Summary of Significant Accounting Policies - Basic and Diluted Loss Per Common Share (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
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)	1,461,987	1,132,618	976,777
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)		52,063	104,127
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