Segment reporting (Details) $ in Millions	3 Months Ended
Nov. 30, 2019 USD ($) segment	Nov. 30, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| segment	3
Sales	$ 34,339	$ 33,793
Adjusted operating income	1,463	1,732
Acquisition-related costs	(124)	(66)
Acquisition-related amortization and impairment	(118)	(123)
Transformational cost management	(86)	(30)
Adjustments to equity earnings in AmerisourceBergen	(80)	(44)
LIFO provision	(33)	(39)
Store optimization	(9)	(20)
Certain legal and regulatory accruals and settlements	0	(10)
Operating income	1,013	1,400
Reportable Segments \| Retail Pharmacy USA
Segment Reporting Information [Line Items]
Sales	26,133	25,721
Adjusted operating income	1,155	1,379
Reportable Segments \| Retail Pharmacy International
Segment Reporting Information [Line Items]
Sales	2,745	2,901
Adjusted operating income	79	132
Reportable Segments \| Pharmaceutical Wholesale
Segment Reporting Information [Line Items]
Sales	6,007	5,708
Adjusted operating income	229	220
Eliminations
Segment Reporting Information [Line Items]
Sales	(545)	(537)
Adjusted operating income	$ 0	$ 1

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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Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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