Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Details 2)

v3.6.0.2
Fair Value Measurements (Details 2) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Liabilities:    
Interest rate derivatives $ 1,572 $ 3,160
Fair value measurement on a recurring basis [Member]    
Assets:    
Interest rate derivatives 158 53
Assets 5,595 5,816
Liabilities:    
Deferred compensation plan liability 5,437 5,763
Interest rate derivatives 1,572 3,160
Redeemable preferred shares of beneficial interest 26,583  
Liabilities 33,592 8,923
Fair value measurement on a recurring basis [Member] | Mutual funds [Member]    
Assets:    
Marketable securities in deferred compensation plan 5,346 5,658
Fair value measurement on a recurring basis [Member] | Other [Member]    
Assets:    
Marketable securities in deferred compensation plan 91 105
Fair value measurement on a recurring basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]    
Assets:    
Assets 5,437 5,763
Liabilities:    
Liabilities 0 0
Fair value measurement on a recurring basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mutual funds [Member]    
Assets:    
Marketable securities in deferred compensation plan 5,346 5,658
Fair value measurement on a recurring basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other [Member]    
Assets:    
Marketable securities in deferred compensation plan 91 105
Fair value measurement on a recurring basis [Member] | Significant Other Observable Inputs (Level 2) [Member]    
Assets:    
Interest rate derivatives 158 53
Assets 158 53
Liabilities:    
Deferred compensation plan liability 5,437 5,763
Interest rate derivatives 1,572 3,160
Redeemable preferred shares of beneficial interest 26,583  
Liabilities 33,592 8,923
Corporate Office Properties, L.P. [Member]    
Liabilities:    
Interest rate derivatives 1,572 3,160
Corporate Office Properties, L.P. [Member] | Fair value measurement on a recurring basis [Member]    
Assets:    
Interest rate derivatives 158 53
Liabilities:    
Interest rate derivatives 1,572 3,160
Redeemable preferred shares of beneficial interest 26,583  
Liabilities 28,155  
Corporate Office Properties, L.P. [Member] | Fair value measurement on a recurring basis [Member] | Significant Other Observable Inputs (Level 2) [Member]    
Assets:    
Interest rate derivatives 158 53
Liabilities:    
Interest rate derivatives 1,572 $ 3,160
Redeemable preferred shares of beneficial interest 26,583  
Liabilities $ 28,155