v3.25.2

VARIABLE INTEREST ENTITIES, CONSOLIDATED JOINT VENTURES AND CONTINGENT LIABILITY - Ground Leases (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Nov. 30, 2020	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2016
Variable Interest Entities - Ground Lease
Revenue		$ 24,545,000	$ 21,800,000	$ 48,715,000	$ 44,496,000
Variable Interest Entity, Not Primary Beneficiary \| The Vue
Variable Interest Entities - Ground Lease
Maximum exposure to loss		17,472,000		17,472,000
Owner/ Operator Mortgage from Third Party							$ 67,444,000
Current Balance of Owner or Operator Mortgage Debt Obtained From Third Party		61,603,000		61,603,000
Percentage of operating expense shortfalls & cap-ex covered by the Company	78.00%
Amount of operating expense shortfalls & cap-ex covered by the Company		$ 52,000		$ 62,000		$ 100,000

The amount of operating expense shortfalls and capital expenditures in excess of the initial operating expense deposit to be covered by the Company.

+ References

No definition available.

+ Details

Name:	olp_GroundLeaseOperatingExpenseShortfallsAndCapitalExpendituresCoveredByCompanyAmount
Namespace Prefix:	olp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The percentage of operating expense shortfalls and capital expenditures in excess of the initial operating expense deposit to be covered by the Company.

+ References

No definition available.

+ Details

Name:	olp_GroundLeaseOperatingExpenseShortfallsAndCapitalExpendituresCoveredByCompanyPercentage
Namespace Prefix:	olp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Current balance of owner/operator mortgage debt obtained from a third party.

+ References

No definition available.

+ Details

Name:	olp_OwnerOrOperatorCurrentBalanceOfMortgageDebtFromThirdParty
Namespace Prefix:	olp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the original amount of mortgage debt related obtained from a third party.

+ References

No definition available.

+ Details

Name:	olp_OwnerOrOperatorMortgageDebtFromThirdParty
Namespace Prefix:	olp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_GroundLeasesDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of operating lease income from lease payments and variable lease payments paid and payable to lessor. Includes, but is not limited to, variable lease payments not included in measurement of lease receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482964/270-10-50-6A

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479016/842-30-45-3

+ Details

Name:	us-gaap_OperatingLeaseLeaseIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481203/810-10-50-6

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481203/810-10-50-4

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=olp_VueApartmentsBeachwoodOhioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

ONE LIBERTY PROPERTIES INC 10-Q