Identified Intangible Assets and Intangible Liabilities (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets (included in other assets): Gross	$ 726,981	$ 631,162
Identified intangible assets (included in other assets): Accumulated amortization	(356,379)	(343,318)
Finite-Lived Intangible Assets, Net, Total	370,602	287,844
Identified intangible liabilities (included in deferred credit): Gross	805,811	838,103
Identified intangible liabilities (included in deferred credit): Accumulated amortization	(342,379)	(371,360)
Identified intangible liabilities (included in deferred credit): Net	463,432	466,743
Below Market Leases Net Of Above Market Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	54,193	62,105	65,373
Future Amortization Expense, Year One	45,098
Future Amortization Expense, Year Two	39,304
Future Amortization Expense, Year Three	36,533
Future Amortization Expense, Year Four	34,088
Future Amortization Expense, Year Five	28,610
Other Identified Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	51,244	54,126	56,949
Future Amortization Expense, Year One	47,959
Future Amortization Expense, Year Two	29,785
Future Amortization Expense, Year Three	24,812
Future Amortization Expense, Year Four	22,300
Future Amortization Expense, Year Five	19,735
Tenant Under Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	1,712	1,377	2,157
Future Amortization Expense, Year One	2,933
Future Amortization Expense, Year Two	2,918
Future Amortization Expense, Year Three	2,918
Future Amortization Expense, Year Four	2,918
Future Amortization Expense, Year Five	$ 2,918