Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Operating revenues, net	$ 158,093	$ 214,733	$ 489,245	$ 617,477
Expenses:
Direct expenses	144,938	182,064	449,909	520,099
Selling, general and administrative expenses	13,381	11,575	36,832	34,859
Total operating expenses	158,319	193,639	486,741	554,958
Loss (gain) on disposal of assets	85	(165)	(3,854)	(238)
Equity in loss of unconsolidated affiliate	198	75	274	249
Operating (loss) income	(509)	21,184	6,084	62,508
Interest expense	7,719	7,366	22,792	21,691
Other income, net	(462)	(472)	(1,571)	(1,501)
Total expenses	7,257	6,894	21,221	20,190
(Loss) earnings before income taxes	(7,766)	14,290	(15,137)	42,318
Income tax (benefit) expense	(2,799)	6,621	(5,515)	17,832
Net (loss) earnings	$ (4,967)	$ 7,669	$ (9,622)	$ 24,486
Weighted average shares outstanding:
Basic	15,683	15,587	15,655	15,558
Diluted	15,683	15,652	15,655	15,640
Net (loss) earnings per share:
Basic	$ (0.32)	$ 0.49	$ (0.61)	$ 1.57
Diluted	$ (0.32)	$ 0.49	$ (0.61)	$ 1.57