Other Assets, Net (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Intangible assets:
Finite-Lived Intangible Assets, Net, Total	$ 38,285,000		$ 38,285,000		$ 23,263,000
Other assets:
Accounts receivables, net	118,331,000		118,331,000		123,259,000
Deferred charges, net	47,728,000		47,728,000		44,988,000
Prepaids	8,721,000		8,721,000		11,566,000
Deposits	39,306,000		39,306,000		41,160,000
Other assets	4,140,000		4,140,000		3,473,000
Total other assets, net	256,511,000		256,511,000		247,709,000
Other Assets, Net (Textuals) [Abstract]
Amortization expense	1,800,000	1,600,000	5,400,000	5,000,000
Straight-line rent receivables, net	55,900,000		55,900,000		56,200,000
Leases, Acquired-in-Place [Member]
Intangible assets:
Finite-Lived Intangible Assets, Net, Total	21,389,000		21,389,000		14,228,000
Tenant Relations [Member]
Intangible assets:
Finite-Lived Intangible Assets, Net, Total	$ 16,896,000		$ 16,896,000		$ 9,035,000