Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Revenues
Revenue		$ 291,585	$ 220,889
Operating expenses:
Salaries, wages, and related expenses		95,338	82,586
Fuel expense		35,502	22,822
Operations and maintenance		17,936	14,719
Revenue equipment rentals and purchased transportation		83,661	57,236
Operating taxes and licenses		2,740	2,585
Insurance and claims		9,179	7,838
Communications and utilities		1,170	1,247
General supplies and expenses		8,934	8,183
Depreciation and amortization		13,445	14,087
Gain on disposition of property and equipment, net		(167)	(923)
Total operating expenses		267,738	210,380
Operating income		23,847	10,509
Interest expense, net		555	743
Income from equity method investment		(6,785)	(2,960)
Income before income taxes		30,077	12,726
Income tax expense		7,910	4,145
Income from continuing operations, net of tax		22,167	8,581
Income from discontinued operations, net of tax		0	2,559
Net income		$ 22,167	$ 11,140
Basic income per share:
Income from continuing operations (in dollars per share)		$ 1.34	$ 0.51
Income from discontinued operations (in dollars per share)		0	0.15
Net income (in dollars per share)	[1]	1.34	0.66
Diluted income per share:
Income from continuing operations (in dollars per share)		1.32	0.50
Income from discontinued operations (in dollars per share)		0	0.15
Net income (in dollars per share)	[1]	$ 1.32	$ 0.65
Basic weighted average shares outstanding (in shares)		16,602	16,954
Diluted weighted average shares outstanding (in shares)		16,769	17,086
Cargo and Freight [Member]
Revenues
Revenue		$ 257,614	$ 200,688
Fuel Surcharge [Member]
Revenues
Revenue		$ 33,971	$ 20,201

[1] Sum of the individual amounts may not add due to rounding.