XML 36 R23.htm IDEA: XBRL DOCUMENT
v3.19.1

Financial Instruments with Off-Balance Sheet Risk | 12 Months Ended
--- | ---
Dec. 31, 2018
Fair Value Disclosures [Abstract] |
Financial Instruments with Off-Balance Sheet Risk | Financial Instruments with Off-Balance Sheet Risk We make commitments to extend credit in the normal course of business to meet the financing needs of our customers. These financial instruments include commitments to extend credit in the form of loans or through standby letters of credit. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Because various commitments will expire without being fully drawn, the total commitment amount does not necessarily represent future cash requirements. Our credit loss exposure is equal to the contractual amount of the commitment in the event of nonperformance by the borrower. We use the same credit underwriting criteria for all credit exposure. The amount of collateral obtained, if deemed necessary by us, is based on Management's credit evaluation of the borrower. Collateral types pledged may include accounts receivable, inventory, other personal property and real property. The contractual amount of undrawn loan commitments and standby letters of credit not reflected in the consolidated statements of condition are as follows:
(in thousands) | December 31, 2018 |  | December 31, 2017 |
Commercial lines of credit | $ | 238,361 |  | $ | 224,370 |
Revolving home equity lines | 189,971 |  | 177,678 |
Undisbursed construction loans | 46,229 |  | 35,322 |
Personal and other lines of credit | 14,109 |  | 11,758 |
Standby letters of credit | 2,636 |  | 4,074 |
Total commitments and standby letters of credit | $ | 491,306 |  | $ | 453,202 |
We record an allowance for losses on these off-balance sheet commitments based on an estimate of probabilities of the utilization of these commitments according to our historical experience on different types of commitments and expected loss. The allowance for losses on off-balance sheet commitments totaled $958 thousand as of December 31, 2018 and 2017, which is recorded in interest payable and other liabilities in the consolidated statements of condition. Approximately 35% of the commitments expire in 2019, approximately 51% expire between 2020 and 2026 and approximately 14% expire thereafter.

X
- Definition Financial Instruments with Off-Balance Sheet Risk [Text Block] + References No definition available. + Details
Name: | bmrc_FinancialInstrumentsWithOffBalanceSheetRiskTextBlock
Namespace Prefix: | bmrc_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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