Commitments and Contingencies - Guarantor Obligations (Details) $ in Millions	Mar. 31, 2019 USD ($)
Guarantor Obligations [Line Items]
Fiscal 2020	$ 525
Fiscal 2021	234
Fiscal 2022 and Thereafter	522
Total	1,281
Surety bonds
Guarantor Obligations [Line Items]
Fiscal 2020	254
Fiscal 2021	125
Fiscal 2022 and Thereafter	145
Total	524
Letters of credit
Guarantor Obligations [Line Items]
Fiscal 2020	190
Fiscal 2021	28
Fiscal 2022 and Thereafter	364
Total	582
Standby letters of credit
Guarantor Obligations [Line Items]
Fiscal 2020	81
Fiscal 2021	81
Fiscal 2022 and Thereafter	13
Total	$ 175