Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ (158,227)	$ 17,698
Adjustments to reconcile net income (loss) to net cash provided by operating activities
Depreciation, depletion, amortization and accretion	140,579	114,331
Exploration expense	30,311	36,193
Stock-based compensation	3,585	7,614
Impairment of oil and gas properties	6,849
Net cash for plugging wells	(222)	(444)
(Gain) loss on derivative instruments	11,329	(40,620)
Net cash receipts on settled derivatives	61,877	11,072
Gain on sale of assets	(1,478)	(734)
Amortization of deferred financing costs	2,041	2,160
Amortization of debt discount	1,000	998
Changes in operating assets and liabilities:
Accounts receivable	15,437	68,056
Other assets	(126)	619
Accounts payable and accrued liabilities	(40,124)	(40,634)
Net cash provided by operating activities	72,831	176,309
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures for oil and gas properties	(122,019)	(268,768)
Capital expenditures for other property and equipment	(271)	(576)
Proceeds from sale of assets	1,393	1,810
Cash acquired in merger		12,894
Change in deposits and other long-term assets		(53)
Net cash used in investing activities	(120,897)	(254,693)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from other notes payable	1,141
Debt issuance costs	(80)	(4,242)
Repayments of long-term debt	(575)	(260)
Proceeds from revolving credit facility	40,000	95,000
Equity issuance costs		(31)
Employee tax withholding for settlement of equity compensation awards	(463)	(6,511)
Net cash provided by financing activities	40,023	83,956
Net increase (decrease) in cash and cash equivalents	(8,043)	5,572
Cash and cash equivalents at beginning of period	12,056	5,959
Cash and cash equivalents at end of period	4,013	11,531
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for interest	52,590	51,280
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES
Asset retirement obligations incurred, including changes in estimate	196	1,006
Additions to oil and natural gas properties - changes in accounts payable, accrued liabilities, and accrued capital expenditures	$ (18,541)	16,583
BRMR Merger consideration		$ 275,759