STATEMENT OF CONSOLIDATED COMPREHENSIVE INCOME (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
NET INCOME	$ 2,001	$ 4,584	$ 3,032
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and postretirement benefit plan, net of tax	(2)	(1)	(2)
Commodity cash flow hedge activity, net of tax:
Reclassification of (gain) loss on settled derivative instruments	(199)	19	(106)
Change in fair value of derivative instruments	79	115	256
Derivative hedge ineffectiveness reclassified into earnings		(1)	1
Other Comprehensive income (Loss), Net of Tax, Total	(122)	132	149
COMPREHENSIVE INCOME	1,879	4,716	3,181
Preferred stock dividends	76	76	32
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON STOCK	$ 1,803	$ 4,640	$ 3,149