Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Operating revenues, net	$ 169,243	$ 146,424	$ 329,607	$ 281,042
Expenses:
Direct expenses	155,083	126,951	311,309	263,464
Selling, general and administrative expenses	14,485	14,247	29,944	27,290
Total operating expenses	169,568	141,198	341,253	290,754
(Gain) loss on disposal of assets	(171)	7	708	7
Equity in (gain) loss of unconsolidated affiliate, net	(81)	991	(45)	1,994
Operating (loss) income	(73)	4,228	(12,309)	(11,713)
Interest expense	8,340	8,083	16,537	16,278
Other loss (income) – net	364	(705)	1,404	(1,768)
Total expenses	8,704	7,378	17,941	14,510
Loss before income taxes	(8,777)	(3,150)	(30,250)	(26,223)
Income tax (benefit) expense	(1,684)	123	(6,175)	(7,702)
Net loss	$ (7,093)	$ (3,273)	$ (24,075)	$ (18,521)
Weighted average shares outstanding:
Basic (shares)	15,806	15,716	15,806	15,716
Diluted (shares)	15,806	15,716	15,806	15,716
Net loss per share:
Basic (in USD per share)	$ (0.45)	$ (0.21)	$ (1.52)	$ (1.18)
Diluted (in USD per share)	$ (0.45)	$ (0.21)	$ (1.52)	$ (1.18)