MORTGAGE NOTES PAYABLE (Mortgages Payable) (Details) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
MORTGAGE NOTES PAYABLE
Effective interest rate (as a percent)	3.98%
Financing fees, net	$ 42,000	$ 36,000
Annual maturities of mortgage debt
Secured Debt	283,444,533	281,771,246
Mortgages payable
MORTGAGE NOTES PAYABLE
Amount of monthly installments including principal	$ 1,257,000
Weighted average interest rate (as a percent)	4.43%
Effective interest rate (as a percent)	4.51%
Financing fees, net	$ 1,345,000	1,449,000
Accumulated amortization on financing and leasing fees	1,564,000	$ 1,411,000
Annual maturities of mortgage debt
2021-current maturities	2,531,000
2022	2,697,000
2023	102,569,000
2024	10,965,000
2025	3,439,000
Thereafter	162,589,000
Total	284,790,000
Less: unamortized deferred financing costs	(1,345,000)
Secured Debt	$ 283,445,000
Mortgages payable \| Minimum
MORTGAGE NOTES PAYABLE
Interest rate (as a percent)	3.53%
Mortgages payable \| Maximum
MORTGAGE NOTES PAYABLE
Interest rate (as a percent)	5.66%

Represents the accumulated amortization on financing and leasing fees.

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This element represents the deferred financing and leasing cost incurred by the entity during the reporting period.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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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Amount of the required periodic payments including both interest and principal payments.

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Weighted average interest rate of debt outstanding.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the third rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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