Derivatives and Other Hedging Instruments (Effect of Derivative Instruments on Consolidated Income Statement) (Details) (USD $) In Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2011		Jun. 30, 2010
Amount of Gain or (Loss) Recognized in Income of Derivative	$ 20		$ 34		$ 9		$ 39
Amount of Gain or (Loss) Recognized in Income on Hedged Item	(20)		(34)		(9)		(39)
Gain (loss) recognized in interest expense, offset	0		0		0		0
Interest Rate Swaps [Member]
Amount of Gain or (Loss) Recognized in Income of Derivative	20	[1]	34	[1]	9	[1]	39	[1]
Amount of Gain or (Loss) Recognized in Income on Hedged Item	$ (20)	[1]	$ (34)	[1]	$ (9)	[1]	$ (39)	[1]

[1] Gain (loss) was recognized in interest expense, which offset to $0.