Fair Value Measurements - Summary of Issuances, Exercises, Changes in Fair Value and Reclassifications of Level 3 Financial Instruments (Detail) - Common Stock Warrants Liability - (Level 3) - Common Stock Warrant Liability $ in Thousands	9 Months Ended
	Sep. 30, 2021 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 447
Exercise of warrants	(202)
Change in estimated fair value	(50)
Ending balance	$ 195