Quarterly report pursuant to Section 13 or 15(d)

Marketable Securities and Fair Value - Additional Information (Detail)

v3.5.0.2
Marketable Securities and Fair Value - Additional Information (Detail) - USD ($)
shares in Millions
6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Schedule Of Available For Sale Securities [Line Items]      
Realized gain or losses $ 0 $ 0  
Weighted average maturity for available for sale securities 3 months 6 days    
February 2015 Warrants      
Schedule Of Available For Sale Securities [Line Items]      
Warrants to purchase shares of common stock 8.3   8.3
Maximum      
Schedule Of Available For Sale Securities [Line Items]      
Available for sale securities, longest maturity date 2017-06