Investments (Rollforward of expected credit-losses, AFS) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available for sale, Allowance for Credit Loss	$ 193	$ 78	$ 193	$ 78	$ 168	$ 169	$ 27	$ 14
Debt Securities, Available-for-sale, Allowance for Credit Loss, Period Increase (Decrease)	79	61	138	78
Debt Securities, Available-for-sale, Allowance for Credit Loss, Writeoff	(2)	0	(4)	0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Recovery	$ (52)	$ (10)	$ (110)	$ (14)