Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details 2)

v3.8.0.1
Fair Value Measurements (Details 2) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Assets:    
Marketable securities in deferred compensation plan $ 4,481 $ 4,616
Fair value measurement on a recurring basis    
Assets:    
Interest rate derivatives 7,960  
Total assets 12,441  
Liabilities:    
Deferred compensation plan liability 4,481  
Fair value measurement on a recurring basis | Mutual funds    
Assets:    
Marketable securities in deferred compensation plan 4,433  
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 4,481  
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 4,433  
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 7,960  
Total assets 7,960  
Liabilities:    
Deferred compensation plan liability 4,481  
Fair value measurement on a recurring basis | Corporate Office Properties, L.P.    
Assets:    
Interest rate derivatives 7,960  
Fair value measurement on a recurring basis | Corporate Office Properties, L.P. | Significant Other Observable Inputs (Level 2)    
Assets:    
Interest rate derivatives $ 7,960