Investments (Details 6) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	$ (44)	$ (55)	$ (124)	$ (82)
Portion of loss recognized in other comprehensive income	(1)	(5)	(2)	(15)
Net other-than-temporary impairment losses recognized in earnings	(45)	(60)	(126)	(97)
Fixed income securities
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	3	(6)	(3)	(38)
Portion of loss recognized in other comprehensive income	(1)	(5)	(2)	(15)
Net other-than-temporary impairment losses recognized in earnings	2	(11)	(5)	(53)
Municipal
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	(1)	(4)	(6)	(17)
Portion of loss recognized in other comprehensive income		(3)		(5)
Net other-than-temporary impairment losses recognized in earnings	(1)	(7)	(6)	(22)
Asset-backed securities ("ABS")
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	(2)		(3)
Portion of loss recognized in other comprehensive income		(1)		(1)
Net other-than-temporary impairment losses recognized in earnings	(2)	(1)	(3)	(1)
Residential mortgage-backed securities ("RMBS")
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	6	(1)	6	(1)
Portion of loss recognized in other comprehensive income	(1)	(1)	(2)	(2)
Net other-than-temporary impairment losses recognized in earnings	5	(2)	4	(3)
Commercial mortgage-backed securities ("CMBS")
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses		(1)		(20)
Portion of loss recognized in other comprehensive income				(7)
Net other-than-temporary impairment losses recognized in earnings		(1)		(27)
Equity securities
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	(21)	(32)	(86)	(51)
Net other-than-temporary impairment losses recognized in earnings	(21)	(32)	(86)	(51)
Mortgage loans
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses		(9)	4	17
Net other-than-temporary impairment losses recognized in earnings		(9)	4	17
Limited partnership interests
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	(26)	(8)	(39)	(8)
Net other-than-temporary impairment losses recognized in earnings	(26)	(8)	(39)	(8)
Other
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses				(2)
Net other-than-temporary impairment losses recognized in earnings				$ (2)