Annual report pursuant to Section 13 and 15(d)

Recent Transactions (Consolidations) (Narrative) (Details)

v3.8.0.1
Recent Transactions (Consolidations) (Narrative) (Details)
$ in Thousands
1 Months Ended 3 Months Ended 12 Months Ended
Feb. 28, 2017
USD ($)
ft²
item
shares
Feb. 03, 2017
USD ($)
shares
Jul. 08, 2016
USD ($)
Jan. 19, 2016
USD ($)
Jan. 05, 2016
USD ($)
item
Apr. 30, 2017
USD ($)
shares
Jun. 30, 2016
USD ($)
item
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2015
USD ($)
Feb. 02, 2017
Real Estate Properties [Line Items]                      
Acquisition cost               $ 36,060 $ 35,930 $ 78,027  
Consolidated joint ventures, total real estate assets               215,500 $ 201,900    
Net assets acquired               $ 394,589      
Percentage of ownership interest               89.60% 89.50%    
Purchase price of property               $ 90,068 $ 121,582 94,073  
Gain on sale of investment in unconsolidated joint venture               23,131 5,670 6,448  
Mortgage loan carrying amount               45,734      
Gain on change of control of interests                 15,347    
Series A-1 Units [Member]                      
Real Estate Properties [Line Items]                      
Percentage of ownership interest 29.00%                    
Mack-Cali Realty LP [Member]                      
Real Estate Properties [Line Items]                      
Acquisition cost               36,060 35,930 78,027  
Purchase price of property               90,068 121,582 94,073  
Gain on sale of investment in unconsolidated joint venture               $ 23,131 5,670 $ 6,448  
Gain on change of control of interests                 15,347    
Mack-Cali Realty LP [Member] | Series A Units [Member]                      
Real Estate Properties [Line Items]                      
Preferred units shares issued | shares   42,800                  
Percentage of interest in venture   37.50%                  
Preferred unit annual rate   3.50%                  
Preferred units aggregate amount   $ 42,800                  
Mack-Cali Realty LP [Member] | Series A-1 Units [Member]                      
Real Estate Properties [Line Items]                      
Preferred units shares issued | shares 9,213         91          
Percentage of interest in venture 13.80%                    
Preferred unit annual rate 3.50%                    
Overlook Ridge Apartments Investors, L.L.C. [Member]                      
Real Estate Properties [Line Items]                      
Percentage of interest in venture         50.00%            
Loans assumed       $ 72,500 $ 52,700            
Net assets acquired                 52,035    
Number of units | item         371            
Purchase price of property         $ 39,800            
Gain on sale of investment in unconsolidated joint venture                 $ 10,200    
Mortgage loan, maturity date                 Feb. 01, 2023    
Spread over LIBOR       3.625%              
Portside Apartment Holdings, L.L.C. [Member]                      
Real Estate Properties [Line Items]                      
Percentage of interest in venture             38.25%        
Net assets acquired                 $ 44,827    
Number of units | item             175        
Purchase price of property             $ 39,600        
Mortgage loan, maturity date               Aug. 01, 2023      
Spread over LIBOR     3.44%                
Mortgage loan carrying amount     $ 59,000       $ 42,500        
Gain on change of control of interests                 $ 5,200    
Plaza VIII & IX Associates, L.L.C. [Member]                      
Real Estate Properties [Line Items]                      
Percentage of interest in venture                     50.00%
Percentage of additional interest acquired   12.50%                  
Acquisition cost   $ 14,300                  
Consolidated joint ventures, total real estate assets   $ 60,600                  
Monaco [Member]                      
Real Estate Properties [Line Items]                      
Number of towers | item 2                    
Net assets acquired               $ 139,886      
Garage Parking Spaces | item 558                    
Number of stories | item 50                    
Area of property (in square feet) | ft² 12,300                    
Number of units | item 523                    
Monaco [Member] | Series A-1 Units [Member]                      
Real Estate Properties [Line Items]                      
Percentage of interest in venture 13.80%                    
Monaco [Member] | Mack-Cali Realty LP [Member] | Series A-1 Units [Member]                      
Real Estate Properties [Line Items]                      
Preferred units shares issued | shares 9,122         91          
Percentage of interest in venture           71.20%          
Preferred units aggregate amount $ 9,100                    
Acquisition cost           $ 130,900          
Debt assumed           $ 171,200