Mack-Cali Realty Corporation Stockholders' Equity (Deferred Stock Compensation Plan For Directors) (Narrative) (Details) - shares	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]
Maximum percentage of retainer fee that directors may defer	100.00%
Deferred stock units earned	7,859	10,264
Deferred stock units outstanding	186,835		178,039

Maximum Percentage Of Retainer Fee Directors May Elect To Defer To Stock Units

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