Consolidated Statements of Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
Operating Revenue	$ 270,320	$ 330,916
Operating Expenses
Salaries, wages, and benefits	112,697	123,333
Rent and purchased transportation	23,863	33,144
Fuel	47,321	57,528
Operations and maintenance	16,264	15,026
Operating taxes and licenses	5,315	5,543
Insurance and claims	14,584	11,002
Communications and utilities	2,440	2,876
Depreciation and amortization	46,504	48,469
Other operating expenses	15,626	17,891
Loss (gain) on disposal of property and equipment	89	(6,786)
Total operating expenses	284,703	308,026
Operating (loss) income	(14,383)	22,890
Interest income	366	484
Interest Expense	(5,302)	(6,075)
(Loss) income before income taxes	(19,319)	17,299
Federal and state income taxes	(4,211)	4,687
Net (loss) income	(15,108)	12,612
Other comprehensive income, net of tax	0	0
Comprehensive (loss) income	$ (15,108)	$ 12,612
Net (loss) income per share
Basic	$ (0.19)	$ 0.16
Diluted	$ (0.19)	$ 0.16
Weighted average shares outstanding
Basic	79,044	78,987
Diluted	79,122	79,022
Dividends declared per share	$ 0.02	$ 0.02