CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Cash Flows From Operating Activities:
Net loss	$ (609)	$ (880)	$ (529)	$ (2,427)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization	100	84	196	197
Amortization of debt issuance costs			4	4
Impairments	0	655	0	2,134
Deferred income taxes	0	0	0	408
(Gain) loss on derivatives, unsettled			941	(17)
Stock-based compensation	2	1	2	2
Gain on early extinguishment of debt	0	(7)	0	(35)
Other			1	0
Change in assets and liabilities:
Accounts receivable			(40)	94
Accounts payable			75	(121)
Taxes payable			(12)	(11)
Interest payable			0	(1)
Inventories			3	6
Other assets and liabilities			(24)	21
Net cash provided by operating activities			617	254
Cash Flows From Investing Activities:
Capital investments			(493)	(472)
Proceeds from sale of property and equipment			2	2
Other			(1)	0
Net cash used in investing activities			(492)	(470)
Cash Flows From Financing Activities:
Payments on long-term debt			0	(72)
Payments on revolving credit facility			(1,782)	(919)
Borrowings under revolving credit facility			1,650	1,221
Change in bank drafts outstanding			0	(8)
Debt issuance/amendment costs			(1)	0
Cash paid for tax withholding			(3)	(1)
Net cash provided by (used in) financing activities			(136)	221
Increase (decrease) in cash and cash equivalents			(11)	5
Cash and cash equivalents at beginning of year			13	5
Cash and cash equivalents at end of period	$ 2	$ 10	$ 2	$ 10