Annual report pursuant to Section 13 and 15(d)

Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Restricted Stock Awards And Performance Share Units) (Narrative) (Details)

v3.19.3.a.u2
Mack-Cali Realty Corporation Stockholders' Equity And Mack-Cali Realty, L.P.'s Partners' Capital (Restricted Stock Awards And Performance Share Units) (Narrative) (Details) - USD ($)
12 Months Ended
Jun. 05, 2018
Jun. 05, 2015
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unvested stock outstanding     42,690 67,289 108,318 145,278
Shares granted     42,690 40,185 59,985  
Restricted Stock [Member] | 2013 Incentive Stock Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock compensation vesting period     3 years      
Shares granted   37,550.54        
Restricted Stock [Member] | Minimum [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock compensation vesting period     1 year      
Restricted Stock [Member] | Maximum [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock compensation vesting period     7 years      
Unvested Restricted Stock [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unvested stock outstanding     42,690 67,289 95,801  
Total Stockholder Return Based Awards [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Total unrecognized compensation cost     $ 800,000      
Total unrecognized compensation cost, period of recognition     4 months 24 days      
Performance Shares [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Unvested stock outstanding     0      
Total unrecognized compensation cost     $ 0      
Performance Shares [Member] | 2013 Incentive Stock Plan [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Shares granted   112,651.64        
Performance period     3 years      
Performance Shares [Member] | 2013 Incentive Stock Plan [Member] | Three Years Period Award [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Percentage of shares vested 100.00%          
Performance Shares [Member] | Minimum [Member] | 2013 Incentive Stock Plan [Member] | Three Years Period Award [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Percentage of shares vested   0.00%        
Performance Shares [Member] | Maximum [Member] | 2013 Incentive Stock Plan [Member] | Three Years Period Award [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Percentage of shares vested   150.00%