Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
OPERATING REVENUE	$ 967,996	$ 607,284	$ 645,262
Operating Expenses
Salaries, wages and benefits	346,271	250,035	269,482
Rent and purchased transportation	54,288	3,810	4,643
Fuel	194,608	99,597	86,094
Operations and maintenance	39,092	21,522	27,647
Operating taxes and licenses	16,387	13,595	14,962
Insurance and claims	34,436	20,826	22,229
Communications and utilities	6,995	4,447	5,281
Depreciation and amortization	133,047	104,083	109,937
Other operating expenses	51,420	21,400	26,398
Gain on disposal of property and equipment	(96,906)	(37,438)	(14,830)
Total operating expenses	779,638	501,877	551,843
Operating income	188,358	105,407	93,419
Interest income	1,288	640	842
Interest expense	(8,555)	0	0
Income before income taxes	181,091	106,047	94,261
Federal and state income tax expense	47,507	26,770	23,455
Net Income	133,584	79,277	70,806
Other comprehensive income, net of tax	0	0	0
Comprehensive income	$ 133,584	$ 79,277	$ 70,806
Net income per share
Basic	$ 1.69	$ 1.00	$ 0.87
Diluted	$ 1.69	$ 1.00	$ 0.87
Weighted average shares outstanding
Basic	78,941	79,573	81,388
Diluted	78,974	79,612	81,444
Dividends declared per share	$ 0.08	$ 0.58	$ 0.08