Quarterly report pursuant to Section 13 or 15(d)

Noncontrolling Interests In Subsidiaries (Narrative) (Details)

v3.19.1
Noncontrolling Interests In Subsidiaries (Narrative) (Details)
$ in Thousands
 3 Months Ended
Mar. 26, 2019
USD ($)
Jun. 05, 2015
shares
Mar. 31, 2019
USD ($)
property
item
shares
Mar. 31, 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     $ 1,600        
Purchase price of property     $ 43,307 $ 55,935      
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     $ 43,307 $ 55,935      
Mack-Cali Realty LP [Member]              
Noncontrolling Interest [Line Items]              
Percentage of noncontrolling interest     10.00%     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     $ 555,635        
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