Net Loss Per Common Share - Schedule of Potentially Dilutive Securities Excluded from Diluted Net Loss Per Common Share (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	1,596,695	1,747,718
Options to Purchase Common Stock
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	1,475,299	1,593,195
RSU
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	93,560	30,680
Common Stock Subject to Repurchase
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share		96,153
Common Stock Warrants
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	27,836	27,690