Quarterly Results (Unaudited) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Quarterly Financial Information [Line Items]
Revenues	$ 1,625,859	$ 1,537,966	$ 1,503,224	$ 1,413,208	$ 1,535,729	$ 1,534,460	$ 1,507,833	$ 1,414,193	$ 6,080,257		$ 5,992,215		$ 6,161,537
Net revenues	478,072	484,902	471,872	448,007	461,510	467,934	456,532	449,394	1,882,853	[1]	1,835,370	[1]	1,907,516	[1]
Net earnings	84,009	92,729	92,663	80,610	83,499	88,727	84,021	76,722	350,011		332,969		386,243
Net earnings attributable to shareholders	$ 83,496	$ 92,400	$ 92,315	$ 80,315	$ 84,208	$ 88,490	$ 83,955	$ 76,707	$ 348,526		$ 333,360		$ 385,679
Diluted earnings attributable to shareholders per share	$ 0.41	$ 0.45	$ 0.45	$ 0.39	$ 0.40	$ 0.42	$ 0.39	$ 0.36	$ 1.68		$ 1.57		$ 1.79
Basic earnings attributable to shareholders per share	$ 0.41	$ 0.45	$ 0.45	$ 0.39	$ 0.41	$ 0.42	$ 0.40	$ 0.36	$ 1.69		$ 1.58		$ 1.82

[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.