Intangible Assets and Intangible Liabilities - Summary of Intangible Assets and 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
Intangible assets:
Gross amount	$ 438,402		$ 438,402		$ 466,099
Accumulated amortization	(259,158)		(259,158)		(262,930)
Intangible assets, Net	179,244		179,244		203,169
Intangible liabilities:
Gross amount	163,977		163,977		174,670
Accumulated amortization	(98,208)		(98,208)		(100,881)
Intangible Liabilities, Net	65,769		65,769		$ 73,789
Leases, Acquired-in-Place, Market Adjustment [Member]
Intangible liabilities:
Amortization of above and below-market leases, net (component of "rental revenue")	1,235	$ 2,747	2,778	$ 6,043
Leases, Acquired-in-Place [Member]
Intangible liabilities:
Amortization of acquired in-place leases (component of "depreciation and amortization")	$ 9,190	$ 11,777	$ 18,682	$ 24,530

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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