Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income (loss)	$ (69,642)	$ 74,016
Adjustments to reconcile net income (loss) to cash flows from operating activities
Depletion, depreciation, and amortization	39,450	96,862
Write-down of oil and natural gas properties	14,377	72,541
Deferred income taxes	(51)	(4,209)
Stock-based compensation	17,680	2,453
Commodity derivatives expense (income)	115,743	(146,771)
Receipt (payment) on settlements of commodity derivatives	(38,453)	24,638
Gain on debt extinguishment	0	(18,994)
Debt issuance costs and discounts	685	4,926
Other, net	727	(673)
Changes in assets and liabilities, net of effects from acquisitions
Accrued production receivable	(36,750)	66,937
Trade and other receivables	865	(22,914)
Other current and long-term assets	(2,542)	2,539
Accounts payable and accrued liabilities	(1,402)	(72,607)
Oil and natural gas production payable	12,795	(15,948)
Other liabilities	(826)	(954)
Net cash provided by operating activities	52,656	61,842
Cash flows from investing activities
Oil and natural gas capital expenditures	(19,627)	(46,016)
Acquisitions of oil and natural gas properties	(10,665)	(42)
Pipelines and plants capital expenditures	(458)	(6,294)
Net proceeds from sales of oil and natural gas properties and equipment	3	40,543
Other	(2,916)	(4,479)
Net cash used in investing activities	(33,663)	(16,288)
Cash flows from financing activities
Bank repayments	(202,000)	(161,000)
Bank borrowings	207,000	161,000
Interest payments treated as a reduction of debt	0	(18,211)
Cash paid in conjunction with debt repurchases	0	(14,171)
Pipeline financing debt repayments	(16,509)	(3,690)
Other	(3,013)	(2,953)
Net cash used in financing activities	(14,522)	(39,025)
Net increase in cash, cash equivalents, and restricted cash	4,471	6,529
Cash, cash equivalents, and restricted cash at beginning of period	42,248	33,045
Cash, cash equivalents, and restricted cash at end of period	$ 46,719	$ 39,574