v3.26.3
Revenue Recognition (Performance Obligations) (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Sep. 30, 2025
Dec. 31, 2024
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Contract with Customer, Liability $ 454 $ 469 $ 491 $ 459
Deferred subscription revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Contract with Customer, Liability 143 147    
Deferred VOI trial package revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Contract with Customer, Liability 133 138    
Deferred VOI incentive revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Contract with Customer, Liability 88 90    
Deferred exchange-related revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Contract with Customer, Liability [1] 55 57    
Deferred co-branded credit card programs revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Contract with Customer, Liability 32 36    
Deferred other revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Contract with Customer, Liability 3 $ 1    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 346      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01 | Deferred subscription revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 80      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01 | Deferred VOI trial package revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 119      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01 | Deferred VOI incentive revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 88      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01 | Deferred exchange-related revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 52      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01 | Deferred co-branded credit card programs revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 4      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-10-01 | Deferred other revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 3      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 42      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01 | Deferred subscription revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 31      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01 | Deferred VOI trial package revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 5      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01 | Deferred VOI incentive revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 0      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01 | Deferred exchange-related revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 2      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01 | Deferred co-branded credit card programs revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 4      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-10-01 | Deferred other revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 0      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 24      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01 | Deferred subscription revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 14      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01 | Deferred VOI trial package revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 5      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01 | Deferred VOI incentive revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 0      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01 | Deferred exchange-related revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 1      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01 | Deferred co-branded credit card programs revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 4      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-10-01 | Deferred other revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 0      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-10-01        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 42      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-10-01 | Deferred subscription revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 18      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-10-01 | Deferred VOI trial package revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 4      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-10-01 | Deferred VOI incentive revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 0      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-10-01 | Deferred exchange-related revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 0      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-10-01 | Deferred co-branded credit card programs revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 20      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-10-01 | Deferred other revenue        
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]        
Remaining performance obligations $ 0      
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period 1 year      
[1] Includes contractual liabilities to accommodate members for cancellations initiated by the Company due to unexpected events. As of both September 30, 2026 and December 31, 2025, there were $1 million of these contractual liabilities included within Accrued expenses and other liabilities on the Condensed Consolidated Balance Sheets.