CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - unaudited - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues
Gain on sales of assets, net	$ 6	$ 25
Total revenues	91,379	105,228
Operating expenses
Lease operating	10,532	11,004
Gathering, processing and transportation	5,444	3,929
Production and ad valorem taxes	6,154	5,692
General and administrative	7,230	7,065
Depreciation, depletion and amortization	40,718	38,870
Total operating expenses	70,078	66,560
Operating income (loss)	21,301	38,668
Other income (expense)
Interest expense	(8,180)	(9,478)
Derivatives	151,119	(68,017)
Other, net	(8)	106
Income (loss) before income taxes	164,232	(38,721)
Income tax benefit (expense)	(1,138)	24
Net income (loss) attributable to common shareholders	$ 163,094	$ (38,697)
Net income (loss) per share:
Basic (in dollars per share)	$ 10.76	$ (2.56)
Diluted (in dollars per share)	$ 10.76	$ (2.56)
Weighted average shares outstanding – basic (in shares)	15,152	15,098
Weighted average shares outstanding – diluted (in shares)	15,160	15,098
Oil and Gas, Exploration and Production [Member]
Revenues
Revenues	$ (86,308)	$ (94,812)
Oil and Condensate [Member]
Revenues
Revenues	(1,893)	(5,548)
Natural Gas, Production [Member]
Revenues
Revenues	(2,690)	(4,277)
Product and Service, Other [Member]
Revenues
Revenues	$ (482)	$ (566)