Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenues
Freight revenue	$ 1,046,003	$ 838,561
Operating expenses:
Salaries, wages, and related expenses	350,246	315,023
Fuel expense	103,641	77,443
Operations and maintenance	59,269	48,368
Revenue equipment rentals and purchased transportation	331,685	222,705
Operating taxes and licenses	10,899	11,621
Insurance and claims	38,788	53,052
Communications and utilities	4,558	5,898
General supplies and expenses	29,673	34,143
Depreciation and amortization	53,881	65,472
Gain on disposition of property and equipment, net	(3,799)	(7,706)
Impairment of long lived property, equipment, and right-of-use assets	0	26,569
Total operating expenses	978,841	852,588
Operating income (loss)	67,162	(14,027)
Interest expense, net	2,791	6,841
Income from equity method investment	(14,782)	(3,944)
Income (loss) from continuing operations	79,153	(16,924)
Income tax expense (benefit)	20,962	(2,804)
Income (loss) from continuing operations	58,191	(14,120)
Income (loss) from discontinued operations, net of tax	2,540	(28,598)
Net income (loss)	$ 60,731	$ (42,718)
Basic income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	$ 3.46	$ (0.81)
Income (loss) from discontinued operations (in dollars per share)	0.15	(1.65)
Net income (loss) (in dollars per share)	3.61	(2.46)
Diluted income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	3.42	(0.81)
Income (loss) from discontinued operations (in dollars per share)	0.15	(1.65)
Net income (loss) (in dollars per share)	$ 3.57	$ (2.46)
Basic weighted average shares outstanding (in shares)	16,803	17,358
Diluted weighted average shares outstanding (in shares)	17,020	17,358
Cargo and Freight [Member]
Revenues
Freight revenue	$ 949,913	$ 776,218
Fuel Surcharge [Member]
Revenues
Freight revenue	$ 96,090	$ 62,343