Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating activities - cash provided by (used in):
Net income for the period	$ 40,674	$ 47,493
Adjustments to reconcile net income to cash provided by operating activities:
Depletion, depreciation and amortization	51,653	50,540
Unrealized loss (gain) on commodity derivatives	(14,292)	7,606
Deferred gain on sale of liquids gathering system		(2,638)
Stock compensation	841	8,810
Payable-in-Kind (“PIK”) interest payable	3,183
Amortization of premium on debt exchange	(9,716)
Amortization of deferred financing costs	3,123	2,727
Other	582	209
Net changes in operating assets and liabilities:
Accounts receivable	50,243	12,561
Other current assets	(307)	2,485
Other non-current assets	30	30
Accounts payable	(359)	(5,263)
Accrued liabilities	4,425	(7,486)
Production taxes payable	25,743	23,622
Interest payable	99	17,172
Other long-term obligations	(11,663)	(12,708)
Income taxes payable/receivable	6,431	6,836
Net cash provided by operating activities	150,690	151,996
Investing Activities - cash provided by (used in):
Oil and gas property expenditures	(92,352)	(134,500)
Change in capital cost accrual and accounts payable	1,702	(8,079)
Inventory	419	(5,074)
Purchase of capital assets	(211)	(1,196)
Net cash used in investing activities	(90,442)	(148,849)
Financing activities - cash provided by (used in):
Deferred financing costs	(488)
Repurchased shares/net share settlements		(2,061)
Net cash used in financing activities	(66,488)	(2,061)
(Decrease) increase in cash during the period	(6,240)	1,086
Cash, cash equivalents, and restricted cash, beginning of period	19,305	18,269
Cash, cash equivalents and restricted cash, end of period	13,065	19,355
Credit Agreement
Financing activities - cash provided by (used in):
Borrowings under Credit / Term Loan Agreement	232,000	191,000
Payments under Credit Agreement	$ (298,000)	$ (191,000)