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The Company and Summary of Significant Accounting Policies - Impairment of Investments (Details) - USD ($)
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]      
Impairment charge $ 0 $ 0 $ 0
Investments, equity method $ 14,607,000 $ 10,166,000  
Xilingol Tongli Germanium Co. Ltd Investment      
Schedule of Equity Method Investments [Line Items]      
Ownership (as a percent) 25.00%