Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Revenue from Contract with Customer, Excluding Assessed Tax	$ 1,957,559	$ 1,672,279	$ 3,811,821	$ 3,217,411
Operating Expenses:
Salaries and related costs	350,948	318,529	690,843	611,109
Rent and occupancy costs	38,071	29,163	74,984	57,293
Depreciation and amortization	13,576	12,042	27,498	23,969
Selling and promotion	10,788	10,953	21,753	21,868
Other	45,579	24,706	86,904	62,645
Total operating expenses	1,773,975	1,504,039	3,435,419	2,903,057
Operating income	183,584	168,240	376,402	314,354
Other Income (Expense):
Interest income	5,153	3,380	9,467	6,121
Other, net	1,167	2,190	1,791	2,488
Other income (expense), net	6,320	5,570	11,258	8,609
Earnings before income taxes	189,904	173,810	387,660	322,963
Income tax expense	48,958	65,055	110,514	120,641
Net earnings	140,946	108,755	277,146	202,322
Less net earnings (loss) attributable to the noncontrolling interest	341	(96)	849	207
Net earnings attributable to shareholders	$ 140,605	$ 108,851	$ 276,297	$ 202,115
Diluted earnings attributable to shareholders per share	$ 0.79	$ 0.60	$ 1.54	$ 1.11
Basic earnings attributable to shareholders per share	0.80	0.60	1.58	1.12
Dividends declared and paid per common share	$ 0.45	$ 0.42	$ 0.45	$ 0.42
Weighted average diluted shares outstanding	178,603	182,033	179,120	182,091
Weighted average basic shares outstanding	174,754	180,012	175,324	180,037
Airfreight services
Revenues:
Revenue from Contract with Customer, Excluding Assessed Tax	$ 801,761	$ 671,868	$ 1,532,988	$ 1,287,413
Operating Expenses:
Direct Operating Costs	593,325	499,418	1,106,829	942,822
Ocean freight and ocean services
Revenues:
Revenue from Contract with Customer, Excluding Assessed Tax	530,008	528,585	1,050,891	1,022,344
Operating Expenses:
Direct Operating Costs	385,156	385,927	764,574	751,990
Customs brokerage and other services
Revenues:
Revenue from Contract with Customer, Excluding Assessed Tax	625,790	471,826	1,227,942	907,654
Operating Expenses:
Direct Operating Costs	$ 336,532	$ 223,301	$ 662,034	$ 431,361