Revenue Recognition Accounting Policy (Details 3) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total Revenues		$ 1,448	$ 1,339	$ 3,909	$ 3,903
Deferred Revenue		$ 414		414		$ 441
Deferred Revenue, Revenue Recognized				(55)
Deferred Revenue, Additions				36
Foreign Currency Gain (Loss) and Refranchising Gain (Loss) [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred Revenue, Period Increase (Decrease)	[1]			$ (8)

[1] (a)    Primarily includes impact of foreign currency translation.