XML 50 R41.htm IDEA: XBRL DOCUMENT v3.22.2

Loans and Allowance for Credit Losses on Loans - CARES Act Narrative (Details) $ in Thousands	Jun. 30, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan	Aug. 06, 2021 USD ($) branch	Dec. 31, 2020 USD ($) loan branch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans at amortized cost	$ 2,162,632	$ 2,255,645
SBA PPP
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of PPP participated | branch				2
Commercial loans | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans at amortized cost	$ 213,122	$ 301,602
Commercial loans | Commercial and industrial | SBA PPP
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan	112	368		2,876
Loans at amortized cost	$ 17,000	$ 111,200		$ 444,100
Financing receivable, unamortized loan fee	$ 420	$ 2,500
Commercial loans | Commercial and industrial | SBA PPP | American River Bank (ARB)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | branch			113
Loans at amortized cost			$ 18,600

X

- Definition

Number Of Loans

+ References

No definition available.

+ Details

Name:	bmrc_NumberOfLoans
Namespace Prefix:	bmrc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Number Of Paycheck Protection Programs Participated

+ References

No definition available.

+ Details

Name:	bmrc_NumberOfPaycheckProtectionProgramsParticipated
Namespace Prefix:	bmrc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

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

X

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 3B
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of unamortized loan commitment, origination, and other costs (fees) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5074-111524

Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=84159169&loc=d3e10152-111534

+ Details

Name:	us-gaap_FinancingReceivableUnamortizedLoanFeeCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_UnusualOrInfrequentItemAxis=bmrc_SmallBusinessAdministrationPaycheckProtectionProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bmrc_CommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_BusinessAcquisitionAxis=bmrc_AmericanRiverBankARBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: