Segment reporting (Details) $ in Millions	3 Months Ended	6 Months Ended
Feb. 28, 2021 USD ($) segment	Feb. 29, 2020 USD ($)	Feb. 28, 2021 USD ($)	Feb. 29, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment	2
Sales	$ 32,779	$ 31,336	$ 64,217	$ 61,247
Adjusted operating income	1,225	1,582	2,422	2,926
Adjustments to equity earnings (loss) in AmerisourceBergen	(45)	(73)	(1,526)	(152)
Transformational cost management	(178)	(118)	(278)	(198)
Acquisition-related amortization	(114)	(98)	(209)	(197)
Certain legal and regulatory accruals and settlements	(60)	0	(60)	0
LIFO provision	(2)	(28)	(35)	(61)
Acquisition-related costs	5	(99)	(16)	(223)
Store optimization	0	(30)	0	(39)
Operating income	832	1,136	298	2,057
Reportable Segments \| United States
Segment Reporting Information [Line Items]
Sales	27,344	27,245	54,507	53,377
Adjusted operating income	1,163	1,422	2,318	2,725
Reportable Segments \| International
Segment Reporting Information [Line Items]
Sales	5,425	4,091	9,709	7,870
Adjusted operating income	146	203	232	290
Corporate and Other
Segment Reporting Information [Line Items]
Sales	10	0	0	0
Adjusted operating income	$ (83)	$ (43)	$ (129)	$ (89)

The amount of expense recognized in the current period that reflects the allocation of capitalized costs associated with acquisition of business. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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