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Goodwill and other intangible assets - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022	Aug. 31, 2022	Jun. 01, 2022	Jun. 01, 2021
Goodwill [Line Items]
Goodwill	$ 28,343		$ 28,343		$ 22,280
Indefinite-lived intangible assets	5,628		5,628		5,528
Amortization of intangible assets	199	$ 175	357	$ 340
Minimum
Goodwill [Line Items]
Reporting unit fair value in excess of carrying amount (as a percent)						7.00%	7.00%
Maximum
Goodwill [Line Items]
Reporting unit fair value in excess of carrying amount (as a percent)						198.00%	18.00%
Boots Reporting Unit
Goodwill [Line Items]
Goodwill	940		940		906
Indefinite-lived intangible assets	$ 5,600		$ 5,600		$ 5,500