Annual report pursuant to Section 13 and 15(d)

Organization (Details)

v2.4.1.9
Organization (Details)
 12 Months Ended
Dec. 31, 2014
acre
sqft
Operating office properties  
Investments in real estate  
Number of real estate properties 173us-gaap_NumberOfRealEstateProperties
/ ofc_RealEstatePropertiesStatusAxis
= ofc_OperatingOfficePropertiesMember
Square footage of real estate properties (in square feet) 16,800,000us-gaap_AreaOfRealEstateProperty
/ ofc_RealEstatePropertiesStatusAxis
= ofc_OperatingOfficePropertiesMember
Office properties under, or contractually committed for, construction or approved for redevelopment  
Investments in real estate  
Number of real estate properties 13us-gaap_NumberOfRealEstateProperties
/ ofc_RealEstatePropertiesStatusAxis
= ofc_OfficePropertiesUnderConstructionRedevelopmentOrContractuallyCommittedForConstructionMember
Square footage of real estate properties (in square feet) 1,600,000us-gaap_AreaOfRealEstateProperty
/ ofc_RealEstatePropertiesStatusAxis
= ofc_OfficePropertiesUnderConstructionRedevelopmentOrContractuallyCommittedForConstructionMember
Land Controlled for Future Development [Member]  
Investments in real estate  
Area of land we control (in acres) 1,464ofc_AcresOfRealEstateProperty
/ ofc_RealEstatePropertiesStatusAxis
= ofc_LandControlledforFutureDevelopmentMember
Developable square footage of real estate properties (in square feet) 18,300,000ofc_DevelopableSquareFeet
/ ofc_RealEstatePropertiesStatusAxis
= ofc_LandControlledforFutureDevelopmentMember
Partially operational, wholesale data center  
Investments in real estate  
The expected stabilization critical load after completion of development (in megawatts) 19.25ofc_ExpectedStabilizationCriticalLoad
/ ofc_RealEstatePropertiesStatusAxis
= ofc_PartiallyOperationalWholesaleDataCenterMember
Debt in Default of Payment Terms  
Investments in real estate  
Number of real estate properties 2us-gaap_NumberOfRealEstateProperties
/ us-gaap_DebtInstrumentAxis
= ofc_DebtinDefaultofPaymentTermsMember