XML 69 R57.htm IDEA: XBRL DOCUMENT v3.21.1

OTHER INCOME - Interest Income on Loan Receivable (Details) - Real Estate in Houston, TX	1 Months Ended	3 Months Ended
	Dec. 31, 2020 USD ($) item	Mar. 31, 2021 USD ($)
Interest Income on Loan Receivable
Number of properties sold | item	2
Term of loan	1 year
Percentage of seller-financing provided by the Company	50.00%
Other income
Interest Income on Loan Receivable
Interest income on loans		$ 46,000
Other receivables
Interest Income on Loan Receivable
Seller-financing provided by the Company	$ 4,612,500	$ 4,612,500

X

- Definition

Interest income generated by loans.

+ References

No definition available.

+ Details

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

X

- References

No definition available.

+ Details

Name:	olp_InterestIncomeOnLoanReceivableAbstract
Namespace Prefix:	olp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of properties sold.

+ References

No definition available.

+ Details

Name:	olp_NumberOfPropertiesSold
Namespace Prefix:	olp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The percentage of seller-financing financing provided by the Company

+ References

No definition available.

+ Details

Name:	olp_PercentageOfSellerFinancingProvidedByCompany
Namespace Prefix:	olp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The term of the loan provided by the Company.

+ References

No definition available.

+ Details

Name:	olp_TermOfSellerFinancing
Namespace Prefix:	olp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount, before allowance and fees, of loans and leases receivable. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

+ Details

Name:	us-gaap_LoansAndLeasesReceivableBeforeFeesGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=olp_RealEstateInHoustonTexasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=olp_OtherNonoperatingIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_BalanceSheetLocationAxis=olp_OtherReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: