Identified Intangible Assets and Liabilities - Schedule of Identified Intangible Assets and Intangible Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross amount	$ 116,969	$ 129,552
Accumulated amortization	(93,113)	(98,587)
Net	23,856	30,965
Identified intangible liabilities (included in deferred revenue):
Gross amount	273,902	316,119
Accumulated amortization	(238,541)	(262,580)
Net	$ 35,361	$ 53,539