TriCo Bancshares (TCBK) 10-K 13 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 27, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	TCBK
Entity Registrant Name	TRICO BANCSHARES /
Entity Central Index Key	356171
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		22,740,503
Entity Public Float			$289,650,631

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets:
Cash and due from banks	$93,150	$76,915
Cash at Federal Reserve and other banks	517,578	521,453
Cash and cash equivalents	610,728	598,368
Investment securities:
Available for sale	83,205	104,647
Held to maturity	676,426	240,504
Restricted equity securities	16,956	9,163
Loans held for sale	3,579	2,270
Loans	2,282,524	1,672,007
Allowance for loan losses	-36,585	-38,245
Total loans, net	2,245,939	1,633,762
Foreclosed assets, net	4,894	6,262
Premises and equipment, net	43,493	31,612
Cash value of life insurance	92,337	52,309
Accrued interest receivable	9,275	6,516
Goodwill	63,462	15,519
Other intangible assets, net	7,051	883
Mortgage servicing rights	7,378	6,165
Other assets	51,735	36,086
Total assets	3,916,458	2,744,066
Deposits:
Noninterest-bearing demand	1,083,900	789,458
Interest-bearing	2,296,523	1,621,025
Total deposits	3,380,423	2,410,483
Accrued interest payable	978	938
Reserve for unfunded commitments	2,145	2,415
Other liabilities	49,192	31,711
Other borrowings	9,276	6,335
Junior subordinated debt	56,272	41,238
Total liabilities	3,498,286	2,493,120
Commitments and contingencies (Note 18)
Shareholders' equity:
Common stock, no par value: 50,000,000 shares authorized; issued and outstanding: 22,714,964 at December 31, 2014 16,076,662 at December 31, 2013	244,318	89,356
Retained earnings	176,057	159,733
Accumulated other comprehensive income, net of tax	-2,203	1,857
Total shareholders' equity	418,172	250,946
Total liabilities and shareholders' equity	$3,916,458	$2,744,066

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Aug. 21, 2007
Statement of Financial Position [Abstract]
Common stock, no par value
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	22,714,964	16,076,662
Common stock, shares outstanding	22,714,964	16,076,662	15,814,662

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest and dividend income:
Loans, including fees	$103,887	$97,548	$100,496
Debt securities:
Taxable	14,753	6,349	6,072
Tax exempt	505	583	428
Dividends	837	387	105
Interest bearing cash at Federal Reserve and other banks	1,133	1,693	1,615
Total interest and dividend income	121,115	106,560	108,716
Interest expense:
Deposits	3,274	3,445	4,416
Other borrowings	4	4	1,604
Junior subordinated debt	1,403	1,247	1,324
Total interest expense	4,681	4,696	7,344
Net interest income	116,434	101,864	101,372
(Benefit from) provision for loan losses	-4,045	-715	9,423
Net interest income after provision for loan losses	120,479	102,579	91,949
Noninterest income:
Service charges and fees	24,236	25,257	23,925
Gain on sale of loans	2,032	5,602	6,810
Commissions on sale of non-deposit investment products	2,995	2,983	3,209
Increase in cash value of life insurance	1,953	1,727	1,820
Other	3,300	1,260	2,216
Total noninterest income	34,516	36,829	37,980
Noninterest expense:
Salaries and related benefits	57,544	51,936	49,952
Other	52,835	41,668	48,046
Total noninterest expense	110,379	93,604	97,998
Income before income taxes	44,616	45,804	31,931
Provision for income taxes	18,508	18,405	12,937
Net income	$26,108	$27,399	$18,994
Earnings per share:
Basic	$1.47	$1.71	$1.19
Diluted	$1.46	$1.69	$1.18

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$5,650	$8,234	$4,859	$7,365	$5,236	$7,361	$6,325	$8,477	$26,108	$27,399	$18,994
Other comprehensive (loss) income, net of tax:
Unrealized holding (losses) gains on securities arising during the period									-94	-2,452	-1,216
Change in minimum pension liability									-4,114	1,750	-2
Change in joint beneficiary agreement liability									148	400	-434
Other comprehensive (loss) income									-4,060	-302	-1,652
Comprehensive income									$22,048	$27,097	$17,342

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Shareholders' Equity (USD $)	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
In Thousands, except Share data
Beginning balance at Dec. 31, 2011	$216,441	$84,079	$128,551	$3,811
Beginning balance, shares at Dec. 31, 2011		15,978,958
Net income	18,994		18,994
Other comprehensive loss	-1,652			-1,652
Stock option vesting	1,083	1,083
Stock options exercised	430	430
Stock options exercised, shares		36,000
Tax benefit of stock options exercised	44	44
Repurchase of common stock	-224	-75	-149
Repurchase of common stock, shares		-14,120
Dividends paid	-5,757		-5,757
Ending balance at Dec. 31, 2012	229,359	85,561	141,639	2,159
Ending balance, shares at Dec. 31, 2012		16,000,838
Net income	27,399		27,399
Other comprehensive loss	-302			-302
Stock option vesting	1,151	1,151
Stock options forfeited	-22	-22
Stock options exercised	3,240	3,240
Stock options exercised, shares		248,765
Tax benefit of stock options exercised	356	356
Repurchase of common stock	-3,490	-930	-2,560
Repurchase of common stock, shares		-172,941
Dividends paid	-6,745		-6,745
Ending balance at Dec. 31, 2013	250,946	89,356	159,733	1,857
Ending balance, shares at Dec. 31, 2013	16,076,662	16,076,662
Net income	26,108		26,108
Other comprehensive loss	-4,060			-4,060
Stock option vesting	965	965
RSU vesting	126	126
PSU vesting	42	42
Stock options exercised	2,875	2,875
Stock options exercised, shares	166,020	166,020
Tax benefit of stock options exercised	225	225
Issuance of common stock, value	151,303	151,303
Issuance of common stock, shares		6,575,550
Repurchase of common stock	-2,551	-574	-1,977
Repurchase of common stock, shares		-103,268
Dividends paid	-7,807		-7,807
Ending balance at Dec. 31, 2014	$418,172	$244,318	$176,057	($2,203)
Ending balance, shares at Dec. 31, 2014	22,714,964	22,714,964

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Dividends paid, per share	$0.44	$0.42	$0.36
Retained Earnings [Member]
Dividends paid, per share	$0.44	$0.42	$0.36

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities:
Net income	$26,108	$27,399	$18,994
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of premises and equipment, and amortization	5,735	4,623	4,292
Amortization of intangible assets	446	209	209
(Benefit from) provision for loan losses	-4,045	-715	9,423
Amortization of investment securities premium, net	970	752	1,151
Originations of loans for resale	-49,241	-123,834	-225,602
Proceeds from sale of loans originated for resale	49,394	137,859	238,352
Gain on sale of loans	-2,032	-5,602	-6,810
Change in market value of mortgage servicing rights	1,301	-253	2,016
Provision for losses on foreclosed assets	208	682	1,728
Gain on sale of foreclosed assets	-2,153	-1,640	-786
Loss on disposal of fixed assets	-49	39	420
Increase in cash value of life insurance	-1,953	-1,727	-1,820
Gain on life insurance death benefit			-675
Equity compensation vesting expense	1,133	1,151	1,083
Stock option excess tax benefits	-225	-356	-44
Deferred income tax expense (benefit)	-993	2,526	-383
Change in:
Reserve for unfunded commitments	-395	-1,200	875
Interest receivable	-619	120	676
Interest payable	-67	-98	-638
Other assets and liabilities, net	3,894	1,151	9,602
Net cash from operating activities	27,417	41,086	52,063
Investing activities:
Proceeds from maturities of securities available for sale	24,016	53,468	76,764
Proceeds from sale of securities available for sale	14,130
Purchases of securities available for sale			-13,815
Proceeds from maturities of securities held to maturity	34,172	4,391
Purchases of securities held to maturity	-280,692	-244,967
(Purchase) redemption of restricted equity securities, net	-2,415	484	963
Loan origination and principal collections, net	-82,079	-59,411	-44,601
Loans purchased	-32,017	-62,698
Proceeds from sale of premises and equipment	121	12	30
Improvement of foreclosed assets	-462	-479	-983
Proceeds from sale of other real estate owned	9,762	13,910	17,257
Purchases of premises and equipment	-4,665	-8,313	-10,792
Life insurance proceeds		706	4,423
Cash received from acquisition, net	141,405
Net cash (used) provided by investing activities	-178,724	-302,897	29,246
Financing activities:
Net increase (decrease) in deposits	167,984	120,781	99,166
Net change in other borrowings	2,941	-2,862	-63,344
Stock option excess tax benefits	225	356	44
Repurchase of common stock	-292	-501
Dividends paid	-7,807	-6,745	-5,757
Exercise of stock options	616	251	206
Net cash from financing activities	163,667	111,280	30,315
Net change in cash and cash equivalents	12,360	-150,531	111,624
Cash and cash equivalents and beginning of year	598,368	748,899	637,275
Cash and cash equivalents at end of year	610,728	598,368	748,899
Supplemental disclosure of noncash activities:
Unrealized (loss) gain on securities available for sale	-162	-4,232	-2,096
Loans transferred to foreclosed assets	5,291	11,717	8,382
Loans transferred to held-for-sale			9,739
Market value of shares tendered in-lieu of cash to pay for exercise of options and/or related taxes	2,259	2,989	224
Supplemental disclosure of cash flow activity:
Cash paid for interest expense	4,641	4,794	7,982
Cash paid for income taxes	22,685	17,395	10,995
Assets acquired in acquisition	978,682
Liabilities assumed in acquisition	$827,372

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1 – Summary of Significant Accounting Policies
	Description of Business and Basis of Presentation
	TriCo Bancshares (the “Company”) is a California corporation organized to act as a bank holding company for Tri Counties Bank (the “Bank”). The Company and the Bank are headquartered in Chico, California. The Bank is a California-chartered bank that is engaged in the general commercial banking business in 26 California counties. Tri Counties Bank currently operates from 57 traditional branches and 16 in-store branches. The Company has five capital subsidiary business trusts (collectively, the Capital Trusts) that issued trust preferred securities, including two organized by TriCo and three acquired with the acquisition of North Valley Bancorp. See Note 17 – Junior Subordinated Debt.
	The consolidated financial statements are prepared in accordance with accounting policies generally accepted in the United States of America and general practices in the banking industry. The financial statements include the accounts of the Company. All inter-company accounts and transactions have been eliminated in consolidation. For financial reporting purposes, the Company’s investments in the Capital Trusts of $1,690,000 are accounted for under the equity method and, accordingly, are not consolidated and are included in other assets on the consolidated balance sheet. The subordinated debentures issued and guaranteed by the Company and held by the Capital Trusts are reflected as debt on the Company’s consolidated balance sheet.
	Use of Estimates in the Preparation of Financial Statements
	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 assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, the Company evaluates its estimates, including those related to the adequacy of the allowance for loan losses, investments, intangible assets, income taxes and contingencies. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. The allowance for loan losses, indemnification asset, foreclosed assets, goodwill and other intangible assets, income taxes, fair value of assets acquired and liabilities assumed in business combinations, the valuation of securities available-for-sale, and the valuation of mortgage servicing rights are the only accounting estimates that materially affect the Company’s consolidated financial statements.
	As described in Note 2, the Company acquired North Valley Bancorp on October 3, 2014. The acquired assets and assumed liabilities were measured at estimated fair value values under the acquisition method of accounting. The Company made significant estimates and exercised significant judgment in accounting for the acquisition. The Company determined loan fair values based on loan file reviews, loan risk ratings, appraised collateral values, expected cash flows and historical loss factors. Foreclosed assets were primarily valued based on appraised values of the repossessed loan collateral. Land and building were valued based on appraised values. An identifiable intangible was also recorded representing the fair value of the core deposit customer base based on an evaluation of the cost of such deposits relative to alternative funding sources. The fair value of time deposits and borrowings were determined based on the present value of estimated future cash flows using current rates as of the acquisition date.
	Significant Group Concentration of Credit Risk
	The Company grants agribusiness, commercial, consumer, and residential loans to customers located throughout the northern San Joaquin Valley, the Sacramento Valley and northern mountain regions of California. The Company has a diversified loan portfolio within the business segments located in this geographical area. The Company currently classifies all its operation into one business segment that it denotes as community banking.
	Cash and Cash Equivalents
	For purposes of the consolidated statements of cash flows, cash and cash equivalents include cash on hand, amounts due from banks, and federal funds sold. Net cash flows are reported for loan and deposit transactions and other borrowings.
	Investment Securities
	The Company classifies its debt and marketable equity securities into one of three categories: trading, available for sale or held to maturity. Trading securities are bought and held principally for the purpose of selling in the near term. Held to maturity securities are those securities which the Company has the ability and intent to hold until maturity. These securities are carried at cost adjusted for amortization of premium and accretion of discount, computed by the effective interest method over their contractual lives. All other securities not included in trading or held to maturity are classified as available for sale. Available for sale securities are recorded at fair value. Unrealized gains and losses, net of the related tax effect, on available for sale securities are reported as a separate component of other accumulated comprehensive income in shareholders’ equity until realized. Premiums and discounts are amortized or accreted over the life of the related investment security as an adjustment to yield using the effective interest method. Dividend and interest income are recognized when earned. Realized gains and losses are derived from the amortized cost of the security sold. During the years ended December 31, 2014 and 2013, the Company did not have any securities classified as trading.
	The Company assesses other-than-temporary impairment (“OTTI”) based on whether it intends to sell a security or if it is likely that the Company would be required to sell the security before recovery of the amortized cost basis of the investment, which may be maturity. For debt securities, if we intend to sell the security or it is likely that we will be required to sell the security before recovering its cost basis, the entire impairment loss would be recognized in earnings as an OTTI. If we do not intend to sell the security and it is not likely that we will be required to sell the security but we do not expect to recover the entire amortized cost basis of the security, only the portion of the impairment loss representing credit losses would be recognized in earnings. The credit loss on a security is measured as the difference between the amortized cost basis and the present value of the cash flows expected to be collected. Projected cash flows are discounted by the original or current effective interest rate depending on the nature of the security being measured for potential OTTI. The remaining impairment related to all other factors, the difference between the present value of the cash flows expected to be collected and fair value, is recognized as a charge to other comprehensive income (“OCI”). Impairment losses related to all other factors are presented as separate categories within OCI. The accretion of the amount recorded in OCI increases the carrying value of the investment and does not affect earnings. If there is an indication of additional credit losses the security is re-evaluated according to the procedures described above. No OTTI losses were recognized during the years ended December 31, 2014 and 2013.
	Restricted Equity Securities
	Restricted equity securities represent the Company’s investment in the stock of the Federal Home Loan Bank of San Francisco (“FHLB”) and are carried at par value, which reasonably approximates its fair value. While technically these are considered equity securities, there is no market for the FHLB stock. Therefore, the shares are considered as restricted investment securities. Management periodically evaluates FHLB stock for other-than-temporary impairment. Management’s determination of whether these investments are impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value. The determination of whether a decline affects the ultimate recoverability of cost is influenced by criteria such as (1) the significance of any decline in net assets of the FHLB as compared to the capital stock amount for the FHLB and the length of time this situation has persisted, (2) commitments by the FHLB to make payments required by law or regulation and the level of such payments in relation to the operating performance of the FHLB, (3) the impact of legislative and regulatory changes on institutions and, accordingly, the customer base of the FHLB, and (4) the liquidity position of the FHLB.
	As a member of the FHLB system, the Company is required to maintain a minimum level of investment in FHLB stock based on specific percentages of its outstanding mortgages, total assets, or FHLB advances. The Company may request redemption at par value of any stock in excess of the minimum required investment. Stock redemptions are at the discretion of the FHLB.
	Loans Held for Sale
	Loans originated and intended for sale in the secondary market are carried at the lower of aggregate cost or fair value, as determined by aggregate outstanding commitments from investors of current investor yield requirements. Net unrealized losses are recognized through a valuation allowance by charges to noninterest income.
	Mortgage loans held for sale are generally sold with the mortgage servicing rights retained by the Company. Gains or losses on the sale of loans that are held for sale are recognized at the time of the sale and determined by the difference between net sale proceeds and the net book value of the loans less the estimated fair value of any retained mortgage servicing rights.
	Loans and Allowance for Loan Losses
	Loans originated by the Company, i.e., not purchased or acquired in a business combination, are referred to as originated loans. Originated loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at the principal amount outstanding, net of deferred loan fees and costs. Loan origination and commitment fees and certain direct loan origination costs are deferred, and the net amount is amortized as an adjustment of the related loan’s yield over the actual life of the loan. Originated loans on which the accrual of interest has been discontinued are designated as nonaccrual loans.
	Originated loans are placed in nonaccrual status when reasonable doubt exists as to the full, timely collection of interest or principal, or a loan becomes contractually past due by 90 days or more with respect to interest or principal and is not well secured and in the process of collection. When an originated loan is placed on nonaccrual status, all interest previously accrued but not collected is reversed. Income on such loans is then recognized only to the extent that cash is received and where the future collection of principal is probable. Interest accruals are resumed on such loans only when they are brought fully current with respect to interest and principal and when, in the judgment of Management, the loan is estimated to be fully collectible as to both principal and interest.
	An allowance for loan losses for originated loans is established through a provision for loan losses charged to expense. The allowance is maintained at a level which, in Management’s judgment, is adequate to absorb probable incurred credit losses inherent in the loan portfolio as of the balance sheet date. Originated loans and deposit related overdrafts are charged against the allowance for loan losses when Management believes that the collectability of the principal is unlikely or, with respect to consumer installment loans, according to an established delinquency schedule. The allowance is an amount that Management believes will be adequate to absorb probable incurred losses inherent in existing loans and leases, based on evaluations of the collectability, impairment and prior loss experience of loans and leases. The evaluations take into consideration such factors as changes in the nature and size of the portfolio, overall portfolio quality, loan concentrations, specific problem loans, and current economic conditions that may affect the borrower’s ability to pay. The Company defines an originated loan as impaired when it is probable the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. Impaired originated loans are measured based on the present value of expected future cash flows discounted at the loan’s original effective interest rate. As a practical expedient, impairment may be measured based on the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. When the measure of the impaired loan is less than the recorded investment in the loan, the impairment is recorded through a valuation allowance.
	In situations related to originated loans where, for economic or legal reasons related to a borrower’s financial difficulties, the Company grants a concession for other than an insignificant period of time to the borrower that the Company would not otherwise consider, the related loan is classified as a troubled debt restructuring (TDR). The Company strives to identify borrowers in financial difficulty early and work with them to modify to more affordable terms before their loan reaches nonaccrual status. These modified terms may include rate reductions, principal forgiveness, payment forbearance and other actions intended to minimize the economic loss and to avoid foreclosure or repossession of the collateral. In cases where the Company grants the borrower new terms that result in the loan being classified as a TDR, the Company measures any impairment on the restructuring as noted above for impaired loans. TDR loans are classified as impaired until they are fully paid off or charged off. Loans that are in nonaccrual status at the time they become TDR loans, remain in nonaccrual status until the borrower demonstrates a sustained period of performance which the Company generally believes to be six consecutive months of payments, or equivalent. Otherwise, TDR loans are subject to the same nonaccrual and charge-off policies as noted above with respect to their restructured principal balance.
	Credit risk is inherent in the business of lending. As a result, the Company maintains an allowance for loan losses to absorb probable incurred losses inherent in the Company’s originated loan portfolio. This is maintained through periodic charges to earnings. These charges are included in the Consolidated Statements of Income as provision for loan losses. All specifically identifiable and quantifiable losses are immediately charged off against the allowance. However, for a variety of reasons, not all losses are immediately known to the Company and, of those that are known, the full extent of the loss may not be quantifiable at that point in time. The balance of the Company’s allowance for originated loan losses is meant to be an estimate of these unknown but probable losses inherent in the portfolio.
	The Company formally assesses the adequacy of the allowance for originated loan losses on a quarterly basis. Determination of the adequacy is based on ongoing assessments of the probable risk in the outstanding originated loan portfolio, and to a lesser extent the Company’s originated loan commitments. These assessments include the periodic re-grading of credits based on changes in their individual credit characteristics including delinquency, seasoning, recent financial performance of the borrower, economic factors, changes in the interest rate environment, growth of the portfolio as a whole or by segment, and other factors as warranted. Loans are initially graded when originated. They are re-graded as they are renewed, when there is a new loan to the same borrower, when identified facts demonstrate heightened risk of nonpayment, or if they become delinquent. Re-grading of larger problem loans occurs at least quarterly. Confirmation of the quality of the grading process is obtained by independent credit reviews conducted by consultants specifically hired for this purpose and by various bank regulatory agencies.
	The Company’s method for assessing the appropriateness of the allowance for originated loan losses includes specific allowances for impaired originated loans and leases, formula allowance factors for pools of credits, and allowances for changing environmental factors (e.g., interest rates, growth, economic conditions, etc.). Allowance factors for loan pools were based on historical loss experience by product type and prior risk rating.
	During the three months ended March 31, 2013, the Company changed the method it uses to estimate net sale proceeds from real estate collateral sales when calculating the allowance for loan losses associated with impaired real estate collateral dependent loans. Previously, the Company used the greater of fifteen percent or actual estimated selling costs. Currently, the Company uses the actual estimated selling costs, and an adjustment to appraised value based on the age of the appraisal. These changes are intended to more accurately reflect the estimated net sale proceeds from the sale of impaired collateral dependent real estate loans. This change in methodology resulted in the allowance for loan losses as of March 31, 2013 being $494,000 more than it would have been without this change in methodology.
	During the three months ended June 30, 2013, the Company modified its loss migration analysis methodology used to determine the formula allowance factors. When the Company originally established its loss migration analysis methodology during the quarter ended March 31, 2012, it reviewed the loss experience of each rolling twelve month period over the previous three years in order to calculate an annualized loss rate by loan category and risk rating. The use of three years of loss experience data was originally used because that was the extent of the detailed loss data by loan category and risk rating that was available at the time. This three year historical look-back period was used through the quarter ended March 31, 2013. Starting with the quarter ended June 30, 2013, the Company reviews all available detailed loss experience data, going back to, and including, the twelve month period ended June 30, 2009, and does not limit the look-back period to the most recent three years of historical loss data. Using this data, the Company calculates loss factors for each quarter from the quarter ended June 30, 2009 to the most recent quarter. The Company then calculates a weighted average formula allowance factor for each loan category and risk rating with the most recent quarterly loss factor being weighted 125%, the quarter ended June 30, 2009 loss factor being weighted 75%, and the loss factors for all the quarters between the most recent quarter and the quarter ended June 30, 2009, being weighted on a linear scale from 75% to 125%. This change is intended to more accurately reflect the risk inherent in the loan portfolio by considering historical loss data for all years as the data for new periods becomes available. This change in methodology resulted in the allowance for loan losses as of June 30, 2013 being $1,314,000 more than it would have been without this change in methodology.
	During the three months ended September 30, 2013, the Company modified its methodology used to determine the allowance for changing environmental factors. Previously, the Company compared the current value of each environmental factor to a fixed baseline value. The deviation of the current value from the baseline value was then multiplied by a conversion factor to determine the required allowance related to each environmental factor. As of September 30, 2013, the Company replaced the fixed baseline values with average baseline values derived from historical averages, and adjusted the conversion factors. This change is intended to more accurately reflect the risk inherent in the portfolio by recognizing that baseline, or normal, levels for environmental factors may change over time. This change in methodology resulted in the allowance for loan losses as of September 30, 2013 being $1,665,000 more than it would have been without this change in methodology.
	During the three months ended March 31, 2014, the Company modified its methodology used to determine the allowance for changing environmental factors by adding a new environmental factor based on the California Home Affordability Index (“CHAI”). The CHAI measures the percentage of households in California that can afford to purchase the median priced home in California based on current home prices and mortgage interest rates. The use of the CHAI environmental factor consists of comparing the current CHAI to its historical baseline, and allows management to consider the adverse impact that a lower than historical CHAI may have on general economic activity and the performance of our borrowers. Based on an analysis of historical data, management believes this environmental factor gives a better estimate of current economic activity compared to other environmental factors that may lag current economic activity to some extent. This change in methodology resulted in no change to the allowance for loan losses as of March 31, 2014 compared to what it would have been without this change in methodology.
	During the three months ended June 30, 2014, the Company refined the method it uses to evaluate historical losses for the purpose of estimating the pool allowance for unimpaired loans. In the third quarter of 2010, the Company moved from a six point grading system (Grades A-F) to a nine point risk rating system (Risk Ratings 1-9), primarily to allow for more distinction within the “Pass” risk rating. Initially, there was not sufficient loss experience within the nine point scale to complete a migration analysis for all nine risk ratings, all loans risk rated Pass or 2-5 were grouped together, a loss rate was calculated for that group, and that loss rate was established as the loss rate for risk rating 4. The reserve ratios for risk ratings 2, 3 and 5 were then interpolated from that figure. As of June 30, 2014, the Company was able to compile twelve quarters of historical loss information for all risk ratings and use that information to calculate the loss rates for each of the nine risk ratings without interpolation. This refinement led to an increase of $1,438,000 in the reserve requirement for unimpaired loans, driven primarily by home equity lines of credit with a risk rating of 5 or “Pass-Watch.”
	Loans purchased or acquired in a business combination are referred to as acquired loans. Acquired loans are valued as of the acquisition date in accordance with Financial Accounting Standards Board Accounting Standards Codification (“FASB ASC”) Topic 805, Business Combinations. Loans acquired with evidence of credit deterioration since origination for which it is probable that all contractually required payments will not be collected are referred to as purchased credit impaired (PCI) loans. PCI loans are accounted for under FASB ASC Topic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality. Under FASB ASC Topic 805 and FASB ASC Topic 310-30, PCI loans are recorded at fair value at acquisition date, 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 as of the acquisition date. Fair value is defined as the present value of the future estimated principal and interest payments of the loan, with the discount rate used in the present value calculation representing the estimated effective yield of the loan. Default rates, loss severity, and prepayment speed assumptions are periodically reassessed and our estimate of future payments is adjusted accordingly. The difference between contractual future payments and estimated future payments is referred to as the nonaccretable difference. The difference between estimated future payments and the present value of the estimated future payments is referred to as the accretable yield. The accretable yield represents the amount that is expected to be recorded as interest income over the remaining life of the loan. If after acquisition, the Company determines that the estimated future cash flows of a PCI loan are expected to be more than originally estimated, an increase in the discount rate (effective yield) would be made such that the newly increased accretable yield would be recognized, on a level yield basis, over the remaining estimated life of the loan. If, after acquisition, the Company determines that the estimated future cash flows of a PCI loan are expected to be less than previously estimated, the discount rate would first be reduced until the present value of the reduced cash flow estimate equals the previous present value however, the discount rate may not be lowered below its original level at acquisition. If the discount rate has been lowered to its original level and the present value has not been sufficiently lowered, an allowance for loan loss would be established through a provision for loan losses charged to expense to decrease the present value to the required level. If the estimated cash flows improve after an allowance has been established for a loan, the allowance may be partially or fully reversed depending on the improvement in the estimated cash flows. Only after the allowance has been fully reversed may the discount rate be increased. PCI loans are put on nonaccrual status when cash flows cannot be reasonably estimated. PCI loans on nonaccrual status are accounted for using the cost recovery method or cash basis method of income recognition. The Company refers to PCI loans on nonaccrual status that are accounted for using the cash basis method of income recognition as “PCI – cash basis” loans; and the Company refers to all other PCI loans as “PCI – other” loans PCI loans are charged off when evidence suggests cash flows are not recoverable. Foreclosed assets from PCI loans are recorded in foreclosed assets at fair value with the fair value at time of foreclosure representing cash flow from the loan. ASC 310-30 allows PCI loans with similar risk characteristics and acquisition time frame to be “pooled” and have their cash flows aggregated as if they were one loan. The Company elected to use the “pooled” method of ASC 310-30 for PCI – other loans in the acquisition of certain assets and liabilities of Granite Community Bank, N.A. (“Granite”) during 2010 and Citizens Bank of Northern California (“Citizens”) during 2011.
	Acquired loans that are not PCI loans are referred to as purchased not credit impaired (PNCI) loans. PNCI loans are accounted for under FASB ASC Topic 310-20, Receivables – Nonrefundable Fees and Other Costs, in which interest income is accrued on a level-yield basis for performing loans. For income recognition purposes, this method assumes that all contractual cash flows will be collected, and no allowance for loan losses is established at the time of acquisition. Post-acquisition date, an allowance for loan losses may need to be established for acquired loans through a provision charged to earnings for credit losses incurred subsequent to acquisition. Under ASC 310-20, the loss would be measured based on the probable shortfall in relation to the contractual note requirements, consistent with our allowance for loan loss policy for similar loans.
	Throughout these financial statements, and in particular in Note 4 and Note 5, when we refer to “Loans” or “Allowance for loan losses” we mean all categories of loans, including Originated, PNCI, PCI – cash basis, and PCI – other. When we are not referring to all categories of loans, we will indicate which we are referring to – Originated, PNCI, PCI – cash basis, or PCI – other.
	When referring to PNCI and PCI loans we will use the terms “nonaccretable difference”, “accretable yield”, or “purchase discount”. Nonaccretable difference is the difference between undiscounted contractual cash flows due and undiscounted cash flows we expect to collect, or put another way, it is the undiscounted contractual cash flows we do not expect to collect. Accretable yield is the difference between undiscounted cash flows we expect to collect and the value at which we have recorded the loan on our financial statements. On the date of acquisition, all purchased loans are recorded on our consolidated financial statements at estimated fair value. Purchase discount is the difference between the estimated fair value of loans on the date of acquisition and the principal amount owed by the borrower, net of charge offs, on the date of acquisition. We may also refer to “discounts to principal balance of loans owed, net of charge-offs”. Discounts to principal balance of loans owed, net of charge-offs is the difference between principal balance of loans owed, net of charge-offs, and loans as recorded on our financial statements. Discounts to principal balance of loans owed, net of charge-offs arise from purchase discounts, and equal the purchase discount on the acquisition date.
	Loans are also categorized as “covered” or “noncovered”. Covered loans refer to loans covered by a Federal Deposit Insurance Corporation (“FDIC”) loss sharing agreement. Noncovered loans refer to loans not covered by a FDIC loss sharing agreement.
	Foreclosed Assets
	Foreclosed assets include assets acquired through, or in lieu of, loan foreclosure. Foreclosed assets are held for sale and are initially recorded at fair value less estimated costs to sell at the date of foreclosure, establishing a new cost basis. Subsequent to foreclosure, management periodically performs valuations and the assets are carried at the lower of carrying amount or fair value less cost to sell. Revenue and expenses from operations and changes in the valuation allowance are included in other noninterest expense. Gain or loss on sale of foreclosed assets is included in noninterest income. Foreclosed assets that are not subject to a FDIC loss-share agreement are referred to as noncovered foreclosed assets.
	Foreclosed assets acquired through FDIC-assisted acquisitions that are subject to a FDIC loss-share agreement, and all assets acquired via foreclosure of covered loans are referred to as covered foreclosed assets. Covered foreclosed assets are reported exclusive of expected reimbursement cash flows from the FDIC. Foreclosed covered loan collateral is transferred into covered foreclosed assets at the loan’s carrying value, inclusive of the acquisition date fair value discount.
	Covered foreclosed assets are initially recorded at estimated fair value less estimated costs to sell on the acquisition date based on similar market comparable valuations less estimated selling costs. Any subsequent valuation adjustments due to declines in fair value will be charged to noninterest expense, and will be mostly offset by noninterest income representing the corresponding increase to the FDIC indemnification asset for the offsetting loss reimbursement amount. Any recoveries of previous valuation adjustments will be credited to noninterest expense with a corresponding charge to noninterest income for the portion of the recovery that is due to the FDIC.
	Premises and Equipment
	Land is carried at cost. Land improvements, buildings and equipment, including those acquired under capital lease, are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expenses are computed using the straight-line method over the estimated useful lives of the related assets or lease terms. Asset lives range from 3-10 years for furniture and equipment and 15-40 years for land improvements and buildings.
	Goodwill and Other Intangible Assets
	Goodwill represents the excess of costs over fair value of net assets of businesses acquired. Goodwill and other intangible assets acquired in a purchase business combination and determined to have an indefinite useful life are not amortized, but instead tested for impairment at least annually. Intangible assets with estimable useful lives are amortized over their respective estimated useful lives to their estimated residual values, and reviewed for impairment.
	The Company has an identifiable intangible asset consisting of core deposit intangibles (CDI). CDI are amortized over their respective estimated useful lives, and reviewed for impairment.
	Impairment of Long-Lived Assets and Goodwill
	Long-lived assets, such as premises and equipment, and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of would be separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell, and are no longer depreciated. The assets and liabilities of a disposed group classified as held for sale would be presented separately in the appropriate asset and liability sections of the consolidated balance sheet.
	As of December 31 of each year, goodwill is tested for impairment, and is tested for impairment more frequently if events and circumstances indicate that the asset might be impaired. An impairment loss is recognized to the extent that the carrying amount exceeds the asset’s fair value. This determination is made at the reporting unit level. The Company may choose to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events or circumstances, the Company determines it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then goodwill is deemed not to be impaired. However, if the Company concludes otherwise, or if the Company elected not to first assess qualitative factors, then the Company performs the first step of a two-step impairment test by calculating the fair value of the reporting unit and comparing the fair value with the carrying amount of the reporting unit. Second, if the carrying amount of the reporting unit exceeds its fair value, an impairment loss is recognized for any excess of the carrying amount of the reporting unit’s goodwill over the implied fair value of that goodwill. The implied fair value of goodwill is determined by allocating the fair value of the reporting unit in a manner similar to a purchase price allocation. The residual fair value after this allocation is the implied fair value of the reporting unit goodwill. Currently, and historically, the Company is comprised of only one reporting unit that operates within the business segment it has identified as “community banking”. Goodwill was not impaired as of December 31, 2014 because the fair value of the reporting unit exceeded its carrying value.
	Mortgage Servicing Rights
	Mortgage servicing rights (MSR) represent the Company’s right to a future stream of cash flows based upon the contractual servicing fee associated with servicing mortgage loans. Our MSR arise from residential and commercial mortgage loans that we originate and sell, but retain the right to service the loans. The net gain from the retention of the servicing right is included in gain on sale of loans in noninterest income when the loan is sold. Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the cost to service, the discount rate, the custodial earnings rate, an inflation rate, ancillary income, prepayment speeds and default rates and losses. Servicing fees are recorded in noninterest income when earned.
	The Company accounts for MSR at fair value. The determination of fair value of our MSR requires management judgment because they are not actively traded. The determination of fair value for MSR requires valuation processes which combine the use of discounted cash flow models and extensive analysis of current market data to arrive at an estimate of fair value. The cash flow and prepayment assumptions used in our discounted cash flow model are based on empirical data drawn from the historical performance of our MSR, which we believe are consistent with assumptions used by market participants valuing similar MSR, and from data obtained on the performance of similar MSR. The key assumptions used in the valuation of MSR include mortgage prepayment speeds and the discount rate. These variables can, and generally will, change from quarter to quarter as market conditions and projected interest rates change. The key risks inherent with MSR are prepayment speed and changes in interest rates. The Company uses an independent third party to determine fair value of MSR.
	Indemnification Asset/Liability
	The Company accounts for amounts receivable or payable under its loss-share agreements entered into with the FDIC in connection with its purchase and assumption of certain assets and liabilities of Granite as indemnification assets in accordance with FASB ASC Topic 805, Business Combinations. FDIC indemnification assets are initially recorded at fair value, based on the discounted value of expected future cash flows under the loss-share agreements. The difference between the fair value and the undiscounted cash flows the Company expects to collect from or pay to the FDIC will be accreted into noninterest income over the life of the FDIC indemnification asset. FDIC indemnification assets are reviewed quarterly and adjusted for any changes in expected cash flows based on recent performance and expectations for future performance of the covered portfolios. These adjustments are measured on the same basis as the related covered loans and covered other real estate owned. Any increases in cash flow of the covered assets over those expected will reduce the FDIC indemnification asset and any decreases in cash flow of the covered assets under those expected will increase the FDIC indemnification asset. Increases and decreases to the FDIC indemnification asset are recorded as adjustments to noninterest income.
	Reserve for Unfunded Commitments
	The reserve for unfunded commitments is established through a provision for losses – unfunded commitments charged to noninterest expense. The reserve for unfunded commitments is an amount that Management believes will be adequate to absorb probable losses inherent in existing commitments, including unused portions of revolving lines of credits and other loans, standby letters of credits, and unused deposit account overdraft privilege. The reserve for unfunded commitments is based on evaluations of the collectability, and prior loss experience of unfunded commitments. The evaluations take into consideration such factors as changes in the nature and size of the loan portfolio, overall loan portfolio quality, loan concentrations, specific problem loans and related unfunded commitments, and current economic conditions that may affect the borrower’s or depositor’s ability to pay.
	During the three months ended June 30, 2013, the Company modified the methodology employed to estimate potential losses on unfunded commitments. Similar to the Allowance for Loan Losses, the Company performs a migration analysis of historical loss experience. Prior to this quarter, the loss experience of each quarter over the previous three years was reviewed in order to calculate an annualized loss rate by loan category. Going forward, the Company has chosen to review all loss experience available since the conversion to a loss migration analysis. This change is intended to more accurately reflect the risk inherent in the unfunded commitments and appropriately consider all losses incurred in prior years. This change in methodology resulted in the reserve for unfunded commitments as of June 30, 2013 being $335,000 more than it would have been without this change in methodology.
	Income Taxes
	The Company’s accounting for income taxes is based on an asset and liability approach. The Company recognizes 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 its financial statements or tax returns. The measurement of tax assets and liabilities is based on the provisions of enacted tax laws. A valuation allowance, if needed, reduces deferred tax assets to the expected amount most likely to be realized. Realization of deferred tax assets is dependent upon the generation of a sufficient level of future taxable income and recoverable taxes paid in prior years. Although realization is not assured, management believes it is more likely than not that all of the deferred tax assets will be realized. Interest and/or penalties related to income taxes are reported as a component of noninterest income.
	Off-Balance Sheet Credit Related Financial Instruments
	In the ordinary course of business, the Company has entered into commitments to extend credit, including commitments under credit card arrangements, commercial letters of credit, and standby letters of credit. Such financial instruments are recorded when they are funded.
	Geographical Descriptions
	For the purpose of describing the geographical location of the Company’s loans, the Company has defined northern California as that area of California north of, and including, Stockton; central California as that area of the state south of Stockton, to and including, Bakersfield; and southern California as that area of the state south of Bakersfield.
Reclassifications
Certain amounts reported in previous consolidated financial statements have been reclassified to conform to the presentation in this report. These reclassifications did not affect previously reported net income or total shareholders’ equity.
Recent Accounting Pronouncements
FASB issued ASU No. 2014-04, Receivables (Topic 310): Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure. ASU 2014-04 clarifies when an in substance repossession or foreclosure occurs, that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan receivable should be derecognized and the real estate property recognized. ASU 2014-04 is effective for public business entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2014. ASU 2014-04 is not expected to have a significant impact on the Company’s consolidated financial statements.
FASB issued ASU No. 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. ASU 2014-08 improves the definition of discontinued operations by limiting discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have (or will have) a major effect on an entity’s operations and financial results. ASU 2014-08 requires expanded disclosures for discontinued operations that provide users of financial statements with more information about the assets, liabilities, revenues, and expenses of discontinued operations. ASU 2014-08 also requires an entity to disclose the pretax profit or loss of an individually significant component of an entity that does not qualify for discontinued operations reporting, and provide users with information about the financial effects of significant disposals that do not qualify for discontinued operations reporting. The amendments in ASU 2014-08 include several changes to the Accounting Standards Codification to improve the organization and readability of Subtopic 205-20 and Subtopic 360-10, Property, Plant, and Equipment—Overall. ASU 2014-08 is effective for public business entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2014. ASU 2014-08 is not expected to have a significant impact on the Company’s consolidated financial statements.
FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). The core principle of the guidance under ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 is effective for a public entity for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early application is not permitted. The Company is currently evaluating the effects of ASU 2014-09 on its financial statements and disclosures, if any.
FASB issued ASU No. 2014-11, Transfers and Servicing (Topic 860): Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures. ASU 2014-11 requires that repurchase-to-maturity transactions be accounted for as secured borrowings consistent with the accounting for other repurchase agreements. In addition, ASU 2014-11 requires separate accounting for repurchase financings, which entails the transfer of a financial asset executed contemporaneously with a repurchase agreement with the same counterparty. ASU 2014-11 requires entities to disclose certain information about transfers accounted for as sales in transactions that are economically similar to repurchase agreements. In addition, ASU 2014-11 requires disclosures related to collateral, remaining contractual tenor and of the potential risks associated with repurchase agreements, securities lending transactions and repurchase-to-maturity transactions. ASU 2014-11 is effective for public business entities for the first interim or annual period beginning after December 15, 2014. An entity is required to present changes in accounting for transactions outstanding on the effective date as a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. Earlier application for a public business entity is prohibited. ASU 2014-11 is not expected to have a significant impact on the Company’s consolidated financial statements.
FASB issued ASU No. 2014-12, Compensation—Stock Compensation (Topic 718): Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be achieved after the Requisite Service Period. ASU 2014-12 requires that a performance target that affects the vesting of a share-based payment award and that could be achieved after the requisite service period be treated as a performance condition. A reporting entity should apply existing guidance in Topic 718 as it relates to awards with performance conditions that affect vesting to account for such awards. As such, the performance target should not be reflected in estimating the grant-date fair value of the award. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. If the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The requisite service period ends when the employee can cease rendering service and still be eligible to vest in the award if the performance target is achieved. The stated vesting period (which includes the period in which the performance target could be achieved) may differ from the requisite service period. Current U.S. GAAP does not contain explicit guidance on whether to treat a performance target that could be achieved after the requisite service period as a performance condition that affects vesting or as a nonvesting condition that affects the grant-date fair value of an award. ASU 2014-12 provides explicit guidance for those awards. For all entities, ASU 2014-12 is effective for annual periods and interim periods within those annual periods beginning after December 15, 2015. Earlier adoption is permitted.
FASB issued ASU No. 2014-14, Receivables—Troubled Debt Restructurings by Creditors (Topic 310): Classification of Certain Government Mortgage Loans upon Foreclosure. ASU 2014-14 requires that a mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if the following conditions are met: 1) the loan has a government guarantee that is not separable from the loan before foreclosure, 2) at the time of foreclosure, the creditor has the intent to convey the real estate property to the guarantor and make a claim on the guarantee, and the creditor has the ability to recover under that claim, and 3) at the time of foreclosure, any amount of the claim that is determined on the basis of the fair value of the real estate is fixed. Upon foreclosure, the separate other receivable should be measured based on the amount of the loan balance (principal and interest) expected to be recovered from the guarantor. For public business entities, ASU 2014-14 is effective for annual periods and interim periods within those annual periods beginning after December 15, 2014. Earlier adoption is permitted.

Business_Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Business Combinations	Note 2 - Business Combinations
	On October 3, 2014, TriCo completed its acquisition of North Valley Bancorp originally announced January 21, 2014. Based on a fixed exchange ratio of 0.9433 shares of TriCo common stock for each share of North Valley Bancorp common stock, North Valley Bancorp shareholders received 6,575,550 shares of TriCo common stock and $6,823 of cash in-lieu of fractional shares. The 6,575,550 shares of TriCo common stock issued to North Valley Bancorp shareholders represented, on a pro forma basis, approximately 28.9% of the 22,714,964 shares of the combined company outstanding on October 3, 2014. Based on TriCo’s closing stock price of $23.01 on October 3, 2014, North Valley Bancorp shareholders received consideration valued at $151,310,000 or approximately $21.71 per share of North Valley common stock outstanding.
	The acquisition of North Valley Bancorp was to expand the Company’s market presence in Northern California. The customer base and locations of North Valley Bancorp’s branches had significant overlap when compared to the Company’s Northern California customer base and branch locations. This made North Valley Bancorp a very good fit in terms of potential cost savings and future growth potential. With the levels of excess capital at the time, the acquisitions fit well into the Company’s growth strategy.
	North Valley Bancorp, was headquartered in Redding, California, and was the parent of North Valley Bank that had approximately $935 million in assets and 22 commercial banking offices in Shasta, Humboldt, Del Norte, Mendocino, Yolo, Sonoma, Placer and Trinity Counties in Northern California at June 30, 2014. In connection with the acquisition, North Valley Bank was merged into Tri Counties Bank on October 3, 2014.
	On October 25, 2014, North Valley Bank’s electronic customer service and other data processing systems were converted into Tri Counties Bank’s systems. Between January 7, 2015 and January 21, 2015, four Tri Counties Bank branches and four former North Valley Bank branches were consolidated into other Tri Counties Bank or other former North Valley Bank branches.
	Beginning on October 4, 2014, the effect of revenue and expenses from the operations of North Valley Bancorp, and the issuance of TriCo Bancshares common shares as consideration in the merger are included in the results of the Company.
	The assets acquired and liabilities assumed from North Valley Bancorp were accounted for in accordance with ASC 805 “Business Combinations,” using the acquisition method of accounting and were recorded at their estimated fair values on the October 3, 2014 acquisition date, and its results of operations are included in the Company’s consolidated statements of income since that date. The excess of the fair value of consideration transferred over total identifiable net assets was recorded as goodwill. The goodwill arising from the acquisition consists largely of the synergies and economies of scale expected from combining the operations of the Company and North Valley Bancorp. None of the goodwill is deductible for income tax purposes as the acquisition was accounted for as a tax-free exchange. The fair value estimate for loans is considered provisional as additional information related to the fair value of such loans as of October 3, 2014 may become available in the future. Management may adjust the fair value of loans acquired from North Valley Bancorp for a period of up to one year from the date of the acquisition. Any adjustment to the fair value of loans acquired from North Valley Bancorp would have residual effects on deferred tax assets and goodwill.
	The following table discloses the calculation of the fair value of consideration transferred, the total identifiable net assets acquired and the resulting goodwill relating to the North Valley Bancorp acquisition:
	(in thousands)	North Valley Bancorp
		October 3, 2014
	Fair value of consideration transferred:
	Fair value of shares issued	$	151,303
	Cash consideration		7
	Total fair value of consideration transferred		151,310
	Asset acquired:
	Cash and cash equivalents		141,412
	Securities available for sale		17,297
	Securities held to maturity		189,949
	Restricted equity securities		5,378
	Loans		499,327
	Foreclosed assets		695
	Premises and equipment		11,936
	Cash value of life insurance		38,075
	Core deposit intangible		6,614
	Other assets		20,056
	Total assets acquired		930,739
	Liabilities assumed:
	Deposits		801,956
	Other liabilities		10,429
	Junior subordinated debt		14,987
	Total liabilities assumed		827,372
	Total net assets acquired		103,367
	Goodwill recognized	$	47,943
	A summary of the estimated fair value adjustments resulting in the goodwill recorded in the North Valley Bancorp acquisition are presented below:
	(in thousands)	North Valley Bancorp
		October 3, 2014
	Value of stock consideration paid to North Valley Bancorp Shareholders		151,303
	Cash payments to North
	Valley Bancorp Shareholders		7
	Cost basis net assets acquired	$	(98,040	)
	Fair value adjustments:
	Loans		5,832
	Premises and Equipment		(4,785	)
	Core deposit intangible		(6,283	)
	Deferred income taxes		6,293
	Junior subordinated debt		(6,664	)
	Other		280
	Goodwill	$	47,943
	The loan portfolio of North Valley Bancorp was recorded at fair value at the date of each acquisition. A valuation of North Valley Bancorp’s loan portfolio was performed as of the acquisition date to assess the fair value of the loan portfolio. The North Valley Bancorp loan portfolio was segmented into two groups; loans with credit deterioration (PCI loans) and loans without credit deterioration (PNCI). For North Valley Bancorp PNCI loans, the present value of estimated future cash flows, based primarily on contractual cash flows, was used to determine fair value. For North Valley Bancorp PCI loans, the present value of estimated future cash flows, based primarily on liquidation value of collateral, was used to determine fair value.
	North Valley Bancorp PNCI loans were grouped into pools based on similar loan characteristics such as loan type, payment amortization method, and fixed or variable interest rates. A discounted cash flow schedule was prepared for each pool in which the present value of all estimated future cash flows was calculated using a specifically calculated discount rate for each pool. The discount rate used to estimate the fair value of each loan pool was composed of the sum of: an estimated cost of funds rate, an estimated capital charge reflecting the market participant required return on capital, estimated loan servicing costs, and a liquidity premium. All PNCI loan pools included some estimate regarding prepayment rates, and estimated principal default and loss rates, based primarily on North Valley Bancorp’s historical loss experience. The difference between the sum of recorded balances of the North Valley Bancorp PNCI loans in each pool and the present value of each pool represented the total discount (if the recorded value exceeded the present value) or premium (if the present value exceeded the recorded value) for each pool. The total discount, or premium, for each pool was then allocated to the individual loans within each pool based on outstanding loan balance, individual loan risk rating as compared to the weighted average risk rating of the pool, and the contractual payments remaining for the individual loan as compared to the pool.
	North Valley Bancorp PCI loans were fair valued on an individual basis. A discounted cash flow schedule was prepared for each loan in which the present value of all future estimated cash flows was calculated using a specifically calculated discount rate, estimated liquidation value and estimated liquidation timing for each loan. The discount rate used in the calculation of the present value of North Valley Bancorp PCI loans was composed of the sum of: an estimated cost of funds rate, an estimated capital charge reflecting the market participant required return on capital, estimated loan servicing costs, and a liquidity premium. The difference between the recorded balance and the present value of each North Valley Bancorp PCI loan represented the discount for each PCI loan. All North Valley Bancorp PCI loans had recorded values in excess of their present value of estimated future cash flows.
	The Company identified the North Valley Bancorp PCI loans as having cash flows that were not reasonably estimable and placed these loans in nonaccrual status under ASC 310-30 and included them in the category of loans the Company refers to as “PCI – other” loans.
	The following table presents the cost basis, fair value discount, and fair value of loans acquired from North Valley Bancorp on October 3, 2014:
		North Valley Bancorp Acquired Loans
		October 3, 2014
	(in thousands)	Cost Basis			Discount			Fair Value
	PNCI	$	502,637		$	(12,721	)	$	489,916
	PCI – other		11,488			(2,077	)		9,411
	Total	$	514,125		$	(14,798	)	$	499,327
	Although the discount on PNCI loans is completely accretable to interest income over the remaining life of such loans, the discount on PCI – other loans from the North Valley Bancorp acquisition are not accretable into interest income until the loan principal balance has been reduced to the loan’s fair value recorded at acquisition. This method of accounting for the PCI – other loans from the North Valley Bancorp acquisition is often referred to as the “cost recovery” method of income recognition.
	The following table presents a reconciliation of the undiscounted contractual cash flows, nonaccretable difference, accretable yield, fair value, purchase discount, and principal balance of loans for the PNCI and PCI—other categories of North Valley Bancorp loans as of the acquisition date. For North Valley Bancorp PCI – other loans, the purchase discount does not necessarily represent cash flows to be collected:
		North Valley Bancorp Loans – October 3, 2014
	(in thousands)	PNCI			PCI—other			Total
	Undiscounted contractual cash flows	$	718,731		$	15,706		$	734,437
Undiscounted cash flows not expected to be collected (nonaccretable difference)		—			(6,295	)		(6,295	)
Undiscounted cash flows expected to be collected		718,731			9,411			728,142
Accretable yield at acquisition		(228,815	)		—			(228,815	)
Estimated fair value of loans acquired at acquisition		489,916			9,411			499,327
Purchase discount		12,721			2,077			14,798
Principal balance loans acquired	$	502,637		$	11,488		$	514,125
As part of the acquisition of North Valley Bancorp, the Company performed a valuation of premises and equipment acquired. This valuation resulted in a $4,785,000 increase in the net book value of land and buildings acquired, and was based on current appraisals of such land and buildings.
The Company recognized a core deposit intangible of $6,614,000 related to the acquisition of North Valley Bancorp’s core deposits. The recorded core deposit intangibles represented approximately 0.97% of core deposits for North Valley Bancorp and will be amortized over their useful lives of 7 years.
A valuation of time deposits for North Valley Bancorp was also performed as of the acquisition date. Time deposits were split into similar pools based on size, type of time deposits, and maturity. A discounted cash flow analysis was performed on the pools based on current market rates currently paid on similar time deposits. The valuation resulted in no material fair value discount or premium, and none was recorded.
The fair value of junior subordinated debentures assumed from North Valley Bancorp was estimated using a discounted cash flow method based on the current market rates for similar liabilities. As a result a discount of $6,664,000 was recorded on the junior subordinated debentures acquired from North Valley Bancorp. The discount on the subordinated debentures will be amortized using the effective yield method the remaining life to maturity of the debentures at acquisition which range from 18 years to 21 years.
The Company assumed 13 lease contracts from North Valley Bancorp. The fair value measurements of theses leasehold interests were performed to determine whether the lease terms were favorable or unfavorable relative to current market rates of similar leases. The fair value of leasehold interests was recorded based on estimated future cash flow projections using market rates for similar leases. As a result, on the acquisition dates, we recorded unfavorable leasehold interests of $293,000.
The Company recorded a $6,293,000 reduction in deferred tax assets due to the tax effects of the other acquisition accounting fair value adjustments noted above, and a $1,341,000 decrease in the North Valley Bancorp deferred tax asset related to net operating loss carryforwards that the Company determined will not be realizable.
During the 2014, the Company recorded approximately $4,858,000 in one-time costs associated with the acquisition of North Valley Bancorp, including $1,269,000 that was not tax deductible. These costs included expense related to severance and other salaries and benefits expenses, consulting fees, legal fees, contract termination fees, and other expense. The system integration and conversion for North Valley Bancorp was completed during the fourth quarter of 2014. The Company consolidated four former North Valley Bank, and four Tri Counties Bank branches into other Tri Counties Bank branches or other former North Valley Bank branches during January 2015.
The table below presents the unaudited proforma information as if the acquisition of North Valley Bancorp had occurred on January 1, 2013 after giving effect to certain acquisition accounting adjustments. The proforma information for the years ended December 31, 2014 and 2013 includes acquisition adjustments for the amortization/accretion on loans, core deposit intangibles, junior subordinated debt and related income tax effects. The proforma financial information also includes one-time costs associated with the acquisitions but does not include expected costs savings synergies that we expect to achieve. The unaudited pro forma financial information is not necessarily indicative of the results of operations that would have occurred had the transaction been effected on the assumed date.
	Proforma for the
	Year Ended December 31,
	2014			2013
(Unaudited, in thousands, except per share data)
Summarized Income Statement Data:
Net interest income	$	139,520		$	132,635
Provision for (benefit from) loan losses		(4,045	)		(715	)
Noninterest income		43,587			50,966
Noninterest expense		147,295			133,073
Income before income taxes		39,857			51,243
Income taxes		16,453			20,091
Net income	$	23,404		$	31,152
Basic earnings per share	$	1.03		$	1.38
Diluted earnings per share	$	1.02		$	1.37
It is impracticable to separately provide information regarding the revenue and earnings of North Valley Bancorp included in the Company’s consolidated income statement from the October 3, 2014 acquisition date to December 31, 2014 because the operations of North Valley Bancorp were substantially comingled with the operations of the Company as of the system conversion date of October 25, 2014.

Investment_Securities

Investment Securities	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Note 3 - Investment Securities
	The amortized cost and estimated fair values of investments in debt and equity securities are summarized in the following tables:
		December 31, 2014
		Amortized		Gross			Gross			Estimated
		Cost		Unrealized			Unrealized			Fair Value
				Gains			Losses
		(in thousands)
	Securities Available for Sale
	Obligations of U.S. government corporations and agencies	$	71,144		4,001			(25	)	$	75,120
	Obligations of states and political subdivisions		3,130		45			—			3,175
	Corporate debt securities		1,891		17			—			1,908
	Marketable equity securities		3,000		2			—			3,002
	Total securities available for sale	$	79,165	$	4,065		$	(25	)	$	83,205
	Securities Held to Maturity
	Obligations of U.S. government corporations and agencies	$	660,836		13,055			(677	)	$	673,214
	Obligations of states and political subdivisions		15,590		130			(155	)		15,565
	Total securities held to maturity	$	676,426	$	13,185		$	(832	)	$	688,779
		December 31, 2013
		Amortized		Gross			Gross			Estimated
		Cost		Unrealized			Unrealized			Fair
				Gains			Losses			Value
		(in thousands)
	Securities Available for Sale
	Obligations of U.S. government corporations and agencies	$	93,055	$	4,445		$	(357	)	$	97,143
	Obligations of states and political subdivisions		5,513		77			(1	)		5,589
	Corporate debt securities		1,877		38			—			1,915
	Total securities available for sale	$	100,445	$	4,560		$	(358	)	$	104,647
	Securities Held to Maturity
	Obligations of U.S. government corporations and agencies	$	227,864	$	298		$	(5,540	)	$	222,622
	Obligations of states and political subdivisions		12,640		—			(1,455	)		11,185
	Total securities held to maturity	$	240,504	$	298		$	(6,995	)	$	233,807
	Investment securities totaling $14,130,000 were sold in 2014 resulting in no gain or loss on sale. No investment securities were sold during 2013, or 2012. Investment securities with an aggregate carrying value of $143,992,000 and $62,064,000 at December 31, 2014 and 2013, respectively, were pledged as collateral for specific borrowings, lines of credit and local agency deposits.
	The amortized cost and estimated fair value of debt securities at December 31, 2014 by contractual maturity are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. At December 31, 2014, obligations of U.S. government corporations and agencies with a cost basis totaling $755,591,000 consist almost entirely of mortgage-backed securities whose contractual maturity, or principal repayment, will follow the repayment of the underlying mortgages. For purposes of the following table, the entire outstanding balance of these mortgage-backed securities issued by U.S. government corporations and agencies is categorized based on final maturity date. At December 31, 2014, the Company estimates the average remaining life of these mortgage-backed securities issued by U.S. government corporations and agencies to be approximately 5.3 years. Average remaining life is defined as the time span after which the principal balance has been reduced by half.
	Investment Securities	Available for Sale					Held to Maturity
	(In thousands)	Amortized		Estimated			Amortized			Estimated
		Cost		Fair Value			Cost			Fair Value
	Due in one year	$	1,924	$	1,942			—			—
	Due after one year through five years		1,095		1,135			—			—
	Due after five years through ten years		30,977		32,316		$	1,118		$	1,106
	Due after ten years		45,169		47,812			675,308			687,673
	Totals	$	79,165	$	83,205		$	676,426		$	688,779
	Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, were as follows:
		Less than 12 months					12 months or more						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Loss			Value			Loss			Value		Loss
	December 31, 2014	(in thousands)
	Securities Available for Sale:
	Obligations of U.S. government corporations and agencies	$	6,774		(25	)		—			—			6,774		(25	)
	Obligations of states and political subdivisions		—		—			—			—			—		—
	Corporate debt securities		—		—			—			—			—		—
	Marketable equity securities		—		—			—			—			—		—
	Total securities available-for-sale	$	6,774		(25	)		—			—			6,774		(25	)
	Securities Held to Maturity:
	Obligations of U.S. government corporations and agencies	$	335		(1	)		56,288			(676	)		56,623		(677	)
	Obligations of states and political subdivisions		1,600		(26	)		1,858			(129	)		3,458		(155	)
	Corporate debt securities		—		—			—			—			—		—
	Total securities held-to-maturity	$	1,935		(27	)		58,146			(805	)		60,081		(832	)
		Less than 12 months					12 months or more						Total
		Fair Value		Unrealized			Fair			Unrealized			Fair Value		Unrealized
				Loss			Value			Loss					Loss
	December 31, 2013	(in thousands)
	Securities Available for Sale:
	Obligations of U.S. government corporations and agencies	$	10,287	$	(357	)		—			—		$	10,287	$	(357	)
	Obligations of states and political subdivisions		199		(1	)		—			—			199		(1	)
Corporate debt securities		—		—			—			—			—		—
Total securities available-for-sale	$	10,486	$	(358	)		—			—		$	10,486	$	(358	)
Securities Held to Maturity:
Obligations of U.S. government corporations and agencies	$	188,218	$	(5,540	)		—			—		$	188,218	$	(5,540	)
Obligations of states and political subdivisions		11,185		(1,455	)		—			—			11,185		(1,455	)
Corporate debt securities		—		—			—			—			—		—
Total securities held-to-maturity	$	199,403	$	(6,995	)		—			—		$	199,403	$	(6,995	)
Obligations of U.S. government corporations and agencies: Unrealized losses on investments in obligations of U.S. government corporations and agencies are caused by interest rate increases. The contractual cash flows of these securities are guaranteed by U.S. Government Sponsored Entities (principally Fannie Mae and Freddie Mac). It is expected that the securities would not be settled at a price less than the amortized cost of the investment. Because the decline in fair value is attributable to changes in interest rates and not credit quality, and because the Company does not intend to sell and more likely than not will not be required to sell, these investments are not considered other-than-temporarily impaired. At December 31, 2014, 8 debt securities representing obligations of U.S. government corporations and agencies had unrealized losses with aggregate depreciation of 1.10% from the Company’s amortized cost basis.
Obligations of states and political subdivisions: The unrealized losses on investments in obligations of states and political subdivisions were caused by increases in required yields by investors in these types of securities. It is expected that the securities would not be settled at a price less than the amortized cost of the investment. Because the decline in fair value is attributable to changes in interest rates and not credit quality, and because the Company does not intend to sell and more likely than not will not be required to sell, these investments are not considered other-than-temporarily impaired. At December 31, 2014, 5 debt securities representing obligations of states and political subdivisions had unrealized losses with aggregate depreciation of 4.26% from the Company’s amortized cost basis.
Corporate debt securities: At December 31, 2014, no corporate debt securities had unrealized losses.
Marketable equity securities: At December 31, 2014, no marketable equity securities had unrealized losses.

Loans

Loans	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Loans	Note 4 – Loans
	A summary of loan balances follows (in thousands):
		December 31, 2014
		Originated			PNCI			PCI -			PCI -			Total
								Cash basis			Other
	Mortgage loans on real estate:
	Residential 1-4 family	$	154,594		$	120,821			—		$	4,005		$	279,420
	Commercial		928,797			376,225			—			30,917			1,335,939
	Total mortgage loan on real estate		1,083,391			497,046			—			34,922			1,615,359
	Consumer:
	Home equity lines of credit		305,166			38,397		$	5,478			3,543			352,584
	Home equity loans		23,559			6,985			125			645			31,314
	Auto Indirect		112			—			—			—			112
	Other		28,230			4,770			—			74			33,074
	Total consumer loans		357,067			50,152			5,603			4,262			417,084
	Commercial		126,611			40,899			8			7,427			174,945
	Construction:
	Residential		21,135			16,808			—			675			38,618
	Commercial		24,545			11,973			—			—			36,518
	Total construction		45,680			28,781			—			675			75,136
	Total loans, net of deferred loan fees and discounts	$	1,612,749		$	616,878		$	5,611		$	47,286		$	2,282,524
	Total principal balance of loans owed, net of charge-offs	$	1,617,542		$	634,490		$	14,805		$	56,016		$	2,322,853
	Unamortized net deferred loan fees		(4,793	)		—			—			—			(4,793	)
	Discounts to principal balance of loans owed, net of charge-offs		—			(17,612	)		(9,194	)		(8,730	)		(35,536	)
	Total loans, net of unamortized deferred loan fees and discounts	$	1,612,749		$	616,878		$	5,611		$	47,286		$	2,282,524
	Noncovered loans	$	1,612,749		$	616,878		$	5,611		$	25,018		$	2,260,256
	Covered loans		—			—			—			22,268			22,268
	Total loans, net of unamortized deferred loan fees and discounts	$	1,612,749		$	616,878		$	5,611		$	47,286		$	2,282,524
	Allowance for loan losses	$	(29,860	)	$	(3,296	)	$	(348	)	$	(3,081	)	$	(36,585	)
	A summary of loan balances follows (in thousands):
		December 31, 2013
		Originated			PNCI			PCI -			PCI -			Total
								Cash basis			Other
	Mortgage loans on real estate:
	Residential 1-4 family	$	129,882		$	60,475			—		$	4,656		$	195,013
	Commercial		824,912			57,678			—			30,260			912,850
	Total mortgage loan on real estate		954,794			118,153			—			34,916			1,107,863
	Consumer:
	Home equity lines of credit		316,207			13,576		$	6,200			3,883			339,866
	Home equity loans		13,849			253			—			486			14,588
	Auto Indirect		946			—			—			—			946
	Other		25,608			2,074			—			81			27,763
	Total consumer loans		356,610			15,903			6,200			4,450			383,163
	Commercial		124,650			693			19			6,516			131,878
	Construction:
	Residential		30,367			—			—			1,566			31,933
	Commercial		17,125			—			—			45			17,170
	Total construction		47,492			—			—			1,611			49,103
	Total loans, net of deferred loan fees and discounts	$	1,483,546		$	134,749		$	6,219		$	47,493		$	1,672,007
	Total principal balance of loans owed, net of charge-offs	$	1,487,240		$	142,786		$	16,475		$	56,879		$	1,703,380
	Unamortized net deferred loan fees		(3,694	)		—			—			—			(3,694	)
	Discounts to principal balance of loans owed, net of charge-offs		—			(8,037	)		(10,256	)		(9,386	)		(27,679	)
	Total loans, net of unamortized deferred loan fees and discounts	$	1,483,546		$	134,749		$	6,219		$	47,493		$	1,672,007
	Noncovered loans	$	1,483,546		$	134,749		$	6,219		$	19,581		$	1,644,095
	Covered loans		—			—			—			27,912			27,912
	Total loans, net of unamortized deferred loan fees and discounts	$	1,483,546		$	134,749		$	6,219		$	47,493		$	1,672,007
	Allowance for loan losses	$	(31,354	)	$	(2,850	)	$	(385	)	$	(3,656	)	$	(38,245	)
	The following is a summary of the change in accretable yield for PCI – other loans during the periods indicated (in thousands):
		Year ended December 31,
		2014			2013
	Change in accretable yield:
	Balance at beginning of period	$	18,232		$	22,337
	Accretion to interest income		(4,368	)		(6,305	)
	Reclassification (to) from nonaccretable difference		1,009			2,201
Balance at end of period	$	14,873		$	18,232

Allowance_for_Loan_Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Allowance for Loan Losses	Note 5 – Allowance for Loan Losses
	The following tables summarize the activity in the allowance for loan losses, and ending balance of loans, net of unearned fees for the periods indicated.
			Allowance for Loan Losses - Year Ended December 31, 2014
			RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Beginning balance		$	3,154		$	9,700		$	16,375		$	1,208		$	66		$	589		$	4,331		$	1,559		$	1,263		$	38,245
	Charge-offs			(171	)		(110	)		(1,094	)		(29	)		(3	)		(599	)		(479	)		(4	)		(69	)		(2,558	)
	Recoveries			2			540			960			34			86			495			1,268			1,377			181			4,943
	(Benefit) provision			101			(903	)		(565	)		584			(140	)		234			(894	)		(1,498	)		(964	)		(4,045	)
	Ending balance		$	3,086		$	9,227		$	15,676		$	1,797		$	9		$	719		$	4,226		$	1,434		$	411		$	36,585
	Ending balance:
	Individ. evaluated for impairment		$	974		$	410		$	1,974		$	284			—		$	142		$	423		$	60			—		$	4,267
	Loans pooled for evaluation		$	1,915		$	8,408		$	13,251		$	1,513		$	9		$	572		$	2,569		$	332		$	322		$	28,891
	Loans acquired with deteriorated credit quality		$	197		$	409		$	451			—			—		$	5		$	1,234		$	1,042		$	89		$	3,427
			Loans, net of unearned fees - As of December 31, 2014
			RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Ending balance:
	Total loans		$	279,420		$	1,335,939		$	352,584		$	31,314		$	112		$	33,074		$	174,945		$	38,618		$	35,518		$	2,282,524
	Individ. evaluated for impairment		$	7,188		$	41,932		$	6,968		$	1,278		$	18		$	323		$	1,757		$	2,683		$	99		$	62,246
	Loans pooled for evaluation		$	268,227		$	1,263,090		$	336,595		$	29,266		$	94		$	32,677		$	165,753		$	35,260		$	36,419		$	2,167,381
	Loans acquired with deteriorated credit quality		$	4,005		$	30,917		$	9,021		$	770			—		$	74		$	7,435		$	675			—		$	52,897
			Allowance for Loan Losses - Year Ended December 31, 2013
			RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Beginning balance		$	3,523		$	8,782		$	21,367		$	1,155		$	243		$	696		$	4,703		$	1,400		$	779		$	42,648
	Charge-offs			(46	)		(2,038	)		(2,651	)		(94	)		(68	)		(887	)		(1,599	)		(20	)		(140	)		(7,543	)
	Recoveries			345			994			1,053			41			195			759			340			63			65			3,855
	(Benefit) provision			(668	)		1,962			(3,394	)		106			(304	)		21			887			116			559			(715	)
	Ending balance		$	3,154		$	9,700		$	16,375		$	1,208		$	66		$	589		$	4,331		$	1,559		$	1,263		$	38,245
	Ending balance:
	Individ. evaluated for impairment		$	775		$	1,198		$	1,140		$	169		$	1		$	8		$	585		$	91		$	8		$	3,975
	Loans pooled for evaluation		$	2,039		$	7,815		$	14,749		$	1,039		$	65		$	581		$	2,402		$	751		$	789		$	30,230
	Loans acquired with deteriorated credit quality		$	340		$	687		$	486			—			—			—		$	1,344		$	717		$	466		$	4,040
			Loans, net of unearned fees - As of December 31, 2013
			RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Ending balance:
	Total loans		$	195,013		$	912,850		$	339,866		$	14,588		$	946		$	27,763		$	131,878		$	31,933		$	17,170		$	1,672,007
	Individ. evaluated for impairment		$	7,342		$	59,936		$	6,918		$	778		$	60		$	90		$	3,177		$	2,756		$	178		$	81,235
	Loans pooled for evaluation		$	183,015		$	822,654		$	322,865		$	13,324		$	886		$	27,592		$	122,166		$	27,611		$	16,947		$	1,537,060
	Loans acquired with deteriorated credit quality		$	4,656		$	30,260		$	10,083		$	486			—		$	81		$	6,535		$	1,566		$	45		$	53,712
			Allowance for Loan Losses - Year Ended December 31, 2012
			RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Beginning balance		$	2,404		$	13,217		$	18,258		$	1,101		$	215		$	932		$	6,545		$	1,817		$	1,425		$	45,914
	Charge-offs			(1,558	)		(3,457	)		(8,042	)		(385	)		(83	)		(1,202	)		(1,251	)		(406	)		(100	)		(16,484	)
	Recoveries			147			1,020			398			100			215			860			643			412			—			3,795
	Provision (benefit)			2,530			(1,998	)		10,753			339			(104	)		106			(1,234	)		(423	)		(546	)		9,423
	Ending balance		$	3,523		$	8,782		$	21,367		$	1,155		$	243		$	696		$	4,703		$	1,400		$	779		$	42,648
	Ending balance:
	Individ. evaluated for impairment		$	631		$	515		$	2,264		$	81		$	5		$	47		$	840		$	11		$	111		$	4,505
	Loans pooled for evaluation		$	2,526		$	8,026		$	17,862		$	995		$	238		$	649		$	2,342		$	430		$	165		$	33,233
	Loans acquired with deteriorated credit quality		$	366		$	241		$	1,241		$	79			—			—		$	1,521		$	959		$	503		$	4,910
			Loans, net of unearned fees – As of December 31, 2012
			RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Ending balance:
	Total loans		$	131,684		$	878,446		$	342,025		$	13,557		$	3,816		$	26,713		$	135,528		$	18,459		$	14,595		$	1,564,823
	Individ. evaluated for impairment		$	6,586		$	71,077		$	10,056		$	528		$	197		$	121		$	8,562		$	3,596		$	607		$	101,330
	Loans pooled for evaluation		$	120,082		$	776,137		$	318,403		$	12,825		$	3,619		$	26,560		$	117,429		$	8,281		$	10,589		$	1,393,925
	Loans acquired with deteriorated credit quality		$	5,016		$	31,232		$	13,566		$	204			—		$	32		$	9,537		$	6,582		$	3,399		$	69,568
	As part of the on-going monitoring of the credit quality of the Company’s loan portfolio, management tracks certain credit quality indicators including, but not limited to, trends relating to (i) the level of criticized and classified loans, (ii) net charge-offs, (iii) non-performing loans, and (iv) delinquency within the portfolio.
	The Company utilizes a risk grading system to assign a risk grade to each of its loans. Loans are graded on a scale ranging from Pass to Loss. A description of the general characteristics of the risk grades is as follows:
	•		Pass – This grade represents loans ranging from acceptable to very little or no credit risk. These loans typically meet most if not all policy standards in regard to: loan amount as a percentage of collateral value, debt service coverage, profitability, leverage, and working capital.
	•		Special Mention – This grade represents “Other Assets Especially Mentioned” in accordance with regulatory guidelines and includes loans that display some potential weaknesses which, if left unaddressed, may result in deterioration of the repayment prospects for the asset or may inadequately protect the Company’s position in the future. These loans warrant more than normal supervision and attention.
	•		Substandard – This grade represents “Substandard” loans in accordance with regulatory guidelines. Loans within this rating typically exhibit weaknesses that are well defined to the point that repayment is jeopardized. Loss potential is, however, not necessarily evident. The underlying collateral supporting the credit appears to have sufficient value to protect the Company from loss of principal and accrued interest, or the loan has been written down to the point where this is true. There is a definite need for a well defined workout/rehabilitation program.
	•		Doubtful – This grade represents “Doubtful” loans in accordance with regulatory guidelines. An asset classified as Doubtful has all the weaknesses inherent in a loan classified Substandard with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions and values, highly questionable and improbable. Pending factors include proposed merger, acquisition, or liquidation procedures, capital injection, perfecting liens on additional collateral, and financing plans.
	•		Loss – This grade represents “Loss” loans in accordance with regulatory guidelines. A loan classified as Loss is considered uncollectible and of such little value that its continuance as a bankable asset is not warranted. This classification does not mean that the loan has absolutely no recovery or salvage value, but rather that it is not practical or desirable to defer writing off the loan, even though some recovery may be affected in the future. The portion of the loan that is graded loss should be charged off no later than the end of the quarter in which the loss is identified.
The following tables present ending loan balances by loan category and risk grade for the periods indicated:
		Credit Quality Indicators – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
Originated loans:
Pass		$	146,949		$	883,102		$	292,244		$	20,976		$	66		$	27,396		$	124,707		$	18,112		$	24,436		$	1,537,988
Special mention			1,122			11,521			3,590			743			11			591			636			622			—			18,836
Substandard			6,523			34,174			9,332			1,840			35			243			1,268			2,401			109			55,925
Loss			—			—			—			—			—			—			—			—			—			—
Total originated		$	154,594		$	928,797		$	305,166		$	23,559		$	112		$	28,230		$	126,611		$	21,135		$	24,545		$	1,612,749
PNCI loans:
Pass		$	119,643		$	359,537		$	36,531		$	6,813			—		$	4,399		$	40,628		$	16,808		$	11,973		$	596,332
Special mention			547			12,979			936			147			—			230			268			—			—			15,107
Substandard			631			3,709			930			25			—			141			3			—			—			5,439
Loss			—			—			—			—			—			—			—			—			—			—
Total PNCI		$	120,821		$	376,225		$	38,397		$	6,985			—		$	4,770		$	40,899		$	16,808		$	11,973		$	616,878
PCI loans		$	4,005		$	30,917		$	9,021		$	770			—		$	74		$	7,435		$	675			—		$	52,897
Total loans		$	279,420		$	1,335,939		$	352,584		$	31,314		$	112		$	33,074		$	174,945		$	38,618		$	36,518		$	2,282,524
					Credit Quality Indicators – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
Originated loans:
Pass		$	121,969		$	768,596		$	203,232		$	12,284		$	717		$	24,653		$	121,580		$	25,836		$	16,571		$	1,394,438
Special mention			1,265			15,862			4,529			504			118			756			938			96			343			24,411
Substandard			6,648			40,454			9,446			1,061			111			196			2,122			4,435			211			64,684
Loss			—			—			—			—			—			3			10			—			—			13
Total originated		$	129,882		$	824,912		$	316,207		$	13,849		$	946		$	25,608		$	124,650		$	30,367		$	17,125		$	1,483,546
PNCI loans:
Pass		$	59,798		$	48,548		$	12,716		$	253			—		$	2,020		$	380			—			—		$	123,715
Special mention			—			5,810			195			—			—			18			313			—			—			6,336
Substandard			677			3,320			665			—			—			36			—			—			—			4,698
Loss			—			—			—			—			—			—			—			—			—			—
Total PNCI		$	60,475		$	57,678		$	13,576		$	253			—		$	2,074		$	693			—			—		$	134,749
PCI loans		$	4,656		$	30,260		$	10,083		$	486			—		$	81		$	6,535		$	1,566		$	45		$	53,712
Total loans		$	195,013		$	912,850		$	339,866		$	14,588		$	946		$	27,763		$	131,878		$	31,933		$	17,170		$	1,672,007
Consumer loans, whether unsecured or secured by real estate, automobiles, or other personal property, are susceptible to three primary risks; non-payment due to income loss, over-extension of credit and, when the borrower is unable to pay, shortfall in collateral value. Typically non-payment is due to loss of job and will follow general economic trends in the marketplace driven primarily by rises in the unemployment rate. Loss of collateral value can be due to market demand shifts, damage to collateral itself or a combination of the two.
Problem consumer loans are generally identified by payment history of the borrower (delinquency). The Bank manages its consumer loan portfolios by monitoring delinquency and contacting borrowers to encourage repayment, suggest modifications if appropriate, and, when continued scheduled payments become unrealistic, initiate repossession or foreclosure through appropriate channels. Collateral values may be determined by appraisals obtained through Bank approved, licensed appraisers, qualified independent third parties, public value information (blue book values for autos), sales invoices, or other appropriate means. Appropriate valuations are obtained at initiation of the credit and periodically (every 3-12 months depending on collateral type) once repayment is questionable and the loan has been classified.
Commercial real estate loans generally fall into two categories, owner-occupied and non-owner occupied. Loans secured by owner occupied real estate are primarily susceptible to changes in the business conditions of the related business. This may be driven by, among other things, industry changes, geographic business changes, changes in the individual fortunes of the business owner, and general economic conditions and changes in business cycles. These same risks apply to commercial loans whether secured by equipment or other personal property or unsecured. Losses on loans secured by owner occupied real estate, equipment, or other personal property generally are dictated by the value of underlying collateral at the time of default and liquidation of the collateral. When default is driven by issues related specifically to the business owner, collateral values tend to provide better repayment support and may result in little or no loss. Alternatively, when default is driven by more general economic conditions, underlying collateral generally has devalued more and results in larger losses due to default. Loans secured by non-owner occupied real estate are primarily susceptible to risks associated with swings in occupancy or vacancy and related shifts in lease rates, rental rates or room rates. Most often these shifts are a result of changes in general economic or market conditions or overbuilding and resultant over-supply. Losses are dependent on value of underlying collateral at the time of default. Values are generally driven by these same factors and influenced by interest rates and required rates of return as well as changes in occupancy costs.
Construction loans, whether owner occupied or non-owner occupied commercial real estate loans or residential development loans, are not only susceptible to the related risks described above but the added risks of construction itself including cost over-runs, mismanagement of the project, or lack of demand or market changes experienced at time of completion. Again, losses are primarily related to underlying collateral value and changes therein as described above.
Problem C&I loans are generally identified by periodic review of financial information which may include financial statements, tax returns, rent rolls and payment history of the borrower (delinquency). Based on this information the Bank may decide to take any of several courses of action including demand for repayment, additional collateral or guarantors, and, when repayment becomes unlikely through borrower’s income and cash flow, repossession or foreclosure of the underlying collateral.
Collateral values may be determined by appraisals obtained through Bank approved, licensed appraisers, qualified independent third parties, public value information (blue book values for autos), sales invoices, or other appropriate means. Appropriate valuations are obtained at initiation of the credit and periodically (every 3-12 months depending on collateral type) once repayment is questionable and the loan has been classified.
Once a loan becomes delinquent and repayment becomes questionable, a Bank collection officer will address collateral shortfalls with the borrower and attempt to obtain additional collateral. If this is not forthcoming and payment in full is unlikely, the Bank will estimate its probable loss, using a recent valuation as appropriate to the underlying collateral less estimated costs of sale, and charge the loan down to the estimated net realizable amount. Depending on the length of time until ultimate collection, the Bank may revalue the underlying collateral and take additional charge-offs as warranted. Revaluations may occur as often as every 3-12 months depending on the underlying collateral and volatility of values. Final charge-offs or recoveries are taken when collateral is liquidated and actual loss is known. Unpaid balances on loans after or during collection and liquidation may also be pursued through lawsuit and attachment of wages or judgment liens on borrower’s other assets.
The following table shows the ending balance of current, past due, and nonaccrual originated loans by loan category as of the date indicated:
		Analysis of Past Due and Nonaccrual Originated Loans – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
Originated loan balance:
Past due:
30-59 Days		$	1,296		$	735		$	2,066		$	615		$	4		$	64		$	739			—			—		$	5,519
60-89 Days			919			—			296			192			—			24			99			—			—			1,530
> 90 Days			100			900			754			202			17			46			61			—			—			2,080
Total past due		$	2,315		$	1,635		$	3,116		$	1,009		$	21		$	134		$	899			—			—		$	9,129
Current			152,279			927,162			302,050			22,550			91			28,096			125,712			21,135			24,545			1,603,620
Total orig. loans		$	154,594		$	928,797		$	305,166		$	23,559		$	112		$	28,230		$	126,611		$	21,135		$	24,545		$	1,612,749
> 90 Days and still accruing			—			—			—			—			—			—			—			—			—			—
Nonaccrual loans		$	3,430		$	20,736		$	4,336		$	1,197		$	18		$	66		$	246		$	2,401		$	99		$	32,529
The following table shows the ending balance of current, past due, and nonaccrual PNCI loans by loan category as of the date indicated:
		Analysis of Past Due and Nonaccrual PNCI Loans – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
PNCI loan balance:
Past due:
30-59 Days		$	2,041		$	260		$	275			—			—		$	25		$	67			—			—		$	2,668
60-89 Days			24			—			118			—			—			3			—			—			—			145
> 90 Days			239			—			73			25			—			76			—			—			—			413
Total past due		$	2,304		$	260		$	466		$	25			—		$	104		$	67			—			—		$	3,226
Current			118,517			375,965			37,931			6,960			—			4,666			40,832			16,808			11,973		$	613,652
Total PNCI loans		$	120,821		$	376,225		$	38,397		$	6,985			—		$	4,770		$	40,899		$	16,808		$	11,973		$	616,878
> 90 Days and still accruing			—			—			—			—			—			—			—			—			—			—
Nonaccrual loans		$	799		$	366		$	346		$	25			—		$	110			—			—			—		$	1,646
The following table shows the ending balance of current, past due, and nonaccrual originated loans by loan category as of the date indicated:
		Analysis of Past Due and Nonaccrual Originated Loans – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
Originated loan balance:
Past due:
30-59 Days		$	2,272		$	2,304		$	3,121		$	264		$	24		$	40		$	296			—			—		$	8,321
60-89 Days			284			—			1,070			16			1			16			76			—		$	198			1,661
> 90 Days			447			2,213			1,050			312			33			7			749			13			—			4,824
Total past due		$	3,003		$	4,517		$	5,241		$	592		$	58		$	63		$	1,121		$	13		$	198		$	14,806
Current			126,879			820,395			310,966			13,257			888			25,545			123,529			30,354			16,927			1,468,740
Total orig. loans		$	129,882		$	824,912		$	316,207		$	13,849		$	946			25,608		$	124,650		$	30,367		$	17,125		$	1,483,546
> 90 Days and still accruing			—			—			—			—			—			—			—			—			—			—
Nonaccrual loans		$	4,697		$	30,732		$	4,972		$	719		$	54		$	26		$	1,280		$	2,473		$	178		$	45,131
The following table shows the ending balance of current, past due, and nonaccrual PNCI loans by loan category as of the date indicated:
		Analysis of Past Due and Nonaccrual PNCI Loans – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
PNCI loan balance:
Past due:
30-59 Days		$	799		$	512		$	313			—			—		$	49			—			—			—		$	1,673
60-89 Days			—			352			38			—			—			—			—			—			—			390
> 90 Days			—			217			—			—			—			—			—			—			—			217
Total past due		$	799		$	1,081		$	351			—			—		$	49			—			—			—		$	2,280
Current			59,676			56,597			13,225		$	253			—			2,025		$	693			—			—			132,469
Total PNCI loans		$	60,475		$	57,678		$	13,576		$	253			—		$	2,074		$	693			—			—		$	134,749
> 90 Days and still accruing			—			—			—			—			—			—			—			—			—			—
Nonaccrual loans		$	262		$	1,139		$	429			—			—		$	36			—			—			—		$	1,866
Impaired originated loans are those where management has concluded that it is probable that the borrower will be unable to pay all amounts due under the contractual terms. The following tables show the recorded investment (financial statement balance), unpaid principal balance, average recorded investment, and interest income recognized for impaired Originated and PNCI loans, segregated by those with no related allowance recorded and those with an allowance recorded for the periods indicated.
		Impaired Originated Loans – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
With no related allowance recorded:
Recorded investment		$	3,287		$	38,477		$	3,001		$	750		$	14		$	25		$	412		$	2,401		$	99		$	48,466
Unpaid principal		$	5,138		$	41,949		$	6,094		$	1,187		$	49		$	32		$	433		$	6,588		$	190		$	61,660
Average recorded Investment		$	3,826		$	45,915		$	3,355		$	651		$	35		$	21		$	1,030		$	2,437		$	84		$	57,354
Interest income Recognized		$	38		$	995		$	26		$	6			—		$	1		$	26			—		$	3		$	1,095
With an allowance recorded:
Recorded investment		$	2,724		$	2,943		$	3,185		$	504		$	4		$	41		$	1,338		$	282			—		$	11,021
Unpaid principal		$	2,865		$	3,101		$	3,533		$	597		$	6		$	41		$	1,438		$	282			—		$	11,863
Related allowance		$	797		$	302		$	1,769		$	284			—		$	11		$	423		$	60			—		$	3,646
Average recorded Investment		$	2,677		$	4,119		$	2,982		$	365		$	4		$	25		$	1,428		$	283		$	55		$	11,938
Interest income Recognized		$	91		$	144		$	71		$	13			—			—		$	71		$	19			—		$	409
		Impaired PNCI Loans – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
With no related allowance recorded:
Recorded investment		$	343		$	366		$	346		$	25			—		$	37		$	7			—			—		$	1,124
Unpaid principal		$	353		$	2,620		$	374		$	25			—		$	54		$	7			—			—		$	3,433
Average recorded Investment		$	246		$	753		$	287		$	12			—		$	36		$	10			—			—		$	1,344
Interest income Recognized		$	14			—		$	(1	)		—			—			—		$	1			—			—		$	14
With an allowance recorded:
Recorded investment		$	834		$	146		$	436			—			—		$	220			—			—			—		$	1,636
Unpaid principal		$	852		$	146		$	436			—			—		$	220			—			—			—		$	1,654
Related allowance		$	177		$	108		$	205			—			—		$	131			—			—			—		$	621
Average recorded Investment		$	516		$	148		$	319			—			—		$	124			—			—			—		$	1,107
Interest income Recognized		$	8		$	8		$	20			—			—		$	12			—			—			—		$	48
		Impaired Originated Loans – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
With no related allowance recorded:
Recorded investment		$	4,366		$	53,352		$	3,710		$	552		$	55		$	16		$	1,648		$	2,473		$	69		$	66,241
Unpaid principal		$	6,489		$	58,894		$	7,299		$	1,249		$	123		$	21		$	1,665		$	6,611		$	138		$	82,489
Average recorded Investment		$	4,123		$	58,205		$	4,410		$	463		$	93		$	18		$	2,154		$	1,567		$	83		$	71,116
Interest income Recognized		$	336		$	3,361		$	352		$	36		$	12		$	1		$	113		$	108		$	7		$	4,326
With an allowance recorded:
Recorded investment		$	2,630		$	5,296		$	2,779		$	226		$	4		$	10		$	1,517		$	284		$	109		$	12,855
Unpaid principal		$	2,689		$	5,659		$	3,053		$	291		$	6		$	10		$	1,616		$	284		$	288		$	13,896
Related allowance Average recorded		$	648		$	1,084		$	968		$	169		$	1		$	5		$	585		$	91		$	7		$	3,558
Investment		$	2,245		$	6,077		$	3,064		$	141		$	12		$	7		$	1,817		$	1,499		$	188		$	15,050
Interest income Recognized		$	124		$	287		$	146		$	18		$	1		$	2		$	95		$	19		$	15		$	707
		Impaired PNCI Loans – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
With no related allowance recorded:
Recorded investment		$	148		$	1,139		$	227			—			—		$	36		$	12			—			—		$	1,562
Unpaid principal		$	158		$	3,323		$	287			—			—		$	45		$	12			—			—		$	3,825
Average recorded Investment		$	37		$	1,005		$	333			—			—		$	39		$	7			—			—		$	1,421
Interest income Recognized		$	11		$	233		$	21			—			—		$	5		$	1			—			—		$	271
With an allowance recorded:
Recorded investment		$	198		$	149		$	203			—			—		$	28			—			—			—		$	578
Unpaid principal		$	207		$	149		$	215			—			—		$	28			—			—			—		$	599
Related allowance		$	128		$	114		$	172			—			—		$	3			—			—			—		$	417
Average recorded Investment		$	275		$	250		$	162			—			—		$	29			—			—			—		$	716
Interest income Recognized		$	12		$	9		$	10			—			—		$	1			—			—			—		$	32
		Impaired Originated Loans – As of December 31, 2012
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
With no related allowance recorded:
Recorded investment		$	3,520		$	66,031		$	4,241		$	361		$	163		$	19		$	4,238		$	3,554		$	284		$	82,411
Unpaid principal		$	5,349		$	70,709		$	6,691		$	781		$	311		$	40		$	4,613		$	8,227		$	484		$	97,205
Average recorded Investment		$	6,329		$	61,299		$	4,311		$	329		$	263		$	42		$	7,500		$	3,505		$	517		$	84,095
Interest income Recognized		$	71		$	2,513		$	58		$	1		$	3			—		$	73		$	20		$	10		$	2,749
With an allowance recorded:
Recorded investment		$	2,867		$	3,258		$	5,412		$	167		$	34		$	30		$	4,324		$	42		$	323		$	16,457
Unpaid principal		$	3,432		$	3,556		$	7,103		$	396		$	51		$	32		$	4,992		$	42		$	523		$	20,127
Related allowance		$	603		$	352		$	2,237		$	81		$	5		$	12		$	840		$	11		$	111		$	4,252
Average recorded Investment		$	3,890		$	7,841		$	6,331		$	317		$	102		$	49		$	2,800		$	1,543		$	6,570		$	29,443
Interest income Recognized		$	67		$	129		$	103		$	16		$	1		$	1		$	100		$	6		$	5		$	428
		Impaired PNCI Loans – As of December 31, 2012
		RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
With no related allowance recorded:
Recorded investment			—		$	1,468		$	365			—			—			—			—			—			—		$	1,833
Unpaid principal			—		$	3,452		$	586			—			—			—			—			—			—		$	4,038
Average recorded Investment		$	16		$	2,097		$	308		$	11			—		$	31		$	11			—			—		$	2,474
Interest income Recognized			—		$	133		$	5			—			—			—			—			—			—		$	138
With an allowance recorded:
Recorded investment		$	199		$	320		$	38			—			—		$	72			—			—			—		$	629
Unpaid principal		$	225		$	331		$	41			—			—		$	76			—			—			—		$	673
Related allowance		$	28		$	163		$	27			—			—		$	35			—			—			—		$	253
Average recorded Investment		$	213		$	121		$	148			—			—		$	43			—			—			—		$	525
Interest income Recognized		$	9		$	12		$	1			—			—		$	2			—			—			—		$	24
At December 31, 2014, $45,676,000 of Originated loans were TDRs and classified as impaired. The Company had obligations to lend $54,000 of additional funds on these TDRs as of December 31, 2014. At December 31, 2014, $1,307,000 of PNCI loans were TDRs and classified as impaired. The Company had no obligations to lend additional funds on these TDRs as of December 31, 2014.
At December 31, 2013, $56,739,000 of Originated loans were TDRs and classified as impaired. The Company had obligations to lend $25,000 of additional funds on these TDRs as of December 31, 2013. At December 31, 2013, $901,000 of PNCI loans were TDRs and classified as impaired. The Company had no obligations to lend additional funds on these TDRs as of December 31, 2013.
At December 31, 2012, $57,223,000 of Originated loans were TDRs and classified as impaired. The Company had obligations to lend $137,000 of additional funds on these TDRs as of December 31, 2012. At December 31, 2012, $950,000 of PNCI loans were TDRs and classified as impaired. The Company had no obligations to lend additional funds on these TDRs as of December 31, 2012.
The following tables show certain information regarding Troubled Debt Restructurings (TDRs) that occurred during the periods indicated:
		TDR Information for the Year Ended December 31, 2014
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
(dollars in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
Number			5			7			6			2			—			1			7			1			2			31
Pre-mod outstanding principal balance		$	1,048		$	1,980		$	940		$	100			—		$	147		$	218		$	102		$	219		$	4,754
Post-mod outstanding principal balance		$	1,050		$	1,890		$	967		$	102			—		$	147		$	219		$	85		$	196		$	4,656
Financial impact due to TDR taken as additional provision		$	91		$	22			—		$	(1	)		—		$	66		$	101			—			—		$	279
Number that defaulted during the period			2			2			1			—			—			—			1			—			—			6
Recorded investment of TDRs that defaulted during the period		$	344		$	423		$	20			—			—			—		$	116			—			—		$	903
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions			—			—			—			—			—			—		$	(8	)		—			—		$	(8	)
		TDR Information for the Year Ended December 31, 2013
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
(dollars in thousands)		Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
Number			9			11			12			2			—			—			8			—			—			42
Pre-mod outstanding principal balance		$	2,173		$	13,145		$	1,546		$	251			—			—		$	274			—			—		$	17,389
Post-mod outstanding principal balance		$	2,177		$	13,146		$	1,557		$	253			—			—		$	275			—			—		$	17,408
Financial impact due to TDR taken as additional provision		$	148		$	27		$	340		$	(1	)		—			—		$	88			—			—		$	602
Number that defaulted during the period			4			8			3			1			—			—			4			1			—			21
Recorded investment of TDRs that defaulted during the period		$	443		$	1,702		$	150		$	15			—			—		$	1,363		$	73			—		$	3,746
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions		$	(3	)	$	7			—			—			—			—		$	3		$	5			—		$	12
Modifications classified as Troubled Debt Restructurings can include one or a combination of the following: rate modifications, term extensions, interest only modifications, either temporary or long-term, payment modifications, and collateral substitutions/additions.
For all new Troubled Debt Restructurings, an impairment analysis is conducted. If the loan is determined to be collateral dependent, any additional amount of impairment will be calculated based on the difference between estimated collectible value and the current carrying balance of the loan. This difference could result in an increased provision and is typically charged off. If the asset is determined not to be collateral dependent, the impairment is measured on the net present value difference between the expected cash flows of the restructured loan and the cash flows which would have been received under the original terms. The effect of this could result in a requirement for additional provision to the reserve. The effect of these required provisions for the period are indicated above.
Typically if a TDR defaults during the period, the loan is then considered collateral dependent and, if it was not already considered collateral dependent, an appropriate provision will be reserved or charge will be taken. The additional provisions required resulting from default of previously modified TDR’s are noted above.

Foreclosed_Assets

Foreclosed Assets	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Foreclosed Assets	Note 6 – Foreclosed Assets
	A summary of the activity in the balance of foreclosed assets follows (dollars in thousands):
		Year ended December 31, 2014									Year ended December 31, 2013
		Noncovered			Covered			Total			Noncovered			Covered			Total
	Beginning balance, net	$	5,588		$	674		$	6,262		$	5,957		$	1,541		$	7,498
	Acquisitions		695			—			695			—			—			—
	Additions/transfers from loans		5,753			—			5,753			11,224			493			11,717
	Dispositions/sales		(7,391	)		(217	)		(7,608	)		(10,992	)		(1,279	)		(12,271	)
	Valuation adjustments		(196	)		(12	)		(208	)		(601	)		(81	)		(682	)
	Ending balance, net	$	4,449		$	445		$	4,894		$	5,588		$	674		$	6,262
	Ending valuation allowance	$	(208	)		—		$	(208	)	$	(414	)		—		$	(414	)
	Ending number of foreclosed assets		28			1			29			28			4			32
	Proceeds from sale of foreclosed assets	$	9,517		$	245		$	9,762		$	12,483		$	1,427		$	13,910
	Gain on sale of foreclosed assets	$	2,125		$	28		$	2,153		$	1,492		$	148		$	1,640

Premises_and_Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Premises and Equipment	Note 7 - Premises and Equipment
	Premises and equipment were comprised of:
		December 31,			December 31,
		2014			2013
		(In thousands)
	Land & land improvements	$	8,933		$	5,975
	Buildings		39,638			30,103
	Furniture and equipment		28,446			27,881
			77,017			63,959
	Less: Accumulated depreciation		(33,570	)		(32,397	)
			43,447			31,562
	Construction in progress		46			50
	Total premises and equipment	$	43,493		$	31,612
	Depreciation expense for premises and equipment amounted to $4,648,000, $3,635,000, and $3,250,000 in 2014, 2013, and 2012, respectively.

Cash_Value_of_Life_Insurance

Cash Value of Life Insurance	12 Months Ended
	Dec. 31, 2014
Investments, All Other Investments [Abstract]
Cash Value of Life Insurance	Note 8 – Cash Value of Life Insurance
	A summary of the activity in the balance of cash value of life insurance follows (dollars in thousands):
		Year ended December 31,
		2014		2013
	Beginning balance	$	52,309	$	50,582
	Acquisitions		38,075		—
	Increase in cash value of life insurance		1,953		1,727
	Ending balance	$	92,337	$	52,309
	End of period death benefit	$	165,966	$	95,513
	Number of policies owned		189		133
	Insurance companies used		14		6
	Current and former employees and directors covered		60		36
	As of December 31, 2014, the Bank was the owner and beneficiary of 189 life insurance policies, issued by 14 life insurance companies, covering 60 current and former employees and directors. These life insurance policies are recorded on the Company’s financial statements at their reported cash (surrender) values. As a result of current tax law and the nature of these policies, the Bank records any increase in cash value of these policies as nontaxable noninterest income. If the Bank decided to surrender any of the policies prior to the death of the insured, such surrender may result in a tax expense related to the life-to-date cumulative increase in cash value of the policy. If the Bank retains such policies until the death of the insured, the Bank would receive nontaxable proceeds from the insurance company equal to the death benefit of the policies. The Bank has entered into Joint Beneficiary Agreements (JBAs) with certain of the insured that for certain of the policies provide some level of sharing of the death benefit, less the cash surrender value, among the Bank and the beneficiaries of the insured upon the receipt of death benefits. See Note 15 of these consolidated financial statements for additional information on JBAs.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Note 9 - Goodwill and Other Intangible Assets
	The following table summarizes the Company’s goodwill intangible as of the dates indicated:
	(Dollar in Thousands)	December 31,			Additions		Reductions			December 31,
		2014								2013
	Goodwill	$	63,462		$	47,943		—		$	15,519
	The following table summarizes the Company’s core deposit intangibles as of the dates indicated:
	(Dollar in Thousands)	December 31,			Additions		Reductions/			Fully		December 31,
		2014					Amortization			Depreciated		2013
	Core deposit intangibles	$	8,074		$	6,614		—			—	$	1,460
	Accumulated amortization		(1,023	)		—	$	(446	)		—		(577	)
	Core deposit intangibles, net	$	7,051		$	6,614	$	(446	)		—	$	883
	The Company recorded additions to CDI of $6,614,000 in conjunction with the North Valley Bancorp acquisition on October 3, 2014, $898,000 in conjunction with the Citizens acquisition on September 23, 2011, and $562,000 in conjunction with the Granite acquisition on May 28, 2010. The following table summarizes the Company’s estimated core deposit intangible amortization (dollars in thousands):
	Years Ended	Estimated Core Deposit
		Intangible Amortization
	2015	$	1,157
	2016		1,157
	2017		1,109
	2018		1,044
	2019		948
	Thereafter	$	1,636

Mortgage_Servicing_Rights

Mortgage Servicing Rights	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Mortgage Servicing Rights	Note 10 - Mortgage Servicing Rights
	The following tables summarize the activity in, and the main assumptions we used to determine the fair value of mortgage servicing rights for the periods indicated (dollars in thousands):
		Years ended December 31,
		2014			2013			2012
	Balance at beginning of period	$	6,165		$	4,552		$	4,603
	Acquisition		1,944			—			—
	Originations		570			1,360			1,965
	Change in fair value		(1,301	)		253			(2,016	)
	Balance at end of period	$	7,378		$	6,165		$	4,552
	Contractually specified servicing fees, late fees and ancillary fees earned	$	1,869		$	1,774		$	1,666
	Balance of loans serviced at:
	Beginning of period	$	680,197		$	666,512		$	598,185
	End of period	$	840,288		$	680,197		$	666,512
	Weighted-average prepayment speed (CPR)		12	%		10.3	%		20.3	%
	Weighted-average discount rate		10	%		10	%		10	%
	The changes in fair value of MSRs that occurred during 2014 and 2013 were mainly due to changes in principal balances and changes in estimate life of the MSRs.

Indemnification_Asset

Indemnification Asset	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Indemnification Asset	Note 11 - Indemnification Asset
	A summary of the activity in the balance of indemnification asset (liability) included in other assets is follows (in thousands):
		Year ended December 31,
		2014			2013			2012
	Beginning balance	$	206		$	1,997		$	4,405
	Effect of actual covered losses (recoveries) and increase (decrease) in estimated future covered losses		(869	)		(1,419	)		(245	)
	Reimbursable (revenue) expenses incurred		69			(159	)		69
	Payments made (received)		245			(213	)		(2,232	)
	Ending balance	$	(349	)	$	206		$	1,997

Other_Assets

Other Assets	12 Months Ended
	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	Note 12 – Other Assets
	Other assets were comprised of (in thousands):
		As of December 31,
		2014		2013
	Deferred tax asset, net (Note 22)	$	37,706	$	26,781
	Prepaid expense		2,034		2,131
	Software		1,327		1,318
	Advanced compensation		908		1,175
	Capital Trusts		1,690		1,238
	Miscellaneous other assets		8,070		3,443
	Total other assets	$	51,735	$	36,086

Deposits

Deposits	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Deposits	Note 13 - Deposits
	A summary of the balances of deposits follows (in thousands):
		December 31,
		2014		2013
	Noninterest-bearing demand	$	1,083,900	$	789,458
	Interest-bearing demand		782,385		533,351
	Savings		1,156,126		798,986
	Time certificates, $250,000 and over		38,217		31,542
	Other time certificates		319,795		257,146
	Total deposits	$	3,380,423	$	2,410,483
	Certificate of deposit balances of $5,000,000 and $5,000,000 from the State of California were included in time certificates, $250,000 and over, at December 31, 2014 and 2013, respectively. The Bank participates in a deposit program offered by the State of California whereby the State may make deposits at the Bank’s request subject to collateral and credit worthiness constraints. The negotiated rates on these State deposits are generally more favorable than other wholesale funding sources available to the Bank. Overdrawn deposit balances of $1,216,000 and $1,212,000 were classified as consumer loans at December 31, 2014 and 2013, respectively.
	At December 31, 2014, the scheduled maturities of time deposits were as follows (in thousands):
		Scheduled
		Maturities
	2015	$	282,629
	2016		46,606
	2017		17,017
	2018		6,241
	2019		5,516
	Thereafter		3
	Total	$	358,012

Reserve_for_Unfunded_Commitmen

Reserve for Unfunded Commitments	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Reserve for Unfunded Commitments	Note 14 – Reserve for Unfunded Commitments
	The following tables summarize the activity in reserve for unfunded commitments for the periods indicated (dollars in thousands):
		Years ended December 31,
		2014			2013			2012
	Balance at beginning of period	$	2,415		$	3,615		$	2,740
	Acquisitions		125			—			—
	Provision for losses – Unfunded commitments		(395	)		(1,200	)		875
	Balance at end of period	$	2,145		$	2,415		$	3,615

Other_Liabilities

Other Liabilities	12 Months Ended
	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Other Liabilities	Note 15 – Other Liabilities
	Other liabilities were comprised of (in thousands):
		December 31,
		2014		2013
	Deferred compensation	$	7,408	$	7,357
	Pension liability		26,798		14,634
	Joint beneficiary agreements		2,728		2,623
	Miscellaneous other liabilities		12,258		7,097
	Total other liabilities	$	49,192	$	31,711

Other_Borrowings

Other Borrowings	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Other Borrowings	Note 16 - Other Borrowings
	A summary of the balances of other borrowings follows:
		December 31,
		2014		2013
		(in thousands)
	Other collateralized borrowings, fixed rate, as of December 31, 2014 of 0.05%, payable on January 2, 2014	$	9,276	$	6,335
	Total other borrowings	$	9,276	$	6,335
	The Company did not enter into any other borrowings or repurchase agreements during 2014 or 2013.
	The Company had $9,276,000 and $6,335,000 of other collateralized borrowings at December 31, 2014 and 2013, respectively. Other collateralized borrowings are generally overnight maturity borrowings from non-financial institutions that are collateralized by securities owned by the Company. As of December 31, 2014, the Company has pledged as collateral and sold under agreements to repurchase investment securities with fair value of $29,298,000 under these other collateralized borrowings.
	The Company maintains a collateralized line of credit with the Federal Home Loan Bank of San Francisco. Based on the FHLB stock requirements at December 31, 2014, this line provided for maximum borrowings of $865,466,000 of which none was outstanding, leaving $865,466,000 available. As of December 31, 2014, the Company had designated investment securities with a fair value of $108,917,000 and loans totaling $1,217,944,000 as potential collateral under this collateralized line of credit with the FHLB.
	The Company maintains a collateralized line of credit with the Federal Reserve Bank of San Francisco. As of December 31, 2014, this line provided for maximum borrowings of $138,545,000 of which none was outstanding, leaving $138,545,000 available. As of December 31, 2014, the Company has designated investment securities with fair value of $451,000 and loans totaling $200,282,000 as potential collateral under this collateralized line of credit with the FRB.
	The Company has available unused correspondent banking lines of credit from commercial banks totaling $15,000,000 for federal funds transactions at December 31, 2014.

Junior_Subordinated_Debt

Junior Subordinated Debt	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Junior Subordinated Debt	Note 17 – Junior Subordinated Debt
	On July 31, 2003, the Company formed a subsidiary business trust, TriCo Capital Trust I, to issue trust preferred securities. Concurrently with the issuance of the trust preferred securities, the trust issued 619 shares of common stock to the Company for $1,000 per share or an aggregate of $619,000. In addition, the Company issued a junior subordinated debenture to the trust in the amount of $20,619,000. The terms of the junior subordinated debenture are materially consistent with the terms of the trust preferred securities issued by TriCo Capital Trust I. Also on July 31, 2003, TriCo Capital Trust I completed an offering of 20,000 shares of cumulative trust preferred securities for cash in an aggregate amount of $20,000,000. The trust preferred securities are mandatorily redeemable upon maturity on October 7, 2033 with an interest rate that resets quarterly at three-month LIBOR plus 3.05%. TriCo Capital Trust I has the right to redeem the trust preferred securities on or after October 7, 2008. The trust preferred securities were issued through an underwriting syndicate to which the Company paid underwriting fees of $7.50 per trust preferred security or an aggregate of $150,000. The net proceeds of $19,850,000 were used to finance the opening of new branches, improve bank services and technology, repurchase shares of the Company’s common stock under its repurchase plan and increase the Company’s capital.
	On June 22, 2004, the Company formed a second subsidiary business trust, TriCo Capital Trust II, to issue trust preferred securities. Concurrently with the issuance of the trust preferred securities, the trust issued 619 shares of common stock to the Company for $1,000 per share or an aggregate of $619,000. In addition, the Company issued a junior subordinated debenture to the trust in the amount of $20,619,000. The terms of the junior subordinated debenture are materially consistent with the terms of the trust preferred securities issued by TriCo Capital Trust II. Also on June 22, 2004, TriCo Capital Trust II completed an offering of 20,000 shares of cumulative trust preferred securities for cash in an aggregate amount of $20,000,000. The trust preferred securities are mandatorily redeemable upon maturity on July 23, 2034 with an interest rate that resets quarterly at three-month LIBOR plus 2.55%. TriCo Capital Trust II has the right to redeem the trust preferred securities on or after July 23, 2009. The trust preferred securities were issued through an underwriting syndicate to which the Company paid underwriting fees of $2.50 per trust preferred security or an aggregate of $50,000. The net proceeds of $19,950,000 were used to finance the opening of new branches, improve bank services and technology, repurchase shares of the Company’s common stock under its repurchase plan and increase the Company’s capital.
	As a result of the Company’s acquisition of North Valley Bancorp on October 3, 2014, the Company assumed the junior subordinated debentures issued by North Valley Bancorp to North Valley Capital Trusts II, III & IV with face amounts of $6,186,000, $5,155,000 and $10,310,000, respectively. Also, as a result of the North Valley Bancorp acquisition, the Company acquired common stock interests in North Valley Capital Trusts II, III and IV with face valley of $186,000, $155,000, and $310,000, respectively. At the acquisition date of October 3, 2014, the junior subordinated debentures associated with North Valley Capital Trust II, III and IV were recorded on the Company’s books at their fair values of $5,006,000, $3,918,000, and $6,063,000, respectively. The related fair value discounts to face value of these debentures will be amortized over the remaining time to maturity for each of these debentures using the effective interest method. Similar, and proportional, discounts were applied to the acquired common stock interest in North Valley Capital Trusts II, III and IV, and these discounts will be proportionally amortized over the remaining time to maturity for each related debenture.
	TriCo Capital Trusts I and II, and North Valley Capital Trusts II, III and IV are collectively referred to as the Capital Trusts. The recorded book values of the junior subordinated debentures issued by the Capital Trusts are reflected as junior subordinated debt in the Company’s consolidated balance sheets. The common stock issued by the Capital Trusts and owned by the Company is recorded in other assets in the Company’s consolidated balance sheets. The recorded book value of the debentures issued by the Capital Trusts, less the recorded book value of the common stock of the Capital Trusts owned by the Company, continues to qualify as Tier 1 or Tier 2 capital under interim guidance issued by the Board of Governors of the Federal Reserve System.
	The following table summarizes the terms and recorded balance of each subordinated debenture as of the date indicated (dollars in thousands):
	Subordinated	Maturity		Face		Coupon Rate			As of December 31, 2014
	Debt Series	Date		Value		(Variable)
						3 mo. LIBOR +			Current			Recorded
									Coupon Rate			Book Value
	TriCo Cap Trust I		10/7/33	$	20,619		3.05	%		3.28	%	$	20,619
	TriCo Cap Trust II		7/23/34		20,619		2.55	%		2.78	%		20,619
	North Valley Trust II		4/24/33		6,186		3.25	%		3.48	%		5,015
	North Valley Trust III		4/24/34		5,155		2.8	%		3.03	%		3,927
	North Valley Trust IV		3/15/36		10,310		1.33	%		1.57	%		6,092
				$	62,889							$	56,272

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 18 - Commitments and Contingencies
	Restricted Cash Balances— Reserves (in the form of deposits with the San Francisco Federal Reserve Bank) of $57,616,000 and $38,359,000 were maintained to satisfy Federal regulatory requirements at December 31, 2014 and 2013. These reserves are included in cash and due from banks in the accompanying consolidated balance sheets.
	Lease Commitments— The Company leases 53 sites under non-cancelable operating leases. The leases contain various provisions for increases in rental rates, based either on changes in the published Consumer Price Index or a predetermined escalation schedule. Substantially all of the leases provide the Company with the option to extend the lease term one or more times following expiration of the initial term. The Company currently does not have any capital leases.
	At December 31, 2014, future minimum commitments under non-cancelable operating leases with initial or remaining terms of one year or more are as follows:
		Operating
		Leases
		(in thousands)
	2015	$	3,419
	2016		2,510
	2017		1,856
	2018		1,323
	2019		859
	Thereafter		1,180
	Future minimum lease payments	$	11,147
	Rent expense under operating leases was $4,786,000 in 2014, $4,300,000 in 2013, and $4,332,000 in 2012. Rent expense was offset by rent income of $225,000 in 2014, $216,000 in 2013, and $138,000 in 2012.
	Financial Instruments with Off-Balance-Sheet Risk— The Company is a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit, standby letters of credit, and deposit account overdraft privilege. Those instruments involve, to varying degrees, elements of risk in excess of the amount recognized in the balance sheet. The contract amounts of those instruments reflect the extent of involvement the Company has in particular classes of financial instruments.
	The Company’s exposure to loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit and standby letters of credit written is represented by the contractual amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. The Company’s exposure to loss in the event of nonperformance by the other party to the financial instrument for deposit account overdraft privilege is represented by the overdraft privilege amount disclosed to the deposit account holder.
	The following table presents a summary of the Bank’s commitments and contingent liabilities:
	(in thousands)	December 31,		December 31,
		2014		2013
	Financial instruments whose amounts represent risk:
	Commitments to extend credit:
	Commercial loans	$	177,557	$	136,986
	Consumer loans		392,705		360,194
	Real estate mortgage loans		36,139		35,309
	Real estate construction loans		49,774		22,897
	Standby letters of credit		17,531		2,601
	Deposit account overdraft privilege		101,060		68,932
	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 of one year or less or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Company evaluates each customer’s credit worthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Company upon extension of credit, is based on Management’s credit evaluation of the customer. Collateral held varies, but may include accounts receivable, inventory, property, plant and equipment, residential properties, and income-producing commercial properties.
	Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. Those guarantees are primarily issued to support private borrowing arrangements. Most standby letters of credit are issued for one year or less. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. Collateral requirements vary, but in general follow the requirements for other loan facilities.
	Deposit account overdraft privilege amount represents the unused overdraft privilege balance available to the Company’s deposit account holders who have deposit accounts covered by an overdraft privilege. The Company has established an overdraft privilege for certain of its deposit account products whereby all holders of such accounts who bring their accounts to a positive balance at least once every thirty days receive the overdraft privilege. The overdraft privilege allows depositors to overdraft their deposit account up to a predetermined level. The predetermined overdraft limit is set by the Company based on account type.
	Legal Proceedings— The Bank owns 13,396 shares of Class B common stock of Visa Inc. which are convertible into Class A common stock at a conversion ratio of 0.4121 per Class A share. As of December 31, 2014, the value of the Class A shares was $262.20 per share. Utilizing the conversion ratio, the value of unredeemed Class A equivalent shares owned by the Bank was $1,447,000 as of December 31, 2014, and has not been reflected in the accompanying financial statements. The shares of Visa Class B common stock are restricted and may not be transferred. Visa Member Banks are required to fund an escrow account to cover settlements, resolution of pending litigation and related claims. If the funds in the escrow account are insufficient to settle all the covered litigation, Visa may sell additional Class A shares, use the proceeds to settle litigation, and further reduce the conversion ratio. If funds remain in the escrow account after all litigation is settled, the Class B conversion ratio will be increased to reflect that surplus.
	On January 24, 2014, a putative shareholder class action lawsuit was filed against TriCo, North Valley Bancorp and certain other defendants in connection with TriCo entering into the merger agreement with North Valley Bancorp. The lawsuit, which was filed in the Shasta County, California Superior Court, alleges that the members of the North Valley Bancorp board of directors breached their fiduciary duties to North Valley Bancorp shareholders by approving the proposed merger for inadequate consideration; approving the transaction in order receive benefits not equally shared by other North Valley Bancorp shareholders; entering into the merger agreement containing preclusive deal protection devices; and failing to take steps to maximize the value to be paid to the North Valley Bancorp shareholders. The lawsuit alleges claims against TriCo for aiding and abetting these alleged breaches of fiduciary duties. The plaintiff seeks, among other things, declaratory and injunctive relief concerning the alleged breaches of fiduciary duties injunctive relief prohibiting consummation of the merger, rescission, attorneys’ of the merger agreement, fees and costs, and other and further relief. On July 31, 2014 the defendants entered into a memorandum of understanding with the plaintiffs regarding the settlement of this lawsuit. In connection with the settlement contemplated by the memorandum of understanding and in consideration for the full settlement and release of all claims, TriCo and North Valley Bancorp agreed to make certain additional disclosures related to the proposed merger, which are contained in a Current Report on Form 8-K filed by each of the companies. The memorandum of understanding contemplates that the parties will negotiate in good faith and use their reasonable best efforts to enter into a stipulation of settlement. The stipulation of settlement will be subject to customary conditions, including court approval following notice to North Valley Bancorp’s shareholders. In the event that the parties enter into a stipulation of settlement, a hearing will be scheduled at which the court will consider the settlement. There can be no assurance that the parties will ultimately enter into a stipulation of settlement or that the court will approve the settlement even if the parties were to enter into such stipulation. In such event, the proposed settlement as contemplated by the memorandum of understanding may be terminated.
	On September 15, 2014, a former Personal Banker at one of the Bank’s in-store branches filed a Class Action Complaint against the Bank in Butte County Superior Court, alleging causes of action related to the observance of meal periods. Plaintiff seeks to represent a class of “current and former hourly-paid or non-exempt ‘personal bankers’, or employees with the same or similar job duties, employed by Defendants within the State of California during the preceding four years.” The Bank filed an Answer to the Complaint on November 6, 2014, denies the charges, and the Bank intends to vigorously defend the lawsuit against class certification and liability.
	On January 20, 2015, a current Personal Banker at one of the Bank’s in-store branches filed a First Amended Complaint against Tri Counties Bank and TriCo Bancshares, dba Tri Counties Bank, in Sacramento County Superior Court, alleging causes of action related to wage statement violations. Plaintiff seeks to represent a class of current and former exempt and non-exempt employees who worked for the Bank “during the time period beginning October 18, 2013 through the date of the filing of this action”. The Company and the Bank have not yet responded to the First Amended Complaint, deny the charges, and intend to vigorously defend the lawsuit against class certification and liability.
	Neither the Company nor its subsidiaries, are party to any other material pending legal proceeding, nor is their property the subject of any material pending legal proceeding, except routine legal proceedings arising in the ordinary course of their business. None of these proceedings is expected to have a material adverse impact upon the Company’s business, consolidated financial position or results of operations.
	Other Commitments and Contingencies—The Company has entered into employment agreements or change of control agreements with certain officers of the Company providing severance payments and accelerated vesting of benefits under supplemental retirement agreements to the officers in the event of a change in control of the Company and termination for other than cause or after a substantial and material change in the officer’s title, compensation or responsibilities.
	Mortgage loans sold to investors may be sold with servicing rights retained, with only the standard legal representations and warranties regarding recourse to the Bank. Management believes that any liabilities that may result from such recourse provisions are not significant.

Shareholders_Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Shareholders' Equity	Note 19 – Shareholders’ Equity
	Dividends Paid
	The Bank paid to the Company cash dividends in the aggregate amounts of $8,270,000, $8,175,000, and $8,522,000 in 2014, 2013, and 2012, respectively. The Bank is regulated by the Federal Deposit Insurance Corporation (FDIC) and the State of California Department of Business Oversight. Absent approval from the Commissioner of Department of Business Oversight, California banking laws generally limit the Bank’s ability to pay dividends to the lesser of (1) retained earnings or (2) net income for the last three fiscal years, less cash distributions paid during such period. Under this law, at December 31, 2014, the Bank may pay dividends of $52,798,000.
	Shareholders’ Rights Plan
	On June 25, 2001, the Company announced that its Board of Directors adopted and entered into a Shareholder Rights Agreement designed to protect and maximize shareholder value and to assist the Board of Directors in ensuring fair and equitable benefit to all shareholders in the event of a hostile bid to acquire the Company. The Company adopted this Rights Agreement to protect shareholders from coercive or otherwise unfair takeover tactics. In general terms, the Rights Plan would have imposed a significant penalty upon any person or group that acquired 15% or more of the Company’s outstanding common stock without approval of the Company’s Board of Directors.
	On June 4, 2014, the Company entered into an amendment to its Rights Agreement that accelerated the expiration of the Rights from July 10, 2021 to July 1, 2014 and had the effect of terminating the Rights Agreement as of that date. At the time of the termination, all Rights distributed to holders of the Company’s common stock pursuant to the Rights Agreement expired.
	Stock Repurchase Plan
	On August 21, 2007, the Board of Directors adopted a plan to repurchase, as conditions warrant, up to 500,000 shares of the Company’s common stock on the open market. The timing of purchases and the exact number of shares to be purchased will depend on market conditions. The 500,000 shares authorized for repurchase under this stock repurchase plan represented approximately 3.2% of the Company’s 15,814,662 outstanding common shares as of August 21, 2007. This stock repurchase plan has no expiration date. As of December 31, 2013, the Company had repurchased 166,600 shares under this plan.
	Stock Repurchased Under Equity Compensation Plans
	During the years ended December 31, 2014, 2013, and 2012, employees tendered 103,268, 172,941, and 14,120, respectively, of the Company’s common stock with market value of $2,551,000, $3,490,000, and $224,000, respectively, in lieu of cash to exercise options to purchase shares of the Company’s stock and to pay income taxes related to such exercises as permitted by the Company’s shareholder-approved equity compensation plans. The tendered shares were retired. The market value of tendered shares is the last market trade price at closing on the day an option is exercised. Stock repurchased under equity incentive plans are not counted in the total of stock repurchased under the stock repurchase plan announced August 21, 2007.

Stock_Options_and_Other_Equity

Stock Options and Other Equity-Based Incentive Instruments	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Options and Other Equity-Based Incentive Instruments	Note 20 - Stock Options and Other Equity-Based Incentive Instruments
	In March 2009, the Company’s Board of Directors adopted the TriCo Bancshares 2009 Equity Incentive Plan (2009 Plan) covering officers, employees, directors of, and consultants to, the Company. The 2009 Plan was approved by the Company’s shareholders in May 2009. The 2009 Plan allows for the granting of the following types of “stock awards” (Awards): incentive stock options, nonstatutory stock options, performance awards, restricted stock, restricted stock unit (RSU) awards and stock appreciation rights. RSUs that vest based solely on the grantee remaining in the service of the Company for a certain amount of time, are referred to as “service condition vesting RSUs”. RSUs that vest based on the grantee remaining in the service of the Company for a certain amount of time and a market condition such as the total return of the Company’s common stock versus the total return of an index of bank stocks, are referred to as “market plus service condition vesting RSUs”. In May 2013, the Company’s shareholders approved an amendment to the 2009 Plan increasing the maximum aggregate number of shares of TriCo’s common stock which may be issued pursuant to or subject to Awards from 650,000 to 1,650,000. The number of shares available for issuance under the 2009 Plan is reduced by: (i) one share for each share of common stock issued pursuant to a stock option or a Stock Appreciation Right and (ii) two shares for each share of common stock issued pursuant to a Performance Award, a Restricted Stock Award or a Restricted Stock Unit Award. When Awards made under the 2009 Plan expire or are forfeited or cancelled, the underlying shares will become available for future Awards under the 2009 Plan. To the extent that a share of common stock pursuant to an Award that counted as two shares against the number of shares again becomes available for issuance under the 2009 Plan, the number of shares of common stock available for issuance under the 2009 Plan shall increase by two shares. Shares awarded and delivered under the 2009 Plan may be authorized but unissued, or reacquired shares. As of December 31, 2014, 706,000 options for the purchase of common shares, and 46,286 restricted stock units were outstanding, and 822,428 shares remain available for issuance, under the 2009 Plan.
	In May 2001, the Company adopted the TriCo Bancshares 2001 Stock Option Plan (2001 Plan) covering officers, employees, directors of, and consultants to, the Company. Under the 2001 Plan, the option exercise price cannot be less than the fair market value of the Common Stock at the date of grant except in the case of substitute options. Options for the 2001 Plan expire on the tenth anniversary of the grant date. Vesting schedules under the 2001 Plan are determined individually for each grant. As of December 31, 2014, 396,850 options for the purchase of common shares were outstanding under the 2001 Plan. As of May 2009, as a result of the shareholder approval of the 2009 Plan, no new options may be granted under the 2001 Plan.
	Stock option activity is summarized in the following table for the dates indicated:
		Number of			Option Price								Weighted
		Shares			per Share								Average
													Exercise
													Price
	Outstanding at December 31, 2013		1,246,370		$	12.63			to		$	25.91	$	18.04
	Options granted		22,500		$	23.21			to		$	23.21	$	23.21
	Options exercised		(166,020	)	$	14.54			to		$	20.58	$	17.32
	Options forfeited		—			—			to			—		-
	Outstanding at September 30, 2014		1,102,850		$	12.63			to		$	25.91	$	18.25
	The following table shows the number, weighted-average exercise price, intrinsic value, and weighted average remaining contractual life of options exercisable, options not yet exercisable and total options outstanding as of December 31, 2014:
		Currently			Currently Not			Total
		Exercisable			Exercisable			Outstanding
	Number of options		818,350			284,500			1,102,850
	Weighted average exercise price	$	18.62		$	17.19		$	18.25
	Intrinsic value (in thousands)	$	5,007		$	2,136		$	7,143
	Weighted average remaining contractual term (yrs.)		4.5			7.6			5.3
	The 284,500 options that are currently not exercisable as of December 31, 2014 are expected to vest, on a weighted-average basis, over the next 2.6 years, and the Company is expected to recognize $1,783,000 of pre-tax compensation costs related to these options as they vest. The Company did not modify any option grants during 2013 or 2014.
	The following table shows the total intrinsic value of options exercised, the total fair value of options vested, total compensation costs for options recognized in income, and total tax benefit recognized in income related to compensation costs for options during the periods indicated:
		Years Ended December 31,
		2014			2013			2012
	Intrinsic value of options exercised	$	1,209,000		$	1,777,000		$	138,000
	Fair value of options that vested	$	965,000		$	1,150,000		$	1,083,000
	Total compensation costs for options recognized in income	$	965,000		$	1,150,000		$	1,083,000
	Total tax benefit recognized in income related to compensation costs for options	$	378,000		$	484,000		$	455,000
	Weighted average fair value of grants (per option)	$	8.17		$	8.91		$	6.63
	The fair value of the Company’s stock option grants is estimated on the measurement date, which, for the Company, is the date of grant. The fair value of stock options is estimated using the Black-Scholes option-pricing model. The Company estimated expected market price volatility and expected term of the options based on historical data and other factors. The weighted-average assumptions used to determine the fair value of options granted are detailed in the table below:
		Years Ended December 31,
		2014			2013			2012
	Assumptions used to value option grants:
	Average expected terms (years)		6.3			7			8.8
	Volatility		42.1	%		56.2	%		51.5	%
	Annual rate of dividends		1.9	%		1.87	%		2.36	%
	Discount rate		1.69	%		1.26	%		1.49	%
	Restricted stock unit (RSU) activity is summarized in the following table for the dates indicated:
		Service Condition Vesting RSUs						Market Plus Service Condition Vesting RSUs
		Number			Weighted			Number			Weighted
		of RSUs			Average Fair			of RSUs			Average Fair
					Value on						Value on
					Date of Grant						Date of Grant
	Outstanding at December 31, 2013		—			—			—			—
	RSUs granted		30,642		$	22.54			15,366		$	21.39
	RSUs added through dividend credits		278						—
	RSUs released		—						—
	RSUs forfeited/expired		—						—
	Outstanding at December 31, 2014		30,920						15,366
	The 30,642 of service condition vesting RSUs granted during 2014 include a feature whereby each RSU outstanding is credited with a dividend amount equal to any common stock cash dividend declared and paid, and the credited amount is divided by the closing price of the Company’s stock on the dividend payable date to arrive at an additional amount of RSUs outstanding under the original grant. The 30,920 of service condition vesting RSUs that are currently outstanding as of December 31, 2014 are expected to vest, and be released, on a weighted-average basis, over the next 2.8 years. The Company is expected to recognize $566,000 of pre-tax compensation costs related to these service condition vesting RSUs between December 31, 2014 and their vesting dates. During the three months ended December 31, 2014, the Company modified 13,749 service condition vesting RSUs that were granted on August 11, 2014 such that their vesting schedule was changed from 100% vesting on August 11, 2018 to 25% vesting on each of August 11, 2015, 2016, 2017 and 2018.
	The 15,366 of market plus service condition vesting RSUs that are currently outstanding as of December 31, 2014 are expected to vest, and be released, on a weighted-average basis, over the next 2.6 years. The Company is expected to recognize $286,000 of pre-tax compensation costs related to these RSUs between December 31, 2014 and their vesting dates. As of December 31, 2014, the number of market plus service condition vesting RSUs outstanding that will actually vest, and be released, may be reduced to zero or increased to 23,049 depending on the total return of the Company’s common stock versus the total return of an index of bank stocks from the grant date to the vesting date. The Company did not modify any market plus service condition vesting RSUs during 2014.

Noninterest_Income_and_Expense

Noninterest Income and Expense	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Noninterest Income and Expense	Note 21 - Noninterest Income and Expense
	The components of other noninterest income were as follows (in thousands):	Years Ended December 31,
		2014			2013			2012
	Service charges on deposit accounts	$	11,811		$	12,716		$	14,290
	ATM and interchange fees		9,651			8,370			7,762
	Other service fees		2,206			2,144			2,223
	Mortgage banking service fees		1,869			1,774			1,666
	Change in value of mortgage servicing rights		(1,301	)		253			(2,016	)
	Total service charges and fees		24,236			25,257			23,925
	Gain on sale of loans		2,032			5,602			6,810
	Commissions on sale of non-deposit investment products		2,995			2,983			3,209
	Increase in cash value of life insurance		1,953			1,727			1,820
	Change in indemnification asset		(856	)		(1,649	)		(286	)
	Gain on sale of foreclosed assets		2,153			1,640			786
	Sale of customer checks		450			377			346
	Lease brokerage income		504			337			276
	Gain (loss) on disposal of fixed assets		49			(39	)		(420	)
	Commission rebates		—			—			(56	)
	Gain on life insurance death benefit		—			—			675
	Other		1,000			594			895
	Total other noninterest income		10,280			11,572			14,055
	Total noninterest income	$	34,516		$	36,829		$	37,980
	Mortgage loan servicing fees, net of change in fair value of mortgage loan servicing rights, totaling $568,000, $2,027,000, and ($350,000) were recorded in service charges and fees noninterest income for the years ended December 31, 2014, 2013, and 2012, respectively.
	The components of noninterest expense were as follows (in thousands):
		Years Ended December 31,
		2014			2013			2012
	Base salaries, net of deferred loan origination costs	$	39,342		$	34,404		$	33,093
	Incentive compensation		5,068			4,694			5,138
	Benefits and other compensation costs		13,134			12,838			11,721
	Total salaries and benefits expense		57,544			51,936			49,952
	Occupancy		8,203			7,405			7,263
	Equipment		4,514			4,162			4,444
	Data processing and software		6,512			4,844			4,793
	Assessments		2,107			2,248			2,393
	ATM network charges		2,996			2,480			2,390
	Advertising		2,413			1,981			2,876
	Professional fees		3,888			2,707			2,879
	Telecommunications		2,870			2,449			2,250
	Postage		949			786			920
	Courier service		1,055			988			1,013
	Foreclosed assets expense		528			514			1,474
	Intangible amortization		446			209			209
	Operational losses		764			618			787
	Provision for foreclosed asset losses		208			682			1,728
	Change in reserve for unfunded commitments		(395	)		(1,200	)		875
	Legal settlement		—			339			2,090
	Merger expense		4,858			312			—
	Other		10,919			10,144			9,662
	Total other noninterest expense		52,835			41,668			48,046
	Total noninterest expense	$	110,379		$	93,604		$	97,998
	Merger expense:
	Incentive compensation	$	1,174			—			—
	Benefits and other compensation costs		94			—			—
	Data processing and software		475			—			—
	Professional fees		2,390		$	312			—
	Other		725			—			—
	Total merger expense	$	4,858		$	312			—

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Note 22 - Income Taxes
	The components of consolidated income tax expense are as follows:
		2014			2013			2012
		(in thousands)
	Current tax expense
	Federal	$	14,485		$	11,618		$	9,895
	State		5,016			4,261			3,425
			19,501			15,879			13,320
	Deferred tax expense (benefit)
	Federal		(794	)		1,976			(235	)
	State		(199	)		550			(148	)
			(993	)		2,526			(383	)
	Total tax expense	$	18,508		$	18,405		$	12,937
	A deferred tax asset or liability is recognized for the tax consequences of temporary differences in the recognition of revenue and expense for financial and tax reporting purposes. The net change during the year in the deferred tax asset or liability results in a deferred tax expense or benefit.
	Taxes recorded directly to shareholders’ equity are not included in the preceding table. These taxes (benefits) relating to changes in unfunded status of the supplemental retirement plans amounting to $(2,984,000) in 2014, $1,269,000 in 2013, and $(2,000) in 2012, taxes (benefits) related to unrealized gains and losses on available-for-sale investment securities amounting to $(68,000) in 2014, $(1,780,000) in 2013, and $(880,000) in 2012, taxes (benefits) related to employee stock options of $97,000 in 2014, $138,000 in 2013, and $13,000 in 2012, and taxes (benefits) related to changes in joint beneficiary agreement liability of $0 in 2014, $0 in 2013, and $64,000 in 2012, were recorded directly to shareholders’ equity.
	The temporary differences, tax effected, which give rise to the Company’s net deferred tax asset recorded in other assets are as follows as of December 31 for the years indicated:
		2014			2013
		(in thousands)
	Deferred tax assets:
	Allowance for losses	$	16,284		$	17,096
	Deferred compensation		3,115			3,093
	Accrued pension liability		7,925			5,817
	Accrued bonus		1,149			1,037
	Other accrued expenses		124			—
	Unfunded status of the supplemental retirement plans		3,315			331
	State taxes		1,713			1,390
	Stock option expense		2,534			2,225
	Nonaccrual interest		2,714			1,840
	OREO write downs		198			331
	Acquisition cost basis		6,017			699
	Tax credits		490			—
	Net operating loss carryforwards		7,128			—
	Other		625			—
	Total deferred tax assets		53,331			33,859
	Deferred tax liabilities:
	Securities income		(1,362	)		(986	)
	Unrealized gain on securities		(1,699	)		(1,767	)
	Depreciation		(3,072	)		(392	)
	Merger related fixed asset valuations		(54	)		(379	)
	Securities accretion		(287	)		(256	)
	Mortgage servicing rights valuation		(2,977	)		(2,416	)
	Indemnification asset		147			(87	)
	Core deposit intangible		(2,802	)		(193	)
	Junior subordinated debt		(2,782	)		—
	Prepaid expenses and other		(737	)		(602	)
	Total deferred tax liability		(15,625	)		(7,078	)
	Net deferred tax asset	$	37,706		$	26,781
	As part of the merger with North Valley, TriCo acquired federal and state net operating loss carryforwards, capital loss carryforwards, and tax credit carryforwards. These tax attribute carryforwards will be subject to provisions of the tax law that limit the use of such losses and credits generated by a company prior to the date certain ownership changes occur. The amount of the Company’s net operating loss carryforwards that would be subject to these limitations as of December 31, 2014 are $13.7 million and $35.2 million for federal and California, respectively. The amount of the Company’s capital loss carryforwards that would be subject to these limitations as of December 31, 2014 are $131,000 and $404,000 for federal and California, respectively. The amount of the Company’s tax credits that would be subject to these limitations as of December 31, 2014 are $69,000 and $2.7 million for federal and California, respectively. Due to the limitation, a significant portion of the state tax credits will expire regardless of whether the Company generates future taxable income. As such, the Company has recorded the future benefit of these tax credits at the value which is more likely than not to be realized. These tax loss and tax credit carryforwards expire at various dates beginning in 2015.
	The Company believes that a valuation allowance is not needed to reduce the deferred tax assets as it is more likely than not that the results of future operations will generate sufficient taxable income to realize the deferred tax assets, including the tax attribute carryforwards acquired as part of the North Valley merger.
	As part of the North Valley merger, TriCo inherited an unrecognized tax benefit for tax positions claimed on prior year tax returns filed by North Valley. The Company had an unrecognized tax benefit of $245,000 as of December 31, 2014, the recognition of which would reduce the Company’s tax expense by $158,000. Management does not expect the unrecognized tax benefit will materially change in the next 12 months. A summary of changes in the Company’s unrecognized tax benefit (including interest and penalties) in 2014 is as follows:
	(in thousands)	UTB			Interest/Penalties			Total
	As of December 31, 2013		—			—			—
	Additions for tax positions for prior years		227			18			245
	As of December 31, 2014		227			18			245
	During the years ended December 31, 2014 and December 31, 2013, the Company recognized no interest and penalties related to taxes. During the year ended December 31, 2012, the Company recognized interest and penalties related to taxes of $22,000 and $5,000, respectively. The Company files income tax returns in the U.S. federal jurisdiction, and California. With few exceptions, the Company is no longer subject to U.S. federal and state/local income tax examinations by tax authorities for years before 2011 and 2010, respectively.
	The provisions for income taxes applicable to income before taxes for the years ended December 31, 2014, 2013 and 2012 differ from amounts computed by applying the statutory Federal income tax rates to income before taxes. The effective tax rate and the statutory federal income tax rate are reconciled as follows:
		Years Ended December 31,
		2014			2013			2012
	Federal statutory income tax rate		35	%		35	%		35	%
	State income taxes, net of federal tax benefit		7			6.8			6.7
	Tax-exempt interest on municipal obligations		(0.4	)		(0.4	)		(0.5	)
	Tax-exempt life insurance related income		(1.5	)		(1.3	)		(2.0	)
	Non-deductible joint beneficiary agreement expense		0.2			0.2			0.3
	Non-deductible merger expense		1			—			—
Other		0.2			(0.1	)		1
Effective Tax Rate		41.5	%		40.2	%		40.5	%

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share	Note 23 - Earnings Per Share
	Basic earnings per share represents income available to common shareholders divided by the weighted-average number of common shares outstanding during the period. Diluted earnings per share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued, as well as any adjustments to income that would result from assumed issuance. Potential common shares that may be issued by the Company relate solely from outstanding stock options, and are determined using the treasury stock method. Earnings per share have been computed based on the following:
		Years ended December 31,
		2014		2013		2012
	Net income (in thousands)	$	26,108	$	27,399	$	18,994
	(number of shares in thousands)
	Average number of common shares outstanding		17,716		16,045		15,988
	Effect of dilutive stock options		207		152		64
	Average number of common shares outstanding used to calculate diluted earnings per share		17,923		16,197		16,052
	Based on an average of quarterly computations, there were 95,600, 407,985 and 967,120 options and restricted stock units excluded from the computation of annual diluted earnings per share for the years ended December 31, 2014, 2013 and 2012, respectively, because the effect of these options and restricted stock units were antidilutive.

Comprehensive_Income

Comprehensive Income	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Comprehensive Income	Note 24 – Comprehensive Income
	Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income. Although certain changes in assets and liabilities, such as unrealized gains and losses on available-for-sale securities, are reported as a separate component of the equity section of the balance sheet, such items, along with net income, are components of comprehensive income. The components of other comprehensive income and related tax effects are as follows:
		Years Ended December 31,
		2014			2013			2012
		(in thousands)
	Unrealized holding (losses) gains on available for sale securities before reclassifications	$	(162	)	$	(4,232	)	$	(2,096	)
	Amounts reclassified out of accumulated other comprehensive income		—			—			—
	Unrealized holding (losses) gains on available for sale securities after reclassifications		(162	)		(4,232	)		(2,096	)
	Tax effect		68			1,780			880
	Unrealized holding (losses) gains on available for sale securities, net of tax		(94	)		(2,452	)		(1,216	)
	Change in unfunded status of the supplemental retirement plans before reclassifications		(7,253	)		2,575			(445	)
	Amounts reclassified out of accumulated other comprehensive income:
	Amortization of prior service cost		138			153			153
	Amortization of actuarial losses		17			291			288
	Total amounts reclassified out of accumulated other comprehensive income		155			444			441
	Change in unfunded status of the supplemental retirement plans after reclassifications		(7,098	)		3,019			(4	)
	Tax effect		2,984			(1,269	)		2
	Change in unfunded status of the supplemental retirement plans, net of tax		(4,114	)		1,750			(2	)
	Change in joint beneficiary agreement liability before reclassifications		148			400			(370	)
	Amounts reclassified out of accumulated other comprehensive income		—			—			—
	Change in joint beneficiary agreement liability after reclassifications		148			400			(370	)
	Tax effect		—			—			(64	)
	Change in joint beneficiary agreement liability, net of tax		148			400			(434	)
	Total other comprehensive (loss) income	$	(4,060	)	$	(302	)	$	(1,652	)
	The components of accumulated other comprehensive income, included in shareholders’ equity, are as follows:
		December 31,
		2014			2013
		(in thousands)
	Net unrealized gains on available for sale securities	$	4,040		$	4,202
	Tax effect		(1,699	)		(1,767	)
	Unrealized holding gains on available for sale securities, net of tax		2,341			2,435
	Unfunded status of the supplemental retirement plans		(7,885	)		(787	)
	Tax effect		3,315			331
	Unfunded status of the supplemental retirement plans, net of tax		(4,570	)		(456	)
	Joint beneficiary agreement liability		26			(122	)
	Tax effect		—			—
	Joint beneficiary agreement liability, net of tax		26			(122	)
	Accumulated other comprehensive income	$	(2,203	)	$	1,857

Retirement_Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Retirement Plans	Note 25 – Retirement Plans
	401(k) Plan
	The Company sponsors a 401(k) Plan whereby substantially all employees age 21 and over with 90 days of service may participate. Participants may contribute a portion of their compensation subject to certain limits based on federal tax laws. During 2014, 2013, and 2012 the Company did not contribute to the 401(k) Plan. The Company did not incur any material expenses attributable to the 401(k) Plan during 2014, 2013, and 2012.
	Employee Stock Ownership Plan
	Substantially all employees with at least one year of service are covered by a discretionary employee stock ownership plan (ESOP). Contributions are made to the plan at the discretion of the Board of Directors. Contributions to the plan totaling $1,294,000 in 2014, $1,648,000 in 2013, and $1,229,000 in 2012, are included in salary expense. Company shares owned by the ESOP are paid dividends and included in the calculation of earnings per share exactly as other common shares outstanding.
	Deferred Compensation Plans
	The Company has deferred compensation plans for certain directors and key executives, which allow certain directors and key executives designated by the Board of Directors of the Company to defer a portion of their compensation. The Company has purchased insurance on the lives of the participants and intends to hold these policies until death as a cost recovery of the Company’s deferred compensation obligations of $7,408,000 and $7,357,000 at December 31, 2014 and 2013, respectively. Earnings credits on deferred balances totaling $551,000 in 2014, $568,000 in 2013, and $599,000 in 2012.
	Supplemental Retirement Plans
	The Company has supplemental retirement plans for certain directors and key executives. These plans are non-qualified defined benefit plans and are unsecured and unfunded. The Company has purchased insurance on the lives of the participants and intends to hold these policies until death as a cost recovery of the Company’s retirement obligations. The cash values of the insurance policies purchased to fund the deferred compensation obligations and the supplemental retirement obligations were $92,337,000 and $52,309,000 at December 31, 2014 and 2013, respectively.
	The Company recorded in other liabilities the unfunded status of the supplemental retirement plans of $7,885,000 and $787,000 related to the supplemental retirement plans as of December 31, 2014 and 2013, respectively. These amounts represent the amount by which the projected benefit obligations for these retirement plans exceeded the fair value of plan assets plus amounts previously accrued related to the plans. The projected benefit obligation is recorded in other liabilities.
	At December 31, 2014 and 2013, the unfunded status of the supplemental retirement plans of $7,885,000 and $787,000 were offset by a reduction of shareholders’ equity accumulated other comprehensive loss of $4,570,000 and $456,000, respectively, representing the after-tax impact of the unfunded status of the supplemental retirement plans, and the related deferred tax asset of $3,315,000 and $331,000, respectively. Amounts recognized as a component of accumulated other comprehensive loss as of year-end that have not been recognized as a component of the combined net period benefit cost of the Company’s defined benefit pension plans are presented in the following table. The Company expects to recognize approximately $823,000 of the net actuarial loss reported in the following table as of December 31, 2014 as a component of net periodic benefit cost during 2015.
		December 31,
	(in thousands)	2014			2013
	Transition obligation	$	9		$	11
	Prior service cost		(173	)		(35	)
	Net actuarial loss		8,049			811
	Amount included in accumulated other comprehensive loss	$	7,885			787
	Deferred tax benefit		(3,315	)		(331	)
	Amount included in accumulated other comprehensive loss, net of tax	$	4,570		$	456
	Information pertaining to the activity in the supplemental retirement plans, using a measurement date of December 31, is as follows:
		December 31,
		2014			2013
		(in thousands)
	Change in benefit obligation:
	Benefit obligation at beginning of year	$	(14,634	)	$	(16,345	)
	Acquisition		(4,150	)		—
	Service cost		(652	)		(742	)
	Interest cost		(739	)		(643	)
	Actuarial (loss)/gain		(7,254	)		2,573
	Benefits paid		631			523
	Benefit obligation at end of year	$	(26,798	)	$	(14,634	)
	Change in plan assets:
	Fair value of plan assets at beginning of year	$	—		$	—
	Fair value of plan assets at end of year	$	—		$	—
	Funded status	$	(26,798	)	$	(14,634	)
	Unrecognized net obligation existing at January 1, 1986		9			11
	Unrecognized net actuarial loss		8,049			811
	Unrecognized prior service cost		(173	)		(35	)
	Accumulated other comprehensive income		(7,885	)		(787	)
	Accrued benefit cost	$	(26,798	)	$	(14,634	)
	Accumulated benefit obligation	$	(24,739	)	$	(12,954	)
	The following table sets forth the net periodic benefit cost recognized for the supplemental retirement plans:
		Years Ended December 31,
		2014			2013			2012
		(in thousands)
	Net pension cost included the following components:
	Service cost-benefits earned during the period	$	652		$	743		$	680
	Interest cost on projected benefit obligation		739			643			687
	Amortization of net obligation at transition		2			2			2
	Amortization of prior service cost		138			153			153
	Recognized net actuarial loss		16			291			288
	Net periodic pension cost	$	1,547		$	1,832		$	1,810
	The following table sets forth assumptions used in accounting for the plans:
		Years Ended December 31,
		2014			2013			2012
	Discount rate used to calculate benefit obligation		3.65	%		4.85	%		4	%
	Discount rate used to calculate net periodic pension cost		3.65	%		4.85	%		4	%
	Average annual increase in executive compensation		2.5	%		2.5	%		2.5	%
	Average annual increase in director compensation		2.5	%		2.5	%		2.5	%
	The following table sets forth the expected benefit payments to participants and estimated contributions to be made by the Company under the supplemental retirement plans for the years indicated:
	Years Ended	Expected Benefit			Estimated
		Payments to			Company
		Participants			Contributions
		(in thousands)
2015	$	1,145		$	1,145
2016		1,036			1,036
2017		1,001			1,001
2018		1,330			1,330
2019		519			519
2020-2024	$	3,719		$	3,719

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	Note 26 – Related Party Transactions
	Certain directors, officers, and companies with which they are associated were customers of, and had banking transactions with, the Company or the Bank in the ordinary course of business.
	The following table summarizes the activity in these loans for the periods indicated (in thousands):
	Balance December 31, 2012	$	2,368
	Advances/new loans		1,154
	Removed/payments		(886	)
	Balance December 31, 2013	$	2,636
	Advances/new loans		2,106
	Removed/payments		(1,610	)
	Balance December 31, 2014	$	3,132
	Director Chrysler is a principal owner and CEO of Modern Building Inc. Modern Building Inc. provided construction services to the Company related to new and existing Bank facilities for aggregate payments of $1,181,000, $4,261,000, and $3,587,000 during 2014, 2013 and 2012, respectively.

Fair_Value_Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurement	Note 27 – Fair Value Measurement
	The Company utilizes fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. In estimating fair value, the Company utilizes valuation techniques that are consistent with the market approach, income approach, and/or the cost approach. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability including assumptions about the risk inherent in a particular valuation technique, the effect of a restriction on the sale or use of an asset and the risk of nonperformance. Securities available-for-sale and mortgage servicing rights are recorded at fair value on a recurring basis. Additionally, from time to time, the Company may be required to record at fair value other assets on a nonrecurring basis, such as loans held for sale, loans held for investment and certain other assets. These nonrecurring fair value adjustments typically involve application of lower of cost or market accounting or impairment write-downs of individual assets.
	The Company groups assets and liabilities at fair value in three levels, based on the markets in which the assets and liabilities are traded and the observable nature of the assumptions used to determine fair value. These levels are:
	Level 1 -	Valuation is based upon quoted prices for identical instruments traded in active markets.
	Level 2 -	Valuation is based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market.
	Level 3 -	Valuation is generated from model-based techniques that use at least one significant assumption not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques include use of option pricing models, discounted cash flow models and similar techniques.
	Securities available for sale - Securities available for sale are recorded at fair value on a recurring basis. Fair value measurement is based upon quoted prices, if available. If quoted prices are not available, fair values are measured using independent pricing models or other model-based valuation techniques such as the present value of future cash flows, adjusted for the security’s credit rating, prepayment assumptions and other factors such as credit loss assumptions. Level 1 securities include those traded on an active exchange, such as the New York Stock Exchange, U.S. Treasury securities that are traded by dealers or brokers in active over-the-counter markets and money market funds. Level 2 securities include mortgage-backed securities issued by government sponsored entities, municipal bonds and corporate debt securities. The Company had no securities classified as Level 3 during any of the periods covered in these financial statements.
	Loans held for sale – Loans held for sale are carried at the lower of cost or fair value. The fair value of loans held for sale is based on what secondary markets are currently offering for loans with similar characteristics. As such, we classify those loans subjected to nonrecurring fair value adjustments as Level 2.
	Impaired originated and PNCI loans – Originated and PNCI loans are not recorded at fair value on a recurring basis. However, from time to time, an originated or PNCI loan is considered impaired and an allowance for loan losses is established. Originated and PNCI loans for which it is probable that payment of interest and principal will not be made in accordance with the contractual terms of the loan agreement are considered impaired. The fair value of an impaired originated or PNCI loan is estimated using one of several methods, including collateral value, fair value of similar debt, enterprise value, liquidation value and discounted cash flows. Those impaired originated and PNCI loans not requiring an allowance represent loans for which the fair value of the expected repayments or collateral exceed the recorded investments in such loans. Impaired originated and PNCI loans where an allowance is established based on the fair value of collateral require classification in the fair value hierarchy. When the fair value of the collateral is based on an observable market price or a current appraised value which uses substantially observable data, the Company records the impaired originated or PNCI loan as nonrecurring Level 2. When an appraised value is not available or management determines the fair value of the collateral is further impaired below the appraised value, or the appraised value contains a significant unobservable assumption, such as deviations from comparable sales, and there is no observable market price, the Company records the impaired originated or PNCI loan as nonrecurring Level 3.
	Foreclosed assets - Foreclosed assets include assets acquired through, or in lieu of, loan foreclosure. Foreclosed assets are held for sale and are initially recorded at fair value at the date of foreclosure, establishing a new cost basis. Subsequent to foreclosure, management periodically performs valuations and the assets are carried at the lower of carrying amount or fair value less cost to sell. When the fair value of foreclosed assets is based on an observable market price or a current appraised value which uses substantially observable data, the Company records the impaired originated loan as nonrecurring Level 2. When an appraised value is not available or management determines the fair value of the collateral is further impaired below the appraised value, or the appraised value contains a significant unobservable assumption, such as deviations from comparable sales, and there is no observable market price, the Company records the foreclosed asset as nonrecurring Level 3. Revenue and expenses from operations and changes in the valuation allowance are included in other noninterest expense.
	Mortgage servicing rights - Mortgage servicing rights are carried at fair value. A valuation model, which utilizes a discounted cash flow analysis using a discount rate and prepayment speed assumptions is used in the computation of the fair value measurement. While the prepayment speed assumption is currently quoted for comparable instruments, the discount rate assumption currently requires a significant degree of management judgment and is therefore considered an unobservable input. As such, the Company classifies mortgage servicing rights subjected to recurring fair value adjustments as Level 3. Additional information regarding mortgage servicing rights can be found in Note 10 in the consolidated financial statements at Item 1 of this report.
	The table below presents the recorded amount of assets and liabilities measured at fair value on a recurring basis (in thousands):
	Fair value at December 31, 2014	Total			Level 1			Level 2			Level 3
	Securities available-for-sale:
	Obligations of U.S. government corporations and agencies	$	75,120			—		$	75,120			—
	Obligations of states and political subdivisions		3,175			—			3,175			—
	Corporate debt securities		1,908			—			1,908			—
	Marketable equity securities		3,002		$	3,002			—			—
	Mortgage servicing rights		7,378			—			—		$	7,378
	Total assets measured at fair value	$	90,583		$	3,002		$	80,203		$	7,378
	Fair value at December 31, 2013	Total			Level 1			Level 2			Level 3
	Securities available-for-sale:
	Obligations of U.S. government corporations and agencies	$	97,143			—		$	97,143			—
	Obligations of states and political subdivisions		5,589			—			5,589			—
	Corporate debt securities		1,915			—			1,915			—
	Mortgage servicing rights		6,165			—			—			6,165
	Total assets measured at fair value	$	110,812			—		$	104,647		$	6,165
	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 corresponds with the Company’s quarterly valuation process. There were no transfers between any levels during 2014 or 2013.
	The following table provides a reconciliation of assets and liabilities measured at fair value using significant unobservable inputs (Level 3) on a recurring basis during the years ended December 31, 2014 and 2013. Had there been any transfer into or out of Level 3 during 2014 or 2013, the amount included in the “Transfers into (out of) Level 3” column would represent the beginning balance of an item in the period (interim quarter) during which it was transferred (in thousands):
	Year ended December 31,	Beginning			Transfers			Change			Issuances		Ending
		Balance			into (out of)			Included					Balance
					Level 3			in Earnings
	2014: Mortgage servicing rights	$	6,165		$	1,944		$	(1,301	)	$	570	$	7,378
	2013: Mortgage servicing rights	$	4,552			—		$	253		$	1,360	$	6,165
	The Company’s method for determining the fair value of mortgage servicing rights is described in Note 1. The key unobservable inputs used in determining the fair value of mortgage servicing rights are mortgage prepayment speeds and the discount rate used to discount cash projected cash flows. Generally, any significant increases in the mortgage prepayment speed and discount rate utilized in the fair value measurement of the mortgage servicing rights will result in a negative fair value adjustments (and decrease in the fair value measurement). Conversely, a decrease in the mortgage prepayment speed and discount rate will result in a positive fair value adjustment (and increase in the fair value measurement). Note 10 contains additional information regarding mortgage servicing rights.
	The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2014:
		Fair Value			Valuation			Unobservable			Range,
		(in thousands)			Technique			Inputs			Weighted Average
	Mortgage Servicing Rights	$	7,378			Discounted cash flow			Constant prepayment rate		5.7%-23.4%, 12.0%
									Discount rate		10.0%-12.0%, 10.0%
	The tables below present the recorded amount of assets and liabilities measured at fair value on a nonrecurring basis, as of the dates indicated, that had a write-down or an additional allowance provided during the periods indicated (in thousands):
	Year ended December 31, 2014	Total			Level 1			Level 2			Level 3		Total Gains
													(Losses)
	Fair value:
	Impaired Originated & PNCI loans	$	2,480			—			—		$	2,480	$	(636	)
	Foreclosed assets		2,611			—			—			2,611	$	(137	)
	Total assets measured at fair value	$	5,091			—			—		$	5,091	$	(773	)
	Year ended December 31, 2013	Total			Level 1			Level 2			Level 3		Total Gains
													(Losses)
	Fair value:
	Impaired Originated & PNCI loans	$	20,334			—			—		$	20,334	$	(2,539	)
	Foreclosed assets		948			—			—			948		(397	)
	Total assets measured at fair value	$	21,282			—			—		$	21,282	$	(2,936	)
	The impaired Originated and PNCI loan amount above represents impaired, collateral dependent loans that have been adjusted to fair value. When we identify a collateral dependent loan as impaired, we measure the impairment using the current fair value of the collateral, less selling costs. Depending on the characteristics of a loan, the fair value of collateral is generally estimated by obtaining external appraisals. If we determine that the value of the impaired loan is less than the recorded investment in the loan, we recognize this impairment and adjust the carrying value of the loan to fair value through the allowance for loan and lease losses. The loss represents charge-offs or impairments on collateral dependent loans for fair value adjustments based on the fair value of collateral. The carrying value of loans fully charged-off is zero.
	The foreclosed assets amount above represents impaired real estate that has been adjusted to fair value. Foreclosed assets represent real estate which the Bank has taken control of in partial or full satisfaction of loans. At the time of foreclosure, other real estate owned is recorded at the lower of the carrying amount of the loan or fair value less costs to sell, which becomes the property’s new basis. Any write-downs based on the asset’s fair value at the date of acquisition are charged to the allowance for loan and lease losses. After foreclosure, management periodically performs valuations such that the real estate is carried at the lower of its new cost basis or fair value, net of estimated costs to sell. Fair value adjustments on other real estate owned are recognized within net loss on real estate owned. The loss represents impairments on non-covered other real estate owned for fair value adjustments based on the fair value of the real estate.
	The Company’s property appraisals are primarily based on the sales comparison approach and income approach methodologies, which consider recent sales of comparable properties, including their income generating characteristics, and then make adjustments to reflect the general assumptions that a market participant would make when analyzing the property for purchase. These adjustments may increase or decrease an appraised value and can vary significantly depending on the location, physical characteristics and income producing potential of each property. Additionally, the quality and volume of market information available at the time of the appraisal can vary from period to period and cause significant changes to the nature and magnitude of comparable sale adjustments. Given these variations, comparable sale adjustments are generally not a reliable indicator for how fair value will increase or decrease from period to period. Under certain circumstances, management discounts are applied based on specific characteristics of an individual property.
	The following table presents quantitative information about Level 3 fair value measurements for financial instruments measured at fair value on a nonrecurring basis at December 31, 2014:
		Fair Value			Valuation Technique		Unobservable Inputs	Range, Weighted Average
		(in thousands)
	Impaired Originated & PNCI loans	$	2,480		Sales comparison approach		Adjustment for differences between comparable sales	(5.0)%-(42.5)%, (10.1)%
					Income approach		Capitalization rate	9.09%-9.09 %, 9.09%
	Foreclosed assets	$	2,611		Sales comparison approach		Adjustment for differences between comparable sales	(5.0)%-(29.4)%, (8.2)%
	In addition to the methods and assumptions used to estimate the fair value of each class of financial instrument noted above, the following methods and assumptions were used to estimate the fair value of other classes of financial instruments for which it is practical to estimate the fair value.
	Short-term Instruments—Cash and due from banks, fed funds purchased and sold, interest receivable and payable, and short-term borrowings are considered short-term instruments. For these short-term instruments their carrying amount approximates their fair value.
Securities held to maturity – The fair value of securities held to maturity is based upon quoted prices, if available. If quoted prices are not available, fair values are measured using independent pricing models or other model-based valuation techniques such as the present value of future cash flows, adjusted for the security’s credit rating, prepayment assumptions and other factors such as credit loss assumptions. Level 1 securities include those traded on an active exchange, such as the New York Stock Exchange, U.S. Treasury securities that are traded by dealers or brokers in active over-the-counter markets and money market funds. Level 2 securities include mortgage-backed securities issued by government sponsored entities, municipal bonds and corporate debt securities. The Company had no securities held to maturity classified as Level 3 during any of the periods covered in these financial statements.
Restricted Equity Securities—It is not practical to determine the fair value of restricted equity securities due to restrictions placed on its transferability.
Originated and PNCI loans - The fair value of variable rate originated and PNCI loans is the current carrying value. The interest rates on these originated and PNCI loans are regularly adjusted to market rates. The fair value of other types of fixed rate originated and PNCI loans is estimated by discounting the future cash flows using current rates at which similar loans would be made to borrowers with similar credit ratings for the same remaining maturities. The allowance for loan losses is a reasonable estimate of the valuation allowance needed to adjust computed fair values for credit quality of certain originated and PNCI loans in the portfolio.
PCI Loans—PCI loans are measured at estimated fair value on the date of acquisition. Carrying value is calculated as the present value of expected cash flows and approximates fair value.
FDIC Indemnification Asset—The fair value of the FDIC indemnification asset is based on the discounted value of expected future cash flows under the loss-share agreement.
Deposit Liabilities - The fair value of demand deposits, savings accounts, and certain money market deposits is the amount payable on demand at the reporting date. These values do not consider the estimated fair value of the Company’s core deposit intangible, which is a significant unrecognized asset of the Company. The fair value of time deposits and other borrowings is based on the discounted value of contractual cash flows.
Other Borrowings - The fair value of other borrowings is calculated based on the discounted value of the contractual cash flows using current rates at which such borrowings can currently be obtained.
Junior Subordinated Debentures - The fair value of junior subordinated debentures is estimated using a discounted cash flow model. The future cash flows of these instruments are extended to the next available redemption date or maturity date as appropriate based upon the spreads of recent issuances or quotes from brokers for comparable bank holding companies compared to the contractual spread of each junior subordinated debenture measured at fair value.
Commitments to Extend Credit and Standby Letters of Credit - The fair value of commitments is estimated using the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the present credit worthiness of the counter parties. For fixed rate loan commitments, fair value also considers the difference between current levels of interest rates and the committed rates. The fair value of letters of credit is based on fees currently charged for similar agreements or on the estimated cost to terminate them or otherwise settle the obligation with the counter parties at the reporting date.
Fair values for financial instruments are management’s estimates of the values at which the instruments could be exchanged in a transaction between willing parties. These estimates are subjective and may vary significantly from amounts that would be realized in actual transactions. In addition, other significant assets are not considered financial assets including, any mortgage banking operations, deferred tax assets, and premises and equipment. Further, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on the fair value estimates and have not been considered in any of these estimates.
The estimated fair values of financial instruments that are reported at amortized cost in the Corporation’s consolidated balance sheets, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value, were as follows (in thousands):
	December 31, 2014						December 31, 2013
	Carrying			Fair			Carrying			Fair
	Amount			Value			Amount			Value
Financial assets:
Level 1 inputs:
Cash and due from banks	$	93,150		$	93,150		$	76,915		$	76,915
Cash at Federal Reserve and other banks		517,578			517,578			521,453			521,453
Level 2 inputs:
Securities held to maturity		676,426			688,779			240,504			233,807
Restricted equity securities		16,956			N/A			9,163			N/A
Loans held for sale		3,579			3,579			2,270			2,270
Level 3 inputs:
Loans, net		2,282,524			2,379,155			1,672,007			1,760,274
Indemnification (liability) asset		(349	)		(349	)		206			206
Financial liabilities:
Level 2 inputs:
Deposits		3,380,423			3,380,486			2,410,483			2,411,402
Other borrowings		9,276			9,276			6,335			6,335
Level 3 inputs:
Junior subordinated debt		56,272			45,053			41,238			25,774
	Contract			Fair			Contract			Fair
	Amount			Value			Amount			Value
Off-balance sheet:
Level 3 inputs:
Commitments	$	656,175		$	6,562		$	555,386		$	5,554
Standby letters of credit		17,531			175			2,601			26
Overdraft privilege commitments		101,060			1,011			68,932			689

TriCo_Bancshares_Condensed_Fin

TriCo Bancshares Condensed Financial Statements (Parent Only)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
TriCo Bancshares Condensed Financial Statements (Parent Only)	Note 28 - TriCo Bancshares Condensed Financial Statements (Parent Only)
	Condensed Balance Sheets
		December 31,
		2014			2013
		(in thousands)
	Assets
	Cash and Cash equivalents	$	2,229		$	2,520
	Investment in Tri Counties Bank		470,797			288,746
	Other assets		1,902			1,280
	Total assets	$	474,928		$	292,546
	Liabilities and shareholders’ equity
	Other liabilities	$	484		$	362
	Junior subordinated debt		56,272			41,238
	Total liabilities		56,756			41,600
	Shareholders’ equity:
	Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 22,714,964 and 16,076,662 shares, respectively		244,318			89,356
	Retained earnings		176,057			159,733
	Accumulated other comprehensive loss, net		(2,203	)		1,857
	Total shareholders’ equity		418,172			250,946
	Total liabilities and shareholders’ equity	$	474,928		$	292,546
	Condensed Statements of Income
		Years ended December 31,
		2014			2013			2012
		(in thousands)
	Interest expense	$	(1,403	)	$	(1,247	)	$	(1,325	)
	Administration expense		(2,720	)		(862	)		(669	)
	Loss before equity in net income of Tri Counties Bank		(4,123	)		(2,109	)		(1,994	)
	Equity in net income of Tri Counties Bank:
	Distributed		8,270			8,175			8,522
	Undistributed		20,720			20,446			11,632
	Income tax benefit		1,241			887			834
	Net income	$	26,108		$	27,399		$	18,994
	Condensed Statements of Comprehensive Income
		Years ended December 31,
		2014			2013			2012
		(in thousands)
	Net income	$	26,108		$	27,399		$	18,994
	Other comprehensive (loss) income, net of tax:
	Unrealized holding (losses) gains on securities arising during the period		(94	)		(2,452	)		(1,216	)
	Change in minimum pension liability		(4,114	)		1,750			(2	)
	Change in joint beneficiary agreement liability		148			400			(434	)
	Other comprehensive (loss) income		(4,060	)		(302	)		(1,652	)
	Net income	$	22,048		$	27,097		$	17,342
	Condensed Statements of Cash Flows
		Years ended December 31,
		2014			2013			2012
		(in thousands)
	Operating activities:
	Net income	$	26,108		$	27,399		$	18,994
	Adjustments to reconcile net income to net cash provided by operating activities:
	Undistributed equity in earnings of Tri Counties Bank		(20,720	)		(20,446	)		(11,632	)
	Stock option vesting expense		1,133			1,151			1,083
	Stock option excess tax benefits		(225	)		(356	)		(44	)
	Net change in other assets and liabilities		671			(1,100	)		(1,089	)
	Net cash provided by operating activities		6,967			6,648			7,312
	Investing activities: None
	Financing activities:
	Issuance of common stock through option exercise		616			251			206
	Stock option excess tax benefits		225			356			44
	Repurchase of common stock		(292	)		(501	)		—
	Cash dividends paid — common		(7,807	)		(6,745	)		(5,757	)
	Net cash used for financing activities		(7,258	)		(6,639	)		(5,507	)
	(decrease) increase in cash and cash equivalents		(291	)		9			1,805
	Cash and cash equivalents at beginning of year		2,520			2,511			706
Cash and cash equivalents at end of year	$	2,229		$	2,520		$	2,511

Regulatory_Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Regulatory Matters	Note 29 - Regulatory Matters
	The Company is subject to various regulatory capital requirements administered by 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 direct material effect on the Company’s consolidated financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company must meet specific capital guidelines that involve quantitative measures of the Company’s assets, liabilities and certain off-balance-sheet items as calculated under regulatory accounting practices. The Company’s capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk weightings and other factors.
	Quantitative measures established by regulation to ensure capital adequacy require the Company 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 average assets. Management believes, as of December 31, 2014, that the Company meets all capital adequacy requirements to which it is subject.
	As of December 31, 2014, the Bank was well capitalized under the regulatory framework for prompt corrective action. To be categorized as well capitalized the Bank must maintain minimum total risk-based, Tier 1 risk-based and Tier 1 leverage ratios as set forth in the table below. There are no conditions or events since that date that Management believes have changed the institution’s category. The Bank’s actual capital amounts and ratios are also presented in the table.
		Actual					Minimum					Minimum
							Capital Requirement					To Be Well
												Capitalized Under
												Prompt Corrective
												Action Provisions
		Amount		Ratio			Amount		Ratio			Amount		Ratio
		(dollars in thousands)
	As of December 31, 2014:
	Total Capital (to Risk Weighted Assets):
	Consolidated	$	436,955		15.63	%	$	223,603		8	%		N/A		N/A
	Tri Counties Bank	$	433,286		15.51	%	$	223,449		8	%	$	279,311		10	%
	Tier 1 Capital (to Risk Weighted Assets):
	Consolidated	$	401,971		14.38	%	$	111,801		4	%		N/A		N/A
	Tri Counties Bank	$	398,325		14.26	%	$	111,724		4	%	$	167,587		6	%
	Tier 1 Capital (to Average Assets):
	Consolidated	$	401,971		10.8	%	$	148,819		4	%		N/A		N/A
	Tri Counties Bank	$	398,325		10.71	%	$	148,734		4	%	$	185,918		5	%
	As of December 31, 2013:
	Total Capital (to Risk Weighted Assets):
	Consolidated	$	297,429		14.77	%	$	161,064		8	%		N/A		N/A
	Tri Counties Bank	$	295,212		14.67	%	$	160,961		8	%	$	201,201		10	%
	Tier 1 Capital (to Risk Weighted Assets):
	Consolidated	$	272,071		13.51	%	$	80,532		4	%		N/A		N/A
	Tri Counties Bank	$	269,870		13.41	%	$	80,480		4	%	$	120,720		6	%
	Tier 1 Capital (to Average Assets):
	Consolidated	$	272,071		10.17	%	$	107,017		4	%		N/A		N/A
	Tri Counties Bank	$	269,870		10.09	%	$	106,965		4	%	$	133,706		5	%

Summary_of_Quarterly_Results_o

Summary of Quarterly Results of Operations (unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results of Operations (unaudited)	Note 30 - Summary of Quarterly Results of Operations (unaudited)
	The following table sets forth the results of operations for the four quarters of 2014 and 2013, and is unaudited; however, in the opinion of Management, it reflects all adjustments (which include only normal recurring adjustments) necessary to present fairly the summarized results for such periods.
		2014 Quarters Ended
		December 31,			September 30,			June 30,		March 31,
		(dollars in thousands, except per share data)
	Interest and dividend income:
	Loans:
	Discount accretion PCI – cash basis	$	107		$	290		$	69	$	203
	Discount accretion PCI – other		919			822			811		984
	Discount accretion PNCI		796			402			624		379
	All other loan interest income		28,914			23,466			22,929		22,172
	Total loan interest income		30,736			24,980			24,433		23,738
	Debt securities, dividends and interest bearing cash at Banks (not FTE)		5,671			4,151			3,985		3,421
	Total interest income		36,407			29,131			28,418		27,159
	Interest expense		1,437			1,082			1,075		1,087
	Net interest income		34,970			28,049			27,343		26,072
	(Benefit from) provision for loan losses		(1,421	)		(2,977	)		1,708		(1,355	)
	Net interest income after provision for loan losses		36,391			31,026			25,635		27,427
	Noninterest income		9,755			8,589			7,877		8,295
	Noninterest expense		36,566			25,380			25,116		23,317
	Income before income taxes		9,580			14,235			8,396		12,405
	Income tax expense		3,930			6,001			3,537		5,040
	Net income	$	5,650		$	8,234		$	4,859	$	7,365
	Per common share:
	Net income (diluted)	$	0.25		$	0.5		$	0.3	$	0.45
	Dividends	$	0.11		$	0.11		$	0.11	$	0.11
		2013 Quarters Ended
		December 31,			September 30,			June 30,		March 31,
		(dollars in thousands, except per share data)
	Interest and dividend income:
	Loans:
	Discount accretion PCI – cash basis	$	255		$	140		$	129	$	167
	Discount accretion PCI – other		893			898			732		597
	Discount accretion PNCI		568			1,115			815		766
	All other loan interest income		22,754			22,970			22,207		22,542
	Total loan interest income		24,470			25,123			23,883		24,072
	Debt securities, dividends and interest bearing cash at Banks (not FTE)		2,992			2,413			1,873		1,734
	Total interest income		27,462			27,536			25,756		25,806
	Interest expense		1,123			1,169			1,167		1,237
	Net interest income		26,339			26,367			24,589		24,569
	Provision for (benefit from) loan losses		172			(393	)		614		(1,108	)
	Net interest income after provision for loan losses		26,167			26,760			23,975		25,677
	Noninterest income		7,353			9,127			10,131		10,218
	Noninterest expense		24,878			23,616			23,509		21,601
	Income before income taxes		8,642			12,271			10,597		14,294
	Income tax expense		3,406			4,910			4,272		5,817
	Net income	$	5,236		$	7,361		$	6,325	$	8,477
	Per common share:
	Net income (diluted)	$	0.32		$	0.45		$	0.39	$	0.53
	Dividends	$	0.11		$	0.11		$	0.11	$	0.09

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation
	TriCo Bancshares (the “Company”) is a California corporation organized to act as a bank holding company for Tri Counties Bank (the “Bank”). The Company and the Bank are headquartered in Chico, California. The Bank is a California-chartered bank that is engaged in the general commercial banking business in 26 California counties. Tri Counties Bank currently operates from 57 traditional branches and 16 in-store branches. The Company has five capital subsidiary business trusts (collectively, the Capital Trusts) that issued trust preferred securities, including two organized by TriCo and three acquired with the acquisition of North Valley Bancorp. See Note 17 – Junior Subordinated Debt.
	The consolidated financial statements are prepared in accordance with accounting policies generally accepted in the United States of America and general practices in the banking industry. The financial statements include the accounts of the Company. All inter-company accounts and transactions have been eliminated in consolidation. For financial reporting purposes, the Company’s investments in the Capital Trusts of $1,690,000 are accounted for under the equity method and, accordingly, are not consolidated and are included in other assets on the consolidated balance sheet. The subordinated debentures issued and guaranteed by the Company and held by the Capital Trusts are reflected as debt on the Company’s consolidated balance sheet.
Use of Estimates in the Preparation of Financial Statements	Use of Estimates in the Preparation of Financial Statements
	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 assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, the Company evaluates its estimates, including those related to the adequacy of the allowance for loan losses, investments, intangible assets, income taxes and contingencies. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. The allowance for loan losses, indemnification asset, foreclosed assets, goodwill and other intangible assets, income taxes, fair value of assets acquired and liabilities assumed in business combinations, the valuation of securities available-for-sale, and the valuation of mortgage servicing rights are the only accounting estimates that materially affect the Company’s consolidated financial statements.
	As described in Note 2, the Company acquired North Valley Bancorp on October 3, 2014. The acquired assets and assumed liabilities were measured at estimated fair value values under the acquisition method of accounting. The Company made significant estimates and exercised significant judgment in accounting for the acquisition. The Company determined loan fair values based on loan file reviews, loan risk ratings, appraised collateral values, expected cash flows and historical loss factors. Foreclosed assets were primarily valued based on appraised values of the repossessed loan collateral. Land and building were valued based on appraised values. An identifiable intangible was also recorded representing the fair value of the core deposit customer base based on an evaluation of the cost of such deposits relative to alternative funding sources. The fair value of time deposits and borrowings were determined based on the present value of estimated future cash flows using current rates as of the acquisition date.
Significant Group Concentration of Credit Risk	Significant Group Concentration of Credit Risk
	The Company grants agribusiness, commercial, consumer, and residential loans to customers located throughout the northern San Joaquin Valley, the Sacramento Valley and northern mountain regions of California. The Company has a diversified loan portfolio within the business segments located in this geographical area. The Company currently classifies all its operation into one business segment that it denotes as community banking.
Cash and Cash Equivalents	Cash and Cash Equivalents
	For purposes of the consolidated statements of cash flows, cash and cash equivalents include cash on hand, amounts due from banks, and federal funds sold. Net cash flows are reported for loan and deposit transactions and other borrowings.
Investment Securities	Investment Securities
	The Company classifies its debt and marketable equity securities into one of three categories: trading, available for sale or held to maturity. Trading securities are bought and held principally for the purpose of selling in the near term. Held to maturity securities are those securities which the Company has the ability and intent to hold until maturity. These securities are carried at cost adjusted for amortization of premium and accretion of discount, computed by the effective interest method over their contractual lives. All other securities not included in trading or held to maturity are classified as available for sale. Available for sale securities are recorded at fair value. Unrealized gains and losses, net of the related tax effect, on available for sale securities are reported as a separate component of other accumulated comprehensive income in shareholders’ equity until realized. Premiums and discounts are amortized or accreted over the life of the related investment security as an adjustment to yield using the effective interest method. Dividend and interest income are recognized when earned. Realized gains and losses are derived from the amortized cost of the security sold. During the years ended December 31, 2014 and 2013, the Company did not have any securities classified as trading.
	The Company assesses other-than-temporary impairment (“OTTI”) based on whether it intends to sell a security or if it is likely that the Company would be required to sell the security before recovery of the amortized cost basis of the investment, which may be maturity. For debt securities, if we intend to sell the security or it is likely that we will be required to sell the security before recovering its cost basis, the entire impairment loss would be recognized in earnings as an OTTI. If we do not intend to sell the security and it is not likely that we will be required to sell the security but we do not expect to recover the entire amortized cost basis of the security, only the portion of the impairment loss representing credit losses would be recognized in earnings. The credit loss on a security is measured as the difference between the amortized cost basis and the present value of the cash flows expected to be collected. Projected cash flows are discounted by the original or current effective interest rate depending on the nature of the security being measured for potential OTTI. The remaining impairment related to all other factors, the difference between the present value of the cash flows expected to be collected and fair value, is recognized as a charge to other comprehensive income (“OCI”). Impairment losses related to all other factors are presented as separate categories within OCI. The accretion of the amount recorded in OCI increases the carrying value of the investment and does not affect earnings. If there is an indication of additional credit losses the security is re-evaluated according to the procedures described above. No OTTI losses were recognized during the years ended December 31, 2014 and 2013.
Restricted Equity Securities	Restricted Equity Securities
	Restricted equity securities represent the Company’s investment in the stock of the Federal Home Loan Bank of San Francisco (“FHLB”) and are carried at par value, which reasonably approximates its fair value. While technically these are considered equity securities, there is no market for the FHLB stock. Therefore, the shares are considered as restricted investment securities. Management periodically evaluates FHLB stock for other-than-temporary impairment. Management’s determination of whether these investments are impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value. The determination of whether a decline affects the ultimate recoverability of cost is influenced by criteria such as (1) the significance of any decline in net assets of the FHLB as compared to the capital stock amount for the FHLB and the length of time this situation has persisted, (2) commitments by the FHLB to make payments required by law or regulation and the level of such payments in relation to the operating performance of the FHLB, (3) the impact of legislative and regulatory changes on institutions and, accordingly, the customer base of the FHLB, and (4) the liquidity position of the FHLB.
	As a member of the FHLB system, the Company is required to maintain a minimum level of investment in FHLB stock based on specific percentages of its outstanding mortgages, total assets, or FHLB advances. The Company may request redemption at par value of any stock in excess of the minimum required investment. Stock redemptions are at the discretion of the FHLB.
Loans Held for Sale	Loans Held for Sale
	Loans originated and intended for sale in the secondary market are carried at the lower of aggregate cost or fair value, as determined by aggregate outstanding commitments from investors of current investor yield requirements. Net unrealized losses are recognized through a valuation allowance by charges to noninterest income.
	Mortgage loans held for sale are generally sold with the mortgage servicing rights retained by the Company. Gains or losses on the sale of loans that are held for sale are recognized at the time of the sale and determined by the difference between net sale proceeds and the net book value of the loans less the estimated fair value of any retained mortgage servicing rights.
Loans and Allowance for Loan Losses	Loans and Allowance for Loan Losses
	Loans originated by the Company, i.e., not purchased or acquired in a business combination, are referred to as originated loans. Originated loans that management has the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at the principal amount outstanding, net of deferred loan fees and costs. Loan origination and commitment fees and certain direct loan origination costs are deferred, and the net amount is amortized as an adjustment of the related loan’s yield over the actual life of the loan. Originated loans on which the accrual of interest has been discontinued are designated as nonaccrual loans.
	Originated loans are placed in nonaccrual status when reasonable doubt exists as to the full, timely collection of interest or principal, or a loan becomes contractually past due by 90 days or more with respect to interest or principal and is not well secured and in the process of collection. When an originated loan is placed on nonaccrual status, all interest previously accrued but not collected is reversed. Income on such loans is then recognized only to the extent that cash is received and where the future collection of principal is probable. Interest accruals are resumed on such loans only when they are brought fully current with respect to interest and principal and when, in the judgment of Management, the loan is estimated to be fully collectible as to both principal and interest.
	An allowance for loan losses for originated loans is established through a provision for loan losses charged to expense. The allowance is maintained at a level which, in Management’s judgment, is adequate to absorb probable incurred credit losses inherent in the loan portfolio as of the balance sheet date. Originated loans and deposit related overdrafts are charged against the allowance for loan losses when Management believes that the collectability of the principal is unlikely or, with respect to consumer installment loans, according to an established delinquency schedule. The allowance is an amount that Management believes will be adequate to absorb probable incurred losses inherent in existing loans and leases, based on evaluations of the collectability, impairment and prior loss experience of loans and leases. The evaluations take into consideration such factors as changes in the nature and size of the portfolio, overall portfolio quality, loan concentrations, specific problem loans, and current economic conditions that may affect the borrower’s ability to pay. The Company defines an originated loan as impaired when it is probable the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement. Impaired originated loans are measured based on the present value of expected future cash flows discounted at the loan’s original effective interest rate. As a practical expedient, impairment may be measured based on the loan’s observable market price or the fair value of the collateral if the loan is collateral dependent. When the measure of the impaired loan is less than the recorded investment in the loan, the impairment is recorded through a valuation allowance.
	In situations related to originated loans where, for economic or legal reasons related to a borrower’s financial difficulties, the Company grants a concession for other than an insignificant period of time to the borrower that the Company would not otherwise consider, the related loan is classified as a troubled debt restructuring (TDR). The Company strives to identify borrowers in financial difficulty early and work with them to modify to more affordable terms before their loan reaches nonaccrual status. These modified terms may include rate reductions, principal forgiveness, payment forbearance and other actions intended to minimize the economic loss and to avoid foreclosure or repossession of the collateral. In cases where the Company grants the borrower new terms that result in the loan being classified as a TDR, the Company measures any impairment on the restructuring as noted above for impaired loans. TDR loans are classified as impaired until they are fully paid off or charged off. Loans that are in nonaccrual status at the time they become TDR loans, remain in nonaccrual status until the borrower demonstrates a sustained period of performance which the Company generally believes to be six consecutive months of payments, or equivalent. Otherwise, TDR loans are subject to the same nonaccrual and charge-off policies as noted above with respect to their restructured principal balance.
	Credit risk is inherent in the business of lending. As a result, the Company maintains an allowance for loan losses to absorb probable incurred losses inherent in the Company’s originated loan portfolio. This is maintained through periodic charges to earnings. These charges are included in the Consolidated Statements of Income as provision for loan losses. All specifically identifiable and quantifiable losses are immediately charged off against the allowance. However, for a variety of reasons, not all losses are immediately known to the Company and, of those that are known, the full extent of the loss may not be quantifiable at that point in time. The balance of the Company’s allowance for originated loan losses is meant to be an estimate of these unknown but probable losses inherent in the portfolio.
	The Company formally assesses the adequacy of the allowance for originated loan losses on a quarterly basis. Determination of the adequacy is based on ongoing assessments of the probable risk in the outstanding originated loan portfolio, and to a lesser extent the Company’s originated loan commitments. These assessments include the periodic re-grading of credits based on changes in their individual credit characteristics including delinquency, seasoning, recent financial performance of the borrower, economic factors, changes in the interest rate environment, growth of the portfolio as a whole or by segment, and other factors as warranted. Loans are initially graded when originated. They are re-graded as they are renewed, when there is a new loan to the same borrower, when identified facts demonstrate heightened risk of nonpayment, or if they become delinquent. Re-grading of larger problem loans occurs at least quarterly. Confirmation of the quality of the grading process is obtained by independent credit reviews conducted by consultants specifically hired for this purpose and by various bank regulatory agencies.
	The Company’s method for assessing the appropriateness of the allowance for originated loan losses includes specific allowances for impaired originated loans and leases, formula allowance factors for pools of credits, and allowances for changing environmental factors (e.g., interest rates, growth, economic conditions, etc.). Allowance factors for loan pools were based on historical loss experience by product type and prior risk rating.
	During the three months ended March 31, 2013, the Company changed the method it uses to estimate net sale proceeds from real estate collateral sales when calculating the allowance for loan losses associated with impaired real estate collateral dependent loans. Previously, the Company used the greater of fifteen percent or actual estimated selling costs. Currently, the Company uses the actual estimated selling costs, and an adjustment to appraised value based on the age of the appraisal. These changes are intended to more accurately reflect the estimated net sale proceeds from the sale of impaired collateral dependent real estate loans. This change in methodology resulted in the allowance for loan losses as of March 31, 2013 being $494,000 more than it would have been without this change in methodology.
	During the three months ended June 30, 2013, the Company modified its loss migration analysis methodology used to determine the formula allowance factors. When the Company originally established its loss migration analysis methodology during the quarter ended March 31, 2012, it reviewed the loss experience of each rolling twelve month period over the previous three years in order to calculate an annualized loss rate by loan category and risk rating. The use of three years of loss experience data was originally used because that was the extent of the detailed loss data by loan category and risk rating that was available at the time. This three year historical look-back period was used through the quarter ended March 31, 2013. Starting with the quarter ended June 30, 2013, the Company reviews all available detailed loss experience data, going back to, and including, the twelve month period ended June 30, 2009, and does not limit the look-back period to the most recent three years of historical loss data. Using this data, the Company calculates loss factors for each quarter from the quarter ended June 30, 2009 to the most recent quarter. The Company then calculates a weighted average formula allowance factor for each loan category and risk rating with the most recent quarterly loss factor being weighted 125%, the quarter ended June 30, 2009 loss factor being weighted 75%, and the loss factors for all the quarters between the most recent quarter and the quarter ended June 30, 2009, being weighted on a linear scale from 75% to 125%. This change is intended to more accurately reflect the risk inherent in the loan portfolio by considering historical loss data for all years as the data for new periods becomes available. This change in methodology resulted in the allowance for loan losses as of June 30, 2013 being $1,314,000 more than it would have been without this change in methodology.
	During the three months ended September 30, 2013, the Company modified its methodology used to determine the allowance for changing environmental factors. Previously, the Company compared the current value of each environmental factor to a fixed baseline value. The deviation of the current value from the baseline value was then multiplied by a conversion factor to determine the required allowance related to each environmental factor. As of September 30, 2013, the Company replaced the fixed baseline values with average baseline values derived from historical averages, and adjusted the conversion factors. This change is intended to more accurately reflect the risk inherent in the portfolio by recognizing that baseline, or normal, levels for environmental factors may change over time. This change in methodology resulted in the allowance for loan losses as of September 30, 2013 being $1,665,000 more than it would have been without this change in methodology.
	During the three months ended March 31, 2014, the Company modified its methodology used to determine the allowance for changing environmental factors by adding a new environmental factor based on the California Home Affordability Index (“CHAI”). The CHAI measures the percentage of households in California that can afford to purchase the median priced home in California based on current home prices and mortgage interest rates. The use of the CHAI environmental factor consists of comparing the current CHAI to its historical baseline, and allows management to consider the adverse impact that a lower than historical CHAI may have on general economic activity and the performance of our borrowers. Based on an analysis of historical data, management believes this environmental factor gives a better estimate of current economic activity compared to other environmental factors that may lag current economic activity to some extent. This change in methodology resulted in no change to the allowance for loan losses as of March 31, 2014 compared to what it would have been without this change in methodology.
	During the three months ended June 30, 2014, the Company refined the method it uses to evaluate historical losses for the purpose of estimating the pool allowance for unimpaired loans. In the third quarter of 2010, the Company moved from a six point grading system (Grades A-F) to a nine point risk rating system (Risk Ratings 1-9), primarily to allow for more distinction within the “Pass” risk rating. Initially, there was not sufficient loss experience within the nine point scale to complete a migration analysis for all nine risk ratings, all loans risk rated Pass or 2-5 were grouped together, a loss rate was calculated for that group, and that loss rate was established as the loss rate for risk rating 4. The reserve ratios for risk ratings 2, 3 and 5 were then interpolated from that figure. As of June 30, 2014, the Company was able to compile twelve quarters of historical loss information for all risk ratings and use that information to calculate the loss rates for each of the nine risk ratings without interpolation. This refinement led to an increase of $1,438,000 in the reserve requirement for unimpaired loans, driven primarily by home equity lines of credit with a risk rating of 5 or “Pass-Watch.”
	Loans purchased or acquired in a business combination are referred to as acquired loans. Acquired loans are valued as of the acquisition date in accordance with Financial Accounting Standards Board Accounting Standards Codification (“FASB ASC”) Topic 805, Business Combinations. Loans acquired with evidence of credit deterioration since origination for which it is probable that all contractually required payments will not be collected are referred to as purchased credit impaired (PCI) loans. PCI loans are accounted for under FASB ASC Topic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality. Under FASB ASC Topic 805 and FASB ASC Topic 310-30, PCI loans are recorded at fair value at acquisition date, 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 as of the acquisition date. Fair value is defined as the present value of the future estimated principal and interest payments of the loan, with the discount rate used in the present value calculation representing the estimated effective yield of the loan. Default rates, loss severity, and prepayment speed assumptions are periodically reassessed and our estimate of future payments is adjusted accordingly. The difference between contractual future payments and estimated future payments is referred to as the nonaccretable difference. The difference between estimated future payments and the present value of the estimated future payments is referred to as the accretable yield. The accretable yield represents the amount that is expected to be recorded as interest income over the remaining life of the loan. If after acquisition, the Company determines that the estimated future cash flows of a PCI loan are expected to be more than originally estimated, an increase in the discount rate (effective yield) would be made such that the newly increased accretable yield would be recognized, on a level yield basis, over the remaining estimated life of the loan. If, after acquisition, the Company determines that the estimated future cash flows of a PCI loan are expected to be less than previously estimated, the discount rate would first be reduced until the present value of the reduced cash flow estimate equals the previous present value however, the discount rate may not be lowered below its original level at acquisition. If the discount rate has been lowered to its original level and the present value has not been sufficiently lowered, an allowance for loan loss would be established through a provision for loan losses charged to expense to decrease the present value to the required level. If the estimated cash flows improve after an allowance has been established for a loan, the allowance may be partially or fully reversed depending on the improvement in the estimated cash flows. Only after the allowance has been fully reversed may the discount rate be increased. PCI loans are put on nonaccrual status when cash flows cannot be reasonably estimated. PCI loans on nonaccrual status are accounted for using the cost recovery method or cash basis method of income recognition. The Company refers to PCI loans on nonaccrual status that are accounted for using the cash basis method of income recognition as “PCI – cash basis” loans; and the Company refers to all other PCI loans as “PCI – other” loans PCI loans are charged off when evidence suggests cash flows are not recoverable. Foreclosed assets from PCI loans are recorded in foreclosed assets at fair value with the fair value at time of foreclosure representing cash flow from the loan. ASC 310-30 allows PCI loans with similar risk characteristics and acquisition time frame to be “pooled” and have their cash flows aggregated as if they were one loan. The Company elected to use the “pooled” method of ASC 310-30 for PCI – other loans in the acquisition of certain assets and liabilities of Granite Community Bank, N.A. (“Granite”) during 2010 and Citizens Bank of Northern California (“Citizens”) during 2011.
	Acquired loans that are not PCI loans are referred to as purchased not credit impaired (PNCI) loans. PNCI loans are accounted for under FASB ASC Topic 310-20, Receivables – Nonrefundable Fees and Other Costs, in which interest income is accrued on a level-yield basis for performing loans. For income recognition purposes, this method assumes that all contractual cash flows will be collected, and no allowance for loan losses is established at the time of acquisition. Post-acquisition date, an allowance for loan losses may need to be established for acquired loans through a provision charged to earnings for credit losses incurred subsequent to acquisition. Under ASC 310-20, the loss would be measured based on the probable shortfall in relation to the contractual note requirements, consistent with our allowance for loan loss policy for similar loans.
	Throughout these financial statements, and in particular in Note 4 and Note 5, when we refer to “Loans” or “Allowance for loan losses” we mean all categories of loans, including Originated, PNCI, PCI – cash basis, and PCI – other. When we are not referring to all categories of loans, we will indicate which we are referring to – Originated, PNCI, PCI – cash basis, or PCI – other.
	When referring to PNCI and PCI loans we will use the terms “nonaccretable difference”, “accretable yield”, or “purchase discount”. Nonaccretable difference is the difference between undiscounted contractual cash flows due and undiscounted cash flows we expect to collect, or put another way, it is the undiscounted contractual cash flows we do not expect to collect. Accretable yield is the difference between undiscounted cash flows we expect to collect and the value at which we have recorded the loan on our financial statements. On the date of acquisition, all purchased loans are recorded on our consolidated financial statements at estimated fair value. Purchase discount is the difference between the estimated fair value of loans on the date of acquisition and the principal amount owed by the borrower, net of charge offs, on the date of acquisition. We may also refer to “discounts to principal balance of loans owed, net of charge-offs”. Discounts to principal balance of loans owed, net of charge-offs is the difference between principal balance of loans owed, net of charge-offs, and loans as recorded on our financial statements. Discounts to principal balance of loans owed, net of charge-offs arise from purchase discounts, and equal the purchase discount on the acquisition date.
	Loans are also categorized as “covered” or “noncovered”. Covered loans refer to loans covered by a Federal Deposit Insurance Corporation (“FDIC”) loss sharing agreement. Noncovered loans refer to loans not covered by a FDIC loss sharing agreement.
Foreclosed Assets	Foreclosed Assets
	Foreclosed assets include assets acquired through, or in lieu of, loan foreclosure. Foreclosed assets are held for sale and are initially recorded at fair value less estimated costs to sell at the date of foreclosure, establishing a new cost basis. Subsequent to foreclosure, management periodically performs valuations and the assets are carried at the lower of carrying amount or fair value less cost to sell. Revenue and expenses from operations and changes in the valuation allowance are included in other noninterest expense. Gain or loss on sale of foreclosed assets is included in noninterest income. Foreclosed assets that are not subject to a FDIC loss-share agreement are referred to as noncovered foreclosed assets.
	Foreclosed assets acquired through FDIC-assisted acquisitions that are subject to a FDIC loss-share agreement, and all assets acquired via foreclosure of covered loans are referred to as covered foreclosed assets. Covered foreclosed assets are reported exclusive of expected reimbursement cash flows from the FDIC. Foreclosed covered loan collateral is transferred into covered foreclosed assets at the loan’s carrying value, inclusive of the acquisition date fair value discount.
	Covered foreclosed assets are initially recorded at estimated fair value less estimated costs to sell on the acquisition date based on similar market comparable valuations less estimated selling costs. Any subsequent valuation adjustments due to declines in fair value will be charged to noninterest expense, and will be mostly offset by noninterest income representing the corresponding increase to the FDIC indemnification asset for the offsetting loss reimbursement amount. Any recoveries of previous valuation adjustments will be credited to noninterest expense with a corresponding charge to noninterest income for the portion of the recovery that is due to the FDIC.
Premises and Equipment	Premises and Equipment
	Land is carried at cost. Land improvements, buildings and equipment, including those acquired under capital lease, are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expenses are computed using the straight-line method over the estimated useful lives of the related assets or lease terms. Asset lives range from 3-10 years for furniture and equipment and 15-40 years for land improvements and buildings.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets
	Goodwill represents the excess of costs over fair value of net assets of businesses acquired. Goodwill and other intangible assets acquired in a purchase business combination and determined to have an indefinite useful life are not amortized, but instead tested for impairment at least annually. Intangible assets with estimable useful lives are amortized over their respective estimated useful lives to their estimated residual values, and reviewed for impairment.
	The Company has an identifiable intangible asset consisting of core deposit intangibles (CDI). CDI are amortized over their respective estimated useful lives, and reviewed for impairment.
Impairment of Long-Lived Assets and Goodwill	Impairment of Long-Lived Assets and Goodwill
	Long-lived assets, such as premises and equipment, and purchased intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized by the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of would be separately presented in the balance sheet and reported at the lower of the carrying amount or fair value less costs to sell, and are no longer depreciated. The assets and liabilities of a disposed group classified as held for sale would be presented separately in the appropriate asset and liability sections of the consolidated balance sheet.
	As of December 31 of each year, goodwill is tested for impairment, and is tested for impairment more frequently if events and circumstances indicate that the asset might be impaired. An impairment loss is recognized to the extent that the carrying amount exceeds the asset’s fair value. This determination is made at the reporting unit level. The Company may choose to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events or circumstances, the Company determines it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then goodwill is deemed not to be impaired. However, if the Company concludes otherwise, or if the Company elected not to first assess qualitative factors, then the Company performs the first step of a two-step impairment test by calculating the fair value of the reporting unit and comparing the fair value with the carrying amount of the reporting unit. Second, if the carrying amount of the reporting unit exceeds its fair value, an impairment loss is recognized for any excess of the carrying amount of the reporting unit’s goodwill over the implied fair value of that goodwill. The implied fair value of goodwill is determined by allocating the fair value of the reporting unit in a manner similar to a purchase price allocation. The residual fair value after this allocation is the implied fair value of the reporting unit goodwill. Currently, and historically, the Company is comprised of only one reporting unit that operates within the business segment it has identified as “community banking”. Goodwill was not impaired as of December 31, 2014 because the fair value of the reporting unit exceeded its carrying value.
Mortgage Servicing Rights	Mortgage Servicing Rights
	Mortgage servicing rights (MSR) represent the Company’s right to a future stream of cash flows based upon the contractual servicing fee associated with servicing mortgage loans. Our MSR arise from residential and commercial mortgage loans that we originate and sell, but retain the right to service the loans. The net gain from the retention of the servicing right is included in gain on sale of loans in noninterest income when the loan is sold. Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the cost to service, the discount rate, the custodial earnings rate, an inflation rate, ancillary income, prepayment speeds and default rates and losses. Servicing fees are recorded in noninterest income when earned.
	The Company accounts for MSR at fair value. The determination of fair value of our MSR requires management judgment because they are not actively traded. The determination of fair value for MSR requires valuation processes which combine the use of discounted cash flow models and extensive analysis of current market data to arrive at an estimate of fair value. The cash flow and prepayment assumptions used in our discounted cash flow model are based on empirical data drawn from the historical performance of our MSR, which we believe are consistent with assumptions used by market participants valuing similar MSR, and from data obtained on the performance of similar MSR. The key assumptions used in the valuation of MSR include mortgage prepayment speeds and the discount rate. These variables can, and generally will, change from quarter to quarter as market conditions and projected interest rates change. The key risks inherent with MSR are prepayment speed and changes in interest rates. The Company uses an independent third party to determine fair value of MSR.
Indemnification Asset/Liability	Indemnification Asset/Liability
	The Company accounts for amounts receivable or payable under its loss-share agreements entered into with the FDIC in connection with its purchase and assumption of certain assets and liabilities of Granite as indemnification assets in accordance with FASB ASC Topic 805, Business Combinations. FDIC indemnification assets are initially recorded at fair value, based on the discounted value of expected future cash flows under the loss-share agreements. The difference between the fair value and the undiscounted cash flows the Company expects to collect from or pay to the FDIC will be accreted into noninterest income over the life of the FDIC indemnification asset. FDIC indemnification assets are reviewed quarterly and adjusted for any changes in expected cash flows based on recent performance and expectations for future performance of the covered portfolios. These adjustments are measured on the same basis as the related covered loans and covered other real estate owned. Any increases in cash flow of the covered assets over those expected will reduce the FDIC indemnification asset and any decreases in cash flow of the covered assets under those expected will increase the FDIC indemnification asset. Increases and decreases to the FDIC indemnification asset are recorded as adjustments to noninterest income.
Reserve for Unfunded Commitments	Reserve for Unfunded Commitments
	The reserve for unfunded commitments is established through a provision for losses – unfunded commitments charged to noninterest expense. The reserve for unfunded commitments is an amount that Management believes will be adequate to absorb probable losses inherent in existing commitments, including unused portions of revolving lines of credits and other loans, standby letters of credits, and unused deposit account overdraft privilege. The reserve for unfunded commitments is based on evaluations of the collectability, and prior loss experience of unfunded commitments. The evaluations take into consideration such factors as changes in the nature and size of the loan portfolio, overall loan portfolio quality, loan concentrations, specific problem loans and related unfunded commitments, and current economic conditions that may affect the borrower’s or depositor’s ability to pay.
	During the three months ended June 30, 2013, the Company modified the methodology employed to estimate potential losses on unfunded commitments. Similar to the Allowance for Loan Losses, the Company performs a migration analysis of historical loss experience. Prior to this quarter, the loss experience of each quarter over the previous three years was reviewed in order to calculate an annualized loss rate by loan category. Going forward, the Company has chosen to review all loss experience available since the conversion to a loss migration analysis. This change is intended to more accurately reflect the risk inherent in the unfunded commitments and appropriately consider all losses incurred in prior years. This change in methodology resulted in the reserve for unfunded commitments as of June 30, 2013 being $335,000 more than it would have been without this change in methodology.
Income Taxes	Income Taxes
	The Company’s accounting for income taxes is based on an asset and liability approach. The Company recognizes 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 its financial statements or tax returns. The measurement of tax assets and liabilities is based on the provisions of enacted tax laws. A valuation allowance, if needed, reduces deferred tax assets to the expected amount most likely to be realized. Realization of deferred tax assets is dependent upon the generation of a sufficient level of future taxable income and recoverable taxes paid in prior years. Although realization is not assured, management believes it is more likely than not that all of the deferred tax assets will be realized. Interest and/or penalties related to income taxes are reported as a component of noninterest income.
Off-Balance Sheet Credit Related Financial Instruments	Off-Balance Sheet Credit Related Financial Instruments
	In the ordinary course of business, the Company has entered into commitments to extend credit, including commitments under credit card arrangements, commercial letters of credit, and standby letters of credit. Such financial instruments are recorded when they are funded.
Geographical Descriptions	Geographical Descriptions
	For the purpose of describing the geographical location of the Company’s loans, the Company has defined northern California as that area of California north of, and including, Stockton; central California as that area of the state south of Stockton, to and including, Bakersfield; and southern California as that area of the state south of Bakersfield.
Reclassifications	Reclassifications
	Certain amounts reported in previous consolidated financial statements have been reclassified to conform to the presentation in this report. These reclassifications did not affect previously reported net income or total shareholders’ equity.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	FASB issued ASU No. 2014-04, Receivables (Topic 310): Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure. ASU 2014-04 clarifies when an in substance repossession or foreclosure occurs, that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan receivable should be derecognized and the real estate property recognized. ASU 2014-04 is effective for public business entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2014. ASU 2014-04 is not expected to have a significant impact on the Company’s consolidated financial statements.
	FASB issued ASU No. 2014-08, Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. ASU 2014-08 improves the definition of discontinued operations by limiting discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have (or will have) a major effect on an entity’s operations and financial results. ASU 2014-08 requires expanded disclosures for discontinued operations that provide users of financial statements with more information about the assets, liabilities, revenues, and expenses of discontinued operations. ASU 2014-08 also requires an entity to disclose the pretax profit or loss of an individually significant component of an entity that does not qualify for discontinued operations reporting, and provide users with information about the financial effects of significant disposals that do not qualify for discontinued operations reporting. The amendments in ASU 2014-08 include several changes to the Accounting Standards Codification to improve the organization and readability of Subtopic 205-20 and Subtopic 360-10, Property, Plant, and Equipment—Overall. ASU 2014-08 is effective for public business entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2014. ASU 2014-08 is not expected to have a significant impact on the Company’s consolidated financial statements.
	FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). The core principle of the guidance under ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 is effective for a public entity for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early application is not permitted. The Company is currently evaluating the effects of ASU 2014-09 on its financial statements and disclosures, if any.
	FASB issued ASU No. 2014-11, Transfers and Servicing (Topic 860): Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures. ASU 2014-11 requires that repurchase-to-maturity transactions be accounted for as secured borrowings consistent with the accounting for other repurchase agreements. In addition, ASU 2014-11 requires separate accounting for repurchase financings, which entails the transfer of a financial asset executed contemporaneously with a repurchase agreement with the same counterparty. ASU 2014-11 requires entities to disclose certain information about transfers accounted for as sales in transactions that are economically similar to repurchase agreements. In addition, ASU 2014-11 requires disclosures related to collateral, remaining contractual tenor and of the potential risks associated with repurchase agreements, securities lending transactions and repurchase-to-maturity transactions. ASU 2014-11 is effective for public business entities for the first interim or annual period beginning after December 15, 2014. An entity is required to present changes in accounting for transactions outstanding on the effective date as a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. Earlier application for a public business entity is prohibited. ASU 2014-11 is not expected to have a significant impact on the Company’s consolidated financial statements.
	FASB issued ASU No. 2014-12, Compensation—Stock Compensation (Topic 718): Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be achieved after the Requisite Service Period. ASU 2014-12 requires that a performance target that affects the vesting of a share-based payment award and that could be achieved after the requisite service period be treated as a performance condition. A reporting entity should apply existing guidance in Topic 718 as it relates to awards with performance conditions that affect vesting to account for such awards. As such, the performance target should not be reflected in estimating the grant-date fair value of the award. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. If the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The requisite service period ends when the employee can cease rendering service and still be eligible to vest in the award if the performance target is achieved. The stated vesting period (which includes the period in which the performance target could be achieved) may differ from the requisite service period. Current U.S. GAAP does not contain explicit guidance on whether to treat a performance target that could be achieved after the requisite service period as a performance condition that affects vesting or as a nonvesting condition that affects the grant-date fair value of an award. ASU 2014-12 provides explicit guidance for those awards. For all entities, ASU 2014-12 is effective for annual periods and interim periods within those annual periods beginning after December 15, 2015. Earlier adoption is permitted.
	FASB issued ASU No. 2014-14, Receivables—Troubled Debt Restructurings by Creditors (Topic 310): Classification of Certain Government Mortgage Loans upon Foreclosure. ASU 2014-14 requires that a mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if the following conditions are met: 1) the loan has a government guarantee that is not separable from the loan before foreclosure, 2) at the time of foreclosure, the creditor has the intent to convey the real estate property to the guarantor and make a claim on the guarantee, and the creditor has the ability to recover under that claim, and 3) at the time of foreclosure, any amount of the claim that is determined on the basis of the fair value of the real estate is fixed. Upon foreclosure, the separate other receivable should be measured based on the amount of the loan balance (principal and interest) expected to be recovered from the guarantor. For public business entities, ASU 2014-14 is effective for annual periods and interim periods within those annual periods beginning after December 15, 2014. Earlier adoption is permitted.

Business_Combinations_Tables

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Principal Balance Loans Acquired	The following table presents a reconciliation of the undiscounted contractual cash flows, nonaccretable difference, accretable yield, fair value, purchase discount, and principal balance of loans for the PNCI and PCI—other categories of North Valley Bancorp loans as of the acquisition date. For North Valley Bancorp PCI – other loans, the purchase discount does not necessarily represent cash flows to be collected:
		North Valley Bancorp Loans – October 3, 2014
	(in thousands)	PNCI			PCI—other			Total
	Undiscounted contractual cash flows	$	718,731		$	15,706		$	734,437
	Undiscounted cash flows not expected to be collected (nonaccretable difference)		—			(6,295	)		(6,295	)
	Undiscounted cash flows expected to be collected		718,731			9,411			728,142
	Accretable yield at acquisition		(228,815	)		—			(228,815	)
	Estimated fair value of loans acquired at acquisition		489,916			9,411			499,327
	Purchase discount		12,721			2,077			14,798
	Principal balance loans acquired	$	502,637		$	11,488		$	514,125
Schedule of Pro Forma Financial Information	The unaudited pro forma financial information is not necessarily indicative of the results of operations that would have occurred had the transaction been effected on the assumed date.
		Proforma for the
		Year Ended December 31,
		2014			2013
	(Unaudited, in thousands, except per share data)
	Summarized Income Statement Data:
	Net interest income	$	139,520		$	132,635
	Provision for (benefit from) loan losses		(4,045	)		(715	)
	Noninterest income		43,587			50,966
	Noninterest expense		147,295			133,073
	Income before income taxes		39,857			51,243
	Income taxes		16,453			20,091
	Net income	$	23,404		$	31,152
	Basic earnings per share	$	1.03		$	1.38
	Diluted earnings per share	$	1.02		$	1.37
North Valley Bancorp [Member]
Schedule of Fair Value of Consideration Transferred, Identifiable Net Assets Acquired and Resulting Goodwill	The following table discloses the calculation of the fair value of consideration transferred, the total identifiable net assets acquired and the resulting goodwill relating to the North Valley Bancorp acquisition:
	(in thousands)	North Valley Bancorp
		October 3, 2014
	Fair value of consideration transferred:
	Fair value of shares issued	$	151,303
	Cash consideration		7
	Total fair value of consideration transferred		151,310
	Asset acquired:
	Cash and cash equivalents		141,412
	Securities available for sale		17,297
	Securities held to maturity		189,949
	Restricted equity securities		5,378
	Loans		499,327
	Foreclosed assets		695
	Premises and equipment		11,936
	Cash value of life insurance		38,075
	Core deposit intangible		6,614
	Other assets		20,056
	Total assets acquired		930,739
	Liabilities assumed:
	Deposits		801,956
	Other liabilities		10,429
	Junior subordinated debt		14,987
	Total liabilities assumed		827,372
	Total net assets acquired		103,367
	Goodwill recognized	$	47,943
Summary of Estimated Fair Value Adjustments Resulting In Goodwill	A summary of the estimated fair value adjustments resulting in the goodwill recorded in the North Valley Bancorp acquisition are presented below:
	(in thousands)	North Valley Bancorp
		October 3, 2014
	Value of stock consideration paid to North Valley Bancorp Shareholders		151,303
	Cash payments to North
	Valley Bancorp Shareholders		7
	Cost basis net assets acquired	$	(98,040	)
	Fair value adjustments:
	Loans		5,832
	Premises and Equipment		(4,785	)
	Core deposit intangible		(6,283	)
	Deferred income taxes		6,293
	Junior subordinated debt		(6,664	)
	Other		280
	Goodwill	$	47,943
Schedule of Cost Basis, Fair Value Discount and loan Acquired	The following table presents the cost basis, fair value discount, and fair value of loans acquired from North Valley Bancorp on October 3, 2014:
		North Valley Bancorp Acquired Loans
		October 3, 2014
	(in thousands)	Cost Basis			Discount			Fair Value
	PNCI	$	502,637		$	(12,721	)	$	489,916
	PCI – other		11,488			(2,077	)		9,411
	Total	$	514,125		$	(14,798	)	$	499,327

Investment_Securities_Tables

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Amortized Cost and Estimated Fair Values of Investments in Debt and Equity Securities	The amortized cost and estimated fair values of investments in debt and equity securities are summarized in the following tables:
		December 31, 2014
		Amortized		Gross			Gross			Estimated
		Cost		Unrealized			Unrealized			Fair Value
				Gains			Losses
		(in thousands)
	Securities Available for Sale
	Obligations of U.S. government corporations and agencies	$	71,144		4,001			(25	)	$	75,120
	Obligations of states and political subdivisions		3,130		45			—			3,175
	Corporate debt securities		1,891		17			—			1,908
	Marketable equity securities		3,000		2			—			3,002
	Total securities available for sale	$	79,165	$	4,065		$	(25	)	$	83,205
	Securities Held to Maturity
	Obligations of U.S. government corporations and agencies	$	660,836		13,055			(677	)	$	673,214
	Obligations of states and political subdivisions		15,590		130			(155	)		15,565
	Total securities held to maturity	$	676,426	$	13,185		$	(832	)	$	688,779
		December 31, 2013
		Amortized		Gross			Gross			Estimated
		Cost		Unrealized			Unrealized			Fair
				Gains			Losses			Value
		(in thousands)
	Securities Available for Sale
	Obligations of U.S. government corporations and agencies	$	93,055	$	4,445		$	(357	)	$	97,143
	Obligations of states and political subdivisions		5,513		77			(1	)		5,589
	Corporate debt securities		1,877		38			—			1,915
	Total securities available for sale	$	100,445	$	4,560		$	(358	)	$	104,647
	Securities Held to Maturity
	Obligations of U.S. government corporations and agencies	$	227,864	$	298		$	(5,540	)	$	222,622
	Obligations of states and political subdivisions		12,640		—			(1,455	)		11,185
	Total securities held to maturity	$	240,504	$	298		$	(6,995	)	$	233,807
Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity	For purposes of the following table, the entire outstanding balance of these mortgage-backed securities issued by U.S. government corporations and agencies is categorized based on final maturity date.
	Investment Securities	Available for Sale					Held to Maturity
	(In thousands)	Amortized		Estimated			Amortized			Estimated
		Cost		Fair Value			Cost			Fair Value
	Due in one year	$	1,924	$	1,942			—			—
	Due after one year through five years		1,095		1,135			—			—
	Due after five years through ten years		30,977		32,316		$	1,118		$	1,106
	Due after ten years		45,169		47,812			675,308			687,673
	Totals	$	79,165	$	83,205		$	676,426		$	688,779
Gross Unrealized Losses on Investment	Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, were as follows:
		Less than 12 months					12 months or more						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Loss			Value			Loss			Value		Loss
	December 31, 2014	(in thousands)
	Securities Available for Sale:
	Obligations of U.S. government corporations and agencies	$	6,774		(25	)		—			—			6,774		(25	)
	Obligations of states and political subdivisions		—		—			—			—			—		—
	Corporate debt securities		—		—			—			—			—		—
	Marketable equity securities		—		—			—			—			—		—
	Total securities available-for-sale	$	6,774		(25	)		—			—			6,774		(25	)
	Securities Held to Maturity:
	Obligations of U.S. government corporations and agencies	$	335		(1	)		56,288			(676	)		56,623		(677	)
	Obligations of states and political subdivisions		1,600		(26	)		1,858			(129	)		3,458		(155	)
	Corporate debt securities		—		—			—			—			—		—
	Total securities held-to-maturity	$	1,935		(27	)		58,146			(805	)		60,081		(832	)
		Less than 12 months					12 months or more						Total
		Fair Value		Unrealized			Fair			Unrealized			Fair Value		Unrealized
				Loss			Value			Loss					Loss
	December 31, 2013	(in thousands)
	Securities Available for Sale:
	Obligations of U.S. government corporations and agencies	$	10,287	$	(357	)		—			—		$	10,287	$	(357	)
	Obligations of states and political subdivisions		199		(1	)		—			—			199		(1	)
	Corporate debt securities		—		—			—			—			—		—
	Total securities available-for-sale	$	10,486	$	(358	)		—			—		$	10,486	$	(358	)
	Securities Held to Maturity:
	Obligations of U.S. government corporations and agencies	$	188,218	$	(5,540	)		—			—		$	188,218	$	(5,540	)
	Obligations of states and political subdivisions		11,185		(1,455	)		—			—			11,185		(1,455	)
	Corporate debt securities		—		—			—			—			—		—
	Total securities held-to-maturity	$	199,403	$	(6,995	)		—			—		$	199,403	$	(6,995	)

Loans_Tables

Loans (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Summary of Loan Balances	A summary of loan balances follows (in thousands):
		December 31, 2014
		Originated			PNCI			PCI -			PCI -			Total
								Cash basis			Other
	Mortgage loans on real estate:
	Residential 1-4 family	$	154,594		$	120,821			—		$	4,005		$	279,420
	Commercial		928,797			376,225			—			30,917			1,335,939
	Total mortgage loan on real estate		1,083,391			497,046			—			34,922			1,615,359
	Consumer:
	Home equity lines of credit		305,166			38,397		$	5,478			3,543			352,584
	Home equity loans		23,559			6,985			125			645			31,314
	Auto Indirect		112			—			—			—			112
	Other		28,230			4,770			—			74			33,074
	Total consumer loans		357,067			50,152			5,603			4,262			417,084
	Commercial		126,611			40,899			8			7,427			174,945
	Construction:
	Residential		21,135			16,808			—			675			38,618
	Commercial		24,545			11,973			—			—			36,518
	Total construction		45,680			28,781			—			675			75,136
	Total loans, net of deferred loan fees and discounts	$	1,612,749		$	616,878		$	5,611		$	47,286		$	2,282,524
	Total principal balance of loans owed, net of charge-offs	$	1,617,542		$	634,490		$	14,805		$	56,016		$	2,322,853
	Unamortized net deferred loan fees		(4,793	)		—			—			—			(4,793	)
	Discounts to principal balance of loans owed, net of charge-offs		—			(17,612	)		(9,194	)		(8,730	)		(35,536	)
	Total loans, net of unamortized deferred loan fees and discounts	$	1,612,749		$	616,878		$	5,611		$	47,286		$	2,282,524
	Noncovered loans	$	1,612,749		$	616,878		$	5,611		$	25,018		$	2,260,256
	Covered loans		—			—			—			22,268			22,268
	Total loans, net of unamortized deferred loan fees and discounts	$	1,612,749		$	616,878		$	5,611		$	47,286		$	2,282,524
	Allowance for loan losses	$	(29,860	)	$	(3,296	)	$	(348	)	$	(3,081	)	$	(36,585	)
	A summary of loan balances follows (in thousands):
		December 31, 2013
		Originated			PNCI			PCI -			PCI -			Total
								Cash basis			Other
	Mortgage loans on real estate:
	Residential 1-4 family	$	129,882		$	60,475			—		$	4,656		$	195,013
	Commercial		824,912			57,678			—			30,260			912,850
	Total mortgage loan on real estate		954,794			118,153			—			34,916			1,107,863
	Consumer:
	Home equity lines of credit		316,207			13,576		$	6,200			3,883			339,866
	Home equity loans		13,849			253			—			486			14,588
	Auto Indirect		946			—			—			—			946
	Other		25,608			2,074			—			81			27,763
	Total consumer loans		356,610			15,903			6,200			4,450			383,163
	Commercial		124,650			693			19			6,516			131,878
	Construction:
	Residential		30,367			—			—			1,566			31,933
	Commercial		17,125			—			—			45			17,170
	Total construction		47,492			—			—			1,611			49,103
	Total loans, net of deferred loan fees and discounts	$	1,483,546		$	134,749		$	6,219		$	47,493		$	1,672,007
	Total principal balance of loans owed, net of charge-offs	$	1,487,240		$	142,786		$	16,475		$	56,879		$	1,703,380
	Unamortized net deferred loan fees		(3,694	)		—			—			—			(3,694	)
	Discounts to principal balance of loans owed, net of charge-offs		—			(8,037	)		(10,256	)		(9,386	)		(27,679	)
	Total loans, net of unamortized deferred loan fees and discounts	$	1,483,546		$	134,749		$	6,219		$	47,493		$	1,672,007
	Noncovered loans	$	1,483,546		$	134,749		$	6,219		$	19,581		$	1,644,095
	Covered loans		—			—			—			27,912			27,912
	Total loans, net of unamortized deferred loan fees and discounts	$	1,483,546		$	134,749		$	6,219		$	47,493		$	1,672,007
	Allowance for loan losses	$	(31,354	)	$	(2,850	)	$	(385	)	$	(3,656	)	$	(38,245	)
Change in Accretable Yield for PCI	The following is a summary of the change in accretable yield for PCI – other loans during the periods indicated (in thousands):
		Year ended December 31,
		2014			2013
	Change in accretable yield:
	Balance at beginning of period	$	18,232		$	22,337
	Accretion to interest income		(4,368	)		(6,305	)
	Reclassification (to) from nonaccretable difference		1,009			2,201
	Balance at end of period	$	14,873		$	18,232

Allowance_for_Loan_Losses_Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Summary of Activity in Allowance for Loan Losses, and Ending Balance of Loans, Net of Unearned Fees for Periods Indicated	The following tables summarize the activity in the allowance for loan losses, and ending balance of loans, net of unearned fees for the periods indicated.
		Allowance for Loan Losses - Year Ended December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Beginning balance	$	3,154		$	9,700		$	16,375		$	1,208		$	66		$	589		$	4,331		$	1,559		$	1,263		$	38,245
	Charge-offs		(171	)		(110	)		(1,094	)		(29	)		(3	)		(599	)		(479	)		(4	)		(69	)		(2,558	)
	Recoveries		2			540			960			34			86			495			1,268			1,377			181			4,943
	(Benefit) provision		101			(903	)		(565	)		584			(140	)		234			(894	)		(1,498	)		(964	)		(4,045	)
	Ending balance	$	3,086		$	9,227		$	15,676		$	1,797		$	9		$	719		$	4,226		$	1,434		$	411		$	36,585
	Ending balance:
	Individ. evaluated for impairment	$	974		$	410		$	1,974		$	284			—		$	142		$	423		$	60			—		$	4,267
	Loans pooled for evaluation	$	1,915		$	8,408		$	13,251		$	1,513		$	9		$	572		$	2,569		$	332		$	322		$	28,891
	Loans acquired with deteriorated credit quality	$	197		$	409		$	451			—			—		$	5		$	1,234		$	1,042		$	89		$	3,427
		Loans, net of unearned fees - As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Ending balance:
	Total loans	$	279,420		$	1,335,939		$	352,584		$	31,314		$	112		$	33,074		$	174,945		$	38,618		$	35,518		$	2,282,524
	Individ. evaluated for impairment	$	7,188		$	41,932		$	6,968		$	1,278		$	18		$	323		$	1,757		$	2,683		$	99		$	62,246
	Loans pooled for evaluation	$	268,227		$	1,263,090		$	336,595		$	29,266		$	94		$	32,677		$	165,753		$	35,260		$	36,419		$	2,167,381
	Loans acquired with deteriorated credit quality	$	4,005		$	30,917		$	9,021		$	770			—		$	74		$	7,435		$	675			—		$	52,897
		Allowance for Loan Losses - Year Ended December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Beginning balance	$	3,523		$	8,782		$	21,367		$	1,155		$	243		$	696		$	4,703		$	1,400		$	779		$	42,648
	Charge-offs		(46	)		(2,038	)		(2,651	)		(94	)		(68	)		(887	)		(1,599	)		(20	)		(140	)		(7,543	)
	Recoveries		345			994			1,053			41			195			759			340			63			65			3,855
	(Benefit) provision		(668	)		1,962			(3,394	)		106			(304	)		21			887			116			559			(715	)
	Ending balance	$	3,154		$	9,700		$	16,375		$	1,208		$	66		$	589		$	4,331		$	1,559		$	1,263		$	38,245
	Ending balance:
	Individ. evaluated for impairment	$	775		$	1,198		$	1,140		$	169		$	1		$	8		$	585		$	91		$	8		$	3,975
	Loans pooled for evaluation	$	2,039		$	7,815		$	14,749		$	1,039		$	65		$	581		$	2,402		$	751		$	789		$	30,230
	Loans acquired with deteriorated credit quality	$	340		$	687		$	486			—			—			—		$	1,344		$	717		$	466		$	4,040
		Loans, net of unearned fees - As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Ending balance:
	Total loans	$	195,013		$	912,850		$	339,866		$	14,588		$	946		$	27,763		$	131,878		$	31,933		$	17,170		$	1,672,007
	Individ. evaluated for impairment	$	7,342		$	59,936		$	6,918		$	778		$	60		$	90		$	3,177		$	2,756		$	178		$	81,235
	Loans pooled for evaluation	$	183,015		$	822,654		$	322,865		$	13,324		$	886		$	27,592		$	122,166		$	27,611		$	16,947		$	1,537,060
	Loans acquired with deteriorated credit quality	$	4,656		$	30,260		$	10,083		$	486			—		$	81		$	6,535		$	1,566		$	45		$	53,712
		Allowance for Loan Losses - Year Ended December 31, 2012
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Beginning balance	$	2,404		$	13,217		$	18,258		$	1,101		$	215		$	932		$	6,545		$	1,817		$	1,425		$	45,914
	Charge-offs		(1,558	)		(3,457	)		(8,042	)		(385	)		(83	)		(1,202	)		(1,251	)		(406	)		(100	)		(16,484	)
	Recoveries		147			1,020			398			100			215			860			643			412			—			3,795
	Provision (benefit)		2,530			(1,998	)		10,753			339			(104	)		106			(1,234	)		(423	)		(546	)		9,423
	Ending balance	$	3,523		$	8,782		$	21,367		$	1,155		$	243		$	696		$	4,703		$	1,400		$	779		$	42,648
	Ending balance:
	Individ. evaluated for impairment	$	631		$	515		$	2,264		$	81		$	5		$	47		$	840		$	11		$	111		$	4,505
	Loans pooled for evaluation	$	2,526		$	8,026		$	17,862		$	995		$	238		$	649		$	2,342		$	430		$	165		$	33,233
	Loans acquired with deteriorated credit quality	$	366		$	241		$	1,241		$	79			—			—		$	1,521		$	959		$	503		$	4,910
		Loans, net of unearned fees – As of December 31, 2012
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Ending balance:
	Total loans	$	131,684		$	878,446		$	342,025		$	13,557		$	3,816		$	26,713		$	135,528		$	18,459		$	14,595		$	1,564,823
	Individ. evaluated for impairment	$	6,586		$	71,077		$	10,056		$	528		$	197		$	121		$	8,562		$	3,596		$	607		$	101,330
	Loans pooled for evaluation	$	120,082		$	776,137		$	318,403		$	12,825		$	3,619		$	26,560		$	117,429		$	8,281		$	10,589		$	1,393,925
	Loans acquired with deteriorated credit quality	$	5,016		$	31,232		$	13,566		$	204			—		$	32		$	9,537		$	6,582		$	3,399		$	69,568
Presentation of Credit Quality Indicators	The following tables present ending loan balances by loan category and risk grade for the periods indicated:
		Credit Quality Indicators – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Originated loans:
	Pass	$	146,949		$	883,102		$	292,244		$	20,976		$	66		$	27,396		$	124,707		$	18,112		$	24,436		$	1,537,988
	Special mention		1,122			11,521			3,590			743			11			591			636			622			—			18,836
	Substandard		6,523			34,174			9,332			1,840			35			243			1,268			2,401			109			55,925
	Loss		—			—			—			—			—			—			—			—			—			—
	Total originated	$	154,594		$	928,797		$	305,166		$	23,559		$	112		$	28,230		$	126,611		$	21,135		$	24,545		$	1,612,749
	PNCI loans:
	Pass	$	119,643		$	359,537		$	36,531		$	6,813			—		$	4,399		$	40,628		$	16,808		$	11,973		$	596,332
	Special mention		547			12,979			936			147			—			230			268			—			—			15,107
	Substandard		631			3,709			930			25			—			141			3			—			—			5,439
	Loss		—			—			—			—			—			—			—			—			—			—
	Total PNCI	$	120,821		$	376,225		$	38,397		$	6,985			—		$	4,770		$	40,899		$	16,808		$	11,973		$	616,878
	PCI loans	$	4,005		$	30,917		$	9,021		$	770			—		$	74		$	7,435		$	675			—		$	52,897
	Total loans	$	279,420		$	1,335,939		$	352,584		$	31,314		$	112		$	33,074		$	174,945		$	38,618		$	36,518		$	2,282,524
					Credit Quality Indicators – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Originated loans:
	Pass	$	121,969		$	768,596		$	203,232		$	12,284		$	717		$	24,653		$	121,580		$	25,836		$	16,571		$	1,394,438
	Special mention		1,265			15,862			4,529			504			118			756			938			96			343			24,411
	Substandard		6,648			40,454			9,446			1,061			111			196			2,122			4,435			211			64,684
	Loss		—			—			—			—			—			3			10			—			—			13
	Total originated	$	129,882		$	824,912		$	316,207		$	13,849		$	946		$	25,608		$	124,650		$	30,367		$	17,125		$	1,483,546
	PNCI loans:
	Pass	$	59,798		$	48,548		$	12,716		$	253			—		$	2,020		$	380			—			—		$	123,715
	Special mention		—			5,810			195			—			—			18			313			—			—			6,336
	Substandard		677			3,320			665			—			—			36			—			—			—			4,698
	Loss		—			—			—			—			—			—			—			—			—			—
	Total PNCI	$	60,475		$	57,678		$	13,576		$	253			—		$	2,074		$	693			—			—		$	134,749
	PCI loans	$	4,656		$	30,260		$	10,083		$	486			—		$	81		$	6,535		$	1,566		$	45		$	53,712
	Total loans	$	195,013		$	912,850		$	339,866		$	14,588		$	946		$	27,763		$	131,878		$	31,933		$	17,170		$	1,672,007
Analysis of Past Due and Nonaccrual Loans	The following table shows the ending balance of current, past due, and nonaccrual originated loans by loan category as of the date indicated:
		Analysis of Past Due and Nonaccrual Originated Loans – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	Originated loan balance:
	Past due:
	30-59 Days	$	1,296		$	735		$	2,066		$	615		$	4		$	64		$	739			—			—		$	5,519
	60-89 Days		919			—			296			192			—			24			99			—			—			1,530
	> 90 Days		100			900			754			202			17			46			61			—			—			2,080
	Total past due	$	2,315		$	1,635		$	3,116		$	1,009		$	21		$	134		$	899			—			—		$	9,129
	Current		152,279			927,162			302,050			22,550			91			28,096			125,712			21,135			24,545			1,603,620
	Total orig. loans	$	154,594		$	928,797		$	305,166		$	23,559		$	112		$	28,230		$	126,611		$	21,135		$	24,545		$	1,612,749
	> 90 Days and still accruing		—			—			—			—			—			—			—			—			—			—
	Nonaccrual loans	$	3,430		$	20,736		$	4,336		$	1,197		$	18		$	66		$	246		$	2,401		$	99		$	32,529
	The following table shows the ending balance of current, past due, and nonaccrual PNCI loans by loan category as of the date indicated:
		Analysis of Past Due and Nonaccrual PNCI Loans – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
	PNCI loan balance:
	Past due:
	30-59 Days	$	2,041		$	260		$	275			—			—		$	25		$	67			—			—		$	2,668
	60-89 Days		24			—			118			—			—			3			—			—			—			145
	> 90 Days		239			—			73			25			—			76			—			—			—			413
	Total past due	$	2,304		$	260		$	466		$	25			—		$	104		$	67			—			—		$	3,226
	Current		118,517			375,965			37,931			6,960			—			4,666			40,832			16,808			11,973		$	613,652
	Total PNCI loans	$	120,821		$	376,225		$	38,397		$	6,985			—		$	4,770		$	40,899		$	16,808		$	11,973		$	616,878
	> 90 Days and still accruing		—			—			—			—			—			—			—			—			—			—
	Nonaccrual loans	$	799		$	366		$	346		$	25			—		$	110			—			—			—		$	1,646
	The following table shows the ending balance of current, past due, and nonaccrual originated loans by loan category as of the date indicated:
		Analysis of Past Due and Nonaccrual Originated Loans – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
	Originated loan balance:
	Past due:
	30-59 Days	$	2,272		$	2,304		$	3,121		$	264		$	24		$	40		$	296			—			—		$	8,321
	60-89 Days		284			—			1,070			16			1			16			76			—		$	198			1,661
	> 90 Days		447			2,213			1,050			312			33			7			749			13			—			4,824
	Total past due	$	3,003		$	4,517		$	5,241		$	592		$	58		$	63		$	1,121		$	13		$	198		$	14,806
	Current		126,879			820,395			310,966			13,257			888			25,545			123,529			30,354			16,927			1,468,740
	Total orig. loans	$	129,882		$	824,912		$	316,207		$	13,849		$	946			25,608		$	124,650		$	30,367		$	17,125		$	1,483,546
	> 90 Days and still accruing		—			—			—			—			—			—			—			—			—			—
	Nonaccrual loans	$	4,697		$	30,732		$	4,972		$	719		$	54		$	26		$	1,280		$	2,473		$	178		$	45,131
	The following table shows the ending balance of current, past due, and nonaccrual PNCI loans by loan category as of the date indicated:
		Analysis of Past Due and Nonaccrual PNCI Loans – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	PNCI loan balance:
	Past due:
	30-59 Days	$	799		$	512		$	313			—			—		$	49			—			—			—		$	1,673
	60-89 Days		—			352			38			—			—			—			—			—			—			390
	> 90 Days		—			217			—			—			—			—			—			—			—			217
	Total past due	$	799		$	1,081		$	351			—			—		$	49			—			—			—		$	2,280
	Current		59,676			56,597			13,225		$	253			—			2,025		$	693			—			—			132,469
	Total PNCI loans	$	60,475		$	57,678		$	13,576		$	253			—		$	2,074		$	693			—			—		$	134,749
	> 90 Days and still accruing		—			—			—			—			—			—			—			—			—			—
	Nonaccrual loans	$	262		$	1,139		$	429			—			—		$	36			—			—			—		$	1,866
Impaired Loans	Impaired originated loans are those where management has concluded that it is probable that the borrower will be unable to pay all amounts due under the contractual terms. The following tables show the recorded investment (financial statement balance), unpaid principal balance, average recorded investment, and interest income recognized for impaired Originated and PNCI loans, segregated by those with no related allowance recorded and those with an allowance recorded for the periods indicated.
		Impaired Originated Loans – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	With no related allowance recorded:
	Recorded investment	$	3,287		$	38,477		$	3,001		$	750		$	14		$	25		$	412		$	2,401		$	99		$	48,466
	Unpaid principal	$	5,138		$	41,949		$	6,094		$	1,187		$	49		$	32		$	433		$	6,588		$	190		$	61,660
	Average recorded Investment	$	3,826		$	45,915		$	3,355		$	651		$	35		$	21		$	1,030		$	2,437		$	84		$	57,354
	Interest income Recognized	$	38		$	995		$	26		$	6			—		$	1		$	26			—		$	3		$	1,095
	With an allowance recorded:
	Recorded investment	$	2,724		$	2,943		$	3,185		$	504		$	4		$	41		$	1,338		$	282			—		$	11,021
	Unpaid principal	$	2,865		$	3,101		$	3,533		$	597		$	6		$	41		$	1,438		$	282			—		$	11,863
	Related allowance	$	797		$	302		$	1,769		$	284			—		$	11		$	423		$	60			—		$	3,646
	Average recorded Investment	$	2,677		$	4,119		$	2,982		$	365		$	4		$	25		$	1,428		$	283		$	55		$	11,938
	Interest income Recognized	$	91		$	144		$	71		$	13			—			—		$	71		$	19			—		$	409
		Impaired PNCI Loans – As of December 31, 2014
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	With no related allowance recorded:
	Recorded investment	$	343		$	366		$	346		$	25			—		$	37		$	7			—			—		$	1,124
	Unpaid principal	$	353		$	2,620		$	374		$	25			—		$	54		$	7			—			—		$	3,433
	Average recorded Investment	$	246		$	753		$	287		$	12			—		$	36		$	10			—			—		$	1,344
	Interest income Recognized	$	14			—		$	(1	)		—			—			—		$	1			—			—		$	14
	With an allowance recorded:
	Recorded investment	$	834		$	146		$	436			—			—		$	220			—			—			—		$	1,636
	Unpaid principal	$	852		$	146		$	436			—			—		$	220			—			—			—		$	1,654
	Related allowance	$	177		$	108		$	205			—			—		$	131			—			—			—		$	621
	Average recorded Investment	$	516		$	148		$	319			—			—		$	124			—			—			—		$	1,107
	Interest income Recognized	$	8		$	8		$	20			—			—		$	12			—			—			—		$	48
		Impaired Originated Loans – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	With no related allowance recorded:
	Recorded investment	$	4,366		$	53,352		$	3,710		$	552		$	55		$	16		$	1,648		$	2,473		$	69		$	66,241
	Unpaid principal	$	6,489		$	58,894		$	7,299		$	1,249		$	123		$	21		$	1,665		$	6,611		$	138		$	82,489
	Average recorded Investment	$	4,123		$	58,205		$	4,410		$	463		$	93		$	18		$	2,154		$	1,567		$	83		$	71,116
	Interest income Recognized	$	336		$	3,361		$	352		$	36		$	12		$	1		$	113		$	108		$	7		$	4,326
	With an allowance recorded:
	Recorded investment	$	2,630		$	5,296		$	2,779		$	226		$	4		$	10		$	1,517		$	284		$	109		$	12,855
	Unpaid principal	$	2,689		$	5,659		$	3,053		$	291		$	6		$	10		$	1,616		$	284		$	288		$	13,896
	Related allowance Average recorded	$	648		$	1,084		$	968		$	169		$	1		$	5		$	585		$	91		$	7		$	3,558
	Investment	$	2,245		$	6,077		$	3,064		$	141		$	12		$	7		$	1,817		$	1,499		$	188		$	15,050
	Interest income Recognized	$	124		$	287		$	146		$	18		$	1		$	2		$	95		$	19		$	15		$	707
		Impaired PNCI Loans – As of December 31, 2013
		RE Mortgage						Home Equity						Auto			Other						Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
	With no related allowance recorded:
	Recorded investment	$	148		$	1,139		$	227			—			—		$	36		$	12			—			—		$	1,562
	Unpaid principal	$	158		$	3,323		$	287			—			—		$	45		$	12			—			—		$	3,825
	Average recorded Investment	$	37		$	1,005		$	333			—			—		$	39		$	7			—			—		$	1,421
	Interest income Recognized	$	11		$	233		$	21			—			—		$	5		$	1			—			—		$	271
	With an allowance recorded:
	Recorded investment	$	198		$	149		$	203			—			—		$	28			—			—			—		$	578
	Unpaid principal	$	207		$	149		$	215			—			—		$	28			—			—			—		$	599
	Related allowance	$	128		$	114		$	172			—			—		$	3			—			—			—		$	417
	Average recorded Investment	$	275		$	250		$	162			—			—		$	29			—			—			—		$	716
	Interest income Recognized	$	12		$	9		$	10			—			—		$	1			—			—			—		$	32
		Impaired Originated Loans – As of December 31, 2012
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
	(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
	With no related allowance recorded:
	Recorded investment	$	3,520		$	66,031		$	4,241		$	361		$	163		$	19		$	4,238		$	3,554		$	284		$	82,411
	Unpaid principal	$	5,349		$	70,709		$	6,691		$	781		$	311		$	40		$	4,613		$	8,227		$	484		$	97,205
	Average recorded Investment	$	6,329		$	61,299		$	4,311		$	329		$	263		$	42		$	7,500		$	3,505		$	517		$	84,095
Interest income Recognized	$	71		$	2,513		$	58		$	1		$	3			—		$	73		$	20		$	10		$	2,749
With an allowance recorded:
Recorded investment	$	2,867		$	3,258		$	5,412		$	167		$	34		$	30		$	4,324		$	42		$	323		$	16,457
Unpaid principal	$	3,432		$	3,556		$	7,103		$	396		$	51		$	32		$	4,992		$	42		$	523		$	20,127
Related allowance	$	603		$	352		$	2,237		$	81		$	5		$	12		$	840		$	11		$	111		$	4,252
Average recorded Investment	$	3,890		$	7,841		$	6,331		$	317		$	102		$	49		$	2,800		$	1,543		$	6,570		$	29,443
Interest income Recognized	$	67		$	129		$	103		$	16		$	1		$	1		$	100		$	6		$	5		$	428
	Impaired PNCI Loans – As of December 31, 2012
	RE Mortgage						Home Equity						Auto			Other						Construction
(in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.			C&I			Resid.			Comm.			Total
With no related allowance recorded:
Recorded investment		—		$	1,468		$	365			—			—			—			—			—			—		$	1,833
Unpaid principal		—		$	3,452		$	586			—			—			—			—			—			—		$	4,038
Average recorded Investment	$	16		$	2,097		$	308		$	11			—		$	31		$	11			—			—		$	2,474
Interest income Recognized		—		$	133		$	5			—			—			—			—			—			—		$	138
With an allowance recorded:
Recorded investment	$	199		$	320		$	38			—			—		$	72			—			—			—		$	629
Unpaid principal	$	225		$	331		$	41			—			—		$	76			—			—			—		$	673
Related allowance	$	28		$	163		$	27			—			—		$	35			—			—			—		$	253
Average recorded Investment	$	213		$	121		$	148			—			—		$	43			—			—			—		$	525
Interest income Recognized	$	9		$	12		$	1			—			—		$	2			—			—			—		$	24
Troubled Debt Restructurings	The following tables show certain information regarding Troubled Debt Restructurings (TDRs) that occurred during the periods indicated:
		TDR Information for the Year Ended December 31, 2014
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
	(dollars in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
	Number		5			7			6			2			—			1			7			1			2			31
	Pre-mod outstanding principal balance	$	1,048		$	1,980		$	940		$	100			—		$	147		$	218		$	102		$	219		$	4,754
	Post-mod outstanding principal balance	$	1,050		$	1,890		$	967		$	102			—		$	147		$	219		$	85		$	196		$	4,656
	Financial impact due to TDR taken as additional provision	$	91		$	22			—		$	(1	)		—		$	66		$	101			—			—		$	279
	Number that defaulted during the period		2			2			1			—			—			—			1			—			—			6
	Recorded investment of TDRs that defaulted during the period	$	344		$	423		$	20			—			—			—		$	116			—			—		$	903
	Financial impact due to the default of previous TDR taken as charge-offs or additional provisions		—			—			—			—			—			—		$	(8	)		—			—		$	(8	)
		TDR Information for the Year Ended December 31, 2013
		RE Mortgage						Home Equity						Auto			Other			C&I			Construction
	(dollars in thousands)	Resid.			Comm.			Lines			Loans			Indirect			Consum.						Resid.			Comm.			Total
	Number		9			11			12			2			—			—			8			—			—			42
	Pre-mod outstanding principal balance	$	2,173		$	13,145		$	1,546		$	251			—			—		$	274			—			—		$	17,389
	Post-mod outstanding principal balance	$	2,177		$	13,146		$	1,557		$	253			—			—		$	275			—			—		$	17,408
	Financial impact due to TDR taken as additional provision	$	148		$	27		$	340		$	(1	)		—			—		$	88			—			—		$	602
	Number that defaulted during the period		4			8			3			1			—			—			4			1			—			21
	Recorded investment of TDRs that defaulted during the period	$	443		$	1,702		$	150		$	15			—			—		$	1,363		$	73			—		$	3,746
	Financial impact due to the default of previous TDR taken as charge-offs or additional provisions	$	(3	)	$	7			—			—			—			—		$	3		$	5			—		$	12

Foreclosed_Assets_Tables

Foreclosed Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Summary of Activity in Balance of Foreclosed Assets	A summary of the activity in the balance of foreclosed assets follows (dollars in thousands):
		Year ended December 31, 2014									Year ended December 31, 2013
		Noncovered			Covered			Total			Noncovered			Covered			Total
	Beginning balance, net	$	5,588		$	674		$	6,262		$	5,957		$	1,541		$	7,498
	Acquisitions		695			—			695			—			—			—
	Additions/transfers from loans		5,753			—			5,753			11,224			493			11,717
	Dispositions/sales		(7,391	)		(217	)		(7,608	)		(10,992	)		(1,279	)		(12,271	)
	Valuation adjustments		(196	)		(12	)		(208	)		(601	)		(81	)		(682	)
	Ending balance, net	$	4,449		$	445		$	4,894		$	5,588		$	674		$	6,262
	Ending valuation allowance	$	(208	)		—		$	(208	)	$	(414	)		—		$	(414	)
	Ending number of foreclosed assets		28			1			29			28			4			32
	Proceeds from sale of foreclosed assets	$	9,517		$	245		$	9,762		$	12,483		$	1,427		$	13,910
	Gain on sale of foreclosed assets	$	2,125		$	28		$	2,153		$	1,492		$	148		$	1,640

Premises_and_Equipment_Tables

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Summary of Premises and Equipment	Premises and equipment were comprised of:
		December 31,			December 31,
		2014			2013
		(In thousands)
	Land & land improvements	$	8,933		$	5,975
	Buildings		39,638			30,103
	Furniture and equipment		28,446			27,881
			77,017			63,959
	Less: Accumulated depreciation		(33,570	)		(32,397	)
			43,447			31,562
	Construction in progress		46			50
	Total premises and equipment	$	43,493		$	31,612

Cash_Value_of_Life_Insurance_T

Cash Value of Life Insurance (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, All Other Investments [Abstract]
Summary of Activity in Balance of Cash Value of Life Insurance	A summary of the activity in the balance of cash value of life insurance follows (dollars in thousands):
		Year ended December 31,
		2014		2013
	Beginning balance	$	52,309	$	50,582
	Acquisitions		38,075		—
	Increase in cash value of life insurance		1,953		1,727
	Ending balance	$	92,337	$	52,309
	End of period death benefit	$	165,966	$	95,513
	Number of policies owned		189		133
	Insurance companies used		14		6
	Current and former employees and directors covered		60		36

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill Intangible	The following table summarizes the Company’s goodwill intangible as of the dates indicated:
	(Dollar in Thousands)	December 31,			Additions		Reductions			December 31,
		2014								2013
	Goodwill	$	63,462		$	47,943		—		$	15,519
Summary of Core Deposit Intangibles	The following table summarizes the Company’s core deposit intangibles as of the dates indicated:
	(Dollar in Thousands)	December 31,			Additions		Reductions/			Fully		December 31,
		2014					Amortization			Depreciated		2013
	Core deposit intangibles	$	8,074		$	6,614		—			—	$	1,460
	Accumulated amortization		(1,023	)		—	$	(446	)		—		(577	)
	Core deposit intangibles, net	$	7,051		$	6,614	$	(446	)		—	$	883
Estimated Core Deposit Intangible Amortization	The following table summarizes the Company’s estimated core deposit intangible amortization (dollars in thousands):
	Years Ended	Estimated Core Deposit
		Intangible Amortization
	2015	$	1,157
	2016		1,157
	2017		1,109
	2018		1,044
	2019		948
	Thereafter	$	1,636

Mortgage_Servicing_Rights_Tabl

Mortgage Servicing Rights (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Fair Value of Mortgage Servicing Rights	The following tables summarize the activity in, and the main assumptions we used to determine the fair value of mortgage servicing rights for the periods indicated (dollars in thousands):
		Years ended December 31,
		2014			2013			2012
	Balance at beginning of period	$	6,165		$	4,552		$	4,603
	Acquisition		1,944			—			—
	Originations		570			1,360			1,965
	Change in fair value		(1,301	)		253			(2,016	)
	Balance at end of period	$	7,378		$	6,165		$	4,552
	Contractually specified servicing fees, late fees and ancillary fees earned	$	1,869		$	1,774		$	1,666
	Balance of loans serviced at:
	Beginning of period	$	680,197		$	666,512		$	598,185
	End of period	$	840,288		$	680,197		$	666,512
	Weighted-average prepayment speed (CPR)		12	%		10.3	%		20.3	%
	Weighted-average discount rate		10	%		10	%		10	%

Indemnification_Asset_Tables

Indemnification Asset (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Summary of Activity in Balance of Indemnification Asset (Liability)	A summary of the activity in the balance of indemnification asset (liability) included in other assets is follows (in thousands):
		Year ended December 31,
		2014			2013			2012
	Beginning balance	$	206		$	1,997		$	4,405
	Effect of actual covered losses (recoveries) and increase (decrease) in estimated future covered losses		(869	)		(1,419	)		(245	)
	Reimbursable (revenue) expenses incurred		69			(159	)		69
	Payments made (received)		245			(213	)		(2,232	)
	Ending balance	$	(349	)	$	206		$	1,997

Other_Assets_Tables

Other Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Other Assets	Other assets were comprised of (in thousands):
		As of December 31,
		2014		2013
	Deferred tax asset, net (Note 22)	$	37,706	$	26,781
	Prepaid expense		2,034		2,131
	Software		1,327		1,318
	Advanced compensation		908		1,175
	Capital Trusts		1,690		1,238
	Miscellaneous other assets		8,070		3,443
	Total other assets	$	51,735	$	36,086

Deposits_Tables

Deposits (Tables)	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Summary of Balances of Deposits	A summary of the balances of deposits follows (in thousands):
		December 31,
		2014		2013
	Noninterest-bearing demand	$	1,083,900	$	789,458
	Interest-bearing demand		782,385		533,351
	Savings		1,156,126		798,986
	Time certificates, $250,000 and over		38,217		31,542
	Other time certificates		319,795		257,146
	Total deposits	$	3,380,423	$	2,410,483
Schedule of Maturities of Time Deposits	At December 31, 2014, the scheduled maturities of time deposits were as follows (in thousands):
		Scheduled
		Maturities
	2015	$	282,629
	2016		46,606
	2017		17,017
	2018		6,241
	2019		5,516
	Thereafter		3
	Total	$	358,012

Reserve_for_Unfunded_Commitmen1

Reserve for Unfunded Commitments (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Summary of Activity in Reserve for Unfunded Commitments	The following tables summarize the activity in reserve for unfunded commitments for the periods indicated (dollars in thousands):
		Years ended December 31,
		2014			2013			2012
	Balance at beginning of period	$	2,415		$	3,615		$	2,740
	Acquisitions		125			—			—
	Provision for losses – Unfunded commitments		(395	)		(1,200	)		875
	Balance at end of period	$	2,145		$	2,415		$	3,615

Other_Liabilities_Tables

Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Components of Other Liabilities	Other liabilities were comprised of (in thousands):
		December 31,
		2014		2013
	Deferred compensation	$	7,408	$	7,357
	Pension liability		26,798		14,634
	Joint beneficiary agreements		2,728		2,623
	Miscellaneous other liabilities		12,258		7,097
	Total other liabilities	$	49,192	$	31,711

Other_Borrowings_Tables

Other Borrowings (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Summary of Balances of Other Borrowings	A summary of the balances of other borrowings follows:
		December 31,
		2014		2013
		(in thousands)
	Other collateralized borrowings, fixed rate, as of December 31, 2014 of 0.05%, payable on January 2, 2014	$	9,276	$	6,335
	Total other borrowings	$	9,276	$	6,335

Junior_Subordinated_Debt_Table

Junior Subordinated Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Summary of Terms and Recorded Balance of Subordinated Debenture	The following table summarizes the terms and recorded balance of each subordinated debenture as of the date indicated (dollars in thousands):
	Subordinated	Maturity		Face		Coupon Rate			As of December 31, 2014
	Debt Series	Date		Value		(Variable)
						3 mo. LIBOR +			Current			Recorded
									Coupon Rate			Book Value
	TriCo Cap Trust I		10/7/33	$	20,619		3.05	%		3.28	%	$	20,619
	TriCo Cap Trust II		7/23/34		20,619		2.55	%		2.78	%		20,619
	North Valley Trust II		4/24/33		6,186		3.25	%		3.48	%		5,015
	North Valley Trust III		4/24/34		5,155		2.8	%		3.03	%		3,927
	North Valley Trust IV		3/15/36		10,310		1.33	%		1.57	%		6,092
				$	62,889							$	56,272

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Commitments under Non-Cancelable Operating Leases with Initial or Remaining Terms of One Year or More	At December 31, 2014, future minimum commitments under non-cancelable operating leases with initial or remaining terms of one year or more are as follows:
		Operating
		Leases
		(in thousands)
	2015	$	3,419
	2016		2,510
	2017		1,856
	2018		1,323
	2019		859
	Thereafter		1,180
	Future minimum lease payments	$	11,147
Summary of Bank's Commitments and Contingent Liabilities	The following table presents a summary of the Bank’s commitments and contingent liabilities:
	(in thousands)	December 31,		December 31,
		2014		2013
	Financial instruments whose amounts represent risk:
	Commitments to extend credit:
	Commercial loans	$	177,557	$	136,986
	Consumer loans		392,705		360,194
	Real estate mortgage loans		36,139		35,309
	Real estate construction loans		49,774		22,897
	Standby letters of credit		17,531		2,601
	Deposit account overdraft privilege		101,060		68,932

Stock_Options_and_Other_Equity1

Stock Options and Other Equity-Based Incentive Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Activity	Stock option activity is summarized in the following table for the dates indicated:
		Number of			Option Price								Weighted
		Shares			per Share								Average
													Exercise
													Price
	Outstanding at December 31, 2013		1,246,370		$	12.63			to		$	25.91	$	18.04
	Options granted		22,500		$	23.21			to		$	23.21	$	23.21
	Options exercised		(166,020	)	$	14.54			to		$	20.58	$	17.32
	Options forfeited		—			—			to			—		-
	Outstanding at September 30, 2014		1,102,850		$	12.63			to		$	25.91	$	18.25
Summary of Options Outstanding	The following table shows the number, weighted-average exercise price, intrinsic value, and weighted average remaining contractual life of options exercisable, options not yet exercisable and total options outstanding as of December 31, 2014:
		Currently			Currently Not			Total
		Exercisable			Exercisable			Outstanding
	Number of options		818,350			284,500			1,102,850
	Weighted average exercise price	$	18.62		$	17.19		$	18.25
	Intrinsic value (in thousands)	$	5,007		$	2,136		$	7,143
	Weighted average remaining contractual term (yrs.)		4.5			7.6			5.3
Information about Options	The following table shows the total intrinsic value of options exercised, the total fair value of options vested, total compensation costs for options recognized in income, and total tax benefit recognized in income related to compensation costs for options during the periods indicated:
		Years Ended December 31,
		2014			2013			2012
	Intrinsic value of options exercised	$	1,209,000		$	1,777,000		$	138,000
	Fair value of options that vested	$	965,000		$	1,150,000		$	1,083,000
	Total compensation costs for options recognized in income	$	965,000		$	1,150,000		$	1,083,000
	Total tax benefit recognized in income related to compensation costs for options	$	378,000		$	484,000		$	455,000
	Weighted average fair value of grants (per option)	$	8.17		$	8.91		$	6.63
Weighted-Average Assumptions Used to Determine Fair Value of Options Granted	The weighted-average assumptions used to determine the fair value of options granted are detailed in the table below:
		Years Ended December 31,
		2014			2013			2012
	Assumptions used to value option grants:
	Average expected terms (years)		6.3			7			8.8
	Volatility		42.1	%		56.2	%		51.5	%
	Annual rate of dividends		1.9	%		1.87	%		2.36	%
	Discount rate		1.69	%		1.26	%		1.49	%
Restricted Stock Unit (RSU) Activity	Restricted stock unit (RSU) activity is summarized in the following table for the dates indicated:
		Service Condition Vesting RSUs						Market Plus Service Condition Vesting RSUs
		Number			Weighted			Number			Weighted
		of RSUs			Average Fair			of RSUs			Average Fair
					Value on						Value on
					Date of Grant						Date of Grant
	Outstanding at December 31, 2013		—			—			—			—
	RSUs granted		30,642		$	22.54			15,366		$	21.39
	RSUs added through dividend credits		278						—
	RSUs released		—						—
	RSUs forfeited/expired		—						—
	Outstanding at December 31, 2014		30,920						15,366

Noninterest_Income_and_Expense1

Noninterest Income and Expense (Tables)	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Components of Other Noninterest Income
	The components of other noninterest income were as follows (in thousands):	Years Ended December 31,
		2014			2013			2012
	Service charges on deposit accounts	$	11,811		$	12,716		$	14,290
	ATM and interchange fees		9,651			8,370			7,762
	Other service fees		2,206			2,144			2,223
	Mortgage banking service fees		1,869			1,774			1,666
	Change in value of mortgage servicing rights		(1,301	)		253			(2,016	)
	Total service charges and fees		24,236			25,257			23,925
	Gain on sale of loans		2,032			5,602			6,810
	Commissions on sale of non-deposit investment products		2,995			2,983			3,209
	Increase in cash value of life insurance		1,953			1,727			1,820
	Change in indemnification asset		(856	)		(1,649	)		(286	)
	Gain on sale of foreclosed assets		2,153			1,640			786
	Sale of customer checks		450			377			346
	Lease brokerage income		504			337			276
	Gain (loss) on disposal of fixed assets		49			(39	)		(420	)
	Commission rebates		—			—			(56	)
	Gain on life insurance death benefit		—			—			675
	Other		1,000			594			895
	Total other noninterest income		10,280			11,572			14,055
	Total noninterest income	$	34,516		$	36,829		$	37,980
Components of Noninterest Expense	The components of noninterest expense were as follows (in thousands):
		Years Ended December 31,
		2014			2013			2012
	Base salaries, net of deferred loan origination costs	$	39,342		$	34,404		$	33,093
	Incentive compensation		5,068			4,694			5,138
	Benefits and other compensation costs		13,134			12,838			11,721
	Total salaries and benefits expense		57,544			51,936			49,952
	Occupancy		8,203			7,405			7,263
	Equipment		4,514			4,162			4,444
	Data processing and software		6,512			4,844			4,793
	Assessments		2,107			2,248			2,393
	ATM network charges		2,996			2,480			2,390
	Advertising		2,413			1,981			2,876
	Professional fees		3,888			2,707			2,879
	Telecommunications		2,870			2,449			2,250
	Postage		949			786			920
	Courier service		1,055			988			1,013
	Foreclosed assets expense		528			514			1,474
	Intangible amortization		446			209			209
	Operational losses		764			618			787
	Provision for foreclosed asset losses		208			682			1,728
	Change in reserve for unfunded commitments		(395	)		(1,200	)		875
	Legal settlement		—			339			2,090
	Merger expense		4,858			312			—
	Other		10,919			10,144			9,662
	Total other noninterest expense		52,835			41,668			48,046
	Total noninterest expense	$	110,379		$	93,604		$	97,998
	Merger expense:
	Incentive compensation	$	1,174			—			—
	Benefits and other compensation costs		94			—			—
	Data processing and software		475			—			—
	Professional fees		2,390		$	312			—
	Other		725			—			—
	Total merger expense	$	4,858		$	312			—

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Components of Consolidated Income Tax Expense	The components of consolidated income tax expense are as follows:
		2014			2013			2012
		(in thousands)
	Current tax expense
	Federal	$	14,485		$	11,618		$	9,895
	State		5,016			4,261			3,425
			19,501			15,879			13,320
	Deferred tax expense (benefit)
	Federal		(794	)		1,976			(235	)
	State		(199	)		550			(148	)
			(993	)		2,526			(383	)
	Total tax expense	$	18,508		$	18,405		$	12,937
Company's Net Deferred Tax Asset Recorded in Other Assets	The temporary differences, tax effected, which give rise to the Company’s net deferred tax asset recorded in other assets are as follows as of December 31 for the years indicated:
		2014			2013
		(in thousands)
	Deferred tax assets:
	Allowance for losses	$	16,284		$	17,096
	Deferred compensation		3,115			3,093
	Accrued pension liability		7,925			5,817
	Accrued bonus		1,149			1,037
	Other accrued expenses		124			—
	Unfunded status of the supplemental retirement plans		3,315			331
	State taxes		1,713			1,390
	Stock option expense		2,534			2,225
	Nonaccrual interest		2,714			1,840
	OREO write downs		198			331
	Acquisition cost basis		6,017			699
	Tax credits		490			—
	Net operating loss carryforwards		7,128			—
	Other		625			—
	Total deferred tax assets		53,331			33,859
	Deferred tax liabilities:
	Securities income		(1,362	)		(986	)
	Unrealized gain on securities		(1,699	)		(1,767	)
	Depreciation		(3,072	)		(392	)
	Merger related fixed asset valuations		(54	)		(379	)
	Securities accretion		(287	)		(256	)
	Mortgage servicing rights valuation		(2,977	)		(2,416	)
	Indemnification asset		147			(87	)
	Core deposit intangible		(2,802	)		(193	)
	Junior subordinated debt		(2,782	)		—
	Prepaid expenses and other		(737	)		(602	)
	Total deferred tax liability		(15,625	)		(7,078	)
	Net deferred tax asset	$	37,706		$	26,781
Summary of Changes in Unrecognized Tax Benefit (Including Interest and Penalties)	A summary of changes in the Company’s unrecognized tax benefit (including interest and penalties) in 2014 is as follows:
	(in thousands)	UTB			Interest/Penalties			Total
	As of December 31, 2013		—			—			—
	Additions for tax positions for prior years		227			18			245
	As of December 31, 2014		227			18			245
Reconciliation of Effective Tax Rate and Statutory Federal Income Tax Rate	The effective tax rate and the statutory federal income tax rate are reconciled as follows:
		Years Ended December 31,
		2014			2013			2012
	Federal statutory income tax rate		35	%		35	%		35	%
	State income taxes, net of federal tax benefit		7			6.8			6.7
	Tax-exempt interest on municipal obligations		(0.4	)		(0.4	)		(0.5	)
	Tax-exempt life insurance related income		(1.5	)		(1.3	)		(2.0	)
	Non-deductible joint beneficiary agreement expense		0.2			0.2			0.3
	Non-deductible merger expense		1			—			—
	Other		0.2			(0.1	)		1
	Effective Tax Rate		41.5	%		40.2	%		40.5	%

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Computation of Earnings Per Share	Earnings per share have been computed based on the following:
		Years ended December 31,
		2014		2013		2012
	Net income (in thousands)	$	26,108	$	27,399	$	18,994
	(number of shares in thousands)
	Average number of common shares outstanding		17,716		16,045		15,988
	Effect of dilutive stock options		207		152		64
	Average number of common shares outstanding used to calculate diluted earnings per share		17,923		16,197		16,052

Comprehensive_Income_Tables

Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Components of Other Comprehensive Income and Related Tax Effects	The components of other comprehensive income and related tax effects are as follows:
		Years Ended December 31,
		2014			2013			2012
		(in thousands)
	Unrealized holding (losses) gains on available for sale securities before reclassifications	$	(162	)	$	(4,232	)	$	(2,096	)
	Amounts reclassified out of accumulated other comprehensive income		—			—			—
	Unrealized holding (losses) gains on available for sale securities after reclassifications		(162	)		(4,232	)		(2,096	)
	Tax effect		68			1,780			880
	Unrealized holding (losses) gains on available for sale securities, net of tax		(94	)		(2,452	)		(1,216	)
	Change in unfunded status of the supplemental retirement plans before reclassifications		(7,253	)		2,575			(445	)
	Amounts reclassified out of accumulated other comprehensive income:
	Amortization of prior service cost		138			153			153
	Amortization of actuarial losses		17			291			288
	Total amounts reclassified out of accumulated other comprehensive income		155			444			441
	Change in unfunded status of the supplemental retirement plans after reclassifications		(7,098	)		3,019			(4	)
	Tax effect		2,984			(1,269	)		2
	Change in unfunded status of the supplemental retirement plans, net of tax		(4,114	)		1,750			(2	)
	Change in joint beneficiary agreement liability before reclassifications		148			400			(370	)
	Amounts reclassified out of accumulated other comprehensive income		—			—			—
	Change in joint beneficiary agreement liability after reclassifications		148			400			(370	)
	Tax effect		—			—			(64	)
	Change in joint beneficiary agreement liability, net of tax		148			400			(434	)
	Total other comprehensive (loss) income	$	(4,060	)	$	(302	)	$	(1,652	)
Components of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income, included in shareholders’ equity, are as follows:
		December 31,
		2014			2013
		(in thousands)
	Net unrealized gains on available for sale securities	$	4,040		$	4,202
	Tax effect		(1,699	)		(1,767	)
	Unrealized holding gains on available for sale securities, net of tax		2,341			2,435
	Unfunded status of the supplemental retirement plans		(7,885	)		(787	)
	Tax effect		3,315			331
	Unfunded status of the supplemental retirement plans, net of tax		(4,570	)		(456	)
	Joint beneficiary agreement liability		26			(122	)
	Tax effect		—			—
	Joint beneficiary agreement liability, net of tax		26			(122	)
	Accumulated other comprehensive income	$	(2,203	)	$	1,857

Retirement_Plans_Tables

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Defined Benefit Pension Plans	Amounts recognized as a component of accumulated other comprehensive loss as of year-end that have not been recognized as a component of the combined net period benefit cost of the Company’s defined benefit pension plans are presented in the following table. The Company expects to recognize approximately $823,000 of the net actuarial loss reported in the following table as of December 31, 2014 as a component of net periodic benefit cost during 2015.
		December 31,
	(in thousands)	2014			2013
	Transition obligation	$	9		$	11
	Prior service cost		(173	)		(35	)
	Net actuarial loss		8,049			811
	Amount included in accumulated other comprehensive loss	$	7,885			787
	Deferred tax benefit		(3,315	)		(331	)
	Amount included in accumulated other comprehensive loss, net of tax	$	4,570		$	456
Information Pertaining to Activity in Supplemental Retirement Plans	Information pertaining to the activity in the supplemental retirement plans, using a measurement date of December 31, is as follows:
		December 31,
		2014			2013
		(in thousands)
	Change in benefit obligation:
	Benefit obligation at beginning of year	$	(14,634	)	$	(16,345	)
	Acquisition		(4,150	)		—
	Service cost		(652	)		(742	)
	Interest cost		(739	)		(643	)
	Actuarial (loss)/gain		(7,254	)		2,573
	Benefits paid		631			523
	Benefit obligation at end of year	$	(26,798	)	$	(14,634	)
	Change in plan assets:
	Fair value of plan assets at beginning of year	$	—		$	—
	Fair value of plan assets at end of year	$	—		$	—
	Funded status	$	(26,798	)	$	(14,634	)
	Unrecognized net obligation existing at January 1, 1986		9			11
	Unrecognized net actuarial loss		8,049			811
	Unrecognized prior service cost		(173	)		(35	)
	Accumulated other comprehensive income		(7,885	)		(787	)
	Accrued benefit cost	$	(26,798	)	$	(14,634	)
	Accumulated benefit obligation	$	(24,739	)	$	(12,954	)
Net Periodic Benefit Cost Recognized for Supplemental Retirement Plans	The following table sets forth the net periodic benefit cost recognized for the supplemental retirement plans:
		Years Ended December 31,
		2014			2013			2012
		(in thousands)
	Net pension cost included the following components:
	Service cost-benefits earned during the period	$	652		$	743		$	680
	Interest cost on projected benefit obligation		739			643			687
	Amortization of net obligation at transition		2			2			2
	Amortization of prior service cost		138			153			153
	Recognized net actuarial loss		16			291			288
	Net periodic pension cost	$	1,547		$	1,832		$	1,810
Assumptions Used in Accounting for Plans	The following table sets forth assumptions used in accounting for the plans:
		Years Ended December 31,
		2014			2013			2012
	Discount rate used to calculate benefit obligation		3.65	%		4.85	%		4	%
	Discount rate used to calculate net periodic pension cost		3.65	%		4.85	%		4	%
	Average annual increase in executive compensation		2.5	%		2.5	%		2.5	%
	Average annual increase in director compensation		2.5	%		2.5	%		2.5	%
Expected Benefit Payments to Participants and Estimated Contributions to be Made by Company	The following table sets forth the expected benefit payments to participants and estimated contributions to be made by the Company under the supplemental retirement plans for the years indicated:
	Years Ended	Expected Benefit			Estimated
		Payments to			Company
		Participants			Contributions
		(in thousands)
	2015	$	1,145		$	1,145
	2016		1,036			1,036
	2017		1,001			1,001
	2018		1,330			1,330
	2019		519			519
	2020-2024	$	3,719		$	3,719

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Summary of Loan Activity	The following table summarizes the activity in these loans for the periods indicated (in thousands):
	Balance December 31, 2012	$	2,368
	Advances/new loans		1,154
	Removed/payments		(886	)
	Balance December 31, 2013	$	2,636
	Advances/new loans		2,106
	Removed/payments		(1,610	)
	Balance December 31, 2014	$	3,132

Fair_Value_Measurement_Tables

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Recorded Amount of Assets and Liabilities Measured at Fair Value on Recurring Basis	The table below presents the recorded amount of assets and liabilities measured at fair value on a recurring basis (in thousands):
	Fair value at December 31, 2014	Total			Level 1			Level 2			Level 3
	Securities available-for-sale:
	Obligations of U.S. government corporations and agencies	$	75,120			—		$	75,120			—
	Obligations of states and political subdivisions		3,175			—			3,175			—
	Corporate debt securities		1,908			—			1,908			—
	Marketable equity securities		3,002		$	3,002			—			—
	Mortgage servicing rights		7,378			—			—		$	7,378
	Total assets measured at fair value	$	90,583		$	3,002		$	80,203		$	7,378
	Fair value at December 31, 2013	Total			Level 1			Level 2			Level 3
	Securities available-for-sale:
	Obligations of U.S. government corporations and agencies	$	97,143			—		$	97,143			—
	Obligations of states and political subdivisions		5,589			—			5,589			—
	Corporate debt securities		1,915			—			1,915			—
	Mortgage servicing rights		6,165			—			—			6,165
	Total assets measured at fair value	$	110,812			—		$	104,647		$	6,165
Reconciliation of Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3) on Recurring Basis	The following table provides a reconciliation of assets and liabilities measured at fair value using significant unobservable inputs (Level 3) on a recurring basis during the years ended December 31, 2014 and 2013. Had there been any transfer into or out of Level 3 during 2014 or 2013, the amount included in the “Transfers into (out of) Level 3” column would represent the beginning balance of an item in the period (interim quarter) during which it was transferred (in thousands):
	Year ended December 31,	Beginning			Transfers			Change			Issuances		Ending
		Balance			into (out of)			Included					Balance
					Level 3			in Earnings
	2014: Mortgage servicing rights	$	6,165		$	1,944		$	(1,301	)	$	570	$	7,378
	2013: Mortgage servicing rights	$	4,552			—		$	253		$	1,360	$	6,165
Quantitative Information about Recurring Level 3 Fair Value Measurements	The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2014:
		Fair Value			Valuation			Unobservable			Range,
		(in thousands)			Technique			Inputs			Weighted Average
	Mortgage Servicing Rights	$	7,378			Discounted cash flow			Constant prepayment rate		5.7%-23.4%, 12.0%
									Discount rate		10.0%-12.0%, 10.0%
Assets and Liabilities Measured at Fair Value on Nonrecurring Basis	The tables below present the recorded amount of assets and liabilities measured at fair value on a nonrecurring basis, as of the dates indicated, that had a write-down or an additional allowance provided during the periods indicated (in thousands):
	Year ended December 31, 2014	Total			Level 1			Level 2			Level 3		Total Gains
													(Losses)
	Fair value:
	Impaired Originated & PNCI loans	$	2,480			—			—		$	2,480	$	(636	)
	Foreclosed assets		2,611			—			—			2,611	$	(137	)
	Total assets measured at fair value	$	5,091			—			—		$	5,091	$	(773	)
	Year ended December 31, 2013	Total			Level 1			Level 2			Level 3		Total Gains
													(Losses)
	Fair value:
	Impaired Originated & PNCI loans	$	20,334			—			—		$	20,334	$	(2,539	)
	Foreclosed assets		948			—			—			948		(397	)
	Total assets measured at fair value	$	21,282			—			—		$	21,282	$	(2,936	)
Quantitative Information about Level 3 Fair Value Measurements for Financial Instruments Measured at Fair Value on Nonrecurring Basis	The following table presents quantitative information about Level 3 fair value measurements for financial instruments measured at fair value on a nonrecurring basis at December 31, 2014:
		Fair Value			Valuation Technique		Unobservable Inputs	Range, Weighted Average
		(in thousands)
	Impaired Originated & PNCI loans	$	2,480		Sales comparison approach		Adjustment for differences between comparable sales	(5.0)%-(42.5)%, (10.1)%
					Income approach		Capitalization rate	9.09%-9.09 %, 9.09%
	Foreclosed assets	$	2,611		Sales comparison approach		Adjustment for differences between comparable sales	(5.0)%-(29.4)%, (8.2)%
Estimated Fair Values of Financial Instruments that are Reported at Amortized Cost in Consolidated Balance Sheets	The estimated fair values of financial instruments that are reported at amortized cost in the Corporation’s consolidated balance sheets, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value, were as follows (in thousands):
		December 31, 2014						December 31, 2013
		Carrying			Fair			Carrying			Fair
		Amount			Value			Amount			Value
	Financial assets:
	Level 1 inputs:
	Cash and due from banks	$	93,150		$	93,150		$	76,915		$	76,915
	Cash at Federal Reserve and other banks		517,578			517,578			521,453			521,453
	Level 2 inputs:
	Securities held to maturity		676,426			688,779			240,504			233,807
	Restricted equity securities		16,956			N/A			9,163			N/A
	Loans held for sale		3,579			3,579			2,270			2,270
	Level 3 inputs:
	Loans, net		2,282,524			2,379,155			1,672,007			1,760,274
	Indemnification (liability) asset		(349	)		(349	)		206			206
	Financial liabilities:
	Level 2 inputs:
	Deposits		3,380,423			3,380,486			2,410,483			2,411,402
	Other borrowings		9,276			9,276			6,335			6,335
	Level 3 inputs:
	Junior subordinated debt		56,272			45,053			41,238			25,774
		Contract			Fair			Contract			Fair
		Amount			Value			Amount			Value
	Off-balance sheet:
	Level 3 inputs:
	Commitments	$	656,175		$	6,562		$	555,386		$	5,554
	Standby letters of credit		17,531			175			2,601			26
	Overdraft privilege commitments		101,060			1,011			68,932			689

TriCo_Bancshares_Condensed_Fin1

TriCo Bancshares Condensed Financial Statements (Parent Only) (Tables)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets
		December 31,
		2014			2013
		(in thousands)
	Assets
	Cash and Cash equivalents	$	2,229		$	2,520
	Investment in Tri Counties Bank		470,797			288,746
	Other assets		1,902			1,280
	Total assets	$	474,928		$	292,546
	Liabilities and shareholders’ equity
	Other liabilities	$	484		$	362
	Junior subordinated debt		56,272			41,238
	Total liabilities		56,756			41,600
	Shareholders’ equity:
	Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 22,714,964 and 16,076,662 shares, respectively		244,318			89,356
	Retained earnings		176,057			159,733
	Accumulated other comprehensive loss, net		(2,203	)		1,857
	Total shareholders’ equity		418,172			250,946
	Total liabilities and shareholders’ equity	$	474,928		$	292,546
Condensed Statements of Income	Condensed Statements of Income
		Years ended December 31,
		2014			2013			2012
		(in thousands)
	Interest expense	$	(1,403	)	$	(1,247	)	$	(1,325	)
	Administration expense		(2,720	)		(862	)		(669	)
	Loss before equity in net income of Tri Counties Bank		(4,123	)		(2,109	)		(1,994	)
	Equity in net income of Tri Counties Bank:
	Distributed		8,270			8,175			8,522
	Undistributed		20,720			20,446			11,632
	Income tax benefit		1,241			887			834
	Net income	$	26,108		$	27,399		$	18,994
Condensed Statements of Comprehensive Income
	Condensed Statements of Comprehensive Income
		Years ended December 31,
		2014			2013			2012
		(in thousands)
	Net income	$	26,108		$	27,399		$	18,994
	Other comprehensive (loss) income, net of tax:
	Unrealized holding (losses) gains on securities arising during the period		(94	)		(2,452	)		(1,216	)
	Change in minimum pension liability		(4,114	)		1,750			(2	)
	Change in joint beneficiary agreement liability		148			400			(434	)
	Other comprehensive (loss) income		(4,060	)		(302	)		(1,652	)
	Net income	$	22,048		$	27,097		$	17,342
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows
		Years ended December 31,
		2014			2013			2012
		(in thousands)
	Operating activities:
	Net income	$	26,108		$	27,399		$	18,994
	Adjustments to reconcile net income to net cash provided by operating activities:
	Undistributed equity in earnings of Tri Counties Bank		(20,720	)		(20,446	)		(11,632	)
	Stock option vesting expense		1,133			1,151			1,083
	Stock option excess tax benefits		(225	)		(356	)		(44	)
	Net change in other assets and liabilities		671			(1,100	)		(1,089	)
	Net cash provided by operating activities		6,967			6,648			7,312
	Investing activities: None
	Financing activities:
	Issuance of common stock through option exercise		616			251			206
	Stock option excess tax benefits		225			356			44
	Repurchase of common stock		(292	)		(501	)		—
	Cash dividends paid — common		(7,807	)		(6,745	)		(5,757	)
	Net cash used for financing activities		(7,258	)		(6,639	)		(5,507	)
	(decrease) increase in cash and cash equivalents		(291	)		9			1,805
	Cash and cash equivalents at beginning of year		2,520			2,511			706
	Cash and cash equivalents at end of year	$	2,229		$	2,520		$	2,511

Regulatory_Matters_Tables

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2014
Banking and Thrift [Abstract]
Actual Capital Amounts and Ratios of Bank	To be categorized as well capitalized the Bank must maintain minimum total risk-based, Tier 1 risk-based and Tier 1 leverage ratios as set forth in the table below. There are no conditions or events since that date that Management believes have changed the institution’s category. The Bank’s actual capital amounts and ratios are also presented in the table.
		Actual					Minimum					Minimum
							Capital Requirement					To Be Well
												Capitalized Under
												Prompt Corrective
												Action Provisions
		Amount		Ratio			Amount		Ratio			Amount		Ratio
		(dollars in thousands)
	As of December 31, 2014:
	Total Capital (to Risk Weighted Assets):
	Consolidated	$	436,955		15.63	%	$	223,603		8	%		N/A		N/A
	Tri Counties Bank	$	433,286		15.51	%	$	223,449		8	%	$	279,311		10	%
	Tier 1 Capital (to Risk Weighted Assets):
	Consolidated	$	401,971		14.38	%	$	111,801		4	%		N/A		N/A
	Tri Counties Bank	$	398,325		14.26	%	$	111,724		4	%	$	167,587		6	%
	Tier 1 Capital (to Average Assets):
	Consolidated	$	401,971		10.8	%	$	148,819		4	%		N/A		N/A
	Tri Counties Bank	$	398,325		10.71	%	$	148,734		4	%	$	185,918		5	%
	As of December 31, 2013:
	Total Capital (to Risk Weighted Assets):
	Consolidated	$	297,429		14.77	%	$	161,064		8	%		N/A		N/A
	Tri Counties Bank	$	295,212		14.67	%	$	160,961		8	%	$	201,201		10	%
	Tier 1 Capital (to Risk Weighted Assets):
	Consolidated	$	272,071		13.51	%	$	80,532		4	%		N/A		N/A
	Tri Counties Bank	$	269,870		13.41	%	$	80,480		4	%	$	120,720		6	%
	Tier 1 Capital (to Average Assets):
	Consolidated	$	272,071		10.17	%	$	107,017		4	%		N/A		N/A
	Tri Counties Bank	$	269,870		10.09	%	$	106,965		4	%	$	133,706		5	%

Summary_of_Quarterly_Results_o1

Summary of Quarterly Results of Operations (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Results of Operations	The following table sets forth the results of operations for the four quarters of 2014 and 2013, and is unaudited; however, in the opinion of Management, it reflects all adjustments (which include only normal recurring adjustments) necessary to present fairly the summarized results for such periods.
		2014 Quarters Ended
		December 31,			September 30,			June 30,		March 31,
		(dollars in thousands, except per share data)
	Interest and dividend income:
	Loans:
	Discount accretion PCI – cash basis	$	107		$	290		$	69	$	203
	Discount accretion PCI – other		919			822			811		984
	Discount accretion PNCI		796			402			624		379
	All other loan interest income		28,914			23,466			22,929		22,172
	Total loan interest income		30,736			24,980			24,433		23,738
	Debt securities, dividends and interest bearing cash at Banks (not FTE)		5,671			4,151			3,985		3,421
	Total interest income		36,407			29,131			28,418		27,159
	Interest expense		1,437			1,082			1,075		1,087
	Net interest income		34,970			28,049			27,343		26,072
	(Benefit from) provision for loan losses		(1,421	)		(2,977	)		1,708		(1,355	)
	Net interest income after provision for loan losses		36,391			31,026			25,635		27,427
	Noninterest income		9,755			8,589			7,877		8,295
	Noninterest expense		36,566			25,380			25,116		23,317
	Income before income taxes		9,580			14,235			8,396		12,405
	Income tax expense		3,930			6,001			3,537		5,040
	Net income	$	5,650		$	8,234		$	4,859	$	7,365
	Per common share:
	Net income (diluted)	$	0.25		$	0.5		$	0.3	$	0.45
	Dividends	$	0.11		$	0.11		$	0.11	$	0.11
		2013 Quarters Ended
		December 31,			September 30,			June 30,		March 31,
		(dollars in thousands, except per share data)
	Interest and dividend income:
	Loans:
	Discount accretion PCI – cash basis	$	255		$	140		$	129	$	167
	Discount accretion PCI – other		893			898			732		597
	Discount accretion PNCI		568			1,115			815		766
	All other loan interest income		22,754			22,970			22,207		22,542
	Total loan interest income		24,470			25,123			23,883		24,072
	Debt securities, dividends and interest bearing cash at Banks (not FTE)		2,992			2,413			1,873		1,734
	Total interest income		27,462			27,536			25,756		25,806
	Interest expense		1,123			1,169			1,167		1,237
	Net interest income		26,339			26,367			24,589		24,569
	Provision for (benefit from) loan losses		172			(393	)		614		(1,108	)
	Net interest income after provision for loan losses		26,167			26,760			23,975		25,677
	Noninterest income		7,353			9,127			10,131		10,218
	Noninterest expense		24,878			23,616			23,509		21,601
	Income before income taxes		8,642			12,271			10,597		14,294
	Income tax expense		3,406			4,910			4,272		5,817
	Net income	$	5,236		$	7,361		$	6,325	$	8,477
	Per common share:
	Net income (diluted)	$	0.32		$	0.45		$	0.39	$	0.53
	Dividends	$	0.11		$	0.11		$	0.11	$	0.09

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended		66 Months Ended
	Mar. 31, 2013	Jun. 30, 2009	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2013
			Segment
			Trust
Significant Of Accounting Policies [Line Items]
Number of subsidiary business trusts			5
Company's investments in the trusts			$1,690,000		1,690,000
Number of business segment			1
Trading securities			0	0	0
Recognized OTTI losses			0	0
Loans contractual past due			90 days
TDR loans payment period in nonaccrual status			6 months
Method used to estimate net sale proceeds	Greater of fifteen percent or actual estimated selling costs.
Allowance for loan losses			36,585,000	38,245,000	36,585,000			42,648,000	45,914,000
Allowance for loss factor weighted percentage		75.00%	125.00%
Reserve for unimpaired loans						1,438,000
Reserve for unfunded commitments due to change in methodology							335,000
Change in Accounting Method Accounted for as Change in Estimate [Member]
Significant Of Accounting Policies [Line Items]
Allowance for loan losses										1,665,000
Impaired real estate collateral dependent loans [Member]
Significant Of Accounting Policies [Line Items]
Allowance for loan losses	$494,000						$1,314,000
Tri Counties Bank [Member]
Significant Of Accounting Policies [Line Items]
Number of traditional operating branches			57
Number of in-store operating branches			16
California [Member]
Significant Of Accounting Policies [Line Items]
Number of counties			26
Minimum [Member]
Significant Of Accounting Policies [Line Items]
Allowance for loss factor weighted percentage					75.00%
Maximum [Member]
Significant Of Accounting Policies [Line Items]
Allowance for loss factor weighted percentage					125.00%
Furniture and equipment [Member] | Minimum [Member]
Significant Of Accounting Policies [Line Items]
Estimated useful lives of the related assets or lease terms			3 years
Furniture and equipment [Member] | Maximum [Member]
Significant Of Accounting Policies [Line Items]
Estimated useful lives of the related assets or lease terms			10 years
Land improvements and buildings [Member] | Minimum [Member]
Significant Of Accounting Policies [Line Items]
Estimated useful lives of the related assets or lease terms			15 years
Land improvements and buildings [Member] | Maximum [Member]
Significant Of Accounting Policies [Line Items]
Estimated useful lives of the related assets or lease terms			40 years

Business_Combinations_Addition

Business Combinations - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended	6 Months Ended
	Oct. 03, 2014	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013	Aug. 21, 2007
			Bank
Business Acquisition [Line Items]
Business acquisition, common stock issued to acquiree's shareholders	6,575,550
Fixed share exchange ratio	0.9433
Aggregate ownership percentage	28.90%
Cash in-lieu of fractional shares	$6,823
Business combination share outstanding		22,714,964		16,076,662	15,814,662
Assets		3,916,458,000		2,744,066,000
Decrease in deferred tax asset		7,128,000
Consolidation description		The Company consolidated four former North Valley Bank, and four Tri Counties Bank branches into other Tri Counties Bank branches or other former North Valley Bank branches during January 2015.
North Valley Bancorp [Member]
Business Acquisition [Line Items]
Acquisition, completion date		3-Oct-14
Closing stock price	$23.01
Consideration paid per share	$21.71
Cash in-lieu of fractional shares	7,000
Business combination share outstanding	22,714,964
Business combination consideration value	151,310,000
Number of commercial banks			22
Assets			935,000,000
Increase in net book value of land and buildings acquired	4,785,000
Recognized intangible related to acquisition	6,614,000
Number of lease contracts assumed	13
Unfavorable leasehold interests	293,000
Decrease in deferred tax asset	1,341,000
One-time costs associated with acquisitions	4,858,000
Non-tax deductible acquisition costs	1,269,000
North Valley Bancorp [Member] | Junior subordinated debt [Member]
Business Acquisition [Line Items]
Discount on debt instrument	6,664,000
Reduction in deferred tax assets, fair value adjustments	-6,664,000
North Valley Bancorp [Member] | Minimum [Member] | Junior subordinated debt [Member]
Business Acquisition [Line Items]
Amortization period of debt discount	18 years
North Valley Bancorp [Member] | Maximum [Member] | Junior subordinated debt [Member]
Business Acquisition [Line Items]
Amortization period of debt discount	21 years
North Valley Bancorp [Member] | Deferred income taxes [Member]
Business Acquisition [Line Items]
Reduction in deferred tax assets, fair value adjustments	6,293,000
North Valley Bancorp [Member] | Core deposit intangibles [Member]
Business Acquisition [Line Items]
Recognized intangible related to acquisition	6,614,000
Percentage of acquired intangibles	0.97%
Finite lived intangible asset useful life	7 years
Reduction in deferred tax assets, fair value adjustments	($6,283,000)

Business_Combinations_Schedule

Business Combinations - Schedule of Fair Value of Consideration Transferred, Identifiable Net Assets Acquired and Resulting Goodwill (Detail) (USD $)	0 Months Ended
	Oct. 03, 2014	Dec. 31, 2014	Dec. 31, 2013
Fair value of consideration transferred:
Cash consideration	$6,823
Liabilities assumed:
Goodwill recognized		63,462,000	15,519,000
North Valley Bancorp [Member]
Fair value of consideration transferred:
Fair value of shares issued	151,303,000
Cash consideration	7,000
Total fair value of consideration transferred	151,310,000
Asset acquired:
Cash and cash equivalents	141,412,000
Securities available for sale	17,297,000
Securities held to maturity	189,949,000
Restricted equity securities	5,378,000
Loans	499,327,000
Foreclosed assets	695,000
Premises and equipment	11,936,000
Cash value of life insurance	38,075,000
Core deposit intangible	6,614,000
Other assets	20,056,000
Total assets acquired	930,739,000
Liabilities assumed:
Deposits	801,956,000
Other liabilities	10,429,000
Junior subordinated debt	14,987,000
Total liabilities assumed	827,372,000
Total net assets acquired	103,367,000
Goodwill recognized	$47,943,000

Business_Combinations_Summary_

Business Combinations - Summary of Estimated Fair Value Adjustments Resulting In Goodwill (Detail) (USD $)	0 Months Ended
	Oct. 03, 2014	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Cash payments to North Valley Bancorp Shareholders	$6,823
Goodwill		63,462,000	15,519,000
North Valley Bancorp [Member]
Business Acquisition [Line Items]
Value of stock consideration paid to North Valley Bancorp Shareholders	151,303,000
Cash payments to North Valley Bancorp Shareholders	7,000
Cost basis net assets acquired	-98,040,000
Goodwill	47,943,000
North Valley Bancorp [Member] | Deferred income taxes [Member]
Business Acquisition [Line Items]
Fair Value Adjustments	6,293,000
North Valley Bancorp [Member] | Loans [Member]
Business Acquisition [Line Items]
Fair Value Adjustments	5,832,000
North Valley Bancorp [Member] | Premises and equipment [Member]
Business Acquisition [Line Items]
Fair Value Adjustments	-4,785,000
North Valley Bancorp [Member] | Core deposit intangibles [Member]
Business Acquisition [Line Items]
Fair Value Adjustments	-6,283,000
North Valley Bancorp [Member] | Junior subordinated debt [Member]
Business Acquisition [Line Items]
Fair Value Adjustments	-6,664,000
North Valley Bancorp [Member] | Other [Member]
Business Acquisition [Line Items]
Fair Value Adjustments	$280,000

Business_Combinations_Schedule1

Business Combinations - Schedule of Cost Basis, Fair Value Discount and loan Acquired (Detail) (North Valley Bancorp [Member], USD $)	Oct. 03, 2014
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Cost Basis	$514,125
Discount	-14,798
Fair Value	499,327
PNCI [Member]
Business Acquisition [Line Items]
Cost Basis	502,637
Discount	-12,721
Fair Value	489,916
PCI - Other [Member]
Business Acquisition [Line Items]
Cost Basis	11,488
Discount	-2,077
Fair Value	$9,411

Business_Combinations_Summary_1

Business Combinations - Summary of Principal Balance Loans Acquired (Detail) (North Valley Bancorp [Member], USD $)	Oct. 03, 2014
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Undiscounted contractual cash flows	$734,437
Undiscounted cash flows not expected to be collected (nonaccretable difference)	-6,295
Undiscounted cash flows expected to be collected	728,142
Accretable yield at acquisition	-228,815
Estimated fair value of loans acquired at acquisition	499,327
Purchase discount	14,798
Cost Basis	514,125
PNCI [Member]
Business Acquisition [Line Items]
Undiscounted contractual cash flows	718,731
Undiscounted cash flows expected to be collected	718,731
Accretable yield at acquisition	-228,815
Estimated fair value of loans acquired at acquisition	489,916
Purchase discount	12,721
Cost Basis	502,637
PCI - Other [Member]
Business Acquisition [Line Items]
Undiscounted contractual cash flows	15,706
Undiscounted cash flows not expected to be collected (nonaccretable difference)	-6,295
Undiscounted cash flows expected to be collected	9,411
Estimated fair value of loans acquired at acquisition	9,411
Purchase discount	2,077
Cost Basis	$11,488

Business_Combinations_Schedule2

Business Combinations - Schedule of Pro Forma Financial Information (Detail) (North Valley Bancorp [Member], USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
North Valley Bancorp [Member]
Business Acquisition [Line Items]
Net interest income	$139,520	$132,635
Provision for (benefit from) loan losses	-4,045	-715
Noninterest income	43,587	50,966
Noninterest expense	147,295	133,073
Income before income taxes	39,857	51,243
Income taxes	16,453	20,091
Net income	$23,404	$31,152
Basic earnings per share	$1.03	$1.38
Diluted earnings per share	$1.02	$1.37

Investment_Securities_Amortize

Investment Securities - Amortized Cost and Estimated Fair Values of Investments in Debt and Equity Securities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$79,165	$100,445
Gross Unrealized Gains	4,065	4,560
Gross Unrealized Losses	-25	-358
Estimated Fair Value	83,205	104,647
Amortized Cost, Held to Maturity	676,426	240,504
Gross Unrealized Gains, Held to Maturity	13,185	298
Gross Unrealized Losses, Held to Maturity	-832	-6,995
Estimated Fair Value, Held to Maturity	688,779	233,807
Obligations of U.S. government corporations and agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	71,144	93,055
Gross Unrealized Gains	4,001	4,445
Gross Unrealized Losses	-25	-357
Estimated Fair Value	75,120	97,143
Amortized Cost, Held to Maturity	660,836	227,864
Gross Unrealized Gains, Held to Maturity	13,055	298
Gross Unrealized Losses, Held to Maturity	-677	-5,540
Estimated Fair Value, Held to Maturity	673,214	222,622
Obligations of states and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,130	5,513
Gross Unrealized Gains	45	77
Gross Unrealized Losses		-1
Estimated Fair Value	3,175	5,589
Amortized Cost, Held to Maturity	15,590	12,640
Gross Unrealized Gains, Held to Maturity	130
Gross Unrealized Losses, Held to Maturity	-155	-1,455
Estimated Fair Value, Held to Maturity	15,565	11,185
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,891	1,877
Gross Unrealized Gains	17	38
Estimated Fair Value	1,908	1,915
Marketable equity securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,000
Gross Unrealized Gains	2
Estimated Fair Value	$3,002

Investment_Securities_Addition

Investment Securities - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Investmentsecurities	Investmentsecurities	Investmentsecurities
Investment Securities [Line Items]
Investment securities sold	14,130,000	0	0
Gain or loss on sale of investment securities	$0
Investment securities carrying value	143,992,000	62,064,000
Mortgage-backed securities	$755,591,000
Life of mortgage-backed securities	5 years 3 months 18 days
Obligations of U.S. government corporations and agencies [Member]
Investment Securities [Line Items]
Debt securities	8
Percentage of aggregate depreciation in unrealized losses	1.10%
Obligations of states and political subdivisions [Member]
Investment Securities [Line Items]
Debt securities	5
Percentage of aggregate depreciation in unrealized losses	4.26%
Corporate debt securities [Member]
Investment Securities [Line Items]
Debt securities	0
Marketable equity securities [Member]
Investment Securities [Line Items]
Debt securities	0

Investment_Securities_Amortize1

Investment Securities - Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Due in one year, Amortized Cost	$1,924
Due after one year through five years, Amortized Cost	1,095
Due after five years through ten years, Amortized Cost	30,977
Due after ten years, Amortized Cost	45,169
Totals, Amortized Cost	79,165
Due in one year, Amortized Cost, Held to Maturity	0
Due after one year through five years, Amortized Cost, Held to Maturity	0
Due after five years through ten years, Amortized Cost, Held to Maturity	1,118
Due after ten years, Amortized Cost, Held to Maturity	675,308
Totals, Amortized Cost, Held to Maturity	676,426	240,504
Due in one year, Estimated Fair Value	1,942
Due after one year through five years, Estimated Fair Value	1,135
Due after five years through ten years, Estimated Fair Value	32,316
Due after ten years, Estimated Fair Value	47,812
Totals, Estimated Fair Value	83,205
Due in one year, Estimated Fair Value, Held to Maturity	0
Due after one year through five years, Estimated Fair Value, Held to Maturity	0
Due after five years through ten years, Estimated Fair Value, Held to Maturity	1,106
Due after ten years, Estimated Fair Value, Held to Maturity	687,673
Estimated Fair Value, Held to Maturity	$688,779	$233,807

Investment_Securities_Gross_Un

Investment Securities - Gross Unrealized Losses on Investment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	$6,774	$10,486
Less than 12 months, Unrealized Loss	-25	-358
12 months or more, Fair Value	0	0
12 months or more, Unrealized Loss	0	0
Total Fair Value	6,774	10,486
Total Unrealized Loss	-25	-358
Less than 12 months, Fair Value, held to maturity	1,935	199,403
Less than 12 months, Unrealized Loss, held to maturity	-27	-6,995
12 months or more, Fair Value, held to maturity	58,146
12 months or more, Unrealized Loss, held to maturity	-805
Total Fair Value, held to maturity	60,081	199,403
Total Unrealized Loss, held to maturity	-832	-6,995
Obligations of U.S. government corporations and agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value	6,774	10,287
Less than 12 months, Unrealized Loss	-25	-357
12 months or more, Fair Value	0	0
12 months or more, Unrealized Loss	0	0
Total Fair Value	6,774	10,287
Total Unrealized Loss	-25	-357
Less than 12 months, Fair Value, held to maturity	335	188,218
Less than 12 months, Unrealized Loss, held to maturity	-1	-5,540
12 months or more, Fair Value, held to maturity	56,288
12 months or more, Unrealized Loss, held to maturity	-676
Total Fair Value, held to maturity	56,623	188,218
Total Unrealized Loss, held to maturity	-677	-5,540
Obligations of states and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months, Fair Value		199
Less than 12 months, Unrealized Loss		-1
12 months or more, Fair Value	0	0
12 months or more, Unrealized Loss	0	0
Total Fair Value		199
Total Unrealized Loss		-1
Less than 12 months, Fair Value, held to maturity	1,600	11,185
Less than 12 months, Unrealized Loss, held to maturity	-26	-1,455
12 months or more, Fair Value, held to maturity	1,858
12 months or more, Unrealized Loss, held to maturity	-129
Total Fair Value, held to maturity	3,458	11,185
Total Unrealized Loss, held to maturity	-155	-1,455
Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
12 months or more, Fair Value	0	0
12 months or more, Unrealized Loss	0	0
Marketable equity securities [Member]
Schedule of Available-for-sale Securities [Line Items]
12 months or more, Fair Value	0
12 months or more, Unrealized Loss	$0

Loans_Summary_of_Loan_Balances

Loans - Summary of Loan Balances (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Mortgage loans on real estate:
Total mortgage loan on real estate	$1,615,359	$1,107,863
Consumer:
Total consumer loans	417,084	383,163
Commercial	174,945	131,878
Construction:
Total construction	75,136	49,103
Total loans, net of deferred loan fees and discounts	2,282,524	1,672,007
Total principal balance of loans owed, net of charge-offs	2,322,853	1,703,380
Unamortized net deferred loan fees	-4,793	-3,694
Discounts to principal balance of loans owed, net of charge-offs	-35,536	-27,679
Total loans, net of unamortized deferred loan fees and discounts	2,282,524	1,672,007
Noncovered loans	2,260,256	1,644,095
Covered loans	22,268	27,912
Total loans, net of unamortized deferred loan fees and discounts	2,282,524	1,672,007
Allowance for loan losses	-36,585	-38,245	-42,648	-45,914
Auto Indirect [Member]
Consumer:
Total consumer loans	112	946
Other [Member]
Consumer:
Total consumer loans	33,074	27,763
Residential 1-4 family [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	279,420	195,013
Commercial [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	1,335,939	912,850
Construction:
Total construction	36,518	17,170
Home equity lines of credit [Member]
Consumer:
Total consumer loans	352,584	339,866
Construction:
Allowance for loan losses	-15,676	-16,375	-21,367	-18,258
Home equity loans [Member]
Consumer:
Total consumer loans	31,314	14,588
Residential [Member]
Construction:
Total construction	38,618	31,933
Originated [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	1,083,391	954,794
Consumer:
Total consumer loans	357,067	356,610
Commercial	126,611	124,650
Construction:
Total construction	45,680	47,492
Total loans, net of deferred loan fees and discounts	1,612,749	1,483,546
Total principal balance of loans owed, net of charge-offs	1,617,542	1,487,240
Unamortized net deferred loan fees	-4,793	-3,694
Total loans, net of unamortized deferred loan fees and discounts	1,612,749	1,483,546
Noncovered loans	1,612,749	1,483,546
Total loans, net of unamortized deferred loan fees and discounts	1,612,749	1,483,546
Allowance for loan losses	-29,860	-31,354
Originated [Member] | Auto Indirect [Member]
Consumer:
Total consumer loans	112	946
Originated [Member] | Other [Member]
Consumer:
Total consumer loans	28,230	25,608
Originated [Member] | Residential 1-4 family [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	154,594	129,882
Originated [Member] | Commercial [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	928,797	824,912
Construction:
Total construction	24,545	17,125
Originated [Member] | Home equity lines of credit [Member]
Consumer:
Total consumer loans	305,166	316,207
Originated [Member] | Home equity loans [Member]
Consumer:
Total consumer loans	23,559	13,849
Originated [Member] | Residential [Member]
Construction:
Total construction	21,135	30,367
PNCI [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	497,046	118,153
Consumer:
Total consumer loans	50,152	15,903
Commercial	40,899	693
Construction:
Total construction	28,781
Total loans, net of deferred loan fees and discounts	616,878	134,749
Total principal balance of loans owed, net of charge-offs	634,490	142,786
Discounts to principal balance of loans owed, net of charge-offs	-17,612	-8,037
Total loans, net of unamortized deferred loan fees and discounts	616,878	134,749
Noncovered loans	616,878	134,749
Total loans, net of unamortized deferred loan fees and discounts	616,878	134,749
Allowance for loan losses	-3,296	-2,850
PNCI [Member] | Other [Member]
Consumer:
Total consumer loans	4,770	2,074
PNCI [Member] | Residential 1-4 family [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	120,821	60,475
PNCI [Member] | Commercial [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	376,225	57,678
Construction:
Total construction	11,973
PNCI [Member] | Home equity lines of credit [Member]
Consumer:
Total consumer loans	38,397	13,576
PNCI [Member] | Home equity loans [Member]
Consumer:
Total consumer loans	6,985	253
PNCI [Member] | Residential [Member]
Construction:
Total construction	16,808
PCI - Cash basis [Member]
Consumer:
Total consumer loans	5,603	6,200
Commercial	8	19
Construction:
Total loans, net of deferred loan fees and discounts	5,611	6,219
Total principal balance of loans owed, net of charge-offs	14,805	16,475
Discounts to principal balance of loans owed, net of charge-offs	-9,194	-10,256
Total loans, net of unamortized deferred loan fees and discounts	5,611	6,219
Noncovered loans	5,611	6,219
Total loans, net of unamortized deferred loan fees and discounts	5,611	6,219
Allowance for loan losses	-348	-385
PCI - Cash basis [Member] | Home equity lines of credit [Member]
Consumer:
Total consumer loans	5,478	6,200
PCI - Cash basis [Member] | Home equity loans [Member]
Consumer:
Total consumer loans	125
PCI - Other [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	34,922	34,916
Consumer:
Total consumer loans	4,262	4,450
Commercial	7,427	6,516
Construction:
Total construction	675	1,611
Total loans, net of deferred loan fees and discounts	47,286	47,493
Total principal balance of loans owed, net of charge-offs	56,016	56,879
Discounts to principal balance of loans owed, net of charge-offs	-8,730	-9,386
Total loans, net of unamortized deferred loan fees and discounts	47,286	47,493
Noncovered loans	25,018	19,581
Covered loans	22,268	27,912
Total loans, net of unamortized deferred loan fees and discounts	47,286	47,493
Allowance for loan losses	-3,081	-3,656
PCI - Other [Member] | Other [Member]
Consumer:
Total consumer loans	74	81
PCI - Other [Member] | Residential 1-4 family [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	4,005	4,656
PCI - Other [Member] | Commercial [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	30,917	30,260
Construction:
Total construction		45
PCI - Other [Member] | Home equity lines of credit [Member]
Consumer:
Total consumer loans	3,543	3,883
PCI - Other [Member] | Home equity loans [Member]
Consumer:
Total consumer loans	645	486
PCI - Other [Member] | Residential [Member]
Construction:
Total construction	$675	$1,566

Loans_Change_in_Accretable_Yie

Loans - Change in Accretable Yield for PCI (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Change in accretable yield:
Balance at beginning of period	$18,232	$22,337
Accretion to interest income	-4,368	-6,305
Reclassification (to) from nonaccretable difference	1,009	2,201
Balance at end of period	$14,873	$18,232

Allowance_for_Loan_Losses_Summ

Allowance for Loan Losses - Summary of Activity in Allowance for Loan Losses, and Ending Balance of Loans, Net of Unearned Fees for Periods Indicated (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$2,282,524	$1,672,007	$1,564,823
Individ. evaluated for impairment	62,246	81,235	101,330
Loans pooled for evaluation	2,167,381	1,537,060	1,393,925
Loans acquired with deteriorated credit quality	52,897	53,712	69,568
Beginning balance	38,245	42,648	45,914
Charge-offs	-2,558	-7,543	-16,484
Recoveries	4,943	3,855	3,795
(Benefit) provision	-4,045	-715	9,423
Ending balance	36,585	38,245	42,648
Ending balance:
Individ. evaluated for impairment	4,267	3,975	4,505
Loans pooled for evaluation	28,891	30,230	33,233
Loans acquired with deteriorated credit quality	3,427	4,040	4,910
Home equity lines of credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	352,584	339,866	342,025
Individ. evaluated for impairment	6,968	6,918	10,056
Loans pooled for evaluation	336,595	322,865	318,403
Loans acquired with deteriorated credit quality	9,021	10,083	13,566
Beginning balance	16,375	21,367	18,258
Charge-offs	-1,094	-2,651	-8,042
Recoveries	960	1,053	398
(Benefit) provision	-565	-3,394	10,753
Ending balance	15,676	16,375	21,367
Ending balance:
Individ. evaluated for impairment	1,974	1,140	2,264
Loans pooled for evaluation	13,251	14,749	17,862
Loans acquired with deteriorated credit quality	451	486	1,241
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	33,074	27,763	26,713
Individ. evaluated for impairment	323	90	121
Loans pooled for evaluation	32,677	27,592	26,560
Loans acquired with deteriorated credit quality	74	81	32
Beginning balance	589	696	932
Charge-offs	-599	-887	-1,202
Recoveries	495	759	860
(Benefit) provision	234	21	106
Ending balance	719	589	696
Ending balance:
Individ. evaluated for impairment	142	8	47
Loans pooled for evaluation	572	581	649
Loans acquired with deteriorated credit quality	5
Construction [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	38,618	31,933	18,459
Individ. evaluated for impairment	2,683	2,756	3,596
Loans pooled for evaluation	35,260	27,611	8,281
Loans acquired with deteriorated credit quality	675	1,566	6,582
Beginning balance	1,559	1,400	1,817
Charge-offs	-4	-20	-406
Recoveries	1,377	63	412
(Benefit) provision	-1,498	116	-423
Ending balance	1,434	1,559	1,400
Ending balance:
Individ. evaluated for impairment	60	91	11
Loans pooled for evaluation	332	751	430
Loans acquired with deteriorated credit quality	1,042	717	959
Construction [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	35,518	17,170	14,595
Individ. evaluated for impairment	99	178	607
Loans pooled for evaluation	36,419	16,947	10,589
Loans acquired with deteriorated credit quality		45	3,399
Beginning balance	1,263	779	1,425
Charge-offs	-69	-140	-100
Recoveries	181	65
(Benefit) provision	-964	559	-546
Ending balance	411	1,263	779
Ending balance:
Individ. evaluated for impairment		8	111
Loans pooled for evaluation	322	789	165
Loans acquired with deteriorated credit quality	89	466	503
RE Mortgage [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	279,420	195,013	131,684
Individ. evaluated for impairment	7,188	7,342	6,586
Loans pooled for evaluation	268,227	183,015	120,082
Loans acquired with deteriorated credit quality	4,005	4,656	5,016
Beginning balance	3,154	3,523	2,404
Charge-offs	-171	-46	-1,558
Recoveries	2	345	147
(Benefit) provision	101	-668	2,530
Ending balance	3,086	3,154	3,523
Ending balance:
Individ. evaluated for impairment	974	775	631
Loans pooled for evaluation	1,915	2,039	2,526
Loans acquired with deteriorated credit quality	197	340	366
RE Mortgage [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,335,939	912,850	878,446
Individ. evaluated for impairment	41,932	59,936	71,077
Loans pooled for evaluation	1,263,090	822,654	776,137
Loans acquired with deteriorated credit quality	30,917	30,260	31,232
Beginning balance	9,700	8,782	13,217
Charge-offs	-110	-2,038	-3,457
Recoveries	540	994	1,020
(Benefit) provision	-903	1,962	-1,998
Ending balance	9,227	9,700	8,782
Ending balance:
Individ. evaluated for impairment	410	1,198	515
Loans pooled for evaluation	8,408	7,815	8,026
Loans acquired with deteriorated credit quality	409	687	241
Home equity loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	31,314	14,588	13,557
Individ. evaluated for impairment	1,278	778	528
Loans pooled for evaluation	29,266	13,324	12,825
Loans acquired with deteriorated credit quality	770	486	204
Beginning balance	1,208	1,155	1,101
Charge-offs	-29	-94	-385
Recoveries	34	41	100
(Benefit) provision	584	106	339
Ending balance	1,797	1,208	1,155
Ending balance:
Individ. evaluated for impairment	284	169	81
Loans pooled for evaluation	1,513	1,039	995
Loans acquired with deteriorated credit quality			79
Auto Indirect [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	112	946	3,816
Individ. evaluated for impairment	18	60	197
Loans pooled for evaluation	94	886	3,619
Beginning balance	66	243	215
Charge-offs	-3	-68	-83
Recoveries	86	195	215
(Benefit) provision	-140	-304	-104
Ending balance	9	66	243
Ending balance:
Individ. evaluated for impairment		1	5
Loans pooled for evaluation	9	65	238
C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	174,945	131,878	135,528
Individ. evaluated for impairment	1,757	3,177	8,562
Loans pooled for evaluation	165,753	122,166	117,429
Loans acquired with deteriorated credit quality	7,435	6,535	9,537
Beginning balance	4,331	4,703	6,545
Charge-offs	-479	-1,599	-1,251
Recoveries	1,268	340	643
(Benefit) provision	-894	887	-1,234
Ending balance	4,226	4,331	4,703
Ending balance:
Individ. evaluated for impairment	423	585	840
Loans pooled for evaluation	2,569	2,402	2,342
Loans acquired with deteriorated credit quality	$1,234	$1,344	$1,521

Allowance_for_Loan_Losses_Pres

Allowance for Loan Losses - Presentation of Credit Quality Indicators (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$2,282,524	$1,672,007	$1,564,823
Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,612,749	1,483,546
PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	616,878	134,749
PCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	52,897	53,712
Pass [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,537,988	1,394,438
Pass [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	596,332	123,715
Special mention [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	18,836	24,411
Special mention [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	15,107	6,336
Substandard [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	55,925	64,684
Substandard [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	5,439	4,698
Loss [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans		13
RE Mortgage [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	279,420	195,013	131,684
RE Mortgage [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	154,594	129,882
RE Mortgage [Member] | Residential [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	120,821	60,475
RE Mortgage [Member] | Residential [Member] | PCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	4,005	4,656
RE Mortgage [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,335,939	912,850	878,446
RE Mortgage [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	928,797	824,912
RE Mortgage [Member] | Commercial [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	376,225	57,678
RE Mortgage [Member] | Commercial [Member] | PCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	30,917	30,260
RE Mortgage [Member] | Pass [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	146,949	121,969
RE Mortgage [Member] | Pass [Member] | Residential [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	119,643	59,798
RE Mortgage [Member] | Pass [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	883,102	768,596
RE Mortgage [Member] | Pass [Member] | Commercial [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	359,537	48,548
RE Mortgage [Member] | Special mention [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,122	1,265
RE Mortgage [Member] | Special mention [Member] | Residential [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	547
RE Mortgage [Member] | Special mention [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	11,521	15,862
RE Mortgage [Member] | Special mention [Member] | Commercial [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	12,979	5,810
RE Mortgage [Member] | Substandard [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	6,523	6,648
RE Mortgage [Member] | Substandard [Member] | Residential [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	631	677
RE Mortgage [Member] | Substandard [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	34,174	40,454
RE Mortgage [Member] | Substandard [Member] | Commercial [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,709	3,320
Home equity lines of credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	352,584	339,866
Home equity lines of credit [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	305,166	316,207
Home equity lines of credit [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	38,397	13,576
Home equity lines of credit [Member] | PCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	9,021	10,083
Home equity lines of credit [Member] | Pass [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	292,244	203,232
Home equity lines of credit [Member] | Pass [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	36,531	12,716
Home equity lines of credit [Member] | Special mention [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3,590	4,529
Home equity lines of credit [Member] | Special mention [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	936	195
Home equity lines of credit [Member] | Substandard [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	9,332	9,446
Home equity lines of credit [Member] | Substandard [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	930	665
Home equity loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	31,314	14,588	13,557
Home equity loans [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	23,559	13,849
Home equity loans [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	6,985	253
Home equity loans [Member] | PCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	770	486
Home equity loans [Member] | Pass [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	20,976	12,284
Home equity loans [Member] | Pass [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	6,813	253
Home equity loans [Member] | Special mention [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	743	504
Home equity loans [Member] | Special mention [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	147
Home equity loans [Member] | Substandard [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,840	1,061
Home equity loans [Member] | Substandard [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	25
Auto Indirect [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	112	946	3,816
Auto Indirect [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	112	946
Auto Indirect [Member] | Pass [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	66	717
Auto Indirect [Member] | Special mention [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	11	118
Auto Indirect [Member] | Substandard [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	35	111
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	33,074	27,763
Other Consumer [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	28,230	25,608
Other Consumer [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	4,770	2,074
Other Consumer [Member] | PCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	74	81
Other Consumer [Member] | Pass [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	27,396	24,653
Other Consumer [Member] | Pass [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	4,399	2,020
Other Consumer [Member] | Special mention [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	591	756
Other Consumer [Member] | Special mention [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	230	18
Other Consumer [Member] | Substandard [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	243	196
Other Consumer [Member] | Substandard [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	141	36
Other Consumer [Member] | Loss [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans		3
C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	174,945	131,878	135,528
C&I [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	126,611	124,650
C&I [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	40,899	693
C&I [Member] | PCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	7,435	6,535
C&I [Member] | Pass [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	124,707	121,580
C&I [Member] | Pass [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	40,628	380
C&I [Member] | Special mention [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	636	938
C&I [Member] | Special mention [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	268	313
C&I [Member] | Substandard [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	1,268	2,122
C&I [Member] | Substandard [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	3
C&I [Member] | Loss [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans		10
Construction [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	38,618	31,933
Construction [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	21,135	30,367
Construction [Member] | Residential [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	16,808
Construction [Member] | Residential [Member] | PCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	675	1,566
Construction [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	35,518	17,170
Construction [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	24,545	17,125
Construction [Member] | Commercial [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	11,973
Construction [Member] | Commercial [Member] | PCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans		45
Construction [Member] | Pass [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	18,112	25,836
Construction [Member] | Pass [Member] | Residential [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	16,808
Construction [Member] | Pass [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	24,436	16,571
Construction [Member] | Pass [Member] | Commercial [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	11,973
Construction [Member] | Special mention [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	622	96
Construction [Member] | Special mention [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans		343
Construction [Member] | Substandard [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	2,401	4,435
Construction [Member] | Substandard [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	$109	$211

Allowance_for_Loan_Losses_Addi

Allowance for Loan Losses - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Category
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of categories occupied under commercial real estate loans	2
Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired TDRs Loans	45,676,000	$56,739,000	$57,223,000
Additional funds in TDRs	54,000	25,000	137,000
PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Impaired TDRs Loans	1,307,000	901,000	950,000
Obligations to lend additional funds on TDRs	0	$0	$0
Minimum [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Period of collateral payment of loan	3 months
Maximum [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Period of collateral payment of loan	12 months

Allowance_for_Loan_Losses_Anal

Allowance for Loan Losses - Analysis of Past Due and Nonaccrual Loans (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	$5,519	$8,321
60-89 Days	1,530	1,661
> 90 Days	2,080	4,824
Total past due	9,129	14,806
Current	1,603,620	1,468,740
Total orig. loans	1,612,749	1,483,546
> 90 Days and still accruing	0	0
Nonaccrual loans	32,529	45,131
PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	2,668	1,673
60-89 Days	145	390
> 90 Days	413	217
Total past due	3,226	2,280
Current	613,652	132,469
Total orig. loans	616,878	134,749
> 90 Days and still accruing	0	0
Nonaccrual loans	1,646	1,866
RE Mortgage [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	1,296	2,272
60-89 Days	919	284
> 90 Days	100	447
Total past due	2,315	3,003
Current	152,279	126,879
Total orig. loans	154,594	129,882
> 90 Days and still accruing	0	0
Nonaccrual loans	3,430	4,697
RE Mortgage [Member] | Residential [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	2,041	799
60-89 Days	24
> 90 Days	239
Total past due	2,304	799
Current	118,517	59,676
Total orig. loans	120,821	60,475
> 90 Days and still accruing	0	0
Nonaccrual loans	799	262
RE Mortgage [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	735	2,304
> 90 Days	900	2,213
Total past due	1,635	4,517
Current	927,162	820,395
Total orig. loans	928,797	824,912
> 90 Days and still accruing	0	0
Nonaccrual loans	20,736	30,732
RE Mortgage [Member] | Commercial [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	260	512
60-89 Days		352
> 90 Days		217
Total past due	260	1,081
Current	375,965	56,597
Total orig. loans	376,225	57,678
> 90 Days and still accruing	0	0
Nonaccrual loans	366	1,139
Home equity lines of credit [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	2,066	3,121
60-89 Days	296	1,070
> 90 Days	754	1,050
Total past due	3,116	5,241
Current	302,050	310,966
Total orig. loans	305,166	316,207
> 90 Days and still accruing	0	0
Nonaccrual loans	4,336	4,972
Home equity lines of credit [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	275	313
60-89 Days	118	38
> 90 Days	73
Total past due	466	351
Current	37,931	13,225
Total orig. loans	38,397	13,576
> 90 Days and still accruing	0	0
Nonaccrual loans	346	429
Home equity loans [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	615	264
60-89 Days	192	16
> 90 Days	202	312
Total past due	1,009	592
Current	22,550	13,257
Total orig. loans	23,559	13,849
> 90 Days and still accruing	0	0
Nonaccrual loans	1,197	719
Home equity loans [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
> 90 Days	25
Total past due	25
Current	6,960	253
Total orig. loans	6,985	253
> 90 Days and still accruing	0	0
Nonaccrual loans	25
Auto Indirect [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	4	24
60-89 Days		1
> 90 Days	17	33
Total past due	21	58
Current	91	888
Total orig. loans	112	946
> 90 Days and still accruing	0	0
Nonaccrual loans	18	54
Auto Indirect [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
> 90 Days and still accruing	0	0
Other Consumer [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	64	40
60-89 Days	24	16
> 90 Days	46	7
Total past due	134	63
Current	28,096	25,545
Total orig. loans	28,230	25,608
> 90 Days and still accruing	0	0
Nonaccrual loans	66	26
Other Consumer [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	25	49
60-89 Days	3
> 90 Days	76
Total past due	104	49
Current	4,666	2,025
Total orig. loans	4,770	2,074
> 90 Days and still accruing	0	0
Nonaccrual loans	110	36
C&I [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	739	296
60-89 Days	99	76
> 90 Days	61	749
Total past due	899	1,121
Current	125,712	123,529
Total orig. loans	126,611	124,650
> 90 Days and still accruing	0	0
Nonaccrual loans	246	1,280
C&I [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due: 30-59 Days	67
Total past due	67
Current	40,832	693
Total orig. loans	40,899	693
> 90 Days and still accruing	0	0
Construction [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
> 90 Days		13
Total past due		13
Current	21,135	30,354
Total orig. loans	21,135	30,367
> 90 Days and still accruing	0	0
Nonaccrual loans	2,401	2,473
Construction [Member] | Residential [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	16,808
Total orig. loans	16,808
> 90 Days and still accruing	0	0
Construction [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
60-89 Days		198
Total past due		198
Current	24,545	16,927
Total orig. loans	24,545	17,125
> 90 Days and still accruing	0	0
Nonaccrual loans	99	178
Construction [Member] | Commercial [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	11,973
Total orig. loans	11,973
> 90 Days and still accruing	$0	$0

Allowance_for_Loan_Losses_Impa

Allowance for Loan Losses - Impaired Loans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	$48,466	$66,241	$82,411
Unpaid principal, With no related allowance recorded	61,660	82,489	97,205
Average recorded Investment, With no related allowance recorded	57,354	71,116	84,095
Interest income Recognized, With no related allowance recorded	1,095	4,326	2,749
Recorded investment, With an allowance recorded	11,021	12,855	16,457
Unpaid principal, With an allowance recorded	11,863	13,896	20,127
Related allowance, With an allowance recorded	3,646	3,558	4,252
Average recorded Investment, With an allowance recorded	11,938	15,050	29,443
Interest income Recognized, With an allowance recorded	409	707	428
PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	1,124	1,562	1,833
Unpaid principal, With no related allowance recorded	3,433	3,825	4,038
Average recorded Investment, With no related allowance recorded	1,344	1,421	2,474
Interest income Recognized, With no related allowance recorded	14	271	138
Recorded investment, With an allowance recorded	1,636	578	629
Unpaid principal, With an allowance recorded	1,654	599	673
Related allowance, With an allowance recorded	621	417	253
Average recorded Investment, With an allowance recorded	1,107	716	525
Interest income Recognized, With an allowance recorded	48	32	24
RE Mortgage [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	3,287	4,366	3,520
Unpaid principal, With no related allowance recorded	5,138	6,489	5,349
Average recorded Investment, With no related allowance recorded	3,826	4,123	6,329
Interest income Recognized, With no related allowance recorded	38	336	71
Recorded investment, With an allowance recorded	2,724	2,630	2,867
Unpaid principal, With an allowance recorded	2,865	2,689	3,432
Related allowance, With an allowance recorded	797	648	603
Average recorded Investment, With an allowance recorded	2,677	2,245	3,890
Interest income Recognized, With an allowance recorded	91	124	67
RE Mortgage [Member] | Residential [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	343	148
Unpaid principal, With no related allowance recorded	353	158
Average recorded Investment, With no related allowance recorded	246	37	16
Interest income Recognized, With no related allowance recorded	14	11
Recorded investment, With an allowance recorded	834	198	199
Unpaid principal, With an allowance recorded	852	207	225
Related allowance, With an allowance recorded	177	128	28
Average recorded Investment, With an allowance recorded	516	275	213
Interest income Recognized, With an allowance recorded	8	12	9
RE Mortgage [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	38,477	53,352	66,031
Unpaid principal, With no related allowance recorded	41,949	58,894	70,709
Average recorded Investment, With no related allowance recorded	45,915	58,205	61,299
Interest income Recognized, With no related allowance recorded	995	3,361	2,513
Recorded investment, With an allowance recorded	2,943	5,296	3,258
Unpaid principal, With an allowance recorded	3,101	5,659	3,556
Related allowance, With an allowance recorded	302	1,084	352
Average recorded Investment, With an allowance recorded	4,119	6,077	7,841
Interest income Recognized, With an allowance recorded	144	287	129
RE Mortgage [Member] | Commercial [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	366	1,139	1,468
Unpaid principal, With no related allowance recorded	2,620	3,323	3,452
Average recorded Investment, With no related allowance recorded	753	1,005	2,097
Interest income Recognized, With no related allowance recorded		233	133
Recorded investment, With an allowance recorded	146	149	320
Unpaid principal, With an allowance recorded	146	149	331
Related allowance, With an allowance recorded	108	114	163
Average recorded Investment, With an allowance recorded	148	250	121
Interest income Recognized, With an allowance recorded	8	9	12
Home equity lines of credit [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	3,001	3,710	4,241
Unpaid principal, With no related allowance recorded	6,094	7,299	6,691
Average recorded Investment, With no related allowance recorded	3,355	4,410	4,311
Interest income Recognized, With no related allowance recorded	26	352	58
Recorded investment, With an allowance recorded	3,185	2,779	5,412
Unpaid principal, With an allowance recorded	3,533	3,053	7,103
Related allowance, With an allowance recorded	1,769	968	2,237
Average recorded Investment, With an allowance recorded	2,982	3,064	6,331
Interest income Recognized, With an allowance recorded	71	146	103
Home equity lines of credit [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	346	227	365
Unpaid principal, With no related allowance recorded	374	287	586
Average recorded Investment, With no related allowance recorded	287	333	308
Interest income Recognized, With no related allowance recorded	-1	21	5
Recorded investment, With an allowance recorded	436	203	38
Unpaid principal, With an allowance recorded	436	215	41
Related allowance, With an allowance recorded	205	172	27
Average recorded Investment, With an allowance recorded	319	162	148
Interest income Recognized, With an allowance recorded	20	10	1
Home equity loans [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	750	552	361
Unpaid principal, With no related allowance recorded	1,187	1,249	781
Average recorded Investment, With no related allowance recorded	651	463	329
Interest income Recognized, With no related allowance recorded	6	36	1
Recorded investment, With an allowance recorded	504	226	167
Unpaid principal, With an allowance recorded	597	291	396
Related allowance, With an allowance recorded	284	169	81
Average recorded Investment, With an allowance recorded	365	141	317
Interest income Recognized, With an allowance recorded	13	18	16
Home equity loans [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	25
Unpaid principal, With no related allowance recorded	25
Average recorded Investment, With no related allowance recorded	12		11
Auto Indirect [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	14	55	163
Unpaid principal, With no related allowance recorded	49	123	311
Average recorded Investment, With no related allowance recorded	35	93	263
Interest income Recognized, With no related allowance recorded		12	3
Recorded investment, With an allowance recorded	4	4	34
Unpaid principal, With an allowance recorded	6	6	51
Related allowance, With an allowance recorded		1	5
Average recorded Investment, With an allowance recorded	4	12	102
Interest income Recognized, With an allowance recorded		1	1
Other Consumer [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	25	16	19
Unpaid principal, With no related allowance recorded	32	21	40
Average recorded Investment, With no related allowance recorded	21	18	42
Interest income Recognized, With no related allowance recorded	1	1
Recorded investment, With an allowance recorded	41	10	30
Unpaid principal, With an allowance recorded	41	10	32
Related allowance, With an allowance recorded	11	5	12
Average recorded Investment, With an allowance recorded	25	7	49
Interest income Recognized, With an allowance recorded		2	1
Other Consumer [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	37	36
Unpaid principal, With no related allowance recorded	54	45
Average recorded Investment, With no related allowance recorded	36	39	31
Interest income Recognized, With no related allowance recorded		5
Recorded investment, With an allowance recorded	220	28	72
Unpaid principal, With an allowance recorded	220	28	76
Related allowance, With an allowance recorded	131	3	35
Average recorded Investment, With an allowance recorded	124	29	43
Interest income Recognized, With an allowance recorded	12	1	2
C&I [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	412	1,648	4,238
Unpaid principal, With no related allowance recorded	433	1,665	4,613
Average recorded Investment, With no related allowance recorded	1,030	2,154	7,500
Interest income Recognized, With no related allowance recorded	26	113	73
Recorded investment, With an allowance recorded	1,338	1,517	4,324
Unpaid principal, With an allowance recorded	1,438	1,616	4,992
Related allowance, With an allowance recorded	423	585	840
Average recorded Investment, With an allowance recorded	1,428	1,817	2,800
Interest income Recognized, With an allowance recorded	71	95	100
C&I [Member] | PNCI loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	7	12
Unpaid principal, With no related allowance recorded	7	12
Average recorded Investment, With no related allowance recorded	10	7	11
Interest income Recognized, With no related allowance recorded	1	1
Construction [Member] | Residential [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	2,401	2,473	3,554
Unpaid principal, With no related allowance recorded	6,588	6,611	8,227
Average recorded Investment, With no related allowance recorded	2,437	1,567	3,505
Interest income Recognized, With no related allowance recorded		108	20
Recorded investment, With an allowance recorded	282	284	42
Unpaid principal, With an allowance recorded	282	284	42
Related allowance, With an allowance recorded	60	91	11
Average recorded Investment, With an allowance recorded	283	1,499	1,543
Interest income Recognized, With an allowance recorded	19	19	6
Construction [Member] | Commercial [Member] | Originated loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investment, With no related allowance recorded	99	69	284
Unpaid principal, With no related allowance recorded	190	138	484
Average recorded Investment, With no related allowance recorded	84	83	517
Interest income Recognized, With no related allowance recorded	3	7	10
Recorded investment, With an allowance recorded		109	323
Unpaid principal, With an allowance recorded		288	523
Related allowance, With an allowance recorded		7	111
Average recorded Investment, With an allowance recorded	55	188	6,570
Interest income Recognized, With an allowance recorded		$15	$5

Allowance_for_Loan_Losses_Trou

Allowance for Loan Losses - Troubled Debt Restructurings (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	SecurityLoan	SecurityLoan
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number	31	42
Pre-mod outstanding principal balance	$4,754	$17,389
Post-mod outstanding principal balance	4,656	17,408
Financial impact due to TDR taken as additional provision	279	602
Number that defaulted during the period	6	21
Recorded investment of TDRs that defaulted during the period	903	3,746
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions	-8	12
Home equity lines of credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number	6	12
Pre-mod outstanding principal balance	940	1,546
Post-mod outstanding principal balance	967	1,557
Financial impact due to TDR taken as additional provision		340
Number that defaulted during the period	1	3
Recorded investment of TDRs that defaulted during the period	20	150
RE Mortgage [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number	5	9
Pre-mod outstanding principal balance	1,048	2,173
Post-mod outstanding principal balance	1,050	2,177
Financial impact due to TDR taken as additional provision	91	148
Number that defaulted during the period	2	4
Recorded investment of TDRs that defaulted during the period	344	443
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions		-3
RE Mortgage [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number	7	11
Pre-mod outstanding principal balance	1,980	13,145
Post-mod outstanding principal balance	1,890	13,146
Financial impact due to TDR taken as additional provision	22	27
Number that defaulted during the period	2	8
Recorded investment of TDRs that defaulted during the period	423	1,702
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions		7
Home equity loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number	2	2
Pre-mod outstanding principal balance	100	251
Post-mod outstanding principal balance	102	253
Financial impact due to TDR taken as additional provision	-1	-1
Number that defaulted during the period		1
Recorded investment of TDRs that defaulted during the period		15
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number	1
Pre-mod outstanding principal balance	147
Post-mod outstanding principal balance	147
Financial impact due to TDR taken as additional provision	66
C&I [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number	7	8
Pre-mod outstanding principal balance	218	274
Post-mod outstanding principal balance	219	275
Financial impact due to TDR taken as additional provision	101	88
Number that defaulted during the period	1	4
Recorded investment of TDRs that defaulted during the period	116	1,363
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions	-8	3
Construction [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number	1
Pre-mod outstanding principal balance	102
Post-mod outstanding principal balance	85
Number that defaulted during the period		1
Recorded investment of TDRs that defaulted during the period		73
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions		5
Construction [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number	2
Pre-mod outstanding principal balance	219
Post-mod outstanding principal balance	$196

Foreclosed_Assets_Summary_of_A

Foreclosed Assets - Summary of Activity in Balance of Foreclosed Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	Assets	Assets
Schedule Of Foreclosed Assets Activity [Line Items]
Beginning balance, net	$6,262	$7,498
Acquisitions	695
Additions/transfers from loans	5,753	11,717
Dispositions/sales	-7,608	-12,271
Valuation adjustments	-208	-682
Ending balance, net	4,894	6,262
Ending valuation allowance	-208	-414
Ending number of foreclosed assets	29	32
Proceeds from sale of foreclosed assets	9,762	13,910
Gain on sale of foreclosed assets	2,153	1,640
Noncovered [Member]
Schedule Of Foreclosed Assets Activity [Line Items]
Beginning balance, net	5,588	5,957
Acquisitions	695
Additions/transfers from loans	5,753	11,224
Dispositions/sales	-7,391	-10,992
Valuation adjustments	-196	-601
Ending balance, net	4,449	5,588
Ending valuation allowance	-208	-414
Ending number of foreclosed assets	28	28
Proceeds from sale of foreclosed assets	9,517	12,483
Gain on sale of foreclosed assets	2,125	1,492
Covered [Member]
Schedule Of Foreclosed Assets Activity [Line Items]
Beginning balance, net	674	1,541
Additions/transfers from loans		493
Dispositions/sales	-217	-1,279
Valuation adjustments	-12	-81
Ending balance, net	445	674
Ending number of foreclosed assets	1	4
Proceeds from sale of foreclosed assets	245	1,427
Gain on sale of foreclosed assets	$28	$148

Premises_and_Equipment_Summary

Premises and Equipment - Summary of Premises and Equipment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, Plant and Equipment, Net, by Type [Abstract]
Land & land improvements	$8,933	$5,975
Buildings	39,638	30,103
Furniture and equipment	28,446	27,881
Premises and equipment, gross	77,017	63,959
Less: Accumulated depreciation	-33,570	-32,397
Premises and equipment less depreciation, gross	43,447	31,562
Construction in progress	46	50
Total premises and equipment	$43,493	$31,612

Premises_and_Equipment_Additio

Premises and Equipment - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Depreciation expense for premises and equipment	$4,648,000	$3,635,000	$3,250,000

Cash_Value_of_Life_Insurance_S

Cash Value of Life Insurance - Summary of Activity in Balance of Cash Value of Life Insurance (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	Company	Employees
	Policies	Company
	Employees	Policies
Increase (Decrease) in Insurance Liabilities [Abstract]
Beginning balance	$52,309	$50,582
Acquisitions	38,075
Increase in cash value of life insurance	1,953	1,727
Ending balance	92,337	52,309
End of period death benefit	$165,966	$95,513
Number of policies owned	189	133
Insurance companies used	14	6
Current and former employees and directors covered	60	36

Cash_Value_of_Life_Insurance_A

Cash Value of Life Insurance - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
	Company	Company
	Policies
Insurance [Abstract]
Number of life insurance policies owned by the Company	189
Insurance companies used	14	6
Policies covering current and former employees and directors	60

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets - Summary of Goodwill Intangible (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Ending Balance	$63,462
Goodwill, Additions	47,943
Goodwill, Reductions	0
Goodwill, Beginning Balance	$15,519

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets - Summary of Core Deposit Intangibles (Detail) (Core deposit intangibles [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Core deposit intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Core deposit intangibles, Beginning balance	$8,074
Core deposit intangibles, Reductions/Amortization	0
Core deposit intangibles, Additions	6,614
Core deposit intangibles, Ending balance	1,460
Accumulated amortization, Beginning balance	-1,023
Accumulated amortization, Reductions/Amortization	-446
Accumulated amortization, Additions	0
Accumulated amortization, Ending balance	-577
Core deposit intangibles, net, Beginning balance	7,051
Core deposit intangibles, net, Reductions/Amortization	-446
Core deposit intangibles, net, Additions	6,614
Core deposit intangibles, net, Ending balance	$883

Goodwill_and_Other_Intangible_4

Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	Oct. 03, 2014	Sep. 23, 2011	28-May-10
North Valley Bancorp [Member]
Finite-Lived Intangible Assets [Line Items]
Additions to core deposit intangibles	$6,614,000
Citizens [Member]
Finite-Lived Intangible Assets [Line Items]
Additions to core deposit intangibles		898,000
Granite [Member]
Finite-Lived Intangible Assets [Line Items]
Additions to core deposit intangibles			$562,000

Goodwill_and_Other_Intangible_5

Goodwill and Other Intangible Assets - Estimated Core Deposit Intangible Amortization (Detail) (Core deposit intangibles [Member], USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Core deposit intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
2015	$1,157
2016	1,157
2017	1,109
2018	1,044
2019	948
Thereafter	$1,636

Mortgage_Servicing_Rights_Fair

Mortgage Servicing Rights - Fair Value of Mortgage Servicing Rights (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Servicing Assets at Fair Value [Line Items]
Contractually specified servicing fees, late fees and ancillary fees earned	$1,869	$1,774	$1,666
Weighted-average prepayment speed (CPR)	12.00%	10.30%	20.30%
Weighted-average discount rate	10.00%	10.00%	10.00%
Loans [Member]
Servicing Assets at Fair Value [Line Items]
Balance at beginning of period				598,185
Balance at end of period	840,288	680,197	666,512	598,185
Mortgage servicing rights [Member]
Servicing Assets at Fair Value [Line Items]
Balance at beginning of period	6,165	4,552	4,603
Acquisition	1,944
Originations	570	1,360	1,965
Change in fair value	-1,301	253	-2,016
Balance at end of period	$7,378	$6,165	$4,552

Indemnification_Asset_Summary_

Indemnification Asset - Summary of Activity in Balance of Indemnification Asset (Liability) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
FDIC Indemnification Asset [Roll Forward]
Beginning balance	$206	$1,997	$4,405
Effect of actual covered losses (recoveries) and increase (decrease) in estimated future covered losses	-869	-1,419	-245
Reimbursable (revenue) expenses incurred	69	-159	69
Payments made (received)	245	-213	-2,232
Ending balance	($349)	$206	$1,997

Other_Assets_Summary_of_Other_

Other Assets - Summary of Other Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred tax asset, net (Note 22)	$37,706	$26,781
Prepaid expense	2,034	2,131
Software	1,327	1,318
Advanced compensation	908	1,175
Capital Trusts	1,690	1,238
Miscellaneous other assets	8,070	3,443
Total other assets	$51,735	$36,086

Deposits_Summary_of_Balances_o

Deposits - Summary of Balances of Deposits (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deposits [Abstract]
Noninterest-bearing demand	$1,083,900	$789,458
Interest-bearing demand	782,385	533,351
Savings	1,156,126	798,986
Time certificates, $250,000 and over	38,217	31,542
Other time certificates	319,795	257,146
Total deposits	$3,380,423	$2,410,483

Deposits_Additional_Informatio

Deposits - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Deposits [Line Items]
Overdrawn deposit balances classified as consumer loans	$1,216,000	$1,212,000
California [Member]
Schedule Of Deposits [Line Items]
Certificate of deposits, included in time certificates $100,000 and over	$5,000,000	$5,000,000

Deposits_Schedule_of_Maturitie

Deposits - Schedule of Maturities of Time Deposits (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Summary of maturities of time deposits [Abstract]
2015	$282,629
2016	46,606
2017	17,017
2018	6,241
2019	5,516
Thereafter	3
Total	$358,012

Reserve_for_Unfunded_Commitmen2

Reserve for Unfunded Commitments - Summary of Activity in Reserve for Unfunded Commitments (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Balance at beginning of period	$2,415	$3,615	$2,740
Acquisitions	125
Provision for losses - Unfunded commitments	-395	-1,200	875
Balance at end of period	$2,145	$2,415	$3,615

Other_Liabilities_Components_o

Other Liabilities - Components of Other Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other Liabilities Disclosure [Abstract]
Deferred compensation	$7,408	$7,357
Pension liability	26,798	14,634
Joint beneficiary agreements	2,728	2,623
Miscellaneous other liabilities	12,258	7,097
Total other liabilities	$49,192	$31,711

Other_Borrowings_Summary_of_Ba

Other Borrowings - Summary of Balances of Other Borrowings (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Total other borrowings	$9,276	$6,335
Other collateralized borrowings, fixed rate, as of December 31, 2014 of 0.05%, payable on January 2, 2014 [Member]
Debt Instrument [Line Items]
Other collateralized borrowings, fixed rate, as of December 31, 2014 of 0.05%, payable on January 2, 2014	$9,276	$6,335

Other_Borrowings_Summary_of_Ba1

Other Borrowings - Summary of Balances of Other Borrowings (Parenthetical) (Detail) (Other collateralized borrowings, fixed rate, as of December 31, 2014 of 0.05%, payable on January 2, 2014 [Member])	12 Months Ended
	Dec. 31, 2014
Other collateralized borrowings, fixed rate, as of December 31, 2014 of 0.05%, payable on January 2, 2014 [Member]
Debt Instrument [Line Items]
Other collateralized borrowings, fixed rate	0.05%
Other collateralized borrowings, maturity date	2-Jan-14

Other_Borrowings_Additional_In

Other Borrowings - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Debt Disclosure [Abstract]
Security repurchase agreement	$0	$0
Other collateralized borrowings	9,276,000	6,335,000
Repurchase investment securities sold and pledged as collateral under securities repurchase agreement	29,298,000
FHLB collateral line of credit, maximum borrowings capacity	865,466,000
FHLB collateral line of credit, outstanding balance	0
FHLB collateral line of credit, remaining borrowing capacity	865,466,000
Investment securities designated as potential collateral under collateral line of credit	108,917,000
Loans designated as potential collateral under collateralized line of credit with FHLB	1,217,944,000
Collateralized line of credit with San Francisco Federal Reserve Bank, maximum borrowings capacity	138,545,000
Collateralized line of credit with San Francisco Federal Reserve Bank, outstanding balance	0
Collateralized line of credit with San Francisco Federal Reserve Bank, remaining borrowing capacity	138,545,000
Investment securities designated as potential collateral under collateral line of credit with San Francisco Federal Reserve Bank	451,000
Loans designated as potential collateral under collateral line of credit with San Francisco Federal Reserve Bank	200,282,000
Unused correspondent banking lines of credit from commercial banks for federal funds	$15,000,000

Junior_Subordinated_Debt_Addit

Junior Subordinated Debt - Additional Information (Detail) (USD $)	12 Months Ended	0 Months Ended
	Dec. 31, 2014	Oct. 03, 2014	Dec. 31, 2013	Jul. 31, 2003	Jun. 22, 2004
Class of Stock [Line Items]
Common stock shares issued	22,714,964		16,076,662
Subordinated debenture, Face Value	62,889,000
Subordinated debenture, recorded fair value	56,272,000		41,238,000
North Valley Bancorp [Member]
Class of Stock [Line Items]
Acquisition, completion date	3-Oct-14
North Valley Trust II [Member]
Class of Stock [Line Items]
Subordinated debenture, Face Value	6,186,000	6,186,000
Acquisition of common stock interests		186,000
Subordinated debenture, recorded fair value	5,015,000	5,006,000
North Valley Trust III [Member]
Class of Stock [Line Items]
Subordinated debenture, Face Value	5,155,000	5,155,000
Acquisition of common stock interests		155,000
Subordinated debenture, recorded fair value	3,927,000	3,918,000
North Valley Trust IV [Member]
Class of Stock [Line Items]
Subordinated debenture, Face Value	10,310,000	10,310,000
Acquisition of common stock interests		310,000
Subordinated debenture, recorded fair value	6,092,000	6,063,000
TriCo Capital Trust I [Member]
Class of Stock [Line Items]
Common stock shares issued				619
Common stock par value				$1,000
Issuance of common stock, aggregate value				619,000
Issued Junior Subordinated Debenture to the trust				20,619,000
Offering of cumulative trust preferred securities				20,000
Cumulative trust preferred securities for cash in an aggregate amount				20,000,000
Redeem the trust preferred securities	7-Oct-33
LIBOR Rate, Description	Three-month LIBOR plus 3.05%
Preferred securities redeemable interest rate	3.05%
Company paid underwriting fees, per trust preferred security	7.5
Company paid underwriting fees aggregate	150,000
Net proceeds were used to finance the opening of new branches, services and technology	19,850,000
TriCo Capital Trust II [Member]
Class of Stock [Line Items]
Common stock shares issued					619
Common stock par value					$1,000
Issuance of common stock, aggregate value					619,000
Issued Junior Subordinated Debenture to the trust					20,619,000
Offering of cumulative trust preferred securities					20,000
Cumulative trust preferred securities for cash in an aggregate amount					20,000,000
Redeem the trust preferred securities	23-Jul-34
LIBOR Rate, Description	Three-month LIBOR plus 2.55%
Preferred securities redeemable interest rate	2.55%
Company paid underwriting fees, per trust preferred security	2.5
Company paid underwriting fees aggregate	50,000
Net proceeds were used to finance the opening of new branches, services and technology	19,950,000

Junior_Subordinated_Debt_Summa

Junior Subordinated Debt - Summary of Terms and Recorded Balance of Subordinated Debenture (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Oct. 03, 2014
Subordinated Borrowing [Line Items]
Subordinated debenture, Face Value	$62,889,000
Subordinated debenture, Recorded Book Value	56,272,000	41,238,000
TriCo Capital Trust I [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	7-Oct-33
Subordinated debenture, Face Value	20,619,000
Subordinated debenture, Current Coupon Rate	3.28%
Subordinated debenture, Recorded Book Value	20,619,000
TriCo Capital Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	23-Jul-34
Subordinated debenture, Face Value	20,619,000
Subordinated debenture, Current Coupon Rate	2.78%
Subordinated debenture, Recorded Book Value	20,619,000
North Valley Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	24-Apr-33
Subordinated debenture, Face Value	6,186,000		6,186,000
Subordinated debenture, Current Coupon Rate	3.48%
Subordinated debenture, Recorded Book Value	5,015,000		5,006,000
North Valley Trust III [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	24-Apr-34
Subordinated debenture, Face Value	5,155,000		5,155,000
Subordinated debenture, Current Coupon Rate	3.03%
Subordinated debenture, Recorded Book Value	3,927,000		3,918,000
North Valley Trust IV [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	15-Mar-36
Subordinated debenture, Face Value	10,310,000		10,310,000
Subordinated debenture, Current Coupon Rate	1.57%
Subordinated debenture, Recorded Book Value	$6,092,000		$6,063,000
LIBOR PLUS [Member] | TriCo Capital Trust I [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	3.05%
LIBOR PLUS [Member] | TriCo Capital Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	2.55%
LIBOR PLUS [Member] | North Valley Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	3.25%
LIBOR PLUS [Member] | North Valley Trust III [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	2.80%
LIBOR PLUS [Member] | North Valley Trust IV [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Coupon Rate	1.33%

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 21, 2007
	site
Conversion of Stock [Line Items]
Reserves to satisfy Federal regulatory requirements	$57,616,000	$38,359,000
Number of sites leased under non-cancelable operating leases	53
Rent expense under operating leases	4,786,000	4,300,000	4,332,000
Rent expense offset by rent income	225,000	216,000	138,000
Commitment expiration date	One year or less or other termination clauses and may require payment of a fee.
Letters of credit, issue period	One year or less
Overdraft privilege receivable criteria	All holders of such accounts who bring their accounts to a positive balance at least once every thirty days receive the overdraft privilege.
Class B common stock of Visa Inc.	22,714,964	16,076,662		15,814,662
Conversion ratio	0.4121
Common Class B [Member]
Conversion of Stock [Line Items]
Class B common stock of Visa Inc.	13,396
Common Class A [Member]
Conversion of Stock [Line Items]
The value of the Class A shares	$262.20
Value of unredeemed Class A equivalent shares	$1,447,000

Commitments_and_Contingencies_2

Commitments and Contingencies - Future Minimum Commitments under Non-Cancelable Operating Leases with Initial or Remaining Terms of One Year or More (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Leases [Abstract]
2015	$3,419
2016	2,510
2017	1,856
2018	1,323
2019	859
Thereafter	1,180
Future minimum lease payments	$11,147

Commitments_and_Contingencies_3

Commitments and Contingencies - Summary of Bank's Commitments and Contingent Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit
Real estate construction loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	49,774	22,897
Deposit account overdraft privilege [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	101,060	68,932
RE Mortgage [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	36,139	35,309
Standby letters of credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	17,531	2,601
Commercial [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	177,557	136,986
Other Consumer [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	$392,705	$360,194

Shareholders_Equity_Additional

Shareholders' Equity - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 21, 2007	Dec. 31, 2011
Class of Stock [Line Items]
Dividend payable by bank	$52,798,000
Shareholder Rights Plan	25-Jun-01
Percentage of restriction on acquiring outstanding common stock by person or group	15.00%
Repurchase of common stock				500,000
Stock repurchase plan percentage of common stock				3.20%
Common stock, shares outstanding	22,714,964	16,076,662		15,814,662
Repurchased shares outstanding		166,600
Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares outstanding	22,714,964	16,076,662	16,000,838		15,978,958
Company's common stock in lieu of cash to exercise options to purchase shares	103,268	172,941	14,120
Market value of common stock	2,551,000	3,490,000	224,000
Tri Counties Bank [Member]
Class of Stock [Line Items]
Cash dividends received	$8,270,000	$8,175,000	$8,522,000
Mellon Investor Services LLC [Member] | Amendment [Member]
Class of Stock [Line Items]
Amendment date of Right Plan	4-Jun-14
Schedule expiration date plan	1-Jul-14

Stock_Options_and_Other_Equity2

Stock Options and Other Equity-Based Incentive Instruments - Additional Information (Detail) (USD $)	12 Months Ended	3 Months Ended	0 Months Ended				9 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Aug. 11, 2018	Aug. 11, 2017	Aug. 11, 2016	Aug. 11, 2015	Sep. 30, 2014	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding options under the plan	1,102,850	1,102,850						1,246,370
Options currently not exercisable yet expected to vest	284,500	284,500
Weighted-average remaining contractual term	2 years 7 months 6 days
Pre-tax compensation costs expected to recognize	$1,783,000	$1,783,000
Restricted Stock Units (RSUs) [Member] | Service Condition Vesting RSUs [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of units outstanding expected to vest	30,920	30,920						0
Weighted-average remaining contractual term	2 years 9 months 18 days
Pre-tax compensation costs	566,000	566,000
Number of units granted	30,642	13,749
RSUs vesting grant date	11-Aug-14
Number of units released	0
Restricted Stock Units (RSUs) [Member] | Service Condition Vesting RSUs [Member] | Forecast [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Percentage of vesting schedule			25.00%	25.00%	25.00%	25.00%
Restricted Stock Units (RSUs) [Member] | Market Plus Service Condition Vesting RSUs [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of units outstanding expected to vest	15,366	15,366						0
Weighted-average remaining contractual term	2 years 7 months 6 days
Pre-tax compensation costs	$286,000	$286,000
Number of units granted	15,366
Number of units released	0
Minimum [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Maximum aggregate number of shares of TriCo's common stock issued	650,000	650,000
Minimum [Member] | Restricted Stock Units (RSUs) [Member] | Market Plus Service Condition Vesting RSUs [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of units released	0
Maximum [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Maximum aggregate number of shares of TriCo's common stock issued	1,650,000	1,650,000
Maximum [Member] | Restricted Stock Units (RSUs) [Member] | Market Plus Service Condition Vesting RSUs [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of units released	23,049
2009 Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares to be reduced pursuant to stock option for computation of available number of shares for issuance	1	1
Number of shares to be reduced pursuant to restricted stock award for computation of available number of shares for issuance	2	2
Outstanding options under the plan	706,000	706,000
Options available for grant under the plan	822,428	822,428
2009 Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of units outstanding expected to vest	46,286	46,286
2001 Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding options under the plan							396,850
Options available for grant under the plan							0
Share based compensation grant expiry period							10 years

Stock_Options_and_Other_Equity3

Stock Options and Other Equity-Based Incentive Instruments - Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Number of Shares, beginning balance	1,246,370
Options granted, Number of Shares	22,500
Options exercised, Number of Shares	-166,020
Options forfeited, Number of Shares	0
Options outstanding, Number of Shares, ending balance	1,102,850
Options outstanding, Weighted Average Exercise Price, beginning balance	$18.04
Options granted, Weighted Average Exercise Price	$23.21
Options exercised, Weighted Average Exercise Price	$17.32
Options forfeited, Weighted Average Exercise Price	$0
Options outstanding, Weighted Average Exercise Price, ending balance	$18.25
Minimum [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Option Price per Share, beginning balance	$12.63
Options granted, Option Price per Share	$23.21
Options exercised, Option Price per Share	$14.54
Options forfeited, Option Price per Share	$0
Options outstanding, Option Price per Share, ending balance	$12.63
Maximum [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Option Price per Share, beginning balance	$25.91
Options granted, Option Price per Share	$23.21
Options exercised, Option Price per Share	$20.58
Options forfeited, Option Price per Share	$0
Options outstanding, Option Price per Share, ending balance	$25.91

Stock_Options_and_Other_Equity4

Stock Options and Other Equity-Based Incentive Instruments - Summary of Options Outstanding (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options	1,102,850
Weighted average exercise price	$18.25
Intrinsic value (in thousands)	$7,143
Weighted average remaining contractual term (yrs.)	5 years 3 months 18 days
Currently Exercisable [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options	818,350
Weighted average exercise price	$18.62
Intrinsic value (in thousands)	5,007
Weighted average remaining contractual term (yrs.)	4 years 6 months
Currently Not Exercisable [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options	284,500
Weighted average exercise price	$17.19
Intrinsic value (in thousands)	$2,136
Weighted average remaining contractual term (yrs.)	7 years 7 months 6 days

Stock_Options_and_Other_Equity5

Stock Options and Other Equity-Based Incentive Instruments - Information about Options (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Information about Options
Intrinsic value of options exercised	$1,209,000	$1,777,000	$138,000
Fair value of options that vested	965,000	1,150,000	1,083,000
Total compensation costs for options recognized in income	965,000	1,150,000	1,083,000
Total tax benefit recognized in income related to compensation costs for options	$378,000	$484,000	$455,000
Weighted average fair value of grants (per option)	$8.17	$8.91	$6.63

Stock_Options_and_Other_Equity6

Stock Options and Other Equity-Based Incentive Instruments - Weighted-Average Assumptions Used to Determine Fair Value of Options Granted (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assumptions used to value option grants [Abstract]
Average expected terms (years)	6 years 3 months 18 days	7 years	8 years 9 months 18 days
Volatility	42.10%	56.20%	51.50%
Annual rate of dividends	1.90%	1.87%	2.36%
Discount rate	1.69%	1.26%	1.49%

Stock_Options_and_Other_Equity7

Stock Options and Other Equity-Based Incentive Instruments - Restricted Stock Unit (RSU) Activity (Detail) (Restricted Stock Units (RSUs) [Member], USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014
Service Condition Vesting RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs outstanding, Number of RSUs, beginning balance		0
RSUs granted, Number of RSUs	13,749	30,642
RSUs added through dividend credits, Number of RSUs		278
RSUs released, Number of RSUs		0
RSUs forfeited/expired, Number of RSUs		0
RSUs outstanding, Number of RSUs, ending balance	30,920	30,920
Outstanding, Weighted Average Fair Value on Date of Grant, beginning balance		$0
RSUs granted, Weighted Average Fair Value on Date of Grant		$22.54
RSUs added through dividend credits, Weighted Average Fair Value on Date of Grant		$0
RSUs released, Weighted Average Fair Value on Date of Grant		$0
RSUs forfeited/expired, Weighted Average Fair Value on Date of Grant		$0
Market Plus Service Condition Vesting RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs outstanding, Number of RSUs, beginning balance		0
RSUs granted, Number of RSUs		15,366
RSUs released, Number of RSUs		0
RSUs forfeited/expired, Number of RSUs		0
RSUs outstanding, Number of RSUs, ending balance	15,366	15,366
RSUs granted, Weighted Average Fair Value on Date of Grant		$21.39
RSUs added through dividend credits, Weighted Average Fair Value on Date of Grant		$0
RSUs released, Weighted Average Fair Value on Date of Grant		$0
RSUs forfeited/expired, Weighted Average Fair Value on Date of Grant		$0

Noninterest_Income_and_Expense2

Noninterest Income and Expense - Components of Other Noninterest Income (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Service charges on deposit accounts									$11,811	$12,716	$14,290
ATM and interchange fees									9,651	8,370	7,762
Other service fees									2,206	2,144	2,223
Mortgage banking service fees									1,869	1,774	1,666
Change in value of mortgage servicing rights									-1,301	253	-2,016
Total service charges and fees									24,236	25,257	23,925
Gain on sale of loans									2,032	5,602	6,810
Commissions on sale of non-deposit investment products									2,995	2,983	3,209
Increase in cash value of life insurance									1,953	1,727	1,820
Change in indemnification asset									-856	-1,649	-286
Gain on sale of foreclosed assets									2,153	1,640	786
Sale of customer checks									450	377	346
Lease brokerage income									504	337	276
Gain (loss) on disposal of fixed assets									49	-39	-420
Commission rebates											-56
Gain on life insurance death benefit											675
Other									1,000	594	895
Total other noninterest income									10,280	11,572	14,055
Total noninterest income	$9,755	$8,589	$7,877	$8,295	$7,353	$9,127	$10,131	$10,218	$34,516	$36,829	$37,980

Noninterest_Income_and_Expense3

Noninterest Income and Expense - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Mortgage loan servicing fees, net of change in fair value of mortgage loan servicing rights	$568,000	$2,027,000	($350,000)

Noninterest_Income_and_Expense4

Noninterest Income and Expense - Components of Noninterest Expense (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Other Noninterest Income And Expense [Line Items]
Base salaries, net of deferred loan origination costs									$39,342	$34,404	$33,093
Incentive compensation									5,068	4,694	5,138
Benefits and other compensation costs									13,134	12,838	11,721
Total salaries and benefits expense									57,544	51,936	49,952
Occupancy									8,203	7,405	7,263
Equipment									4,514	4,162	4,444
Data processing and software									6,512	4,844	4,793
Assessments									2,107	2,248	2,393
ATM network charges									2,996	2,480	2,390
Advertising									2,413	1,981	2,876
Professional fees									3,888	2,707	2,879
Telecommunications									2,870	2,449	2,250
Postage									949	786	920
Courier service									1,055	988	1,013
Foreclosed assets expense									528	514	1,474
Intangible amortization									446	209	209
Operational losses									764	618	787
Provision for foreclosed asset losses									208	682	1,728
Reserve for unfunded commitments									-395	-1,200	875
Legal settlement										339	2,090
Merger expense									4,858	312
Other									10,919	10,144	9,662
Total other noninterest expense									52,835	41,668	48,046
Total noninterest expense	36,566	25,380	25,116	23,317	24,878	23,616	23,509	21,601	110,379	93,604	97,998
Merger expense:
Merger expense									4,858	312
Merger expense									4,858	312
North Valley Bancorp [Member] | Incentive compensation [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Merger expense									1,174
Merger expense:
Merger expense									1,174
Merger expense									1,174
North Valley Bancorp [Member] | Benefits and other compensation costs [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Merger expense									94
Merger expense:
Merger expense									94
Merger expense									94
North Valley Bancorp [Member] | Data processing and software [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Merger expense									475
Merger expense:
Merger expense									475
Merger expense									475
North Valley Bancorp [Member] | Professional fees [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Merger expense									2,390	312
Merger expense:
Merger expense									2,390	312
Merger expense									2,390	312
North Valley Bancorp [Member] | Other [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Merger expense									725
Merger expense:
Merger expense									725
Merger expense									$725

Income_Taxes_Components_of_Con

Income Taxes - Components of Consolidated Income Tax Expense (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current tax expense
Federal									$14,485	$11,618	$9,895
State									5,016	4,261	3,425
Current tax expense, Total									19,501	15,879	13,320
Deferred tax expense (benefit)
Federal									-794	1,976	-235
State									-199	550	-148
Deferred tax benefit, Total									-993	2,526	-383
Total tax expense	$3,930	$6,001	$3,537	$5,040	$3,406	$4,910	$4,272	$5,817	$18,508	$18,405	$12,937

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes (Textual) [Abstract]
Unfunded status of the supplemental retirement plans, net of tax	($4,570,000)	($456,000)	($2,000)
Unrealized gains and losses on available-for-sale investment securities	-68,000	-1,780,000	-880,000
Taxes (benefits) related to employee stock options	97,000	138,000	13,000
Taxes (benefits) related to changes in joint beneficiary agreement liability	0	0	64,000
Unrecognized tax benefit	227,000	0	0	0
Interest	0	0	22,000
Penalties	0	0	5,000
North Valley Bancorp [Member]
Income Taxes (Textual) [Abstract]
Unrecognized tax benefits, if recognized	158,000
Unrecognized tax benefit	245,000
Federal [Member]
Income Taxes (Textual) [Abstract]
Net operating loss carryforwards	13,700,000
Capital loss carryforwards	131,000
Tax credit carryforwards	69,000
California [Member]
Income Taxes (Textual) [Abstract]
Net operating loss carryforwards	35,200,000
Capital loss carryforwards	404,000
Tax credit carryforwards	$2,700,000

Income_Taxes_Companys_Net_Defe

Income Taxes - Company's Net Deferred Tax Asset Recorded in Other Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Allowance for losses	$16,284	$17,096
Deferred compensation	3,115	3,093
Accrued pension liability	7,925	5,817
Accrued bonus	1,149	1,037
Other accrued expenses	124
Unfunded status of the supplemental retirement plans	3,315	331
State taxes	1,713	1,390
Stock option expense	2,534	2,225
Nonaccrual interest	2,714	1,840
OREO write downs	198	331
Acquisition cost basis	6,017	699
Tax credits	490
Net operating loss carryforwards	7,128
Other	625
Total deferred tax assets	53,331	33,859
Deferred tax liabilities:
Securities income	-1,362	-986
Unrealized gain on securities	-1,699	-1,767
Depreciation	-3,072	-392
Merger related fixed asset valuations	-54	-379
Securities accretion	-287	-256
Mortgage servicing rights valuation	-2,977	-2,416
Indemnification asset	147	-87
Core deposit intangible	-2,802	-193
Junior subordinated debt	-2,782
Prepaid expenses and other	-737	-602
Total deferred tax liability	-15,625	-7,078
Net deferred tax asset	$37,706	$26,781

Income_Taxes_Summary_of_Change

Income Taxes - Summary of Changes in Unrecognized Tax Benefit (Including Interest and Penalties) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
UTB, Beginning Balance	$0	$0	$0
UTB, Additions for tax positions for prior years	227
UTB, Ending Balance	227	0	0
Interest/Penalties, Beginning Balance	0
Interest/Penalties, Additions for tax positions for prior years	18
Interest/Penalties, Ending Balance	18
Total, Beginning Balance	0
Total, Additions for tax positions for prior years	245
Total, Ending Balance	$245

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Effective Tax Rate and Statutory Federal Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal tax benefit	7.00%	6.80%	6.70%
Tax-exempt interest on municipal obligations	-0.40%	-0.40%	-0.50%
Tax-exempt life insurance related income	-1.50%	-1.30%	-2.00%
Non-deductible joint beneficiary agreement expense	0.20%	0.20%	0.30%
Non-deductible merger expense	1.00%
Other	0.20%	-0.10%	1.00%
Effective Tax Rate	41.50%	40.20%	40.50%

Earnings_Per_Share_Computation

Earnings Per Share - Computation of Earnings Per Share (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Net income	$5,650	$8,234	$4,859	$7,365	$5,236	$7,361	$6,325	$8,477	$26,108	$27,399	$18,994
Average number of common shares outstanding									17,716	16,045	15,988
Effect of dilutive stock options									207	152	64
Average number of common shares outstanding used to calculate diluted earnings per share									17,923	16,197	16,052

Earnings_Per_Share_Additional_

Earnings Per Share - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Options and restricted stock units excluded from diluted earnings per share because the effect of these options and restricted stock units was antidilutive	95,600	407,985	967,120

Comprehensive_Income_Component

Comprehensive Income - Components of Other Comprehensive Income and Related Tax Effects (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Unrealized holding (losses) gains on available for sale securities before reclassifications	($162)	($4,232)	($2,096)
Amounts reclassified out of accumulated other comprehensive income	0	0	0
Unrealized holding (losses) gains on available for sale securities after reclassifications	-162	-4,232	-2,096
Tax effect	68	1,780	880
Unrealized holding (losses) gains on available for sale securities, net of tax	-94	-2,452	-1,216
Change in unfunded status of the supplemental retirement plans before reclassifications	-7,253	2,575	-445
Amounts reclassified out of accumulated other comprehensive income:
Amortization of prior service cost	138	153	153
Amortization of actuarial losses	17	291	288
Total amounts reclassified out of accumulated other comprehensive income	155	444	441
Change in unfunded status of the supplemental retirement plans after reclassifications	-7,098	3,019	-4
Tax effect	2,984	-1,269	2
Change in unfunded status of the supplemental retirement plans, net of tax	-4,114	1,750	-2
Change in joint beneficiary agreement liability before reclassifications	148	400	-370
Amounts reclassified out of accumulated other comprehensive income	0	0	0
Change in joint beneficiary agreement liability after reclassifications	148	400	-370
Tax effect	0	0	-64
Change in joint beneficiary agreement liability, net of tax	148	400	-434
Total other comprehensive (loss) income	($4,060)	($302)	($1,652)

Comprehensive_Income_Component1

Comprehensive Income - Components of Accumulated Other Comprehensive Income (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Net unrealized gains on available for sale securities	$4,040	$4,202
Tax effect	-1,699	-1,767
Unrealized holding gains on available for sale securities, net of tax	2,341	2,435
Unfunded status of the supplemental retirement plans	-7,885	-787
Tax effect	3,315	331
Unfunded status of the supplemental retirement plans, net of tax	-4,570	-456	-2
Joint beneficiary agreement liability	26	-122
Tax effect	0	0
Joint beneficiary agreement liability, net of tax	26	-122
Accumulated other comprehensive income	($2,203)	$1,857

Retirement_Plans_Additional_In

Retirement Plans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Employee service period under ESOP	1 year
Contributions to the plan included in salary expense	$1,294,000	$1,648,000	$1,229,000
Deferred compensation obligations	7,408,000	7,357,000
Earnings credits on deferred balances	551,000	568,000	599,000
Accumulated other comprehensive loss	4,570,000	456,000	2,000
Deferred tax asset	3,315,000	331,000
Net actuarial loss	823,000
401(k) Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum age for employees	21 years
Minimum period for employees to participate	90 days
Supplemental Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash values of the insurance policies purchased to fund deferred compensation obligations	92,337,000	52,309,000
Unfunded status of the supplemental retirement plans	7,885,000	787,000
Accumulated other comprehensive loss	4,570,000	456,000
Deferred tax asset	$3,315,000	$331,000

Retirement_Plans_Defined_Benef

Retirement Plans - Defined Benefit Pension Plans (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Compensation and Retirement Disclosure [Abstract]
Transition obligation	$9	$11
Prior service cost	-173	-35
Net actuarial loss	8,049	811
Amount included in accumulated other comprehensive loss	7,885	787
Deferred tax benefit	-3,315	-331
Amount included in accumulated other comprehensive loss, net of tax	$4,570	$456

Retirement_Plans_Information_P

Retirement Plans - Information Pertaining to Activity in Supplemental Retirement Plans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in benefit obligation:
Benefit obligation at beginning of year	($14,634)	($16,345)
Acquisition	-4,150
Service cost	-652	-742	-680
Interest cost	-739	-643	-687
Actuarial (loss)/gain	-7,254	2,573
Benefits paid	631	523
Benefit obligation at end of year	-26,798	-14,634	-16,345
Change in plan assets:
Fair value of plan assets at beginning of year
Fair value of plan assets at end of year
Funded status	-26,798	-14,634
Unrecognized net obligation existing at January 1, 1986	9	11
Unrecognized net actuarial loss	8,049	811
Unrecognized prior service cost	-173	-35
Unfunded status of the supplemental retirement plans	-7,885	-787
Accrued benefit cost	-26,798	-14,634
Accumulated benefit obligation	($24,739)	($12,954)

Retirement_Plans_Net_Periodic_

Retirement Plans - Net Periodic Benefit Cost Recognized for Supplemental Retirement Plans (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net pension cost included the following components:
Service cost-benefits earned during the period	$652	$742	$680
Interest cost on projected benefit obligation	739	643	687
Amortization of net obligation at transition	2	2	2
Amortization of prior service cost	138	153	153
Recognized net actuarial loss	16	291	288
Net periodic pension cost	$1,547	$1,832	$1,810

Retirement_Plans_Assumptions_U

Retirement Plans - Assumptions Used in Accounting for Plans (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Discount rate used to calculate benefit obligation	3.65%	4.85%	4.00%
Discount rate used to calculate net periodic pension cost	3.65%	4.85%	4.00%
Executive compensation [Member]
Defined Benefit Plan Disclosure [Line Items]
Average annual increase in compensation	2.50%	2.50%	2.50%
Director compensation [Member]
Defined Benefit Plan Disclosure [Line Items]
Average annual increase in compensation	2.50%	2.50%	2.50%

Retirement_Plans_Expected_Bene

Retirement Plans - Expected Benefit Payments to Participants and Estimated Contributions to be Made by Company (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Expected Benefit Payments to Participants, 2015	$1,145
Expected Benefit Payments to Participants, 2016	1,036
Expected Benefit Payments to Participants, 2017	1,001
Expected Benefit Payments to Participants, 2018	1,330
Expected Benefit Payments to Participants, 2019	519
Expected Benefit Payments to Participants, 2020-2024	3,719
Estimated Company Contributions, 2015	1,145
Estimated Company Contributions, 2016	1,036
Estimated Company Contributions, 2017	1,001
Estimated Company Contributions, 2018	1,330
Estimated Company Contributions, 2019	519
Estimated Company Contributions, 2020-2024	$3,719

Related_Party_Transactions_Sum

Related Party Transactions - Summary of Loan Activity (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Related Party Transaction, Due from (to) Related Party, Noncurrent [Abstract]
Beginning balance	$2,636	$2,368
Advances/new loans	2,106	1,154
Removed/payments	-1,610	-886
Ending balance	$3,132	$2,636

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Detail) (Modern Building Inc. [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Modern Building Inc. [Member]
Related Party Transaction [Line Items]
Aggregate payments for construction services	$1,181,000	$4,261,000	$3,587,000

Fair_Value_Measurement_Recorde

Fair Value Measurement - Recorded Amount of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$5,091	$21,282
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	5,091	21,282
Fair value measurements on recurring basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	90,583	110,812
Fair value measurements on recurring basis [Member] | Obligations of U.S. government corporations and agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	75,120	97,143
Fair value measurements on recurring basis [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	3,175	5,589
Fair value measurements on recurring basis [Member] | Corporate debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	1,908	1,915
Fair value measurements on recurring basis [Member] | Marketable equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	3,002
Fair value measurements on recurring basis [Member] | Mortgage servicing rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	7,378	6,165
Fair value measurements on recurring basis [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	3,002
Fair value measurements on recurring basis [Member] | Level 1 [Member] | Marketable equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	3,002
Fair value measurements on recurring basis [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	80,203	104,647
Fair value measurements on recurring basis [Member] | Level 2 [Member] | Obligations of U.S. government corporations and agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	75,120	97,143
Fair value measurements on recurring basis [Member] | Level 2 [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	3,175	5,589
Fair value measurements on recurring basis [Member] | Level 2 [Member] | Corporate debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	1,908	1,915
Fair value measurements on recurring basis [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	7,378	6,165
Fair value measurements on recurring basis [Member] | Level 3 [Member] | Mortgage servicing rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$7,378	$6,165

Fair_Value_Measurement_Additio

Fair Value Measurement - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between any levels	$0	$0
Carrying value of loans fully charged-off	0
Securities held to maturity	676,426,000	240,504,000
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	$0	$0

Fair_Value_Measurement_Reconci

Fair Value Measurement - Reconciliation of Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3) on Recurring Basis (Detail) (Mortgage servicing rights [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Mortgage servicing rights [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$6,165	$4,552
Transfers into (out of) Level 3	1,944
Change Included in Earnings	-1,301	253
Issuances	570	1,360
Ending Balance	$7,378	$6,165

Fair_Value_Measurement_Quantit

Fair Value Measurement - Quantitative Information about Recurring Level 3 Fair Value Measurements (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate	12.00%	10.30%	20.30%
Discount rate	10.00%	10.00%	10.00%
Mortgage servicing rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortgages Servicing Rights, Fair Value	7,378
Minimum [Member] | Mortgage servicing rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	10.00%
Minimum [Member] | Mortgage servicing rights [Member] | Discounted Cash Flow [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate	5.70%
Maximum [Member] | Mortgage servicing rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	12.00%
Maximum [Member] | Mortgage servicing rights [Member] | Discounted Cash Flow [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate	23.40%
Weighted Average [Member] | Mortgage servicing rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	10.00%
Weighted Average [Member] | Mortgage servicing rights [Member] | Discounted Cash Flow [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate	12.00%

Fair_Value_Measurement_Assets_

Fair Value Measurement - Assets and Liabilities Measured at Fair Value on Nonrecurring Basis (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$5,091	$21,282
Total Losses	-773	-2,936
Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,480	20,334
Total Losses	-636	-2,539
Foreclosed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,611	948
Total Losses	-137	-397
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	5,091	21,282
Level 3 [Member] | Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,480	20,334
Level 3 [Member] | Foreclosed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$2,611	$948

Fair_Value_Measurement_Quantit1

Fair Value Measurement - Quantitative Information about Level 3 Fair Value Measurements for Financial Instruments Measured at Fair Value on Nonrecurring Basis (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,091	$21,282
Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,480	20,334
Foreclosed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,611	948
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	5,091	21,282
Level 3 [Member] | Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,480	20,334
Level 3 [Member] | Foreclosed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	2,611	$948
Level 3 [Member] | Sales comparison approach [Member] | Minimum [Member] | Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustment for differences between comparable sales	-5.00%
Level 3 [Member] | Sales comparison approach [Member] | Minimum [Member] | Foreclosed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustment for differences between comparable sales	-5.00%
Level 3 [Member] | Sales comparison approach [Member] | Maximum [Member] | Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustment for differences between comparable sales	-42.50%
Level 3 [Member] | Sales comparison approach [Member] | Maximum [Member] | Foreclosed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustment for differences between comparable sales	-29.40%
Level 3 [Member] | Sales comparison approach [Member] | Weighted Average [Member] | Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustment for differences between comparable sales	-10.10%
Level 3 [Member] | Sales comparison approach [Member] | Weighted Average [Member] | Foreclosed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustment for differences between comparable sales	-8.20%
Level 3 [Member] | Income approach [Member] | Minimum [Member] | Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization rate	9.09%
Level 3 [Member] | Income approach [Member] | Maximum [Member] | Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization rate	9.09%
Level 3 [Member] | Income approach [Member] | Weighted Average [Member] | Impaired Originated & PNCI loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Capitalization rate	9.09%

Fair_Value_Measurement_Estimat

Fair Value Measurement - Estimated Fair Values of Financial Instruments that are Reported at Amortized Cost in Consolidated Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financial assets:
Cash and due from banks	$93,150,000	$76,915,000
Cash at Federal Reserve and other banks	517,578,000	521,453,000
Securities held to maturity	676,426,000	240,504,000
Indemnification (liability) asset	-349,000	206,000	1,997,000	4,405,000
Financial liabilities:
Other borrowings	9,276,000	6,335,000
Junior subordinated debt	56,272,000	41,238,000
Level 3 [Member]
Financial assets:
Securities held to maturity	0	0
Contract Amount [Member] | Level 3 [Member]
Off-balance sheet:
Commitments	656,175,000	555,386,000
Standby letters of credit	17,531,000	2,601,000
Overdraft privilege commitments	101,060,000	68,932,000
Fair Value [Member] | Level 3 [Member]
Financial assets:
Loans, net	2,379,155,000	1,760,274,000
Indemnification (liability) asset	-349,000	206,000
Off-balance sheet:
Commitments	6,562,000	5,554,000
Standby letters of credit	175,000	26,000
Overdraft privilege commitments	1,011,000	689,000
Fair Value [Member] | Level 1 [Member]
Financial assets:
Cash and due from banks	93,150,000	76,915,000
Cash at Federal Reserve and other banks	517,578,000	521,453,000
Fair Value [Member] | Level 2 [Member]
Financial assets:
Securities held to maturity	688,779,000	233,807,000
Loans held for sale	3,579,000	2,270,000
Financial liabilities:
Deposits	3,380,486,000	2,411,402,000
Other borrowings	9,276,000	6,335,000
Junior subordinated debt	45,053,000	25,774,000
Carrying Amount [Member] | Level 3 [Member]
Financial assets:
Loans, net	2,282,524,000	1,672,007,000
Indemnification (liability) asset	-349,000	206,000
Carrying Amount [Member] | Level 1 [Member]
Financial assets:
Cash and due from banks	93,150,000	76,915,000
Cash at Federal Reserve and other banks	517,578,000	521,453,000
Carrying Amount [Member] | Level 2 [Member]
Financial assets:
Securities held to maturity	676,426,000	240,504,000
Restricted equity securities	16,956,000	9,163,000
Loans held for sale	3,579,000	2,270,000
Financial liabilities:
Deposits	3,380,423,000	2,410,483,000
Other borrowings	9,276,000	6,335,000
Junior subordinated debt	$56,272,000	$41,238,000

TriCo_Bancshares_Condensed_Fin2

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and Cash equivalents	$610,728,000	$598,368,000	$748,899,000	$637,275,000
Other assets	51,735,000	36,086,000
Total assets	3,916,458,000	2,744,066,000
Liabilities and shareholders' equity
Other liabilities	49,192,000	31,711,000
Junior subordinated debt	56,272,000	41,238,000
Total liabilities	3,498,286,000	2,493,120,000
Shareholders' equity:
Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 22,714,964 and 16,076,662 shares, respectively	244,318,000	89,356,000
Retained earnings	176,057,000	159,733,000
Accumulated other comprehensive loss, net	-2,203,000	1,857,000
Total shareholders' equity	418,172,000	250,946,000	229,359,000	216,441,000
Total liabilities and shareholders' equity	3,916,458,000	2,744,066,000
Parent [Member]
Assets
Cash and Cash equivalents	2,229,000	2,520,000	2,511,000	706,000
Investment in Tri Counties Bank	470,797,000	288,746,000
Other assets	1,902,000	1,280,000
Total assets	474,928,000	292,546,000
Liabilities and shareholders' equity
Other liabilities	484,000	362,000
Junior subordinated debt	56,272,000	41,238,000
Total liabilities	56,756,000	41,600,000
Shareholders' equity:
Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 22,714,964 and 16,076,662 shares, respectively	244,318,000	89,356,000
Retained earnings	176,057,000	159,733,000
Accumulated other comprehensive loss, net	-2,203,000	1,857,000
Total shareholders' equity	418,172,000	250,946,000
Total liabilities and shareholders' equity	$474,928,000	$292,546,000

TriCo_Bancshares_Condensed_Fin3

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Balance Sheets (Parenthetical) (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Aug. 21, 2007
Condensed Financial Statements, Captions [Line Items]
Common stock, par value
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	22,714,964	16,076,662
Common stock, shares outstanding	22,714,964	16,076,662	15,814,662
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Common stock, par value
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	22,714,964	16,076,662
Common stock, shares outstanding	22,714,964	16,076,662

TriCo_Bancshares_Condensed_Fin4

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Income (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Interest expense	($1,437)	($1,082)	($1,075)	($1,087)	($1,123)	($1,169)	($1,167)	($1,237)	($4,681)	($4,696)	($7,344)
Income before income taxes	9,580	14,235	8,396	12,405	8,642	12,271	10,597	14,294	44,616	45,804	31,931
Equity in net income of Tri Counties Bank:
Income tax benefit	3,930	6,001	3,537	5,040	3,406	4,910	4,272	5,817	18,508	18,405	12,937
Net income	5,650	8,234	4,859	7,365	5,236	7,361	6,325	8,477	26,108	27,399	18,994
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Interest expense									-1,403	-1,247	-1,325
Administration expense									-2,720	-862	-669
Income before income taxes									-4,123	-2,109	-1,994
Equity in net income of Tri Counties Bank:
Distributed									8,270	8,175	8,522
Undistributed									20,720	20,446	11,632
Income tax benefit									1,241	887	834
Net income									$26,108	$27,399	$18,994

TriCo_Bancshares_Condensed_Fin5

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Comprehensive Income (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Net income	$5,650	$8,234	$4,859	$7,365	$5,236	$7,361	$6,325	$8,477	$26,108	$27,399	$18,994
Other comprehensive (loss) income, net of tax:
Unrealized holding (losses) gains on securities arising during the period									-94	-2,452	-1,216
Change in minimum pension liability									-4,114	1,750	-2
Change in joint beneficiary agreement liability									148	400	-434
Other comprehensive (loss) income									-4,060	-302	-1,652
Net income									22,048	27,097	17,342
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net income									26,108	27,399	18,994
Other comprehensive (loss) income, net of tax:
Unrealized holding (losses) gains on securities arising during the period									-94	-2,452	-1,216
Change in minimum pension liability									-4,114	1,750	-2
Change in joint beneficiary agreement liability									148	400	-434
Other comprehensive (loss) income									-4,060	-302	-1,652
Net income									$22,048	$27,097	$17,342

TriCo_Bancshares_Condensed_Fin6

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Cash Flows (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities:
Net income	$26,108	$27,399	$18,994
Adjustments to reconcile net income to net cash provided by operating activities:
Stock option vesting expense	1,133	1,151	1,083
Stock option excess tax benefits	-225	-356	-44
Net cash provided by operating activities	27,417	41,086	52,063
Financing activities:
Stock option excess tax benefits	225	356	44
Repurchase of common stock	-292	-501
Cash dividends paid - common	-7,807	-6,745	-5,757
Net cash used for financing activities	163,667	111,280	30,315
(decrease) increase in cash and cash equivalents	12,360	-150,531	111,624
Cash and cash equivalents and beginning of year	598,368	748,899	637,275
Cash and cash equivalents at end of year	610,728	598,368	748,899
Parent [Member]
Operating activities:
Net income	26,108	27,399	18,994
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed equity in earnings of Tri Counties Bank	-20,720	-20,446	-11,632
Stock option vesting expense	1,133	1,151	1,083
Stock option excess tax benefits	-225	-356	-44
Net change in other assets and liabilities	671	-1,100	-1,089
Net cash provided by operating activities	6,967	6,648	7,312
Financing activities:
Issuance of common stock through option exercise	616	251	206
Stock option excess tax benefits	225	356	44
Repurchase of common stock	-292	-501
Cash dividends paid - common	-7,807	-6,745	-5,757
Net cash used for financing activities	-7,258	-6,639	-5,507
(decrease) increase in cash and cash equivalents	-291	9	1,805
Cash and cash equivalents and beginning of year	2,520	2,511	706
Cash and cash equivalents at end of year	$2,229	$2,520	$2,511

Regulatory_Matters_Actual_Capi

Regulatory Matters - Actual Capital Amounts and Ratios of Bank (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$279,311	$201,201
Tier 1 Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	167,587	120,720
Tier 1 Capital (to Average Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	185,918	133,706
Total Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier 1 Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.00%	6.00%
Tier 1 Capital (to Average Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%	5.00%
Parent [Member]
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Actual, Amount	436,955	297,429
Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	401,971	272,071
Tier 1 Capital (to Average Assets), Actual, Amount	401,971	272,071
Total Capital (to Risk Weighted Assets), Actual, Ratio	15.63%	14.77%
Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	14.38%	13.51%
Tier 1 Capital (to Average Assets), Actual, Ratio	10.80%	10.17%
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	223,603	161,064
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	111,801	80,532
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	148,819	107,017
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	8.00%	8.00%
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%
Tri Countries Bank [Member]
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Actual, Amount	433,286	295,212
Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	398,325	269,870
Tier 1 Capital (to Average Assets), Actual, Amount	398,325	269,870
Total Capital (to Risk Weighted Assets), Actual, Ratio	15.51%	14.67%
Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	14.26%	13.41%
Tier 1 Capital (to Average Assets), Actual, Ratio	10.71%	10.09%
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	223,449	160,961
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	111,724	80,480
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$148,734	$106,965
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	8.00%	8.00%
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%

Summary_of_Quarterly_Results_o2

Summary of Quarterly Results of Operations (Unaudited) - Result of Operations (Detail) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loans:
Discount accretion PCI - cash basis	$107	$290	$69	$203	$255	$140	$129	$167
Discount accretion PCI - other	919	822	811	984	893	898	732	597
Discount accretion PNCI	796	402	624	379	568	1,115	815	766
All other loan interest income	28,914	23,466	22,929	22,172	22,754	22,970	22,207	22,542
Total loan interest income	30,736	24,980	24,433	23,738	24,470	25,123	23,883	24,072
Debt securities, dividends and interest bearing cash at Banks (not FTE)	5,671	4,151	3,985	3,421	2,992	2,413	1,873	1,734
Total interest and dividend income	36,407	29,131	28,418	27,159	27,462	27,536	25,756	25,806	121,115	106,560	108,716
Interest expense	1,437	1,082	1,075	1,087	1,123	1,169	1,167	1,237	4,681	4,696	7,344
Net interest income	34,970	28,049	27,343	26,072	26,339	26,367	24,589	24,569	116,434	101,864	101,372
(Benefit from) provision for loan losses	-1,421	-2,977	1,708	-1,355	172	-393	614	-1,108	-4,045	-715	9,423
Net interest income after provision for loan losses	36,391	31,026	25,635	27,427	26,167	26,760	23,975	25,677	120,479	102,579	91,949
Noninterest income	9,755	8,589	7,877	8,295	7,353	9,127	10,131	10,218	34,516	36,829	37,980
Noninterest expense	36,566	25,380	25,116	23,317	24,878	23,616	23,509	21,601	110,379	93,604	97,998
Income before income taxes	9,580	14,235	8,396	12,405	8,642	12,271	10,597	14,294	44,616	45,804	31,931
Income tax expense	3,930	6,001	3,537	5,040	3,406	4,910	4,272	5,817	18,508	18,405	12,937
Net income	$5,650	$8,234	$4,859	$7,365	$5,236	$7,361	$6,325	$8,477	$26,108	$27,399	$18,994
Per common share:
Net income (diluted)	$0.25	$0.50	$0.30	$0.45	$0.32	$0.45	$0.39	$0.53	$1.46	$1.69	$1.18
Dividends	$0.11	$0.11	$0.11	$0.11	$0.11	$0.11	$0.11	$0.09