Discontinued operations - Schedules of Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Net earnings from discontinued operations	$ 0	$ 107	$ 0	$ 194
Discontinued Operations, Disposed of by Sale | Alliance Healthcare
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Sales		5,243		10,570
Cost of sales		4,713		9,530
Gross profit		530		1,039
Selling, general and administrative expense		401		816
Operating income from discontinued operations		129		223
Other expense		(9)		(15)
Earnings before income tax – discontinued operations		120		208
Income tax provision		16		24
Post tax earnings from other equity method investments		3		10
Net earnings from discontinued operations		107		194
Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract]
Sales		5,243		10,570
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Cash used for operating activities - discontinued operations				(138)
Cash used for investing activities - discontinued operations				(31)
Discontinued Operations, Disposed of by Sale | Alliance Healthcare | Continuing Operations
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Sales		456		914
Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract]
Sales		$ 456		$ 914