Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Operating Revenue	$ 273,976	$ 152,612	$ 613,073	$ 459,142
Operating Expenses
Salaries, wages, and benefits	97,429	62,733	221,935	190,446
Rent and purchased transportation	17,046	950	20,921	2,922
Fuel	53,412	25,258	125,170	74,220
Operating Costs and Expenses	12,273	5,372	23,419	16,729
Cost, Direct Tax and License	4,343	3,311	10,905	10,345
Insurance and claims	10,794	5,053	22,699	15,171
Communications and utilities	1,876	1,218	4,080	3,412
Depreciation and amortization	34,789	25,280	82,408	78,162
Other operating expenses	14,108	5,418	32,150	16,173
Gain on disposal of property and equipment	(6,836)	(15,254)	(92,806)	(27,341)
Total operating expenses	239,234	119,339	450,881	380,239
Operating income	34,742	33,273	162,192	78,903
Interest income	537	181	943	493
Interest Expense	(2,345)	0	(2,520)	0
Income before income taxes	32,934	33,454	160,615	79,396
Federal and state income taxes	8,519	8,988	42,520	20,454
Net Income	24,415	24,466	118,095	58,942
Other comprehensive income, net of tax	0	0	0	0
Comprehensive income	$ 24,415	$ 24,466	$ 118,095	$ 58,942
Net income per share
Basic	$ 0.31	$ 0.31	$ 1.50	$ 0.74
Diluted	$ 0.31	$ 0.31	$ 1.50	$ 0.74
Weighted average shares outstanding
Basic	78,937	79,336	78,933	79,795
Diluted	78,974	79,364	78,962	79,839
Dividends declared per share	$ 0.02	$ 0.52	$ 0.06	$ 0.56