COPT Defense Properties Quarterly report pursuant to Section 13 or 15(d)

Organization (Details)

Organization (Details) ft² in Thousands	Sep. 30, 2017 a ft² buillding Property MW
Operating office properties
Investments in real estate
Number of real estate properties	159
Area of real estate property (in square feet or acres) \| ft²	17,400
Operating office properties \| Single-tenant data centers
Investments in real estate
Number of real estate properties \| buillding	15
Office properties under, or contractually committed for, construction or approved for redevelopment
Investments in real estate
Number of real estate properties	10
Area of real estate property (in square feet or acres) \| ft²	1,087
Office properties under, or contractually committed for, construction or approved for redevelopment \| Single-tenant data centers
Investments in real estate
Number of real estate properties \| buillding	3
Office properties under, or contractually committed for, construction or approved for redevelopment \| Partially operational properties
Investments in real estate
Number of real estate properties	3
Office properties under, or contractually committed for, construction or approved for redevelopment \| Properties completed Held-for-future lease
Investments in real estate
Number of real estate properties	2
Land controlled for future development
Investments in real estate
Area of real estate property (in square feet or acres) \| a	984
Developable square feet \| ft²	12,300
Other Land
Investments in real estate
Area of real estate property (in square feet or acres) \| a	152
Operating wholesale data centers
Investments in real estate
Critical load (in megawatts) \| MW	19.25
GI-COPT \| Operating office properties \| Single-tenant data centers
Investments in real estate
Number of real estate properties	6