Earnings Per Share ("EPS") and Earnings Per Unit (“EPU”) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
3 Months Ended | 12 Months Ended | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
||||||
| Numerator: | ||||||||||||||||
| Net income attributable to COPT/COPLP | $ 17,020 | $ 18,697 | $ 19,434 | $ 17,150 | $ 9,621 | $ 20,579 | $ 17,526 | $ 21,019 | $ 72,301 | $ 68,745 | $ 28,890 | |||||
| Preferred share/ unit dividends/ distributions | 0 | 0 | 0 | 0 | 0 | 0 | (3,039) | (3,180) | 0 | (6,219) | (14,297) | |||||
| Issuance costs associated with redeemed preferred shares | $ 0 | $ 0 | $ 0 | $ 0 | $ 0 | $ 0 | $ (6,847) | $ 0 | 0 | (6,847) | (17) | |||||
| Income attributable to share-based compensation awards | (462) | (449) | (419) | |||||||||||||
| Numerator for basic and diluted EPS/EPU on net income attributable to COPT/COPLP common shareholders/unitholders | $ 71,839 | $ 55,230 | $ 14,157 | |||||||||||||
| Denominator (all weighted averages): | ||||||||||||||||
| Denominator for basic EPS (common shares) | 103,946 | 98,969 | 94,502 | |||||||||||||
| Dilutive effect of share-based compensation awards (common shares) | 134 | 132 | 92 | |||||||||||||
| Dilutive effect of forward equity sale agreements (common shares) | 45 | 54 | 0 | |||||||||||||
| Denominator for diluted EPS (common shares) | 104,125 | 99,155 | 94,594 | |||||||||||||
| Basic earnings per common share/unit (in dollars per share/unit) | $ 0.16 | $ 0.18 | $ 0.19 | $ 0.17 | $ 0.10 | $ 0.21 | $ 0.08 | $ 0.18 | $ 0.69 | $ 0.56 | $ 0.15 | |||||
| Diluted earnings per common share/unit (in dollars per share/unit) | $ 0.16 | $ 0.18 | $ 0.19 | $ 0.17 | $ 0.10 | $ 0.21 | $ 0.08 | $ 0.18 | $ 0.69 | $ 0.56 | $ 0.15 | |||||
| Corporate Office Properties, L.P. [Member] | ||||||||||||||||
| Numerator: | ||||||||||||||||
| Net income attributable to COPT/COPLP | $ 17,395 | $ 19,242 | $ 20,207 | $ 17,859 | $ 10,100 | $ 21,437 | $ 17,952 | $ 21,806 | $ 74,703 | $ 71,295 | $ 30,053 | |||||
| Preferred share/ unit dividends/ distributions | (165) | (165) | (165) | (165) | (165) | (165) | (3,204) | (3,345) | (660) | (6,879) | (14,957) | |||||
| Issuance costs associated with redeemed preferred shares | $ 0 | $ 0 | $ 0 | $ 0 | $ 0 | $ 0 | $ (6,847) | $ 0 | 0 | (6,847) | (17) | |||||
| Income attributable to share-based compensation awards | (462) | (449) | (419) | |||||||||||||
| Numerator for basic and diluted EPS/EPU on net income attributable to COPT/COPLP common shareholders/unitholders | $ 73,581 | $ 57,120 | $ 14,660 | |||||||||||||
| Denominator (all weighted averages): | ||||||||||||||||
| Denominator for basic EPS (common shares) | 106,414 | 102,331 | 98,135 | |||||||||||||
| Dilutive effect of share-based compensation awards (common shares) | 134 | 132 | 92 | |||||||||||||
| Dilutive effect of forward equity sale agreements (common shares) | 45 | 54 | 0 | |||||||||||||
| Denominator for diluted EPS (common shares) | 106,593 | 102,517 | 98,227 | |||||||||||||
| Basic earnings per common share/unit (in dollars per share/unit) | $ 0.16 | $ 0.18 | $ 0.19 | $ 0.17 | $ 0.10 | $ 0.21 | $ 0.08 | $ 0.18 | $ 0.69 | [1] | $ 0.56 | [1] | $ 0.15 | [1] | ||
| Diluted earnings per common share/unit (in dollars per share/unit) | $ 0.16 | $ 0.18 | $ 0.19 | $ 0.17 | $ 0.10 | $ 0.21 | $ 0.08 | $ 0.18 | $ 0.69 | [1] | $ 0.56 | [1] | $ 0.15 | [1] | ||
| ||||||||||||||||
| X | ||||||||||
- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Additional shared included in the calculation of diluted EPS as a result of the potentially dilutive effect of equity forward arrangements using the reverse treasury stock method. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities, and addition from assumption of issuance of common shares for dilutive potential common shares; of income (loss) available to common shareholders. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of preferred stock dividends and adjustments classified as other. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of earnings (loss) distributed and earnings (loss) allocated to participating securities for the basic earnings (loss) per share or per unit calculation under the two-class method. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition The amount of preferred stock dividends that is an adjustment to net income apportioned to common stockholders. No definition available.
|
| X | ||||||||||
- Definition The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|