Accumulated Other Comprehensive Income (Details) (USD $) In Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 8		$ 116	$ (135)	$ (79)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(3,593)	(3,403)		(3,593)		(3,578)
Other Comprehensive Income, Defined Benefit Plan's Net Unamortized Gain (Loss) Arising During Period, before Tax	0	0
Other Comprehensive Income, Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(135)	214
OtherComprehensiveIncomeValuationAllowanceChangesInFairValue	0	0
Accumulated Other Comprehensive Income Loss Changes In Fair Value Before Tax	(135)	214
Other Comprehensive Income, Reclassification of Defined Benefit Plan's Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Tax	(8)	(10)
Other Comprehensive Income, Reclassification Adjustment on Derivatives Included in Net Income, Tax	63	49
OtherComprehensiveIncomeValuationAllowanceReclassificationToEarnings	0	0
Accumulated Other Comprehensive Income Loss Income Reclassification To Earnings Before Tax	(55)	(39)
Other Comprehensive Income, Defined Benefit Plans, Tax	(3)	(4)
Other Comprehensive Income, Derivatives Qualifying as Hedges, Tax Effect	73	(61)
Other Comprehensive Income Valuation Allowance Tax	70	(65)
AccumulatedOtherComprehensiveLossIncomeTaxEffect	0	0
Accumulated Other Comprehensive Income (Loss), Defined Benefit Pension and Other Postretirement Plans, Net of Tax	(2,042)	(2,047)		(2,042)		(2,053)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(333)	(208)		(333)		(312)
Accumulated Other Comprehensive Income Valuation Allowance Net Of Tax	$ (1,218)	$ (1,148)		$ (1,218)		$ (1,213)