Sales (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Aug. 31, 2022	May 31, 2022	Feb. 28, 2022	Nov. 30, 2021	Aug. 31, 2021	May 31, 2021	Feb. 28, 2021	Nov. 30, 2020	Aug. 31, 2022	Aug. 31, 2021	Aug. 31, 2020
Disaggregation of Revenue [Line Items]
Sales	$ 32,449	$ 32,597	$ 33,756	$ 33,901	$ 34,262	$ 34,030	$ 32,779	$ 31,438	$ 132,703	$ 132,509	$ 121,982
Reportable Segments | U.S. Retail Pharmacy
Disaggregation of Revenue [Line Items]
Sales									109,078	112,005	107,701
Reportable Segments | U.S. Retail Pharmacy | Pharmacy
Disaggregation of Revenue [Line Items]
Sales									80,434	84,892	80,481
Reportable Segments | U.S. Retail Pharmacy | Retail
Disaggregation of Revenue [Line Items]
Sales									28,643	27,113	27,220
Reportable Segments | International
Disaggregation of Revenue [Line Items]
Sales									21,830	20,505	14,281
Reportable Segments | International | Pharmacy
Disaggregation of Revenue [Line Items]
Sales									3,727	3,808	3,503
Reportable Segments | International | Retail
Disaggregation of Revenue [Line Items]
Sales									6,924	6,225	5,902
Reportable Segments | International | Wholesale
Disaggregation of Revenue [Line Items]
Sales									11,178	10,472	4,876
Reportable Segments | Walgreens health
Disaggregation of Revenue [Line Items]
Sales									$ 1,795	$ 0	$ 0