Annual report pursuant to Section 13 and 15(d)

Real Estate Joint Ventures (Details)

v3.3.1.900
Real Estate Joint Ventures (Details)
$ in Thousands
12 Months Ended
Aug. 07, 2014
USD ($)
Dec. 11, 2013
Sep. 17, 2013
USD ($)
shares
Dec. 31, 2015
USD ($)
ft²
Dec. 31, 2013
USD ($)
Property
Dec. 31, 2014
USD ($)
Dec. 31, 2012
USD ($)
Investments in consolidated real estate joint ventures              
Investing receivables       $ 47,875   $ 52,147  
Notes receivable from City of Huntsville [Member]              
Investments in consolidated real estate joint ventures              
Amount of advanced       37,200      
Investing receivables       $ 44,875   $ 49,147  
Stevens Investors, LLC [Member] | Minimum [Member]              
Investments in consolidated real estate joint ventures              
Percentage of residual distributable cash flows in excess of unpaid cumulative preferred returns and return of invested capital entitled to the company       60.00%      
LW Redstone Company, LLC [Member]              
Investments in consolidated real estate joint ventures              
Partner's capital account upon formation       $ 9,000      
Percentage of residual distributable cash flows in excess of unpaid cumulative preferred returns and return of invested capital entitled to the company       85.00%      
Percentage of residual distributable cash flows in excess of unpaid cumulative preferred returns and return of invested capital entitled to the entity's partners       15.00%      
Number of years following construction commencement threshold achievement before partner's interest can be purchased at fair value       5 years      
Construction commencement threshold (in square feet) | ft²       4,400,000.0      
Construction commencement completed (in sqft) | ft²       594,000      
LW Redstone Company, LLC [Member] | Maximum [Member]              
Investments in consolidated real estate joint ventures              
Infrastructure costs anticipated to be funded by entity for reimbursement by the City of Huntsville (in dollars)       $ 76,000      
Percentage of residual distributable cash flows in excess of unpaid cumulative preferred returns and return of invested capital entitled to the company       85.00%      
M Square Associates, LLC [Member]              
Investments in consolidated real estate joint ventures              
Percentage of residual amounts distributed to each member       50.00%      
Consolidated real estate joint ventures [Member]              
Investments in consolidated real estate joint ventures              
Total Assets       $ 209,351      
Encumbered Assets       130,966      
Total Liabilities       $ 91,983      
Arundel Preserve 5, LLC [Member]              
Investments in consolidated real estate joint ventures              
Ownership (as a percent)     50.00%        
Arundel Preserve 5, LLC [Member] | Common Shares [Member]              
Investments in consolidated real estate joint ventures              
Acquisition of property and noncontrolling interest in other consolidated entity for COPLP common units (in units) | shares     221,501        
Acquisition of property and noncontrolling interest in other consolidated entity for COPLP common units (in dollars)     $ 5,200        
MOR Forbes 2 LLC [Member]              
Investments in consolidated real estate joint ventures              
Ownership (as a percent)   50.00%          
Unconsolidated real estate joint ventures [Member]              
Investments in consolidated real estate joint ventures              
Ownership (as a percent)         20.00%    
Number of buildings operated by the joint venture | Property         16    
Investment balance             $ (6,400)
Gain on disposal         $ 6,300    
LW Redstone Company, LLC [Member] | Primary Beneficiary [Member]              
Investments in consolidated real estate joint ventures              
Ownership (as a percent)       85.00%      
Total Assets       $ 147,612      
Encumbered Assets       82,721      
Total Liabilities       $ 54,022      
M Square Associates, LLC [Member] | Primary Beneficiary [Member]              
Investments in consolidated real estate joint ventures              
Ownership (as a percent)       50.00%      
Total Assets       $ 56,455      
Encumbered Assets       48,245      
Total Liabilities       $ 37,568      
Stevens Investors, LLC [Member] | Primary Beneficiary [Member]              
Investments in consolidated real estate joint ventures              
Ownership (as a percent)       95.00%      
Total Assets       $ 5,284      
Encumbered Assets       0      
Total Liabilities       $ 393      
COPT-FD Indian Head LLC [Member] | Primary Beneficiary [Member]              
Investments in consolidated real estate joint ventures              
Proceeds from real estate and real estate joint ventures $ 6,400