Market risk benefits (MRB Roll-Forward) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Jan. 01, 2021	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Market Risk Benefit [Line Items]
Market Risk Benefit, Liability, beginning of period				$ 800
Market Risk Benefit, Liability, end of period		$ 722		722
Market risk benefits gains (losses)		(7)	$ (33)	(122)	$ 16
Variable Annuity
Market Risk Benefit [Line Items]
Market Risk Benefit, Liability, end of period	$ 1,163
Long-Duration Insurance, Other | Variable Annuity
Market Risk Benefit [Line Items]
Market Risk Benefit, Liability, beginning of period				800	812
Balance, beginning of period, before effect of changes in the instrument-specific credit risk				776	755
Interest rate changes				37	(356)
Effect of changes in equity markets				(144)	482
Effect of changes in volatilities				31	62
Effect of timing and all other				6	(46)
Balance, end of period, before effect of changes in the instrument-specific credit risk		706	897	706	897
Effect of changes in the instrument-specific credit risk		16	17	16	17
Market Risk Benefit, Liability, end of period		722	914	$ 722	$ 914
Market risk benefit, weighted-average age of policyholders (age)				73 years	73 years
Market Risk Benefit, Net Amount at Risk		$ 2,048	$ 2,667	$ 2,048	$ 2,667
Market Risk Benefits Other Gains (Losses)				$ (192)	$ 158