Contingencies (Notes)	9 Months Ended
Contingencies (Notes)	Oct. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Legal Proceedings The Company is involved in a number of legal proceedings. The Company has made accruals with respect to these matters, where appropriate, which are reflected in the Company's Condensed Consolidated Financial Statements. For some matters, a liability is not probable or the amount cannot be reasonably estimated and therefore an accrual has not been made. However, where a liability is reasonably possible and may be material, such matters have been disclosed. The Company may enter into discussions regarding settlement of these matters, and may enter into settlement agreements, if it believes settlement is in the best interest of the Company and its shareholders. Unless stated otherwise, the matters discussed below, if decided adversely or settled by the Company, individually or in the aggregate, may result in a liability material to the Company's financial condition, results of operations or cash flows. ASDA Equal Value Claims ASDA Stores Ltd., an Asda subsidiary, is a defendant in over 40,000 equal value ("Equal Value") claims that began in 2008 and are proceeding before an Employment Tribunal in Manchester (the "Employment Tribunal") in the United Kingdom ("U.K.") on behalf of current and former Asda store employees, and further claims may be asserted in the future. The claimants allege that the work performed by employees in Asda's retail stores is of equal value in terms of, among other things, the demands of their jobs compared to that of employees working in Asda's warehouse and distribution facilities, and that the difference in pay between these job positions disparately impacts women because more women work in retail stores while more men work in warehouses and distribution facilities, and that the pay difference is not objectively justified. The claimants are requesting differential back pay based on higher wage rates in the warehouse and distribution facilities and higher wage rates on a prospective basis. In October 2016, following a preliminary hearing, the Employment Tribunal ruled that claimants could compare their positions in Asda's retail stores with those of employees in Asda's warehouse and distribution facilities. Asda appealed the ruling and the oral argument was held before the Supreme Court of the United Kingdom in July 2020. The Company is awaiting a decision. Notwithstanding the appeal, claimants are proceeding in the next phase of their claims. That phase will determine whether the work performed by the claimants is of equal value to the work performed by employees in Asda's warehouse and distribution facilities. At present, the Company cannot predict the number of such claims that may be filed, and cannot reasonably estimate any loss or range of loss that may arise from these proceedings. Accordingly, the Company can provide no assurance as to the scope and outcomes of these matters and no assurance as to whether its business, financial position, results of operations or cash flows will not be materially adversely affected. The Company believes it has substantial factual and legal defenses to these claims, and intends to defend the claims vigorously. Prescription Opiate Litigation and Other Matters In December 2017, the U.S. Judicial Panel on Multidistrict Litigation consolidated numerous lawsuits filed against a wide array of defendants by various plaintiffs, including counties, cities, healthcare providers, Native American tribes, individuals, and third-party payors, asserting claims generally concerning the impacts of widespread opioid abuse. The consolidated multidistrict litigation entitled 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 some of the cases included in this multidistrict litigation. Similar cases that name the Company have also been filed in state courts by state, local and tribal governments, health care providers and other plaintiffs. Plaintiffs are seeking compensatory and punitive damages, as well as injunctive relief including abatement. The Company cannot predict the number of such claims that may be filed, but believes it has substantial factual and legal defenses to these claims, and intends to defend the claims vigorously. The Company has also been responding to subpoenas, information requests and investigations from governmental entities related to nationwide controlled substance dispensing and distribution practices involving opioids. On October 22, 2020, the Company filed a declaratory judgment action against the U.S. Department of Justice and the U.S. Drug Enforcement Administration, asking a federal court to clarify the roles and responsibilities of pharmacists and pharmacies as to the dispensing and distribution of opioids under the Controlled Substances Act. The Company cannot reasonably estimate any loss or range of loss that may arise from these matters. Accordingly, the Company can provide no assurance as to the scope and outcome of these matters and no assurance as to whether its business, financial position, results of operations or cash flows will not be materially adversely affected.