FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value of Financial Instruments Not Recorded at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Carrying Amount
Liabilities:
Mortgages payable	$ 97,100	$ 97,100
Junior subordinated notes	27,070	27,070
Carrying Amount \| SBA 7(a) loans receivable, subject to credit risk
Assets:
Loans receivable	37,517	32,509
Carrying Amount \| SBA 7(a) loans receivable, subject to loan-backed notes
Assets:
Loans receivable	22,015	23,606
Carrying Amount \| SBA 7(a) loans receivable, paycheck protection program
Assets:
Loans receivable	11,916	14,089
Carrying Amount \| SBA 7(a) loans receivable, subject to secured borrowings
Assets:
Loans receivable	8,504	8,822
Carrying Amount \| SBA 7(a) loans receivable, held for sale
Assets:
Loans receivable	1,990	4,109
Fair Value, Measurements, Nonrecurring \| Estimated Fair Value \| Level 3
Liabilities:
Mortgages payable	100,855	100,799
Junior subordinated notes	24,293	24,236
Fair Value, Measurements, Nonrecurring \| Estimated Fair Value \| Level 3 \| SBA 7(a) loans receivable, subject to credit risk
Assets:
Loans receivable	37,728	32,397
Fair Value, Measurements, Nonrecurring \| Estimated Fair Value \| Level 3 \| SBA 7(a) loans receivable, subject to loan-backed notes
Assets:
Loans receivable	22,740	24,850
Fair Value, Measurements, Nonrecurring \| Estimated Fair Value \| Level 3 \| SBA 7(a) loans receivable, paycheck protection program
Assets:
Loans receivable	12,409	14,484
Fair Value, Measurements, Nonrecurring \| Estimated Fair Value \| Level 3 \| SBA 7(a) loans receivable, subject to secured borrowings
Assets:
Loans receivable	8,593	8,914
Fair Value, Measurements, Nonrecurring \| Estimated Fair Value \| Level 3 \| SBA 7(a) loans receivable, held for sale
Assets:
Loans receivable	$ 2,150	$ 4,527

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
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- Definition

Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
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-Section 50
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- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

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