Net Loss Per Share - Antidilutive (Details) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	5,262,690	1,921,974
Stock Options
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	2,250,080	1,867,458
Warrants assumed from Macrocure
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	54,516	54,516
Warrants issued with the Private Placement
Securities excluded from computation of diluted net loss per share
Anti-dilutive securities excluded from calculation of diluted net loss per share	2,958,094