Segment Information and Foreign Operations - Segment and Geographical Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment Information and Foreign Operations
Number of operating segments | segment			1
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	$ 23,645	$ 17,366	$ 74,256	$ 55,366
Long-lived assets by geographic region, net of depreciation:
Long-lived assets	168,910		168,910		$ 169,147
CHINA
Long-lived assets by geographic region, net of depreciation:
Long-lived assets	167,487		167,487		167,516
North America (primarily the United States)
Long-lived assets by geographic region, net of depreciation:
Long-lived assets	1,423		1,423		$ 1,631
Reportable Geographical Components [Member]
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	23,645	17,366	74,256	55,366
Reportable Geographical Components [Member] | CHINA
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	13,807	10,307	42,271	28,698
Reportable Geographical Components [Member] | TAIWAN
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	2,140	2,491	10,142	6,369
Reportable Geographical Components [Member] | JAPAN
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	1,623	558	3,409	3,489
Reportable Geographical Components [Member] | Asia Pacific (excluding China, Taiwan and Japan)
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	797	894	2,307	2,722
Reportable Geographical Components [Member] | Europe (primarily Germany)
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	2,720	2,407	11,134	8,992
Reportable Geographical Components [Member] | North America (primarily the United States)
Geographic Areas, Revenues from External Customers [Abstract]
Revenue	$ 2,558	$ 709	$ 4,993	$ 5,096