Segments of Business - Schedule of Segment Information (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2022	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Segment revenues
Total revenues		$ 308,951	$ 276,711	$ 263,966
Segment operating profit (loss)
Total operating profit (loss)		4,892	5,025	3,370
Corporate expenses, net		(851)	(147)	(1,073)
Loss on debt extinguishment		0	0	(191)
Interest expense		(252)	(248)	(178)
Income from continuing operations before income taxes		3,789	4,630	1,928
Segment depreciation and amortization
Total depreciation and amortization		635	608	760
Segment expenditures for long-lived assets
Total expenditures for long-lived assets		687	558	535
Provision for bad debts		819	45	29
Charges (credits) associated with last-in, first-out inventory method		(157)	1	(23)
Restructuring charges		115	209	245
Charge for remeasurement to fair value		0	0	1,509
Net gains (losses) on investments in equity securities		(24)	(36)	98
Gain on derivative termination			(97)
Tax Receivable Agreement (“TRA”)
Segment expenditures for long-lived assets
Gain for early termination of tax receivable agreement			126
German Wholesale Business
Segment expenditures for long-lived assets
Gain from sale of equity method investment				42
Held-for-sale | E.U. Businesses (Disposal Group)
Segment expenditures for long-lived assets
Charge for remeasurement to fair value			438	438
Held-for-sale | U.K. Businesses (Disposal Group)
Segment expenditures for long-lived assets
Charge for remeasurement to fair value				1,200
Disposal Group, Disposed of by Sale, Not Discontinued Operations | E.U. Businesses (Disposal Group)
Segment expenditures for long-lived assets
Charge for remeasurement to fair value			(66)	$ (66)
Operating Segments | German Wholesale Business
Segment expenditures for long-lived assets
Noncontrolling interest (percent)				30.00%
Corporate
Segment depreciation and amortization
Total depreciation and amortization		121	124	$ 117
Segment expenditures for long-lived assets
Total expenditures for long-lived assets		229	173	137
Restructuring charges		55	83	100
Corporate | National Prescription Opiate Litigation
Segment expenditures for long-lived assets
Litigation settlement payments		35	36	130
Corporate | Held-for-sale | E.U. Businesses (Disposal Group)
Segment expenditures for long-lived assets
Charge for remeasurement to fair value			(306)	55
Corporate | Held-for-sale | U.K. Businesses (Disposal Group)
Segment expenditures for long-lived assets
Charge for remeasurement to fair value				42
Corporate | National Prescription Opiate Litigation
Segment expenditures for long-lived assets
Loss contingency accrual, period increase (decrease)		73	(8)	274
U.S. Pharmaceutical
Segment revenues
Total revenues		278,739	240,616	212,149
Segment expenditures for long-lived assets
Provision for bad debts		725
U.S. Pharmaceutical | Operating Segments
Segment operating profit (loss)
Total operating profit (loss)		2,786	3,206	2,879
Segment depreciation and amortization
Total depreciation and amortization		229	212	228
Segment expenditures for long-lived assets
Total expenditures for long-lived assets		$ 193	$ 154	$ 137
Revenue derived from services, percentage (less than)		1.00%	1.00%	1.00%
Net cash proceeds from settlements		$ 244	$ 129	$ 46
Charges (credits) associated with last-in, first-out inventory method		(157)	1	(23)
Gain from sale of equity method investment			142
Proceeds from sale of equity method investment	$ 179
Restructuring charges		17	38	35
U.S. Pharmaceutical | Operating Segments | New York Opioid Tax Surcharge
Segment expenditures for long-lived assets
Charge recorded related to Company's share of the litigation settlement			18
U.S. Pharmaceutical | Operating Segments | National Prescription Opiate Litigation
Segment expenditures for long-lived assets
Loss contingency accrual, period increase (decrease)		74
Prescription Technology Solutions
Segment revenues
Total revenues		4,769	4,387	3,864
Prescription Technology Solutions | Operating Segments
Segment operating profit (loss)
Total operating profit (loss)		835	566	500
Segment depreciation and amortization
Total depreciation and amortization		84	77	82
Segment expenditures for long-lived assets
Total expenditures for long-lived assets		$ 31	$ 35	$ 10
Revenue derived from services, percentage (less than)		39.00%	39.00%	39.00%
Restructuring charges		$ 11	$ 43	$ 25
Medical-Surgical Solutions
Segment revenues
Total revenues		11,313	11,110	11,608
Segment expenditures for long-lived assets
Inventory write-down charges			164
Medical-Surgical Solutions | Operating Segments
Segment operating profit (loss)
Total operating profit (loss)		952	1,117	959
Segment depreciation and amortization
Total depreciation and amortization		84	80	129
Segment expenditures for long-lived assets
Total expenditures for long-lived assets		$ 159	$ 117	$ 74
Revenue derived from services, percentage (less than)		3.00%	3.00%	3.00%
Restructuring charges		$ 11	$ 10	$ 9
International
Segment revenues
Total revenues		14,130	20,598	36,345
International | Operating Segments
Segment operating profit (loss)
Total operating profit (loss)		319	136	(968)
Segment depreciation and amortization
Total depreciation and amortization		117	115	204
Segment expenditures for long-lived assets
Total expenditures for long-lived assets		$ 75	$ 79	$ 177
Revenue derived from services, percentage (less than)		8.00%	8.00%	8.00%
Restructuring charges		$ 21	$ 35	$ 76
International | Operating Segments | Held-for-sale | E.U. Businesses (Disposal Group)
Segment expenditures for long-lived assets
Charge for remeasurement to fair value			$ 240	383
International | Operating Segments | Held-for-sale | U.K. Businesses (Disposal Group)
Segment expenditures for long-lived assets
Charge for remeasurement to fair value				1,100
International | Operating Segments | Held-for-sale | German Wholesale Business | Walgreens Boots Alliance Joint Venture
Segment expenditures for long-lived assets
Gain from sale of equity method investment				42
International | Operating Segments | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Canadian Health Benefit Claims Management and Plan Administrative Services Business
Segment expenditures for long-lived assets
Pre-tax gain on sale of business				$ 59