Basis of Presentation, Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Summary of Fair Value Measurements, Recurring and Nonrecurring (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Assets included in:
Fair value	$ 36,766	$ 36,758
Liabilities included in:
Fair value		5,413
Preferred stock tranche rights liability [Member]
Liabilities included in:
Fair value		5,033
Preferred stock warrant liability [Member]
Liabilities included in:
Fair value		380
Cash and Cash Equivalents [Member] | Money Market Funds [Member]
Assets included in:
Fair value	36,766	36,758
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets included in:
Fair value	36,766	36,758
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Cash and Cash Equivalents [Member] | Money Market Funds [Member]
Assets included in:
Fair value	$ 36,766	36,758
Significant Unobservable Inputs (Level 3) [Member]
Liabilities included in:
Fair value		5,413
Significant Unobservable Inputs (Level 3) [Member] | Preferred stock tranche rights liability [Member]
Liabilities included in:
Fair value		5,033
Significant Unobservable Inputs (Level 3) [Member] | Preferred stock warrant liability [Member]
Liabilities included in:
Fair value		$ 380