Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash Flows from Operating Activities:
Net income	$ 94,215,000	$ 45,668,000
Adjustments to reconcile net income to net cash provided by operating activities:
Net amortization/accretion	(2,883,000)	13,077,000
Realized (gain) loss on investment securities and related hedges, net	(20,419,000)	8,334,000
Realized gain on distressed residential mortgage loans	(9,477,000)	(1,057,000)
Unrealized loss (gain) on investment securities and related hedges, net	4,047,000	(3,014,000)
Unrealized gain on loans and debt held in multi-family securitization trusts	(43,060,000)	(22,370,000)
Impairment loss on investment securities		225,000
Loss on extinguishment of debt	3,397,000
Net decrease in loans held for sale	38,000	338,000
Provision for loan losses	1,234,000	905,000
Income from investments in limited partnerships and limited liability companies	(2,192,000)	(445,000)
Distributions of income from investments in limited partnership and limited liability companies	1,019,000	402,000
Amortization of stock based compensation, net	929,000	708,000
Changes in operating assets and liabilities:
Receivables and other assets	(825,000)	(8,163,000)
Accrued expenses and other liabilities and accrued expenses, related parties	2,629,000	10,484,000
Net cash provided by operating activities	28,652,000	45,092,000
Cash Flows from Investing Activities:
Restricted cash	(19,754,000)	5,185,000
Proceeds from sales of investment securities	41,442,000	1,254,000
Purchases of investment securities	(20,273,000)	(60,476,000)
Return of capital from investments in limited partnerships and limited liability companies		2,967,000
Purchases of other assets	(100,000)	(39,000)
Funding of first mortgage loan	(1,142,000)	(6,500,000)
Funding of mezzanine loan and preferred equity investments	(12,567,000)	(16,788,000)
Proceeds from sale of mezzanine loans	5,590,000
Proceeds from mortgage loans held for investment		21,000
Net proceeds (payments) on other derivative instruments settled during the period	4,360,000	(9,357,000)
Principal paydowns on investment securities - available for sale	75,140,000	104,896,000
Proceeds from sale of real estate owned	3,559,000
Net cash provided by (used in) investing activities	146,920,000	(145,582,000)
Cash Flows from Financing Activities:
(Payments) of financing arrangements	(163,244,000)	(94,953,000)
Common stock issuance	186,081,000	98,172,000
Preferred stock issuance		72,637,000
Costs associated with common stock and preferred stock issued	(347,000)	(531,000)
Payments made on collateralized debt obligations	(71,074,000)	(2,307,000)
Net cash (used in) provided by financing activities	(178,857,000)	89,222,000
Proceeds from securitized debt		136,589,000
Net Decrease in Cash and Cash Equivalents	(3,285,000)	(11,268,000)
Cash and Cash Equivalents - Beginning of Period	31,798,000	31,777,000
Cash and Cash Equivalents - End of Period	28,513,000	20,509,000
Supplemental Disclosure:
Cash paid for interest	265,842,000	192,751,000
Cash paid for income taxes	5,741,000	444,000
Non-Cash Investment Activities:
Purchase of investment securities not yet settled	215,417,000	186,062,000
Consolidation of multi-family loans held in securitization trusts		1,700,865,000
Consolidation of multi-family collateralized debt obligations		1,659,630,000
Distressed Residential Mortgage Loans [Member]
Cash Flows from Investing Activities:
Principal repayments received on loans	9,949,000	16,007,000
Purchases of loans	(50,515,000)	(206,384,000)
Residential Distressed Mortgage Loans Held in Securitization Trust [Member]
Cash Flows from Investing Activities:
Principal repayments received on loans	61,036,000	5,526,000
Multi-Family Collateralized Debt Obligations [Member]
Cash Flows from Investing Activities:
Principal repayments received on loans	50,195,000	59,341,000
Purchases of loans		(41,235,000)
Residential Collateralized Debt Obligations [Member]
Cash Flows from Financing Activities:
Payments made on collateralized debt obligations	(10,151,000)	(16,268,000)
Collateralized Loan Obligation [Member]
Cash Flows from Financing Activities:
Payments made on collateralized debt obligations	(53,543,000)	(59,367,000)
Common Stock [Member]
Cash Flows from Financing Activities:
Dividends paid	(62,220,000)	(44,088,000)
Non-Cash Financing Activities:
Dividends declared on stock to be paid in subsequent period	24,485,000	17,214,000
Preferred Stock [Member]
Cash Flows from Financing Activities:
Dividends paid	(4,359,000)	(662,000)
Non-Cash Financing Activities:
Dividends declared on stock to be paid in subsequent period	$ 1,453,000	$ 1,453,000