Fair Value Measurements (Fair Value of Financial Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($)
$ in Millions |
6 Months Ended |
|
Mar. 31, 2017 |
Mar. 31, 2016 |
Sep. 30, 2016 |
| Fair Value of Assets and Liabilities Measured on Recurring Basis |
|
|
|
| Fair Value, Assets, Level 1 to Level 2 Transfers, Amount |
$ 0
|
$ 0
|
|
| Fair Value, Assets, Level 2 to Level 1 Transfers, Amount |
0
|
0
|
|
| Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount |
0
|
0
|
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 |
0
|
0
|
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3 |
0
|
0
|
|
| Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3 |
0
|
$ 0
|
|
| Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Deferred Compensation Plan Investments [Member] |
|
|
|
| Fair Value of Assets and Liabilities Measured on Recurring Basis |
|
|
|
| Assets at fair value |
57
|
|
$ 55
|
| Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Exchange Forward [Member] |
|
|
|
| Fair Value of Assets and Liabilities Measured on Recurring Basis |
|
|
|
| Liabilities at fair value |
(10)
|
|
(13)
|
| Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Swap Assets [Member] |
|
|
|
| Fair Value of Assets and Liabilities Measured on Recurring Basis |
|
|
|
| Assets at fair value |
15
|
|
35
|
| Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Exchange Forward [Member] |
|
|
|
| Fair Value of Assets and Liabilities Measured on Recurring Basis |
|
|
|
| Assets at fair value |
11
|
|
11
|
| ICG [Member] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Contingent Consideration [Member] |
|
|
|
| Fair Value of Assets and Liabilities Measured on Recurring Basis |
|
|
|
| Liabilities at fair value |
(13)
|
|
(13)
|
| Pulse.aero [Member] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Contingent Consideration [Member] |
|
|
|
| Fair Value of Assets and Liabilities Measured on Recurring Basis |
|
|
|
| Liabilities at fair value |
$ (5)
|
|
$ 0
|