Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Intangible Assets

The carrying values of intangible assets as of December 31, 2020 and 2019, respectively, consists of the following (in thousands except years):

	December 31, 2020
	Gross		Accumulated Amortization		Foreign Exchange Rate Changes		Net		Estimated Useful Life (in years)
Patents	$	2,963	$	(1,975)	$	—	$	988	10
Developed technology - 150V	560		(555)		(5)		—		6
Developed technology - 600V	1,701		(1,684)		(17)		—		6
Total	$	5,224	$	(4,214)	$	(22)	$	988
	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

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

Estimated future amortization expenses related to intangible assets at December 31, 2020 are as follows (in thousands):

Year Ending December 31,	Amount
2021	$	296
2022	296
2023	296
2024	100
Thereafter	—
Total	$	988