Name:	mcb_CommitmentsTerm
Namespace Prefix:	mcb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Loans and Leases Receivable, Commitments, Fixed Rates, Interest Rate Percentage

No definition available.

Name:	mcb_LoansAndLeasesReceivableCommitmentsFixedRatesInterestRatePercentage
Namespace Prefix:	mcb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Represents the loans and leases receivable commitments pledged interest-bearing.

No definition available.

Name:	mcb_LoansAndLeasesReceivableCommitmentsPledged
Namespace Prefix:	mcb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Loans and Leases Receivable, Commitments, variable Rates, Interest Rate Percentage.

No definition available.

Name:	mcb_LoansAndLeasesReceivableCommitmentsVariableRatesInterestRatePercentage
Namespace Prefix:	mcb_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

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.

No definition available.

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

Reflects the amount of cash required to fully fund agreements to provide advances to borrowers and lessees at stated interest rates.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480981/942-825-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 825
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480981/942-825-50-1