Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Summary of Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share (Detail)

v3.19.3
Summary of Significant Accounting Policies - Summary of Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share (Detail) - shares
shares in Thousands
9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Outstanding potentially dilutive securities 3,647 8,059
ESPP shares pending issuance [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Outstanding potentially dilutive securities 0 18
Warrants to purchase common stock [Member] | Common Stock [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Outstanding potentially dilutive securities 13 13
Common stock options issued and outstanding [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Outstanding potentially dilutive securities 2,094 5,370
RSUs outstanding [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Outstanding potentially dilutive securities 1,540 0
Shares issuable upon conversion of convertible note payable [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Outstanding potentially dilutive securities 0 2,658