Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Summary of Employee and Nonemployee Stock Option Activity (Detail)

v3.6.0.2
Stock-Based Compensation - Summary of Employee and Nonemployee Stock Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Options Outstanding, Number of Shares Outstanding      
Outstanding, beginning balance (shares) 1,961,000 1,839,000  
Granted (shares) 417,000 312,000  
Exercised (shares) 0 (4,000)  
Canceled or expired (shares) (180,000) (186,000)  
Outstanding, ending balance (shares) 2,198,000 1,961,000 1,839,000
Exercisable (shares) 1,343,000    
Options Outstanding, Weighted Average Exercise Price      
Outstanding, beginning balance (usd per share) $ 10.55 $ 10.58  
Granted (usd per share) 1.95 9.77  
Exercised (usd per share)   5.37  
Canceled or expired (usd per share) 8.44 9.69  
Outstanding, ending balance (usd per share) 9.09 $ 10.55 $ 10.58
Exercisable (usd per share) $ 10.18    
Weighted-Average Remaining Contractual Term (in years)      
Outstanding 7 years 15 days 7 years 8 months 5 days 8 years 5 months 27 days
Exercisable 6 years 1 month 17 days    
Aggregate Intrinsic Value      
Outstanding $ 0 $ 0 $ 618
Exercisable $ 0