Other Assets (Summary of other assets) (Details) - USD ($) $ in Millions |
Mar. 31, 2016 |
Sep. 30, 2015 |
|---|---|---|
| Other Assets [Abstract] | ||
| Long-term receivables | $ 110 | $ 109 |
| Investments in equity affiliates | 11 | 13 |
| Exchange and rental assets (net of accumulated depreciation of $99 at March 31, 2016 and $97 at September 30, 2015) | 65 | 66 |
| Other | 158 | 156 |
| Other assets | 344 | 344 |
| Accumulated Depreciation Exchange And Rental Assets | $ 99 | $ 97 |