Revenue (Disaggregation of Revenue by Revenue Source) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of revenue
Revenues	$ 2,734,372	$ 2,372,178	$ 2,463,701
Truckload Transportation Services
Disaggregation of revenue
Revenues	2,045,073	1,843,209	1,909,776
Werner Logistics
Disaggregation of revenue
Revenues	622,461	469,791	489,729
Inter-segment eliminations
Disaggregation of revenue
Revenues	(899)	(107)	(243)
Transportation Services
Disaggregation of revenue
Revenues	2,666,635	2,312,893	2,399,262
Other revenues
Disaggregation of revenue
Revenues	$ 67,737	$ 59,285	$ 64,439