Basis Of Presentation (Policy)	9 Months Ended
May 30, 2020
Basis Of Presentation [Abstract]
Principles Of Consolidation	Principles of Consolidation The Condensed Consolidated Financial Statements include the accounts of MSC Industrial Direct Co., Inc., its wholly owned subsidiaries and entities in which it maintains a controlling financial interest. All significant intercompany balances and transactions have been eliminated in consolidation.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements Effective September 1, 2019, the Company adopted the Financial Accounting Standards Board (“FASB”) standard Accounting Standard Update (“ASU”) 2016-02, Leases (Topic 842) as subsequently amended (collectively, “ASU 2016-02”). This is a comprehensive new standard that amends various aspects of existing accounting guidance for leases, including the recognition of a right-of-use asset and a lease liability on the balance sheet and disclosing key information about leasing arrangements. The Company utilized the optional transition method set forth in ASU 2018-11 that allows entities to initially apply the new lease accounting standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Therefore, the adoption did not require restatement of prior periods. In addition, the Company elected the transition package of practical expedients permitted within the standard, which allowed it to carry forward the historical lease classification for arrangements that commenced prior to the effective date. As a result of the adoption of ASU 2016-02 on September 1, 2019, the Company recorded both operating lease assets of $61,212 and operating lease liabilities of $60,730. The adoption of ASU 2016-02 had an immaterial impact on the Company’s Condensed Consolidated Statement of Income and Condensed Consolidated Statement of Cash Flows. The adoption of this standard also resulted in a change in the naming convention for leases classified historically as capital leases. These leases are now referred to as finance leases. See Note 7 “Leases” for additional qualitative and quantitative information about the Company's leases.
Accounting Pronouncements Not Yet Adopted	Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued its final standard on measurement of credit losses on financial instruments. This standard, issued as ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), requires that an entity measure impairment of certain financial instruments, including trade receivables, based on expected losses rather than incurred losses. This update is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted for financial statement periods beginning after December 15, 2019. The new standard is effective for the Company for its fiscal year 2021. The Company is currently evaluating the standard to determine the impact, if any, of adoption to its consolidated financial statements. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides temporary optional expedients and exceptions to accounting guidance on contract modifications and hedge accounting to ease entities financial reporting burdens as the market transitions from the London Interbank Offered Rate (“LIBOR”) and other interbank offered rates to alternative reference rates. The guidance was effective upon issuance and may be applied prospectively to contract modifications made and hedging relationships entered into or evaluated on or before December 31, 2022. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements. Other pronouncements issued by the FASB or other authoritative accounting standards groups with future effective dates are either not applicable or are not expected to be significant to the Company’s financial position, results of operations or cash flows.

Basis Of Presentation (Policy)

9 Months Ended

May 30, 2020

Principles of Consolidation

The Condensed Consolidated Financial Statements include the accounts of MSC Industrial Direct Co., Inc., its wholly owned subsidiaries and entities in which it maintains a controlling financial interest. All significant intercompany balances and transactions have been eliminated in consolidation.

Recently Adopted Accounting Pronouncements

Effective September 1, 2019, the Company adopted the Financial Accounting Standards Board (“FASB”) standard Accounting Standard Update (“ASU”) 2016-02, Leases (Topic 842) as subsequently amended (collectively, “ASU 2016-02”). This is a comprehensive new standard that amends various aspects of existing accounting guidance for leases, including the recognition of a right-of-use asset and a lease liability on the balance sheet and disclosing key information about leasing arrangements. The Company utilized the optional transition method set forth in ASU 2018-11 that allows entities to initially apply the new lease accounting standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Therefore, the adoption did not require restatement of prior periods. In addition, the Company elected the transition package of practical expedients permitted within the standard, which allowed it to carry forward the historical lease classification for arrangements that commenced prior to the effective date.

As a result of the adoption of ASU 2016-02 on September 1, 2019, the Company recorded both operating lease assets of $61,212 and operating lease liabilities of $60,730. The adoption of ASU 2016-02 had an immaterial impact on the Company’s Condensed Consolidated Statement of Income and Condensed Consolidated Statement of Cash Flows. The adoption of this standard also resulted in a change in the naming convention for leases classified historically as capital leases. These leases are now referred to as finance leases. See Note 7 “Leases” for additional qualitative and quantitative information about the Company's leases.

Accounting Pronouncements Not Yet Adopted

In June 2016, the FASB issued its final standard on measurement of credit losses on financial instruments. This standard, issued as ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), requires that an entity measure impairment of certain financial instruments, including trade receivables, based on expected losses rather than incurred losses. This update is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted for financial statement periods beginning after December 15, 2019. The new standard is effective for the Company for its fiscal year 2021. The Company is currently evaluating the standard to determine the impact, if any, of adoption to its consolidated financial statements.

In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting, which provides temporary optional expedients and exceptions to accounting guidance on contract modifications and hedge accounting to ease entities financial reporting burdens as the market transitions from the London Interbank Offered Rate (“LIBOR”) and other interbank offered rates to alternative reference rates. The guidance was effective upon issuance and may be applied prospectively to contract modifications made and hedging relationships entered into or evaluated on or before December 31, 2022. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements.

Other pronouncements issued by the FASB or other authoritative accounting standards groups with future effective dates are either not applicable or are not expected to be significant to the Company’s financial position, results of operations or cash flows.