| Mack-Cali Realty Corporation Stockholders' Equity (Stock Compensation) (Narrative) (Details) (USD $) | 12 Months Ended | 12 Months Ended | 1 Months Ended | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009 | Dec. 31, 2012
 Restricted Stock [Member] | Dec. 31, 2012
 Restricted Stock [Member]
 Minimum [Member] | Dec. 31, 2012
 Restricted Stock [Member]
 Maximum [Member] | Dec. 31, 2012
 Ratified Restricted Stock Awards [Member]
 Minimum [Member] | Dec. 31, 2012
 Ratified Restricted Stock Awards [Member]
 Maximum [Member] | Dec. 31, 2012
 Total Stockholder Return Based Awards [Member] | Jan. 31, 2014
 Scenario, Forecast [Member]
 Ratified Restricted Stock Awards [Member] | Dec. 31, 2013
 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 | 5 years | ||||||||||||||||
| Unvested restricted stock outstanding | 134,328 | 187,447 | 239,759 | 323,088 | |||||||||||||||||
| Restricted stock awards unvested shares outstanding, performance contingent | 40,877 | ||||||||||||||||||||
| Awards issued | 70,758 | [1] | 81,736 | [2] | 111,127 | [3] | 319,667 | 5,160 | |||||||||||||
| Value of common stock received upon vesting of awards | $ 1,000 | ||||||||||||||||||||
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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 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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