Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Activities:
Net (loss) income	$ 57,821	$ 16,006	$ (96,378)
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Loss (gain) on sale of non-oil and gas assets	181	(102)	(374)
Net loss (gain) on derivative contracts	(8,060)	1,849	18,028
Net cash settlements received (paid) on derivative contracts	(20,241)	2,450	1,790
Monetization of derivative contracts			14,370
Depreciation, depletion and amortization	42,759	26,226	24,431
Proved property impairment			67,626
Amortization of deferred financing fees	440	423	1,019
Accretion expense and other	516	451	491
Stock-based Compensation	2,366	3,238	3,194
Non-cash compensation			40
Changes in operating assets and liabilities:
Accounts receivable	(7,543)	(18,569)	(4,018)
Other assets	18	155	627
Accounts payable	11,576	6,231	(3,535)
Accrued expenses	167	(235)	(439)
Net cash provided by operating activities	80,000	38,123	26,872
Investing Activities
Capital expenditures, including purchase and development of properties	(179,509)	(108,236)	(31,663)
Proceeds from the sale of oil and gas properties	3,279	16,979	13,570
Proceeds from the sale of non-oil and gas assets	26	204	4,022
Net cash used in investing activities	(176,204)	(91,053)	(14,071)
Financing Activities
Proceeds from exercise of stock options and restricted stock	15		49
Proceeds from issuance of common stock, net of offering cost of $1.6 million and $3.8 million, respectively		65,224	27,135
Proceeds from long-term borrowings	127,000	82,000	22,000
Payments of long-term borrowings	(31,258)	(91,786)	(65,330)
Deferred financing fees	(304)	(890)	(195)
Net cash (used in) provided by financing activities	95,453	54,548	(16,341)
(Decrease) increase in cash and cash equivalents	(751)	1,618	(3,540)
Cash and cash equivalents at beginning of period	1,618		3,540
Cash and cash equivalents at end of period	867	1,618
Supplemental disclosure of cash flow information:
Interest paid	6,858	2,401	3,899
Income tax paid
Non-cash investing and financing activities
Change in asset retirement obligation cost and liabilities	1	1,252	285
Properties classified as held for sale			9,685
Asset retirement obligations associated with property acquisitions and dispositions, net	(1,799)	(1,551)	(1,832)
Issuance of stock for acquisition of oil and gas properties		3,335
Change in capital expenditures included in accounts payable	$ (6,014)	$ 23,507