Property, net - Components of Property (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Land	$ 1,567,152	$ 1,607,590
Buildings and improvements	6,385,035	6,511,741
Tenant improvements	620,352	622,878
Equipment and furnishings	187,998	177,036
Construction in progress	366,996	289,966
Total	9,127,533	9,209,211
Less accumulated depreciation	(2,018,303)	(1,851,901)
Property, net	$ 7,109,230	$ 7,357,310