Subsequent Events (Details) (Subsequent Event [Member], USD $)	0 Months Ended	12 Months Ended
Jun. 03, 2015	Mar. 31, 2015
Secured Debt [Member]
Financing Agreement [Abstract]
Maximum borrowing capacity	$ 125,000,000
Reference rate under credit facility	LIBOR
Maximum ratio of funded debt to EBITDA	2.50
Secured Debt [Member] \| Minimum [Member]
Financing Agreement [Abstract]
Line of credit facility, commitment fee percentage (in hundredths)	0.25%
Minimum ratio of EBITDA to fixed charges	1.05
Secured Debt [Member] \| Maximum [Member]
Financing Agreement [Abstract]
Line of credit facility, commitment fee percentage (in hundredths)	0.375%
Minimum ratio of EBITDA to fixed charges	1.15
Secured Debt [Member] \| Variable Rate 1 [Member]
Financing Agreement [Abstract]
LIBOR variable interest rate (in hunderedths)	2.50%
Other reference variable interest rate (in hundredths)	1.50%
Secured Debt [Member] \| Variable Rate 2 [Member]
Financing Agreement [Abstract]
LIBOR variable interest rate (in hunderedths)	2.75%
Other reference variable interest rate (in hundredths)	1.75%
Secured Debt [Member] \| Variable Rate 3 [Member]
Financing Agreement [Abstract]
LIBOR variable interest rate (in hunderedths)	3.00%
Other reference variable interest rate (in hundredths)	2.00%
Term Loans [Member]
Financing Agreement [Abstract]
Maximum borrowing capacity	25,000,000
Term of revolving loan facility	5 years
Quarterly principal payment	781,250
Revolving Credit Facility [Member]
Financing Agreement [Abstract]
Maximum borrowing capacity	100,000,000
Term of revolving loan facility	5 years
Letter of Credit [Member]
Financing Agreement [Abstract]
Maximum borrowing capacity	$ 15,000,000
OE Plus [Member]
Acquisition [Abstract]
Purchase agreement date		May 15, 2015

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

No definition available.

Name:	mpaa_DebtInstrumentBasisSpreadOnVariableRateOther
Namespace Prefix:	mpaa_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum ratio of consolidated funded debt to consolidated EBITDA.

+ References

No definition available.

+ Details

Name:	mpaa_MaximumRatioOfFundedDebtToEBITDA
Namespace Prefix:	mpaa_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum ratio of consolidated EBITDA to fixed charges.

+ References

No definition available.

+ Details

Name:	mpaa_MinimumRatioOfEBITDAToFixedCharges
Namespace Prefix:	mpaa_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the business acquisition agreement was executed, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

Name:	us-gaap_BusinessAcquisitionDateOfAcquisitionAgreement1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Details

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

- 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

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentDescriptionOfVariableRateBasis
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

- Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ 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