Summary of Significant Accounting Policies - Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net loss per share
Potentially dilutive common shares not been included in net loss per common share calculations because the effect would have been anti-dilutive	3,042,229	1,700,312	869,684
Stock options
Net loss per share
Potentially dilutive common shares not been included in net loss per common share calculations because the effect would have been anti-dilutive	3,042,229	1,699,202	866,132
Restricted Stock
Net loss per share
Potentially dilutive common shares not been included in net loss per common share calculations because the effect would have been anti-dilutive		1,110	3,552