Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Impact of Adoption on Condensed Consolidated Income Statement) (Details)

v3.10.0.1
Summary of Significant Accounting Policies (Impact of Adoption on Condensed Consolidated Income Statement) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Net revenues                      
Net revenues $ 527 $ 604 $ 435 $ 302 $ 312 $ 347 $ 331 $ 289 $ 1,868 $ 1,280 $ 1,269
Expenses                      
Operating                 182 183 168
Total expenses 445 499 396 246 304 245 247 232 1,585 1,031 974
Income/(loss) before income taxes 57 81 29 55 7 100 82 55 223 243 294
Provision (benefit) for income taxes 14 23 8 16 (85) 42 34 22 61 13 118
Net income $ 43 $ 58 $ 21 $ 39 92 $ 58 $ 48 $ 33 162 230 176
Income tax benefit from impact of U.S. Tax Cuts and Jobs Act         $ 85            
Royalties and franchise fees                      
Net revenues                      
Net revenues                 441 364 354
Marketing, reservation and loyalty                      
Net revenues                      
Net revenues                 491 371 375
Expenses                      
Cost of revenues                 486 373 376
Other                      
Net revenues                      
Net revenues                 $ 115 98 97
Accounting Standards Update 2014-09                      
Expenses                      
Provision (benefit) for income taxes                   (4)  
Previously Reported Balance                      
Net revenues                      
Net revenues                   1,347 1,312
Expenses                      
Operating                   205 187
Total expenses                   1,086 1,024
Income/(loss) before income taxes                   255 287
Provision (benefit) for income taxes                   12 115
Net income                   243 172
Previously Reported Balance | Royalties and franchise fees                      
Net revenues                      
Net revenues                   375 353
Previously Reported Balance | Marketing, reservation and loyalty                      
Net revenues                      
Net revenues                   407 405
Expenses                      
Cost of revenues                   406 407
Previously Reported Balance | Other                      
Net revenues                      
Net revenues                   118 111
New Revenue Standard Adjustments | Accounting Standards Update 2014-09                      
Net revenues                      
Net revenues                   (67) (43)
Expenses                      
Operating                   (22) (19)
Total expenses                   (55) (50)
Income/(loss) before income taxes                   (12) 7
Provision (benefit) for income taxes                   1 3
Net income                   (13) 4
New Revenue Standard Adjustments | Accounting Standards Update 2014-09 | Royalties and franchise fees                      
Net revenues                      
Net revenues                   (11) 1
New Revenue Standard Adjustments | Accounting Standards Update 2014-09 | Marketing, reservation and loyalty                      
Net revenues                      
Net revenues                   (36) (30)
Expenses                      
Cost of revenues                   (33) (31)
New Revenue Standard Adjustments | Accounting Standards Update 2014-09 | Other                      
Net revenues                      
Net revenues                   (20) $ (14)
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                      
Expenses                      
Income/(loss) before income taxes                   $ (12)