XML 34 R23.htm IDEA: XBRL DOCUMENT v3.10.0.1
Note 7 - Marketable Securities (Tables)
 6 Months Ended
Jun. 30, 2018
Notes Tables  
Debt Securities, Held-to-maturity [Table Text Block]
       
   
June 30, 2018
  
(in thousands)
  
Cost
    
Unrealized
Gains
    
Unrealized
Losses
    
Fair Value
  
U.S. municipal securities
   $
18,013
     $
-
     $
(58
 )   $
17,955
  
Corporate debt securities
    
34,346
      
-
      
(157
 )    
34,189
  
U.S. government agency securities
    
24,674
      
-
      
(178
 )    
24,496
  
Certificates of deposit/time deposits
    
3,968
      
-
      
(38
 )    
3,930
  
Commercial paper
    
1,254
      
-
      
(0
 )    
1,254
  
Total marketable securities
   $
82,255
     $
-
     $
(431
 )   $
81,824
  
                                 
       
   
December 31, 2017
  
(in thousands)
  
Cost
    
Unrealized
Gains
    
Unrealized
Losses
    
Fair Value
  
U.S. municipal securities
   $
28,364
     $
-
     $
(104
 )   $
28,260
  
Corporate debt securities
    
29,806
      
-
      
(128
 )    
29,678
  
U.S. government agency securities
    
32,320
      
-
      
(199
 )    
32,121
  
Certificates of deposit/time deposits
    
3,968
      
-
      
(32
 )    
3,936
  
Total marketable securities
   $
94,458
     $
-
     $
(463
 )   $
93,995
  
                                 
Investments Classified by Contractual Maturity Date [Table Text Block]
       
   
June 30,
  
(in thousands)
  
2018
  
Due in one year or less
   $
57,619
  
Due after one year through five years
    
24,636
  
Total marketable securities
   $
82,255