Name:	ifrs-full_DisclosureOfTransactionsBetweenRelatedPartiesLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The amount of current payables due to related parties. [Refer: Total for all related parties [member]; Payables to related parties]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 78
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_78&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_TradeAndOtherCurrentPayablesToRelatedParties
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The amount of current receivables due from related parties. [Refer: Total for all related parties [member]]

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Note Effective 2027-01-01
-Name IFRS
-Number 19
-IssueDate 2025-01-01
-Paragraph B9
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=19&code=ifrs-tx-2025-en-r&anchor=para_B9_b&doctype=Appendix&subtype=B
-URIDate 2025-03-27

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Note Expiry date 2027-01-01
-Name IAS
-Number 1
-IssueDate 2025-01-01
-Paragraph 78
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2025-en-b&anchor=para_78_b&doctype=Standard
-URIDate 2025-03-27

Name:	ifrs-full_TradeAndOtherCurrentReceivablesDueFromRelatedParties
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of receivables due from related parties. [Refer: Total for all related parties [member]]

Name:	ifrs-full_TradeAndOtherReceivablesDueFromRelatedParties
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The amount of allowance for related party credit losses.

No definition available.

Name:	namm_AllowanceforRelatedPartyCreditLosses
Namespace Prefix:	namm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=namm_MetallonCorporationLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=namm_MetallonCorporationLimitedUSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	ifrs-full_CategoriesOfRelatedPartiesAxis=namm_MetallonManagementServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: