Annual report pursuant to Section 13 and 15(d)

Other Balance Sheet Details - Investment categories (Details)

v3.6.0.2
Other Balance Sheet Details - Investment categories (Details) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Short-term investments    
Schedule of Available-for-sale Securities [Line Items]    
Cost $ 120,758 $ 97,891
Gross unrealized gains 1,564 4,944
Gross unrealized losses (26) (44)
Estimated fair value 122,296 102,791
Bank Deposits    
Schedule of Available-for-sale Securities [Line Items]    
Cost 40,715 43,043
Gross unrealized gains 19 0
Gross unrealized losses 0 (4)
Estimated fair value 40,734 43,039
Corporate Bonds    
Schedule of Available-for-sale Securities [Line Items]    
Cost 11,031 41,238
Gross unrealized gains 0 0
Gross unrealized losses (5) (35)
Estimated fair value 11,026 41,203
Corporate Equity Securities    
Schedule of Available-for-sale Securities [Line Items]    
Cost 1,512 1,843
Gross unrealized gains 1,542 4,944
Gross unrealized losses 0 0
Estimated fair value 3,054 6,787
Commercial Paper    
Schedule of Available-for-sale Securities [Line Items]    
Cost 33,074 1,747
Gross unrealized gains 2 0
Gross unrealized losses (9) 0
Estimated fair value 33,067 1,747
Agency bonds    
Schedule of Available-for-sale Securities [Line Items]    
Cost 7,294  
Gross unrealized gains 1  
Gross unrealized losses 0  
Estimated fair value 7,295  
U.S. Government bonds    
Schedule of Available-for-sale Securities [Line Items]    
Cost 7,508  
Gross unrealized gains 0  
Gross unrealized losses (1)  
Estimated fair value 7,507  
Asset-backed Securities    
Schedule of Available-for-sale Securities [Line Items]    
Cost   10,020
Gross unrealized gains   0
Gross unrealized losses   (5)
Estimated fair value   $ 10,015
Municipal bonds    
Schedule of Available-for-sale Securities [Line Items]    
Cost 19,624  
Gross unrealized gains 0  
Gross unrealized losses (11)  
Estimated fair value $ 19,613