Summary of Significant Accounting Policies - Potentially dilutive securities (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Potentially dilutive securities
Potentially dilutive securities excluded from computation of diluted weighted average shares	1,958,037	1,586,946	1,510,253
Stock Options
Potentially dilutive securities
Potentially dilutive securities excluded from computation of diluted weighted average shares	1,706,438	1,498,390	1,421,697
Restricted stock units
Potentially dilutive securities
Potentially dilutive securities excluded from computation of diluted weighted average shares	163,043
Common Stock Warrants
Potentially dilutive securities
Potentially dilutive securities excluded from computation of diluted weighted average shares	88,556	88,556	88,556