2.4.0.8 Html 125 265 1 false 48 0 false 6 false false R1.htm 0000 - Document - Document and Entity Information Sheet http://www.onelibertyproperties.com/role/DocumentAndEntityInformation Document and Entity Information true false R2.htm 0010 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://www.onelibertyproperties.com/role/BalanceSheet CONSOLIDATED BALANCE SHEETS false false R3.htm 0015 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://www.onelibertyproperties.com/role/BalanceSheetParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) false false R4.htm 0020 - Statement - CONSOLIDATED STATEMENTS OF INCOME Sheet http://www.onelibertyproperties.com/role/StatementOfIncome CONSOLIDATED STATEMENTS OF INCOME false false R5.htm 0025 - Statement - CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) Sheet http://www.onelibertyproperties.com/role/StatementOfIncomeParenthetical CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) false false R6.htm 0030 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Sheet http://www.onelibertyproperties.com/role/StatementOfComprehensiveIncome CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME false false R7.htm 0040 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY Sheet http://www.onelibertyproperties.com/role/StatementOfStockholdersEquity CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY false false R8.htm 0045 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) Sheet http://www.onelibertyproperties.com/role/StatementOfStockholdersEquityParenthetical CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) false false R9.htm 0050 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.onelibertyproperties.com/role/CashFlows CONSOLIDATED STATEMENTS OF CASH FLOWS false false R10.htm 1010 - Disclosure - Organization and Background Sheet http://www.onelibertyproperties.com/role/DisclosureOrganizationAndBackground Organization and Background false false R11.htm 1020 - Disclosure - Basis of Preparation Sheet http://www.onelibertyproperties.com/role/DisclosureBasisOfPreparation Basis of Preparation false false R12.htm 1030 - Disclosure - Earnings Per Common Share Sheet http://www.onelibertyproperties.com/role/DisclosureEarningsPerCommonShare Earnings Per Common Share false false R13.htm 1040 - Disclosure - Real Estate Acquisitions Sheet http://www.onelibertyproperties.com/role/DisclosureRealEstateAcquisitions Real Estate Acquisitions false false R14.htm 1050 - Disclosure - Investment in Unconsolidated Joint Ventures Sheet http://www.onelibertyproperties.com/role/DisclosureInvestmentInUnconsolidatedJointVentures Investment in Unconsolidated Joint Ventures false false R15.htm 1060 - Disclosure - Allowance for Doubtful Accounts Sheet http://www.onelibertyproperties.com/role/DisclosureAllowanceForDoubtfulAccounts Allowance for Doubtful Accounts false false R16.htm 1070 - Disclosure - Discontinued Operations Sheet http://www.onelibertyproperties.com/role/DisclosureDiscontinuedOperations Discontinued Operations false false R17.htm 1080 - Disclosure - Line of Credit Sheet http://www.onelibertyproperties.com/role/DisclosureLineOfCredit Line of Credit false false R18.htm 1090 - Disclosure - Common Stock Cash Dividend Sheet http://www.onelibertyproperties.com/role/DisclosureCommonStockCashDividend Common Stock Cash Dividend false false R19.htm 1100 - Disclosure - Shares Issued Through Equity Offering Program Sheet http://www.onelibertyproperties.com/role/DisclosureSharesIssuedThroughEquityOfferingProgram Shares Issued Through Equity Offering Program false false R20.htm 1110 - Disclosure - Stock Based Compensation Sheet http://www.onelibertyproperties.com/role/DisclosureStockBasedCompensation Stock Based Compensation false false R21.htm 1120 - Disclosure - Fair Value Measurements Sheet http://www.onelibertyproperties.com/role/DisclosureFairValueMeasurements Fair Value Measurements false false R22.htm 1130 - Disclosure - New Accounting Pronouncement Sheet http://www.onelibertyproperties.com/role/DisclosureNewAccountingPronouncement New Accounting Pronouncement false false R23.htm 1140 - Disclosure - Subsequent Event Sheet http://www.onelibertyproperties.com/role/DisclosureSubsequentEvent Subsequent Event false false R24.htm 2020 - Disclosure - Basis of Preparation (Policies) Sheet http://www.onelibertyproperties.com/role/DisclosureBasisOfPreparationPolicies Basis of Preparation (Policies) false false R25.htm 3030 - Disclosure - Earnings Per Common Share (Tables) Sheet http://www.onelibertyproperties.com/role/DisclosureEarningsPerCommonShareTables Earnings Per Common Share (Tables) false false R26.htm 3040 - Disclosure - Real Estate Acquisitions (Tables) Sheet http://www.onelibertyproperties.com/role/DisclosureRealEstateAcquisitionsTables Real Estate Acquisitions (Tables) false false R27.htm 3070 - Disclosure - Discontinued Operations (Tables) Sheet http://www.onelibertyproperties.com/role/DisclosureDiscontinuedOperationsTables Discontinued Operations (Tables) false false R28.htm 3110 - Disclosure - Stock Based Compensation (Tables) Sheet http://www.onelibertyproperties.com/role/DisclosureStockBasedCompensationTables Stock Based Compensation (Tables) false false R29.htm 3120 - Disclosure - Fair Value Measurements (Tables) Sheet http://www.onelibertyproperties.com/role/DisclosureFairValueMeasurementsTables Fair Value Measurements (Tables) false false R30.htm 4010 - Disclosure - Organization and Background (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureOrganizationAndBackgroundDetails Organization and Background (Details) false false R31.htm 4020 - Disclosure - Basis of Preparation (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureBasisOfPreparationDetails Basis of Preparation (Details) false false R32.htm 4030 - Disclosure - Earnings Per Common Share (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureEarningsPerCommonShareDetails Earnings Per Common Share (Details) false false R33.htm 4040 - Disclosure - Real Estate Acquisitions (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureRealEstateAcquisitionsDetails Real Estate Acquisitions (Details) false false R34.htm 4050 - Disclosure - Investment in Unconsolidated Joint Ventures (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureInvestmentInUnconsolidatedJointVenturesDetails Investment in Unconsolidated Joint Ventures (Details) false false R35.htm 4060 - Disclosure - Allowance for Doubtful Accounts (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureAllowanceForDoubtfulAccountsDetails Allowance for Doubtful Accounts (Details) false false R36.htm 4070 - Disclosure - Discontinued Operations (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureDiscontinuedOperationsDetails Discontinued Operations (Details) false false R37.htm 4080 - Disclosure - Line of Credit (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureLineOfCreditDetails Line of Credit (Details) false false R38.htm 4090 - Disclosure - Common Stock Cash Dividend (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureCommonStockCashDividendDetails Common Stock Cash Dividend (Details) false false R39.htm 4100 - Disclosure - Shares Issued Through Equity Offering Program (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureSharesIssuedThroughEquityOfferingProgramDetails Shares Issued Through Equity Offering Program (Details) false false R40.htm 4110 - Disclosure - Stock Based Compensation (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureStockBasedCompensationDetails Stock Based Compensation (Details) false false R41.htm 4120 - Disclosure - Fair Value Measurements (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureFairValueMeasurementsDetails Fair Value Measurements (Details) false false R42.htm 4121 - Disclosure - Fair Value Measurements (Details 2) Sheet http://www.onelibertyproperties.com/role/DisclosureFairValueMeasurementsDetails2 Fair Value Measurements (Details 2) false false R43.htm 4122 - Disclosure - Fair Value Measurements (Details 3) Sheet http://www.onelibertyproperties.com/role/DisclosureFairValueMeasurementsDetails3 Fair Value Measurements (Details 3) false false R44.htm 4123 - Disclosure - Fair Value Measurements (Details 4) Sheet http://www.onelibertyproperties.com/role/DisclosureDerivativeFinancialInstrumentsDetails4 Fair Value Measurements (Details 4) false false R45.htm 4140 - Disclosure - Subsequent Event (Details) Sheet http://www.onelibertyproperties.com/role/DisclosureSubsequentEventDetails Subsequent Event (Details) false false All Reports Book All Reports Element olp_GainLossOnDispositionOfRealEstateInUnconsolidatedJointVenture had a mix of decimals attribute values: -3 0. Element us-gaap_AvailableForSaleSecuritiesEquitySecurities had a mix of decimals attribute values: -3 0. Element us-gaap_DerivativeFairValueOfDerivativeAsset had a mix of decimals attribute values: -3 0. Element us-gaap_DerivativeFairValueOfDerivativeLiability had a mix of decimals attribute values: -3 0. Element us-gaap_DividendsCommonStockCash had a mix of decimals attribute values: -3 0. Element us-gaap_GainLossOnSaleOfProperties had a mix of decimals attribute values: -3 0. 'Monetary' elements on report '0040 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY' had a mix of different decimal attribute values. 'Monetary' elements on report '4040 - Disclosure - Real Estate Acquisitions (Details)' had a mix of different decimal attribute values. 'Monetary' elements on report '4050 - Disclosure - Investment in Unconsolidated Joint Ventures (Details)' had a mix of different decimal attribute values. Process Flow-Through: 0010 - Statement - CONSOLIDATED BALANCE SHEETS Process Flow-Through: Removing column 'Sep. 30, 2012' Process Flow-Through: Removing column 'Dec. 31, 2011' Process Flow-Through: 0015 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Process Flow-Through: 0020 - Statement - CONSOLIDATED STATEMENTS OF INCOME Process Flow-Through: Removing column '12 Months Ended Dec. 31, 2012' Process Flow-Through: 0025 - Statement - CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) Process Flow-Through: 0030 - Statement - CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Process Flow-Through: Removing column '12 Months Ended Dec. 31, 2012' Process Flow-Through: 0045 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) Process Flow-Through: 0050 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Process Flow-Through: Removing column '12 Months Ended Dec. 31, 2012' olp-20130930.xml olp-20130930.xsd olp-20130930_cal.xml olp-20130930_def.xml olp-20130930_lab.xml olp-20130930_pre.xml true true