Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2022	Mar. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 8,303	$ 8,502
Accumulated Amortization	5,186	5,124
Net Carrying Value	3,117	3,378
Software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	4,025	4,063
Accumulated Amortization	3,071	3,039
Net Carrying Value	954	1,024
Customer related intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	3,985	4,148
Accumulated Amortization	2,016	1,995
Net Carrying Value	1,969	2,153
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	293	291
Accumulated Amortization	99	90
Net Carrying Value	$ 194	$ 201