v3.8.0.1
Document and Entity Information - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Jan. 31, 2018
Jun. 30, 2017
Entity Registrant Name Liberty TripAdvisor Holdings, Inc.    
Entity Central Index Key 0001606745    
Document Type 10-K    
Document Period End Date Dec. 31, 2017    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 797.8
Document Fiscal Year Focus 2017    
Document Fiscal Period Focus FY    
Series A      
Entity Common Stock, Shares Outstanding   72,127,285  
Series B      
Entity Common Stock, Shares Outstanding   2,929,777