Derivatives and Hedge Accounting - Derivatives not Designated as Hedging Instruments (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ 109	$ (62)	$ 50	$ (266)
Net investment income - Fortitude Re funds withheld assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ 0	$ 0	$ 0	$ (1)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Investment Income	Net Investment Income	Net Investment Income	Net Investment Income
Excluding Fortitude Re Funds Withheld Assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ 23	$ (10)	$ 3	$ (136)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Investments	Investments	Investments	Investments
Fortitude Re funds withheld assets
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ 86	$ (52)	$ 47	$ (129)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Investments	Investments	Investments	Investments
Interest rate contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ 2	$ 0	$ 1	$ (5)
Foreign exchange contracts
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	22	(8)	5	(152)
Embedded derivatives
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total	$ 85	$ (54)	$ 44	$ (109)

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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