Quarterly report pursuant to Section 13 or 15(d)

Noncontrolling Interests In Subsidiaries (Narrative) (Details)

v3.19.2
Noncontrolling Interests In Subsidiaries (Narrative) (Details)
$ in Thousands
 3 Months Ended 6 Months Ended
Mar. 26, 2019
USD ($)
Jun. 05, 2015
shares
Mar. 31, 2019
USD ($)
shares
Jun. 30, 2019
USD ($)
property
item
shares
Jun. 30, 2018
USD ($)
Mar. 25, 2019
item
Dec. 31, 2018
Dec. 31, 2015
item
Noncontrolling Interest [Line Items]                
Number of common shares received upon redemption of common units | shares       1        
Rebalance of ownership percentage       $ 200        
Purchase price of property       $ 70,577 $ 97,085      
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       $ 70,577 $ 97,085      
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        
Flex Portfolio [Member]                
Noncontrolling Interest [Line Items]                
Proceeds from sale of properties     $ 6,600          
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 | item       2        
Proceeds from sale of properties       $ 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%   90.00%
Number of units | item           372   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   164
XS Hotel Urban Renewal Associates LLC, Marriott Envue [Member]                
Noncontrolling Interest [Line Items]                
Number of units | item           208   208
AO LTIP Units Award [Member] | Messr DeMarco, CEO [Member]                
Noncontrolling Interest [Line Items]                
Shares granted | shares       625,000