Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale $ 912,443 $ 1,034,711
Derivative liabilities 1,432 5,542
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale 876,874 1,001,239
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale 876,874 1,001,239
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Fair Value, Inputs, Level 2 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale 2,361 2,687
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale 2,361 2,687
Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale 33,208 30,785
Collateralized Debt Obligations [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale 33,208 30,785
Collateralized Mortgage Backed Securities Held In Securitization Trusts [Member] | Fair Value, Inputs, Level 3 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale 92,578 71,159
Collateralized Mortgage Backed Securities Held In Securitization Trusts [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale 92,578 71,159
TBA Securities [Member] | Fair Value, Inputs, Level 2 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 190,742 244,789
TBA Securities [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 190,742 244,789
US Treasury Futures Options [Member] | Fair Value, Inputs, Level 1 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 7  
US Treasury Futures Options [Member] | Fair Value, Inputs, Level 2 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets   59
US Treasury Futures Options [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 7 59
US Treasury Futures [Member] | Fair Value, Inputs, Level 1 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 3,257 676
US Treasury Futures [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 3,257 676
Future [Member] | Fair Value, Inputs, Level 1 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 238 8
Future [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 238 8
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 2,041  
Derivative liabilities   1,744
Interest Rate Swap [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 2,041  
Derivative liabilities   1,744
Swaption [Member] | Fair Value, Inputs, Level 2 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 1,305 597
Swaption [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative assets 1,305 597
Eurodollar Future [Member] | Fair Value, Inputs, Level 1 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative liabilities 1,432 3,798
Eurodollar Future [Member] | Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Derivative liabilities 1,432 3,798
Fair Value, Inputs, Level 1 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Total 3,502 684
Total 1,432 3,798
Fair Value, Inputs, Level 2 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Investment Securities Available for Sale 912,443 1,034,711
Total 1,106,531 1,280,156
Total   1,744
Fair Value, Inputs, Level 3 [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Multi-family loans held in securitization trusts 8,111,022 5,442,906
Total 8,203,600 5,514,065
Multi-family collateralized debt obligations 7,871,020 5,319,573
Total 7,871,020 5,319,573
Estimate of Fair Value Measurement [Member]
   
Note 13 - Fair Value of Financial Instruments (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Line Items]    
Multi-family loans held in securitization trusts 8,111,022 5,442,906
Total 9,313,633 6,794,905
Multi-family collateralized debt obligations 7,871,020 5,319,573
Total $ 7,872,452 $ 5,325,115