Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.5.0.2
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
6 Months Ended
Jun. 30, 2016
Dec. 31, 2015
Product Information [Line Items]    
Cash and cash equivalents, maturity description 90 days or less  
Short-term contractual maturities 1 year  
Restricted cash $ 170,000 $ 170,000
Government Debt Securities [Member] | Maximum [Member]    
Product Information [Line Items]    
Marketable securities contractual maturities 1 year  
Corporate Debt Securities [Member] | Maximum [Member]    
Product Information [Line Items]    
Marketable securities contractual maturities 1 year  
Debt Securities [Member]    
Product Information [Line Items]    
Marketable investments continuous unrealized loss position $ 0 $ 0
Asset-backed Securities [Member] | Minimum [Member]    
Product Information [Line Items]    
Marketable securities contractual maturities 2 years  
Asset-backed Securities [Member] | Maximum [Member]    
Product Information [Line Items]    
Marketable securities contractual maturities 5 years