Derivative Financial Instruments (Schedule of Changes in Fair Value of Derivatives) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Derivative [Line Items]
Gain (loss) recognized in Other comprehensive income (loss)	$ (5)		$ (16)		$ (6)		$ (17)
Gain (loss) recognized in Earnings (loss)	(21)		(20)		(29)		(48)
Tax expense recognized in Other comprehensive income (loss)	4		3		11		11
Foreign Currency Forwards and Swaps [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) recognized in Other comprehensive income (loss)	0		0		0		0
Equity Method Investments' Derivative [Member]
Derivative [Line Items]
Gain (loss) associated with equity method investments' derivative							(1)
Interest Rate Swap [Member]
Derivative [Line Items]
Tax expense recognized in Other comprehensive income (loss)	1		(1)				(6)
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) recognized in Other comprehensive income (loss)	(5)	[1]	(16)	[2]	(6)		(17)	[3]
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) recognized in Other comprehensive income (loss)	0		0		0		0
Interest Expense [Member] | Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) recognized in Earnings (loss)	(4)	[4]	(14)	[4]	(7)	[4]	(30)	[4]
Interest Expense [Member] | Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) recognized in Earnings (loss)	0	[5]	(3)	[5]	0	[6]	(3)	[6]
Foreign Currency Gain (Loss) [Member] | Foreign Currency Forwards and Swaps [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) recognized in Earnings (loss)	$ (17)	[7]	$ (3)	[7]	$ (22)	[7]	$ (15)	[7]

[1] Amount excludes $1 million of tax benefit recognized in Other comprehensive income (loss).

[2] Amount excludes $1 million of tax expense recognized in Other comprehensive income (loss).

[3] Amount excludes $1 million of losses associated with the Company's equity method investments' derivative activity and $6 million of tax expense recognized in Other comprehensive income (loss).

[4] Amount represents reclassification from Accumulated other comprehensive income (loss), net and is included in Interest expense in the unaudited interim consolidated statements of operations.

[5] Included in Interest expense in the unaudited interim consolidated statements of operations.

[6] Included in Interest expense in the unaudited interim consolidated statements of operations

[7] Included in Foreign exchange gain (loss), net for operating activity or Other income (expense), net for non-operating activity in the unaudited interim consolidated statements of operations.