Debt - short and long-term debt (Details)		12 Months Ended
	Apr. 26, 2021 USD ($)	Aug. 31, 2022 USD ($)	Aug. 31, 2021 USD ($)	Aug. 31, 2020 USD ($)	Aug. 31, 2022 GBP (£)	Aug. 31, 2022 EUR (€)	Jul. 05, 2022 USD ($)	Jun. 03, 2022	Nov. 17, 2021 USD ($)	Nov. 15, 2021 USD ($)	Sep. 18, 2021 USD ($)
Debt Instrument [Line Items]
Total short-term debt		$ 1,059,000,000	$ 1,305,000,000
Other		26,000,000	29,000,000
Total long-term debt, less current portion		10,615,000,000	7,675,000,000
Long-term debt purchased and retired		8,360,000,000	15,257,000,000	$ 21,414,000,000
Loss on early extinguishment of debt		6,000,000	414,000,000	$ 0
3.300% unsecured notes due 2021
Debt Instrument [Line Items]
Face amount		$ 8,000,000,000
Stated interest rate (as a percent)		3.30%			3.30%	3.30%					3.30%
Total short-term debt		$ 0	1,250,000,000
Debt redeemed											$ 1,250,000,000
Other
Debt Instrument [Line Items]
Total short-term debt		59,000,000	56,000,000
Unsecured notes
Debt Instrument [Line Items]
Long-term debt purchased and retired	$ 3,300,000,000
Weighted average interest rate of long-term debt purchased and retired	4.02%
Loss on early extinguishment of debt	$ 414,000,000	6,000,000	387,000,000
Redemption premiums paid in cash	$ 386,000,000
Unsecured notes | Unsecured credit facility due 2023
Debt Instrument [Line Items]
Long-term debt		1,998,000,000	0
Unsecured notes | Unsecured credit facility due 2024
Debt Instrument [Line Items]
Long-term debt		999,000,000	0
Unsecured notes | 0.9500% notes payable, due 2023
Debt Instrument [Line Items]
Face amount		$ 850,000,000							$ 850,000,000
Stated interest rate (as a percent)		0.95%			0.95%	0.95%			95.00%
Long-term debt		$ 848,000,000	0
Unsecured notes | $1.5 billion debt issuance
Debt Instrument [Line Items]
Face amount		$ 1,500,000,000
Unsecured notes | 3.200% unsecured notes due 2030
Debt Instrument [Line Items]
Stated interest rate (as a percent)		3.20%			3.20%	3.20%
Long-term debt		$ 498,000,000	497,000,000
Unsecured notes | 4.100% unsecured notes due 2050
Debt Instrument [Line Items]
Stated interest rate (as a percent)		4.10%			4.10%	4.10%
Long-term debt		$ 792,000,000	792,000,000
Unsecured notes | Total $6 billion note issuance
Debt Instrument [Line Items]
Face amount		$ 6,000,000,000
Unsecured notes | 3.450% unsecured notes due 2026
Debt Instrument [Line Items]
Stated interest rate (as a percent)		3.45%			3.45%	3.45%
Long-term debt		$ 1,443,000,000	1,442,000,000
Unsecured notes | 4.650% unsecured notes due 2046
Debt Instrument [Line Items]
Stated interest rate (as a percent)		4.65%			4.65%	4.65%
Long-term debt		$ 318,000,000	318,000,000
Unsecured notes | Total $8 billion note issuance
Debt Instrument [Line Items]
Face amount		$ 8,000,000,000
Unsecured notes | 3.800% unsecured notes due 2024
Debt Instrument [Line Items]
Stated interest rate (as a percent)		3.80%			3.80%	3.80%
Long-term debt		$ 1,155,000,000	1,154,000,000
Unsecured notes | 4.500% unsecured notes due 2034
Debt Instrument [Line Items]
Stated interest rate (as a percent)		4.50%			4.50%	4.50%
Long-term debt		$ 301,000,000	301,000,000
Unsecured notes | 4.800% unsecured notes due 2044
Debt Instrument [Line Items]
Stated interest rate (as a percent)		4.80%			4.80%	4.80%
Long-term debt		$ 869,000,000	868,000,000
Unsecured notes | Total £700 million note issuance
Debt Instrument [Line Items]
Face amount | £					£ 700,000,000
Unsecured notes | 3.600% unsecured Pound sterling notes due 2025
Debt Instrument [Line Items]
Stated interest rate (as a percent)		3.60%			3.60%	3.60%
Long-term debt		$ 354,000,000	408,000,000
Unsecured notes | Total €750 million note issuance
Debt Instrument [Line Items]
Face amount | €						€ 750,000,000
Unsecured notes | 2.125% unsecured Euro notes due 2026
Debt Instrument [Line Items]
Stated interest rate (as a percent)		2.125%			2.125%	2.125%
Long-term debt		$ 752,000,000	873,000,000
Unsecured notes | Total $4 billion note issuance
Debt Instrument [Line Items]
Face amount		$ 4,000,000,000
Unsecured notes | 3.100% unsecured notes due 2022
Debt Instrument [Line Items]
Stated interest rate (as a percent)		3.10%			3.10%	3.10%		3.10%
Long-term debt		$ 0	731,000,000
Debt redeemed							$ 731,000,000
Unsecured notes | 4.400% unsecured notes due 2042
Debt Instrument [Line Items]
Stated interest rate (as a percent)		4.40%			4.40%	4.40%
Long-term debt		$ 263,000,000	263,000,000
Term loan | Credit facilities
Debt Instrument [Line Items]
Face amount										$ 3,000,000,000
Credit facilities
Debt Instrument [Line Items]
Total short-term debt		$ 1,000,000,000	$ 0