Quarterly report pursuant to Section 13 or 15(d)

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

v3.8.0.1
New Accounting Pronouncements (Impact of Adoption on Condensed Consolidated Income Statement) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Net revenues      
Net revenues $ 302 $ 289 $ 1,280
Expenses      
Operating 41 44 183
Total expenses 246 232 1,031
Income/(loss) before income taxes 55 55 243
Provision (benefit) for income taxes 16 22 13
Net income 39 33 230
Royalties and franchise fees      
Net revenues      
Net revenues 82 75 364
Marketing, reservation and loyalty      
Net revenues      
Net revenues 84 77 371
Expenses      
Cost of revenues 84 81 373
Other      
Net revenues      
Net revenues $ 23 $ 26 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 Adjustment      
Expenses      
Income tax benefit from impact of U.S. Tax Cuts and Jobs Act     3
New Revenue Standard Adjustment | 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 Adjustment | Accounting Standards Update 2014-09 | Royalties and franchise fees      
Net revenues      
Net revenues     (11)
New Revenue Standard Adjustment | Accounting Standards Update 2014-09 | Marketing, reservation and loyalty      
Net revenues      
Net revenues     (36)
Expenses      
Cost of revenues     (33)
New Revenue Standard Adjustment | Accounting Standards Update 2014-09 | Other      
Net revenues      
Net revenues     $ (20)