CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2017
Income Statement [Abstract]
Sales	$ 136,866	$ 131,537	$ 118,214
Cost of sales	106,790	100,745	89,052
Gross profit	30,076	30,792	29,162
Selling, general and administrative expenses	25,242	24,694	23,813
Equity earnings in AmerisourceBergen	164	191	135
Operating income	4,998	6,289	5,484
Other income	233	302	62
Earnings before interest and income tax provision	5,231	6,591	5,546
Interest expense, net	704	616	693
Earnings before income tax provision	4,527	5,975	4,853
Income tax provision	588	998	760
Post tax earnings from other equity method investments	23	54	8
Net earnings	3,962	5,031	4,101
Net (loss) earnings attributable to noncontrolling interests	(20)	7	23
Net earnings attributable to Walgreens Boots Alliance, Inc.	$ 3,982	$ 5,024	$ 4,078
Net earnings per common share:
Basic (in dollars per share)	$ 4.32	$ 5.07	$ 3.80
Diluted (in dollars per share)	$ 4.31	$ 5.05	$ 3.78
Weighted average common shares outstanding:
Basic (in shares)	921.5	991.0	1,073.5
Diluted (in shares)	923.5	995.0	1,078.5