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

Organization - Narrative 1 (Details)

Organization - Narrative 1 (Details) - Sep. 30, 2021 ft² in Millions	property	ft²	MW	a
Unconsolidated Real Estate Joint Ventures
Investments in real estate
Number of real estate properties	19
Operating Properties
Investments in real estate
Number of real estate properties	186
Area of real estate property (in sqft or acres) \| ft²		21.7
Operating Properties \| Office Properties
Investments in real estate
Number of real estate properties	160
Area of real estate property (in sqft or acres) \| ft²		16.9
Operating Properties \| Single-tenant data centers
Investments in real estate
Number of real estate properties	26
Area of real estate property (in sqft or acres) \| ft²		4.7
Operating Properties \| Single-tenant data centers \| Unconsolidated Real Estate Joint Ventures
Investments in real estate
Number of real estate properties	19
Operating wholesale data center
Investments in real estate
Capacity (in megawatts) \| MW			19.25
Properties under development
Investments in real estate
Number of real estate properties	13
Area of real estate property (in sqft or acres) \| ft²		1.8
Properties under development \| Office Properties
Investments in real estate
Number of real estate properties	10
Properties under development \| Single-tenant data centers
Investments in real estate
Number of real estate properties	3
Properties under development, partially-operational
Investments in real estate
Number of real estate properties	3
Land controlled for future development
Investments in real estate
Area of real estate property (in sqft or acres)		8.9		720
Other Land
Investments in real estate
Area of real estate property (in sqft or acres) \| a				43