Investments (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net Investment Income [Line Items]
Investment income	$ 380	$ 342	$ 1,126	$ 1,008
Investment expenses	(3)	(4)	(9)	(12)
Net investment income	377	338	1,117	996
Fixed maturities [Member]
Net Investment Income [Line Items]
Investment income	342	310	1,007	920
Equity securities [Member]
Net Investment Income [Line Items]
Investment income	16	15	48	36
Equity method investments [Member]
Net Investment Income [Line Items]
Investment income	2	0	15	0
Other [Member]
Net Investment Income [Line Items]
Investment income	$ 20	$ 17	$ 56	$ 52