Representing the price per share or per unit of warrants or rights outstanding.

No definition available.

Name:	mtal_ClassOfWarrantOrRightPriceOfWarrantsOrRights
Namespace Prefix:	mtal_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of conversion of sponsor convertible note into private placement warrants.

+ References

No definition available.

+ Details

Name:	mtal_ConversionOfConvertibleNoteIntoWarrants
Namespace Prefix:	mtal_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The maximum amount which a potential loan could have repaid through issuance of warrants.

+ References

No definition available.

+ Details

Name:	mtal_MaximumLoansConvertibleIntoWarrants
Namespace Prefix:	mtal_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares.

+ References

No definition available.

+ Details

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

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

+ Details

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

- Definition

Face amount or stated value per share of common stock.

+ 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(29))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from a long-term borrowing made from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Alternate caption: Proceeds from Advances from Affiliates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=mtal_PrivatePlacementWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=mtal_SponsorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=mtal_ConvertiblePromissoryNoteFromRelatedParty2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events (Details) - USD ($)		12 Months Ended
Subsequent Events (Details) - USD ($)	Jan. 09, 2023	Dec. 31, 2022	May 24, 2022	May 06, 2022	Dec. 31, 2021	Sep. 03, 2021	Aug. 02, 2021
Subsequent Event
Amount borrowed		$ 786,096
Common Class A [Member]
Subsequent Event
Ordinary shares, par value	$ 0.0001	$ 0.0001			$ 0.0001		$ 0.0001
Exercise price of warrant			$ 11.50			$ 11.50
Warrants issued upon conversion of notes						14,373,564
Private Placement Warrants \| Sponsor
Subsequent Event
Number of shares per warrant				1
Exercise price of warrant				$ 11.50
Subsequent Event \| 2023 Sponsor Convertible Note \| Common Class A [Member]
Subsequent Event
Number of shares per warrant	1
Exercise price of warrant	$ 11.50
Subsequent Event \| 2023 Sponsor Convertible Note \| Sponsor
Subsequent Event
Amount borrowed	$ 300,000
Maximum note value converted into warrants	$ 300,000
Subsequent Event \| 2023 Sponsor Convertible Note \| Sponsor \| Common Class A [Member]
Subsequent Event
Price of warrant	$ 1.50
Subsequent Event \| 2023 Sponsor Convertible Note \| Private Placement Warrants \| Sponsor
Subsequent Event
Conversion of convertible note into warrants	$ 300,000
Warrants issued upon conversion of notes	200,000