Quarterly report pursuant to Section 13 or 15(d)

Income Taxes (Details)

v2.4.1.9
Income Taxes (Details) (Taxable REIT Subsidiary, USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Taxable REIT Subsidiary
   
Deferred income tax (expense) benefit    
Federal $ 45us-gaap_DeferredFederalIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= ofc_TaxableReitSubsidiaryMember
$ 53us-gaap_DeferredFederalIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= ofc_TaxableReitSubsidiaryMember
State 10us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= ofc_TaxableReitSubsidiaryMember
11us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= ofc_TaxableReitSubsidiaryMember
Total income tax expense $ 55us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= ofc_TaxableReitSubsidiaryMember
$ 64us-gaap_DeferredIncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= ofc_TaxableReitSubsidiaryMember
Effective tax rate (as a percent) 37.80%us-gaap_EffectiveIncomeTaxRateContinuingOperations
/ dei_LegalEntityAxis
= ofc_TaxableReitSubsidiaryMember
38.10%us-gaap_EffectiveIncomeTaxRateContinuingOperations
/ dei_LegalEntityAxis
= ofc_TaxableReitSubsidiaryMember