Intangible Assets, Net and Other non-current assets - Schedule of Finite Lived Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 2,867	$ 2,867
Less: accumulated amortization	(2,816)	(2,765)
Intangible assets, net	51	102
Royalty receivable	6,000	7,000
Other	903	836
Total other non-current assets	6,903	7,836
Purchase technology-based intangible
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	2,358	2,358
Purchased patent
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 509	$ 509