Investments (Details 4) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Realized capital gains and losses by asset type
Realized capital gains and losses	$ 33	$ 33	$ (92)	$ 280
Fixed income securities
Realized capital gains and losses by asset type
Realized capital gains and losses	(1)	221	(48)	361
Equity securities
Realized capital gains and losses by asset type
Realized capital gains and losses	45	(150)	(34)	(24)
Mortgage loans
Realized capital gains and losses by asset type
Realized capital gains and losses	0	1	1	2
Limited partnership interests
Realized capital gains and losses by asset type
Realized capital gains and losses	12	(55)	25	(52)
Derivatives
Realized capital gains and losses by asset type
Realized capital gains and losses	(15)	24	(22)	4
Other
Realized capital gains and losses by asset type
Realized capital gains and losses	$ (8)	$ (8)	$ (14)	$ (11)