Identified Intangible Assets and Liabilities - Schedule of Identified Intangible Assets and Intangible Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross amount	$ 130,396	$ 308,895
Accumulated amortization	(99,623)	(172,114)
Total, net	30,773	136,781
Identified intangible liabilities (included in deferred revenue):
Gross amount	321,838	503,373
Accumulated amortization	(265,388)	(341,779)
Total, net	$ 56,450	$ 161,594