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Commitments, Contingencies, And Guarantees (Balance Sheet Locations, Fair Values In Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments) (Detail) - USD ($) $ in Millions | Sep. 30, 2025 | Dec. 31, 2024
--- | --- | ---
Foreign currency forward contracts | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative, Notional Amount |  | $ 4,695 | $ 3,959
Options/Futures/Forward contracts on notes and bonds | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative, Notional Amount |  | 1,096 | 449
Convertible securities | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative, Notional Amount | [1] | 7 | 12
Investment And Embedded Derivative Instruments [Member] | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 29 | 53
Fair Value, Liability |  | (173) | (303)
Derivative, Notional Amount |  | 5,798 | 4,420
Futures contracts on equities | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative, Notional Amount | [2] | 909 | 1,047
Other derivative instruments | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative, Notional Amount |  | 435 | 211
Other Derivative Instruments [Member] | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative, Notional Amount |  | 1,344 | 1,258
Currency Swap [Member] | Designated as Hedging Instrument |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 261 | 146
Fair Value, Liability |  | (183) | 116
Derivative, Notional Amount |  | 5,062 | 4,475
Currency Swap [Member] | Fair Value Hedging | Designated as Hedging Instrument |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative, Notional Amount |  | 2,048 | 1,579
Currency Swap [Member] | Net Investment Hedging | Designated as Hedging Instrument |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative, Notional Amount |  | 3,014 | 2,896
Other Assets [Member] | Foreign currency forward contracts | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 18 | 41
Other Assets [Member] | Options/Futures/Forward contracts on notes and bonds | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 4 | 0
Other Assets [Member] | Futures contracts on equities | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset | [2] | 0 | 35
Other Assets [Member] | Other derivative instruments | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 5 | 0
Other Assets [Member] | Other Derivative Instruments [Member] | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 5 | 35
Other Assets [Member] | Currency Swap [Member] | Fair Value Hedging | Designated as Hedging Instrument |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 216 | 103
Other Assets [Member] | Currency Swap [Member] | Net Investment Hedging | Designated as Hedging Instrument |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Fair Value, Gross Asset |  | 45 | 43
Fixed Maturities [Member] | Convertible securities | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Asset, Not Subject to Master Netting Arrangement | [1] | 7 | 12
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Foreign currency forward contracts | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Fair Value, Liability |  | (169) | (295)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Options/Futures/Forward contracts on notes and bonds | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Fair Value, Liability |  | (4) | (8)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures contracts on equities | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Fair Value, Liability | [2] | (11) | 0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other derivative instruments | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Fair Value, Liability |  | (5) | (2)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other Derivative Instruments [Member] | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Fair Value, Liability |  | (16) | (2)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Currency Swap [Member] | Fair Value Hedging | Designated as Hedging Instrument |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Fair Value, Liability |  | 0 | 0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Currency Swap [Member] | Net Investment Hedging | Designated as Hedging Instrument |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Fair Value, Liability |  | (183) | (116)
Equity Securities | Convertible securities | Not Designated as Hedging Instrument [Member] |  |  |
Derivatives, Fair Value [Line Items] |  |  |
Derivative Liability, Not Subject to Master Netting Arrangement | [1] | $ 0 | $ 0
[1] | Includes fair value of embedded derivatives.
[2] | Related to MRB book of business.

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