Goodwill and Intangible Assets, Net - Schedule of Changes in the Carrying Amount of Goodwill (Details) $ in Millions	6 Months Ended
	Sep. 30, 2025 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 10,022
Goodwill acquired	1,277
Disposals	(37)
Foreign currency translation adjustments, net	45
Other adjustments	(24)
Goodwill, ending balance	11,283
Goodwill, transfer to held-for-sale	37
Core Ventures
Goodwill [Roll Forward]
Other adjustments	21
PRISM Vision LLC
Goodwill [Roll Forward]
Other adjustments	3
Operating Segments | North American Pharmaceutical
Goodwill [Roll Forward]
Goodwill, beginning balance	2,737
Goodwill acquired	0
Disposals	0
Foreign currency translation adjustments, net	44
Other adjustments	0
Goodwill, ending balance	2,781
Goodwill, transfer to held-for-sale	0
Operating Segments | Oncology & Multispecialty
Goodwill [Roll Forward]
Goodwill, beginning balance	2,724
Goodwill acquired	1,238
Disposals	(9)
Foreign currency translation adjustments, net	0
Other adjustments	(24)
Goodwill, ending balance	3,929
Goodwill, transfer to held-for-sale	9
Operating Segments | Prescription Technology Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	2,027
Goodwill acquired	39
Disposals	0
Foreign currency translation adjustments, net	0
Other adjustments	0
Goodwill, ending balance	2,066
Goodwill, transfer to held-for-sale	0
Operating Segments | Medical-Surgical Solutions
Goodwill [Roll Forward]
Goodwill, beginning balance	2,507
Goodwill acquired	0
Disposals	0
Foreign currency translation adjustments, net	0
Other adjustments	0
Goodwill, ending balance	2,507
Goodwill, transfer to held-for-sale	0
Other
Goodwill [Roll Forward]
Goodwill, beginning balance	27
Goodwill acquired	0
Disposals	(28)
Foreign currency translation adjustments, net	1
Other adjustments	0
Goodwill, ending balance	0
Goodwill, transfer to held-for-sale	$ 28