XML 116 R103.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Income Taxes - Schedule of Effective Income Tax Reconciliation (Details) | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Percent |  |  |
Federal statutory income tax rate | 21.00% | 21.00% | 21.00%
California franchise tax, net of federal tax benefit | 7.90% | 8.30% | 8.40%
Tax exempt interest on municipal securities and loans | (3.10%) | (1.90%) | (2.50%)
Tax exempt earnings on bank owned life insurance | (1.50%) | (0.40%) | (1.00%)
Non-deductible acquisition related expenses | 0.00% | 0.00% | 0.60%
Non-deductible executive compensation | 0.00% | 0.00% | 0.40%
Low income housing and qualified zone academy bond tax credits | (0.60%) | (0.20%) | (0.40%)
Stock-based compensation and excess tax deficiencies (benefits) | 0.20% | 0.00% | (0.10%)
Other | (0.30%) | (0.20%) | (0.40%)
Effective Tax Rate | 23.60% | 26.60% | 26.00%

X
- Definition Effective Income Tax Rate Reconciliation, Deduction, Share-Based Compensation And Excess Tax Benefits + References No definition available. + Details
Name: | bmrc_EffectiveIncomeTaxRateReconciliationDeductionShareBasedCompensationAndExcessTaxBenefits
Namespace Prefix: | bmrc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective Income Tax Rate Reconciliation, Non-Deductible Acquisition Related Expenses + References No definition available. + Details
Name: | bmrc_EffectiveIncomeTaxRateReconciliationNonDeductibleAcquisitionRelatedExpenses
Namespace Prefix: | bmrc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective Income Tax Rate Reconciliation, Non-Deductible Executive Compensation + References No definition available. + Details
Name: | bmrc_EffectiveIncomeTaxRateReconciliationNonDeductibleExecutiveCompensation
Namespace Prefix: | bmrc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective Income Tax Rate Reconciliation, Tax Credit, Affordable Housing + References No definition available. + Details
Name: | bmrc_EffectiveIncomeTaxRateReconciliationTaxCreditAffordableHousing
Namespace Prefix: | bmrc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective Income Tax Rate Reconciliation, Tax Exempt Income, Earnings on Bank Owned Life Insurance + References No definition available. + Details
Name: | bmrc_EffectiveIncomeTaxRateReconciliationTaxExemptIncomeEarningsOnBankOwnedLifeInsurance
Namespace Prefix: | bmrc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective Income Tax Rate Reconciliation, Tax Exempt Income, Interest on Municipal Securities and Loans + References No definition available. + Details
Name: | bmrc_EffectiveIncomeTaxRateReconciliationTaxExemptIncomeInterestOnMunicipalSecuritiesAndLoans
Namespace Prefix: | bmrc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-12 + Details
Name: | us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-12 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.Fact.4) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-12 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.Fact.4) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-12 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.Fact.4) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1 + Details
Name: | us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration