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Investment Securities - Amortized Cost and Fair Value (Details) (USD $) In Thousands, unless otherwise specified | Mar. 31, 2015 | Dec. 31, 2014
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Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | $ 107,476 us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment | $ 116,437 us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment
Held to maturity, Fair Value | 109,785 us-gaap_HeldToMaturitySecuritiesFairValue | 118,643 us-gaap_HeldToMaturitySecuritiesFairValue
Held-to-maturity, Gross Unrealized Gains | 2,325 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain | 2,271 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
Held-to-maturity, Gross Unrealized Losses | (16)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss | (65)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Available-for-sale, Amortized Cost | 201,568 us-gaap_AvailableForSaleSecuritiesAmortizedCost | 199,045 us-gaap_AvailableForSaleSecuritiesAmortizedCost
Available-for-sale, Fair Value | 204,680 us-gaap_AvailableForSaleSecurities | 200,848 us-gaap_AvailableForSaleSecurities
Available-for-sale, Gross Unrealized Gains | 3,285 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax | 2,234 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Available-for-sale, Gross Unrealized Losses | (173)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax | (431)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Total investment securities, Amortized Cost | 309,044 bmrc_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesAmortizedCostBasis | 315,482 bmrc_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesAmortizedCostBasis
Total investment securities, Fair Value | 314,465 bmrc_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesFairValue | 319,491 bmrc_AvailableForSaleSecuritiesAndHeldToMaturitySecuritiesFairValue
Total investment securities, Gross Unrealized Gains | 5,610 bmrc_AvailableforsaleSecuritiesandHeldtomaturitySecuritiesAccumulatedGrossUnrealizedGain | 4,505 bmrc_AvailableforsaleSecuritiesandHeldtomaturitySecuritiesAccumulatedGrossUnrealizedGain
Total investment securities, Gross Unrealized Losses | (189)bmrc_AvailableforsaleSecuritiesandHeldtomaturitySecuritiesAccumulatedGrossUnrealizedLoss | (496)bmrc_AvailableforsaleSecuritiesandHeldtomaturitySecuritiesAccumulatedGrossUnrealizedLoss
MBS pass-through securities issued by FNMA and FHLMC |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, Amortized Cost | 90,215 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember | 92,963 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Available-for-sale, Fair Value | 92,057 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember | 94,214 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Available-for-sale, Gross Unrealized Gains | 1,842 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember | 1,262 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Available-for-sale, Gross Unrealized Losses | 0 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember | (11)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
CMOs issued by FNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, Amortized Cost | 13,896 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember | 14,771 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember
Available-for-sale, Fair Value | 14,055 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember | 14,790 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember
Available-for-sale, Gross Unrealized Gains | 197 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember | 77 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember
Available-for-sale, Gross Unrealized Losses | (38)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember | (58)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember
CMOs issued by FHLMC |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, Amortized Cost | 29,482 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember | 31,238 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember
Available-for-sale, Fair Value | 29,799 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember | 31,260 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember
Available-for-sale, Gross Unrealized Gains | 339 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember | 109 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember
Available-for-sale, Gross Unrealized Losses | (22)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember | (87)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FederalHomeLoanMortgageCorporationCertificatesAndObligationsFHLMCMember
CMOs issued by GNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, Amortized Cost | 15,933 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember | 17,573 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember
Available-for-sale, Fair Value | 16,231 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember | 17,855 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember
Available-for-sale, Gross Unrealized Gains | 308 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember | 298 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember
Available-for-sale, Gross Unrealized Losses | (10)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember | (16)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentNationalMortgageAssociationCertificatesAndObligationsGNMAMember
Debentures of government sponsored agencies |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, Amortized Cost | 26,154 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember | 14,694 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Available-for-sale, Fair Value | 26,174 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember | 14,557 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Available-for-sale, Gross Unrealized Gains | 119 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember | 95 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Available-for-sale, Gross Unrealized Losses | (99)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember | (232)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Privately-issued CMOs |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, Amortized Cost | 5,353 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember | 7,137 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Available-for-sale, Fair Value | 5,493 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember | 7,294 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Available-for-sale, Gross Unrealized Gains | 142 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember | 172 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Available-for-sale, Gross Unrealized Losses | (2)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember | (15)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Obligations of state and political subdivisions |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, Amortized Cost | 15,596 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember | 15,733 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember
Available-for-sale, Fair Value | 15,850 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember | 15,880 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember
Available-for-sale, Gross Unrealized Gains | 256 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember | 155 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember
Available-for-sale, Gross Unrealized Losses | (2)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember | (8)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember
Corporate bonds |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Available-for-sale, Amortized Cost | 4,939 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateBondSecuritiesMember | 4,936 us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateBondSecuritiesMember
Available-for-sale, Fair Value | 5,021 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateBondSecuritiesMember | 4,998 us-gaap_AvailableForSaleSecurities / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateBondSecuritiesMember
Available-for-sale, Gross Unrealized Gains | 82 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateBondSecuritiesMember | 66 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateBondSecuritiesMember
Available-for-sale, Gross Unrealized Losses | 0 us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateBondSecuritiesMember | (4)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateBondSecuritiesMember
Obligations of state and political subdivisions |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | 60,529 us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment / us-gaap_DebtSecurityAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember | 63,425 us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment / us-gaap_DebtSecurityAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember
Held to maturity, Fair Value | 62,257 us-gaap_HeldToMaturitySecuritiesFairValue / us-gaap_DebtSecurityAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember | 65,121 us-gaap_HeldToMaturitySecuritiesFairValue / us-gaap_DebtSecurityAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember
Held-to-maturity, Gross Unrealized Gains | 1,741 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain / us-gaap_DebtSecurityAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember | 1,736 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain / us-gaap_DebtSecurityAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember
Held-to-maturity, Gross Unrealized Losses | (13)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss / us-gaap_DebtSecurityAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember | (40)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss / us-gaap_DebtSecurityAxis = us-gaap_USStatesAndPoliticalSubdivisionsMember
Corporate bonds |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | 32,175 us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment / us-gaap_DebtSecurityAxis = us-gaap_CorporateBondSecuritiesMember | 40,257 us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment / us-gaap_DebtSecurityAxis = us-gaap_CorporateBondSecuritiesMember
Held to maturity, Fair Value | 32,345 us-gaap_HeldToMaturitySecuritiesFairValue / us-gaap_DebtSecurityAxis = us-gaap_CorporateBondSecuritiesMember | 40,448 us-gaap_HeldToMaturitySecuritiesFairValue / us-gaap_DebtSecurityAxis = us-gaap_CorporateBondSecuritiesMember
Held-to-maturity, Gross Unrealized Gains | 173 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain / us-gaap_DebtSecurityAxis = us-gaap_CorporateBondSecuritiesMember | 216 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain / us-gaap_DebtSecurityAxis = us-gaap_CorporateBondSecuritiesMember
Held-to-maturity, Gross Unrealized Losses | (3)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss / us-gaap_DebtSecurityAxis = us-gaap_CorporateBondSecuritiesMember | (25)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss / us-gaap_DebtSecurityAxis = us-gaap_CorporateBondSecuritiesMember
MBS pass-through securities issued by FNMA and FHLMC |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | 14,772 us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment / us-gaap_DebtSecurityAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember | 12,755 us-gaap_HeldToMaturitySecuritiesAmortizedCostBeforeOtherThanTemporaryImpairment / us-gaap_DebtSecurityAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held to maturity, Fair Value | 15,183 us-gaap_HeldToMaturitySecuritiesFairValue / us-gaap_DebtSecurityAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember | 13,074 us-gaap_HeldToMaturitySecuritiesFairValue / us-gaap_DebtSecurityAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity, Gross Unrealized Gains | 411 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain / us-gaap_DebtSecurityAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember | 319 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain / us-gaap_DebtSecurityAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity, Gross Unrealized Losses | $ 0 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss / us-gaap_DebtSecurityAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember | $ 0 us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss / us-gaap_DebtSecurityAxis = us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember

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