Segment Information (Summary Of Segment Information) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Revenues	$ 836,276	$ 649,814	$ 1,600,881	$ 1,266,260
Operating Income	74,923	76,863	158,434	139,334
Depreciation and amortization	68,471	63,865	135,700	127,816
Truckload Transportation Services
Segment Reporting Information [Line Items]
Revenues	613,616	491,200	1,172,033	954,149
Operating Income	64,004	73,108	140,097	130,736
Depreciation and amortization	62,867	58,533	124,704	117,058
Werner Logistics
Segment Reporting Information [Line Items]
Revenues	203,861	141,673	392,869	279,526
Operating Income	12,490	3,927	21,171	8,501
Depreciation and amortization	2,351	2,085	4,619	4,306
Other
Segment Reporting Information [Line Items]
Revenues	18,946	16,725	36,459	32,124
Operating Income	461	1,663	906	2,529
Depreciation and amortization	2,791	2,761	5,472	5,490
Corporate
Segment Reporting Information [Line Items]
Revenues	478	409	867	788
Operating Income	(2,032)	(1,835)	(3,740)	(2,432)
Depreciation and amortization	462	486	905	962
Subtotal
Segment Reporting Information [Line Items]
Revenues	836,901	650,007	1,602,228	1,266,587
Inter-segment eliminations
Segment Reporting Information [Line Items]
Revenues	$ (625)	$ (193)	$ (1,347)	$ (327)