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Represents the amount of addition, improvement, or renovation to a facility held for productive use including parking lot improvements acquired at the acquisition date.

No definition available.

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The amount of identifiable intangible liabilities recognized as of the acquisition date.

No definition available.

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Expense consisting of acquisition related transaction costs.

No definition available.

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Balance Type:	debit
Period Type:	duration

No definition available.

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Represents the period during which amount of rent is to be billed and received pursuant to the lease terms.

No definition available.

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Represents the amount of unbilled rent receivable relating to lease termination fees.

No definition available.

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Data Type:	xbrli:monetaryItemType
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The percentage of ownership of common stock or equity participation acquired under the equity method of accounting.

No definition available.

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n/a

No definition available.

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Amount represents gross lease termination fee.

No definition available.

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Portion of the contract price used to pay off the underlying mortgage of the unconsolidated joint venture.

No definition available.

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Payment directly made to the partner of unconsolidated Joint venture for purchasing their share.

No definition available.

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Data Type:	xbrli:monetaryItemType
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The cash outflow associated with purchase of partner's interest in which the reporting entity shares control of the entity with another party or group.

No definition available.

Name:	olp_PaymentsToPurchasePartnersInterestInUnconsolidatedJointVenture
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

No definition available.

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Represents the real estate acquisition cost capitalized.

No definition available.

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Represents the amount of unbilled rent receivable written off during the period relating to properties sold.

No definition available.

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Represents the amount of unbilled rent receivable written off during the period relating to tenant filed for bankruptcy.

No definition available.

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Write-off of Unbilled Rent Receivable and Intangible Lease Asset

No definition available.

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Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
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Amount of non-cash amortization of intangible asset (liability) for above and below market leases.

No definition available.

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Amount of addition (reduction) to the amount at which an asset could be incurred (settled) in a current transaction between willing parties.

No definition available.

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Amount of accumulated amortization of leases acquired as part of a real property acquisition at below market lease rate with a finite life.

No definition available.

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Amount of amortization income for leases with a finite life acquired as part of a real property acquisition at below market lease rate expected to be recognized after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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Amount of amortization income for leases with a finite life acquired as part of a real property acquisition at below market lease rate expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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Amount of amortization income for leases with a finite life acquired as part of a real property acquisition at below market lease rate expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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Amount of amortization income for leases with a finite life acquired as part of a real property acquisition at below market lease rate expected to be recognized during the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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Amount of amortization income for leases with a finite life acquired as part of a real property acquisition at below market lease rate expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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Amount of amortization income for leases with a finite life acquired as part of a real property acquisition at below market lease rate expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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Amount after amortization of leases acquired as part of a real property acquisition at below market lease rate with a finite life.

No definition available.

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- References

No definition available.

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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.

No definition available.

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Amount of facility held for productive use including, but not limited to, office, production, storage and distribution facilities, acquired at the acquisition date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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The amount of identifiable intangible assets recognized as of the acquisition date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of real estate acquired, at the acquisition date.

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Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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- References

No definition available.

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The cumulative difference between the rental payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense over the term of the leased property, by the lessor or lessee, respectively. Such receivable is reduced by allowances attributable to, for instance, credit risk associated with a lessee.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

Name:	us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive
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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.