Sales (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022
Disaggregation of Revenue [Line Items]
Sales	$ 34,862	$ 33,756	$ 68,244	$ 67,656
Reportable Segments | U.S. Retail Pharmacy
Disaggregation of Revenue [Line Items]
Sales	27,577	27,667	54,781	55,699
Reportable Segments | U.S. Retail Pharmacy | Pharmacy
Disaggregation of Revenue [Line Items]
Sales	19,874	19,820	40,092	40,925
Reportable Segments | U.S. Retail Pharmacy | Retail
Disaggregation of Revenue [Line Items]
Sales	7,703	7,847	14,689	14,774
Reportable Segments | International
Disaggregation of Revenue [Line Items]
Sales	5,651	5,563	10,840	11,381
Reportable Segments | International | Pharmacy
Disaggregation of Revenue [Line Items]
Sales	898	958	1,766	1,975
Reportable Segments | International | Retail
Disaggregation of Revenue [Line Items]
Sales	1,994	1,880	3,643	3,676
Reportable Segments | International | Wholesale
Disaggregation of Revenue [Line Items]
Sales	2,759	2,725	5,431	5,730
Reportable Segments | U.S. Healthcare
Disaggregation of Revenue [Line Items]
Sales	1,634	527	2,622	577
Corporate and Other
Disaggregation of Revenue [Line Items]
Sales	$ 0	$ (1)	$ 0	$ (1)