Income Taxes - Components of Deferred Taxes (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets:
Deductible stock compensation expense, net	$ 14,265	$ 18,569
Operating lease liabilities	52,223	52,966
Accrued third party obligations, deductible for taxes upon economic performance	6,242	5,333
Excess of financial statement over tax depreciation	8,123	5,802
Foreign currency translation adjustments	4,604	9,248
Retained liability for cargo claims	1,128	1,006
Provision for credit losses on accounts receivable	954	916
Total gross deferred tax assets	87,539	93,840
Deferred Tax Liabilities:
Unremitted foreign earnings, net of related foreign tax credits	43,805	31,615
Operating lease assets	49,865	52,351
Deferred contract costs	917	1,840
Total gross deferred tax liabilities	94,587	85,806
Net deferred tax (liabilities) assets	$ (7,048)
Net deferred tax (liabilities) assets		$ 8,034