Investments (Components of other-than-temporary impairment losses recognized in earnings) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities available-for-sale	$ 14	$ 3	$ 34	$ 9
Corporate and other bonds
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities available-for-sale	12	1	24	6
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities available-for-sale	$ 2	$ 2	$ 10	$ 3