Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

v2.4.0.8
Fair Value Measurements (Details) (USD $)
In Thousands, unless otherwise specified
 6 Months Ended
Jun. 30, 2013
Dec. 31, 2012
Jun. 30, 2012
Jun. 30, 2013
Corporate Office Properties, L.P.
Dec. 31, 2012
Corporate Office Properties, L.P.
Jun. 30, 2013
Fair value measurement on a recurring basis
Quoted Prices in Active Markets for Identical Assets (Level 1)
Jun. 30, 2013
Fair value measurement on a recurring basis
Quoted Prices in Active Markets for Identical Assets (Level 1)
Corporate Office Properties, L.P.
Jun. 30, 2013
Fair value measurement on a recurring basis
Quoted Prices in Active Markets for Identical Assets (Level 1)
Mutual funds
Jun. 30, 2013
Fair value measurement on a recurring basis
Quoted Prices in Active Markets for Identical Assets (Level 1)
Common stocks
Jun. 30, 2013
Fair value measurement on a recurring basis
Quoted Prices in Active Markets for Identical Assets (Level 1)
Other
Jun. 30, 2013
Fair value measurement on a recurring basis
Significant Other Observable Inputs (Level 2)
Jun. 30, 2013
Fair value measurement on a recurring basis
Significant Other Observable Inputs (Level 2)
Corporate Office Properties, L.P.
Jun. 30, 2013
Fair value measurement on a recurring basis
Significant Unobservable Inputs (Level 3)
Jun. 30, 2013
Fair value measurement on a recurring basis
Significant Unobservable Inputs (Level 3)
Corporate Office Properties, L.P.
Jun. 30, 2013
Fair value measurement on a recurring basis
Total Estimated Fair Value
Jun. 30, 2013
Fair value measurement on a recurring basis
Total Estimated Fair Value
Corporate Office Properties, L.P.
Jun. 30, 2013
Fair value measurement on a recurring basis
Total Estimated Fair Value
Mutual funds
Jun. 30, 2013
Fair value measurement on a recurring basis
Total Estimated Fair Value
Common stocks
Jun. 30, 2013
Fair value measurement on a recurring basis
Total Estimated Fair Value
Other
Jun. 30, 2013
Minimum
Fair value measurement on a recurring basis
Significant Unobservable Inputs (Level 3)
Jun. 30, 2013
Maximum
Fair value measurement on a recurring basis
Significant Unobservable Inputs (Level 3)
Jun. 30, 2013
Weighted Average
Fair value measurement on a recurring basis
Significant Unobservable Inputs (Level 3)
Assets:                                            
Marketable securities in deferred compensation plan               $ 6,649 [1] $ 216 [1] $ 211 [1]             $ 6,649 [1] $ 216 [1] $ 211 [1]      
Common stock           1,825 [1] 1,825 [2]               1,825 [1] 1,825 [2]            
Interest rate derivatives 3,407 (6,185)                 6,963 [3] 6,963 [4]     6,963 [3] 6,963 [4]            
Warrants to purchase common stock                     299 [3] 299 [4]     299 [3] 299 [4]            
Assets           8,901 1,825       7,262 7,262     16,163 9,087            
Liabilities:                                            
Deferred compensation plan liability           7,076 [5]                 7,076 [5]              
Interest rate derivatives 3,555 6,185   3,555 6,185           3,556 3,556     3,556 3,556            
Liabilities           7,076         3,556       10,632              
Redeemable noncontrolling interest $ 15,571 $ 10,298 $ 9,578 $ 15,571 $ 10,298               $ 15,571 $ 15,571 $ 15,571 $ 15,571            
Discount rate                                       10.00% 20.00% 15.70%
[1] Included in the line entitled “restricted cash and marketable securities” on COPT’s consolidated balance sheet.
[2] Included in the line entitled “restricted cash and marketable securities” on COPLP’s consolidated balance sheet.
[3] Included in the line entitled “prepaid expenses and other assets” on COPT’s consolidated balance sheet.
[4] Included in the line entitled “prepaid expenses and other assets” on COPLP’s consolidated balance sheet.
[5] Included in the line entitled “other liabilities” on COPT’s consolidated balance sheet.