Segment Information (Summary Of Segment Information) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Revenues	$ 764,605	$ 616,446
Operating Income	83,511	62,471
Depreciation and amortization	67,229	63,951
Truckload Transportation Services
Segment Reporting Information [Line Items]
Revenues	558,417	462,949
Operating Income	76,093	57,628
Depreciation and amortization	61,837	58,525
Werner Logistics
Segment Reporting Information [Line Items]
Revenues	189,008	137,853
Operating Income	8,681	4,574
Depreciation and amortization	2,268	2,221
Other
Segment Reporting Information [Line Items]
Revenues	17,513	15,399
Operating Income	445	866
Depreciation and amortization	2,681	2,729
Corporate
Segment Reporting Information [Line Items]
Revenues	389	379
Operating Income	(1,708)	(597)
Depreciation and amortization	443	476
Subtotal
Segment Reporting Information [Line Items]
Revenues	765,327	616,580
Inter-segment eliminations
Segment Reporting Information [Line Items]
Revenues	$ (722)	$ (134)