Intangible Assets and Below Market Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Assets:
Deferred leasing costs (including lease incentives and above market lease and in-place lease acquisition-related intangible assets)	$ 348,628		$ 348,628		$ 353,581
Deferred leasing costs, accumulated amortization	(145,814)		(145,814)		(140,081)
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	202,814		202,814		213,500
Liabilities (in accounts payable, accrued expenses and other liabilities):
Acquisition-related below market lease liabilities, gross	60,304		60,304		61,221
Acquisition-related below market lease liabilities, accumulated amortization	(26,905)		(26,905)		(23,074)
Acquisition-related below market lease liabilities, net	33,399		33,399		$ 38,147
Deferred Leasing Costs and Acquisition-Related Intangible Assets (in Depreciation and Amortization) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	184,476		184,476
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	10,130	$ 10,111	30,882	$ 33,177
Lease Incentives (in Rental and Other Revenues) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	9,639		9,639
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	444	273	1,284	1,374
Acquisition-Related Intangible Assets (in Rental and Other Revenues) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	6,934		6,934
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	671	901	2,382	2,904
Acquisition-Related Intangible Assets (in Rental Property and Other Expenses) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	1,765		1,765
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	140	140	416	417
Acquisition-Related Below Market Lease Liabilities (in Rental and Other Revenues) [Member]
Liabilities (in accounts payable, accrued expenses and other liabilities):
Acquisition-related below market lease liabilities, net	33,399		33,399
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of acquisition-related below market lease liabilities	$ (1,576)	$ (1,734)	$ (4,748)	$ (6,294)