Net Loss Per Common Share - Schedule of Potentially Dilutive Securities Excluded from Diluted Net Loss Per Common Share (Details) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	1,928,586	1,692,014
Options to Purchase Common Stock
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	1,766,959	1,481,632
RSU
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	66,630
Common Stock Subject to Repurchase
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	67,307	182,692
Common Stock Warrants
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	27,690	27,690