Intangible Assets and Below Market Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Assets:
Deferred leasing costs (including lease incentives and above market lease and in-place lease acquisition-related intangible assets)	$ 373,075		$ 373,075		$ 377,472
Deferred leasing costs, accumulated amortization	(151,170)		(151,170)		(146,125)
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	221,905		221,905		231,347
Liabilities (in accounts payable, accrued expenses and other liabilities):
Acquisition-related below market lease liabilities, gross	65,039		65,039		65,971
Acquisition-related below market lease liabilities, accumulated amortization	(36,164)		(36,164)		(34,014)
Acquisition-related below market lease liabilities, net	28,875		28,875		$ 31,957
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	206,923		206,923
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	8,566	$ 8,759	17,364	$ 19,074
Lease Incentives (in Rental and Other Revenues) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	9,871		9,871
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	429	460	919	3,308
Acquisition-Related Intangible Assets (in Rental and Other Revenues) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	4,878		4,878
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	321	343	609	700
Acquisition-Related Intangible Assets (in Rental Property and Other Expenses) [Member]
Assets:
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	233		233
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of intangible assets	138	139	277	276
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	28,875		28,875
Amortization of intangible assets and below market lease liabilities [Abstract]
Amortization of acquisition-related below market lease liabilities	$ (1,517)	$ (1,763)	$ (3,083)	$ (3,416)