Revenue from Contracts with Customers - Schedule of Deferred Revenue, Cost of VOI Sales and Direct Selling Costs from Sales of VOIs Related to Project Under Construction (Details) - USD ($) $ in Millions		9 Months Ended	12 Months Ended
		Sep. 30, 2021	Dec. 31, 2020
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Sales of VOIs, net		$ 270	$ 262
Sales of VOIs
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Sales of VOIs, net		0	169
Cost of VOI sales	[1]	0	50
Sales and marketing expense		$ 0	$ 25

[1] Includes anticipated Cost of VOI sales related to inventory associated with Sales of VOIs under construction that will be acquired under a just-in-time arrangement once construction is complete.