Restructuring, Impairment, and Related Charges, Net - Summary of Activity Related to Restructuring Liability (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Cost Alignment Plan
Beginning balance	$ 92	$ 130
Restructuring, impairment, and related charges, net	115	209	$ 245
Non-cash charges	(43)	(72)
Cash payments	(105)	(115)
Other	(4)	(60)
Ending balance	55	92	130
Operating Segments | U.S. Pharmaceutical
Cost Alignment Plan
Beginning balance	15	11
Restructuring, impairment, and related charges, net	17	38	35
Non-cash charges	(4)	(25)
Cash payments	(15)	(9)
Other	5	0
Ending balance	18	15	11
Operating Segments | Prescription Technology Solutions
Cost Alignment Plan
Beginning balance	26	3
Restructuring, impairment, and related charges, net	11	43	25
Non-cash charges	0	(13)
Cash payments	(32)	(7)
Other	0	0
Ending balance	5	26	3
Operating Segments | Medical-Surgical Solutions
Cost Alignment Plan
Beginning balance	3	1
Restructuring, impairment, and related charges, net	11	10	9
Non-cash charges	0	(5)
Cash payments	(13)	(3)
Other	0	0
Ending balance	1	3	1
Operating Segments | International
Cost Alignment Plan
Beginning balance	13	56
Restructuring, impairment, and related charges, net	21	35	76
Non-cash charges	(10)	(10)
Cash payments	(5)	(10)
Other	(9)	(58)
Ending balance	10	13	56
Corporate
Cost Alignment Plan
Beginning balance	35	59
Restructuring, impairment, and related charges, net	55	83	100
Non-cash charges	(29)	(19)
Cash payments	(40)	(86)
Other	0	(2)
Ending balance	21	35	$ 59
Other Accrued Liabilities
Cost Alignment Plan
Beginning balance	66
Ending balance	24	66
Other Noncurrent Liabilities
Cost Alignment Plan
Beginning balance	26
Ending balance	$ 31	$ 26