Revenue Recognition - Retail Value of Complimentaries (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Food and Beverage [Member]
Direct Operating Costs	$ 284	$ 143	$ 823	$ 426
Rooms
Direct Operating Costs	123	83	359	245
Other Promotional Allowances [Member]
Direct Operating Costs	295	145	843	425
Other Promotional Allowances [Member] | Food and Beverage [Member]
Direct Operating Costs	146	70	438	209
Other Promotional Allowances [Member] | Rooms
Direct Operating Costs	133	68	359	194
Other Promotional Allowances [Member] | Other [Member]
Direct Operating Costs	$ 16	$ 7	$ 46	$ 22