Intangible Assets and Intangible Liabilities - Summary of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Intangible assets:
Gross amount	$ 436,851	$ 466,099
Accumulated amortization	(283,332)	(262,930)
Intangible assets, Net	153,519	203,169
Intangible liabilities:
Gross amount	163,977	174,670
Accumulated amortization	(107,981)	(100,881)
Intangible Liabilities, Net	55,996	73,789
Leases, Acquired-in-Place, Market Adjustment [Member]
Intangible liabilities:
Amortization of above and below-market leases, net (component of "rental revenue")	4,775	11,097	$ 14,652
Leases, Acquired-in-Place [Member]
Intangible liabilities:
Amortization of acquired in-place leases (component of "depreciation and amortization")	$ 36,628	$ 46,917	$ 54,208