Property, Equipment and Technology, Net - Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Sep. 30, 2015 |
Sep. 30, 2014 |
Sep. 30, 2013 |
|
| Finite-Lived Intangible Assets [Line Items] | |||
| Technology, accumulated amortization | $ 1,400 | $ 1,100 | |
| Depreciation and amortization | 494 | 435 | $ 397 |
| Depreciation and amortization, amortization expense on technology | 63 | 66 | 69 |
| Property, Equipment and Technology | |||
| Finite-Lived Intangible Assets [Line Items] | |||
| Depreciation and amortization | 431 | 369 | 328 |
| Technology and Software | |||
| Finite-Lived Intangible Assets [Line Items] | |||
| Depreciation and amortization, amortization expense on technology | $ 251 | $ 198 | $ 173 |