Intangible Assets and Below Market Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Assets:
Deferred leasing costs (including lease incentives and above market lease and in-place lease acquisition-related intangible assets)	$ 406,580		$ 406,580		$ 361,027
Deferred leasing costs, accumulated amortization	(139,175)		(139,175)		(151,698)
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	267,405		267,405		209,329
Liabilities (in accounts payable, accrued expenses and other liabilities):
Acquisition-related below market lease liabilities, gross	60,802		60,802		63,748
Acquisition-related below market lease liabilities, accumulated amortization	(30,598)		(30,598)		(37,838)
Acquisition-related below market lease liabilities, net	30,204		30,204		$ 25,910
Amortization of intangible assets and below market lease liabilities [Abstract]
Acquired intangible assets (amortized in rental and other revenue)	13,824		13,824
Acquired intangible assets (amortized in depreciation and amortization)	84,298		84,298
Assumed below market lease liabilities (amortized in rental and other revenue)	(8,535)		(8,535)
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	239,644		239,644
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	10,070	$ 8,466	27,267	$ 25,830
Lease Incentives (in Rental and Other Revenues) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	10,799		10,799
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	424	477	1,317	1,396
Acquisition-Related Intangible Assets (in Rental and Other Revenues) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	16,962		16,962
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	636	273	1,154	882
Acquisition-Related Intangible Assets (in Rental Property and Other Expenses) [Member]
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	0	140	0	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	30,204		30,204
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of acquisition-related below market lease liabilities	$ (1,391)	$ (1,479)	$ (4,241)	$ (4,562)