Segment Information and Foreign Operations - Segment and Geographical Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Segment Information and Foreign Operations
Number of operating segments | segment	1
Net revenues reported for products shipped to customers in corresponding geographic region
Revenue	$ 75,795	$ 141,118	$ 137,393
Long-lived assets by geographic region, net of depreciation:
Long-lived assets	169,147	162,778
China
Long-lived assets by geographic region, net of depreciation:
Long-lived assets	167,516	162,432
North America (primarily the United States)
Long-lived assets by geographic region, net of depreciation:
Long-lived assets	1,631	346
Reportable Geographical Components
Net revenues reported for products shipped to customers in corresponding geographic region
Revenue	75,795	141,118	137,393
Reportable Geographical Components | China
Net revenues reported for products shipped to customers in corresponding geographic region
Revenue	39,778	55,414	67,394
Reportable Geographical Components | Taiwan
Net revenues reported for products shipped to customers in corresponding geographic region
Revenue	8,651	28,780	16,841
Reportable Geographical Components | Japan
Net revenues reported for products shipped to customers in corresponding geographic region
Revenue	4,641	11,724	10,112
Reportable Geographical Components | Asia Pacific (excluding China, Taiwan and Japan)
Net revenues reported for products shipped to customers in corresponding geographic region
Revenue	3,814	4,188	7,540
Reportable Geographical Components | Europe (primarily Germany)
Net revenues reported for products shipped to customers in corresponding geographic region
Revenue	12,315	20,592	23,069
Reportable Geographical Components | North America (primarily the United States)
Net revenues reported for products shipped to customers in corresponding geographic region
Revenue	$ 6,596	$ 20,420	$ 12,437