Quarterly report pursuant to Section 13 or 15(d)

Earnings Per Share ("EPS") and Earnings Per Unit ("EPU") (Details)

v3.8.0.1
Earnings Per Share ("EPS") and Earnings Per Unit ("EPU") (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Numerator:    
Net income attributable to COPT $ 17,150 $ 21,019
Preferred share/unit dividends/distributions 0 (3,180)
Income attributable to share-based compensation awards (117) (125)
Numerator for basic and diluted EPS on net income attributable to COPT common shareholders $ 17,033 $ 17,714
Denominator (all weighted averages):    
Denominator for basic EPS (common shares) 100,999 98,411
Dilutive effect of share-based compensation awards (shares) 144 155
Denominator for diluted EPS (common shares) 101,143 98,566
Basic EPS:    
Net income attributable to COPT common shareholders - basic (in dollars per share/unit) $ 0.17 $ 0.18
Diluted EPS:    
Net income attributable to COPT common shareholders - diluted (in dollars per share/unit) $ 0.17 $ 0.18
Corporate Office Properties, L.P.    
Numerator:    
Net income attributable to COPT $ 17,859 $ 21,806
Preferred share/unit dividends/distributions (165) (3,345)
Income attributable to share-based compensation awards (117) (125)
Numerator for basic and diluted EPS on net income attributable to COPT common shareholders $ 17,577 $ 18,336
Denominator (all weighted averages):    
Denominator for basic EPS (common shares) 104,220 101,857
Dilutive effect of share-based compensation awards (shares) 144 155
Denominator for diluted EPS (common shares) 104,364 102,012
Basic EPS:    
Net income attributable to COPT common shareholders - basic (in dollars per share/unit) $ 0.17 $ 0.18
Diluted EPS:    
Net income attributable to COPT common shareholders - diluted (in dollars per share/unit) $ 0.17 $ 0.18