Mack-Cali Realty Corporation Stockholders' Equity (Schedule Of Stock Option Plans) (Details) (USD $)
 3 Months Ended
Mar. 31, 2013
Shares Under Options - Outstanding, beginning balance 183,870
Shares Under Options - Lapsed or Cancelled (168,870)
Shares Under Options - Outstanding, ending balance 15,000
Shares Under Options - Options exercisable 15,000
Shares Under Options - Available for grant 1,739,553 [1]
Weighted Average Exercise Price - Outstanding, beginning balance $ 29.51
Weighted Average Exercise Price - Lapsed or Cancelled $ 28.53
Weighted Average Exercise Price - Outstanding, ending balance $ 40.54
Outstanding stock option price range, lower range $ 35.59
Outstanding stock option price range, upper range $ 45.47
TSR-Performance Shares And Deferred Retirement Stock Units [Member]
  
Common stock reserved for future issuance 212,969
[1] After reserving for 212,969 shares underlying outstanding TSR-based Performance Shares and deferred retirement Stock Units.