Intangible Assets and Intangible Liabilities - Summary of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Intangible assets:
Gross amount	$ 395,730		$ 436,851
Accumulated amortization	(251,569)		(283,332)
Intangible assets, Net	144,161		153,519
Intangible liabilities:
Gross amount	162,237		163,977
Accumulated amortization	(109,233)		(107,981)
Intangible Liabilities, Net	53,004		$ 55,996
Leases, Acquired-in-Place, Market Adjustment [Member]
Intangible liabilities:
Amortization of above and below-market leases, net (component of "rental revenue")	855	$ 1,543
Leases, Acquired-in-Place [Member]
Intangible liabilities:
Amortization of acquired in-place leases (component of "depreciation and amortization")	$ 7,219	$ 9,492