Restructuring Costs - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 36	$ 104	$ 248	$ 441
Fiscal 2022 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs			246
Amortization of right-of-use assets and interest expense for leases vacated			12
Fiscal 2022 Plan | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs			181
Fiscal 2022 Plan | Facilities Costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs			65
Fiscal 2021 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs			6
Cost incurred to date	544		544
Fiscal 2021 Plan | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0
Cost incurred to date	501		501
Fiscal 2021 Plan | Facilities Costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs			6
Cost incurred to date	43		43
Fiscal 2020 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(1)
Cost incurred to date	295		295
Fiscal 2020 Plan | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring costs			(1)
Cost incurred to date	278		278
Fiscal 2020 Plan | Facilities Costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs			0
Cost incurred to date	17		17
Other Prior Year Plans
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	1,478		1,478
Other Prior Year Plans | Employee Severance
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	1,140		1,140
Other Prior Year Plans | Facilities Costs
Restructuring Cost and Reserve [Line Items]
Cost incurred to date	$ 338		$ 338