Note 15 - Deferred Revenue and Contingent Liability (Tables)
 12 Months Ended
Dec. 31, 2015
Deferred Revenue Disclosure [Abstract]  
Deferred Revenue, by Arrangement, Disclosure [Table Text Block]
   

2015

    

2014

  

Beginning balance

   $ 17,867     $ 20,391  

Amortization

     (2,468

)

     (6,790

)

Additions

     3,365       4,283  

Impairment

     (176

)

     (17

)

Balance at December 31

   $ 18,588     $ 17,867