Investments (Components of other-than-temporary impairment losses recognized in earnings) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Debt Securities, Available-for-sale [Line Items]
Impairment losses (gains) recognized in earnings	$ 12	$ 25	$ 37	$ 55
Corporate and other bonds
Debt Securities, Available-for-sale [Line Items]
Impairment losses (gains) recognized in earnings	8	24	25	53
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Impairment losses (gains) recognized in earnings	$ 4	$ 1	$ 12	$ 2