Market risk benefits (MRB Roll-Forward) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Market Risk Benefit [Line Items]
Market risk benefits gains (losses)		$ (17)	$ (29)	$ (109)	$ (8)
Long-Duration Insurance, Other | Variable Annuity
Market Risk Benefit [Line Items]
Balance - beginning of period				607	771
Balance, beginning of period, before effect of changes in the instrument-specific credit risk				592	749
Interest rate changes				41	(87)
Effect of market movements (1)	[1]			(50)	(83)
Effect of changes in volatilities				19	(13)
Market Risk Benefit, Increase (Decrease) from Actual Policyholder Behavior Different from Expected				28	31
Effect of timing and all other				(31)	(33)
Balance, end of period, before effect of changes in the instrument-specific credit risk		599	564	599	564
Effect of changes in the instrument-specific credit risk		10	12	10	12
Balance - end of period		609	576	609	576
Market Risk Benefit, Net Amount at Risk	[2]	$ 1,479	$ 1,630	1,479	1,630
Market Risk Benefits Other Gains (Losses)				$ (103)	$ (191)
Weighted-average age of policyholders (years)				74 years	74 years

[1] Market movements are predominantly driven by changes in equities.

[2] The net amount at risk is defined as the present value of future claim payments assuming policy account values and guaranteed values are fixed at the valuation date, and reinsurance coverage ends at the earlier of the maturity of the underlying variable annuity policy or the reinsurance treaty. No withdrawals, lapses, and mortality improvements are assumed in the projection. GLB-related risks contain conservative mortality and annuitization assumptions.