XML 108 R96.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Acquisition - Net Assets Acquired, Consideration Paid and Estimated Fair Value Adjustments (Details) - USD ($) $ in Thousands | Nov. 21, 2017 | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | --- | ---
Business Acquisition [Line Items] |  |  |
Fair value of net assets acquired from Bank of Napa | $ 29,480 |  |
Fair value of net assets acquired from Bank of Napa | $ (29,480) |  |
Goodwill |  | $ 30,140 | $ 6,436
Tax rate on purchase accounting adjustments | 42.05% |  |
Bank of Napa, N.A. (Napa) |  |  |
Business Acquisition [Line Items] |  |  |
Book value of net assets acquired from Bank of Napa | $ 26,152 |  |
Fair value adjustment, loans | 1,301 |  |
Fair value adjustment, core deposit intangible | 4,441 |  |
Total purchase accounting adjustments | 5,742 |  |
Deferred tax liabilities (tax effect of purchase accounting adjustments at 42.05%) | (2,414) |  |
Fair value of net assets acquired from Bank of Napa | 29,480 |  |
Merger consideration | 53,185 |  |
Fair value of net assets acquired from Bank of Napa | (29,480) |  |
Goodwill | $ 23,705 |  |

X
- Definition Business Combination, Book Value Of Net Assets Acquired + References No definition available. + Details
Name: | bmrc_BusinessCombinationBookValueOfNetAssetsAcquired
Namespace Prefix: | bmrc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Business Combination, Fair Value Adjustment, Assets Acquired and Liabilities Assumed, Acquiree + References No definition available. + Details
Name: | bmrc_BusinessCombinationFairValueAdjustmentAssetsAcquiredandLiabilitiesAssumedAcquiree
Namespace Prefix: | bmrc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Business Combination, Fair Value Adjustment, Core Deposit Intangible Asset + References No definition available. + Details
Name: | bmrc_BusinessCombinationFairValueAdjustmentCoreDepositIntangibleAsset
Namespace Prefix: | bmrc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Business Combination, Fair Value Adjustment, Loans + References No definition available. + Details
Name: | bmrc_BusinessCombinationFairValueAdjustmentLoans
Namespace Prefix: | bmrc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Business Combination, Purchase Accounting Tax Effects, Deferred Tax Liabilities + References No definition available. + Details
Name: | bmrc_BusinessCombinationPurchaseAccountingTaxEffectsDeferredTaxLiabilities
Namespace Prefix: | bmrc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Purchase Accounting Adjustments, Tax Rate + References No definition available. + Details
Name: | bmrc_PurchaseAccountingAdjustmentsTaxRate
Namespace Prefix: | bmrc_
Data Type: | num: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 No definition available. + Details
Name: | us-gaap_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477 + Details
Name: | us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 55 -Paragraph 37 -URI http://asc.fasb.org/extlink&oid=84160947&loc=d3e2207-128464 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=bmrc_BankofNapaN.A.NapaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |