2.2.0.25truefalse009170 - Disclosure - Subsequent Events (Details)truefalseIn Millions, except Per Share datafalse1falsefalseUSDtruefalse{us-gaap_SubsequentEventTypeAxis} : Pending Sale [Member] 9/1/2010 - 2/28/2011 c00075http://www.sec.gov/CIK0000104207duration2010-09-01T00:00:002011-02-28T00:00:00falsefalseWalgreens Health Initiatives, Inc. [Member]us-gaap_SubsequentEventTypeAxisxbrldihttp://xbrl.org/2006/xbrldiwag_PendingSaleMemberus-gaap_SubsequentEventTypeAxisexplicitMemberu000Standardhttp://www.xbrl.org/2003/iso4217USDiso42170u002Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0$1false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://walgreens.com/role/subsequenteventsdetails1falsefalsefalse00falsefalsefalsefalsefalse1falsefalseUSDtruefalse{us-gaap_SubsequentEventTypeAxis} : Pending Sale [Member] 9/1/2010 - 2/28/2011 c00075http://www.sec.gov/CIK0000104207duration2010-09-01T00:00:002011-02-28T00:00:00falsefalseWalgreens Health Initiatives, Inc. [Member]us-gaap_SubsequentEventTypeAxisxbrldihttp://xbrl.org/2006/xbrldiwag_PendingSaleMemberus-gaap_SubsequentEventTypeAxisexplicitMemberu000Standardhttp://www.xbrl.org/2003/iso4217USDiso42170u002Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0$OthernaNo definition available.No authoritative reference available.falsefalseWalgreens Health Initiatives, Inc. [Member]2true0us-gaap_SubsequentEventLineItemsus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringLine 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.falsefalseSubsequent Event [Line Items]3false0us-gaap_SubsequentEventDescriptionus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00On March 9, 2011, the Company announced a definitive agreement with Catalyst Health Solutions, Inc. under which Catalyst will acquire the Company's pharmacy benefit management business, Walgreens Health Initiatives, Inc. (WHI), in a cash transaction for $525 million, subject to certain adjustments. The transaction is structured as an acquisition of all of the capital stock of WHI. Completion of the transaction is subject to customary conditions, including receipt of regulatory approvals and clearances. We anticipate recording a gain on the transaction which is expected to close by the end of June 2011.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDescribes the event or transaction that occurred between the balance sheet date and the date the financial statements are issued.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 11 falsefalseSubsequent Event, Description4false0wag_ExpectedCashProceedsFromDivestitureOfBusinesswagfalsedebitinstantThe expected cash inflow associated with the amount to be received during the current fiscal year from the sale of a portion...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse525000000525falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe expected cash inflow associated with the amount to be received during the current fiscal year from the sale of a portion of the company's business.No authoritative reference available.falsefalseExpected cash proceeds, subject to certain adjustments, as a result of the anticipated Company's pharmacy benefit management business divestiture5false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://walgreens.com/role/subsequenteventsdetails1falsefalsefalse00falsefalsefalsefalsefalse2falsefalseUSDtruefalse{us-gaap_SubsequentEventTypeAxis} : Pending Acquisition [Member] 9/1/2010 - 2/28/2011 c00076http://www.sec.gov/CIK0000104207duration2010-09-01T00:00:002011-02-28T00:00:00falsefalseDrugstore.com [Member]us-gaap_SubsequentEventTypeAxisxbrldihttp://xbrl.org/2006/xbrldiwag_PendingAcquisitionMemberus-gaap_SubsequentEventTypeAxisexplicitMemberu000Standardhttp://www.xbrl.org/2003/iso4217USDiso42170u002Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0$OthernaNo definition available.No authoritative reference available.falsefalseDrugstore.com [Member]6true0us-gaap_SubsequentEventLineItemsus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringLine 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.falsefalseSubsequent Event [Line Items]7false0us-gaap_SubsequentEventDescriptionus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00On March 24, 2011, the Company announced a definitive merger agreement pursuant to which it will acquire drugstore.com. Under the terms of the merger agreement, drugstore.com stockholders will receive $3.80 in cash for each share of stock, which represents an equity value of approximately $429 million. Consummation of the merger is subject to customary conditions, including satisfaction of regulatory requirements and approval of the transaction by drugstore.com's stockholders. The Company will fund the acquisition with existing cash and anticipates the merger will close by the end of June 2011.falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDescribes the event or transaction that occurred between the balance sheet date and the date the financial statements are issued.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 5 -Paragraph 11 falsefalseSubsequent Event, Description8false0wag_ExpectedAcquireeDollarPerSharewagfalsenainstantThe amount per share expected to be paid during the current fiscal year to the Acquiree under the terms of the definitive...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse3.803.80falsetruefalsefalsefalseEPSus-types:perShareItemTypedecimalThe amount per share expected to be paid during the current fiscal year to the Acquiree under the terms of the definitive merger agreement.No authoritative reference available.falsetrueCash for each share of stock Acquiree (drugstore.com) will receive as a result of expected business acquisition9false0wag_ExpectedBusinessAcquisitionCostOfAcquiredEntityPurchasePricewagfalsecreditinstantThe expected total cost of the cash to be paid during the current fiscal year to the shareholders of the acquired entity...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse429000000429falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe expected total cost of the cash to be paid during the current fiscal year to the shareholders of the acquired entity under the terms of the definitive merger agreement.No authoritative reference available.falsefalseExpected equity value of Acquiree19Subsequent Events (Details) (USD $)MillionsUnKnownNoRoundingUnKnownfalsetrue