Note 8 - Patents and Trademarks, Net (Tables)
 12 Months Ended
Dec. 31, 2016
Notes Tables  
Schedule of Finite-Lived Intangible Assets [Table Text Block]
 
 
December 31,
 
 
 
2016
 
 
2015
 
                 
Purchased and licensed patent rights
   $
566
    $
566
 
Internally developed patents
    
1,686
     
1,664
 
Trademarks
    
148
     
148
 
Total
    
2,400
     
2,378
 
Accumulated amortization
   $
(1,906
 )   $
(1,808
 )
Total intangible assets, net
   $
494
    $
570
 
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]
December 31,
Aggregate Amortization Expense
  
2017
   $
86
 
2018
    
86
 
2019
    
84
 
2020
    
81
 
2021
    
56
 
Thereafter
    
101
 
    $
494
 
Finite-lived Intangible Assets, Accumulated Amortization [Table Text Block]
 
 
December 31,
 
 
 
2016
 
 
2015
 
                 
Purchased and licensed patent rights
   $
(534
 )   $
(517
 )
Internally developed patents
    
(1,253
 )    
(1,177
 )
Trademarks
    
(119
 )    
(114
 )
Total
   $
(1,906
 )   $
(1,808
 )
Finite-lived Intangible Assets, Weighted Average Amortization Periods [Table Text Block]
 
 
December 31,
 
 
 
2016
 
 
2015
 
                 
Purchased and licensed patent rights
    
17
     
17
 
Internally developed patents
    
17
     
17
 
Trademarks
    
10
     
10