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Balance Sheet Items - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Disclosure Of Balance Sheet Items [Abstract]        
Depreciation $ 86 $ 80 $ 165 $ 174