Document and Entity Information	9 Months Ended
	May 31, 2018 shares
Document and Entity Information [Abstract]
Entity Registrant Name	Walgreens Boots Alliance, Inc.
Entity Central Index Key	0001618921
Current Fiscal Year End Date	--08-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)	992,411,822
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	May 31, 2018