Annual report pursuant to Section 13 and 15(d)

Marketable Securities - Additional Information (Detail)

v3.6.0.2
Marketable Securities - Additional Information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Government Debt Securities [Member] | Minimum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Marketable securities contractual maturities 1 year  
Government Debt Securities [Member] | Maximum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Marketable securities contractual maturities   2 years
Corporate Debt Securities [Member] | Minimum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Marketable securities contractual maturities 1 year  
Corporate Debt Securities [Member] | Maximum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Marketable securities contractual maturities   2 years
Debt Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Marketable investments continuous unrealized loss position $ 0 $ 0
Commercial Paper [Member] | Minimum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Marketable securities contractual maturities 1 year  
Commercial Paper [Member] | Maximum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Marketable securities contractual maturities   2 years
Asset-backed Securities [Member] | Minimum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Marketable securities contractual maturities 2 years  
Asset-backed Securities [Member] | Maximum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Marketable securities contractual maturities   5 years