Discontinued operations - narrative (Details) - Discontinued operations, disposed of by sale - Alliance Healthcare - USD ($) shares in Millions, $ in Millions		12 Months Ended
	Jun. 01, 2021	Aug. 31, 2022	Aug. 31, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from disposal	$ 6,900
Proceeds from disposal, subject to net working capital and net cash adjustments	$ 6,700
Shares issued as part of disposal (in shares)	2
Estimated gain before currency translation adjustments	$ 1,100
Net gain on disposal	$ 322		$ 322
Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]	Net earnings from discontinued operations
Receivable for purchase consideration		$ 98
Disposal group, contingent consideration, working capital adjustments		$ 38