Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Anti-Dilutive Securities Excluded from the Computation of Diluted Net Loss per Share (Detail)

v3.10.0.1
Summary of Significant Accounting Policies - Anti-Dilutive Securities Excluded from the Computation of Diluted Net Loss per Share (Detail) - shares
shares in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive securities excluded from the computation of diluted loss per share 5,723 5,947 4,627
Common Stock Warrants [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive securities excluded from the computation of diluted loss per share   1,461 1,667
Common Stock Options [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive securities excluded from the computation of diluted loss per share 5,593 4,356 2,721
Incentive Awards [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive securities excluded from the computation of diluted loss per share 130 130 239