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share awards Restricted Stock [Member] Accumulated other comprehensive income (loss), net of tax AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] TP GP Third Point Advisors LLC [Member] Third Point Advisors LLC [Member] Name Forgone Recovery, Individual Name 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] Schedule of Net Realized Investment Losses Realized Gain (Loss) on Investments [Table Text Block] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Statement [Line Items] Statement [Line Items] Total assets Assets Assets Entity [Domain] Entity [Domain] Preference shares, shares issued (in shares) Preferred Stock, Shares Issued Other unconsolidated investments, at fair value Other Unconsolidated Investments, At Fair Value [Member] Other Unconsolidated Investments, At 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gains (losses) from debt securities held as available for sale investments AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Unrealized gains (losses) from debt securities held as available for sale investments Unrealized gains (losses) from debt securities held as available for sale investments OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Common share, shares outstanding (in shares) Common shares outstanding, beginning of period (in shares) Common shares outstanding, end of period (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Carrying Amount Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, On-Balance Sheet, Amount Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, On-Balance Sheet, Amount Change in foreign currency translation adjustment Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Corporate debt securities Corporate Debt Securities [Member] Diluted earnings per share available to SiriusPoint common shareholders (in dollars per share) Diluted earnings per share available to SiriusPoint common shareholders (in dollars per share) Earnings Per Share, Diluted Foreign currency translation Liability for Unpaid Claims and Claims Adjustment Expense, Foreign Currency Translation Gain (Loss) Entity Current Reporting Status Entity Current Reporting Status Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Exercise of options and warrants Stock Issued During Period, Value, Stock Options And Warrants Exercised Stock Issued During Period, Value, Stock Options And Warrants Exercised Current expected credit losses Financing Receivable, Credit Loss, Expense (Reversal) Liabilities, Fair Value Disclosure [Abstract] Liabilities, Fair Value Disclosure [Abstract] Redemption of preference shares Stock Redeemed or Called During Period, Value Intangible asset amortization Amortization of intangible assets Intangible asset amortization Intangible Asset, Finite-Lived, Amortization Expense Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Deferred acquisition costs, net Increase (Decrease) In Deferred Policy Acquisition Costs And Present Value Of Future Insurance Profits Increase (Decrease) In Deferred Policy Acquisition Costs And Present Value Of Future Insurance Profits Ownership [Domain] Ownership [Domain] Held for sale asset Increase (Decrease) in Asset, Held-for-Sale Adjustments to reconcile net income to net cash provided by (used in) operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Net written premium Premiums Written, Net Financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Other unconsolidated investments, at cost Other Unconsolidated Investments, At Cost [Member] Other Unconsolidated Investments, At Cost Financial Instruments [Domain] Financial Instruments [Domain] Unearned premiums ceded Increase (Decrease) in Prepaid Reinsurance Premiums Unearned premiums ceded Prepaid Reinsurance Premiums International Medical Group, Inc. International Medical Group, Inc. [Member] International Medical Group, Inc. Derivative assets Derivative assets at fair value Derivative Asset Other revenues Services revenues Other Income Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Underlying Securities Award Underlying Securities Amount Net (income) loss attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Fair Value Estimate of Fair Value Measurement [Member] Sales & Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Allowance for expected credit losses Assets Within Scope Of Credit Losses, Allowance For Credit Loss Assets Within Scope Of Credit Losses, Allowance For Credit Loss Due after ten years Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After Ten Years, Amortized Cost Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After Ten Years, Amortized Cost Preferred shares Preferred Stock [Member] Due after on year through five years Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost Weighted average discount rate Operating Lease, Weighted Average Discount Rate, Percent Net unrealized gains (losses)  Debt Securities, Trading, Unrealized Gain (Loss) Net income available to SiriusPoint common shareholders, basic Net income available to SiriusPoint common shareholders Undistributed Earnings, Basic Change in total noncontrolling interests, net Proceeds from (Payments to) Noncontrolling Interests Segment Reporting [Table] Segment Reporting [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Table] Series B preference shares Equity, Fair Value Disclosure Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Net impact on earnings Derivative, Gain (Loss) on Derivative, Net 12 Months or Less Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Schedule of Investments, Categorized by the Level of the Fair Value Hierarchy Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] Other Performance Measure, Amount Other Performance Measure, Amount Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Services Service [Member] Current Fiscal Year End Date Current Fiscal Year End Date Debt securities, trading Debt Securities, Trading [Member] Debt Securities, Trading Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Derivative [Line Items] Derivative [Line Items] Related Party Transaction [Domain] Related Party Transaction [Domain] Top-up tax Effective Income Tax Rate Reconciliation, NCTI, Amount Equity method eligible unconsolidated entities, using the fair value option Equity Method Eligible Unconsolidated Entities [Member] Equity Method Eligible Unconsolidated Entities Non-U.S. government and government agency Debt Security, Government, Non-US [Member] 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] Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Earnings Per Share, Diluted, by Common Class, Including Two-Class Method [Table] Gross investment income Investment Income And Gain (Loss) On Investments Investment Income And Gain (Loss) On Investments Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Due in one year or less Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Fair Value Issuance of common shares, net Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture Schedule of Debt Securities by Contractual Maturity Investments Classified by Contractual Maturity Date [Table Text Block] Other long-term investments Net Realized Or Unrealized Gain Loss On Other Long-Term Investments [Abstract] Net Realized Or Unrealized Gain Loss On Other Long-Term Investments Schedule of Loss and Loss Adjustment Expense Reserves Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Debt securities, available for sale Debt Securities, Available-for-Sale, Realized Gain (Loss) [Abstract] Restricted Cash and Cash Equivalent 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Accumulated Loss Funds held liability Funds Held under Reinsurance Agreements, Liability Equity Components [Axis] Equity Components [Axis] Net corporate and other expenses Services expenses Net corporate and other expenses Other Cost and Expense, Operating Related Party Related Party [Member] Insurance Product Line [Domain] Product and Service [Domain] Class of Stock [Line Items] Class of Stock [Line Items] Due after one year through five years Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After One Through Five Years, Amortized Cost Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After One Through Five Years, Amortized Cost Entity Interactive Data Current Entity Interactive Data Current Net (income) loss attributable to noncontrolling interests Net income (loss) attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Collateral pledged Derivative Asset, Fair Value of Collateral Deferred tax liability Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Small Business Entity Small Business Comprehensive income available to SiriusPoint Comprehensive Income (Loss), Net of Tax, Attributable to Parent Unearned premium reserves Unearned Premiums Alta Signa Consolidated Entity, Excluding VIE [Member] 2029 Lessee, Operating Lease, Liability, to be Paid, Year Three Unamortized discount Debt Instrument, Unamortized Discount Termination Date Trading Arrangement Termination Date Variable Interest Entity, Not Primary Beneficiary, Excluding Investments In Related Party Investment Funds Variable Interest Entity, Not Primary Beneficiary, Excluding Investments In Related Party Investment Funds [Member] Variable Interest Entity, Not Primary Beneficiary, Excluding Investments In Related Party Investment Funds Fair Value Disclosure of Asset and Liability Not Measured at Fair Value [Table] Fair Value Disclosure of Asset and Liability Not Measured at Fair Value [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Net proceeds from exercise of options Proceeds From Options And Warrants Exercised Proceeds From Options And Warrants Exercised Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Current year Current Year Claims and Claims Adjustment Expense Document Type Document Type Business acquisitions, net (cash and restricted cash acquired of $4.9) Payments to Acquire Businesses, Net of Cash Acquired Transfers in to (out of) Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net 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] Fair Value as of Grant Date Award Grant Date Fair Value Third Point Enhanced LP Related Party Fund - Third Point Enhanced LP [Member] Related Party Fund - Third Point Enhanced LP Mortgage-backed and asset-backed securities Mortgage Backed And Asset-Backed Securities [Member] Mortgage Backed And Asset-Backed Securities Schedule of Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Significant accounting policies Significant Accounting Policies [Text Block] Debt securities, available for sale, allowance for credit losses Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest A- Or Better Rating A- Or Better Rating [Member] A- Or Better Rating Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Stock repurchase program, remaining authorized amount Share Repurchase Program, Remaining Authorized, Amount Cash and Cash Equivalents Cash and Cash Equivalents [Member] Arrangement Duration Trading Arrangement Duration Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Debt Securities, Trading, and Equity Securities, FV-NI [Table] Debt Securities, Trading, and Equity Securities, FV-NI [Table] Local Phone Number Local Phone Number Consolidation Items [Axis] Consolidation Items [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Restrictions on Cash and Cash Equivalents [Table] Restrictions on Cash and Cash Equivalents [Table] Short-term investments, at fair value (cost - $7.2; 2025 - $28.4) Short-term investments Other Short-Term Investments 12 Months or Less Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 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Investment Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Executive Category: Executive Category [Axis] Business combinations Business Combination [Policy Text Block] Counterparty Name [Axis] Counterparty Name [Axis] Significant transactions Reinsurance [Text Block] Award Type [Domain] Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Remainder of 2026 Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year Fair value measurements Fair Value Disclosures [Text Block] Schedule of Variable Interest Entities [Table] Variable Interest Entity [Table] Significant unobservable inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Other Gains (Losses) On Other Investments Gains (Losses) On Other Investments Deferred acquisition costs, net Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Net PEO Name PEO Name Total net paid losses Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid Valued at NAV Fair Value Measured at Net Asset Value Per Share [Member] Cash and restricted cash acquired Cash Acquired from Acquisition Other assets Other Assets Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Entity Tax Identification Number Entity Tax Identification Number Debt securities, AFS - Cost or amortized cost Debt Securities, Available-for-Sale, Amortized Cost, Rolling Maturity [Abstract] Legal Entity [Axis] Legal Entity [Axis] Interest expense Interest Expense, Debt Net foreign currency gains (losses) Debt Securities, Trading, Accumulated Net Foreign Currency Gains (Losses) Debt Securities, Trading, Accumulated Net Foreign Currency Gains (Losses) Cash, cash equivalents and restricted cash at beginning of period Cash, cash equivalents and restricted cash at end of period Total cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Non-NEOs Non-NEOs [Member] 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] Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Debt Instrument [Axis] Debt Instrument [Axis] Share compensation Share-Based Payment Arrangement, Noncash Expense Operating lease expense Lease, Cost Due after ten years Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Amortized Cost Strategic investments and Limited liability companies and private equity securities Strategic Investments And Limited Liability Companies And Private Equity Securities [Member] Strategic Investments And Limited Liability Companies And Private Equity Securities Restricted share awards and units Restricted Stock And Restricted Stock Units (RSUs) [Member] Restricted Stock And Restricted Stock Units (RSUs) Due in one year or less Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling Within One Year, Amortized Cost Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling Within One Year, Amortized Cost Investment, Name [Domain] Investment, Name [Domain] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Basic earnings per share available to SiriusPoint common shareholders (in dollars per share) Earnings Per Share, Basic Debt securities, trading - Cost or 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Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common shares Common Stock Common Stock [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Reclassifications Reclassification, Comparability Adjustment [Policy Text Block] Insurance [Abstract] Series B preference shares Series B Preferred Stock [Member] Loss reserves Reinsurance, Loss Portfolio Transfer, Loss Reserves Covered Reinsurance, Loss Portfolio Transfer, Loss Reserves Covered Concentration risk, percentage Concentration Risk, Percentage Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Equity Awards Adjustments Equity Awards Adjustments [Member] Due after five years through ten years Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After Five Through Ten Years, Amortized Cost Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After Five Through Ten Years, Amortized Cost Managing general underwriters Managing General Underwriters [Member] Managing General Underwriters Net realized gains (losses) on Debt securities, available for sale Debt Securities, Available-for-Sale, Realized Gain (Loss) Net derivatives Derivative Financial Instruments, Assets [Member] Total liabilities, noncontrolling interests and shareholders’ equity Liabilities and Equity Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Due after five years through ten years Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After Five Through Ten Years, Fair Value Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After Five Through Ten Years, Fair Value Options Share-Based Payment Arrangement, Option [Member] Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Noncontrolling interests Equity, Attributable to Noncontrolling Interest Segments [Axis] Segments [Axis] Other liabilities Increase (Decrease) in Other Operating Liabilities Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Asset Class [Axis] Asset Class [Axis] Related Party [Domain] Related and Nonrelated Parties [Domain] Debt securities, trading, at fair value (cost - $88.6; 2025 - $114.6) Total debt securities, trading Fair value Debt securities, trading Debt Securities, Trading Proceeds from sales and maturities of debt securities, trading and short-term investments Proceeds From Sales And Maturities Of Debt Securities, Trading And Short-term Investments Proceeds From Sales And Maturities Of Debt Securities, Trading And Short-term Investments Insurance and reinsurance balances receivable, net Increase (Decrease) in Premiums Receivable Tabular List, Table Tabular List [Table Text Block] Additional paid-in capital Additional Paid in Capital Schedule of Net Unrealized Investment Losses Unrealized Gain (Loss) on Investments [Table Text Block] Loss and loss adjustment expenses recoverable, net Increase (Decrease) in Reinsurance Recoverable Loss and loss adjustment expense reserves Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] Arcadian Holdings Limited Arcadian Holdings Limited [Member] Arcadian Holdings Limited Parent Parent [Member] Name Awards Close in Time to MNPI Disclosures, Individual Name Entity Address, Country Entity Address, Country Gross unrealized losses Debt Securities, Held-to-Maturity, Continuous Unrealized Loss Position [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Net income allocated to SiriusPoint participating shareholders Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted Due after one year through five years Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Fair Value Preference shares, shares authorized (in shares) Preferred Stock, Shares Authorized Series B preference shares (2025 - par value $0.10; authorized and issued: 8,000,000) Preferred Stock, Value, Issued Adjustment to Compensation: Adjustment to Compensation [Axis] Commercial mortgage-backed securities Commercial Mortgage-Backed Securities [Member] Debt securities, trading - Fair value Debt Securities, Trading, Fair Value, Rolling Maturity [Abstract] Debt Securities, Trading, Fair Value, Rolling Maturity Insurance & Services Insurance And Services Segment [Member] Insurance And Services Segment Reclassifications from accumulated other comprehensive income (loss) Reclassifications from accumulated other comprehensive income (loss) Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Share Repurchase Program [Axis] Share Repurchase Program [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Catastrophe loss ratio Catastrophe Loss Ratio Catastrophe Loss Ratio Class of Stock [Domain] Class of Stock [Domain] Due after ten years Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After Ten Years, Fair Value Debt Securities, Trading, Maturity, Allocated And Single Maturity Date, Rolling After Ten Years, Fair Value Credit concentration risk Credit Concentration Risk [Member] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Other underwriting expenses ratio Underwriting Expense Ratio Business Insurance Recoveries [Table] Business Insurance Recoveries [Table] Net income allocated to SiriusPoint participating shareholders Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Foreign currency forwards Foreign currency forwards Foreign Exchange Forward [Member] Hedging Designation [Axis] Hedging Designation [Axis] Credit Facility [Axis] Credit Facility [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Total assets Assets, Fair Value Disclosure Other long-term investments, Gross unrealized gains Other Long-Term Investments, Accumulated Unrecognized Gain Other Long-Term Investments, Accumulated Unrecognized Gain Name Measure Name Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Income taxes Income Tax Disclosure [Text Block] Pay vs Performance Disclosure [Line Items] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Other items, net Other Noncash Income (Expense) Debt Instrument [Line Items] Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Aggregate consideration Business Combination, Consideration Transferred Loss and loss adjustment expense reserves Increase (Decrease) in Liability for Claims and Claims Adjustment Expense Reserve Additional paid-in capital Additional Paid-in Capital [Member] Entity Filer Category Entity Filer Category Total Debt Securities, Available-for-Sale, Unrealized Loss Position Director Director [Member] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Schedule of Lease Balances Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee Due in one year or less Debt Securities, 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America Assist America [Member] Assist America Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] Preferred stock, accrued cumulative dividend (in dollars per share) Preferred Stock, Accrued Cumulative Dividend Preferred Stock, Accrued Cumulative Dividend TP Enhanced Fund Third Point Enhanced LP [Member] Third Point Enhanced LP Pallas Reinsurance Company Ltd. Pallas Reinsurance Company Ltd. [Member] Pallas Reinsurance Company Ltd. Cash, cash equivalents, restricted cash and restricted investments Cash and Cash Equivalents Disclosure [Text Block] Entity Address, Address Line Two Entity Address, Address Line Two Redemption of preference shares Payments for Repurchase of Redeemable Preferred Stock Schedule of Stock by Class [Table] Stock, Class of Stock [Table] Net income Net income Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Amortization of premium and accretion of discount, net Accretion (Amortization) Of Discounts And Premiums Accretion (Amortization) Of Discounts And Premiums Unrecognized tax benefits that would impact the effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Weighted average lease term (years) Operating Lease, Weighted Average Remaining Lease Term Derivative liabilities Derivative liabilities at fair value Derivative Liability Non-PEO NEO Non-PEO NEO [Member] Credit default swap Credit Risk Contract [Member] Senior Notes Senior Notes [Member] Entity Address, Address Line One Entity Address, Address Line One Combined ratio Combined Ratio Total expenses Benefits, Losses and Expenses Income tax expense Income tax expense Income tax expense Income Tax Expense (Benefit) Foreign exchange (gains) losses Foreign exchange gains (losses) Gain (Loss), Foreign Currency Transaction, before Tax Variable Interest Entity, Primary Beneficiary, Alstead Re Insurance Company Variable Interest Entity, Primary Beneficiary, Alstead Re Insurance Company [Member] Variable Interest Entity, Primary Beneficiary, Alstead Re Insurance Company Net income Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest Award Timing Method Award Timing Method [Text Block] Consolidation Consolidation, Policy [Policy Text Block] Net increase (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Insurance and reinsurance balances receivable, net Premiums Receivable, Net Variable interest entity, primary beneficiary Variable Interest Entity, Primary Beneficiary [Member] Net income available to SiriusPoint Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Statement [Table] Statement [Table] 2030 and thereafter Lessee, Operating Lease, Liability, To Be Paid, Due After Year Three Lessee, Operating Lease, Liability, To Be Paid, Due After Year Three Segment Measure Reclass Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment [Member] Prior year loss development ratio Prior Accident Year Loss Ratio Prior Accident Year Loss Ratio Restatement Determination Date: Restatement Determination Date [Axis] Net income available to SiriusPoint common shareholders, diluted Net income available to SiriusPoint common shareholders Undistributed Earnings, Diluted Acquisition cost ratio Acquisition Cost Ratio Net realized gains (losses) Debt Securities, Trading, Realized Gain (Loss) Net foreign currency gains (losses) Debt Securities, Available-for-sale, Accumulated Net Foreign Currency Gains (Losses) Debt Securities, Available-for-sale, Accumulated Net Foreign Currency Gains (Losses) Revenues Revenues [Abstract] Other long-term investments, Gross unrealized losses Other Long-Term Investments, Accumulated Unrecognized Loss Other Long-Term Investments, Accumulated Unrecognized Loss Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Other long-term investments Other long-term investments Other Long-Term Investments [Member] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract]