Intangible Assets and Below Market Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Assets:
Deferred leasing costs (including lease incentives and above market lease and in-place lease acquisition-related intangible assets)	$ 356,575		$ 356,575		$ 361,027
Deferred leasing costs, accumulated amortization	(140,257)		(140,257)		(151,698)
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	216,318		216,318		209,329
Liabilities (in accounts payable, accrued expenses and other liabilities):
Acquisition-related below market lease liabilities, gross	55,581		55,581		63,748
Acquisition-related below market lease liabilities, accumulated amortization	(31,159)		(31,159)		(37,838)
Acquisition-related below market lease liabilities, net	24,422		24,422		$ 25,910
Amortization of intangible assets and below market lease liabilities [Abstract]
Acquired intangible assets (amortized in rental and other revenue)	2,036		2,036
Acquired intangible assets (amortized in depreciation and amortization)	13,168		13,168
Assumed below market lease liabilities (amortized in rental and other revenue)	(1,361)		(1,361)
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	199,359		199,359
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	8,626	$ 8,566	17,197	$ 17,364
Lease Incentives (in Rental and Other Revenues) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	11,148		11,148
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	445	429	893	919
Acquisition-Related Intangible Assets (in Rental and Other Revenues) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	5,811		5,811
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	241	321	518	609
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	138	0	277
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	24,422		24,422
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of acquisition-related below market lease liabilities	$ (1,421)	$ (1,517)	$ (2,850)	$ (3,083)