Summary of Revenue by Business Line (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Revenue	$ 779,243	$ 921,163	$ 1,618,102	$ 1,854,161
Intermodal [Member]
Disaggregation Of Revenue [Line Items]
Revenue	460,676	542,890	955,999	1,078,923
Logistics [Member]
Disaggregation Of Revenue [Line Items]
Revenue	163,743	193,463	346,999	396,725
Truck brokerage [Member]
Disaggregation Of Revenue [Line Items]
Revenue	86,675	107,081	184,692	224,669
Dedicated [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 68,149	$ 77,729	$ 130,412	$ 153,844

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details