Annual report pursuant to Section 13 and 15(d)

Earnings Per Share ("EPS") and Earnings Per Unit (???EPU???) (Details 2)

v3.10.0.1
Earnings Per Share ("EPS") and Earnings Per Unit (“EPU”) (Details 2) - shares
shares in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Conversion of common units [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 2,468 3,362 3,633
Conversion of redeemable noncontrolling interests [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 936 689 809
Conversion of Series I preferred units [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 176 176 176
Conversion of Series K preferred shares [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 0 0 434
Weighted average restricted shares/units and deferred share awards [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 452 433 385
Weighted average stock options [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 42 70 285
Corporate Office Properties, L.P. [Member] | Conversion of Series I preferred units [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 176 176 176
Corporate Office Properties, L.P. [Member] | Conversion of Series K preferred units [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 0 0 434
Corporate Office Properties, L.P. [Member] | Weighted average restricted shares/units and deferred share awards [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 452 433 385
Corporate Office Properties, L.P. [Member] | Weighted average stock options [Member]      
Antidilutive securities      
Weighted average antidilutive securities excluded from computation of diluted earnings per share (in shares) 42 70 285