Name:	us-gaap_BusinessAcquisitionLineItems
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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Section 45
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
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-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

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The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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Asset Purchase Agreement, Consideration Transferred

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Asset Purchase Agreement Consideration to be Transferred

No definition available.

Name:	wba_AssetPurchaseAgreementConsiderationtobeTransferred
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Asset Purchase Agreement, Number of Distribution Centers Expected To Be Acquired

No definition available.

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Namespace Prefix:	wba_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Number of Locations Acquired

No definition available.