XML 48 R37.htm IDEA: XBRL DOCUMENT
v3.20.2

Loans and Allowance for Loan Losses - CARES Act Narrative (Details) $ in Thousands | 1 Months Ended | 7 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Oct. 31, 2020 | Sep. 30, 2020 USD ($) loan | Oct. 19, 2020 USD ($) loan | Jun. 30, 2020 loan | Dec. 31, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Payroll Protection Program loans, balance |  | $ 2,107,991 |  |  | $ 1,843,286
Number of loan modifications under CARES Act | loan |  | 264 |  |  |
Payment deferral period, loans modified under CARES Act |  | 120 days |  |  |
Total loan balance modified under CARES Act |  | $ 388,500 |  |  |
SBA PPP |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Number of loans (over) | loan |  |  |  | 1,800 |
Commercial loans | Commercial and industrial |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Payroll Protection Program loans, balance |  | 512,973 |  |  | $ 246,687
Commercial loans | Commercial and industrial | SBA PPP |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Payroll Protection Program loans, balance |  | $ 301,700 |  |  |
Subsequent event |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loan modifications under CARES Act, additional relief | loan |  |  | 20 |  |
Loans and leases receivable, net of deferred income, modified under CARES Act, additional relief |  |  | $ 47,200 |  |
Subsequent event | SBA PPP |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Payment deferral period, before extension due to PPP forgiveness process delay | 6 months |  |  |  |
Payment deferral period, before extension due to PPP forgiveness process delay | 16 months |  |  |  |

X
- Definition Loan Modifications Under CARES Act, Additional Relief + References No definition available. + Details
Name: | bmrc_LoanModificationsUnderCARESActAdditionalRelief
Namespace Prefix: | bmrc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Loan Modifications Under CARES Act During Period + References No definition available. + Details
Name: | bmrc_LoanModificationsUnderCARESActDuringPeriod
Namespace Prefix: | bmrc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loans And Leases Receivable, Net Of Deferred Income, Modified Under CARES Act, Additional Relief + References No definition available. + Details
Name: | bmrc_LoansAndLeasesReceivableNetOfDeferredIncomeModifiedUnderCARESActAdditionalRelief
Namespace Prefix: | bmrc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Loans And Leases Receivable, Net Of Deferred Income, Modified Under CARES Act During Period + References No definition available. + Details
Name: | bmrc_LoansAndLeasesReceivableNetOfDeferredIncomeModifiedUnderCARESActDuringPeriod
Namespace Prefix: | bmrc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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 Payment Deferral Period, After Extension Due To PPP Forgiveness Process Delay + References No definition available. + Details
Name: | bmrc_PaymentDeferralPeriodAfterExtensionDueToPPPForgivenessProcessDelay
Namespace Prefix: | bmrc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Payment Deferral Period, Before Extension Due To PPP Forgiveness Process Delay + References No definition available. + Details
Name: | bmrc_PaymentDeferralPeriodBeforeExtensionDueToPPPForgivenessProcessDelay
Namespace Prefix: | bmrc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Payment Deferral Period, Loans Modified Under CARES Act + References No definition available. + Details
Name: | bmrc_PaymentDeferralPeriodLoansModifiedUnderCARESAct
Namespace Prefix: | bmrc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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 Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5074-111524 + Details
Name: | us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
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_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |