Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Operating revenues, net	$ 150,167	$ 158,093	$ 431,209	$ 489,245
Expenses:
Direct expenses	136,786	144,938	400,250	449,909
Selling, general and administrative expenses	11,401	13,381	38,691	36,832
Total operating expenses	148,187	158,319	438,941	486,741
Gain (loss) on disposal of assets	(4)	85	3	(3,854)
Equity in (earnings) loss of unconsolidated affiliates, net	(438)	198	1,556	274
Operating income (loss)	2,422	(509)	(9,291)	6,084
Interest expense	8,027	7,719	24,305	22,792
Other income – net	(706)	(462)	(2,474)	(1,571)
Total expenses	7,321	7,257	21,831	21,221
Loss before income taxes	(4,899)	(7,766)	(31,122)	(15,137)
Income tax benefit	(1,622)	(2,799)	(9,324)	(5,515)
Net loss	$ (3,277)	$ (4,967)	$ (21,798)	$ (9,622)
Weighted average shares outstanding:
Basic (shares)	15,799	15,683	15,750	15,655
Diluted (shares)	15,799	15,683	15,750	15,655
Net loss per share:
Basic (in USD per share)	$ (0.21)	$ (0.32)	$ (1.38)	$ (0.61)
Diluted (in USD per share)	$ (0.21)	$ (0.32)	$ (1.38)	$ (0.61)