Goodwill and other intangible assets - schedule of goodwill (Details) - USD ($) $ in Millions		12 Months Ended
Dec. 29, 2020	Aug. 31, 2021	Aug. 31, 2020
Goodwill [Roll Forward]
Beginning balance		$ 12,013	$ 13,542
Acquisitions		414	62
Impairment			(1,675)
Currency translation adjustments		(7)	83
Ending balance		12,421	12,013
Rite Aid Corporation Distribution Centers
Goodwill [Roll Forward]
Acquisitions			62
Payments to acquire business			91
Innovation Associates, Inc.
Goodwill [Roll Forward]
Acquisitions		394
Ending balance	$ 394
Payments to acquire business	$ 451
McKesson Corporation, GEHE Pharma Handel
Goodwill [Roll Forward]
Acquisitions		21
Reportable Segments \| United States
Goodwill [Roll Forward]
Beginning balance		10,553	10,491
Acquisitions		394	62
Impairment			0
Currency translation adjustments		0	0
Ending balance		10,947	10,553
Reportable Segments \| International
Goodwill [Roll Forward]
Beginning balance		1,460	3,051
Acquisitions		21	0
Impairment			(1,675)
Currency translation adjustments		(7)	83
Ending balance		$ 1,474	$ 1,460

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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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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