Reserves for Future Policy Benefits (Details) - Annuitization Benefit - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Movement in Liabilities for Guarantees on Long-Duration Contracts, Guaranteed Benefit Liability, Gross [Roll Forward]
Beginning Balance	$ 642	$ 713
Incurred	27	10
Paid	28	8
Change in unrealized investment gains and losses	7	(37)
Ending Balance	648	678
Movement in Liabilities for Guarantees on Long-Duration Contracts, Reinsurance Recoverable [Roll Forward]
Beginning Balance	27	26
Incurred	5	8
Paid	2	0
Ending Balance	$ 30	$ 34