| Mack-Cali Realty Corporation Stockholders' Equity (Restricted Stock Awards And TSR-Based Awards) (Narrative) (Details) (USD $) | 9 Months Ended | 9 Months Ended | 1 Months Ended | 12 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Sep. 30, 2013 | Dec. 31, 2012 | Sep. 30, 2013
 Restricted Stock [Member] | Sep. 30, 2012
 Restricted Stock [Member] | Sep. 30, 2013
 Restricted Stock [Member]
 Minimum [Member] | Sep. 30, 2013
 Restricted Stock [Member]
 Maximum [Member] | Sep. 30, 2013
 Ratified Restricted Stock Awards [Member]
 Minimum [Member] | Sep. 30, 2013
 Ratified Restricted Stock Awards [Member]
 Maximum [Member] | Sep. 30, 2013
 Total Stockholder Return Based Awards [Member] | Jan. 31, 2014
 Scenario, Forecast [Member]
 Ratified Restricted Stock Awards [Member] | Dec. 31, 2014
 Scenario, Forecast [Member]
 Total Stockholder Return Based Awards [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||||||
| Restricted Stock Award vesting period | 1 year | 7 years | 5 years | 7 years | 4 years | ||||||
| Unvested restricted stock outstanding | 95,858 | 134,328 | 351,592 | 105,843 | |||||||
| Restricted stock awards unvested shares outstanding, performance contingent | 319,667 | ||||||||||
| Awards issued | 68,139 | 1,032 | 319,667 | 5,160 | |||||||
| Value of common stock received upon vesting of awards | $ 1,000 | ||||||||||
| Total unrecognized compensation cost | $ 700,000 | ||||||||||
| Total unrecognized compensation cost, period of recognition | 4 months 24 days | ||||||||||
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- Definition The number of unvested restricted stock award shares issued and outstanding contingent upon performance. No definition available. 
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- Definition Restricted Stock Award Vesting Period No definition available. 
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- Definition Value Of Common Stock Received Upon Vesting Of Awards No definition available. 
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- Definition Unrecognized cost of unvested share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). 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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