Segment reporting (Details) $ in Millions	3 Months Ended	6 Months Ended
Feb. 28, 2025 USD ($)	Feb. 29, 2024 USD ($)	Feb. 28, 2025 USD ($) segment	Feb. 29, 2024 USD ($)
Segment Reporting [Abstract]
Number of reportable segments \| segment			3
Segment Reporting Information [Line Items]
Sales	$ 38,588	$ 37,052	$ 78,048	$ 73,760
Adjusted operating income (Non-GAAP measure)	785	900	1,378	1,588
Impairment of goodwill, intangibles and long-lived assets	(5,343)	(13,090)	(5,343)	(13,090)
Acquisition-related amortization	(250)	(270)	(520)	(545)
Acquisition and disposition-related costs	(94)	(249)	(198)	(412)
Certain legal and regulatory accruals and settlements	(548)	(242)	(607)	(324)
Transformational cost management	(3)	(197)	12	(306)
Adjustments to equity earnings in Cencora	(33)	(22)	(109)	(72)
LIFO provision	(12)	0	(24)	(48)
Footprint optimization	(68)	0	(400)	0
Operating loss	(5,567)	(13,171)	(5,812)	(13,209)
Reportable Segments \| U.S. Retail Pharmacy
Segment Reporting Information [Line Items]
Sales	30,380	28,861	61,246	57,805
Adjusted operating income (Non-GAAP measure)	487	752	928	1,446
Reportable Segments \| International
Segment Reporting Information [Line Items]
Sales	6,060	6,022	12,485	11,854
Adjusted operating income (Non-GAAP measure)	234	245	401	387
Reportable Segments \| U.S. Healthcare
Segment Reporting Information [Line Items]
Sales	2,152	2,176	4,325	4,107
Adjusted operating income (Non-GAAP measure)	117	(34)	142	(129)
Reportable Segments \| Pharmacy \| U.S. Retail Pharmacy
Segment Reporting Information [Line Items]
Sales	23,432	21,508	48,143	43,892
Reportable Segments \| Pharmacy \| International
Segment Reporting Information [Line Items]
Sales	837	898	1,749	1,824
Reportable Segments \| Retail \| U.S. Retail Pharmacy
Segment Reporting Information [Line Items]
Sales	6,948	7,353	13,103	13,913
Reportable Segments \| Retail \| International
Segment Reporting Information [Line Items]
Sales	2,182	2,158	4,298	4,090
Reportable Segments \| Wholesale \| International
Segment Reporting Information [Line Items]
Sales	3,041	2,966	6,438	5,940
Corporate and Other
Segment Reporting Information [Line Items]
Sales	(4)	(6)	(8)	(6)
Adjusted operating income (Non-GAAP measure)	$ (52)	$ (63)	$ (93)	$ (117)

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