Discontinued Operations (Narrative) (Details) (USD $)	0 Months Ended	12 Months Ended
	Jan. 19, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Spin-off costs		$ 14,000,000
Cash received from TripAdvisor		400,000,000
Current assets of discontinued operations		456,426,000	195,026,000
Current liabilities of discontinued operations		419,800,000	75,408,000
Leisure [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sale and marketing expense		207,000,000	171,000,000	140,000,000
8.5% Senior Notes Due 2016 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Senior unsecured notes principal amount		400,000,000	400,000,000
Senior notes, interest rate		8.50%
Senior notes, maturity date		2016
Percentage of redemption price		100.00%
Redemption of senior notes and accrued interest on senior notes	450,000,000	451,000,000
Loss from early extinguishment of debt, pre-tax	38,000,000
Loss from early extinguishment of debt, net of tax	25,000,000
Redemption premium of senior note	33,000,000
Write-off of unamortized debt issuance and discount costs	5,000,000
Interest expense and amortization of debt issuance and discount costs		$ 35,000,000	$ 35,000,000	$ 35,000,000