Income Taxes - Tax Effects (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income (loss) before income taxes
United States	$ 116,380	$ 51,934	$ 18,148
Foreign	4,048	3,952	2,774
Income before income taxes	120,428	55,886	20,922
Current:
State	82	157	5
Foreign	1,439	1,062	579
Total current	1,521	1,219	584
Deferred:
Federal	20,521	4,594	3,962
State	406	295	(855)
Foreign	(670)	(204)	197
Total deferred	20,257	4,685	3,304
Income tax provision	21,778	5,904	3,888
Reconciliation of income taxes at the United States Federal statutory rate to the effective income tax rate
Income taxes at the United States statutory rate	25,290	11,736	4,393
State income taxes	387	226	78
Unrecognized tax benefits	(222)		(251)
Effect of change in valuation allowance	(1,443)	806	1,492
Foreign income tax rate differentials	152	181	129
Stock based compensation	(3,658)	(2,803)	(1,257)
Credit expirations	2,342	(14)	894
Rate change	159	151	194
Credit generation	(3,096)	(2,473)	(3,124)
Discrete items, net	72	(147)	18
Previously unrecognized tax benefit		(4,063)
GILTI inclusion	301	732	566
Other, net	1,494	1,572	756
Income tax provision	21,778	5,904	$ 3,888
Deferred tax assets:
Federal net operating loss carryforwards	5,635	23,193
State net operating loss carryforwards	727	969
Foreign net operating loss carryforwards	371	529
Federal tax credit carryforwards	18,840	19,377
State tax credit carryforwards	8,138	7,358
Property, plant and equipment	8,967	9,501
Operating lease liability	792	348
Accrued compensation	280	16
Inventories	1,729	2,271
Stock compensation	1,401	1,566
Warranty	1,471	982
Deferred revenue	836	1,032
Capitalized research and development costs		5,785
Gross deferred tax assets	49,187	72,927
Valuation allowance	(7,689)	(9,133)
Net deferred tax assets	41,498	63,794
Deferred tax liabilities:
Intangible assets	(72)	(80)
Right-of-use asset	(4,918)	(4,756)
Other	(1,054)	(1,107)
Gross deferred tax liabilities	(6,044)	(5,943)
Deferred taxes, net	35,454	$ 57,851
Decrease in valuation allowance	$ 1,400