Segments of Business - Reportable operating segment (Details) $ in Millions	1 Months Ended	3 Months Ended
	May 30, 2024 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)
Segment revenues
Total revenues		$ 79,283	$ 74,483
Segment operating profit (loss)
Total operating profit (loss)		1,029	1,100
Subtotal		1,262	1,342
Corporate income (expenses), net		(103)	(204)
Interest expense		(75)	(47)
Income before income taxes		$ 1,084	1,091
Number of reportable segments | segment		4
Proceeds from legal settlements	$ 90	$ 90	118
Pre-tax credits related to LIFO accounting		(2)	32
Income (loss) from equity method investments		(43)
Gains (losses) associated with equity investments		110	0
Restructuring, impairment, and related charges, net		$ 10	52
Rx Savings Solutions, LLC
Segment operating profit (loss)
Fair value adjustment gain			28
United States
Segment operating profit (loss)
Number of reportable segments | segment		3
Corporate
Segment operating profit (loss)
Gains (losses) associated with equity investments		$ 110
Restructuring, impairment, and related charges, net		1	40
Corporate | National Prescription Opioid Litigation
Segment operating profit (loss)
Pre-tax expenses related to estimated litigation liability		55
U.S. Pharmaceutical
Segment revenues
Total revenues		71,715	67,160
Segment operating profit (loss)
Total operating profit (loss)		781	827
U.S. Pharmaceutical | Operating Segments
Segment operating profit (loss)
Pre-tax credits related to LIFO accounting		(2)	32
Restructuring, impairment, and related charges, net		1	2
U.S. Pharmaceutical | Operating Segments | National Prescription Opioid Litigation
Segment operating profit (loss)
Pre-tax expenses related to estimated litigation liability		57
Prescription Technology Solutions
Segment revenues
Total revenues		1,241	1,244
Segment operating profit (loss)
Total operating profit (loss)		203	231
Prescription Technology Solutions | Operating Segments
Segment operating profit (loss)
Restructuring, impairment, and related charges, net		4	2
Medical-Surgical Solutions
Segment revenues
Total revenues		2,636	2,611
Segment operating profit (loss)
Total operating profit (loss)		188	227
Medical-Surgical Solutions | Operating Segments
Segment operating profit (loss)
Restructuring, impairment, and related charges, net		3	2
International
Segment revenues
Total revenues		3,691	3,468
Segment operating profit (loss)
Total operating profit (loss)		90	57
International | Operating Segments
Segment operating profit (loss)
Restructuring, impairment, and related charges, net		$ 1	$ 6
Revenue from Contract with Customer, Product and Service Benchmark | Product Concentration Risk | U.S. Pharmaceutical
Segment operating profit (loss)
Revenue derived from services, percentage (approximately or less than)		1.00%
Revenue from Contract with Customer, Product and Service Benchmark | Product Concentration Risk | Prescription Technology Solutions
Segment operating profit (loss)
Revenue derived from services, percentage (approximately or less than)		39.00%
Revenue from Contract with Customer, Product and Service Benchmark | Product Concentration Risk | Medical-Surgical Solutions
Segment operating profit (loss)
Revenue derived from services, percentage (approximately or less than)		1.00%
Revenue from Contract with Customer, Product and Service Benchmark | Product Concentration Risk | International
Segment operating profit (loss)
Revenue derived from services, percentage (approximately or less than)		1.00%