Number of forms of outstanding common stock of the company.

No definition available.

Name:	bcml_NumberOfFormsOfOutstandingCommonStock
Namespace Prefix:	bcml_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Amount Authorized, Annual Stock Grant Limit Per Person, Officers and Employees

+ References

No definition available.

+ Details

Name:	bcml_ShareBasedCompensationArrangementByShareBasedPaymentAwardAmountAuthorizedAnnualStockGrantLimitPerPersonOfficersAndEmployees
Namespace Prefix:	bcml_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Stock Grant Limit Per Person, Directors

+ References

No definition available.

+ Details

Name:	bcml_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedAnnualStockGrantLimitPerPersonDirectors
Namespace Prefix:	bcml_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Stock Grant Limit Per Person, Officers and Employees

+ References

No definition available.

+ Details

Name:	bcml_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorizedAnnualStockGrantLimitPerPersonOfficersAndEmployees
Namespace Prefix:	bcml_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate number of common shares reserved for future issuance.

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

- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

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

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

+ Details

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

- Details

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

- Details

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

- Details

Name:	srt_TitleOfIndividualAxis=srt_DirectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_TitleOfIndividualAxis=srt_ExecutiveOfficerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

EQUITY INCENTIVE PLANS - General Information (Details) $ in Millions	1 Months Ended	3 Months Ended				12 Months Ended
	Nov. 30, 2017 USD ($) shares	Sep. 30, 2023 item shares	Mar. 31, 2023 shares	Sep. 30, 2022 shares	Mar. 31, 2022 shares	Dec. 31, 2014 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of forms of outstanding common stock \| item		2
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		13,457	28,392	10,618	22,473
2017 Omnibus Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	450,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Stock Grant Limit Per Person, Officers and Employees	50,000
Share-based Compensation Arrangement by Share-based Payment Award, Amount Authorized, Annual Stock Grant Limit Per Person, Officers and Employees \| $	$ 2.0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized, Annual Stock Grant Limit Per Person, Directors	25,000
Common Stock, Capital Shares Reserved for Future Issuance		44,236
2017 Omnibus Equity Incentive Plan [Member] \| Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
2017 Omnibus Equity Incentive Plan [Member] \| Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period	1 year
2017 Omnibus Equity Incentive Plan [Member] \| Minimum \| Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
2017 Omnibus Equity Incentive Plan [Member] \| Maximum \| Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	5 years
2014 Omnibus Equity Incentive Plan [Member] \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period						1 year
2014 Omnibus Equity Incentive Plan [Member] \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period						5 years
2014 Omnibus Equity Incentive Plan [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period						148,962