Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Accounts receivable, due to allowance for doubtful accounts	$ 221	$ 364
Inventories	1,335	858
Operating loss carry-forwards	4,546	5,784
Stock-based compensation expense	881	1,106
Property and equipment, due to difference in depreciation	283	1,944
Research and development tax credit carry-forwards	5,743	6,247
Foreign tax credit carry-forwards	2,345	2,345
State tax credit carry-forwards	3,710	3,975
Capitalized research and development	5,003	2,690
Warranty reserve	302	255
Accrued expenses	1,486	1,089
Lease liability	483	700
Gross deferred tax assets	26,338	27,357
Less valuation allowance	(22,094)	(26,542)
Total deferred tax assets	4,244	815
Deferred tax liabilities:
Purchased intangible assets	(39)	(199)
Property and equipment, due to differences in depreciation	(3,514)	(86)
Right of use asset	(487)	(689)
Total deferred tax liabilities	(4,040)	(974)
Net deferred tax asset	204
Net deferred tax asset (liability)		(159)
Deferred income tax asset	259	56
Deferred income tax liability	$ (55)	$ (215)