Income Taxes - Components of Deferred Taxes (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets:
Accrued third party obligations, deductible for taxes upon economic performance	$ 8,075	$ 15,153
Provision for doubtful accounts receivable	628	497
Excess of financial statement over tax depreciation	4,804	10,650
Deductible stock compensation expense, net	17,326	21,758
Foreign currency translation adjustment	24,448	57,207
Retained liability for cargo claims	1,062	1,178
Total gross deferred tax assets	56,343	106,443
Deferred Tax Liabilities:
Unremitted foreign earnings, net of related foreign tax credits	43,136	120,170
Total gross deferred tax liabilities	43,136	120,170
Net Deferred tax assets	13,207	0
Net deferred tax liabilities	$ 0	$ 13,727