Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Intangible Assets

The carrying values of intangible assets as of December 31, 2019 and 2018, respectively, consists of the following (in thousands except years):

	December 31, 2019
	Gross		Accumulated Amortization		Foreign Exchange Rate Changes		Net		Estimated Useful Life (in years)
Patents	$	2,963	$	(1,679)	$	—	$	1,284	10
Developed technology - 150V	560		(519)		(34)		7		6
Developed technology - 600V	1,701		(1,575)		(104)		22		6
Total	$	5,224	$	(3,773)	$	(138)	$	1,313
	December 31, 2018
	Gross		Accumulated Amortization		Foreign Exchange Rate Changes		Net		Estimated Useful Life (in years)
Patents	$	2,963	$	(1,383)	$	—	$	1,580	10
Developed technology - 150V	560		(425)		(41)		94		6
Developed technology - 600V	1,701		(1,291)		(126)		284		6
Total	$	5,224	$	(3,099)	$	(167)	$	1,958

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

Estimated future amortization expenses related to intangible assets at December 31, 2019 are as follows (in thousands):

Year Ending December 31,	Amount
2020	$	325
2021	296
2022	296
2023	296
Thereafter	100
Total	$	1,313