Investments- Other-than-temporary impairment losses (Details 6) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	$ (19)	$ (25)	$ (41)	$ (41)
Portion of loss recognized in other comprehensive income	0	8	(1)	(2)
Net other-than-temporary impairment losses recognized in earnings	(19)	(17)	(42)	(43)
Fixed income securities
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	(3)	(13)	(2)	(39)
Portion of loss recognized in other comprehensive income	0	8	(1)	(2)
Net other-than-temporary impairment losses recognized in earnings	(3)	(5)	(3)	(41)
Municipal
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	0	0	(1)	(8)
Portion of loss recognized in other comprehensive income	0	0	0
Net other-than-temporary impairment losses recognized in earnings	0	0	(1)	(8)
Corporate
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	(3)		(3)
Portion of loss recognized in other comprehensive income	0		0
Net other-than-temporary impairment losses recognized in earnings	(3)		(3)
ABS
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	0	0	(1)	0
Portion of loss recognized in other comprehensive income	0	0	0	(1)
Net other-than-temporary impairment losses recognized in earnings	0	0	(1)	(1)
RMBS
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	0	(5)	3	(4)
Portion of loss recognized in other comprehensive income	0	4	(1)	3
Net other-than-temporary impairment losses recognized in earnings	0	(1)	2	(1)
CMBS
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses		(8)		(27)
Portion of loss recognized in other comprehensive income		4		(4)
Net other-than-temporary impairment losses recognized in earnings		(4)		(31)
Mortgage loans
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	2	(6)	6	11
Portion of loss recognized in other comprehensive income	0	0	0	0
Net other-than-temporary impairment losses recognized in earnings	2	(6)	6	11
Equity securities
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	(21)	(4)	(29)	(5)
Portion of loss recognized in other comprehensive income	0	0	0	0
Net other-than-temporary impairment losses recognized in earnings	(21)	(4)	(29)	(5)
Limited partnership interests
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses	3	(1)	(16)	(5)
Portion of loss recognized in other comprehensive income	0	0	0	0
Net other-than-temporary impairment losses recognized in earnings	3	(1)	(16)	(5)
Other
Other-than-temporary impairment losses by asset type
Total other-than-temporary impairment losses		(1)		(3)
Portion of loss recognized in other comprehensive income		0		0
Net other-than-temporary impairment losses recognized in earnings		$ (1)		$ (3)