Business Segment Information - Net Revenues Calculation (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Schedule of Net Revenues Calculation [Line Items]
Total revenues		$ 2,020,051	$ 1,854,262
Expenses [Abstract]
Net revenues	[1]	654,114	635,838
Airfreight services
Schedule of Net Revenues Calculation [Line Items]
Total revenues		714,901	731,227
Expenses [Abstract]
Direct Operating Costs		509,210	513,504
Ocean freight and ocean services
Schedule of Net Revenues Calculation [Line Items]
Total revenues		568,641	520,883
Expenses [Abstract]
Direct Operating Costs		420,331	379,418
Customs brokerage and other services
Schedule of Net Revenues Calculation [Line Items]
Total revenues		736,509	602,152
Expenses [Abstract]
Direct Operating Costs		$ 436,396	$ 325,502

[1] Net revenues are a non-GAAP measure calculated as revenues less directly related operating expenses attributable to the Company's principal services. The Company's management believes that net revenues are a better measure than total revenues when evaluating the Company's operating segment performance since total revenues earned as a freight consolidator include the carriers' charges for carrying the shipment, whereas revenues earned in other capacities include primarily the commissions and fees earned by the Company. Net revenue is one of the Company's primary operational and financial measures and demonstrates the Company's ability to concentrate and leverage purchasing power through effective consolidation of shipments from customers utilizing a variety of transportation carriers and optimal routings.