Segment Information - Other Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 34,646		$ 31,907
Capital expenditures	275	$ 194
Operating Segments | Expedia
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	34,474
Capital expenditures	274
Corporate and other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	172
Capital expenditures	$ 1