Prepayments and Other Current Assets - Schedule of Prepayments (Details) - USD ($)
$ in Thousands
Dec. 31, 2021
Dec. 31, 2020
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]    
Prepayments $ 2,820 $ 1,772
Interest receivables 2,674 1,446
VAT recoverable 1,806 1,353
Employee loans and advances 888 2,186
Proceeds receivable for employee share option exercises 329 612
Restricted cash 130 80
Others 154 10
Prepayments and other current assets $ 8,801 $ 7,459