Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Taxes

Schedule of income before income taxes

	Year ended December 31,
	2021		2020		2019
	(in thousands)
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

Schedule of provision for income taxes

	Year ended December 31,
	2021		2020		2019
	(in thousands)
Current:
United States
Federal	$	—	$	—	$	—
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

Schedule of reconciliation of income taxes at the United States Federal statutory rate to the effective income tax rate

	Year ended December 31,
	2021		2020		2019
	(in thousands)
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

Schedule of significant components of current and long-term deferred income taxes

	Year ended December 31,
	2021		2020
	(in thousands)
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

Schedule of reconciliation of the beginning and ending balance of unrecognized tax benefits

		Year ended December 31,
	2021		2020		2019
	(in thousands)
Balance at beginning of year	$	10,044	$	9,799	$	9,127
(Decrease) / increase in unrecognized tax benefits as a result of tax positions taken during a prior period		(546)		(502)		215
Reductions to unrecognized tax benefits as a result of a lapse of the applicable statute of limitation		(472)		—		(334)
Increases in unrecognized tax benefits as a result of tax positions taken during the current period		935		747		791
Balance at end of year	$	9,961	$	10,044	$	9,799
Recorded as other long-term liability	$	—	$	472	$	409
Recorded as a decrease in deferred tax assets		9,961		9,572		9,390
Balance at end of year	$	9,961	$	10,044	$	9,799