Fair Value Measurements - Summary of Significant Quantitative Inputs Used in the Valuation Of the Anti-Dilution Right (Detail) - Anti-dilution Right	Sep. 30, 2021
Volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Preferred stock tranche rights, measurement input, percent	1.25
Risk-free rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Preferred stock tranche rights, measurement input, percent	0.001
Risk-free rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Preferred stock tranche rights, measurement input, percent	0.000
Measurement Input, Discount Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Preferred stock tranche rights, measurement input, percent	0.475
Implied issuance price of Series B | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Preferred stock tranche rights, measurement input, percent	0.0611
Implied issuance price of Series B | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Preferred stock tranche rights, measurement input, percent	0.0084
Probability of settlement | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Preferred stock tranche rights, measurement input, percent	0.80
Probability of settlement | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Preferred stock tranche rights, measurement input, percent	0.10