Quarterly report pursuant to Section 13 or 15(d)

Consolidated Balance Sheets (Parenthetical)

v2.4.1.9
Consolidated Balance Sheets (Parenthetical) (USD $)
In Thousands, except Share data, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Allowance for doubtful accounts - AR $ 784us-gaap_AllowanceForDoubtfulAccountsReceivable $ 717us-gaap_AllowanceForDoubtfulAccountsReceivable
Allowance - Deferred rent receivable 1,695ofc_AllowanceforDoubtfulAccountsDeferredRent 1,418ofc_AllowanceforDoubtfulAccountsDeferredRent
Preferred Shares of beneficial interest, par value (in dollars per share) $ 0.01us-gaap_PreferredStockParOrStatedValuePerShare $ 0.01us-gaap_PreferredStockParOrStatedValuePerShare
Preferred Shares of beneficial interest, shares authorized 25,000,000us-gaap_PreferredStockSharesAuthorized 25,000,000us-gaap_PreferredStockSharesAuthorized
Preferred Shares of beneficial interest, shares issued 7,431,667us-gaap_PreferredStockSharesIssued 7,431,667us-gaap_PreferredStockSharesIssued
Preferred Shares of beneficial interest, shares outstanding 7,431,667us-gaap_PreferredStockSharesOutstanding 7,431,667us-gaap_PreferredStockSharesOutstanding
Common Shares of beneficial interest, par value (in dollars per share) $ 0.01us-gaap_CommonStockParOrStatedValuePerShare $ 0.01us-gaap_CommonStockParOrStatedValuePerShare
Common Shares of beneficial interest, shares authorized 125,000,000us-gaap_CommonStockSharesAuthorized 125,000,000us-gaap_CommonStockSharesAuthorized
Common Stock, Shares, Issued 94,536,269us-gaap_CommonStockSharesIssued 93,255,284us-gaap_CommonStockSharesIssued
Common Shares of beneficial interest, shares outstanding 94,536,269us-gaap_CommonStockSharesOutstanding 93,255,284us-gaap_CommonStockSharesOutstanding
Corporate Office Properties, L.P.    
Allowance for doubtful accounts - AR 784us-gaap_AllowanceForDoubtfulAccountsReceivable
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
717us-gaap_AllowanceForDoubtfulAccountsReceivable
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
Allowance - Deferred rent receivable $ 1,695ofc_AllowanceforDoubtfulAccountsDeferredRent
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
$ 1,418ofc_AllowanceforDoubtfulAccountsDeferredRent
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
Corporate Office Properties, L.P. | General Partner    
Common Shares of beneficial interest, shares outstanding 94,536,269us-gaap_CommonStockSharesOutstanding
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_PartnerTypeOfPartnersCapitalAccountAxis
= us-gaap_GeneralPartnerMember
93,255,284us-gaap_CommonStockSharesOutstanding
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_PartnerTypeOfPartnersCapitalAccountAxis
= us-gaap_GeneralPartnerMember
Preferred Units, Outstanding 7,431,667us-gaap_PreferredUnitsOutstanding
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_PartnerTypeOfPartnersCapitalAccountAxis
= us-gaap_GeneralPartnerMember
7,431,667us-gaap_PreferredUnitsOutstanding
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_PartnerTypeOfPartnersCapitalAccountAxis
= us-gaap_GeneralPartnerMember
Corporate Office Properties, L.P. | Limited Partner    
Common Shares of beneficial interest, shares outstanding 3,679,551us-gaap_CommonStockSharesOutstanding
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_PartnerTypeOfPartnersCapitalAccountAxis
= us-gaap_LimitedPartnerMember
3,837,551us-gaap_CommonStockSharesOutstanding
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_PartnerTypeOfPartnersCapitalAccountAxis
= us-gaap_LimitedPartnerMember
Preferred Units, Outstanding 352,000us-gaap_PreferredUnitsOutstanding
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_PartnerTypeOfPartnersCapitalAccountAxis
= us-gaap_LimitedPartnerMember
352,000us-gaap_PreferredUnitsOutstanding
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
/ us-gaap_PartnerTypeOfPartnersCapitalAccountAxis
= us-gaap_LimitedPartnerMember