Segment reporting (Details) $ in Millions	3 Months Ended
Nov. 30, 2024 USD ($) segment	Nov. 30, 2023 USD ($)
Segment Reporting [Abstract]
Number of reportable segments \| segment	3
Segment Reporting Information [Line Items]
Sales	$ 39,459	$ 36,707
Adjusted operating income (Non-GAAP measure)	593	687
Footprint optimization	(333)	0
Acquisition-related amortization	(269)	(275)
Acquisition and disposition-related costs	(104)	(163)
Adjustments to equity earnings in Cencora	(76)	(50)
Certain legal and regulatory accruals and settlements	(59)	(82)
LIFO provision	(12)	(48)
Transformational cost management	15	(109)
Operating loss	(245)	(39)
Reportable Segments \| U.S. Retail Pharmacy
Segment Reporting Information [Line Items]
Sales	30,866	28,944
Adjusted operating income (Non-GAAP measure)	441	694
Reportable Segments \| International
Segment Reporting Information [Line Items]
Sales	6,425	5,832
Adjusted operating income (Non-GAAP measure)	168	142
Reportable Segments \| U.S. Healthcare
Segment Reporting Information [Line Items]
Sales	2,172	1,931
Adjusted operating income (Non-GAAP measure)	25	(96)
Reportable Segments \| Pharmacy \| U.S. Retail Pharmacy
Segment Reporting Information [Line Items]
Sales	24,711	22,384
Reportable Segments \| Pharmacy \| International
Segment Reporting Information [Line Items]
Sales	912	926
Reportable Segments \| Retail \| U.S. Retail Pharmacy
Segment Reporting Information [Line Items]
Sales	6,155	6,560
Reportable Segments \| Retail \| International
Segment Reporting Information [Line Items]
Sales	2,117	1,932
Reportable Segments \| Wholesale \| International
Segment Reporting Information [Line Items]
Sales	3,397	2,974
Corporate and Other
Segment Reporting Information [Line Items]
Sales	(4)	0
Adjusted operating income (Non-GAAP measure)	$ (41)	$ (53)

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