Commitments and contingencies	12 Months Ended
Aug. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies The Company is involved in legal proceedings, including litigation, arbitration and other claims, and investigations, inspections, audits, claims, inquiries and similar actions by pharmacy, healthcare, tax and other governmental authorities, arising in the normal course of the Company’s business, including the matters described below. Legal proceedings, in general, and securities, class action and multi-district litigation, in particular, can be expensive and disruptive. Some of these suits may purport or may be determined to be class actions and/or involve parties seeking large and/or indeterminate amounts, including punitive or exemplary damages, and may remain unresolved for several years. The Company also may be named from time to time in qui tam actions initiated by private third parties. In such actions, the private parties purport to act on behalf of federal or state governments, allege that false claims have been submitted for payment by the government and may receive an award if their claims are successful. After a private party has filed a qui tam action, the government must investigate the private party's claim and determine whether to intervene in and take control over the litigation. These actions may remain under seal while the government makes this determination. If the government declines to intervene, the private party may nonetheless continue to pursue the litigation on his or her own purporting to act on behalf of the government. From time to time, the Company is also involved in legal proceedings as a plaintiff involving antitrust, tax, contract, intellectual property and other matters. Gain contingencies, if any, are recognized when they are realized. The results of legal proceedings are often uncertain and difficult to predict, and the costs incurred in litigation can be substantial, regardless of the outcome. With respect to litigation and other legal proceedings where the Company has determined that a loss is reasonably possible, the Company is unable to estimate the amount or range of reasonably possible loss due to the inherent difficulty of predicting the outcome of and uncertainties regarding such litigation and legal proceedings. The Company believes that its defenses and assertions in pending legal proceedings have merit, and does not believe that any of these pending matters, after consideration of applicable reserves and rights to indemnification, will have a material adverse effect on the Company’s consolidated financial position. However, substantial unanticipated verdicts, fines and rulings do sometimes occur. As a result, the Company could from time to time incur judgments, enter into settlements or revise its expectations regarding the outcome of certain matters, and such developments could have a material adverse effect on its results of operations in the period in which the amounts are accrued and/or its cash flows in the period in which the amounts are paid. On December 29, 2014, a putative shareholder filed a derivative action in federal court in the Northern District of Illinois against certain current and former directors and officers of Walgreen Co., and Walgreen Co. as a nominal defendant, arising out of certain public statements the Company made regarding its former fiscal 2016 goals. The action asserts claims for breach of fiduciary duty, waste and unjust enrichment. On April 10, 2015, the defendants filed a motion to dismiss. On May 18, 2015, the case was stayed in light of a securities class action that was filed on April 10, 2015. After a ruling issued on September 30, 2016 in the securities class action, which is described below, on November 3, 2016, the Court entered a stipulation and order extending the stay until the securities case is fully resolved. On April 10, 2015, a putative shareholder filed a securities class action in federal court in the Northern District of Illinois against Walgreen Co. and certain former officers of Walgreen Co. The action asserts claims for violation of the federal securities laws arising out of certain public statements the Company made regarding its former fiscal 2016 goals. On June 16, 2015, the Court entered an order appointing a lead plaintiff. Pursuant to the Court’s order, lead plaintiff filed an amended complaint on August 17, 2015, and defendants moved to dismiss the amended complaint on October 16, 2015. On September 30, 2016, the Court issued an order granting in part and denying in part defendants’ motion to dismiss. Defendants filed their answer to the amended complaint on November 4, 2016 and filed an amended answer on January 16, 2017. Plaintiff filed its motion for class certification on April 21, 2017. The Court granted plaintiff’s motion on March 29, 2018 and merits discovery is proceeding. As of August 31, 2017, the Company was aware of two putative class action lawsuits filed by purported Rite Aid stockholders against Rite Aid and its board of directors, Walgreens Boots Alliance and Victoria Merger Sub, Inc. for claims arising out of the transactions contemplated by the original Merger Agreement (prior to its amendment on January 29, 2017) (such transactions, the “Rite Aid Transactions”). One Rite Aid action was filed in the State of Pennsylvania in the Court of Common Pleas of Cumberland County (the “Pennsylvania action”), and one action was filed in the United States District Court for the Middle District of Pennsylvania (the “federal action”). The Pennsylvania action primarily alleged that the Rite Aid board of directors breached its fiduciary duties in connection with the Rite Aid Transactions by, among other things, agreeing to an unfair and inadequate price, agreeing to deal protection devices that preclude other bidders from making successful competing offers for Rite Aid, and failing to disclose all allegedly material information concerning the proposed merger, and also alleged that Walgreens Boots Alliance and Victoria Merger Sub, Inc. aided and abetted these alleged breaches of fiduciary duty. There has been no activity in this lawsuit since the complaint was filed. The federal action alleged, among other things, that Rite Aid and its board of directors disseminated an allegedly false and misleading proxy statement in connection with the Rite Aid Transactions. The plaintiffs in the federal action also filed a motion for preliminary injunction seeking to enjoin the Rite Aid shareholder vote relating to the Rite Aid Transactions. That motion was denied, and the matter was stayed. On March 17, 2017, plaintiffs moved to lift the stay to allow plaintiffs to file an amended complaint. That motion was granted, and plaintiffs filed their amended complaint on December 11, 2017, alleging that the Company and certain of its officers made false or misleading statements regarding the Rite Aid Transactions. On July 11, 2018, the Court denied the Company’s motion to dismiss, but narrowed the time scope of the subject statements. The Company filed an answer and affirmative defenses on August 8, 2018, and on August 24, 2018 filed a new motion to dismiss based on the named plaintiff’s lack of standing. The Company was also named as a defendant in eight putative class action lawsuits filed in the Court of Chancery of the State of Delaware (the “Delaware actions”). Those actions were consolidated, and plaintiffs filed a motion for preliminary injunction seeking to enjoin the Rite Aid shareholder vote relating to the Rite Aid Transactions. That motion was denied and the plaintiffs in the Delaware actions agreed to settle this matter for an immaterial amount. The Delaware actions all have been dismissed. In December 2017, the United States Judicial Panel on Multidistrict Litigation consolidated numerous cases filed against an array of defendants by various plaintiffs such as counties, cities, hospitals, Indian tribes and others, alleging claims generally concerning the impacts of widespread opioid abuse. The consolidated multidistrict litigation, captioned In re National Prescription Opiate Litigation (MDL No. 2804), is pending in the U.S. District Court for the Northern District of Ohio. The Company is named as a defendant in a subset of the cases included in this multidistrict litigation. The Company also has been named as a defendant in several lawsuits brought in state courts relating to opioid matters. The relief sought by various plaintiffs is compensatory and punitive damages, as well as injunctive relief. Additionally, the Company has received from the Attorney Generals of several states subpoenas, civil investigative demands, and/or other requests concerning opioid matters. On September 28, 2018, the Company announced that it had reached an agreement with the SEC to fully resolve an investigation into certain forward-looking financial goals and related disclosures by Walgreens. The disclosures at issue were made prior to the strategic combination with Alliance Boots and the merger pursuant to which Walgreens Boots Alliance became the parent holding company on December 31, 2014. The settlement does not involve any of the Company’s current officers or executives, nor does it allege intentional or reckless conduct by the Company. In agreeing to the settlement, the Company neither admitted nor denied the SEC’s allegations. Pursuant to the agreement with the SEC, the Company consented to the SEC’s issuance of an administrative order, and the Company paid a $34.5 million penalty, which was fully reserved for in the Company’s Consolidated Financial Statements as of August 31, 2018. The Company has been responding to a civil investigation involving allegations under the False Claims Act by a United States Attorney’s Office, working in conjunction with several states, regarding certain dispensing practices. The Company believes it has meritorious defenses against any action that might be brought against it. The Company is cooperating with this investigation, has entered into discussions with the government concerning a potential resolution of the matter, and has established reserves in relation to such a potential resolution.

Commitments and contingencies

The Company is involved in legal proceedings, including litigation, arbitration and other claims, and investigations, inspections, audits, claims, inquiries and similar actions by pharmacy, healthcare, tax and other governmental authorities, arising in the normal course of the Company’s business, including the matters described below. Legal proceedings, in general, and securities, class action and multi-district litigation, in particular, can be expensive and disruptive. Some of these suits may purport or may be determined to be class actions and/or involve parties seeking large and/or indeterminate amounts, including punitive or exemplary damages, and may remain unresolved for several years. The Company also may be named from time to time in qui tam actions initiated by private third parties. In such actions, the private parties purport to act on behalf of federal or state governments, allege that false claims have been submitted for payment by the government and may receive an award if their claims are successful. After a private party has filed a qui tam action, the government must investigate the private party's claim and determine whether to intervene in and take control over the litigation. These actions may remain under seal while the government makes this determination. If the government declines to intervene, the private party may nonetheless continue to pursue the litigation on his or her own purporting to act on behalf of the government. From time to time, the Company is also involved in legal proceedings as a plaintiff involving antitrust, tax, contract, intellectual property and other matters. Gain contingencies, if any, are recognized when they are realized.

The results of legal proceedings are often uncertain and difficult to predict, and the costs incurred in litigation can be substantial, regardless of the outcome. With respect to litigation and other legal proceedings where the Company has determined that a loss is reasonably possible, the Company is unable to estimate the amount or range of reasonably possible loss due to the inherent difficulty of predicting the outcome of and uncertainties regarding such litigation and legal proceedings. The Company believes that its defenses and assertions in pending legal proceedings have merit, and does not believe that any of these pending matters, after consideration of applicable reserves and rights to indemnification, will have a material adverse effect on the Company’s consolidated financial position. However, substantial unanticipated verdicts, fines and rulings do sometimes occur. As a result, the Company could from time to time incur judgments, enter into settlements or revise its expectations regarding the outcome of certain matters, and such developments could have a material adverse effect on its results of operations in the period in which the amounts are accrued and/or its cash flows in the period in which the amounts are paid.

On December 29, 2014, a putative shareholder filed a derivative action in federal court in the Northern District of Illinois against certain current and former directors and officers of Walgreen Co., and Walgreen Co. as a nominal defendant, arising out of certain public statements the Company made regarding its former fiscal 2016 goals. The action asserts claims for breach of fiduciary duty, waste and unjust enrichment. On April 10, 2015, the defendants filed a motion to dismiss. On May 18, 2015, the case was stayed in light of a securities class action that was filed on April 10, 2015. After a ruling issued on September 30, 2016 in the securities class action, which is described below, on November 3, 2016, the Court entered a stipulation and order extending the stay until the securities case is fully resolved.

On April 10, 2015, a putative shareholder filed a securities class action in federal court in the Northern District of Illinois against Walgreen Co. and certain former officers of Walgreen Co. The action asserts claims for violation of the federal securities laws arising out of certain public statements the Company made regarding its former fiscal 2016 goals. On June 16, 2015, the Court entered an order appointing a lead plaintiff. Pursuant to the Court’s order, lead plaintiff filed an amended complaint on August 17, 2015, and defendants moved to dismiss the amended complaint on October 16, 2015. On September 30, 2016, the Court issued an order granting in part and denying in part defendants’ motion to dismiss. Defendants filed their answer to the amended complaint on November 4, 2016 and filed an amended answer on January 16, 2017. Plaintiff filed its motion for class certification on April 21, 2017. The Court granted plaintiff’s motion on March 29, 2018 and merits discovery is proceeding.

As of August 31, 2017, the Company was aware of two putative class action lawsuits filed by purported Rite Aid stockholders against Rite Aid and its board of directors, Walgreens Boots Alliance and Victoria Merger Sub, Inc. for claims arising out of the transactions contemplated by the original Merger Agreement (prior to its amendment on January 29, 2017) (such transactions, the “Rite Aid Transactions”). One Rite Aid action was filed in the State of Pennsylvania in the Court of Common Pleas of Cumberland County (the “Pennsylvania action”), and one action was filed in the United States District Court for the Middle District of Pennsylvania (the “federal action”). The Pennsylvania action primarily alleged that the Rite Aid board of directors breached its fiduciary duties in connection with the Rite Aid Transactions by, among other things, agreeing to an unfair and inadequate price, agreeing to deal protection devices that preclude other bidders from making successful competing offers for Rite Aid, and failing to disclose all allegedly material information concerning the proposed merger, and also alleged that Walgreens Boots Alliance and Victoria Merger Sub, Inc. aided and abetted these alleged breaches of fiduciary duty. There has been no activity in this lawsuit since the complaint was filed. The federal action alleged, among other things, that Rite Aid and its board of directors disseminated an allegedly false and misleading proxy statement in connection with the Rite Aid Transactions. The plaintiffs in the federal action also filed a motion for preliminary injunction seeking to enjoin the Rite Aid shareholder vote relating to the Rite Aid Transactions. That motion was denied, and the matter was stayed. On March 17, 2017, plaintiffs moved to lift the stay to allow plaintiffs to file an amended complaint. That motion was granted, and plaintiffs filed their amended complaint on December 11, 2017, alleging that the Company and certain of its officers made false or misleading statements regarding the Rite Aid Transactions. On July 11, 2018, the Court denied the Company’s motion to dismiss, but narrowed the time scope of the subject statements. The Company filed an answer and affirmative defenses on August 8, 2018, and on August 24, 2018 filed a new motion to dismiss based on the named plaintiff’s lack of standing.

The Company was also named as a defendant in eight putative class action lawsuits filed in the Court of Chancery of the State of Delaware (the “Delaware actions”). Those actions were consolidated, and plaintiffs filed a motion for preliminary injunction seeking to enjoin the Rite Aid shareholder vote relating to the Rite Aid Transactions. That motion was denied and the plaintiffs in the Delaware actions agreed to settle this matter for an immaterial amount. The Delaware actions all have been dismissed.

In December 2017, the United States Judicial Panel on Multidistrict Litigation consolidated numerous cases filed against an array of defendants by various plaintiffs such as counties, cities, hospitals, Indian tribes and others, alleging claims generally concerning the impacts of widespread opioid abuse. The consolidated multidistrict litigation, captioned In re National Prescription Opiate Litigation (MDL No. 2804), is pending in the U.S. District Court for the Northern District of Ohio. The Company is named as a defendant in a subset of the cases included in this multidistrict litigation. The Company also has been named as a defendant in several lawsuits brought in state courts relating to opioid matters. The relief sought by various plaintiffs is compensatory and punitive damages, as well as injunctive relief. Additionally, the Company has received from the Attorney Generals of several states subpoenas, civil investigative demands, and/or other requests concerning opioid matters.

On September 28, 2018, the Company announced that it had reached an agreement with the SEC to fully resolve an investigation into certain forward-looking financial goals and related disclosures by Walgreens. The disclosures at issue were made prior to the strategic combination with Alliance Boots and the merger pursuant to which Walgreens Boots Alliance became the parent holding company on December 31, 2014. The settlement does not involve any of the Company’s current officers or executives, nor does it allege intentional or reckless conduct by the Company. In agreeing to the settlement, the Company neither admitted nor denied the SEC’s allegations. Pursuant to the agreement with the SEC, the Company consented to the SEC’s issuance of an administrative order, and the Company paid a $34.5 million penalty, which was fully reserved for in the Company’s Consolidated Financial Statements as of August 31, 2018.

The Company has been responding to a civil investigation involving allegations under the False Claims Act by a United States Attorney’s Office, working in conjunction with several states, regarding certain dispensing practices. The Company believes it has meritorious defenses against any action that might be brought against it. The Company is cooperating with this investigation, has entered into discussions with the government concerning a potential resolution of the matter, and has established reserves in relation to such a potential resolution.