Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Statement of Cash Flows [Abstract]
Net income (loss)	$ (717,630)	$ (35,720)
Adjustments to net income (loss) to reconcile to net cash provided by operating activities:
Net change in fair value of unsettled commodity derivatives	(18,338)	68,058
Depreciation, depletion and amortization	470,152	491,784
Impairment of properties and equipment	882,327	37,021
Accretion of asset retirement obligations	7,398	4,503
Non-cash stock-based compensation	17,441	18,124
Loss (gain) on sale of properties and equipment	(642)	9,599
Amortization of debt discount and issuance costs	12,546	10,139
Deferred income taxes	(2,431)	(4,389)
Other	1,950	2,761
Changes in assets and liabilities	(3,461)	49,092
Net cash from operating activities	649,312	650,972
Cash flows from investing activities:
Capital expenditures for development of crude oil and natural gas properties	(445,505)	(755,828)
Capital expenditures for other properties and equipment	(1,940)	(15,522)
Acquisition of crude oil and natural gas properties, including settlement adjustments	(139,812)	(12,445)
Proceeds from sale of properties and equipment	1,539	1,528
Proceeds from Divestiture of Businesses	1,796	202,046
Increase (Decrease) in Restricted Cash	0	8,001
Net cash from investing activities	(583,922)	(572,220)
Cash flows from financing activities:
Proceeds from revolving credit facility	1,485,600	1,300,000
Repayment of revolving credit facility	(1,204,600)	(1,235,500)
Proceeds from Secured Notes Payable	148,500	0
Payments of Debt Issuance Costs	6,197	53
Proceeds from (Repurchase of) Equity	(23,819)	(142,665)
Payments for Repurchase of Common Stock	(8,412)	(3,874)
Early Repayment of Senior Debt	452,153	0
Finance Lease, Principal Payments	(1,454)	(1,492)
Net cash from financing activities	(62,535)	(83,584)
Net change in cash, cash equivalents, and restricted cash	2,855	(4,832)
Cash, cash equivalents and restricted cash, beginning of period	963	9,399
Cash, cash equivalents and restricted cash, end of period	3,818	4,567
Cash payments (receipts) for:
Interest, net of capitalized interest	51,556	41,483
Income taxes	(204)	261
Non-cash investing and financing activities:
Change in accounts payable related to purchases of properties and equipment	31,403	32,943
Change in asset retirement obligation, with a corresponding change to crude oil and natural gas properties, net of disposals	$ 44,339	$ 13,493