Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOW FROM OPERATING ACTIVITIES
Net (loss) income	$ (127)	$ 356
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, depletion and amortization	412	422
Deferred income tax benefit		(78)
Net derivative (gains) losses	(51)	157
Net proceeds on settled derivatives	15	86
Net gains on early extinguishment of debt	(4)	(793)
Amortization of deferred gain	(55)	(53)
Gains on asset divestitures	(21)	(31)
Other non-cash charges to income, net	46	84
Dry hole expenses	1
Changes in operating assets and liabilities, net	9	(5)
Net cash provided by operating activities	225	145
CASH FLOW FROM INVESTING ACTIVITIES
Capital investments	(232)	(45)
Changes in capital investment accruals	26	(5)
Asset divestitures	33	19
Other	(1)
Net cash used by investing activities	(174)	(31)
CASH FLOW FROM FINANCING ACTIVITIES
Proceeds from 2014 Revolving Credit Facility	1,000	1,761
Repayments of 2014 Revolving Credit Facility	(1,010)	(1,728)
Proceeds from 2016 Credit Agreement		990
Payments on 2014 Term Loan	(91)	(329)
Debt repurchases	(24)	(770)
Debt transaction costs	(2)	(44)
Contribution from noncontrolling interest, net	98
Distributions paid to noncontrolling interest holders	(6)
Employee stock purchases and other	2	4
Shares cancelled for taxes	(2)
Net cash used by financing activities	(35)	(116)
Increase (decrease) in cash and cash equivalents	16	(2)
Cash and cash equivalents-beginning of period	12	12
Cash and cash equivalents-end of period	$ 28	$ 10