Sales (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Aug. 31, 2023	May 31, 2023	Feb. 28, 2023	Nov. 30, 2022	Aug. 31, 2022	May 31, 2022	Feb. 28, 2022	Nov. 30, 2021	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2021
Disaggregation of Revenue [Line Items]
Sales	$ 35,422	$ 35,415	$ 34,862	$ 33,382	$ 32,449	$ 32,597	$ 33,756	$ 33,901	$ 139,081	$ 132,703	$ 132,509
Reportable Segments | U.S. Retail Pharmacy
Disaggregation of Revenue [Line Items]
Sales									110,314	109,078	112,005
Reportable Segments | U.S. Retail Pharmacy | Pharmacy
Disaggregation of Revenue [Line Items]
Sales									82,118	80,434	84,892
Reportable Segments | U.S. Retail Pharmacy | Retail
Disaggregation of Revenue [Line Items]
Sales									28,195	28,643	27,113
Reportable Segments | International
Disaggregation of Revenue [Line Items]
Sales									22,198	21,830	20,505
Reportable Segments | International | Pharmacy
Disaggregation of Revenue [Line Items]
Sales									3,664	3,727	3,808
Reportable Segments | International | Retail
Disaggregation of Revenue [Line Items]
Sales									7,324	6,924	6,225
Reportable Segments | International | Wholesale
Disaggregation of Revenue [Line Items]
Sales									11,211	11,178	10,472
Reportable Segments | U.S. Healthcare
Disaggregation of Revenue [Line Items]
Sales									$ 6,570	$ 1,795	$ 0