Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets related to:
Accrued liabilities	$ 1,030	$ 1,105
Intangible assets	3,020	3,054
Net operating loss carryforward	15,246	15,970
Non-qualified stock options	586	672
Foreign tax credits	2,570	1,489
Goodwill	7,232	8,200
Leases	9,038
Other	1,347	2,684
Total gross deferred tax assets	40,069	33,174
Less valuation allowance	(16,960)	(15,815)
Total net deferred tax assets	23,109	17,359
Liabilities related to:
Depreciation and amortization	(22,634)	(16,974)
Other	(595)	(434)
Total liabilities	(23,229)	(17,408)
Net deferred tax liabilities	$ (120)	$ (49)