Intangible Assets and Below Market Lease Liabilities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, accumulated amortization	$ (100,639)		$ (92,220)
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	218,831		222,211
Deferred Financing Costs [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, gross	17,329		17,363
Deferred financing and leasing costs, accumulated amortization	(5,789)		(5,204)
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	11,540		12,159
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	652	949
Deferred Leasing Costs [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, gross	302,141		297,068
Deferred financing and leasing costs, accumulated amortization	(94,850)		(87,016)
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	207,291		210,052
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	179,424
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	9,928	8,075
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	7,040
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	351	376
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	17,113
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	1,116	466
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	3,714
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	137	137
Acquisition-Related Below Market Lease Liabilities [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Acquisition-related below market lease liabilities, gross	54,996		55,323
Acquisition-related below market lease liabilities, accumulated amortization	(9,673)		(8,478)
Acquisition-related below market lease liabilities, net	45,323		46,845
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of acquisition-related below market lease liabilities	$ (1,522)	$ (1,122)