General (Policies)	3 Months Ended
Nov. 17, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Fiscal Period	Operating results for the twelve weeks ended November 17, 2018 are not necessarily indicative of the results that may be expected for the full fiscal year ending August 31, 2019. Each of the first three quarters of AutoZone’s fiscal year consists of 12 weeks, and the fourth quarter consists of 16 or 17 weeks. The fourth quarter of fiscal 2019 has 17 weeks and fiscal 2018 had 16 weeks. Additionally, the Company’s business is somewhat seasonal in nature, with the highest sales generally occurring during the months of February through September and the lowest sales generally occurring in the months of December and January.
Recently Adopted and Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements: In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606). This ASU, along with subsequent ASUs issued to clarify certain provisions of ASU 2014-09, is a comprehensive new revenue recognition model that expands disclosure requirements and requires a company to recognize revenue to depict the transfer of goods or services to a customer at an amount that reflects the consideration a company expects to receive in exchange for those goods or services. It also requires more detailed disclosures to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Companies that transition to this new standard may either retrospectively restate each prior reporting period or follow the modified retrospective method, which reflects the cumulative effect of initially applying the updates with an adjustment to retained earnings at the date of adoption. The Company adopted this standard using the modified retrospective approach with its first quarter ended November 17, 2018. Results for the quarter ended November 17, 2018 were presented under ASU 2014-09, while prior period amounts were not adjusted and continue to be reported under the accounting standards in effect for the prior periods. The cumulative effect of the adoption of ASU 2014-09 did not have a material impact on the Company’s consolidated financial condition, results of operations, cash flows, business processes, controls or systems. Refer to “Note L – Revenue Recognition”. In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other than Inventory. ASU 2016-16 requires that an entity recognize the income tax consequences of an intra-entity transfer of assets other than inventory when the transfer occurs. The guidance must be applied using the modified retrospective approach. The Company adopted this standard with its first quarter ended November 17, 2018 and evaluated the effects from this adoption. The Company determined the provision of ASU 2016-16 did not have an impact on the Company’s consolidated financial statements. On August 17, 2018, the SEC adopted a final rule that eliminates or amends certain disclosure requirements that were deemed redundant and outdated in light of changes in SEC requirements, U.S. GAAP or changes in technology or the business environment. The rule also requires registrants to include in their interim financial statements a reconciliation of changes in stockholders’ equity in the notes or as a separate statement. The analysis should reconcile the beginning balance to the ending balance of each caption in shareholders’ equity for each period for which an income statement is required to be filed. The final rule became effective November 5, 2018. Beginning in the first quarter of fiscal 2019, we have provided a reconciliation for the quarterly period as well as the comparable prior period in this Form 10-Q. The eliminated or amended disclosures did not have a material impact on the Company’s unaudited condensed consolidated financial statements. Recently Issued Accounting Pronouncements: In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). ASU 2016-02 requires a two-fold approach for lessee accounting, under which a lessee will account for leases as finance leases or operating leases. For all leases with terms greater than 12 months, both lease classifications will result in the lessee recognizing a right-of-use asset and a corresponding lease liability on its balance sheet, with differing methodology for income statement recognition. This guidance also requires certain quantitative and qualitative disclosures about leasing arrangements. The amendment will be effective for the Company at the beginning of its fiscal 2020 year, and early adoption is permitted. As originally issued, this guidance required a modified retrospective approach for all leases existing or entered into after the beginning of the earliest comparative period in the consolidated financial statements. In July 2018, the FASB issued additional guidance, which allows companies to record the cumulative effect of applying the new standard as an adjustment to the opening balance of retained earnings in the year of adoption, which the Company intends to apply, as an alternative to the modified retrospective approach. The Company intends to elect transition practical expedients under which the Company will not be required to reassess (i) whether expired or existing contracts are or contain leases as defined by the new standard, (ii) the classification of such leases, and (iii) whether previously capitalized initial direct costs would qualify for capitalization under the new standard. The Company established a cross-functional implementation team to evaluate and identify the impact of ASU 2016-02 on the Company’s financial position, results of operations and cash flows. Based on the preliminary work completed, the Company has concluded its assessment on its leasing arrangements, evaluated the impact of applying the practical expedients and accounting policy elections and is working on implementing software to meet the reporting requirements of this standard. The Company is currently in the process of identifying changes to its business processes and controls to support the adoption of the new standard. The team is continuing to understand the full analysis of the adoption, but is unable to quantify the impact at this time. The Company anticipates the adoption of this new standard to result in a significant increase in lease-related assets and liabilities on the Company’s consolidated balance sheets. The impact on the Company’s Consolidated Statements of Income is currently being evaluated. As the impact of this standard is non-cash in nature, the Company does not anticipate its adoption to have an impact on the Company’s Consolidated Statement of Cash Flows. In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. ASU 2018-07 aims to simplify the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The amendment will be effective for the Company at the beginning of its fiscal 2020 year, and early adoption is permitted. The Company does not expect the provisions of ASU 2018-07 to have a material impact on its consolidated financial statements.

Recently Adopted Accounting Pronouncements:

In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606). This ASU, along with subsequent ASUs issued to clarify certain provisions of ASU 2014-09, is a comprehensive new revenue recognition model that expands disclosure requirements and requires a company to recognize revenue to depict the transfer of goods or services to a customer at an amount that reflects the consideration a company expects to receive in exchange for those goods or services. It also requires more detailed disclosures to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Companies that transition to this new standard may either retrospectively restate each prior reporting period or follow the modified retrospective method, which reflects the cumulative effect of initially applying the updates with an adjustment to retained earnings at the date of adoption. The Company adopted this standard using the modified retrospective approach with its first quarter ended November 17, 2018. Results for the quarter ended November 17, 2018 were presented under ASU 2014-09, while prior period amounts were not adjusted and continue to be reported under the accounting standards in effect for the prior periods. The cumulative effect of the adoption of ASU 2014-09 did not have a material impact on the Company’s consolidated financial condition, results of operations, cash flows, business processes, controls or systems. Refer to “Note L – Revenue Recognition”.

In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other than Inventory. ASU 2016-16 requires that an entity recognize the income tax consequences of an intra-entity transfer of assets other than inventory when the transfer occurs. The guidance must be applied using the modified retrospective approach. The Company adopted this standard with its first quarter ended November 17, 2018 and evaluated the effects from this adoption. The Company determined the provision of ASU 2016-16 did not have an impact on the Company’s consolidated financial statements.

On August 17, 2018, the SEC adopted a final rule that eliminates or amends certain disclosure requirements that were deemed redundant and outdated in light of changes in SEC requirements, U.S. GAAP or changes in technology or the business environment. The rule also requires registrants to include in their interim financial statements a reconciliation of changes in stockholders’ equity in the notes or as a separate statement. The analysis should reconcile the beginning balance to the ending balance of each caption in shareholders’ equity for each period for which an income statement is required to be filed. The final rule became effective November 5, 2018. Beginning in the first quarter of fiscal 2019, we have provided a reconciliation for the quarterly period as well as the comparable prior period in this Form 10-Q. The eliminated or amended disclosures did not have a material impact on the Company’s unaudited condensed consolidated financial statements.

Recently Issued Accounting Pronouncements:

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). ASU 2016-02 requires a two-fold approach for lessee accounting, under which a lessee will account for leases as finance leases or operating leases. For all leases with terms greater than 12 months, both lease classifications will result in the lessee recognizing a right-of-use asset and a corresponding lease liability on its balance sheet, with differing methodology for income statement recognition. This guidance also requires certain quantitative and qualitative disclosures about leasing arrangements. The amendment will be effective for the Company at the beginning of its fiscal 2020 year, and early adoption is permitted. As originally issued, this guidance required a modified retrospective approach for all leases existing or entered into after the beginning of the earliest comparative period in the consolidated financial statements. In July 2018, the FASB issued additional guidance, which allows companies to record the cumulative effect of applying the new standard as an adjustment to the opening balance of retained earnings in the year of adoption, which the Company intends to apply, as an alternative to the modified retrospective approach. The Company intends to elect transition practical expedients under which the Company will not be required to reassess (i) whether expired or existing contracts are or contain leases as defined by the new standard, (ii) the classification of such leases, and (iii) whether previously capitalized initial direct costs would qualify for capitalization under the new standard.

The Company established a cross-functional implementation team to evaluate and identify the impact of ASU 2016-02 on the Company’s financial position, results of operations and cash flows. Based on the preliminary work completed, the Company has concluded its assessment on its leasing arrangements, evaluated the impact of applying the practical expedients and accounting policy elections and is working on implementing software to meet the reporting requirements of this standard. The Company is currently in the process of identifying changes to its business processes and controls to support the adoption of the new standard. The team is continuing to understand the full analysis of the adoption, but is unable to quantify the impact at this time. The Company anticipates the adoption of this new standard to result in a significant increase in lease-related assets and liabilities on the Company’s consolidated balance sheets. The impact on the Company’s Consolidated Statements of Income is currently being evaluated. As the impact of this standard is non-cash in nature, the Company does not anticipate its adoption to have an impact on the Company’s Consolidated Statement of Cash Flows.

In June 2018, the FASB issued ASU 2018-07, Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting. ASU 2018-07 aims to simplify the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The amendment will be effective for the Company at the beginning of its fiscal 2020 year, and early adoption is permitted. The Company does not expect the provisions of ASU 2018-07 to have a material impact on its consolidated financial statements.