Identified Intangible Assets and Intangible Liabilities (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Finite Lived Intangible Assets [Line Items]
Identified intangible assets (included in other assets): Gross	$ 679,648	$ 681,270
Identified intangible assets (included in other assets): Accumulated amortization	(359,944)	(335,113)
Finite-Lived Intangible Assets, Net, Total	319,704	346,157
Identified intangible liabilities (included in deferred credit): Gross	841,440	856,689
Identified intangible liabilities (included in deferred credit): Accumulated amortization	(374,253)	(335,317)
Identified intangible liabilities (included in deferred credit): Net	467,187	521,372
Below Market Leases Net Of Above Market Leases [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	62,442	65,542	70,401
Future Amortization Expense, Year One	49,032
Future Amortization Expense, Year Two	44,373
Future Amortization Expense, Year Three	37,715
Future Amortization Expense, Year Four	34,590
Future Amortization Expense, Year Five	31,518
Other Identified Intangible Assets [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	56,922	59,674	63,691
Future Amortization Expense, Year One	46,572
Future Amortization Expense, Year Two	39,355
Future Amortization Expense, Year Three	21,002
Future Amortization Expense, Year Four	16,043
Future Amortization Expense, Year Five	13,507
Tenant Under Ground Leases [Member]
Finite Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	1,377	2,157	1,952
Future Amortization Expense, Year One	1,377
Future Amortization Expense, Year Two	1,377
Future Amortization Expense, Year Three	1,377
Future Amortization Expense, Year Four	1,377
Future Amortization Expense, Year Five	$ 1,377