Mack-Cali Realty Corporation Stockholders' Equity (Earnings Per Share) (Narrative) (Details) - $ / shares |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2015 |
Jun. 30, 2014 |
Jun. 30, 2015 |
Jun. 30, 2014 |
Dec. 31, 2014 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Anti-dilutive securities excluded from the computation of earnings per share | 410,000 | 10,000 | |||
| Dividends declared per common share | $ 0.15 | $ 0.15 | $ 0.30 | $ 0.45 | |
| Unvested restricted stock outstanding | 350,888 | 350,888 | 346,946 | ||
| Unvested Restricted Stock [Member] | |||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||
| Unvested restricted stock outstanding | 103,337 | 304,816 | 103,337 | 304,816 | |