Mack-Cali Realty Corporation Stockholders' Equity (Schedule Of Stock Option Plans) (Details) (USD $) In Thousands, except Share data | 9 Months Ended |
|---|---|
Sep. 30, 2011 | |
| Mack-Cali Realty Corporation Stockholders' Equity [Abstract] | |
| Shares Under Options - Outstanding as January 1, 2011 | 295,676 |
| Share Under Options - Exercised | (107,806) |
| Share Under Options - Cancelled | (4,000) |
| Shares Under Options - Outstanding at September 30, 2011 | 183,870 |
| Shares Under Options - Options exercisable at September 30, 2011 | 183,870 |
| Shares Under Options - Available for grant at September 30, 2011 | 2,425,073 |
| Weighted Average Exercise Price - Outstanding as January 1, 2011 | $ 29.05 |
| Weighted Average Exercise Price - Exercised | $ 28.27 |
| Weighted Average Exercise Price - Cancelled | $ 28.80 |
| Weighted Average Exercise Price - Outstanding at September 30, 2011 | $ 29.51 |
| Aggregate Intrinsic Value, Outstanding as January 1, 2011 | $ 1,186 |
| Outstanding stock option price range, lower range | $ 28.47 |
| Outstanding stock option price range, upper range | $ 45.47 |