Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net income (loss)	$ 122,982	$ 299,764	$ 138,007
Adjustments to reconcile net income to net cash provided by operating activities
Unrealized loss (gain) on derivatives	53,727	(65,085)	(9,715)
Depletion, depreciation and amortization	350,540	265,142	177,502
Accretion of asset retirement obligations	1,822	1,530	1,290
Full-cost ceiling impairment	0	0	0
Stock-based compensation expense	18,505	17,200	16,654
Prepayment premium on extinguishment of debt	0	31,226	0
Deferred income tax provision (benefit)	35,532	(7,236)	0
Amortization of debt issuance cost	2,484	1,357	468
Net loss (gain) on asset sales and inventory impairment	967	196	(23)
Changes in operating assets and liabilities
Accounts receivable	(43,261)	(4,934)	(82,549)
Lease and well equipment inventory	4,777	(12,176)	(3,623)
Prepaid expenses	(4,844)	(1,770)	(2,960)
Other assets	678	3,418	(6,425)
Accounts payable, accrued liabilities and other current liabilities	(19,004)	68,647	33,559
Royalties payable	20,417	3,418	37,370
Advances from joint interest owners	3,869	8,179	1,089
Other long-term liabilities	2,851	(353)	(1,519)
Net cash provided by operating activities	552,042	608,523	299,125
Investing activities
Oil and natural gas properties capital expenditures	(730,161)	(1,357,802)	(699,445)
Midstream capital expenditures	(192,035)	(163,222)	(115,128)
Expenditures for other property and equipment	(3,701)	(2,562)	(5,688)
Proceeds from sale of assets	21,921	8,333	977
Net cash used in investing activities	(903,976)	(1,515,253)	(819,284)
Financing activities
Repayments of borrowings	(35,000)	(370,000)	0
Borrowings under Credit Agreement	250,000	410,000	0
Borrowings under San Mateo Credit Facility	68,000	220,000	0
Cost to enter into or amend credit facilities	(1,443)	(3,077)	0
Proceeds from issuance of senior unsecured notes	0	1,051,500	0
Cost to issue senior unsecured notes	0	(14,098)	0
Purchase of senior unsecured notes	0	(605,780)	0
Proceeds from issuance of common stock	0	226,612	208,720
Cost to issue equity	0	(204)	(280)
Proceeds from stock options exercised	3,300	815	2,920
Contributions related to formation of San Mateo I	14,700	14,700	171,500
Contributions from non-controlling interest owners of less-than-wholly-owned subsidiaries	77,330	85,750	44,100
Distributions to non-controlling interest owners of less-than-wholly-owned subsidiaries	(39,200)	(121,520)	(10,045)
Taxes paid related to net share settlement of stock-based compensation	(3,691)	(6,466)	(5,763)
Purchase of non-controlling interest of less-than-wholly-owned subsidiary	0	0	(2,653)
Cash paid under financing lease obligations	(918)	0	0
Net cash provided by financing activities	333,078	888,232	408,499
Decrease in cash and restricted cash	(18,856)	(18,498)	(111,660)
Cash and restricted cash at beginning of year	83,984	102,482	214,142
Cash and restricted cash at end of year	$ 65,128	$ 83,984	$ 102,482