Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Deferred Tax Asset [Domain] Deferred Tax Asset [Domain] Trading Arrangement: Trading Arrangement [Axis] Maximum Maximum [Member] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Short-Term Debt, Type [Axis] Short-Term Debt, Type [Axis] Title of 12(b) Security Title of 12(b) Security Subsequent Event Subsequent Event [Member] Reported Value Measurement [Member] Reported Value Measurement [Member] Schedule of Available-for-sale Securities [Table] Debt Securities, Available-for-Sale [Table] Make Whole Premium Additional Percent Make Whole Premium Additional Percent Upon election of early redemption, the interest rate percentage in addition to the applicable Treasury Rate which is required to be paid by the Company. Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Adjustment to Compensation, Amount Adjustment to Compensation Amount Repurchase agreements Pledged Status [Axis] 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] Policyholder Account Balances Policyholder Account Balance [Table Text Block] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instrument [Axis] Segment Reporting [Abstract] Segment Reporting [Abstract] Separate Account Asset Category [Axis] Separate Account Asset Category [Axis] Reinsurance recoverable on policy benefits Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance Foreign Currency Transaction Gain (Loss), Realized Realized Gain (Loss), Foreign Currency Transaction, before Tax Unearned premiums Increase (Decrease) in Unearned Premiums Debt Securities, Available-for-sale, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase Debt Securities, Available-for-Sale, Allowance for Credit Loss, Purchased with Credit Deterioration, Increase Integration expenses and severance Business Combination, Integration-Related Cost, Expense Separate account assets Separate Account Asset Derivative Instrument [Axis] Derivative, by Nature [Axis] Derivative Instrument [Axis] Insurance and reinsurance balances payable Reinsurance Payable Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Effect of timing and all other Market Risk Benefit, Increase (Decrease) from Other Assumption Accumulated Defined Benefit Plans Adjustment Attributable to Noncontrolling Interest Accumulated Defined Benefit Plans Adjustment Attributable to Noncontrolling Interest [Member] Interest Accretion Rate Liability for Future Policy Benefit, Weighted-Average Interest Accretion Rate Measurement Frequency [Axis] Measurement Frequency [Axis] U.S. and local government securities US Treasury and Government [Member] Other Other increase (decrease) in noncontrolling interest Other increase (decrease) in noncontrolling interest Consolidated Entities [Axis] Consolidated Entities [Axis] LMG Insurance, Thailand [Member] LMG Insurance, Thailand [Member] LMG Insurance, Thailand Common Shares Outstanding Entity Common Stock, Shares Outstanding INA CNH Bond Due May 2031 [Member] INA CNH Bond Due May 2031 [Member] INA CNH Bond Due May 2031 [Member] Separate Account, Liability, Increase (Decrease) from Other Change Separate Account, Liability, Increase (Decrease) from Other Change INA CNH Bonds Due 2036 INA CNH Bonds Due 2036 [Member] INA CNH Bonds Due 2036 Reinsurance Recoverables on Unpaid Losses, Allowance Reinsurance Recoverables on Unpaid Losses, Allowance INA EUR Senior Notes Due June 2027 [Member] INA EUR Senior Notes Due June 2027 [Member] INA EUR Senior Notes Due June 2027 Policyholder Account Balance, above Guaranteed Minimum Crediting Rate [Axis] Policyholder Account Balance, above Guaranteed Minimum Crediting Rate [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Common Shares, par value Common Shares, par value Common Stock, Par or Stated Value Per Share Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Catastrophic Event [Domain] Catastrophic Event [Domain] Other intangible assets Intangible Asset, Excluding Goodwill, after Accumulated Amortization Market Risk Benefit, Net Amount at Risk Market Risk Benefit, Net Amount at Risk AOCI, Market Risk Benefit, Instrument-Specific Credit Risk, Noncontrolling Interest AOCI, Market Risk Benefit, Instrument-Specific Credit Risk, Noncontrolling Interest [Member] Retirement Benefits [Abstract] Retirement Benefits [Abstract] Amortization of premiums (discounts) on fixed maturities Accretion (Amortization) of Discounts and Premiums, Investments Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Number of Reportable Segments Number of Reportable Segments Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period Short-Term Debt, Type [Domain] Short-Term Debt, Type [Domain] Securities Sold under Agreements to Repurchase Securities Sold under Agreements to Repurchase [Member] Entity Address, City or Town Entity Address, City or Town Effect of changes in discount rate assumptions AOCI, Liability for Future Policy Benefit, Expected Future Policy Benefit, before Tax Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Foreign Plan [Member] Foreign Plan [Member] Other (including foreign exchange) Deferred Policy Acquisition Cost, Foreign Currency Translation Adjustment and Other Market risk benefits Market Risk Benefit, Liability, Amount Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Weighted-average age of policyholders (years) Net Amount at Risk by Product and Guarantee, Weighted Average Attained Age Level 2 Fair Value, Inputs, Level 2 [Member] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Other Comprehensive Income (Loss), Net of Tax Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Net premiums collected (1) Liability for Future Policy Benefit, Expected Net Premium, Net Premium Collected Transfers of Financial Assets Accounted for as Secured Borrowings [Abstract] Transfers of Financial Assets Accounted for as Secured Borrowings [Abstract] UNITED STATES UNITED STATES Subsequent Event Type [Axis] Subsequent Event Type [Axis] Adjustments to Additional Paid in Capital, Other Adjustments to Additional Paid in Capital, Other Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Securities lending collateral Securities Held as Collateral, at Fair Value Benefits payments Liability for Future Policy Benefit, Expected Future Policy Benefit, Benefit Payment Class of Treasury Stock [Table] Class of Treasury Stock [Table] OCI, before Reclassifications, before Tax, Attributable to Parent Gain (loss) recognized in OCI OCI, before Reclassifications, before Tax, Attributable to Parent Operations By Segment Segment Reporting [Table Text Block] Gain (Loss) on Investments [Abstract] Gain (Loss) on Investments [Abstract] Other comprehensive income (loss): Other Comprehensive Income (Loss), before Tax [Abstract] INA Senior Notes Due May 2036 INA Senior Notes Due May 2036 [Member] INA Senior Notes Due May 2036 Guaranteed Insurance Contract, Type of Guarantee [Domain] Guaranteed Insurance Contract, Type of Guarantee [Domain] Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member] Debt Securities, Available-for-sale, Allowance for Credit Loss, Writeoff Debt Securities, Available-for-Sale, Allowance for Credit Loss, Writeoff Fixed maturities Separate Account, Debt Security [Member] North America Commercial P&C Insurance [Member] Segment Insurance North American Commercial P&C [Member] Segment Insurance North American Commercial P&C Available for sale, Due after 1 year through 5 years, Fair Value & Net Carrying Value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Private debt held-to-maturity, valuation allowance Private Debt Held-for-investment, Allowance for Credit Loss, Beginning Balance Private Debt Held-for-investment, Allowance for Credit Loss, Ending Balance Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest Document Period End Date Document Period End Date Debt Instrument, Face Amount Debt Instrument, Face Amount Debt Securities, Available-for-Sale, Realized Loss Debt Securities, Available-for-Sale, Realized Loss Total Level 1, Level 2, and Level 3 Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Securities Sold under Agreements to Repurchase Securities Sold under Agreements to Repurchase Insurance and reinsurance balances payable Increase (Decrease) in Reinsurance Payables Balance - beginning of period Balance - end of period Market Risk Benefit, after Increase (Decrease) from Instrument-Specific Credit Risk Accumulated other comprehensive income (loss) (AOCI) Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Shell Company Entity Shell Company Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest [Member] AOCI, Liability for Future Policy Benefit, Parent AOCI, Liability for Future Policy Benefit, Parent [Member] Earnings per share Earnings Per Share [Text Block] Earnings per share Earnings Per Share [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Total liabilities Liabilities Trading Symbol Trading Symbol Policyholder Account Balance [Abstract] Policyholder Account Balance [Abstract] Company Selected Measure Name Company Selected Measure Name Change in Net Unrealized Gains (Losses) included in OCI, Assets Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Purchases of fixed maturities available-for-sale Payments to Acquire Debt Securities, Available-for-Sale Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Fixed Rate or No Guarantee Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Fixed Rate or No Guarantee [Member] Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Fixed Rate or No Guarantee Single-Stock Future [Member] Futures contracts on equities Single-Stock Future [Member] Unpaid losses and loss expenses Gross unpaid losses and loss expenses – beginning of period Gross unpaid losses and loss expenses – end of period Liability for Claims and Claims Adjustment Expense Liability for Future Policy Benefit, Remeasurement Gain (Loss) Liability for Future Policy Benefit, Remeasurement Gain (Loss) Securities lending collateral Securities lending collateral The carrying amount (fair value) as of the balance sheet date of securities held that had been pledged by counterparties under financing and lending arrangements, pursuant to which the entity has the right by agreement or custom to sell or re-pledge such securities. Whole Life Insurance Whole Life Insurance [Member] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Vintage Alternative Investments [Member] Vintage Alternative Investments [Member] Consists of investments in private equity fundsmade before 2002 and where the funds’ commitment periods had already expired Defined Benefit Plans and Other Postretirement Benefit Plans Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Transfers out of Level 3, Assets Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Credit Loss [Abstract] Credit Loss [Abstract] Policyholders' Account Balances, Separate Accounts, and Unearned Revenue Liability Market Risk Benefits Long-Duration Insurance Contracts Disclosure [Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 [Member] Policyholder account balance, guaranteed minimum credit rating, range from 0201 to 0400 Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Other Increase (Decrease) in Other Operating Assets and Liabilities, Net Huatai Group Huatai Group [Member] Huatai Group [Member] Award Timing Predetermined Award Timing Predetermined [Flag] Underwriting Income (Loss) Underwriting Income (Loss) Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Share-based compensation expense APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Losses and loss expenses Policyholder Benefits and Claims Incurred, Net Level 1 Level 1 Fair Value, Inputs, Level 1 [Member] Net unpaid losses and loss expenses – beginning of period Net unpaid losses and loss expenses – end of period Liability for Unpaid Claims and Claims Adjustment Expense, Net Goodwill, Period Increase (Decrease) Goodwill, Period Increase (Decrease) July 2026 Stock Repurchase Plan July 2026 Stock Repurchase Plan [Member] July 2026 Stock Repurchase Plan CAD Bonds [Domain] CAD Bonds [Member] CAD Bonds Less: Net gains (losses) recognized from sales of securities Gain (Loss) on Sale of Investments Separate Account, Liability, Premium and Deposit Separate Account, Liability, Premium and Deposit Share-based compensation plans Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Net shares issued (redeemed) under employee share-based compensation plans Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture INA CAD Senior Notes Due June 2031 INA CAD Senior Notes Due June 2031 [Member] INA CAD Senior Notes Due June 2031 Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table] Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table] Effect of changes in the instrument-specific credit risk AOCI, Market Risk Benefit, Instrument-Specific Credit Risk, before Tax Long-term Debt, Fair Value Long-Term Debt, Fair Value Schedule of Net Investment Hedges, Statements of Financial Performance and Financial Position, Location Schedule of Net Investment Hedges, Statements of Financial Performance and Financial Position, Location [Table Text Block] Plan Name [Domain] Plan Name [Domain] Prior Period Development, by Segment [Table Text Block] Schedule of Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block] Scenario [Domain] Scenario [Domain] Term Life Insurance Term Life Insurance [Member] Operating Lease, Right-of-Use Asset Operating Lease, Right-of-Use Asset Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract] Deferred Policy Acquisition Costs Deferred Policy Acquisition Costs [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Policyholder contract withdrawals Withdrawal from Contract Holders Funds Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Balance, beginning of period, before effect of changes in the instrument-specific credit risk Balance, end of period, before effect of changes in the instrument-specific credit risk Market Risk Benefit, before Reinsurance and Cumulative Increase (Decrease) from Instrument-Specific Credit Risk Change Dividends paid on Common Shares Payments of Ordinary Dividends, Common Stock Expiration Date Trading Arrangement Expiration Date Hedging Relationship [Axis] Hedging Relationship [Axis] Restricted assets in cash Restricted Cash and Cash Equivalent Adjusted beginning of period balance Liability for Future Policy Benefit, Expected Future Benefit, Original Discount Rate, before Reinsurance, after Cash Flow Change Total shareholders' equity Total shareholders' equity Equity, Including Portion Attributable to Noncontrolling Interest Collateral pledged under repurchase agreements [Table] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Table] INA Senior Notes Due March 2028 [Member] INA Senior Notes Due March 2028 [Member] INA Senior Notes Due March 2028 [Member] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Derivative [Table] Derivative [Table] Other Income and Expenses [Abstract] Private equity distributions Proceeds from Limited Partnership Investments Cash flows from investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Segments [Domain] Segments [Domain] Debt Disclosure Debt Disclosure [Text Block] Scenario [Axis] Scenario [Axis] Other (including foreign exchange) Liability for Future Policy Benefit, Expected Net Premium, Increase (Decrease) for Other Change Business Combinations [Table] Business Combination [Table] Acquisitions Mergers, Acquisitions and Dispositions Disclosures [Text Block] PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Other (including foreign exchange) Unearned Revenue Liability, Other Increase (Decrease) Unearned Revenue Liability, Other Increase (Decrease) Asset management and performance fee revenue Asset management and performance fee revenue Asset management and performance fee revenue Policyholder Account Balance, above Guaranteed Minimum Crediting Rate [Domain] Policyholder Account Balance, above Guaranteed Minimum Crediting Rate [Domain] Text Block [Abstract] Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Interest Rate, Stated Percentage Liability for Claims and Claims Adjustment Expense [Line Items] Liability for Claims and Claims Adjustment Expense [Line Items] Dividends declared on Common Shares Dividends, Common Stock, Cash Insurance and reinsurance balances receivable, valuation allowance Premium Receivable, Allowance for Credit Loss Total Chubb shareholders’ equity Equity, Attributable to Parent Settlements Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Assets Assets [Abstract] Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Table] Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Table] Fixed maturities available-for-sale, amortized cost Debt Securities, Available-for-sale, Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost Insider Trading Policies and Procedures [Line Items] Private equities Alternative Investment [Member] Alternative Investment Policyholder Account Balance, Surrender and Withdrawal Policyholder Account Balance, Surrender and Withdrawal Measurement-period adjustments Goodwill, Measurement Period Adjustment Performance Shares [Member] Performance Shares [Member] Total, Incurred Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims Issuances Liability for Future Policy Benefit, Expected Net Premium, Issuance Potential anti-dilutive share conversions Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Goodwill roll-forward by business segment Goodwill [Table Text Block] Entity Central Index Key Entity Central Index Key Policyholder Account Balance, Weighted Average Crediting Rate Policyholder Account Balance, Weighted Average Crediting Rate Additional paid-in capital Additional Paid in Capital, Common Stock Equity [Abstract] Equity [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Separate Account, Liability, Policy Charge Separate Account, Liability, Policy Charge Variable Annuity Variable Annuity [Member] Experience adjustment Deferred Policy Acquisition Cost, Experience Adjustment Ownership [Axis] Ownership [Axis] Universal Life Universal Life [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Liability for Claims and Claims Adjustment Expense [Table] Liability for Claims and Claims Adjustment Expense [Table] Investment, Name [Axis] Investment, Name [Axis] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Fixed Maturities [Member] Fixed Maturities [Member] Restricted Stock [Member] Restricted Stock [Member] Accumulated Other Comprehensive Income (Loss) [Member] AOCI Attributable to Parent [Member] All Individuals All Individuals [Member] Corporate Segment [Member] Corporate Segment [Member] North American Personal P&C Insurance [Member] Segment Insurance North American Personal P&C [Member] Segment Insurance North American Personal P&C [Member] [Member] Balance – beginning of period Balance – end of period Policyholder Account Balance, excluding Unearned Revenue Liability Policyholder Account Balance, excluding Unearned Revenue Liability Other Derivative Instruments [Member] Other Derivatives Total [Member] Total of other derivative instruments Statement [Line Items] Statement [Line Items] Total assets Assets Deferred revenue Unearned Revenue Liability, Deferred Revenue Unearned Revenue Liability, Deferred Revenue Private Equity Funds [Member] Private Equity Funds [Member] Business Combination [Abstract] Business Combination [Abstract] Equity Securities, FV-NI, Realized Gain (Loss) Equity Securities, FV-NI, Realized Gain (Loss) Equity Securities, FV-NI, Realized Gain (Loss) Liability for Future Policy Benefit Activity [Table] Liability for Future Policy Benefit Activity [Table] Weighted-average grant date fair value for stock options granted Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Share-based compensation Share-Based Payment Arrangement [Text Block] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Available for sale, Mortgage backed securities, Fair Value & Net Carrying Value Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Fair Value PEO PEO [Member] Goodwill Balance at beginning of period Balance at end of period Goodwill Retirement Plan Type [Axis] Retirement Plan Type [Axis] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Liability for Future Policy Benefit, Activity [Line Items] Liability for Future Policy Benefit, Activity [Line Items] Derivatives designated as hedging instruments Derivative Instruments in Hedges, Liabilities, at Fair Value Other derivative instruments Other Derivative Instruments Fair Value The fair value of all other derivative instruments held by the Company. Deposits with U.S. regulatory authorities Restricted Assets Deposits With United States Regulatory Authorities Restricted assets that are deposits with US regulatory authorities. Retained Earnings [Member] Retained Earnings [Member] Fair Value Measurement, Policy Fair Value Measurement, Policy [Policy Text Block] Common Shares, shares outstanding Common Stock, Shares, Outstanding Award Timing Disclosures [Line Items] Cumulative Foreign Currency Translation Adjustment [Member] Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Carrying Values And Fair Values Of Financial Instruments Not Measured At Fair Value Fair Value, by Balance Sheet Grouping [Table Text Block] Corporate and asset-backed securities Corporate Debt Securities [Member] Diluted earnings per share attributable to Chubb Diluted earnings (loss) per share (US$ per share) Earnings Per Share, Diluted Third-party capital distributed by consolidated investment products Third-party capital distributed by consolidated investment products Third-party capital distributed by consolidated investment products Other derivative instruments Other Contract [Member] Investments [Table] Investments [Table] This table lists the investments. The line items identify information about all investments. Country Region Country Region Unrealized Gain (Loss) on Investments Unrealized Gain (Loss) on Investments Amortization of purchased intangibles Intangible Asset, Finite-Lived, Amortization Expense Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest [Member] Ownership [Domain] Ownership [Domain] Net premiums written Premiums Written, Net Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Unearned Revenue Liability Balance – beginning of period Balance – end of period Unearned Revenue Liability Unearned Revenue Liability Schedule Of Components Of Restricted Assets Schedule of Financial Instruments Owned and Pledged as Collateral [Table Text Block] Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Private Debt, Held-for-investment, Allowance for Credit Loss [Line Items] Private Debt, Held-for-investment, Allowance for Credit Loss [Line Items] Private Debt, Held-for-investment, Allowance for Credit Loss Future policy benefits Increase (Decrease) in Future Policy Benefit Reserves Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total liabilities measured at fair value Liabilities Related to Investment Contracts, Fair Value Disclosure Policyholder Account Balance, Net Amount at Risk Policyholder Account Balance, Net Amount at Risk Sales, Assets Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Write-offs charged against the valuation allowance Reinsurance, Loss on Uncollectible Accounts in Period, Amount Undiscounted expected future gross premiums Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance Cash flows from operating activities Cash Provided by (Used in) Operating Activity, Continuing Operation [Abstract] Gain (Loss) on Derivative Derivative, Gain (Loss) on Derivative, Net Dividends Declared Dividends Declared [Table Text Block] Valuation Allowance by Deferred Tax Asset [Axis] Valuation Allowance by Deferred Tax Asset [Axis] Non-U.S. Debt Security, Government, Non-US [Member] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Service cost Defined Benefit Plan, Service Cost Equity Securities Equity Securities [Member] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] INA CAD Senior Notes Due June 2033 INA CAD Senior Notes Due June 2033 [Member] INA CAD Senior Notes Due June 2033 Common Shares, shares issued Common Stock, Shares, Issued Balance- Beginning of Period, Assets Balance-End of Period, Assets Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Policyholder Account Balance, at Guaranteed Minimum Crediting Rate Policyholder Account Balance, at Guaranteed Minimum Crediting Rate [Member] Private debt held-for-investment, allowance for credit loss Private debt held-for-investment, allowance for credit losses [Table Text Block] Private debt held-for-investment, allowance for credit losses Other (including foreign exchange) Liability for Future Policy Benefit, Expected Future Policy Benefit, Increase (Decrease) for Other Change Fixed maturities available-for-sale, valuation allowance Debt Securities, Available-for-sale, Allowance for Credit Loss Debt Securities, Available-for-Sale, Allowance for Credit Loss, Beginning Balance Debt Securities, Available-for-Sale, Allowance for Credit Loss, Ending Balance Debt Securities, Available-for-Sale, Allowance for Credit Loss Guaranteed Insurance Contract, Type of Benefit [Axis] Guaranteed Insurance Contract, Type of Benefit [Axis] Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Risk Management Business Risk Management Business [Member] Risk Management Business Partially-owned Investment Companies Partially-owned Investment Companies [Member] Partially-owned Investment Companies Currency [Axis] Currency [Axis] Effect of changes in cash flow assumptions Liability for Future Policy Benefit, Expected Net Premium, Cumulative Increase (Decrease) from Cash Flow Change Product and Service [Domain] Product and Service [Domain] Debt Securities, Available-for-sale, Gain (Loss), Total Debt Securities, Available-for-Sale, Gain (Loss) Gains (losses) from fair value changes in separate account assets Gains Losses On Fair Value Changes In Separate Account Assets Gains Losses On Fair Value Changes In Separate Account Assets Deferred tax liabilities Deferred Income Tax Liabilities, Net Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Termination Date Trading Arrangement Termination Date Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Derivative Asset, Not Subject to Master Netting Arrangement Derivative Asset, Not Subject to Master Netting Arrangement Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Current Year Claims and Claims Adjustment Expense Current Year Claims and Claims Adjustment Expense Award term period in years Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period Fair Value as of Grant Date Award Grant Date Fair Value Schedule of Goodwill [Table] Goodwill [Table] Liberty Insurance, Vietnam [Member] Liberty Insurance, Vietnam [Member] Liberty Insurance, Vietnam Insurance, Other Insurance, Other [Member] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Repurchase authorization remaining at end of period (1) Share Repurchase Program, Remaining Authorized, Amount Arrangement Duration Trading Arrangement Duration Deferred Policy Acquisition Cost [Line Items] Deferred Policy Acquisition Cost [Line Items] North America Agricultural Insurance [Member] North American Agriculture Insurance [Member] Segment Insurance North American Agriculture [Member] Segment comprises North American based businesses that provide a variety of coverages in the U.S. and Canada including crop insurance, primarily MPCI and crop-hail as well as farm and ranch and specialty P&C commercial insurance products and services. Annual dividend per share approved by shareholders Annual dividend per share approved by shareholders Annual dividend per share approved by shareholders Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Registrant Name Entity Registrant Name Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Market Risk Benefit [Table] Market Risk Benefit [Table] Valuation allowance for uncollectible reinsurance Reinsurance Recoverable, Allowance for Credit Loss, Total Valuation allowance for uncollectible reinsurance - beginning of period Valuation allowance for uncollectible reinsurance - end of period Reinsurance Recoverable, Allowance for Credit Loss Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Net Consolidations of consolidated investment products Cash And Cash Equivalents Increase (Decrease) Due To Consolidation And Deconsolidation Of Investment Products Cash And Cash Equivalents Increase (Decrease) Due To Consolidation And Deconsolidation Of Investment Products Total revenues Revenues Market Risk Benefit [Abstract] Market Risk Benefit [Abstract] Equity in net income (loss) of partially-owned entities Equity in net income (loss) of partially-owned entities Income (Loss) from Equity Method Investments Accounts payable, accrued expenses, and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Private equities (includes VIE balances of $25 and $22) Private equities Alternative Investment Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value Award vesting period in years Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items] Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Financial Instruments Measured At Fair Value On A Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Award Type [Domain] Award Type [Domain] Fair value measurements Fair Value Disclosures [Text Block] Level 3 Fair Value, Inputs, Level 3 [Member] Liability for Future Policy Benefit, Activity Liability for Future Policy Benefit, Activity [Table Text Block] Separate Account, Liability, Cash Surrender Value, Amount Separate Account, Liability, Cash Surrender Value, Amount schedule of reinsurance recoverable on ceded insurance schedule of reinsurance recoverable on ceded insurance [Table Text Block] schedule of reinsurance recoverable on ceded insurance Number of shares repurchased Treasury Stock, Shares, Acquired Share Repurchase Authorization, Expired Share Repurchase Program, Amount Expired Share Repurchase Program, Amount Expired Non-service (benefit) cost Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component Restricted cash Restricted Cash Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items] Debt Securities, Available-for-Sale, Allowance for Credit Loss [Line Items] Interest accrual Liability for Future Policy Benefit, Expected Net Premium, Interest Income Other assets (includes VIE balances of $110 and $58) Other assets Other Assets Legal Entity [Axis] Legal Entity [Axis] Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease) Debt Securities, Available-for-Sale, Allowance for Credit Loss, Period Increase (Decrease) Debt Securities, Available-for-Sale, Allowance for Credit Loss, Period Increase (Decrease) Net derivative instruments settlements Payments for (Proceeds from) Derivative Instrument, Investing Activities Maturity Less than 30 Days [Member] Maturity Less than 30 Days [Member] Hedged Liability, Fair Value Hedge Hedged Liability, Fair Value Hedge Common Shares repurchased Cost of shares repurchased Treasury Stock, Value, Acquired, Cost Method Cash, including restricted cash $243 and $198 (includes VIE balances of $243 and $168) Cash, including restricted cash Cash and restricted cash - beginning of period Cash and restricted cash - end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Financial Instruments Pledged as Collateral [Abstract] Financial Instruments Pledged as Collateral [Abstract] goodwill attributable to noncontrolling interests goodwill attributable to noncontrolling interests goodwill attributable to noncontrolling interests Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Non-NEOs Non-NEOs [Member] Separate Account, Liability [Table] Separate Account, Liability [Table] Overnight and Continuous [Member] Maturity Overnight [Member] Payments to Acquire Businesses, Gross Payments to Acquire Businesses, Gross Policyholder Account Balance, Interest Expense Policyholder Account Balance, Interest Expense Funding of dividends declared from Additional paid-in capital Funding Dividends Declared From Additional Paid In Capital This element represents the amount transferred from additional paid-in-capital to retained earnings to fund the dividends declared. Investment, Name [Domain] Investment, Name [Domain] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Equity, Class of Treasury Stock [Line Items] Equity, Class of Treasury Stock [Line Items] Common Shares repurchased Payments for Repurchase of Common Stock Mortgage-backed securities Collateralized Mortgage-Backed Securities [Member] Statistical Measurement [Axis] Statistical Measurement [Axis] Net Realized Gains (Losses) Of Derivative Instrument Activity In Consolidated Statement Of Operations Derivative Instruments, Gain (Loss) [Table Text Block] Amortization Unearned Revenue Liability, Amortization Unearned Revenue Liability, Amortization Award Type [Axis] Award Type [Axis] Effect of actual variances from expected experience Liability for Future Policy Benefit, Expected Future Policy Benefit, Cumulative Increase (Decrease) of Actual Variance from Expected Experience Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Retained earnings Retained Earnings (Accumulated Deficit) Product and Service [Axis] Product and Service [Axis] All Currencies [Domain] All Currencies [Domain] Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Pension Plan [Member] Pension Plan [Member] Common Stock [Member] Common Stock [Member] Fixed maturities available-for-sale, at fair value, net of valuation allowance – $48 and $52 (amortized cost – $129,028 and $124,726) Available for sale, Fair Value Debt Securities, Available-for-Sale Debt Securities, Available-for-Sale Additional percent ownership interest obtained in subsidiary Additional percent ownership interest obtained in subsidiary Additional percent ownership interest obtained in subsidiary Restricted stock awards granted to employees and officers of the company Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period Non-US [Member] Non-US [Member] Change in Net Unrealized Gains/Losses included in OCI at the Balance Sheet Date, Assets Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), OCI Private Credit Alternative Investments [Member] Private Credit Alternative Investments [Member] Consists of investments in private equity funds targeting privately originated corporate debt investments including senior secured loans and subordinated bonds Equity securities, Private equities and Other investments Equity securities, Private equities and other investments [Member] Equity securities and other investments [Member] Derivative Contract [Domain] Derivative, Name [Domain] Derivative Contract [Domain] Foreign exchange revaluation Goodwill, Foreign Currency Translation, Gain (Loss) Secured Borrowings, Gross, Difference, Amount Secured Borrowings, Gross, Difference, Amount Debt Securities, Available-for-Sale, Realized Gain (Loss) Debt Securities, Available-for-Sale, Realized Gain (Loss) Total liabilities and shareholders’ equity Liabilities and Equity Investments [Line Items] Investments [Line Items] [Line Items] for This table lists the investments. The line items identify information about all investments. Deferred Policy Acquisition Costs Deferred Policy Acquisition Costs [Text Block] Net realized gains (losses) Net realized (gains) losses Net realized gains (losses) Realized Investment Gains (Losses) Stock Options [Member] Share-Based Payment Arrangement, Option [Member] Purchases, Assets Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Net Realized Gains (Losses) Reclassified from AOCI Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Noncontrolling interests (includes VIE balances of $4,655 and $5,133) Noncontrolling interests Equity, Attributable to Noncontrolling Interest Segments [Axis] Segments [Axis] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Asset Class [Axis] Asset Class [Axis] Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Repurchase agreements (includes VIE balances of $930 and $956) Repurchase agreements Secured Debt, Repurchase Agreements Tabular List, Table Tabular List [Table Text Block] Reinsurance recoverable on unpaid losses and loss expenses Reinsurance recoverable on unpaid losses and loss expenses - beginning of period Reinsurance recoverable on unpaid losses and loss expenses - end of period Reinsurance Recoverable for Unpaid Claims and Claims Adjustments Distressed Alternative Investments [Member] Distressed Alternative Investments [Member] Consists of investments in private equity funds targeting distressed corporate debt/credit and equity opportunities in the United States Unrealized Gain (Loss) on Investments Unrealized Gain (Loss) on Investments [Table Text Block] Reinsurance recoverable Increase (Decrease) in Reinsurance Recoverable Issuances Liability for Future Policy Benefit, Expected Future Policy Benefit, Issuance Other (income) expense Other Operating Income (Expense), Net Name Awards Close in Time to MNPI Disclosures, Individual Name 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] Interest rate changes Market Risk Benefit, Increase (Decrease) from Interest Rate Change Annuities [Member] Annuities [Member] Annuities Portion at Other than Fair Value Measurement Portion at Other than Fair Value Measurement [Member] Adjustment to Compensation: Adjustment to Compensation [Axis] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activity Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range from 0400 and Greater [Member] Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member] prior period development, net adjustments Prior Period Development, net adjustments Prior Period Development, net adjustments Hedging Designation [Axis] Hedging Designation [Axis] Total assets measured at fair value Assets, Fair Value Disclosure Private equity contributions Payments to Acquire Limited Partnership Interests Name Measure Name Net liability for future policy benefits Liability for Future Policy Benefit, before Reinsurance and Deferred profit liability Liability for Future Policy Benefit, before Reinsurance and Deferred profit liability Interest Accretion Liability for Future Policy Benefit, Interest Expense Cumulative foreign currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax Pay vs Performance Disclosure [Line Items] Adjusted beginning of period balance Liability for Future Policy Benefit, Expected Net Premium, Original Discount Rate, before Reinsurance, after Cash Flow Change Other Segments Other Operating Segment [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Debt Instrument [Line Items] Debt Instrument [Line Items] Sales of equity securities Proceeds from Sale of Equity Securities, FV-NI Unpaid losses and loss expenses Increase (Decrease) in Liability for Claims and Claims Adjustment Expense Reserve Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Securities lending payable Obligation to Return Securities Received as Collateral Repayment of repurchase agreements Repayments of Short-Term Debt Name Trading Arrangement, Individual Name Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location [Axis] Market Risk Benefit [Line Items] Market Risk Benefit [Line Items] Actual policyholder behavior different from expected behavior Market Risk Benefit, Increase (Decrease) from Actual Policyholder Behavior Different from Expected Effect of actual variances from expected experience Liability for Future Policy Benefit, Expected Net Premium, Cumulative Increase (Decrease) of Actual Variance from Expected Experience Separate Account, Liability, Increase (Decrease) from Invested Performance Separate Account, Liability, Increase (Decrease) from Invested Performance Transfer of Certain Financial Assets Accounted for as Secured Borrowings Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Table Text Block] Company Selected Measure Amount Company Selected Measure Amount Segment Net Investment Income Segment Net Investment Income Segment Net Investment Income Retirement Plan Sponsor Location [Domain] Retirement Plan Sponsor Location [Domain] July 2025 Stock Repurchase Plan July 2025 Stock Repurchase Plan [Member] July 2025 Stock Repurchase Plan Non-PEO NEO Non-PEO NEO [Member] Foreign exchange Gain (Loss), Foreign Currency Transaction, before Tax Other Income and Expense Disclosure Other Income and Other Expense Disclosure [Text Block] Short-term investments, amortized cost short-term investments amortized cost Amount of short-term investments at amortized cost Award Timing Method Award Timing Method [Text Block] Net increase (decrease) in cash 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] Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater [Member] Defined Benefit Plan, Amortization of Gain (Loss) Defined Benefit Plan, Amortization of Gain (Loss) Net income attributable to Chubb Net income (loss) Net Income (Loss) Attributable to Parent Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Investments Investments [Member] Restatement Determination Date: Restatement Determination Date [Axis] Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Private Debt Held-for-investment, Allowance for Credit Loss, Recovery Financing Receivable, Allowance for Credit Loss, Recovery Reinsurance Disclosures [Abstract] Reinsurance Disclosures [Abstract] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Business Combination, Effective Date of Acquisition Business Combination, Effective Date of Acquisition Revenues Revenues [Abstract] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Segment Corporate and Other Segment Corporate and Other [Member] This segment includes ACE Limited, ACE Group Management and Holdings Ltd., ACE INA Holdings, Inc. and intercompany eliminations. Statistical Measurement [Domain] Statistical Measurement [Domain] Policyholder Account Balance [Line Items] Policyholder Account Balance [Line Items] Document Fiscal Year Focus Document Fiscal Year Focus Liability for Unpaid Claims and Claims Adjustment Expense, Activity in Liability [Abstract] Liability for Unpaid Claims and Claims Adjustment Expense, Activity in Liability [Abstract] Common Shares (CHF 0.50 par value; 400,120,847 and 412,107,421 shares issued; 385,634,049 and 391,101,227 shares outstanding) Common Stock, Value, Issued Other investments - Fixed Maturities [Member] Other investments - Fixed Maturities [Member] Other investments - Fixed Maturities Interest expense Interest expense reclassified from OCI Interest Expense, Operating and Nonoperating Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period Short-Duration Insurance, Other Short-Duration Insurance, Other [Member] Restatement Determination Date Restatement Determination Date Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Short-duration Insurance Contracts, Claim Duration [Domain] Short-Duration Insurance Contracts, Claim Duration [Domain] Effect of changes in discount rate assumptions AOCI, Liability for Future Policy Benefit, Expected Net Premium, before Tax Amendment Flag Amendment Flag Goodwill [Line Items] Goodwill [Line Items] Global Reinsurance [Member] Segment Global Reinsurance [Member] Segment Global Reinsurance [Member] Net investment income Net Investment Income Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before tax Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Investments Investment [Text Block] Schedule Of Amortized Cost and Fair Value of Available-for-sale Securities Debt Securities, Available-for-Sale [Table Text Block] Beginning balance at original discount rate Ending balance at original discount rate Liability for Future Policy Benefit, Expected Future Policy Benefit, Original Discount Rate, before Cash Flow and Reinsurance Investments [Domain] Investments [Domain] Variable Interest Entity, Nonconsolidated, Comparison of Carrying Amount of Assets and Liabilities to Maximum Loss Exposure Variable Interest Entity, Nonconsolidated, Comparison of Carrying Amount of Assets and Liabilities to Maximum Loss Exposure Deferred income taxes Increase (Decrease) in Deferred Income Taxes Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Transfers Into Level 3, Asset Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Purchases of equity securities Payments to Acquire Equity Securities, FV-NI PEO Total Compensation Amount PEO Total Compensation Amount Weighted-average shares outstanding Weighted Average Number of Shares Outstanding, Basic Share Repurchase Program [Domain] Share Repurchase Program [Domain] Derivative, Notional Amount Derivative, Notional Amount Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Fair Value, by Balance Sheet Grouping [Table] INA Senior Notes Due March 2038 [Member] INA Senior Notes Due March 2038 [Member] INA Senior Notes Due March 2038 [Member] Deferred policy acquisition costs Increase (Decrease) in Deferred Policy Acquisition Costs Debt Securities, Available-for-sale, Allowance for Credit Loss Debt Securities, Available-for-Sale, Allowance for Credit Loss [Table Text Block] Investments [Abstract] Investments [Abstract] Funding of dividends declared to Retained earnings FundingDividendsDeclaredToRetainedEarnings Funding of dividends declared to Retained earnings Available for sale, Due after 5 years through 10 years, Fair Value & Net Carrying Value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Third-party capital invested into consolidated investment products Third-party capital invested into consolidated investment products Third-party capital invested into consolidated investment products Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Abstract] Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Abstract] Long-Duration Insurance, Other Long-Duration Insurance, Other [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Class of Stock [Axis] Class of Stock [Axis] Current discount rate on future policy benefits OCI, Liability for Future Policy Benefit, Gain (Loss), after Reclassification Adjustment, before Tax Provision for uncollectible reinsurance Reinsurance Recoverable, Credit Loss Expense (Reversal) Private debt held-for-investment, at amortized cost, net of valuation allowance – $2 and $3 Private debt held-for-investment Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss Common Shares in treasury (14,486,798 and 21,006,194 shares) Treasury Stock, Value New Accounting Pronouncements, Policy [Policy Text Block] New Accounting Pronouncements, Policy [Policy Text Block] Noncontrolling Interest Noncontrolling Interest [Member] Domestic Plan Domestic Plan [Member] Other, including postretirement benefit liability adjustment Other Comprehensive (Income) Loss, Defined Benefit Plan and Other, after Reclassification Adjustment, before Tax Other Comprehensive (Income) Loss, Defined Benefit Plan and Other, after Reclassification Adjustment, before Tax Market Risk Benefits Other Gains (Losses) Market Risk Benefits Other Gains (Losses) Market Risk Benefits Other Gains (Losses) Unsecured Debt Unsecured Debt [Member] INA Senior Notes Due May 2026 INA Senior Notes Due May 2026 [Member] INA Senior Notes Due May 2026 Options/Futures/Forward contracts on notes and bonds Future [Member] Other comprehensive income (loss), before income tax Other comprehensive income (loss), before income tax Other Comprehensive Income (Loss), before Tax Long-term debt Long-Term Debt Unearned revenue liabilities Unearned Revenue Liabilities [Table Text Block] Unearned Revenue Liabilities Policyholder Account Balance, Guaranteed Minimum Crediting Rates Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Table Text Block] Maturity 30 to 90 Days [Member] Maturity 30 to 90 Days [Member] Income taxes Increase (Decrease) in Income Taxes Payable Net cash flows used for 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] Shareholders' equity Equity [Text Block] Security Exchange Name Security Exchange Name Other Income and Expense [Table] Other Income and Expense [Table] Other Income and Expense AOCI, Liability for Future Policy Benefit, Noncontrolling Interest AOCI, Liability for Future Policy Benefit, Noncontrolling Interest [Member] Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document Document and Entity Information [Abstract] Liabilities, Fair Value Disclosure Liabilities, Fair Value Disclosure Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Statement of Comprehensive Income [Abstract] Repurchase Agreements [Member] Repurchase Agreements [Member] Name Outstanding Recovery, Individual Name Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract] Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Policyholder account balance, guaranteed minimum credit rating, range from 0000 to 0200 Policyholder account balance, guaranteed minimum credit rating, range up to 0200 [Member] Policyholder account balance, guaranteed minimum credit rating, range up to 0200 Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Undiscounted expected future benefit payments Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance Private Debt, Held-for-investment, Allowance for Credit Loss [Table] Private Debt, Held-for-investment, allowance for credit loss [Table] Private Debt, Held-for-investment, allowance for credit loss Other investments (includes VIE balances of $5,050 and $5,818) Other investments Other Long-Term Investments Subsidiary, Ownership Percentage, Parent Subsidiary, Ownership Percentage, Parent Postretirement Benefit Liability Adjustment [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Asset Class [Domain] Asset Class [Domain] Policy benefits (includes remeasurement losses of nil, $2, $2, and $5) Liability for Future Policy Benefits, Period Expense (Income) Guaranteed Insurance Contract, Type of Guarantee [Axis] Guaranteed Insurance Contract, Type of Guarantee [Axis] Compensation Amount Outstanding Recovery Compensation Amount Individual: Individual [Axis] Weighted-average shares outstanding and assumed conversions Weighted Average Number of Shares Outstanding, Diluted AOCI, Liability for Future Policy Benefit, Including Noncontrolling Interest AOCI, Liability for Future Policy Benefit, Including Noncontrolling Interest [Member] Entity Emerging Growth Company Entity Emerging Growth Company Underlying Security Market Price Change Underlying Security Market Price Change, Percent Net increase (decrease) due to consolidation, deconsolidation, and other transactions Net increase (decrease) due to consolidation, deconsolidation, and other transactions Net increase (decrease) due to consolidation, deconsolidation, and other transactions Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] Short-term debt Short-Term Debt Fair Value, Liability Derivative Liability, Subject to Master Netting Arrangement, before Offset Accrued investment income Accrued Investment Income Receivable Gross Premiums or Assessments Liability for Future Policy Benefit, Gross Premium Income Treasury Stock, Common Treasury Stock, Common [Member] Reinsurance recoverable on paid losses and loss expenses Reinsurance Recoverable for Paid Claims and Claims Adjustments Goodwill [Roll Forward] Intangible Asset, Goodwill and Other [Abstract] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Other, including federal excise and capital taxes Other Nonoperating Expense Derivative Liability, Subject to Master Netting Arrangement, after Offset Derivative Liability, Subject to Master Netting Arrangement, after Offset AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Including Noncontrolling Interest AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Including Noncontrolling Interest [Member] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] July 2023 Stock Repurchase Plan July 2023 Stock Repurchase Plan [Member] July 2023 Stock Repurchase Plan All Executive Categories All Executive Categories [Member] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Restricted assets in fixed maturities and short-term investments Restricted Investments Schedule of Net Benefit Costs [Table Text Block] Schedule of Net Benefit Costs [Table Text Block] Effect of changes in future expected policyholder behavior Market Risk Benefit, Increase (Decrease) from Future Expected Policyholder Behavior Assumption Settlements, Assets Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Fair Value, Separate Account Investment [Line Items] Fair Value, Separate Account Investment [Line Items] Schedule Of Earnings Per Share, Basic And Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Policyholder Account Balance, Guaranteed Minimum Crediting Rate Range [Domain] Policyholder Account Balance, Guaranteed Minimum Crediting Rate Range [Domain] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Reinsurance recoverable on losses and loss expenses, net of valuation allowance – $324 and $320 Reinsurance recoverable on losses and loss expenses Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments Capitalizations Deferred Policy Acquisition Cost, Capitalization Segment information Segment Reporting [Text Block] Maturities and redemptions of fixed maturities available-for-sale Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Minimum Minimum [Member] Net Prior Period Development Net Prior Period Development Net Prior Period Development - Amount, after effects of reinstatement premiums, expense adjustments, and net premiums earned adjustments for claims incurred in prior reporting periods and related claims settlement costs. Investment Type [Axis] Investment Type [Axis] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Assets, Fair Value Disclosure Investments, Fair Value Disclosure Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Separate Account Investment Fair Value, Separate Account Investment [Table Text Block] Liabilities Liabilities [Abstract] Effect of foreign currency rate changes on cash and restricted 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] Goodwill and Intangible Assets, Goodwill, Policy Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block] Policyholder Account Balance, Premium Received Policyholder Account Balance, Premium Received 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] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Guaranteed Insurance Contract, Type of Benefit [Domain] Guaranteed Insurance Contract, Type of Benefit [Domain] Other liabilities Other Liabilities Business Combination [Line Items] Business Combination [Line Items] Net periodic benefit cost (benefit) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Deferred Policy Acquisition Cost [Table] Deferred Policy Acquisition Cost [Table] Common Stock, Shares Authorized Common Stock, Shares Authorized Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Debt Securities, Available-for-Sale, Realized Gain Debt Securities, Available-for-Sale, Realized Gain Available for sale, Due after 10 years, Fair Value & Net Carrying Value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Exercise Price Award Exercise Price Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Fair Value, Recurring Fair Value, Recurring [Member] Debt Securities, Available-for-sale, Allowance for Credit Loss, Recovery Debt Securities, Available-for-Sale, Allowance for Credit Loss, Recovery Segment Reporting [Line Items] Segment Reporting [Line Items] Stock Repurchase Program, Authorized Amount Share Repurchase Program, Authorized, Amount Fair Value, Separate Account Investment [Table] Fair Value, Separate Account Investment [Table] Document Quarterly Report Document Quarterly Report Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items] Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items] Compensation and Employee Benefit Plans [Text Block] Compensation and Employee Benefit Plans [Text Block] Sales of fixed maturities available-for-sale Proceeds from Sale of Debt Securities, Available-for-Sale Net loss and loss expenses paid, Prior Years Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years Repayment of 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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] Measurement Frequency [Domain] Measurement Frequency [Domain] Foreign [Member] Foreign Government Debt [Member] Policyholder Account Balance, Cash Surrender Value Policyholder Account Balance, Cash Surrender Value PerformanceBasedStockUnits(PSU) Performance_Based_Stock_Units_(PSU) [Member] Performance_Based_Stock_Units_(PSU) Balance Sheet Locations, Fair Values In An Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Basic earnings per share attributable to Chubb Basic earnings (loss) per share (US$ per share) Earnings Per Share, Basic Measurement Input Type [Axis] Measurement Input Type [Axis] Deferred profit liability Deferred Revenue Reinsurance Recoverables on Future Policy Benefits, Allowance Reinsurance Recoverables on Future Policy Benefits, Allowance Reinsurance Recoverables on Future Policy Benefits, Allowance Value of business acquired Present Value of Future Insurance Profits, Net Insider Trading Arrangements [Line Items] Short-Term Debt, Fair Value Short-Term Debt, Fair Value Reinsurance Recoverables on Paid Losses, Allowance Reinsurance Recoverables on Paid Losses, Allowance Other Investment Not Readily Marketable [Axis] Other Investment Not Readily Marketable [Axis] Debt Designated as net investment hedge [Member] Debt Designated as net investment hedge [Member] Debt Designated as net investment hedge Share Repurchase Program [Table Text Block] Class of Treasury Stock [Table Text Block] Policy acquisition costs Amortization expense Deferred Policy Acquisition Costs, Amortization Expense Aggregate Change in Present Value of Accumulated Benefit for All Pension 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ACE International (excluding its life insurance business), the wholesale insurance operations of ACE Global Markets, and the international A&H and life insurance business of Combined Insurance. Investment derivatives Investment Derivative Instruments Fair Value The fair value for actively traded investment derivative instruments including futures, options, and exchange traded forward contracts reflected as an asset. Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Plan Name [Axis] Plan Name [Axis] Insurance and reinsurance balances receivable Increase (Decrease) in Premiums Receivable Total Other Nonoperating Income (Expense) Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block] Financial [Member] Financial [Member] Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] Parent Parent [Member] Short-term Investments Short-Term Investments [Member] Entity Address, Country Entity Address, Country Reinsurance Recoverable, Allowance for Credit Loss [Table Text Block] Reinsurance Recoverable, Allowance for Credit Loss [Table Text Block] Administrative expenses General and Administrative Expense Schedule of Realized Gain (Loss) Schedule of Realized Gain (Loss) [Table Text Block] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Significant Unobservable Inputs Annuitization Rate Significant Unobservable Inputs Annuitization Rate Significant Unobservable Inputs Annuitization Rate Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Class of Stock [Domain] Class of Stock [Domain] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Effect of changes in volatilities Market Risk Benefit, Increase (Decrease) from Volatility Market risk benefits gains (losses) Market Risk Benefit, Change in Fair Value, Gain (Loss) Investment Funds Limited Partnerships Partially Owned Investment Companies Fair Value Investment Funds Limited Partnerships Partially Owned Investment Companies Fair Value [Member] Alternative Investments comprised of investment funds, limited partnerships, and partially owned investment companies measured at fair value using NAV as a practical expedient as provided by the provisions of SAU 2009-12, Investment in Certain Entities That Calculate Net Asset Value per Share (or its Equivalent). 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