Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Revenues	$ 20,236	$ 22,455
Costs and expenses
Operating costs	14,898	12,567
Selling, general and administrative	3,718	3,621
Depreciation and amortization	6,256	5,825
Asset impairment, net of insurance recoveries	129	0
Loss (gain) on disposition of assets, net	828	(125)
Total costs and expenses	25,829	21,888
Operating (loss) income	(5,593)	567
Interest expense	(630)	(977)
Loss before income taxes	(6,223)	(410)
Income tax expense	46	4
Net loss	$ (6,269)	$ (414)
Loss per share:
Basic and diluted (usd per share)	$ (0.17)	$ (0.02)
Weighted average number of common shares outstanding:
Basic and diluted (shares)	37,546	24,015