Income, Sales-Based And Other Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income, Sales-Based And Other Taxes [Abstract]
Net deferred income tax expense (credits)/charges for tax rate and law changes	$ 244,000,000	$ (330,000,000)	$ 175,000,000
Reconciliation between income tax expense and theoretical U.S. tax rate, statutory rate	35.00%	35.00%	35.00%
Indefinitely reinvested, undistributed earnings from subsidiary companies outside the U.S.	43,000,000,000
Potential percentage increase in unrecognized tax benefits	25.00%
Credit of net interest expense on income tax reserves			39,000,000
Interest expense on income tax reserves	46,000,000	62,000,000
Interest payable on income tax reserves	$ 385,000,000	$ 662,000,000