Condensed Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
OPERATING REVENUE:
Freight revenue	$ 249,311	$ 187,205	$ 487,123	$ 344,909
Fuel surcharge revenue	26,088	35,166	54,397	70,878
Total revenue	275,399	222,371	541,520	415,787
OPERATING EXPENSES:
Salaries, wages, and employee benefits	85,877	63,569	167,354	120,791
Fuel	26,688	39,199	54,416	79,184
Purchased transportation	93,948	58,228	182,978	101,865
Revenue equipment rentals	2,201	2,648	4,423	5,238
Operations and maintenance	18,243	12,990	35,849	24,229
Insurance and claims	7,709	7,221	14,637	12,898
Depreciation and amortization	19,187	17,734	40,788	33,291
Communications and utilities	2,611	2,097	4,955	3,927
Operating taxes and licenses	5,532	3,699	10,504	7,013
General and other operating	4,803	3,427	9,085	6,882
Gain on disposition of equipment	(5,479)	(4,010)	(18,721)	(8,568)
Total operating expenses	261,320	206,802	506,268	386,750
Operating income	14,079	15,569	35,252	29,037
Interest expense	$ 3,758	2,008	$ 6,910	3,177
Interest income		(3)		(7)
Other income	$ 21	(36)	$ 121	(110)
Income before income taxes	10,300	13,600	28,221	25,977
Income tax expense	3,685	5,057	10,239	9,387
Net income	$ 6,615	$ 8,543	$ 17,982	$ 16,590
Income per common share:
Diluted (in dollars per share)	$ 0.24	$ 0.36	$ 0.64	$ 0.69
Basic (in dollars per share)	$ 0.24	$ 0.37	$ 0.65	$ 0.71
Diluted weighted average shares outstanding (in shares)	27,940	23,991	27,953	23,963
Basic weighted average shares outstanding (in shares)	27,480	23,327	27,467	23,284