Statement of Consolidated Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
NET INCOME (LOSS) INCLUDING NONCONTROLLING INTEREST	$ (23,528)	$ (5,060)	$ 2,288
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and postretirement benefit plan, net of tax			9
Commodity cash flow hedge activity, net of tax:
Reclassification of (gain) loss on settled derivative instruments			11
Change in fair value of derivative instruments		(1)	(5)
Derivative hedge ineffectiveness reclassified into earnings			1
Commodity cash flow hedge activity, net of tax		(1)	16
COMPREHENSIVE INCOME (LOSS) INCLUDING NONCONTROLLING INTEREST	(23,528)	(5,061)	2,304
Preferred stock dividends			44
Comprehensive income (loss) attributable to noncontrolling interest	(409)	343	56
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCK	$ (23,119)	$ (5,404)	$ 2,204