Goodwill and Intangible Assets, Net - Schedule of Changes in the Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 9,947	$ 9,451
Goodwill acquired	195	628
Foreign currency translation adjustments, net	(3)	(120)
Other adjustments	(7)	(12)
Goodwill, ending balance	10,132	9,947
U.S. Pharmaceutical
Goodwill [Roll Forward]
Goodwill, beginning balance	4,050	3,923
Goodwill acquired	80	160
Foreign currency translation adjustments, net	0	(21)
Other adjustments	(7)	(12)
Goodwill, ending balance	4,123	4,050
Prescription Technology Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	2,005	1,542
Goodwill acquired	19	463
Foreign currency translation adjustments, net	0	0
Other adjustments	0	0
Goodwill, ending balance	2,024	2,005
Medical-Surgical Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	2,453	2,453
Goodwill acquired	83	0
Foreign currency translation adjustments, net	0	0
Other adjustments	0	0
Goodwill, ending balance	2,536	2,453
International
Goodwill [Roll Forward]
Goodwill, beginning balance	1,439	1,533
Goodwill acquired	13	5
Foreign currency translation adjustments, net	(3)	(99)
Other adjustments	0	0
Goodwill, ending balance	$ 1,449	$ 1,439