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

No definition available.

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Namespace Prefix:	mtal_
Data Type:	dtr-types:perShareItemType
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Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Amount of maximum borrowing capacity of related party promissory note.

+ References

No definition available.

+ Details

Name:	mtal_MaximumBorrowingCapacityOfRelatedPartyPromissoryNote
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

The amounts of proceeds advances from related parties.

+ References

No definition available.

+ Details

Name:	mtal_ProceedsAdvancesFromRelatedParties
Namespace Prefix:	mtal_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of working capital loans outstanding.

+ References

No definition available.

+ Details

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

- Definition

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
-Section 45
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-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227

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

- 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

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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

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

- Definition

Carrying value as of the balance sheet date of the portion of long-term debt due within one year or the operating cycle if longer identified as Convertible Notes Payable. Convertible Notes Payable is a written promise to pay a note which can be exchanged for a specified amount of another, related security, at the option of the issuer and the holder.

+ 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 210.5-02.20)
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount for notes payable (written promise to pay), due to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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

- Details

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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_RelatedPartyTransactionAxis=mtal_PromissoryNoteWithRelatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mtal_UnsecuredPromissoryNoteOctober2022Member
Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Related Party Transactions - Additional Information (Details) - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2022	Oct. 31, 2022	May 24, 2022	May 06, 2022
Related Party Transaction
Advances from related parties	$ 150,000
Amount outstanding		$ 786,096
Interest expense related to amortization of the debt discount		$ 8,000
Working capital loans warrant
Related Party Transaction
Price of warrant		$ 1.50
Amount outstanding		$ 0
Private Placement Warrants
Related Party Transaction
Working Capital Loans		1,500,000
Sponsor \| Private Placement Warrants
Related Party Transaction
Amount borrowed		0
Number of shares per warrant					1
Exercise price of warrants					$ 11.50
Sponsor \| Promissory notes with related party \| October 2022 Note
Related Party Transaction
Maximum borrowing capacity of related party promissory note			$ 300,000
Amount outstanding	0	300,000
Sponsor \| Promissory notes with related party \| December 2022 Note
Related Party Transaction
Maximum borrowing capacity of related party promissory note		1,254,533
Amount outstanding	$ 0	$ 486,096
Sponsor \| Convertible promissory note
Related Party Transaction
Maximum borrowing capacity of related party promissory note					$ 1,200,000
Loan conversion agreement warrant					$ 1,200,000
Price of warrant					$ 1.50
Amount borrowed					$ 1,200,000
Sponsor \| Convertible promissory note \| Private Placement Warrants
Related Party Transaction
Warrants issued upon conversion of notes				800,000
Conversion of convertible note into warrants				$ 1,200,000