Investments (Net realized investment gains (losses)) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Fixed maturity securities:
Gross gains	$ 50,000,000	$ 44,000,000	$ 159,000,000	$ 175,000,000
Gross losses	(28,000,000)	(18,000,000)	(68,000,000)	(207,000,000)
Net investment gains (losses) on fixed maturity securities	22,000,000	26,000,000	91,000,000	(32,000,000)
Equity securities	(2,000,000)	25,000,000	17,000,000	(45,000,000)
Derivatives	2,000,000	(2,000,000)	7,000,000	(7,000,000)
Mortgage loans	0	(3,000,000)	0	(16,000,000)
Short term investments and other	0	(19,000,000)	2,000,000	(20,000,000)
Net investment gains (losses)	$ 22,000,000	$ 27,000,000	$ 117,000,000	$ (120,000,000)