Intangible Assets and Below Market Lease Liabilities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, accumulated amortization	$ (85,548)		$ (85,548)		$ (76,840)
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	181,802		181,802		168,019
Acquired above market lease intangible assets	3,383		3,383
Acquired in-place lease intangible assets	19,180		19,180
Assumed below market lease liabilities	(8,582)		(8,582)
Deferred Financing Costs [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, gross	21,368		21,368		21,759
Deferred financing and leasing costs, accumulated amortization	(9,528)		(9,528)		(7,862)
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	11,840		11,840		13,897
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	948	900	1,897	1,802
Deferred Leasing Costs [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, gross	245,982		245,982		223,100
Deferred financing and leasing costs, accumulated amortization	(76,020)		(76,020)		(68,978)
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	169,962		169,962		154,122
Deferred Leasing Costs and Acquisition-Related Intangible Assets [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	152,130		152,130
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	8,123	7,180	16,431	13,505
Lease Incentives [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	6,222		6,222
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	344	330	725	664
Acquisition-Related Intangible Assets (in Rental and Other Revenues) [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	7,479		7,479
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	484	324	951	594
Acquisition-Related Intangible Assets (in Rental Property and Other Expenses) [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	4,131		4,131
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	139	0	276	0
Acquisition-Related Below Market Lease Liabilities [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Acquisition-related below market lease liabilities, gross	45,415		45,415		37,019
Acquisition-related below market lease liabilities, accumulated amortization	(5,350)		(5,350)		(3,383)
Acquisition-related below market lease liabilities, net	40,065		40,065		33,636
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of acquisition-related below market lease liabilities	$ (1,031)	$ (553)	$ (2,153)	$ (1,097)