Quarterly report pursuant to Section 13 or 15(d)

Segment Information (Summary of Net Revenues and Adjusted EBITDA by Segment) (Details)

v3.10.0.1
Segment Information (Summary of Net Revenues and Adjusted EBITDA by Segment) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2017
Segment Reporting Information [Line Items]          
Net Revenues $ 435 $ 331 $ 737 $ 620 $ 1,280
Adjusted EBITDA 125 105 217 183  
Reportable Segments          
Segment Reporting Information [Line Items]          
Net Revenues 435 331 737 620  
Adjusted EBITDA 137 115 238 203  
Reportable Segments | Hotel Franchising          
Segment Reporting Information [Line Items]          
Net Revenues 289 233 491 424  
Adjusted EBITDA 129 111 214 189  
Reportable Segments | Hotel Management          
Segment Reporting Information [Line Items]          
Net Revenues 146 98 246 196  
Adjusted EBITDA 8 4 24 14  
Corporate and Other          
Segment Reporting Information [Line Items]          
Net Revenues 0 0 0 0  
Adjusted EBITDA $ (12) $ (10) $ (21) $ (20)