Note 10 - Promissory Notes (Tables)
 12 Months Ended
Dec. 31, 2014
Debt Disclosure [Abstract]  
Schedule of Maturities of Long-term Debt [Table Text Block]
 

Year 1

  $ 735  
 

Year 2

    1,887  
 

Year 3

    2,074  
 

Year 4

    1,604  
 

Total

  $ 6,300  
Contractual Interest Expense and Amortization of Debt Issuance Costs and Debt Discount [Table Text Block]
   

For the Years Ended December 31,

 
   

2014

   

2013

   

2012

 

Stated interest

  $ 500     $ 840     $ 1,325  

Amortization of debt discount

    188       380       509  

Amortization of promissory notes issuance costs

    38       108       155  
    $ 726     $ 1,328     $ 1,989