Income Taxes (Schedule Of Components Of Net Deferred Tax Assets And Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Deferred tax assets, Depreciation	$ 74	$ 204
Deferred tax assets, Employee benefits	2,668	2,383
Deferred tax assets, Loss provisions	325	391
Deferred tax assets, Deferred income/expense	45	104
Deferred tax assets, Tax loss carryforwards	2,035	1,953
Deferred tax assets, Tax credit carryforwards	477	503
Deferred tax assets, Derivatives and hedging activities	109	162
Deferred tax assets, Other	315	633
Deferred tax assets, Gross	6,048	6,333
Deferred tax assets, Valuation allowance	(1,398)	(1,268)
Deferred tax assets, net	4,650	5,065
Deferred tax liabilities, Depreciation	933	1,330
Deferred tax liabilities, Employee benefits	51	45
Deferred tax liabilities, Loss provisions	9	40
Deferred tax liabilities, Deferred income/expense	181	159
Deferred tax liabilities, Tax loss carryforwards
Deferred tax liabilities, Tax credit carryforwards
Deferred tax liabilities, Derivatives and hedging activities	43	12
Deferred tax liabilities, Other	288	547
Deferred tax liabilities, Gross	1,505	2,133
Deferred tax liabilities, Net	$ 1,505	$ 2,133