Quarterly report pursuant to Section 13 or 15(d)

Noncontrolling Interests In Subsidiaries (Narrative) (Details)

v3.19.3
Noncontrolling Interests In Subsidiaries (Narrative) (Details)
$ in Thousands
 3 Months Ended 9 Months Ended
Mar. 26, 2019
USD ($)
Jun. 05, 2015
shares
Mar. 31, 2019
USD ($)
shares
Sep. 30, 2019
USD ($)
property
item
shares
Sep. 30, 2018
USD ($)
Mar. 25, 2019
item
Dec. 31, 2018
Noncontrolling Interest [Line Items]              
Number of common shares received upon redemption of common units | shares       1      
Rebalance of ownership percentage       $ 1,600      
Number of units | item       208      
Purchase price of property       $ 109,338 $ 132,252    
Shares granted | shares   800,000          
Participation Rights [Member]              
Noncontrolling Interest [Line Items]              
Number of properties | property       2      
Excess net cash flow remaining after the distribution to the Company       50.00%      
Internal rate of return       10.00%      
Mack-Cali Realty LP [Member]              
Noncontrolling Interest [Line Items]              
Purchase price of property       $ 109,338 $ 132,252    
Mack-Cali Realty LP [Member]              
Noncontrolling Interest [Line Items]              
Percentage of noncontrolling interest       9.90%     10.20%
Future Developments [Member] | Participation Rights [Member]              
Noncontrolling Interest [Line Items]              
Number of properties | property       1      
Disposal Group, Not Discontinued Operations [Member]              
Noncontrolling Interest [Line Items]              
Sales proceeds       $ 593,436      
Disposal Group, Not Discontinued Operations [Member] | Flex Portfolio [Member]              
Noncontrolling Interest [Line Items]              
Sales proceeds       $ 470,348      
Number of properties disposed | property       2      
Proceeds from sale of properties     $ 6,600 $ 6,600      
Redemption of common units, shares | shares     301,638        
XS Hotel Urban Renewal Associates LLC [Member]              
Noncontrolling Interest [Line Items]              
Percentage of interest in venture           90.00%  
Number of units | item           372  
Percentage of additional interest acquired 10.00%            
Purchase price of property $ 5,000            
XS Hotel Urban Renewal Associates LLC, Residence Inn [Member]              
Noncontrolling Interest [Line Items]              
Number of units | item           164  
XS Hotel Urban Renewal Associates LLC, Marriott Envue [Member]              
Noncontrolling Interest [Line Items]              
Number of units | item           208  
AO LTIP Units Award [Member] | Messr DeMarco, CEO [Member]              
Noncontrolling Interest [Line Items]              
Shares granted | shares       625,000