Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues
Total revenue	$ 219,181	$ 173,566
Operating expenses:
Salaries, wages, and related expenses	79,503	60,619
Fuel expense	27,832	27,181
Operations and maintenance	15,174	11,730
Revenue equipment rentals and purchased transportation	48,670	30,691
Operating taxes and licenses	3,183	2,660
Insurance and claims	11,235	8,685
Communications and utilities	1,718	1,741
General supplies and expenses	6,731	4,139
Depreciation and amortization, including gains and losses on disposition of property and equipment	19,709	19,695
Total operating expenses	213,755	167,141
Operating income	5,426	6,425
Interest expense, net	2,446	1,960
Income from equity method investment	(3,035)	(1,490)
Income before income taxes	6,015	5,955
Income tax expense	1,582	1,538
Net income	$ 4,433	$ 4,417
Income per share:
Basic and diluted income per share (in dollars per share)	$ 0.24	$ 0.24
Basic weighted average shares outstanding (in shares)	18,381	18,331
Diluted weighted average shares outstanding (in shares)	18,533	18,406
Cargo and Freight [Member]
Revenues
Total revenue	$ 195,761	$ 150,463
Fuel Surcharge [Member]
Revenues
Total revenue	$ 23,420	$ 23,103