Intangible Assets and Intangible Liabilities - Summary of Intangible Assets and 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
Intangible assets:
Gross amount	$ 381,169		$ 381,169		$ 436,851
Accumulated amortization	(245,405)		(245,405)		(283,332)
Intangible assets, Net	135,764		135,764		153,519
Intangible liabilities:
Gross amount	156,478		156,478		163,977
Accumulated amortization	(106,086)		(106,086)		(107,981)
Intangible Liabilities, Net	50,392		50,392		$ 55,996
Leases, Acquired-in-Place, Market Adjustment [Member]
Intangible liabilities:
Amortization of above and below-market leases, net (component of "rental revenue")	758	$ 1,235	1,613	$ 2,778
Leases, Acquired-in-Place [Member]
Intangible liabilities:
Amortization of acquired in-place leases (component of "depreciation and amortization")	$ 6,551	$ 9,190	$ 13,770	$ 18,682

Amount of non-cash amortization of intangible asset (liability) for above and below market leases.

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Amount of accumulated amortization of leases acquired as part of a real property acquisition at below market lease rate with a finite life.

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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