CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Operating revenues	$ 817,744	$ 827,606	$ 2,461,554	$ 2,428,487
Operating expenses:
Salaries, wages and benefits	268,054	264,443	802,742	760,078
Fuel	90,369	111,985	259,523	325,852
Supplies and maintenance	60,181	68,009	193,370	187,690
Taxes and licenses	25,852	25,016	76,685	72,640
Insurance and claims	31,261	34,501	104,552	103,064
Depreciation and amortization	74,586	70,397	223,797	206,097
Rent and purchased transportation	224,556	187,449	661,866	569,802
Communications and utilities	4,555	3,720	13,957	11,427
Other	430	(14,175)	(13,422)	(42,858)
Total operating expenses	779,844	751,345	2,323,070	2,193,792
Operating income	37,900	76,261	138,484	234,695
Other expense (income):
Interest expense	8,661	2,778	24,716	6,004
Interest income	(1,727)	(392)	(5,178)	(980)
Loss (gain) on investments in equity securities, net	34	(114)	36	(14,403)
Loss from equity method investment	110	0	954	0
Other	284	77	377	276
Total other expense (income)	7,362	2,349	20,905	(9,103)
Income before income taxes	30,538	73,912	117,579	243,798
Income tax expense	7,034	17,987	28,521	59,229
Net income	23,504	55,925	89,058	184,569
Net loss (income) attributable to noncontrolling interest	200	(874)	(249)	(3,479)
Net income attributable to Werner	$ 23,704	$ 55,051	$ 88,809	$ 181,090
Earnings per share:
Basic (in dollars per share)	$ 0.37	$ 0.87	$ 1.40	$ 2.81
Diluted (in dollars per share)	$ 0.37	$ 0.86	$ 1.39	$ 2.79
Weighted-average common shares outstanding:
Basic (in shares)	63,390	63,386	63,360	64,433
Diluted (in shares)	63,737	63,782	63,703	64,819