Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3179-108585

Name:	us-gaap_ProceedsFromDivestitureOfBusinesses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Disposal Group, Contingent Consideration, Purchase Price Receivable

No definition available.

Name:	wba_DisposalGroupContingentConsiderationPurchasePriceReceivable
Namespace Prefix:	wba_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Disposal Group, Contingent Consideration, Working Capital Adjustments

No definition available.

Name:	wba_DisposalGroupContingentConsiderationWorkingCapitalAdjustments
Namespace Prefix:	wba_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Noncash or Part Noncash Divestiture, Noncash Consideration, Shares Issued

No definition available.