Represents the amount of additional payment to related party for the share of direct office expenses.

No definition available.

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- Definition

Represents the amount to be paid under the agreement with the related party.

+ References

No definition available.

+ Details

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- Definition

Represents the amount of property management costs allocated to real estate expenses.

+ References

No definition available.

+ Details

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Namespace Prefix:	olp_
Data Type:	xbrli:monetaryItemType
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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	debit
Period Type:	duration

- Definition

The percentage charged for managing real estate properties.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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- Definition

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.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Namespace Prefix:
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- Details

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- Details

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Related Party Transactions - Compensation and Services Agreement (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Majestic
Related Party Transactions
Fees under compensation and services agreement	$ 714,000	$ 702,000	$ 1,481,000	$ 1,405,000
Property management costs allocated to real estate expenses	278,000	322,000	608,000	646,000
Additional payment for the entity's share of all direct office expenses	69,000	54,000	138,000	108,000
Executive officers and others
Related Party Transactions
Total charge to operations	$ 453,000	$ 462,000	$ 903,000	$ 932,000
Net lease tenants \| Majestic
Related Party Transactions
Property management costs (as a percent)			1.50%
Operating lease tenants \| Majestic
Related Party Transactions
Property management costs (as a percent)			2.00%