Annual report pursuant to Section 13 and 15(d)

Information by Business Segment (Details 3)

v3.3.1.900
Information by Business Segment (Details 3) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Reconciliation of segment assets to total assets      
Total COPT consolidated assets $ 3,909,312 $ 3,664,236  
Segment assets [Member]      
Reconciliation of segment assets to total assets      
Total COPT consolidated assets 3,265,469 2,951,495 $ 2,905,630
Non-operating property assets [Member]      
Reconciliation of segment assets to total assets      
Total COPT consolidated assets 450,679 567,586  
Other assets [Member]      
Reconciliation of segment assets to total assets      
Total COPT consolidated assets $ 193,164 $ 145,155