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Supplemental Financial Statement Information - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2021
Jun. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]          
Depreciation and amortization expense $ 278,000   $ 363,000 $ 965,000 $ 1,200,000
Contractual settlement of upside payment received   $ 2,500,000