Annual report pursuant to Section 13 and 15(d)

Marketable Securities - Marketable Available-for-Sale Securities (Detail)

v3.3.1.900
Marketable Securities - Marketable Available-for-Sale Securities (Detail) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 33,795 $ 23,222
Gross Unrealized Gains   1
Gross Unrealized Losses (21) (14)
Estimated Fair Value 33,774 23,209
Government Debt Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 1,509  
Gross Unrealized Losses (2)  
Estimated Fair Value 1,507  
Corporate Debt Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 27,663 19,706
Gross Unrealized Gains   1
Gross Unrealized Losses (17) (14)
Estimated Fair Value 27,646 19,693
Asset-backed Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 4,623 3,516
Gross Unrealized Losses (2)  
Estimated Fair Value $ 4,621 $ 3,516