Revenue Recognition (Performance Obligations) (Details) $ in Millions | Jun. 30, 2019USD ($) |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 121 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | Initial franchise fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 26 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | Loyalty program revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 53 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | Co-branded credit cards program | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 14 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | Hotel management fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 1 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | Other revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 27 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 | Initial franchise fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 | Loyalty program revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 | Hotel management fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 | Other revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 37 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01 | Initial franchise fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 13 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01 | Loyalty program revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 21 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01 | Co-branded credit cards program | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 0 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01 | Hotel management fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 0 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01 | Other revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 3 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01 | Initial franchise fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01 | Loyalty program revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01 | Hotel management fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01 | Other revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 23 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | Initial franchise fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 12 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | Loyalty program revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 9 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | Co-branded credit cards program | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 0 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | Hotel management fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 0 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | Other revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 2 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 | Initial franchise fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 | Loyalty program revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 | Hotel management fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 | Other revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 88 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 | Initial franchise fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 79 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 | Loyalty program revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 3 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 | Co-branded credit cards program | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 0 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 | Hotel management fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | 1 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 | Other revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 5 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | Initial franchise fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | Loyalty program revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | Hotel management fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | Other revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation, period | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 269 |
Remaining performance obligation, period | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Initial franchise fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 130 |
Remaining performance obligation, period | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Loyalty program revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 86 |
Remaining performance obligation, period | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Co-branded credit cards program | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 14 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Hotel management fee revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 2 |
Remaining performance obligation, period | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Other revenue | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Remaining performance obligation | $ 37 |
Remaining performance obligation, period | |