CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2018
Income Statement [Abstract]
Sales	$ 139,537	$ 136,866	$ 131,537
Cost of sales	111,520	106,790	100,745
Gross profit	28,017	30,076	30,792
Selling, general and administrative expenses	27,045	25,242	24,694
Equity earnings in AmerisourceBergen	341	164	191
Operating income	1,312	4,998	6,289
Other income	70	233	302
Earnings before interest and income tax provision	1,382	5,231	6,591
Interest expense, net	639	704	616
Earnings before income tax provision	743	4,527	5,975
Income tax provision	360	588	998
Post tax earnings from other equity method investments	41	23	54
Net earnings	424	3,962	5,031
Net (loss) earnings attributable to noncontrolling interests	(32)	(20)	7
Net earnings attributable to Walgreens Boots Alliance, Inc.	$ 456	$ 3,982	$ 5,024
Net earnings per common share:
Basic (in dollars per share)	$ 0.52	$ 4.32	$ 5.07
Diluted (in dollars per share)	$ 0.52	$ 4.31	$ 5.05
Weighted average common shares outstanding:
Basic (in shares)	879.4	921.5	991.0
Diluted (in shares)	880.3	923.5	995.0