Business Segment Information - Financial Information Regarding Company's Operations by Geographic Area (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	$ 2,464,797	$ 2,074,855	$ 6,947,293	$ 6,130,485
Directly related cost of transportation and other expenses	[2]	1,730,418	1,400,499	4,848,187	4,140,320
Salaries and other operating expenses	[3]	482,434	467,806	1,440,480	1,403,813
Operating income		251,945	206,550	658,626	586,352
Identifiable assets at period end		4,358,554	3,706,453	4,358,554	3,706,453		$ 3,691,884
Capital expenditures		9,178	15,521	37,419	37,943
Equity		2,504,473	2,209,287	2,504,473	2,209,287	$ 2,161,598	$ 2,197,219	$ 2,052,394	$ 1,987,720
Operating Segments | United States Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	686,245	692,229	1,975,883	2,033,088
Directly related cost of transportation and other expenses	[2]	379,588	389,254	1,108,173	1,142,701
Salaries and other operating expenses	[3]	197,749	210,767	631,396	636,243
Operating income		108,908	92,208	236,314	254,144
Identifiable assets at period end		2,336,071	2,059,345	2,336,071	2,059,345
Capital expenditures		4,703	7,644	28,276	23,544
Equity		1,791,658	1,578,682	1,791,658	1,578,682
Operating Segments | Other North America Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	78,129	88,088	234,274	265,035
Directly related cost of transportation and other expenses	[2]	44,911	51,420	132,250	157,997
Salaries and other operating expenses	[3]	25,325	25,731	74,320	76,283
Operating income		7,893	10,937	27,704	30,755
Identifiable assets at period end		163,943	128,336	163,943	128,336
Capital expenditures		483	513	1,692	1,509
Equity		77,915	60,526	77,915	60,526
Operating Segments | Latin America Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	39,193	38,341	114,636	111,277
Directly related cost of transportation and other expenses	[2]	23,361	22,990	69,827	64,149
Salaries and other operating expenses	[3]	12,359	14,547	36,220	41,342
Operating income		3,473	804	8,589	5,786
Identifiable assets at period end		76,173	72,029	76,173	72,029
Capital expenditures		180	833	498	1,071
Equity		31,324	27,217	31,324	27,217
Operating Segments | North Asia Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	883,104	624,351	2,538,117	1,879,155
Directly related cost of transportation and other expenses	[2]	720,807	489,195	2,054,023	1,475,395
Salaries and other operating expenses	[3]	81,876	70,410	236,480	208,781
Operating income		80,421	64,746	247,614	194,979
Identifiable assets at period end		689,525	489,322	689,525	489,322
Capital expenditures		1,075	523	1,785	1,167
Equity		246,557	216,061	246,557	216,061
Operating Segments | South Asia Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	267,228	196,569	660,583	555,128
Directly related cost of transportation and other expenses	[2]	200,334	145,345	481,971	407,642
Salaries and other operating expenses	[3]	39,926	32,482	109,018	97,324
Operating income		26,968	18,742	69,594	50,162
Identifiable assets at period end		231,771	164,976	231,771	164,976
Capital expenditures		665	631	1,035	1,235
Equity		97,564	77,733	97,564	77,733
Operating Segments | Europe Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	378,048	320,769	1,086,118	952,790
Directly related cost of transportation and other expenses	[2]	261,325	221,149	754,863	657,720
Salaries and other operating expenses	[3]	96,658	86,156	274,269	258,339
Operating income		20,065	13,464	56,986	36,731
Identifiable assets at period end		642,124	563,289	642,124	563,289
Capital expenditures		1,780	5,119	3,418	8,015
Equity		185,352	169,450	185,352	169,450
Operating Segments | Middle East Africa And India Segment
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	133,765	115,397	340,415	336,383
Directly related cost of transportation and other expenses	[2]	100,619	81,592	248,503	236,184
Salaries and other operating expenses	[3]	28,925	28,151	80,063	86,385
Operating income		4,221	5,654	11,849	13,814
Identifiable assets at period end		228,423	226,657	228,423	226,657
Capital expenditures		292	258	715	1,402
Equity		110,714	111,355	110,714	111,355
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	[1]	(915)	(889)	(2,733)	(2,371)
Directly related cost of transportation and other expenses	[2]	(527)	(446)	(1,423)	(1,468)
Salaries and other operating expenses	[3]	(384)	(438)	(1,286)	(884)
Operating income		(4)	(5)	(24)	(19)
Identifiable assets at period end		(9,476)	2,499	(9,476)	2,499
Equity		$ (36,611)	$ (31,737)	$ (36,611)	$ (31,737)

[1] Beginning in the second quarter of 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 impact of these changes on reported segment revenues was immaterial and in the nine months ended September 30, 2019, segment revenues have not been revised.

[2] 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 condensed consolidated statements of earnings

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