Liability for Closed Locations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
Nov. 30, 2014	Nov. 30, 2013	Aug. 31, 2014
Liability for Closed Locations [Abstract]
Charges recorded during the period for facilities that were closed or relocated under long-term leases	$ 26	$ 27
Changes in reserve for facility closings and related lease termination charges [Roll Forward]
Balance - beginning of period	257	123	123
Provision for present value of non-cancellable lease payments of closed facilities	8	23	171
Assumptions about future sublease income, terminations, and changes in interest rates	9	3	(8)
Interest accretion	9us-gaap_AccretionExpense	1us-gaap_AccretionExpense	14us-gaap_AccretionExpense
Cash payments, net of sublease income	(18)	(7)	(43)
Balance - end of period	$ 265	$ 143	$ 257

Amount recognized for the passage of time, typically for liabilities, that have been discounted to their net present values. Excludes accretion associated with asset retirement obligations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 410

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 35

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6394232&loc=d3e17558-110866

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Balance Type:	debit
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- Details

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- Definition

Recorded charges during the period relating to facilities that were closed or relocated under long-term leases.

+ References

No definition available.

+ Details

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Namespace Prefix:	wag_
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Period Type:	duration

- Definition

Liability as of the balance sheet date for facility closings and related lease termination charges. This liability is based on the present value of future rent obligations and other related costs (net of estimated sublease rent) to the first lease option date.

+ References

No definition available.

+ Details

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- Definition

Amount of any reversal and other adjustment made during the period to the amount of a previously accrued liability for facility closings and related lease termination charges for assumptions about future sublease income, terminations and changes in interest rates.

+ References

No definition available.

+ Details

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- Definition

Amount of cash paid in the period to fully or partially settle a specified, previously accrued type of facility closing or related lease termination cost, net of sublease income.

+ References

No definition available.

+ Details

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- Definition

Reserve increase representing the amount charged against earnings in the period for the present value of non-cancellable lease payments of closed facilities.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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