Annual report pursuant to Section 13 and 15(d)

Consolidated Statements of Equity (Parenthetical)

v2.4.1.9
Consolidated Statements of Equity (Parenthetical)
 1 Months Ended 12 Months Ended 0 Months Ended
Nov. 30, 2014
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Jul. 16, 2013
Dec. 31, 2011
Balance (in units/ shares)     93,255,284us-gaap_CommonStockSharesOutstanding 87,394,512us-gaap_CommonStockSharesOutstanding 80,952,986us-gaap_CommonStockSharesOutstanding   72,011,324us-gaap_CommonStockSharesOutstanding
Conversion of common units to common shares (in shares/units)     140,149us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits 311,343us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits 234,246us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits    
Shares issued to the public (in units/shares) 5,520,000us-gaap_StockIssuedDuringPeriodSharesNewIssues 4,485,000us-gaap_StockIssuedDuringPeriodSharesNewIssues          
Exercise of share options (in units/shares)     62,888us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised 39,331us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised 61,624us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised    
Restricted common units/shares redemptions     57,537us-gaap_StockRepurchasedDuringPeriodShares 78,440us-gaap_StockRepurchasedDuringPeriodShares 139,851us-gaap_StockRepurchasedDuringPeriodShares    
Preferred Shares              
Shares issued to the public (in units/shares)         6,900,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_PreferredStockMember 		   
Stock redeemed or called during period (in units/ shares)     (2,000,000)us-gaap_StockRedeemedOrCalledDuringPeriodShares
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_PreferredStockMember 		(3,390,000)us-gaap_StockRedeemedOrCalledDuringPeriodShares
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_PreferredStockMember 		(2,200,000)us-gaap_StockRedeemedOrCalledDuringPeriodShares
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_PreferredStockMember 		   
Common Shares              
Shares issued to the public (in units/shares)     5,520,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		4,485,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		8,625,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonStockMember 		   
Common Stock Issued to Public Under At-the-Market Program              
Shares issued to the public (in units/shares)       1,500,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= ofc_CommonStockIssuedtoPublicUnderAttheMarketProgramMember 		  1,500,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= ofc_CommonStockIssuedtoPublicUnderAttheMarketProgramMember