Restructuring, Impairment, and Related Charges, Net - Summary of Restructuring Activity (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Restructuring Reserve [Roll Forward]
Beginning balance			$ 55
Restructuring, impairment, and related charges, net	$ 234	$ 28	244	$ 80
Non-cash charges			(76)
Cash payments			(25)
Other			(10)
Ending balance	188		188
Operating Segments | U.S. Pharmaceutical
Restructuring Reserve [Roll Forward]
Beginning balance			18
Restructuring, impairment, and related charges, net	64	9	65	11
Non-cash charges			(64)
Cash payments			(4)
Other			(1)
Ending balance	14		14
Operating Segments | Prescription Technology Solutions
Restructuring Reserve [Roll Forward]
Beginning balance			5
Restructuring, impairment, and related charges, net	1	3	5	5
Non-cash charges			(2)
Cash payments			(2)
Other			(2)
Ending balance	4		4
Operating Segments | Medical-Surgical Solutions
Restructuring Reserve [Roll Forward]
Beginning balance			1
Restructuring, impairment, and related charges, net	147	4	150	6
Non-cash charges			0
Cash payments			(7)
Other			0
Ending balance	144		144
Operating Segments | International
Restructuring Reserve [Roll Forward]
Beginning balance			10
Restructuring, impairment, and related charges, net	(1)	6	0	12
Non-cash charges			(1)
Cash payments			(2)
Other			(5)
Ending balance	2		2
Corporate
Restructuring Reserve [Roll Forward]
Beginning balance			21
Restructuring, impairment, and related charges, net	23	$ 6	24	$ 46
Non-cash charges			(9)
Cash payments			(10)
Other			(2)
Ending balance	24		24
Accrued Liabilities
Restructuring Reserve [Roll Forward]
Beginning balance			24
Ending balance	160		160
Other Non-Current Liabilities
Restructuring Reserve [Roll Forward]
Beginning balance			31
Ending balance	$ 28		$ 28