Quarterly report pursuant to Section 13 or 15(d)

Information by Business Segment (Details)

v2.4.1.9
Information by Business Segment (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
segment
Mar. 31, 2014
Dec. 31, 2014
Segment Reporting [Abstract]      
Number of primary office property segments 10ofc_NumberOfPrimaryOfficePropertySegments    
Segment financial information for real estate operations      
Revenues from real estate operations $ 122,710us-gaap_RealEstateRevenueNet $ 124,896us-gaap_RealEstateRevenueNet  
Property operating expenses 50,686ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment 49,752ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment  
NOI from real estate operations 72,024ofc_SegmentReportingOperatingIncome 75,144ofc_SegmentReportingOperatingIncome  
Segment assets 3,777,155us-gaap_Assets 3,605,897us-gaap_Assets 3,670,257us-gaap_Assets
Operating Segment Total      
Segment financial information for real estate operations      
Revenues from real estate operations 122,710us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		124,896us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		 
Property operating expenses 50,686ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		49,752ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		 
NOI from real estate operations 72,024ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		75,144ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		 
Additions to long-lived assets 71,971us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		13,729us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		 
Transfers from non-operating properties 117,272ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		56,940ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		 
Segment assets 3,110,380us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		2,932,749us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_OperatingSegmentsMember 		 
Baltimore and Washington Corridor      
Segment financial information for real estate operations      
Revenues from real estate operations 61,792us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		61,113us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		 
Property operating expenses 23,583ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		23,597ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		 
NOI from real estate operations 38,209ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		37,516ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		 
Additions to long-lived assets 3,445us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		5,741us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		 
Transfers from non-operating properties 12,930ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		6,911ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		 
Segment assets 1,280,742us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		1,244,876us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_BaltimoreAndWashingtonCorridorMember 		 
Northern Virginia      
Segment financial information for real estate operations      
Revenues from real estate operations 21,749us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		24,968us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		 
Property operating expenses 9,121ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		8,973ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		 
NOI from real estate operations 12,628ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		15,995ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		 
Additions to long-lived assets 2,821us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		3,495us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		 
Transfers from non-operating properties 58,571ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		26,588ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		 
Segment assets 696,276us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		636,895us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_NorthernVirginiaMember 		 
San Antonio      
Segment financial information for real estate operations      
Revenues from real estate operations 9,171us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		8,479us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		 
Property operating expenses 4,975ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		4,474ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		 
NOI from real estate operations 4,196ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		4,005ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		 
Additions to long-lived assets 21us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		(6)us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		 
Transfers from non-operating properties 31,091ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		0ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		 
Segment assets 147,078us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		117,812us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_SanAntonioMember 		 
Huntsville      
Segment financial information for real estate operations      
Revenues from real estate operations 2,446us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		2,555us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		 
Property operating expenses 829ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		653ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		 
NOI from real estate operations 1,617ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		1,902ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		 
Additions to long-lived assets 83us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		2,507us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		 
Transfers from non-operating properties 2,997ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		20,102ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		 
Segment assets 99,335us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		99,378us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_HuntsvilleMember 		 
Washington, DC - Capitol Riverfront      
Segment financial information for real estate operations      
Revenues from real estate operations 3,364us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		3,634us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		 
Property operating expenses 1,814ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		1,765ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		 
NOI from real estate operations 1,550ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		1,869ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		 
Additions to long-lived assets 393us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		63us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		 
Transfers from non-operating properties 0ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		0ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		 
Segment assets 94,400us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		97,843us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WashingtonDcCapitolRiverfrontMember 		 
St. Mary's and King George Counties      
Segment financial information for real estate operations      
Revenues from real estate operations 3,901us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		4,316us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		 
Property operating expenses 1,584ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		1,504ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		 
NOI from real estate operations 2,317ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		2,812ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		 
Additions to long-lived assets 1,200us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		839us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		 
Transfers from non-operating properties 0ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		0ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		 
Segment assets 100,849us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		95,645us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_StMarysAndKingGeorgeCountiesMember 		 
Greater Baltimore      
Segment financial information for real estate operations      
Revenues from real estate operations 11,485us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		11,496us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		 
Property operating expenses 4,997ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		5,476ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		 
NOI from real estate operations 6,488ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		6,020ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		 
Additions to long-lived assets 63,604us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		1,012us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		 
Transfers from non-operating properties 0ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		74ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		 
Segment assets 334,271us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		300,619us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterBaltimoreMember 		 
Greater Philadelphia      
Segment financial information for real estate operations      
Revenues from real estate operations 3,224us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		3,340us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		 
Property operating expenses 1,375ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		1,300ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		 
NOI from real estate operations 1,849ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		2,040ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		 
Additions to long-lived assets 294us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		11us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		 
Transfers from non-operating properties 11,498ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		3,176ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		 
Segment assets 117,919us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		94,428us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_GreaterPhiladelphiaMember 		 
Other      
Segment financial information for real estate operations      
Revenues from real estate operations 2,543us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		2,594us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		 
Property operating expenses 196ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		322ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		 
NOI from real estate operations 2,347ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		2,272ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		 
Additions to long-lived assets 80us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		55us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		 
Transfers from non-operating properties 8ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		11ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		 
Segment assets 77,340us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		79,542us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_OtherSegmentReportingMember 		 
Wholesale Data Center      
Segment financial information for real estate operations      
Revenues from real estate operations 3,035us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		2,401us-gaap_RealEstateRevenueNet
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		 
Property operating expenses 2,212ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		1,688ofc_SegmentReportingDirectCostsOfLeasedAndRentedPropertyOrEquipment
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		 
NOI from real estate operations 823ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		713ofc_SegmentReportingOperatingIncome
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		 
Additions to long-lived assets 30us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		12us-gaap_PropertyPlantAndEquipmentAdditions
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		 
Transfers from non-operating properties 177ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		78ofc_SegmentReportingTransfersFromNonOperatingProperties
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		 
Segment assets $ 162,170us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember 		$ 165,711us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= ofc_WholesaleDataCenterMember