Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Taxes

Schedule of income before income taxes

	Year ended December 31,
	2018		2017		2016
	(in thousands)
United States	$	52,172	$	40,752	$	8,880
Foreign		2,533		3,079		2,144
Income before income taxes	$	54,705	$	43,831	$	11,024

Schedule of provision for income taxes

	Year ended December 31,
	2018		2017		2016
	(in thousands)
Current:
United States
Federal	$	41	$	430	$	—
State		112		32		49
Foreign		323		230		(217)
Total current		476		692		(168)
Deferred:
Federal		8,108		(82,048)		—
State		425		(1,698)		—
Foreign		(189)		(74)		191
Total deferred		8,344		(83,820)		191
Income tax provision (benefit)	$	8,820	$	(83,128)	$	23

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

	Year ended December 31,
	2018		2017		2016
	(in thousands)
Income taxes at the United States statutory rate	$	11,488	$	15,341	$	3,859
State income taxes		299		203		32
Unrecognized tax benefits		(345)		(285)		(615)
Effect of change in valuation allowance		(441)		(115,831)		(7,765)
Foreign income tax rate differentials		73		(312)		233
Unremitted earnings of foreign subsidiaries		—		(8,933)		305
Stock options		(715)		(10,342)		264
Credit expirations		—		—		3,565
Repatriation of foreign earnings		—		4,556		—
Recognition of equity NOL's		—		(1,165)		—
Rate change		160		42,531		—
Credit generation		(3,530)		(8,778)		—
Discrete items, net		972		31		—
Other, net		859		(144)		145
Income tax provision (benefit)	$	8,820	$	(83,128)	$	23

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

	Year ended December 31,
	2018		2017
	(in thousands)
Federal net operating loss carryforwards	$	42,397	$	56,646
State net operating loss carryforwards		1,387		1,586
Foreign net operating loss carryforwards		641		758
Federal tax credit carryforwards		16,200		14,312
State tax credit carryforwards		6,489		6,908
Unremitted earnings of foreign subsidiaries		—		(21)
Intangible assets		(29)		116
Property, plant and equipment		5,924		5,838
Accrued compensation		97		45
Inventories		3,713		3,798
Stock compensation		2,760		2,351
Warranty		1,090		980
Deferred revenue		1,004		187
Other		(2,899)		(3,220)
Deferred taxes, gross		78,774		90,284
Valuation allowance		(6,835)		(7,136)
Deferred taxes, net	$	71,939	$	83,148

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

		Year ended December 31,
	2018		2017		2016
	(in thousands)
Balance at beginning of year	$	9,105	$	6,844	$	7,671
(Decrease) / increase in unrecognized tax benefits as a result of tax positions taken during a prior period		(132)		81		76
Decreases in unrecognized tax benefits related to settlements with tax authorities		—		—		—
Reductions to unrecognized tax benefits as a result of a lapse of the applicable statute of limitation		(543)		(511)		(903)
Increases in unrecognized tax benefits as a result of tax positions taken during the current period		697		2,691		—
Balance at end of year	$	9,127	$	9,105	$	6,844
Recorded as other long-term liability	$	676	$	1,109	$	1,462
Recorded as a decrease in deferred tax assets and offsetting valuation allowance		8,451		7,996		5,382
Balance at end of year	$	9,127	$	9,105	$	6,844