Investments (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Net Investment Income [Line Items]
Investment income	$ 366	$ 330
Investment expenses	(5)	(4)
Net investment income	361	326
Fixed maturities [Member]
Net Investment Income [Line Items]
Investment income	327	302
Equity securities [Member]
Net Investment Income [Line Items]
Investment income	16	12
Equity method investments [Member]
Net Investment Income [Line Items]
Investment income	6	0
Other [Member]
Net Investment Income [Line Items]
Investment income	$ 17	$ 16