Segment Information and Foreign Operations - Segment and Geographical Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment Information and Foreign Operations
Number of operating segments | segment			1
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	$ 27,923	$ 18,595	$ 50,611	$ 38,000
Long-lived assets by geographic region, net of depreciation:
Long-lived assets	163,863		163,863		$ 169,147
CHINA
Long-lived assets by geographic region, net of depreciation:
Long-lived assets	162,370		162,370		167,516
North America (primarily the United States)
Long-lived assets by geographic region, net of depreciation:
Long-lived assets	1,493		1,493		$ 1,631
Reportable Geographical Components [Member]
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	27,923	18,595	50,611	38,000
Reportable Geographical Components [Member] | CHINA
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	16,947	10,289	28,464	18,391
Reportable Geographical Components [Member] | TAIWAN
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	3,420	1,407	8,002	3,878
Reportable Geographical Components [Member] | JAPAN
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	796	1,396	1,786	2,931
Reportable Geographical Components [Member] | Asia Pacific (excluding China, Taiwan and Japan)
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	712	737	1,510	1,828
Reportable Geographical Components [Member] | Europe (primarily Germany)
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	4,689	3,015	8,414	6,585
Reportable Geographical Components [Member] | North America (primarily the United States)
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	$ 1,359	$ 1,751	$ 2,435	$ 4,387