Annual report pursuant to Section 13 and 15(d)

Transactions With Former Parent (Narrative) (Details)

v3.10.0.1
Transactions With Former Parent (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Wyndham Worldwide      
Related Party Transaction [Line Items]      
Outstanding borrowings from Parent   $ 184  
Revenue from former parent $ 7    
Wyndham Worldwide | Information technology support, financial services, human resources and other shared services      
Related Party Transaction [Line Items]      
Expense for services provided by Parent 13 29 $ 29
Wyndham Worldwide | Indirect general corporate overhead allocations      
Related Party Transaction [Line Items]      
Expense for services provided by Parent 12 35 34
Wyndham Worldwide | Insurance      
Related Party Transaction [Line Items]      
Expense for services provided by Parent 1 3 3
Wyndham Worldwide | Defined contribution benefit plan      
Related Party Transaction [Line Items]      
Expense for services provided by Parent 2 6 5
Wyndham Worldwide | Licensing Agreements [Member]      
Related Party Transaction [Line Items]      
Revenue from former parent 84 59 56
Wyndham Worldwide | Wyndham Rewards [Member]      
Related Party Transaction [Line Items]      
Revenue from former parent 21 $ 16 $ 9
Wyndham Hotels Defined Contribution Plans      
Related Party Transaction [Line Items]      
Defined contribution plan, cost $ 4