Inventory - Schedule of Expenses Incurred, Recorded in Cost of VOI Sales (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Time Share
Inventory [Line Items]
Expenses	[1]	$ 6	$ 14	$ 10
Fee For Service Upgrades
Inventory [Line Items]
Expenses		$ 9	$ 31	$ 34

[1] Cost of sales true ups reduced costs of VOI sales and increased inventory in all periods presented.