Business Segment Information - Financial Information Regarding Company's Operations by Geographic Area (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information [Line Items]
Total revenues	$ 1,768,830	$ 1,705,105	$ 1,599,141	$ 1,491,645	$ 1,625,859	$ 1,537,966	$ 1,503,224	$ 1,413,208	$ 6,564,721		$ 6,080,257		$ 5,992,215
Net revenues	518,871	513,256	484,714	464,586	478,072	484,902	471,872	448,007	1,981,427	[1]	1,882,853	[1]	1,835,370	[1]
Operating income									594,648		552,073		530,798
Identifiable assets at year end	2,890,905				3,014,812				2,890,905		3,014,812		2,954,125
Capital expenditures									37,472		53,411		47,626
Depreciation and amortization									49,292		48,071		39,940
Equity	1,871,608				2,086,331				1,871,608		2,086,331		2,032,570		2,010,069
United States Segment
Segment Reporting Information [Line Items]
Total revenues									1,694,819		1,561,468		1,529,917
Net revenues									823,111	[1]	770,519	[1]	748,320	[1]
Operating income									221,166		195,799		179,015
Identifiable assets at year end	1,408,598				1,582,557				1,408,598		1,582,557		1,459,425
Capital expenditures									19,610		28,699		28,088
Depreciation and amortization									31,553		29,569		23,678
Equity	1,165,488				1,330,262				1,165,488		1,330,262		1,197,239
Other North America Segment
Segment Reporting Information [Line Items]
Total revenues									218,735		215,968		201,521
Net revenues									108,631	[1]	102,864	[1]	95,798	[1]
Operating income									36,475		35,224		32,385
Identifiable assets at year end	111,324				104,735				111,324		104,735		92,075
Capital expenditures									1,439		1,870		832
Depreciation and amortization									1,170		882		756
Equity	54,338				72,772				54,338		72,772		58,071
Latin America Segment
Segment Reporting Information [Line Items]
Total revenues									89,058		86,050		82,337
Net revenues									65,016	[1]	61,478	[1]	57,795	[1]
Operating income									19,855		15,734		17,356
Identifiable assets at year end	53,815				58,027				53,815		58,027		48,995
Capital expenditures									1,574		1,010		1,301
Depreciation and amortization									911		901		873
Equity	34,386				29,590				34,386		29,590		29,504
Asia Pacific Segment
Segment Reporting Information [Line Items]
Total revenues									3,233,539		3,046,039		3,059,070
Net revenues									570,793	[1]	560,900	[1]	548,858	[1]
Operating income									230,092		223,980		215,351
Identifiable assets at year end	655,148				668,032				655,148		668,032		774,569
Capital expenditures									9,073		17,231		11,199
Depreciation and amortization									8,233		8,381		6,782
Equity	361,529				406,728				361,529		406,728		536,384
Europe Segment
Segment Reporting Information [Line Items]
Total revenues									1,012,389		876,967		833,688
Net revenues									313,325	[1]	288,407	[1]	285,175	[1]
Operating income									62,101		53,294		58,790
Identifiable assets at year end	447,349				414,710				447,349		414,710		392,180
Capital expenditures									4,246		3,313		4,490
Depreciation and amortization									5,690		6,569		5,962
Equity	169,117				178,729				169,117		178,729		150,264
Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Total revenues									316,181		293,765		285,682
Net revenues									100,551	[1]	98,685	[1]	99,424	[1]
Operating income									24,959		28,042		27,901
Identifiable assets at year end	208,684				180,646				208,684		180,646		186,077
Capital expenditures									1,530		1,288		1,716
Depreciation and amortization									1,735		1,769		1,889
Equity	121,520				102,628				121,520		102,628		94,764
Operating Segments | United States Segment
Segment Reporting Information [Line Items]
Total revenues									1,791,847		1,651,038		1,624,438
Operating Segments | Other North America Segment
Segment Reporting Information [Line Items]
Total revenues									229,626		227,006		211,997
Operating Segments | Latin America Segment
Segment Reporting Information [Line Items]
Total revenues									109,692		107,761		101,117
Operating Segments | Asia Pacific Segment
Segment Reporting Information [Line Items]
Total revenues									3,283,138		3,092,617		3,102,672
Operating Segments | Europe Segment
Segment Reporting Information [Line Items]
Total revenues									1,051,930		915,695		873,765
Operating Segments | Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Total revenues									335,835		310,463		302,643
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenues									(237,347)		(224,323)		(224,417)
Identifiable assets at year end	5,987				6,105				5,987		6,105		804
Equity	(34,770)				(34,378)				(34,770)		(34,378)		(33,656)
Intersegment Eliminations | United States Segment
Segment Reporting Information [Line Items]
Total revenues									(97,028)		(89,570)		(94,521)
Intersegment Eliminations | Other North America Segment
Segment Reporting Information [Line Items]
Total revenues									(10,891)		(11,038)		(10,476)
Intersegment Eliminations | Latin America Segment
Segment Reporting Information [Line Items]
Total revenues									(20,634)		(21,711)		(18,780)
Intersegment Eliminations | Asia Pacific Segment
Segment Reporting Information [Line Items]
Total revenues									(49,599)		(46,578)		(43,602)
Intersegment Eliminations | Europe Segment
Segment Reporting Information [Line Items]
Total revenues									(39,541)		(38,728)		(40,077)
Intersegment Eliminations | Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Total revenues									$ (19,654)		$ (16,698)		$ (16,961)

[1] Net revenues are a non-GAAP measure calculated as revenues less directly related operations 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.