BORROWINGS (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Short-term Debt [Line Items]
Repurchase Agreements, Amount outstanding	$ 746,625,821	$ 568,432,457	[1]
Repurchase Agreements, Weighted average interest rate	0.89%	1.19%
Repurchase Agreements, Market value of collateral held	$ 831,157,394	$ 697,384,372
Agency [Member]
Short-term Debt [Line Items]
Repurchase Agreements, Amount outstanding	$ 668,713,000	$ 358,239,000
Repurchase Agreements, Weighted average interest rate	0.72%	0.66%
Repurchase Agreements, Market value of collateral held	$ 701,998,993	$ 374,952,510
Non-Agency [Member]
Short-term Debt [Line Items]
Repurchase Agreements, Amount outstanding	$ 17,999,000	$ 114,512,000
Repurchase Agreements, Weighted average interest rate	2.12%	2.24%
Repurchase Agreements, Market value of collateral held	$ 27,712,606	$ 121,475,112
Multifamily [Member]
Short-term Debt [Line Items]
Repurchase Agreements, Amount outstanding	$ 52,788,000	$ 86,177,000
Repurchase Agreements, Weighted average interest rate	2.40%	1.83%
Repurchase Agreements, Market value of collateral held	$ 92,691,756	$ 190,056,347
Mortgage loans [Member]
Short-term Debt [Line Items]
Repurchase Agreements, Amount outstanding	$ 7,125,821	$ 9,504,457
Repurchase Agreements, Weighted average interest rate	2.88%	2.87%
Repurchase Agreements, Market value of collateral held	$ 8,754,039	$ 10,900,403

[1] Counterparties domiciled in Europe and Asia, or their U.S. subsidiaries.