Revenue (Disaggregation of Revenue by Revenue Source) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of revenue
Revenues	$ 649,814	$ 568,959	$ 1,266,260	$ 1,161,662
Truckload Transportation Services
Disaggregation of revenue
Revenues	491,200	445,053	954,149	909,916
Werner Logistics
Disaggregation of revenue
Revenues	141,673	110,163	279,526	222,327
Inter-segment eliminations
Disaggregation of revenue
Revenues	(193)	(14)	(327)	(25)
Transportation Services
Disaggregation of revenue
Revenues	632,680	555,202	1,233,348	1,132,218
Other revenues
Disaggregation of revenue
Revenues	$ 17,134	$ 13,757	$ 32,912	$ 29,444

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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+ Details