STATEMENT OF CONSOLIDATED COMPREHENSIVE INCOME (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]
NET INCOME (LOSS) INCLUDING NONCONTROLLING INTEREST	$ 613	$ 1,035	$ 947	$ 1,752
Commodity cash flow hedge activity, net of tax:
Reclassification of loss on settled derivative instruments	0	8	0	14
Change in fair value of derivative instruments	0	7	(1)	(1)
Commodity cash flow hedge activity, net of tax	0	15	(1)	13
COMPREHENSIVE INCOME INCLUDING NONCONTROLLING INTEREST	613	1,050	946	1,765
Preferred stock dividends	0	19	0	38
Comprehensive income attributable to noncontrolling interest	108		206
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON STOCK	$ 505	$ 1,031	$ 740	$ 1,727