Note 8 - Derivatives Instruments and Hedging Activities (Details) - Fair Value Of Derivative Instruments Not Designated As Hedging Instruments (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
TBA Securities [Member]
    
Note 8 - Derivatives Instruments and Hedging Activities (Details) - Fair Value Of Derivative Instruments Not Designated As Hedging Instruments [Line Items]    
Derivatives Not Designated As Hedging Instruments - Assets $ 190,742 [1] $ 244,789 [1]
US Treasury Futures [Member]
    
Note 8 - Derivatives Instruments and Hedging Activities (Details) - Fair Value Of Derivative Instruments Not Designated As Hedging Instruments [Line Items]    
Derivatives Not Designated As Hedging Instruments - Assets 3,257 676
Swaption [Member]
    
Note 8 - Derivatives Instruments and Hedging Activities (Details) - Fair Value Of Derivative Instruments Not Designated As Hedging Instruments [Line Items]    
Derivatives Not Designated As Hedging Instruments - Assets 1,305 597
Interest Rate Swap [Member]
    
Note 8 - Derivatives Instruments and Hedging Activities (Details) - Fair Value Of Derivative Instruments Not Designated As Hedging Instruments [Line Items]    
Derivatives Not Designated As Hedging Instruments - Assets 238 8
Options on U.S. Treasury Futures [Member]
    
Note 8 - Derivatives Instruments and Hedging Activities (Details) - Fair Value Of Derivative Instruments Not Designated As Hedging Instruments [Line Items]    
Derivatives Not Designated As Hedging Instruments - Assets 7 59
Eurodollar Future [Member]
    
Note 8 - Derivatives Instruments and Hedging Activities (Details) - Fair Value Of Derivative Instruments Not Designated As Hedging Instruments [Line Items]    
Eurodollar futures $ 1,432 $ 3,798
[1] Open TBA purchases and sales involving the same counterparty, same underlying deliverable and the same settlement date are reflected in our accompanying consolidated financial statements on a net basis. TBA sales amounting to $0 million and $245.6 million have been netted against TBA purchases and are included in payable for securities purchased in the accompanying consolidated balance sheets at December 31, 2013 and December 31, 2012, respectively.