COPT Defense Properties Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Debt, Net - Narrative (Details)

Debt, Net - Narrative (Details)			12 Months Ended
Debt, Net - Narrative (Details)	Dec. 31, 2024 USD ($) extension $ / shares	Sep. 12, 2023 USD ($) day $ / shares	Dec. 31, 2024 USD ($) extension $ / shares	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Oct. 26, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Capitalized interest costs			$ 2,900,000	$ 4,500,000	$ 6,700,000
Debt, net	$ 2,391,755,000		$ 2,391,755,000	2,416,287,000
Revolving Credit Facility
Debt Instrument [Line Items]
Variable rate, additional spread			0.0010
Weighted average interest rate	5.70%		5.70%
Debt, net	$ 75,000,000		$ 75,000,000	75,000,000
Term Loan Facility
Debt Instrument [Line Items]
Number of extensions \| extension	2		2
Extension option period			12 months
Line of credit facility, extension fee			0.125%
Variable rate, additional spread			0.0010
Debt, net	$ 124,633,000		$ 124,633,000	124,291,000			$ 300,000,000.0
Repayments of term loan					$ 300,000,000.0
Interest rate	5.95%		5.95%
Term Loan Facility \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate, additional spread			0.0010
Minimum \| Revolving Credit Facility
Debt Instrument [Line Items]
Variable rate, spread			0.725%
Minimum \| Term Loan Facility
Debt Instrument [Line Items]
Variable rate, spread			0.85%
Minimum \| Term Loan Facility \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate, spread			0.85%
Maximum \| Revolving Credit Facility
Debt Instrument [Line Items]
Variable rate, spread			1.40%
Maximum \| Term Loan Facility
Debt Instrument [Line Items]
Variable rate, spread			1.70%
Maximum \| Term Loan Facility \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate, spread			1.70%
Revolving Credit Facility
Debt Instrument [Line Items]
Weighted average borrowings			$ 78,300,000	$ 133,300,000
Weighted average interest rate	6.29%		6.29%	6.17%
Revolving Credit Facility \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate, additional spread			0.0010
Revolving Credit Facility \| Minimum \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate, spread			0.725%
Revolving Credit Facility \| Maximum \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Variable rate, spread			1.40%
Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Current borrowing capacity	$ 600,000,000.0		$ 600,000,000.0			$ 600,000,000.0
Number of extensions \| extension	2		2
Extension option period			6 months
Line of credit facility, extension fee			0.0625%
Remaining borrowing capacity	$ 525,000,000.0		$ 525,000,000.0
Line of Credit \| Revolving Credit Facility \| Minimum
Debt Instrument [Line Items]
Commitment fee percentage			0.125%
Line of Credit \| Revolving Credit Facility \| Maximum
Debt Instrument [Line Items]
Commitment fee percentage			0.30%
Unsecured Debt \| Term Loan Facility
Debt Instrument [Line Items]
Loan amount						$ 125,000,000.0
Unsecured Senior Notes \| 2.25%, 2.75%, 2.00% and 2.90% Senior Notes
Debt Instrument [Line Items]
Redemption price			100.00%
Unsecured Senior Notes \| 2.25% Senior Notes
Debt Instrument [Line Items]
Loan amount	400,000,000		$ 400,000,000
Debt, net	$ 398,699,000		$ 398,699,000	$ 397,608,000
Interest rate	2.25%		2.25%
Basis point used in determining redemption price prior to maturity			0.35%
Unsecured Senior Notes \| 2.75%, $600,000 aggregate principal
Debt Instrument [Line Items]
Loan amount	$ 600,000,000		$ 600,000,000
Debt, net	$ 592,330,000		$ 592,330,000	591,212,000
Interest rate	2.75%		2.75%
Unsecured Senior Notes \| 2.75%, $600,000 aggregate principal \| Adjusted Treasury
Debt Instrument [Line Items]
Basis point used in determining redemption price prior to maturity			0.25%
Unsecured Senior Notes \| 2.00%, $400,000 aggregate principal
Debt Instrument [Line Items]
Loan amount	$ 400,000,000		$ 400,000,000
Debt, net	$ 397,961,000		$ 397,961,000	397,471,000
Interest rate	2.00%		2.00%
Unsecured Senior Notes \| 2.00%, $400,000 aggregate principal \| Adjusted Treasury
Debt Instrument [Line Items]
Basis point used in determining redemption price prior to maturity			0.20%
Unsecured Senior Notes \| 2.90%, $400,000 aggregate principal
Debt Instrument [Line Items]
Loan amount	$ 400,000,000		$ 400,000,000
Debt, net	$ 395,692,000		$ 395,692,000	395,265,000
Interest rate	2.90%		2.90%
Unsecured Senior Notes \| 2.90%, $400,000 aggregate principal \| Adjusted Treasury
Debt Instrument [Line Items]
Basis point used in determining redemption price prior to maturity			0.25%
Unsecured Senior Notes \| 5.25%, $345,000 aggregate principal
Debt Instrument [Line Items]
Loan amount	$ 345,000,000	$ 345,000,000	$ 345,000,000
Debt, net	$ 337,588,000		$ 337,588,000	$ 335,802,000
Interest rate	5.25%	5.25%	5.25%
Proceeds from issuance of debt		$ 336,400,000
Exchange rate	0.0334238	0.0333739
Exchange price per share (in dollars per share) \| $ / shares	$ 29.92	$ 29.96	$ 29.92
Threshold percentage of stock price trigger		130.00%
Threshold trading days \| day		20
Threshold consecutive trading days \| day		30
Redemption price		100.00%