Debt instrument, Allowable acquisitions cost in next year

No definition available.

Name:	mnro_DebtInstrumentAllowableAcquisitionsCostInNextYear
Namespace Prefix:	mnro_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt instrument, Allowable dividend or distribution in next year

+ References

No definition available.

+ Details

Name:	mnro_DebtInstrumentAllowableDividendOrDistributionInNextYear
Namespace Prefix:	mnro_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument during the debt covenant relief period.

+ References

No definition available.

+ Details

Name:	mnro_DebtInstrumentBasisSpreadOnVariableRateDuringDebtCovenantReliefPeriod
Namespace Prefix:	mnro_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Increase in borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

No definition available.

+ Details

Name:	mnro_LineOfCreditFacilityIncreaseDecreaseBorrowingCapacity
Namespace Prefix:	mnro_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line of Credit Facility, Interest Rate at Period End, Variable Spread

+ References

No definition available.

+ Details

Name:	mnro_LineOfCreditFacilityInterestRateAtPeriodEndVariableSpread
Namespace Prefix:	mnro_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Revolving credit facility agreement, number of participating banks.

+ References

No definition available.

+ Details

Name:	mnro_LineOfCreditFacilityNumberOfBanks
Namespace Prefix:	mnro_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermDebtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=mnro_FirstAmendmentToCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_StandbyLettersOfCreditMember
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:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Long-Term Debt (Narrative) (Details)		12 Months Ended
Long-Term Debt (Narrative) (Details)	Jun. 11, 2020 USD ($)	Mar. 27, 2021 USD ($) entity	Mar. 28, 2020 USD ($)
Debt Instrument [Line Items]
Fair value of long-term debt (including current portion)		$ 190,000,000.0	$ 566,400,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility term		5 years
Revolving credit facility agreement		$ 600,000,000
Revolving credit facility agreement, number of participating banks \| entity		8
Credit Facility Increased Availability		$ 250,000,000
Amount outstanding under Credit Facility		190,000,000.0
Net availability under the credit facility		$ 376,400,000
Revolving Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate at period end over LIBOR		2.25%	1.00%
First Amendment To Credit Facility [Member]
Debt Instrument [Line Items]
Allowable dividend or distribution	$ 38,500,000
Allowable acquisitions	$ 100,000,000
Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Revolving credit facility agreement		$ 80,000,000
Amount outstanding under Credit Facility		$ 33,600,000
Minimum [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Percentage of fees on amount available		0.125%
Minimum [Member] \| Revolving Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate over LIBOR on the facility		0.75%
Minimum [Member] \| First Amendment To Credit Facility [Member]
Debt Instrument [Line Items]
Interest rate	0.75%
Minimum [Member] \| First Amendment To Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate spread during debt covenant relief period	2.25%
Minimum [Member] \| Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Percentage of fees on amount available		0.875%
Maximum [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Percentage of fees on amount available		0.35%
Maximum [Member] \| Revolving Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Interest rate over LIBOR on the facility		2.00%
Maximum [Member] \| Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Percentage of fees on amount available		2.125%