Variable Interest Entities (Assets and Liabilities of the SPE) (Details) - USD ($) $ in Millions		Sep. 30, 2019	Dec. 31, 2018
Schedule Of Transfer And Financial Assets [Line Items]
Property and equipment, net		$ 723	$ 712
Total SPE assets	[1]	7,563	7,158
Accrued expenses and other liabilities		1,018	1,004
Debt		5,541
Total SPE liabilities		8,133	7,727
Mortgage Note - SPE | Vactaion Ownership NYC Property [Member]
Schedule Of Transfer And Financial Assets [Line Items]
Debt instrument, face amount			32
Variable Interest Entity, Primary Beneficiary [Member]
Schedule Of Transfer And Financial Assets [Line Items]
SPE assets in excess of SPE liabilities		$ 629	669
Variable Interest Entity, Primary Beneficiary [Member] | St Thomas Property [Member]
Schedule Of Transfer And Financial Assets [Line Items]
Property and equipment, net			23
Total SPE assets			23
Debt	[2]		32
Total SPE liabilities			32
SPE assets in excess of SPE liabilities			$ (9)

[1] Excludes investment in consolidated subsidiaries.

[2] Included $32 million relating to mortgage notes, which are included in Debt on the Condensed Consolidated Balance Sheets as of December 31, 2018.