Litigation (Details) - Fapco [Member]	May. 31, 2011
Business Acquisition [Line Items]
Direct ownership interest acquired (in hundredths)	1.00%
FAPL's ownership interest prior to acquisition (in hundredths)	99.00%
Combined direct and indirect ownership interest subsequent to acquisition (in hundredths)	100.00%

The acquired company's ownership interest in one of its subsidiaries prior to acquisition by the company.

No definition available.

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- Definition

The company's ownership interest in the acquired subsidiary subsequent to acquisition.

+ References

No definition available.

+ Details

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Namespace Prefix:	mpaa_
Data Type:	num:percentItemType
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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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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- Details

Name:	us-gaap_BusinessAcquisitionAxis=mpaa_FapcoMember
Namespace Prefix:
Data Type:	na
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Period Type: