Summary of Significant Accounting Policies - Schedule of Disaggregation of Revenue Streams of Rental Income and Percentage of Rental Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Amount of rental income	$ 652,677	$ 623,951	$ 1,925,128	$ 1,840,170
Percentage of rental income	100.00%		100.00%
Leasing Revenue [Member]
Percentage of rental income	93.60%		93.70%
Amount of rental income	$ 611,119		$ 1,803,908
Utility Recoveries [Member]
Amount of rental income	$ 15,817		$ 46,752
Percentage of rental income	2.40%		2.40%
Parking Revenue [Member]
Amount of rental income	$ 6,185		$ 20,249
Percentage of rental income	1.00%		1.10%
Other Revenue [Member]
Amount of rental income	$ 19,556		$ 54,219
Percentage of rental income	3.00%		2.80%