Sales (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	May 31, 2024	May 31, 2023	May 31, 2024	May 31, 2023
Disaggregation of Revenue [Line Items]
Sales	$ 36,351	$ 35,415	$ 110,111	$ 103,659
Reportable Segments | U.S. Retail Pharmacy
Disaggregation of Revenue [Line Items]
Sales	28,503	27,866	86,308	82,648
Reportable Segments | U.S. Retail Pharmacy | Pharmacy
Disaggregation of Revenue [Line Items]
Sales	21,812	20,898	65,704	60,991
Reportable Segments | U.S. Retail Pharmacy | Retail
Disaggregation of Revenue [Line Items]
Sales	6,691	6,968	20,604	21,657
Reportable Segments | International
Disaggregation of Revenue [Line Items]
Sales	5,727	5,573	17,581	16,414
Reportable Segments | International | Pharmacy
Disaggregation of Revenue [Line Items]
Sales	874	924	2,698	2,690
Reportable Segments | International | Retail
Disaggregation of Revenue [Line Items]
Sales	1,839	1,769	5,928	5,412
Reportable Segments | International | Wholesale
Disaggregation of Revenue [Line Items]
Sales	3,014	2,880	8,955	8,311
Reportable Segments | U.S. Healthcare
Disaggregation of Revenue [Line Items]
Sales	2,125	1,975	6,232	4,597
Corporate and Other
Disaggregation of Revenue [Line Items]
Sales	$ (3)	$ 0	$ (9)	$ 0