| Mack-Cali Realty Corporation Stockholders' Equity (Earnings Per Share) (Narrative) (Details) (USD $) | 3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
| Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012 | Dec. 31, 2012 | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Unvested restricted stock outstanding | 95,858 | 95,858 | 134,328 | ||
| Dividends declared per common share | $ 0.30 | $ 0.45 | $ 1.05 | $ 1.35 | |
| Restricted Stock [Member] | |||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Unvested restricted stock outstanding | 351,592 | 105,843 | 351,592 | 105,843 | |
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- Definition Aggregate dividends declared during the period for each share of common stock outstanding. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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