Common Stock, Ownership Percentage

No definition available.

Name:	msm_CommonStockOwnershipPercentage
Namespace Prefix:	msm_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Common Stock, Ownership Percentage Threshold, Transferee Percentage

+ References

No definition available.

+ Details

Name:	msm_CommonStockOwnershipPercentageThresholdTransfereePercentage
Namespace Prefix:	msm_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Common Stock, Ownership Percentage Threshold, Two Board-Member Nomination

+ References

No definition available.

+ Details

Name:	msm_CommonStockOwnershipPercentageThresholdTwoBoardMemberNomination
Namespace Prefix:	msm_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Components Of Shareholders Equity [Line Items]

+ References

No definition available.

+ Details

Name:	msm_ComponentsOfShareholdersEquityLineItems
Namespace Prefix:	msm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Individuals Eligible For Nomination

+ References

No definition available.

+ Details

Name:	msm_NumberOfIndividualsEligibleForNomination
Namespace Prefix:	msm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Stock Repurchased During Period, Including Treasury Stock, Shares

+ References

No definition available.

+ Details

Name:	msm_StockRepurchasedDuringPeriodIncludingTreasuryStockShares
Namespace Prefix:	msm_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Treasury Stock, Shares Withheld For Tax Withholding Obligation

+ References

No definition available.

+ Details

Name:	msm_TreasuryStockSharesWithheldForTaxWithholdingObligation
Namespace Prefix:	msm_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares authorized to be purchased under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481520/505-30-50-4

+ Details

Name:	srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	srt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares.

+ References

No definition available.

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of paid and unpaid cash, stock, and paid-in-kind (PIK) dividends declared, for example, but not limited to, common and preferred stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-SubTopic 405
-Topic 942
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477787/942-405-45-2

+ Details

Name:	us-gaap_Dividends
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The per share amount of a dividend declared, but not paid, as of the financial reporting date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-3

+ Details

Name:	us-gaap_DividendsPayableAmountPerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow to reacquire common stock during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 15
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

+ Details

Name:	us-gaap_PaymentsForRepurchaseOfCommonStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Cash outflow in the form of ordinary dividends to common shareholders, preferred shareholders and noncontrolling interests, generally out of earnings.

+ References

+ Details

Name:	us-gaap_PaymentsOfOrdinaryDividends
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of shares of capital stock issued (purchased by employees) in connection with an employee stock ownership plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 25
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480637/718-40-25-10

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesEmployeeStockOwnershipPlan
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares remaining authorized to be purchased under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_TreasuryStockCommonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ShareRepurchaseProgramAxis=msm_ShareRepurchasePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Shareholders' Equity (Details) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Jun. 25, 2024 USD ($) $ / shares	Jun. 01, 2024 USD ($) $ / shares shares	Jun. 03, 2023 USD ($) $ / shares shares	Jun. 01, 2024 USD ($) $ / shares shares	Jun. 03, 2023 USD ($) $ / shares shares	Oct. 31, 2023 individual shares	Jun. 30, 2021 shares
Components Of Shareholders Equity [Line Items]
Repurchases of common stock \| $				$ 167,166	$ 31,072
Stock issued during period, shares, employee stock ownership plan		14,000	14,000	41,000	45,000
Payments of regular cash dividends \| $				$ 140,695	$ 132,484
Dividends payable per share (in usd per share) \| $ / shares		$ 830	$ 2.37	$ 830	$ 2.37
Dividend payable amount \| $					$ 132,484
Number of individuals eligible for nomination \| individual						2
Common stock, ownership percentage threshold, two board-member nomination						0.10
Common stock, ownership percentage threshold, transferee percentage						0.15
Subsequent Event
Components Of Shareholders Equity [Line Items]
Dividends payable per share (in usd per share) \| $ / shares	$ 0.83
Dividend payable amount \| $	$ 46,582
Maximum
Components Of Shareholders Equity [Line Items]
Common stock, ownership percentage						0.10
Minimum
Components Of Shareholders Equity [Line Items]
Common stock, ownership percentage						0.05
Treasury Stock
Components Of Shareholders Equity [Line Items]
Repurchases of common stock \| $		$ 18,489	$ 65	$ 167,166	$ (31,072)
Class A Common Stock
Components Of Shareholders Equity [Line Items]
Stock repurchased during period, including held in treasury (in shares)		200,000	1,000	1,742,000	386,000
Treasury stock, shares repurchased to satisfy tax withholding obligation		1,000	1,000	96,000	55,000
Dividends declared per common share (in usd per share) \| $ / shares		$ 830	$ 790	$ 2,490	$ 2,370
Class of warrant or right, number of securities called by each warrant or right (in shares)						1.225
Share Repurchase Plan \| Class A Common Stock
Components Of Shareholders Equity [Line Items]
Number of shares authorized for repurchase							5,000
Maximum number of shares that can be repurchased		2,078,000		2,078,000