INVESTMENTS IN RESIDENTIAL MORTGAGE LOANS - Summary of the Geographic Distribution of the Underlying Residential Mortgage Loans (Details) (Residential Mortgage Loans Held-for-Investment [Member])	Mar. 31, 2015	Dec. 31, 2014
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	100.00%	100.00%
New York [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	11.20%	12.20%
California [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	9.00%	15.00%
Florida [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	7.10%	6.30%
New Jersey [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	5.50%	7.00%
Georgia [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	4.80%	3.60%
Texas [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	4.70%	4.10%
Pennsylvania [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	4.70%	3.90%
North Carolina [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	4.60%	3.00%
Ohio [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	4.40%	3.10%
Illinois [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	4.10%	4.40%
Other U.S. [Member]
Mortgage Loans on Real Estate [Line Items]
Percentage of Total Outstanding Unpaid Principal Amount as of	39.90%	37.40%