XML 88 R70.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Loans and Allowance for Credit Losses on Loans - Schedule of Amortized Cost of Loans Modified (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications | $ 188 | $ 2,309
Term Extension |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications | 188 | 2,309
Total Modifications |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications | 188 | 2,309
Residential loans | Home equity |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications | 188 |
Residential loans | Home equity | Term Extension |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications | 188 |
Residential loans | Home equity | Total Modifications |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications | $ 188 |
Percent of Portfolio Class Total | 0.20% |
Commercial and industrial | Commercial owner-occupied |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications |  | 1,431
Commercial and industrial | Commercial owner-occupied | Term Extension |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications |  | 1,431
Commercial and industrial | Commercial owner-occupied | Total Modifications |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications |  | $ 1,431
Percent of Portfolio Class Total |  | 0.40%
Commercial and industrial | Commercial non-owner occupied |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications |  | $ 878
Commercial and industrial | Commercial non-owner occupied | Term Extension |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications |  | 878
Commercial and industrial | Commercial non-owner occupied | Total Modifications |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |
Total Modifications |  | $ 878
Percent of Portfolio Class Total |  | 0.10%

X
- Definition Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage, excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 + Details
Name: | us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
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 Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-34 Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 33 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-33 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 12A -Publisher FASB -URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-42 + Details
Name: | us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=bmrc_TotalLoanRestructuringModificationMember
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_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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