Revenue Recognition Revenue Recognition (Disaggregation of Net Revenues) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Net revenues		$ 1,105	$ 1,062	$ 3,062	$ 2,976
Vacation ownership interest sales
Disaggregation of Revenue [Line Items]
Net revenues		528	503	1,384	1,323
Consumer financing
Disaggregation of Revenue [Line Items]
Net revenues		132	126	385	363
Operating Segments
Disaggregation of Revenue [Line Items]
Net revenues		1,108	1,063	3,067	2,978
Operating Segments | Vacation Ownership
Disaggregation of Revenue [Line Items]
Net revenues		858	820	2,351	2,251
Operating Segments | Vacation Ownership | Vacation ownership interest sales
Disaggregation of Revenue [Line Items]
Net revenues		528	503	1,384	1,323
Operating Segments | Vacation Ownership | Property management fees and reimbursable revenues
Disaggregation of Revenue [Line Items]
Net revenues		178	172	519	497
Operating Segments | Vacation Ownership | Consumer financing
Disaggregation of Revenue [Line Items]
Net revenues		132	126	385	363
Operating Segments | Vacation Ownership | Fee-for-Service commissions
Disaggregation of Revenue [Line Items]
Net revenues		0	4	12	23
Operating Segments | Vacation Ownership | Ancillary revenues
Disaggregation of Revenue [Line Items]
Net revenues		20	15	51	45
Operating Segments | Exchange & Rentals
Disaggregation of Revenue [Line Items]
Net revenues		250	243	716	727
Operating Segments | Exchange & Rentals | Ancillary revenues
Disaggregation of Revenue [Line Items]
Net revenues		32	24	72	69
Operating Segments | Exchange & Rentals | Exchange revenues
Disaggregation of Revenue [Line Items]
Net revenues		158	158	498	512
Operating Segments | Exchange & Rentals | Vacation rental revenues
Disaggregation of Revenue [Line Items]
Net revenues		60	61	146	146
Corporate and Other
Disaggregation of Revenue [Line Items]
Net revenues	[1]	(3)	(1)	(5)	(2)
Corporate and Other | Ancillary revenues
Disaggregation of Revenue [Line Items]
Net revenues		(1)	0	1	0
Corporate and Other | Eliminations
Disaggregation of Revenue [Line Items]
Net revenues		$ (2)	$ (1)	$ (6)	$ (2)

[1] Includes the elimination of transactions between segments