Goodwill and other intangible assets - schedule of goodwill (Details) - USD ($) $ in Millions	12 Months Ended
Aug. 31, 2024	Aug. 31, 2023	Aug. 31, 2022
Goodwill [Roll Forward]
Beginning balance	$ 28,187	$ 22,280
Acquisitions		5,588
Measurement period adjustments	19	252
Impairment of goodwill	(12,701)	0	$ 0
Currency translation adjustments and other	1	67
Ending balance	15,506	28,187	22,280
VillageMD
Goodwill [Roll Forward]
Measurement period adjustments	125
Shields Health Solutions
Goodwill [Roll Forward]
Measurement period adjustments	72
CareCentrix, Inc.
Goodwill [Roll Forward]
Beginning balance		509
Measurement period adjustments		56
Ending balance			509
International
Goodwill [Roll Forward]
Impairment of goodwill			(1,700)
Reportable Segments \| U.S. Retail Pharmacy
Goodwill [Roll Forward]
Beginning balance	10,947	10,947
Acquisitions		0
Measurement period adjustments	0	0
Impairment of goodwill	0
Currency translation adjustments and other	0	0
Ending balance	10,947	10,947	10,947
Reportable Segments \| International
Goodwill [Roll Forward]
Beginning balance	1,378	1,293
Acquisitions		0
Measurement period adjustments	0	0
Impairment of goodwill	0
Currency translation adjustments and other	9	85
Ending balance	1,388	1,378	1,293
Reportable Segments \| U.S. Healthcare
Goodwill [Roll Forward]
Beginning balance	15,863	10,040
Acquisitions		5,588
Measurement period adjustments	19	252
Impairment of goodwill	(12,701)
Currency translation adjustments and other	(8)	(18)
Ending balance	$ 3,173	$ 15,863	$ 10,040

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