Income Taxes - Components of Deferred Taxes (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets:
Accrued third party obligations, deductible for taxes upon economic performance	$ 7,726	$ 8,075
Provision for doubtful accounts receivable	1,443	628
Excess of financial statement over tax depreciation	5,134	4,804
Deductible stock compensation expense, net	19,011	17,326
Foreign currency translation adjustments	37,299	24,448
Retained liability for cargo claims	1,025	1,062
Total gross deferred tax assets	71,638	56,343
Deferred Tax Liabilities:
Unremitted foreign earnings, net of related foreign tax credits	31,173	43,136
Total gross deferred tax liabilities	31,173	43,136
Net Deferred tax assets	$ 40,465	$ 13,207