Net Loss per Share - Anti-dilutive (Details) - shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Anti-dilutive securities
Anti-dilutive securities excluded from the calculation of net loss per share	3,625,931	2,911,838
Restricted common stock
Anti-dilutive securities
Anti-dilutive securities excluded from the calculation of net loss per share	126,646	480,663
Warrant
Anti-dilutive securities
Anti-dilutive securities excluded from the calculation of net loss per share	7,614	7,614
Stock options
Anti-dilutive securities
Anti-dilutive securities excluded from the calculation of net loss per share	3,491,671	2,423,561