Investments (Components of other-than-temporary impairment losses recognized in earnings) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities available-for-sale	$ 6	$ 0	$ 20	$ 6
Corporate and other bonds
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities available-for-sale	6	0	12	5
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities available-for-sale	$ 0	$ 0	$ 8	$ 1