Business Combinations - Purchase Price Allocation (Details) - USD ($) $ in Millions		Jul. 16, 2018	Sep. 30, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill			$ 4,083	$ 3,815
Centaur Holdings, LLC [Member]
Business Acquisition [Line Items]
Cash and cash equivalents		$ 39
Receivables, net		2
Other current assets		26
Property and equipment		297
Total assets		1,809
Current liabilities		(92)
Deferred income taxes		(285)
Total liabilities		(377)
Net identifiable assets acquired		1,432
Goodwill		270
Total purchase price		1,702
Trademarks [Member] | Centaur Holdings, LLC [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill		$ 14
Weighted Average Remaining Useful Life (in years)		2 years 6 months
Gaming rights | Centaur Holdings, LLC [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	[1]	$ 1,390
Customer relationships | Centaur Holdings, LLC [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill		$ 41
Weighted Average Remaining Useful Life (in years)		15 years

[1] (1) Indefinite-lived intangible assets.