Derivatives and Hedge Accounting - Fair value hedging relationships (Details) - Derivatives designated as hedging instruments - Fair value hedging - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Interest rate contracts \| Income Statement Location [Axis]: us-gaap:InterestCreditedToPolicyholdersAccountBalances
Derivative instruments gain (loss):
Gains/(losses) recognized in earnings on hedging derivatives	$ (205)	$ 2	$ (326)	$ 144
Gains/(losses) recognized in earnings for excluded components	0	0	0	0
Gain (losses) recognized in earnings on hedged items	207	(4)	324	(150)
Net Impact	2	(2)	$ (2)	$ (6)
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Interest credited to policyholder account balances	Interest credited to policyholder account balances
Interest rate contracts \| Income Statement Location [Axis]: us-gaap:NetInvestmentIncome
Derivative instruments gain (loss):
Gains/(losses) recognized in earnings on hedging derivatives	111	0	$ 153	$ 0
Gains/(losses) recognized in earnings for excluded components	0	0	0	0
Gain (losses) recognized in earnings on hedged items	(110)	0	(152)	0
Net Impact	1	0	$ 1	$ 0
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Interest credited to policyholder account balances, Net Investment Income	Interest credited to policyholder account balances, Net Investment Income
Foreign exchange contracts
Derivative instruments gain (loss):
Gains/(losses) recognized in earnings on hedging derivatives	40	36	$ 250	$ (847)
Gains/(losses) recognized in earnings for excluded components	(42)	109	(60)	236
Gain (losses) recognized in earnings on hedged items	(40)	(36)	(250)	847
Net Impact	$ (42)	$ 109	$ (60)	$ 236

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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

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Indicates line item in statement of income or comprehensive income that includes gain (loss) from derivative.

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Net gain (loss) relating to components of the gain (loss) on the fair value hedging instrument excluded from the assessment of fair value hedge effectiveness. Recognized in earnings.

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Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

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