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Stock-Based Compensation - Summary of Restricted Common Stock Units (Detail) - Restricted Stock Units [Member]
9 Months Ended
Sep. 30, 2021
$ / shares
shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Number of shares, Issued and unvested beginning balance | shares 1,198
Number of shares, Granted | shares 771,600
Number of shares, Vested | shares (431)
Number of shares, Forfeited, cancelled or expired | shares (63,342)
Number of shares, Issued and unvested ending balance | shares 709,025
Weighted average grant date fair value, Issued and unvested, beginning balance | $ / shares $ 15.65
Weighted average grant date fair value, Granted | $ / shares 9.63
Weighted average grant date fair value, Vested | $ / shares 15.65
Weighted average grant date fair value, Forfeited, canceled or expired | $ / shares 9.63
Weighted average grant date fair value, Issued and unvested, ending balance | $ / shares $ 9.64