Consolidated Condensed Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Operating revenue	$ 285,672	$ 329,565	$ 583,695	$ 616,846
Operating expenses (income):
Salaries, wages and benefits	96,332	96,460	194,848	185,809
Purchased transportation	48,299	67,480	102,402	124,790
Fuel and fuel taxes	42,215	61,337	89,011	105,705
Supplies and maintenance	17,408	13,352	33,395	25,665
Depreciation	29,427	26,865	58,957	53,008
Operating taxes and licenses	2,756	2,663	5,524	5,303
Insurance and claims	12,481	13,443	27,551	26,147
Communications and utilities	2,510	2,239	5,041	4,504
Gain on disposition of revenue equipment	(3,550)	(4,812)	(8,796)	(9,352)
Other	9,581	9,601	18,539	18,472
Total operating expenses	257,459	288,628	526,472	540,051
Operating income	(28,213)	(40,937)	(57,223)	(76,795)
Other	1,077	36	1,921	43
Income before income taxes	29,290	40,973	59,144	76,838
Income taxes expense	7,416	9,312	14,768	17,644
Net income	$ 21,874	$ 31,661	$ 44,376	$ 59,194
Basic earnings per common share (in dollars per share)	$ 0.27	$ 0.39	$ 0.55	$ 0.72
Diluted earnings per common share (in dollars per share)	0.27	0.39	0.55	0.72
Dividends declared per common share (in dollars per share)	$ 0.06	$ 0.06	$ 0.12	$ 0.12