Share-based Payments, Summary (Details) - shares	Mar. 31, 2022	Mar. 31, 2021
2004 Non-Employee Director Stock Option Plan [Member]
Share-based Compensation Description [Abstract]
Shares of common stock available for grant (in shares)	0	0
Option to purchase common stock, outstanding (in shares)	21,000	30,000
2010 Incentive Award Plan [Member]
Share-based Compensation Description [Abstract]
Common stock shares reserved for grants (in shares)	5,150,000
Shares of common stock available for grant (in shares)	682,160	1,267,802
Option to purchase common stock, outstanding (in shares)	1,674,499	1,714,885
2010 Incentive Award Plan [Member] \| Restricted Stock Units [Member]
Share-based Compensation Description [Abstract]
Number of shares outstanding (in shares)	216,739	184,752
2010 Incentive Award Plan [Member] \| Restricted Shares [Member]
Share-based Compensation Description [Abstract]
Number of shares outstanding (in shares)	100,000	100,000
2010 Incentive Award Plan [Member] \| Performance Stock Units [Member]
Share-based Compensation Description [Abstract]
Number of shares outstanding (in shares)	84,593	0
2014 Non-Employee Director Incentive Award Plan [Member]
Share-based Compensation Description [Abstract]
Common stock shares reserved for grants (in shares)	342,000
Shares of common stock available for grant (in shares)	628	76,746
2014 Non-Employee Director Incentive Award Plan [Member] \| Restricted Stock Units [Member]
Share-based Compensation Description [Abstract]
Number of shares outstanding (in shares)	82,324	69,732

No definition available.

Name:	mpaa_ShareBasedCompensationArrangementAbstract
Namespace Prefix:	mpaa_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

+ Details

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

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

+ Details

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

- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Details

Name:	us-gaap_PlanNameAxis=mpaa_NonEmployeeDirectorStockOptionPlan2004Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=mpaa_IncentiveAwardPlan2010Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=mpaa_NonEmployeeDirectorIncentiveAwardPlan2014Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: