Derivatives and Other Hedging Instruments (Effect of Derivative Instruments on Consolidated Income Statement) (Details) (USD $) In Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Amount of Gain or (Loss) Recognized in Income of Derivative	$ 22		$ 28		$ 31		$ 67
Amount of Gain or (Loss) Recognized in Income on Hedged Item	(22)		(28)		(31)		(67)
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	22	[1]	28	[1]	31	[1]	67	[1]
Amount of Gain or (Loss) Recognized in Income on Hedged Item	$ (22)	[1]	$ (28)	[1]	$ (31)	[1]	$ (67)	[1]

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