Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities
Net income (loss)	$ 121,018	$ 69,800
Adjustments to reconcile net income to cash flows from operating activities
Depletion, depreciation, and amortization	115,561	105,395
Deferred income taxes	52,545	25,237
Stock-based compensation	6,865	5,152
Commodity derivatives expense (income)	58,617	145,024
Receipt (payment) on settlements of commodity derivatives	6,657	(88,127)
Gain on debt extinguishment	(100,346)	0
Debt issuance costs and discounts	2,901	2,268
Other, net	(57)	(5,107)
Changes in assets and liabilities, net of effects from acquisitions
Accrued production receivable	(9,909)	(17,385)
Trade and other receivables	(271)	(320)
Other current and long-term assets	(3,389)	(5,627)
Accounts payable and accrued liabilities	(33,320)	14,999
Oil and natural gas production payable	1,746	(4,501)
Other liabilities	(5,618)	(1,182)
Net cash provided by operating activities	213,000	245,626
Cash flows from investing activities
Oil and natural gas capital expenditures	(148,254)	(134,458)
Pipelines and plants capital expenditures	(10,591)	(7,882)
Net proceeds from sales of oil and natural gas properties and equipment	431	2,077
Other	(725)	5,365
Net cash used in investing activities	(159,139)	(134,898)
Cash flows from financing activities
Bank repayments	(281,000)	(1,153,653)
Bank borrowings	361,000	1,093,653
Interest payments treated as a reduction of debt	(42,558)	(37,233)
Cash paid in conjunction with debt exchange	(120,007)	0
Costs of debt financing	(9,332)	0
Pipeline financing and capital lease debt repayments	(7,273)	(12,625)
Other	12,899	(628)
Net cash used in financing activities	(86,271)	(110,486)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(32,410)	242
Cash, cash equivalents, and restricted cash at beginning of period	54,949	15,992
Cash, cash equivalents, and restricted cash at end of period	$ 22,539	$ 16,234