Operating Expenses by Nature - Summary of Depreciation Expense (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Disclosure Of Depreciation Expense [Line Items]      
Total depreciation $ 736 $ 721 $ 737
Research and development expenses [Member]      
Disclosure Of Depreciation Expense [Line Items]      
Total depreciation 441 447 429
General and administrative expenses [Member]      
Disclosure Of Depreciation Expense [Line Items]      
Total depreciation $ 295 $ 274 $ 308