XML 43 R40.htm IDEA: XBRL DOCUMENT v2.4.1.9
SIGNIFICANT ACCOUNTING POLICIES (Details 5) (USD $)
 3 Months Ended 12 Months Ended
Dec. 31, 2014
state
property
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
state
property
Dec. 31, 2013
Dec. 31, 2012
Concentration of Credit Risk                      
Number of states in which properties are located 30us-gaap_NumberOfStatesInWhichEntityOperates               30us-gaap_NumberOfStatesInWhichEntityOperates    
Number of real estate investments 115us-gaap_NumberOfRealEstateProperties               115us-gaap_NumberOfRealEstateProperties    
Rental revenues $ 15,223,000us-gaap_RealEstateRevenueNet $ 15,187,000us-gaap_RealEstateRevenueNet $ 15,665,000us-gaap_RealEstateRevenueNet $ 14,402,000us-gaap_RealEstateRevenueNet $ 14,166,000us-gaap_RealEstateRevenueNet $ 12,970,000us-gaap_RealEstateRevenueNet $ 11,981,000us-gaap_RealEstateRevenueNet $ 11,862,000us-gaap_RealEstateRevenueNet $ 60,477,000us-gaap_RealEstateRevenueNet $ 50,979,000us-gaap_RealEstateRevenueNet $ 43,793,000us-gaap_RealEstateRevenueNet
Rental income | Geographic concentration | Texas                      
Concentration of Credit Risk                      
Concentration risk percentage                 13.30%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_TX		 13.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_TX		 10.80%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_TX
Rental income | Geographic concentration | New York                      
Concentration of Credit Risk                      
Concentration risk percentage                 9.50%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_NY		 11.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_NY		 12.80%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_NY
Rental income | Geographic concentration | New Jersey                      
Concentration of Credit Risk                      
Concentration risk percentage                 9.50%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_NJ		 10.70%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_NJ		 8.30%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_NJ
Rental income | Geographic concentration | Pennsylvania                      
Concentration of Credit Risk                      
Concentration risk percentage                 7.80%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_PA		 8.80%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_PA		 10.10%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_GeographicConcentrationRiskMember
/ us-gaap_StatementGeographicalAxis
= stpr_PA
Rental income | Customer concentration | Haverty Furniture Companies, Inc.                      
Concentration of Credit Risk                      
Number of states in which properties are located 6us-gaap_NumberOfStatesInWhichEntityOperates
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		               6us-gaap_NumberOfStatesInWhichEntityOperates
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		    
Concentration risk percentage                 8.20%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		 9.50%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		 11.10%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember
Number of real estate investments 11us-gaap_NumberOfRealEstateProperties
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		               11us-gaap_NumberOfRealEstateProperties
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		    
Real estate investments (as a percent)                 9.10%olp_ConcentrationRiskRealEstateInvestmentsAsPercentageOfDepreciatedBookValue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		 9.50%olp_ConcentrationRiskRealEstateInvestmentsAsPercentageOfDepreciatedBookValue
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		  
Rental revenues                 $ 4,844,000us-gaap_RealEstateRevenueNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		 $ 4,844,000us-gaap_RealEstateRevenueNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember		 $ 4,844,000us-gaap_RealEstateRevenueNet
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= olp_RentalRevenueMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
/ us-gaap_MajorCustomersAxis
= olp_HavertyFurnitureCompaniesIncMember