Separate accounts (Liabilities) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Separate Account, Liability, Surrender and Withdrawal [Abstract]
Separate Account, Liability, Beginning Balance		$ 5,190	$ 5,560
Separate Account, Liability, Premium and Deposit		158	467
Separate Account, Liability, Policy Charge		(15)	(31)
Separate Account, Liability, Surrender and Withdrawal		(6)	(124)
Separate Account, Liability, Benefit Payment		(98)	(95)
Separate Account, Liability, Increase (Decrease) from Invested Performance		83	(283)
Separate Account, Liability, Increase (Decrease) from Other Change		(12)	66
Separate Account, Liability, Ending Balance		5,300	5,560
Separate Account, Liability, Cash Surrender Value, Amount	[1]	$ 5,124	$ 4,994

[1] Cash surrender value represents the amount of the contract holder's account balances distributable at the balance sheet date less certain surrender charges.