CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Freight	$ 149,654	$ 136,792	$ 275,209	$ 263,051
Brokerage	28,656	21,778	49,525	42,382
Logistics	2,700		2,700
Fuel surcharge	16,313	11,787	30,323	21,805
Total revenue	197,323	170,357	357,757	327,238
Operating expenses:
Salaries, wages and employee benefits	58,186	50,207	108,307	100,562
Fuel	20,466	17,283	39,689	31,780
Operations and maintenance	28,967	24,358	52,191	45,059
Communications	549	354	952	838
Purchased freight	49,760	41,185	87,346	77,960
Administrative expenses	8,022	5,096	15,400	12,490
Sales and marketing	555	483	937	846
Taxes and licenses	2,611	2,345	4,892	4,678
Insurance and claims	5,042	4,542	9,165	8,583
Acquisition-related transaction expenses	1,037	3	1,483	18
Depreciation and amortization	17,638	16,644	33,953	33,517
(Gain) loss on disposition of revenue property and equipment	26	571	(174)	652
Total operating expenses	192,859	163,071	354,141	316,983
Income from operations	4,464	7,286	3,616	10,255
Other (income) expense:
Interest income	(50)	(16)	(54)	(36)
Interest expense	6,544	5,446	12,440	10,797
Write-off of unamortized deferred financing fees			3,883
Other	(107)	(129)	(215)	(202)
Total other expense	6,387	5,301	16,054	10,559
Income (loss) before provision (benefit) for income taxes	(1,923)	1,985	(12,438)	(304)
Provision (benefit) for income taxes	2,184	974	(586)	(75)
Net income (loss)	(4,107)	1,011	(11,852)	(229)
Other comprehensive loss:
Unrealized income (loss) on interest rate swaps		(1)	52	(61)
Foreign currency translation adjustments	507		507
Comprehensive income (loss)	(3,600)	1,010	(11,293)	(290)
Net income (loss)	(4,107)	1,011	(11,852)	(229)
Net loss attributable to common stockholders	$ (5,800)	$ (232)	$ (14,352)	$ (2,715)
Net loss per common share:
Basic and Diluted	$ (0.15)	$ (0.01)	$ (0.44)	$ (0.13)
Weighted-average common shares outstanding:
Basic and Diluted	37,945,310	20,980,961	32,468,674	20,980,961
Series A
Other comprehensive loss:
Dividends to convertible preferred stockholders	$ (1,693)		$ (1,694)
Weighted-average common shares outstanding:
Dividends declared per convertible preferred share	$ 0.68		$ 0.68
Series B
Other comprehensive loss:
Dividends to convertible preferred stockholders		$ (1,243)	$ (806)	$ (2,486)
Weighted-average common shares outstanding:
Dividends declared per convertible preferred share		$ 18.75	$ 12.50	$ 37.50