Note 12 - Income Taxes (Details Textual) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent                 35.00% 35.00% 35.00%
Deferred Tax Assets, Net $ 25,722       $ 28,971       $ 25,722 $ 28,971  
Net Income (Loss) Attributable to Parent 5,289 $ 6,368 $ 5,550 $ 2,741 3,776 $ 4,778 $ 4,269 $ 3,783 $ 19,948 16,606 $ 12,889
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent                 (3.00%)    
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]                      
Operating Loss Carryforwards 14,200       24,800       $ 14,200 24,800  
State and Local Jurisdiction [Member]                      
Operating Loss Carryforwards $ 19,700       $ 37,400       $ 19,700 $ 37,400