Restructuring Costs - Narrative (Details) $ in Millions	Sep. 30, 2019 USD ($)
Fiscal 2019 Plan
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	$ 497
Fiscal 2019 Plan | Workforce Reductions
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	353
Fiscal 2019 Plan | Facilities Costs
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	144
Fiscal 2018 Plan
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	772
Fiscal 2018 Plan | Workforce Reductions
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	585
Fiscal 2018 Plan | Facilities Costs
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	187
Fiscal 2017 Plan
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	215
Fiscal 2017 Plan | Workforce Reductions
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	206
Fiscal 2017 Plan | Facilities Costs
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	$ 9