Investments (Net Inv Inc summary) (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Investment income on fixed maturities	$ 339	$ 340	$ 1,002	$ 1,012
Net realized gains (losses)	4	(3)	15	35
Affordable housing partnerships	(24)	(17)	(49)	(42)
Other	43	26	132	70
Consolidated investment entities	24	26	101	79
Total	$ 386	$ 372	$ 1,201	$ 1,154