Condensed Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Oil and natural gas sales	$ 25,266	$ 18,178	$ 77,337	$ 59,869
Operating costs and expenses:
Production expense	7,481	10,336	31,258	28,148
Exploration expense		4	12	4
Depreciation, depletion and amortization	1,130	1,700	3,289	5,539
Gain on revision of asset retirement obligations	(3,325)		(3,325)
General and administrative expense	2,811	2,463	10,422	8,654
Bad debt expense (recovery) and other	(157)	(49)	(68)	232
Total operating costs and expenses	7,940	14,454	41,588	42,577
Other operating income (loss), net	(6)	(3)	332	164
Operating income	17,320	3,721	36,081	17,456
Other income (expense):
Interest income (expense), net	111	(327)	(273)	(1,108)
Other, net	(1,029)	(793)	(2,184)	(571)
Total other expense, net	(918)	(1,120)	(2,457)	(1,679)
Income from continuing operations before income taxes	16,402	2,601	33,624	15,777
Income tax expense (benefit)	(62,224)	2,749	(54,600)	9,039
Income (loss) from continuing operations	78,626	(148)	88,224	6,738
Loss from discontinued operations	(21)	(174)	(416)	(518)
Net income (loss)	$ 78,605	$ (322)	$ 87,808	$ 6,220
Basic net income (loss) per share:
Income from continuing operations	$ 1.31	$ 0.00	$ 1.48	$ 0.11
Loss from discontinued operations	0.00	(0.01)	(0.01)	(0.01)
Net income (loss) per share	$ 1.31	$ (0.01)	$ 1.47	$ 0.10
Basic weighted average shares outstanding	59,481	58,817	59,147	58,682
Diluted net income (loss) per share:
Income from continuing operations	$ 1.28	$ 0.00	$ 1.46	$ 0.11
Loss from discontinued operations	0.00	(0.01)	(0.01)	(0.01)
Net income (loss) per share	$ 1.28	$ (0.01)	$ 1.45	$ 0.10
Diluted weighted average shares outstanding	60,818	58,817	59,846	58,686