Summary of Significant Accounting Policies - Basic and Diluted Loss Per Common Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock options
Anti-dilutive securities
Outstanding securities not included in the computation of diluted net loss per common share as their inclusion would be anti-dilutive (in shares)	2,301,574	1,837,540	1,461,987
Unvested restricted common stock
Anti-dilutive securities
Outstanding securities not included in the computation of diluted net loss per common share as their inclusion would be anti-dilutive (in shares)	0	0	0
Preferred Stock
Anti-dilutive securities
Outstanding securities not included in the computation of diluted net loss per common share as their inclusion would be anti-dilutive (in shares)	1,969,797	1,969,797	1,969,797