COPT Defense Properties Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Liabilities:
Interest rate derivatives	$ 4,282	$ 1,855
Redeemable noncontrolling interest	18,895	18,417	17,654	17,758
Corporate Office Properties, L.P.
Liabilities:
Interest rate derivatives	4,282	1,855
Fair value measurement on a recurring basis
Assets:
Warrants to purchase common stock	89
Assets	6,025
Liabilities:
Deferred compensation plan liability	5,936
Interest rate derivatives	4,282
Liabilities	10,218
Redeemable noncontrolling interest	18,895
Fair value measurement on a recurring basis \| Mutual funds
Assets:
Marketable securities in deferred compensation plan	5,826
Fair value measurement on a recurring basis \| Other
Assets:
Marketable securities in deferred compensation plan	110
Fair value measurement on a recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Assets	5,936
Fair value measurement on a recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Mutual funds
Assets:
Marketable securities in deferred compensation plan	5,826
Fair value measurement on a recurring basis \| Quoted Prices in Active Markets for Identical Assets (Level 1) \| Other
Assets:
Marketable securities in deferred compensation plan	110
Fair value measurement on a recurring basis \| Significant Other Observable Inputs (Level 2)
Assets:
Warrants to purchase common stock	89
Assets	89
Liabilities:
Deferred compensation plan liability	5,936
Interest rate derivatives	4,282
Liabilities	10,218
Fair value measurement on a recurring basis \| Significant Unobservable Inputs (Level 3)
Liabilities:
Redeemable noncontrolling interest	18,895
Fair value measurement on a recurring basis \| Corporate Office Properties, L.P.
Assets:
Warrants to purchase common stock	89
Liabilities:
Interest rate derivatives	4,282
Redeemable noncontrolling interest	18,895
Fair value measurement on a recurring basis \| Corporate Office Properties, L.P. \| Significant Other Observable Inputs (Level 2)
Assets:
Warrants to purchase common stock	89
Liabilities:
Interest rate derivatives	4,282
Fair value measurement on a recurring basis \| Corporate Office Properties, L.P. \| Significant Unobservable Inputs (Level 3)
Liabilities:
Redeemable noncontrolling interest	$ 18,895