Segment Information - Other Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 33,968	$ 33,982
Capital expenditures	719	125	$ 21
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	33,968	33,982
Capital expenditures	719	125
Operating Segments | Expedia
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	33,692	33,746
Capital expenditures	710	111
Operating Segments | Corporate and Other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	276	236
Capital expenditures	$ 9	$ 14