Investments (Net realized investment gains (losses)) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Fixed maturity securities:
Gross gains	$ 51,000,000	$ 102,000,000	$ 109,000,000	$ 131,000,000
Gross losses	(20,000,000)	(85,000,000)	(40,000,000)	(189,000,000)
Net investment gains (losses) on fixed maturity securities	31,000,000	17,000,000	69,000,000	(58,000,000)
Equity securities	17,000,000	63,000,000	19,000,000	(70,000,000)
Derivatives	(12,000,000)	(10,000,000)	5,000,000	(5,000,000)
Mortgage loans	0	0	0	(13,000,000)
Short term investments and other	2,000,000	(1,000,000)	2,000,000	(1,000,000)
Net investment gains (losses)	$ 38,000,000	$ 69,000,000	$ 95,000,000	$ (147,000,000)