Business Segment Information - Financial Information Regarding Company's Operations by Geographic Area (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Segment Reporting Information [Line Items]
Total revenues		$ 1,642,007	$ 1,562,394	$ 1,475,164	$ 1,418,472	$ 1,596,221	$ 1,651,332	$ 1,691,553	$ 1,677,526	$ 6,098,037		$ 6,616,632		$ 6,564,721
Net revenues		548,591	$ 545,259	$ 553,117	$ 517,069	536,169	$ 569,981	$ 552,141	$ 529,486	2,164,036	[1]	2,187,777	[1]	1,981,427	[1]
Operating income										670,163		721,484		594,648
Identifiable assets at year end		2,790,871				2,565,577				2,790,871		2,565,577		2,870,626
Capital expenditures										59,316		44,383		37,472
Depreciation and amortization										46,796		46,012		49,292
Equity		1,847,213				1,694,676				1,847,213		1,694,676		1,871,608		$ 2,086,331
United States Segment
Segment Reporting Information [Line Items]
Total revenues										1,683,006		1,763,361		1,694,819
Other North America Segment
Segment Reporting Information [Line Items]
Total revenues										226,561		226,284		218,735
Latin America Segment
Segment Reporting Information [Line Items]
Total revenues										84,665		94,229		89,058
North Asia Segment
Segment Reporting Information [Line Items]
Total revenues										2,242,670		2,557,398		2,576,350
South Asia Segment
Segment Reporting Information [Line Items]
Total revenues										603,980		677,628		657,189
Europe Segment
Segment Reporting Information [Line Items]
Total revenues										918,561		958,827		1,012,389
Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Total revenues										338,594		338,905		316,181
Geography Eliminations | United States Segment
Segment Reporting Information [Line Items]
Total revenues										(106,076)		(118,884)		(97,028)
Geography Eliminations | Other North America Segment
Segment Reporting Information [Line Items]
Total revenues										(10,778)		(13,383)		(10,891)
Geography Eliminations | Latin America Segment
Segment Reporting Information [Line Items]
Total revenues										(15,037)		(19,158)		(20,634)
Geography Eliminations | North Asia Segment
Segment Reporting Information [Line Items]
Total revenues										(21,212)		(21,722)		(23,020)
Geography Eliminations | South Asia Segment
Segment Reporting Information [Line Items]
Total revenues										(24,251)		(25,018)		(26,579)
Geography Eliminations | Europe Segment
Segment Reporting Information [Line Items]
Total revenues										(41,102)		(42,787)		(39,541)
Geography Eliminations | Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Total revenues										(21,876)		(21,322)		(19,654)
Operating Segments | United States Segment
Segment Reporting Information [Line Items]
Total revenues										1,789,082		1,882,245		1,791,847
Net revenues	[1]									918,110		906,780		823,111
Operating income										250,715		245,257		221,166
Identifiable assets at year end		1,455,722				1,185,671				1,455,722		1,185,671		1,388,319
Capital expenditures										39,531		26,807		19,610
Depreciation and amortization										29,939		29,532		31,553
Equity		1,166,582				986,330				1,166,582		986,330		1,165,488
Operating Segments | Other North America Segment
Segment Reporting Information [Line Items]
Total revenues										237,339		239,667		229,626
Net revenues	[1]									119,492		124,381		108,631
Operating income										32,530		46,846		36,475
Identifiable assets at year end		104,804				111,549				104,804		111,549		111,324
Capital expenditures										1,727		3,915		1,439
Depreciation and amortization										1,479		1,331		1,170
Equity		46,448				70,932				46,448		70,932		54,338
Operating Segments | Latin America Segment
Segment Reporting Information [Line Items]
Total revenues										99,702		113,387		109,692
Net revenues	[1]									56,066		65,017		65,016
Operating income										13,321		19,656		19,855
Identifiable assets at year end		49,231				48,678				49,231		48,678		53,815
Capital expenditures										1,038		1,756		1,574
Depreciation and amortization										1,187		1,041		911
Equity		27,164				33,161				27,164		33,161		34,386
Operating Segments | North Asia Segment
Segment Reporting Information [Line Items]
Total revenues										2,263,882		2,579,120		2,599,370
Net revenues	[1]									471,275		493,235		407,410
Operating income										230,777		245,854		177,496
Identifiable assets at year end		511,851				446,914				511,851		446,914		513,649
Capital expenditures										3,889		2,203		5,955
Depreciation and amortization										5,455		5,425		5,938
Equity		327,672				253,097				327,672		253,097		262,295
Operating Segments | South Asia Segment
Segment Reporting Information [Line Items]
Total revenues										628,231		702,646		683,768
Net revenues	[1]									171,033		179,110		163,383
Operating income										64,967		69,643		52,596
Identifiable assets at year end		120,300				127,014				120,300		127,014		141,499
Capital expenditures										3,038		2,383		3,118
Depreciation and amortization										2,177		2,110		2,295
Equity		91,983				99,220				91,983		99,220		99,234
Operating Segments | Europe Segment
Segment Reporting Information [Line Items]
Total revenues										959,663		1,001,614		1,051,930
Net revenues	[1]									304,429		308,301		313,325
Operating income										42,195		65,024		62,101
Identifiable assets at year end		351,960				421,590				351,960		421,590		447,349
Capital expenditures										7,554		5,222		4,246
Depreciation and amortization										4,576		4,931		5,690
Equity		108,430				154,174				108,430		154,174		169,117
Operating Segments | Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Total revenues										360,470		360,227		335,835
Net revenues	[1]									123,335		110,953		100,551
Operating income										35,672		29,204		24,959
Identifiable assets at year end		190,902				221,835				190,902		221,835		208,684
Capital expenditures										2,539		2,097		1,530
Depreciation and amortization										1,983		1,642		1,735
Equity		112,633				130,105				112,633		130,105		121,520
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenues										(240,332)		(262,274)		(237,347)
Net revenues										296
Operating income										(14)
Identifiable assets at year end		6,101				2,326				6,101		2,326		5,987
Equity		$ (33,699)				$ (32,343)				$ (33,699)		$ (32,343)		$ (34,770)

[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.