CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Lease, Payments	$ 16,774	$ 0	$ 0
Operating Lease, Payments, Use	20,905	0	0
Cash flows from operating activities:
Net income	16,414	212,736	83,555
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	444,243	326,462	161,628
Stock-based compensation expense	28,997	20,670	13,759
Impairment and abandonment expense	47,245	11,136	(29)
Exploratory dry hole costs	0	528	5,658
Deferred tax expense	5,797	59,440	29,930
Net (gain) loss on sale of long-lived assets	857	(475)	(8,796)
Non-cash portion of derivative (gain) loss	(4,094)	5,274	(5,805)
Amortization of debt issuance costs and discount	2,861	1,749	887
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(10,098)	(33,001)	(43,553)
(Increase) decrease in prepaid and other assets	(1,882)	(1,168)	(4,088)
Increase (decrease) in accounts payable and other liabilities	33,833	66,660	26,772
Net cash provided by operating activities	564,173	670,011	259,918
Cash flows from investing activities:
Acquisition of oil and natural gas properties	(103,709)	(212,513)	(435,547)
Drilling and development capital expenditures	(855,153)	(998,242)	(574,334)
Purchases of other property and equipment	(8,857)	(6,058)	(4,921)
Proceeds from sales of oil and natural gas properties	34,730	148,149	22,496
Net cash used in investing activities	(932,989)	(1,068,664)	(992,306)
Cash flows from financing activities:
Issuance of Class A common stock	0	0	340,750
Underwriting discount and offering costs	0	0	(7,291)
Proceeds from borrowings under revolving credit facility	595,000	475,000	275,000
Repayment of borrowings under revolving credit facility	(720,000)	(175,000)	(275,000)
Proceeds from issuance of Senior Notes	496,175	0	400,000
Proceeds from exercise of stock options	0	982	877
Restricted stock used for tax withholdings	(1,038)	(1,665)	(644)
Debt issuance costs	(7,200)	(5,157)	(9,472)
Net cash provided by financing activities	362,937	294,160	724,220
Net increase (decrease) in cash, cash equivalents and restricted cash	(5,879)	(104,493)	(8,168)
Cash, cash equivalents and restricted cash, beginning of period	21,422	125,915	134,083
Cash, cash equivalents and restricted cash, end of period	15,543	21,422	125,915
Supplemental cash flow information
Cash paid for interest	48,905	18,284	4,280
Supplemental non-cash activity
Accrued capital expenditures included in accounts payable and accrued expenses	97,090	119,492	126,480
Asset retirement obligations incurred, including revisions to estimates	2,262	1,451	4,044
Restricted Cash and Cash Equivalents [Abstract]
Total cash, cash equivalents and restricted cash	15,543	21,422	134,083
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 34,833	$ 0	$ 0