Guarantees and Indemnifications (Details) - USD ($) $ in Millions |
6 Months Ended | |
|---|---|---|
Mar. 31, 2017 |
Mar. 31, 2016 |
|
| Guarantees and Indemnifications | ||
| Balance at beginning of year | $ 87 | $ 89 |
| Warranty costs incurred | (20) | (21) |
| Product warranty accrual | 19 | 18 |
| Changes in estimates for prior years | (5) | (2) |
| Balance at March 31, 2017 | 81 | $ 84 |
| Outstanding letters of credit | $ 224 | |