Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details 2)

v3.10.0.1
Fair Value Measurements (Details 2) - USD ($)
$ in Thousands
Jun. 30, 2018
Dec. 31, 2017
Assets:    
Marketable securities in deferred compensation plan $ 4,194 $ 4,616
Fair value measurement on a recurring basis    
Assets:    
Interest rate derivatives 9,792  
Total assets 13,986  
Liabilities:    
Deferred compensation plan liability 4,194  
Fair value measurement on a recurring basis | Mutual funds    
Assets:    
Marketable securities in deferred compensation plan 4,146  
Fair value measurement on a recurring basis | Other    
Assets:    
Marketable securities in deferred compensation plan 48  
Fair value measurement on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)    
Assets:    
Total assets 4,194  
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 4,146  
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 48  
Fair value measurement on a recurring basis | Significant Other Observable Inputs (Level 2)    
Assets:    
Interest rate derivatives 9,792  
Total assets 9,792  
Liabilities:    
Deferred compensation plan liability 4,194  
Fair value measurement on a recurring basis | Corporate Office Properties, L.P.    
Assets:    
Interest rate derivatives 9,792  
Fair value measurement on a recurring basis | Corporate Office Properties, L.P. | Significant Other Observable Inputs (Level 2)    
Assets:    
Interest rate derivatives $ 9,792