Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Details 2)

v3.10.0.1
Fair Value Measurements (Details 2) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Assets:    
Marketable securities in deferred compensation plan $ 3,868 $ 4,616
Fair value measurement on a recurring basis [Member]    
Assets:    
Interest rate derivatives 5,617 3,073
Total assets 9,485 7,689
Liabilities:    
Deferred compensation plan liability 3,868 4,616
Interest rate derivatives 5,459  
Total liabilities 9,327  
Fair value measurement on a recurring basis [Member] | Mutual funds [Member]    
Assets:    
Marketable securities in deferred compensation plan 3,819 4,547
Fair value measurement on a recurring basis [Member] | Other [Member]    
Assets:    
Marketable securities in deferred compensation plan 49 69
Fair value measurement on a recurring basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]    
Assets:    
Total assets 3,868 4,616
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 3,819 4,547
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 49 69
Fair value measurement on a recurring basis [Member] | Significant Other Observable Inputs (Level 2) [Member]    
Assets:    
Interest rate derivatives 5,617 3,073
Total assets 5,617 3,073
Liabilities:    
Deferred compensation plan liability 3,868 4,616
Interest rate derivatives 5,459  
Total liabilities 9,327  
Corporate Office Properties, L.P. [Member] | Fair value measurement on a recurring basis [Member]    
Assets:    
Interest rate derivatives 5,617 3,073
Liabilities:    
Interest rate derivatives 5,459  
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 5,617 $ 3,073
Liabilities:    
Interest rate derivatives $ 5,459