Intangible Assets - Amortization Expense Maturity (Details) $ in Millions |
Sep. 30, 2018
USD ($)
|
|---|---|
| Intangible Assets, Net (Excluding Goodwill) [Abstract] | |
| 2019 | $ 333 |
| 2020 | 333 |
| 2021 | 332 |
| 2022 | 305 |
| 2023 and thereafter | 1,594 |
| Finite-lived intangible assets, net | $ 2,897 |