Investments (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Net Investment Income [Line Items]
Investment income	$ 380	$ 336	$ 746	$ 666
Investment expenses	(1)	(4)	(6)	(8)
Net investment income	379	332	740	658
Fixed maturities [Member]
Net Investment Income [Line Items]
Investment income	338	308	665	610
Equity securities [Member]
Net Investment Income [Line Items]
Investment income	16	9	32	21
Equity method investments [Member]
Net Investment Income [Line Items]
Investment income	7	0	13	0
Other [Member]
Net Investment Income [Line Items]
Investment income	$ 19	$ 19	$ 36	$ 35