Market risk benefits (MRB Roll-Forward) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Market Risk Benefit [Line Items]
Market Risk Benefit, Liability, beginning of period		$ 771
Market Risk Benefit, Liability, end of period		611
Market risk benefits gains (losses)		21	$ (115)
Long-Duration Insurance, Other | Variable Annuity
Market Risk Benefit [Line Items]
Market Risk Benefit, Liability, beginning of period		771	800
Balance, beginning of period, before effect of changes in the instrument-specific credit risk		749	776
Interest rate changes		(57)	63
Effect of changes in equity markets		(77)	(75)
Effect of changes in volatilities		(20)	57
Market Risk Benefit, Increase (Decrease) from Actual Policyholder Behavior Different from Expected		30	(2)
Effect of timing and all other		(31)	(16)
Balance, end of period, before effect of changes in the instrument-specific credit risk		594	803
Effect of changes in the instrument-specific credit risk		17	27
Market Risk Benefit, Liability, end of period		611	830
Market Risk Benefit, Net Amount at Risk	[1]	1,683	2,296
Market Risk Benefits Other Gains (Losses)		$ (134)	$ (89)
Weighted-average age of policyholders (years)		74 years	73 years

[1] 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.