Net Loss Per Share - Summary of Anti-Dilutive Common Stock Equivalents Outstanding (Detail) - shares |
3 Months Ended | 6 Months Ended | ||
---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
Anti-dilutive common stock equivalents | 6,229,126 | 5,352,918 | 6,229,126 | 5,352,918 |
Stock Options [Member] | ||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
Anti-dilutive common stock equivalents | 6,207,172 | 5,313,821 | 6,207,172 | 5,313,821 |
Restricted Stock Units [Member] | ||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
Anti-dilutive common stock equivalents | 13,950 | 30,400 | 13,950 | 30,400 |
Employee Stock Purchase Plan [Member] | ||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
Anti-dilutive common stock equivalents | 8,004 | 8,697 | 8,004 | 8,697 |