CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Income Statement [Abstract]
Sales	$ 131,537	$ 118,214	$ 117,351
Cost of sales	100,745	89,052	87,477
Gross profit	30,792	29,162	29,874
Selling, general and administrative expenses	24,569	23,740	23,910
Equity earnings in AmerisourceBergen	191	135	37
Operating income	6,414	5,557	6,001
Other income (expense)	177	(11)	(261)
Earnings before interest and income tax provision	6,591	5,546	5,740
Interest expense, net	616	693	596
Earnings before income tax provision	5,975	4,853	5,144
Income tax provision	998	760	997
Post tax earnings from other equity method investments	54	8	44
Net earnings	5,031	4,101	4,191
Net earnings attributable to noncontrolling interests	7	23	18
Net earnings attributable to Walgreens Boots Alliance, Inc.	$ 5,024	$ 4,078	$ 4,173
Net earnings per common share:
Basic (in dollars per share)	$ 5.07	$ 3.80	$ 3.85
Diluted (in dollars per share)	5.05	3.78	3.82
Dividends declared per share (in dollars per share)	$ 1.640	$ 1.525	$ 1.455
Weighted average common shares outstanding:
Basic (in shares)	991.0	1,073.5	1,083.1
Diluted (in shares)	995.0	1,078.5	1,091.1