Intangible Assets and Below Market Lease Liabilities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, accumulated amortization	$ (108,878)		$ (108,878)		$ (92,220)
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	218,725		218,725		222,211
Acquired above market lease intangible assets	27		27
Acquired in-place lease intangible assets	6,293		6,293
Assumed below market lease liabilities	(1,353)		(1,353)
Deferred Financing Costs [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, gross	19,512		19,512		17,363
Deferred financing and leasing costs, accumulated amortization	(7,193)		(7,193)		(5,204)
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	12,319		12,319		12,159
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	819	963	2,270	2,860
Deferred Leasing Costs [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred financing and leasing costs, gross	308,091		308,091		297,068
Deferred financing and leasing costs, accumulated amortization	(101,685)		(101,685)		(87,016)
Deferred financing and leasing costs, net/Total scheduled future amortization of intangible assets	206,406		206,406		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	181,058		181,058
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	9,465	10,639	29,443	26,603
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	6,968		6,968
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	327	347	1,077	1,061
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	14,946		14,946
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	1,080	1,548	3,310	2,499
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	3,434		3,434
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	140	140	416	416
Acquisition-Related Below Market Lease Liabilities [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Acquisition-related below market lease liabilities, gross	55,639		55,639		55,323
Acquisition-related below market lease liabilities, accumulated amortization	(11,994)		(11,994)		(8,478)
Acquisition-related below market lease liabilities, net	43,645		43,645		46,845
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of acquisition-related below market lease liabilities	$ (1,532)	$ (1,584)	$ (4,554)	$ (3,737)