Debt - narrative (Details) € in Millions			12 Months Ended
	Apr. 26, 2021 USD ($)	Dec. 23, 2020 USD ($)	Aug. 31, 2021 USD ($)	Aug. 31, 2021 EUR (€)	Aug. 31, 2020 USD ($)	Aug. 31, 2019 USD ($)	Apr. 23, 2021 USD ($)	Apr. 09, 2021 USD ($)	May 29, 2020 USD ($)	Apr. 15, 2020 USD ($)	Apr. 07, 2020 USD ($)	Apr. 02, 2020 USD ($)	Apr. 01, 2020 USD ($)	Aug. 30, 2019 USD ($) agreement	Jan. 18, 2019 USD ($)	Dec. 05, 2018 USD ($)	Aug. 29, 2018 USD ($)
Line of Credit Facility [Line Items]
Long-term debt purchased and retired			$ 15,257,000,000		$ 21,414,000,000	$ 10,461,000,000
Interest paid, net of capitalized interest			916,000,000		584,000,000	676,000,000
Loss on early extinguishment of debt			414,000,000		0	$ 0
Commercial paper
Line of Credit Facility [Line Items]
Average daily short-term borrowings			$ 1,900,000,000		$ 2,500,000,000
Weighted-average interest rate			0.45%		2.15%
Commercial paper, amount outstanding			$ 0
Commercial paper | Guarantor Subsidiaries | Reportable Legal Entities
Line of Credit Facility [Line Items]
Average daily short-term borrowings			$ 424,000,000	€ 300
Weighted-average interest rate for subsidiaries borrowings			0.43%	0.43%
Maximum
Line of Credit Facility [Line Items]
Debt to total capitalization ratio			0.60
$1.5 billion debt issuance
Line of Credit Facility [Line Items]
Face amount										$ 1,500,000,000
Underwriting discounts and estimated offering expenses			$ 13,000,000
Unsecured notes
Line of Credit Facility [Line Items]
Long-term debt purchased and retired	$ 3,300,000,000
Loss on early extinguishment of debt	414,000,000		387,000,000
Unsecured notes | $1.5 billion debt issuance
Line of Credit Facility [Line Items]
Face amount			$ 1,500,000,000
Unsecured notes | 3.200% unsecured notes due 2030
Line of Credit Facility [Line Items]
Face amount										$ 500,000,000
Stated interest rate (as a percent)			3.20%							3.20%
Unsecured notes | 4.100% unsecured notes due 2050
Line of Credit Facility [Line Items]
Face amount										$ 1,000,000,000
Stated interest rate (as a percent)			4.10%							4.10%
Debt retired	$ 200,000,000
Unsecured notes | December 2018 Term Loan Credit Agreement
Line of Credit Facility [Line Items]
Face amount																$ 1,000,000,000
Credit facilities | December 23, 2020 Revolving Credit Agreement, 364-Day Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 1,250,000,000
Credit facilities | December 23, 2020 Revolving Credit Agreement, 18-Month Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 2,250,000,000
Debt term		18 months
Borrowings outstanding			$ 0
Credit facilities | April 7, 2020 Revolving Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity											$ 500,000,000
Credit facilities | April 2020 Revolving Bilateral Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity													$ 750,000,000
Credit facilities | April 2020 Revolving Club Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity												$ 1,325,000,000
Credit facilities | August 2019 Revolving Credit Agreements
Line of Credit Facility [Line Items]
Maximum borrowing capacity														$ 500,000,000
Number of credit agreements | agreement														3
Credit facilities | January 2019 364-Day Revolving Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity															$ 2,000,000,000
Credit facilities | A&R December 2018 Credit Agreement
Line of Credit Facility [Line Items]
Face amount												2,000,000,000
Credit facilities | August 2018 Revolving Credit Agreement
Line of Credit Facility [Line Items]
Face amount																	$ 3,500,000,000
Borrowings outstanding			$ 0
Credit facilities | Line of Credit | Amended November 2018 Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity									$ 500,000,000
Credit facilities | Unsecured notes | A&R December 2018 Credit Agreement
Line of Credit Facility [Line Items]
Face amount												$ 1,000,000,000
Credit facilities | Unsecured notes | Amended November 2018 Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity									$ 1,000,000,000
Credit facilities | Term loan | April 2021 Credit Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity							$ 3,800,000,000	$ 2,800,000,000
Letter of Credit | August 2018 Revolving Credit Agreement
Line of Credit Facility [Line Items]
Face amount																	$ 500,000,000
Bridge Loan | December 23, 2020 Revolving Credit Agreement, 18-Month Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 350,000,000