Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Stock-based compensation
Vesting of early exercised options (in shares)	21,149		53,741
Unvested early exercises of stock options	$ 0.1		$ 0.2
Future awards under the 2021 Employee Stock Purchase Plan
Stock-based compensation
Stock authorized for issuance (in shares)	861,286		563,115
Stock options to purchase common stock
Stock-based compensation
Weighted-average grant-date fair value of stock options granted (in dollars per share)	$ 9.19	$ 7.26
Unrecognized compensation cost	$ 23.8
Unrecognized compensation cost, weighted-average period for recognition	2 years 4 months 24 days
Restricted Stock
Stock-based compensation
Unrecognized compensation cost	$ 14.9
Unrecognized compensation cost, weighted-average period for recognition	3 years 3 months 18 days
Future awards under the 2021 Stock Option and Incentive Plan
Stock-based compensation
Stock authorized for issuance (in shares)	6,368,021		5,262,917
2016 Stock Plan
Stock-based compensation
Stock authorized for issuance (in shares)	2,081,561		2,206,655