Long-Term Debt And Borrowing Arrangements (Summary Of Indebtedness-Long-Term Debt) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Less: Current portion of securitized vacation ownership debt	$ 200		$ 209
Long-term securitized vacation ownership debt	1,898		1,897
Less: Current portion of long-term debt	33		44
Long-term vacation ownership contract receivables	$ 3,057		2,962
Term Loan (Due March 2021) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	2.01%
Debt instrument, face amount		$ 325
6.00% Senior Unsecured Notes (Due December 2016) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		6.00%
2.95% Senior Unsecured Notes (Due March 2017) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	2.95%
5.75% Senior Unsecured Notes (Due February 2018) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	5.75%
2.50% Senior Unsecured Notes (Due March 2018) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	2.50%
7.375% Senior Unsecured Notes (Due March 2020) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	7.375%
5.625% Senior Unsecured Notes (Due March 2021) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	5.625%
4.25% Senior Unsecured Notes (Due March 2022) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	4.25%
3.90% Senior Unsecured Notes (Due March 2023) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	3.90%
5.10% Senior Unsecured Notes (Due October 2025) [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	5.10%
Term Notes [Member]
Debt Instrument [Line Items]
Secured Debt	$ 1,818		1,867
Debt Issuance Cost	24		24
Bank Conduit Facility (Due August 2016) [Member]
Debt Instrument [Line Items]
Secured Debt	280		239
Securitized Vacation Ownership Debt [Member]
Debt Instrument [Line Items]
Secured Debt	2,098		2,106
Less: Current portion of securitized vacation ownership debt	200		209
Long-term securitized vacation ownership debt	1,898		1,897
Long-term vacation ownership contract receivables	2,560		2,576
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility	12
Commercial paper	404
Revolving Credit Facility [Member] | Revolving Credit Facility (Due July 2020) [Member]
Debt Instrument [Line Items]
Revolving credit facility	12		7
Commercial Paper [Member]
Debt Instrument [Line Items]
Commercial paper	404		109
Other [Member]
Debt Instrument [Line Items]
Capital leases	151		153
Other	18		49
Total long-term debt	3,351		3,075
Less: Current portion of long-term debt	33		44
Long-term debt	3,318		3,031
Other [Member] | Term Loan (Due March 2021) [Member]
Debt Instrument [Line Items]
Other	323		0
Other [Member] | 6.00% Senior Unsecured Notes (Due December 2016) [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 315
Senior notes	0		316
Unamortized (gains)/losses from the settlement of a derivative			1
Other [Member] | 2.95% Senior Unsecured Notes (Due March 2017) [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	300
Senior notes	300		299
Other [Member] | 5.75% Senior Unsecured Notes (Due February 2018) [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	14
Senior notes	14		14
Other [Member] | 2.50% Senior Unsecured Notes (Due March 2018) [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	450
Senior notes	449		448
Other [Member] | 7.375% Senior Unsecured Notes (Due March 2020) [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	40
Senior notes	40		40
Other [Member] | 5.625% Senior Unsecured Notes (Due March 2021) [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	250
Senior notes	247		247
Other [Member] | 4.25% Senior Unsecured Notes (Due March 2022) [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	650
Senior notes	648		648
Unamortized (gains)/losses from the settlement of a derivative	2		2
Other [Member] | 3.90% Senior Unsecured Notes (Due March 2023) [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	400
Senior notes	407		408
Unamortized (gains)/losses from the settlement of a derivative	10		11
Other [Member] | 5.10% Senior Unsecured Notes (Due October 2025) [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	350
Senior notes	338		337
Unamortized (gains)/losses from the settlement of a derivative	(9)		(10)
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Issuance Cost	4		3
Unamortized discount	$ 12		$ 14