Goodwill and Intangible Assets, Net - Schedule of Information Regarding Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,996	$ 6,646
Accumulated Amortization	(2,937)	(3,768)
Net Carrying Amount	2,059	2,878
Held-for-sale | European Assets Held for Sale
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	$ 384
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Remaining Amortization Period (Years)	12 years
Gross Carrying Amount	$ 2,777	3,739
Accumulated Amortization	(1,691)	(2,269)
Net Carrying Amount	$ 1,086	1,470
Service agreements
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Remaining Amortization Period (Years)	9 years
Gross Carrying Amount	$ 1,085	1,081
Accumulated Amortization	(573)	(513)
Net Carrying Amount	512	568
Pharmacy licenses
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	0	497
Accumulated Amortization	0	(244)
Net Carrying Amount	$ 0	253
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Remaining Amortization Period (Years)	12 years
Gross Carrying Amount	$ 819	925
Accumulated Amortization	(386)	(394)
Net Carrying Amount	$ 433	531
Technology
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Remaining Amortization Period (Years)	1 year
Gross Carrying Amount	$ 128	150
Accumulated Amortization	(116)	(122)
Net Carrying Amount	$ 12	28
Other
Finite-Lived Intangible Assets [Line Items]
Weighted- Average Remaining Amortization Period (Years)	9 years
Gross Carrying Amount	$ 187	254
Accumulated Amortization	(171)	(226)
Net Carrying Amount	$ 16	$ 28