Reinsurance (Reinsurance on premiums - long-duration contracts) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effects of Reinsurance [Line Items]
Net premiums	$ 1,214	$ 1,426	$ 1,394
Traditional long-duration products [Member]
Effects of Reinsurance [Line Items]
Direct premiums	621	621	637
Reinsurance ceded	(224)	(225)	(227)
Net premiums	$ 397	$ 396	$ 410