Segment Information (Summary Of Segment Information) (Details) (USD $) In Millions	3 Months Ended					9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Mar. 31, 2010	Sep. 30, 2011		Sep. 30, 2010
Net revenues	$ 1,212		$ 1,065			$ 3,253		$ 2,914
EBITDA	329		323			809		715
Depreciation and amortization	43		43			133		128
Interest expense	34		47	[1]		115	[2]	133	[3]
Interest income	(19)	[4]	(2)			(22)	[4]	(3)
Income before income taxes	271		235			583		457
Non-cash impairment charges			4			13		4
Cost of repurchase of convertible notes					2
Cost of early extinguishment of debt facilities					2
Benefit for reversal of costs incurred						1
Value Added Taxes [Member]
Interest income						(16)
Value Added Taxes [Member] | Corporate [Member]
Net benefit related to adjustment of contingent liabilities and assets						31
Value Added Tax Accrual [Member]
Interest income						(3)
Lodging [Member]
Net revenues	222		203			561		525
EBITDA	67		67			160	[5]	148	[6]
Non-cash impairment charges						13
Cost of repurchase of convertible notes			11
Cost of early extinguishment of debt facilities			11
Lodging [Member] | Tryp [Member]
Acquisition cost						1
Vacation Exchange and Rentals [Member]
Net revenues	436		330			1,152		912
EBITDA	131	[7]	103	[8]		330	[9]	261	[10]
Non-cash impairment charges						4
Acquisition cost						4
Restructuring costs						7
Vacation Exchange and Rentals [Member] | ResortQuest [Member]
Acquisition cost						1
Vacation Ownership [Member]
Net revenues	559		533			1,550		1,483
EBITDA	149		123			376	[11]	310
Corporate [Member]
Net revenues	(5)	[12]	(1)	[12]		(10)	[12]	(6)	[12]
EBITDA	(18)	[12],[13]	30	[12],[13]		(57)	[12],[14]	(4)	[12],[14]
Net benefit related to adjustment of contingent liabilities and assets	52		8			16		51
Corporate costs	26		23			73		55
Cost of repurchase of convertible notes						12
Cost of early extinguishment of debt facilities						12
Corporate [Member] | Revolving Foreign Credit Facility [Member]
Cost of repurchase of convertible notes						16
Cost of early extinguishment of debt facilities						16
Reportable Segments [Member]
Net revenues	1,217		1,066			3,263		2,920
EBITDA	347		293			866		719
Convertible Notes [Member]
Cost of repurchase of convertible notes						11
Cost of early extinguishment of debt facilities						$ 11

[1] Includes $11 million of costs incurred for the repurchase of a portion of the Company's Convertible Notes during the third quarter of 2010.

[2] Includes (i) $12 million of costs incurred for the repurchase of a portion of the Company's Convertible Notes during the first nine months of 2011 and (ii) $3 million of interest related to value added tax accruals.

[3] Includes (i) $16 million of costs incurred for the early extinguishment of the Company's term loan and revolving foreign credit facilities during March 2010 and (ii) $11 million of costs incurred for the repurchase of a portion of the Company's Convertible Notes during the third quarter of 2010.

[4] Includes $16 million of interest income related to a refund of value added taxes.

[5] Includes a non-cash impairment charge of $13 million related to a write-down of an international joint venture in the Company's lodging business.

[6] Includes $1 million related to costs incurred in connection with the Company's acquisition of the Tryp brand during June 2010.

[7] Includes a $4 million charge related to the write-off of foreign exchange translation adjustments associated with the liquidation of a foreign entity.

[8] Includes $1 million related to costs incurred in connection with the Company's acquisition of ResortQuest during September 2010.

[9] Includes (i) a $31 million net benefit resulting from a refund of value added taxes, (ii) $7 million of restructuring cost incurred in connection with a strategic initiative commenced by the Company during 2010 and (iii) a $4 million charge related to the write-off of foreign exchange translation adjustments associated with the liquidation of a foreign entity.

[10] Includes (i) $4 million related to costs incurred in connection with the Company's acquisition of Hoseasons during March 2010 and (ii) $1 million related to costs incurred in connection with the Company's acquisition of ResortQuest during September 2010.

[11] Includes a $1 million benefit for the reversal of costs incurred as a result of various strategic initiatives commenced by the Company during 2008.

[12] Includes the elimination of transactions between segments.

[13] Includes (i) $8 million and $52 million of a net benefit related to the resolution of and adjustment to certain contingent liabilities and assets resulting from the Separation during the three months ended September 30, 2011 and 2010, respectively, and (ii) $26 million and $23 million of corporate costs during the three months ended September 30, 2011 and 2010, respectively.

[14] Includes (i) $16 million and $51 million of a net benefit related to the resolution of and adjustment to certain contingent liabilities and assets resulting from the Separation during the nine months ended September 30, 2011 and 2010, respectively, and (ii) $73 million and $55 million of corporate costs during the nine months ended September 30, 2011 and 2010, respectively.