Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation These consolidated financial statements include the accounts of COPT Defense, the Operating Partnership, their subsidiaries and other entities in which COPT Defense has a majority voting interest and control. We also consolidate certain entities when control of such entities can be achieved through means other than voting rights (“variable interest entities” or “VIEs”) if we are deemed to be the primary beneficiary of such entities. We eliminate all intercompany balances and transactions in consolidation. We use the equity method of accounting when we own an interest in an entity and can exert significant influence over but cannot control the entity’s operations. We discontinue equity method accounting if our investment in an entity (and net advances) is reduced to zero unless we have guaranteed obligations of the entity or are otherwise committed to provide further financial support for the entity. When we own an equity investment in an entity and cannot exert significant influence over its operations, we measure the investment at fair value, with changes recognized through net income. For an investment without a readily determinable fair value, we measure the investment at cost, less any impairments, plus or minus changes resulting from observable price changes for an identical or similar investment of the same issuer. These interim financial statements should be read together with the consolidated financial statements and notes thereto as of and for the year ended December 31, 2023 included in our 2023 Annual Report on Form 10-K. The unaudited consolidated financial statements include all adjustments that are necessary, in the opinion of management, to fairly state our financial position and results of operations. All adjustments are of a normal recurring nature. The consolidated financial statements have been prepared using the accounting policies described in our 2023 Annual Report on Form 10-K. Reclassifications We reclassified certain amounts from prior periods to conform to the current period presentation of our consolidated financial statements with no effect on previously reported net income or equity. Recent Accounting Pronouncements In November 2023, the Financial Accounting Standard Board (“FASB”) issued guidance to improve reportable segment disclosure requirements. This guidance requires disclosure of incremental segment information on an annual and interim basis and is effective for us beginning after December 15, 2024. Early adoption is permitted. The guidance will be applied retrospectively to all periods presented unless it is impracticable to do so. We are currently assessing the impact of this guidance on our future related disclosures. In December 2023, the FASB issued guidance to improve income tax disclosures. This guidance requires enhanced annual disclosures primarily related to existing rate reconciliation and income taxes paid disclosure requirements and is effective for us for annual periods beginning after December 15, 2024. Early adoption is permitted. We expect to apply this guidance prospectively. We are currently assessing the application of this guidance but do not expect it to materially affect our future related disclosures. In March 2024, the FASB issued guidance to reduce complexity and diversity in practice in determining whether a profits interest award is accounted for as a share-based payment. This guidance is effective for us for annual and interim periods beginning after December 15, 2024. Early adoption is permitted. This guidance can be applied either retrospectively to all prior periods presented in the financial statements or prospectively to profits interest or similar awards granted or modified on or after the effective date for our application of this guidance. We are currently assessing the application of this guidance on our future related disclosures.