Investments (Details 7) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Investments
Net unrealized gains related to changes in valuation of fixed income securities subsequent to impairment measurement date	$ 164	$ 134
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	(117)	(142)
Credit Losses on Fixed Income Securities
Beginning balance	(345)	(581)	(701)
Additional credit loss for securities previously other-than-temporarily impaired	(13)	(33)	(76)
Additional credit loss for securities not previously other-than-temporarily impaired	(19)	(20)	(114)
Reduction in credit loss for securities disposed or collected	75	288	288
Reduction in credit loss for securities the Company has made the decision to sell or more likely than not will be required to sell	2		13
Change in credit loss due to accretion of increase in cash flows	1	1	9
Ending balance	(299)	(345)	(581)
Cumulative credit losses recognized in earnings for securities classified as held for sale	60
Municipal
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	(5)	(5)
Corporate
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings		(1)
ABS
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	(10)	(14)
RMBS
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	(90)	(103)
CMBS
Other-than-temporary impairment losses included in accumulated other comprehensive income
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings	$ (12)	$ (19)