Mack-Cali Realty Corporation Stockholders' Equity (Preferred And Common Stock And Repurchase Of General Partner Units) (Narrative) (Details) (USD $)	0 Months Ended	3 Months Ended	9 Months Ended
	Feb. 18, 2011	Sep. 30, 2011	Sep. 30, 2011	Oct. 05, 2011	Jan. 05, 2011	Dec. 31, 2010
Preferred stock, shares outstanding		10,000	10,000	10,000	10,000	10,000
Preferred stock, percentage			8.00%
Amount of depositary shares converted from the preferred shares		1,000,000	1,000,000
Depositary shares value, per share		$ 25	$ 25
One depositary share equivalent of one Series C Preferred Stock		1/100th	1/100th
Dividends in arrears			$ 0
Preferred stock, redemption price per share		$ 2,500	$ 2,500
Series C preferred stock redemption value						$ 25,000,000
Write off of preferred stock issuance costs		164,000	164,000
Shares of common stock issued in public offering	7,187,500
Partner's capital amount, public sale of units net of offering price	227,400,000
Capacity available for additional repurchase of outstanding common stock			46,000,000
Series C Preferred Stock [Member]
Series C preferred stock redemption value		25,000,000	25,000,000
Repurchase Of Equity [Member]
Capacity of share repurchase program			150,000,000
Date share repurchase program was initiated		September 12, 2007	September 12, 2007
Stock repurchased and retired shares		2,893,630	2,893,630
Aggregate cost of stocks repurchased			$ 104,000,000