Consolidated Condensed Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Operating revenue	$ 214,973	$ 199,649	$ 626,086	$ 583,633
Operating expenses (income):
Salaries, wages and benefits	69,312	64,051	201,449	186,123
Purchased transportation	40,435	35,867	117,352	105,941
Fuel and fuel taxes	31,275	31,658	89,904	92,444
Supplies and maintenance	12,116	10,574	34,739	31,261
Depreciation	24,290	22,272	70,295	66,280
Operating taxes and licenses	2,651	2,404	7,422	7,055
Insurance and claims	9,618	8,567	29,355	27,798
Communications and utilities	1,901	1,663	5,801	4,993
Gain on disposition of assets	(2,559)	(1,835)	(5,337)	(5,206)
Other	5,900	5,435	17,395	16,134
Total operating expenses	194,939	180,656	568,375	532,823
Operating income	20,034	18,993	57,711	50,810
Other	(255)	(120)	(928)	(447)
Income before income taxes	20,289	19,113	58,639	51,257
Income taxes expense	3,702	3,856	13,316	11,967
Net income	$ 16,587	$ 15,257	$ 45,323	$ 39,290
Basic earnings per common share (in dollars per share)	$ 0.30	$ 0.28	$ 0.83	$ 0.72
Diluted earnings per common share (in dollars per share)	0.30	0.28	0.82	0.71
Dividends declared per common share (in dollars per share)	$ 0.68	$ 0.025	$ 0.74	$ 0.075