Quarterly report pursuant to Section 13 or 15(d)

Equity (Details)

v3.19.2
Equity (Details) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Class of Stock [Line Items]        
Conversion of common units to common shares (in units/shares)     5,500 53,817
Dividends declared per share (in usd per share) $ 0.275 $ 0.275 $ 0.55 $ 0.55
Common Shares | Forward Equity Sale Agreement        
Class of Stock [Line Items]        
Number of shares issued     1,600,000  
Proceeds from common shares issued under forward equity sale agreements     $ 46.5  
Common Shares | 2018 Common Stock Issued to Public Under At-the-Market Program        
Class of Stock [Line Items]        
Aggregate gross sales price $ 300.0   $ 300.0  
Corporate Office Properties, L.P.        
Class of Stock [Line Items]        
Dividends declared per share (in usd per share) $ 0.275 $ 0.275 $ 0.55 $ 0.55