Derivative Instruments and Hedging Activities (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Fair values of derivative instruments recorded in Balance Sheet
Derivative Assets Designated as Hedging Instruments	$ 84	$ 38
Derivative Liabilities Designated as Hedging Instruments	69	28
Interest Rate Contracts [Member] | Current other assets [Member]
Fair values of derivative instruments recorded in Balance Sheet
Derivative Assets Designated as Hedging Instruments	0	1
Interest Rate Contracts [Member] | Long-term other assets [Member]
Fair values of derivative instruments recorded in Balance Sheet
Derivative Assets Designated as Hedging Instruments	75	37
Interest Rate Contracts [Member] | Current accrued liabilities [Member]
Fair values of derivative instruments recorded in Balance Sheet
Derivative Liabilities Designated as Hedging Instruments	0	11
Interest Rate Contracts [Member] | Long-term accrued liabilities [Member]
Fair values of derivative instruments recorded in Balance Sheet
Derivative Liabilities Designated as Hedging Instruments	68	13
Electricity Commodity Contracts [Member] | Current other assets [Member]
Fair values of derivative instruments recorded in Balance Sheet
Derivative Assets Designated as Hedging Instruments	1	0
Electricity Commodity Contracts [Member] | Current accrued liabilities [Member]
Fair values of derivative instruments recorded in Balance Sheet
Derivative Liabilities Designated as Hedging Instruments	1	1
Foreign Exchange Contracts [Member] | Long-term other assets [Member]
Fair values of derivative instruments recorded in Balance Sheet
Derivative Assets Designated as Hedging Instruments	8	0
Foreign Exchange Contracts [Member] | Long-term accrued liabilities [Member]
Fair values of derivative instruments recorded in Balance Sheet
Derivative Liabilities Designated as Hedging Instruments	$ 0	$ 3