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
OPERATING REVENUES:
Revenue, before fuel surcharge	$ 95,926	$ 92,076	$ 288,496	$ 265,813
Fuel surcharge	13,467	15,034	36,002	48,813
Total operating revenues	109,393	107,110	324,498	314,626
OPERATING EXPENSES AND COSTS:
Salaries, wages and benefits	28,167	26,533	83,490	79,032
Operating supplies and expenses	21,155	21,912	61,315	69,202
Rent and purchased transportation	40,013	35,255	118,119	97,883
Depreciation	10,166	8,452	29,011	23,753
Insurance and claims	3,609	3,889	12,158	11,246
Other	1,937	2,200	6,121	6,867
Gain on disposition of equipment	(949)	(1,357)	(3,951)	(4,611)
Total operating expenses and costs	104,098	96,884	306,263	283,372
OPERATING INCOME	5,295	10,226	18,235	31,254
NON-OPERATING INCOME (EXPENSE)	1,235	(732)	1,203	385
INTEREST EXPENSE	(927)	(132)	(2,659)	(1,992)
INCOME BEFORE INCOME TAXES	5,603	9,362	16,779	29,647
FEDERAL AND STATE INCOME TAX EXPENSE:
Current	115	337	168	1,176
Deferred	2,037	3,230	6,233	10,268
Total federal and state income tax expense	2,152	3,567	6,401	11,444
NET INCOME	$ 3,451	$ 5,795	$ 10,378	$ 18,203
INCOME PER COMMON SHARE:
Basic (in dollars per share)	$ 0.54	$ 0.81	$ 1.55	$ 2.48
Diluted (in dollars per share)	$ 0.53	$ 0.80	$ 1.54	$ 2.46
Basic (in shares)	6,439	7,186	6,703	7,346
Diluted (in shares)	6,458	7,219	6,725	7,385