Net Loss Per Common Share - Schedule of Potentially Dilutive Securities Excluded from Diluted Net Loss Per Common Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	1,851,569	1,450,201	1,851,569	1,450,201
Options to Purchase Common Stock
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	1,696,187	1,268,665	1,696,187	1,268,665
RSU
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	89,230		89,230
Common Stock Subject to Repurchase
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	38,462	153,846	38,462	153,846
Common Stock Warrants
Antidilutive Securities
Potentially dilutive securities excluded from diluted net loss per common share	27,690	27,690	27,690	27,690