Note 11 - Convertible Preferred Stock, Net (Details Textual) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 2 Months Ended 12 Months Ended
Mar. 12, 2015
Feb. 11, 2015
Feb. 05, 2015
Oct. 30, 2015
Dec. 31, 2016
Dec. 31, 2016
Nov. 03, 2016
Dec. 31, 2015
Dec. 31, 2014
Convertible Preferred Stock, Pro Rata Share     $ 65,500            
Rights Offering, Right to Purchase Preferred Stock, Price Per Share     $ 100            
Common Stock, Par or Stated Value Per Share         $ 0.001 $ 0.001   $ 0.001  
Conversion Price     $ 39.88            
Registered Rights Offering, Convertible Preferred Stock, Value     $ 65,500            
Treasury Stock, Value, Acquired, Cost Method       $ 29,000 $ 12,377 $ 70,248 $ 62,981 $ 34,111  
Payments of Ordinary Dividends, Preferred Stock and Preference Stock           4,419   3,928
Common Stock [Member]                  
Treasury Stock, Value, Acquired, Cost Method              
Preferred Stock, Conversion Rate per Share of Common Stock     $ 2.51            
Conversion of Stock, Shares Converted                 222,532
Convertible Preferred Stock, Shares Issued upon Conversion         300 300   3,715  
Convertible Preferred Stock Shares Issuable Upon Conversion         2,014,538 2,014,538   2,014,840  
Convertible Preferred Stock [Member]                  
Temporary Equity, Shares Issued         803,398 803,398   803,518  
Conversion of Stock, Shares Converted           1,602      
Convertible Preferred Stock, Shares Issued upon Conversion         4,015 4,015      
Payments of Ordinary Dividends, Preferred Stock and Preference Stock           $ 4,419   $ 3,928  
Convertible Preferred Stock [Member] | Cash Dividends [Member]                  
Preferred Stock, Dividend Rate, Percentage   5.50%       5.50%   8.50%  
Convertible Preferred Stock [Member] | Paid-in-kind Dividends [Member]                  
Preferred Stock, Dividend Rate, Percentage   8.50%              
Non-Standby Purchasers [Member] | Convertible Preferred Stock [Member]                  
Temporary Equity, Shares Issued     130,884            
The Standby Purchasers [Member] | Convertible Preferred Stock [Member]                  
Rights Offering, Right to Purchase Preferred Stock, Price Per Share $ 105   $ 100            
Temporary Equity, Shares Issued 150,000   524,116            
Treasury Stock, Value, Acquired, Cost Method $ 15,750