COPT Defense Properties Annual report [Section 13 and 15(d), not S-K Item 405]

Annual report [Section 13 and 15(d), not S-K Item 405]

Leases - Percentage of Revenue (Details)

Leases - Percentage of Revenue (Details) - United States Government - Concentration risk	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Lease Revenue From Continuing Operations, Risk Benchmark
Concentration Risk [Line Items]
Percentage of revenue	37.00%	37.00%	37.00%
Fixed Lease Revenue From Continuing Operations Benchmark
Concentration Risk [Line Items]
Percentage of revenue	26.00%	27.00%	27.00%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 275
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-20

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 275
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 275
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-Section 55
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 275
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-Topic 954
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478785/954-310-50-2

+ Details

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References + Details