Income Taxes - Components of Net Deferred Income Tax Asset and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Net deferred income tax asset - Non-current
Warranty cost	$ 305	$ 310
Inventory reserve	2,287	5,234
Unearned service revenue	9,913	11,607
Employee stock options	3,282	3,271
Tax credits	3,688	2,828
Loss carryforwards	18,487	8,530
Depreciation	1,295	1,419
Other, net	1,402	735
Intangibles & goodwill	14,400	19,295
Lease liability	4,749	6,986
Total deferred tax assets	59,808	60,215
Valuation allowance	(35,148)	(6,916)
Total deferred tax assets net of valuation allowance	24,660	53,299
Net deferred income tax liability - Non-current
Operating lease right-of-use asset	(4,441)	(6,636)
Total deferred tax liabilities	(4,441)	(6,636)
Net deferred tax assets	$ 20,219	$ 46,663