Note 9 - Income Taxes (Details) - USD ($) $ in Thousands  | 
3 Months Ended | |
|---|---|---|
Mar. 31, 2016  | 
Mar. 31, 2015  | 
|
| Provision (benefit) for income tax | $ 9 | $ (73) | 
| Effective income tax rate | 0.20% | 1.00% | 
| X | ||||||||||
- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
| X | ||||||||||
- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  |