Property and Equipment (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 9,025	$ 9,134
Less: accumulated depreciation	(1,902)	(1,688)
Property and equipment, net	7,123	7,446
Land and land improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,576	3,584
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	4,021	4,149
Furniture, fixtures, and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,309	1,346
Construction in progress
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 119	$ 55