Supplemental information - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Feb. 28, 2025	Feb. 29, 2024	Feb. 28, 2025	Feb. 29, 2024	Aug. 31, 2024	Aug. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Antidilutive securities excluded from EPS calculations (in shares)	36	23	32	21
VillageMD Secured Loan | Line of Credit | Secured Debt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Face amount						$ 2,250
VillageMD Secured Loan | Line of Credit | Revolving credit facilities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Face amount						500
Pre-tax non-controlling interest benefit			$ 160
VillageMD Secured Loan | Line of Credit | Term Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Face amount						$ 1,750
Related Party | Cencora
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables	$ 1,000		1,000		$ 1,000
Trade Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables	$ 5,000		$ 5,000		$ 4,800