Accounting policies (Policies)	9 Months Ended
May 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of presentation The Consolidated Condensed Financial Statements of Walgreens Boots Alliance, Inc. (“Walgreens Boots Alliance” or the “Company”) included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission regarding interim financial reporting. The Consolidated Condensed Financial Statements include all subsidiaries in which the Company holds a controlling interest. Investments in less than majority-owned subsidiaries in which the Company does not have a controlling interest, but does have significant influence, are accounted for as equity method investments. All intercompany transactions have been eliminated. The Consolidated Condensed Balance Sheets as of May 31, 2017 and August 31, 2016, the Consolidated Condensed Statements of Equity for the nine months ended May 31, 2017, the Consolidated Condensed Statements of Cash Flows for the nine months ended May 31, 2017 and May 31, 2016, the Consolidated Condensed Statements of Earnings and the Consolidated Condensed Statements of Comprehensive Income for the three and nine months ended May 31, 2017 and May 31, 2016 are unaudited. Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations, although the Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited Consolidated Condensed Financial Statements should be read in conjunction with the audited financial statements and the notes thereto included in the Walgreens Boots Alliance Annual Report on Form 10-K for the fiscal year ended August 31, 2016. The Company has evaluated subsequent events from the balance sheet date through the date the financial statements were issued and determined there were no subsequent events to disclose other than as disclosed in notes 1, 7 and 10. In the opinion of the Company, the unaudited Consolidated Condensed Financial Statements for the interim periods presented include all adjustments (consisting only of normal recurring adjustments) necessary to present a fair statement of the results for such interim periods. The influence of certain holidays, seasonality, foreign currency rates, changes in vendor, payer and customer relationships and terms and other factors on the Company’s operations, net earnings for any period may not be comparable to the same period in previous years. With respect to the Company’s Retail Pharmacy USA segment, the positive impact on gross margins and gross profit dollars typically has been significant in the first several months after a generic version of a drug is first allowed to compete with the branded version, which is generally referred to as a “generic conversion.” In any given year, the number of major brand name drugs that undergo a conversion from branded to generic status can increase or decrease, which can have a significant impact on the Company’s Retail Pharmacy USA segment’s sales, gross margin and gross profit dollars making the Company’s operations or net earnings for any period incomparable. To improve comparability, certain classification changes were made to prior periods to conform to current year classifications. These reclassifications were made in the fourth quarter of fiscal 2016. Terminated acquisition of Rite Aid Corporation (“Rite Aid”) and related matters On October 27, 2015, Walgreens Boots Alliance entered into an Agreement and Plan of Merger with Rite Aid and Victoria Merger Sub, Inc., a wholly-owned subsidiary of Walgreens Boots Alliance (as amended as described below, the “Merger Agreement”), pursuant to which the Company agreed, subject to the terms and conditions thereof, to acquire Rite Aid, a drugstore chain in the United States. The Merger Agreement was amended by Amendment No. 1 thereto on January 29, 2017. In connection with regulatory review of the merger contemplated by the Merger Agreement, on December 20, 2016, Walgreens Boots Alliance and Rite Aid announced that they had entered into an agreement (the “Fred’s Asset Purchase Agreement”), subject to the terms and conditions thereof, to sell certain Rite Aid stores and certain assets related to store operations to Fred’s, Inc. (“Fred’s”) for $950 million in an all-cash transaction. The transaction was subject to the approval and completion of the acquisition of Rite Aid by Walgreens Boots Alliance pursuant to the Merger Agreement. On June 28, 2017, Walgreens Boots Alliance and Rite Aid entered into a mutual termination agreement (the “Termination Agreement”) pursuant to which the parties agreed to terminate the Merger Agreement, including all schedules and exhibits thereto, and all ancillary agreements contemplated thereby, or entered pursuant thereto (other than as expressly specified) (collectively with the Merger Agreement, the “Transaction Documents”), effective as of June 28, 2017. Pursuant to the Termination Agreement, the Company agreed to pay Rite Aid the termination fee of $325 million, which amount the Company plans to pay on or before June 30, 2017 in full satisfaction of any amounts required to be paid by the Company under the Merger Agreement and other Transaction Documents. The parties also agreed to release each other from, among other things, any and all liability, claims, rights, actions, causes of action, damages, expenses and fees, however arising, in connection with, arising out of or related to the Transaction Documents, the transactions contemplated therein or thereby or certain related matters. On June 28, 2017, following the termination of the Merger Agreement, the Fred’s Asset Purchase Agreement was terminated. In connection with the termination of the Fred’s Asset Purchase Agreement, the Company agreed to reimburse certain of Fred’s transaction costs in an amount not to exceed $25 million in full satisfaction of any amounts required to be paid by the Company under the Fred’s Asset Purchase Agreement. The Company expects to pay the applicable amount during the fourth quarter of fiscal 2017. See note 7, Borrowings and note 10, Commitments and contingencies for additional information relating to the termination of the Merger Agreement and related matters. Pending acquisition of certain Rite Aid assets On June 28, 2017, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Rite Aid, pursuant to which the Company agreed, subject to the terms and conditions thereof, to acquire 2,186 stores, three distribution centers and related inventory from Rite Aid. The consideration for the transaction will be $5.175 billion in cash, the assumption by the Company of the related real estate leases and the grant of an option to Rite Aid, exercisable through May 2019 and subject to certain conditions, to become a member of the Company’s group purchasing organization, Walgreens Boots Alliance Development GmbH. The Company will also assume certain limited store-related liabilities as part of the transaction. The transaction is subject to the expiration or termination of applicable waiting periods under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and other customary closing conditions. The initial closing is expected to occur within the next six months. Upon the initial closing of the transaction, the Company will begin acquiring the stores and related assets on a phased basis.

Basis of presentation

The Consolidated Condensed Financial Statements of Walgreens Boots Alliance, Inc. (“Walgreens Boots Alliance” or the “Company”) included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission regarding interim financial reporting. The Consolidated Condensed Financial Statements include all subsidiaries in which the Company holds a controlling interest. Investments in less than majority-owned subsidiaries in which the Company does not have a controlling interest, but does have significant influence, are accounted for as equity method investments. All intercompany transactions have been eliminated.

The Consolidated Condensed Balance Sheets as of May 31, 2017 and August 31, 2016, the Consolidated Condensed Statements of Equity for the nine months ended May 31, 2017, the Consolidated Condensed Statements of Cash Flows for the nine months ended May 31, 2017 and May 31, 2016, the Consolidated Condensed Statements of Earnings and the Consolidated Condensed Statements of Comprehensive Income for the three and nine months ended May 31, 2017 and May 31, 2016 are unaudited. Certain information and footnote disclosures normally included in financial statements prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations, although the Company believes that the disclosures are adequate to make the information presented not misleading. These unaudited Consolidated Condensed Financial Statements should be read in conjunction with the audited financial statements and the notes thereto included in the Walgreens Boots Alliance Annual Report on Form 10-K for the fiscal year ended August 31, 2016. The Company has evaluated subsequent events from the balance sheet date through the date the financial statements were issued and determined there were no subsequent events to disclose other than as disclosed in notes 1, 7 and 10.

In the opinion of the Company, the unaudited Consolidated Condensed Financial Statements for the interim periods presented include all adjustments (consisting only of normal recurring adjustments) necessary to present a fair statement of the results for such interim periods. The influence of certain holidays, seasonality, foreign currency rates, changes in vendor, payer and customer relationships and terms and other factors on the Company’s operations, net earnings for any period may not be comparable to the same period in previous years. With respect to the Company’s Retail Pharmacy USA segment, the positive impact on gross margins and gross profit dollars typically has been significant in the first several months after a generic version of a drug is first allowed to compete with the branded version, which is generally referred to as a “generic conversion.” In any given year, the number of major brand name drugs that undergo a conversion from branded to generic status can increase or decrease, which can have a significant impact on the Company’s Retail Pharmacy USA segment’s sales, gross margin and gross profit dollars making the Company’s operations or net earnings for any period incomparable.

To improve comparability, certain classification changes were made to prior periods to conform to current year classifications. These reclassifications were made in the fourth quarter of fiscal 2016.

Terminated acquisition of Rite Aid Corporation (“Rite Aid”) and related matters

On October 27, 2015, Walgreens Boots Alliance entered into an Agreement and Plan of Merger with Rite Aid and Victoria Merger Sub, Inc., a wholly-owned subsidiary of Walgreens Boots Alliance (as amended as described below, the “Merger Agreement”), pursuant to which the Company agreed, subject to the terms and conditions thereof, to acquire Rite Aid, a drugstore chain in the United States. The Merger Agreement was amended by Amendment No. 1 thereto on January 29, 2017.

In connection with regulatory review of the merger contemplated by the Merger Agreement, on December 20, 2016, Walgreens Boots Alliance and Rite Aid announced that they had entered into an agreement (the “Fred’s Asset Purchase Agreement”), subject to the terms and conditions thereof, to sell certain Rite Aid stores and certain assets related to store operations to Fred’s, Inc. (“Fred’s”) for $950 million in an all-cash transaction. The transaction was subject to the approval and completion of the acquisition of Rite Aid by Walgreens Boots Alliance pursuant to the Merger Agreement.

On June 28, 2017, Walgreens Boots Alliance and Rite Aid entered into a mutual termination agreement (the “Termination Agreement”) pursuant to which the parties agreed to terminate the Merger Agreement, including all schedules and exhibits thereto, and all ancillary agreements contemplated thereby, or entered pursuant thereto (other than as expressly specified) (collectively with the Merger Agreement, the “Transaction Documents”), effective as of June 28, 2017. Pursuant to the Termination Agreement, the Company agreed to pay Rite Aid the termination fee of $325 million, which amount the Company plans to pay on or before June 30, 2017 in full satisfaction of any amounts required to be paid by the Company under the Merger Agreement and other Transaction Documents. The parties also agreed to release each other from, among other things, any and all liability, claims, rights, actions, causes of action, damages, expenses and fees, however arising, in connection with, arising out of or related to the Transaction Documents, the transactions contemplated therein or thereby or certain related matters.

On June 28, 2017, following the termination of the Merger Agreement, the Fred’s Asset Purchase Agreement was terminated. In connection with the termination of the Fred’s Asset Purchase Agreement, the Company agreed to reimburse certain of Fred’s transaction costs in an amount not to exceed $25 million in full satisfaction of any amounts required to be paid by the Company under the Fred’s Asset Purchase Agreement. The Company expects to pay the applicable amount during the fourth quarter of fiscal 2017.

See note 7, Borrowings and note 10, Commitments and contingencies for additional information relating to the termination of the Merger Agreement and related matters.

Pending acquisition of certain Rite Aid assets

On June 28, 2017, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Rite Aid, pursuant to which the Company agreed, subject to the terms and conditions thereof, to acquire 2,186 stores, three distribution centers and related inventory from Rite Aid. The consideration for the transaction will be $5.175 billion in cash, the assumption by the Company of the related real estate leases and the grant of an option to Rite Aid, exercisable through May 2019 and subject to certain conditions, to become a member of the Company’s group purchasing organization, Walgreens Boots Alliance Development GmbH. The Company will also assume certain limited store-related liabilities as part of the transaction.

The transaction is subject to the expiration or termination of applicable waiting periods under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and other customary closing conditions. The initial closing is expected to occur within the next six months. Upon the initial closing of the transaction, the Company will begin acquiring the stores and related assets on a phased basis.