Summary of Significant Accounting Policies Summary of Significant Accounting Policies - Contract and Contract Related Liabilities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Outstanding Chip Liability [Member]
Contract and Contract Related Liabilities [Line Items]
Contract and contract related, liability		$ 540	$ 551	$ 478
Change in contract and contract related liabilities		(11)	73
Loyalty Program Liability [Member]
Contract and Contract Related Liabilities [Line Items]
Contract and contract related, liability		68	66	63
Change in contract and contract related liabilities		2	3
Customer Deposits and Other Deferred Revenue [Member]
Contract and Contract Related Liabilities [Line Items]
Contract and contract related, liability	[1]	724	827	714
Change in contract and contract related liabilities		(103)	113
Mall [Member] | Customer Deposits and Other Deferred Revenue [Member]
Contract and Contract Related Liabilities [Line Items]
Contract and contract related, liability	[1]	$ 154	$ 152	$ 145

[1] Of this amount, $154 million, $152 million and $145 million as of December 31, 2019, December 31, 2018 and January 1, 2018, respectively, relates to mall deposits that are accounted for based on lease terms usually greater than one year.