Long-Term Debt and Capital Lease Obligations - Maturity and Fair Value (Details) € in Millions	9 Months Ended
	Sep. 30, 2017 EUR (€) item	Sep. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Fair value of debt securities		$ 427,000,000	$ 0
Financial covenants out of compliance | item	1
Expedia | Expedia 7.456% Notes | Level 2
Fair value of debt securities		524,000,000
Expedia | Expedia 5.95% Notes | Level 2
Fair value of debt securities		822,000,000
Expedia | Expedia 4.5% Notes | Level 2
Fair value of debt securities		531,000,000
Expedia | Expedia 2.5% Notes
Fair value of debt securities | €	€ 694
Expedia | Expedia 2.5% Notes | Level 2
Fair value of debt securities		820,000,000
Expedia | Expedia 5.0% Notes | Level 2
Fair value of debt securities		819,000,000
Expedia | Expedia 3.8% Notes | Level 2
Fair value of debt securities		992,000,000
Vitalize | Vitalize Secured Notes | Fixed charge coverage ratio
Outstanding debt for which debt covenant is applicable		2,000,000
Vitalize | Vitalize Secured Notes | Funded debt ratio
Outstanding debt for which debt covenant is applicable		8,000,000
Vitalize | Vitalize Revolving line of credit due 2020 | Fixed charge coverage ratio
Outstanding debt for which debt covenant is applicable		$ 11,000,000