Intangible Assets (Change in Goodwill) (Details) $ in Millions |
6 Months Ended |
|---|---|
|
Jun. 30, 2018
USD ($)
| |
| Goodwill [Roll Forward] | |
| Balance as of December 31, 2017 | $ 423 |
| Goodwill Acquired During 2018 | 1,113 |
| Adjustments to Goodwill | (4) |
| Balance as of June 30, 2018 | 1,532 |
| Hotel Franchising | |
| Goodwill [Roll Forward] | |
| Balance as of December 31, 2017 | 385 |
| Goodwill Acquired During 2018 | 1,041 |
| Adjustments to Goodwill | (4) |
| Balance as of June 30, 2018 | 1,422 |
| Hotel Management | |
| Goodwill [Roll Forward] | |
| Balance as of December 31, 2017 | 38 |
| Goodwill Acquired During 2018 | 72 |
| Adjustments to Goodwill | 0 |
| Balance as of June 30, 2018 | $ 110 |
| X | ||||||||||
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|