Consolidated Statement of Comprehensive Income (Loss) (Parenthetical) (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Other Comprehensive Income Derivatives Qualifying As Hedges Tax Effect Period Increase Decrease [Abstract]
Other Comprehensive Income, Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	$ 0	$ (14)	$ 0	$ (12)
Other Comprehensive Income Loss Reclassification Adjustment On Derivatives Included In Net Income Tax	0	2	0	2
Other Comprehensive Income Defined Benefit Plans Tax [Abstract]
Other Comprehensive Income Amortization Of Defined Benefit Plan Net Prior Service Cost Recognized In Net Periodic Pension Cost Tax	0	0	0	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax	0	1	0	1
Other Comprehensive Income Loss Reclassification Pension And Other Postretirement Benefit Plans Net Gain Loss Recognized In Net Periodic Benefit Cost Tax	(5)	(6)	(11)	(11)
Other Comprehensive Income Available For Sale Securities Tax [Abstract]
Other Comprehensive Income Loss Reclassification Adjustment For Sale Of Securities Included In Net Income Tax	$ 0	$ 0	$ 0	$ 2