Schedule Of Revenue By Major Customers By Reporting Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 25, 2021	Sep. 26, 2020	Sep. 25, 2021	Sep. 26, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 1,734,299	$ 1,085,546	$ 4,592,551	$ 2,836,626
BCO Independent Contractors – Truck
Disaggregation of Revenue [Line Items]
Percentage of Consolidated Revenue	40.00%	46.00%	41.00%	46.00%
Brokerage Carriers - Truck
Disaggregation of Revenue [Line Items]
Percentage of Consolidated Revenue	51.00%	46.00%	50.00%	46.00%
Rail Intermodal
Disaggregation of Revenue [Line Items]
Percentage of Consolidated Revenue	3.00%	3.00%	3.00%	3.00%
Ocean and air cargo carriers
Disaggregation of Revenue [Line Items]
Percentage of Consolidated Revenue	5.00%	3.00%	4.00%	3.00%
BCO Independent Contractor Truck and Brokerage Carriers Truck | Van Equipment
Disaggregation of Revenue [Line Items]
Revenue	$ 918,115	$ 578,166	$ 2,502,025	$ 1,485,553
BCO Independent Contractor Truck and Brokerage Carriers Truck | Unsided/Platform Equipment
Disaggregation of Revenue [Line Items]
Revenue	422,979	294,273	1,112,358	807,966
BCO Independent Contractor Truck and Brokerage Carriers Truck | Less than Truckload
Disaggregation of Revenue [Line Items]
Revenue	30,819	25,125	85,551	70,984
BCO Independent Contractor Truck and Brokerage Carriers Truck | Other Truck Transportation
Disaggregation of Revenue [Line Items]
Revenue	$ 208,817	$ 108,614	$ 518,472	$ 249,584