Derivatives (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Net After-tax Derivative Activity recorded in AOCI
Beginning Balance - AOCI	$ (9)		$ (11)		$ (7)		$ 1
Unrealized (losses) gains recognized in AOCI			(2)	[1]	1	[1]	10	[1]
Gains reclassified to income	(1)	[2]			(4)	[2]	(24)	[2]
Ending Balance - AOCI	$ (10)		$ (13)		$ (10)		$ (13)

[1] Net of tax of zero and $1 for the three months ended September 30, 2013 and 2012, respectively, and $(1) and $(7) for the nine months ended September 30, 2013 and 2012.

[2] Net of tax of zero for each of the three months ended September 30, 2013 and 2012, and $2 and $14 for the nine months ended September 30, 2013 and 2012, respectively.