Income Taxes (Tables)

12 Months Ended

Dec. 31, 2019

Income Taxes

Schedule of income before income taxes

	Year ended December 31,
	2019		2018		2017
	(in thousands)
United States	$	18,148	$	52,172	$	40,752
Foreign		2,774		2,533		3,079
Income before income taxes	$	20,922	$	54,705	$	43,831

Schedule of provision for income taxes

	Year ended December 31,
	2019		2018		2017
	(in thousands)
Current:
United States
Federal	$	—	$	41	$	430
State		5		112		32
Foreign		579		323		230
Total current		584		476		692
Deferred:
Federal		3,962		8,108		(82,048)
State		(855)		425		(1,698)
Foreign		197		(189)		(74)
Total deferred		3,304		8,344		(83,820)
Income tax provision (benefit)	$	3,888	$	8,820	$	(83,128)

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

	Year ended December 31,
	2019		2018		2017
	(in thousands)
Income taxes at the United States statutory rate	$	4,393	$	11,488	$	15,341
State income taxes		78		299		203
Unrecognized tax benefits		(251)		(345)		(285)
Effect of change in valuation allowance		1,492		(441)		(115,831)
Foreign income tax rate differentials		129		73		(312)
Unremitted earnings of foreign subsidiaries		—		—		(8,933)
Stock options		(1,257)		(715)		(10,342)
Credit expirations		894		—		—
Repatriation of foreign earnings		—		—		4,556
Recognition of equity NOL's		—		—		(1,165)
Rate change		194		160		42,531
Credit generation		(3,124)		(3,530)		(8,778)
Discrete items, net		18		972		31
Other, net		1,322		859		(144)
Income tax provision (benefit)	$	3,888	$	8,820	$	(83,128)

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

	Year ended December 31,
	2019		2018
	(in thousands)
Deferred tax assets:
Federal net operating loss carryforwards	$	39,380	$	42,397
State net operating loss carryforwards		1,211		1,387
Foreign net operating loss carryforwards		554		641
Federal tax credit carryforwards		18,061		16,200
State tax credit carryforwards		6,837		6,489
Property, plant and equipment		10,098		5,924
Operating lease liability		503		—
Accrued compensation		266		97
Inventories		2,674		3,713
Stock compensation		2,477		2,760
Warranty		689		1,090
Deferred revenue		1,086		1,004
Gross deferred tax assets		83,836		81,702
Valuation allowance		(8,327)		(6,835)
Net deferred tax assets		75,509		74,867
Deferred tax liabilities:
Intangible assets		(47)		(29)
Right-of-use asset		(5,141)		—
Internal Revenue Code 481(a) adjustment		(412)		—
Other		(1,849)		(2,899)
Gross deferred tax liabilities		(7,449)		(2,928)
Deferred taxes, net	$	68,060	$	71,939

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

		Year ended December 31,
	2019		2018		2017
	(in thousands)
Balance at beginning of year	$	9,127	$	9,105	$	6,844
Increase / (decrease) in unrecognized tax benefits as a result of tax positions taken during a prior period		215		(132)		81
Reductions to unrecognized tax benefits as a result of a lapse of the applicable statute of limitation		(334)		(543)		(511)
Increases in unrecognized tax benefits as a result of tax positions taken during the current period		791		697		2,691
Balance at end of year	$	9,799	$	9,127	$	9,105
Recorded as other long-term liability	$	409	$	676	$	1,109
Recorded as a decrease in deferred tax assets and offsetting valuation allowance		9,390		8,451		7,996
Balance at end of year	$	9,799	$	9,127	$	9,105