Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue
Operating revenue	$ 132,583	$ 114,235	$ 392,977	$ 323,263
Operating expenses
Salaries, wages and employee benefits	31,540	29,813	95,423	89,674
Fuel and fuel taxes	13,823	11,759	41,286	33,012
Depreciation and amortization	6,735	6,790	21,392	21,313
Insurance and claims	5,946	5,344	16,889	19,236
Equipment rent	2,916	2,703	7,785	7,449
Operations and maintenance	8,237	8,259	25,111	22,780
Purchased transportation	52,640	42,543	157,495	120,951
Operating taxes and licenses	1,136	972	2,900	2,946
Communications and utilities	674	679	2,064	1,943
Gain on disposal of assets, net	(901)	(215)	(1,466)	(551)
Restructuring, impairment and other costs (reversal)	0	0	(639)	0
Other	4,034	3,784	12,231	12,071
Total operating expenses	126,780	112,431	380,471	330,824
Operating income (loss)	5,803	1,804	12,506	(7,561)
Other expenses
Interest expense, net	811	970	2,462	2,922
Other, net	420	86	653	311
Total other expenses, net	1,231	1,056	3,115	3,233
Income (loss) before income taxes	4,572	748	9,391	(10,794)
Income tax expense (benefit)	1,272	339	2,512	(3,469)
Consolidated net income (loss) and comprehensive income (loss)	$ 3,300	$ 409	$ 6,879	$ (7,325)
Net earnings (loss) per share
Average shares outstanding (basic) (in usd per share)	8,223	8,027	8,170	8,029
Basic earnings (loss) per share (in usd per share)	$ 0.40	$ 0.05	$ 0.84	$ (0.91)
Average shares outstanding (diluted) (in shares)	8,240	8,039	8,193	8,029
Diluted earnings (loss) per share (in usd per shares)	$ 0.40	$ 0.05	$ 0.84	$ (0.91)