CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
REVENUES :
Gains (losses) on commodity derivative contracts-net	$ (3,939)	$ 4,865
Total revenues	48,905	65,015
EXPENSES :
Lease operating and workover	14,808	15,852
Gathering and transportation (Note 3)	57	3,687
Severance and other taxes	2,861	2,121
Asset retirement accretion	297	276
Depreciation, depletion, and amortization	15,213	15,342
General and administrative	9,857	8,275
Total expenses	43,093	45,553
OPERATING INCOME	5,812	19,462
OTHER EXPENSE:
Interest income	19
Interest expense-net of amounts capitalized	(1,827)	(977)
Total other expense	(1,808)	(977)
INCOME BEFORE TAXES	4,004	18,485
Income tax expense	0
NET INCOME	4,004	18,485
Participating securities-non-vested restricted stock	(99)	(546)
NET INCOME ATTRIBUTABLE TO COMMON SHAREHOLDERS	$ 3,905	$ 17,939
Basic and diluted net income per share attributable to common shareholders	$ 0.15	$ 0.72
Basic and diluted weighted average number of common shares outstanding (Note 12)	25,299	25,012
Revenue from contracts with customers
REVENUES :
Total revenues	$ 52,844	$ 60,150
Oil
REVENUES :
Total revenues	32,414	31,036
Natural gas liquid
REVENUES :
Total revenues	11,038	11,194
Natural gas
REVENUES :
Total revenues	8,337	17,098
Other
REVENUES :
Total revenues	$ 1,055	$ 822