Investments (Components of Net Investment Gains (Losses)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Net investment gains (losses), fixed maturity securities	$ (6)	$ (15)
Net investment gains (losses), equity securities	(14)	10
Net investment gains (losses), mortgage loans	(4)	(4)
Net investment gains (losses), limited partnerships and LLCs	(1)	(2)
Net investment gains (losses), other	6	1
Net investment gains (losses)	$ (19)	$ (10)