Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net income (loss)	$ (553,560)	$ 122,982	$ 299,764
Adjustments to reconcile net (loss) income to net cash provided by operating activities
Unrealized loss (gain) on derivatives	32,008	53,727	(65,085)
Depletion, depreciation and amortization	361,831	350,540	265,142
Accretion of asset retirement obligations	1,948	1,822	1,530
Full-cost ceiling impairment	684,743	0	0
Stock-based compensation expense	13,625	18,505	17,200
Prepayment premium on extinguishment of debt	0	0	31,226
Net deferred income tax (benefit) provision	(45,599)	35,532	(7,236)
Amortization of debt issuance cost	2,832	2,484	1,357
Net loss on asset sales and inventory impairment	2,832	967	196
Changes in operating assets and liabilities
Accounts receivable	53,001	(43,261)	(4,934)
Lease and well equipment inventory	(655)	4,777	(12,176)
Prepaid expenses	(3,010)	(4,844)	(1,770)
Other assets	1,681	678	3,418
Accounts payable, accrued liabilities and other current liabilities	(43,844)	(19,004)	68,647
Royalties payable	(19,144)	20,417	3,418
Advances from joint interest owners	(10,646)	3,869	8,179
Other long-term liabilities	(461)	2,851	(353)
Net cash provided by operating activities	477,582	552,042	608,523
Investing activities
Drilling, completion and equipping capital expenditures	(471,087)	(679,395)	(704,947)
Acquisition of oil and natural gas properties	(72,809)	(50,766)	(652,855)
Midstream capital expenditures	(234,359)	(192,035)	(163,222)
Expenditures for other property and equipment	(2,200)	(3,701)	(2,562)
Proceeds from sale of assets	4,789	21,921	8,333
Net cash used in investing activities	(775,666)	(903,976)	(1,515,253)
Financing activities
Repayments of borrowings	(35,000)	(35,000)	(370,000)
Borrowings under Credit Agreement	220,000	250,000	410,000
Borrowings under San Mateo Credit Facility	46,000	68,000	220,000
Cost to enter into or amend credit facilities	(660)	(1,443)	(3,077)
Proceeds from issuance of senior unsecured notes	0	0	1,051,500
Cost to issue senior unsecured notes	0	0	(14,098)
Purchase of senior unsecured notes	0	0	(605,780)
Proceeds from issuance of common stock	0	0	226,612
Cost to issue equity	0	0	(204)
Proceeds from stock options exercised	45	3,300	815
Contributions related to formation of San Mateo I	14,700	14,700	14,700
Contributions from non-controlling interest owners of less-than-wholly-owned subsidiaries	119,700	77,330	85,750
Distributions to non-controlling interest owners of less-than-wholly-owned subsidiaries	(45,570)	(39,200)	(121,520)
Taxes paid related to net share settlement of stock-based compensation	(1,556)	(3,691)	(6,466)
Other	6,680	(918)	0
Net cash provided by financing activities	324,339	333,078	888,232
Increase (decrease) in cash and restricted cash	26,255	(18,856)	(18,498)
Cash and restricted cash at beginning of period	65,128	83,984	102,482
Cash and restricted cash at end of period	$ 91,383	$ 65,128	$ 83,984