CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues
Gain on sales of assets, net	$ 25	$ 75
Total revenues	105,228	77,211
Operating expenses
Lease operating	11,004	7,296
Gathering, processing and transportation	3,929	3,359
Production and ad valorem taxes	5,692	4,092
General and administrative	7,065	6,471
Depreciation, depletion and amortization	38,870	22,081
Total operating expenses	66,560	43,299
Operating income (loss)	38,668	33,912
Other income (expense)
Interest expense	(9,478)	(4,601)
Derivatives	(68,017)	(18,795)
Other, net	106	(58)
Income (loss) before income taxes	(38,721)	10,458
Income tax benefit (expense)	24	(163)
Net income (loss) attributable to common shareholders	$ (38,697)	$ 10,295
Net income (loss) per share:
Basic (in dollars per share)	$ (2.56)	$ 0.68
Diluted (in dollars per share)	$ (2.56)	$ 0.68
Weighted average shares outstanding – basic (in shares)	15,098	15,042
Weighted average shares outstanding – diluted (in shares)	15,098	15,081
Oil and Gas, Exploration and Production [Member]
Revenues
Revenues	$ 94,812	$ 71,258
Oil and Condensate [Member]
Revenues
Revenues	5,548	2,946
Natural Gas, Production [Member]
Revenues
Revenues	4,277	2,790
Product and Service, Other [Member]
Revenues
Revenues	$ 566	$ 142