Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets related to:
Accrued liabilities	$ 1,058	$ 1,030
Intangible assets	2,818	3,020
Net operating loss carryforward	10,259	15,246
Stock-based compensation	377	586
Foreign tax credits	3,782	2,570
Goodwill	6,199	7,232
Leases	10,235	9,038
Other	1,518	1,347
Total gross deferred tax assets	36,246	40,069
Less valuation allowance	(12,493)	(16,960)
Total net deferred tax assets	23,753	23,109
Liabilities related to:
Depreciation and amortization	(23,308)	(22,634)
Other	(582)	(595)
Total deferred tax liabilities	(23,890)	(23,229)
Net deferred tax liabilities	$ (137)	$ (120)