Intangible Assets and Intangible Liabilities - Summary of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Intangible assets:
Gross amount	$ 451,534		$ 466,099
Accumulated amortization	(260,351)		(262,930)
Intangible assets, Net	191,183		203,169
Intangible liabilities:
Gross amount	165,583		174,670
Accumulated amortization	(95,831)		(100,881)
Intangible Liabilities, Net	69,752		$ 73,789
Leases, Acquired-in-Place, Market Adjustment [Member]
Intangible liabilities:
Amortization of above and below-market leases, net (component of "rental revenue")	(1,543)	$ (3,296)
Leases, Acquired-in-Place [Member]
Intangible liabilities:
Amortization of acquired in-place leases (component of "depreciation and amortization")	$ 9,492	$ 12,753