Acquired Leases Intangibles (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		$ 473,679	$ 502,132
Accumulated amortization		(284,880)	(259,310)
Acquired lease intangible assets, net of amortization		188,799	242,822
Finite-Lived Intangible Liabilities, Accumulated Accretion		(145,966)	(131,676)
Off-market Lease, Unfavorable		377,712	427,260
Finite-Lived Intangible Assets, Amortization Expense		55,955	69,362	$ 88,770
Acquired lease intangible liability accretion		50,103	54,730	45,655
Partnership Interest [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization		(284,880)	(259,310)
Acquired lease intangible assets, net of amortization		188,799	242,822
Off-market Lease, Unfavorable		377,712	427,260
In-place leases, net [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		414,298	438,188
Finite-Lived Intangible Assets, Amortization Expense		48,297	60,250	76,649
Above Market Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		59,381	63,944
Finite-Lived Intangible Assets, Amortization Expense		7,658	9,112	10,433
Off-Market Favorable Lease [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense	[1]			1,688
Off-Market Lease, Unfavorable [Member]
Finite-Lived Intangible Assets [Line Items]
Finite Lived Intangible Liabilities, Gross		523,678	558,936
Acquired lease intangible liability accretion		$ 50,103	$ 54,730	45,561
Above Market Ground Lease Amortization [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired lease intangible liability accretion	[1]			$ 94

[1] On January 1, 2019, the Company adopted the new accounting guidance in ASC Topic 842, Leases, including all related ASUs, and correspondingly reclassified Below-market ground leases and Above-market ground leases against the Company’s Right of use asset, where they continue to be amortized to Operating and maintenance in the accompanying Consolidated Statements of Operations.