Quarterly report pursuant to Section 13 or 15(d)

New Accounting Pronouncements (Impact of Adoption on Condensed Consolidated Income Statement) (Details)

v3.10.0.1
New Accounting Pronouncements (Impact of Adoption on Condensed Consolidated Income Statement) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Net revenues          
Net revenues $ 604 $ 347 $ 1,341 $ 967 $ 1,280
Expenses          
Operating 51 46 139 135 183
Total expenses 499 245 1,140 726 1,031
Income/(loss) before income taxes 81 100 165 236 243
Provision (benefit) for income taxes 23 42 47 98 13
Net income 58 58 118 138 230
Royalties and franchise fees          
Net revenues          
Net revenues 138 107 332 277 364
Marketing, reservation and loyalty          
Net revenues          
Net revenues 151 109 359 282 371
Expenses          
Cost of revenues 139 95 347 269 373
Other          
Net revenues          
Net revenues $ 28 $ 25 $ 83 $ 75 98
Accounting Standards Update 2014-09          
Expenses          
Provision (benefit) for income taxes         (4)
Previously Reported Balance          
Net revenues          
Net revenues         1,347
Expenses          
Operating         205
Total expenses         1,086
Income/(loss) before income taxes         255
Provision (benefit) for income taxes         12
Net income         243
Previously Reported Balance | Royalties and franchise fees          
Net revenues          
Net revenues         375
Previously Reported Balance | Marketing, reservation and loyalty          
Net revenues          
Net revenues         407
Expenses          
Cost of revenues         406
Previously Reported Balance | Other          
Net revenues          
Net revenues         118
New Revenue Standard Adjustments          
Expenses          
Income tax benefit from impact of U.S. Tax Cuts and Jobs Act         (3)
New Revenue Standard Adjustments | Accounting Standards Update 2014-09          
Net revenues          
Net revenues         (67)
Expenses          
Operating         (22)
Total expenses         (55)
Income/(loss) before income taxes         (12)
Provision (benefit) for income taxes         1
Net income         (13)
New Revenue Standard Adjustments | Accounting Standards Update 2014-09 | Royalties and franchise fees          
Net revenues          
Net revenues         (11)
New Revenue Standard Adjustments | Accounting Standards Update 2014-09 | Marketing, reservation and loyalty          
Net revenues          
Net revenues         (36)
Expenses          
Cost of revenues         (33)
New Revenue Standard Adjustments | Accounting Standards Update 2014-09 | Other          
Net revenues          
Net revenues         $ (20)