Income Taxes - Components of Deferred Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Deferred Tax Assets:
Accrued third party charges, deductible for taxes upon economic performance	$ 9,220	$ 6,503
Provision for doubtful accounts receivable	1,074	1,561
Excess of financial statement over tax depreciation	8,138	8,079
Deductible stock compensation expense, net	4,651	5,450
Foreign currency translation adjustment	1,625	0
Partnership basis difference	1,043	0
Retained liability for cargo claims	192	713
Total gross deferred tax assets	25,943	22,306
Deferred Tax Liabilities:
Unremitted foreign earnings, net of related foreign tax credits	(76,070)	(78,112)
Foreign currency translation adjustment	0	(4,453)
Other	(71)	(82)
Total gross deferred tax liabilities	(76,141)	(82,647)
Net deferred tax liabilities	(50,198)	(60,341)
Current deferred tax assets	(10,415)	(8,706)
Noncurrent deferred tax liabilities	$ (60,613)	$ (69,047)