Income Taxes - Components of Deferred Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred Tax Assets:
Accrued third party charges, deductible for taxes upon economic performance	$ 10,144	$ 9,220
Provision for doubtful accounts receivable	1,111	1,074
Excess of financial statement over tax depreciation	8,122	8,138
Deductible stock compensation expense, net	9,382	4,651
Foreign currency translation adjustment	0	1,625
Partnership basis difference	1,426	1,043
Retained liability for cargo claims	983	192
Total gross deferred tax assets	31,168	25,943
Deferred Tax Liabilities:
Unremitted foreign earnings, net of related foreign tax credits	(94,787)	(76,070)
Foreign currency translation adjustment	(3,141)	0
Other	(135)	(71)
Total gross deferred tax liabilities	(98,063)	(76,141)
Net deferred tax liabilities	(66,895)	(50,198)
Current deferred tax assets	(12,102)	(10,415)
Noncurrent deferred tax liabilities	$ (78,997)	$ (60,613)