Annual report pursuant to Section 13 and 15(d)

Equity - COPLP and Subsidiaries (Details)

v3.3.1.900
Equity - COPLP and Subsidiaries (Details) - USD ($)
$ / shares in Units, $ in Thousands
 1 Months Ended 12 Months Ended
Jun. 16, 2014
Jul. 16, 2013
Jul. 15, 2013
Nov. 30, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Preferred Stock              
Number of shares issued         7,431,667    
Aggregate liquidation preference         $ 199,083 $ 199,083  
Stock redeemed or called during period value           50,000 $ 84,750
Common Shares              
Shares issued to the public       5,520,000      
Per share value of common and preferred shares issued to the public (in dollars per share)       $ 27.30      
Net proceeds from issue of shares after underwriter discounts but before offering expenses       $ 148,900   $ 148,666 $ 117,961
Number of common shares for each converted common unit (in shares)         1    
Number of operating partnerships units converted into common shares (in units)         160,160 140,149 311,343
Dividends declared per common share         $ 1.1000 $ 1.10 $ 1.10
Preferred units in COPLP         $ 8,800 $ 8,800  
Common Stock Issued to Public Under At-the-Market Program [Member]              
Common Shares              
Shares issued to the public     1,500,000.0   890,241   1,500,000
Issuance of stock, weighted average price per share         $ 30.29    
Payments of stock issuance costs     $ 600   $ 400    
Series H [Member]              
Preferred Stock              
Annual dividend yield 7.50%            
Preferred stock, redemption price per share $ 25            
Stock redeemed or called during period value $ 50,000            
Issuance costs associated with redeemed preferred shares $ 1,800            
Series K [Member]              
Preferred Stock              
Number of shares issued         531,667    
Aggregate liquidation preference         $ 26,583    
Annual dividend yield         5.60%    
Annual dividend per share (in dollars per share)         $ 2.80000    
Number of common shares to be issued on conversion of each preferred share         0.8163    
Series L [Member]              
Preferred Stock              
Number of shares issued         6,900,000    
Aggregate liquidation preference         $ 172,500    
Annual dividend yield         7.375%    
Annual dividend per share (in dollars per share)         $ 1.84375    
Corporate Office Properties, L.P. [Member]              
Preferred Stock              
Number of shares issued         7,431,667    
Aggregate liquidation preference         $ 199,083    
Stock redeemed or called during period value           50,000 $ 84,750
Common Shares              
Net proceeds from issue of shares after underwriter discounts but before offering expenses           $ 148,666 $ 117,961
Number of common shares for each converted common unit (in shares)         1    
Number of operating partnerships units converted into common shares (in units)         160,160.00 140,149.000 311,343.000
Dividends declared per common share         $ 1.1 $ 1.10 $ 1.10
Corporate Office Properties, L.P. [Member] | Common Stock Issued to Public Under At-the-Market Program [Member]              
Common Shares              
Shares issued to the public   1,500,000     890,241    
Net proceeds from issue of shares after underwriter discounts but before offering expenses   $ 38,500     $ 26,600    
Issuance of stock, weighted average price per share   $ 26.05     $ 30.29    
Payments of stock issuance costs   $ 600     $ 400    
Corporate Office Properties, L.P. [Member] | Common Units [Member]              
Common Shares              
Percentage ownership in operating partnership         96.30% 96.00%  
Corporate Office Properties, L.P. [Member] | Conversion of Series I preferred units [Member]              
Preferred Stock              
Annual dividend yield         7.50%    
Annual cumulative preferred return increment frequency         5 years    
Common Shares              
Limited partners' capital account, units issued         352,000    
Preferred units in COPLP         $ 8,800    
Preferred stock, liquidation preference per share         $ 25    
Common units conversion basis units issuable         0.5    
Corporate Office Properties, L.P. [Member] | Series H [Member]              
Preferred Stock              
Annual dividend yield 7.50%            
Preferred stock, redemption price per share $ 25            
Stock redeemed or called during period value $ 50,000            
Issuance costs associated with redeemed preferred shares $ 1,800            
Corporate Office Properties, L.P. [Member] | Series K [Member]              
Preferred Stock              
Number of shares issued         531,667    
Aggregate liquidation preference         $ 26,583    
Annual dividend yield         5.60%    
Annual dividend per share (in dollars per share)         $ 2.80000    
Number of common shares to be issued on conversion of each preferred share         0.8163    
Corporate Office Properties, L.P. [Member] | Series L [Member]              
Preferred Stock              
Number of shares issued         6,900,000    
Aggregate liquidation preference         $ 172,500    
Annual dividend yield         7.375%    
Annual dividend per share (in dollars per share)         $ 1.84375    
Corporate Office Properties, L.P. [Member] | Common Shares [Member]              
Common Shares              
Shares issued to the public       5,520,000      
Per share value of common and preferred shares issued to the public (in dollars per share)       $ 27.30      
Net proceeds from issue of shares after underwriter discounts but before offering expenses       $ 148,900