Quarterly report pursuant to Section 13 or 15(d)

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

v3.5.0.2
Stock-Based Compensation - Summary of Employee and Nonemployee Stock Option Activity (Detail) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 9 Months Ended 12 Months Ended
Oct. 11, 2016
Oct. 31, 2016
Sep. 30, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares granted (in shares)     304,000  
Options Outstanding, Number of Shares Outstanding        
Outstanding, beginning balance (in shares)   2,128,000 1,961,000  
Shares granted (in shares)     304,000  
Canceled or expired (in shares)     (137,000)  
Outstanding, ending balance (in shares)     2,128,000 1,961,000
Exercisable (in shares)     1,250,000  
Options Outstanding, Weighted-Average Exercise Price        
Outstanding, beginning balance (usd per share)   $ 9.44 $ 10.55  
Shares granted (usd per share)     2.01  
Cancelled or expired (usd per share)     8.78  
Outstanding, ending balance (usd per share)     9.44 $ 10.55
Exercisable (usd per share)     $ 10.35  
Weighted-Average Remaining Contractual Term (in years)        
Outstanding     7 years 2 months 5 days 7 years 8 months 5 days
Exercisable     6 years 2 months 27 days  
Aggregate Intrinsic Value        
Outstanding, beginning balance   $ 0 $ 0  
Outstanding, ending balance     0 $ 0
Exercisable     $ 0  
Subsequent Event        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares granted (in shares)   43,000    
Options granted in period, grant date intrinsic value (in dollars per share)   $ 1.70    
Options Outstanding, Number of Shares Outstanding        
Shares granted (in shares)   43,000    
Subsequent Event | Restricted shares of common stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Restricted stock units awarded to each non-employee director (in shares) 2,500      
Options granted during period to each non-employee director (in shares) 10,000