Investments - Components of Net Realized Gains and Losses (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Components of net realized capital gains (losses)
Net realized gains (losses)	$ (110)	$ (490)	$ (510)	$ (851)
Aggregate fair value of available for sale securities sold	3,300	2,500	9,800	9,900
Gross realized gains	18	15	56	45
Gross realized losses	249	117	480	560
Excluding Fortitude Re Funds Withheld Assets
Components of net realized capital gains (losses)
Net realized gains (losses)	(167)	(431)	(507)	(683)
Fortitude Re Funds Withheld Assets
Components of net realized capital gains (losses)
Net realized gains (losses)	57	(59)	(3)	(168)
Excluding modified coinsurance and funds withheld embedded derivative
Components of net realized capital gains (losses)
Sales and impairments of fixed maturity securities	(231)	(102)	(424)	(515)
Change in allowance for credit losses on fixed maturity securities	11	2	13	(5)
Foreign exchange transactions	(12)	(11)	(41)	201
Derivatives and hedge accounting	23	(9)	7	(157)
Sales of alternative investments	(11)	(2)	(27)	1
Other	35	(263)	(105)	(275)
Net realized gains (losses)	(195)	(436)	(554)	(742)
Excluding modified coinsurance and funds withheld embedded derivative \| Loans Receivable
Components of net realized capital gains (losses)
Change in allowance for credit losses on loans	(10)	(51)	23	8
Excluding modified coinsurance and funds withheld embedded derivative \| Excluding Fortitude Re Funds Withheld Assets
Components of net realized capital gains (losses)
Sales and impairments of fixed maturity securities	(202)	(96)	(376)	(453)
Change in allowance for credit losses on fixed maturity securities	11	2	12	(5)
Foreign exchange transactions	(12)	(10)	(39)	183
Derivatives and hedge accounting	22	(11)	4	(137)
Sales of alternative investments	(11)	(2)	(27)	1
Other	35	(262)	(103)	(270)
Net realized gains (losses)	(167)	(431)	(507)	(683)
Excluding modified coinsurance and funds withheld embedded derivative \| Excluding Fortitude Re Funds Withheld Assets \| Loans Receivable
Components of net realized capital gains (losses)
Change in allowance for credit losses on loans	(10)	(52)	22	(2)
Excluding modified coinsurance and funds withheld embedded derivative \| Fortitude Re Funds Withheld Assets
Components of net realized capital gains (losses)
Sales and impairments of fixed maturity securities	(29)	(6)	(48)	(62)
Change in allowance for credit losses on fixed maturity securities	0	0	1	0
Foreign exchange transactions	0	(1)	(2)	18
Derivatives and hedge accounting	1	2	3	(20)
Sales of alternative investments	0	0	0	0
Other	0	(1)	(2)	(5)
Net realized gains (losses)	(28)	(5)	(47)	(59)
Excluding modified coinsurance and funds withheld embedded derivative \| Fortitude Re Funds Withheld Assets \| Loans Receivable
Components of net realized capital gains (losses)
Change in allowance for credit losses on loans	0	1	1	10
Fortitude Re funds withheld embedded derivative
Components of net realized capital gains (losses)
Net realized gains (losses)	85	(54)	44	(109)
Fortitude Re funds withheld embedded derivative \| Excluding Fortitude Re Funds Withheld Assets
Components of net realized capital gains (losses)
Net realized gains (losses)	0	0	0	0
Fortitude Re funds withheld embedded derivative \| Fortitude Re Funds Withheld Assets
Components of net realized capital gains (losses)
Net realized gains (losses)	$ 85	$ (54)	$ 44	$ (109)

Gain Loss On Sale Of Alternative Investments

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Represents other investment charges not specified in the taxonomy.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with interest rate reset through auction process, sold at par value.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Amount, excluding accrued interest, of increase (decrease) in allowance for credit loss of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

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Amount, before tax, of realized and unrealized gain (loss) from foreign currency transaction.

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Amount of realized and unrealized gain (loss) on investment.

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The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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