Quarterly report pursuant to Section 13 or 15(d)

Noncontrolling Interests In Subsidiaries (Narrative) (Details)

v3.8.0.1
Noncontrolling Interests In Subsidiaries (Narrative) (Details)
$ in Millions
 6 Months Ended 9 Months Ended
Jun. 30, 2017
USD ($)
shares
Sep. 30, 2017
USD ($)
property
shares
Dec. 31, 2016
Noncontrolling Interest [Line Items]      
Number of common shares received upon redemption of common units | shares   1  
Rebalance of ownership percentage   $ 3.8  
Percentage of noncontrolling interest   10.40% 10.50%
Cash consideration $ 2.0    
Issuance of common units | shares 99,412    
Common unit value $ 2.8    
Participation Rights [Member]      
Noncontrolling Interest [Line Items]      
Number of properties | property   3  
Excess net cash flow remaining after the distribution to the Company   50.00%  
Internal rate of return   10.00%  
150 Main St [Member]      
Noncontrolling Interest [Line Items]      
Cash consideration $ 2.0    
Issuance of common units | shares 99,412    
Common unit value $ 2.8    
Mack-Cali Realty LP [Member]      
Noncontrolling Interest [Line Items]      
Cash consideration $ 2.0    
Issuance of common units | shares 99,412    
Common unit value $ 2.8    
Future Developments [Member] | Participation Rights [Member]      
Noncontrolling Interest [Line Items]      
Number of properties | property   1