Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Operating revenues, net	$ 146,424	$ 167,136	$ 281,042	$ 331,152
Expenses:
Direct expenses	126,951	152,417	263,464	304,971
Selling, general and administrative expenses	14,247	11,778	27,290	23,451
Total operating expenses	141,198	164,195	290,754	328,422
Loss (gain) on disposal of assets	7	(4,298)	7	(3,939)
Equity in loss of unconsolidated affiliates, net	991	76	1,994	76
Operating income (loss)	4,228	7,163	(11,713)	6,593
Interest expense	8,083	7,540	16,278	15,073
Other income – net	(705)	(494)	(1,768)	(1,109)
Total expenses	7,378	7,046	14,510	13,964
(Loss) earnings before income taxes	(3,150)	117	(26,223)	(7,371)
Income tax expense (benefit)	123	(4,160)	(7,702)	(2,716)
Net (loss) earnings	$ (3,273)	$ 4,277	$ (18,521)	$ (4,655)
Weighted average shares outstanding:
Basic (shares)	15,716	15,677	15,716	15,650
Diluted (shares)	15,716	15,718	15,716	15,650
Net (loss) earnings per share:
Basic (in USD per share)	$ (0.21)	$ 0.27	$ (1.18)	$ (0.30)
Diluted (in USD per share)	$ (0.21)	$ 0.27	$ (1.18)	$ (0.30)