Bank of Marin Bancorp (BMRC) 10-K 17 Mar 14 2013 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Feb. 28, 2014	Jun. 30, 2013
Document and Entity Information [Abstract]	'	'	'
Entity Registrant Name	'Bank of Marin Bancorp	'	'
Entity Central Index Key	'0001403475	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Well-known Seasoned Issuer	'No	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Filer Category	'Accelerated Filer	'	'
Entity Public Float	'	'	$210
Entity Common Stock, Shares Outstanding	'	5,900,891	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	31-Dec-13	'	'

CONSOLIDATED_STATEMENTS_OF_CON

CONSOLIDATED STATEMENTS OF CONDITION (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Assets	'	'
Cash and due from banks	$103,773	$28,349
Investment securities	'	'
Held to maturity, at amortized cost	122,495	139,452
Available for sale (at fair value; amortized cost $245,158 and $150,420 at December 31, 2013 and 2012, respectively)	243,998	153,962
Total investment securities	366,493	293,414
Loans, net of allowance for loan losses of $14,224 and $13,661 at December 31, 2013 and 2012, respectively	1,255,098	1,060,291
Bank premises and equipment, net	9,110	9,344
Interest receivable and other assets	70,720	43,351
Total assets	1,805,194	1,434,749
Deposits	'	'
Non-interest bearing	648,191	389,722
Interest bearing	'	'
Transaction accounts	137,748	169,647
Savings accounts	118,770	93,404
Money market accounts	520,525	443,742
CDARS® time accounts	400	15,718
Other time accounts	161,468	141,056
Total deposits	1,587,102	1,253,289
Federal Home Loan Bank (FHLB) borrowings	15,000	15,000
Subordinated debentures	4,969	0
Interest payable and other liabilities	17,236	14,668
Total liabilities	1,624,307	1,282,957
Stockholders' Equity	'	'
Preferred stock, no par value, Authorized - 5,000,000 shares, none issued	0	0
Common stock, no par value, Authorized - 15,000,000 shares; Issued and outstanding - 5,877,524 and 5,389,210 at December 31, 2013 and 2012, respectively	80,095	58,573
Retained earnings	101,464	91,164
Accumulated other comprehensive (loss) income, net	-672	2,055
Total stockholders' equity	180,887	151,792
Total liabilities and stockholders' equity	$1,805,194	$1,434,749

CONSOLIDATED_STATEMENTS_OF_CON1

CONSOLIDATED STATEMENTS OF CONDITION (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Investment Securities	'	'
Available for sale, amortized cost	$245,158	$150,420
Loans, allowance for loan losses	$14,224	$13,661
Stockholders' Equity	'	'
Preferred stock, no par value (in dollars per share)	$0	$0
Preferred stock, authorized (in shares)	5,000,000	5,000,000
Preferred stock, issued, (in shares)	0	0
Common stock, no par value (in dollars per share)	$0	$0
Common stock, authorized (in shares)	15,000,000	15,000,000
Common stock, issued (in shares)	5,877,524	5,389,210
Common stock, outstanding (in shares)	5,877,524	5,389,210

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Interest income	'	'	'
Interest and fees on loans	$54,408	$59,403	$63,479
Interest on investment securities	'	'	'
Securities of U.S. government agencies	2,573	3,195	3,478
Obligations of state and political subdivisions	2,214	1,789	1,299
Corporate debt securities and other	1,245	1,165	636
Interest on Federal funds sold and short-term investments	120	214	222
Total interest income	60,560	65,766	69,114
Interest expense	'	'	'
Interest on interest bearing transaction accounts	52	151	151
Interest on savings accounts	35	88	98
Interest on money market accounts	419	689	1,286
Interest on CDARS® time accounts	8	83	237
Interest on other time accounts	914	1,068	1,314
Interest on FHLB and overnight borrowings	322	345	2,062
Interest on subordinated debentures	35	152	147
Total interest expense	1,785	2,576	5,295
Net interest income	58,775	63,190	63,819
Provision for loan losses	540	2,900	7,050
Net interest income after provision for loan losses	58,235	60,290	56,769
Non-interest income	'	'	'
Service charges on deposit accounts	2,062	2,130	1,836
Wealth Management and Trust Services	2,162	1,964	1,834
Debit card interchange fees	1,104	1,015	845
Merchant interchange fees	822	739	353
Earnings on Bank-owned life insurance	954	762	752
Loss on sale of securities	-1	-34	0
Other income	963	536	649
Total non-interest income	8,066	7,112	6,269
Non-interest expense	'	'	'
Salaries and related benefits	21,974	21,139	20,211
Occupancy and equipment	4,347	4,230	4,002
Depreciation and amortization	1,395	1,355	1,293
Federal Deposit Insurance Corporation insurance	921	917	1,000
Data processing	5,334	2,514	2,690
Professional services	2,985	2,340	2,499
Other expense	7,136	6,199	6,588
Total non-interest expense	44,092	38,694	38,283
Income before provision for income taxes	22,209	28,708	24,755
Provision for income taxes	7,939	10,891	9,191
Net income	14,270	17,817	15,564
Net income per common share:	'	'	'
Basic (in dollars per share)	$2.62	$3.34	$2.94
Diluted (in dollars per share)	$2.57	$3.28	$2.89
Weighted-average shares used to compute net income per common share:	'	'	'
Basic (in shares)	5,457	5,341	5,302
Diluted (in shares)	5,558	5,438	5,384
Dividends declared per common share (in dollars per share)	$0.73	$0.70	$0.65
Comprehensive income	'	'	'
Net income	14,270	17,817	15,564
Other comprehensive (loss) income	'	'	'
Change in net unrealized gain on available for sale securities	-4,720	752	90
Reclassification adjustment for loss on sale of securities included in net income	18	34	0
Net change in unrealized gain on available for sale securities, before tax	-4,702	786	90
Deferred tax (benefit) expense	-1,975	330	37
Other comprehensive (loss) income, net of tax	-2,727	456	53
Comprehensive income	$11,543	$18,273	$15,617

CONSOLIDATED_STATEMENT_OF_CHAN

CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (USD $)	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss), Net of Taxes
In Thousands, except Share data
Balance at Dec. 31, 2010	$121,920	$55,383	$64,991	$1,546
Balance (in shares) at Dec. 31, 2010	'	5,290,082	'	'
Net income	15,564	0	15,564	0
Other comprehensive income	53	0	0	53
Stock options exercised (in shares)	34,913	34,913	'	'
Stock options exercised	741	741	0	'
Excess tax benefit - stock-based compensation	120	120	0	0
Stock issued under employee stock purchase plan (in shares)	'	982	'	'
Stock issued under employee stock purchase plan	33	33	0	0
Restricted stock granted (in shares)	'	5,675	'	'
Restricted stock granted	0	0	0	0
Restricted stock forfeited/cancelled (in shares)	'	-315	'	'
Restricted stock forfeited/cancelled	0	0	0	0
Stock-based compensation - stock options	234	234	0	0
Stock-based compensation - restricted stock	143	143	0	0
Cash dividends paid on common stock	-3,457	0	-3,457	0
Stock issued in payment of director fees (in shares)	'	5,590	'	'
Stock issued in payment of director fees	200	200	0	0
Stock issued to NorCal Community Bancorp shareholders	0	'	'	'
Balance at Dec. 31, 2011	135,551	56,854	77,098	1,599
Balance (in shares) at Dec. 31, 2011	'	5,336,927	'	'
Net income	17,817	0	17,817	0
Other comprehensive income	456	0	0	456
Stock options exercised (in shares)	37,563	37,563	'	'
Stock options exercised	1,041	1,041	0	0
Excess tax benefit - stock-based compensation	42	42	0	0
Stock issued under employee stock purchase plan (in shares)	'	700	'	'
Stock issued under employee stock purchase plan	25	25	0	0
Restricted stock granted (in shares)	'	9,030	'	'
Restricted stock granted	0	0	0	0
Restricted stock forfeited/cancelled (in shares)	'	-380	'	'
Restricted stock forfeited/cancelled	0	0	0	0
Stock-based compensation - stock options	206	206	0	0
Stock-based compensation - restricted stock	202	202	0	0
Cash dividends paid on common stock	-3,751	0	-3,751	0
Stock purchased by directors under director stock plan (in shares)	'	100	'	'
Stock purchased by directors under director stock plan	4	4	0	0
Stock issued in payment of director fees (in shares)	'	5,270	'	'
Stock issued in payment of director fees	199	199	0	0
Stock issued to NorCal Community Bancorp shareholders	0	'	'	'
Balance at Dec. 31, 2012	151,792	58,573	91,164	2,055
Balance (in shares) at Dec. 31, 2012	5,389,210	5,389,210	'	'
Net income	14,270	0	14,270	0
Other comprehensive income	-2,727	0	0	-2,727
Stock options exercised (in shares)	71,237	71,237	'	'
Stock options exercised	2,218	2,218	0	0
Excess tax benefit - stock-based compensation	125	125	0	0
Stock issued under employee stock purchase plan (in shares)	'	870	'	'
Stock issued under employee stock purchase plan	34	34	0	0
Restricted stock granted (in shares)	'	11,850	'	'
Restricted stock granted	0	0	0	0
Restricted stock forfeited/cancelled (in shares)	'	-3,998	'	'
Restricted stock forfeited/cancelled	0	0	0	0
Stock-based compensation - stock options	175	175	0	0
Stock-based compensation - restricted stock	228	228	0	0
Cash dividends paid on common stock	-3,970	0	-3,970	0
Stock purchased by directors under director stock plan (in shares)	'	160	'	'
Stock purchased by directors under director stock plan	6	6	0	0
Stock issued in payment of director fees (in shares)	'	5,619	'	'
Stock issued in payment of director fees	222	222	0	0
Stock issued to NorCal Community Bancorp shareholders (in shares)	'	402,576	'	'
Stock issued to NorCal Community Bancorp shareholders	18,514	18,514	0	0
Balance at Dec. 31, 2013	$180,887	$80,095	$101,464	($672)
Balance (in shares) at Dec. 31, 2013	5,877,524	5,877,524	'	'

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities:	'	'	'
Net income	$14,270	$17,817	$15,564
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Provision for loan losses	540	2,900	7,050
Compensation expense--common stock for director fees	215	209	200
Stock-based compensation expense	403	408	377
Excess tax benefits from exercised stock options	-96	-29	-99
Amortization and impairment write-off of core deposit intangible	69	0	725
Amortization of investment security premiums, net of accretion of discounts	3,004	2,332	1,385
Accretion of discount on acquired loans	-1,871	-2,430	-4,275
Accretion of discount on subordinated debentures	19	0	0
Decrease in deferred loan origination fees, net	-793	-831	-1,200
Net loss on sale of security transactions	1	34	0
Depreciation and amortization	1,395	1,355	1,293
Loss on disposal of premises and equipment	0	20	117
Bargain purchase gain on acquisition, net of tax	0	0	-85
(Gain) loss on sale of repossessed assets	-43	14	-10
Earnings on bank owned life insurance policies	-954	-762	-752
Net change in operating assets and liabilities:	'	'	'
Interest receivable	-694	-435	-431
Interest payable	28	-156	-33
Deferred rent and other rent-related expenses	338	331	236
Other assets	299	555	1,051
Other liabilities	5,071	-526	1,268
Total adjustments	6,931	2,989	6,817
Net cash provided by operating activities	21,201	20,806	22,381
Cash Flows from Investing Activities:	'	'	'
Proceeds from sale of premises and equipment	0	0	18
Purchase of securities held to maturity	0	-87,290	-26,804
Purchase of securities available for sale	-86,372	-73,405	-92,686
Proceeds from sale of securities available for sale	7,973	2,186	0
Proceeds from sale of securities held to maturity	6,442	0	0
Proceeds from paydowns/maturities of securities held to maturity	8,570	6,458	1,755
Proceeds from paydowns/maturities of securities available for sale	36,332	51,899	68,251
Loans originated and principal collected, net	-23,087	-43,169	-25,182
Purchase of bank owned life insurance policies	-1,421	-364	-2,500
Purchase of premises and equipment	-958	-1,221	-2,472
Proceeds from sale of repossessed assets	270	41	421
Cash acquired from acquisitions, net of cash paid	15,785	0	44,042
(Purchase) redemption of Federal Home Loan Bank stock	-420	0	219
Cash paid for low income housing investment	-62	0	0
Net cash used in investing activities	-36,948	-144,865	-34,938
Cash Flows from Financing Activities:	'	'	'
Net increase in deposits	92,787	50,317	93,152
Proceeds from stock options exercised	2,218	1,041	741
Repayment of Federal Home Loan Bank borrowings	0	-20,000	-33,500
Repayment of subordinated debenture	0	-5,000	0
Cash dividends paid on common stock	-3,970	-3,751	-3,457
Stock issued under employee and director stock purchase plans	40	29	33
Excess tax benefits from exercised stock options	96	29	99
Net cash provided by (used by) financing activities	91,171	22,665	57,068
Net (decrease) increase in cash and cash equivalents	75,424	-101,394	44,511
Cash and cash equivalents at beginning of period	28,349	129,743	85,232
Cash and cash equivalents at end of period	103,773	28,349	129,743
Supplemental disclosure of cash flow information:	'	'	'
Cash paid in interest	1,740	2,732	5,328
Cash paid in income taxes	9,239	11,421	9,159
Supplemental disclosure of non-cash investing and financing activities:	'	'	'
Change in unrealized gain on available-for- sale securities	-4,702	786	90
Loans transferred to repossessed assets	192	65	301
Stock issued in payment of director fees	222	199	200
Acquisitions:	'	'	'
Fair value of assets acquired	280,917	0	107,763
Fair value of liabilities assumed	246,384	0	107,678
Stock issued to NorCal Community Bancorp shareholders	$18,514	$0	$0

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Basis of Presentation: The consolidated financial statements include the accounts of Bank of Marin Bancorp (“Bancorp”), a bank holding company, and its wholly-owned bank subsidiary, Bank of Marin (the “Bank”, a California state-chartered commercial bank). All material intercompany transactions have been eliminated. In the opinion of Management, the consolidated financial statements contain all adjustments necessary to present fairly the financial position, results of operations, changes in stockholders' equity and cash flows. All adjustments are of a normal, recurring nature. We have evaluated subsequent events through the date of filing with the Securities and Exchange Commission (“SEC”) and have determined that there are no subsequent events that require additional recognition or disclosure.
	On November 29, 2013, we completed the merger of NorCal Community Bancorp ("NorCal"), parent company of Bank of Alameda, to enhance our market presence (the “Acquisition”). On the date of acquisition, Bancorp assumed ownership of NorCal Community Bancorp Trusts I and II, respectively (the "Trusts"), which were formed for the sole purpose of issuing trust preferred securities. Bancorp is not considered the primary beneficiary of the Trusts (variable interest entities), therefore the Trusts are not consolidated in our consolidated financial statements, but rather the subordinated debentures are shown as a liability on our consolidated statements of condition. Bancorp's investment in the common stock of the Trusts is accounted for under the equity method and is included in interest receivable and other assets on the consolidated statements of condition.
	Nature of Operations: Bancorp, headquartered in Novato, CA, conducts business primarily through its wholly-owned subsidiary, the Bank, which provides a wide range of financial services to customers, who are predominantly professionals, small and middle-market businesses, and individuals who work and/or reside in Marin, Sonoma, Napa, San Francisco and Alameda counties. Besides the headquarters office in Novato, CA, the Bank operates ten branches in Marin County, one in Napa County, one in San Francisco, five in Sonoma County and four in Alameda County. Our accounting and reporting policies conform to generally accepted accounting principles, general practice, and regulatory guidance within the banking industry. A summary of our significant policies follows.
	Cash and Cash Equivalents include cash, due from banks, Federal funds sold and other short-term investments with maturity less than three months at the time of origination.
	Investment Securities are classified as "held to maturity," "trading securities" or "available for sale." Investments classified as held-to-maturity are those that we have the ability and intent to hold until maturity and are reported at cost, adjusted for the amortization or accretion of premiums or discounts. Investments held for resale in anticipation of short-term market movements are classified as trading securities and are reported at fair value, with unrealized gains and losses included in earnings. Investments that are neither held-to-maturity nor trading are classified as available-for-sale and are reported at fair value. Unrealized gains and losses for available-for-sale securities, net of related tax, are reported as a separate component of comprehensive income and included in stockholders' equity until realized. For discussion of our methodology in determining fair value, see Note 10.
	At each financial statement date, Management assesses whether declines in the fair value of held-to-maturity and available-for-sale securities below their costs are deemed to be other-than-temporary. Management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) our intent and ability to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value. Evidence evaluated includes, but is not limited to, the remaining payment terms of the instrument and economic factors that are relevant to the collectability of the instrument, such as: current prepayment speeds, the current financial condition of the issuer(s), industry analyst reports, credit ratings, credit default rates, interest rate trends, the quality of any credit enhancement and the value of any underlying collateral.
	For each security in an unrealized loss position, we assess whether we intend to sell the security or if it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis less any current-period credit losses. If we intend to sell the security or it is more likely than not we will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the entire difference between the investment’s amortized cost basis and its fair value at the balance sheet date is recognized in earnings.
	For impaired securities that are not intended for sale and will not be required to be sold prior to recovery of our amortized cost basis, we determine if the impairment has a credit loss component. For held-to-maturity securities, if there is no credit loss, no further action is required. For both held-to-maturity and available-for-sale securities, if the amount or timing of cash flows expected to be collected are less than those at the last reporting date, an other-than-temporary impairment shall be considered to have occurred and the credit loss component is recognized in earnings as the present value of the change in expected future cash flows. In determining the present value of the expected cash flows we discount the expected cash flows at the effective interest rate implicit in the security at the date of purchase. The remaining difference between the security's fair value and the amortized basis is deemed to be due to factors that are not credit related and is recognized in other comprehensive income, net of applicable taxes.
	The other-than-temporary impairment recognized in other comprehensive income for debt securities classified as held-to-maturity is accreted from other comprehensive income to the amortized cost of the debt security over the remaining life of the debt security in a prospective manner on the basis of the amount and timing of future estimated cash flows.
	Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to yield using the effective interest method. Dividend and interest income are recognized when earned. Realized gains and losses for securities are included in earnings and are derived using the specific identification method for determining the cost of securities sold.
	Originated Loans are reported at the principal amount outstanding net of deferred fees, charge-offs and the allowance for loan losses (“ALLL”). Interest income is accrued daily using the simple interest method. Loans are placed on non-accrual status when Management believes that there is doubt as to the collection of principal or interest, generally when they become contractually past due by ninety days or more with respect to principal or interest, except for loans that are well-secured and in the process of collection. When loans are placed on non-accrual status, any accrued but uncollected interest is reversed from current-period interest income and interest income is recorded only after the loan is brought current or after all principal and past due interest has been collected. For loans whose contractual terms have been restructured in a manner which grants a concession to a borrower experiencing financial difficulties (“troubled debt restructuring”), they are returned to accrual status when there has been a sustained period of repayment performance (generally, six consecutive monthly payments) according to the modified terms and there is reasonable assurance of repayment and of performance.
	Loan origination fees and commitment fees, offset by certain direct loan origination costs, are deferred and amortized as yield adjustments over the contractual lives of the related loans.
	Loan Charge-Off Policy: For all loans types excluding overdraft accounts, we generally make a charge-off determination at or before 90 days past due. A collateral-dependent loan is partially charged down to the fair value of collateral securing it if: (1) it is deemed uncollectable; or (2) it has been classified as a loss by either our internal loan review process or external examiners. A non-collateral-dependent loan is partially charged down to its net realizable value under the same circumstances. Additionally, unless the obligation is both well-secured and in the process of collection, any closed-end loan that exceeds 120 days past due and any open-end loan that exceeds 180 days past due is charged-off.  For overdraft accounts, we generally charge them off when they exceeds 60 days past due.
	Allowance for Loan Losses is based upon estimates of loan losses and is maintained at a level considered adequate to provide for probable losses inherent in the loan portfolio. The allowance is increased by provisions for loan losses charged against earnings and reduced by charge-offs, net of recoveries.
	In periodic evaluations of the adequacy of the allowance balance, Management considers current economic conditions, known and inherent risks in the portfolio, adverse situations that may affect the borrower's ability to repay, the estimated value of any underlying collateral, our past loan loss experience and other factors. The ALLL is based on estimates, and ultimate losses may vary from current estimates. Our Asset/Liability Management Committee (“ALCO”) reviews the adequacy of the ALLL at least quarterly. The allowance is adjusted based on that review if, in the judgment of the ALCO and Management, changes are warranted.
	The overall allowance consists of 1) specific allowances for individually identified impaired loans ("ASC 310-10") and 2) general allowances for pools of loans ("ASC 450-20"), which incorporate changing qualitative and environmental factors (e.g., portfolio growth and trends, credit concentrations, economic and regulatory factors, etc.).
	The first component, specific allowances, result from the analysis of identified problem credits and the evaluation of sources of repayment including collateral, as applicable. Through Management's ongoing loan grading and credit monitoring process, individual loans are identified that have conditions that indicate the borrower may be unable to pay all amounts due in accordance with the contractual terms. These loans are evaluated for impairment individually by Management. Management considers an originated loan to be impaired when it is probable we will be unable to collect all amounts due according to the contractual terms of the loan agreement. For allowance established on acquired loans, refer to Acquired Loans discussed below. When the fair value of the impaired loan is less than the recorded investment in the loan, the difference is recorded as impairment through the establishment of a specific allowance. For loans determined to be impaired, the extent of the impairment is measured based on the present value of expected future cash flows discounted at the loan's effective interest rate at origination (for originated loans), based on the loan's observable market price, or based on the fair value of the collateral if the loan is collateral dependent or if foreclosure is imminent. Generally with problem credits that are collateral-dependent, we obtain appraisals of the collateral at least annually. We may obtain appraisals more frequently if we believe the collateral value is subject to market volatility, if a specific event has occurred to the collateral, or if we believe foreclosure is imminent.
	The second component is an estimate of the probable inherent losses in each loan pool with similar characteristics. Beginning with the quarter-ended September 30, 2013, Management refined the methodology for estimating general allowances in order to provide a more comprehensive evaluation of the potential risk of loss in our loan portfolio. This analysis encompasses our entire loan portfolio and excludes acquired loans where the discount has not been fully accreted. For allowance established on acquired loans, see below under Acquired Loans.
	Under our allowance model, loans are evaluated on a pool basis by loan segment which is further delineated by Federal regulatory reporting codes ("call codes"). Each segment is assigned an expected loss factor which is based on a number of objective and subjective factors. Objective factors include a rolling historical loss rate using a twelve quarter look-back, changes in the volume and nature of the loan portfolio, changes in credit quality metrics (past due loans, non-accrual loans, net charge-offs), and the existence of credit concentrations. Subjective factors include changes in the overall economic environment, legal and regulatory conditions, lending management and other relevant staff, uncertainties related to acquisitions, as well as the quality of our loan review process. The total amount allocated is determined by applying loss multipliers to outstanding loans by call code.
	For further information regarding our ALLL methodology, including a change in methodology in 2013, see Note 4.
	Acquired Loans: From time to time, we acquire loans through business acquisitions. Acquired loans are recorded at their estimated fair values at acquisition date in accordance with ASC 805 Business Combinations, factoring in credit losses expected to be incurred over the life of the loan. Accordingly, an allowance for loan losses is not carried over or recorded for acquired loans as of the acquisition date.
	The process of estimating fair values of the acquired loans, including the estimate of losses that are expected to be incurred over the estimated remaining lives of the loans at acquisition date and the ongoing updates to Management's expectation of future cash flows, requires significant subjective judgments and assumptions, particularly considering the economic environment. The economic environment and the lack of market liquidity and transparency are factors that have influenced, and may continue to affect, these assumptions and estimates.
	We estimated the fair value of acquired loans at the acquisition date based on a discounted cash flow methodology that considered factors including the type of loan and related collateral, risk classification, fixed or variable interest rate, term of loan, whether or not the loan was amortizing, and current discount rates. Loans, except for purchased credit-impaired loans or "PCI loans", were grouped together according to similar characteristics and were treated in the aggregate when applying various valuation techniques. The estimate of expected cash flows incorporates our best estimate of key assumptions, such as property values, default rates, loss severity and prepayment speeds. The discount rates used for loans were based on current market rates for new originations of comparable loans, where available, and include adjustments for liquidity concerns.
	To the extent comparable market rates are not readily available, a discount rate was derived based on the assumptions of market participants' cost of funds, servicing costs and return requirements for comparable risk assets. In either case, the discount rate does not include a factor for credit losses, as that has been considered in estimating the cash flows. The initial estimate of cash flows to be collected was derived from assumptions such as default rates, loss severities and prepayment speeds.
	We acquired some loans from business combinations with evidence of credit quality deterioration subsequent to their origination and for which it was probable, at acquisition, that we would be unable to collect all contractually required payments (PCI loans). These loans are evaluated on an individual basis. Management has applied significant subjective judgment in determining which loans are PCI loans. Evidence of credit quality deterioration as of the purchase date may include data such as past due and nonaccrual status, risk grades and recent loan-to-value percentages. Revolving credit agreements (e.g., home equity lines of credit and revolving commercial loans) where the borrower had revolving privileges at acquisition date are not considered PCI loans because the timing and amount of cash flows cannot be reasonably estimated.
	The accounting guidance for PCI loans provides that the difference between the contractually required payments and the cash flows expected to be collected at acquisition, considering the impact of prepayments, is referred to as the nonaccretable difference and is not recorded. Furthermore, the difference between the expected cash flows and the fair value at acquisition date is accreted into interest income at a level yield of return over the remaining term of the loan, provided that the timing and amount of future cash flows is reasonably estimable.
	The initial estimate of cash flows expected to be collected is updated each quarter and requires the continued usage of key assumptions and estimates similar to the initial estimate of fair value. Given the current economic environment, we apply judgment to develop our estimate of cash flows for PCI loans given the impact of real estate value changes, changing probability of default, loss severities and prepayment speeds.
	For purposes of accounting for the PCI loans from past business combinations, we elected not to apply the pooling method but to account for these loans individually. Disposals of loans, which may include sales of loans to third parties, receipt of payments in full by the borrower, or foreclosure of the collateral, result in removal of the loan from the PCI loan portfolio at its carrying amount.
	All PCI loans that were classified as non-accrual loans prior to the acquisition were no longer classified as non-accrual if we believed that we would fully collect the new carrying value of these loans at acquisition. Subsequent to the acquisition, specific allowances are established for PCI loans that have experienced subsequent credit deterioration. The amount of cash flows expected to be collected and, accordingly, the adequacy of the allowance for loan losses are particularly sensitive to changes in loan credit quality. When there is doubt as to the timing and amount of future cash flows to be collected, PCI loans are classified as non-accrual loans. It is important to note that judgment is required to classify PCI loans as accruing or non-accrual, and is dependent on having a reasonable expectation about the timing and amount of cash flows expected to be collected. If we have probable and significant increases in cash flows expected to be collected on PCI loans, we first reverse any previously established specific allowance for loan loss and then increase interest income as a prospective yield adjustment over the remaining life of the loans. The impact of changes in variable interest rates is recognized prospectively as adjustments to interest income.
	For acquired loans not considered PCI loans, we recognize the entire fair value discount accretion based on the acquired loan's contractual cash flows using an effective interest rate method for term loans, and on a straight line basis to interest income for revolving lines, as the timing and amount of cash flows under revolving lines are not predictable. Subsequent to acquisition, if the probable and estimable losses for non-PCI loans exceed the amount of the remaining unaccreted discount, the excess is established as an allowance for loan losses.
	For further information regarding our acquired loans, see Note 2 and Note 4.
	Transfers of Financial Assets: We have entered into certain participation agreements with other organizations. We account for these transfers of financial assets as sales when control over the transferred financial assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from us, (2) the transferee has the right to pledge or exchange the assets (or beneficial interests) it received, free of conditions that constrain it from taking advantage of that right, and (3) we do not maintain effective control over the transferred financial assets or third-party beneficial interests related to those transferred assets. No gain or loss has been recognized by us on the sale of these participation interests through December 31, 2013.
	Premises and Equipment consist of leasehold improvements, furniture, fixtures, software and equipment and are stated at cost, less accumulated depreciation and amortization, which are calculated on a straight-line basis. Furniture and fixtures are depreciated over eight years and equipment is generally depreciated over three to twenty years. Leasehold improvements are amortized over the lesser of their estimated useful lives or the terms of the leases. When assets are sold or otherwise disposed of, the cost and related accumulated depreciation or amortization are removed from the accounts and any resulting gain or loss is recognized in income for the period. The cost of maintenance and repairs is charged to expense as incurred.
	Other Real Estate Owned ("OREO"): OREO is comprised of property acquired through foreclosure or acceptance of deeds-in-lieu of foreclosure. OREO is recorded at fair value less estimated costs to sell, establishing a new cost basis, and are subsequently accounted for at the lower of cost or fair value less estimated costs to sell. Losses recognized at the time of acquiring property in full or partial satisfaction of debt are charged against the allowance for loan losses. Fair value is generally based on an independent appraisal of the property. Revenues and expenses associated with OREO, and subsequent adjustments to the fair value of the property and to the estimated costs of disposal, are realized and reported as a component of non-interest expense when incurred.
	Employee Stock Ownership Plan (“ESOP”): We recognize compensation cost of the ESOP contribution when funds become committed for the purchase of Bancorp's common shares into the ESOP in the year in which the employees render service entitling them to the contribution. If we contribute stock, the compensation cost is the fair value of the shares when they are committed to be released, i.e. when the number of shares becomes known. During 2013 and 2012, the Bank only made cash contributions to the ESOP without leveraging.
	Income Taxes reported in the consolidated financial statements are computed based on an asset and liability approach. We recognize the amount of taxes payable or refundable for the current year, and deferred tax assets and liabilities for the future tax consequences that have been recognized in the financial statement or tax returns. The measurement of tax assets and liabilities is based on the provisions of enacted tax laws. Bancorp files consolidated federal and combined state income tax returns.
	Earnings per share (“EPS”) are based upon the weighted average number of common shares outstanding during each year. The following table shows: 1) weighted average basic shares, 2) potential common shares related to stock options, unvested restricted stock and stock warrant, and 3) weighted average diluted shares. Basic earnings per share (“EPS”) are calculated by dividing net income by the weighted average number of common shares outstanding during each period, excluding unvested restricted stock. Diluted EPS are calculated using the weighted average diluted shares. The number of potential common shares included in quarterly diluted EPS is computed using the average market prices during the three months included in the reporting period under the treasury stock method. The number of potential common shares included in year-to-date diluted EPS is a year-to-date weighted average of potential common shares included in each quarterly diluted EPS computation. We have two forms of our outstanding common stock: common stock and unvested restricted stock awards. Holders of restricted stock awards receive non-forfeitable dividends at the same rate as common shareholders and they both share equally in undistributed earnings.
	(in thousands, except per share data)	2013		2012		2011
	Weighted average basic shares outstanding	5,457		5,341		5,302
	Add: Potential common shares related to stock options	44		47		41
	Potential common shares related to unvested restricted stock awards	4		5		4
	Potential common shares related to warrants	53		45		37
	Weighted average diluted shares outstanding	5,558		5,438		5,384
	Net income	$	14,270	$	17,817	$	15,564
	Basic EPS	$	2.62	$	3.34	$	2.94
	Diluted EPS	$	2.57	$	3.28	$	2.89
	Weighted average anti-dilutive shares not included in the calculation of diluted EPS	49		50		70
	Share-Based Compensation: All share-based payments granted subsequent to January 1, 2006, including stock options and restricted stock, are recognized as stock-based compensation expense in the statements of comprehensive income based on the grant-date fair value of the award with a corresponding increase in common stock. The grant-date fair value of the award is amortized on a straight-line basis over the requisite service period, which is generally the vesting period. The stock-based compensation expense excludes stock grants to directors as compensation for their services, which are recognized as director expenses separately based on the grant-date value of the stock. See Note 9 for further discussion.
	We determine fair value of stock options at grant date using the Black-Scholes pricing model that takes into account the stock price at the grant date, the exercise price, the expected life of the option, the volatility of the underlying stock, the expected dividend yield and the risk-free interest rate over the expected life of the option. The Black-Scholes option valuation model requires the input of highly subjective assumptions, including the expected life of the stock-based award and stock price volatility. The assumptions used represent Management's best estimates based on historical information, but these estimates involve inherent uncertainties and the application of Management's judgment. As a result, if other assumptions had been used, the recorded stock-based compensation expense could have been materially different from that recorded in the consolidated financial statements. In addition, we are required to estimate the expected forfeiture rates. If our actual forfeiture rate is materially different from the estimate, the share-based compensation expense could be materially different. Fair value of restricted stock is based on the stock price on grant date.
	Derivative Financial Instruments and Hedging Activities
	Fair Value Hedges: All of our interest rate swap contracts are designated and qualified as fair value hedges. We apply shortcut hedge accounting for one of our interest rate swap contracts, as it is structured to mirror all of the provisions of the hedged loan agreement. This interest rate swap is carried on the consolidated statements of condition at its fair value in other assets (when the fair value is positive) or in other liabilities (when the fair value is negative). The change in the fair value of the interest rate swap is recorded in other non-interest income. As a result of interest rate fluctuations, the hedged fixed-rate loan also gains or loses value. The unrealized gain or loss resulting from the change in fair value of the hedged-loan is recorded as an adjustment to the hedged loan and offset in other non-interest income. Under shortcut hedge accounting treatment, the change in fair value of the interest rate swap is deemed perfectly offset by the change in fair value of the hedged loan, resulting in zero impact to net income.
	The eight remaining interest rate swap contracts are accounted for using non-shortcut hedge accounting treatment. The interest rate swaps are closely aligned to the terms of the designated fixed-rate loans. The hedging relationships are tested for effectiveness on a quarterly basis. The interest rate swaps are carried on the consolidated statements of condition at their fair value in other assets (when the fair value is positive) or in other liabilities (when the fair value is negative). The changes in the fair value of the interest rate swaps are recorded in interest income. The unrealized gains or losses due to changes in fair value of the hedged fixed-rate loans are recorded as an adjustment to the hedged loans and offset in interest income. For derivative instruments executed with the same counterparty under a master netting arrangement, we do not offset fair value amounts of interest rate swaps in liability position with the ones in asset position. For further detail, see Note 15.
	Advertising Costs are expensed as incurred. For the years ended December 31, 2013, 2012, and 2011, advertising costs totaled $490 thousand, $541 thousand, and $589 thousand, respectively.
	Comprehensive Income for Bancorp includes net income reported on the statements of comprehensive income and changes in the fair value of investment securities available-for-sale, net of related taxes, reported on the statements of comprehensive income and as a component of stockholders' equity.
	Segment Information: Our two operating segments include the traditional community banking activities provided through our branch network and our Wealth Management and Trust Services (“WMTS”). The activities of these two segments are monitored and reported by Management as separate operating segments. The accounting policies of the segments are the same as those described in this note. We evaluate segment performance based on total segment revenue and do not allocate expenses between the segments. WMTS revenues were $2.2 million, $2.0 million and $1.8 million in 2013, 2012 and 2011, respectively, which are included in non-interest income in the statements of comprehensive income. Non-interest expenses applicable to WMTS totaled $1.5 million, $1.4 million and $1.3 million in 2013, 2012 and 2011, respectively. Income tax applicable to WMTS totaled $220 thousand, $200 thousand and $184 thousand in 2013, 2012 and 2011, respectively, which resulted in after-tax income of $394 thousand, $327 thousand and $312 thousand in those respective periods. The revenues of the community banking segment are reflected in all other income lines in the consolidated statements of income.
	Use of Estimates: The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires Management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Significant accounting estimates reflected in the consolidated financial statements include ALLL, other-than-temporary impairment of investment securities, estimated cash flows on PCI loans, accounting for income taxes and fair value measurements (including fair values of acquired assets and assumed liabilities at acquisition dates) as discussed in the Notes herein.
	Recently Issued Accounting Standards
	In December 2011, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2011-11 Balance Sheet (Topic 210) Disclosures about Offsetting Assets and Liabilities. The ASU enhances disclosures in order to improve the comparability of offsetting (netting) assets and liabilities reported in accordance with U.S. generally accepted accounting principles (“GAAP”) and International Financial Reporting Standards (“IFRS”) by requiring entities to disclose both gross information and net information about both instruments and transactions eligible for offset in the statements of condition and instruments and transactions subject to an agreement similar to a master netting arrangement.
	In January 2013, the FASB issued ASU No. 2013-01 Balance Sheet (Topic 210) Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities, which clarifies that ordinary trade receivables and receivables are not in the scope of ASU 2011-11. It further clarifies that the scope of ASU No. 2011-11 applies to derivatives, repurchase agreements and reverse repurchase agreements, and securities borrowing and securities lending transactions that are either offset in accordance with specific criteria contained in FASB Accounting Standards Codification® or subject to a master netting arrangement or similar agreement. Both ASU 2011-11 and ASU 2013-01 are effective for annual periods beginning on or after January 1, 2013, and interim periods within those annual periods. We adopted these ASUs in the first quarter of 2013. This ASU affects presentation only and therefore there is no financial statement impact on our financial condition or results of operations. See Note 15.
	In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220) Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. The ASU requires entities to present separately by component reclassifications out of accumulated other comprehensive income. An entity is required to disclose in the notes of the financial statements or parenthetically on the face of the financial statements the effect of significant items reclassified out of accumulated other comprehensive income on the respective line items of net income, but only if the item reclassified is required under U.S. GAAP to be reclassified to net income in its entirety. ASU 2013-02 is effective for fiscal years, and interim periods beginning on or after December 15, 2012 for public entities. We adopted this ASU in the first quarter of 2013. This ASU affects presentation only and therefore there is no financial statement impact on our financial condition or results of operations. See the consolidated statements of comprehensive income.
	In February 2013, the FASB issued ASU No. 2013-04, Liabilities (Topic 405) Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation is Fixed at the Reporting Date. The ASU requires an entity to measure obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. Entities are required to record the amount the entity agreed to pay on the basis of its arrangement among its co-obligors and any additional amount the reporting entity expects to pay on behalf of its co-obligors at the reporting date. Examples of obligations within the scope of this guidance include debt arrangements, other contractual obligations, settled litigation and judicial rulings. ASU 2013-04 is effective retrospectively to all periods presented for fiscal years and interim periods beginning after December 15, 2013 for public entities. We do not expect this ASU to have a significant impact on our financial condition or results of operations.
	In July 2013, the FASB issued ASU No. 2013-10, Derivatives and Hedging (Topic 815) Inclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedging Accounting Purposes.
The ASU provides for the inclusion of the Fed Funds Effective Swap Rate or also referred to as the Overnight Index Swap Rate ("OIS") as a U.S. benchmark interest rate for hedge accounting purposes, in addition to direct Treasury obligations of the U.S. government ("UST") and London Interbank Offered Rate ("LIBOR"). The ASU is a result of the financial crisis in 2008, as the exposure to and the demand for hedging the Fund Funds rate have increased significantly. ASU 2013-10 is effective prospectively for qualifying new or re-designated hedging relationships entered into on or after July 17, 2013. We do not expect this ASU to have a significant impact on our financial condition or results of operations.
In July 2013, the FASB issued ASU No. 2013-11, Income Taxes (Topic 740) Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The ASU requires that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward except as follows. To the extent that a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date to settle any additional income taxes that would result from the disallowance of a tax position, or the tax law does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purposes, then the unrecognized tax benefit should be presented as a liability.
ASU 2013-11 is effective prospectively for fiscal years, and interim periods beginning after December 15, 2013 for public entities. We do not expect this ASU to have a significant impact on our financial condition or results of operations.
In January 2014, the FASB issued ASU No. 2014-01, Investments-Equity and Joint Ventures (Topic 323) Accounting for Investments in Qualified Affordable Projects. This ASU permits entities to make an accounting policy election to account for their investments in qualified affordable housing projects using the proportional amortization method if certain conditions are met. Under the proportional amortization method, the initial cost of the investment is amortized in proportion to the tax credits and other tax benefits received and the net investment performance is recognized in the income statement as part of income tax expense (benefit). We plan on adopting this ASU starting in 2014 and elect to account for all low income housing investments using the proportional amortization method instead of cost method. The change in accounting policy will not have a significant impact on our financial condition or results of operations.
In January 2014, the FASB issued ASU No. 2014-04, Receivables - Troubled Debt Restructurings by Creditors (Subtopic 310-40) Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure. Current accounting literature on troubled debt restructurings include guidance on when a creditor obtains one or more collateral assets in satisfaction of all or part of the receivable. The accounting literature indicates that a creditor should reclassify a collateralized mortgage loan such that the loan should be de-recognized and the collateral asset recognized when it is determined that there has been in substance a repossession or foreclosure by the creditor. However, in substance a repossession or foreclosure and physical possession are not currently defined and there is diversity about when a creditor should de-recognize the loan receivable and recognize the real estate property. This ASU clarifies when an in substance repossession or foreclosure occurs. ASU 2014-04 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2014 for public entities. We do not expect this ASU to have a significant impact on our financial condition or results of operations.

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Acquisition	'
	Acquisition
	On February 18, 2011, we entered into a modified whole-bank purchase and assumption agreement without loss share (the “P&A Agreement”) with the Federal Deposit Insurance Corporation (the “FDIC”), the receiver of Charter Oak Bank of Napa, California. We purchased $107.8 million in assets and assumed $107.7 million in liabilities from the former Charter Oak Bank to enhance our market presence. The P&A Agreement only covered designated assets and liabilities of Charter Oak Bank. Common stock of Charter Oak Bank, certain assets and certain liabilities, such as claims against any officer, director, employee, accountant, attorney, or any other person employed by the former Charter Oak Bank, were not purchased or assumed by us. We recorded an $85 thousand bargain purchase gain which represents the excess of the estimated fair value of the assets acquired over the estimated fair value of the liabilities assumed.
	On November 29, 2013, we completed the merger of NorCal, parent company of Bank of Alameda, to enhance our market presence. The merger added 173.8 million in loans, $241.0 million in deposits and $53.7 million in investment securities to Bank of Marin as well as four branch offices serving Alameda, Emeryville, and Oakland. The assets acquired and liabilities assumed, both tangible and intangible, were recorded at their fair values as of the acquisition date in accordance with ASC 805, Business Combinations. These fair value estimates are subject to change for up to one year after the acquisition date as additional information relative to acquisition date fair values becomes available. The acquisition was treated as a "reorganization" within the definition of section 368(a) of the Internal Revenue Code and is generally considered tax-free for U.S. federal income tax purposes.
	The following table reflects the estimated fair values of the assets acquired and liabilities assumed related to the NorCal Acquisition:
	(Dollars in thousands)		Acquisition Date (November 29, 2013)
	Assets:
	Cash and cash equivalents		$	31,804
	Investment securities		53,731
	Loans		173,759
	Core deposit intangible		4,572
	Deferred tax asset		4,114
	Goodwill		6,435
	Bank premises and equipment		203
	Other assets		6,299
	Total assets acquired		$	280,917
	Liabilities:
	Deposits:
	Non-interest bearing		$	69,123
	Interest bearing
	Transaction accounts		57,337
	Savings accounts		10,835
	Money market accounts		81,464
	Other time accounts		22,267
	Total deposits		241,026
	Subordinated debentures		4,950
	Other liabilities		408
	Total liabilities assumed		$	246,384
	Merger consideration (cash payment of $16.019 million and $18.514 million in stock)		$	34,533
	The following table presents the net assets acquired from NorCal and the estimated fair value adjustments:
	(Dollars in thousands)		Acquisition Date (November 29, 2013)
	Book value of net assets acquired from NorCal		$	25,552
	Fair value adjustments:
	Loans		(3,462		)
	Subordinated debentures		3,298
	Core deposit intangible asset		$	4,572
	Time deposits		(14		)
	Total purchase accounting adjustments		4,394
	Deferred tax liabilities (tax effect of purchase accounting adjustments at 42.05%)		(1,848		)
	Fair value of net assets acquired from NorCal		$	28,098
	Merger consideration		$	34,533
	Less: fair value of net assets acquired		(28,098		)
	Goodwill		$	6,435
	Goodwill represents the excess of the total purchase price paid over the fair value of the assets acquired, net of the fair values of liabilities assumed. It arises mainly from expected synergies from combined operations of NorCal and Bank of Marin. It is evaluated for impairment annually. We determined that the fair value of our Community Banking segment exceeded its carrying amount and no impairment on goodwill was recorded in 2013. The goodwill is not expected to be deductible for tax purposes. The following is a description of the methods used to determine the fair values of significant assets and liabilities at acquisition date presented above.
	Loans
	The fair values for acquired loans were developed based upon the present values of the expected cash flows utilizing market-derived discount rates. Expected cash flows for each acquired loan were projected based on contractual cash flows adjusted for expected prepayment, expected default (i.e. probability of default and loss severity), and principal recovery.
	Prepayment rates were applied to the principal outstanding based on the type of loan, where appropriate. Prepayments were based on a constant prepayment rate (“CPR”) applied across the life of a loan. We used annual CPRs between 0 percent and 5 percent, depending on the characteristics of the loan pool (e.g. construction, commercial real estate, etc.).
	Non-credit-impaired loans with similar characteristics were grouped together and were treated in the aggregate when applying the discount rate on the expected cash flows. Aggregation factors considered included the type of loan and related collateral, risk classification, fixed or variable interest rate, term of loan and whether or not the loan was amortizing. The discount rates used for the similar groups of loans were based on current market rates for new originations of comparable loans, where available, and include adjustments for credit and liquidity factors. To the extent comparable market rates are not readily available, a discount rate was derived based on the assumptions of a market participant's cost of funds, servicing costs, and return requirements for comparable risk assets. Purchased credit-impaired loans were valued on an individual basis. See Note 4 for additional information.
	Subordinated Debentures
	The discounted cash flow method was used to establish the fair value of the subordinated debentures. In determining the fair value, cash flows were projected through the remaining term of the issuances. As the issuances are variable rate, to determine the cash flows, future interest payments were determined based on forward rates plus the stated margin.
	The cash flows were then discounted to their present values. Each payment was discounted at a spot rate that was determined based on the yields and terms of comparable issuances. We recognized the effects of illiquidity associated with size and the lack of marketability of the securities through the inclusion of an additional premium.
	Core Deposit Intangible
	The core deposit intangible represents estimated future benefits of acquired deposits and is booked separately from the liability in other assets. The value of the core deposit intangible asset was determined using a discounted cash flow approach to arrive at the cost differential between the core deposits (non-maturity deposits such as checking, savings and money market accounts) and alternative funding sources. It is calculated as the present value of the   difference  in  cash flows between maintaining the  existing  deposits (interest  and  net  maintenance  costs) and the cost of an equal amount of  funds from an alternative source having a similar term as the deposit  base. It is amortized on an accelerated basis over an estimated ten-year life. The core deposit intangible asset is evaluated periodically for impairment, and no impairment loss was recognized in 2013.
	We recorded a core deposit intangible asset of $4.6 million at Acquisition, of which $69 thousand was amortized in 2013. At December 31, 2013, the future estimated amortization expense is as follows:
	(in thousands)	2014			2015			2016			2017			2018		Thereafter		Total
	Core deposit intangible amortization	$	771		$	619		$	533		$	472		$	413	$	1,695	$	4,503
	Deposits
	The fair values used for the retail DDA and NOW deposits were equal to the amounts payable on demand at the acquisition date. The fair values for time deposits were estimated using a discounted cash flow calculation that applied interest rates offered by market participants as of the acquisition date on time deposits with similar maturity terms as the discount rates.
	Pro Forma Results of Operations
	The contribution of the acquired operations of the former NorCal Community Bancorp to our results of operations for the period November 29 to December 31, 2013 is as follows: interest income of $1.1 million, interest expense of $68 thousand, non-interest income of $95 thousand, non-interest expense of $1.1 million and income before income taxes of $109 thousand. These amounts include acquisition-related costs, accretion of the discount on the acquired loans, amortization of the fair value mark on time deposits, core deposit intangible amortization, and subordinated debentures amortization. NorCal Community Bancorp's results of operations prior to the acquisition date are not included in our operating results for 2013.
	The following table presents NorCal Community Bancorp's revenue (interest income and non-interest income) and earnings included in our consolidated statement of comprehensive income for the year ended December 31, 2013, and the revenue and earnings of the combined entity had the acquisition date been January 1, 2012. This pro forma information does not necessarily reflect the results of operations that would have resulted had the acquisition been completed at the beginning of the periods presented, nor is it indicative of the results of operations in future periods.
	Pro Forma Revenue and Earnings		NorCal Community Bancorp Only							Combined
	(in thousands; unaudited)		Revenue			Earnings				Revenue			Earnings
	Actual from November 29, 2013 to December 31, 2013		$	1,239		$	70			$	6,984		$	963
2013 supplemental pro forma from January 1, 2013 to December 31, 2013		12,199			315				68,626			14,270
2013 supplemental pro forma from January 1, 2013 to December 31, 20131		12,199			1,506				68,626			17,866
2012 supplemental pro forma from January 1, 2012 to December 31, 20121		12,433			(2,841		)		85,310			13,731
1  2013 supplemental pro forma earnings were adjusted to exclude $3.7 million of one-time acquisition related expenses booked at Bank of Marin Bancorp and $1.9 million of one-time acquisition related expenses booked at NorCal Community Bancorp in 2013. 2012 supplemental pro forma earnings were adjusted to include these charges.
Acquisition-related expenses are recognized as incurred and continue until all systems have been converted and operational functions become fully integrated. We incurred one-time third-party acquisition-related expenses in the consolidated statements of comprehensive income in 2013 for the NorCal acquisition and in 2011 for the Charter Oak acquisition as follows:
	2013 NorCal Acquisition				2011 Charter Oak Acquisition
(Dollars in thousands)	Year Ended December 31, 2013				Year Ended December 31, 2011
Data processing	$	2,807		*	$	455
Professional services	660				457
Personnel severance	203				—
Other	74				88
Total	$	3,744			$	1,000
*Primarily relates to NorCal's core processing system contract termination and deconversion fees.

Investment_Securities

Investment Securities	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Investment Securities	'
	Investment Securities
	Our investment securities portfolio consists of obligations of state and political subdivisions, corporate bonds, U.S. government agency securities, including mortgage-backed securities (“MBS”) and collateralized mortgage obligations (“CMOs”) issued or guaranteed by Federal National Mortgage Association ("FNMA"), Federal Home Loan Mortgage Corporation ("FHLMC"), or Government National Mortgage Association ("GNMA"), debentures issued by government-sponsored agencies such as FNMA and FHLMC, as well as privately issued CMOs, as reflected in the table below:
		31-Dec-13													31-Dec-12
		Amortized			Fair			Gross Unrealized							Amortized			Fair			Gross Unrealized
	(in thousands;)	Cost			Value			Gains			(Losses)				Cost			Value			Gains			(Losses)
	Held-to-maturity
	Obligations of state and	$	80,381		$	81,429		$	1,764		$	(716	)		$	96,922		$	99,350		$	2,855		$	(427	)
	political subdivisions
	Corporate bonds	42,114			42,429			375			(60		)		42,530			42,881			458			(107		)
	Total held-to-maturity	122,495			123,858			2,139			(776		)		139,452			142,231			3,313			-534
	Available-for-sale
	Securities of U. S. government agencies:
	MBS pass-through securities issued by FHLMC and FNMA	124,063			123,033			616			(1,646		)		52,042			53,713			1,711			(40		)
	CMOs issued by FNMA	18,573			18,438			60			(195		)		4,447			4,550			105			(2		)
	CMOs issued by FHLMC	23,710			23,679			144			(175		)		13,527			13,778			251			—
	CMOs issued by GNMA	24,944			25,454			609			(99		)		38,871			39,756			886			(1		)
	Debentures of government- sponsored agencies	21,845			21,312			108			(641		)		20,462			20,589			228			(101		)
	Privately issued CMOs	10,649			10,874			257			(32		)		21,071			21,576			595			(90		)
	Obligations of state and	15,948			15,771			14			(191		)		—			—			—			—
	political subdivisions
	Corporate bonds	5,426			5,437			25			(14		)		—			—			—			—
	Total available-for-sale	245,158			243,998			1,833			(2,993		)		150,420			153,962			3,776			-234
	Total investment securities	$	367,653		$	367,856		$	3,972		$	(3,769	)		$	289,872		$	296,193		$	7,089		$	(768	)
	The amortized cost and fair value of investment debt securities by contractual maturity at December 31, 2013 and 2012 are shown below. Expected maturities will differ from contractual maturities because the issuers of the securities may have the right to call or prepay obligations with or without call or prepayment penalties.
		December 31, 2013															31-Dec-12
		Held-to-Maturity								Available-for-Sale							Held-to-Maturity								Available-for-Sale
	(in thousands)	Amortized Cost				Fair Value				Amortized Cost				Fair Value			Amortized Cost				Fair Value				Amortized Cost		Fair Value
	Within one year	$	8,731			$	8,784			$	5,522			$	5,521		$	764			$	763			$	—	$	—
	After one but within five years	88,255				89,095				42,229				42,338			98,672				99,689				26,417		27,060
	After five years through ten years	24,244				24,786				26,232				25,478			29,165				30,898				23,719		23,820
	After ten years	1,265				1,193				171,175				170,661			10,851				10,881				100,284		103,082
	Total	$	122,495			$	123,858			$	245,158			$	243,998		$	139,452			$	142,231			$	150,420	$	153,962
	$8.0 million of available-for-sale securities were sold in 2013, resulting in net proceeds from sales of $8.0 million and net losses of $18 thousand. During 2013, we also sold $6.4 million of held-to-maturity securities due to evidence of significant deterioration of credit worthiness since purchase. The proceeds from the sales totaled $6.4 million and the transactions resulted in net gains of $17 thousand. One available-for-sale security was sold in 2012 with proceeds of $2.2 million and a loss of $34 thousand.
	Investment securities carried at $61.8 million and $47.7 million at December 31, 2013 and December 31, 2012, respectively, were pledged with the State of California: $61.1 million and $47 million to secure public deposits in compliance with the Local Agency Security Program at December 31, 2013 and 2012, respectively, and $732 thousand and $719 thousand to provide collateral for trust deposits at December 31, 2013 and 2012, respectively. In addition, investment securities carried at $1.1 million were pledged to collateralize an internal Wealth Management and Trust Services (“WMTS”) checking account at both December 31, 2013 and 2012.
	Other-Than-Temporarily Impaired Debt Securities
	The table below shows investment securities that were in unrealized loss positions at December 31, 2013 and December 31, 2012, respectively. They are summarized and classified according to the duration of the loss period as follows:
	December 31, 2013		< 12 continuous months								> 12 continuous months								Total securities
																			in a loss position
	(In thousands)		Fair value				Unrealized loss				Fair value				Unrealized loss				Fair value				Unrealized loss
	Held-to-maturity
	Obligations of state & political subdivisions		$	13,933			$	(419	)		$	9,033			$	(297	)		$	22,966			$	(716	)
	Corporate bonds		3,017				(11		)		4,963				(49		)		7,980				(60		)
	Total held-to-maturity		16,950				(430		)		13,996				(346		)		30,946				(776		)
	Available-for-sale
	MBS pass-through securities issued by FHLMC and FNMA		90,914				(1,297		)		3,172				(349		)		94,086				(1,646		)
	CMOs issued by FNMA		17,535				(195		)		—				—				17,535				(195		)
	CMOs issued by FHLMC		17,899				(175		)		—				—				17,899				(175		)
	CMOs issued by GNMA		3,966				(99		)		—				—				3,966				(99		)
	Debentures of government- sponsored agencies		16,872				(641		)		—				—				16,872				(641		)
	Privately issued CMOs		4,634				(31		)		159				(1		)		4,793				(32		)
	Obligations of state & political subdivisions		11,516				(191		)		—				—				11,516				(191		)
	Corporate bonds		1,479				(14		)		—				—				1,479				(14		)
	Total available-for-sale		164,815				(2,643		)		3,331				(350		)		168,146				(2,993		)
	Total temporarily impaired securities		$	181,765			$	(3,073	)		$	17,327			$	(696	)		$	199,092			$	(3,769	)
	December 31, 2012		< 12 continuous months								> 12 continuous months								Total securities
																			in a loss position
	(In thousands)		Fair value				Unrealized loss				Fair value				Unrealized loss				Fair value				Unrealized loss
	Held-to-maturity
	Obligations of state & political subdivisions		$	33,196			$	(427	)		$	—			$	—			$	33,196			$	(427	)
	Corporate bonds		15,649				(107		)		—				—				15,649				(107		)
	Total held-to-maturity		48,845				(534		)		—				—				48,845				(534		)
	Available-for-sale
	MBS pass-through securities issued by FHLMC and FNMA		3,569				(40		)		—				—				3,569				(40		)
CMOs issued by FNMA		3,185				(2		)		—				—				3,185				(2		)
CMOs issued by GNMA		1,550				(1		)		—				—				1,550				(1		)
Debentures of government- sponsored agencies		9,899				(101		)		—				—				9,899				(101		)
Privately issued CMOs		4,214				(89		)		203				(1		)		4,417				(90		)
Total available-for-sale		22,417				(233		)		203				(1		)		22,620				(234		)
Total temporarily impaired securities		$	71,262			$	(767	)		$	203			$	(1	)		$	71,465			$	(768	)
As of December 31, 2013, there were fourteen investment positions totaling $17.3 million that had been in a continuous loss position for more than 12 months. These securities had an unrealized loss of $696 thousand and consisted of U.S. state and political subdivisions, corporate bonds, MBS and privately issued CMOs. We have evaluated each of the bonds and believe that the decline in fair value is primarily driven by factors other than credit. It is probable that we will be able to collect all amounts due according to the contractual terms and no other-than-temporary impairment exists. MBS are supported by the U.S. Federal government to protect us from credit losses. Additionally, the obligations of state and political subdivisions and corporate bonds were rated as investment grade by at least one rating agency. The CMO is collateralized by residential mortgages with low loan-to-value and delinquency ratios, may be prepaid at par prior to maturity and is rated AA+ by Standard & Poors. Based upon our assessment of expected credit losses given the performance of the underlying collateral and the credit enhancements, we concluded that the security was not other-than-temporarily impaired at December 31, 2013.
Investment securities in our portfolio that were in a temporary loss position for less than twelve months as of December 31, 2013 consisted of eighty-one U.S. state and political subdivisions, corporate bonds, MBS, CMOs, Debentures and privately issued CMOs. We determine that the strengths of GNMA and FNMA through guarantee or support from the U.S. Federal Government are sufficient to protect us from credit losses. The other temporarily impaired securities are deemed credit worthy after our internal analysis. Additionally, all are rated as investment grade by at least one major rating agency. We also monitor the financial information of the issuers of obligations of U.S. states and political subdivisions. As a result of this impairment analysis, we concluded that these securities were not other-than-temporarily impaired at December 31, 2013.
In January 2014, we sold a $2.0 million available-for-sale security that was temporarily impaired at December 31, 2013. The security had recovered essentially all of its amortized cost basis, and the sale resulted in a net loss of approximately $15 thousand. We do not have the intent, and it is more likely than not that we will not have to sell the remaining securities temporarily impaired at December 31, 2013 before recovery of the cost basis.
Securities Carried at Cost
As a member of the FHLB, we are required to maintain a minimum investment in the FHLB capital stock determined by the Board of Directors of the FHLB. The minimum investment requirements can increase in the event we increase our borrowings with the FHLB. Shares cannot be purchased or sold except between the FHLB and its members at $100 per share par value. We held $7.8 million and $6.0 million of FHLB stock recorded at cost in other assets at December 31, 2013 and 2012, respectively. On February 20, 2014, FHLB declared a cash dividend for the fourth quarter of 2013 at an annualized dividend rate of 6.67%. Management does not believe that the FHLB stock is other-than-temporarily-impaired, as we expect to be able to redeem this stock at cost.
As a member bank of Visa U.S.A., we hold 16,939 shares of Visa Inc. Class B common stock with a carrying value of zero, which is equal to our cost basis. These shares are restricted from resale until their conversion into Class A (voting) shares upon the termination of Visa Inc.'s covered litigation escrow account. As a result of the restriction, these shares are not considered available-for-sale and are not carried at fair value. The fair value of the Class B common stock we own was $1.6 million and $1.1 million at December 31, 2013 and 2012, respectively, based on the Class A as-converted rate of 0.4206, which is subject to further reduction upon the final settlement of the covered litigation against Visa Inc. and its member banks. See Note 13 herein.

Loans_and_Allowance_for_Loan_L

Loans and Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2013
Receivables [Abstract]	'
Loans and Allowance for Loan Losses	'
	Loans and Allowance for Loan Losses
	Credit Quality of Loans
	The majority of our loan activity is with customers located in California, primarily in the counties of Marin, Sonoma, Alameda, San Francisco and Napa. At December 31, 2013, 68% of our loans are for commercial real estate, 83% of which are secured by real estate located in Marin, Sonoma, Alameda, San Francisco and Napa counties (California). Approximately 86% and 85% of total loans were secured by real estate, while 2% and 3% were unsecured at both December 31, 2013 and 2012, respectively.
	Outstanding loans by class and payment aging as of December 31, 2013 and 2012 are as follows:
	Loan Aging Analysis by Class as of December 31, 2013 and 2012
	(dollars in thousands)	Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential 1				Installment and other consumer				Total
	31-Dec-13
	30-59 days past due	$	18			$	—			$	—			$	—			$	240			$	717			$	17			$	992
	60-89 days past due	—				—				—				—				—				—				3				3
	Greater than 90 days past due (non-accrual) 2	1,187				1,403				2,807				5,218				234				660				169				11,678
	Total past due	1,205				1,403				2,807				5,218				474				1,377				189				12,673
	Current	182,086				239,710				622,212				26,359				97,995				71,257				17,030				1,256,649
	Total loans 3	$	183,291			$	241,113			$	625,019			$	31,577			$	98,469			$	72,634			$	17,219			$	1,269,322
	Non-accrual loans to total loans	0.6		%		0.6		%		0.4		%		16.5		%		0.2		%		0.9		%		1		%		0.9		%
	December 31, 2012
	30-59 days past due	$	29			$	—			$	—			$	—			$	294			$	167			$	98			$	588
	60-89 days past due	—				—				—				—				—				—				—				—
	Greater than 90 days past due (non-accrual) 2	4,893				1,403				6,843				2,239				545				1,196				533				17,652
	Total past due	4,922				1,403				6,843				2,239				839				1,363				631				18,240
	Current	171,509				195,003				502,163				28,426				92,398				48,069				18,144				1,055,712
	Total loans 3	$	176,431			$	196,406			$	509,006			$	30,665			$	93,237			$	49,432			$	18,775			$	1,073,952
	Non-accrual loans to total loans	2.8		%		0.7		%		1.3		%		7.3		%		0.6		%		2.4		%		2.8		%		1.6		%
	1 Our residential loan portfolio includes no sub-prime loans, nor is it our normal practice to underwrite loans commonly referred to as "Alt-A mortgages," the characteristics of which are loans lacking full documentation, borrowers having low FICO scores or higher loan-to-value ratios.
	2 Amounts include $1.4 million and $1.6 million of Purchased Credit Impaired ("PCI") loans that have stopped accreting interest at December 31, 2013 and 2012, respectively, and exclude accreting PCI loans of $5.7 million and $3.0 million at December 31, 2013 and 2012, respectively, as their accretable yield interest recognition is independent from the underlying contractual loan delinquency status. There were no accruing loans past due more than ninety days at December 31, 2013 or 2012.
	3 Amounts were net of deferred loan (costs)/fees of $(24) thousand and $769 thousand at December 31, 2013 and 2012, respectively. Amounts were also net of unaccreted purchase discounts on non-PCI loans of $7.6 million and $2.1 million at December 31, 2013 and 2012, respectively.
	Our commercial loans are generally made to established small to mid-sized businesses to provide financing for their working capital needs, acquisitions, or refinancings.  Management examines historical, current, and projected cash flows to determine the ability of the borrower to repay obligations as agreed. Commercial loans are primarily made based on the identified cash flows of the borrower and secondarily on the underlying collateral. The cash flows of borrowers, however, may not occur as expected, and the collateral securing these loans may fluctuate in value. Most commercial and industrial loans are secured by the assets being financed, such as accounts receivable or inventory, and include a personal guarantee. Some short-term loans may be made on an unsecured basis. We target stable local businesses with guarantors that have proven to be more resilient in periods of economic stress.  Typically, the guarantors provide an additional source of repayment for most of our credit extensions.
	Commercial real estate loans are subject to underwriting standards and processes similar to commercial loans discussed above. We underwrite these loans to be repaid from cash flow and to be supported by real property collateral. Repayment of commercial real estate loans is largely dependent on the successful operation of the property securing the loan, or of the business conducted on the property securing the loan. Underwriting standards for commercial real estate loans include, but are not limited to, conservative debt coverage and loan-to-value ratios. Furthermore, substantially all of our loans are guaranteed by the owners of the properties.  Commercial real estate loans may be adversely affected by conditions in the real estate markets or in the general economy. In the event of a vacancy, strong guarantors have historically carried the loans until a replacement tenant can be found.  The owner's substantial equity investment provides a strong economic incentive to continue to support the commercial real estate projects. As such, we have generally experienced a relatively low level of loss and delinquencies in this portfolio.
	Construction loans are generally made to developers and builders to finance land acquisition as well as the subsequent construction. These loans are underwritten after evaluation of the borrower's financial strength, reputation, prior track record, and after obtaining independent appraisals. The construction industry can be impacted by major factors, including: the inherent volatility of real estate markets and vulnerability to delays due to weather, change orders, ability to obtain construction permits, labor or material shortages, and price hikes. Estimates of construction costs and value associated with the complete project may be inaccurate. Repayment of construction loans is largely dependent on the ultimate success of the project.
	Consumer loans primarily consist of home equity lines of credit, other residential (tenancy-in-common, or “TIC”) loans, and other personal loans. We originate consumer loans utilizing credit score information, debt-to-income ratio and loan-to-value ratio analysis. This activity, coupled with relatively small loan amounts that are spread across many individual borrowers, mitigates risk. Additionally, trend reports are reviewed by Management on a regular basis. Underwriting standards for home equity lines of credit include, but are not limited to, a conservative loan-to-value ratio, the number of such loans a borrower can have at one time, and documentation requirements. Our underwriting of the other residential loans, mostly secured by TIC units in San Francisco, is cautious compared to traditional residential mortgages due to the unique ownership structure.  In addition, these borrowers tend to have more equity in their properties, which mitigates risk. Personal loans are nearly evenly split between mobile home loans and floating home loans along with a small number of installment loans.
	We use a risk rating system to evaluate asset quality, and to identify and monitor credit risk in individual loans, and ultimately in the portfolio. Definitions of loans that are risk graded “Special Mention” or worse are consistent with those used by the Federal Deposit Insurance Corporation ("FDIC").  Our internally assigned grades are as follows:
	Pass – Loans to borrowers of acceptable or better credit quality. Borrowers in this category demonstrate fundamentally sound financial positions, repayment capacity, credit history and management expertise.  Loans in this category must have an identifiable and stable source of repayment and meet the Bank’s policy regarding debt service coverage ratios.  These borrowers are capable of sustaining normal economic, market or operational setbacks without significant financial impacts.  Financial ratios and trends are acceptable.  Negative external industry factors are generally not present.  The loan may be secured, unsecured or supported by non-real estate collateral for which the value is more difficult to determine and/or marketability is more uncertain. This category also includes “Watch” loans, where the primary source of repayment has been delayed. “Watch” is intended to be a transitional grade, with either an upgrade or downgrade within a reasonable period.
	Special Mention - Potential weaknesses that deserve close attention. If left uncorrected, those potential weaknesses may result in deterioration of the payment prospects for the asset. Special Mention assets do not present sufficient risk to warrant adverse classification.
	Substandard - Inadequately protected by either the current sound worth and paying capacity of the obligor or the collateral pledged, if any. A Substandard asset has a well-defined weakness or weaknesses that jeopardize(s) the liquidation of the debt. Substandard assets are characterized by the distinct possibility that we will sustain some loss if such weaknesses or deficiencies are not corrected. Well-defined weaknesses include adverse trends or developments of the borrower’s financial condition, managerial weaknesses and/or significant collateral deficiencies.
	Doubtful - Critical weaknesses that make collection or liquidation in full improbable. There may be specific pending events that work to strengthen the asset; however, the amount or timing of the loss may not be determinable. Pending events generally occur within one year of the asset being classified as Doubtful. Examples include: merger, acquisition, or liquidation; capital injection; guarantee; perfecting liens on additional collateral; and refinancing. Such loans are placed on non-accrual status and usually are collateral-dependent.
	We regularly review our credits for accuracy of risk grades whenever new information is received. Borrowers are required to submit financial information at regular intervals:
	•	Generally, commercial borrowers with lines of credit are required to submit financial information with reporting intervals ranging from monthly to annually depending on credit size, risk and complexity.
	•	Investor commercial real estate borrowers with loans greater than $750 thousand are required to submit rent rolls or property income statements at least annually.
	•	Construction loans are monitored monthly, and assessed on an ongoing basis.
	•	Home equity and other consumer loans are assessed based on delinquency.
	•	Loans graded “Watch” or more severe, regardless of loan type, are assessed no less than quarterly.
	The following table represents our analysis of loans by internally assigned grades, including the PCI loans, at December 31, 2013 and 2012:
	(in thousands)	Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Purchased credit-impaired			Total
	Credit Risk Profile by Internally Assigned Grade:
	31-Dec-13
	Pass	$	162,625			$	216,537			$	609,157			$	25,069			$	93,792			$	69,176			$	16,336			$	1,340		$	1,194,032
	Special Mention	13,990				16,533				8,570				725				2,164				1,047				227				894			44,150
	Substandard	6,343				3,224				5,413				5,768				2,444				2,411				656				4,881			31,140
	Total loans	$	182,958			$	236,294			$	623,140			$	31,562			$	98,400			$	72,634			$	17,219			$	7,115		$	1,269,322
	December 31, 2012
	Pass	$	148,771			$	170,553			$	489,978			$	26,287			$	86,957			$	45,634			$	17,809			$	1,862		$	987,851
	Special Mention	13,267				20,346				8,671				1,970				2,931				1,067				—				933			49,185
	Substandard	13,753				2,992				8,963				2,408				3,349				2,731				966				1,754			36,916
	Total loans	$	175,791			$	193,891			$	507,612			$	30,665			$	93,237			$	49,432			$	18,775			$	4,549		$	1,073,952
	Troubled Debt Restructuring
	Our loan portfolio includes certain loans that have been modified in a Troubled Debt Restructuring (“TDR”), where economic concessions have been granted to borrowers experiencing financial difficulties. These concessions typically result from our loss mitigation activities and could include reductions in the interest rate, payment extensions, forgiveness of principal, forbearance or other actions. TDRs on nonaccrual status at the time of restructure may be returned to accruing status after considering the borrower’s sustained repayment performance for a reasonable period, generally six months, and there is reasonable assurance of repayment and performance.
	When a loan is modified, Management evaluates any possible impairment based on the present value of expected future cash flows, discounted at the contractual interest rate of the original loan agreement, except when the sole (remaining) source of repayment for the loan is the operation or liquidation of the collateral. In these cases Management uses the current fair value of the collateral, less selling costs, instead of discounted cash flows. If Management determines that the value of the modified loan is less than the recorded investment in the loan (net of previous charge-offs and unamortized premium or discount), impairment is recognized through a specific allowance or a charge-off of the loan.
	The table below summarizes outstanding TDR loans by loan class as of December 31, 2013, 2012 and 2011. The summary includes those TDRs that are on nonaccrual status and those that continue to accrue interest.
	(in thousands)			As of
	Recorded investment in Troubled Debt Restructurings 1			December 31, 2013				December 31, 2012				31-Dec-11
	Commercial			$	5,117			$	9,470			$	4,969
	Commercial real estate, owner-occupied			4,333				1,403				1,403
	Commercial real estate, investor			534				—				—
	Construction			6,335				1,929				800
Home equity			506				908				467
Other residential			2,063				2,831				1,464
Installment and other consumer			1,693				1,743				1,552
Total			$	20,581			$	18,284			$	10,655
1 Includes $12.9 million, $10.8 million and $6.3 million of TDR loans that were accruing interest as of December 31, 2013, 2012 and 2011 respectively.
The table below presents the following information for TDRs modified during the periods presented: number of contracts modified, the recorded investment in the loans prior to modification, and the recorded investment in the loans after the loans were restructured. The table below excludes fully paid-off or fully charged-off TDR loans.
(dollars in thousands)	Number of Contracts Modified			Pre-Modification Outstanding Recorded Investment				Post-Modification Outstanding Recorded Investment				Post-Modification Outstanding Recorded Investment at period end
Troubled Debt Restructurings during the year ended December 31, 2013:
Commercial	8			$	1,176			$	1,377			$	1,274
Commercial real estate, owner occupied	1			2,961				2,956				2,930
Commercial real estate, investor	1			539				538				534
Construction	3			7,135				7,156				5,368
Installment and other consumer	2			11				9				7
Total	15			$	11,822			$	12,036			$	10,113
Troubled Debt Restructurings during the year ended December 31, 2012:
Commercial	14			$	9,980			$	9,903			$	5,965
Construction	2			2,793				2,793				1,760
Home Equity	2			472				473				469
Other residential	2			1,422				1,401				1,392
Installment and other consumer	2			231				231				228
Total	22			$	14,898			$	14,801			$	9,814
Troubled Debt Restructurings during the year ended December 31, 2011:
Commercial	27			$	5,854			$	5,940			$	4,969
Commercial real estate, owner occupied	2			1,366				1,403				1,403
Construction	2			817				817				800
Home Equity	3			478				469				467
Other residential	3			1,467				1,467				1,464
Installment and other consumer	13			1,607				1,605				1,552
Total	50			$	11,589			$	11,701			$	10,655
Modifications during the year ended December 31, 2013 primarily involved maturity or payment extensions and interest rate concessions or some combination thereof, while modifications in 2012 primarily involved payment extensions, forbearances, and interest rate concessions. Modifications in 2011 primarily involved interest rate concessions, maturity extensions and payment deferrals. There were no loans modified as troubled debt restructuring that subsequently defaulted during the year ended December 31, 2013, where the default occurred within the first twelve months after modification into a TDR. There were three commercial loans, two commercial real estate loans and one construction loan modified as troubled debt restructurings within the previous twelve months with recorded investments of $4.5 million that subsequently defaulted and $730 thousand were charged-off, net of recoveries, in the year ended December 31, 2012. There were three TDRs in 2011 with loan balances of $1.0 million that subsequently defaulted within twelve months of restructuring and were charged-off during 2011. We are reporting these defaulted TDRs based on a payment default definition of more than ninety days past due.
Allowance for Loan Losses
Beginning with the quarter-ended September 30, 2013, Management refined the methodology for estimating general allowances in order to provide a more comprehensive evaluation of the potential risk of loss in our loan portfolio. This analysis encompasses our entire loan portfolio and excludes acquired loans where the discount has not been fully accreted. For allowance established on acquired loans, refer to Note 1. Under the prior model, loans were pooled into the following segments:
•	Commercial real estate loans, owner occupied
•	Commercial real estate loans, investor
•	Construction loans
•	Subdivision land loans
•	Residential real estate loans
•	Residential loans, fractional tenants-in-common
•	Commercial loans
•	Commercial asset-based lines
•	Commercial quick qualifier loans
•	Personal loans
•	Personal floating home loans
•	Personal mobile home loans
•	Home equity loans
•	Other loans
Under the new model, the loans are evaluated on a pool basis by loan segment which is further delineated by Federal regulatory reporting codes ("call codes"). Each segment is assigned an expected loss factor which is primarily based on a twelve quarter look-back at our historical losses for that particular segment, as well as a number of other factors. We believe this change in methodology will provide a more comprehensive evaluation of the potential risk in our portfolio because the additional delineation by call code establishes a stronger focus on areas of weakness and strength within the portfolio. Loans are pooled into the following segments under the new model:
•	Loans secured by real estate:
- 1-4 family residential construction loans
- Other construction loans and all land development and other land loans
- Secured by farmland (including farm residential and other improvements)
- Revolving, open-end loans secured by 1-4 family residential properties and extended under lines of credit
- Closed-end loans secured by 1-4 family residential properties, secured by first liens
- Closed-end loans secured by 1-4 family residential properties, secured by junior liens
- Secured by multifamily (5 or more) residential properties
- Loans secured by owner-occupied non-farm nonresidential properties
- Loans secured by other non-farm nonresidential properties
•	Loans to finance agricultural production and other loans to farmers
•	Commercial and industrial loans
•	Loans to individuals for household, family and other personal expenditures (i.e., consumer loans)
•	Other loans
The model determines loan loss reserves based on objective and subjective factors. Objective factors include the rolling historical loss rate using a twelve quarter look-back, changes in the volume and nature of the loan portfolio, changes in credit quality metrics (past due loans, non-accrual loans, net charge-offs), and the existence of credit concentrations. Subjective factors include changes in the overall economic environment, legal and regulatory conditions, lending management and other relevant staff, uncertainties related to acquisitions, as well as the quality of our loan review process. The total amount allocated is determined by applying loss multipliers to outstanding loans by call code.
The following table represents the effect on the 2013 provision for loan losses due to the change in methodology by loan class. Commercial real estate loans have increased provisions of $565 thousand in the owner-occupied category and $1.8 million in the investor category under the new methodology, which allocates additional reserves based on concentration levels.  When a loan class exceeds 100% of Tier 1 capital, additional reserves are allocated.  Such factor was not considered under the old methodology.
In addition, under the previous methodology, certain commercial loans collateralized by real estate were grouped under commercial and industrial loans and thus received a higher loss factor than the current methodology.
Lastly, we added a subjective factor for the impact of the acquisition in 2013, which added approximately $800 thousand in reserves by loan class, which would have been unallocated under the previous methodology.
		The year ended December 31, 2013
(in thousands)		Calculated Provision Based on New Methodology				Calculated Provision Based on Prior Methodology				Difference In ALLL
Commercial and industrial		$	(1,393	)		$	(449	)		$	(944	)
Commercial real estate, owner-occupied		615				50				565
Commercial real estate, investor		1,940				174				1,766
Construction		83				167				(84		)
Home equity		(223		)		(39		)		(184		)
Other residential		(234		)		(138		)		(96		)
Installment and other consumer		(535		)		(319		)		(216		)
Unallocated		287				1,094				(807		)
Total provision for loan losses		$	540			$	540			$	—
Impaired Loan Balances and Their Related Allowance by Major Classes of Loans
The table below summarizes information on impaired loans and their related allowance. Total impaired loans include non-accrual loans, accruing TDR loans and accreting PCI loans that have experienced post-acquisition declines in cash flows expected to be collected.
(dollars in thousands)		Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Total
31-Dec-13
Recorded investment in impaired loans:
With no specific allowance recorded		$	977			$	1,403			$	3,341			$	2,806			$	349			$	1,254			$	112			$	10,242
With a specific allowance recorded		4,725				4,085				—				3,927				157				809				1,750				15,453
Total recorded investment in impaired loans		$	5,702			$	5,488			$	3,341			$	6,733			$	506			$	2,063			$	1,862			$	25,695
Unpaid principal balance of impaired loans:
With no specific allowance recorded		$	977			$	3,060			$	5,333			$	5,547			$	835			$	1,254			$	154			$	17,160
With a specific allowance recorded		4,930				5,088				—				4,114				157				809				1,750				16,848
Total unpaid principal balance of impaired loans		$	5,907			$	8,148			$	5,333			$	9,661			$	992			$	2,063			$	1,904			$	34,008
Specific allowance		$	1,170			$	90			$	—			$	341			$	1			$	23			$	364			$	1,989
Average recorded investment in impaired loans during 2013		$	7,168			$	3,519			$	5,847			$	7,200			$	909			$	2,632			$	1,872			$	29,147
Interest income recognized on impaired loans during 2013		$	476			$	253			$	14			$	249			$	29			$	89			$	71			$	1,181
December 31, 2012
Recorded investment in impaired loans:
With no specific allowance recorded		$	6,825			$	1,403			$	3,725			$	2,328			$	931			$	2,598			$	978			$	18,788
With a specific allowance recorded		2,645				471				4,513				1,840				261				715				1,070				11,515
Total recorded investment in impaired loans		$	9,470			$	1,874			$	8,238			$	4,168			$	1,192			$	3,313			$	2,048			$	30,303
Unpaid principal balance of impaired loans:
With no specific allowance recorded		$	7,633			$	3,060			$	5,717			$	2,514			$	1,417			$	2,598			$	1,020			$	23,959
With a specific allowance recorded		2,930				966				4,887				4,519				324				715				1,070				15,411
Total recorded investment in impaired loans		$	10,563			$	4,026			$	10,604			$	7,033			$	1,741			$	3,313			$	2,090			$	39,370
Specific allowance		$	1,131			$	26			$	374			$	118			$	154			$	120			$	431			$	2,354
Average recorded investment in impaired loans during 2012		$	11,772			$	1,538			$	5,135			$	12,909			$	1,314			$	2,509			$	2,151			$	37,328
Interest income recognized on impaired loans during 2012		$	803			$	111			$	512			$	570			$	32			$	175			$	96			$	2,299
Average recorded investment in impaired loans during 2011		$	4,695			$	1,873			$	595			$	3,505			$	813			$	1,612			$	1,844			$	14,937
Interest income recognized on impaired loans during 2011		$	102			$	—			$	38			$	—			$	14			$	72			$	26			$	252
The gross interest income that would have been recorded had non-accrual loans been current totaled $1.0 million, $937 thousand and $821 thousand in the years ended December 31, 2013, 2012 and 2011 respectively. $229 thousand, $182 thousand and $6 thousand interest income was recognized during the time the loans were considered impaired using the cash-basis method of accounting in 2013, 2012 and 2011, respectively. PCI loans are excluded from the foregone interest data above as their accretable yield interest recognition is independent from the underlying contractual loan delinquency status. See “Purchased Credit-Impaired Loans” below for further discussion.
Management monitors delinquent loans continuously and identifies problem loans, generally loans graded substandard or worse, to be evaluated individually for impairment testing. Generally, we charge off our estimated losses related to specifically-identified impaired loans when it is deemed uncollectible. The charged-off portion of impaired loans outstanding at December 31, 2013 totaled approximately $5.8 million.  At December 31, 2013, there were $837 thousand of outstanding commitments to extend credit on impaired loans, including loans to borrowers whose terms have been modified in troubled debt restructurings.
The following table discloses loans by major portfolio category and activity in the ALLL, as well as the related ALLL disaggregated by impairment evaluation method:
Allowance for Loan Losses and Recorded Investment in Loans as of and for the year ended December 31, 2013
(dollars in thousands)		Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Unallocated			Total
For the year ended December 31, 2013
Allowance for loan losses:
Beginning balance		$	4,100			$	1,313			$	4,372			$	611			$	1,264			$	551			$	1,231			$	219		$	13,661
Provision (reversal)		(1,393		)		615				1,940				83				(223		)		(234		)		(535		)		287			540
Charge-offs		(672		)		—				(156		)		(62		)		(176		)		—				(88		)		—			(1,154		)
Recoveries		1,021				84				40				1				10				—				21				—			1,177
Ending balance		$	3,056			$	2,012			$	6,196			$	633			$	875			$	317			$	629			$	506		$	14,224
Ending ALLL related to loans collectively evaluated for impairment		$	1,886			$	1,922			$	6,196			$	292			$	874			$	294			$	265			$	506		$	12,235
Ending ALLL related to loans  individually evaluated for impairment		$	987			$	31			$	—			$	341			$	1			$	23			$	364			$	—		$	1,747
Ending ALLL related to purchased  credit-impaired loans		$	183			$	59			$	—			$	—			$	—			$	—			$	—			$	—		$	242
Loans outstanding:
Collectively evaluated for impairment		$	177,550			$	233,330			$	619,833			$	24,829			$	97,894			$	70,571			$	15,357			$	—		$	1,239,364
Individually evaluated for impairment1		5,408				2,930				3,341				6,733				506				2,063				1,862				—			22,843
Purchased credit-impaired		333				4,853				1,845				15				69				—				—				—			7,115
Total		$	183,291			$	241,113			$	625,019			$	31,577			$	98,469			$	72,634			$	17,219			$	—		$	1,269,322
Ratio of allowance for loan losses to total loans		1.67		%		0.83		%		0.99		%		2		%		0.89		%		0.44		%		3.65		%		NM			1.12		%
Allowance for loan losses to non-accrual loans		257		%		143		%		221		%		12		%		374		%		48		%		372		%		NM			122		%
1 Total excludes $2.9 million of PCI loans that have experienced post-acquisition declines in cash flows expected to be collected.These loans are included in the "purchased credit-impaired" amount in the next line below.
NM Not Meaningful
Allowance for Loan Losses and Recorded Investment in Loans as of and for the year ended December 31, 2012
(dollars in thousands)		Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Unallocated			Total
As of December 31, 2012:
Allowance for loan losses:
Beginning balance		$	4,334			$	1,305			$	3,710			$	1,505			$	1,444			$	940			$	1,182			$	219		$	14,639
Provision (reversal)		117				184				3,076				(643		)		190				(193		)		169				—			2,900
Charge-offs		(892		)		(181		)		(2,414		)		(373		)		(382		)		(196		)		(122		)		—			(4,560		)
Recoveries		541				5				—				122				12				—				2				—			682
Ending balance		$	4,100			$	1,313			$	4,372			$	611			$	1,264			$	551			$	1,231			$	219		$	13,661
Ending ALLL related to loans collectively evaluated for impairment		$	2,969			$	1,287			$	3,998			$	493			$	1,110			$	431			$	800			$	219		$	11,307
Ending ALLL related to loans  individually evaluated for impairment		$	1,090			$	—			$	178			$	118			$	154			$	120			$	431			$	—		$	2,091
Ending ALLL related to purchased  credit-impaired loans		$	41			$	26			$	196			$	—			$	—			$	—			$	—			$	—		$	263
Loans outstanding:
Collectively evaluated for impairment		$	166,860			$	193,891			$	500,768			$	26,497			$	92,045			$	46,119			$	16,727			$	—		$	1,042,907
Individually evaluated for impairment1		8,931				—				6,844				4,168				1,192				3,313				2,048				—			26,496
Purchased credit-impaired		640				2,515				1,394				—				—				—				—				—			4,549
Total		$	176,431			$	196,406			$	509,006			$	30,665			$	93,237			$	49,432			$	18,775			$	—		$	1,073,952
Ratio of allowance for loan losses to total loans		2.32		%		0.67		%		0.86		%		1.99		%		1.36		%		1.11		%		6.56		%		NM			1.27		%
Allowance for loan losses to non-accrual loans		84		%		94		%		64		%		27		%		232		%		46		%		231		%		NM			77		%
1 Total excludes $3.8 million PCI loans that have experienced credit deterioration post-acquisition, which are included in the "purchased credit-impaired" amount in the next line below.
NM Not Meaningful
Allowance for Loan Losses and Recorded Investment in Loans as of and for the year ended December 31, 2011
(dollars in thousands)		Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Unallocated			Total
As of December 31, 2011:
Allowance for loan losses:
Beginning balance		$	3,114			$	1,037			$	4,134			$	1,694			$	643			$	738			$	835			$	197		$	12,392
Provision (reversal)		4,469				377				(424		)		275				1,342				202				787				22			7,050
Charge-offs		(3,306		)		(113		)		—				(473		)		(554		)		—				(456		)		—			(4,902		)
Recoveries		57				4				—				9				13				—				16				—			99
Ending balance		$	4,334			$	1,305			$	3,710			$	1,505			$	1,444			$	940			$	1,182			$	219		$	14,639
Ending ALLL related to loans  collectively evaluated for impairment		$	3,049			$	1,136			$	3,547			$	1,311			$	1,182			$	532			$	717			$	219		$	11,693
Ending ALLL related to loans  individually evaluated for impairment		$	957			$	—			$	91			$	194			$	262			$	408			$	465			$	—		$	2,377
Ending ALLL related to purchased credit-impaired loans		$	328			$	169			$	72			$	—			$	—			$	—			$	—			$	—		$	569
Loans outstanding:
Collectively evaluated for impairment		$	169,564			$	171,492			$	444,060			$	48,653			$	96,998			$	58,095			$	20,661			$	—		$	1,009,523
Individually evaluated for impairment 1		5,110				—				741				3,304				1,045				3,407				2,071				—			15,678
Purchased credit-impaired		1,116				3,213				1,624				—				—				—				—				—			5,953
Total		$	175,790			$	174,705			$	446,425			$	51,957			$	98,043			$	61,502			$	22,732			$	—		$	1,031,154
Ratio of allowance for loan losses to total loans		2.47		%		0.75		%		0.83		%		2.9		%		1.47		%		1.53		%		5.2		%		NM			1.42		%
Allowance for loan losses to non-accrual loans		147		%		64		%		501		%		50		%		189		%		48		%		228		%		NM			122		%
1 Total excludes $4.5 million PCI loans that have experienced credit deterioration post-acquisition, which are included in the "purchased credit-impaired" amount in the next line below.
NM Not Meaningful
Purchased Credit-Impaired Loans
We evaluated loans purchased in acquisitions in accordance with accounting guidance in ASC 310-30 related to loans acquired with deteriorated credit quality. Acquired loans are considered credit-impaired if there is evidence of deterioration of credit quality since origination and it is probable, at the acquisition date, that we will be unable to collect all contractually required payments receivable. Management has determined certain loans purchased in the Acquisition to be PCI loans based on credit indicators such as nonaccrual status, past due status, loan risk grade, loan-to-value ratio, etc. Revolving credit agreements (e.g. home equity lines of credit and revolving commercial loans) are not considered PCI loans as cash flows cannot be reasonably estimated.
For acquired loans not considered credit-impaired, the difference between the contractual amounts due (principal amount) and the fair value is accounted for subsequently through accretion. We elect to recognize discount accretion based on the acquired loan’s contractual cash flows using an effective interest rate method. The accretion is recognized through the net interest margin.
The following table presents the fair value of loans acquired from Bank of Alameda for purchased credit-impaired loans and other purchased loans as of the acquisition date:
	29-Nov-13
(dollars in thousands)	Purchased credit-impaired loans				Other purchased loans				Total
Contractually required payments including interest	$	5,706			$	211,769			$	217,475
Less: nonaccretable difference	(1,183		)		—				(1,183		)
Cash flows expected to be collected (undiscounted)	4,523				211,769				216,292
Accretable yield	(707		)		(41,826		)	1	(42,533		)
Fair value of purchased loans	$	3,816			$	169,943			$	173,759
1 $6.6 million of the $41.8 million represents the difference between the contractual principal amounts due and the fair value. This discount is to be accreted to interest income over the remaining lives of the loans. The remaining $35.2 million is the contractual interest to be earned over the life of the loans.
The following table reflects the outstanding balance and related carrying value of PCI loans as of the acquisition date:
	29-Nov-13
PCI Loans	Unpaid principal balance				Fair value
(dollars in thousands)
Commercial	$	847			$	369
Commercial real estate	3,757				3,362
Construction	150				16
Home equity	239				69
Total purchased credit-impaired loans	$	4,993			$	3,816
For the PCI loans, the accretable yield initially represents the excess of the cash flows expected to be collected at acquisition over the fair value of the loans at the acquisition date, and is accreted into interest income over the estimated remaining life of the purchased credit-impaired loans using the effective yield method, provided that the timing and amount of future cash flows is reasonably estimable. The accretable yield is affected by:
(1) Changes in interest rate indices for variable rate loans – Expected future cash flows are based on the variable rates in effect at the time of the regular evaluations of cash flows expected to be collected;
(2) Changes in prepayment assumptions – Prepayments affect the estimated life of the loans which may change the amount of interest income, and possibly principal, expected to be collected; and
(3) Changes in the expected principal and interest payments over the estimated life – Updates to expected cash flows are driven by the credit outlook and actions taken with borrowers. Changes in expected future cash flows from loan modifications are included in the regular evaluations of cash flows expected to be collected.
When the timing and/or amounts of expected cash flows on such loans are not reasonably estimable, no interest is accreted and the loan is reported as a non-accrual loan; otherwise, if the timing and amounts of expected cash flows for purchased credit-impaired loans can be reasonably estimated, then interest is accreted and the loans are reported as accruing loans. The initial estimated cash flows expected to be collected are updated each quarter based on current assumptions regarding default rates, loss severities, and other factors that are reflective of current market conditions. Probable decreases in expected cash flows after acquisition result in the recognition of impairment as a specific allowance for loan losses or a charge-off to the allowance. The increase of specific allowance for PCI loan losses amounted to $203 thousand, $36 thousand and $569 thousand during 2013, 2012 and 2011, respectively. Probable and significant increases in expected cash flows would first reverse any related allowance for loan losses and any remaining increases would be recognized prospectively as interest income over the estimated remaining lives of the loans. During 2013, 2012 and 2011, the amount of reduction in the allowance for loan losses established for PCI loans due to the increase in the present value of cash flows expected to be collected was $237 thousand, $76 thousand and $0, respectively. The impact of changes in variable interest rates is recognized prospectively as adjustments to interest income.
The non-accretable difference represents the difference between the undiscounted contractual cash flows and the undiscounted expected cash flows, and also reflects the estimated credit losses in the acquired loan portfolio at the acquisition date and can fluctuate due to changes in expected cash flows during the life of the PCI loans.
The following table reflects the outstanding balance and related carrying value of PCI loans related to the 2013 NorCal acquisition and the 2011 Charter Oak acquisition as of December 31, 2013 and 2012:
	31-Dec-13								31-Dec-12
PCI Loans	Unpaid principal balance				Carrying value				Unpaid principal balance				Carrying value
(dollars in thousands)
Commercial	$	1,094			$	333			$	2,163			$	640
Commercial real estate	9,152				6,698				6,370				3,909
Construction	149				15				—				—
Home equity	239				69				—				—
Total purchased credit-impaired loans	$	10,634			$	7,115			$	8,533			$	4,549
The activities in the accretable yield, or income expected to be earned, for PCI loans were as follows:
Accretable Yield		Years ended
(dollars in thousands)		December 31, 2013				December 31, 2012				December 31, 2011
Balance at beginning of period		$	3,960			$	5,405			$	—
Additions		707				—				1,902
Removals 1		(793		)		(1,221		)		(1,019		)
Accretion		(725		)		(1,641		)		(1,418		)
Reclassifications (to)/from nonaccretable difference 2		500				1,417				5,940
Balance at end of period		$	3,649			$	3,960			$	5,405
1 Represents the accretable difference that is relieved when a loan exits the PCI population due to payoff, full charge-off, or transfer to repossessed assets, etc.
2 Primarily relates to improvements in expected credit performance and changes in expected timing of cash flows.
Pledged Loans
Our FHLB line of credit is secured under terms of a blanket collateral agreement by a pledge of certain qualifying loans with an unpaid principal balance of $716.2 million and $567.8 million at December 31, 2013 and 2012, respectively. Our FHLB line of credit totaled $416.3 million and $321.3 million at December 31, 2013 and 2012, respectively. In addition, we pledge a certain residential loan portfolio, which totaled $24.4 million and $30.1 million at December 31, 2013 and 2012, respectively, to secure our borrowing capacity with the Federal Reserve Bank (“FRB”). Also see Note 8 below.
Related Party Loans
The Bank has, and expects to have in the future, banking transactions in the ordinary course of its business with directors, officers, principal stockholders and their associates. These transactions, including loans, are granted on substantially the same terms, including interest rates and collateral on loans, as those prevailing at the same time for comparable transactions with persons not related to us. Likewise, these transactions do not involve more than the normal risk of collectability or present other unfavorable features.
An analysis of net loans to related parties for each of the three years ended December 31, 2013, 2012 and 2011 is as follows:
(in thousands)	2013				2012				2011
Balance at beginning of year	$	3,425			$	6,866			$	6,997
Additions	550				826				1,690
Advances	569				3				43
Repayments	—				(2,730		)		(1,864		)
Reclassified as unrelated-party loan	(795		)		(1,540		)		—
Balance at end of year	$	3,749			$	3,425			$	6,866
The undisbursed commitment to related parties was $657 thousand as of December 31, 2013.

Bank_Premises_and_Equipment

Bank Premises and Equipment	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Bank Premises and Equipment	'
	Bank Premises and Equipment
	A summary of Bank premises and equipment at December 31 follows:
	(in thousands)	2013			2012
	Leasehold improvements	$	12,684		$	12,116
	Furniture and equipment	7,888			7,402
	Subtotal	20,572			19,518
	Accumulated depreciation and amortization	(11,462		)	(10,174		)
	Bank premises and equipment, net	$	9,110		$	9,344
	The amount of depreciation and amortization was $1.4 million for the years ended December 31, 2013 and 2012, and $1.3 million for the year ended 2011.
	We contracted with a construction company managed and owned by a member of the Board of Directors of the Bank and Bancorp for the construction of leasehold improvements to our corporate office. During 2013 and 2012, we paid $70 thousand and $29 thousand, respectively, for these improvements.

Bank_Owned_Life_Insurance

Bank Owned Life Insurance	12 Months Ended
	Dec. 31, 2013
Insurance [Abstract]	'
Bank Owned Life Insurance	'
	Bank Owned Life Insurance
	We have purchased life insurance policies on the lives of certain officers designated by the Board of Directors to finance employee benefit programs as of December 31, 2013. Death benefits provided under the specific terms of these programs are estimated to be $63.3 million at December 31, 2013 and the benefits to employees' beneficiaries are limited to the employee's active service period. The investment in the Bank owned life insurance (“BOLI”) policies are reported in interest receivable and other assets at their cash surrender value of $27.8 million and $22.7 million at December 31, 2013 and December 31, 2012, respectively. The cash surrender value includes both the original premiums we paid in the life insurance policies and the accumulated accretion of policy income since inception of the policies. Income of $954 thousand, $762 thousand and $752 thousand was recognized on the life insurance policies in 2013, 2012 and 2011, respectively, and is reported in non-interest income. The increase in BOLI income in 2013 relates to a $228 thousand benefit realized on the death of an insured employee in 2013. We regularly monitor the credit ratings of our insurance carriers to ensure that they are in compliance with our policy.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2013
Banking and Thrift [Abstract]	'
Deposits	'
	Deposits
	Total time deposits were $161.9 million and $156.8 million at December 31, 2013 and 2012, respectively. Of these amounts, $111.7 million and $114.7 million represented time deposits of $100,000 or more at December 31, 2013 and 2012, respectively. Interest on time deposits was $0.9 million, $1.2 million and $1.6 million in 2013, 2012 and 2011, respectively. Scheduled maturities of these deposits at December 31, 2013 are presented as follows:
	(in thousands)	2014	2015	2016	2017	2018	Thereafter	Total
	Scheduled maturities of time deposits	$100,350	$16,474	$22,457	$13,304	$9,283	$—	$161,868
	We offer the CDARS® deposit product, short for Certificate of Deposit Account Registry Service. Through CDARS®, we may accept deposits in excess of the Federal Deposit Insurance Corporation (“FDIC”) insured maximum from a depositor and place the deposits through a network to other member banks in increments of less than the FDIC insured maximum to provide the depositor full FDIC insurance coverage. The Bank acts as the point of contact for the client and provides a monthly summary of where the deposits are placed.
	As of December 31, 2013, $45.7 million in securities held-to-maturity and $15.6 million securities available-for-sale were pledged as collateral for our local agency deposits.
	The aggregate amount of deposit overdrafts that have been reclassified as loan balances was $207 thousand and $276 thousand at December 31, 2013 and 2012, respectively. Collectability of these overdrafts is subject to the same credit review process as other loans.
	The Bank accepts deposits from shareholders, directors and employees in the normal course of business, and the terms are comparable to those with non-affiliated parties. The total deposits from directors and their businesses, and executive officers were $8.1 million at December 31, 2013 and $7.3 million at December 31, 2012.

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Borrowings	'
	Borrowings
	Federal Funds Purchased – We had unsecured lines of credit totaling $87.0 million with correspondent banks for overnight borrowings at both December 31, 2013 and 2012, respectively.  In general, interest rates on these lines approximate the Federal funds target rate. At December 31, 2013 and December 31, 2012, we had no overnight borrowings outstanding under these credit facilities.
	Federal Home Loan Bank Borrowings – As of December 31, 2013 and December 31, 2012, we had lines of credit with the FHLB totaling $416.3 million and $321.3 million, respectively, based on eligible collateral of certain loans.  At December 31, 2013 and December 31, 2012, we had no FHLB overnight borrowings.
	On February 5, 2008, we entered into a ten-year borrowing agreement under the same FHLB line of credit for $15.0 million at a fixed rate of 2.07%, which remained outstanding at December 31, 2013. Interest-only payments are required every three months until the entire principal is due on February 5, 2018. The FHLB has the unconditional right to accelerate the due date on May 5, 2014 and every three months thereafter (the “put dates”). If the FHLB exercises its right to accelerate the due date, the FHLB will offer replacement funding at the current market rate, subject to certain conditions. We must comply with the put date, but are not required to accept replacement funding.
	At December 31, 2013, $401.3 million was remaining as available for borrowing from the FHLB. The FHLB overnight borrowing and the FHLB line of credit are secured by a certain loan portfolio under a blanket lien.
	Federal Reserve Line of Credit – We have a line of credit with the FRB secured by a certain residential loan portfolio.  At December 31, 2013 and December 31, 2012, we had borrowing capacity under this line totaling $24.4 million and $30.1 million, respectively, and had no outstanding borrowings with the FRB.
	Subordinated Debt – On September 17, 2004, we issued a 15-year, $5.0 million subordinated debenture. Interest-only payments were to be paid quarterly until maturity on September 17, 2019.  The interest rate on the debenture changed quarterly at the 3-month LIBOR plus 2.48%. The debenture was subordinated to the claims of depositors and our other creditors. We had the right to repay the debenture, in whole or in part, on any interest payment date. We paid off the subordinated debenture entirely on September 17, 2012 without prepayment penalty and accelerated the unamortized debt issuance cost of $42 thousand in the third quarter of 2012.
	As part of the Acquisition, we assumed two subordinated debentures due to the NorCal Community Bancorp grantor trusts at fair values totaling $4.95 million at acquisition date and contractual values totaling $8.2 million. The difference between the contractual balance and the fair value at acquisition date is accreted into interest expense over the lives of the debentures. The Trusts have the option to defer payment of the distributions for a period of up to five years, as long as there is no default on the subordinated debentures. In the event of interest deferral, dividends to common stock holders are limited. The trust preferred securities were sold and issued in private transactions pursuant to an exemption from registration under the Securities Act of 1933, as amended. Bancorp has guaranteed, on a subordinated basis, distributions and other payments due on trust preferred securities totaling $8.0 million issued by the grantor trusts which have identical maturity, repricing and payment terms as the subordinated debentures.
	The following is a summary of the contractual terms of the subordinated debentures due to NorCal Community Bancorp grantor trusts as of December 31, 2013:
	Subordinated debentures due to NorCal Community Bancorp Trust I on October 7, 2033 with interest payable quarterly, based on 3-month LIBOR plus 3.05%, repricing quarterly (3.29% as of December 31, 2013), redeemable, in whole or in part, on any interest payment date.		$	4,124
	Subordinated debentures due to NorCal Community Bancorp Trust II on March 15, 2036 with interest payable quarterly, based on 3-month LIBOR plus 1.40%, repricing quarterly (1.64% as of December 31, 2013), redeemable, in whole or in part, on any interest payment date.		$	4,124
	Total		$	8,248
	Borrowings at December 31, 2013 and 2012 are summarized as follows:
		2013								2012
	(in thousands)	Carrying Value			Average Balance		Average Rate			Carrying Value		Average Balance		Average Rate
	FHLB borrowings	$	15,000		$	19,054	1.67	%		$	15,000	$	16,205	2.09	%
	Subordinated debentures	$	4,969		$	407	8.48	%	1,000	$	—	$	3,552	4.21	%	2
	1Amount includes the impact of $19 thousand of accretion on the fair value discount.
	2 Amount includes the impact of the $42 thousand accelerated unamortized debt issuance cost in 2012 discussed above.

Stockholders_Equity_and_Stock_

Stockholders' Equity and Stock Plans	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Stockholders' Equity and Stock Option Plans	'
	Stockholders' Equity and Stock Plans
	Preferred Stock
	Under the United States Department of the Treasury Capital Purchase Program (the “TCPP”), which was intended to stabilize and inject liquidity into the financial industry, on December 5, 2008, Bancorp issued to the U.S. Treasury 28,000 shares of senior preferred stock with a zero par value and a $1,000 per share liquidation preference, along with a warrant to purchase 154,242 shares of common stock at a per share exercise price of $27.23, in exchange for aggregate consideration of $28.0 million. The proceeds of $28.0 million were allocated between the preferred stock and the warrant with $27.0 million allocated to preferred stock and $961 thousand allocated to the warrant, based on their relative fair value at the time of issuance. The warrant was immediately exercisable and expires 10 years after the issuance date.
	Under the American Recovery and Reinvestment Act of 2009, which allows participants in the TCPP to withdraw from the program, we repurchased all 28,000 shares of outstanding preferred stock from the U.S. Treasury at $28 million plus accrued but unpaid dividends of $179 thousand on March 31, 2009. At the time of repurchase, we also accelerated the remaining accretion of the preferred stock totaling $945 thousand through retained earnings, reducing our net income available to common stockholders. The warrant was subsequently auctioned to two institutional investors in November 2011 and remains outstanding. It is adjusted for cash dividend increases to represent a right to purchase 156,134 shares of common stock at $26.90 per share as of December 31, 2013 in accordance with Section 13(c) of the Form of Warrant to Purchase Common Stock.
	Share-Based Awards
	On May 11, 2010, our shareholders approved the 2010 Director Stock Plan to pay director fees in shares of Bancorp common stock up to 150,000 shares. In 2013 and 2012, our directors were awarded a total of 5,619 and 5,270 common shares, respectively from the 2010 Director Stock Plan in addition to their cash compensation. As of December 31, 2013, 130,071 shares were available for future grants under this plan.
	On May 8, 2007, the 2007 Equity Plan was approved by the Bank shareholders. The 2007 Equity Plan was subsequently adopted by Bancorp as part of the holding company formation. All new share-based awards from the approval date forward are granted through the 2007 Equity Plan.
	The 2007 Equity Plan provides financial incentives for selected employees, advisors and non-employee directors. Terms of the plan provide for the issuance of up to 500,000 shares of common stock for these employees, advisors and non-employee directors. As of December 31, 2013, there were 278,572 shares available for future grants under the 2007 Equity Plan. The Compensation Committee of the Board of Directors has the discretion to determine which employees, advisors and non-employee directors will receive an award, the timing of awards, the vesting schedule for each award, the type of award to be granted limited to 250,000 restricted or unrestricted shares, the number of shares of Bancorp stock to be subject to each option and restricted stock award, and any other terms and conditions. In 2013 and 2012, there were no common shares awarded to directors from the 2007 Equity Plan.
	Effective July 1, 2007, we adopted an Employee Stock Purchase Plan whereby our employees may purchase Bancorp common shares through payroll deductions of between one percent and fifteen percent of pay in each pay period. Shares are purchased quarterly at a five percent discount from the closing market price on the last day of the quarter. The plan calls for 200,000 common shares to be set aside for employee purchases, and there were 194,446 shares available for future grants under the plan as of December 31, 2013.
	We also had the 1999 Stock Option Plan for certain full-time employees and directors who have substantial responsibility for the successful operation of the Bank. Stock options granted pursuant to the 1999 Stock Option Plan were subsequently adopted by Bancorp as part of the holding company formation. Stock options under that plan now relate to shares of common stock of Bancorp. Upon approval of the 2007 Equity Plan, no new awards were granted under the 1999 Stock Option Plan.
	Options are issued at an exercise price equal to the fair value of the stock at the date of grant. Options to officers and employees granted prior to January 1, 2006 vested 20% immediately and 20% on each anniversary of the grant date for four years. Options granted subsequent to January 1, 2006 and restricted stock awards vested 20% on each anniversary of the grant date for five years. All officer and employee options expire ten years from the grant date. Options granted to non-employee directors vest 20% immediately and 20% on each anniversary of the grant date for four years. Director options expire seven years from the grant date.
	A summary of activity for stock options for the years ended December 31, 2013, 2012 and 2011 is presented below. The intrinsic value is calculated as the number of in-the-money options times the difference between the market price of our stock as of each year end presented and the exercise prices of the in-the-money options.
													Average
				Weighted			Aggregate			Weighted			Remaining
				Average			Intrinsic Value			Average			Contractual
		Number of		Exercise			as of year-end			Grant-Date			Term
		Shares		Price			(in thousands)			Fair Value			(in years)
	Options outstanding at December 31, 2010	317,804		$	29.27		$	1,828		$	8.39		5.18
	Granted	17,585		37.76			3			11.19			—
	Cancelled, expired or forfeited	(670	)	29.28			6			7.07			—
	Exercised	(34,913	)	21.22			534			7.51			—
	Options outstanding at December 31, 2011	299,806		30.71			2,068			8.66			4.7
	Exercisable (vested) at December 31, 2011	226,989		30.64			1,579			8.81			3.82
	Options outstanding at December 31, 2011	299,806		30.71			2,068			8.66			4.7
	Granted	23,930		38.18			—			9.82			—
	Cancelled, expired or forfeited	(640	)	31.51			4			8			—
	Exercised	(37,563	)	27.7			400			8.19			—
	Options outstanding at December 31, 2012	285,533		31.73			1,661			8.82			4.43
	Exercisable (vested) at December 31, 2012	217,232		31.15			1,372			8.77			3.39
	Options outstanding at December 31, 2012	285,533		31.73			1,661			8.82			4.43
	Granted	30,000		39.99			102			10.59			—
	Cancelled, expired or forfeited	(23,840	)	35.12			151			9.31			—
	Exercised	(71,237	)	31.13			664			8.3			—
	Options outstanding at December 31, 2013	220,456		32.74			2,349			9.21			4.05
	Exercisable (vested) at December 31, 2013	163,301		31.09			2,008			8.92			2.56
	The following table summarizes non-vested share-based awards at December 31, 2013, and changes during the year ended December 31, 2013.
		Options						Restricted Stock Awards
				Weighted						Weighted
				Average						Average
		Number of		Grant-Date				Number of		Grant-Date
		Shares		Fair Value				Shares		Fair Value
	Non-vested awards at December 31, 2012	73,876		$	8.98			21,610		$	34.05
	Granted	30,000		10.59				11,850		39.96
	Vested	(22,881	)	8.17				(6,941	)	31.42
	Forfeited	(23,840	)	9.31				(3,998	)	36.19
	Non-vested awards at December 31, 2013	57,155		10.05				22,521		37.59
	As of December 31, 2013, there was $1.1 million of total unrecognized compensation expense related to non-vested stock options and restricted stock awards. This cost is expected to be recognized over a weighted-average period of approximately four years. The total grant-date fair value of option shares vested during the years ended December 31, 2013, 2012 and 2011 was $187 thousand, $212 thousand and $270 thousand, respectively. The total grant-date fair value of restricted stock awards vested during 2013, 2012 and 2011 was $218 thousand, $152 thousand and $115 thousand, respectively.
	A summary of the options outstanding and exercisable by price range as of December 31, 2013 is presented in the following table:
		Stock Options Outstanding as of December 31, 2013							Stock Options Exercisable as of December 31, 2013
				Remaining	Weighted						Weighted
		Stock Options		Contractual Life	Average				Stock Options		Average
	Range of Exercise Prices	Outstanding		(in years)	Exercise Price				Exercisable		Exercise Price
	$20.01 - $25.00	15,328		5.3	$	22.25			10,798		$	22.25
	$25.01 - $30.00	47,711		1.6	27.11				47,711		27.11
	$30.01 - $35.00	81,724		2.4	33.04				77,474		33.04
	$35.01 - $40.00	59,193		6.5	37.39				27,318		36.02
	$40.01 - $45.00	16,500		9.5	40.52				—		—
		220,456		4.1	32.74				163,301		31.09
	The fair value of stock options on the grant date is recorded as a stock-based compensation expense in the consolidated statements of comprehensive income over the requisite service period with a corresponding increase in common stock. Stock-based compensation also includes compensation expense related to the issuance of unvested restricted common shares pursuant to the 2007 Equity Plan. The grant-date fair value of the restricted common shares, which equals its intrinsic value on that date, is being recorded as compensation expense over the requisite service period with a corresponding increase in common stock as the shares vest. In addition, we record excess tax benefits on the exercise of non-qualified stock options, the disqualifying disposition of incentive stock options and vesting of restricted stock as an addition to common stock with a corresponding decrease in current taxes payable. The total related income tax benefit recognized in the consolidated statements of comprehensive income during 2013, 2012 and 2011 was $94 thousand, $35 thousand and $37 thousand, respectively.
	We determine the fair value of stock options at the grant date using the Black-Scholes pricing model that takes into account the stock price at the grant date, the exercise price, the expected life of the option, the volatility of the underlying stock, the expected dividend yield and the risk-free interest rate over the expected life of the option.
	The weighted-average assumptions used in the pricing model are noted in the table below. The expected term of options granted is derived from historical data on employee exercise and post-vesting employment termination behavior. The risk-free rate for periods within the expected life of the option is based on the U.S. Treasury yield curve in effect at the time of the grant. Expected volatility is based on the historical volatility of the common stock.
		Years ended December 31,
		2013		2012		2011
Risk-free interest rate	1.6	%	1.6	%	2.77	%
Expected dividend yield on common stock	1.8	%	1.78	%	1.69	%
Expected life in years	6.8		7		7.5
Expected price volatility	30.01	%	28.7	%	28.92	%
The fair value of the option is expensed on a straight-line basis over the vesting period. Forfeitures are estimated based on historical forfeiture experience and expense is recognized only for those shares expected to vest. The estimated forfeiture rate over the entire vesting period was 7.5% in 2013, 2012 and 2011 for stock options and was 10.0% in both 2013 and 2012 and 7.5% in 2011 for restricted stock awards.
The Black-Scholes option valuation model requires the input of highly subjective assumptions, including the expected life of the stock-based award and stock price volatility. The assumptions listed above represent Management's best estimates based on historical information, but these estimates involve inherent uncertainties and the application of Management's judgment. As a result, if other assumptions had been used, the recorded share-based compensation expense could have been materially different from that reflected in these financial statements. If the actual forfeiture rate is materially different from the estimate, the share-based compensation expense could also be materially different.
Dividends
Presented below is a summary of cash dividends paid to common shareholders, recorded as a reduction of retained earnings.
		Years ended December 31,
(in thousands except per share data)		2013			2012			2011
Cash dividends to common stockholders		$	3,970		$	3,751		$	3,457
Cash dividends per common share		0.73			0.7			0.65
The holders of the unvested restricted common stock awards are entitled to dividends on the same per-share ratio as the holders of common stock. Dividends paid on the portion of share-based awards not expected to vest are also included in stock-based compensation expense. Tax benefits on dividends paid on the portion of share-based awards expected to vest are recorded as an increase to common stock with a corresponding decrease in current taxes payable.
Under the California Corporations Code effective January 1, 2012, payment of dividends by Bancorp is restricted to the amount of retained earnings immediately prior to the distribution or the amount of assets that exceeds the total liabilities immediately after the distribution. As of December 31, 2013, Bancorp's retained earnings and the amount of assets that exceeds the total liabilities were $101.5 million and $180.9 million, respectively.
Under the California Financial Code, payment of dividends by the Bank to Bancorp is restricted to the lesser of retained earnings or the amount of undistributed net profits of the Bank from the three most recent fiscal years. Under this restriction, approximately $18.8 million of the Bank's retained earnings balance was available for payment of dividends to Bancorp as of December 31, 2013. Bancorp holds $8.7 million in cash at December 31, 2013. This cash, combined with the $18.8 million dividends available to be distributed (discussed above), is expected to be adequate to cover Bancorp's estimated operational needs and cash dividends to shareholders for 2014.
Shareholder Rights Plan
On July 2, 2007, Bancorp executed a shareholder rights agreement (“Rights Agreement”) designed to discourage takeovers that involve abusive tactics or do not provide fair value to shareholders. As of December 31, 2013, Bancorp was also authorized to issue five million shares of preferred stock with no par value under the Rights Agreement. In the event of a proposed merger, tender offer or other attempt to gain control of Bancorp that the Board of Directors does not approve, it might be possible for the Board of Directors to authorize the issuance of shares of common or preferred stock that would impede the completion of such a transaction. An effect of the possible issuance of common or preferred stock, therefore, may be to deter a future takeover attempt. The Board of Directors has no present plans or understandings for the issuance of any common or preferred stock.
Refer to Exhibit 4.1 Registration Statement on Form 8-A12B filed with the Securities and Exchange Commission on July 2, 2007.

Fair_Value_of_Assets_and_Liabi

Fair Value of Assets and Liabilities	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Assets and Liabilities	'
	Fair Value of Assets and Liabilities
	Fair Value Hierarchy and Fair Value Measurement
	We group our assets and liabilities that are measured at fair value in three levels within the fair value hierarchy, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. These levels are:
	Level 1: Valuations are based on quoted prices in active markets for identical assets or liabilities. Since valuations are based on quoted prices that are readily and regularly available in an active market, valuation of these products does not involve a significant degree of judgment.
	Level 2: Valuations are based on quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuations for which all significant assumptions are observable or can be corroborated by observable market data.
	Level 3: Valuations are based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Values are determined using pricing models and discounted cash flow models and include management judgment and estimation which may be significant.
	Transfers between levels of the fair value hierarchy are recognized on the actual date of the event or circumstances that caused the transfer, which generally coincides with the our monthly and/or quarterly valuation process.
	The following table summarizes our assets and liabilities that were required to be recorded at fair value on a recurring basis.
	(in thousands)	Carrying Value			Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
	Description of Financial Instruments
	At December 31, 2013:
	Securities available-for-sale:
	Mortgage-backed securities and collateralized mortgage obligations issued by U.S. government-sponsored agencies	$	190,604		$	—		$	190,604		$	—
	Debentures of government-sponsored agencies	$	21,312		$	—		$	21,312		$	—
	Privately-issued collateralized mortgage obligations	$	10,874		$	—		$	10,874		$	—
	Obligations of state and political subdivisions	$	15,948		$	—		$	15,771		$	—
	Corporate bonds	$	5,426		$	—		$	5,437		$	—
	Derivative financial assets (interest rate contracts)	$	961		$	—		$	961		$	—
	Derivative financial liabilities (interest rate contracts)	$	2,519		$	—		$	2,519		$	—
	At December 31, 2012:
	Securities available-for-sale:
	Mortgage-backed securities and collateralized mortgage obligations issued by U.S. government-sponsored agencies	$	111,797		$	—		$	111,797		$	—
	Debentures of government-sponsored agencies	$	20,589		$	—		$	20,589		$	—
	Privately-issued collateralized mortgage obligations	$	21,576		$	—		$	21,576		$	—
	Derivative financial assets (interest rate contracts)	$	1		$	—		$	1		$	—
	Derivative financial liabilities (interest rate contracts)	$	5,240		$	—		$	5,240		$	—
	Securities available-for-sale are recorded at fair value on a recurring basis. When available, quoted market prices (Level 1) are used to determine the fair value of securities available-for-sale. If quoted market prices are not available, we obtain pricing information from a reputable third-party service provider, who may utilize valuation techniques that use current market-based or independently sourced parameters, such as bid/ask prices, dealer-quoted prices, interest rates, benchmark yield curves, prepayment speeds, probability of default, loss severity and credit spreads (Level 2).   Level 2 securities include U.S. agencies’ or government sponsored agencies' debt securities, mortgage-backed securities, government agency-issued and privately-issued collateralized mortgage obligations. As of December 31, 2013 and 2012, there are no securities that are considered Level 1 or Level 3 securities.
	On a recurring basis, derivative financial instruments are recorded at fair value, which is based on the income approach using observable Level 2 market inputs, reflecting market expectations of future interest rates as of the measurement date.  Standard valuation techniques are used to calculate the present value of the future expected cash flows assuming an orderly transaction.  Valuation adjustments may be made to reflect both our own credit risk and the counterparties’ credit quality in determining the fair value of the derivatives. Level 2 inputs for the valuations are limited to observable market prices for London Interbank Offered Rate (“LIBOR”) cash rates (for the very short term), quoted prices for LIBOR futures contracts, observable market prices for LIBOR swap rates, and one-month and three-month LIBOR basis spreads at commonly quoted intervals.  Mid-market pricing of the inputs is used as a practical expedient in the fair value measurements.  Key inputs for interest rate valuations are used to project spot rates at resets specified by each swap, as well as to discount those future cash flows to present value at the measurement date.  When the value of any collateral placed with counterparties is less than the interest rate derivative liability, the interest rate liability position is further discounted to reflect our potential credit risk to counterparties.  We have used the spread between the Standard & Poors BBB rated U.S. Bank Composite rate and LIBOR with maturity term corresponding to the duration of the swaps to calculate this credit-risk-related discount of future cash flows.
	Certain financial assets may be measured at fair value on a non-recurring basis. These assets are subject to fair value adjustments that result from the application of the lower of cost or fair value accounting or write-downs of individual assets, such as other real estate owned ("OREO") and impaired loans.
	When a loan is identified as impaired, it is reported at the lower of cost or fair value, measured based on the loan's observable market price (Level 1) or the current net realizable value of the underlying collateral securing the loan, if the loan is collateral dependent (Level 3).  Net realizable value of the underlying collateral is the fair value of the collateral less estimated selling costs and any prior liens. Appraisals, recent comparable sales, offers and listing prices are factored in when valuing the collateral. We review and verify the qualifications and licenses of  the certified general appraisers used for appraising commercial properties or certified residential appraisers for residential properties. Real estate appraisals may utilize a combination of approaches including replacement cost, sales comparison and the income approach. Comparable sales and income data are analyzed by the appraisers and adjusted to reflect differences between them and the subject property such as type, leasing status and physical condition. When the appraisals are received, Management reviews the assumptions and methodology utilized in the appraisal, as well as the overall resulting value in conjunction with independent data sources such as recent market data and industry-wide statistics. We generally use a 6% discount for selling costs which is applied to all properties, regardless of size. Appraised values may be adjusted to reflect changes in market conditions that have occurred subsequent to the appraisal date, or for revised estimates regarding the timing or cost of the property sale. These adjustments are based on qualitative judgments made by management on a case-by-case basis. There have been no significant changes in the valuation techniques during the period ended December 31, 2013. OREO represents collateral acquired through foreclosure and is initially recorded at fair value as established by a current appraisal, adjusted for disposition costs. Subsequently, OREO is measured at lower of cost or fair value. OREO values are reviewed on an ongoing basis and any subsequent decline in fair value is recorded as a foreclosed asset expense in the current period. The value of OREO is determined based on independent appraisals, similar to the process used for impaired loans, discussed above, and is generally classified as Level 3. At December 31, 2013, we had $461 thousand of OREO acquired from Bank of Alameda as part of the Acquisition. There was no change in the estimated fair value of the OREO from the date of the Acquisition through December 31, 2013.
	Securities held-to-maturity may be written down to fair value (determined using the same techniques discussed above for securities available-for-sale) as a result of an other-than-temporary impairment, if any.
	The following table presents the carrying value of financial instruments that were measured at fair value on a non-recurring basis and that were still held in the consolidated statements of condition at each respective period end, by level within the fair value hierarchy as of December 31, 2013 and 2012.
	(in thousands)	Carrying Value			Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
	Description of Financial Instruments				(Level 1)			(Level 2)			(Level 3) 1
	At December 31, 2013:
	Impaired loans carried at fair value:
	Construction	$	3,037		$	—		$	—		$	3,037
	Installment and other consumer	35			—			—			35
	Total	$	3,072		$	—		$	—		$	3,072
	At December 31, 2012:
	Impaired loans carried at fair value:
	Commercial and industrial	$	51		$	—		$	—		$	51
	Commercial real estate, investor	2,941			—			—			2,941
	Construction	1,722			—			—			1,722
	Home equity	107			—			—			107
	Other residential	594			—			—			594
	Installment and other consumer	159			—			—			159
	Total	$	5,574		$	—		$	—		$	5,574
	1 Represents collateral-dependent loan principal balances that had been generally written down to the values of the underlying collateral, net of specific valuation allowance of $363 thousand and $729 thousand at December 31, 2013 and 2012, respectively. The carrying value of loans fully charged-off, which includes unsecured lines of credit, overdrafts and all other loans, is zero.
	Disclosures about Fair Value of Financial Instruments
	The table below is a summary of fair value estimates for financial instruments as of December 31, 2013 and 2012, excluding financial instruments recorded at fair value on a recurring basis (summarized in the first table in this note). The carrying amounts in the following table are recorded in the consolidated statements of condition under the indicated captions. We have excluded non-financial assets and non-financial liabilities defined by the Codification (ASC 820-10-15-1A), such as Bank premises and equipment, deferred taxes and other liabilities.  In addition, we have not disclosed the fair value of financial instruments specifically excluded from disclosure requirements of the Financial Instruments Topic of the Codification (ASC 825-10-50-8), such as Bank-owned life insurance policies.
		December 31, 2013						December 31, 2012
	(in thousands)	Carrying Amounts		Fair Value			Fair Value Hierarchy	Carrying Amounts		Fair Value			Fair Value Hierarchy
	Financial assets
	Cash and cash equivalents	$	103,773	$	103,773		Level 1	$	28,349	$	28,349		Level 1
	Investment securities held-to-maturity	122,495		123,858			Level 2	139,452		142,231			Level 2
	Loans, net	1,255,098		1,245,475			Level 3	1,060,291		1,111,355			Level 3
	Interest receivable	5,767		5,767			Level 2	5,073		5,073			Level 2
	Financial liabilities
	Deposits	1,587,102		1,588,278			Level 2	1,253,289		1,254,713			Level 2
	Federal Home Loan Bank borrowing	15,000		15,665			Level 2	15,000		15,989			Level 2
	Subordinated debentures	4,969		4,950			Level 3	—		—			—
	Interest payable	253		253			Level 2	225		225			Level 2
Following is a description of methods and assumptions used to estimate the fair value of each class of financial instrument not recorded at fair value but required for disclosure purposes:
Cash and Cash Equivalents - The carrying amounts of cash and cash equivalents approximate their fair value because of the short-term nature of these instruments.
Held-to-maturity Securities - Held-to-maturity securities, which generally consist of obligations of state and political subdivisions and corporate bonds, are recorded at their amortized cost. Their fair value for disclosure purposes is determined using methodologies similar to those described above for available-for-sale securities using Level 2 inputs. If Level 2 inputs are not available, we may utilize pricing models that incorporate unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities (Level 3).  As of December 31, 2013 and 2012, we did not hold any securities whose fair value was measured using significant unobservable inputs.
Loans - The fair value of loans with variable interest rates approximates their current carrying value, because their rates are regularly adjusted to current market rates. The fair value of fixed rate loans or variable loans at negotiated interest rate floors or ceilings with remaining maturities in excess of one year is estimated by discounting the future cash flows using current market rates at which similar loans would be made to borrowers with similar credit worthiness and similar remaining maturities. The allowance for loan losses (“ALLL”) is considered to be a reasonable estimate of loan discount due to credit risks.
Interest Receivable and Payable - The interest receivable and payable balances approximate their fair value due to the short-term nature of their settlement dates.
Deposits - The fair value of deposits without stated maturity, such as transaction accounts, savings accounts and money market accounts is the amount payable on demand at the reporting date. The fair value of time deposits is estimated by discounting the future cash flows using current rates offered for deposits of similar remaining maturities.
Federal Home Loan Bank Borrowing - The fair value is estimated by discounting the future cash flows using current rates offered by the Federal Home Loan Bank of San Francisco ("FHLB") for similar credit advances corresponding to the remaining duration of our fixed-rate borrowing.
Subordinated Debentures - As part of the Acquisition, we assumed two subordinated debentures from NorCal. See Note 8 for further information. The fair values of the subordinated debentures were estimated by discounting the future cash flows (interest payment at a rate of three-month LIBOR plus 3.05% and 1.40%, respectively) to their present values using current market rates at which similar bonds would be issued with similar credit ratings as ours and similar remaining maturities. Each payment was discounted at a spot rate of the corresponding term, determined based on the yields and terms of comparable trust preferred securities, plus an illiquidity premium of 3.00%. In July 2010, the Dodd-Frank Act was signed into law and limits the ability of certain bank holding companies to treat trust preferred security debt issuances as Tier 1 capital. This law effectively closed the trust-preferred securities markets for new issuance and led to the absence of observable or comparable transactions in the market place. Due to the unobservable inputs of trust preferred securities, we consider the fair value to be a Level 3 measurement.
Commitments - Loan commitments and standby letters of credit generate ongoing fees, which are recognized over the term of the commitment period. In situations where the borrower's credit quality has declined, we record a reserve for these off-balance sheet commitments. Given the uncertainty in the likelihood and timing of a commitment being drawn upon, a reasonable estimate of the fair value of these commitments is the carrying value of the related unamortized loan fees plus the reserve, which is not material.

Benefit_Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2013
Compensation and Retirement Disclosure [Abstract]	'
Benefit Plans	'
	Benefit Plans
	In 2003, we established a Deferred Compensation Plan that allows certain key management personnel designated by the Board of Directors of the Bank to defer up to 80% of their salary and 100% of their annual bonus. The Plan was amended in 2007 in order to comply with the most recent Internal Revenue Code Section 409A changes. Under the amended plan, amounts deferred earn interest that is equal to the prime rate as published in the Wall Street Journal, on the first business day of the year, which remained unchanged at 3.25% for the past five years. Our deferred compensation obligation totaled $2.8 million and $2.7 million at December 31, 2013 and 2012, respectively, is included in interest payable and other liabilities.
	Our 401(k) Defined Contribution Plan (the “401(k) Plan”) commenced in May 1990 and is available to all regular employees at least eighteen years of age who complete ninety days of service, and enter the plan during one of the four open enrollment dates (January 1, April 1, July 1, and October 1) of each year. Under this plan employees can defer between 1% and 50% of their eligible compensation, up to the maximum amount allowed by the Internal Revenue Code. The Bank matched 50% of each participant's contribution in prior years and increased the matching to 60% in 2013, up to total matching of $4 thousand annually. Employer contributions totaled $473 thousand, $432 thousand and $366 thousand for the years ended December 31, 2013, 2012 and 2011, respectively.
	In 1999, the 401(k) Plan was amended to include an employee stock ownership component and was renamed the Bank of Marin Employee Stock Ownership and Savings Plan (the “Plan”). Under the terms of the Plan, as amended, the Board of Directors determines a specific portion of the Bank's profits to be contributed to the ESOP each year either in common stock or in cash for the purchase of Bancorp stock to be allocated to all eligible employees based on a set percentage of their salaries, regardless of whether an employee is participating in the 401(k) plan or not. The Bank contributed cash in the amount of $886 thousand for the year ended December 31, 2013 and $1.1 million in both 2012 and 2011 to the ESOP, which purchased Bancorp stock from the open market or private parties who are diversifying their portfolio or taking distributions. Contributions to the Plan for both the 401(k) employer matching contribution and for the ESOP are included in salaries and benefits expenses and vested at a rate of 20% per year over a five-year period. As of December 31, 2013, cash dividends on Bancorp's stock held by the Plan are used to purchase additional shares in the open market. All shares of the Bancorp's stock held by the Plan are included in the calculations of basic and diluted earnings per share.
	In January 2010, the Plan was bifurcated into a separate 401(k) Plan and a separate ESOP Plan. The same eligibility criteria and employer contribution allocation apply under the ESOP Plan, while employees' contributions are not permitted. For participants who join the ESOP on or after January 1, 2010, employer contributions vest 0% in year one, 20% in years two through four and 40% in year five.
	On January 1, 2011, we established a Salary Continuation Plan to a select group of Executive management, who will receive twenty-five percent of their salary continuation benefit payments upon retirement.  Each participant will need to participate in this plan for five years before vesting begins. After five years, the participant will vest ratably in the benefit over the remaining period until age 65. This Plan is unfunded and nonqualified for tax purposes and for purposes of Title I of the Employee Retirement Income Security Act of 1974. Our liability under the Salary Continuation Plan was $493 thousand and $326 thousand recorded in interest payable and other liabilities at December 31, 2013 and 2012, respectively.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The current and deferred components of the income tax provision for each of the three years ended December 31 are as follows:
	(in thousands)	2013			2012			2011
	Current tax provision
	Federal	$	6,717		$	7,994		$	7,045
	State	2,574			2,875			2,635
	Total current	9,291			10,869			9,680
	Deferred tax (benefit) provision
	Federal	(873		)	(4		)	(205		)
	State	(479		)	26			(284		)
	Total deferred	(1,352		)	22			(489		)
	Total income tax provision	$	7,939		$	10,891		$	9,191
	Income taxes related to changes in the unrealized gains and losses on available-for-sale securities are recorded directly to other comprehensive income in stockholders' equity and are not included above. These deferred income tax (benefits) expenses amounted to $(2.0) million, $330 thousand, and $37 thousand in 2013, 2012 and 2011, respectively.
	The following table shows the tax effect of our cumulative temporary differences as of December 31:
	(in thousands)	2013			2012
	Deferred tax assets:
	Net operating loss carryforwards from the NorCal acquisition	$	5,096		$	—
	Allowance for loan losses and off-balance sheet credit commitments	4,671			5,955
	Fair value adjustment on loans acquired from the NorCal acquisition	3,182			—
	Deferred compensation plan and salary continuation plan	1,376			1,271
	Accrued but unpaid expenses	1,177			957
	Net unrealized loss on securities available-for-sale	830			—
	State franchise tax	737			1,000
	Deferred rent and other lease incentives	591			571
	Accretion on loans and investment securities	520			—
	Other real estate owned	448			—
	Stock-based compensation	225			259
	Core deposit intangible asset	—			266
	Other	264			—
	Total gross deferred tax assets	19,117			10,279
	Deferred tax liabilities:
	Deferred loan origination costs and fees	(2,024		)	(1,052		)
	Core deposit intangible asset	(1,647		)	—
	Unaccreted discount on subordinated debentures from acquisition	(1,379		)	—
	Depreciation and disposals on premises and equipment	(159		)	(637		)
	Net unrealized gain on securities available-for-sale	—			(1,488		)
	Accretion on loans and investment securities	—			(449		)
	Total gross deferred tax liabilities	(5,209		)	(3,626		)
	Net deferred tax assets	$	13,908		$	6,653
	As of December 31, 2013, we had federal and California net operating loss carryforwards ("NOLs") from the NorCal acquisition of approximately $9.9 million and $23.7 million, respectively. If not fully utilized, the federal NOLs will begin to expire in 2030, and the California NOLs will begin to expire in 2028. The NorCal acquisition resulted in limitations on the annual utilization of these NOLs under section 382 of the Internal Revenue Code. Although we expect to fully utilize all of the federal NOLs prior to their expiration, $788 thousand of California NOLs are expected to expire in 2031 and be unutilized. As a result, we wrote down $56 thousand of deferred tax asset associated with these California NOLs as part of purchase accounting adjustment in 2013. Based upon the level of historical taxable income and projections for future taxable income over the periods during which the deferred tax assets are expected to be deductible, Management believes it is more likely than not we will realize the benefit of the remaining deferred tax assets. Accordingly, no other valuation allowance has been established as of December 31, 2013 or 2012.
	The effective tax rate for 2013, 2012 and 2011 differs from the current Federal statutory income tax rate as follows:
		2013		2012		2011
	Federal statutory income tax rate	35	%	35	%	35	%
	Increase (decrease) due to:
	California franchise tax, net of federal tax benefit	6.5	%	6.5	%	6.2	%
	Tax exempt interest on municipal securities and loans	(4.0	)%	(2.9	)%	(2.8	)%
	Tax exempt earnings on bank owned life insurance	(1.5	)%	(0.9	)%	(1.1	)%
	Low income housing tax credits	(0.3	)%	—	%	—	%
	Other	—	%	0.2	%	(0.2	)%
	Effective Tax Rate	35.7	%	37.9	%	37.1	%
	Bancorp and the Bank have entered into a tax allocation agreement which provides that income taxes shall be allocated between the parties on a separate entity basis. The intent of this agreement is that each member of the consolidated group will incur no greater tax liability than it would have incurred on a stand-alone basis.
	We file a consolidated return in the U.S. Federal tax jurisdiction and a combined return in the State of California tax jurisdiction. We are no longer subject to tax examinations by taxing authorities for years beginning before 2010 for U.S. Federal or before 2009 for California. There were no ongoing federal income tax examinations at the issuance of this report.
	The State of California is currently examining 2011 and 2012 corporate income tax returns. At the time of issuance of this report, no adjustments have been proposed by the California Franchise Tax Board in connection with the examination. Although timing of the resolution or closure of the examination is uncertain, we do not anticipate a need to provide for a reserve for uncertain tax positions in the next 12 months. At December 31, 2013 and 2012, neither the Bank nor Bancorp had an accrual for interest and penalties related to unrecognized tax benefits.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	We rent certain premises and equipment under long-term, non-cancelable operating leases expiring at various dates through the year 2024. Most of the leases contain certain renewal options and escalation clauses. At December 31, 2013, the approximate minimum future commitments payable under non-cancelable contracts for leased premises are as follows:
	(in thousands)	2014		2015		2016		2017		2018		Thereafter		Total
	Operating leases	$	3,524	$	3,575	$	3,654	$	3,681	$	3,708	$	10,078	$	28,220
	Rent expense included in occupancy expense totaled $3.3 million in 2013 and 2012, and $3.1 million in 2011.
	We may be party to legal actions which arise from time to time as part of the normal course of our business.  We believe, after consultation with legal counsel, that we have meritorious defenses in these actions, and that litigation contingent liability, if any, will not have a material adverse effect on our financial position, results of operations, or cash flows.
	We are responsible for our proportionate share of certain litigation indemnifications provided to Visa U.S.A. ("Visa") by its member banks in connection with lawsuits related to anti-trust charges and interchange fees. On December 13, 2013, the district court issued a memorandum and order approving Visa's definitive class settlement agreement in the interchange multidistrict litigation ("Settlement Agreement") with the class plaintiffs. On January 14, 2014, the court entered the final judgment order approving the settlement. A number of objectors to the settlement have appealed from that order. Until the appeals are finally adjudicated, no assurance can be provided that Visa will be able to resolve the class plaintiffs ' claims as contemplated by the Settlement Agreement. On January 27, 2014, Visa's portion of the takedown payments related to the opt-out merchants, which was calculated to be approximately $1.1 billion, was deposited into the litigation escrow account, and is expected to reduce our conversion rate of Visa Class B common stock that we hold. The full impact to member banks is still uncertain. However, we are not aware of significant future cash settlement payments required by us on the litigation.
	As permitted or required under California law and to the maximum extent allowable under that law, we have certain obligations to indemnify our current and former officers and directors for certain events or occurrences while the officer or director is, or was serving, at our request in such capacity. These indemnification obligations are valid as long as the director or officer acted in good faith and in a manner the person reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful. The maximum potential amount of future payments we could be required to make under these indemnification obligations is unlimited; however, we have a director and officer insurance policy that mitigates our exposure and enables us to recover a portion of any future amounts paid. We believe the estimated fair value of these indemnification obligations is minimal.

Concentrations_of_Credit_Risk

Concentrations of Credit Risk	12 Months Ended
	Dec. 31, 2013
Risks and Uncertainties [Abstract]	'
Concentrations of Credit Risk	'
	Concentrations of Credit Risk
	Concentration of credit risk is the risk associated with a lack of diversification, such as having substantial investments in a few individual issuers, thereby exposing us to greater risks resulting from adverse economic, political, regulatory, geographic, industrial or credit developments. Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash and cash equivalents, investment securities and loans.
	Our cash in correspondent bank accounts, at times, may exceed FDIC insured limits. We place cash and cash equivalents with high quality financial institutions, periodically monitor their credit worthiness and limit the amount of credit exposure with any one institution. Concentrations of credit risk with respect to investment securities are limited to the U.S. Government, its agencies and Government Sponsored Enterprises. Our exposure, which primarily results from positions in securities available-for-sale issued and sponsored by the U.S. Government, and its agencies, was $211.9 million, or 58% of our total investment portfolio at December 31, 2013 and $132.3 million, or 45% at December 31, 2012. The second largest concentration was obligations of state and political subdivisions in California which consist of $52.6 million, or 14% of our total investment portfolio at December 31, 2013 and $51.0 million, or 17% at December 31, 2012.
	We also manage our credit exposure related to our loan portfolio to avoid the risk of undue concentration of credits in a particular industry by reducing significant exposure to highly leveraged transactions or to any individual customer or counterparty, and by obtaining collateral as appropriate. No individual borrower accounts for more than 5% of loans held in the portfolio. The largest loan concentration group by industry of the borrowers is real estate, which accounts for 80% and 78% of our loan portfolio at December 31, 2013 and 2012, respectively.

Derivative_Financial_Instrumen

Derivative Financial Instruments and Hedging Activities	12 Months Ended
	Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Financial Instruments and Hedging Activities	'
	Derivative Financial Instruments and Hedging Activities
	We have entered into interest rate swap agreements, primarily as an asset/liability management strategy, in order to mitigate the changes in the fair value of specified long-term fixed-rate loans (or firm commitments to enter into long-term fixed-rate loans) caused by changes in interest rates. These hedges allow us to offer long-term fixed rate loans to customers without assuming the interest rate risk of a long-term asset. Converting our fixed-rate interest payments to floating-rate interest payments, generally benchmarked to the one-month U.S. dollar LIBOR index, protects us against changes in the fair value of our loans associated with fluctuating interest rates.
	The fixed-rate payment features of the interest rate swap agreements are generally structured at inception to mirror substantially all of the provisions of the hedged loan agreements. These interest rate swaps, designated and qualified as fair value hedges, are carried on the consolidated statements of condition at their fair value in other assets (when the fair value is positive) or in other liabilities (when the fair value is negative). One of our interest rate swap agreements qualifies for shortcut hedge accounting treatment. The change in fair value of the swap using the shortcut accounting treatment is recorded in other non-interest income, while the change in fair value of swaps using non-shortcut accounting is recorded in interest income. The unrealized gain or loss in fair value of the hedged fixed-rate loan due to LIBOR interest rate movements is recorded as an adjustment to the hedged loan and offset in other non-interest income (for shortcut accounting treatment) or interest income (for non-shortcut accounting treatment).
	From time to time, we make firm commitments to enter into long-term fixed-rate loans with borrowers backed by yield maintenance agreements and simultaneously enter into forward interest rate swap agreements with correspondent banks to mitigate the change in fair value of the yield maintenance agreement. Prior to loan funding, yield maintenance agreements with net settlement features that meet the definition of a derivative are considered as non-designated hedges and are carried on the consolidated statements of condition at their fair value in other assets (when the fair value is positive) or in other liabilities (when the fair value is negative). The offsetting changes in the fair value of the forward swap and the yield maintenance agreement are recorded in interest income. In June 2007, August 2010 and June 2011, three previously undesignated forward swaps were designated to offset the change in fair value of a fixed-rate loan originated in each of those periods. Subsequent to the point of the swap designations, the related yield maintenance agreements are no longer considered derivatives. Their fair value at the designation date was recorded in other assets and is amortized using the effective yield method over the life of the respective designated loans.
	The net effect of the change in fair value of interest rate swaps, the amortization of the yield maintenance agreement and the change in the fair value of the hedged loans result in an insignificant amount of hedge ineffectiveness recognized in interest income.
	Our credit exposure, if any, on interest rate swaps is limited to the favorable value (net of any collateral pledged to us) and interest payments of all swaps by each counterparty. Conversely, when an interest rate swap is in a liability position exceeding a certain threshold, we may be required to post collateral to the counterparty in an amount determined by the agreements (generally when our derivative liability position is greater than $100 thousand or $1.3 million, depending upon the counterparty). Collateral levels are monitored and adjusted on a regular basis for changes in interest rate swap values. As of December 31, 2013, five of our nine derivative instruments were in a liability position totaling $2.5 million and had collateral requirements, for which we had posted cash collateral of $2.8 million.
	As of December 31, 2013, we had nine interest rate swap agreements, which are scheduled to mature in September 2018, June 2020, August 2020, June 2022, June 2031, October 2031, July 2032, August 2037 and October 2037. All of our derivatives are accounted for as fair value hedges. Our interest rate swaps are settled monthly with counterparties. Accrued interest on the swaps totaled $70 thousand and $75 thousand as of December 31, 2013 and December 31, 2012, respectively. Information on our derivatives follows:
		Asset derivatives							Liability derivatives
	(in thousands;)	December 31, 2013				December 31, 2012			December 31, 2013				December 31, 2012
	Fair value hedges:
	Interest rate contracts notional amount	$	17,956			$	4,932		$	21,577			$	38,156
	Interest rate contracts fair value 1	961				1			2,519				5,240
		Year ended December 31,
	(in thousands;)	2013				2012				2011
	Increase (decrease) in value of designated interest rate swaps recognized in interest income	$	3,680			$	(188	)		$	(2,582	)
	Payment on interest rate swaps recorded in interest income	(1,422		)		(1,342		)		(1,076		)
	(Decrease) increase in value of hedged loans recognized in interest income	(3,971		)		311				2,436
	(Decrease) increase in value of yield maintenance agreement recognized against interest income	(71		)		168				(14		)
	Net loss on derivatives recognized against interest income 2	$	(1,784	)		$	(1,051	)		$	(1,236	)
	1 See Note 4 for valuation methodology.
	2 Ineffectiveness of $362 thousand, $291 thousand and $(160) thousand was recorded in interest income during the years December 31, 2013, 2012 and 2011, respectively. Changes in value of swaps were included in the assessment of hedge effectiveness.
	Our derivative transactions with counterparties are under International Swaps and Derivative Association (“ISDA”) master agreements that include “right of set-off” provisions. “Right of set-off” provisions are legally enforceable rights to offset recognized amounts and there may be an intention to settle such amounts on a net basis. We do not offset such financial instruments for financial reporting purposes.
	Information on financial instruments that are eligible for offset in the consolidated statements of condition follows:
	Offsetting of Financial Assets and Derivative Assets
	(in thousands;)										Gross Amounts Not Offset in the Statements of Condition
					Gross Amounts			Net Amounts
		Gross Amounts			Offset in the			of Assets Presented
		of Recognized			Statements of			in the Statements			Financial			Cash Collateral
		Assets1			Condition			of Condition1			Instruments			Received			Net Amount
	As of December 31, 2013
	Derivatives by Counterparty
	Counterparty A	$	961		$	—		$	961		$	(825	)	$	—		$	136
	Counterparty B	—			—			—			—			—			—
	Total	$	961		$	—		$	961		$	(825	)	$	—		$	136
	As of December 31, 2012
	Derivatives by Counterparty
	Counterparty A	$	1		$	—		$	1		$	(1	)	$	—		$	—
	Counterparty B	—			—			—			—			—			—
	Total	$	1		$	—		$	1		$	(1	)	$	—		$	—
	1 Amounts exclude accrued interest totaling $10 thousand and $1 thousand at December 31, 2013 and December 31, 2012, respectively.
	Offsetting of Financial Liabilities and Derivative Liabilities
	(in thousands;)										Gross Amounts Not Offset in the Statements of Condition
					Gross Amounts			Net Amounts of
		Gross Amounts			Offset in the			Liabilities Presented
		of Recognized			Statements of			in the Statements of			Financial			Cash Collateral
		Liabilities2			Condition			Condition2			Instruments			Pledged			Net Amount
	As of December 31, 2013
	Derivatives by Counterparty
	Counterparty A	$	825		$	—		$	825		$	(825	)	—			$	—
	Counterparty B	1,694			—			1,694			—			(1,694		)	—
	Total	$	2,519		$	—		$	2,519		$	(825	)	$	(1,694	)	$	—
	As of December 31, 2012
	Derivatives by Counterparty
	Counterparty A	$	2,616		$	—		$	2,616		$	(1	)	$	(1,860	)	$	755
	Counterparty B	2,624			—			2,624			—			(2,624		)	—
	Total	$	5,240		$	—		$	5,240		$	(1	)	$	(4,484	)	$	755
	2 Amounts exclude accrued interest totaling $60 thousand and $74 thousand at December 31, 2013 and December 31, 2012, respectively.

Regulatory_Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2013
Banking and Thrift [Abstract]	'
Regulatory Matters	'
	Regulatory Matters
	We are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a material effect on our consolidated financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, we must meet specific capital guidelines that involve quantitative measures of our assets, liabilities, and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and the Bank’s prompt corrective action classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. Prompt corrective action provisions are not directly applicable to bank holding companies such as Bancorp.
	Quantitative measures established by regulation to ensure capital adequacy require Bancorp and the Bank to maintain minimum amounts and ratios (set forth in the table below) of total and Tier 1 capital to risk-weighted assets and of Tier 1 capital to quarterly average assets.
	Capital ratios are reviewed by Management on a regular basis to ensure that capital exceeds the prescribed regulatory minimums and is adequate to meet our anticipated future needs.  For all periods presented, the Bank’s ratios exceed the regulatory definition of “well capitalized” under the regulatory framework for prompt corrective action and Bancorp’s ratios exceed the required minimum ratios for capital adequacy purposes. The total risk-based capital ratio declined year over year due to the NorCal acquisition in the fourth quarter of 2013. We expect the Bank to remain well-capitalized under the current minimum requirements for capital adequacy, as well as under the new Basel III rules.
	In December 2010, the Basel Committee on Bank Supervision finalized a set of international guidelines for determining regulatory capital known as “Basel III.” These guidelines were developed to address many of the weaknesses in the banking industry that contributed to the past financial crisis, including excessive leverage, inadequate and low-quality capital and insufficient liquidity buffers. In July 2013, the Board of Governors of the Federal Reserve, the FDIC and the Office of the Comptroller, finalized a rule to implement Basel III. The rule is subject to a phase-in period beginning January 2015, and all the changes should be implemented by January 2019. The guidelines, among other things, increase minimum capital requirements of bank holding companies, including increasing the Tier 1 capital to risk-weighted assets ratio to 6%, introducing a new requirement to maintain a minimum ratio of common equity Tier 1 capital to risk-weighted assets of 4.5%, and in 2019, when fully phased in, a capital conservation buffer of an additional 2.5% of risk-weighted assets. In addition, there have been several updates to the way risk-weighted assets are assessed. The three changes that will affect the Bank most significantly are: the movement of past due exposures from 100% to 150% risk weight; the movement of off-balance sheet items with an original maturity of one year or less from 0% to 20% risk weight; and the risk weighting of mortgage-backed securities using the gross-up approach instead of the ratings-based approach. As a result of their implementation, we have modeled our ratios under the finalized rules and we do not expect that we will be required to raise additional capital.
	The Bank’s and Bancorp’s capital adequacy ratios as of December 31, 2013 and December 31, 2012 are presented in the following tables.
	Capital Ratios for Bancorp (in thousands)	Actual Ratio				Ratio for Capital Adequacy Purposes
	As of December 31, 2013	Amount		Ratio		Amount		Ratio
	Total Capital (to risk-weighted assets)	$	190,738	13.21	%	≥ $	115,524	≥ 8.0	%
	Tier 1 Capital (to risk-weighted assets)	$	175,835	12.18	%	≥ $	57,762	≥ 4.0	%
	Tier 1 Capital (to average assets)	$	175,835	10.78	%	≥ $	65,222	≥ 4.0	%
	As of December 31, 2012
	Total Capital (to risk-weighted assets)	$	163,900	13.71	%	≥ $	95,655	≥ 8.0	%
	Tier 1 Capital (to risk-weighted assets)	$	149,737	12.52	%	≥ $	47,827	≥ 4.0	%
	Tier 1 Capital (to average assets)	$	149,737	10.3	%	≥ $	58,169	≥ 4.0	%
	Capital Ratios for the Bank (in thousands)	Actual Ratio				Ratio for Capital Adequacy Purposes				Ratio to be Well Capitalized under Prompt Corrective Action Provisions
	As of December 31, 2013	Amount		Ratio		Amount		Ratio		Amount		Ratio
	Total Capital (to risk-weighted assets)	$	181,911	12.6	%	≥ $	115,495	≥ 8.0	%	≥ $	144,368	≥ 10.0	%
	Tier 1 Capital (to risk-weighted assets)	$	167,007	11.57	%	≥ $	57,747	≥ 4.0	%	≥ $	86,621	≥ 6.0	%
	Tier 1 Capital (to average assets)	$	167,007	10.24	%	≥ $	65,215	≥ 4.0	%	≥ $	81,519	≥ 5.0	%
	As of December 31, 2012
	Total Capital (to risk-weighted assets)	$	162,554	13.6	%	≥ $	95,652	≥ 8.0	%	≥ $	119,566	≥ 10.0	%
	Tier 1 Capital (to risk-weighted assets)	$	148,391	12.41	%	≥ $	47,826	≥ 4.0	%	≥ $	71,739	≥ 6.0	%
	Tier 1 Capital (to average assets)	$	148,391	10.2	%	≥ $	58,168	≥ 4.0	%	≥ $	72,710	≥ 5.0	%

Financial_Instruments_with_Off

Financial Instruments with Off-Balance Sheet Risk	12 Months Ended
	Dec. 31, 2013
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. Since many of the commitments are expected to expire without being fully drawn upon, the total commitment amount does not necessarily represent future cash requirements.
	We are exposed to credit loss equal to the contract amount of the commitment in the event of nonperformance by the borrower. We use the same credit policies in making commitments as we do for on-balance-sheet instruments and we evaluate each customer’s credit worthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by us, is based on Management's credit evaluation of the borrower. Collateral held varies, but may include accounts receivable, inventory, property, plant and equipment, and real property.
	The contractual amount of loan commitments and standby letters of credit not reflected on the consolidated statements of condition was $336.9 million at December 31, 2013 at rates ranging from 1.70% to 18.00%. This amount included $173.9 million under commercial lines of credit (these commitments are contingent upon customers maintaining specific credit standards), $104.8 million under revolving home equity lines, $13.0 million under standby letters of credit, $33.4 million under undisbursed construction loans, and a remaining $11.7 million under personal and other lines of credit. We have set aside an allowance for losses in the amount of $679 thousand for these commitments as of December 31, 2013, which is recorded in interest payable and other liabilities. Approximately 39% of the commitments expire in 2014 and approximately 61% expire between 2015 and 2021.

Condensed_Bank_of_Marin_Bancor

Condensed Bank of Marin Bancorp Parent Only Financial Statements	12 Months Ended
	Dec. 31, 2013
Condensed Financial Information of Parent Company Only Disclosure [Abstract]	'
Condensed Bank of Marin Bancorp Parent Only Financial Statements	'
	Condensed Bank of Marin Bancorp Parent Only Financial Statements
	Presented below is financial information for Bank of Marin Bancorp, parent holding company only.
	CONDENSED UNCONSOLIDATED STATEMENTS OF CONDITION
	at December 31, 2013 and 2012
		At December 31,
	(in thousands)	2013			2012
	Assets
	Cash and due from Bank of Marin	$	8,664		$	1,293
	Investment in bank subsidiary	177,028			150,445
	Other assets	366			92
	Total assets	$	186,058		$	151,830
	Liabilities and Stockholders' Equity
	Subordinated debentures	$	4,969		$	—
	Accrued expenses payable	202			38
	Total liabilities	5,171			38
	Stockholders' equity	180,887			151,792
	Total liabilities and stockholders' equity	$	186,058		$	151,830
	CONDENSED UNCONSOLIDATED STATEMENTS OF INCOME
	for the fiscal years ended December 31, 2013, 2012 and 2011
		Years ended December 31,
	(in thousands)	2013			2012			2011
	Income
	Dividends from bank subsidiary	$	28,000		$	2,700		$	—
	Total income	28,000			2,700			—
	Expense
	Interest expense	34			—			—
	Non-interest expense	1,313			716			748
	Total expense	1,347			716			748
	Income (loss) before income taxes and equity in undistributed net income of subsidiary	26,653			1,984			(748		)
	Income tax benefit	382			301			249
	Income (loss) before equity in undistributed net income of subsidiary	27,035			2,285			(499		)
	Earnings of bank subsidiary (less) greater than dividends received from bank subsidiary	(12,765		)	15,532			16,063
	Net income	$	14,270		$	17,817		$	15,564
	CONDENSED UNCONSOLIDATED STATEMENTS OF CASH FLOWS
	for the fiscal years ended December 31, 2013, 2012 and 2011
		Years ended December 31,
	(in thousands)	2013			2012			2011
	Cash Flows from Operating Activities:
	Net income	$	14,270		$	17,817		$	15,564
	Adjustments to reconcile net income to net cash used
	in operating activities:
	Earnings of bank subsidiary less (greater) than	12,765			(15,532		)	(16,063		)
	dividends received from bank subsidiary
	Net change in operating assets and liabilities
	Accretion of discount on subordinated debentures	19			—			—
	Other assets	74			(71		)	58
	Other liabilities	165			(6		)	46
	Net cash used in operating activities	27,293			2,208			(395		)
	Cash Flows from Investing Activities:
	Capital contribution to subsidiary	(2,258		)	(1,070		)	(774		)
	Cash consideration paid for acquisition, net of cash	(15,952		)	—			—
	acquired
	Net cash used in investing activities	(18,210		)	(1,070		)	(774		)
	Cash Flows from Financing Activities:
	Stock options exercised and stock purchases	2,258			1,070			774
	Dividends paid on common stock	(3,970		)	(3,751		)	(3,457		)
	Net cash provided by (used by) financing activities	(1,712		)	(2,681		)	(2,683		)
	Net increase (decrease) in cash and cash equivalents	7,371			(1,543		)	(3,852		)
	Cash and cash equivalents at beginning of period	1,293			2,836			6,688
	Cash and cash equivalents at end of period	$	8,664		$	1,293		$	2,836
	Supplemental schedule of non-cash investing and financing activities:
	Stock issued in payment of director fees	$	222		$	199		$	200
	Acquisition:
Fair value of assets acquired	$	39,503		$	—		$	—
Fair value of liabilities assumed	$	4,970		$	—		$	—
Stock issued to NorCal Community Bancorp shareholders	$	18,514		$	—		$	—
End of 2013 Audited Consolidated Financial Statements

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation: The consolidated financial statements include the accounts of Bank of Marin Bancorp (“Bancorp”), a bank holding company, and its wholly-owned bank subsidiary, Bank of Marin (the “Bank”, a California state-chartered commercial bank). All material intercompany transactions have been eliminated. In the opinion of Management, the consolidated financial statements contain all adjustments necessary to present fairly the financial position, results of operations, changes in stockholders' equity and cash flows. All adjustments are of a normal, recurring nature. We have evaluated subsequent events through the date of filing with the Securities and Exchange Commission (“SEC”) and have determined that there are no subsequent events that require additional recognition or disclosure.
	On November 29, 2013, we completed the merger of NorCal Community Bancorp ("NorCal"), parent company of Bank of Alameda, to enhance our market presence (the “Acquisition”). On the date of acquisition, Bancorp assumed ownership of NorCal Community Bancorp Trusts I and II, respectively (the "Trusts"), which were formed for the sole purpose of issuing trust preferred securities. Bancorp is not considered the primary beneficiary of the Trusts (variable interest entities), therefore the Trusts are not consolidated in our consolidated financial statements, but rather the subordinated debentures are shown as a liability on our consolidated statements of condition. Bancorp's investment in the common stock of the Trusts is accounted for under the equity method and is included in interest receivable and other assets on the consolidated statements of condition.
Nature of Operations	'
	Nature of Operations: Bancorp, headquartered in Novato, CA, conducts business primarily through its wholly-owned subsidiary, the Bank, which provides a wide range of financial services to customers, who are predominantly professionals, small and middle-market businesses, and individuals who work and/or reside in Marin, Sonoma, Napa, San Francisco and Alameda counties. Besides the headquarters office in Novato, CA, the Bank operates ten branches in Marin County, one in Napa County, one in San Francisco, five in Sonoma County and four in Alameda County. Our accounting and reporting policies conform to generally accepted accounting principles, general practice, and regulatory guidance within the banking industry. A summary of our significant policies follows.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents include cash, due from banks, Federal funds sold and other short-term investments with maturity less than three months at the time of origination.
Investment Securities	'
	Investment Securities are classified as "held to maturity," "trading securities" or "available for sale." Investments classified as held-to-maturity are those that we have the ability and intent to hold until maturity and are reported at cost, adjusted for the amortization or accretion of premiums or discounts. Investments held for resale in anticipation of short-term market movements are classified as trading securities and are reported at fair value, with unrealized gains and losses included in earnings. Investments that are neither held-to-maturity nor trading are classified as available-for-sale and are reported at fair value. Unrealized gains and losses for available-for-sale securities, net of related tax, are reported as a separate component of comprehensive income and included in stockholders' equity until realized. For discussion of our methodology in determining fair value, see Note 10.
	At each financial statement date, Management assesses whether declines in the fair value of held-to-maturity and available-for-sale securities below their costs are deemed to be other-than-temporary. Management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) our intent and ability to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value. Evidence evaluated includes, but is not limited to, the remaining payment terms of the instrument and economic factors that are relevant to the collectability of the instrument, such as: current prepayment speeds, the current financial condition of the issuer(s), industry analyst reports, credit ratings, credit default rates, interest rate trends, the quality of any credit enhancement and the value of any underlying collateral.
	For each security in an unrealized loss position, we assess whether we intend to sell the security or if it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis less any current-period credit losses. If we intend to sell the security or it is more likely than not we will be required to sell the security before recovery of its amortized cost basis less any current-period credit loss, the entire difference between the investment’s amortized cost basis and its fair value at the balance sheet date is recognized in earnings.
	For impaired securities that are not intended for sale and will not be required to be sold prior to recovery of our amortized cost basis, we determine if the impairment has a credit loss component. For held-to-maturity securities, if there is no credit loss, no further action is required. For both held-to-maturity and available-for-sale securities, if the amount or timing of cash flows expected to be collected are less than those at the last reporting date, an other-than-temporary impairment shall be considered to have occurred and the credit loss component is recognized in earnings as the present value of the change in expected future cash flows. In determining the present value of the expected cash flows we discount the expected cash flows at the effective interest rate implicit in the security at the date of purchase. The remaining difference between the security's fair value and the amortized basis is deemed to be due to factors that are not credit related and is recognized in other comprehensive income, net of applicable taxes.
	The other-than-temporary impairment recognized in other comprehensive income for debt securities classified as held-to-maturity is accreted from other comprehensive income to the amortized cost of the debt security over the remaining life of the debt security in a prospective manner on the basis of the amount and timing of future estimated cash flows.
	Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to yield using the effective interest method. Dividend and interest income are recognized when earned. Realized gains and losses for securities are included in earnings and are derived using the specific identification method for determining the cost of securities sold.
Originated Loans	'
	Originated Loans are reported at the principal amount outstanding net of deferred fees, charge-offs and the allowance for loan losses (“ALLL”). Interest income is accrued daily using the simple interest method. Loans are placed on non-accrual status when Management believes that there is doubt as to the collection of principal or interest, generally when they become contractually past due by ninety days or more with respect to principal or interest, except for loans that are well-secured and in the process of collection. When loans are placed on non-accrual status, any accrued but uncollected interest is reversed from current-period interest income and interest income is recorded only after the loan is brought current or after all principal and past due interest has been collected. For loans whose contractual terms have been restructured in a manner which grants a concession to a borrower experiencing financial difficulties (“troubled debt restructuring”), they are returned to accrual status when there has been a sustained period of repayment performance (generally, six consecutive monthly payments) according to the modified terms and there is reasonable assurance of repayment and of performance.
	Loan origination fees and commitment fees, offset by certain direct loan origination costs, are deferred and amortized as yield adjustments over the contractual lives of the related loans.
Loan Charge-Off Policy	'
	Loan Charge-Off Policy: For all loans types excluding overdraft accounts, we generally make a charge-off determination at or before 90 days past due. A collateral-dependent loan is partially charged down to the fair value of collateral securing it if: (1) it is deemed uncollectable; or (2) it has been classified as a loss by either our internal loan review process or external examiners. A non-collateral-dependent loan is partially charged down to its net realizable value under the same circumstances. Additionally, unless the obligation is both well-secured and in the process of collection, any closed-end loan that exceeds 120 days past due and any open-end loan that exceeds 180 days past due is charged-off.  For overdraft accounts, we generally charge them off when they exceeds 60 days past due.
Allowance for Loan Losses	'
	Allowance for Loan Losses is based upon estimates of loan losses and is maintained at a level considered adequate to provide for probable losses inherent in the loan portfolio. The allowance is increased by provisions for loan losses charged against earnings and reduced by charge-offs, net of recoveries.
	In periodic evaluations of the adequacy of the allowance balance, Management considers current economic conditions, known and inherent risks in the portfolio, adverse situations that may affect the borrower's ability to repay, the estimated value of any underlying collateral, our past loan loss experience and other factors. The ALLL is based on estimates, and ultimate losses may vary from current estimates. Our Asset/Liability Management Committee (“ALCO”) reviews the adequacy of the ALLL at least quarterly. The allowance is adjusted based on that review if, in the judgment of the ALCO and Management, changes are warranted.
	The overall allowance consists of 1) specific allowances for individually identified impaired loans ("ASC 310-10") and 2) general allowances for pools of loans ("ASC 450-20"), which incorporate changing qualitative and environmental factors (e.g., portfolio growth and trends, credit concentrations, economic and regulatory factors, etc.).
	The first component, specific allowances, result from the analysis of identified problem credits and the evaluation of sources of repayment including collateral, as applicable. Through Management's ongoing loan grading and credit monitoring process, individual loans are identified that have conditions that indicate the borrower may be unable to pay all amounts due in accordance with the contractual terms. These loans are evaluated for impairment individually by Management. Management considers an originated loan to be impaired when it is probable we will be unable to collect all amounts due according to the contractual terms of the loan agreement. For allowance established on acquired loans, refer to Acquired Loans discussed below. When the fair value of the impaired loan is less than the recorded investment in the loan, the difference is recorded as impairment through the establishment of a specific allowance. For loans determined to be impaired, the extent of the impairment is measured based on the present value of expected future cash flows discounted at the loan's effective interest rate at origination (for originated loans), based on the loan's observable market price, or based on the fair value of the collateral if the loan is collateral dependent or if foreclosure is imminent. Generally with problem credits that are collateral-dependent, we obtain appraisals of the collateral at least annually. We may obtain appraisals more frequently if we believe the collateral value is subject to market volatility, if a specific event has occurred to the collateral, or if we believe foreclosure is imminent.
	The second component is an estimate of the probable inherent losses in each loan pool with similar characteristics. Beginning with the quarter-ended September 30, 2013, Management refined the methodology for estimating general allowances in order to provide a more comprehensive evaluation of the potential risk of loss in our loan portfolio. This analysis encompasses our entire loan portfolio and excludes acquired loans where the discount has not been fully accreted. For allowance established on acquired loans, see below under Acquired Loans.
	Under our allowance model, loans are evaluated on a pool basis by loan segment which is further delineated by Federal regulatory reporting codes ("call codes"). Each segment is assigned an expected loss factor which is based on a number of objective and subjective factors. Objective factors include a rolling historical loss rate using a twelve quarter look-back, changes in the volume and nature of the loan portfolio, changes in credit quality metrics (past due loans, non-accrual loans, net charge-offs), and the existence of credit concentrations. Subjective factors include changes in the overall economic environment, legal and regulatory conditions, lending management and other relevant staff, uncertainties related to acquisitions, as well as the quality of our loan review process. The total amount allocated is determined by applying loss multipliers to outstanding loans by call code.
	For further information regarding our ALLL methodology, including a change in methodology in 2013, see Note 4.
Acquired Loans	'
	Acquired Loans: From time to time, we acquire loans through business acquisitions. Acquired loans are recorded at their estimated fair values at acquisition date in accordance with ASC 805 Business Combinations, factoring in credit losses expected to be incurred over the life of the loan. Accordingly, an allowance for loan losses is not carried over or recorded for acquired loans as of the acquisition date.
	The process of estimating fair values of the acquired loans, including the estimate of losses that are expected to be incurred over the estimated remaining lives of the loans at acquisition date and the ongoing updates to Management's expectation of future cash flows, requires significant subjective judgments and assumptions, particularly considering the economic environment. The economic environment and the lack of market liquidity and transparency are factors that have influenced, and may continue to affect, these assumptions and estimates.
	We estimated the fair value of acquired loans at the acquisition date based on a discounted cash flow methodology that considered factors including the type of loan and related collateral, risk classification, fixed or variable interest rate, term of loan, whether or not the loan was amortizing, and current discount rates. Loans, except for purchased credit-impaired loans or "PCI loans", were grouped together according to similar characteristics and were treated in the aggregate when applying various valuation techniques. The estimate of expected cash flows incorporates our best estimate of key assumptions, such as property values, default rates, loss severity and prepayment speeds. The discount rates used for loans were based on current market rates for new originations of comparable loans, where available, and include adjustments for liquidity concerns.
	To the extent comparable market rates are not readily available, a discount rate was derived based on the assumptions of market participants' cost of funds, servicing costs and return requirements for comparable risk assets. In either case, the discount rate does not include a factor for credit losses, as that has been considered in estimating the cash flows. The initial estimate of cash flows to be collected was derived from assumptions such as default rates, loss severities and prepayment speeds.
	We acquired some loans from business combinations with evidence of credit quality deterioration subsequent to their origination and for which it was probable, at acquisition, that we would be unable to collect all contractually required payments (PCI loans). These loans are evaluated on an individual basis. Management has applied significant subjective judgment in determining which loans are PCI loans. Evidence of credit quality deterioration as of the purchase date may include data such as past due and nonaccrual status, risk grades and recent loan-to-value percentages. Revolving credit agreements (e.g., home equity lines of credit and revolving commercial loans) where the borrower had revolving privileges at acquisition date are not considered PCI loans because the timing and amount of cash flows cannot be reasonably estimated.
	The accounting guidance for PCI loans provides that the difference between the contractually required payments and the cash flows expected to be collected at acquisition, considering the impact of prepayments, is referred to as the nonaccretable difference and is not recorded. Furthermore, the difference between the expected cash flows and the fair value at acquisition date is accreted into interest income at a level yield of return over the remaining term of the loan, provided that the timing and amount of future cash flows is reasonably estimable.
	The initial estimate of cash flows expected to be collected is updated each quarter and requires the continued usage of key assumptions and estimates similar to the initial estimate of fair value. Given the current economic environment, we apply judgment to develop our estimate of cash flows for PCI loans given the impact of real estate value changes, changing probability of default, loss severities and prepayment speeds.
	For purposes of accounting for the PCI loans from past business combinations, we elected not to apply the pooling method but to account for these loans individually. Disposals of loans, which may include sales of loans to third parties, receipt of payments in full by the borrower, or foreclosure of the collateral, result in removal of the loan from the PCI loan portfolio at its carrying amount.
	All PCI loans that were classified as non-accrual loans prior to the acquisition were no longer classified as non-accrual if we believed that we would fully collect the new carrying value of these loans at acquisition. Subsequent to the acquisition, specific allowances are established for PCI loans that have experienced subsequent credit deterioration. The amount of cash flows expected to be collected and, accordingly, the adequacy of the allowance for loan losses are particularly sensitive to changes in loan credit quality. When there is doubt as to the timing and amount of future cash flows to be collected, PCI loans are classified as non-accrual loans. It is important to note that judgment is required to classify PCI loans as accruing or non-accrual, and is dependent on having a reasonable expectation about the timing and amount of cash flows expected to be collected. If we have probable and significant increases in cash flows expected to be collected on PCI loans, we first reverse any previously established specific allowance for loan loss and then increase interest income as a prospective yield adjustment over the remaining life of the loans. The impact of changes in variable interest rates is recognized prospectively as adjustments to interest income.
	For acquired loans not considered PCI loans, we recognize the entire fair value discount accretion based on the acquired loan's contractual cash flows using an effective interest rate method for term loans, and on a straight line basis to interest income for revolving lines, as the timing and amount of cash flows under revolving lines are not predictable. Subsequent to acquisition, if the probable and estimable losses for non-PCI loans exceed the amount of the remaining unaccreted discount, the excess is established as an allowance for loan losses.
	For further information regarding our acquired loans, see Note 2 and Note 4.
Transfers of Financial Assets	'
	Transfers of Financial Assets: We have entered into certain participation agreements with other organizations. We account for these transfers of financial assets as sales when control over the transferred financial assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from us, (2) the transferee has the right to pledge or exchange the assets (or beneficial interests) it received, free of conditions that constrain it from taking advantage of that right, and (3) we do not maintain effective control over the transferred financial assets or third-party beneficial interests related to those transferred assets. No gain or loss has been recognized by us on the sale of these participation interests through December 31, 2013.
Premises and Equipment	'
	Premises and Equipment consist of leasehold improvements, furniture, fixtures, software and equipment and are stated at cost, less accumulated depreciation and amortization, which are calculated on a straight-line basis. Furniture and fixtures are depreciated over eight years and equipment is generally depreciated over three to twenty years. Leasehold improvements are amortized over the lesser of their estimated useful lives or the terms of the leases. When assets are sold or otherwise disposed of, the cost and related accumulated depreciation or amortization are removed from the accounts and any resulting gain or loss is recognized in income for the period. The cost of maintenance and repairs is charged to expense as incurred.
Other Real Estate Owned (OREO)	'
	Other Real Estate Owned ("OREO"): OREO is comprised of property acquired through foreclosure or acceptance of deeds-in-lieu of foreclosure. OREO is recorded at fair value less estimated costs to sell, establishing a new cost basis, and are subsequently accounted for at the lower of cost or fair value less estimated costs to sell. Losses recognized at the time of acquiring property in full or partial satisfaction of debt are charged against the allowance for loan losses. Fair value is generally based on an independent appraisal of the property. Revenues and expenses associated with OREO, and subsequent adjustments to the fair value of the property and to the estimated costs of disposal, are realized and reported as a component of non-interest expense when incurred.
Employee Stock Ownership Plan (ESOP)	'
	Employee Stock Ownership Plan (“ESOP”): We recognize compensation cost of the ESOP contribution when funds become committed for the purchase of Bancorp's common shares into the ESOP in the year in which the employees render service entitling them to the contribution. If we contribute stock, the compensation cost is the fair value of the shares when they are committed to be released, i.e. when the number of shares becomes known. During 2013 and 2012, the Bank only made cash contributions to the ESOP without leveraging.
Income Taxes	'
	Income Taxes reported in the consolidated financial statements are computed based on an asset and liability approach. We recognize the amount of taxes payable or refundable for the current year, and deferred tax assets and liabilities for the future tax consequences that have been recognized in the financial statement or tax returns. The measurement of tax assets and liabilities is based on the provisions of enacted tax laws. Bancorp files consolidated federal and combined state income tax returns.
Earnings per share (EPS)	'
	Earnings per share (“EPS”) are based upon the weighted average number of common shares outstanding during each year. The following table shows: 1) weighted average basic shares, 2) potential common shares related to stock options, unvested restricted stock and stock warrant, and 3) weighted average diluted shares. Basic earnings per share (“EPS”) are calculated by dividing net income by the weighted average number of common shares outstanding during each period, excluding unvested restricted stock. Diluted EPS are calculated using the weighted average diluted shares. The number of potential common shares included in quarterly diluted EPS is computed using the average market prices during the three months included in the reporting period under the treasury stock method. The number of potential common shares included in year-to-date diluted EPS is a year-to-date weighted average of potential common shares included in each quarterly diluted EPS computation. We have two forms of our outstanding common stock: common stock and unvested restricted stock awards. Holders of restricted stock awards receive non-forfeitable dividends at the same rate as common shareholders and they both share equally in undistributed earnings.
Share-Based Compensation	'
	Share-Based Compensation: All share-based payments granted subsequent to January 1, 2006, including stock options and restricted stock, are recognized as stock-based compensation expense in the statements of comprehensive income based on the grant-date fair value of the award with a corresponding increase in common stock. The grant-date fair value of the award is amortized on a straight-line basis over the requisite service period, which is generally the vesting period. The stock-based compensation expense excludes stock grants to directors as compensation for their services, which are recognized as director expenses separately based on the grant-date value of the stock. See Note 9 for further discussion.
	We determine fair value of stock options at grant date using the Black-Scholes pricing model that takes into account the stock price at the grant date, the exercise price, the expected life of the option, the volatility of the underlying stock, the expected dividend yield and the risk-free interest rate over the expected life of the option. The Black-Scholes option valuation model requires the input of highly subjective assumptions, including the expected life of the stock-based award and stock price volatility. The assumptions used represent Management's best estimates based on historical information, but these estimates involve inherent uncertainties and the application of Management's judgment. As a result, if other assumptions had been used, the recorded stock-based compensation expense could have been materially different from that recorded in the consolidated financial statements. In addition, we are required to estimate the expected forfeiture rates. If our actual forfeiture rate is materially different from the estimate, the share-based compensation expense could be materially different. Fair value of restricted stock is based on the stock price on grant date.
Derivative Financial Instruments and Hedging Activities	'
	Derivative Financial Instruments and Hedging Activities
	Fair Value Hedges: All of our interest rate swap contracts are designated and qualified as fair value hedges. We apply shortcut hedge accounting for one of our interest rate swap contracts, as it is structured to mirror all of the provisions of the hedged loan agreement. This interest rate swap is carried on the consolidated statements of condition at its fair value in other assets (when the fair value is positive) or in other liabilities (when the fair value is negative). The change in the fair value of the interest rate swap is recorded in other non-interest income. As a result of interest rate fluctuations, the hedged fixed-rate loan also gains or loses value. The unrealized gain or loss resulting from the change in fair value of the hedged-loan is recorded as an adjustment to the hedged loan and offset in other non-interest income. Under shortcut hedge accounting treatment, the change in fair value of the interest rate swap is deemed perfectly offset by the change in fair value of the hedged loan, resulting in zero impact to net income.
	The eight remaining interest rate swap contracts are accounted for using non-shortcut hedge accounting treatment. The interest rate swaps are closely aligned to the terms of the designated fixed-rate loans. The hedging relationships are tested for effectiveness on a quarterly basis. The interest rate swaps are carried on the consolidated statements of condition at their fair value in other assets (when the fair value is positive) or in other liabilities (when the fair value is negative). The changes in the fair value of the interest rate swaps are recorded in interest income. The unrealized gains or losses due to changes in fair value of the hedged fixed-rate loans are recorded as an adjustment to the hedged loans and offset in interest income. For derivative instruments executed with the same counterparty under a master netting arrangement, we do not offset fair value amounts of interest rate swaps in liability position with the ones in asset position. For further detail, see Note 15.
Advertising Costs	'
	Advertising Costs are expensed as incurred.
Comprehensive Income	'
	Comprehensive Income for Bancorp includes net income reported on the statements of comprehensive income and changes in the fair value of investment securities available-for-sale, net of related taxes, reported on the statements of comprehensive income and as a component of stockholders' equity.
Segment Information	'
	Segment Information: Our two operating segments include the traditional community banking activities provided through our branch network and our Wealth Management and Trust Services (“WMTS”). The activities of these two segments are monitored and reported by Management as separate operating segments. The accounting policies of the segments are the same as those described in this note. We evaluate segment performance based on total segment revenue and do not allocate expenses between the segments.
Use of Estimates	'
	Use of Estimates: The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires Management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Significant accounting estimates reflected in the consolidated financial statements include ALLL, other-than-temporary impairment of investment securities, estimated cash flows on PCI loans, accounting for income taxes and fair value measurements (including fair values of acquired assets and assumed liabilities at acquisition dates) as discussed in the Notes herein.
Recently Issued Accounting Standards	'
	Recently Issued Accounting Standards
	In December 2011, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2011-11 Balance Sheet (Topic 210) Disclosures about Offsetting Assets and Liabilities. The ASU enhances disclosures in order to improve the comparability of offsetting (netting) assets and liabilities reported in accordance with U.S. generally accepted accounting principles (“GAAP”) and International Financial Reporting Standards (“IFRS”) by requiring entities to disclose both gross information and net information about both instruments and transactions eligible for offset in the statements of condition and instruments and transactions subject to an agreement similar to a master netting arrangement.
	In January 2013, the FASB issued ASU No. 2013-01 Balance Sheet (Topic 210) Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities, which clarifies that ordinary trade receivables and receivables are not in the scope of ASU 2011-11. It further clarifies that the scope of ASU No. 2011-11 applies to derivatives, repurchase agreements and reverse repurchase agreements, and securities borrowing and securities lending transactions that are either offset in accordance with specific criteria contained in FASB Accounting Standards Codification® or subject to a master netting arrangement or similar agreement. Both ASU 2011-11 and ASU 2013-01 are effective for annual periods beginning on or after January 1, 2013, and interim periods within those annual periods. We adopted these ASUs in the first quarter of 2013. This ASU affects presentation only and therefore there is no financial statement impact on our financial condition or results of operations. See Note 15.
	In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220) Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income. The ASU requires entities to present separately by component reclassifications out of accumulated other comprehensive income. An entity is required to disclose in the notes of the financial statements or parenthetically on the face of the financial statements the effect of significant items reclassified out of accumulated other comprehensive income on the respective line items of net income, but only if the item reclassified is required under U.S. GAAP to be reclassified to net income in its entirety. ASU 2013-02 is effective for fiscal years, and interim periods beginning on or after December 15, 2012 for public entities. We adopted this ASU in the first quarter of 2013. This ASU affects presentation only and therefore there is no financial statement impact on our financial condition or results of operations. See the consolidated statements of comprehensive income.
	In February 2013, the FASB issued ASU No. 2013-04, Liabilities (Topic 405) Obligations Resulting from Joint and Several Liability Arrangements for Which the Total Amount of the Obligation is Fixed at the Reporting Date. The ASU requires an entity to measure obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. Entities are required to record the amount the entity agreed to pay on the basis of its arrangement among its co-obligors and any additional amount the reporting entity expects to pay on behalf of its co-obligors at the reporting date. Examples of obligations within the scope of this guidance include debt arrangements, other contractual obligations, settled litigation and judicial rulings. ASU 2013-04 is effective retrospectively to all periods presented for fiscal years and interim periods beginning after December 15, 2013 for public entities. We do not expect this ASU to have a significant impact on our financial condition or results of operations.
	In July 2013, the FASB issued ASU No. 2013-10, Derivatives and Hedging (Topic 815) Inclusion of the Fed Funds Effective Swap Rate (or Overnight Index Swap Rate) as a Benchmark Interest Rate for Hedging Accounting Purposes.
	The ASU provides for the inclusion of the Fed Funds Effective Swap Rate or also referred to as the Overnight Index Swap Rate ("OIS") as a U.S. benchmark interest rate for hedge accounting purposes, in addition to direct Treasury obligations of the U.S. government ("UST") and London Interbank Offered Rate ("LIBOR"). The ASU is a result of the financial crisis in 2008, as the exposure to and the demand for hedging the Fund Funds rate have increased significantly. ASU 2013-10 is effective prospectively for qualifying new or re-designated hedging relationships entered into on or after July 17, 2013. We do not expect this ASU to have a significant impact on our financial condition or results of operations.
	In July 2013, the FASB issued ASU No. 2013-11, Income Taxes (Topic 740) Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The ASU requires that an unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward except as follows. To the extent that a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date to settle any additional income taxes that would result from the disallowance of a tax position, or the tax law does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purposes, then the unrecognized tax benefit should be presented as a liability.
	ASU 2013-11 is effective prospectively for fiscal years, and interim periods beginning after December 15, 2013 for public entities. We do not expect this ASU to have a significant impact on our financial condition or results of operations.
	In January 2014, the FASB issued ASU No. 2014-01, Investments-Equity and Joint Ventures (Topic 323) Accounting for Investments in Qualified Affordable Projects. This ASU permits entities to make an accounting policy election to account for their investments in qualified affordable housing projects using the proportional amortization method if certain conditions are met. Under the proportional amortization method, the initial cost of the investment is amortized in proportion to the tax credits and other tax benefits received and the net investment performance is recognized in the income statement as part of income tax expense (benefit). We plan on adopting this ASU starting in 2014 and elect to account for all low income housing investments using the proportional amortization method instead of cost method. The change in accounting policy will not have a significant impact on our financial condition or results of operations.
	In January 2014, the FASB issued ASU No. 2014-04, Receivables - Troubled Debt Restructurings by Creditors (Subtopic 310-40) Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure. Current accounting literature on troubled debt restructurings include guidance on when a creditor obtains one or more collateral assets in satisfaction of all or part of the receivable. The accounting literature indicates that a creditor should reclassify a collateralized mortgage loan such that the loan should be de-recognized and the collateral asset recognized when it is determined that there has been in substance a repossession or foreclosure by the creditor. However, in substance a repossession or foreclosure and physical possession are not currently defined and there is diversity about when a creditor should de-recognize the loan receivable and recognize the real estate property. This ASU clarifies when an in substance repossession or foreclosure occurs. ASU 2014-04 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2014 for public entities. We do not expect this ASU to have a significant impact on our financial condition or results of operations.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Schedule of Earnings Per Share Reconciliation	'
	The following table shows: 1) weighted average basic shares, 2) potential common shares related to stock options, unvested restricted stock and stock warrant, and 3) weighted average diluted shares. Basic earnings per share (“EPS”) are calculated by dividing net income by the weighted average number of common shares outstanding during each period, excluding unvested restricted stock. Diluted EPS are calculated using the weighted average diluted shares. The number of potential common shares included in quarterly diluted EPS is computed using the average market prices during the three months included in the reporting period under the treasury stock method. The number of potential common shares included in year-to-date diluted EPS is a year-to-date weighted average of potential common shares included in each quarterly diluted EPS computation. We have two forms of our outstanding common stock: common stock and unvested restricted stock awards. Holders of restricted stock awards receive non-forfeitable dividends at the same rate as common shareholders and they both share equally in undistributed earnings.
	(in thousands, except per share data)	2013		2012		2011
	Weighted average basic shares outstanding	5,457		5,341		5,302
	Add: Potential common shares related to stock options	44		47		41
	Potential common shares related to unvested restricted stock awards	4		5		4
	Potential common shares related to warrants	53		45		37
	Weighted average diluted shares outstanding	5,558		5,438		5,384
	Net income	$	14,270	$	17,817	$	15,564
	Basic EPS	$	2.62	$	3.34	$	2.94
	Diluted EPS	$	2.57	$	3.28	$	2.89
	Weighted average anti-dilutive shares not included in the calculation of diluted EPS	49		50		70

Acquisition_Tables

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2013
Business Acquisition [Line Items]	'
Schedule of Pro Forma Revenue and Earnings	'
	The following table presents NorCal Community Bancorp's revenue (interest income and non-interest income) and earnings included in our consolidated statement of comprehensive income for the year ended December 31, 2013, and the revenue and earnings of the combined entity had the acquisition date been January 1, 2012. This pro forma information does not necessarily reflect the results of operations that would have resulted had the acquisition been completed at the beginning of the periods presented, nor is it indicative of the results of operations in future periods.
	Pro Forma Revenue and Earnings		NorCal Community Bancorp Only							Combined
	(in thousands; unaudited)		Revenue			Earnings				Revenue			Earnings
	Actual from November 29, 2013 to December 31, 2013		$	1,239		$	70			$	6,984		$	963
	2013 supplemental pro forma from January 1, 2013 to December 31, 2013		12,199			315				68,626			14,270
	2013 supplemental pro forma from January 1, 2013 to December 31, 20131		12,199			1,506				68,626			17,866
	2012 supplemental pro forma from January 1, 2012 to December 31, 20121		12,433			(2,841		)		85,310			13,731
	1  2013 supplemental pro forma earnings were adjusted to exclude $3.7 million of one-time acquisition related expenses booked at Bank of Marin Bancorp and $1.9 million of one-time acquisition related expenses booked at NorCal Community Bancorp in 2013. 2012 supplemental pro forma earnings were adjusted to include these charges.
Schedule of Acquisition Related Costs	'
	We incurred one-time third-party acquisition-related expenses in the consolidated statements of comprehensive income in 2013 for the NorCal acquisition and in 2011 for the Charter Oak acquisition as follows:
		2013 NorCal Acquisition				2011 Charter Oak Acquisition
	(Dollars in thousands)	Year Ended December 31, 2013				Year Ended December 31, 2011
	Data processing	$	2,807		*	$	455
	Professional services	660				457
	Personnel severance	203				—
	Other	74				88
	Total	$	3,744			$	1,000
	*Primarily relates to NorCal's core processing system contract termination and deconversion fees.
NorCal Community Bancorp	'
Business Acquisition [Line Items]	'
Schedule of Fair Values of Assets and Liabilities Acquired	'
	The following table reflects the estimated fair values of the assets acquired and liabilities assumed related to the NorCal Acquisition:
	(Dollars in thousands)		Acquisition Date (November 29, 2013)
	Assets:
	Cash and cash equivalents		$	31,804
	Investment securities		53,731
	Loans		173,759
	Core deposit intangible		4,572
	Deferred tax asset		4,114
	Goodwill		6,435
	Bank premises and equipment		203
	Other assets		6,299
	Total assets acquired		$	280,917
	Liabilities:
	Deposits:
	Non-interest bearing		$	69,123
	Interest bearing
	Transaction accounts		57,337
	Savings accounts		10,835
	Money market accounts		81,464
	Other time accounts		22,267
	Total deposits		241,026
	Subordinated debentures		4,950
	Other liabilities		408
	Total liabilities assumed		$	246,384
	Merger consideration (cash payment of $16.019 million and $18.514 million in stock)		$	34,533
Schedule of Net Liabilities and Fair Value Adjustments	'
	(Dollars in thousands)		Acquisition Date (November 29, 2013)
	Book value of net assets acquired from NorCal		$	25,552
	Fair value adjustments:
	Loans		(3,462		)
	Subordinated debentures		3,298
	Core deposit intangible asset		$	4,572
	Time deposits		(14		)
	Total purchase accounting adjustments		4,394
	Deferred tax liabilities (tax effect of purchase accounting adjustments at 42.05%)		(1,848		)
	Fair value of net assets acquired from NorCal		$	28,098
	Merger consideration		$	34,533
	Less: fair value of net assets acquired		(28,098		)
	Goodwill		$	6,435
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	'
	At December 31, 2013, the future estimated amortization expense is as follows:
	(in thousands)	2014			2015			2016			2017			2018		Thereafter		Total
	Core deposit intangible amortization	$	771		$	619		$	533		$	472		$	413	$	1,695	$	4,503

Investment_Securities_Tables

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]	'
Schedule of Available-for-sale Securities and Held-to-maturity Securities Reconciliation	'
		31-Dec-13													31-Dec-12
		Amortized			Fair			Gross Unrealized							Amortized			Fair			Gross Unrealized
	(in thousands;)	Cost			Value			Gains			(Losses)				Cost			Value			Gains			(Losses)
	Held-to-maturity
	Obligations of state and	$	80,381		$	81,429		$	1,764		$	(716	)		$	96,922		$	99,350		$	2,855		$	(427	)
	political subdivisions
	Corporate bonds	42,114			42,429			375			(60		)		42,530			42,881			458			(107		)
	Total held-to-maturity	122,495			123,858			2,139			(776		)		139,452			142,231			3,313			-534
	Available-for-sale
	Securities of U. S. government agencies:
	MBS pass-through securities issued by FHLMC and FNMA	124,063			123,033			616			(1,646		)		52,042			53,713			1,711			(40		)
	CMOs issued by FNMA	18,573			18,438			60			(195		)		4,447			4,550			105			(2		)
	CMOs issued by FHLMC	23,710			23,679			144			(175		)		13,527			13,778			251			—
	CMOs issued by GNMA	24,944			25,454			609			(99		)		38,871			39,756			886			(1		)
	Debentures of government- sponsored agencies	21,845			21,312			108			(641		)		20,462			20,589			228			(101		)
	Privately issued CMOs	10,649			10,874			257			(32		)		21,071			21,576			595			(90		)
	Obligations of state and	15,948			15,771			14			(191		)		—			—			—			—
	political subdivisions
	Corporate bonds	5,426			5,437			25			(14		)		—			—			—			—
	Total available-for-sale	245,158			243,998			1,833			(2,993		)		150,420			153,962			3,776			-234
	Total investment securities	$	367,653		$	367,856		$	3,972		$	(3,769	)		$	289,872		$	296,193		$	7,089		$	(768	)
Investments Classified by Contractual Maturity Date	'
	The amortized cost and fair value of investment debt securities by contractual maturity at December 31, 2013 and 2012 are shown below. Expected maturities will differ from contractual maturities because the issuers of the securities may have the right to call or prepay obligations with or without call or prepayment penalties.
		December 31, 2013															31-Dec-12
		Held-to-Maturity								Available-for-Sale							Held-to-Maturity								Available-for-Sale
	(in thousands)	Amortized Cost				Fair Value				Amortized Cost				Fair Value			Amortized Cost				Fair Value				Amortized Cost		Fair Value
	Within one year	$	8,731			$	8,784			$	5,522			$	5,521		$	764			$	763			$	—	$	—
	After one but within five years	88,255				89,095				42,229				42,338			98,672				99,689				26,417		27,060
	After five years through ten years	24,244				24,786				26,232				25,478			29,165				30,898				23,719		23,820
	After ten years	1,265				1,193				171,175				170,661			10,851				10,881				100,284		103,082
	Total	$	122,495			$	123,858			$	245,158			$	243,998		$	139,452			$	142,231			$	150,420	$	153,962
Schedule of Unrealized Loss on Investments	'
	The table below shows investment securities that were in unrealized loss positions at December 31, 2013 and December 31, 2012, respectively. They are summarized and classified according to the duration of the loss period as follows:
	December 31, 2013		< 12 continuous months								> 12 continuous months								Total securities
																			in a loss position
	(In thousands)		Fair value				Unrealized loss				Fair value				Unrealized loss				Fair value				Unrealized loss
	Held-to-maturity
	Obligations of state & political subdivisions		$	13,933			$	(419	)		$	9,033			$	(297	)		$	22,966			$	(716	)
	Corporate bonds		3,017				(11		)		4,963				(49		)		7,980				(60		)
	Total held-to-maturity		16,950				(430		)		13,996				(346		)		30,946				(776		)
	Available-for-sale
	MBS pass-through securities issued by FHLMC and FNMA		90,914				(1,297		)		3,172				(349		)		94,086				(1,646		)
	CMOs issued by FNMA		17,535				(195		)		—				—				17,535				(195		)
	CMOs issued by FHLMC		17,899				(175		)		—				—				17,899				(175		)
	CMOs issued by GNMA		3,966				(99		)		—				—				3,966				(99		)
	Debentures of government- sponsored agencies		16,872				(641		)		—				—				16,872				(641		)
	Privately issued CMOs		4,634				(31		)		159				(1		)		4,793				(32		)
	Obligations of state & political subdivisions		11,516				(191		)		—				—				11,516				(191		)
	Corporate bonds		1,479				(14		)		—				—				1,479				(14		)
	Total available-for-sale		164,815				(2,643		)		3,331				(350		)		168,146				(2,993		)
	Total temporarily impaired securities		$	181,765			$	(3,073	)		$	17,327			$	(696	)		$	199,092			$	(3,769	)
	December 31, 2012		< 12 continuous months								> 12 continuous months								Total securities
																			in a loss position
	(In thousands)		Fair value				Unrealized loss				Fair value				Unrealized loss				Fair value				Unrealized loss
	Held-to-maturity
	Obligations of state & political subdivisions		$	33,196			$	(427	)		$	—			$	—			$	33,196			$	(427	)
	Corporate bonds		15,649				(107		)		—				—				15,649				(107		)
	Total held-to-maturity		48,845				(534		)		—				—				48,845				(534		)
	Available-for-sale
	MBS pass-through securities issued by FHLMC and FNMA		3,569				(40		)		—				—				3,569				(40		)
	CMOs issued by FNMA		3,185				(2		)		—				—				3,185				(2		)
	CMOs issued by GNMA		1,550				(1		)		—				—				1,550				(1		)
	Debentures of government- sponsored agencies		9,899				(101		)		—				—				9,899				(101		)
	Privately issued CMOs		4,214				(89		)		203				(1		)		4,417				(90		)
	Total available-for-sale		22,417				(233		)		203				(1		)		22,620				(234		)
	Total temporarily impaired securities		$	71,262			$	(767	)		$	203			$	(1	)		$	71,465			$	(768	)

Loans_and_Allowance_for_Loan_L1

Loans and Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2013
Receivables [Abstract]	'
Past Due Financing Receivables	'
	Outstanding loans by class and payment aging as of December 31, 2013 and 2012 are as follows:
	Loan Aging Analysis by Class as of December 31, 2013 and 2012
	(dollars in thousands)	Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential 1				Installment and other consumer				Total
	31-Dec-13
	30-59 days past due	$	18			$	—			$	—			$	—			$	240			$	717			$	17			$	992
	60-89 days past due	—				—				—				—				—				—				3				3
	Greater than 90 days past due (non-accrual) 2	1,187				1,403				2,807				5,218				234				660				169				11,678
	Total past due	1,205				1,403				2,807				5,218				474				1,377				189				12,673
	Current	182,086				239,710				622,212				26,359				97,995				71,257				17,030				1,256,649
	Total loans 3	$	183,291			$	241,113			$	625,019			$	31,577			$	98,469			$	72,634			$	17,219			$	1,269,322
	Non-accrual loans to total loans	0.6		%		0.6		%		0.4		%		16.5		%		0.2		%		0.9		%		1		%		0.9		%
	December 31, 2012
	30-59 days past due	$	29			$	—			$	—			$	—			$	294			$	167			$	98			$	588
	60-89 days past due	—				—				—				—				—				—				—				—
	Greater than 90 days past due (non-accrual) 2	4,893				1,403				6,843				2,239				545				1,196				533				17,652
	Total past due	4,922				1,403				6,843				2,239				839				1,363				631				18,240
	Current	171,509				195,003				502,163				28,426				92,398				48,069				18,144				1,055,712
	Total loans 3	$	176,431			$	196,406			$	509,006			$	30,665			$	93,237			$	49,432			$	18,775			$	1,073,952
	Non-accrual loans to total loans	2.8		%		0.7		%		1.3		%		7.3		%		0.6		%		2.4		%		2.8		%		1.6		%
	1 Our residential loan portfolio includes no sub-prime loans, nor is it our normal practice to underwrite loans commonly referred to as "Alt-A mortgages," the characteristics of which are loans lacking full documentation, borrowers having low FICO scores or higher loan-to-value ratios.
	2 Amounts include $1.4 million and $1.6 million of Purchased Credit Impaired ("PCI") loans that have stopped accreting interest at December 31, 2013 and 2012, respectively, and exclude accreting PCI loans of $5.7 million and $3.0 million at December 31, 2013 and 2012, respectively, as their accretable yield interest recognition is independent from the underlying contractual loan delinquency status. There were no accruing loans past due more than ninety days at December 31, 2013 or 2012.
	3 Amounts were net of deferred loan (costs)/fees of $(24) thousand and $769 thousand at December 31, 2013 and 2012, respectively. Amounts were also net of unaccreted purchase discounts on non-PCI loans of $7.6 million and $2.1 million at December 31, 2013 and 2012, respectively.
Financing Receivable Credit Quality Indicators	'
	The following table represents our analysis of loans by internally assigned grades, including the PCI loans, at December 31, 2013 and 2012:
	(in thousands)	Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Purchased credit-impaired			Total
	Credit Risk Profile by Internally Assigned Grade:
	31-Dec-13
	Pass	$	162,625			$	216,537			$	609,157			$	25,069			$	93,792			$	69,176			$	16,336			$	1,340		$	1,194,032
	Special Mention	13,990				16,533				8,570				725				2,164				1,047				227				894			44,150
	Substandard	6,343				3,224				5,413				5,768				2,444				2,411				656				4,881			31,140
	Total loans	$	182,958			$	236,294			$	623,140			$	31,562			$	98,400			$	72,634			$	17,219			$	7,115		$	1,269,322
	December 31, 2012
	Pass	$	148,771			$	170,553			$	489,978			$	26,287			$	86,957			$	45,634			$	17,809			$	1,862		$	987,851
	Special Mention	13,267				20,346				8,671				1,970				2,931				1,067				—				933			49,185
	Substandard	13,753				2,992				8,963				2,408				3,349				2,731				966				1,754			36,916
	Total loans	$	175,791			$	193,891			$	507,612			$	30,665			$	93,237			$	49,432			$	18,775			$	4,549		$	1,073,952
Troubled Debt Restructurings on Financing Receivables	'
	The table below presents the following information for TDRs modified during the periods presented: number of contracts modified, the recorded investment in the loans prior to modification, and the recorded investment in the loans after the loans were restructured. The table below excludes fully paid-off or fully charged-off TDR loans.
	(dollars in thousands)	Number of Contracts Modified			Pre-Modification Outstanding Recorded Investment				Post-Modification Outstanding Recorded Investment				Post-Modification Outstanding Recorded Investment at period end
	Troubled Debt Restructurings during the year ended December 31, 2013:
	Commercial	8			$	1,176			$	1,377			$	1,274
	Commercial real estate, owner occupied	1			2,961				2,956				2,930
	Commercial real estate, investor	1			539				538				534
	Construction	3			7,135				7,156				5,368
	Installment and other consumer	2			11				9				7
	Total	15			$	11,822			$	12,036			$	10,113
	Troubled Debt Restructurings during the year ended December 31, 2012:
	Commercial	14			$	9,980			$	9,903			$	5,965
	Construction	2			2,793				2,793				1,760
	Home Equity	2			472				473				469
	Other residential	2			1,422				1,401				1,392
	Installment and other consumer	2			231				231				228
	Total	22			$	14,898			$	14,801			$	9,814
	Troubled Debt Restructurings during the year ended December 31, 2011:
	Commercial	27			$	5,854			$	5,940			$	4,969
	Commercial real estate, owner occupied	2			1,366				1,403				1,403
	Construction	2			817				817				800
	Home Equity	3			478				469				467
	Other residential	3			1,467				1,467				1,464
	Installment and other consumer	13			1,607				1,605				1,552
	Total	50			$	11,589			$	11,701			$	10,655
	The table below summarizes outstanding TDR loans by loan class as of December 31, 2013, 2012 and 2011. The summary includes those TDRs that are on nonaccrual status and those that continue to accrue interest.
	(in thousands)			As of
	Recorded investment in Troubled Debt Restructurings 1			December 31, 2013				December 31, 2012				31-Dec-11
	Commercial			$	5,117			$	9,470			$	4,969
	Commercial real estate, owner-occupied			4,333				1,403				1,403
	Commercial real estate, investor			534				—				—
	Construction			6,335				1,929				800
	Home equity			506				908				467
	Other residential			2,063				2,831				1,464
	Installment and other consumer			1,693				1,743				1,552
	Total			$	20,581			$	18,284			$	10,655
	1 Includes $12.9 million, $10.8 million and $6.3 million of TDR loans that were accruing interest as of December 31, 2013, 2012 and 2011 respectively.
Loans Receivable & Allowance For Loan Losses, Schedule Of Provision For Loan Losses, Effect Of Change In Methodology	'
	Lastly, we added a subjective factor for the impact of the acquisition in 2013, which added approximately $800 thousand in reserves by loan class, which would have been unallocated under the previous methodology.
			The year ended December 31, 2013
	(in thousands)		Calculated Provision Based on New Methodology				Calculated Provision Based on Prior Methodology				Difference In ALLL
	Commercial and industrial		$	(1,393	)		$	(449	)		$	(944	)
	Commercial real estate, owner-occupied		615				50				565
	Commercial real estate, investor		1,940				174				1,766
	Construction		83				167				(84		)
	Home equity		(223		)		(39		)		(184		)
	Other residential		(234		)		(138		)		(96		)
	Installment and other consumer		(535		)		(319		)		(216		)
	Unallocated		287				1,094				(807		)
	Total provision for loan losses		$	540			$	540			$	—
Impaired Financing Receivables	'
	The table below summarizes information on impaired loans and their related allowance. Total impaired loans include non-accrual loans, accruing TDR loans and accreting PCI loans that have experienced post-acquisition declines in cash flows expected to be collected.
	(dollars in thousands)		Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Total
	31-Dec-13
	Recorded investment in impaired loans:
	With no specific allowance recorded		$	977			$	1,403			$	3,341			$	2,806			$	349			$	1,254			$	112			$	10,242
	With a specific allowance recorded		4,725				4,085				—				3,927				157				809				1,750				15,453
	Total recorded investment in impaired loans		$	5,702			$	5,488			$	3,341			$	6,733			$	506			$	2,063			$	1,862			$	25,695
	Unpaid principal balance of impaired loans:
	With no specific allowance recorded		$	977			$	3,060			$	5,333			$	5,547			$	835			$	1,254			$	154			$	17,160
	With a specific allowance recorded		4,930				5,088				—				4,114				157				809				1,750				16,848
	Total unpaid principal balance of impaired loans		$	5,907			$	8,148			$	5,333			$	9,661			$	992			$	2,063			$	1,904			$	34,008
	Specific allowance		$	1,170			$	90			$	—			$	341			$	1			$	23			$	364			$	1,989
	Average recorded investment in impaired loans during 2013		$	7,168			$	3,519			$	5,847			$	7,200			$	909			$	2,632			$	1,872			$	29,147
	Interest income recognized on impaired loans during 2013		$	476			$	253			$	14			$	249			$	29			$	89			$	71			$	1,181
	December 31, 2012
	Recorded investment in impaired loans:
	With no specific allowance recorded		$	6,825			$	1,403			$	3,725			$	2,328			$	931			$	2,598			$	978			$	18,788
	With a specific allowance recorded		2,645				471				4,513				1,840				261				715				1,070				11,515
	Total recorded investment in impaired loans		$	9,470			$	1,874			$	8,238			$	4,168			$	1,192			$	3,313			$	2,048			$	30,303
	Unpaid principal balance of impaired loans:
	With no specific allowance recorded		$	7,633			$	3,060			$	5,717			$	2,514			$	1,417			$	2,598			$	1,020			$	23,959
	With a specific allowance recorded		2,930				966				4,887				4,519				324				715				1,070				15,411
	Total recorded investment in impaired loans		$	10,563			$	4,026			$	10,604			$	7,033			$	1,741			$	3,313			$	2,090			$	39,370
	Specific allowance		$	1,131			$	26			$	374			$	118			$	154			$	120			$	431			$	2,354
	Average recorded investment in impaired loans during 2012		$	11,772			$	1,538			$	5,135			$	12,909			$	1,314			$	2,509			$	2,151			$	37,328
	Interest income recognized on impaired loans during 2012		$	803			$	111			$	512			$	570			$	32			$	175			$	96			$	2,299
	Average recorded investment in impaired loans during 2011		$	4,695			$	1,873			$	595			$	3,505			$	813			$	1,612			$	1,844			$	14,937
	Interest income recognized on impaired loans during 2011		$	102			$	—			$	38			$	—			$	14			$	72			$	26			$	252
Allowance for Credit Losses on Financing Receivables	'
	The following table discloses loans by major portfolio category and activity in the ALLL, as well as the related ALLL disaggregated by impairment evaluation method:
	Allowance for Loan Losses and Recorded Investment in Loans as of and for the year ended December 31, 2013
	(dollars in thousands)		Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Unallocated			Total
	For the year ended December 31, 2013
	Allowance for loan losses:
	Beginning balance		$	4,100			$	1,313			$	4,372			$	611			$	1,264			$	551			$	1,231			$	219		$	13,661
	Provision (reversal)		(1,393		)		615				1,940				83				(223		)		(234		)		(535		)		287			540
	Charge-offs		(672		)		—				(156		)		(62		)		(176		)		—				(88		)		—			(1,154		)
	Recoveries		1,021				84				40				1				10				—				21				—			1,177
	Ending balance		$	3,056			$	2,012			$	6,196			$	633			$	875			$	317			$	629			$	506		$	14,224
	Ending ALLL related to loans collectively evaluated for impairment		$	1,886			$	1,922			$	6,196			$	292			$	874			$	294			$	265			$	506		$	12,235
	Ending ALLL related to loans  individually evaluated for impairment		$	987			$	31			$	—			$	341			$	1			$	23			$	364			$	—		$	1,747
	Ending ALLL related to purchased  credit-impaired loans		$	183			$	59			$	—			$	—			$	—			$	—			$	—			$	—		$	242
	Loans outstanding:
	Collectively evaluated for impairment		$	177,550			$	233,330			$	619,833			$	24,829			$	97,894			$	70,571			$	15,357			$	—		$	1,239,364
	Individually evaluated for impairment1		5,408				2,930				3,341				6,733				506				2,063				1,862				—			22,843
	Purchased credit-impaired		333				4,853				1,845				15				69				—				—				—			7,115
	Total		$	183,291			$	241,113			$	625,019			$	31,577			$	98,469			$	72,634			$	17,219			$	—		$	1,269,322
	Ratio of allowance for loan losses to total loans		1.67		%		0.83		%		0.99		%		2		%		0.89		%		0.44		%		3.65		%		NM			1.12		%
	Allowance for loan losses to non-accrual loans		257		%		143		%		221		%		12		%		374		%		48		%		372		%		NM			122		%
	1 Total excludes $2.9 million of PCI loans that have experienced post-acquisition declines in cash flows expected to be collected.These loans are included in the "purchased credit-impaired" amount in the next line below.
	NM Not Meaningful
	Allowance for Loan Losses and Recorded Investment in Loans as of and for the year ended December 31, 2012
	(dollars in thousands)		Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Unallocated			Total
	As of December 31, 2012:
	Allowance for loan losses:
	Beginning balance		$	4,334			$	1,305			$	3,710			$	1,505			$	1,444			$	940			$	1,182			$	219		$	14,639
	Provision (reversal)		117				184				3,076				(643		)		190				(193		)		169				—			2,900
	Charge-offs		(892		)		(181		)		(2,414		)		(373		)		(382		)		(196		)		(122		)		—			(4,560		)
	Recoveries		541				5				—				122				12				—				2				—			682
	Ending balance		$	4,100			$	1,313			$	4,372			$	611			$	1,264			$	551			$	1,231			$	219		$	13,661
	Ending ALLL related to loans collectively evaluated for impairment		$	2,969			$	1,287			$	3,998			$	493			$	1,110			$	431			$	800			$	219		$	11,307
	Ending ALLL related to loans  individually evaluated for impairment		$	1,090			$	—			$	178			$	118			$	154			$	120			$	431			$	—		$	2,091
	Ending ALLL related to purchased  credit-impaired loans		$	41			$	26			$	196			$	—			$	—			$	—			$	—			$	—		$	263
	Loans outstanding:
	Collectively evaluated for impairment		$	166,860			$	193,891			$	500,768			$	26,497			$	92,045			$	46,119			$	16,727			$	—		$	1,042,907
	Individually evaluated for impairment1		8,931				—				6,844				4,168				1,192				3,313				2,048				—			26,496
	Purchased credit-impaired		640				2,515				1,394				—				—				—				—				—			4,549
	Total		$	176,431			$	196,406			$	509,006			$	30,665			$	93,237			$	49,432			$	18,775			$	—		$	1,073,952
	Ratio of allowance for loan losses to total loans		2.32		%		0.67		%		0.86		%		1.99		%		1.36		%		1.11		%		6.56		%		NM			1.27		%
	Allowance for loan losses to non-accrual loans		84		%		94		%		64		%		27		%		232		%		46		%		231		%		NM			77		%
	1 Total excludes $3.8 million PCI loans that have experienced credit deterioration post-acquisition, which are included in the "purchased credit-impaired" amount in the next line below.
	NM Not Meaningful
	Allowance for Loan Losses and Recorded Investment in Loans as of and for the year ended December 31, 2011
	(dollars in thousands)		Commercial				Commercial real estate, owner-occupied				Commercial real estate, investor				Construction				Home equity				Other residential				Installment and other consumer				Unallocated			Total
	As of December 31, 2011:
	Allowance for loan losses:
	Beginning balance		$	3,114			$	1,037			$	4,134			$	1,694			$	643			$	738			$	835			$	197		$	12,392
	Provision (reversal)		4,469				377				(424		)		275				1,342				202				787				22			7,050
	Charge-offs		(3,306		)		(113		)		—				(473		)		(554		)		—				(456		)		—			(4,902		)
	Recoveries		57				4				—				9				13				—				16				—			99
	Ending balance		$	4,334			$	1,305			$	3,710			$	1,505			$	1,444			$	940			$	1,182			$	219		$	14,639
	Ending ALLL related to loans  collectively evaluated for impairment		$	3,049			$	1,136			$	3,547			$	1,311			$	1,182			$	532			$	717			$	219		$	11,693
	Ending ALLL related to loans  individually evaluated for impairment		$	957			$	—			$	91			$	194			$	262			$	408			$	465			$	—		$	2,377
	Ending ALLL related to purchased credit-impaired loans		$	328			$	169			$	72			$	—			$	—			$	—			$	—			$	—		$	569
	Loans outstanding:
	Collectively evaluated for impairment		$	169,564			$	171,492			$	444,060			$	48,653			$	96,998			$	58,095			$	20,661			$	—		$	1,009,523
	Individually evaluated for impairment 1		5,110				—				741				3,304				1,045				3,407				2,071				—			15,678
	Purchased credit-impaired		1,116				3,213				1,624				—				—				—				—				—			5,953
	Total		$	175,790			$	174,705			$	446,425			$	51,957			$	98,043			$	61,502			$	22,732			$	—		$	1,031,154
	Ratio of allowance for loan losses to total loans		2.47		%		0.75		%		0.83		%		2.9		%		1.47		%		1.53		%		5.2		%		NM			1.42		%
	Allowance for loan losses to non-accrual loans		147		%		64		%		501		%		50		%		189		%		48		%		228		%		NM			122		%
	1 Total excludes $4.5 million PCI loans that have experienced credit deterioration post-acquisition, which are included in the "purchased credit-impaired" amount in the next line below.
NM Not Meaningful
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Table Text Block]	'
	The following table reflects the outstanding balance and related carrying value of PCI loans related to the 2013 NorCal acquisition and the 2011 Charter Oak acquisition as of December 31, 2013 and 2012:
		31-Dec-13								31-Dec-12
	PCI Loans	Unpaid principal balance				Carrying value				Unpaid principal balance				Carrying value
	(dollars in thousands)
	Commercial	$	1,094			$	333			$	2,163			$	640
	Commercial real estate	9,152				6,698				6,370				3,909
	Construction	149				15				—				—
	Home equity	239				69				—				—
	Total purchased credit-impaired loans	$	10,634			$	7,115			$	8,533			$	4,549
	The following table presents the fair value of loans acquired from Bank of Alameda for purchased credit-impaired loans and other purchased loans as of the acquisition date:
		29-Nov-13
	(dollars in thousands)	Purchased credit-impaired loans				Other purchased loans				Total
	Contractually required payments including interest	$	5,706			$	211,769			$	217,475
	Less: nonaccretable difference	(1,183		)		—				(1,183		)
	Cash flows expected to be collected (undiscounted)	4,523				211,769				216,292
	Accretable yield	(707		)		(41,826		)	1	(42,533		)
	Fair value of purchased loans	$	3,816			$	169,943			$	173,759
	1 $6.6 million of the $41.8 million represents the difference between the contractual principal amounts due and the fair value. This discount is to be accreted to interest income over the remaining lives of the loans. The remaining $35.2 million is the contractual interest to be earned over the life of the loans.
	The following table reflects the outstanding balance and related carrying value of PCI loans as of the acquisition date:
		29-Nov-13
	PCI Loans	Unpaid principal balance				Fair value
	(dollars in thousands)
	Commercial	$	847			$	369
	Commercial real estate	3,757				3,362
	Construction	150				16
	Home equity	239				69
	Total purchased credit-impaired loans	$	4,993			$	3,816
Accretable Yield Activity	'
	The activities in the accretable yield, or income expected to be earned, for PCI loans were as follows:
	Accretable Yield		Years ended
	(dollars in thousands)		December 31, 2013				December 31, 2012				December 31, 2011
	Balance at beginning of period		$	3,960			$	5,405			$	—
	Additions		707				—				1,902
	Removals 1		(793		)		(1,221		)		(1,019		)
	Accretion		(725		)		(1,641		)		(1,418		)
	Reclassifications (to)/from nonaccretable difference 2		500				1,417				5,940
	Balance at end of period		$	3,649			$	3,960			$	5,405
	1 Represents the accretable difference that is relieved when a loan exits the PCI population due to payoff, full charge-off, or transfer to repossessed assets, etc.
	2 Primarily relates to improvements in expected credit performance and changes in expected timing of cash flows.
Schedule of Related Party Transactions	'
	An analysis of net loans to related parties for each of the three years ended December 31, 2013, 2012 and 2011 is as follows:
	(in thousands)	2013				2012				2011
	Balance at beginning of year	$	3,425			$	6,866			$	6,997
	Additions	550				826				1,690
	Advances	569				3				43
	Repayments	—				(2,730		)		(1,864		)
	Reclassified as unrelated-party loan	(795		)		(1,540		)		—
	Balance at end of year	$	3,749			$	3,425			$	6,866

Bank_Premises_and_Equipment_Ta

Bank Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Summary of Bank Premises and Equipment	'
	A summary of Bank premises and equipment at December 31 follows:
	(in thousands)	2013			2012
	Leasehold improvements	$	12,684		$	12,116
	Furniture and equipment	7,888			7,402
	Subtotal	20,572			19,518
	Accumulated depreciation and amortization	(11,462		)	(10,174		)
	Bank premises and equipment, net	$	9,110		$	9,344

Deposits_Tables

Deposits (Tables)	12 Months Ended
	Dec. 31, 2013
Banking and Thrift [Abstract]	'
Schedule of Maturities for Time Deposits	'
	Scheduled maturities of these deposits at December 31, 2013 are presented as follows:
	(in thousands)	2014	2015	2016	2017	2018	Thereafter	Total
	Scheduled maturities of time deposits	$100,350	$16,474	$22,457	$13,304	$9,283	$—	$161,868

Borrowings_Tables

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Schedule of Subordinated Debentures	'
	The following is a summary of the contractual terms of the subordinated debentures due to NorCal Community Bancorp grantor trusts as of December 31, 2013:
	Subordinated debentures due to NorCal Community Bancorp Trust I on October 7, 2033 with interest payable quarterly, based on 3-month LIBOR plus 3.05%, repricing quarterly (3.29% as of December 31, 2013), redeemable, in whole or in part, on any interest payment date.		$	4,124
	Subordinated debentures due to NorCal Community Bancorp Trust II on March 15, 2036 with interest payable quarterly, based on 3-month LIBOR plus 1.40%, repricing quarterly (1.64% as of December 31, 2013), redeemable, in whole or in part, on any interest payment date.		$	4,124
	Total		$	8,248
Schedule of Borrowings	'
	Borrowings at December 31, 2013 and 2012 are summarized as follows:
		2013								2012
	(in thousands)	Carrying Value			Average Balance		Average Rate			Carrying Value		Average Balance		Average Rate
	FHLB borrowings	$	15,000		$	19,054	1.67	%		$	15,000	$	16,205	2.09	%
	Subordinated debentures	$	4,969		$	407	8.48	%	1,000	$	—	$	3,552	4.21	%	2
	1Amount includes the impact of $19 thousand of accretion on the fair value discount.
	2 Amount includes the impact of the $42 thousand accelerated unamortized debt issuance cost in 2012 discussed above.

Stockholders_Equity_and_Stock_1

Stockholders' Equity and Stock Plans (Tables)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Schedule of Share-based Compensation, Stock Options, Activity	'
	A summary of activity for stock options for the years ended December 31, 2013, 2012 and 2011 is presented below. The intrinsic value is calculated as the number of in-the-money options times the difference between the market price of our stock as of each year end presented and the exercise prices of the in-the-money options.
													Average
				Weighted			Aggregate			Weighted			Remaining
				Average			Intrinsic Value			Average			Contractual
		Number of		Exercise			as of year-end			Grant-Date			Term
		Shares		Price			(in thousands)			Fair Value			(in years)
	Options outstanding at December 31, 2010	317,804		$	29.27		$	1,828		$	8.39		5.18
	Granted	17,585		37.76			3			11.19			—
	Cancelled, expired or forfeited	(670	)	29.28			6			7.07			—
	Exercised	(34,913	)	21.22			534			7.51			—
	Options outstanding at December 31, 2011	299,806		30.71			2,068			8.66			4.7
	Exercisable (vested) at December 31, 2011	226,989		30.64			1,579			8.81			3.82
	Options outstanding at December 31, 2011	299,806		30.71			2,068			8.66			4.7
	Granted	23,930		38.18			—			9.82			—
	Cancelled, expired or forfeited	(640	)	31.51			4			8			—
	Exercised	(37,563	)	27.7			400			8.19			—
	Options outstanding at December 31, 2012	285,533		31.73			1,661			8.82			4.43
	Exercisable (vested) at December 31, 2012	217,232		31.15			1,372			8.77			3.39
	Options outstanding at December 31, 2012	285,533		31.73			1,661			8.82			4.43
	Granted	30,000		39.99			102			10.59			—
	Cancelled, expired or forfeited	(23,840	)	35.12			151			9.31			—
	Exercised	(71,237	)	31.13			664			8.3			—
	Options outstanding at December 31, 2013	220,456		32.74			2,349			9.21			4.05
	Exercisable (vested) at December 31, 2013	163,301		31.09			2,008			8.92			2.56
Schedule of Unrecognized Compensation Cost, Nonvested Awards	'
	The following table summarizes non-vested share-based awards at December 31, 2013, and changes during the year ended December 31, 2013.
		Options						Restricted Stock Awards
				Weighted						Weighted
				Average						Average
		Number of		Grant-Date				Number of		Grant-Date
		Shares		Fair Value				Shares		Fair Value
	Non-vested awards at December 31, 2012	73,876		$	8.98			21,610		$	34.05
	Granted	30,000		10.59				11,850		39.96
	Vested	(22,881	)	8.17				(6,941	)	31.42
	Forfeited	(23,840	)	9.31				(3,998	)	36.19
	Non-vested awards at December 31, 2013	57,155		10.05				22,521		37.59
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range	'
	A summary of the options outstanding and exercisable by price range as of December 31, 2013 is presented in the following table:
		Stock Options Outstanding as of December 31, 2013							Stock Options Exercisable as of December 31, 2013
				Remaining	Weighted						Weighted
		Stock Options		Contractual Life	Average				Stock Options		Average
	Range of Exercise Prices	Outstanding		(in years)	Exercise Price				Exercisable		Exercise Price
	$20.01 - $25.00	15,328		5.3	$	22.25			10,798		$	22.25
	$25.01 - $30.00	47,711		1.6	27.11				47,711		27.11
	$30.01 - $35.00	81,724		2.4	33.04				77,474		33.04
	$35.01 - $40.00	59,193		6.5	37.39				27,318		36.02
	$40.01 - $45.00	16,500		9.5	40.52				—		—
		220,456		4.1	32.74				163,301		31.09
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	'
	The weighted-average assumptions used in the pricing model are noted in the table below. The expected term of options granted is derived from historical data on employee exercise and post-vesting employment termination behavior. The risk-free rate for periods within the expected life of the option is based on the U.S. Treasury yield curve in effect at the time of the grant. Expected volatility is based on the historical volatility of the common stock.
		Years ended December 31,
		2013		2012		2011
	Risk-free interest rate	1.6	%	1.6	%	2.77	%
	Expected dividend yield on common stock	1.8	%	1.78	%	1.69	%
	Expected life in years	6.8		7		7.5
	Expected price volatility	30.01	%	28.7	%	28.92	%
Summary of Cash Dividends Paid to Common Shareholders	'
	Presented below is a summary of cash dividends paid to common shareholders, recorded as a reduction of retained earnings.
			Years ended December 31,
	(in thousands except per share data)		2013			2012			2011
	Cash dividends to common stockholders		$	3,970		$	3,751		$	3,457
	Cash dividends per common share		0.73			0.7			0.65

Fair_Value_of_Assets_and_Liabi1

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	'
	The following table summarizes our assets and liabilities that were required to be recorded at fair value on a recurring basis.
	(in thousands)	Carrying Value			Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
	Description of Financial Instruments
	At December 31, 2013:
	Securities available-for-sale:
	Mortgage-backed securities and collateralized mortgage obligations issued by U.S. government-sponsored agencies	$	190,604		$	—		$	190,604		$	—
	Debentures of government-sponsored agencies	$	21,312		$	—		$	21,312		$	—
	Privately-issued collateralized mortgage obligations	$	10,874		$	—		$	10,874		$	—
	Obligations of state and political subdivisions	$	15,948		$	—		$	15,771		$	—
	Corporate bonds	$	5,426		$	—		$	5,437		$	—
	Derivative financial assets (interest rate contracts)	$	961		$	—		$	961		$	—
	Derivative financial liabilities (interest rate contracts)	$	2,519		$	—		$	2,519		$	—
	At December 31, 2012:
	Securities available-for-sale:
	Mortgage-backed securities and collateralized mortgage obligations issued by U.S. government-sponsored agencies	$	111,797		$	—		$	111,797		$	—
	Debentures of government-sponsored agencies	$	20,589		$	—		$	20,589		$	—
	Privately-issued collateralized mortgage obligations	$	21,576		$	—		$	21,576		$	—
	Derivative financial assets (interest rate contracts)	$	1		$	—		$	1		$	—
	Derivative financial liabilities (interest rate contracts)	$	5,240		$	—		$	5,240		$	—
Fair Value Measurements, Nonrecurring	'
	The following table presents the carrying value of financial instruments that were measured at fair value on a non-recurring basis and that were still held in the consolidated statements of condition at each respective period end, by level within the fair value hierarchy as of December 31, 2013 and 2012.
	(in thousands)	Carrying Value			Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
	Description of Financial Instruments				(Level 1)			(Level 2)			(Level 3) 1
	At December 31, 2013:
	Impaired loans carried at fair value:
	Construction	$	3,037		$	—		$	—		$	3,037
	Installment and other consumer	35			—			—			35
	Total	$	3,072		$	—		$	—		$	3,072
	At December 31, 2012:
	Impaired loans carried at fair value:
	Commercial and industrial	$	51		$	—		$	—		$	51
	Commercial real estate, investor	2,941			—			—			2,941
	Construction	1,722			—			—			1,722
	Home equity	107			—			—			107
	Other residential	594			—			—			594
	Installment and other consumer	159			—			—			159
	Total	$	5,574		$	—		$	—		$	5,574
	1 Represents collateral-dependent loan principal balances that had been generally written down to the values of the underlying collateral, net of specific valuation allowance of $363 thousand and $729 thousand at December 31, 2013 and 2012, respectively. The carrying value of loans fully charged-off, which includes unsecured lines of credit, overdrafts and all other loans, is zero.
Fair Value, by Balance Sheet Grouping	'
	The table below is a summary of fair value estimates for financial instruments as of December 31, 2013 and 2012, excluding financial instruments recorded at fair value on a recurring basis (summarized in the first table in this note). The carrying amounts in the following table are recorded in the consolidated statements of condition under the indicated captions. We have excluded non-financial assets and non-financial liabilities defined by the Codification (ASC 820-10-15-1A), such as Bank premises and equipment, deferred taxes and other liabilities.  In addition, we have not disclosed the fair value of financial instruments specifically excluded from disclosure requirements of the Financial Instruments Topic of the Codification (ASC 825-10-50-8), such as Bank-owned life insurance policies.
		December 31, 2013						December 31, 2012
	(in thousands)	Carrying Amounts		Fair Value			Fair Value Hierarchy	Carrying Amounts		Fair Value			Fair Value Hierarchy
	Financial assets
	Cash and cash equivalents	$	103,773	$	103,773		Level 1	$	28,349	$	28,349		Level 1
	Investment securities held-to-maturity	122,495		123,858			Level 2	139,452		142,231			Level 2
	Loans, net	1,255,098		1,245,475			Level 3	1,060,291		1,111,355			Level 3
	Interest receivable	5,767		5,767			Level 2	5,073		5,073			Level 2
	Financial liabilities
	Deposits	1,587,102		1,588,278			Level 2	1,253,289		1,254,713			Level 2
	Federal Home Loan Bank borrowing	15,000		15,665			Level 2	15,000		15,989			Level 2
	Subordinated debentures	4,969		4,950			Level 3	—		—			—
	Interest payable	253		253			Level 2	225		225			Level 2

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Schedule of Components of Income Tax Expense (Benefit)	'
	The current and deferred components of the income tax provision for each of the three years ended December 31 are as follows:
	(in thousands)	2013			2012			2011
	Current tax provision
	Federal	$	6,717		$	7,994		$	7,045
	State	2,574			2,875			2,635
	Total current	9,291			10,869			9,680
	Deferred tax (benefit) provision
	Federal	(873		)	(4		)	(205		)
	State	(479		)	26			(284		)
	Total deferred	(1,352		)	22			(489		)
	Total income tax provision	$	7,939		$	10,891		$	9,191
Schedule of Deferred Tax Assets and Liabilities	'
	The following table shows the tax effect of our cumulative temporary differences as of December 31:
	(in thousands)	2013			2012
	Deferred tax assets:
	Net operating loss carryforwards from the NorCal acquisition	$	5,096		$	—
	Allowance for loan losses and off-balance sheet credit commitments	4,671			5,955
	Fair value adjustment on loans acquired from the NorCal acquisition	3,182			—
	Deferred compensation plan and salary continuation plan	1,376			1,271
	Accrued but unpaid expenses	1,177			957
	Net unrealized loss on securities available-for-sale	830			—
	State franchise tax	737			1,000
	Deferred rent and other lease incentives	591			571
	Accretion on loans and investment securities	520			—
	Other real estate owned	448			—
	Stock-based compensation	225			259
	Core deposit intangible asset	—			266
	Other	264			—
	Total gross deferred tax assets	19,117			10,279
	Deferred tax liabilities:
	Deferred loan origination costs and fees	(2,024		)	(1,052		)
	Core deposit intangible asset	(1,647		)	—
	Unaccreted discount on subordinated debentures from acquisition	(1,379		)	—
	Depreciation and disposals on premises and equipment	(159		)	(637		)
	Net unrealized gain on securities available-for-sale	—			(1,488		)
	Accretion on loans and investment securities	—			(449		)
	Total gross deferred tax liabilities	(5,209		)	(3,626		)
	Net deferred tax assets	$	13,908		$	6,653
Schedule of Effective Income Tax Rate Reconciliation	'
	The effective tax rate for 2013, 2012 and 2011 differs from the current Federal statutory income tax rate as follows:
		2013		2012		2011
	Federal statutory income tax rate	35	%	35	%	35	%
	Increase (decrease) due to:
	California franchise tax, net of federal tax benefit	6.5	%	6.5	%	6.2	%
	Tax exempt interest on municipal securities and loans	(4.0	)%	(2.9	)%	(2.8	)%
	Tax exempt earnings on bank owned life insurance	(1.5	)%	(0.9	)%	(1.1	)%
	Low income housing tax credits	(0.3	)%	—	%	—	%
	Other	—	%	0.2	%	(0.2	)%
	Effective Tax Rate	35.7	%	37.9	%	37.1	%

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of Future Minimum Rental Payments for Operating Leases	'
	At December 31, 2013, the approximate minimum future commitments payable under non-cancelable contracts for leased premises are as follows:
	(in thousands)	2014		2015		2016		2017		2018		Thereafter		Total
	Operating leases	$	3,524	$	3,575	$	3,654	$	3,681	$	3,708	$	10,078	$	28,220

Derivative_Financial_Instrumen1

Derivative Financial Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	'
	Information on our derivatives follows:
		Asset derivatives							Liability derivatives
	(in thousands;)	December 31, 2013				December 31, 2012			December 31, 2013				December 31, 2012
	Fair value hedges:
	Interest rate contracts notional amount	$	17,956			$	4,932		$	21,577			$	38,156
	Interest rate contracts fair value 1	961				1			2,519				5,240
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]	'
		Year ended December 31,
	(in thousands;)	2013				2012				2011
	Increase (decrease) in value of designated interest rate swaps recognized in interest income	$	3,680			$	(188	)		$	(2,582	)
	Payment on interest rate swaps recorded in interest income	(1,422		)		(1,342		)		(1,076		)
	(Decrease) increase in value of hedged loans recognized in interest income	(3,971		)		311				2,436
	(Decrease) increase in value of yield maintenance agreement recognized against interest income	(71		)		168				(14		)
	Net loss on derivatives recognized against interest income 2	$	(1,784	)		$	(1,051	)		$	(1,236	)
	1 See Note 4 for valuation methodology.
	2 Ineffectiveness of $362 thousand, $291 thousand and $(160) thousand was recorded in interest income during the years December 31, 2013, 2012 and 2011, respectively. Changes in value of swaps were included in the assessment of hedge effectiveness.
Offsetting Assets	'
	Information on financial instruments that are eligible for offset in the consolidated statements of condition follows:
	Offsetting of Financial Assets and Derivative Assets
	(in thousands;)										Gross Amounts Not Offset in the Statements of Condition
					Gross Amounts			Net Amounts
		Gross Amounts			Offset in the			of Assets Presented
		of Recognized			Statements of			in the Statements			Financial			Cash Collateral
		Assets1			Condition			of Condition1			Instruments			Received			Net Amount
	As of December 31, 2013
	Derivatives by Counterparty
	Counterparty A	$	961		$	—		$	961		$	(825	)	$	—		$	136
	Counterparty B	—			—			—			—			—			—
	Total	$	961		$	—		$	961		$	(825	)	$	—		$	136
	As of December 31, 2012
	Derivatives by Counterparty
	Counterparty A	$	1		$	—		$	1		$	(1	)	$	—		$	—
	Counterparty B	—			—			—			—			—			—
	Total	$	1		$	—		$	1		$	(1	)	$	—		$	—
	1 Amounts exclude accrued interest totaling $10 thousand and $1 thousand at December 31, 2013 and December 31, 2012, respectively.
Offsetting Liabilities	'
	Offsetting of Financial Liabilities and Derivative Liabilities
	(in thousands;)										Gross Amounts Not Offset in the Statements of Condition
					Gross Amounts			Net Amounts of
		Gross Amounts			Offset in the			Liabilities Presented
		of Recognized			Statements of			in the Statements of			Financial			Cash Collateral
		Liabilities2			Condition			Condition2			Instruments			Pledged			Net Amount
	As of December 31, 2013
	Derivatives by Counterparty
	Counterparty A	$	825		$	—		$	825		$	(825	)	—			$	—
	Counterparty B	1,694			—			1,694			—			(1,694		)	—
	Total	$	2,519		$	—		$	2,519		$	(825	)	$	(1,694	)	$	—
	As of December 31, 2012
	Derivatives by Counterparty
	Counterparty A	$	2,616		$	—		$	2,616		$	(1	)	$	(1,860	)	$	755
	Counterparty B	2,624			—			2,624			—			(2,624		)	—
	Total	$	5,240		$	—		$	5,240		$	(1	)	$	(4,484	)	$	755
	2 Amounts exclude accrued interest totaling $60 thousand and $74 thousand at December 31, 2013 and December 31, 2012, respectively.

Regulatory_Matters_Tables

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2013
Banking and Thrift [Abstract]	'
Schedule of Capital Adequacy Ratios	'
	The Bank’s and Bancorp’s capital adequacy ratios as of December 31, 2013 and December 31, 2012 are presented in the following tables.
	Capital Ratios for Bancorp (in thousands)	Actual Ratio				Ratio for Capital Adequacy Purposes
	As of December 31, 2013	Amount		Ratio		Amount		Ratio
	Total Capital (to risk-weighted assets)	$	190,738	13.21	%	≥ $	115,524	≥ 8.0	%
	Tier 1 Capital (to risk-weighted assets)	$	175,835	12.18	%	≥ $	57,762	≥ 4.0	%
	Tier 1 Capital (to average assets)	$	175,835	10.78	%	≥ $	65,222	≥ 4.0	%
	As of December 31, 2012
	Total Capital (to risk-weighted assets)	$	163,900	13.71	%	≥ $	95,655	≥ 8.0	%
	Tier 1 Capital (to risk-weighted assets)	$	149,737	12.52	%	≥ $	47,827	≥ 4.0	%
	Tier 1 Capital (to average assets)	$	149,737	10.3	%	≥ $	58,169	≥ 4.0	%
	Capital Ratios for the Bank (in thousands)	Actual Ratio				Ratio for Capital Adequacy Purposes				Ratio to be Well Capitalized under Prompt Corrective Action Provisions
	As of December 31, 2013	Amount		Ratio		Amount		Ratio		Amount		Ratio
	Total Capital (to risk-weighted assets)	$	181,911	12.6	%	≥ $	115,495	≥ 8.0	%	≥ $	144,368	≥ 10.0	%
	Tier 1 Capital (to risk-weighted assets)	$	167,007	11.57	%	≥ $	57,747	≥ 4.0	%	≥ $	86,621	≥ 6.0	%
	Tier 1 Capital (to average assets)	$	167,007	10.24	%	≥ $	65,215	≥ 4.0	%	≥ $	81,519	≥ 5.0	%
	As of December 31, 2012
	Total Capital (to risk-weighted assets)	$	162,554	13.6	%	≥ $	95,652	≥ 8.0	%	≥ $	119,566	≥ 10.0	%
	Tier 1 Capital (to risk-weighted assets)	$	148,391	12.41	%	≥ $	47,826	≥ 4.0	%	≥ $	71,739	≥ 6.0	%
	Tier 1 Capital (to average assets)	$	148,391	10.2	%	≥ $	58,168	≥ 4.0	%	≥ $	72,710	≥ 5.0	%

Condensed_Bank_of_Marin_Bancor1

Condensed Bank of Marin Bancorp Parent Only Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2013
Condensed Financial Information of Parent Company Only Disclosure [Abstract]	'
Schedule of Condensed Balance Sheet	'
	Presented below is financial information for Bank of Marin Bancorp, parent holding company only.
	CONDENSED UNCONSOLIDATED STATEMENTS OF CONDITION
	at December 31, 2013 and 2012
		At December 31,
	(in thousands)	2013			2012
	Assets
	Cash and due from Bank of Marin	$	8,664		$	1,293
	Investment in bank subsidiary	177,028			150,445
	Other assets	366			92
	Total assets	$	186,058		$	151,830
	Liabilities and Stockholders' Equity
	Subordinated debentures	$	4,969		$	—
	Accrued expenses payable	202			38
	Total liabilities	5,171			38
	Stockholders' equity	180,887			151,792
	Total liabilities and stockholders' equity	$	186,058		$	151,830
Schedule of Condensed Income Statement	'
	CONDENSED UNCONSOLIDATED STATEMENTS OF INCOME
	for the fiscal years ended December 31, 2013, 2012 and 2011
		Years ended December 31,
	(in thousands)	2013			2012			2011
	Income
	Dividends from bank subsidiary	$	28,000		$	2,700		$	—
	Total income	28,000			2,700			—
	Expense
	Interest expense	34			—			—
	Non-interest expense	1,313			716			748
	Total expense	1,347			716			748
	Income (loss) before income taxes and equity in undistributed net income of subsidiary	26,653			1,984			(748		)
	Income tax benefit	382			301			249
	Income (loss) before equity in undistributed net income of subsidiary	27,035			2,285			(499		)
	Earnings of bank subsidiary (less) greater than dividends received from bank subsidiary	(12,765		)	15,532			16,063
	Net income	$	14,270		$	17,817		$	15,564
Schedule of Condensed Cash Flow Statement	'
	CONDENSED UNCONSOLIDATED STATEMENTS OF CASH FLOWS
	for the fiscal years ended December 31, 2013, 2012 and 2011
		Years ended December 31,
	(in thousands)	2013			2012			2011
	Cash Flows from Operating Activities:
	Net income	$	14,270		$	17,817		$	15,564
	Adjustments to reconcile net income to net cash used
	in operating activities:
	Earnings of bank subsidiary less (greater) than	12,765			(15,532		)	(16,063		)
	dividends received from bank subsidiary
	Net change in operating assets and liabilities
	Accretion of discount on subordinated debentures	19			—			—
	Other assets	74			(71		)	58
	Other liabilities	165			(6		)	46
	Net cash used in operating activities	27,293			2,208			(395		)
	Cash Flows from Investing Activities:
	Capital contribution to subsidiary	(2,258		)	(1,070		)	(774		)
	Cash consideration paid for acquisition, net of cash	(15,952		)	—			—
	acquired
	Net cash used in investing activities	(18,210		)	(1,070		)	(774		)
	Cash Flows from Financing Activities:
	Stock options exercised and stock purchases	2,258			1,070			774
	Dividends paid on common stock	(3,970		)	(3,751		)	(3,457		)
	Net cash provided by (used by) financing activities	(1,712		)	(2,681		)	(2,683		)
	Net increase (decrease) in cash and cash equivalents	7,371			(1,543		)	(3,852		)
	Cash and cash equivalents at beginning of period	1,293			2,836			6,688
	Cash and cash equivalents at end of period	$	8,664		$	1,293		$	2,836
	Supplemental schedule of non-cash investing and financing activities:
	Stock issued in payment of director fees	$	222		$	199		$	200
	Acquisition:
	Fair value of assets acquired	$	39,503		$	—		$	—
	Fair value of liabilities assumed	$	4,970		$	—		$	—
	Stock issued to NorCal Community Bancorp shareholders	$	18,514		$	—		$	—

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Premises and Equipment (Details)	12 Months Ended
	Dec. 31, 2013
Furniture and equipment	'
Property, Plant and Equipment [Line Items]	'
Premises and equipment useful life	'8 years
Minimum | Equipment	'
Property, Plant and Equipment [Line Items]	'
Premises and equipment useful life	'3 years
Maximum | Equipment	'
Property, Plant and Equipment [Line Items]	'
Premises and equipment useful life	'20 years

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Earnings Per Share (Details) (USD $)	1 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Share, Basic and Diluted [Abstract]	'	'	'	'
Weighted average basic shares outstanding	'	5,457	5,341	5,302
Potential common shares related to stock options	'	44	47	41
Potential common shares related to unvested restricted stock awards	'	4	5	4
Potential common shares related to warrants	'	53	45	37
Weighted average diluted shares outstanding	'	5,558	5,438	5,384
Net income	$963	$14,270	$17,817	$15,564
Basic EPS (in dollars per share)	'	$2.62	$3.34	$2.94
Diluted EPS (in dollars per share)	'	$2.57	$3.28	$2.89
Weighted average anti-dilutive shares not included in the calculation of diluted EPS (shares)	'	49	50	70

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	segment
Derivatives, Fair Value [Line Items]	'	'	'
Advertising costs	$490,000	$541,000	$589,000
Number of operating segments	2	'	'
Wealth Management and Trust Services revenues	2,162,000	1,964,000	1,834,000
Wealth Management and Trust Services expenses	1,500,000	1,400,000	1,300,000
Wealth Management and Trust Services, income tax	220,000	200,000	184,000
Wealth Management and Trust Services, after-tax income	$394,000	$327,000	$312,000
Designated as hedging instrument | Shortcut hedge accounting | Interest rate swap	'	'	'
Derivatives, Fair Value [Line Items]	'	'	'
Number of interest rate swap contracts accounted for using hedge accounting	1	'	'
Designated as hedging instrument | Non-shortcut Hedge Accounting | Interest rate swap	'	'	'
Derivatives, Fair Value [Line Items]	'	'	'
Number of interest rate swap contracts accounted for using hedge accounting	8	'	'

Acquisition_Narrative_Details

Acquisition - Narrative (Details) (USD $)	1 Months Ended	12 Months Ended			1 Months Ended		12 Months Ended		1 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Feb. 18, 2011	Dec. 31, 2013	Dec. 31, 2013	Nov. 29, 2013	Dec. 31, 2013	Nov. 29, 2013
					Charter Oak Bank	NorCal Community Bancorp	NorCal Community Bancorp	NorCal Community Bancorp	Core Deposits	Core Deposits
								branch	NorCal Community Bancorp	NorCal Community Bancorp
Business Acquisition [Line Items]	'	'	'	'	'	'	'	'	'	'
Total assets acquired	'	'	'	'	$107,800	'	'	$280,917	'	'
Total liabilities assumed	'	'	'	'	107,700	'	'	246,384	'	'
Bargain purchase gain, net of tax	'	'	'	'	85	'	'	'	'	'
Loans acquired	'	'	'	'	'	'	'	173,759	'	'
Deposits acquired	'	'	'	'	'	'	'	241,026	'	'
Investment securities	'	'	'	'	'	'	'	53,731	'	'
Number of branches	'	'	'	'	'	'	'	4	'	'
Period core deposit is amortized for income tax purposes	'	'	'	'	'	'	'10 years	'	'	'
Core deposit intangible asset	'	'	'	'	'	'	'	4,572	'	4,600
Amount of core deposit intangible asset amortized	'	'	'	'	'	'	'	'	69	'
Future amortization expense:	'	'	'	'	'	'	'	'	'	'
2014	'	'	'	'	'	'	'	'	771	'
2015	'	'	'	'	'	'	'	'	619	'
2016	'	'	'	'	'	'	'	'	533	'
2017	'	'	'	'	'	'	'	'	472	'
2018	'	'	'	'	'	'	'	'	413	'
Thereafter	'	'	'	'	'	'	'	'	1,695	'
Total	'	'	'	'	'	'	'	'	4,503	'
Business Acquisition, Pro Forma Information [Abstract]	'	'	'	'	'	'	'	'	'	'
Interest income including acquired operations	'	58,775	63,190	63,819	'	1,100	'	'	'	'
Interest expense including acquired operations	'	1,785	2,576	5,295	'	68	'	'	'	'
Non-interest income including acquired operations	'	8,066	7,112	6,269	'	95	'	'	'	'
Non-interest expense including acquired operations	'	44,092	38,694	38,283	'	1,100	'	'	'	'
Income before income taxes including acquired operations	$6,984	$22,209	$28,708	$24,755	'	$109	'	'	'	'

Acquisition_Fair_Value_of_Asse

Acquisition - Fair Value of Assets and Liabilities Assumed (Details) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Nov. 29, 2013
Business Acquisition [Line Items]	'
Merger consideration, cash payment	$16,019
Merger consideration, stock payment	18,514
NorCal Community Bancorp	'
Business Acquisition [Line Items]	'
Total cash and cash equivalents	31,804
Investment securities	53,731
Loans	173,759
Core deposit intangible	4,572
Deferred tax asset	4,114
Goodwill	6,435
Bank premises and equipment	203
Other assets	6,299
Total assets acquired	280,917
Noninterest bearing	69,123
Transaction accounts	57,337
Savings accounts	10,835
Money market accounts	81,464
Other time accounts	22,267
Total deposits	241,026
Subordinated debentures	4,950
Other liabilities	408
Total liabilities assumed	246,384
Merger consideration	$34,533

Acquisition_Net_Assets_Acquire

Acquisition - Net Assets Acquired and Fair Value Adjustments (Details) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Nov. 29, 2013
Business Acquisition [Line Items]	'
Purchase accounting adjustments, tax effect, percent	42.05%
NorCal Community Bancorp	'
Business Acquisition [Line Items]	'
Book value of net assets acquired from NorCal	25,552
Loans	-3,462
Subordinated debentures	3,298
Core deposit intangible asset	4,572
Time deposits	-14
Total purchase accounting adjustments	4,394
Deferred tax liabilities (tax effect of purchase accounting adjustments at 42.05%)	-1,848
Fair value of net assets acquired from NorCal	28,098
Merger consideration	34,533
Fair value of net assets acquired from NorCal	-28,098
Goodwill	6,435

Acquisition_Pro_Forma_Revenue_

Acquisition - Pro Forma Revenue and Earnings (Details) (USD $)	1 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Business Acquisition [Line Items]	'	'		'		'
Revenue	$6,984	$22,209		$28,708		$24,755
Earnings	963	14,270		17,817		15,564
Pro forma revenue	'	68,626	[1]	85,310	[1]	'
Earnings, excluding acquisition related expenses	'	17,866	[1]	'		'
Earnings	'	14,270		13,731	[1]	'
NorCal Community Bancorp	'	'		'		'
Business Acquisition [Line Items]	'	'		'		'
Actual revenue since acquisition date	1,239	'		'		'
Actual earnings since acquisition date	70	'		'		'
Revenue	109	'		'		'
Pro forma revenue	'	12,199	[1]	12,433	[1]	'
Earnings, excluding acquisition related expenses	'	1,506	[1]	'		'
Earnings	'	315		-2,841	[1]	'
Acquisition related expenses	'	3,744		'		'
Bancorp	'	'		'		'
Business Acquisition [Line Items]	'	'		'		'
Earnings	'	14,270		17,817		15,564
Acquisition related expenses	'	3,700		'		'
NorCal Community Bancorp	'	'		'		'
Business Acquisition [Line Items]	'	'		'		'
Acquisition related expenses	'	$1,900		'		'
[1]	2013 supplemental pro forma earnings were adjusted to exclude $3.7 million of one-time acquisition related expenses booked at Bank of Marin Bancorp and $1.9 million of one-time acquisition related expenses booked at NorCal Community Bancorp in 2013. 2012 supplemental pro forma earnings were adjusted to include these charges.

Acquisition_Acquisition_Relate

Acquisition - Acquisition Related Costs (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2013		Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2011
	NorCal Community Bancorp	NorCal Community Bancorp		NorCal Community Bancorp	NorCal Community Bancorp	NorCal Community Bancorp	Charter Oak Bank	Charter Oak Bank	Charter Oak Bank	Charter Oak Bank	Charter Oak Bank
		Data processing		Professional services	Personnel severance	Other		Data processing	Professional services	Personnel severance	Other
Business Acquisition [Line Items]	'	'		'	'	'	'	'	'	'	'
Acquisition related expenses	$3,744	$2,807	[1]	$660	$203	$74	$1,000	$455	$457	$0	$88
[1]	Primarily relates to NorCal's core processing system contract termination and deconversion fees.

Investment_Securities_Amortize

Investment Securities - Amortized Cost and Fair Value (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]	'	'
Held to maturity, Amortized Cost	$122,495	$139,452
Investment securities held to maturity	123,858	142,231
Held to maturity, Gross Unrealized Gains	2,139	3,313
Held-to-maturity Securities, Unrealized (Losses)	-776	-534
Available for sale, Amortized Cost	245,158	150,420
Available for sale, Fair Value	243,998	153,962
Available for sale, Gross Unrealized Gains	1,833	3,776
Available for sale, Gross Unrealized Losses	-2,993	-234
Total investment securities, Amortized Cost	367,653	289,872
Total investment securities, Fair Value	367,856	296,193
Total investment securities, Gross Unrealized Gains	3,972	7,089
Total investment securities, Gross Unrealized (Losses)	-3,769	-768
MBS pass-through securities	'	'
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]	'	'
Available for sale, Amortized Cost	124,063	52,042
Available for sale, Fair Value	123,033	53,713
Available for sale, Gross Unrealized Gains	616	1,711
Available for sale, Gross Unrealized Losses	-1,646	-40
CMOs issued by FNMA	'	'
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]	'	'
Available for sale, Amortized Cost	18,573	4,447
Available for sale, Fair Value	18,438	4,550
Available for sale, Gross Unrealized Gains	60	105
Available for sale, Gross Unrealized Losses	-195	-2
CMOs issued by FHLMC	'	'
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]	'	'
Available for sale, Amortized Cost	23,710	13,527
Available for sale, Fair Value	23,679	13,778
Available for sale, Gross Unrealized Gains	144	251
Available for sale, Gross Unrealized Losses	-175	0
CMOs issued by GNMA	'	'
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]	'	'
Available for sale, Amortized Cost	24,944	38,871
Available for sale, Fair Value	25,454	39,756
Available for sale, Gross Unrealized Gains	609	886
Available for sale, Gross Unrealized Losses	-99	-1
Debentures of government-sponsored agencies	'	'
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]	'	'
Available for sale, Amortized Cost	21,845	20,462
Available for sale, Fair Value	21,312	20,589
Available for sale, Gross Unrealized Gains	108	228
Available for sale, Gross Unrealized Losses	-641	-101
Privately-issued CMOs	'	'
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]	'	'
Available for sale, Amortized Cost	10,649	21,071
Available for sale, Fair Value	10,874	21,576
Available for sale, Gross Unrealized Gains	257	595
Available for sale, Gross Unrealized Losses	-32	-90
Obligations of state and political subdivisions	'	'
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]	'	'
Held to maturity, Amortized Cost	80,381	96,922
Investment securities held to maturity	81,429	99,350
Held to maturity, Gross Unrealized Gains	1,764	2,855
Held-to-maturity Securities, Unrealized (Losses)	-716	-427
Available for sale, Amortized Cost	15,948	0
Available for sale, Fair Value	15,771	0
Available for sale, Gross Unrealized Gains	14	0
Available for sale, Gross Unrealized Losses	-191	0
Corporate bonds	'	'
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]	'	'
Held to maturity, Amortized Cost	42,114	42,530
Investment securities held to maturity	42,429	42,881
Held to maturity, Gross Unrealized Gains	375	458
Held-to-maturity Securities, Unrealized (Losses)	-60	-107
Available for sale, Amortized Cost	5,426	0
Available for sale, Fair Value	5,437	0
Available for sale, Gross Unrealized Gains	25	0
Available for sale, Gross Unrealized Losses	($14)	$0

Investment_Securities_Maturiti

Investment Securities - Maturities (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]	'	'
Held to Maturity, Amortized Cost, Within one year	$8,731	$764
Held to Maturity, Fair Value, Within one year	8,784	763
Available for Sale Securities, Amortized Cost, Within one year	5,522	0
Available for Sale Securities, Debt Maturities, Fair Value, Within one year	5,521	0
Held to Maturity, Amortized Cost, After one but within five years	88,255	98,672
Held to Maturity, Fair Value, After one but within five years	89,095	99,689
Available for Sale, Amortized Cost, After one but within five years	42,229	26,417
Available for Sale, Fair Value, After one but within five years	42,338	27,060
Held to Maturity, Amortized Cost, After five years through ten years	24,244	29,165
Held to Maturity, Fair Value, After five years through ten years	24,786	30,898
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	26,232	23,719
Available for Sale, Fair Value, After five years through ten years	25,478	23,820
Held to Maturity, Amortized Cost, After ten years	1,265	10,851
Held to Maturity, Fair Value, After ten years	1,193	10,881
Available for Sale, Amortized Cost, After five years through ten years	171,175	100,284
Available for Sale, Fair Value, After ten years	170,661	103,082
Held to Maturity, Amortized Cost, Total	122,495	139,452
Held-to-Maturity, Fair Value, Total	123,858	142,231
Available for Sale, Amortized Cost, Total	245,158	150,420
Available for Sale, Fair Value, Total	$243,998	$153,962

Investment_Securities_Securiti

Investment Securities - Securities Sold and Pledged as Collateral (Details) (USD $)	1 Months Ended	12 Months Ended
	Feb. 29, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
			security
Financial Instruments Owned and Pledged as Collateral [Line Items]	'	'	'	'
Amount of available-for-sale securities sold	'	$8,000,000	'	'
Proceeds from sale of securities available for sale	'	7,973,000	2,186,000	0
Net loss on sale of available for sale securities sold	18,000	'	34,000	'
Amount of held-to-maturity securities sold	'	6,400,000	'	'
Proceeds from sale of securities held to maturity	'	6,442,000	0	0
Net (loss) on sale of held to maturity securities sold	'	17,000	'	'
Number of securities sold during period	'	'	1	'
State of California	'	'	'	'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'	'	'	'
Available-for-sale securities pledged as collateral	'	61,800,000	47,700,000	'
Public Deposits	'	'	'	'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'	'	'	'
Available-for-sale securities pledged as collateral	'	61,100,000	47,000,000	'
Trust Deposits	'	'	'	'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'	'	'	'
Available-for-sale securities pledged as collateral	'	732,000	719,000	'
Internal checking account	'	'	'	'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'	'	'	'
Available-for-sale securities pledged as collateral	'	$1,100,000	$1,100,000	'

Investment_Securities_Other_Th

Investment Securities - Other Than Temporarily Impaired Debt Securities (Details) (USD $)

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

Feb. 29, 2012

Dec. 31, 2013

Dec. 31, 2012

Jan. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

security

Subsequent Event

CMOs issued by GNMA

CMOs issued by GNMA

CMOs issued by FNMA

CMOs issued by FNMA

CMOs issued by FHLMC

Privately-issued CMOs

Privately-issued CMOs

Debentures of government-sponsored agencies

Debentures of government-sponsored agencies

MBS pass-through securities

MBS pass-through securities

Obligations of state and political subdivisions

Obligations of state and political subdivisions

Corporate bonds

Corporate bonds

obligations

Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value

'

$16,950,000

$48,845,000

'

'

'

'

'

'

'

'

'

'

'

'

$13,933,000

$33,196,000

$3,017,000

$15,649,000

Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses

'

-430,000

-534,000

'

'

'

'

'

'

'

'

'

'

'

'

-419,000

-427,000

-11,000

-107,000

Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value

'

13,996,000

0

'

'

'

'

'

'

'

'

'

'

'

'

9,033,000

0

4,963,000

0

Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses

'

-346,000

0

'

'

'

'

'

'

'

'

'

'

'

'

-297,000

0

-49,000

0

Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value

'

30,946,000

48,845,000

'

'

'

'

'

'

'

'

'

'

'

'

22,966,000

33,196,000

7,980,000

15,649,000

Held-to-maturity Securities, Continuous Unrealized Loss Position, Unrealized Losses

'

-776,000

-534,000

'

'

'

'

'

'

'

'

'

'

'

'

-716,000

-427,000

-60,000

-107,000

Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value

'

164,815,000

22,417,000

'

3,966,000

1,550,000

17,535,000

3,185,000

17,899,000

4,634,000

4,214,000

16,872,000

9,899,000

90,914,000

3,569,000

11,516,000

'

1,479,000

'

Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses

'

-2,643,000

-233,000

'

-99,000

-1,000

-195,000

-2,000

-175,000

-31,000

-89,000

-641,000

-101,000

-1,297,000

-40,000

-191,000

'

-14,000

'

Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value

'

3,331,000

203,000

'

0

0

0

0

0

159,000

203,000

0

0

3,172,000

0

0

'

0

'

Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses

'

-350,000

-1,000

'

0

0

0

0

0

-1,000

-1,000

0

0

-349,000

0

0

'

0

'

Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value

'

168,146,000

22,620,000

'

3,966,000

1,550,000

17,535,000

3,185,000

17,899,000

4,793,000

4,417,000

16,872,000

9,899,000

94,086,000

3,569,000

11,516,000

'

1,479,000

'

Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses

'

-2,993,000

-234,000

'

-99,000

-1,000

-195,000

-2,000

-175,000

-32,000

-90,000

-641,000

-101,000

-1,646,000

-40,000

-191,000

'

-14,000

'

Total temporarily impaired securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value

'

181,765,000

71,262,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total temporarily impaired securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses

'

-3,073,000

-767,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total temporarily impaired securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value

'

17,327,000

203,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total temporarily impaired securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses

'

-696,000

-1,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Marketable Securities In Unrealized Loss Positions, Qualitative Disclosure, Number Of Positions, Twelve Months or Longer

'

81

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total temporarily impaired securities, Continuous Unrealized Loss Position, Fair Value, Total

'

199,092,000

71,465,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total temporarily impaired securities, Continuous Unrealized Loss Position, Unrealized Losses

'

-3,769,000

-768,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investments in Continuous Loss Position, 12 Months or Longer

'

14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount of available-for-sale securities sold

'

8,000,000

'

2,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net loss on sale of available for sale securities sold

$18,000

'

$34,000

$15,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Investment_Securities_Securiti1

Investment Securities - Securities Carried at Cost (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Feb. 20, 2013	Dec. 31, 2013	Dec. 31, 2012
		Visa Inc. Class B common stock	Visa Inc. Class B common stock	Subsequent Event	Other assets	Other assets
Schedule of Cost-method Investments [Line Items]	'	'	'	'	'	'
Federal Home Loan Bank stock, par value	$100	'	'	'	'	'
Federal Home Loan Bank stock	'	'	'	'	$7,800,000	$6,000,000
Federal Home Loan Bank, dividend rate percentage	'	'	'	6.67%	'	'
Number of shares of securities carried at cost	'	16,939	'	'	'	'
Carrying value of securities carried at cost	0	'	'	'	'	'
Fair value of Class B common stock	'	$1,600,000	$1,100,000	'	'	'
Conversion ratio for common stock	0.4206	'	'	'	'	'

Loans_and_Allowance_for_Loan_L2

Loans and Allowance for Loan Losses - Loans Outstanding and Aging Analysis (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
30 to 59 Days Past Due	$992,000		$588,000		'
60 to 89 Days Past Due	3,000		0		'
Greater than 90 days past due (non-accrual)	11,678,000	[1]	17,652,000	[1]	'
Total past due	12,673,000		18,240,000		'
Current	1,256,649,000		1,055,712,000		'
Total loans	1,269,322,000	[2]	1,073,952,000	[2]	1,031,154,000
Non-accrual loans to total loans	0.90%		1.60%		'
Purchased Credit Impaired (PCI) loans no longer accreting interest	1,400,000		1,600,000		'
Purchased Credit-impaired (PCI) loans accreting interest	5,700,000		3,000,000		'
Deferred loan fees	-24,000		769,000		'
Unaccreted purchase discounts on non-PCI loans	7,600,000		2,100,000		'
Commercial real estate loans	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Percentage of loans by class to all loans	68.00%		'		'
Commercial real estate loans | CALIFORNIA	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Percentage of loans by class and geographic location	83.00%		'		'
Commercial real estate, owner-occupied	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
30 to 59 Days Past Due	0		0		'
60 to 89 Days Past Due	0		0		'
Greater than 90 days past due (non-accrual)	1,403,000	[1]	1,403,000	[1]	'
Total past due	1,403,000		1,403,000		'
Current	239,710,000		195,003,000		'
Total loans	241,113,000	[2]	196,406,000	[2]	174,705,000
Non-accrual loans to total loans	0.60%		0.70%		'
Commercial real estate, investor	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
30 to 59 Days Past Due	0		0		'
60 to 89 Days Past Due	0		0		'
Greater than 90 days past due (non-accrual)	2,807,000	[1]	6,843,000	[1]	'
Total past due	2,807,000		6,843,000		'
Current	622,212,000		502,163,000		'
Total loans	625,019,000	[2]	509,006,000	[2]	446,425,000
Non-accrual loans to total loans	0.40%		1.30%		'
Minimum principal amount of an investor commercial real estate loan that requires annual proof of income	750,000		'		'
Real estate loans	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Percentage of loans by class to all loans	86.00%		85.00%		'
Unsecured loans	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Percentage of loans by class to all loans	2.00%		3.00%		'
Commercial loans	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
30 to 59 Days Past Due	18,000		29,000		'
60 to 89 Days Past Due	0		0		'
Greater than 90 days past due (non-accrual)	1,187,000	[1]	4,893,000	[1]	'
Total past due	1,205,000		4,922,000		'
Current	182,086,000		171,509,000		'
Total loans	183,291,000	[2]	176,431,000	[2]	175,790,000
Non-accrual loans to total loans	0.60%		2.80%		'
Construction	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
30 to 59 Days Past Due	0		0		'
60 to 89 Days Past Due	0		0		'
Greater than 90 days past due (non-accrual)	5,218,000	[1]	2,239,000	[1]	'
Total past due	5,218,000		2,239,000		'
Current	26,359,000		28,426,000		'
Total loans	31,577,000	[2]	30,665,000	[2]	51,957,000
Non-accrual loans to total loans	16.50%		7.30%		'
Home equity	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
30 to 59 Days Past Due	240,000		294,000		'
60 to 89 Days Past Due	0		0		'
Greater than 90 days past due (non-accrual)	234,000	[1]	545,000	[1]	'
Total past due	474,000		839,000		'
Current	97,995,000		92,398,000		'
Total loans	98,469,000	[2]	93,237,000	[2]	98,043,000
Non-accrual loans to total loans	0.20%		0.60%		'
Other residential	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
30 to 59 Days Past Due	717,000	[3]	167,000	[3]	'
60 to 89 Days Past Due	0	[3]	0	[3]	'
Greater than 90 days past due (non-accrual)	660,000	[1],[3]	1,196,000	[1],[3]	'
Total past due	1,377,000	[3]	1,363,000	[3]	'
Current	71,257,000	[3]	48,069,000	[3]	'
Total loans	72,634,000	[2],[3]	49,432,000	[2],[3]	61,502,000
Non-accrual loans to total loans	0.90%	[3]	2.40%	[3]	'
Installment and other consumer	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
30 to 59 Days Past Due	17,000		98,000		'
60 to 89 Days Past Due	3,000		0		'
Greater than 90 days past due (non-accrual)	169,000	[1]	533,000	[1]	'
Total past due	189,000		631,000		'
Current	17,030,000		18,144,000		'
Total loans	$17,219,000	[2]	$18,775,000	[2]	$22,732,000
Non-accrual loans to total loans	1.00%		2.80%		'
[1]	Amounts include $1.4 million and $1.6 million of Purchased Credit Impaired ("PCI") loans that have stopped accreting interest at December 31, 2013 and 2012, respectively, and exclude accreting PCI loans of $5.7 million and $3.0 million at December 31, 2013 and 2012, respectively, as their accretable yield interest recognition is independent from the underlying contractual loan delinquency status. There were no accruing loans past due more than ninety days at December 31, 2013 or 2012.
[2]	Amounts were net of deferred loan (costs)/fees of $(24) thousand and $769 thousand at December 31, 2013 and 2012, respectively. Amounts were also net of unaccreted purchase discounts on non-PCI loans of $7.6 million and $2.1 million at December 31, 2013 and 2012, respectively.
[3]	Our residential loan portfolio includes no sub-prime loans, nor is it our normal practice to underwrite loans commonly referred to as "Alt-A mortgages," the characteristics of which are loans lacking full documentation, borrowers having low FICO scores or higher loan-to-value ratios.

Loans_and_Allowance_for_Loan_L3

Loans and Allowance for Loan Losses - Credit Quality of Loans (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Purchase credit-impaired	$7,115		$4,549		$5,953
Total loans	1,269,322	[1]	1,073,952	[1]	1,031,154
Commercial loans	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	182,958		175,791		'
Purchase credit-impaired	333		640		1,116
Total loans	183,291	[1]	176,431	[1]	175,790
Commercial real estate, owner-occupied	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	236,294		193,891		'
Purchase credit-impaired	4,853		2,515		3,213
Total loans	241,113	[1]	196,406	[1]	174,705
Commercial real estate, investor	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	623,140		507,612		'
Purchase credit-impaired	1,845		1,394		1,624
Total loans	625,019	[1]	509,006	[1]	446,425
Construction	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	31,562		30,665		'
Purchase credit-impaired	15		0		0
Total loans	31,577	[1]	30,665	[1]	51,957
Home equity	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	98,400		93,237		'
Purchase credit-impaired	69		0		0
Total loans	98,469	[1]	93,237	[1]	98,043
Other residential	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Purchase credit-impaired	0		0		0
Total loans	72,634	[1],[2]	49,432	[1],[2]	61,502
Installment and other consumer	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Purchase credit-impaired	0		0		0
Total loans	17,219	[1]	18,775	[1]	22,732
Pass	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Purchase credit-impaired	1,340		1,862		'
Total loans	1,194,032		987,851		'
Pass | Commercial loans	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	162,625		148,771		'
Pass | Commercial real estate, owner-occupied	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	216,537		170,553		'
Pass | Commercial real estate, investor	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	609,157		489,978		'
Pass | Construction	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	25,069		26,287		'
Pass | Home equity	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	93,792		86,957		'
Pass | Other residential	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Total loans	69,176		45,634		'
Pass | Installment and other consumer	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Total loans	16,336		17,809		'
Special Mention	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Purchase credit-impaired	894		933		'
Total loans	44,150		49,185		'
Special Mention | Commercial loans	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	13,990		13,267		'
Special Mention | Commercial real estate, owner-occupied	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	16,533		20,346		'
Special Mention | Commercial real estate, investor	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	8,570		8,671		'
Special Mention | Construction	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	725		1,970		'
Special Mention | Home equity	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	2,164		2,931		'
Special Mention | Other residential	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Total loans	1,047		1,067		'
Special Mention | Installment and other consumer	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Total loans	227		0		'
Substandard	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Purchase credit-impaired	4,881		1,754		'
Total loans	31,140		36,916		'
Substandard | Commercial loans	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	6,343		13,753		'
Substandard | Commercial real estate, owner-occupied	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	3,224		2,992		'
Substandard | Commercial real estate, investor	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	5,413		8,963		'
Substandard | Construction	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	5,768		2,408		'
Substandard | Home equity	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Loans excluding purchased credit-impaired loans	2,444		3,349		'
Substandard | Other residential	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Total loans	2,411		2,731		'
Substandard | Installment and other consumer	'		'		'
Financing Receivable, Recorded Investment [Line Items]	'		'		'
Total loans	$656		$966		'
[1]	Amounts were net of deferred loan (costs)/fees of $(24) thousand and $769 thousand at December 31, 2013 and 2012, respectively. Amounts were also net of unaccreted purchase discounts on non-PCI loans of $7.6 million and $2.1 million at December 31, 2013 and 2012, respectively.
[2]	Our residential loan portfolio includes no sub-prime loans, nor is it our normal practice to underwrite loans commonly referred to as "Alt-A mortgages," the characteristics of which are loans lacking full documentation, borrowers having low FICO scores or higher loan-to-value ratios.

Loans_and_Allowance_for_Loan_L4

Loans and Allowance for Loan Losses - Troubled Debt Restructuring by Class (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Recorded investment in Troubled Debt Restructurings	$20,581,000	[1]	$18,284,000	[1]	$10,655,000	[1]
TDR loans accruing interest as of period end	12,900,000		10,800,000		6,300,000
Commercial loans	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Recorded investment in Troubled Debt Restructurings	5,117,000		9,470,000		4,969,000
Commercial real estate, owner-occupied	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Recorded investment in Troubled Debt Restructurings	4,333,000		1,403,000		1,403,000
Commercial real estate, investor	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Recorded investment in Troubled Debt Restructurings	534,000		0		0
Construction	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Recorded investment in Troubled Debt Restructurings	6,335,000		1,929,000		800,000
Home equity	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Recorded investment in Troubled Debt Restructurings	506,000		908,000		467,000
Other residential	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Recorded investment in Troubled Debt Restructurings	2,063,000		2,831,000		1,464,000
Installment and other consumer	'		'		'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'		'		'
Recorded investment in Troubled Debt Restructurings	$1,693,000		$1,743,000		$1,552,000
[1]	Includes $12.9 million, $10.8 million and $6.3 million of TDR loans that were accruing interest as of December 31, 2013, 2012 and 2011 respectively.

Loans_and_Allowance_for_Loan_L5

Loans and Allowance for Loan Losses - Troubled Debt Restructuring Modifications (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	contract	contract	contract
Financing Receivable, Modifications [Line Items]	'	'	'
Number of Contracts Modified	15	22	50
Pre-Modification Outstanding Recorded Investment	$11,822,000	$14,898,000	$11,589,000
Post-Modification Outstanding Recorded Investment	12,036,000	14,801,000	11,701,000
Post-Modification Outstanding Recorded Investment at period end	10,113,000	9,814,000	10,655,000
Number of contracts modified	'	'	3
Total of TDR loans charged-off within previous 12 months	0	4,500,000	1,000,000
TDRs charged off, net of recoveries	1,000,000	730,000	'
Commercial	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'
Number of Contracts Modified	8	14	27
Pre-Modification Outstanding Recorded Investment	1,176,000	9,980,000	5,854,000
Post-Modification Outstanding Recorded Investment	1,377,000	9,903,000	5,940,000
Post-Modification Outstanding Recorded Investment at period end	1,274,000	5,965,000	4,969,000
Commercial loans	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'
Number of contracts modified	'	3	'
Commercial real estate loans	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'
Number of contracts modified	'	2	'
Commercial real estate, owner-occupied	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'
Number of Contracts Modified	1	'	2
Pre-Modification Outstanding Recorded Investment	2,961,000	'	1,366,000
Post-Modification Outstanding Recorded Investment	2,956,000	'	1,403,000
Post-Modification Outstanding Recorded Investment at period end	2,930,000	'	1,403,000
Commercial real estate, investor	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'
Number of Contracts Modified	1	'	'
Pre-Modification Outstanding Recorded Investment	539,000	'	'
Post-Modification Outstanding Recorded Investment	538,000	'	'
Post-Modification Outstanding Recorded Investment at period end	534,000	'	'
Construction	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'
Number of Contracts Modified	3	2	2
Pre-Modification Outstanding Recorded Investment	7,135,000	2,793,000	817,000
Post-Modification Outstanding Recorded Investment	7,156,000	2,793,000	817,000
Post-Modification Outstanding Recorded Investment at period end	5,368,000	1,760,000	800,000
Number of contracts modified	'	1	'
Home equity	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'
Number of Contracts Modified	'	2	3
Pre-Modification Outstanding Recorded Investment	'	472,000	478,000
Post-Modification Outstanding Recorded Investment	'	473,000	469,000
Post-Modification Outstanding Recorded Investment at period end	'	469,000	467,000
Other residential	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'
Number of Contracts Modified	'	2	3
Pre-Modification Outstanding Recorded Investment	'	1,422,000	1,467,000
Post-Modification Outstanding Recorded Investment	'	1,401,000	1,467,000
Post-Modification Outstanding Recorded Investment at period end	'	1,392,000	1,464,000
Installment and other consumer	'	'	'
Financing Receivable, Modifications [Line Items]	'	'	'
Number of Contracts Modified	2	2	13
Pre-Modification Outstanding Recorded Investment	11,000	231,000	1,607,000
Post-Modification Outstanding Recorded Investment	9,000	231,000	1,605,000
Post-Modification Outstanding Recorded Investment at period end	$7,000	$228,000	$1,552,000

Loans_and_Allowance_for_Loan_L6

Loans and Allowance for Loan Losses - Effects of New Methodology on ALLL (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Provision for loan losses	$540	$2,900	$7,050
Approximate in crease in allocated loan reserves	800	'	'
Commercial and industrial	'	'	'
Provision for loan losses	-1,393	'	'
Commercial real estate, owner-occupied	'	'	'
Provision for loan losses	615	184	377
Commercial real estate, investor	'	'	'
Provision for loan losses	1,940	3,076	-424
Construction	'	'	'
Provision for loan losses	83	-643	275
Home equity	'	'	'
Provision for loan losses	-223	190	1,342
Other residential	'	'	'
Provision for loan losses	-234	-193	202
Installment and other consumer	'	'	'
Provision for loan losses	-535	169	787
Unallocated	'	'	'
Provision for loan losses	287	0	22
Calculated Provision Based on Prior Methodology	'	'	'
Provision for loan losses	540	'	'
Calculated Provision Based on Prior Methodology | Commercial and industrial	'	'	'
Provision for loan losses	-449	'	'
Calculated Provision Based on Prior Methodology | Commercial real estate, owner-occupied	'	'	'
Provision for loan losses	50	'	'
Calculated Provision Based on Prior Methodology | Commercial real estate, investor	'	'	'
Provision for loan losses	174	'	'
Calculated Provision Based on Prior Methodology | Construction	'	'	'
Provision for loan losses	167	'	'
Calculated Provision Based on Prior Methodology | Home equity	'	'	'
Provision for loan losses	-39	'	'
Calculated Provision Based on Prior Methodology | Other residential	'	'	'
Provision for loan losses	-138	'	'
Calculated Provision Based on Prior Methodology | Installment and other consumer	'	'	'
Provision for loan losses	-319	'	'
Calculated Provision Based on Prior Methodology | Unallocated	'	'	'
Provision for loan losses	1,094	'	'
Difference In ALLL	'	'	'
Provision for loan losses	0	'	'
Difference In ALLL | Commercial and industrial	'	'	'
Provision for loan losses	-944	'	'
Difference In ALLL | Commercial real estate, owner-occupied	'	'	'
Provision for loan losses	565	'	'
Threshold percentage that triggers additional reserves allocated	100.00%	'	'
Difference In ALLL | Commercial real estate, investor	'	'	'
Provision for loan losses	1,766	'	'
Difference In ALLL | Construction	'	'	'
Provision for loan losses	-84	'	'
Difference In ALLL | Home equity	'	'	'
Provision for loan losses	-184	'	'
Difference In ALLL | Other residential	'	'	'
Provision for loan losses	-96	'	'
Difference In ALLL | Installment and other consumer	'	'	'
Provision for loan losses	-216	'	'
Difference In ALLL | Unallocated	'	'	'
Provision for loan losses	($807)	'	'

Loans_and_Allowance_for_Loan_L7

Loans and Allowance for Loan Losses - Impaired Loans and Related Allowance (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Recorded investment in impaired loans:	'	'	'
With no specific allowance recorded	$10,242,000	$18,788,000	'
With a specific allowance recorded	15,453,000	11,515,000	'
Total recorded investment in impaired loans	25,695,000	30,303,000	'
Unpaid principal balance of impaired loans:	'	'	'
With no specific allowance recorded	17,160,000	23,959,000	'
With a specific allowance recorded	16,848,000	15,411,000	'
Total unpaid principal balance of impaired loans	34,008,000	39,370,000	'
Specific valuation	1,989,000	2,354,000	'
Average recorded investment in impaired loans during the period	29,147,000	37,328,000	14,937,000
Interest income recognized on impaired loans	1,181,000	2,299,000	252,000
Interest income recognized on impaired loans during the period	229,000	182,000	6,000
Gross interest income that would have been recorded had nonaccrual loans been current	1,000,000	937,000	821,000
Charged-off portion of impaired loans	5,800,000	'	'
Outstanding commitments to extend credit on impaired loans	837,000	'	'
Commercial loans	'	'	'
Recorded investment in impaired loans:	'	'	'
With no specific allowance recorded	977,000	6,825,000	'
With a specific allowance recorded	4,725,000	2,645,000	'
Total recorded investment in impaired loans	5,702,000	9,470,000	'
Unpaid principal balance of impaired loans:	'	'	'
With no specific allowance recorded	977,000	7,633,000	'
With a specific allowance recorded	4,930,000	2,930,000	'
Total unpaid principal balance of impaired loans	5,907,000	10,563,000	'
Specific valuation	1,170,000	1,131,000	'
Average recorded investment in impaired loans during the period	7,168,000	11,772,000	4,695,000
Interest income recognized on impaired loans	476,000	803,000	102,000
Commercial real estate, owner-occupied	'	'	'
Recorded investment in impaired loans:	'	'	'
With no specific allowance recorded	1,403,000	1,403,000	'
With a specific allowance recorded	4,085,000	471,000	'
Total recorded investment in impaired loans	5,488,000	1,874,000	'
Unpaid principal balance of impaired loans:	'	'	'
With no specific allowance recorded	3,060,000	3,060,000	'
With a specific allowance recorded	5,088,000	966,000	'
Total unpaid principal balance of impaired loans	8,148,000	4,026,000	'
Specific valuation	90,000	26,000	'
Average recorded investment in impaired loans during the period	3,519,000	1,538,000	1,873,000
Interest income recognized on impaired loans	253,000	111,000	0
Commercial real estate, investor	'	'	'
Recorded investment in impaired loans:	'	'	'
With no specific allowance recorded	3,341,000	3,725,000	'
With a specific allowance recorded	0	4,513,000	'
Total recorded investment in impaired loans	3,341,000	8,238,000	'
Unpaid principal balance of impaired loans:	'	'	'
With no specific allowance recorded	5,333,000	5,717,000	'
With a specific allowance recorded	0	4,887,000	'
Total unpaid principal balance of impaired loans	5,333,000	10,604,000	'
Specific valuation	0	374,000	'
Average recorded investment in impaired loans during the period	5,847,000	5,135,000	595,000
Interest income recognized on impaired loans	14,000	512,000	38,000
Construction	'	'	'
Recorded investment in impaired loans:	'	'	'
With no specific allowance recorded	2,806,000	2,328,000	'
With a specific allowance recorded	3,927,000	1,840,000	'
Total recorded investment in impaired loans	6,733,000	4,168,000	'
Unpaid principal balance of impaired loans:	'	'	'
With no specific allowance recorded	5,547,000	2,514,000	'
With a specific allowance recorded	4,114,000	4,519,000	'
Total unpaid principal balance of impaired loans	9,661,000	7,033,000	'
Specific valuation	341,000	118,000	'
Average recorded investment in impaired loans during the period	7,200,000	12,909,000	3,505,000
Interest income recognized on impaired loans	249,000	570,000	0
Home equity	'	'	'
Recorded investment in impaired loans:	'	'	'
With no specific allowance recorded	349,000	931,000	'
With a specific allowance recorded	157,000	261,000	'
Total recorded investment in impaired loans	506,000	1,192,000	'
Unpaid principal balance of impaired loans:	'	'	'
With no specific allowance recorded	835,000	1,417,000	'
With a specific allowance recorded	157,000	324,000	'
Total unpaid principal balance of impaired loans	992,000	1,741,000	'
Specific valuation	1,000	154,000	'
Average recorded investment in impaired loans during the period	909,000	1,314,000	813,000
Interest income recognized on impaired loans	29,000	32,000	14,000
Other residential	'	'	'
Recorded investment in impaired loans:	'	'	'
With no specific allowance recorded	1,254,000	2,598,000	'
With a specific allowance recorded	809,000	715,000	'
Total recorded investment in impaired loans	2,063,000	3,313,000	'
Unpaid principal balance of impaired loans:	'	'	'
With no specific allowance recorded	1,254,000	2,598,000	'
With a specific allowance recorded	809,000	715,000	'
Total unpaid principal balance of impaired loans	2,063,000	3,313,000	'
Specific valuation	23,000	120,000	'
Average recorded investment in impaired loans during the period	2,632,000	2,509,000	1,612,000
Interest income recognized on impaired loans	89,000	175,000	72,000
Installment and other consumer	'	'	'
Recorded investment in impaired loans:	'	'	'
With no specific allowance recorded	112,000	978,000	'
With a specific allowance recorded	1,750,000	1,070,000	'
Total recorded investment in impaired loans	1,862,000	2,048,000	'
Unpaid principal balance of impaired loans:	'	'	'
With no specific allowance recorded	154,000	1,020,000	'
With a specific allowance recorded	1,750,000	1,070,000	'
Total unpaid principal balance of impaired loans	1,904,000	2,090,000	'
Specific valuation	364,000	431,000	'
Average recorded investment in impaired loans during the period	1,872,000	2,151,000	1,844,000
Interest income recognized on impaired loans	$71,000	$96,000	$26,000

Loans_and_Allowance_for_Loan_L8

Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]	'		'		'
Beginning balance	$13,661,000		$14,639,000		$12,392,000
Provision for loan losses	540,000		2,900,000		7,050,000
Charge-offs	-1,154,000		-4,560,000		-4,902,000
Recoveries	1,177,000		682,000		99,000
Ending balance	14,224,000		13,661,000		14,639,000
Ending ALLL related to loans collectively evaluated for impairment	12,235,000		11,307,000		11,693,000
Ending ALLL related to loans individually evaluated for impairment	1,747,000		2,091,000		2,377,000
Ending ALLL related to purchased credit-impaired loans	242,000		263,000		569,000
Loans outstanding, Collectively evaluated for impairment	1,239,364,000		1,042,907,000		1,009,523,000
Loans outstanding, Individually evaluated for impairment	22,843,000	[1]	26,496,000	[2]	15,678,000
Purchase credit-impaired	7,115,000		4,549,000		5,953,000
Total	1,269,322,000	[3]	1,073,952,000	[3]	1,031,154,000
Ratio of allowance for loan losses to total loans	1.12%		1.27%		1.42%
Allowance for loan losses to non-accrual loans	122.00%		77.00%		122.00%
PCI loans impaired post-acquisition	2,900,000		3,800,000		4,500,000
Commercial loans	'		'		'
Financing Receivable, Allowance for Credit Losses [Line Items]	'		'		'
Beginning balance	4,100,000		4,334,000		3,114,000
Provision for loan losses	-1,393,000		117,000		4,469,000
Charge-offs	-672,000		-892,000		-3,306,000
Recoveries	1,021,000		541,000		57,000
Ending balance	3,056,000		4,100,000		4,334,000
Ending ALLL related to loans collectively evaluated for impairment	1,886,000		2,969,000		3,049,000
Ending ALLL related to loans individually evaluated for impairment	987,000		1,090,000		957,000
Ending ALLL related to purchased credit-impaired loans	183,000		41,000		328,000
Loans outstanding, Collectively evaluated for impairment	177,550,000		166,860,000		169,564,000
Loans outstanding, Individually evaluated for impairment	5,408,000	[4]	8,931,000	[2]	5,110,000
Purchase credit-impaired	333,000		640,000		1,116,000
Total	183,291,000	[3]	176,431,000	[3]	175,790,000
Ratio of allowance for loan losses to total loans	1.67%		2.32%		2.47%
Allowance for loan losses to non-accrual loans	257.00%		84.00%		147.00%
Commercial real estate, owner-occupied	'		'		'
Financing Receivable, Allowance for Credit Losses [Line Items]	'		'		'
Beginning balance	1,313,000		1,305,000		1,037,000
Provision for loan losses	615,000		184,000		377,000
Charge-offs	0		-181,000		-113,000
Recoveries	84,000		5,000		4,000
Ending balance	2,012,000		1,313,000		1,305,000
Ending ALLL related to loans collectively evaluated for impairment	1,922,000		1,287,000		1,136,000
Ending ALLL related to loans individually evaluated for impairment	31,000		0		0
Ending ALLL related to purchased credit-impaired loans	59,000		26,000		169,000
Loans outstanding, Collectively evaluated for impairment	233,330,000		193,891,000		171,492,000
Loans outstanding, Individually evaluated for impairment	2,930,000	[1]	0	[2]	0
Purchase credit-impaired	4,853,000		2,515,000		3,213,000
Total	241,113,000	[3]	196,406,000	[3]	174,705,000
Ratio of allowance for loan losses to total loans	0.83%		0.67%		0.75%
Allowance for loan losses to non-accrual loans	143.00%		94.00%		64.00%
Commercial real estate, investor	'		'		'
Financing Receivable, Allowance for Credit Losses [Line Items]	'		'		'
Beginning balance	4,372,000		3,710,000		4,134,000
Provision for loan losses	1,940,000		3,076,000		-424,000
Charge-offs	-156,000		-2,414,000		0
Recoveries	40,000		0		0
Ending balance	6,196,000		4,372,000		3,710,000
Ending ALLL related to loans collectively evaluated for impairment	6,196,000		3,998,000		3,547,000
Ending ALLL related to loans individually evaluated for impairment	0		178,000		91,000
Ending ALLL related to purchased credit-impaired loans	0		196,000		72,000
Loans outstanding, Collectively evaluated for impairment	619,833,000		500,768,000		444,060,000
Loans outstanding, Individually evaluated for impairment	3,341,000	[1]	6,844,000	[2]	741,000
Purchase credit-impaired	1,845,000		1,394,000		1,624,000
Total	625,019,000	[3]	509,006,000	[3]	446,425,000
Ratio of allowance for loan losses to total loans	0.99%		0.86%		0.83%
Allowance for loan losses to non-accrual loans	221.00%		64.00%		501.00%
Construction	'		'		'
Financing Receivable, Allowance for Credit Losses [Line Items]	'		'		'
Beginning balance	611,000		1,505,000		1,694,000
Provision for loan losses	83,000		-643,000		275,000
Charge-offs	-62,000		-373,000		-473,000
Recoveries	1,000		122,000		9,000
Ending balance	633,000		611,000		1,505,000
Ending ALLL related to loans collectively evaluated for impairment	292,000		493,000		1,311,000
Ending ALLL related to loans individually evaluated for impairment	341,000		118,000		194,000
Ending ALLL related to purchased credit-impaired loans	0		0		0
Loans outstanding, Collectively evaluated for impairment	24,829,000		26,497,000		48,653,000
Loans outstanding, Individually evaluated for impairment	6,733,000	[1]	4,168,000	[2]	3,304,000
Purchase credit-impaired	15,000		0		0
Total	31,577,000	[3]	30,665,000	[3]	51,957,000
Ratio of allowance for loan losses to total loans	2.00%		1.99%		2.90%
Allowance for loan losses to non-accrual loans	12.00%		27.00%		50.00%
Home equity	'		'		'
Financing Receivable, Allowance for Credit Losses [Line Items]	'		'		'
Beginning balance	1,264,000		1,444,000		643,000
Provision for loan losses	-223,000		190,000		1,342,000
Charge-offs	-176,000		-382,000		-554,000
Recoveries	10,000		12,000		13,000
Ending balance	875,000		1,264,000		1,444,000
Ending ALLL related to loans collectively evaluated for impairment	874,000		1,110,000		1,182,000
Ending ALLL related to loans individually evaluated for impairment	1,000		154,000		262,000
Ending ALLL related to purchased credit-impaired loans	0		0		0
Loans outstanding, Collectively evaluated for impairment	97,894,000		92,045,000		96,998,000
Loans outstanding, Individually evaluated for impairment	506,000	[1]	1,192,000	[2]	1,045,000
Purchase credit-impaired	69,000		0		0
Total	98,469,000	[3]	93,237,000	[3]	98,043,000
Ratio of allowance for loan losses to total loans	0.89%		1.36%		1.47%
Allowance for loan losses to non-accrual loans	374.00%		232.00%		189.00%
Other residential	'		'		'
Financing Receivable, Allowance for Credit Losses [Line Items]	'		'		'
Beginning balance	551,000		940,000		738,000
Provision for loan losses	-234,000		-193,000		202,000
Charge-offs	0		-196,000		0
Recoveries	0		0		0
Ending balance	317,000		551,000		940,000
Ending ALLL related to loans collectively evaluated for impairment	294,000		431,000		532,000
Ending ALLL related to loans individually evaluated for impairment	23,000		120,000		408,000
Ending ALLL related to purchased credit-impaired loans	0		0		0
Loans outstanding, Collectively evaluated for impairment	70,571,000		46,119,000		58,095,000
Loans outstanding, Individually evaluated for impairment	2,063,000	[1]	3,313,000	[2]	3,407,000
Purchase credit-impaired	0		0		0
Total	72,634,000	[3],[5]	49,432,000	[3],[5]	61,502,000
Ratio of allowance for loan losses to total loans	0.44%		1.11%		1.53%
Allowance for loan losses to non-accrual loans	48.00%		46.00%		48.00%
Installment and other consumer	'		'		'
Financing Receivable, Allowance for Credit Losses [Line Items]	'		'		'
Beginning balance	1,231,000		1,182,000		835,000
Provision for loan losses	-535,000		169,000		787,000
Charge-offs	-88,000		-122,000		-456,000
Recoveries	21,000		2,000		16,000
Ending balance	629,000		1,231,000		1,182,000
Ending ALLL related to loans collectively evaluated for impairment	265,000		800,000		717,000
Ending ALLL related to loans individually evaluated for impairment	364,000		431,000		465,000
Ending ALLL related to purchased credit-impaired loans	0		0		0
Loans outstanding, Collectively evaluated for impairment	15,357,000		16,727,000		20,661,000
Loans outstanding, Individually evaluated for impairment	1,862,000	[1]	2,048,000	[2]	2,071,000
Purchase credit-impaired	0		0		0
Total	17,219,000	[3]	18,775,000	[3]	22,732,000
Ratio of allowance for loan losses to total loans	3.65%		6.56%		5.20%
Allowance for loan losses to non-accrual loans	372.00%		231.00%		228.00%
Unallocated	'		'		'
Financing Receivable, Allowance for Credit Losses [Line Items]	'		'		'
Beginning balance	219,000		219,000		197,000
Provision for loan losses	287,000		0		22,000
Charge-offs	0		0		0
Recoveries	0		0		0
Ending balance	506,000		219,000		219,000
Ending ALLL related to loans collectively evaluated for impairment	506,000		219,000		219,000
Ending ALLL related to loans individually evaluated for impairment	0		0		0
Ending ALLL related to purchased credit-impaired loans	0		0		0
Loans outstanding, Collectively evaluated for impairment	0		0		0
Loans outstanding, Individually evaluated for impairment	0	[1]	0	[2]	0
Purchase credit-impaired	0		0		0
Total	$0		$0		$0
[1]	Total excludes $2.9 million of PCI loans that have experienced post-acquisition declines in cash flows expected to be collected.These loans are included in the "purchased credit-impaired" amount in the next line below.NM Not Meaningful
[2]	Total excludes $3.8 million PCI loans that have experienced credit deterioration post-acquisition, which are included in the "purchased credit-impaired" amount in the next line below.
[3]	Amounts were net of deferred loan (costs)/fees of $(24) thousand and $769 thousand at December 31, 2013 and 2012, respectively. Amounts were also net of unaccreted purchase discounts on non-PCI loans of $7.6 million and $2.1 million at December 31, 2013 and 2012, respectively.
[4]	$6.6 million of the $41.8 million represents the difference between the contractual principal amounts due and the fair value. This discount is to be accreted to interest income over the remaining lives of the loans. The remaining $35.2 million is the contractual interest to be earned over the life of the loans.
[5]	Our residential loan portfolio includes no sub-prime loans, nor is it our normal practice to underwrite loans commonly referred to as "Alt-A mortgages," the characteristics of which are loans lacking full documentation, borrowers having low FICO scores or higher loan-to-value ratios.

Loans_and_Allowance_for_Loan_L9

Loans and Allowance for Loan Losses - Purchased Credit-Impaired Loans (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Nov. 29, 2013
PCI Loans, Fair Value [Abstract]	'		'		'		'
Contractually required payments including interest, Purchased credit-impaired loans	'		'		'		$5,706,000
Contractually required payments including interest, Other purchased loans	'		'		'		211,769,000
Contractually required payments including interest, Total	'		'		'		217,475,000
Less: nonaccretable difference, Purchased credit-impaired loans	'		'		'		-1,183,000
Less: nonaccretable difference, Other purchased loans	'		'		'		0
Less: nonaccretable difference, Total	'		'		'		-1,183,000
Cash flows expected to be collected (undiscounted), Purchased credit-impaired loans	'		'		'		4,523,000
Cash flows expected to be collected (undiscounted), Other purchased loans	'		'		'		211,769,000
Cash flows expected to be collected (undiscounted), Total	'		'		'		216,292,000
Accretable yield, Purchased credit-impaired loans	'		'		'		-707,000
Accretable Yield, Other Purchased Loans	'		'		'		-41,826,000	[1]
Accretable Yield, Total	'		'		'		-42,533,000
Fair value of purchased credit-impaired loans	'		'		'		3,816,000
Fair value of other purchased loans	'		'		'		169,943,000
Fair value of purchased loans	'		'		'		173,759,000
Increase of specific allowance for PCI loan losses	203,000		36,000		569,000		'
PCI Loans, Carrying Value [Abstract]	'		'		'		'
Unpaid principal balance	10,634,000		8,533,000		'		4,993,000
Carrying value	7,115,000		4,549,000		'		3,816,000
Accretable Yield [Roll Forward]	'		'		'		'
Balance at beginning of period	3,960,000		5,405,000		0		'
Additions	707,000		0		1,902,000		'
Removals	-793,000	[2]	-1,221,000	[2]	-1,019,000	[2]	'
Accretion	-725,000		-1,641,000		-1,418,000		'
Reclassifications (to)/from nonaccretable difference	500,000	[3]	1,417,000	[3]	5,940,000	[3]	'
Balance at end of period	3,649,000		3,960,000		5,405,000		'
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses, Decreases	237,000		76,000		0		'
Commercial loans	'		'		'		'
PCI Loans, Carrying Value [Abstract]	'		'		'		'
Unpaid principal balance	1,094,000		2,163,000		'		847,000
Carrying value	333,000		640,000		'		369,000
Commercial real estate loans	'		'		'		'
PCI Loans, Carrying Value [Abstract]	'		'		'		'
Unpaid principal balance	9,152,000		6,370,000		'		3,757,000
Carrying value	6,698,000		3,909,000		'		3,362,000
Construction	'		'		'		'
PCI Loans, Carrying Value [Abstract]	'		'		'		'
Unpaid principal balance	149,000		0		'		150,000
Carrying value	15,000		0		'		16,000
Home equity	'		'		'		'
PCI Loans, Carrying Value [Abstract]	'		'		'		'
Unpaid principal balance	239,000		0		'		239,000
Carrying value	69,000		0		'		69,000
Other purchased loans	'		'		'		'
PCI Loans, Fair Value [Abstract]	'		'		'		'
Difference between the contractual principal amounts due and the fair value	'		'		'		6,600,000
Contractual interest to be earned over the life of the loans	'		'		'		$35,200,000
[1]	$6.6 million of the $41.8 million represents the difference between the contractual principal amounts due and the fair value. This discount is to be accreted to interest income over the remaining lives of the loans. The remaining $35.2 million is the contractual interest to be earned over the life of the loans.
[2]	Represents the accretable difference that is relieved when a loan exits the PCI population due to payoff, full charge-off, or transfer to repossessed assets, etc.
[3]	Primarily relates to improvements in expected credit performance and changes in expected timing of cash flows.

Recovered_Sheet1

Loans and Allowance for Loan Losses - Pledged Loans (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financial Instruments Owned and Pledged as Collateral [Line Items]	'	'
Certain qualifying loans pledged for FHLB line of credit	$716.20	$567.80
Other residential	'	'
Financial Instruments Owned and Pledged as Collateral [Line Items]	'	'
Residential loans pledged for FRB borrowings	$24.40	$30.10

Recovered_Sheet2

Loans and Allowance for Loan Losses - Related Party Loans (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Receivables [Abstract]	'	'	'
Balance at beginning of year	$3,425	$6,866	$6,997
Additions	550	826	1,690
Advances	569	3	43
Repayments	0	-2,730	-1,864
Reclassified as unrelated-party loan	-795	-1,540	0
Balance at end of year	3,749	3,425	6,866
Undisbursed commitment to related parties	$657	'	'

Bank_Premises_and_Equipment_De

Bank Premises and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]	'	'	'
Bank premises and equipment, Gross	$20,572,000	$19,518,000	'
Accumulated depreciation and amortization	-11,462,000	-10,174,000	'
Bank premises and equipment, net	9,110,000	9,344,000	'
Depreciation and amortization	1,400,000	1,400,000	1,300,000
Leasehold improvements	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Bank premises and equipment, Gross	12,684,000	12,116,000	'
Leasehold improvements | Director	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Payments for leasehold improvements	70,000	29,000	'
Furniture and equipment	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Bank premises and equipment, Gross	$7,888,000	$7,402,000	'

Bank_Owned_Life_Insurance_Deta

Bank Owned Life Insurance (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Insurance [Abstract]	'	'	'
Estimated death benefits	$63,300,000	'	'
Death benefits provided under terms of the programs	27,800,000	22,700,000	'
Earnings on Bank-owned life insurance	954,000	762,000	752,000
Bank owned life insurance benefit realized	$228,000	'	'

Deposits_Details

Deposits (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Banking and Thrift [Abstract]	'	'	'
Total time deposits	$161,868,000	$156,800,000	'
Time deposits of $100,000 or more	111,700,000	114,700,000	'
Interest on time deposits	900,000	1,200,000	1,600,000
Held-to-maturity securities pledged as collateral	45,700,000	'	'
Available-for-sale securities pledged as collateral	15,600,000	'	'
Deposit overdrafts reclassified as loan balances	207,000	276,000	'
Related party deposit liabilities	$8,100,000	$7,300,000	'

Deposits_Time_Deposit_Maturiti

Deposits - Time Deposit Maturities (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Maturities of Time Deposits [Abstract]	'	'
2014	$100,350	'
2015	16,474	'
2016	22,457	'
2017	13,304	'
2018	9,283	'
Thereafter	0	'
Total	$161,868	$156,800

Borrowings_Lines_of_Credit_and

Borrowings - Lines of Credit and Borrowing Agreements (Details) (USD $)

12 Months Ended

0 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Feb. 05, 2008

Dec. 31, 2013

Dec. 31, 2012

Federal Funds Purchased

Federal Funds Purchased

Federal Home Loan Bank Overnight Borrowings

Federal Home Loan Bank Overnight Borrowings

Federal Reserve Line of Credit

Federal Reserve Line of Credit

Federal Home Loan Bank Borrowings

Federal Home Loan Bank Borrowings

Federal Home Loan Bank Borrowings

Line of Credit

Line of Credit

Line of Credit

Line of Credit

Line of Credit

Line of Credit

Line of Credit

Line of Credit

Line of Credit

Line of Credit Facility [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Lines of credit

'

'

'

$87,000,000

'

'

'

$24,400,000

$30,100,000

'

$416,300,000

$321,300,000

Term of FHLB borrowing agreements

'

'

'

'

'

'

'

'

'

'10 years

'

'

Principal amount of borrowing agreements with FHLB

'

'

'

'

'

'

'

'

'

15,000,000

'

'

Amount of FHLB borrowings outstanding

'

'

'

0

0

0

0

0

0

'

'

'

Repayments of Federal Home Loan Bank Borrowings

0

20,000,000

33,500,000

'

'

'

'

'

'

'

'

'

Fixed interest rate of FHLB borrowing agreement

'

'

'

'

'

'

'

'

'

2.07%

'

'

Remaining available line of credit from FHLB

'

'

'

'

'

'

'

'

'

'

$401,300,000

'

Borrowings_Subordinated_Debt_D

Borrowings - Subordinated Debt (Details) (USD $)	12 Months Ended			0 Months Ended	3 Months Ended				12 Months Ended		0 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Nov. 29, 2013	Sep. 17, 2004	Sep. 30, 2012	Dec. 31, 2013	Nov. 29, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Nov. 29, 2013
			debenture	Subordinated debenture	Subordinated debenture	Subordinated debenture	Subordinated debenture	Subordinated debenture	Subordinated debenture	Subordinated debenture	Subordinated debenture
									NorCal Community Bancorp Trust I	NorCal Community Bancorp Trust II	Maximum
Debt Instrument [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Term of subordinated debenture	'	'	'	'15 years	'	'	'	'	'	'	'
Subordinated debentures	$0	$4,969,000	'	$5,000,000	'	$4,969,000	'	$0	'	'	'
Basis spread on subordinated debenture	'	'	'	2.48%	'	'	'	'	3.05%	1.40%	'
Write off of deferred debt issuance cost	42,000	'	'	'	42,000	'	'	'	'	'	'
Number of subordinated debentures acquired	'	'	2	'	'	'	'	'	'	'	'
Subordinated debenture	'	'	'	'	'	'	4,950,000	'	'	'	'
Long-term Debt, Gross	'	'	'	'	'	8,248,000	8,200,000	'	4,124,000	4,124,000	'
Debenture distribution deferral period	'	'	'	'	'	'	'	'	'	'	'5 years
Effective interest rate	'	'	'	'	'	'	'	'	3.29%	1.64%	'
Amount guaranteed, on subordinated basis, distributions and other payments on trust preferred securities	'	$8,000,000	'	'	'	'	'	'	'	'	'

Borrowings_Schedule_of_Borrowi

Borrowings - Schedule of Borrowings (Details) (USD $)	12 Months Ended			3 Months Ended	12 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012		Sep. 17, 2004	Dec. 31, 2013	Dec. 31, 2012
				Subordinated debenture	Subordinated debenture	Subordinated debenture		Subordinated debenture	Line of Credit	Line of Credit
									Federal Home Loan Bank Borrowings	Federal Home Loan Bank Borrowings
Debt Instrument [Line Items]	'	'	'	'	'	'		'	'	'
FHLB fixed-rate borrowings, Carrying Value	'	'	'	'	'	'		'	$15,000,000	$15,000,000
FHLB fixed-rate borrowings, Average Balance	'	'	'	'	'	'		'	19,054,000	16,205,000
Borrowings, Average Rate	'	'	'	'	8.48%	4.21%	[1]	'	1.67%	2.09%	[1]
Subordinated debenture, Carrying Value	4,969,000	0	'	'	4,969,000	0		5,000,000	'	'
Subordinated debenture, Average Balance	'	'	'	'	407,000	3,552,000		'	'	'
Accretion of discount on subordinated debentures	19,000	0	0	'	'	'		'	'	'
Write off of deferred debt issuance cost	'	$42,000	'	$42,000	'	'		'	'	'
[1]	Amount includes the impact of $19 thousand of accretion on the fair value discount.

Stockholders_Equity_and_Stock_2

Stockholders' Equity and Stock Plans - Equity Narrative (Details) (USD $)	0 Months Ended	1 Months Ended			0 Months Ended			0 Months Ended
	Dec. 05, 2008	Nov. 30, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 05, 2008	Dec. 31, 2013	Dec. 05, 2008	Mar. 31, 2009	Dec. 05, 2008	Dec. 05, 2008
		investor			U.S. Treasury Capital Purchase Program (TCPP)	Common stock	Common stock	Senior preferred stock	Senior preferred stock	Warrant to purchase common stock
							U.S. Treasury Capital Purchase Program (TCPP)	U.S. Treasury Capital Purchase Program (TCPP)	U.S. Treasury Capital Purchase Program (TCPP)	U.S. Treasury Capital Purchase Program (TCPP)
Class of Stock [Line Items]	'	'	'	'	'	'	'	'	'	'
Preferred stock, issued, (in shares)	'	'	0	0	28,000	'	'	'	'	'
Preferred stock, no par value (in dollars per share)	'	'	$0	$0	'	'	'	'	$0	'
Per share liquidation preference for senior preferred stock	'	'	'	'	$1,000	'	'	'	'	'
Number of common stock shares authorized to be purchased by warrant	'	'	'	'	'	156,134	154,242	'	'	'
Exercise price of warrant to purchase common stock	'	'	'	'	'	26.9	27.23	'	'	'
Proceeds from issuance of senior preferred stock and warrant	'	'	'	'	$28,000,000	'	'	'	$27,000,000	$961,000
Exercisable period of warrants	'10 years	'	'	'	'	'	'	'	'	'
Stock repurchased from U.S. Treasury, shares	'	'	'	'	'	'	'	28,000	'	'
Stock repurchased from U.S. Treasury, value	'	'	'	'	'	'	'	28,000,000	'	'
Accrued but unpaid dividends on repurchased preferred stock	'	'	'	'	'	'	'	179,000	'	'
Remaining accretion of repurchased preferred stock	'	'	'	'	'	'	'	$945,000	'	'
Number of institutional investors that purchased warrant	'	2	'	'	'	'	'	'	'	'
Preferred stock, authorized (in shares)	'	'	5,000,000	5,000,000	'	'	'	'	'	'

Stockholders_Equity_and_Stock_3

Stockholders' Equity and Stock Plans - Share Based Awards Narrative (Details) (USD $)

12 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

8-May-07

Dec. 31, 2013

11-May-10

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Jul. 01, 2007

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2005

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2005

Dec. 31, 2005

Dec. 31, 2005

Dec. 31, 2005

Dec. 31, 2005

Dec. 31, 2005

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Director Stock Plan, 2010

Director Stock Plan, 2010

Equity Plan, 2007

Equity Plan, 2007

Employee Stock Purchase Plan, 2007

Employee Stock Purchase Plan, 2007

Former 1999 Stock Option Plan

Officer and Employee

Nonemployee Director

Nonemployee Director

Nonemployee Director

Nonemployee Director

Nonemployee Director

Nonemployee Director

Nonemployee Director

Common Stock

Common Stock

Stock options

Stock options

Stock options

Unvested restricted stock

Unvested restricted stock

Unvested restricted stock

Prior to January 1, 2006

Prior to January 1, 2006

Prior to January 1, 2006

Prior to January 1, 2006

Prior to January 1, 2006

Prior to January 1, 2006

Subsequent to January 1, 2006

Subsequent to January 1, 2006

Subsequent to January 1, 2006

Subsequent to January 1, 2006

Subsequent to January 1, 2006

Subsequent to January 1, 2006

Minimum

Maximum

Maximum

Immediately Upon Grant

Vesting Rate, Year One

Vesting Rate, Year Two

Vesting Rate, Year Three

Vesting Rate Year Four

Director Stock Plan, 2010

Director Stock Plan, 2010

Stock options

Stock options

Stock options

Stock options

Stock options

Stock options

Unvested restricted stock

Unvested restricted stock

Unvested restricted stock

Unvested restricted stock

Unvested restricted stock

Unvested restricted stock

Equity Plan, 2007

Officer and Employee

Officer and Employee

Officer and Employee

Officer and Employee

Officer and Employee

Officer and Employee

Vesting Rate, Year One

Vesting Rate, Year Two

Vesting Rate, Year Three

Vesting Rate Year Four

Vesting Rate Year Five

Immediately Upon Grant

Vesting Rate, Year One

Vesting Rate, Year Two

Vesting Rate, Year Three

Vesting Rate Year Four

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of common shares approved to be issued in each plan

'

'

'

500,000

'

150,000

'

'

'

200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares awarded in period from plan

'

'

'

'

'

'

0

0

'

'

'

'

'

'

'

'

'

'

'

5,619

5,270

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Approved payroll deduction to purchase shares, percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.00%

15.00%

'

Discount from closing market price at end of each quarter

'

'

'

'

'

'

'

'

5.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares available for future grants under plan

'

'

'

'

130,071

'

278,572

'

194,446

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares To Be Granted

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

250,000

Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vesting percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

20.00%

20.00%

20.00%

20.00%

20.00%

'

'

'

'

'

'

'

'

'

20.00%

20.00%

20.00%

20.00%

20.00%

'

20.00%

20.00%

20.00%

20.00%

20.00%

'

'

'

Award vesting period

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'

'

'

'

'

'5 years

'

'

'

'

'

'

'

'

Expiration period of grants

'

'

'

'

'

'

'

'

'

'

'

'10 years

'7 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized compensation expense

$1,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Period unrecognized compensation expense to recognized

'4 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total grant-date fair value of option shares vested

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

187,000

212,000

270,000

218,000

152,000

115,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based compensation income tax benefit recognized

$94,000

$35,000

$37,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated forfeiture rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7.50%

7.50%

7.50%

10.00%

10.00%

7.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stockholders_Equity_and_Stock_4

Stockholders' Equity and Stock Plans - Options Outstanding Rollforward (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'	'	'	'
Options outstanding, beginning balance, Number of Shares	285,533	299,806	317,804	'
Granted, Number of Shares	30,000	23,930	17,585	'
Cancelled, expired or forfeited, Number of Shares	-23,840	-640	-670	'
Exercised, Number of Shares	-71,237	-37,563	-34,913	'
Options outstanding, ending balance, Number of Shares	220,456	285,533	299,806	'
Exercisable (vested), ending balance, Number of Shares	163,301	217,232	226,989	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]	'	'	'	'
Options outstanding, beginning balance, Weighted Average Exercise Price	$31.73	$30.71	$29.27	'
Granted, Weighted Average Exercise Price	$39.99	$38.18	$37.76	'
Cancelled, expired or forfeited, Weighted Average Exercise Price	$35.12	$31.51	$29.28	'
Exercised, Weighted Average Exercise Price	$31.13	$27.70	$21.22	'
Options outstanding, ending balance, Weighted Average Exercise Price	$32.74	$31.73	$30.71	'
Exercisable (vested), ending balance, Weighted Average Exercise Price	$31.09	$31.15	$30.64	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]	'	'	'	'
Options outstanding, beginning balance, Aggregate Intrinsic Value as of year-end	$1,661	$2,068	$1,828	'
Granted, Aggregate Intrinsic Value as of year-end	102	0	3	'
Cancelled, expired or forfeited, Aggregate Intrinsic Value as of year-end	151	4	6	'
Exercised, Aggregate Intrinsic Value as of year-end	664	400	534	'
Options outstanding, ending balance, Aggregate Intrinsic Value as of year-end	2,349	1,661	2,068	'
Exercisable (vested), ending balance	$2,008	$1,372	$1,579	'
Options outstanding, beginning balance, Average Remaining Contractual Term	'4 years 0 months 18 days	'4 years 5 months 4 days	'4 years 8 months 12 days	'5 years 2 months 4 days
Exercisable (vested), ending balance, Average Remaining Contractual Term	'2 years 6 months 21 days	'3 years 4 months 20 days	'3 years 9 months 25 days	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Grant-Date Fair Value [Roll Forward] [Roll Forward]	'	'	'	'
Options outstanding, beginning balance, Weighted Average Grant-Date Fair Value	$9.21	$8.82	$8.66	$8.39
Options, Granted, Weighted Average Grant-Date Fair Value	$10.59	$9.82	$11.19	'
Cancelled, expired or forfeited, Weighted Average Grant-Date Fair Value	$9.31	$8	$7.07	'
Exercised, Weighted Average Grant-Date Fair Value	$8.30	$8.19	$7.51	'
Options outstanding, ending balance, Weighted Average Grant-Date Fair Value	$9.21	$8.82	$8.66	$8.39
Exercisable (vested), ending balance, Weighted Average Grant-Date Fair Value	$8.92	$8.77	$8.81	'

Stockholders_Equity_and_Stock_5

Stockholders' Equity and Stock Plans - Non-vested Awards Activity (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Options, Non-vested awards, beginning balance, Number of Shares	73,876	'	'
Options, Granted, Number of Shares	30,000	23,930	17,585
Options, Vested, Number of Shares	-22,881	'	'
Options, Forfeited, Number of Shares	-23,840	'	'
Options, Non-vested awards, ending balance, Number of Shares	57,155	73,876	'
Options, Non-vested awards, beginning balance, Weighted Average Grant-Date Fair Value	$8.98	'	'
Options, Granted, Weighted Average Grant-Date Fair Value	$10.59	$9.82	$11.19
Options, Vested, Weighted Average Grant-Date Fair Value	$8.17	'	'
Options, Forfeited, Weighted Average Grant-Date Fair Value	$9.31	'	'
Options, Non-vested awards, ending balance, Number of Shares	$10.05	$8.98	'
Restricted Stock, Non-vested awards, beginning balance, Number of Shares	21,610	'	'
Restricted Stock, Granted, Number of Shares	11,850	'	'
Restricted Stock, Vested, Number of Shares	-6,941	'	'
Restricted Stock, Forfeited, Number of Shares	-3,998	'	'
Restricted Stock, Non-vested awards, ending balance, Number of Shares	22,521	21,610	'
Restricted Stock, Non-vested awards, beginning balance, Weighted Average Grant-Date Fair Value	$34.05	'	'
Restricted Stock, Granted, Weighted Average Grant-Date Fair Value	$39.96	'	'
Restricted Stock, Vested, Weighted Average Grant-Date Fair Value	$31.42	'	'
Restricted Stock, Forfeited, Weighted Average Grant-Date Fair Value	$36.19	'	'
Restricted Stock, Non-vested awards, ending balance, Weighted Average Grant-Date Fair Value	$37.59	$34.05	'

Stockholders_Equity_and_Stock_6

Stockholders' Equity and Stock Plans - Options Outstanding by Price Range (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2009	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Stock Options Outstanding	220,456	285,533	299,806	'	317,804
Options outstanding, ending balance, Average Remaining Contractual Term	'4 years 0 months 18 days	'4 years 5 months 4 days	'4 years 8 months 12 days	'5 years 2 months 4 days	'
Stock Options Outstanding, Weighted Average Exercise Price	$32.74	$31.73	$30.71	'	$29.27
$20.01 - $25.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Range of Exercise Prices, Lower Limit	$20.01	'	'	'	'
Range of Exercise Prices, Upper Limit	$25	'	'	'	'
$25.01 - $30.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Range of Exercise Prices, Lower Limit	$25.01	'	'	'	'
Range of Exercise Prices, Upper Limit	$30	'	'	'	'
$30.01 - $35.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Range of Exercise Prices, Lower Limit	$30.01	'	'	'	'
Range of Exercise Prices, Upper Limit	$35	'	'	'	'
$35.01 - $40.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Range of Exercise Prices, Lower Limit	$35.01	'	'	'	'
Range of Exercise Prices, Upper Limit	$40	'	'	'	'
$40.01 - $45.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Range of Exercise Prices, Lower Limit	$40.01	'	'	'	'
Range of Exercise Prices, Upper Limit	$45	'	'	'	'
Stock options	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Stock Options Outstanding	220,456	'	'	'	'
Options outstanding, ending balance, Average Remaining Contractual Term	'4 years 1 month 6 days	'	'	'	'
Stock Options Outstanding, Weighted Average Exercise Price	$32.74	'	'	'	'
Stock Options Exercisable	163,301	'	'	'	'
Stock Options Exercisable, Weighted Average Exercise Price	$31.09	'	'	'	'
Stock options | $20.01 - $25.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Stock Options Outstanding	15,328	'	'	'	'
Options outstanding, ending balance, Average Remaining Contractual Term	'5 years 3 months 18 days	'	'	'	'
Stock Options Outstanding, Weighted Average Exercise Price	$22.25	'	'	'	'
Stock Options Exercisable	10,798	'	'	'	'
Stock Options Exercisable, Weighted Average Exercise Price	$22.25	'	'	'	'
Stock options | $25.01 - $30.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Stock Options Outstanding	47,711	'	'	'	'
Options outstanding, ending balance, Average Remaining Contractual Term	'1 year 7 months 6 days	'	'	'	'
Stock Options Outstanding, Weighted Average Exercise Price	$27.11	'	'	'	'
Stock Options Exercisable	47,711	'	'	'	'
Stock Options Exercisable, Weighted Average Exercise Price	$27.11	'	'	'	'
Stock options | $30.01 - $35.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Stock Options Outstanding	81,724	'	'	'	'
Options outstanding, ending balance, Average Remaining Contractual Term	'2 years 4 months 24 days	'	'	'	'
Stock Options Outstanding, Weighted Average Exercise Price	$33.04	'	'	'	'
Stock Options Exercisable	77,474	'	'	'	'
Stock Options Exercisable, Weighted Average Exercise Price	$33.04	'	'	'	'
Stock options | $35.01 - $40.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Stock Options Outstanding	59,193	'	'	'	'
Options outstanding, ending balance, Average Remaining Contractual Term	'6 years 6 months 0 days	'	'	'	'
Stock Options Outstanding, Weighted Average Exercise Price	$37.39	'	'	'	'
Stock Options Exercisable	27,318	'	'	'	'
Stock Options Exercisable, Weighted Average Exercise Price	$36.02	'	'	'	'
Stock options | $40.01 - $45.00	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Stock Options Outstanding	16,500	'	'	'	'
Options outstanding, ending balance, Average Remaining Contractual Term	'9 years 6 months 0 days	'	'	'	'
Stock Options Outstanding, Weighted Average Exercise Price	$40.52	'	'	'	'
Stock Options Exercisable	0	'	'	'	'
Stock Options Exercisable, Weighted Average Exercise Price	$0	'	'	'	'

Stockholders_Equity_and_Stock_7

Stockholders' Equity and Stock Plans - Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Risk-free interest rate	1.60%	1.60%	2.77%
Expected dividend yield on common stock	1.80%	1.78%	1.69%
Expected life in years	'6 years 9 months 17 days	'7 years	'7 years 6 months
Expected price volatility	30.01%	28.70%	28.92%

Stockholders_Equity_and_Stock_8

Stockholders' Equity and Stock Plans - Dividends (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Equity [Abstract]	'	'	'	'
Cash dividends to common stockholders	$3,970,000	$3,751,000	$3,457,000	'
Cash dividends paid per common share	$0.73	$0.70	$0.65	'
Retained earnings	101,464,000	91,164,000	'	'
Stockholders' equity	180,887,000	151,792,000	135,551,000	121,920,000
Period used to determine amount available for payment of dividends based on restriction	'3 years	'	'	'
Amount of retained earnings available for payment of dividends based on restriction	18,800,000	'	'	'
Cash held	$8,700,000	'	'	'

Fair_Value_of_Assets_and_Liabi2

Fair Value of Assets and Liabilities - Recorded on a Recurring Basis (Details) (USD $)	1 Months Ended		12 Months Ended
	Dec. 31, 2013		Dec. 31, 2013		Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	$243,998,000		$243,998,000		$153,962,000
Derivative financial assets (interest rate contracts)	961,000	[1]	961,000	[1]	1,000	[1]
Derivative financial liabilities (interest rate contracts)	2,519,000	[2]	2,519,000	[2]	5,240,000	[2]
Discount rate for selling costs applied to all properties	'		6.00%		'
OREO acquired as part of acquisition	461,000		461,000		'
Change in estimated fair value of OREO as of acquisition date	0		'		'
Assets and liabilities at fair value measured on a recurring basis | Carrying Value | Interest rate contract	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Derivative financial assets (interest rate contracts)	961,000		961,000		1,000
Derivative financial liabilities (interest rate contracts)	2,519,000		2,519,000		5,240,000
Assets and liabilities at fair value measured on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest rate contract	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Derivative financial assets (interest rate contracts)	0		0		0
Derivative financial liabilities (interest rate contracts)	0		0		0
Assets and liabilities at fair value measured on a recurring basis | Significant Other Observable Inputs (Level 2) | Interest rate contract	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Derivative financial assets (interest rate contracts)	961,000		961,000		1,000
Derivative financial liabilities (interest rate contracts)	2,519,000		2,519,000		5,240,000
Assets and liabilities at fair value measured on a recurring basis | Significant Unobservable Inputs (Level 3) | Interest rate contract	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Derivative financial assets (interest rate contracts)	0		0		0
Derivative financial liabilities (interest rate contracts)	0		0		0
MBS pass-through securities	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	123,033,000		123,033,000		53,713,000
MBS pass-through securities | Assets and liabilities at fair value measured on a recurring basis | Carrying Value	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	190,604,000		190,604,000		111,797,000
MBS pass-through securities | Assets and liabilities at fair value measured on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	0		0		0
MBS pass-through securities | Assets and liabilities at fair value measured on a recurring basis | Significant Other Observable Inputs (Level 2)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	190,604,000		190,604,000		111,797,000
MBS pass-through securities | Assets and liabilities at fair value measured on a recurring basis | Significant Unobservable Inputs (Level 3)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	0		0		0
Debentures of government sponsored agencies | Assets and liabilities at fair value measured on a recurring basis | Carrying Value	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	21,312,000		21,312,000		20,589,000
Debentures of government sponsored agencies | Assets and liabilities at fair value measured on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	0		0		0
Debentures of government sponsored agencies | Assets and liabilities at fair value measured on a recurring basis | Significant Other Observable Inputs (Level 2)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	21,312,000		21,312,000		20,589,000
Debentures of government sponsored agencies | Assets and liabilities at fair value measured on a recurring basis | Significant Unobservable Inputs (Level 3)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	0		0		0
Privately-issued CMOs	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	10,874,000		10,874,000		21,576,000
Privately-issued CMOs | Assets and liabilities at fair value measured on a recurring basis | Carrying Value	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	10,874,000		10,874,000		21,576,000
Privately-issued CMOs | Assets and liabilities at fair value measured on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	0		0		0
Privately-issued CMOs | Assets and liabilities at fair value measured on a recurring basis | Significant Other Observable Inputs (Level 2)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	10,874,000		10,874,000		21,576,000
Privately-issued CMOs | Assets and liabilities at fair value measured on a recurring basis | Significant Unobservable Inputs (Level 3)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	0		0		0
Obligations of state and political subdivisions | Assets and liabilities at fair value measured on a recurring basis | Carrying Value	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	15,948,000		15,948,000		'
Obligations of state and political subdivisions | Assets and liabilities at fair value measured on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	0		0		'
Obligations of state and political subdivisions | Assets and liabilities at fair value measured on a recurring basis | Significant Other Observable Inputs (Level 2)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	15,771,000		15,771,000		'
Obligations of state and political subdivisions | Assets and liabilities at fair value measured on a recurring basis | Significant Unobservable Inputs (Level 3)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	0		0		'
Corporate bonds | Assets and liabilities at fair value measured on a recurring basis | Carrying Value	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	5,426,000		5,426,000		'
Corporate bonds | Assets and liabilities at fair value measured on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	0		0		'
Corporate bonds | Assets and liabilities at fair value measured on a recurring basis | Significant Other Observable Inputs (Level 2)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	5,437,000		5,437,000		'
Corporate bonds | Assets and liabilities at fair value measured on a recurring basis | Significant Unobservable Inputs (Level 3)	'		'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'		'
Available for sale, Fair Value	$0		$0		'
[1]	Amounts exclude accrued interest totaling $10 thousand and $1 thousand at December 31, 2013 and December 31, 2012, respectively.
[2]	Amounts exclude accrued interest totaling $60 thousand and $74 thousand at December 31, 2013 and December 31, 2012, respectively.

Fair_Value_of_Assets_and_Liabi3

Fair Value of Assets and Liabilities - Recorded on Nonrecurring Basis (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	$25,695	$30,303
Specific valuation allowance for impaired loans	1,989	2,354
Impaired loans	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Specific valuation allowance for impaired loans	363	729
Financial instruments at fair value measured on a nonrecurring basis | Carrying Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	3,072	5,574
Financial instruments at fair value measured on a nonrecurring basis | Significant Unobservable Inputs (Level 3)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	3,072	5,574
Financial instruments at fair value measured on a nonrecurring basis | Fair Value Hierarcy (Level 1)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	0	0
Financial instruments at fair value measured on a nonrecurring basis | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	0	0
Commercial real estate, investor	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	3,341	8,238
Specific valuation allowance for impaired loans	0	374
Commercial real estate, investor | Financial instruments at fair value measured on a nonrecurring basis | Carrying Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	2,941
Commercial real estate, investor | Financial instruments at fair value measured on a nonrecurring basis | Significant Unobservable Inputs (Level 3)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	2,941
Commercial real estate, investor | Financial instruments at fair value measured on a nonrecurring basis | Fair Value Hierarcy (Level 1)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	0
Commercial real estate, investor | Financial instruments at fair value measured on a nonrecurring basis | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	0
Construction	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	6,733	4,168
Specific valuation allowance for impaired loans	341	118
Construction | Financial instruments at fair value measured on a nonrecurring basis | Carrying Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	3,037	1,722
Construction | Financial instruments at fair value measured on a nonrecurring basis | Significant Unobservable Inputs (Level 3)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	3,037	1,722
Construction | Financial instruments at fair value measured on a nonrecurring basis | Fair Value Hierarcy (Level 1)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	0	0
Construction | Financial instruments at fair value measured on a nonrecurring basis | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	0	0
Home equity	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	506	1,192
Specific valuation allowance for impaired loans	1	154
Home equity | Financial instruments at fair value measured on a nonrecurring basis | Carrying Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	107
Home equity | Financial instruments at fair value measured on a nonrecurring basis | Significant Unobservable Inputs (Level 3)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	107
Home equity | Financial instruments at fair value measured on a nonrecurring basis | Fair Value Hierarcy (Level 1)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	0
Home equity | Financial instruments at fair value measured on a nonrecurring basis | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	0
Other residential	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	2,063	3,313
Specific valuation allowance for impaired loans	23	120
Other residential | Financial instruments at fair value measured on a nonrecurring basis | Carrying Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	594
Other residential | Financial instruments at fair value measured on a nonrecurring basis | Significant Unobservable Inputs (Level 3)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	594
Other residential | Financial instruments at fair value measured on a nonrecurring basis | Fair Value Hierarcy (Level 1)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	0
Other residential | Financial instruments at fair value measured on a nonrecurring basis | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	0
Installment and other consumer	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	1,862	2,048
Specific valuation allowance for impaired loans	364	431
Installment and other consumer | Financial instruments at fair value measured on a nonrecurring basis | Carrying Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	35	159
Installment and other consumer | Financial instruments at fair value measured on a nonrecurring basis | Significant Unobservable Inputs (Level 3)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	35	159
Installment and other consumer | Financial instruments at fair value measured on a nonrecurring basis | Fair Value Hierarcy (Level 1)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	0	0
Installment and other consumer | Financial instruments at fair value measured on a nonrecurring basis | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	0	0
Commercial and industrial | Financial instruments at fair value measured on a nonrecurring basis | Carrying Value	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	51
Commercial and industrial | Financial instruments at fair value measured on a nonrecurring basis | Significant Unobservable Inputs (Level 3)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	51
Commercial and industrial | Financial instruments at fair value measured on a nonrecurring basis | Fair Value Hierarcy (Level 1)	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	0
Commercial and industrial | Financial instruments at fair value measured on a nonrecurring basis | Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Impaired loans carried at fair value, carrying value	'	$0

Fair_Value_of_Assets_and_Liabi4

Fair Value of Assets and Liabilities - Fair Value of Financial Instruments (Details) (USD $)

12 Months Ended

0 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Nov. 29, 2013

Dec. 31, 2012

Sep. 17, 2004

Dec. 31, 2013

Nov. 29, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

debenture

Subordinated debenture

Subordinated debenture

Subordinated debenture

Subordinated debenture

Subordinated debenture

Subordinated debenture

Fair Value Hierarcy (Level 1)

Fair Value Hierarcy (Level 1)

Fair Value Hierarcy (Level 1)

Fair Value Hierarcy (Level 1)

Significant Other Observable Inputs (Level 2)

Significant Other Observable Inputs (Level 2)

Significant Other Observable Inputs (Level 2)

Significant Other Observable Inputs (Level 2)

Fair Value Hierarchy (Level 3)

Fair Value Hierarchy (Level 3)

Fair Value Hierarchy (Level 3)

Fair Value Hierarchy (Level 3)

NorCal Community Bancorp Trust I

NorCal Community Bancorp Trust II

Carrying Value

Carrying Value

Fair Value

Fair Value

Carrying Value

Carrying Value

Fair Value

Fair Value

Carrying Value

Carrying Value

Fair Value

Fair Value

Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash and cash equivalents

'

'

'

'

'

'

'

'

'

$103,773

$28,349

$103,773

$28,349

'

'

'

'

'

'

'

'

Investment securities held-to-maturity, Carrying Amounts

122,495

'

139,452

'

'

'

'

'

'

'

'

'

'

122,495

'

'

'

'

'

'

'

Investment securities held to maturity, Fair Value

123,858

'

142,231

'

'

'

'

'

'

'

'

'

'

'

139,452

123,858

142,231

'

'

'

'

Loans, net

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,255,098

1,060,291

1,245,475

1,111,355

Interest receivable

'

'

'

'

'

'

'

'

'

'

'

'

'

5,767

5,073

5,767

5,073

'

'

'

'

Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deposits

'

'

'

'

'

'

'

'

'

'

'

'

'

1,587,102

1,253,289

1,588,278

1,254,713

'

'

'

'

Federal Home Loan Bank borrowings

'

'

'

'

'

'

'

'

'

'

'

'

'

15,000

15,000

15,665

15,989

'

'

'

'

Subordinated debenture, Carrying Value

4,969

'

0

5,000

4,969

'

0

'

'

'

'

'

'

'

'

'

'

4,969

0

'

'

Subordinated debentures, Fair Value

'

'

'

'

'

4,950

'

'

'

'

'

'

'

'

'

'

'

'

'

4,950

0

Interest payable

'

'

'

'

'

'

'

'

'

'

'

'

'

$253

$225

$253

$225

'

'

'

'

Number of subordinated debentures acquired

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Basis spread on subordinated debenture

'

'

'

2.48%

'

'

'

3.05%

1.40%

'

'

'

'

'

'

'

'

'

'

'

'

Illiquidity Premium

3.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Benefit_Plans_Deferred_Compens

Benefit Plans - Deferred Compensation Plan (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]	'	'	'
Interest rate earned on deferred amounts, prime rate first business day of year	3.25%	3.25%	3.25%
Deferred Compensation Arrangement with Individual, Deferred Interest Earned, Percent, Number of Years Unchanged	'5 years	'	'
Deferred compensation obligation	$2.80	$2.70	'
Annual Salary | Management	'	'	'
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]	'	'	'
Maximum percentage of compensation allowed to be deferred	80.00%	'	'
Deferred Bonus | Management	'	'	'
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]	'	'	'
Maximum percentage of compensation allowed to be deferred	100.00%	'	'

Benefit_Plans_Defined_Contribu

Benefit Plans - Defined Contribution Plan (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	date
	Y
Defined Contribution Plan Disclosure [Line Items]	'	'	'
Minimum age of eligible employee for 401(k) plan	18	'	'
Minimum employment period to qualify for 401(k) plan	'90 days	'	'
Number of open enrollment dates for 401(k) plan	4	'	'
Minimum annual contribution per employee, percent of eligible compensation	1.00%	'	'
Maximum annual contribution per employee, percent of eligible compensation	50.00%	'	'
Employer matching contribution percentage	60.00%	50.00%	'
Employer matching contribution maximum amount	$4	'	'
Employer contributions	473	432	366
Bank of Marin Employee Stock Ownership and Savings Plan (the Plan)	'	'	'
Defined Contribution Plan Disclosure [Line Items]	'	'	'
Cash contributed to the ESOP	$886	$1,100	$1,100
Annual vesting percentage	20.00%	'	'
Number of years to be fully vested	'5 years	'	'
Employee Stock Option Plan (ESOP), January 2010 | Vesting Rate, Year One	'	'	'
Defined Contribution Plan Disclosure [Line Items]	'	'	'
Annual vesting percentage	0.00%	'	'
Employee Stock Option Plan (ESOP), January 2010 | Vesting Rate, Year Two	'	'	'
Defined Contribution Plan Disclosure [Line Items]	'	'	'
Annual vesting percentage	20.00%	'	'
Employee Stock Option Plan (ESOP), January 2010 | Vesting Rate, Year Three	'	'	'
Defined Contribution Plan Disclosure [Line Items]	'	'	'
Annual vesting percentage	20.00%	'	'
Employee Stock Option Plan (ESOP), January 2010 | Vesting Rate Year Four	'	'	'
Defined Contribution Plan Disclosure [Line Items]	'	'	'
Annual vesting percentage	20.00%	'	'
Employee Stock Option Plan (ESOP), January 2010 | Vesting Rate Year Five	'	'	'
Defined Contribution Plan Disclosure [Line Items]	'	'	'
Annual vesting percentage	40.00%	'	'

Benefit_Plans_Defined_Benefit_

Benefit Plans - Defined Benefit Plan (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]	'	'
Percentage of salary paid upon retirement	25.00%	'
Period before ratable vesting begins	'5 years	'
Liability under the Salary Continuation Plan	$493	$326

Income_Taxes_Components_of_Inc

Income Taxes - Components of Income Tax Provision (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current tax provision	'	'	'
Federal	$6,717	$7,994	$7,045
State	2,574	2,875	2,635
Total current	9,291	10,869	9,680
Deferred tax (benefit) provision	'	'	'
Federal	-873	-4	-205
State	-479	26	-284
Total deferred	-1,352	22	-489
Total income tax provision	7,939	10,891	9,191
Income tax liabilities related to changes in unrealized gains and losses on available for sale securities	($1,975)	$330	$37

Income_Taxes_Deferred_Tax_Asse

Income Taxes - Deferred Tax Asset and Liability (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013
In Thousands, unless otherwise specified			Federal	California	Expiration in Tax Year 2031
					California
Deferred tax assets:	'	'	'	'	'
Net operating loss carryforwards from the NorCal acquisition	$5,096	$0	'	'	'
Allowance for loan losses and off-balance sheet credit commitments	4,671	5,955	'	'	'
Fair value adjustment on loans acquired from the NorCal acquisition	3,182	0	'	'	'
Deferred compensation plan and salary continuation plan	1,376	1,271	'	'	'
Accrued but unpaid expenses	1,177	957	'	'	'
Net unrealized loss on securities available-for-sale	830	0	'	'	'
State franchise tax	737	1,000	'	'	'
Deferred rent and other lease incentives	591	571	'	'	'
Accretion on loans and investment securities	520	0	'	'	'
Other real estate owned	448	0	'	'	'
Stock-based compensation	225	259	'	'	'
Core deposit intangible asset	0	266	'	'	'
Other	264	0	'	'	'
Total gross deferred tax assets	19,117	10,279	'	'	'
Deferred tax liabilities:	'	'	'	'	'
Deferred loan origination costs and fees	-2,024	-1,052	'	'	'
Core deposit intangible asset	-1,647	0	'	'	'
Unaccreted discount on subordinated debentures from acquisition	-1,379	0	'	'	'
Depreciation and disposals on premises and equipment	-159	-637	'	'	'
Net unrealized gain on securities available-for-sale	0	-1,488	'	'	'
Accretion on loans and investment securities	0	-449	'	'	'
Total gross deferred tax liabilities	-5,209	-3,626	'	'	'
Net deferred tax assets	13,908	6,653	'	'	'
Net operating loss carryforwards expected to expire	'	'	9,900	23,700	788
Write-down of deferred tax asset	'	'	'	56	'
Valuation allowance of deferred tax assets	$0	$0	'	'	'

Income_Taxes_Effective_Income_

Income Taxes - Effective Income Tax Reconciliation (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Effective Income Tax Rate Reconciliation, Percent	'	'	'
Federal statutory income tax rate	35.00%	35.00%	35.00%
California franchise tax, net of federal tax benefit	6.50%	6.50%	6.20%
Tax exempt interest on municipal securities and loans	-4.00%	-2.90%	-2.80%
Tax exempt earnings on bank owned life insurance	-1.50%	-0.90%	-1.10%
Low income housing tax credits	-0.30%	0.00%	0.00%
Other	0.00%	0.20%	-0.20%
Effective Tax Rate	35.70%	37.90%	37.10%

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jan. 27, 2014
				Subsequent Event
				Visa
Loss Contingencies [Line Items]	'	'	'	'
Estimated portion of the takedown payments related to the opt-out merchants	'	'	'	$1,100,000,000
Operating Leases	'	'	'	'
Commitments under operating leases, 2014	3,524,000	'	'	'
Commitments under operating leases, 2015	3,575,000	'	'	'
Commitments under operating leases, 2016	3,654,000	'	'	'
Commitments under operating leases, 2017	3,681,000	'	'	'
Commitments under operating leases, 2018	3,708,000	'	'	'
Commitments under operating leases, Thereafter	10,078,000	'	'	'
Commitments under operating leases, Total	28,220,000	'	'	'
Rent expense included in occupancy expense	$3,300,000	$3,300,000	$3,100,000	'

Concentrations_of_Credit_Risk_

Concentrations of Credit Risk (Details) (Credit concentration risk, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
U.S. Government, Agencies and Government Sponsored Enterprises	'	'
Concentration Risk [Line Items]	'	'
Concentration risk percentage	58.00%	45.00%
Concentration risk amount	$211.90	$132.30
Obligations of state and political subdivisions	'	'
Concentration Risk [Line Items]	'	'
Concentration risk percentage	14.00%	17.00%
Concentration risk amount	$52.60	$51
Loans on real estate	'	'
Concentration Risk [Line Items]	'	'
Concentration risk percentage	80.00%	78.00%

Derivative_Financial_Instrumen2

Derivative Financial Instruments and Hedging Activities (Details) (USD $)

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2011

Aug. 31, 2010

Jun. 30, 2007

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Jun. 30, 2011

Aug. 31, 2010

Jun. 30, 2007

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Fair value hedge

Fair value hedge

Fair value hedge

Designated as hedging instrument

Designated as hedging instrument

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest rate swap

Interest income

Interest income

Interest income

Carrying Value

Carrying Value

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair Value, Inputs, Level 2 [Member]

Fair value hedge

Fair value hedge

Not designated as hedging instrument

Not designated as hedging instrument

Not designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Fair value hedge

Fair value hedge

Fair value hedge

Assets and liabilities at fair value measured on a recurring basis

Assets and liabilities at fair value measured on a recurring basis

Assets and liabilities at fair value measured on a recurring basis

Assets and liabilities at fair value measured on a recurring basis

Carrying Value

Carrying Value

Carrying Value

Fair value hedge

Fair value hedge

Fair value hedge

Other liabilities

Fair value hedge

Fair value hedge

Fair value hedge

Fair value hedge

Fair value hedge

Fair value hedge

Fair value hedge

Fair value hedge

Shortcut hedge accounting

Shortcut hedge accounting

Interest rate contract

Interest rate contract

Interest rate contract

Interest rate contract

Assets and liabilities at fair value measured on a recurring basis

Assets and liabilities at fair value measured on a recurring basis

Assets and liabilities at fair value measured on a recurring basis

Forward swap

Forward swap

Forward swap

derivative

derivative

Other assets

Other assets

Other liabilities

Other liabilities

Forward swap

Forward swap

Forward swap

derivative

contract

Interest rate contract

Interest rate contract

Interest rate contract

derivative

derivative

derivative

derivative

derivative

derivative

Designated as hedging instrument

Designated as hedging instrument

Designated as hedging instrument

Fair value hedge

Fair value hedge

Fair value hedge

Other assets

Other assets

Other liabilities

Derivatives, Fair Value [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of interest rate swap contracts accounted for using hedge accounting

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1

1

'

'

'

'

'

'

'

'

'

'

Lower threshold requiring collateral to be posted, liabilities

$100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Higher threshold requiring collateral to be posted, liabilities

1,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative Liability, Number of Instruments Held

'

'

'

'

'

'

'

'

'

'

5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate contracts fair value

2,519,000

[1]

5,240,000

[1]

'

'

'

'

'

'

'

'

2,500,000

'

'

'

'

5,240,000

[2]

'

'

'

'

'

'

'

'

2,519,000

5,240,000

2,519,000

5,240,000

'

'

2,519,000

[2]

Collateral posted, fair value

2,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of derivative instruments

'

'

'

'

'

'

'

1

1

1

'

9

'

'

'

'

1

1

1

'

'

'

'

'

'

'

'

'

'

'

'

Derivatives, accrued interest, interest rate swaps

'

'

'

'

'

70,000

75,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate contracts notional amounts, Asset derivatives

'

'

'

'

'

'

'

'

'

'

'

'

17,956,000

4,932,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate contracts notional amount, Liability derivatives

'

'

'

'

'

'

'

'

'

'

'

'

'

'

21,577,000

38,156,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate contracts fair value, Asset derivatives

961,000

[3]

1,000

[3]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

961,000

1,000

961,000

1,000

961,000

[2]

1,000

[2]

'

Increase (decrease) in value of designated interest rate swaps recognized in interest income

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,680,000

-188,000

-2,582,000

'

'

'

'

'

'

'

Payment on interest rate swaps recorded in interest income

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-1,422,000

-1,342,000

-1,076,000

'

'

'

'

'

'

'

(Decrease) increase in value of hedged loans recognized in interest income

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-3,971,000

311,000

2,436,000

'

'

'

'

'

'

'

(Decrease) increase in value of yield maintenance agreement recognized against interest income

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-71,000

168,000

-14,000

'

'

'

'

'

'

'

Net loss on derivatives recognized against interest income

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-1,784,000

[4]

-1,051,000

[4]

-1,236,000

[4]

'

'

'

'

'

'

'

Net hedge ineffectiveness, derivatives

'

'

$362,000

$291,000

($160,000)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Amounts exclude accrued interest totaling $60 thousand and $74 thousand at December 31, 2013 and December 31, 2012, respectively.

[2]

See Note 4 for valuation methodology.

[3]

Amounts exclude accrued interest totaling $10 thousand and $1 thousand at December 31, 2013 and December 31, 2012, respectively.

[4]

Ineffectiveness of $362 thousand, $291 thousand and $(160) thousand was recorded in interest income during the years December 31, 2013, 2012 and 2011, respectively. Changes in value of swaps were included in the assessment of hedge effectiveness.

Derivative_Financial_Instrumen3

Derivative Financial Instruments and Hedging Activities - Offsetting of Assets (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Offsetting Assets [Line Items]	'		'
Gross Amounts of Recognized Assets	$961	[1]	$1	[1]
Offset in the Statements of Condition	0		0
Net Amounts of Assets Presented in the Statements of Condition	961	[1]	1	[1]
Gross Amounts Not Offset in the Statements of Condition, Financial Instruments	-825		-1
Gross Amounts Not Offset in the Statements of Condition, Cash Collateral Received	0		0
Net Amount	136		0
Counterparty A	'		'
Offsetting Assets [Line Items]	'		'
Gross Amounts of Recognized Assets	961	[1]	1	[1]
Offset in the Statements of Condition	0		0
Net Amounts of Assets Presented in the Statements of Condition	961	[1]	1	[1]
Gross Amounts Not Offset in the Statements of Condition, Financial Instruments	-825		-1
Gross Amounts Not Offset in the Statements of Condition, Cash Collateral Received	0		0
Net Amount	136		0
Counterparty B	'		'
Offsetting Assets [Line Items]	'		'
Gross Amounts of Recognized Assets	0	[1]	0	[1]
Offset in the Statements of Condition	0		0
Net Amounts of Assets Presented in the Statements of Condition	0	[1]	0	[1]
Gross Amounts Not Offset in the Statements of Condition, Financial Instruments	0		0
Gross Amounts Not Offset in the Statements of Condition, Cash Collateral Received	0		0
Net Amount	0		0
Other assets | Interest rate swap	'		'
Offsetting Assets [Line Items]	'		'
Derivative assets, accrued interest, interest rate swaps	$10		$1
[1]	Amounts exclude accrued interest totaling $10 thousand and $1 thousand at December 31, 2013 and December 31, 2012, respectively.

Derivative_Financial_Instrumen4

Derivative Financial Instruments and Hedging Activities - Offsetting of Liabilities (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Offsetting Liabilities [Line Items]	'		'
Gross Amounts of Recognized Liabilities	$2,519	[1]	$5,240	[1]
Gross Amounts Offset in the Statements of Condition	0		0
Net Amounts of Liabilities Presented in the Statements of Condition	2,519	[1]	5,240	[1]
Gross Amounts Not Offset in the Statements of Condition, Financial Instruments	-825		-1
Gross Amounts Not Offset in the Statements of Condition, Cash Collateral Pledged	-1,694		-4,484
Net Amount	0		755
Counterparty A	'		'
Offsetting Liabilities [Line Items]	'		'
Gross Amounts of Recognized Liabilities	825	[1]	2,616	[1]
Gross Amounts Offset in the Statements of Condition	0		0
Net Amounts of Liabilities Presented in the Statements of Condition	825	[1]	2,616	[1]
Gross Amounts Not Offset in the Statements of Condition, Financial Instruments	-825		-1
Gross Amounts Not Offset in the Statements of Condition, Cash Collateral Pledged	0		-1,860
Net Amount	0		755
Counterparty B	'		'
Offsetting Liabilities [Line Items]	'		'
Gross Amounts of Recognized Liabilities	1,694	[1]	2,624	[1]
Gross Amounts Offset in the Statements of Condition	0		0
Net Amounts of Liabilities Presented in the Statements of Condition	1,694	[1]	2,624	[1]
Gross Amounts Not Offset in the Statements of Condition, Financial Instruments	0		0
Gross Amounts Not Offset in the Statements of Condition, Cash Collateral Pledged	-1,694		-2,624
Net Amount	0		0
Other liabilities | Interest rate swap	'		'
Offsetting Liabilities [Line Items]	'		'
Derivative liabilities, accrued interest, interest rate swaps	$60		$74
[1]	Amounts exclude accrued interest totaling $60 thousand and $74 thousand at December 31, 2013 and December 31, 2012, respectively.

Regulatory_Matters_Details

Regulatory Matters (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Bancorp	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Total Capital, Actual, Amount	$190,738	$163,900
Total Capital (to risk-weighted assets), Actual, Ratio	13.21%	13.71%
Total Capital, Minimum Capital for Capital Adequacy Purposes, Amount	115,524	95,655
Total Capital (to risk-weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio	8.00%	8.00%
Tier 1 Risk Based Capital, Actual, Amount	175,835	149,737
Tier 1 Risk Based Capital (to risk-weighted assets), Actual, Ratio	12.18%	12.52%
Tier 1 Capital, Minimum Capital for Capital Adequacy Purposes, Amount	57,762	47,827
Tier 1 Risk Based Capital (to risk-weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Leverage Capital, Amount, Actual	175,835	149,737
Tier 1 Leverage Capital (to average assets), Actual, Ratio	10.78%	10.30%
Tier 1 Leverage Capital, Minimum Capital for Capital Adequacy Purposes, Amount	65,222	58,169
Tier 1 Leverage Capital (to average assets), Minimum Capital for Capital Adequacy Purposes, Ratio	4.00%	4.00%
The Bank	'	'
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]	'	'
Total Capital, Actual, Amount	181,911	162,554
Total Capital (to risk-weighted assets), Actual, Ratio	12.60%	13.60%
Total Capital, Minimum Capital for Capital Adequacy Purposes, Amount	115,495	95,652
Total Capital (to risk-weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total Capital, Minimum Capital to be Well Capitalized, Amount	144,368	119,566
Total Capital (to risk-weighted assets), Minimum to be Well Capitalized, Ratio	10.00%	10.00%
Tier 1 Risk Based Capital, Actual, Amount	167,007	148,391
Tier 1 Risk Based Capital (to risk-weighted assets), Actual, Ratio	11.57%	12.41%
Tier 1 Capital, Minimum Capital for Capital Adequacy Purposes, Amount	57,747	47,826
Tier 1 Risk Based Capital (to risk-weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Risk Based Capital, Minimum Capital to be Well Capitalized, Amount	86,621	71,739
Tier 1 Risk Based Capital (to risk-weighted assets), Minimum Capital to be Well Capitalized, Ratio	6.00%	6.00%
Tier 1 Leverage Capital, Amount, Actual	167,007	148,391
Tier 1 Leverage Capital (to average assets), Actual, Ratio	10.24%	10.20%
Tier 1 Leverage Capital, Minimum Capital for Capital Adequacy Purposes, Amount	65,215	58,168
Tier 1 Leverage Capital (to average assets), Minimum Capital for Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 Leverage Capital, Actual, Amount	$81,519	$72,710
Tier 1 Leverage Capital (to average assets), Minimum Capital to be Well Capitalized, Ratio	5.00%	5.00%

Financial_Instruments_with_Off1

Financial Instruments with Off-Balance Sheet Risk (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Lines of credit and standby letters of credit, unused	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Loan commitments and standby letters of credit, off-balance sheet	$336,900,000
Percentage of commitments expiring in 2014	39.00%
Percentage of commitments expiring between 2015 and 2021	61.00%
Commercial lines of credit	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Loan commitments and standby letters of credit, off-balance sheet	173,900,000
Revolving home equity lines	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Loan commitments and standby letters of credit, off-balance sheet	104,800,000
Standby letters of credit	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Loan commitments and standby letters of credit, off-balance sheet	13,000,000
Undisbursed construction loans	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Loan commitments and standby letters of credit, off-balance sheet	33,400,000
Personal and other lines of credit	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Loan commitments and standby letters of credit, off-balance sheet	11,700,000
Minimum | Lines of credit and standby letters of credit, unused	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Interest rate range on loan commitments and standby letters of credit	1.70%
Maximum | Lines of credit and standby letters of credit, unused	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Interest rate range on loan commitments and standby letters of credit	18.00%
Interest Payable and Other Liabilities | Lines of credit and standby letters of credit, unused	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Allowance for off-balance sheet commitments	$679,000

Condensed_Bank_of_Marin_Bancor2

Condensed Bank of Marin Bancorp Parent Only Financial Statements - Balance Sheet (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Thousands, unless otherwise specified
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Other assets	$70,720	$43,351	'	'
Total assets	1,805,194	1,434,749	'	'
Subordinated debentures	4,969	0	'	'
Total liabilities	1,624,307	1,282,957	'	'
Stockholders' equity	180,887	151,792	135,551	121,920
Total liabilities and stockholders' equity	1,805,194	1,434,749	'	'
Bancorp	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Cash and due from Bank of Marin	8,664	1,293	'	'
Investment in bank subsidiary	177,028	150,445	'	'
Other assets	366	92	'	'
Total assets	186,058	151,830	'	'
Subordinated debentures	4,969	0	'	'
Accrued expenses payable	202	38	'	'
Total liabilities	5,171	38	'	'
Stockholders' equity	180,887	151,792	'	'
Total liabilities and stockholders' equity	$186,058	$151,830	'	'

Condensed_Bank_of_Marin_Bancor3

Condensed Bank of Marin Bancorp Parent Only Financial Statements - Income Statement (Details) (USD $)	1 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Interest Expense	'	$1,785	$2,576	$5,295
Non-interest expense	'	44,092	38,694	38,283
Income tax benefit	'	-7,939	-10,891	-9,191
Net income	963	14,270	17,817	15,564
Bancorp	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Dividends from Bank of Marin	'	28,000	2,700	0
Total income	'	28,000	2,700	0
Interest Expense	'	34	0	0
Non-interest expense	'	1,313	716	748
Total expense	'	1,347	716	748
Income (loss) before income taxes and equity in undistributed net income of subsidiary	'	26,653	1,984	-748
Income tax benefit	'	382	301	249
Income before equity in undistributed net income of subsidiary	'	27,035	2,285	-499
Earnings of bank subsidiary (less) greater than dividends received from bank subsidiary	'	-12,765	15,532	16,063
Net income	'	$14,270	$17,817	$15,564

Condensed_Bank_of_Marin_Bancor4

Condensed Bank of Marin Bancorp Parent Only Financial Statements - Cash Flow Statement (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]	'	'	'
Net income	$14,270	$17,817	$15,564
Accretion of discount on subordinated debentures	19	0	0
Other assets	299	555	1,051
Other liabilities	5,071	-526	1,268
Net cash provided by operating activities	21,201	20,806	22,381
Net cash used in investing activities	-36,948	-144,865	-34,938
Dividends paid on common stock	-3,970	-3,751	-3,457
Net cash provided by (used by) financing activities	91,171	22,665	57,068
Net increase (decrease) in cash and cash equivalents	75,424	-101,394	44,511
Stock issued in payment of director fees	222	199	200
Fair value of assets acquired	280,917	0	107,763
Fair value of liabilities assumed	246,384	0	107,678
Stock issued to NorCal Community Bancorp shareholders	18,514	0	0
Bancorp	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'
Net income	14,270	17,817	15,564
Earnings of bank subsidiary less (greater) than dividends received from bank subsidiary	12,765	-15,532	-16,063
Accretion of discount on subordinated debentures	19	0	0
Other assets	74	-71	58
Other liabilities	165	-6	46
Net cash provided by operating activities	27,293	2,208	-395
Capital contribution to subsidiary	-2,258	-1,070	-774
Cash consideration paid for acquisition, net of cash acquired	-15,952	0	0
Net cash used in investing activities	-18,210	-1,070	-774
Stock options exercised and stock purchases	2,258	1,070	774
Dividends paid on common stock	-3,970	-3,751	-3,457
Net cash provided by (used by) financing activities	-1,712	-2,681	-2,683
Net increase (decrease) in cash and cash equivalents	7,371	-1,543	-3,852
Cash and cash equivalents at beginning of period	1,293	2,836	6,688
Cash and cash equivalents at end of period	8,664	1,293	2,836
Stock issued in payment of director fees	222	199	200
Fair value of assets acquired	39,503	0	0
Fair value of liabilities assumed	4,970	0	0
Stock issued to NorCal Community Bancorp shareholders	$18,514	$0	$0