Quarterly report pursuant to Section 13 or 15(d)

Assets and Liabilities Measured at Fair Value (Details)

v3.10.0.1
Assets and Liabilities Measured at Fair Value (Details)
shares in Millions, $ in Millions
Jun. 30, 2018
USD ($)
Dec. 31, 2017
USD ($)
Jun. 23, 2016
USD ($)
Jun. 06, 2016
$ / item
shares
Forward Contracts        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivative, Floor Price | $ / item       38.90
Derivative, Cap Price | $ / item       98.96
Forward Contracts | Variable postpaid forward        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Debt Instrument, Face Amount     $ 259  
Trip Advisor | Forward Contracts        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Forward Contract Shares indexed | shares       7
Recurring        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Cash equivalents $ 210 $ 32    
Short term marketable securities (note 5) 14 62    
Recurring | Variable postpaid forward        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivative Asset 13 75    
Recurring | Level 1        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Cash equivalents 210 23    
Recurring | Level 2        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Cash equivalents   9    
Short term marketable securities (note 5) 14 62    
Recurring | Level 2 | Variable postpaid forward        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Derivative Asset $ 13 $ 75