Identified Intangible Assets and Intangible Liabilities (Details) (USD $) In Thousands, unless otherwise specified			3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Below Market Leases Net Of Above Market Leases [Member]	Sep. 30, 2012 Below Market Leases Net Of Above Market Leases [Member]	Sep. 30, 2013 Below Market Leases Net Of Above Market Leases [Member]	Sep. 30, 2012 Below Market Leases Net Of Above Market Leases [Member]	Sep. 30, 2013 Other Identified Intangible Assets [Member]	Sep. 30, 2012 Other Identified Intangible Assets [Member]	Sep. 30, 2013 Other Identified Intangible Assets [Member]	Sep. 30, 2012 Other Identified Intangible Assets [Member]	Sep. 30, 2013 Tenant Under Ground Leases [Member]	Sep. 30, 2012 Tenant Under Ground Leases [Member]	Sep. 30, 2013 Tenant Under Ground Leases [Member]	Sep. 30, 2012 Tenant Under Ground Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Identified intangible assets (included in other assets): Gross	$ 572,641	$ 752,922
Identified intangible assets, accumulated amortization	(297,391)	(346,613)
Finite-Lived Intangible Assets, Net, Total	275,250	406,309
Identified intangible liabilities (included in deferred credit): Gross	811,917	902,525
Identified intangible liabilities (included in deferred credit): Accumulated amortization	(372,329)	(341,536)
Identified intangible liabilities (included in deferred credit): Net	439,588	560,989
Amortization of Intangible Assets			11,820	13,256	40,326	39,569	11,257	11,415	53,339	35,519	981	312	3,704	894
2014			41,069		41,069		26,708		26,708		3,921		3,921
2015			38,263		38,263		21,543		21,543		3,921		3,921
2016			36,321		36,321		18,363		18,363		3,921		3,921
2017			30,936		30,936		15,203		15,203		3,921		3,921
2018			$ 29,171		$ 29,171		$ 11,005		$ 11,005		$ 3,921		$ 3,921