Investments (Details 2) (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, Credit Losses Recognized in Earnings [Roll Forward]
Beginning Balance	$ 175	$ 191	$ 194	$ 192
Additional credit impairments on:
Previously impaired securities	0	0	0	0
Securities without prior impairments	0	0	0	0
Reductions due to sales or redemptions	(2)	0	(21)	(1)
Ending Balance	$ 173	$ 191	$ 173	$ 191