Business Segment Information - Financial Information Regarding Company's Operations by Geographic Area (Detail) - USD ($) $ in Thousands		3 Months Ended																12 Months Ended
		Dec. 31, 2019		Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	[1]	Dec. 31, 2018		Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		$ 2,044,941	[1]	$ 2,074,855		$ 2,035,579		$ 2,020,051		$ 2,235,597	[1]	$ 2,090,947		$ 1,957,559		$ 1,854,262		$ 8,175,426	[2]	$ 8,138,365	[2]	$ 6,920,948	[2]
Directly related cost of transportation and other expenses	[3]																	5,538,958		5,517,992		4,601,759
Salaries and other operating expenses	[4]																	1,869,776		1,823,810		1,618,929
Operating income		180,340	[1]	$ 206,550		$ 192,201		$ 187,601		217,007	[1]	$ 203,154		$ 183,584		$ 192,818		766,692		796,563		700,260
Identifiable assets at period end		3,691,884								3,314,559								3,691,884		3,314,559		3,117,008
Capital expenditures																		47,022		47,474		95,016
Depreciation and amortization																		50,950		54,019		49,310
Equity		2,197,219								1,987,720								2,197,219		1,987,720		1,994,373		$ 1,847,213
Operating Segments | United States Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[2]																	2,712,067		2,479,812		1,962,558
Directly related cost of transportation and other expenses	[3]																	1,528,815		1,352,924		953,717
Salaries and other operating expenses	[4]																	859,946		816,817		731,020
Operating income																		323,306		310,071		277,821
Identifiable assets at period end		1,978,307								1,689,950								1,978,307		1,689,950		1,595,140
Capital expenditures																		28,666		21,732		28,212
Depreciation and amortization																		31,049		33,511		32,017
Equity		1,521,059								1,339,673								1,521,059		1,339,673		1,337,568
Operating Segments | Other North America Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[2]																	354,405		355,802		268,186
Directly related cost of transportation and other expenses	[3]																	212,369		216,753		149,115
Salaries and other operating expenses	[4]																	101,654		94,950		80,940
Operating income																		40,382		44,099		38,131
Identifiable assets at period end		153,813								161,604								153,813		161,604		151,181
Capital expenditures																		2,353		4,259		1,563
Depreciation and amortization																		1,881		1,847		1,546
Equity		65,100								72,941								65,100		72,941		60,705
Operating Segments | Latin America Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[2]																	150,202		156,854		111,862
Directly related cost of transportation and other expenses	[3]																	87,297		94,041		53,663
Salaries and other operating expenses	[4]																	55,512		53,970		48,235
Operating income																		7,393		8,843		9,964
Identifiable assets at period end		72,677								53,542								72,677		53,542		55,431
Capital expenditures																		1,556		1,042		4,612
Depreciation and amortization																		1,489		1,508		1,277
Equity		29,148								26,007								29,148		26,007		26,546
Operating Segments | North Asia Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[2]																	2,494,556		2,886,322		2,598,376
Directly related cost of transportation and other expenses	[3]																	1,970,662		2,315,826		2,089,141
Salaries and other operating expenses	[4]																	271,594		289,015		260,813
Operating income																		252,300		281,481		248,422
Identifiable assets at period end		538,526								533,071								538,526		533,071		458,152
Capital expenditures																		1,767		3,057		3,756
Depreciation and amortization																		5,263		5,309		5,326
Equity		247,725								200,371								247,725		200,371		240,721
Operating Segments | South Asia Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[2]																	743,406		777,863		684,877
Directly related cost of transportation and other expenses	[3]																	544,873		591,925		521,427
Salaries and other operating expenses	[4]																	127,478		125,056		110,393
Operating income																		71,055		60,882		53,057
Identifiable assets at period end		178,336								152,646								178,336		152,646		137,279
Capital expenditures																		1,558		2,182		1,688
Depreciation and amortization																		1,912		2,257		2,215
Equity		94,727								100,706								94,727		100,706		94,516
Operating Segments | Europe Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[2]																	1,280,669		1,330,365		1,115,324
Directly related cost of transportation and other expenses	[3]																	884,968		926,949		779,622
Salaries and other operating expenses	[4]																	342,073		337,970		287,211
Operating income																		53,628		65,446		48,491
Identifiable assets at period end		551,576								513,744								551,576		513,744		501,711
Capital expenditures																		9,231		10,815		53,954
Depreciation and amortization																		7,398		7,727		5,068
Equity		159,308								157,003								159,308		157,003		142,971
Operating Segments | Middle East Africa and India Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[2]																	443,487		464,071		426,069
Directly related cost of transportation and other expenses	[3]																	311,997		330,209		304,802
Salaries and other operating expenses	[4]																	112,844		108,131		96,902
Operating income																		18,646		25,731		24,365
Identifiable assets at period end		219,953								206,367								219,953		206,367		215,495
Capital expenditures																		1,891		4,387		1,231
Depreciation and amortization																		1,958		1,860		1,861
Equity		114,726								123,228								114,726		123,228		123,600
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[2]																	(3,366)		(312,724)		(246,304)
Directly related cost of transportation and other expenses	[3]																	(2,023)		(310,635)		(249,728)
Salaries and other operating expenses	[4]																	(1,325)		(2,099)		3,415
Operating income																		(18)		10		9
Identifiable assets at period end		(1,304)								3,635								(1,304)		3,635		2,619
Equity		$ (34,574)								$ (32,209)								$ (34,574)		$ (32,209)		$ (32,254)

[1] The fourth quarter of 2019 was significantly impacted by declines in results in our China operations due to the slowing of trade to and from China, which impacted overall freight movement around the globe. The Company’s consolidated financial results are expected to be further impacted in 2020 due to the significance of its China operations and the effects of the recent outbreak of the Novel Coronavirus (COVID-19). See Note 12 for further detail. In the fourth quarter 2019 and 2018, the People's Republic of China, including Hong Kong, represented 25% and 31%, respectively, of the Company’s total revenues and 25% and 27%, respectively, of the Company’s total operating income.

[2] In 2019, the Company revised its process to record the transfer, between its geographic operating segments, of revenues and the directly related cost of transportation and other expenses for freight service transactions between Company origin and destination locations. This change better aligns revenue reporting with the location where the services are performed, as well as the transactional reporting being developed as part of the Company’s new accounting systems and processes. The change in presentation had no impact on consolidated or segment operating income. The 2019 results also include the effect of changing the presentation of certain import services from a net to a gross basis, which increased segment revenues and directly related operating expenses but did not change operating income. The impact of these changes on reported segment revenues was immaterial and prior year segment revenues have not been revised.

[3] Directly related cost of transportation and other expenses totals operating expenses from airfreight services, ocean freight and ocean services and customs brokerage and other services as shown in the consolidated statements of earnings.

[4] Salaries and other operating expenses totals salaries and related, rent and occupancy, depreciation and amortization, selling and promotion and other as shown in the consolidated statements of earnings.