COPT Defense Properties Quarterly report [Sections 13 or 15(d)]

Interest Rate Derivatives - Schedule of Effect of Interest Rate Derivatives on Consolidated Statements of Operations and Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Effect of interest rate derivatives on consolidated statements of operations and comprehensive income
Amount of (Loss) Income Recognized in AOCI on Derivatives	$ 274	$ 910	$ 194	$ 3,891
Amount of Income Reclassified from AOCI into Interest Expense on Statement of Operations	366	1,172	928	2,352
Interest rate swaps
Effect of interest rate derivatives on consolidated statements of operations and comprehensive income
Amount of (Loss) Income Recognized in AOCI on Derivatives	274	910	194	3,891
Interest rate swaps \| Interest expense
Effect of interest rate derivatives on consolidated statements of operations and comprehensive income
Amount of Income Reclassified from AOCI into Interest Expense on Statement of Operations	$ 366	$ 1,172	$ 928	$ 2,352