FAIR VALUE OF FINANCIAL INSTRUMENTS - Unobservable Inputs (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Mortgages Payable | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, discount rate	4.35%	4.60%
Mortgages Payable | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, discount rate	4.55%	4.72%
Junior Subordinated Debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, discount rate	4.90%	4.83%
Loans Receivable Subject to Credit Risk | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, discount rate	8.50%	8.25%
Fair value inputs, prepayment rates	5.80%	5.80%
Loans Receivable Subject to Credit Risk | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, discount rate	13.50%	13.25%
Fair value inputs, prepayment rates	20.00%	20.00%
SBA 7(a) Loans Receivable, Subject to Secured Borrowings | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, prepayment rates	6.70%	6.70%
SBA 7(a) Loans Receivable, Subject to Secured Borrowings | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs, prepayment rates	20.00%	20.00%