Investments (Details 4) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Realized capital gains and losses by asset type
Realized capital gains and losses	$ 108	$ 240	$ 247	$ 294
Fixed income securities
Realized capital gains and losses by asset type
Realized capital gains and losses	60	62	140	98
Equity securities
Realized capital gains and losses by asset type
Realized capital gains and losses	48	239	126	261
Mortgage loans
Realized capital gains and losses by asset type
Realized capital gains and losses	1	(2)	1	1
Limited partnership interests
Realized capital gains and losses by asset type
Realized capital gains and losses	(3)	(51)	3	(49)
Derivatives
Realized capital gains and losses by asset type
Realized capital gains and losses	5	(7)	(20)	(19)
Other
Realized capital gains and losses by asset type
Realized capital gains and losses	$ (3)	$ (1)	$ (3)	$ 2