Document And Entity Information - shares
 6 Months Ended
Jun. 30, 2017
Jul. 31, 2017
Entity Registrant Name MACK CALI REALTY CORP  
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2017  
Entity Central Index Key 0000924901  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
Entity Common Stock, Shares Outstanding   89,913,345
Mack-Cali Realty LP [Member]    
Entity Registrant Name Mack Cali Realty LP  
Entity Central Index Key 0001067063  
Entity Filer Category Large Accelerated Filer