Acquisitions and other investments - Schedule of Purchase Price Allocation and Identifiable Assets Acquired and Liabilities Assumed - Village MD (Details) - USD ($) $ in Millions	Nov. 24, 2021	Feb. 28, 2023	Aug. 31, 2022
Identifiable assets acquired and liabilities assumed:
Goodwill		$ 28,343	$ 22,280
VillageMD
Purchase Price Allocation:
Total purchase price	$ 5,200
Less: purchase price for issuance of new preferred units at fair value	(2,300)
Net consideration	2,900
Fair value of equity consideration	683
Fair value of previously held equity interests	3,211
Fair value of non-controlling interests	3,257
Total	10,051
Identifiable assets acquired and liabilities assumed:
Tangible assets	634
Intangible assets	1,621
Liabilities	(370)
Total identifiable net assets	1,885
Goodwill	$ 8,166