Investments (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Realized capital gains and losses by asset type
Realized capital gains and losses	$ 594	$ 327	$ 503
Fixed income securities
Realized capital gains and losses by asset type
Realized capital gains and losses	262	107	712
Equity securities
Realized capital gains and losses by asset type
Realized capital gains and losses	327	183	63
Mortgage loans
Realized capital gains and losses by asset type
Realized capital gains and losses	20	8	(27)
Limited partnership interests
Realized capital gains and losses by asset type
Realized capital gains and losses	(5)	13	159
Derivatives
Realized capital gains and losses by asset type
Realized capital gains and losses	(10)	23	(397)
Other
Realized capital gains and losses by asset type
Realized capital gains and losses		$ (7)	$ (7)