Derivatives (Net Derivative Gains Losses) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Components of Net Derivatives Gains (Losses)
Derivatives and hedging gains (losses)	$ (183)	$ (189)	$ (746)	$ (225)
Embedded derivatives	(16)	91	165	270
Total net derivative gains (losses)	$ (199)	$ (98)	$ (581)	$ 45