XML 42 R28.htm IDEA: XBRL DOCUMENT v3.10.0.1
Note 5 - Fair Value Measurements (Tables)
 12 Months Ended
Dec. 31, 2018
Notes Tables  
Fair Value, Assets Measured on Recurring Basis [Table Text Block]
        Fair Value Measurements at Reporting Date Using    
    December 31, 2018   Quoted Prices in
Active Markets
 for Identical Assets 
 (Level 1)		   Significant Other
 Observable Inputs 
 (Level 2)		   Significant 
 Unobservable Inputs 
 (Level 3)		   Amortized Cost
Cash equivalents:                                        
Money Market Funds   $
4,984
     $
4,984
     $
-
     $
-
     $
4,984
  
                                         
Investments:                                        
U.S. treasury bills   $
69,972
     $
69,972
     $
-
     $
-
     $
69,972
  
        Fair Value Measurements at Reporting Date Using    
    December 31, 2017   Quoted Prices in
Active Markets
 for Identical Assets 
 (Level 1)		   Significant Other
 Observable Inputs 
 (Level 2)		   Significant 
 Unobservable Inputs 
 (Level 3)		   Amortized Cost
Cash equivalents:                                        
Money market funds   $
5,893
     $
5,893
     $
-
     $
-
     $
5,893
  
Bank certificates of deposit    
500
      
-
      
500
      
-
      
500
  
Total cash equivalents   $
6,393
     $
5,893
     $
500
     $
-
     $
6,393
  
                                         
Investments:                                        
Bank certificates of deposit   $
24,000
     $
-
     $
24,000
     $
-
     $
24,000