Note 8 - Derivatives Instruments and Hedging Activities (Tables)
12 Months Ended
Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]

Derivatives Not Designated

as Hedging Instruments

 

Balance Sheet Location

 

December 31,

2013

   

December 31,

2012

 

TBA securities (1)

 

Derivative assets

  $ 190,742     $ 244,789  

U.S. Treasury futures

 

Derivative assets

    3,257       676  

Swaptions

 

Derivative assets

    1,305       597  

Interest rate swap futures

 

Derivative assets

    238       8  

Options on U.S. Treasury futures

 

Derivative assets

    7       59  

Eurodollar futures

 

Derivative liabilities

    1,432       3,798  
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]
   

Notional Amount For the Year Ended December 31, 2013

 

Derivatives Not Designated

as Hedging Instruments

 

December 31, 2012

   

Additions

   

Settlement, Expiration

or Exercise

   

December 31, 2013

 

TBA securities

  $ 234,000     $ 2,563,000     $ (2,609,000

)

  $ 188,000  

U.S. Treasury futures

    (172,100

)

    875,600       (715,400

)

    (11,900

)

Interest rate swap futures

    (13,000

)

    542,700       (772,400

)

    (242,700

)

Eurodollar futures

    (2,852,000

)

    3,492,000       (4,000,000

)

    (3,360,000

)

Options on U.S. Treasury futures

    70,000       310,000       (340,000

)

    40,000  

Swaptions

    100,000                   100,000  
   

Notional Amount For the Year Ended December 31, 2012

 

Derivatives Not Designated

as Hedging Instruments

 

December 31, 2011

   

Additions

   

Settlement, Expiration

or Exercise

   

December 31, 2012

 

TBA securities

  $ 202,000     $ 3,088,000     $ (3,056,000

)

  $ 234,000  

U.S. Treasury futures

    (92,800

)

    1,142,100       (1,221,400

)

    (172,100

)

Interest rate swap futures

          6,000       (19,000

)

    (13,000

)

Eurodollar futures

    (2,422,000

)

    1,531,000       (1,961,000

)

    (2,852,000

)

Options on U.S. Treasury futures

    199,500       1,181,500       (1,311,000

)

    70,000  

Swaptions

          100,000             100,000  
Schedule of Components of Realized and Unrealized Gains and Losses To Derivative Not Designated as Hedging Instruments [Table Text Block]
   

Years Ended December 31,

 
   

2013

   

2012

   

2011

 
   

Realized Gains (Losses)

   

Unrealized Gains (Losses)

   

Realized Gains (Losses)

   

Unrealized Gains (Losses)

   

Realized Gains (Losses)

   

Unrealized Gains (Losses)

 

TBA

  $ (12,393

)

   $ (629

)

   $ 16,397      $ (1,347

)

   $ 2,886      $ 1,363  

Eurodollar Futures (1)

    (3,591

)

    2,366       (1,042

)

    (2,049

)

    (1,986

)

    (1,749

)

Swaptions

          1,153             (268

)

           

U.S. Treasury and Interest rate swap futures and options

    5,418       2,866       (9,548

)

    1,300       (197

)

    (740

)

Total

  $ (10,566

)

   $ 5,756      $ 5,807      $ (2,364

)

   $ 703      $ (1,126

)

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

Derivatives Designated

as Hedging Instruments

 

Balance Sheet Location

 

December 31,

2013

   

December 31,

2012

 

Interest Rate Swaps

 

Derivative assets

  $ 2,041     $  

Interest Rate Swaps

 

Derivative liabilities

  $     $ 1,744  
Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block]
   

Years Ended December 31,

 

Derivatives Designated as Hedging Instruments

 

2013

   

2012

   

2011

 

Accumulated other comprehensive income (loss) for derivative instruments:

                       

Balance at beginning of the period

  $ (1,744

)

  $ (304

)

  $ (1,087

)

Unrealized (loss) gain on interest rate swaps

    3,785       (1,440

)

    783  

Balance at end of the period

  $ 2,041     $ (1,744

)

  $ (304

)

Schedule of Interest Rate Derivatives [Table Text Block]
   

Years Ended December 31,

 
   

2013

   

2012

   

2011

 

Interest Rate Swaps:

                       

Interest expense-investment securities

  $ 1,737     $ 810     $ 893  
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]
   

December 31, 2013

   

December 31, 2012

 

Maturity (1)

 

Notional

Amount

   

Weighted Average

Fixed Pay

Interest Rate

   

Notional

Amount

   

Weighted Average

Fixed Pay

Interest Rate

 

Within 30 Days

  $      

%

  $ 8,380       2.93

%

Over 30 days to 3 months

                       

Over 3 months to 6 months

                       

Over 6 months to 12 months

                       

Over 12 months to 24 months

    135,000       0.45              

Over 24 months to 36 months

                135,000       0.45  

Over 36 months to 48 months

    215,000       0.83              

Over 48 months to 60 months

                215,000       0.83  

Total

  $ 350,000       0.69

%

  $ 358,380       0.74

%