FAIR VALUE MEASUREMENTS - Fair Value of Derivatives (Details)	6 Months Ended
Jun. 30, 2021 USD ($) item	Dec. 31, 2020 USD ($)
Interest rate derivatives
FAIR VALUE MEASUREMENTS
Number of mortgage loans outstanding	21
Interest rate derivatives \| Cash flow hedges
FAIR VALUE MEASUREMENTS
Number of interest rate derivatives held	21
Notional Amount \| $	$ 65,735,000
Weighted average maturity	2 years 8 months 12 days
Weighted average annual interest rate (as a percent)	4.08%
Interest rate derivatives \| Cash flow hedges \| Minimum
FAIR VALUE MEASUREMENTS
Fixed interest rate (as a percent)	3.02%
Interest rate derivatives \| Cash flow hedges \| Maximum
FAIR VALUE MEASUREMENTS
Fixed interest rate (as a percent)	5.16%
Interest rate swap \| Not Designated as Hedging Instrument
FAIR VALUE MEASUREMENTS
Number of interest rate derivatives held	1
Notional Amount \| $	$ 3,812,000
Interest rate swap \| Cash flow hedges \| Designated as hedging instruments
FAIR VALUE MEASUREMENTS
Number of interest rate derivatives held	20
Recurring \| Interest rate swap \| Level 2 \| Other liabilities
Financial liabilities:
Derivative financial instruments \| $	$ 2,669,000	$ 5,012,000

The number of mortgage loans outstanding with related interest rate derivatives.

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- Definition

Average fixed interest rate related to the group of interest rate derivatives.

+ References

No definition available.

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- Definition

Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Number of interest rate derivative instruments held by the entity at the reporting date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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