinsurance Gain Subordinated Borrowings [Abstract] Subordinated Borrowings [Abstract] Retirement Benefits [Abstract] Retirement Benefits [Abstract] Deferred policy acquisition costs Disposal Group, Including Discontinued Operation, Deferred Policy Acquisition Costs Disposal Group, Including Discontinued Operation, Deferred Policy Acquisition Costs Accrued expenses Disposal Group, Including Discontinued Operation, Accrued Liabilities Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued External Credit Rating, Standard & Poor's [Domain] External Credit Rating, Standard & Poor's [Domain] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Total gains or losses (realized/unrealized) - Included in earnings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Reserve for Losses and Loss Adjustment Expenses Liability Reserve Estimate, Policy [Policy Text Block] Other Deferred Tax Liabilities, Other Total fair value of shares vested Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Total income tax expense (benefit) Income Tax Expense (Benefit) Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Senior debt repayments Repayments of Senior Debt Excluding Commercial Auto Excluding Commercial Auto [Member] Excluding Commercial Auto [Member] Equity Awards Shareholders' Equity and Share-Based Payments [Text Block] Weighted-average period of unrecognized share based compensation expense (in years) Weighted-average period of unrecognized share based compensation expense Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Net cash provided by (used in) investing activities Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Interest expense Interest expense Interest expense Interest Expense, Operating and Nonoperating Written premiums: Premiums Written, Net [Abstract] Share based compensation, additional shares authorized (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized Business Acquisition [Line Items] Business Acquisition [Line Items] Deemed dividend Issuance of Common Shares, Deemed Dividend Issuance of Common Shares, Deemed Dividend Trust common stock Trust Common Stock Represents trust common stock. All Adjustments to Compensation All Adjustments to Compensation [Member] Deferred interest payment period (in years) Debt Instrument, Deferred Interest Option, Maximum Term Debt Instrument, Deferred Interest Option, Maximum Term Additional paid-in capital Additional paid-in capital Additional Paid in Capital Rasier And Aleka Rasier And Aleka [Member] Rasier And Aleka Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Legal Entity [Axis] Legal Entity [Axis] Disposal Group, Disposed of by Sale, Not Discontinued Operations Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Sales Proceeds From Bank Loan Participations Represents cash inflow from sales of bank loan participations. Dividends from subsidiaries SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries Unearned premiums Increase (Decrease) in Unearned Premiums Losses and loss adjustment expenses excluding retroactive reinsurance Prior Year Claims and Claims Adjustment Expense, Excluding Retroactive Reinsurance Prior Year Claims and Claims Adjustment Expense, Excluding Retroactive Reinsurance Common Shares – 2024 and 2023: $0.0002 par value; 200,000,000 shares authorized; 45,644,318 and 37,641,563 shares issued and outstanding, respectively Common Stock, Value, Outstanding SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Table] SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Table] Interest expense Disposal Group, Including Discontinued Operation, Interest Expense Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Private Specialty Credit Private Specialty Credit [Member] Private Specialty Credit Voting equity percentage Preferred Stock, Convertible, Voting Equity, Maximum Preferred Stock, Convertible, Voting Equity, Maximum Segment assets Assets Excluding Assets Held For Sale Assets Excluding Assets Held For Sale James River Group, Inc. James River Group Inc [Member] Represents information regarding James River Group, Inc. Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Estimated transaction value Disposal Group, Including Discontinued Operation, Consideration Cost or Amortized Cost SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties, Cost Commissions Deferred Policy Acquisition Cost, Capitalization Percentage of prepaid reinsurance premiums ceded for 3 largest reinsurers Prepaid Reinsurance Premiums Ceded Percentage Of Total Balance Represents prepaid reinsurance premiums ceded as percentage of total balance. Financial Instruments [Domain] Financial Instruments [Domain] Sports and Entertainment Sports And Entertainment [Member] Name of underwriting division. Unvested, beginning of year (in dollars per share) Unvested, end of year (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 Liabilities and shareholders’ equity Liabilities and shareholders’ equity Liabilities and Equity [Abstract] Restatement Determination Date Restatement Determination Date Allowance for credit losses Deferred Tax Asset, Tax Deferred Expense, Reserve and Accrual, Accounts Receivable, Allowance for Credit Loss Fair Value Estimate of Fair Value Measurement [Member] Additions Amounts Charged to Expense SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense Net investment income Net investment income Net investment income Net Investment Income Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Other Operating Expenses SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Other Operating Expense SCHEDULE II - Condensed Financial Information of Registrant Condensed Financial Information of Parent Company Only Disclosure [Text Block] Gross written premiums Disposal Group, Including Discontinued Operation, Gross Written Premiums Disposal Group, Including Discontinued Operation, Gross Written Premiums Schedule of Summary of Available-for-Sale Investments Schedule of Available-for-Sale Securities Reconciliation [Table Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Other invested assets: Other Investments [Abstract] Beginning of period (in dollars per share) End of period (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Right-of-use assets Operating Lease, Right-of-Use Asset Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Indemnity Trust Indemnity Trust [Member] Indemnity Trust Excise taxes paid Federal Excise Taxes Paid, Third Party Assumed Written Premiums Represents excise taxes paid on written premiums assumed from third-party insurers with respect to risks located in the U.S. Options outstanding (in shares) Beginning of period (in shares) End of period (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Condensed Financial Information Disclosure [Abstract] Condensed Financial Information Disclosure [Abstract] Reinsurance Disclosures [Abstract] Reinsurance Disclosures [Abstract] Maturities Proceeds From Maturities From Bank Loan Participations Represents cash inflow from maturities of bank loan participations. Rasier Rasier [Member] Rasier Percentage of dividend distribution tax Percentage Of Dividend Distribution Tax Represents percentage of dividend distribution tax. Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Abstract] Temporary Equity, by Class of Stock [Table] Temporary Equity, by Class of Stock [Table] Subsequent Event Subsequent Event [Member] Dividends on Series A preferred shares Dividends on Series A preferred shares Dividends, Preferred Stock 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 Net realized and unrealized gains (losses) on investments Total Net realized and unrealized gains (losses) on investments Gain (Loss) on Investments Subsegments [Domain] Subsegments [Domain] Income Taxes Income Tax, Policy [Policy Text Block] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Other income Other income Other Income Segments [Domain] Segments [Domain] Contingent Liabilities [Table] Contingent Liabilities [Table] Discloses information about contingent liabilities. Standard & Poor's, Below BBB- Rating Standard & Poor's, Below BBB- Rating [Member] Standard & Poor's, Below BBB- Rating [Member] Schedule of Junior Subordinated Debt Schedule of Subordinated Borrowing [Table Text Block] Discontinued operations (in dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share PEO PEO [Member] Premiums receivable and agents’ balances Increase (Decrease) in Premiums Receivable Name Trading Arrangement, Individual Name Premiums receivable and agents’ balances, net Premiums and Other Receivables, Net Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Entity Public Float Entity Public Float Disposal Group Name [Axis] Disposal Group Name [Axis] Income from equity method investments Investment Income Equity in net (loss) income of subsidiaries Income (Loss) from Equity Method Investments 2023 Short-Duration Insurance Contract, Accident Year 2023 [Member] 2014 Non-Employee Director Incentive Plan Non Employee Director Incentive Plan 2014 [Member] Represents information regarding 2014 Non Employee Director Incentive Plan. Reinsurance recoverable on unpaid and paid losses, net Disposal Group, Including Discontinued Operation, Reinsurance Recoverable for Unpaid Claims and Claims Adjustments Disposal Group, Including Discontinued Operation, Reinsurance Recoverable for Unpaid Claims and Claims Adjustments Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] AM Best, Below A- Rating AM Best, Below A- Rating [Member] AM Best, Below A- Rating Direct Written Premiums Revenue Recognition, Premiums Earned, Policy [Policy Text Block] Dividends payable Dividends Payable Common shares reserved for future issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract] 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] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Changes in fair values of bank loan participations Bank Loan Participations, Changes in Fair Value Bank Loan Participations, Changes in Fair Value Transition provision expense Tax Cuts and Jobs Act, Change in Tax Rate, Income Tax Expense (Benefit) Tax Cuts and Jobs Act, Change in Tax Rate, Income Tax Expense (Benefit) Summary of Investments - Other than Investments in Related Parties SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Text Block] Local Phone Number Local Phone Number Total intangible assets, gross Intangible Assets, Gross (Excluding Goodwill) Deferred tax assets, valuation allowance Deferred Tax Assets, Valuation Allowance Dividend Restrictions Dividend Payment Restrictions [Text Block] Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Rate of interest Investment Interest Rate Schedule of Gross Written Premiums by Segment and Underwriting Division Reconciliation of Revenue from Segments to Consolidated [Table Text Block] Deferred reinsurance gain Deferred retroactive reinsurance gain at beginning of period Deferred retroactive reinsurance gain at end of period Deferred Reinsurance Gain Deferred Reinsurance Gain Dividend distributions to intermediate holding company Dividend Distributions To Intermediate Holding Company Represents dividend distributions to intermediate holding company. Change in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Preferred stock convertible voluntary percentage Preferred Stock, Convertible, Voluntary Conversion, Percentage Preferred Stock, Convertible, Voluntary Conversion, Percentage Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward] Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward] Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Increase to deferred tax asset for additional discount Tax Cuts and Jobs Act, Incomplete Accounting, Change in Tax Rate, Deferred Tax Asset, Provisional Income Tax Expense1 Tax Cuts and Jobs Act, Incomplete Accounting, Change in Tax Rate, Deferred Tax Asset, Provisional Income Tax Expense1 2021 Short-Duration Insurance Contract, Accident Year 2021 [Member] PEO Total Compensation Amount PEO Total Compensation Amount Net commissions Insurance Commissions Equity securities, at cost Equity Securities, FV-NI, Cost James River Capital Trust IV James River Capital Trust Iv [Member] Represents information about James River Capital Trust IV. Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Assumed Policyholder Benefits and Claims Incurred, Assumed Supplementary Insurance Information SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Disclosure [Text Block] Accounting Policies [Table] Accounting Policies [Table] Schedule detailing information related to accounting policies. Broker two Broker Two [Member] Name of party. Debt Disclosure [Abstract] Debt Disclosure [Abstract] Amount at which shown on Balance Sheet SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties, Amount Common Shares Common stock Common Stock [Member] Net realized and unrealized losses on investments Gain (Loss) On Investments Including Discontinued Operations Gain (Loss) On Investments Including Discontinued Operations Year 8 Short-Duration Insurance Contracts, Historical Claims Duration, Year Eight Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] PRSU performance adjustment (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Adjustment Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Adjustment Schedule of Premiums Written, Premiums Earned, and Losses and Loss Adjustment Expenses Effects of Reinsurance [Table Text Block] LPT Trust LPT Trust [Member] LPT Trust Earned premiums: Premiums Earned, Net [Abstract] Retroactive reinsurance benefits under the recovery method Retroactive Reinsurance Benefit Recognized Retroactive Reinsurance Benefit Recognized Profit commission amount Profit Commission Maximum Amount Profit Commission Maximum Amount Segment Reporting [Abstract] Segment Reporting [Abstract] Intangible Assets, Net Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Entity Central Index Key Entity Central Index Key Claims Development [Line Items] Claims Development [Line Items] Total incurred losses and loss and adjustment expenses Incurred Losses and Loss Adj Expenses Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims Schedule of Statutory Accounting Statutory Accounting Practices Disclosure [Table Text Block] Discontinued Operations and Disposal Groups [Abstract] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Ceded Credit Risk, Reinsurer [Domain] Reinsurer, Name [Domain] Funds held Funds Held under Reinsurance Agreements, Liability Shareholders' Equity Equity [Text Block] Catastrophic Event [Domain] Catastrophic Event [Domain] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Financial Instrument [Axis] Financial Instrument [Axis] Segment Information Segment Reporting Disclosure [Text Block] Revenues: Disposal Group, Including Discontinued Operation, Revenue [Abstract] Disposal Group, Including Discontinued Operation, Revenue Reinsurance, amount remaining Reinsurance, Aggregate Coverage Limit, Amount Remaining Reinsurance, Aggregate Coverage Limit, Amount Remaining Deferred tax liability Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Liability, Income Tax Benefit Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Liability, Income Tax Benefit Compensation expense under share incentive plans APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Measurement Basis [Axis] Measurement Basis [Axis] Year 3 Short-Duration Insurance Contracts, Historical Claims Duration, Year Three Restricted cash equivalents Restricted cash equivalents at beginning of year Restricted cash equivalents at end of year Restricted Cash Equivalents Title Trading Arrangement, Individual Title Consolidated Entities [Axis] Consolidated Entities [Axis] Unsecured Unsecured Debt [Member] Reserve for future tax contingencies Unrecognized Tax Benefits Variable Interest Entities Consolidation, Variable Interest Entity, Policy [Policy Text Block] City Area Code City Area Code Auditor Location Auditor Location Residential mortgage-backed Residential Mortgage Backed Amortized Cost Represents Amortized Cost of Residential mortgage-backed securities. Disposal Group Classification [Domain] Disposal Group Classification [Domain] Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Reinsurance, aggregate coverage limit Reinsurance, Aggregate Coverage Limit Reinsurance, Aggregate Coverage Limit Other Invested Assets Other Invested Assets [Policy Text Block] Represents disclosure of accounting policy for other invested assets composition and accounting. Preferred Shares Preferred stock Preferred Stock [Member] Schedule of Major Categories of the Company' s Net Investment Income Investment Income [Table Text Block] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] 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] Other income Disposal Group, Including Discontinued Operation, Other Income Subsequent Event Type [Axis] Subsequent Event Type [Axis] Investments Investment [Text Block] Net (loss) income per common share: Earnings Per Share [Abstract] Available-for-sale fixed maturity securities and equity securities Securities (Assets) [Member] Commitment to invest in notes receivable Commitment To Invest In Notes Receivable Commitment To Invest In Notes Receivable Fair Value Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract] Retained deficit Retained deficit Retained Earnings (Accumulated Deficit) Class of Stock [Domain] Class of Stock [Domain] Fixed maturity securities, at fair value Disposal Group, Including Discontinued Operation, Debt Securities, Available-For-Sale Disposal Group, Including Discontinued Operation, Debt Securities, Available-For-Sale Premiums Receivable and Agents' Balances, Net Premiums Receivable, Basis of Accounting, Policy [Policy Text Block] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Changes in fair values of equity securities Equity Securities, FV-NI, Unrealized Gain (Loss) Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Equity Awards Adjustments Equity Awards Adjustments [Member] Lease liabilities Total operating lease liabilities Operating Lease, Liability Number of underlying projects sold Number of Underlying Projects Sold Number of Underlying Projects Sold Underlying Securities Award Underlying Securities Amount Bank loan participations, gross realized losses Bank Loan Participations, Gross Realized Loss Represents the gross realized losses on bank loan participations. Preferred stock, floor conversion price (in dollars per share) Preferred Stock, Convertible, Floor Conversion Price Preferred Stock, Convertible, Floor Conversion Price Total Amount Dividends, Common Stock, Cash Notes Receivable Two Notes Receivable Two [Member] Notes Receivable Two Amendment Flag Amendment Flag Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items] Carrying Value Reported Value Measurement [Member] Short-duration Insurance Contracts, Historical Claims Duration [Table] Short-Duration Insurance Contracts, Historical Claims Duration [Table] Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Losses and loss adjustment expenses: Policyholder Benefits and Claims Incurred, Net [Abstract] Subsequent Events [Abstract] Subsequent Events [Abstract] Excess and Surplus Lines Excess and Surplus Lines Excess and Surplus Lines Written Premiums Excess And Surplus Lines [Member] Represents information regarding excess and surplus lines segment. SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Abstract] SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Abstract] Sales Proceeds from Sale of Equity Securities, FV-NI Number of shares issued during period (in shares) Number of common shares issued during period (in shares) Sale of Stock, Number of Shares Issued in Transaction One year or less Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Senior Debt Debt Disclosure [Text Block] Condensed Income Statement [Table] Condensed Income Statement [Table] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Environmental Environmental [Member] Name of underwriting division. Percentage of available for sale securities Percentage Of Available For Sale Debt Securities Represents percentage of available for sale debt securities. Schedule of Gross Carrying Amounts for Indefinite-Lived Intangible Assets Schedule of Indefinite-Lived Intangible Assets [Table Text Block] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Principal amount of Junior Subordinated Debt Debt Instrument, Face Amount Percentage of excise tax on reinsurance premiums paid Excise Tax On Reinsurance Premiums Paid Represents excise tax on reinsurance premiums paid. Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Loss Fund Trust Loss Fund Trust [Member] Loss Fund Trust Entity Address, Postal Zip Code Entity Address, Postal Zip Code Supplementary Information Concerning Property Casualty Insurance Operations SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Text Block] Dividend payable, record date Dividends Payable, Date of Record Payable to insurance companies Increase (Decrease) in Reinsurance Payables Net earned premiums SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Earned Premium Outstanding commitments to invest Commitment to Investment In Limited Partnership Represents commitment to investment in a limited partnership. Discontinued operations (in dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share Cash and cash equivalents Cash and cash equivalents Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Cash and Cash Equivalents, at Carrying Value Lapsed (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Lapsed in Period, Weighted Average Exercise Price Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Lapsed in Period, Weighted Average Exercise Price Impairment of intangible assets Impairment of intangible assets Impairment of Intangible Assets, Indefinite-Lived (Excluding Goodwill) 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] Auditor Name Auditor Name Amortization of Policy Acquisition Costs SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Amortization of Deferred Policy Acquisition Cost 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 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] Property and equipment, estimated useful lives (in years) Property, Plant and Equipment, Useful Life Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding [Roll Forward] Accrued expenses Accrued expenses Accrued Liabilities Fair Value Measurement [Domain] Fair Value Measurement [Domain] Commercial mortgage and asset-backed Commercial Mortgage And Asset Backed Fair Value Represents fair value of commercial mortgage and asset backed. Other underwriting expenses of the insurance segments Other Underwriting Expense Reserve for Losses and Loss Adjustment Expenses SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Liability for Future Policy Benefit, Loss, Claim and Loss Expense Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Unearned premiums Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Unearned Premiums Reserve Management Liability Management Liability [Member] Management Liability SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract] Net (loss) income available to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Agency two Agency Two [Member] Agency Two [Member] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] 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] 2024 Short-Duration Insurance Contract, Accident Year 2024 [Member] Total assets Segment assets Assets Number of trading days immediately preceding Mandatory Conversion Preferred Stock, Dividend, Trading Days Preferred Stock, Dividend, Trading Days Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Due to subsidiaries Other Liabilities, Noncurrent Cumulative paid losses and loss adjustment expenses, net of reinsurance Short-Duration Insurance Contracts, Cumulative Paid Claims and Allocated Claim Adjustment Expense, Net Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Statutory Accounting Practice, Jurisdiction [Domain] Statutory Accounting Practice, Jurisdiction [Domain] Commitments and contingent liabilities Commitments and contingent liabilities Commitments and Contingencies Net written premiums Disposal Group, Including Discontinued Operation, Premiums Written, Net Disposal Group, Including Discontinued Operation, Premiums Written, Net Share Based Compensation Share-Based Payment Arrangement [Policy Text Block] Statutory capital and surplus Statutory Accounting Practices, Statutory Capital and Surplus, Balance Reclassification adjustment for investment (losses) gains realized in net income Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Schedule of Reconciliation of the Difference Between Federal Income Tax Provision (Benefit) and Expected Tax Provision (Benefit) Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Termination Date Trading Arrangement Termination Date Related Party Transaction [Table] Related Party Transaction [Table] 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] 2026 Lessee, Operating Lease, Liability, to be Paid, Year Two Other liabilities Other liabilities Other Liabilities After one year through five years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Proceeds from sales and repayments Proceeds From Sale and Repayments Of Other Invested Assets Proceeds From Sale and Repayments Of Other Invested Assets Extinguishment of Series A Preferred Shares - deemed dividend (Note 12) Deemed dividend Extinguishment Of Preferred Stock, Deemed Dividend Extinguishment Of Preferred Stock, Deemed Dividend Common stock, covenant, threshold, cash paid (in dollars per share) Common Stock, Covenant Threshold, Per Share Common Stock, Covenant Threshold, Per Share Payables to reinsurers Reinsurance Payable Net (loss) income Net income (loss) Net (loss) income Net Income (Loss) Attributable to Parent Trading Arrangement: Trading Arrangement [Axis] Schedule of Carrying Value and Fair Value Fair Value, by Balance Sheet Grouping [Table Text Block] IBNR before E&S ADC Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Claims, Amount Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Line of credit current capacity Line of Credit Facility, Current Borrowing Capacity Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] After ten years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Other operating expenses of the Corporate and Other segment  Other operating expenses of the Corporate and Other segment Other Operating Expenses Of Corporate And Other Segment Represents Other operating expenses of the Corporate and Other segment. Total expenses Benefits, Losses and Expenses Entity File Number Entity File Number Schedule of Summary of Realized Gains and Losses Realized Gain (Loss) on Investments [Table Text Block] Consolidated Entities [Domain] Consolidated Entities [Domain] Income Statement [Abstract] Income Statement [Abstract] Entity Address, Address Line One Entity Address, Address Line One Weighted average common shares outstanding: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Entity Address, Address Line Three Entity Address, Address Line Three James River Capital Trust II James River Capital Trust II [Member] Represents information about James River Capital Trust II. Entity Address, Address Line Two Entity Address, Address Line Two Dividends on common shares Dividends, Common Stock Weighted-average common shares outstanding: Weighted Average Number of Shares Outstanding, Basic [Abstract] Name Forgone Recovery, Individual Name Weighted average remaining lease term Operating Lease, Weighted Average Remaining Lease Term Excess §162(m) compensation Effective Income Tax Rate Reconciliation, Excess 162(m) Compensation, Amount Effective Income Tax Rate Reconciliation, Excess 162(m) Compensation, Amount Number of equity securities held Number Of Equity Securities Held Number Of Equity Securities Held Investments on deposit with state insurance departments Fair Value of Investments on Deposits with State Insurance Departments Fair Value of Investments on Deposits with State Insurance Departments Short-Term Investments Investment, Policy [Policy Text Block] Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Deferred tax liabilities: Components of Deferred Tax Liabilities [Abstract] Line of credit maximum capacity, accordion feature Line of Credit Facility, Maximum Borrowing Capacity, Accordion Feature Line of Credit Facility, Maximum Borrowing Capacity, Accordion Feature Equity securities, gross realized gains Equity Securities, FV-NI, Realized Gain Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Bank Loan Participations Fair Value, Option, Loans Held as Assets, Aggregate Fair Value, Policy [Policy Text Block] Fair Value, Option, Loans Held as Assets, Aggregate Fair Value, Policy Year 2 Short-Duration Insurance Contracts, Historical Claims Duration, Year Two Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Discontinued Operations, Disposed of by Sale Discontinued Operations, Disposed of by Sale [Member] Change in restricted cash equivalents Increase (Decrease) In Restricted Cash Equivalents Increase (Decrease) In Restricted Cash Equivalents Continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Dividends payable, date to be paid Dividends Payable, Date to be Paid Broker incentive income Broker Incentive Income Broker Incentive Income 2018 Short-Duration Insurance Contracts, Accident Year 2018 [Member] Adjustment to Compensation: Adjustment to Compensation [Axis] Investment in variable interest entities Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Liabilities Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Medical Professionals Medical Professionals [Member] Name of underwriting division. Equity method investments Deferred Tax Liabilities, Investment in Noncontrolled Affiliates After one year through five years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five Payout for achievement, threshold Share-Based Compensation Arrangement by Share-Based Payment Award, Payout For Achievement, Threshold Share-Based Compensation Arrangement by Share-Based Payment Award, Payout For Achievement, Threshold Accumulated other comprehensive loss Accumulated other comprehensive (loss) income Accumulated Other Comprehensive Income (Loss), Net of Tax Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Reserve for losses and loss adjustment expenses Disposal Group, Including Discontinued Operation, Reserve For Losses And Loss Adjustment Expenses Disposal Group, Including Discontinued Operation, Reserve For Losses And Loss Adjustment Expenses Related Party [Axis] Related and Nonrelated Parties [Axis] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] U.S. income taxes OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, Tax Fixed maturity securities, 12 months or more, gross unrealized losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Amortization of discount Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Amortization of Discount Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Amortization of Discount Fixed maturity securities Debt Securities, Available-for-Sale, Realized Gain (Loss) Name Awards Close in Time to MNPI Disclosures, Individual Name Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Fixed maturity securities, less than 12 months, gross unrealized losses Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Policy acquisition costs deferred: Deferred Costs [Abstract] Entity Filer Category Entity Filer Category Cash Flows from Discontinued Operations Net Cash Provided by (Used in) Discontinued Operations [Abstract] Fee income Fee income Fee Income Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] Private Placement Private Placement [Member] Proceeds from unsecured revolver Proceeds from Long-Term Lines of Credit Corporate and Other Corporate and Other Corporate Segment and Other Operating Segment [Member] Short-term investments and other, gross realized gains Short Term Investments And Other Gross Realized Gains Represents the gross profit realized on the sale of short term investment and other. Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] Statistical Measurement [Domain] Statistical Measurement [Domain] Number of brokers Number of Brokers Number of Brokers Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Fixed maturity securities Fixed maturity securities Debt Securities [Member] Short-term investments and other, gross realized losses Short Term Investments And Other Gross Realized Losses Represents the gross loss realized on the sale of short term investment and other. Equity securities, gross realized losses Equity Securities, FV-NI, Realized Loss Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] BBB- or better Standard & Poor's, BBB- or Better Rating [Member] Standard & Poor's, BBB- or Better Rating All Trading Arrangements All Trading Arrangements [Member] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Commercial Auto Commercial Auto [Member] Commercial Auto [Member] Schedule of Reconciliation of Numerator and Denominator of Basic and Diluted (Loss) Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Vesting period (in years) Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period 2017 Short-Duration Insurance Contracts, Accident Year 2017 [Member] 2022 Short-Duration Insurance Contract, Accident Year 2022 [Member] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Assets Disposal Group, Including Discontinued Operation, Assets [Abstract] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] U.S. federal income taxes paid (refunded), net Income Taxes Paid, Net Number of underwriting divisions Number Of Underwriting Divisions Represents number of underwriting divisions. Conversion of Series A Preferred Shares to common shares (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Investment in subsidiaries Equity Method Investments Pay vs Performance Disclosure [Line Items] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Residential mortgage-backed Residential Mortgage-Backed Securities [Member] Allowance for Credit Losses on Reinsurance Balances SEC Schedule, 12-09, Allowance, Reinsurance Recoverable [Member] Specialty Admitted Insurance Specialty Admitted Specialty Admitted Written Premiums Specialty Admitted Insurance [Member] Represents information regarding specialty admitted insurance. Other Increase (Decrease) in Other Operating Assets and Liabilities, Net Issuance of Series A preferred shares (Note 12) Issuance of Series A preferred shares Proceeds from Issuance of Preferred Stock and Preference Stock Other Performance Measure, Amount Other Performance Measure, Amount 2027 Finite-Lived Intangible Asset, Expected Amortization, Year Three Schedule of Summary of RSU Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Available-for-sale securities, change in gross unrealized losses OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, before Tax Leases Lessee, Operating Leases [Text Block] Common stock, shares outstanding (in shares) Balance (in shares) Balance (in shares) Common Stock, Shares, Outstanding Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Operating costs under lease Operating Lease, Cost Number of shares available for grant (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant Fixed maturity securities, gross realized losses Debt Securities, Available-for-Sale, Realized Loss Federal income tax expense (benefit) Federal Income Tax Expense (Benefit), Continuing Operations Convertible preferred stock, shares issued upon conversion Convertible Preferred Stock, Shares Issued upon Conversion Entity Tax Identification Number Entity Tax Identification Number Impairment loss Equity Method Investment, Other-than-Temporary Impairment Cumulative amounts ceded under loss portfolio transfer Cumulative Amounts Ceded Under Loss Portfolio Transfer Cumulative Amounts Ceded Under Loss Portfolio Transfer Deferred policy acquisition costs Balance at beginning of period Balance at end of period Deferred Policy Acquisition Cost Sale of stock, consideration received on transaction Sale of Stock, Consideration Received on Transaction Deferred tax assets: Deferred Tax Assets, Net [Abstract] James River Capital Trust I James River Capital Trust I [Member] Represents information about James River Capital Trust I. Net (loss) income per common share: Earnings Per Share Reconciliation [Abstract] Other operating expenses Total Other operating expenses Other Cost and Expense, Operating Plan Name [Axis] Plan Name [Axis] Equity Components [Axis] Equity Components [Axis] Income taxes receivable Income Taxes Receivable Junior Subordinated Debt [Axis] Junior Subordinated Debt [Axis] Represents information by junior subordinated debt types. Indemnity Trust And Loss Fund Trust Indemnity Trust And Loss Fund Trust [Member] Indemnity Trust And Loss Fund Trust Fixed maturity securities, available-for-sale, at fair value (amortized cost: 2024 – $1,278,337; 2023 – $1,405,136) Fair Value Total, Fair Value Fixed maturity securities, available-for-sale Debt Securities, Available-for-Sale Net cash provided by investing activities of discontinued operations Cash Provided by (Used in) Investing Activities, Discontinued Operations Beginning balance Ending balance Asset value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Lapsed (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Lapsed in Period Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Lapsed in Period Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Aggregate intrinsic value of options outstanding Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value Direct Direct Premiums Earned Investments [Domain] Investments [Domain] Diluted Earnings Per Share, Diluted [Abstract] Loss on disposal of discontinued operations Loss on disposal Loss on disposal of discontinued operations Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax Geographical [Axis] Geographical [Axis] Pre close dividend Selling Agreement, Pre Close Dividend Selling Agreement, Pre Close Dividend Maturities and calls Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Private Debt Private Debt [Member] Private Debt Net deferred tax assets Deferred Tax Assets, Net 2029 Lessee, Operating Lease, Liability, to be Paid, Year Five Deferred policy acquisition costs Deferred Policy Acquisition Cost1 Represents costs related to successful acquisition of insurance that are deferred. Reinsurance balances Increase (Decrease) in Reinsurance Recoverable 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] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Employee Benefits Compensation and Employee Benefit Plans [Text Block] Prior years Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years Operating lease costs Operating Lease, Expense Loss before equity in net (loss) income of subsidiaries Income (Loss) From Continuing Operations Before Equity In Net Earnings Of Subsidiaries Income (Loss) From Continuing Operations Before Equity In Net Earnings Of Subsidiaries Other Operating Expenses and Other Expenses Other Operating Income and Expense [Text Block] Fixed maturity securities, fair value Total fair value Debt Securities, Available-for-Sale, Unrealized Loss Position Cash, cash equivalents, and restricted cash equivalents at beginning of year Cash, cash equivalents, and restricted cash equivalents at end of year Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Equity securities Equity Securities, FV-NI, Current Unrecognized share based compensation expense Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Consolidation Items [Axis] Consolidation Items [Axis] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-Lived Intangible Assets, Major Class Name [Domain] Impairment loss Debt Securities, Available-for-Sale, Impairment Loss Debt Securities, Available-for-Sale, Impairment Loss Net (loss) income from continuing operations Net (loss) income from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Broker one Broker One [Member] Name of party. Junior Subordinated Debt Subordinated Borrowings Disclosure [Text Block] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Product and Service [Domain] Product and Service [Domain] Allowance for Credit Losses on Premiums Receivable and Agents' Balances SEC Schedule, 12-09, Allowance, Credit Loss [Member] Maximum amount of dividends available without regulatory approval Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval 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 Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Development on prior year loss adverse (favorable) reserves Prior years - excluding retroactive reinsurance Adverse prior year development ceded on subject business Prior Year Claims and Claims Adjustment Expense Year 7 Short-Duration Insurance Contracts, Historical Claims Duration, Year Seven Percentage of dividend withholding tax for distributions Percentage Of Dividend Withholding Tax For Distributions Represents the percentage of dividend withholding tax for distributions. Direct Direct Amount Direct Premiums Written Preferred stock, shares outstanding (in shares) Series A preferred shares outstanding Preferred Stock, Shares Outstanding Security Exchange Name Security Exchange Name Interest rate, per annum Debt Instrument, Basis Spread on Variable Rate Less reclassification adjustment: OCI, Debt Securities, Available-for-Sale, Gain (Loss), before Adjustment, after Tax [Abstract] Unrealized (losses) gains arising during the period, before U.S. income taxes OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Credit Rating, AM Best [Axis] Credit Rating, AM Best [Axis] Fixed maturity securities, available-for-sale: Debt Securities [Abstract] Exercised (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] 2013 Facility 2013 Facility [Member] 2013 Facility Tax-exempt investment income Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount Fair Value SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties, Fair Value Employee compensation Labor and Related Expense Claims outstanding Short-Duration Insurance Contract, Number of Reported Claims Outstanding Short-Duration Insurance Contract, Number of Reported Claims Outstanding Premiums receivable and agents’ balances, net Disposal Group, Including Discontinued Operation, Premiums And Other Receivables, Net Disposal Group, Including Discontinued Operation, Premiums And Other Receivables, Net Schedule of Acquired Indefinite-Lived Intangible Assets Schedule of Acquired Indefinite-Lived Intangible Assets by Major Class [Table Text Block] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Schedule of Gross Unrealized Losses and Fair Value for Available-for-Sale Securities Debt Securities, Available-for-Sale [Table Text Block] Schedule of Available-for-Sale Gross Unrealized Gains or Losses Unrealized Gain (Loss) on Investments [Table Text Block] Prepaid reinsurance premiums Prepaid reinsurance premiums ceded Prepaid Reinsurance Premiums Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Subsegments [Axis] Subsegments [Axis] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Incurred losses and loss adjustment expenses, net of reinsurance Short-Duration Insurance Contracts, Incurred Claims and Allocated Claim Adjustment Expense, Net Bank loan participations Loan Participations and Assignments [Member] Common stock, shares issued (in shares) Issued common shares, beginning of year (in shares) Issued common shares, end of year (in shares) Common Stock, Shares, Issued Net Earned Premiums SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Premium Revenue Bank Holding Companies Bank Holding Companies [Member] Name of the investment category. Entity [Domain] Entity [Domain] Total capacity Line of Credit Facility, Maximum Borrowing Capacity Interest paid by discontinued operations Interest Paid, Discontinued Operations SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Abstract] SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Abstract] Gross written premiums Total gross written premiums Premiums Written, Gross Assets held-for-sale (Note 2 - discontinued operations) Assets held for sale Disposal Group, Including Discontinued Operation, Assets Fixed maturity securities, gross unrealized losses Gross unrealized losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Aleka Aleka [Member] Aleka Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Unrealized gains (losses) related impairments Bank Loan Participations, Realized and Unrealized Losses, Credit Related Impairments Bank Loan Participations, Realized and Unrealized Losses, Credit Related Impairments Excess Casualty Excess Casualty [Member] Name of underwriting division. Schedule Of Acquired Intangible Assets [Table] Schedule Of Acquired Intangible Assets [Table] Represents the tabular information related to intangible assets acquired in the acquisition. Common stock, shares authorized (in shares) Common Stock, Shares Authorized Insurance [Abstract] Transfers in to Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Various LLCs Various LLCs [Member] Various LLCs Ceded Credit Risk [Table] Ceded Credit Risk [Table] Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Entity Voluntary Filers Entity Voluntary Filers Net Investment Income SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Net Investment Income Deferred Deferred Income Tax Expense (Benefit) Property and Equipment, Net Property, Plant and Equipment Disclosure [Text Block] Held-for-Sale and Discontinued Operations Discontinued Operations, Policy [Policy Text Block] Entity Address, Country Entity Address, Country Allowance for credit losses written off Accounts Receivable, Allowance for Credit Loss, Writeoff Net Written Premiums SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Premium Written Net unrealized (losses) gains, net of taxes of $(1,668) in 2024, $6,384 in 2023, and $(27,041) in 2022 Other comprehensive (loss) income Other comprehensive (loss) income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Recurring basis Fair Value, Recurring Fair Value, Recurring [Member] Options granted (in shares) Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Fixed maturity securities, 12 months or more, fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Maximum matching employer contribution Defined Contribution Plan, Employer Matching Contribution, Percent of Match Retroactive Reinsurance [Table] Retroactive Reinsurance [Table] Retroactive Reinsurance Operating Lease, Liability, Statement of Financial Position [Extensible List] Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] Manufacturers and Contractors Manufacturers And Contractors [Member] Name of underwriting division. Accrued investment income Disposal Group, Including Discontinued Operation, Accrued Investment Income Receivable Disposal Group, Including Discontinued Operation, Accrued Investment Income Receivable Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Estimated loss on sale Discontinued Operation, Provision for Loss (Gain) on Disposal, before Income Tax Selling costs incurred Discontinued Operations, Transaction Costs Discontinued Operations, Transaction Costs Investment Income [Table] Investment Income [Table] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Investment expense Investment Income, Investment Expense Document Annual Report Document Annual Report Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Identifiable intangibles not subject to amortization Indefinite-Lived Intangible Assets (Excluding Goodwill) Amortization of intangible assets Amortization Amortization of intangible assets Amortization of Intangible Assets SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward] Convertible Preferred Stock Convertible Preferred Stock [Member] Temporary Equity [Abstract] Accounting Policies [Abstract] Accounting Policies [Abstract] Excess tax benefits from equity incentive plan transactions Excess Tax Benefits from Equity Incentive Plan Transactions, Operating Activities Excess Tax Benefits from Equity Incentive Plan Transactions, Operating Activities Liabilities: Liabilities: Liabilities [Abstract] Revenues: Revenues: Revenues [Abstract] Margin above SOFR, percentage rate Long-Term Debt, Percentage Bearing Variable Interest, Percentage Rate Current Fiscal Year End Date Current Fiscal Year End Date Balance at Beginning of Period Balance at End of Period SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount Less imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Catastrophic Event [Axis] Catastrophic Event [Axis] Reserve for losses and loss adjustment expenses SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Reserve for Unpaid Claim and Claim Adjustment Expense PEO Name PEO Name Restricted stock unit dividend equivalents Restricted Stock Unit Dividend Equivalents Represents amount of dividend equivalent of RSU's. Award Type [Domain] Award Type [Domain] Insurance licenses and authorities Licensing Agreements [Member] Share based compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-Based Compensation Cost Issue date Debt Instrument, Issuance Date Schedule of Other Invested Assets Other Invested Asset [Table Text Block] Tabular disclosure of other invested assets consisting of private debt and equity investments. Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Prior years - retroactive reinsurance Less: losses and loss adjustment expense - retroactive reinsurance Losses and loss adjustment expenses - retroactive reinsurance Prior years - retroactive reinsurance Prior Year Claims and Claims Adjustment Expense, Retroactive Reinsurance Prior Year Claims and Claims Adjustment Expense, Retroactive Reinsurance Deferred tax assets, net Deferred Income Tax Assets, Net Non-PEO NEO Non-PEO NEO [Member] Intangible assets, useful life (in years) Life (Years) Finite-Lived Intangible Asset, Useful Life Series A convertible preferred shares (in dollars per share) Temporary Equity, Par or Stated Value Per Share Other expenses Disposal Group, Including Discontinued Operation, Other Expense Additional Paid-in Capital Additional Paid-in Capital [Member] Other assets Disposal Group, Including Discontinued Operation, Other Assets Payments for reinsurance Payments for Reinsurance Other Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Adopted and Prospective Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Class of Stock [Axis] Class of Stock [Axis] Net written premiums SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Premium Written Title and Position [Domain] Title and Position [Domain] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Life Sciences Life Sciences [Member] Name of underwriting division. Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Cavello Bay ADC Cavello Bay ADC [Member] Cavello Bay ADC Name Measure Name Entity Interactive Data Current Entity Interactive Data Current Total loss from discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Reinsurance SEC Schedule, 12-17, Insurance Companies, Reinsurance [Text Block] Dividend limitations percentage of statutory surplus Dividend Limitations Percentage Of Statutory Surplus Represents dividend limitations percentage of statutory surplus. Sales Proceeds from Sale of Debt Securities, Available-for-Sale Losses and loss adjustment expenses Net Policyholder Benefits and Claims Incurred, Net Gross written premiums percentage Gross Written Premiums Percentage Represents gross written premiums percentage. Loss on disposal Discontinued Operation, Gain (Loss) On Disposal Of Discontinued Operation Excluding Transaction Costs, Net Of Tax Discontinued Operation, Gain (Loss) On Disposal Of Discontinued Operation Excluding Transaction Costs, Net Of Tax Junior Subordinated Debt [Domain] Junior Subordinated Debt [Domain] Represents categorization of information by junior subordinated debt. Number of notes issued Number Of Notes Issued Number Of Notes Issued Payout for achievement, target Share-Based Compensation Arrangement by Share-Based Payment Award, Payout For Achievement, Target Share-Based Compensation Arrangement by Share-Based Payment Award, Payout For Achievement, Target Equity securities: Equity Securities, FV-NI and without Readily Determinable Fair Value [Abstract] Share based compensation expense Share based compensation expense Share-Based Payment Arrangement, Noncash Expense Professional Liability Professional Liability [Member] Name of underwriting division. Segment Reporting, Reconciling Item, Corporate Nonsegment Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Largest reinsurer one Credit Risk Reinsurer One [Member] Represents information about credit risk reinsurer one. Ceded written premiums Ceded Ceded to Other Companies Ceded Premiums Written Supplemental information Supplemental information Supplemental Cash Flow Information [Abstract] Equity securities, at fair value (cost: 2024 – $82,678; 2023 – $114,107) Equity securities Equity Securities, FV-NI U.S. state income tax expense State and Local Income Tax Expense (Benefit), Continuing Operations Preferred stock, dividend rate, percentage Preferred Stock, Dividend Rate, Percentage PRSU performance adjustment (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Adjustment, Weighted Average Grant Date Fair Value Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Adjustment, Weighted Average Grant Date Fair Value Valuation and Qualifying Accounts SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Credit Rating, Standard & Poor's [Axis] Credit Rating, Standard & Poor's [Axis] Funds held Increase (Decrease) in Funds Held under Reinsurance Agreements Auditor Firm ID Auditor Firm ID Audit Information [Abstract] Audit Information [Abstract] Variable Rate [Domain] Variable Rate [Domain] Schedule of Incurred But Not Reported Liabilities and Claims Frequency Schedule Of Incurred But Not Reported Liabilities And Claims Frequency [Table Text Block] Represents information of incurred but not reported Liabilities and claims frequency. Number of reportable segments Number of Reportable Segments Total liabilities, Series A redeemable preferred shares, and shareholders’ equity Liabilities and Equity Percentage of Amount Assumed to Net SEC Schedule, 12-17, Insurance Companies, Reinsurance, Premium, Percentage Assumed to Net Subsequent Events Subsequent Events [Text Block] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Ceded Ceded Premiums Earned Fixed Maturity and Equity Securities Marketable Securities, Policy [Policy Text Block] Deferred policy acquisition costs Deferred Tax Liabilities, Deferred Expense, Deferred Policy Acquisition Cost Total invested assets Disposal Group, Including Discontinued Operation, Total Invested Assets Disposal Group, Including Discontinued Operation, Total Invested Assets Unearned premiums SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Unearned Premium All outstanding losses and loss adjustment expenses, net of reinsurance All outstanding losses and loss adjustment expenses, net of reinsurance Short-Duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net, Not Separately Presented Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Contractual life of option (in years) Share Based Arrangement by Share Based Award Option Contractual Life Share Based Arrangement by Share Based Award Option Contractual Life Securities receivable or payable, net Payments for (Proceeds from) Unsettled Investments, Net Payments for (Proceeds from) Unsettled Investments, Net Year 9 Short-Duration Insurance Contracts, Historical Claims Duration, Year Nine Underlying Security Market Price Change Underlying Security Market Price Change, Percent Individual: Individual [Axis] Vesting of RSUs Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Forfeited (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Liabilities held-for-sale (Note 2 - discontinued operations) Liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities Income tax expense recognized per year Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense, Per Year Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Asset, Income Tax Expense, Per Year Dividends [Domain] Dividends [Domain] Product and Service [Axis] Product and Service [Axis] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Statement [Line Items] Statement [Line Items] Net unrealized (losses) gains, net of taxes OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, Tax Number of shares to be received per PRSU (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Contingent Right, Number Of Shares To Be Received Share-Based Compensation Arrangement by Share-Based Payment Award, Contingent Right, Number Of Shares To Be Received Schedule of Underwriting Profit (Loss) of Operating Segments by Individual Segment and Reconciliation to Consolidated Income (Loss) from Continuing Operations Before Taxes Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Expenses: Expenses: Operating Expenses [Abstract] Number of trading days Preferred Stock, Convertible, Number Of Trading Days Preferred Stock, Convertible, Number Of Trading Days Other liabilities Disposal Group, Including Discontinued Operation, Other Liabilities Schedule of Property and Equipment, Net Property, Plant and Equipment [Table Text Block] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Deferred policy acquisition costs SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters, Deferred Policy Acquisition Cost Year 10 Short-Duration Insurance Contracts, Historical Claims Duration, Year 10 O 2024 Q4 Dividends O 2024 Q4 Dividends [Member] O 2024 Q4 Dividends Amortization of policy acquisition costs Amortization Of Policy Acquisition Costs Represents amortization of policy acquisition costs. Schedule of Reconciliation of Securities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Junior Subordinated Debt Junior Subordinated Debt [Member] Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Minimum Minimum [Member] Adoption Date Trading Arrangement Adoption Date Due from subsidiaries Other Receivables Related Party Transactions [Abstract] Related Party Transactions [Abstract] Total expenses Disposal Group, Including Discontinued Operation, Total Expense Disposal Group, Including Discontinued Operation, Total Expense Discontinued operations (Note 2): Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent [Abstract] Amortization of policy acquisition costs Amortization of policy acquisition costs Deferred Policy Acquisition Costs, Amortization Expense After five years through ten years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Ceded Policyholder Benefits and Claims Incurred, Ceded Cash provided by (used in) operating activities excluding reduction in collateral funds Net Cash Provided by (Used in) Operating Activities Excluding Change in Collateral Funds Net Cash Provided by (Used in) Operating Activities Excluding Change in Collateral Funds Credit loss expense Accounts Receivable, Credit Loss Expense (Reversal) Net change Deferred Policy Acquisition Costs, Period Increase (Decrease) Segments [Axis] Segments [Axis] 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] Net earned premiums Disposal Group, Including Discontinued Operation, Premiums Earned, Net Disposal Group, Including Discontinued Operation, Premiums Earned, Net Return of capital Proceeds from Equity Method Investment, Distribution, Return of Capital Exercise Price Award Exercise Price Unpaid principal balance Fair Value, Option, Loans Held as Assets, Aggregate Unpaid Principal Balance Fair Value, Option, Loans Held as Assets, Aggregate Unpaid Principal Balance Schedule of Deferred Tax Assets (Liabilities) at the Current Prevailing Corporate Income Tax Rate Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Commitment to lend Commitment To Lend Represents amount commitment to lend. 2017 Facility 2017 Facility [Member] 2017 Facility Arrangement Duration Trading Arrangement Duration Schedule of Components of Comprehensive Income (Loss) Comprehensive Income (Loss) [Table Text Block] Principal amount of Trust Preferred Securities Face Value Of Trust Preferred Securities Represents face value of trust preferred securities. Net operating loss carryforwards Operating Loss Carryforwards PRSU PRSU [Member] PRSU Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Basic Share Loss from discontinued operations Loss from discontinued operations Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax Shareholders’ equity: Shareholders’ equity: Equity, Attributable to Parent [Abstract] Reserve for losses and loss adjustment expenses Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Loss Reserves Fixed maturity securities, less than 12 months, fair value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Current year Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year Reserve For Losses And Loss Adjustment Expenses [Line Items] Reserve For Losses And Loss Adjustment Expenses [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. Total invested assets Investments Minimum required statutory capital and surplus Statutory Accounting Practices, Statutory Capital and Surplus Required Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] 2028 Finite-Lived Intangible Asset, Expected Amortization, Year Four All Individuals All Individuals [Member] Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Temporary Equity [Line Items] Temporary Equity [Line Items] Variable Rate [Axis] Variable Rate [Axis] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Short-term investments, net Payments for (Proceeds from) Short-Term Investments James River Capital Trust III James River Capital Trust III [Member] Represents information about James River Capital Trust III. Other invested assets Carrying Value Other Investments Total underwriting (loss) profit of operating segments Underwriting Profit Loss Of Operating Segments This element represents amount of underwriting Profit (loss) of operating segments. Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Intangible assets, net Net Carrying Value Net Carrying Value Intangible Assets, Net (Excluding Goodwill) 2015 Short-Duration Insurance Contracts, Accident Year 2015 [Member] Equity securities, at fair value Disposal Group, Including Discontinued Operation, Equity Securities, FV-NI Disposal Group, Including Discontinued Operation, Equity Securities, FV-NI U.S. income taxes Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Cash dividends declared Dividends, Preferred Stock, Cash Percentage of reinsurance recoverables on unpaid losses for 3 largest reinsurers Reinsurance Recoverables On Unpaid Losses Percentage Of Total Balance Represents reinsurance recoverables on unpaid losses percentage of total balance. Gross Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Net (loss) income available to common shareholders Net Income (Loss) from Continuing Operations Available to Common Shareholders, Basic 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] Add: Incurred losses and loss adjustment expenses net of reinsurance: Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract] General Casualty General Casualty [Member] Name of underwriting division. Lender Name [Axis] Lender Name [Axis] Reserve for Losses and Loss Adjustment Expenses Liability For Claims And Claims Adjustment Expense [Text Block] The entire disclosure for the liability for claims and claims adjustment expense. Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Change in net unearned premiums (Increase) Decrease in Unearned Premiums, Net Related Party [Domain] Related and Nonrelated Parties [Domain] Electronic data processing hardware and software Electronic Data Processing Hardware And Software [Member] Represents information about electronic data processing hardware and software. Short-duration Insurance Contracts, Historical Claims Duration [Line Items] Short-Duration Insurance Contracts, Historical Claims Duration [Line Items] Unrealized gains (losses) on bank loan participations Unrealized Gain (Loss) on Investments Schedule of Retroactive Reinsurance Schedule of Retroactive Reinsurance [Table Text Block] Schedule of Retroactive Reinsurance Cash equivalent collateral trust arrangement Cash Equivalent Collateral Held In Trust Arrangement Cash Equivalent Collateral Held In Trust Arrangement Direct Policyholder Benefits and Claims Incurred, Direct Conversion of Series A Preferred Shares to common shares (in shares) Conversion of Stock, Shares Converted Number of issuers Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions Broker relationships Broker Relationships [Member] Represents information related to broker relationships. Commercial Auto LPT Loss Portfolio Transfer [Member] Loss Portfolio Transfer Deferred U.S. federal income tax benefit Deferred Federal Income Tax Expense (Benefit) Reinsurance recoverables Reinsurance Recoverables, Gross Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Impairment of intangible assets Impairment of Intangible Assets, Finite-Lived Issuance costs Payments of Stock Issuance Costs Commitments and Contingent Liabilities Commitments and Contingencies Disclosure [Text Block] Thereafter Finite-Lived Intangible Asset, Expected Amortization, after Year Five Measure: Measure [Axis] Associated Trust Agreement [Axis] Associated Trust Agreement [Axis] Associated Trust Agreement Unearned premiums Unearned Premiums Outstanding commitments to invest in new limited partnership Commitment to Investment In New Limited Partnership Commitment to Investment In New Limited Partnership Losses and Loss Adjustment Expenses SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Benefit, Claim, Loss and Settlement Expenses Asset Class [Domain] Asset Class [Domain] Share price (in dollars per share) Fair value of shares used in calculation of intrinsic values (in dollars per share) Share Price Invested assets: Investments [Abstract] Liquidation preference (in dollars per share) Temporary Equity, Liquidation Preference Per Share Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Enstar common share investment (in shares) Stock Issued During Period, Shares, New Issues Entity Emerging Growth Company Entity Emerging Growth Company Indefinite-lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets [Axis] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Other invested assets Other Investments [Member] Maturity date of Junior Subordinated Debt, unless accelerated earlier Debt Instrument, Maturity Date Other invested assets Other Security Investments [Member] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Equity Component [Domain] Equity Component [Domain] Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Net realized and unrealized (losses) gains on investments Disposal Group, Including Discontinued Operation, Gain (Loss) On Investments Disposal Group, Including Discontinued Operation, Gain (Loss) On Investments Series A redeemable preferred shares, outstanding (in shares) Temporary Equity, Shares Outstanding Commercial mortgage and asset-backed Commercial Mortgage-Backed And Asset Backed Securities [Member] Commercial Mortgage-Backed And Asset Backed Securities Convertible preferred stock, minimum term for conversion Preferred Stock, Convertible, Term Preferred Stock, Convertible, Term Net cash used in operating activities of discontinued operations Cash Provided by (Used in) Operating Activities, Discontinued Operations Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Entity Shell Company Entity Shell Company Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Schedule of Cash Dividends Declared Dividends Declared [Table Text Block] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] Reinsurance recoverable on paid losses Reinsurance Recoverable for Paid Claims and Claims Adjustments Statement [Table] Statement [Table] Measurement Frequency [Domain] Measurement Frequency [Domain] Counterparty Name [Axis] Counterparty Name [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Maturities, calls and paydowns Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Intangible Assets [Roll Forward] Finite-Lived Intangible Assets [Roll Forward] Interest 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Liability for Unpaid Claims and Claims Adjustment Expense, Period Increase (Decrease) [Abstract] Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Other Deferred Tax Assets, Other Schedule of Rollforward of Changes in Common Shares Issued and Outstanding Schedule of Common Stock Outstanding Roll Forward [Table Text Block] Impairment Losses Impairment of Intangible Assets (Excluding Goodwill) Preferred stock, value Preferred Stock, Value, Issued Schedule of Other Operating Expenses Schedule of Other Operating Cost and Expense, by Component [Table Text Block] Consolidated gross written premiums percentage Consolidated Gross Written Premiums Percentage Represents consolidated gross written premiums percentage. 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These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. 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Retroactive Reinsurance [Line Items] Retroactive Reinsurance [Line Items] Retroactive Reinsurance Senior debt Amount outstanding on line of credit Line of credit facility, outstanding drawn balance Long-Term Line of Credit Number of awards granted (in shares) Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Schedule of Acquired Finite-Lived Intangible Assets Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block] U.S. Treasury securities and obligations guaranteed by the U.S. government US Treasury and Government [Member] Schedule of Assets Measured at Fair Value on a Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Other operating expenses Disposal Group, Including Discontinued Operation, Operating Expense Bank loan participations, gross realized gain Bank Loan Participations, Gross Realized Gain Represents the gross realized gains on bank loan participations. Net unrealized losses Deferred Tax Asset, Debt Securities, Available-for-Sale, Unrealized Loss Assumed Assumed from Other Companies Assumed Premiums Written Total revenues Segment revenues Revenues Dividends on Series A preferred shares Dividends on Series A preferred shares Payments of Ordinary Dividends, Preferred Stock and Preference Stock Entity Address, City or Town Entity Address, City or Town Pre close dividend, forgiveness Selling Agreement, Pre Close Dividend, Forgiveness Selling Agreement, Pre Close Dividend, Forgiveness Deferred Policy Acquisition Costs SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information, Deferred Policy Acquisition Cost Leases Lessee, Leases [Policy Text Block] Downward adjustment disputed Disposal Group, Including Discontinued Operation, Amounts Of Material Contingent Liabilities Remaining Disposal Group, Including Discontinued Operation, Amounts Of Material Contingent Liabilities Remaining Schedule of Summary of Option Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Initial loss on contract Initial Loss On Contract Initial Loss On Contract Dividends [Axis] Dividends [Axis] Share based compensation expense Share-Based Payment Arrangement, Expense Discontinued Operations Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Private Speciality Credit Private Speciality Credit [Member] Private Speciality Credit Conversion of Series A Preferred Shares to common shares (Notes 12 and 13) Conversion of shares Stock Issued During Period, Value, Conversion of Convertible Securities Granted (in dollars per share) Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Other Comprehensive (Loss) Income Comprehensive Income (Loss) Note [Text Block] Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Business Acquisition [Axis] Business Acquisition [Axis] Schedule of Gross Carrying Amounts and Accumulated Amortization for Finite-Lived Intangible Assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Net written premiums Premiums Written, Net Renewable energy notes receivable Renewable Energy Bridge Financing Notes [Member] Name of the investment category. 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] Document Fiscal Year Focus Document Fiscal Year Focus All other operating expenses Other Operating Expenses Other Operating Expenses Profit commission percentage Profit Commission Percentage Profit Commission Percentage Excess Property Excess Property [Member] Name of underwriting division. 2029 Finite-Lived Intangible Asset, Expected Amortization, Year Five Document Period End Date Document Period End Date Sale of Stock [Axis] Sale of Stock [Axis] 2014 Long Term Incentive Plan Long Term Incentive Plan 2014 [Member] Represents information regarding Long Term Incentive Plan 2014. Investment in LLC Investment In Llc [Member] Represents investment in LLC`s. Total lease payments Lessee, Operating Lease, Liability, to be Paid Equity in undistributed earnings of subsidiaries Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Unvested, beginning of year (in shares) Unvested, end of year (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Year 1 Short-Duration Insurance Contracts, Historical Claims Duration, Year One Asset Class [Axis] Asset Class [Axis] Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] Insider Trading Arrangements [Line Items] Loss from discontinued operations Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic 2027 Lessee, Operating Lease, Liability, to be Paid, Year Three Cost or Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Fiscal Year Maturity [Abstract] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Table] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Table] Value of awards granted Shares Granted, Value, Share-Based Payment Arrangement, before Forfeiture Document Transition Report Document Transition Report Current year Current year Current Year Claims and Claims Adjustment Expense Purchases Payments to Acquire Other Investments Dividends received deduction Effective Income Tax Rate Reconciliation, Deduction, Dividends, Amount Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Entity Current Reporting Status Entity Current Reporting Status Year 5 Short-Duration Insurance Contracts, Historical Claims Duration, Year Five Retained Deficit Retained Earnings Retained Earnings [Member] Cash paid to JRGH Payment For Selling Agreement, Pre Close Dividend Payment For Selling Agreement, Pre Close Dividend E&S ADC E&S ADC Agreement [Member] E&S ADC Agreement Gross investment income Gross Investment Income, Operating Receivables greater than 90 days past due Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Net earned premiums Net earned premiums Premiums Earned, Net Other Income Other Income [Policy Text Block] Represents disclosure of accounting policy for other income composition and revenue recognition policy. RSUs Restricted Stock Units (RSUs) [Member] SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Table] SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Table] Reinsurance Transaction [Domain] Reinsurance Transaction [Domain] Reinsurance Transaction [Domain] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Executive Category: Executive Category [Axis] Investment in private subordinated notes Other invested assets – notes receivable Notes Receivable Represents carrying value of notes receivable as on reporting date. Increase (Decrease) In Common Stock Issued And Outstanding [Roll Forward] Increase (Decrease) In Common Stock Issued And Outstanding [Roll Forward] Increase (Decrease) In Common Stock Issued And Outstanding Purchases Payments to Acquire Debt Securities, Available-for-Sale Company Selected Measure Name Company Selected Measure Name