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

Annual report pursuant to Section 13 and 15(d)

Cover
- Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- Summary of Significant Accounting Policies (Policies)
Notes Tables
Notes Details

Commitments and Contingencies - Narrative (Details)

v3.8.0.1

Commitments and Contingencies - Narrative (Details)	May 25, 2017 USD ($)	Dec. 31, 2017 USD ($) Property	Dec. 31, 2016 USD ($)	Aug. 31, 2010 USD ($)
Capital Lease
Capital lease term	99 years
Purchase option	$ 1
Capital lease obligation	$ 16,100,000	$ 15,853,000	$ 0
Environmental Indemnity Agreement
Number of lease properties which were provided environmental indemnifications \| Property		3
Maximum environmental indemnification to the tenant against consequential damages after acquisition of property		$ 19,000,000
Specialty Tax Guarantee [Member]
Tax incremental financing obligation
Liability recognized with regard to tax incremental financing obligation at end of current period		981,000
New Development and Redevelopment Obligations [Member]
Capital Lease
Contractual obligation		22,800,000
Capital Expenditures For Operating Properties [Member]
Capital Lease
Contractual obligation		44,200,000
Third Party Construction and Development [Member]
Capital Lease
Contractual obligation		35,800,000
Other Obligations [Member]
Capital Lease
Contractual obligation		$ 900,000
Tax Incremental Financing Bond [Member] \| Anne Arundel County, Maryland [Member] \| Specialty Tax Guarantee [Member]
Commitments and Contingencies
Loan amount				$ 30,000,000

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