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Fair Value Measurements - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Jul. 20, 2021
Jul. 19, 2021
Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]              
Warrant liability         $ 0 $ 5,517,000 $ 1,309,000
Level 3 | Warrant units              
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]              
Warrant expense $ 888,000 $ 0 $ 4,208,000 $ 0