Intangible Assets, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets, gross	$ 2,867		$ 2,867
Less: accumulated amortization	(2,829)		(2,816)
Intangible assets, net	38		51
Amortization expense	13	$ 13
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2022	50
Purchased technology-based intangible
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets, gross	2,358		2,358
Purchased patent
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets, gross	$ 509		$ 509