Goodwill and other intangible assets - Schedule of Goodwill (Details) $ in Millions	3 Months Ended
Nov. 30, 2023 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 28,187
Adjustments	21
Cumulative translation adjustments and other	(25)
Goodwill, ending balance	28,184
Reportable Segments \| U.S. Retail Pharmacy
Goodwill [Roll Forward]
Goodwill, beginning balance	10,947
Adjustments	0
Cumulative translation adjustments and other	0
Goodwill, ending balance	10,947
Reportable Segments \| International
Goodwill [Roll Forward]
Goodwill, beginning balance	1,378
Adjustments	0
Cumulative translation adjustments and other	(17)
Goodwill, ending balance	1,361
Reportable Segments \| U.S. Healthcare
Goodwill [Roll Forward]
Goodwill, beginning balance	15,863
Adjustments	21
Cumulative translation adjustments and other	(8)
Goodwill, ending balance	$ 15,876

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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