Intangible Assets and Below Market Lease Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Intangible assets and below market lease liabilities, net [Abstract]
Deferred leasing costs, gross	$ 377,472	$ 344,548
Deferred leasing costs, accumulated amortization	(146,125)	(149,275)
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	231,347	195,273
Acquisition-related below market lease liabilities, gross	65,971	57,955
Acquisition-related below market lease liabilities, accumulated amortization	(34,014)	(32,307)
Acquisition-related below market lease liabilities, net	31,957	25,648
Acquired intangible assets (amortized in rental and other revenue)	2,059
Acquired intangible assets (amortized in depreciation and amortization)	35,637
Assumed below market lease liabilities (amortized in rental and other revenue)	(12,943)
Deferred Leasing Costs and Acquisition-Related Intangible Assets [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	215,435
Amortization of intangible assets and below market lease liabilities
Amortization of intangible assets	37,386	36,486	$ 41,187
Lease Incentives [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	9,915
Amortization of intangible assets and below market lease liabilities
Amortization of intangible assets	4,281	1,908	1,765
Acquisition-Related Intangible Assets (in Rental and Other Revenue) [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	5,487
Amortization of intangible assets and below market lease liabilities
Amortization of intangible assets	1,290	1,677	2,921
Acquisition-Related Intangible Assets (in Rental Property and Other Expenses) [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	510
Amortization of intangible assets and below market lease liabilities
Amortization of intangible assets	557	557	557
Acquisition-Related Below Market Lease Liabilities [Member]
Intangible assets and below market lease liabilities, net [Abstract]
Acquisition-related below market lease liabilities, net	31,957
Amortization of intangible assets and below market lease liabilities
Amortization of acquisition-related below market lease liabilities	$ (6,633)	$ (6,085)	$ (6,415)