XML 65 R52.htm IDEA: XBRL DOCUMENT v3.6.0.2

Loans and Allowance for Loan Losses - Troubled Debt Restructuring Modifications (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) contract	Dec. 31, 2015 USD ($) contract	Dec. 31, 2014 USD ($) contract
Financing Receivable, Modifications [Line Items]
Number of Contracts Modified | contract	4		17
Pre-Modification Outstanding Recorded Investment	$ 1,985,000		$ 6,734,000
Post-Modification Outstanding Recorded Investment	2,115,000		7,288,000
Post-Modification Outstanding Recorded Investment at Period End	2,063,000		7,223,000
Total of TDR loans charged-off within previous 12 months	$ 0	$ 0	$ 0
Residential loans | Home equity
Financing Receivable, Modifications [Line Items]
Number of Contracts Modified | contract	1
Pre-Modification Outstanding Recorded Investment	$ 87,000
Post-Modification Outstanding Recorded Investment	222,000
Post-Modification Outstanding Recorded Investment at Period End	$ 245,000
Commercial loans | Commercial real estate, investor
Financing Receivable, Modifications [Line Items]
Number of Contracts Modified | contract	2		2
Pre-Modification Outstanding Recorded Investment	$ 1,830,000		$ 224,000
Post-Modification Outstanding Recorded Investment	1,826,000		224,000
Post-Modification Outstanding Recorded Investment at Period End	$ 1,752,000		$ 220,000
Commercial loans | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Contracts Modified | contract		7	6
Pre-Modification Outstanding Recorded Investment		$ 3,271,000	$ 1,039,000
Post-Modification Outstanding Recorded Investment		3,251,000	1,258,000
Post-Modification Outstanding Recorded Investment at Period End		$ 2,811,000	$ 1,251,000
Commercial real estate loans | Commercial real estate, owner-occupied
Financing Receivable, Modifications [Line Items]
Number of Contracts Modified | contract			1
Pre-Modification Outstanding Recorded Investment			$ 4,226,000
Post-Modification Outstanding Recorded Investment			4,216,000
Post-Modification Outstanding Recorded Investment at Period End			$ 4,175,000
Commercial real estate loans | Construction
Financing Receivable, Modifications [Line Items]
Number of Contracts Modified | contract			2
Pre-Modification Outstanding Recorded Investment			$ 964,000
Post-Modification Outstanding Recorded Investment			1,312,000
Post-Modification Outstanding Recorded Investment at Period End			$ 1,309,000
Consumer loans | Installment and other consumer
Financing Receivable, Modifications [Line Items]
Number of Contracts Modified | contract	1		6
Pre-Modification Outstanding Recorded Investment	$ 68,000		$ 281,000
Post-Modification Outstanding Recorded Investment	67,000		278,000
Post-Modification Outstanding Recorded Investment at Period End	$ 66,000		$ 268,000

X

- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings at end of period.

+ References

No definition available.

+ Details

Name:	bmrc_FinancingReceivableModificationsContractsModifiedDuringPeriodRecordedInvestment
Namespace Prefix:	bmrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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_CommercialRealEstateLoanInvestorMember
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=us-gaap_ConstructionLoansMember
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: