Commitments and Contingencies - Guarantor Obligations (Details) $ in Millions	Sep. 30, 2019 USD ($)
Guarantor Obligations [Line Items]
Fiscal 2020	$ 228
Fiscal 2021	482
Fiscal 2022 and Thereafter	557
Total	1,267
Surety bonds
Guarantor Obligations [Line Items]
Fiscal 2020	30
Fiscal 2021	326
Fiscal 2022 and Thereafter	151
Total	507
Letters of credit
Guarantor Obligations [Line Items]
Fiscal 2020	126
Fiscal 2021	55
Fiscal 2022 and Thereafter	385
Total	566
Stand-by letters of credit
Guarantor Obligations [Line Items]
Fiscal 2020	72
Fiscal 2021	101
Fiscal 2022 and Thereafter	21
Total	$ 194