Sales (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 29, 2024	Feb. 28, 2023	Feb. 29, 2024	Feb. 28, 2023
Disaggregation of Revenue [Line Items]
Sales	$ 37,052	$ 34,862	$ 73,760	$ 68,244
Reportable Segments | U.S. Retail Pharmacy
Disaggregation of Revenue [Line Items]
Sales	28,861	27,577	57,805	54,781
Reportable Segments | U.S. Retail Pharmacy | Pharmacy
Disaggregation of Revenue [Line Items]
Sales	21,508	19,874	43,892	40,092
Reportable Segments | U.S. Retail Pharmacy | Retail
Disaggregation of Revenue [Line Items]
Sales	7,353	7,703	13,913	14,689
Reportable Segments | International
Disaggregation of Revenue [Line Items]
Sales	6,022	5,651	11,854	10,840
Reportable Segments | International | Pharmacy
Disaggregation of Revenue [Line Items]
Sales	898	898	1,824	1,766
Reportable Segments | International | Retail
Disaggregation of Revenue [Line Items]
Sales	2,158	1,994	4,090	3,643
Reportable Segments | International | Wholesale
Disaggregation of Revenue [Line Items]
Sales	2,966	2,759	5,940	5,431
Reportable Segments | U.S. Healthcare
Disaggregation of Revenue [Line Items]
Sales	2,176	1,634	4,107	2,622
Corporate and Other
Disaggregation of Revenue [Line Items]
Sales	$ (6)	$ 0	$ (6)	$ 0