Reinsurance (Reinsurance on premiums - long-duration contracts) (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effects of Reinsurance [Line Items]
Total net earned premiums	$ 1,491	$ 1,455	$ 1,385
Traditional Long-Duration Products [Member]
Effects of Reinsurance [Line Items]
Direct premiums earned	642	629	645
Ceded premiums earned	(225)	(223)	(222)
Total net earned premiums	$ 417	$ 406	$ 423