Line of Credit Facility, Accordian Feature, Increase Limit

No definition available.

Name:	mei_LineofCreditFacilityAccordianFeatureIncreaseLimit
Namespace Prefix:	mei_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Periodic Payment, Principal, Percentage of Total Borrowing

+ References

No definition available.

+ Details

Name:	mei_LineofCreditFacilityPeriodicPaymentPrincipalPercentageofTotalBorrowing
Namespace Prefix:	mei_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Long-term Debt, Number of Notes

+ References

No definition available.

+ Details

Name:	mei_LongtermDebtNumberofNotes
Namespace Prefix:	mei_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Term Loan, Maximum Borrowing Capacity

+ References

No definition available.

+ Details

Name:	mei_TermLoanMaximumBorrowingCapacity
Namespace Prefix:	mei_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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+ Details

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

- Definition

Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ 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 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- 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 the required periodic payment applied to principal.

+ References

+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Paragraph 1
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+ Details

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

- 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

- Definition

Weighted average interest rate of long-term debt outstanding calculated at point in time.

+ References

No definition available.

+ Details

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

- Definition

The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

+ References

+ Details

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

- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

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+ Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	dei_LegalEntityAxis=mei_ProcoplastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mei_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Narrative (Details)		12 Months Ended
Debt - Narrative (Details)	Sep. 12, 2018 USD ($)	Apr. 27, 2019 USD ($) debt_note	Apr. 28, 2018 USD ($)	Apr. 29, 2017 USD ($)	Apr. 27, 2019 CAD ($)
Line of Credit Facility [Line Items]
Repayments of lines of credit		$ (120,500,000)	$ (79,400,000)	$ (30,000,000)
Long-term debt, current maturities		15,700,000	4,400,000
Payments of debt issuance costs	$ 3,100,000	3,100,000	0	0
Interest paid		8,800,000	$ 2,400,000	$ 1,100,000
Bank of America Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity		200,000,000
Term loan, maximum borrowing capacity		250,000,000
Optional increase in borrowing capacity, up to		$ 200,000,000
Interest rate		3.98%			3.98%
BMO Harris Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity					$ 10,000,000
Optional increase in borrowing capacity, up to					$ 5,000,000
Roynat Credit Facility
Line of Credit Facility [Line Items]
Repayments of lines of credit		$ (3,800,000)
Prepayment fee		$ 100,000
Procoplast
Line of Credit Facility [Line Items]
Debt, number of notes \| debt_note		18
Weighted average interest rate		1.50%			1.50%
Long-term debt, current maturities		$ 3,200,000
Debt, fair value		$ 16,300,000
Term Loan \| Bank of America Credit Facility
Line of Credit Facility [Line Items]
Periodic payment, principal, percentage of total borrowing		1.25%
Periodic payment, principal		$ 3,100,000