Restructuring, Impairment, and Related Charges, Net - Summary of Restructuring Activity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Restructuring Reserve [Roll Forward]
Beginning balance			$ 92
Restructuring, impairment, and related charges, net	$ 4	$ 31	84	$ 84
Non-cash charges			(28)
Cash payments			(89)
Other			(5)
Ending balance	54		54
Operating Segments | U.S. Pharmaceutical
Restructuring Reserve [Roll Forward]
Beginning balance			15
Restructuring, impairment, and related charges, net	(5)	2	6	9
Non-cash charges			0
Cash payments			(14)
Other			5
Ending balance	12		12
Operating Segments | Prescription Technology Solutions
Restructuring Reserve [Roll Forward]
Beginning balance			26
Restructuring, impairment, and related charges, net	2	1	7	15
Non-cash charges			0
Cash payments			(28)
Other			0
Ending balance	5		5
Operating Segments | Medical-Surgical Solutions
Restructuring Reserve [Roll Forward]
Beginning balance			3
Restructuring, impairment, and related charges, net	3	1	9	3
Non-cash charges			0
Cash payments			(10)
Other			0
Ending balance	2		2
Operating Segments | International
Restructuring Reserve [Roll Forward]
Beginning balance			13
Restructuring, impairment, and related charges, net	0	8	12	19
Non-cash charges			(1)
Cash payments			(4)
Other			(10)
Ending balance	10		10
Corporate
Restructuring Reserve [Roll Forward]
Beginning balance			35
Restructuring, impairment, and related charges, net	4	$ 19	50	$ 38
Non-cash charges			(27)
Cash payments			(33)
Other			0
Ending balance	25		25
Accrued Liabilities
Restructuring Reserve [Roll Forward]
Beginning balance			66
Ending balance	21		21
Other Non-Current Liabilities
Restructuring Reserve [Roll Forward]
Beginning balance			26
Ending balance	$ 33		$ 33