Business Segment Information - Financial Information Regarding Company's Operations by Geographic Area (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total revenues		$ 1,418,472	$ 1,677,526
Net revenues	[1]	517,069	529,486
Operating income		151,826	168,883
Identifiable assets at period end		2,679,743	2,943,778	$ 2,582,438
Capital expenditures		14,035	9,445
Depreciation and amortization		11,329	11,529
Equity		1,782,511	1,927,531	$ 1,694,676	$ 1,871,608
United States Segment
Segment Reporting Information [Line Items]
Total revenues		407,826	444,181
Other North America Segment
Segment Reporting Information [Line Items]
Total revenues		52,106	54,794
Latin America Segment
Segment Reporting Information [Line Items]
Total revenues		20,064	24,081
North Asia Segment
Segment Reporting Information [Line Items]
Total revenues		497,232	645,444
South Asia Segment
Segment Reporting Information [Line Items]
Total revenues		136,418	181,381
Europe Segment
Segment Reporting Information [Line Items]
Total revenues		221,897	242,086
Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Total revenues		82,929	85,559
Geography Eliminations | United States Segment
Segment Reporting Information [Line Items]
Total revenues		26,034	27,675
Geography Eliminations | Other North America Segment
Segment Reporting Information [Line Items]
Total revenues		2,700	2,814
Geography Eliminations | Latin America Segment
Segment Reporting Information [Line Items]
Total revenues		3,601	4,777
Geography Eliminations | North Asia Segment
Segment Reporting Information [Line Items]
Total revenues		5,096	5,697
Geography Eliminations | South Asia Segment
Segment Reporting Information [Line Items]
Total revenues		5,806	5,915
Geography Eliminations | Europe Segment
Segment Reporting Information [Line Items]
Total revenues		10,361	9,637
Geography Eliminations | Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Total revenues		5,394	5,067
Operating Segments | United States Segment
Segment Reporting Information [Line Items]
Total revenues		433,860	471,856
Net revenues	[1]	220,698	219,603
Operating income		48,205	59,181
Identifiable assets at period end		1,255,099	1,451,103
Capital expenditures		8,137	6,325
Depreciation and amortization		7,332	7,393
Equity		978,426	1,182,808
Operating Segments | Other North America Segment
Segment Reporting Information [Line Items]
Total revenues		54,806	57,608
Net revenues	[1]	27,378	30,678
Operating income		7,291	11,091
Identifiable assets at period end		119,258	109,180
Capital expenditures		311	288
Depreciation and amortization		364	292
Equity		79,312	58,998
Operating Segments | Latin America Segment
Segment Reporting Information [Line Items]
Total revenues		23,665	28,858
Net revenues	[1]	13,733	16,559
Operating income		3,852	5,356
Identifiable assets at period end		56,334	57,232
Capital expenditures		485	617
Depreciation and amortization		253	268
Equity		37,325	34,604
Operating Segments | North Asia Segment
Segment Reporting Information [Line Items]
Total revenues		502,328	651,141
Net revenues	[1]	110,791	117,405
Operating income		55,218	57,056
Identifiable assets at period end		455,973	541,983
Capital expenditures		1,085	290
Depreciation and amortization		1,319	1,399
Equity		300,188	306,775
Operating Segments | South Asia Segment
Segment Reporting Information [Line Items]
Total revenues		142,224	187,296
Net revenues	[1]	39,518	42,200
Operating income		15,691	13,880
Identifiable assets at period end		133,940	143,910
Capital expenditures		655	319
Depreciation and amortization		512	530
Equity		115,606	106,139
Operating Segments | Europe Segment
Segment Reporting Information [Line Items]
Total revenues		232,258	251,723
Net revenues	[1]	74,541	75,888
Operating income		12,253	15,071
Identifiable assets at period end		438,711	430,338
Capital expenditures		2,119	1,148
Depreciation and amortization		1,098	1,246
Equity		167,726	154,343
Operating Segments | Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Total revenues		88,323	90,626
Net revenues	[1]	30,407	27,153
Operating income		9,313	7,248
Identifiable assets at period end		216,576	198,954
Capital expenditures		1,243	458
Depreciation and amortization		451	401
Equity		137,112	120,086
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenues		(58,992)	(61,582)
Net revenues		3
Operating income		3
Identifiable assets at period end		3,852	11,078
Equity		$ (33,184)	$ (36,222)

[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.