Derivative Financial Instruments, Fair Value (Details) (Designated as Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives	$ 231	$ 255
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives	48	58
Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives	133	133
Foreign Currency Swaps Cash Flow Hedge Maximum Term	8 years
Interest Rate And Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Derivatives	50	64
Other Long Term Investments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value	3	5
Other Long Term Investments [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value	2	4
Other Long Term Investments [Member] | Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value	1	1
Other Long Term Investments [Member] | Interest Rate And Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value	0	0
Accounts Payable Accrued Expenses And Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value	21	31
Accounts Payable Accrued Expenses And Other Liabilities [Member] | Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value	0	0
Accounts Payable Accrued Expenses And Other Liabilities [Member] | Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value	16	18
Accounts Payable Accrued Expenses And Other Liabilities [Member] | Interest Rate And Foreign Currency Swaps [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value	$ 5	$ 13