Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Cash Flows [Abstract]
Net income (loss)	$ (9,036)	$ (465,015)
Adjustments to net income (loss) to reconcile to net cash provided by operating activities:
Net change in fair value of unsettled commodity derivatives	150,606	(388,875)
Depreciation, depletion and amortization	146,763	176,157
Impairment of properties and equipment	190	881,074
Accretion of asset retirement obligations	3,128	2,620
Non-cash stock-based compensation	5,020	5,672
Loss (gain) on sale of properties and equipment	(212)	(179)
Amortization of debt discount and issuance costs	3,837	3,640
Deferred income taxes	0	(6,331)
Other	(305)	1,011
Changes in assets and liabilities	53,068	56,507
Net cash from operating activities	353,059	266,281
Cash flows from investing activities:
Capital expenditures for development of crude oil and natural gas properties	(109,048)	(190,768)
Capital expenditures for other properties and equipment	(69)	(455)
Acquisition of crude oil and natural gas properties, including settlement adjustments	0	(139,812)
Proceeds from sale of properties and equipment	4,370	793
Proceeds from Divestiture of Businesses	0	62
Net cash from investing activities	(104,747)	(330,180)
Cash flows from financing activities:
Proceeds from revolving credit facility	229,000	917,000
Repayment of revolving credit facility	(397,000)	(304,000)
Payments of Debt Issuance Costs	0	4,666
Proceeds from (Repurchase of) Equity	(21,067)	(23,819)
Payments for Repurchase of Common Stock	(2,356)	(7,693)
Early Repayment of Senior Debt	0	452,153
Finance Lease, Principal Payments	(445)	(489)
Net cash from financing activities	(191,868)	124,180
Net change in cash, cash equivalents, and restricted cash	56,444	60,281
Cash, cash equivalents and restricted cash, beginning of period	2,623	963
Cash, cash equivalents and restricted cash, end of period	59,067	61,244
Cash payments (receipts) for:
Interest, net of capitalized interest	9,043	16,915
Income taxes	(1,388)	(204)
Non-cash investing and financing activities:
Change in accounts payable related to purchases of properties and equipment	(15,393)	(70,026)
Change in asset retirement obligation, with a corresponding change to crude oil and natural gas properties, net of disposals	$ 206	$ 42,126