Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] Ceded Ceded premiums earned Ceded Premiums Earned Title of 12(b) Security Title of 12(b) Security Subsequent Event Subsequent Event [Member] Carrying Value Reported Value Measurement [Member] Document Fiscal Year Focus Document Fiscal Year Focus Insurance-linked securities funds Insurance-Linked Securities Funds [Member] Insurance-Linked Securities Funds Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Table] Gross Amounts Offset in the Balance Sheet Derivative Liability, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Cash Offset Adjustment to Compensation, Amount Adjustment to Compensation Amount Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] Net realized and unrealized gains (losses) on investments (Note 3) Net realized and unrealized gains (losses) on investments Net realized and unrealized gains (losses) on investments Nonoperating Gains (Losses) Financial Instrument [Axis] Financial Instrument [Axis] Total other assets Other Assets, Fair Value Disclosure Customer [Axis] Customer [Axis] Segment Reporting [Abstract] Customer One Customer One [Member] Customer One Fixed maturity investments trading Debt Securities, Trading, Gain (Loss) [Abstract] Common shares: $1.00 par value - 41,811,353 shares issued and outstanding at June 30, 2026 (December 31, 2025 - 43,961,539) (Note 10) Common Stock, Value, Issued Taxes paid on withholding shares Payment, Tax Withholding, Share-Based Payment Arrangement Amortization, accretion and depreciation Depreciation, Amortization and Accretion, Net Unearned premiums Increase (Decrease) in Unearned Premiums Line of Credit Line of Credit [Member] Restatement Determination Date Restatement Determination Date Gross Amounts Offset in the Balance Sheet Derivative Asset, Subject to Master Netting Arrangement, Collateral, Obligation to Return Cash, Offset Against Derivative Asset Derivative Instrument [Axis] Derivative Instrument [Axis] Reinsurance balances payable Reinsurance Payable Standard & Poor's, A- Rating Standard & Poor's, A- Rating [Member] Amendment Flag Amendment Flag Consolidated Entities [Axis] Consolidated Entities [Axis] Shares repurchased, average price per share (in dollars per share) Shares Acquired, Average Cost Per Share Debt and Equity Securities, FV-NI [Line Items] Debt and Equity Securities, FV-NI [Line Items] Credit default swaps Credit Default Swap [Member] Non-company unobservable input Valuation Technique, Not Developed By Company [Member] Valuation Technique, Not Developed By Company Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding Total catastrophe and attritional net claims and claim expenses Large and Small Catastrophe Events And Attritional Loss Movements [Member] Large and Small Catastrophe Events And Attritional Loss Movements [Member] NumberOfAuthorizedSharesNotDisclosed NumberOfAuthorizedSharesNotDisclosed NumberOfAuthorizedSharesNotDisclosed Claims and Claim Expenses Policyholder Benefits and Claims Incurred, Net [Abstract] Net investment income (Note 3) Net investment income Net investment income Net Investment Income Number of segregated accounts Number Of Segregated Accounts Number Of Segregated Accounts Asset-backed Asset-Backed Securities [Member] Investment Type Categorization [Domain] Investments [Domain] Amortized  Cost Debt Securities, Trading, and Equity Securities, FV-NI, Cost [Abstract] Consolidated Entities [Domain] Consolidated Entities [Domain] Proceeds from sales of equity investments Proceeds From Trading Securities, Short-Term Proceeds From Trading Securities, Short-Term Redemptions of third-party redeemable noncontrolling interest shares Payments to Noncontrolling Interests Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Due in less than one year Trading Securities, Debt Maturities, Within One Year, Amortized Cost Basis This item represents debt securities, at cost, net of adjustments including accretion, amortization and collection of cash, if any, which are expected to mature within one year of the balance sheet date and are categorized as trading securities. 3.450% Senior Notes due 2027 3.450% Senior Notes Due July 1 2027 [Member] 3.450% Senior Notes Due July 1 2027 [Member] PEO Total Compensation Amount PEO Total Compensation Amount Accumulated other comprehensive income (loss) Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Common shares, par value (in dollars per share) Common Stock, Par or Stated Value Per Share 2023 Large Loss Events 2023 Large Loss Events [Member] 2023 Large Loss Events Proceeds from sales and maturities of fixed maturity investments trading Proceeds from Sale and Maturity, Debt Security, Trading, and Equity Security, FV-NI, Held-for-Investment Catastrophic Event [Domain] Catastrophic Event [Domain] Participating, Non-voting Common Shares Participating, Non-voting Common Shares [Member] Participating, Non-voting Common Shares [Member] Derivative, notional amount Derivative, Notional Amount Denominator for basic income (loss) per RenaissanceRe common share - weighted average common shares (in shares) Weighted Average Number of Shares Outstanding, Basic PFZW Stichting Pensioenfonds Zorg en Welzijn [Member] Stichting Pensioenfonds Zorg en Welzijn Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Direct Direct Premiums Earned Number of reportable segments Number of Reportable Segments Deferred acquisition costs and value of business acquired Increase (Decrease) in Deferred Policy Acquisition Costs Liquidation period for fund assets Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period Equity exchange traded funds Equity Exchange Traded Funds [Member] Equity Exchange Traded Funds ACR Liability for Unpaid Claims and Claims Adjustment Expense, Additional Case Reserves, Amount Liability for Unpaid Claims and Claims Adjustment Expense, Additional Case Reserves, Amount Entity Address, City or Town Entity Address, City or Town 3.600% Senior Notes due 2029 3.600% Senior Notes Due 2029 [Member] 3.600% Senior Notes Due 2029 [Member] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Dividends paid – preference shares Payments of Ordinary Dividends, Preferred Stock and Preference Stock Class of Stock [Axis] Class of Stock [Axis] Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Return of investments in other ventures Proceeds from Equity Method Investment, Distribution, Return of Capital Net incurred related to: Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract] Net income (loss) available (attributable) to RenaissanceRe common shareholders Net income (loss) available (attributable) to RenaissanceRe common shareholders Net Income (Loss) Available to Common Stockholders, Basic 2025 Large Loss Events 2025 Large Loss Events [Member] 2025 Large Loss Events Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Provision for (release of) allowance Reinsurance Recoverable, Credit Loss Expense (Reversal) Insurance Loss Reserves [Abstract] Insurance Loss Reserves [Abstract] Dividends on preference shares (Note 10) Dividends on preference shares (Note 10) Dividends on preference shares Dividends on preference shares Dividends, Preferred Stock Subsequent Event Type [Axis] Subsequent Event Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Net income (loss) attributable to redeemable noncontrolling interest, net of consolidation adjustments Net Income (Loss) Attributable To Redeemable Noncontrolling Interest, Net Of Adjustments Net Income (Loss) Attributable To Redeemable Noncontrolling Interest, Net Of Adjustments Investment expenses Investment Income, Investment Expense Schedule of Investment Income, Reported Amounts, by Category [Table] Investment Income [Table] Fixed Maturity Investment-Related Derivatives Fixed Maturity Investment-Related Derivatives [Member] Fixed Maturity Investment-Related Derivatives Provision for (release of) allowance Premium Receivable, Credit Loss Expense (Reversal) Schedule of Significant Components of the Company's Revenues and Expenses by Segment Segment Reporting [Table Text Block] Net undiscounted cash flows Measurement Input, Undiscounted Cash Flows [Member] Measurement Input, Undiscounted Cash Flows [Member] Use of Estimates in Financial Statements Use of Estimates, Policy [Policy Text Block] NONCONTROLLING INTERESTS Noncontrolling Interest Disclosure [Text Block] Schedule of Liabilities Measured at Fair Value on a Recurring Basis Using Level 3 Inputs Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Repayment of Medici Revolving Credit Facility Repayments of Lines of Credit 2022 Weather-Related Large Losses 2022 Weather-Related Large Losses [Member] 2022 Weather-Related Large Losses Debt (Note 7) Debt Long-Term Debt Casualty and Specialty Casualty and Specialty Casualty and Specialty Segment [Member] Casualty and Specialty Segment [Member] Ceded Credit Risk, Collateralization [Domain] Ceded Credit Risk, Collateralization [Domain] Document Period End Date Document Period End Date Change in: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Net cash provided by (used in) investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Due after five through ten years Trading Securities, Debt Maturities, After Five Through Ten Years, Amortized Cost Basis This item represents debt securities, at cost, net of adjustments including accretion, amortization and collection of cash, if any, which are expected to mature within one through 5 years of the balance sheet date and are categorized as trading securities. Collateral Received Derivative Asset, Subject to Master Netting Arrangement, Collateral, Obligation to Return Cash Not Offset Preference shares, shares outstanding (in shares) Preferred Stock, Shares Outstanding SHAREHOLDERS’ EQUITY Equity [Text Block] Net assets Net Assets Security Exchange Name Security Exchange Name Commodity Commodity [Member] Change in redeemable noncontrolling interests Noncontrolling Interest, Period Increase (Decrease) Third Party Investor Investor [Member] Proceeds from noncontrolling interests Proceeds from Noncontrolling Interests Fair Value, Inputs, Level 1, 2 and 3 Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Gross premiums written (Note 5) Gross premiums written Premiums Written, Gross Position [Axis] Position [Axis] Reinsurance Recoverable Reinsurance Recoverable Including Reinsurance Premium Paid [Member] Agencies Agency Securities [Member] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Reinsurance balances payable Increase (Decrease) in Reinsurance Payables Claims and claim expenses recovered Policyholder Benefits and Claims Incurred, Assumed and Ceded Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Consolidation Items [Domain] Consolidation Items [Domain] Net claims and claim expense ratio – current accident year Net Claims and Claims Expense Ratio Current Year Net claims and claim expense ratio - current accident year is derived by dividing net claims and claim expense - current accident year by net premiums earned. Underwriting income (loss) Underwriting Income (Loss) Net Net premiums earned less net claims and claim expenses incurred, acquisition expenses and operational expenses directly related to underwriting activities. Medici RenaissanceRe Medici Fund Ltd. [Member] RenaissanceRe Medici Fund Ltd. [Member] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] EARNINGS PER SHARE Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Earnings Per Share [Abstract] Earnings Per Share [Abstract] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Document Fiscal Period Focus Document Fiscal Period Focus Fontana Fontana Holdings L.P. [Member] Fontana Holdings L.P. [Member] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Redeemable Noncontrolling Interest, by Legal Entity [Table] Redeemable Noncontrolling Interest [Table] Total liabilities Liabilities Liabilities Trading Symbol Trading Symbol Discount rate Measurement Input, Discount Rate [Member] 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] Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Expected loss ratio Measurement Input, Expected Loss Ratio [Member] Measurement Input, Expected Loss Ratio [Member] Company Selected Measure Name Company Selected Measure Name Schedule of Investments [Table] Schedule of Investments [Table] RenaissanceRe Upsilon Diversified Fund RenaissanceRe Upsilon Diversified Fund [Member] RenaissanceRe Upsilon Diversified Fund Other investments, at fair value (Notes 3 and 4) Total other investments Other investments Other Long-Term Investments Payments to acquire Interest in subsidiaries and affiliates Payments to Acquire Interest in Subsidiaries and Affiliates Voting, Non-participating Shares Voting, Non-participating Shares [Member] Voting, Non-participating Shares [Member] Purchases of other investments Payments to Acquire Other Investments Parent company ownership in redeemable noncontrolling interest Subsidiary, Ownership Percentage, Parent Transfer in kind from existing investors Noncontrolling Interest, Increase from Subsidiary Equity Issuance, Transfer In Kind From Existing Investors Noncontrolling Interest, Increase from Subsidiary Equity Issuance, Transfer In Kind From Existing Investors Weighted average U.S. dollar equivalent of foreign denominated net assets (liabilities) Derivative, Weighted Average U.S. Dollar Equivalent Of Foreign Denominated Net Assets Derivative, Weighted Average U.S. Dollar Equivalent Of Foreign Denominated Net Assets Unfunded Commitments Other Investments, Unfunded Commitments [Member] Other Investments, Unfunded Commitments Internal valuation model Internal Valuation Model Valuation Technique [Member] Internal Valuation Model Valuation Technique [Member] Credit Facility [Domain] Credit Facility [Domain] Reserve for claims and claim expenses (Note 6) Total Reserve for claims and claim expenses, end of period Reserve for claims and claim expenses Liability for Claims and Claims Adjustment Expense Cash flows provided by (used in) operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Ceded Credit Risk, Secured Ceded Credit Risk, Secured [Member] Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Denominator for diluted income (loss) per RenaissanceRe common share - adjusted weighted average common shares and assumed conversions (in shares) Weighted Average Number of Shares Outstanding, Diluted Entity Emerging Growth Company Entity Emerging Growth Company Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Line of Credit Facility [Table] Line of Credit Facility [Table] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Schedule of Components of Net Investment Income Investment Income [Table Text Block] Drawdown of Medici Revolving Credit Facility Proceeds from Lines of Credit Fontana Third Party Investors Fontana Third Party Investors [Member] Fontana Third Party Investors DERIVATIVE INSTRUMENTS Derivative Instruments and Hedging Activities Disclosure [Text Block] U.S. treasuries US Treasury Securities [Member] Entities [Table] Entities [Table] Other investments, maximum exposure to loss Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Gross Amounts Recognized Derivative Liability, Subject to Master Netting Arrangement, before Offset Schedule of Assets Measured at Fair Value on a Recurring Basis Using Level 3 Inputs Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] RenaissanceRe Holdings Ltd. RenaissanceRe Holdings Ltd. [Member] RenaissanceRe Holdings Ltd. [Member] Accrued investment income Accrued Investment Income Receivable Other Increase (Decrease) in Other Operating Assets and Liabilities, Net Issuance of performance share and restricted stock awards (Note 10) Shares Issued, Value, Share-Based Payment Arrangement, After Forfeiture, Net Shares Issued, Value, Share-Based Payment Arrangement, After Forfeiture, Net Award Timing Predetermined Award Timing Predetermined [Flag] Net realized and unrealized gains (losses) on other investments Debt Securities, Gain (Loss) Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Net claims and claim expenses incurred (Notes 5 and 6) Net claims and claim expenses incurred Net claims and claim expenses incurred Policyholder Benefits and Claims Incurred, Net Short-term investments, amortized cost Other Short-Term Investments, Amortized Cost Other Short-Term Investments, Amortized Cost Quoted Prices in Active Markets for Identical  Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Reserve for claims and claim expenses, net of reinsurance recoverable, beginning of period Reserve for claims and claim expenses, net of reinsurance recoverable, end of period Liability for Unpaid Claims and Claims Adjustment Expense, Net Purchases of fixed maturity investments trading Payment for Acquisition, Trading Security, Held-for-Investment Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Noncatastrophic Event [Domain] Noncatastrophic Event [Domain] Fair Value Measurements Fair Value of Financial Instruments, Policy [Policy Text Block] Per common share equivalents of non-vested shares (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Redeemable Noncontrolling Interest [Line Items] Redeemable Noncontrolling Interest [Line Items] IBNR Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Claims, Amount All Executive Categories All Executive Categories [Member] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Repurchase of shares (Note 10) Value of shares repurchased Stock Repurchased and Retired During Period, Value Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Residential mortgage-backed Residential Mortgage-Backed Securities [Member] Preference shares, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Long-term debt Long-Term Debt, Fair Value Redeemable noncontrolling interests (Note 8) Redeemable noncontrolling interests Beginning balance Ending balance Redeemable Noncontrolling Interest, Equity, Carrying Amount Fund and direct private equity investments Fund And Direct Private Equity Investments [Member] Fund And Direct Private Equity Investments Significant observable and unobservable inputs Alternative Investment, Measurement Input Concentration Risk Type [Domain] Concentration Risk Type [Domain] Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Net paid related to: Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract] 2020 Weather-Related Large Loss Events 2020 Weather-Related Large Loss Events [Member] 2020 Weather-Related Large Loss Events Derivative Liability, Statement of Financial Position [Extensible Enumeration] Derivative Liability, Statement of Financial Position [Extensible Enumeration] Schedule of Computation of Basic and Diluted Earnings Per Common Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fixed maturity investments trading, amortized cost Amortized  Cost Debt Securities, Trading, Amortized Cost Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Reinsurance recoverable (Notes 5 and 6) Reinsurance recoverable, end of period Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments SEGMENT REPORTING Segment Reporting [Text Block] INVESTMENTS Investment in Debt and Equity Securities and Other Trading Assets [Text Block] Issued or Drawn Long-Term Line of Credit Minimum Minimum [Member] Investment Type [Axis] Investment Type [Axis] Dividends paid – common shares Payments of Ordinary Dividends, Common Stock Unfunded Commitments Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Expiration Date Trading Arrangement Expiration Date Hedging Relationship [Axis] Hedging Relationship [Axis] VARIABLE INTEREST ENTITIES Variable Interest Entity Disclosure [Text Block] Liabilities Liabilities [Abstract] Denominator: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Effect of exchange rate changes on foreign currency cash Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement Location [Axis] Location, Statement of Income, Balance [Axis] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] 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] Liquidity discount Measurement Input, Liquidity [Member] Measurement Input, Liquidity [Member] Investment-related derivatives Derivative [Member] Other liabilities Other Liabilities Dividends on common shares (Note 10) Dividends on common shares Dividends, Common Stock Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Derivative [Table] Derivative [Table] Fixed income exchange traded funds Fixed Income Funds [Member] Equity Investment-Related Derivatives Equity Investment-Related Derivatives [Member] Equity Investment-Related Derivatives Numerator: Earnings Per Share Reconciliation [Abstract] Premiums Earned Premiums Written and Earned [Abstract] Schedule of Debt Obligations Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Exercise Price Award Exercise Price Cash flows provided by (used in) investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Segment Reporting [Line Items] Segment Reporting [Line Items] Share repurchase program, authorized amount Share Repurchase Program, Authorized, Amount Document Quarterly Report Document Quarterly Report Derivative Assets Derivative Asset [Abstract] 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] Segment [Domain] Segments [Domain] Interest rate swaps Interest Rate Swap [Member] DEBT AND CREDIT FACILITIES Debt Disclosure [Text Block] Prior years Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years Derivative Liabilities Derivative Liability [Abstract] Investors of Upsilon RFO Diversified IV Investors Of Upsilon RFO Diversified IV [Member] Investors Of Upsilon RFO Diversified IV Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Investments in other ventures, under equity method Equity Method Investments Equity Component [Domain] Equity Component [Domain] Deferred acquisition costs and value of business acquired Deferred Policy Acquisition Cost PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Measurement Input Type [Domain] Measurement Input Type [Domain] Expenses Benefits, Losses and Expenses [Abstract] Other Other Common Stock Investments [Member] Other Common Stock Investments Adoption Date Trading Arrangement Adoption Date Purchases of investments in other ventures Payments to Acquire Equity Method Investments Stated interest rate Debt Instrument, Interest Rate, Stated Percentage Liability for Claims and Claims Adjustment Expense [Line Items] Liability for Claims and Claims Adjustment Expense [Line Items] Premium receivable, allowance for credit loss Beginning balance Ending balance Premium Receivable, Allowance for Credit Loss Counterparty Name [Domain] Counterparty Name [Domain] Total shareholders’ equity attributable to RenaissanceRe Beginning balance Ending balance Equity, Attributable to Parent Payable for investments purchased Broker-Dealer, Payable to Other Broker-Dealer and Clearing Organization Equity investments, at fair value (Notes 3 and 4) Total equity investments Equity investments Equity Securities, FV-NI, Current Assets Assets [Abstract] Receivable for investments sold Receivable from Broker-Dealer and Clearing Organization Title Trading Arrangement, Individual Title Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount 2017 Large Loss Events 2017 Large Loss Events [Member] 2017 Large Loss Events [Member] Allowance for Reinsurance Recoverable SEC Schedule, 12-09, Allowance, Reinsurance Recoverable [Member] Payments of capital distribution Payments of Capital Distribution Direct Direct Premiums Written Accounting Policies [Abstract] Accounting Policies [Abstract] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Actuarial methods - actual reported claims less than expected claims Reported Claims Less than Expected [Member] Reported Claims Less than Expected [Member] Net income (loss) available (attributable) to RenaissanceRe common shareholders per common share – diluted (in dollars per share) Earnings Per Share, Diluted, Undistributed Insider Trading Policies and Procedures [Line Items] Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Schedule of Outstanding Amounts Issued or Drawn under Credit Facilities Schedule of Line of Credit Facilities [Table Text Block] 2024 Large Loss Events 2024 Large Loss Events [Member] 2024 Large Loss Events Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Current year Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year Total net incurred Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims Due after one through five years Trading Securities, Debt Maturities, After One Through Five Years, Amortized Cost Basis This item represents debt securities, at cost, net of adjustments including accretion, amortization and collection of cash, if any, which are expected to mature within one year of the balance sheet date and are categorized as trading securities. Repayment of debt Repayments of Debt Maturity period Investment Owned, Maturity Period Investment Owned, Maturity Period Letter of Credit Letter of Credit [Member] Sale of shares to redeemable noncontrolling interests Sale of shares to redeemable noncontrolling interests, net of adjustments Noncontrolling Interest, Increase from Subsidiary Equity Issuance COMMITMENTS, CONTINGENCIES AND OTHER ITEMS Commitments and Contingencies Disclosure [Text Block] Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Proceeds from sales of short term investments Proceeds from Sale of Short-Term Investments Entity Central Index Key Entity Central Index Key Weighted Average or Actual Weighted Average [Member] Total small catastrophe events and attritional loss movements Other Catastrophe Events And Attritional Loss Movements [Member] Small Catastrophe Events And Attritional Loss Movements [Member] Premiums Written Premiums Written, Net [Abstract] All Adjustments to Compensation All Adjustments to Compensation [Member] Other Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] Ross Curtis [Member] Ross Curtis 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] Net cash provided by (used in) operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Customer Three Customer Three [Member] Customer Three Prior years Total net (favorable) adverse development of prior accident years net claims and claim expenses Net claims and claim expenses incurred – prior accident years Prior Year Claims and Claims Adjustment Expense Income Statement [Abstract] Income Statement [Abstract] Shareholders’ Equity Equity, Attributable to Parent [Abstract] Fund investments Senior Secured Bank Loan Funds [Member] An investment that primarily invests in bank loans and other senior debt instruments. Document Transition Report Document Transition Report Ownership [Axis] Ownership [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Schedule of Investments [Line Items] Schedule of Investments [Line Items] Net realized and unrealized (gains) losses on investments Gain (Loss) on Investments Investment, Name [Axis] Investment, Name [Axis] Liability for Claims and Claims Adjustment Expense [Table] Liability for Claims and Claims Adjustment Expense [Table] Derivative instruments designated as hedges Designated as Hedging Instrument [Member] Dividend rate, percentage Preferred Stock, Dividend Rate, Percentage Series G Preferred Stock Series G Preferred Stock [Member] Fixed maturity investments trading Fixed Maturities [Member] Deferred tax asset Deferred Income Tax Assets, Net Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Schedule of Effect of Reinsurance and Retrocessional Activity on Premiums Written and Earned and on Net Claims and Claim Expenses Incurred Effects of Reinsurance [Table Text Block] Reinsurance recoverable Reinsurance Recoverables, Including Reinsurance Premium Paid City Area Code City Area Code Accumulated other comprehensive income (loss) AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] SUBSEQUENT EVENTS Subsequent Events [Text Block] Unobservable measurement input Debt Securities, Trading, Measurement Input Payments of dividends Payments of Dividends 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] Standard & Poor's, BBB Rating Standard & Poor's, BBB+ Rating [Member] Liquidation preference quarterly (in dollars per share) Preferred Stock, Liquidation Preference Per Share, Quarterly Preferred Stock, Liquidation Preference Per Share, Quarterly Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Vermeer Vermeer Reinsurance Ltd. [Member] Vermeer Reinsurance Ltd. [Member] Proceeds from sales of other investments Proceeds from Sale of Other Investments Statement of Changes in Stockholders' Equity Statement [Line Items] Total assets Assets Assets Entity [Domain] Entity [Domain] Direct private equity investments Private equity funds Private Equity Funds [Member] Charge-offs Premium Receivable, Allowance for Credit Loss, Writeoff Net realized gains (losses) Equity Securities, FV-NI, Realized Gain (Loss) Preference shares, shares issued (in shares) Preferred Stock, Shares Issued Depositary Shares, each representing a 1/1,000th interest in a Series F 5.750% Preference Share, Par Value $1.00 per share Depositary Shares, each representing a 1/1,000th interest in a Series F 5. [Member] Depositary Shares, each representing a 1/1,000th interest in a Series F 5. [Member] Industry Sector [Axis] Industry Sector [Axis] Variable Interest Entity, Not Primary Beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] Operating Segments Operating Segments [Member] Subscriptions of third-party redeemable noncontrolling interest shares Proceeds From Repurchase Of Redeemable Noncontrolling Interest Proceeds From Repurchase Of Redeemable Noncontrolling Interest Interest expense (Note 7) Interest expense Interest Expense, Nonoperating Total assets and (liabilities) measured at fair value on a recurring basis using Level 3 inputs Fair Value, Net Asset (Liability) 7.003% Senior Notes due 2035 (Fontana) 7.003% Senior Notes Due 2035 [Member] 7.003% Senior Notes Due 2035 PEO PEO [Member] Other Assets and (Liabilities) Other Assets (Liabilities) Member The fair value of other assets and liabilities included in the Company's total other assets and liabilities. Large catastrophe events Large Catastrophe Events [Member] Large Catastrophe Events [Member] Share repurchase program, shares repurchased (in shares) Stock Repurchased and Retired During Period, Shares Measurement Basis [Axis] Measurement Basis [Axis] Reinsurer Concentration Risk Reinsurer Concentration Risk [Member] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Fair Value Measurement Inputs and Valuation Techniques [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Total investments Investments Investments Investment in participating notes Variable Interest Entity, Investment In Participating Notes Variable Interest Entity, Investment In Participating Notes Ceded Credit Risk, Unsecured Ceded Credit Risk, Unsecured [Member] Equity investments Equity investments Equity Securities, FV-NI, Gain (Loss) Subsequent Event Type [Domain] Subsequent Event Type [Domain] Retained earnings Retained Earnings [Member] Revolving Credit Facility Revolving Credit Facility [Member] Net investment income Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings [Abstract] Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Assets Held-in-trust Asset, Held-in-Trust Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Change in net unrealized gains (losses) on investments, net of tax Change in net unrealized gains (loss) on investments, net of tax OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Common shares, shares outstanding (in shares) Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Corporate Corporate Debt Securities [Member] Foreign exchange and other Liability for Unpaid Claims and Claims Adjustment Expense, Foreign Currency Translation Gain (Loss) Entity Current Reporting Status Entity Current Reporting Status Net cash provided by (used in) financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Total Shareholder Return Amount Total Shareholder Return Amount Net unrealized gains recognized in earnings Unrealized Gain (Loss) on Investments Reverse repurchase agreements Securities for Reverse Repurchase Agreements Included in earnings (loss) Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract] SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract] Customer Two Customer Two [Member] Customer Two Ownership [Domain] Ownership [Domain] Fair Value Debt Securities, Trading, and Equity Securities, FV-NI [Abstract] Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Ceded Credit Risk [Line Items] Ceded Credit Risk [Line Items] Net premiums written (Note 5) Net premiums written Net premiums written Premiums Written, Net DaVinciRe Holdings Ltd. DaVinciRe Holdings Ltd. [Member] DaVinciRe Holdings Ltd. Third-Party Investors Third-Party Investors [Member] Third-Party Investors Cash flows provided by (used in) financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Schedule of Investment Income, Reported Amounts, by Category [Line Items] Net Investment Income [Line Items] Financial Instruments [Domain] Financial Instruments [Domain] Prepaid reinsurance premiums Increase (Decrease) in Prepaid Reinsurance Premiums Prepaid reinsurance premiums Prepaid Reinsurance Premiums Share repurchase requests, limit Minority Interest, Aggregate Share Repurchase Request, Limit As Percent Of Capital This item limits the aggregate of all share repurchase requests to 25% of DaVinciRe's capital in any given year and satisfying all applicable regulatory requirements. If total shareholder requests exceed 25% of DaVinciRe's capital, the number of shares repurchased will be reduced among the requesting shareholders pro-rata, based on the amounts desired to be repurchased. Derivative assets Net Amounts Presented in the Balance Sheet Derivative Asset Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Underlying Securities Award Underlying Securities Amount Purchases of short term investments Payments to Acquire Short-Term Investments Comprehensive (income) loss attributable to redeemable noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Fair Value Estimate of Fair Value Measurement [Member] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] AlphaCat Managers Ltd AlphaCat Managers Ltd [Member] AlphaCat Managers Ltd Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Derivative Asset, Statement of Financial Position [Extensible Enumeration] Derivative Asset, Statement of Financial Position [Extensible Enumeration] Net Amount Derivative Liability, Including Not Subject to Master Netting Arrangement, after Offset and Deduction Assumed Assumed Premiums Written Preference shares Preferred Stock [Member] Debt Securities, Trading, Unrealized Gain (Loss) Debt Securities, Trading, Unrealized Gain (Loss) Schedule of Gain (Loss) on Securities [Table] Schedule of Gain (Loss) on Securities [Table] RenaissanceRe Finance, Inc. RenaissanceRe Finance Inc. [Member] RenaissanceRe Finance Inc. [Member] Net income (loss) allocated to RenaissanceRe common shareholders Undistributed Earnings, Basic Segment Reporting [Table] Segment Reporting [Table] Liability for Catastrophe Claims [Table] Liability for Catastrophe Claims [Table] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] All Trading Arrangements All Trading Arrangements [Member] Amount of gain (loss) recognized on derivatives Derivative, Gain (Loss) on Derivative, Net Schedule of Quantitative Information Used as Level 3 Inputs 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] Assumed reinsurance contract Assumed and Ceded Re Insurance Contracts, Group Two [Member] Assumed and Ceded Re Insurance Contracts, Group Two [Member] Liability for Catastrophe Claims [Line Items] Liability for Catastrophe Claims [Line Items] Current Fiscal Year End Date Current Fiscal Year End Date Issuance of debt, net of expenses Proceeds from Issuance of Debt Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Derivative [Line Items] Derivative [Line Items] Financials Financial Services Sector [Member] Non-U.S. government 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] Dividends declared per common share (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity File Number Entity File Number Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Investment owned, fair value Investment Owned, Fair Value Schedule of Contractual Maturities of Fixed Maturity Investments Investments Classified by Contractual Maturity Date [Table Text Block] Equity investments Equity Securities [Member] Secured Secured Bilateral Facility [Member] Secured Bilateral Facility [Member] Dividends on common shares Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Schedule of Claims and Claim Expenses Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block] RenaissanceRe Medici UCITS Fund RenaissanceRe Medici UCITS Fund [Member] RenaissanceRe Medici UCITS Fund Recovery of Erroneously Awarded Compensation Disclosure [Line Items] 5.950% Senior Notes due 2035 (DaVinci) 5.950% Senior Notes Due 2035 [Member] 5.950% Senior Notes Due 2035 Common shares, shares issued (in shares) Common Stock, Shares, Issued Measure: Measure [Axis] Beginning balance Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Schedule of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Entity Information [Line Items] Entity Information [Line Items] Net premiums earned (Note 5) Net premiums earned Premiums Earned, Net Equity in undistributed (earnings) losses of other ventures Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Decrease (increase) in unearned premiums (Increase) Decrease in Unearned Premiums, Net Due in less than one year Trading Securities, Debt Maturities, Within One Year, Fair Value This item represents the fair value of debt securities which are expected to mature within one year of the balance sheet date and are categorized as trading securities. Equity Components [Axis] Equity Components [Axis] Class of Stock [Line Items] Class of Stock [Line Items] Entity Interactive Data Current Entity Interactive Data Current Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Small Business Entity Small Business Due after ten years Trading Securities, Debt Maturities, After Ten Years, Fair Value This item represents the fair value of debt securities which are expected to mature after ten years of the balance sheet date and are categorized as trading securities. Comprehensive income (loss) attributable to RenaissanceRe Comprehensive Income (Loss), Net of Tax, Attributable to Parent Unearned premiums Unearned Premiums Premium Receivable, Allowance for Credit Loss [Roll Forward] Premium Receivable, Allowance for Credit Loss [Roll Forward] Termination Date Trading Arrangement Termination Date Number of business days required for redemption notice Noncontrolling Interest, Redemption Notice Required, Number Of Business Days Noncontrolling Interest, Redemption Notice Required, Number Of Business Days Subsequent Events [Abstract] Subsequent Events [Abstract] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Schedule of Other Investments Securities Owned and Other Investments Not Readily Marketable Disclosure [Table Text Block] Schedule of Other Investments Measured Using Net Asset Valuations Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table Text Block] 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] Net Amount Derivative Asset, Including Not Subject to Master Netting Arrangement, after Offset and Deduction Mona Lisa Re Mona Lisa Re [Member] Mona Lisa Re [Member] Baltimore Bridge Collapse Baltimore Bridge Collapse [Member] Baltimore Bridge Collapse Current year Net claims and claim expenses incurred – current accident year Current Year Claims and Claims Adjustment Expense Document Type Document Type 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 Short Short [Member] SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] Commodity futures Commodity Futures [Member] Commodity Futures Series F Preferred Shares, Depositary Shares Series F Preferred Shares, Depositary Shares [Member] Series F Preferred Shares, Depositary Shares Activity in redeemable noncontrolling interest Increase (Decrease) in Temporary Equity [Roll Forward] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Remaining authorized repurchase amount Share Repurchase Program, Remaining Authorized, Amount Cash and cash equivalents Cash and Cash Equivalents [Member] Foreign currency translation adjustments, net of tax Foreign currency translation adjustments, net of tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Operational expenses Operational expenses Operating Costs and Expenses Arrangement Duration Trading Arrangement Duration Subsequent Event [Line Items] Subsequent Event [Line Items] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Fixed maturity investments trading Fixed maturity investments trading Debt Securities, Trading, Gain (Loss) Schedule of Trading Securities and Other Trading Assets [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 2018 Large Loss Events 2018 Large Loss Events [Member] 2018 Large Loss Events [Member] Short term investments, at fair value - amortized cost $3,952,780 at June 30, 2026 (December 31, 2025 - $4,760,027) (Notes 3 and 4) Short term investments Other Short-Term Investments Net Investment Hedging Net Investment Hedging [Member] Reinsurance recoverable, allowance for credit loss Beginning balance Ending balance Reinsurance Recoverable, Allowance for Credit Loss Income (loss) before taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Property Property Property Segment [Member] Property Segment [Member] Commitments and contingencies (Note 14) Commitments and Contingencies Total revenues Revenues Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Equity in earnings (losses) of other ventures Equity in earnings (losses) of other ventures Income (Loss) from Equity Method Investments Fund investments Fund Investments [Member] Fund Investments Gain (Loss) on Securities [Line Items] Gain (Loss) on Securities [Line Items] Fair value Fair Value Alternative Investment Purchases of equity investments Payments To Acquire Trading Securities, Short-Term Payments To Acquire Trading Securities, Short-Term Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount 5.750% Senior Notes due 2033 5.750% Senior Notes Due 2033 [Member] 5.750% Senior Notes Due 2033 External Credit Rating, Standard & Poor's [Domain] External Credit Rating, Standard & Poor's [Domain] Due after one through five years Trading Securities, Debt Maturities, After One Through Five Years, Fair Value This item represents the fair value of debt securities which are expected to mature after one through five years of the balance sheet date and are categorized as trading securities. Executive Category: Executive Category [Axis] Counterparty Name [Axis] Counterparty Name [Axis] Liabilities, Noncontrolling Interests and Shareholders’ Equity Liabilities and Equity [Abstract] Net claims and claim expense ratio – prior accident years Net Claims And Claim Expense Ratio Prior Years Net claims and claim expense ratio - prior accident years is derived by dividing net claims and claim expenses - prior accident years by net premiums earned. REINSURANCE Reinsurance [Text Block] Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] All Award Types Award Type [Domain] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount 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] Private credit funds Private Credit Funds [Member] Private Credit Funds Redemption provision, notice period Noncontrolling Interest, Redemption Provision, Notice Period Noncontrolling Interest, Redemption Provision, Notice Period Noncontrolling ownership percentage Subsidiary, Ownership Percentage, Noncontrolling Owner PEO Name PEO Name Total net paid Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid Series G Preferred Shares, Depositary Shares Series G Preferred Shares, Depositary Shares [Member] Series G Preferred Shares, Depositary Shares Summary of Derivative Instruments [Abstract] Summary of Derivative Instruments [Abstract] Due after five through ten years Trading Securities, Debt Maturities, After Five Through Ten Years, Fair Value This item represents the fair value of debt securities which are expected to mature after five through ten years of the balance sheet date and are categorized as trading securities. Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share [Member] Renaissance Reinsurance Ltd. Renaissance Reinsurance Ltd. [Member] Renaissance Reinsurance Ltd. [Member] 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 Multi-strategy funds Multi-Strategy Funds [Member] Multi-Strategy Funds Legal Entity [Axis] Legal Entity [Axis] Net settlements of derivatives Payments for (Proceeds from) Derivative Instrument, Investing Activities Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Collateral Pledged Derivative Liability, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Cash Not Offset Gross claims and claim expenses incurred Policyholder Benefits and Claims Incurred, Direct Depositary Shares, each representing a 1/1,000th interest in a Series G 4.20% Preference Share, Par Value $1.00 per share Depositary Shares, Each Representing a 1/1,000th Interest in a Series G 4 [Member] Depositary Shares, Each Representing a 1/1,000th Interest in a Series G 4 Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Direct private equity investments Direct Private Equity Investments Direct Private Equity Investments [Member] Direct Private Equity Investments Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table] Equity futures Equity Contract [Member] Net income (loss) available (attributable) to RenaissanceRe common shareholders per common share – basic (in dollars per share) Earnings Per Share, Basic, Undistributed 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 (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Debt Instrument [Axis] Debt Instrument [Axis] Equity investments Equity Securities, FV-NI, Gain (Loss) [Abstract] Subsequent Event [Table] Subsequent Event [Table] Long Long [Member] Redemptions of third-party redeemable noncontrolling interest shares Payments for Repurchase of Redeemable Noncontrolling Interest Carrying Amount Other Investments, Funded Commitments [Member] Other Investments, Funded Commitments Investment, Name [Domain] Investment, Name [Domain] Customer [Domain] Customer [Domain] Net realized and unrealized gains (losses) on investment-related derivatives Derivative Instruments Not Designated As Hedging Instruments Investment Portfolio Gain Loss Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments and relating to the entity's investment portfolio. NOC1 NOC1 [Member] NOC1 Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Schedule of Gross and Net Amounts of Recognized Derivative Assets and Liabilities at Fair Value Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Noncatastrophic Event [Axis] Noncatastrophic Event [Axis] Measurement Input Type [Axis] Measurement Input Type [Axis] RenaissanceRe common share repurchases Payments for Repurchase of Common Stock Mortgage-backed Collateralized Mortgage-Backed Securities [Member] Statistical Measurement [Axis] Statistical Measurement [Axis] Insider Trading Arrangements [Line Items] Schedule of Location and Amount of the Gain (Loss) Recognized Derivative Instruments, Gain (Loss) [Table Text Block] Award Type Award Type [Axis] Interest rate futures Interest Rate Contract [Member] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] 2021 Weather-Related Large Losses 2021 Weather-Related Large Losses [Member] 2021 Weather-Related Large Losses Case Reserves Liability for Unpaid Claims and Claims Adjustment Expense, Reported Claims, Amount Retained earnings (Note 10) Retained Earnings (Accumulated Deficit) Actuarial assumption changes Change In Actuarial Assumption [Member] Change In Actuarial Assumption Unsecured Unsecured Bilateral Facility [Member] Unsecured Bilateral Facility [Member] Acquisition expenses Acquisition expenses Deferred Policy Acquisition Costs, Amortization Expense 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] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Common Shares, Par Value $1.00 per share Common shares Common stock Common Stock [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Foreign currency forward contracts Foreign currency forward contracts, underwriting and non-investment operations Foreign Currency Forward Contracts, Underwriting and Non-investment Operations [Member] Foreign Currency Forward Contracts, Underwriting Operations Related Foreign Currency Contracts [Member] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Cover [Abstract] Cover [Abstract] Noncontrolling Interest [Abstract] Upsilon RFO Re Ltd. Upsilon RFO Re Ltd. [Member] Upsilon RFO Re Ltd. [Member] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Derivative Contract Type [Domain] Derivative Contract [Domain] Concentration risk, percentage Concentration Risk, Percentage Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward] Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward] Equity Awards Adjustments Equity Awards Adjustments [Member] Hedging Relationship [Domain] Hedging Relationship [Domain] Assumed Assumed Premiums Earned 5.800% Senior Notes due 2035 5.800% Senior Notes Due 2035 [Member] 5.800% Senior Notes Due 2035 Total liabilities, noncontrolling interests and shareholders’ equity Liabilities and Equity Goodwill and other intangible assets Intangible Asset, Including Goodwill, after Accumulated Amortization Employee Stock Option Share-Based Payment Arrangement, Option [Member] Ceded Credit Risk [Table] Ceded Credit Risk [Table] Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Industry Sector [Domain] Industry Sector [Domain] Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Fixed maturity investments trading, at fair value - amortized cost $25,281,536 at June 30, 2026 (December 31, 2025 - $24,658,351) (Notes 3 and 4) Total fixed maturity investments trading Fixed maturity investments trading Debt Securities, Trading Premiums receivable Increase (Decrease) in Premiums Receivable Tabular List, Table Tabular List [Table Text Block] Additional paid-in capital (Note 10) Additional Paid in Capital Reinsurance recoverable Increase (Decrease) in Reinsurance Recoverable RESERVE FOR CLAIMS AND CLAIM EXPENSES Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] Short term investments Short-Term Investments [Member] Other income (loss) Other income (loss) Other Operating Income (Expense), Net Name Awards Close in Time to MNPI Disclosures, Individual Name Entity Address, Country Entity Address, Country Net foreign exchange gains (losses) Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Foreign Exchange Gains (Losses) 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] Ceded Ceded premiums written Ceded Premiums Written Schedule of Provision for Current Expected Credit Losses of Reinsurance Recoverable Reinsurance Recoverable, Allowance for Credit Loss [Table Text Block] Schedule of Fair Value of Fixed Maturity Investments Trading and Equity Investments Debt Securities, Trading, and Equity Securities, FV-NI [Table Text Block] Schedule of Redeemable Noncontrolling Interests Redeemable Noncontrolling Interest [Table Text Block] Corporate expenses Corporate expenses General and Administrative Expense Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Preference shares: $1.00 par value - 30,000 shares issued and outstanding at June 30, 2026 (December 31, 2025 - 30,000) (Note 10) Preferred Stock, Value, Issued Investors of Upsilon RFO Diversified I, II and III Investors Of Upsilon RFO Diversified I, II and III [Member] Investors Of Upsilon RFO Diversified I, II and III Due after ten years Trading Securities, Debt Maturities, After Ten Years, Amortized Cost Basis This item represents debt securities, at cost, net of adjustments including accretion, amortization and collection of cash, if any, which are expected to mature after ten years of the balance sheet date and are categorized as trading securities. Adjustment to Compensation: Adjustment to Compensation [Axis] Commercial mortgage-backed Commercial Mortgage-Backed Securities [Member] Net (income) loss attributable to redeemable noncontrolling interests (Note 8) Net income (loss) attributable to redeemable noncontrolling interest Net (income) loss attributable to redeemable noncontrolling interests Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Unobservable Input Developed By The Company Valuation Approach, Unobservable Input Developed By The Company [Member] Valuation Approach, Unobservable Input Developed By The Company Hedging Designation [Domain] Hedging Designation [Domain] Class of Stock [Domain] Class of Stock [Domain] Ceded Credit Risk, Collateralization [Axis] Ceded Credit Risk, Collateralization [Axis] Stratos Stratos [Member] Stratos 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] Underwriting expense ratio Underwriting Expense Ratio Foreign Exchange Forward Foreign Exchange Forward [Member] Amount allocated to participating common shareholders Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Hedging Designation [Axis] Hedging Designation [Axis] Redemption of shares from redeemable noncontrolling interest Redemption of shares from redeemable noncontrolling interests, net of adjustments Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Credit Facility [Axis] Credit Facility [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Name Measure Name Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward] Pay vs Performance Disclosure [Line Items] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Debt Instrument [Line Items] Debt Instrument [Line Items] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Reserve for claims and claim expenses 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 Name Trading Arrangement, Individual Name Total other liabilities Other liabilities Other Liabilities, Fair Value Disclosure Cash and cash equivalents Cash and Cash Equivalent DaVinci Holdings Ltd. DavinciRe Third-Party Investors [Member] DavinciRe Third-Party Investors Position [Domain] Position [Domain] Net claims and claim expense ratio – calendar year Loss Ratio Variable interest entity, ownership percentage Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Company Selected Measure Amount Company Selected Measure Amount Series F Preference Shares Series F Preferred Stock [Member] Schedule of Provision for Current Expected Credit Losses of Premiums Receivable Premium Receivable, Allowance for Credit Loss [Table Text Block] Net unrealized gains (losses) Equity Securities, FV-NI, Unrealized Gain (Loss) Derivative instruments not designated as hedges Not Designated as Hedging Instrument [Member] Investments, Debt and Equity Securities [Abstract] Investments, Debt and Equity Securities [Abstract] PFZW PFZW [Member] PFZW Schedule of Net Realized and Unrealized Gains (Losses) on Investments Gain (Loss) on Securities [Table Text Block] Commodity options Commodity Option [Member] Entity Address, Address Line Two Entity Address, Address Line Two Schedule of Stock by Class [Table] Stock, Class of Stock [Table] Net income (loss) Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Investment income before investment expenses Gross Investment Income, Operating Amortization of fair value adjustments Prior Year Claims and Claims Adjustment Expense, Amortization Of Fair Value Adjustment Prior Year Claims and Claims Adjustment Expense, Amortization Of Fair Value Adjustment Derivative liabilities Net Amounts Presented in the Balance Sheet Derivative Liability Non-PEO NEO Non-PEO NEO [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 Catastrophe bonds Catastrophe bonds Catastrophe Bonds [Member] An investment that invests in catastrophe bonds. Income tax benefit (expense) Income Tax Expense (Benefit) Net foreign exchange gains (losses) Net foreign exchange gains (losses) Gain (Loss), Foreign Currency Transaction, before Tax Foreign currency forward contracts Foreign currency forward contracts, investment operations Foreign Currency Forward Contracts, Investment Operations [Member] Foreign Currency Forward Contracts, Investment Operations Foreign Currency Contracts [Member] 2019 Large Loss Events 2019 Large Loss Events [Member] 2019 Large Loss Events [Member] Customer Concentration Risk Customer Concentration Risk [Member] Assets held by insurance regulators Assets Held by Insurance Regulators Award Timing Method Award Timing Method [Text Block] Equity funds Equity Funds [Member] Basis of Presentation Consolidation, Policy [Policy Text Block] Net increase (decrease) in cash and cash equivalents 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] Premiums receivable (Note 5) Premiums receivable Premiums Receivable, Net Variable Interest Entity, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Liquidation preference per annum (in dollars per share) Preferred Stock, Liquidation Preference Per Share, Per Annum Preferred Stock, Liquidation Preference Per Share, Per Annum Net income (loss) attributable to RenaissanceRe Net income Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Balance Sheet Location [Axis] Location, Statement of Financial Position, Balance [Axis] Discounted cash flow Valuation Technique, Discounted Cash Flow [Member] Assumed and ceded (re)insurance contracts Assumed And Ceded Re Insurance Contracts, Liabilities, Fair Value Assumed And Ceded Re Insurance Contracts, Liabilities, Fair Value Statement [Table] Statement [Table] Catastrophic Event [Axis] Catastrophic Event [Axis] Restatement Determination Date: Restatement Determination Date [Axis] Credit Rating, Standard & Poor's [Axis] Credit Rating, Standard & Poor's [Axis] Gross Amounts Recognized Derivative Asset, Subject to Master Netting Arrangement, before Offset Debt Securities, Trading, Realized Gain (Loss) Debt Securities, Trading, Realized Gain (Loss) Revenues Revenues [Abstract] Recent transaction price Valuation Technique, Recent Transaction Price [Member] Valuation Technique, Recent Transaction Price Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Other Investments Other Long-Term Investments [Member]