Net Loss Per Share - Antidilutive (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	14,394,318	2,816,428
Options to purchase common stock
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	4,024,566	2,761,912
Warrants to purchase common stock
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	10,369,752	54,516
Restricted stock units
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	90,500