Annual report pursuant to Section 13 and 15(d)

Quarterly Data (Unaudited) (Details)

v3.8.0.1
Quarterly Data (Unaudited) (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Quarterly Data [Line Items]                      
Revenues $ 164,567 $ 157,017 $ 151,435 $ 139,801 $ 141,991 $ 142,103 $ 145,927 $ 144,307 $ 612,820 $ 574,328 $ 625,466
Operating income 24,847 38,939 36,618 35,433 37,442 11,525 (27,021) 30,464 135,837 52,410 120,094
Income (loss) from continuing operations 6,904 21,494 19,195 18,850 19,718 (4,829) (48,316) 8,096 66,443 (25,331) 120,675
Net income (loss) 11,356 22,682 19,207 23,088 26,603 29,272 (48,316) 8,096 76,333 15,655 188,878
Net (income) loss attributable to noncontrolling interests (1,398) (1,766) (1,345) (1,733) (1,870) (1,973) 897 (1,270)      
Net income attributable to COPT 9,958 20,916 17,862 21,355 24,733 27,299 (47,419) 6,826 70,091 11,439 178,300
Preferred share/ unit dividends/ distributions 0 0 (3,039) (3,180) (3,640) (3,552) (3,553) (3,552) (6,219) (14,297) (14,210)
Issuance costs associated with redeemed preferred shares 0 0 (6,847) 0 (17) 0 0 0 (6,847) (17) 0
Net income (loss) attributable to COPT common shareholders $ 9,958 $ 20,916 $ 7,976 $ 18,175 $ 21,076 $ 23,747 $ (50,972) $ 3,274 $ 57,025 $ (2,875) $ 164,090
Basic earnings per common share/unit (in dollars per share/unit) $ 0.10 $ 0.21 $ 0.08 $ 0.18 $ 0.22 $ 0.25 $ (0.54) $ 0.03 $ 0.57 [1] $ (0.03) [1] $ 1.74 [1]
Diluted earnings per common share/unit (in dollars per share/unit) $ 0.10 $ 0.21 $ 0.08 $ 0.18 $ 0.22 $ 0.25 $ (0.54) $ 0.03 $ 0.57 [1] $ (0.03) [1] $ 1.74 [1]
Corporate Office Properties, L.P. [Member]                      
Quarterly Data [Line Items]                      
Revenues $ 164,567 $ 157,017 $ 151,435 $ 139,801 $ 141,991 $ 142,103 $ 145,927 $ 144,307 $ 612,820 $ 574,328 $ 625,466
Operating income 24,847 38,939 36,618 35,433 37,442 11,525 (27,021) 30,464 135,837 52,410 120,094
Income (loss) from continuing operations 6,904 21,494 19,195 18,850 19,718 (4,829) (48,316) 8,096 66,443 (25,331) 120,675
Net income (loss) 11,356 22,682 19,207 23,088 26,603 29,272 (48,316) 8,096 76,333 15,655 188,878
Net (income) loss attributable to noncontrolling interests (908) (897) (907) (934) (912) (913) (911) (979) (3,646) (3,715) (3,520)
Net income attributable to COPT 10,448 21,785 18,300 22,154 25,691 28,359 (49,227) 7,117 72,687 11,940 185,358
Preferred share/ unit dividends/ distributions (165) (165) (3,204) (3,345) (3,805) (3,717) (3,718) (3,717) (6,879) (14,957) (14,870)
Issuance costs associated with redeemed preferred shares 0 0 (6,847) 0 (17) 0 0 0 (6,847) (17) 0
Net income (loss) attributable to COPT common shareholders $ 10,283 $ 21,620 $ 8,249 $ 18,809 $ 21,869 $ 24,642 $ (52,945) $ 3,400 $ 58,961 $ (3,034) $ 170,488
Basic earnings per common share/unit (in dollars per share/unit) $ 0.10 $ 0.21 $ 0.08 $ 0.18 $ 0.22 $ 0.25 $ (0.54) $ 0.03 $ 0.57 [2] $ (0.04) [2] $ 1.74 [2]
Diluted earnings per common share/unit (in dollars per share/unit) $ 0.10 $ 0.21 $ 0.08 $ 0.18 $ 0.22 $ 0.25 $ (0.54) $ 0.03 $ 0.57 [2] $ (0.04) [2] $ 1.74 [2]
[1] Basic and diluted earnings per common share are calculated based on amounts attributable to common shareholders of Corporate Office Properties Trust.
[2] Basic and diluted earnings per common unit are calculated based on amounts attributable to common unitholders of Corporate Office Properties, L.P.