XML 58 R42.htm IDEA: XBRL DOCUMENT
v3.19.2

Summary of Significant Accounting Policies (Details) - Accounting Standards Update 2016-02 $ in Millions | Jan. 01, 2019 USD ($)
--- | ---
Operating Lease, Right-of-use Assets |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Effect of new accounting principle | $ 11
Operating Lease, Right-of-use Assets | Properties |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Effect of new accounting principle | 16
Operating Lease Liability | Properties |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Effect of new accounting principle | 16
Finance Lease, Right-of Use Assets | Properties |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Effect of new accounting principle | 38
Total Properties, Net |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
Effect of new accounting principle | $ (38)

X
- Definition Represents the quantification of the effect of adopting the new accounting standard or change in accounting principle expected by the entity to have a significant effect on the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=ofc_OperatingLeaseRightofuseAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201602Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LandBuildingsAndImprovementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=ofc_OperatingLeaseLiabilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=ofc_FinanceLeaseRightofUseAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=ofc_TotalPropertiesNetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |