Mack-Cali Realty Corporation Stockholders' Equity (Earnings Per Share) (Narrative) (Details) (USD $) | 3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2011 | Sep. 30, 2010 | Sep. 30, 2011 | Sep. 30, 2010 | |
| Mack-Cali Realty Corporation Stockholders' Equity [Abstract] | ||||
| Dividends declared per common share | $ 0.45 | $ 0.45 | $ 1.35 | $ 1.35 |
| Unvested restricted stock outstanding | 157,681 | 216,802 | 157,681 | 216,802 |