Market risk benefits (MRB Roll-Forward) (Details) - USD ($) $ in Millions		3 Months Ended
	Jan. 01, 2021	Mar. 31, 2023	Mar. 31, 2022
Market Risk Benefit [Line Items]
Market Risk Benefit, Liability, beginning of period		$ 800
Market Risk Benefit, Liability, end of period		830
Market risk benefits gains (losses)		(115)	$ 49
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		63	(140)
Effect of changes in equity markets		(75)	111
Effect of changes in volatilities		57	37
Effect of timing and all other		(18)	(32)
Balance, end of period, before effect of changes in the instrument-specific credit risk		803	731
Effect of changes in the instrument-specific credit risk		27	34
Market Risk Benefit, Liability, end of period		$ 830	$ 765
Market risk benefit, weighted-average age of policyholders (age)		73 years	73 years
Market Risk Benefit, Net Amount at Risk		$ 2,296	$ 1,913
Market Risk Benefits Other Gains (Losses)		$ (89)	$ 26