Quarterly report pursuant to Section 13 or 15(d)

Recent Transactions (Consolidations) (Narrative) (Details)

v3.10.0.1
Recent Transactions (Consolidations) (Narrative) (Details)
3 Months Ended 9 Months Ended
Aug. 02, 2018
USD ($)
item
Sep. 30, 2018
USD ($)
item
Sep. 30, 2017
USD ($)
Sep. 30, 2018
USD ($)
item
Sep. 30, 2017
USD ($)
Aug. 01, 2018
USD ($)
Dec. 31, 2017
USD ($)
Real Estate Properties [Line Items]              
Acquisition cost       $ 6,658,000 $ 19,279,000    
Consolidated joint ventures, total real estate assets   $ 471,300,000   $ 471,300,000     $ 215,500,000
Percentage of ownership interest   89.80%   89.80%     89.60%
Number of units | item   1,153   1,153      
Purchase price of property       $ 132,252,000 67,797,000    
Gain on sale of investment in unconsolidated joint venture     $ 10,568,000   23,131,000    
Gain on change of control of interests   $ 14,217,000   14,217,000      
Issuance of loan       30,400,000      
Loan balance   2,807,718,000   2,807,718,000     $ 2,809,568,000
Noncontrolling interest's fair value   209,622,000   209,622,000     $ 192,428,000
Mack-Cali Realty LP [Member]              
Real Estate Properties [Line Items]              
Acquisition cost       6,658,000 19,279,000    
Purchase price of property       132,252,000 67,797,000    
Gain on sale of investment in unconsolidated joint venture     $ 10,568,000   $ 23,131,000    
Gain on change of control of interests   14,217,000   $ 14,217,000      
Marbella Tower Urban Renewal Associates LLC [Member]              
Real Estate Properties [Line Items]              
Percentage of interest in venture 24.27%         24.27%  
Percentage of additional interest acquired 50.00%            
Number of units | item 412            
Purchase price of property $ 65,600,000            
Mortgage loan, maturity date       Aug. 01, 2026      
Spread over LIBOR 4.07%            
Mortgage loan carrying amount $ 131,000,000         $ 95,000,000  
Gain on change of control of interests   14,200,000   $ 14,200,000      
Repayment of mortgage loans $ 95,000,000            
Issuance of loan       37,400,000      
Loan balance   14,000,000   14,000,000      
Noncontrolling interest's fair value   $ 29,800,000   $ 29,800,000