Mack-Cali Realty Corporation Stockholders' Equity (Deferred Stock Compensation Plan For Directors) (Narrative) (Details)
9 Months Ended
Sep. 30, 2011
Sep. 30, 2010
Dec. 31, 2010
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]   
Deferred stock units earned10,6209,411 
Deferred stock units outstanding93,773 84,236