XML 50 R41.htm IDEA: XBRL DOCUMENT
v3.23.1

Loans and Allowance for Credit Losses on Loans - Loans Outstanding and Aging Analysis (Details) - USD ($) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2023 | Mar. 31, 2022 | Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | $ 2,112,328,000 |  | $ 2,092,546,000
Loans past due more than 90 days still accruing | 0 |  | 0
Financing receivable, nonaccrual, earning interest on cash basis | 0 |  | 0
Financing receivable, nonaccrual, interest income | 0 | $ 0 |
Financing receivable, accrued interest, writeoff | 16,000 | $ 1,000 |
Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 2,112,328,000 |  | 2,092,546,000
Non-accrual loans | 2,026,000 |  | 2,432,000
Non-accrual loans with no allowance | 2,023,000 |  | 2,432,000
Total past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 2,780,000 |  | 1,342,000
30-59 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 2,146,000 |  | 420,000
60-89 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 244,000
90 days or more past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 634,000 |  | 678,000
Current | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 2,109,548,000 |  | 2,091,204,000
Commercial loans | Commercial and industrial |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 195,964,000 |  | 173,547,000
Commercial loans | Commercial and industrial | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 195,964,000 |  | 173,547,000
Non-accrual loans | 0 |  | 0
Non-accrual loans with no allowance | 0 |  | 0
Commercial loans | Commercial and industrial | Total past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 822,000 |  | 267,000
Commercial loans | Commercial and industrial | 30-59 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 822,000 |  | 3,000
Commercial loans | Commercial and industrial | 60-89 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Commercial loans | Commercial and industrial | 90 days or more past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 264,000
Commercial loans | Commercial and industrial | Current | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 195,142,000 |  | 173,280,000
Commercial real estate loans | Commercial owner-occupied |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 352,529,000 |  | 354,877,000
Commercial real estate loans | Commercial owner-occupied | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 352,529,000 |  | 354,877,000
Non-accrual loans | 331,000 |  | 1,563,000
Non-accrual loans with no allowance | 331,000 |  | 1,563,000
Commercial real estate loans | Commercial owner-occupied | Total past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 33,000 |  | 0
Commercial real estate loans | Commercial owner-occupied | 30-59 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Commercial real estate loans | Commercial owner-occupied | 60-89 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Commercial real estate loans | Commercial owner-occupied | 90 days or more past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 33,000 |  | 0
Commercial real estate loans | Commercial owner-occupied | Current | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 352,496,000 |  | 354,877,000
Commercial real estate loans | Commercial non-owner occupied |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 1,189,962,000 |  | 1,191,889,000
Commercial real estate loans | Commercial non-owner occupied | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 1,189,962,000 |  | 1,191,889,000
Non-accrual loans | 924,000 |  | 0
Non-accrual loans with no allowance | 924,000 |  | 0
Commercial real estate loans | Commercial non-owner occupied | Total past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 924,000 |  | 0
Commercial real estate loans | Commercial non-owner occupied | 30-59 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 924,000 |  | 0
Commercial real estate loans | Commercial non-owner occupied | 60-89 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Commercial real estate loans | Commercial non-owner occupied | 90 days or more past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Commercial real estate loans | Commercial non-owner occupied | Current | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 1,189,038,000 |  | 1,191,889,000
Commercial real estate loans | Construction |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 110,386,000 |  | 114,373,000
Commercial real estate loans | Construction | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 110,386,000 |  | 114,373,000
Non-accrual loans | 0 |  | 0
Non-accrual loans with no allowance | 0 |  | 0
Commercial real estate loans | Construction | Total past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Commercial real estate loans | Construction | 30-59 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Commercial real estate loans | Construction | 60-89 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Commercial real estate loans | Construction | 90 days or more past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Commercial real estate loans | Construction | Current | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 110,386,000 |  | 114,373,000
Residential loans | Home equity |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 86,572,000 |  | 88,748,000
Residential loans | Home equity | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 86,572,000 |  | 88,748,000
Non-accrual loans | 768,000 |  | 778,000
Non-accrual loans with no allowance | 768,000 |  | 778,000
Residential loans | Home equity | Total past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 997,000 |  | 977,000
Residential loans | Home equity | 30-59 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 399,000 |  | 319,000
Residential loans | Home equity | 60-89 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 244,000
Residential loans | Home equity | 90 days or more past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 598,000 |  | 414,000
Residential loans | Home equity | Current | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 85,575,000 |  | 87,771,000
Residential loans | Other residential |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 116,447,000 |  | 112,123,000
Residential loans | Other residential | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 116,447,000 |  | 112,123,000
Non-accrual loans | 0 |  | 0
Non-accrual loans with no allowance | 0 |  | 0
Residential loans | Other residential | Total past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 93,000
Residential loans | Other residential | 30-59 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 93,000
Residential loans | Other residential | 60-89 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Residential loans | Other residential | 90 days or more past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Residential loans | Other residential | Current | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 116,447,000 |  | 112,030,000
Consumer loans | Installment and other consumer loans |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 60,468,000 |  | 56,989,000
Consumer loans | Installment and other consumer loans | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 60,468,000 |  | 56,989,000
Non-accrual loans | 3,000 |  | 91,000
Non-accrual loans with no allowance | 0 |  | 91,000
Consumer loans | Installment and other consumer loans | Total past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 4,000 |  | 5,000
Consumer loans | Installment and other consumer loans | 30-59 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 1,000 |  | 5,000
Consumer loans | Installment and other consumer loans | 60-89 days past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 0 |  | 0
Consumer loans | Installment and other consumer loans | 90 days or more past due | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | 3,000 |  | 0
Consumer loans | Installment and other consumer loans | Current | Financial asset, other than financial asset acquired with credit deterioration |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Loans, at amortized cost | $ 60,464,000 |  | $ 56,984,000

X
- Definition Financing Receivable, Nonaccrual, Earning Interest On Cash Basis + References No definition available. + Details
Name: | bmrc_FinancingReceivableNonaccrualEarningInterestOnCashBasis
Namespace Prefix: | bmrc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 Amount of writeoff of accrued interest on financing receivable recognized by reversing interest income. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3D -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120267969-210447 + Details
Name: | us-gaap_FinancingReceivableAccruedInterestWriteoff
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amortized cost excluding accrued interest, of financing receivable 90 days or more past due and still accruing. 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 16 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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 Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. 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 16 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, of financing receivable on nonaccrual status with no allowance for credit loss. 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 16 -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of interest income on financing receivable on nonaccrual status. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 16 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447 + Details
Name: | us-gaap_FinancingReceivableNonaccrualInterestIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_CreditLossStatusAxis=us-gaap_FinancialAssetOtherThanFinancialAssetAcquiredWithCreditDeteriorationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables60To89DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetNotPastDueMember
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_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bmrc_CommercialRealEstateLoanOwnerOccupiedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bmrc_CommercialRealEstateLoanNonOwnerOccupiedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bmrc_OtherResidentialLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bmrc_InstallmentAndOtherConsumerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |