Note 13 - Fair Value of Financial Instruments (Details) - Carrying Value and Estimated Fair Value of the Company’s Financial Assets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013		Sep. 30, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 28,513		$ 31,798		$ 20,509	$ 31,777
Investment securities available for sale (3)	892,251		912,443
Investment securities available for sale, at fair value held in securitization trusts	38,379		92,578
Loans receivable - carrying amount	152,902		163,237
Derivative assets	217,324		197,590
Financing arrangements, portfolio investments	627,881		791,125
Financing arrangements, portfolio investments	627,881		791,125
Derivative liabilities	419		1,432
Subordinated debentures	45,000		45,000
Residential Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing arrangements	148,298		158,410
Financing arrangements	136,937		151,910
Residential Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing arrangements	148,298		158,410
Multi-Family Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing arrangements	8,005,013		7,871,020
Financing arrangements	8,005,013		7,871,020
Multi-Family Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing arrangements	8,005,013		7,871,020
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	28,513		31,798
Cash and cash equivalents	28,513		31,798
Payable for securities purchased	215,417		191,592
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale (3)	892,251	[1]	912,443	[1]
Financing arrangements, portfolio investments	627,881		791,125
Financing arrangements, portfolio investments	627,881		791,125
Fair Value, Inputs, Level 3 [Member] | Residential Mortgage Loans Held in Securitization Trusts, Net [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable - carrying amount	152,902		163,237
Loans receivable - fair value	139,936		152,104
Fair Value, Inputs, Level 3 [Member] | Distressed Residential Mortgage Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable - carrying amount	262,980	[2]	264,434	[2]
Loans receivable - fair value	280,055	[2]	254,543	[2]
Fair Value, Inputs, Level 3 [Member] | Multi-Family Loans Held in Securitization Trusts, Net [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans receivable - carrying amount	8,303,169		8,111,022
Loans receivable - fair value	8,303,169		8,111,022
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities available for sale, at fair value held in securitization trusts	38,379		92,578
Mortgage loans held for sale (net) (2)	2,486	[3]	2,496	[3]
Mortgage loans held for sale (net) (2)	2,481	[3]	2,595	[3]
First mortgage loans (2)	9,529	[3]	8,249	[3]
First mortgage loans (2)	9,745	[3]	8,318	[3]
Mezzanine loan and equity investments (2)	29,557	[3]	21,568	[3]
Mezzanine loan and equity investments (2)	29,557	[3]	21,568	[3]
Financing arrangements	237,413		304,964
Financing arrangements	247,658		311,535
Subordinated debentures	45,000		45,000
Subordinated debentures	37,342		39,310
Fair Value Inputs Level 1 and Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	217,234		197,590
Derivative assets	217,324		197,590
Derivative liabilities	$ 419		$ 1,432

[1] Includes $46.0 million of CMBS securities classified as level 3.

[2] Includes distressed residential mortgage loans held in securitization trusts with a carrying value amounting to approximately $247.2 million and $254.7 million at September 30, 2014 and December 31, 2013, respectively. Distressed residential mortgage loans with a carrying value amounting to approximately $15.8 million and $9.7 million are included in receivables and other assets in the accompanying condensed consolidated balance sheets at September 30, 2014 and December 31, 2013, respectively.

[3] Included in receivables and other assets in the accompanying condensed consolidated balance sheets.