Investments In Unconsolidated Joint Ventures (Statements Of Operations Of The Joint Ventures) (Parenthetical) (Details) (Unconsolidated Joint Ventures [Member], USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Unconsolidated Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Straight-line rent adjustments	$ 6.7	$ 5.9	$ 14.8	$ 19.8
"Above" and "below" market rent adjustments, net	$ 28.3	$ 30.5	$ 87.0	$ 97.6