CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Cash Flows from Operating Activities:
Net income	$ 78,013	$ 136,191	$ 68,955
Adjustments to reconcile net income to net cash provided by operating activities:
Net amortization	542	(2,671)	13,424
Realized loss (gain) on investment securities and related hedges, net	4,617	(42,091)	10,719
Realized gain on distressed residential mortgage loans	(31,251)	(14,380)	(1,600)
Unrealized loss (gain) on investment securities and related hedges, net	2,641	7,667	(5,464)
Gain on de-consolidation of multi-family loans held in securitization trusts and multi-family collateralized debt obligations	(1,483)	0	0
Unrealized gain on loans and debt held in multi-family securitization trusts	(12,368)	(56,931)	(31,495)
Impairment loss on investment securities	0	0	225
Loss on extinguishment of debt	0	3,397	0
Net decrease in loans held for sale	323	87	341
Provision for loan losses	1,363	1,939	1,262
Income from investments in limited partnerships and limited liability companies	(12,997)	(4,562)	(2,297)
Distributions of income from investments in limited partnership and limited liability companies	9,827	2,238	1,976
Amortization of stock based compensation, net	983	1,180	897
Changes in operating assets and liabilities:
Receivables and other assets	10,945	(3,631)	(18,097)
Accrued expenses and other liabilities and accrued expenses, related parties	(14,819)	9,118	14,457
Net cash provided by operating activities	36,336	37,551	53,303
Cash Flows from Investing Activities:
Restricted cash	33,448	(10,150)	2,467
Proceeds from sales of investment securities	99,235	93,578	1,254
Purchases of investment securities	(152,883)	(20,273)	(72,183)
Return of capital from investments in limited partnerships and limited liability companies	0	0	3,558
Purchases of FHLBI stock	(5,445)	0	0
Purchases of other assets	(61)	(254)	(975)
Funding of first mortgage loan	0	(1,142)	(6,500)
Funding of mezzanine loan and preferred equity investments	(58,215)	(48,674)	(16,788)
Proceeds from sale of mezzanine loan and preferred equity investments	4,308	5,590	0
Net (payments) proceeds from other derivative instruments settled during the period	(5,766)	1,124	(11,011)
Principal paydowns on investment securities - available for sale	105,774	98,877	125,913
Proceeds from sale of real estate owned	1,044	3,882	0
Proceeds from sales of loans held in multi-family securitization trusts	65,587	0	0
Net cash provided by (used in) investing activities	283,965	(125,016)	(152,287)
Cash Flows from Financing Activities:
(Payments made on) proceeds from financing arrangements, net of FHLBI advances	(99,011)	99,789	(98,009)
Common stock issuance, net	31,799	296,546	100,207
Preferred stock issuance, net	86,862	0	72,397
Payments made on collateralized debt obligations	(116,136)	(75,796)	(7,408)
Proceeds from securitized debt	0	0	191,705
Net cash (used in) provided by financing activities	(333,940)	131,265	99,005
Net (Decrease) increase in Cash and Cash Equivalents	(13,639)	43,800	21
Cash and Cash Equivalents - Beginning of Period	75,598	31,798	31,777
Cash and Cash Equivalents - End of Period	61,959	75,598	31,798
Supplemental Disclosure:
Cash paid for interest	307,162	352,232	268,552
Cash paid for income taxes	4,922	8,295	794
Non-Cash Investment Activities:
Purchase of investment securities not yet settled	227,969	283,537	191,592
Consolidation of multi-family loans held in securitization trusts	0	0	3,218,301
Consolidation of multi-family collateralized debt obligations	0	0	3,146,676
Common Stock
Cash Flows from Financing Activities:
Dividends paid	(113,318)	(86,705)	(61,302)
Non-Cash Financing Activities:
Dividends declared on stock to be paid in subsequent period	26,256	28,376	17,295
Preferred Stock
Cash Flows from Financing Activities:
Dividends paid	(9,218)	(5,812)	(2,115)
Non-Cash Financing Activities:
Dividends declared on stock to be paid in subsequent period	3,225	1,453	1,453
Financing arrangements, residential mortgage loans
Cash Flows from Investing Activities:
Principal repayments received on loans	28,166	12,687	22,292
Purchases of loans	(156,005)	(405,427)	(218,166)
Distressed residential mortgage loans held in securitization trusts (net)
Cash Flows from Investing Activities:
Principal repayments received on loans	238,798	64,715	15,646
Multi-family collateralized debt obligations
Cash Flows from Investing Activities:
Principal repayments received on loans	85,980	80,451	73,831
Purchases of loans	0	0	(71,625)
Residential collateralized debt obligations
Cash Flows from Financing Activities:
Payments made on collateralized debt obligations	(28,952)	(12,918)	(22,657)
Collateralized Loan Obligation
Cash Flows from Financing Activities:
Payments made on collateralized debt obligations	(85,966)	(83,839)	(73,813)
Multi-Family Loans Held in Securitization Trusts
Non-Cash Investment Activities:
Deconsolidation of multi-family loans held in securitization trusts	1,075,529	0	0
Multi-family collateralized debt obligations
Non-Cash Investment Activities:
Deconsolidation of multi-family collateralized debt obligations	$ 1,009,942	$ 0	$ 0