FAIR VALUE (Fair Value Measurements By Level 3 Valuation Technique) (Details)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investments in debt securities	$ 31,365,000	$ 97,190,000
Available-for-sale, Multifamily Tax-exempt , Performing Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value		48,221,000
Available-for-sale, Multifamily Tax-exempt , Non-performing Bonds [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investments in debt securities		$ 13,500,000
Debt Securities, Available-for-sale, Measurement Input		0.5
Available-for-sale, Multifamily Tax-exempt , Non-performing Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value		$ 12,882,000
Debt Securities, Available-for-sale, Measurement Input		8.2
Available-for-sale, Multifamily Tax-exempt , Non-performing Bonds [Member] | Measurement Input, Cap Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		7.0
Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 6,026,000	$ 11,114,000
Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	7.3
Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, Cap Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	6.2
Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, NOI Annual Growth Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	0.7
Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, Contract Price [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investments in debt securities	$ 16,611,000
Available-for-sale, Infrastructure Bonds [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 25,339,000	$ 24,973,000
Available-for-sale, Infrastructure Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input	7.0	7.2
Loans Held for Investment
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 500,000
Loans Held for Investment | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Loans receivable, measurement input	8.0
Total Return Swap [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value		$ 1,130,000
Minimum [Member] | Available-for-sale, Multifamily Tax-exempt , Performing Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		4.4
Minimum [Member] | Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		7.4
Minimum [Member] | Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, Cap Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		6.2
Minimum [Member] | Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, NOI Annual Growth Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		0.6
Minimum [Member] | Total Return Swap [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative Asset, Measurement Input		4.7
Maximum [Member] | Available-for-sale, Multifamily Tax-exempt , Performing Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		6.8
Maximum [Member] | Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		7.6
Maximum [Member] | Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, Cap Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		6.5
Maximum [Member] | Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, NOI Annual Growth Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		0.7
Maximum [Member] | Total Return Swap [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative Asset, Measurement Input		4.8
Weighted Average [Member] | Available-for-sale, Multifamily Tax-exempt , Performing Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		4.8
Weighted Average [Member] | Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		7.5
Weighted Average [Member] | Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, Cap Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		6.4
Weighted Average [Member] | Available-for-sale, Multifamily Tax-exempt, Subordinated Cash Flow Bonds [Member] | Measurement Input, NOI Annual Growth Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Measurement Input		0.7
Weighted Average [Member] | Loans Held for Investment | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Loans receivable, measurement input	8.0
Weighted Average [Member] | Total Return Swap [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Derivative Asset, Measurement Input		4.8