CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME (LOSS)	$ 619	$ (4,058)
ADJUSTMENTS TO RECONCILE NET INCOME (LOSS) TO CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES:
Depreciation, depletion and amortization	689	874
Derivative (gains) losses, net	(452)	283
Cash receipts (payments) on derivative settlements, net	(46)	487
Stock-based compensation	38	40
Impairment of oil and natural gas properties	0	2,564
Net gains on sales of fixed assets	0	(5)
Renegotiation of natural gas gathering contract	0	(66)
Impairments of fixed assets and other	9	785
Losses on investments	0	3
Loss on sale of investment	0	10
Gains on purchases or exchanges of debt	(185)	(255)
Restructuring and other termination costs	0	1
Provision for legal contingencies	35	77
Other	(68)	(76)
Changes in assets and liabilities	(366)	(614)
Net Cash Provided By Operating Activities	273	50
CASH FLOWS FROM INVESTING ACTIVITIES:
Drilling and completion costs	(1,597)	(948)
Acquisitions of proved and unproved properties	(226)	(583)
Proceeds from divestitures of proved and unproved properties	1,193	988
Additions to other property and equipment	(12)	(32)
Proceeds from sales of other property and equipment	40	70
Cash paid for title defects	0	(69)
Other	0	(5)
Net Cash Used In Investing Activities	(602)	(579)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from revolving credit facility borrowings	4,775	5,097
Payments on revolving credit facility borrowings	(4,130)	(4,857)
Proceeds from issuance of senior notes, net	742	0
Proceeds from issuance of term loan	0	1,500
Cash paid to purchase debt	(1,751)	(1,979)
Cash paid for preferred stock dividends	(160)	0
Distributions to noncontrolling interest owners	(7)	(8)
Other	(17)	(45)
Net Cash Used In Financing Activities	(548)	(292)
Net decrease in cash and cash equivalents	(877)	(821)
Cash and cash equivalents, beginning of period	882	825
Cash and cash equivalents, end of period	5	4
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid, net of capitalized interest	342	209
Income tax refunds received, net	(15)	(20)
SUPPLEMENTAL DISCLOSURE OF SIGNIFICANT NON-CASH INVESTING AND FINANCING ACTIVITIES:
Debt exchanged for common stock	0	471
Change In Accrued Drilling And Completion Costs [Member]
SUPPLEMENTAL DISCLOSURE OF SIGNIFICANT NON-CASH INVESTING AND FINANCING ACTIVITIES:
Change in accrued drilling and completion costs	134	(22)
Change In Accrued Acquisitions Of Proved And Unproved Properties [Member]
SUPPLEMENTAL DISCLOSURE OF SIGNIFICANT NON-CASH INVESTING AND FINANCING ACTIVITIES:
Change in accrued drilling and completion costs	(1)	(1)
Change In Divested Proved And Unproved Properties [Member]
SUPPLEMENTAL DISCLOSURE OF SIGNIFICANT NON-CASH INVESTING AND FINANCING ACTIVITIES:
Change in accrued drilling and completion costs	$ (23)	$ 12