Mack-Cali Realty Corporation Stockholders' Equity (Schedule Of Reconciliation Of Shares Used In Basic EPS Calculation To Shares Used In Diluted EPS Calculation) (Details) In Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Mack-Cali Realty Corporation Stockholders' Equity [Abstract]
Basic EPS shares	87,019	79,304	85,649	79,161
Add: Operating Partnership - common units	12,799	13,073	12,864	13,196
Stock options	15	32	30	47
Restricted Stock Awards	84	55	88	63
Diluted EPS Shares	99,917	92,464	98,631	92,467

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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