TriCo Bancshares (TCBK) 10-Q 9 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Aug. 03, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Trading Symbol	TCBK
Entity Registrant Name	TRICO BANCSHARES /
Entity Central Index Key	356,171
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		30,411,135

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Assets:
Cash and due from banks	$ 94,661	$ 105,968
Cash at Federal Reserve and other banks	89,401	99,460
Cash and cash equivalents	184,062	205,428
Investment securities:
Marketable equity securities	2,868	2,938
Available for sale debt securities	754,207	727,945
Held to maturity debt securities	477,745	514,844
Restricted equity securities	16,956	16,956
Loans held for sale	3,601	4,616
Loans	3,146,313	3,015,165
Allowance for loan losses	(29,524)	(30,323)
Total loans, net	3,116,789	2,984,842
Foreclosed assets, net	1,374	3,226
Premises and equipment, net	59,014	57,742
Cash value of life insurance	99,047	97,783
Accrued interest receivable	14,253	13,772
Goodwill	64,311	64,311
Other intangible assets, net	4,496	5,174
Mortgage servicing rights	7,021	6,687
Other assets	57,409	55,051
Total assets	4,863,153	4,761,315
Deposits:
Noninterest-bearing demand	1,369,834	1,368,218
Interest-bearing	2,707,388	2,640,913
Total deposits	4,077,222	4,009,131
Accrued interest payable	1,175	930
Reserve for unfunded commitments	3,727	3,164
Other liabilities	58,896	63,258
Other borrowings	152,839	122,166
Junior subordinated debt	56,950	56,858
Total liabilities	4,350,809	4,255,507
Commitments and contingencies (Note 18)
Shareholders' equity:
Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at June 30, 2018 and December 31, 2017
Common stock, no par value: 50,000,000 shares authorized; issued and outstanding: 23,004,153 at June 30, 2018 22,955,963 at December 31, 2017	256,590	255,836
Retained earnings	276,877	255,200
Accumulated other comprehensive loss, net of tax	(21,123)	(5,228)
Total shareholders' equity	512,344	505,808
Total liabilities and shareholders' equity	$ 4,863,153	$ 4,761,315

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2018	Dec. 31, 2017	Aug. 21, 2007
Statement of Financial Position [Abstract]
Preferred stock, no par value	$ 0	$ 0
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, no par value	$ 0	$ 0
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	23,004,153	22,955,963
Common stock, shares outstanding	23,004,153	22,955,963	15,814,662

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest and dividend income:
Loans, including fees	$ 39,304	$ 36,418	$ 77,353	$ 71,332
Investments:
Taxable securities	7,438	6,903	14,760	13,606
Tax exempt securities	1,042	1,042	2,083	2,083
Dividends	298	328	634	719
Interest bearing cash at Federal Reserve and other banks	396	353	769	788
Total interest and dividend income	48,478	45,044	95,599	88,528
Interest expense:
Deposits	1,234	974	2,330	1,868
Other borrowings	586	13	928	15
Junior subordinated debt	789	623	1,486	1,218
Total interest expense	2,609	1,610	4,744	3,101
Net interest income	45,869	43,434	90,855	85,427
Benefit from reversal of provision for loan losses	(638)	(796)	(874)	(2,353)
Net interest income after benefit from reversal of provision for loan losses	46,507	44,230	91,729	87,780
Noninterest income:
Gain on sale of loans	666	777	1,292	1,687
Commissions on sale of non-deposit investment products	810	705	1,686	1,312
Increase in cash value of life insurance	656	626	1,264	1,311
Other	814	1,323	1,638	1,917
Total noninterest income	12,174	12,910	24,464	24,613
Noninterest expense:
Salaries and related benefits	21,453	20,494	43,105	41,387
Other	16,417	15,410	32,927	30,339
Total noninterest expense	37,870	35,904	76,032	71,726
Income before income taxes	20,811	21,236	40,161	40,667
Provision for income taxes	5,782	7,647	11,222	14,999
Net income	$ 15,029	$ 13,589	$ 28,939	$ 25,668
Earnings per share:
Basic	$ 0.65	$ 0.59	$ 1.26	$ 1.12
Diluted	$ 0.65	$ 0.58	$ 1.24	$ 1.10
Financial Service [Member]
Noninterest income:
Service charges and fees	$ 9,228	$ 9,479	$ 18,584	$ 18,386

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	$ 28,939	$ 25,668
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) on available for sale securities arising during the period	(3,998)				2,846		(15,024)	3,303
Change in minimum pension liability	80				55		160	109
Other comprehensive income (loss)	(3,918)				2,901		(14,864)	3,412
Comprehensive income	$ 11,111				$ 16,490		$ 14,075	$ 29,080

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2016	$ 477,347	$ 252,820	$ 232,440	$ (7,913)
Beginning balance, shares at Dec. 31, 2016		22,867,802
Net income	25,668		25,668
Other comprehensive income (loss)	3,412			3,412
Stock option vesting	162	$ 162
Service condition RSU vesting	419	419
Market plus service condition RSU vesting	193	193
Service condition RSUs released	0	$ 0	0	0
Service condition RSUs released, shares		25,069
Stock options exercised	2,163	$ 2,163
Stock options exercised, shares		117,850
Repurchase of common stock, value	(3,092)	$ (949)	(2,143)
Repurchase of common stock, shares		(85,652)
Dividends paid	(7,328)		(7,328)
Ending balance at Jun. 30, 2017	498,944	$ 254,808	248,637	(4,501)
Ending balance, shares at Jun. 30, 2017		22,925,069
Beginning balance at Dec. 31, 2017	$ 505,808	$ 255,836	255,200	(5,228)
Beginning balance, shares at Dec. 31, 2017	22,955,963	22,955,963
Net income	$ 28,939		28,939
Adoption ASU | ASU 2016-01 [Member]			(62)	62
Adoption ASU | ASU 2018-02 [Member]			1,093	(1,093)
Other comprehensive income (loss)	(14,864)			(14,864)
Stock option vesting	54	$ 54
Service condition RSU vesting	471	471
Market plus service condition RSU vesting	197	197
Service condition RSUs released	0	$ 0	0	0
Service condition RSUs released, shares		25,398
Market plus service condition RSUs released	0	$ 0	0	0
Market plus service conditions RSUs released, shares		25,512
Stock options exercised	$ 223	$ 223
Stock options exercised, shares	14,500	14,500
Repurchase of common stock, value	$ (671)	$ (191)	(480)
Repurchase of common stock, shares		(17,220)
Dividends paid	(7,813)		(7,813)
Ending balance at Jun. 30, 2018	$ 512,344	$ 256,590	$ 276,877	$ (21,123)
Ending balance, shares at Jun. 30, 2018	23,004,153	23,004,153

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Retained Earnings [Member]
Dividends paid, per share	$ 0.34	$ 0.30

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net income	$ 28,939	$ 25,668
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of premises and equipment, and amortization	3,229	3,287
Amortization of intangible assets	678	711
Benefit from reversal of provision for loan losses	(874)	(2,353)
Amortization of investment securities premium, net	1,340	1,606
Originations of loans for resale	(43,389)	(63,022)
Proceeds from sale of loans originated for resale	45,437	64,699
Gain on sale of loans	(1,292)	(1,687)
Change in market value of mortgage servicing rights	(75)	470
Provision for losses on foreclosed assets	90	28
Gain on sale of foreclosed assets	(388)	(271)
Loss on disposal of fixed assets	54	28
Gain on sale of premises held for sale		(3)
Increase in cash value of life insurance	(1,264)	(1,311)
Life insurance proceeds in excess of cash value		(108)
Loss on marketable equity securities	70
Equity compensation vesting expense	722	774
Change in:
Reserve for unfunded commitments	563	(120)
Interest receivable	(481)	422
Interest payable	245	(37)
Other assets and liabilities, net	(660)	(1,225)
Net cash from operating activities	32,944	27,556
Investing activities:
Proceeds from maturities of securities available for sale	32,906	27,997
Proceeds from maturities of securities held to maturity	36,587	42,361
Purchases of securities available for sale	(81,300)	(145,584)
Loan origination and principal collections, net	(131,073)	(69,491)
Proceeds from sale of other real estate owned	2,150	1,424
Proceeds from sale of premises held for sale	36	3,338
Purchases of premises and equipment	(4,119)	(5,885)
Life insurance proceeds		649
Net cash from investing activities	(144,813)	(145,191)
Financing activities:
Net change in deposits	68,091	(17,138)
Net change in other borrowings	30,673	5,067
Repurchase of common stock	(633)	(1,122)
Dividends paid	(7,813)	(7,328)
Exercise of stock options	185	193
Net cash from financing activities	90,503	(20,328)
Net change in cash and cash equivalents	(21,366)	(137,963)
Cash and cash equivalents at beginning of year	205,428	305,612
Cash and cash equivalents at end of year	184,062	167,649
Supplemental disclosure of noncash activities:
Unrealized (loss) gain on securities available for sale	(21,304)	5,698
Loans transferred to foreclosed assets		684
Market value of shares tendered in-lieu of cash to pay for exercise of options and/or related taxes	671	3,092
Supplemental disclosure of cash flow activity:
Cash paid for interest expense	4,499	3,138
Cash paid for income taxes	$ 8,525	10,650
Insurance proceeds receivable reclassified to other assets		$ 921

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2018
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” or “we”) 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. The Bank operates from 57 traditional branches, 9 in-store 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 $1,710,000 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. 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. 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. Marketable Equity Securities As of December 31, 2017, marketable equity securities with a fair value of $2,938,000 were recorded within investment securities available for sale on the consolidated balance sheets with changes in the fair value recorded through other comprehensive income and accumulated other comprehensive income (loss). As of January 1, 2018, the Company adopted Accounting Standard Update (“ASU”) 2016-01 Debt Securities The Company classifies its debt 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 six months ended June 30, 2018 and throughout 2017, the Company did not have any debt 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 more likely than not 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 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 Bank 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 Bank 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, based on evaluations of the collectability, impairment and prior loss experience of loans. 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 original 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 specific reserve allocation within the allowance for loan losses. 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 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 probable incurred 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 re-graded Re-grading The Company’s method for assessing the appropriateness of the allowance for originated loan losses includes specific allowances for impaired originated loans, 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. 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 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality 310-30, 310-30 310-30 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, 310-20, 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 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. 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. Physical possession of residential real estate property collateralizing a consumer mortgage loan occurs when legal title is obtained upon completion of foreclosure or when the borrower conveys all interest in the property to satisfy the loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. Any write-downs based on the asset’s fair value less costs to sell at the date of acquisition are charged to the allowance for loan and lease losses. Any recoveries based on the asset’s fair value less estimated costs to sell in excess of the recorded value of the loan at the date of acquisition are recorded to the allowance for loan and lease losses. These assets are subsequently accounted for at lower of cost or fair value less estimated costs to sell. If fair value declines subsequent to foreclosure, a valuation allowance is recorded through expense. Operating costs after acquisition are expensed. 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. On May 9, 2017, the Company and the FDIC terminated their loss sharing agreements. 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 shorter of the estimated useful lives of the related assets or lease terms. Asset lives range from 3-10 15-40 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 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 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. Low Income Housing Tax Credits The Company accounts for low income housing tax credits and the related qualified affordable housing projects using the proportional amortization method. Under the proportional amortization method, the Company amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). Upon entering into a qualified affordable housing project, the Company records, in other liabilities, the entire amount that it has agreed to invest in the project, and an equal amount, in other assets, representing its investment in the project. As the Company disburses cash to satisfy its investment obligation, other liabilities are reduced. Over time, as the tax credits and other tax benefits of the project are realized by the Company, the investment recorded in other assets is reduced using the proportional amortization method. Revenue Recognition The Company records revenue from contracts with customers in accordance with Accounting Standards Codification Topic 606, “Revenue from Contracts with Customers” (“Topic 606”). Under Topic 606, the Company must identify the contract with a customer, identify the performance obligations in the contract, determine the transaction price, allocate the transaction price to the performance obligations in the contract, and recognize revenue when (or as) the Company satisfies a performance obligation. Significant revenue has not been recognized in the current reporting period that results from performance obligations satisfied in previous periods. Most of our revenue-generating transactions are not subject to ASC 606, including revenue generated from financial instruments, such as our loans and investment securities. In addition, certain noninterest income streams such as fees associated with mortgage servicing rights, financial guarantees, derivatives, and certain credit card fees are also not in scope of the new guidance. The Company’s noninterest revenue streams are largely based on transactional activity, or standard month-end month-end 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 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 During the three months ended September 30, 2017, the Company changed its classification of 1st lien and 2nd lien non-owner 1-4 Recent Accounting Pronouncements FASB Accounting Standards Update (ASU) No.2014-09, Revenue from Contracts with Customers (Topic 606): 2014-09 2014-09 2014-09 2014-09 In January 2016, the FASB issued ASU No. 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities.” available-for-sale No. 2016-01 Fair Value Measurement FASB issued ASU No. 2016-02 , Leases (Topic 842) ASU 2016-2, on-balance ASU 2016-02 No. 2018-10 2018-11. FASB issued ASU No. 2016-13, 2016-13 2016-13, 2016-13 available-for-sale 2016-13 2016-13 2016-13 2016-13 one-time FASB issued ASU No. 2016-18, Statement of Cash Flows - Restricted Cash (Topic 230). ASU 2016-18 beginning-of-period end-of-period ASU 2016-18 FASB issued ASU No. 2017-01, Business Combinations - Clarifying the Definition of a Business (Topic 805). ASU 2017-01 ASU 2017-01 ASU 2017-01 FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other: Simplifying the Test for Goodwill Impairment (Topic 350): 2017-04 ASU 2017-04 FASB issued ASU No. 2017-07, Compensation - Retirement Benefits (Topic 715). 2017-07 ASU 2017-07 FASB issued ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Topic 310). ASU 2017-08 non-pooled ASU 2017-08 ASU 2017-08 FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718). ASU 2017-09 ASU 2017-09, ASU 2017-09 FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220). 2018-02 2018-02 2018-02

Business Combinations

Business Combinations	6 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
Business Combinations	Note 2 - Business Combinations Merger with FNB Bancorp On July 6, 2018, pursuant to a previously announced Agreement and Plan of Merger and Reorganization dated as of December 11, 2017 (the “Merger Agreement”) between the Company and FNB Bancorp (“FNB”), FNB merged with and into the Company with the Company continuing as the surviving corporation (the “Merger”). Immediately after the Merger, First National Bank of Northern California, the wholly owned bank subsidiary of FNB (“First National Bank”), merged with and into the Bank, with the Bank continuing as the surviving bank. The Merger and Bank Merger are collectively referred to as the “Transaction.” As part of its business strategy, the Company evaluates opportunities to acquire bank holding companies, banks and other financial institutions, which is an important element of its strategic plan. The Transaction is consistent with the Company’s business strategy, which will (1) extend The Company’s geographic footprint into the San Francisco Peninsula, (2) create opportunities for the Company to provide additional products and services to First National Bank customers and other potential customers, and (3) strengthen the Company’s deposit base with a mature base of core deposits. At the close of the transaction each share of FNBB common stock issued and outstanding immediately prior to the effective time of the Merger was canceled and converted into 0.98 shares of the Company’s common stock (the “Exchange Ratio”), with cash paid in lieu of fractional shares of the Company’s common stock. In addition, on July 6, 2018, each outstanding and unexercised option to acquire shares of FNBB common stock held by FNBB’s employees and directors was canceled and, in exchange, the holder of each option received a lump sum cash payment equal to the product of (1) the number of shares of FNBB common stock remaining under the option multiplied by (2) the Exchange Ratio multiplied by (3) the amount, if any, by which the Average Closing Share Price, as defined in the Merger Agreement, exceeded the exercise price of the option. These exchanges resulted in the Company issuing 7,405,277 shares of common stock, paying $6,000 in lieu of fractional shares, and paying $6,690,000 in exchange for the outstanding FNBB options. Based on the closing price of the Company’s common stock of $38.41 on July 6, 2018, the consideration value issued to the shareholders of FNBB was $284.4 million in aggregate. The 7,405,277 shares of the Company’s shares issued to the shareholders of FNBB on July 6, 2018 represented 24.4% of the Company’s 30,409,430 shares outstanding immediately subsequent to the Transaction. Immediately subsequent to the Transaction, the newly combined company, operating as TriCo Bancshares with its banking subsidiary, Tri Counties Bank, had total assets of approximately $6.1 billion. Immediately prior to the merger on July 6, 2018, FNBB had investment securities of approximately $344 million, loans of approximately $868 million, deposits of approximately $995 million, borrowings from the Federal Home Loan Bank of San Francisco (FHLB) of $165 million, and total assets of approximately $1.3 billion. These amounts are subject to change as the Company is in the process of determining the fair value of FNBB assets and liabilities acquired in accordance with generally accepted accounting principles. The Company anticipates recording goodwill and core deposit intangibles with this acquisition. During July 9 and 10, 2018, the Company sold approximately $292 million of the $344 million of investment securities obtained in the Transaction at no material gain or loss from their fair value on July 6, 2018. The proceeds from these security sales were used to pay off all of the Company’s $136 million of FHLB borrowings that existed at June 30, 2018 and all of FNBB’s $165 million of FHLB borrowings that existed at July 6, 2018 and matured in steps through August 6, 2018. The Company will file an amended Form 8-K While FNBB’s banking subsidiary, First National Bank of Northern California officially became part of Tri Counties Bank on July 6, 2018, the First National Bank branches continued to operate under the name “First National Bank” until the conversion of its operating systems to the operating systems of Tri Counties Bank on July 22, 2018 at which time First National Bank banking centers along with the client relationships and all accounts converted to Tri Counties Bank.

Investment Securities

Investment Securities	6 Months Ended
	Jun. 30, 2018
Investments Schedule [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: June 30, 2018 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value (in thousands) Debt Securities Available for Sale Obligations of U.S. government corporations and agencies $ 657,335 $ 257 $ (22,164 ) $ 635,428 Obligations of states and political subdivisions 121,523 359 (3,103 ) 118,779 Total debt securities available for sale $ 778,858 $ 616 $ (25,267 ) $ 754,207 Debt Securities Held to Maturity Obligations of U.S. government corporations and agencies $ 463,162 $ 291 $ (9,211 ) $ 454,242 Obligations of states and political subdivisions 14,583 77 (281 ) 14,379 Total debt securities held to maturity $ 477,745 $ 368 $ (9,492 ) $ 468,621 December 31, 2017 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value (in thousands) Debt Securities Available for Sale Obligations of U.S. government corporations and agencies $ 609,695 $ 695 $ (5,601 ) $ 604,789 Obligations of states and political subdivisions 121,597 1,888 (329 ) 123,156 Total debt securities available for sale $ 731,292 $ 2,583 $ (5,930 ) $ 727,945 Debt Securities Held to Maturity Obligations of U.S. government corporations and agencies $ 500,271 $ 5,101 $ (1,889 ) $ 503,483 Obligations of states and political subdivisions 14,573 146 (37 ) 14,682 Total debt securities held to maturity $ 514,844 $ 5,247 $ (1,926 ) $ 518,165 No investment securities were sold during the six months ended June 30, 2018 or the six months ended June 30, 2017. Investment securities with an aggregate carrying value of $410,073,000 and $285,596,000 at June 30, 2018 and December 31, 2017, 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 June 30, 2018 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 June 30, 2018, obligations of U.S. government corporations and agencies with a cost basis totaling $1,120,497,000 consist almost entirely of residential real estate 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 June 30, 2018, the Company estimates the average remaining life of these mortgage-backed securities issued by U.S. government corporations and agencies to be approximately 6.1 years. Average remaining life is defined as the time span after which the principal balance has been reduced by half. Debt Securities Available for Sale Held to Maturity (In thousands) Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value Due in one year $ 1 $ 1 $ — $ — Due after one year through five years 233 234 1,223 1,239 Due after five years through ten years 3,229 3,331 27,400 26,800 Due after ten years 775,395 750,641 449,122 440,582 Totals $ 778,858 $ 754,207 $ 477,745 $ 468,621 Gross unrealized losses on debt 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 (in thousands) June 30, 2018 Debt Securities Available for Sale Obligations of U.S. government corporations and agencies $ 437,859 $ (14,490 ) $ 152,004 $ (7,674 ) $ 589,863 $ (22,164 ) Obligations of states and political subdivisions 66,052 (1,785 ) 16,556 (1,318 ) 82,608 (3,103 ) Total debt securities available for sale $ 503,911 $ (16,275 ) $ 168,560 $ (8,992 ) $ 672,471 $ (25,267 ) Debt Securities Held to Maturity Obligations of U.S. government corporations and agencies $ 326,966 $ (5,578 ) $ 91,801 $ (3,633 ) $ 418,767 $ (9,211 ) Obligations of states and political subdivisions 8,884 (152 ) 2,536 (129 ) 11,420 (281 ) Total debt securities held to maturity $ 335,850 $ (5,730 ) $ 94,337 $ (3,762 ) $ 430,187 $ (9,492 ) Less than 12 months 12 months or more Total Fair Unrealized Fair Unrealized Fair Unrealized Value Loss Value Loss Value Loss (in thousands) December 31, 2017 Debt Securities Available for Sale Obligations of U.S. government corporations and agencies $ 284,367 $ (2,176 ) $ 166,338 $ (3,425 ) $ 450,705 $ (5,601 ) Obligations of states and political subdivisions 4,904 (35 ) 17,085 (294 ) 21,989 (329 ) Total securities available for sale $ 289,271 $ (2,211 ) $ 183,423 $ (3,719 ) $ 472,694 $ (5,930 ) Debt Securities Held to Maturity Obligations of U.S. government corporations and agencies $ 93,017 $ (567 ) $ 95,367 $ (1,322 ) $ 188,384 $ (1,889 ) Obligations of states and political subdivisions 1,488 (7 ) 2,637 (30 ) 4,125 (37 ) Total debt securities held to maturity $ 94,505 $ (574 ) $ 98,004 $ (1,352 ) $ 192,509 $ (1,926 ) 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 June 30, 2018, 143 debt securities representing obligations of U.S. government corporations and agencies had unrealized losses with aggregate depreciation of (3.02%) 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 June 30, 2018, 98 debt securities representing obligations of states and political subdivisions had unrealized losses with aggregate depreciation of (3.47%) from the Company’s amortized cost basis. Marketable equity securities: All unrealized losses recognized during the reporting period were for equity securities still held at June 30, 2018.

Loans

Loans	6 Months Ended
	Jun. 30, 2018
Receivables [Abstract]
Loans	Note 4 – Loans A summary of loan balances follows (in thousands): June 30, 2018 Originated PNCI PCI - PCI - Total Cash basis Other Mortgage loans on real estate: Residential 1-4 $ 326,149 $ 56,823 $ — $ 1,720 $ 384,692 Commercial 1,805,830 202,923 — 7,595 2,016,348 Total mortgage loans on real estate 2,131,979 259,746 — 9,315 2,401,040 Consumer: Home equity lines of credit 270,283 14,578 1,530 45 286,436 Home equity loans 38,082 2,449 — 455 40,986 Other 21,421 2,039 — 43 23,503 Total consumer loans 329,786 19,066 1,530 543 350,925 Commercial 227,591 7,555 — 2,473 237,619 Construction: Residential 73,570 8 — — 73,578 Commercial 82,912 239 — — 83,151 Total construction 156,482 247 — — 156,729 Total loans, net of deferred loan fees and discounts $ 2,845,838 $ 286,614 $ 1,530 $ 12,331 $ 3,146,313 Total principal balance of loans owed, net of charge-offs $ 2,855,594 $ 293,151 $ 4,898 $ 16,032 $ 3,169,675 Unamortized net deferred loan fees (9,756 ) — — — (9,756 ) Discounts to principal balance of loans owed, net of charge-offs — (6,537 ) (3,368 ) (3,701 ) (13,606 ) Total loans, net of unamortized deferred loan fees and discounts $ 2,845,838 $ 286,614 $ 1,530 $ 12,331 $ 3,146,313 Allowance for loan losses $ (28,761 ) $ (624 ) $ (7 ) $ (132 ) $ (29,524 ) December 31, 2017 Originated PNCI PCI - PCI - Total Mortgage loans on real estate: Residential 1-4 $ 320,522 $ 63,519 $ — $ 1,385 $ 385,426 Commercial 1,690,510 215,823 — 8,563 1,914,896 Total mortgage loan on real estate 2,011,032 279,342 — 9,948 2,300,322 Consumer: Home equity lines of credit 269,942 16,248 2,069 429 288,688 Home equity loans 39,848 2,698 — 485 43,031 Other 22,859 2,251 — 45 25,155 Total consumer loans 332,649 21,197 2,069 959 356,874 Commercial 209,437 8,391 — 2,584 220,412 Construction: Residential 67,920 10 — — 67,930 Commercial 69,364 263 — — 69,627 Total construction 137,284 273 — — 137,557 Total loans, net of deferred loan fees and discounts $ 2,690,402 $ 309,203 $ 2,069 $ 13,491 $ 3,015,165 Total principal balance of loans owed, net of charge-offs $ 2,699,053 $ 316,238 $ 5,863 $ 17,318 $ 3,038,472 Unamortized net deferred loan fees (8,651 ) — — — (8,651 ) Discounts to principal balance of loans owed, net of charge-offs — (7,035 ) (3,794 ) (3,827 ) (14,656 ) Total loans, net of unamortized deferred loan fees and discounts $ 2,690,402 $ 309,203 $ 2,069 $ 13,491 $ 3,015,165 Allowance for loan losses $ (29,122 ) $ (929 ) $ (17 ) $ (255 ) $ (30,323 ) The following is a summary of the change in accretable yield for PCI – other loans during the periods indicated (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Change in accretable yield: Balance at beginning of period $ 4,147 $ 9,560 $ 4,262 $ 10,348 Accretion to interest income (261 ) (1,058 ) (516 ) (1,960 ) Reclassification (to) from nonaccretable difference 110 (546 ) 250 (432 ) Balance at end of period $ 3,996 $ 7,956 $ 3,996 $ 7,956

Allowance for Loan Losses

Allowance for Loan Losses	6 Months Ended
	Jun. 30, 2018
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 – Three Months Ended June 30, 2018 (in thousands) Beginning Charge-offs Recoveries Provision Ending Mortgage loans on real estate: Residential 1-4 $ 2,170 $ (51 ) $ — $ (128 ) $ 1,991 Commercial 11,495 (15 ) 21 106 11,607 Total mortgage loans on real estate 13,665 (66 ) 21 (22 ) 13,598 Consumer: Home equity lines of credit 5,412 (24 ) 317 (657 ) 5,048 Home equity loans 1,736 — 23 (227 ) 1,532 Other 570 (174 ) 66 95 557 Total consumer loans 7,718 (198 ) 406 (789 ) 7,137 Commercial 6,392 (54 ) 80 (40 ) 6,378 Construction: Residential 1,351 — — 83 1,434 Commercial 847 — — 130 977 Total construction 2,198 — — 213 2,411 Total $ 29,973 $ (318 ) $ 507 $ (638 ) $ 29,524 Allowance for Loan Losses – Six Months Ended June 30, 2018 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,317 $ (52 ) $ — $ (274 ) $ 1,991 Commercial 11,441 (15 ) 36 145 11,607 Total mortgage loans on real estate 13,758 (67 ) 36 (129 ) 13,598 Consumer: Home equity lines of credit 5,800 (104 ) 526 (1,174 ) 5,048 Home equity loans 1,841 — 37 (346 ) 1,532 Other 586 (368 ) 144 195 557 Total consumer loans 8,227 (472 ) 707 (1,325 ) 7,137 Commercial 6,512 (259 ) 130 (5 ) 6,378 Construction: Residential 1,184 — — 250 1,434 Commercial 642 — — 335 977 Total construction 1,826 — — 585 2,411 Total $ 30,323 $ (798 ) $ 873 $ (874 ) $ 29,524 Allowance for Loan Losses – As of June 30, 2018 (in thousands) Individually Loans pooled Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 147 $ 1,794 $ 50 $ 1,991 Commercial 82 11,466 59 11,607 Total mortgage loans on real estate 229 13,260 109 13,598 Consumer: Home equity lines of credit 287 4,754 7 5,048 Home equity loans 192 1,340 — 1,532 Other 54 503 — 557 Total consumer loans 533 6,597 7 7,137 Commercial 2,127 4,228 23 6,378 Construction: Residential — 1,434 — 1,434 Commercial — 977 — 977 Total construction — 2,411 — 2,411 Total $ 2,889 $ 26,496 $ 139 $ 29,524 Loans, Net of Unearned fees – As of June 30, 2018 (in thousands) Individually Loans pooled Loans acquired Total loans, net Mortgage loans on real estate: Residential 1-4 $ 6,344 $ 376,628 $ 1,720 $ 384,692 Commercial 11,162 1,997,591 7,595 2,016,348 Total mortgage loans on real estate 17,506 2,374,219 9,315 2,401,040 Consumer: Home equity lines of credit 2,250 282,611 1,575 286,436 Home equity loans 2,457 38,074 455 40,986 Other 247 23,213 43 23,503 Total consumer loans 4,954 343,898 2,073 350,925 Commercial 4,751 230,395 2,473 237,619 Construction: Residential — 73,578 — 73,578 Commercial — 83,151 — 83,151 Total construction — 156,729 — 156,729 Total $ 27,211 $ 3,105,241 $ 13,861 $ 3,146,313 Allowance for Loan Losses – Year Ended December 31, 2017 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,748 $ (60 ) $ — $ (371 ) $ 2,317 Commercial 11,517 (186 ) 397 (287 ) 11,441 Total mortgage loans on real estate 14,265 (246 ) 397 (658 ) 13,758 Consumer: Home equity lines of credit 7,044 (98 ) 698 (1,844 ) 5,800 Home equity loans 2,644 (332 ) 242 (713 ) 1,841 Other 622 (1,186 ) 375 775 586 Total consumer loans 10,310 (1,616 ) 1,315 (1,782 ) 8,227 Commercial 5,831 (1,444 ) 428 1,697 6,512 Construction: Residential 1,417 (1,104 ) — 871 1,184 Commercial 680 — 1 (39 ) 642 Total construction 2,097 (1,104 ) 1 832 1,826 Total $ 32,503 $ (4,410 ) $ 2,141 $ 89 $ 30,323 Allowance for Loan Losses – As of December 31, 2017 (in thousands) Individually Loans pooled Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 230 $ 1,932 $ 155 $ 2,317 Commercial 30 11,351 60 11,441 Total mortgage loans on real estate 260 13,283 215 13,758 Consumer: Home equity lines of credit 427 5,356 17 5,800 Home equity loans 107 1,734 — 1,841 Other 57 529 — 586 Total consumer loans 591 7,619 17 8,227 Commercial 1,848 4,624 40 6,512 Construction: Residential — 1,184 — 1,184 Commercial — 642 — 642 Total construction — 1,826 — 1,826 Total $ 2,699 $ 27,352 $ 272 $ 30,323 Loans, Net of Unearned fees – As of December 31, 2017 (in thousands) Individually Loans pooled Loans acquired Total loans, net Mortgage loans on real estate: Residential 1-4 $ 5,298 $ 378,743 $ 1,385 $ 385,426 Commercial 13,911 1,892,422 8,563 1,914,896 Total mortgage loans on real estate 19,209 2,271,165 9,948 2,300,322 Consumer: Home equity lines of credit 2,688 283,502 2,498 288,688 Home equity loans 1,470 41,076 485 43,031 Other 257 24,853 45 25,155 Total consumer loans 4,415 349,431 3,028 356,874 Commercial 4,470 213,358 2,584 220,412 Construction: Residential 140 67,790 — 67,930 Commercial — 69,627 — 69,627 Total construction 140 137,417 — 137,557 Total $ 28,234 $ 2,971,371 $ 15,560 $ 3,015,165 Allowance for Loan Losses – Three Months Ended June 30, 2017 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,662 $ — $ — $ (151 ) $ 2,511 Commercial 11,542 (150 ) 17 (1,307 ) 10,102 Total mortgage loans on real estate 14,204 (150 ) 17 (1,458 ) 12,613 Consumer: Home equity lines of credit 6,530 (13 ) 252 (613 ) 6,156 Home equity loans 2,451 (206 ) 13 98 2,356 Other 595 (308 ) 68 290 645 Total consumer loans 9,576 (527 ) 333 (225 ) 9,157 Commercial 5,326 (764 ) 84 83 4,729 Construction: Residential 1,339 (1,071 ) — 910 1,178 Commercial 572 — — (106 ) 466 Total construction 1,911 (1,071 ) — 804 1,644 Total $ 31,017 $ (2,512 ) $ 434 $ (796 ) $ 28,143 Allowance for Loan Losses – Six Months Ended June 30, 2017 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,748 $ — $ $ (237 ) $ 2,511 Commercial 11,517 (150 ) 127 (1,392 ) 10,102 Total mortgage loans on real estate 14,265 (150 ) 127 (1,629 ) 12,613 Consumer: Home equity lines of credit 7,044 (84 ) 298 (1,102 ) 6,156 Home equity loans 2,644 (237 ) 25 (76 ) 2,356 Other 622 (482 ) 209 296 645 Total consumer loans 10,310 (803 ) 532 (882 ) 9,157 Commercial 5,831 (897 ) 254 (459 ) 4,729 Construction: Residential 1,417 (1,071 ) — 832 1,178 Commercial 680 — 1 (215 ) 466 Total construction 2,097 (1,071 ) 1 617 1,644 Total $ 32,503 $ (2,921 ) $ 914 $ (2,353 ) $ 28,143 Allowance for Loan Losses – As of June 30, 2017 (in thousands) Individually Loans pooled Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 249 $ 2,037 $ 225 $ 2,511 Commercial 124 8,531 1,447 10,102 Total mortgage loans on real estate 373 10,568 1,672 12,613 Consumer: Home equity lines of credit 400 5,748 8 6,156 Home equity loans 57 2,233 66 2,356 Other 31 614 — 645 Total consumer loans 488 8,595 74 9,157 Commercial 811 3,276 642 4,729 Construction: Residential 14 1,121 43 1,178 Commercial — 466 — 466 Total construction 14 1,587 43 1,644 Total $ 1,686 $ 24,026 $ 2,431 $ 28,143 Loans, Net of Unearned fees – As of June 30, 2017 (in thousands) Individually Loans pooled Loans acquired Total Loans Mortgage loans on real estate: Residential 1-4 $ 4,726 $ 375,217 $ 1,362 $ 381,305 Commercial 14,524 1,700,046 10,692 1,725,262 Total mortgage loans on real estate 19,250 2,075,263 12,054 2,106,567 Consumer: Home equity lines of credit 2,633 280,672 3,171 286,476 Home equity loans 1,285 43,515 1,136 45,936 Other 323 27,981 66 28,370 Total consumer loans 4,241 352,168 4,373 360,782 Commercial 2,744 219,658 3,341 225,743 Construction: Residential — 62,626 524 63,150 Commercial — 70,151 — 70,151 Total construction — 132,777 524 133,301 Total $ 26,235 $ 2,779,866 $ 20,292 $ 2,826,393 As part of the on-going (iii) non-performing 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 • Special Mention • Substandard • Doubtful • Loss The following tables present ending loan balances by loan category and risk grade for the periods indicated: Credit Quality Indicators Originated Loans– As of June 30, 2018 (in thousands) Pass Special Substandard Loss Total Originated Mortgage loans on real estate: Residential 1-4 $ 323,576 $ 292 $ 2,281 $ — $ 326,149 Commercial 1,760,898 27,717 17,215 — 1,805,830 Total mortgage loans on real estate 2,084,474 28,009 19,496 — 2,131,979 Consumer: Home equity lines of credit 265,724 1,828 2,731 — 270,283 Home equity loans 37,441 163 478 — 38,082 Other 21,083 158 180 — 21,421 Total consumer loans 324,248 2,149 3,389 — 329,786 Commercial 221,108 3,568 2,915 — 227,591 Construction: Residential 70,471 2,953 146 — 73,570 Commercial 82,912 — — — 82,912 Total construction 153,383 2,953 146 — 156,482 Total loans $ 2,783,213 $ 36,679 $ 25,946 $ — $ 2,845,838 Credit Quality Indicators PNCI Loans – As of June 30, 2018 (in thousands) Pass Special Substandard Loss Total PNCI Mortgage loans on real estate: Residential 1-4 $ 55,039 $ — $ 1,784 $ — $ 56,823 Commercial 198,353 2,935 1,635 — 202,923 Total mortgage loans on real estate 253,392 2,935 3,419 — 259,746 Consumer: Home equity lines of credit 13,675 903 — 14,578 Home equity loans 2,220 161 68 — 2,449 Other 2,030 4 5 — 2,039 Total consumer loans 17,925 165 976 — 19,066 Commercial 7,555 — — 7,555 Construction: Residential 8 — — — 8 Commercial 239 — — — 239 Total construction 247 — — — 247 Total loans $ 279,119 $ 3,100 $ 4,395 $ — $ 286,614 Credit Quality Indicators Originated Loans – As of December 31, 2017 (in thousands) Pass Special Substandard Loss Total Originated Mortgage loans on real estate: Residential 1-4 $ 315,120 $ 2,234 $ 3,168 $ — $ 320,522 Commercial 1,649,333 18,434 22,743 — 1,690,510 Total mortgage loans on real estate 1,964,453 20,668 25,911 — 2,011,032 Consumer: Home equity lines of credit 265,345 2,558 2,039 — 269,942 Home equity loans 37,428 800 1,620 — 39,848 Other 22,432 272 155 — 22,859 Total consumer loans 325,205 3,630 3,814 — 332,649 Commercial 195,208 9,492 4,737 — 209,437 Construction: Residential 67,813 — 107 — 67,920 Commercial 64,492 4,872 — — 69,364 Total construction 132,305 4,872 107 — 137,284 Total loans $ 2,617,171 $ 38,662 $ 34,569 $ — $ 2,690,402 Credit Quality Indicators PNCI Loans – As of December 31, 2017 (in thousands) Pass Special Substandard Loss Total PNCI Mortgage loans on real estate: Residential 1-4 $ 61,411 $ 218 $ 1,890 $ — $ 63,519 Commercial 203,751 11,513 559 — 215,823 Total mortgage loans on real estate 265,162 11,731 2,449 — 279,342 Consumer: Home equity lines of credit 14,866 450 932 — 16,248 Home equity loans 2,433 188 77 — 2,698 Other 2,207 38 6 — 2,251 Total consumer loans 19,506 676 1,015 — 21,197 Commercial 8,390 1 — — 8,391 Construction: Residential 10 — — — 10 Commercial 263 — — — 263 Total construction 273 — — — 273 Total $ 293,331 $ 12,408 $ 3,464 $ — $ 309,203 Consumer loans, whether unsecured or secured by real estate, automobiles, or other personal property, are susceptible to three primary risks; non-payment non-payment 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 Commercial real estate loans generally fall into two categories, owner-occupied and non-owner non-owner Construction loans, whether owner occupied or non-owner 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 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 The following table shows the ending balance of current and past due originated loans by loan category as of the date indicated: Analysis of Originated Past Due Loans - As of June 30, 2018 (in thousands) 30-59 days 60-89 days > 90 days Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 271 $ 64 $ 1,219 $ 324,595 $ 326,149 $ — Commercial 1,281 577 792 1,803,180 1,805,830 — Total mortgage loans on real estate 1,552 641 2,011 2,127,775 2,131,979 — Consumer: Home equity lines of credit 158 37 47 270,041 270,283 — Home equity loans 358 150 486 37,088 38,082 — Other 33 26 — 21,362 21,421 — Total consumer loans 549 213 533 328,491 329,786 — Commercial 506 766 1,778 224,541 227,591 — Construction: Residential — — — 73,570 73,570 — Commercial 1,249 831 — 80,832 82,912 — Total construction 1,249 831 — 154,402 156,482 — Total originated loans $ 3,856 $ 2,451 $ 4,322 $ 2,835,209 $ 2,845,838 $ — The following table shows the ending balance of current and past due PNCI loans by loan category as of the date indicated: Analysis of PNCI Past Due Loans - As of June 30, 2018 (in thousands) 30-59 days 60-89 days > 90 days Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 59 $ 78 $ 36 $ 56,650 $ 56,823 $ — Commercial 356 164 — 202,403 202,923 — Total mortgage loans on real estate 415 242 36 259,053 259,746 — Consumer: Home equity lines of credit 182 — 77 14,319 14,578 — Home equity loans — 43 — 2,406 2,449 — Other 2 — — 2,037 2,039 — Total consumer loans 184 43 77 18,762 19,066 — Commercial — — — 7,555 7,555 — Construction: Residential — — — 8 8 — Commercial — — — 239 239 — Total construction — — — 247 247 — Total PNCI loans $ 599 $ 285 $ 113 $ 285,617 $ 286,614 $ — The following table shows the ending balance of current and past due originated loans by loan category as of the date indicated: Analysis of Originated Past Due Loans - As of December 31, 2017 (in thousands) 30-59 days 60-89 days > 90 days Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,740 $ 510 $ 243 $ 318,029 $ 320,522 $ — Commercial 158 987 — 1,689,365 1,690,510 — Total mortgage loans on real estate 1,898 1,497 243 2,007,394 2,011,032 — Consumer: Home equity lines of credit 528 48 372 268,994 269,942 — Home equity loans 511 107 373 38,857 39,848 — Other 56 36 3 22,764 22,859 — Total consumer loans 1,095 191 748 330,615 332,649 — Commercial 956 738 1,527 206,216 209,437 — Construction: Residential 34 — — 67,886 67,920 — Commercial — — — 69,364 69,364 — Total construction 34 — — 137,250 137,284 — Total loans $ 3,983 $ 2,426 $ 2,518 $ 2,681,475 $ 2,690,402 $ — The following table shows the ending balance of current and past due PNCI loans by loan category as of the date indicated: Analysis of PNCI Past Due Loans - As of December 31, 2017 (in thousands) 30-59 days 60-89 days > 90 days Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,495 $ 90 $ 109 $ 61,825 $ 63,519 $ 81 Commercial 70 — — 215,753 215,823 — Total mortgage loans on real estate 1,565 90 109 277,578 279,342 81 Consumer: Home equity lines of credit 298 228 330 15,392 16,248 200 Home equity loans 30 — — 2,668 2,698 — Other 6 26 — 2,219 2,251 — Total consumer loans 334 254 330 20,279 21,197 200 Commercial — — — 8,391 8,391 — Construction: Residential — — — 10 10 — Commercial — — — 263 263 — Total construction — — — 273 273 — Total loans $ 1,899 $ 344 $ 439 $ 306,521 $ 309,203 $ 281 The following table shows the ending balance of nonaccrual originated and PNCI loans by loan category as of the date indicated: Non Accrual Loans As of June 30, 2018 As of December 31, 2017 (in thousands) Originated PNCI Total Originated PNCI Total Mortgage loans on real estate: Residential 1-4 $ 3,027 $ 1,082 $ 4,109 $ 1,725 $ 1,012 $ 2,737 Commercial 5,494 323 5,817 8,144 — 8,144 Total mortgage loans on real estate 8,521 1,405 9,926 9,869 1,012 10,881 Consumer: Home equity lines of credit 1,457 574 2,031 811 402 1,213 Home equity loans 4,419 36 4,455 1,106 44 1,150 Other 341 5 346 7 5 12 Total consumer loans 6,217 615 6,832 1,924 451 2,375 Commercial 2,339 — 2,339 3,669 — 3,669 Construction: Residential — — — — — — Commercial — — — — — — Total construction — — — — Total non accrual loans $ 17,077 $ 2,020 $ 19,097 $ 15,462 $ 1,463 $ 16,925 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 original 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, or for the Six Months Ended, June 30, 2018 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 5,656 $ 3,947 $ 1,050 $ 4,997 $ 147 $ 4,600 $ 76 Commercial 11,280 9,763 1,076 10,839 82 10,975 107 Total mortgage loans on real estate 16,936 13,710 2,126 15,836 229 15,575 183 Consumer: Home equity lines of credit 1,244 1,108 106 1,214 29 1,315 19 Home equity loans 2,558 1,828 351 2,179 38 1,784 20 Other 3 — 3 3 3 3 — Total consumer loans 3,805 2,936 460 3,396 70 3,102 39 Commercial 4,952 809 3,942 4,751 2,127 4,686 48 Construction: Residential — — — — — 68 — Commercial — — — — — — — Total construction — — — — — 68 — Total $ 25,693 $ 17,455 $ 6,528 $ 23,983 $ 2,426 $ 23,431 $ 270 Impaired PNCI Loans – As of, or for the Six Months Ended, June 30, 2018 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 family $ 1,417 $ 1,348 $ — $ 1,348 $ — $ 1,339 $ 10 Commercial 323 323 — 323 — 161 14 Total mortgage loans on real estate 1,740 1,671 — 1,671 — 1,500 24 Consumer: Home equity lines of credit 1,098 529 506 1,035 258 1,035 13 Home equity loans 293 36 242 278 154 281 6 Other 244 — 244 244 51 259 5 Total consumer loans 1,635 565 992 1,557 463 1,575 24 Commercial — — — — — — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total $ 3,375 $ 2,236 $ 992 $ 3,228 $ 463 $ 3,075 $ 48 Impaired Originated Loans – As of, or for the Twelve Months Ended, December 31, 2017 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 4,023 $ 2,058 $ 1,881 $ 3,939 $ 230 $ 3,501 $ 143 Commercial 14,186 13,101 810 13,911 30 13,851 645 Total mortgage loans on real estate 18,209 15,159 2,691 17,850 260 17,352 788 Consumer: Home equity lines of credit 1,581 1,093 401 1,494 111 1,702 47 Home equity loans 1,627 1,107 198 1,305 10 1,193 24 Other 52 4 3 7 3 20 — Total consumer loans 3,260 2,204 602 2,806 124 2,915 71 Commercial 4,566 575 3,895 4,470 1,848 4,283 184 Construction: Residential 140 140 — 140 — 76 9 Commercial — — — — — — — Total construction 140 140 — 140 — 76 9 Total $ 26,175 $ 18,078 $ 7,188 $ 25,266 $ 2,232 $ 24,626 $ 1,052 Impaired PNCI Loans – As of, or for the Twelve Months Ended, December 31, 2017 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 1,404 $ 1,359 $ — $ 1,359 $ $ 1,041 $ 24 Commercial — — — — 979 — Total mortgage loans on real estate 1,404 1,359 — 1,359 — 2,020 24 Consumer: Home equity lines of credit 1,216 591 603 1,194 316 1,240 48 Home equity loans 178 44 121 165 97 117 6 Other 250 — 250 250 54 186 11 Total consumer loans 1,644 635 974 1,609 467 1,543 65 Commercial — — — — — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total $ 3,048 $ 1,994 $ 974 $ 2,968 $ 467 $ 3,563 $ 89 Impaired Originated Loans – As of, or for the Six Months Ended, June 30, 2017 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 3,108 $ 1,623 $ 1,463 $ 3,086 $ 179 $ 1,417 $ 23 Commercial 13,203 11,864 803 12,667 45 724 18 Total mortgage loans on real estate 16,311 13,487 2,266 15,753 224 2,141 41 Consumer: Home equity lines of credit 1,746 1,305 331 1,636 66 380 — Home equity loans 1,633 836 395 1,231 68 440 10 Other 73 22 50 72 23 34 1 Total consumer loans 3,452 2,163 776 2,939 157 854 11 Commercial 3,053 1,007 1,737 2,744 863 2,536 27 Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total $ 22,816 $ 16,657 $ 4,779 $ 21,436 $ 1,244 $ 5,531 $ 79 Impaired PNCI Loans – As of, or for the Six Months Ended, June 30, 2017 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 1,665 $ 1,387 $ 253 $ 1,640 $ 75 $ 256 $ 5 Commercial 2,121 1,728 129 1,857 104 131 3 Total mortgage loans on real estate 3,786 3,115 382 3,497 179 387 8 Consumer: Home equity lines of credit 1,012 387 610 997 332 580 13 Home equity loans 64 54 — 54 — — — Other 251 — 251 251 68 185 5 Total consumer loans 1,327 441 861 1,302 400 765 18 Commercial — — — — — — — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total $ 5,113 $ 3,556 $ 1,243 $ 4,799 $ 579 $ 1,152 $ 26 At June 30, 2018, $9,450,000 of originated loans were TDR and classified as impaired. The Company had no obligations to lend additional funds on these TDR as of June 30, 2018. At June 30, 2018, $1,459,000 of PNCI loans were TDR and classified as impaired. The Company had no obligations to lend additional funds on these TDR as of June 30, 2018. At December 31, 2017, $12,517,000 of Originated loans were TDRs and classified as impaired. The Company had obligations to lend $1,000 of additional funds on these TDRs as of December 31, 2017. At December 31, 2017, $1,352,000 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, 2017. At June 30, 2017, $12,802,000 of originated loans were TDR and classified as impaired. The Company had no obligations to lend additional funds on these TDR as of June 30, 2017. At June 30, 2017, $1,627,000 of PNCI loans were TDR and classified as impaired. The Company had obligations to lend $2,000 of additional funds on these TDR as of June 30, 2017. The following tables show certain information regarding Troubled Debt Restructurings (TDRs) that occurred during the periods indicated: TDR Information for the Three Months Ended June 30, 2018 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial Mortgage loans on real estate: Residential 1-4 — $ — $ — $ — — $ — $ — Commercial 1 34 34 34 — Total mortgage loans on real estate 1 34 34 34 — — — Consumer: Home equity lines of credit — — — — — — — Home equity loans — — — — — — — Other — — — — — — — Total consumer loans — — — — — — — Commercial 2 416 422 (2 ) 4 340 (2 ) Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total 3 $ 450 $ 456 $ 32 4 $ 340 $ (2 ) TDR Information for the Six Months Ended June 30, 2018 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial Mortgage loans on real estate: Residential 1-4 — $ $ — $ — $ $ Commercial 2 417 418 46 1 169 — Total mortgage loans on real estate 2 417 418 46 1 169 — Consumer: Home equity lines of credit 1 133 138 — — — — Home equity loans 1 121 121 — — — — Other — — — — — — — Total consumer loans 2 254 259 — — — — Commercial 2 416 422 (2 ) 4 340 (2 ) Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total 6 $ 1,087 $ 1,099 $ 44 5 $ 509 $ (2 ) The following tables show certain information regarding TDRs that occurred during the periods indicated: TDR Information for the Three Months Ended June 30, 2017 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial Mortgage loans on real estate: Residential 1-4 — $ $ — $ — — $ — $ — Commercial 3 623 596 (125 ) — — — Total mortgage loans on real estate 3 623 596 (125 ) — — — Consumer: Home equity lines of credit 2 167 167 27 — — — Home equity loans — — — — — — — Other — — — — — — — Total consumer loans 2 167 167 27 — — — Commercial 2 645 539 (84 ) — — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total 7 $ 1,435 $ 1,302 $ (182 ) — $ — $ — TDR Information for the Six Months Ended June 30, 2017 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial Mortgage loans on real estate: Residential 1-4 — $ — $ — $ — — $ — $ — Commercial 3 623 596 (125 ) 1 124 — Total mortgage loans on real estate 3 623 596 (125 ) 1 124 — Consumer: Home equity lines of credit 3 187 187 27 — — — Home equity loans — — — — — — — Other 1 14 14 11 — — — Total consumer loans 4 201 201 38 — — — Commercial 3 745 639 10 — Construction: Residential — — — — — — — Commercial — — — — — — Total construction — — — — — — Total 10 $ 1,569 $ 1,436 $ (77 ) 1 $ 124 $ — Modifications classified as TDRs 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 TDRs, 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	6 Months Ended
	Jun. 30, 2018
Text Block [Abstract]
Foreclosed Assets	Note 6 – Foreclosed Assets A summary of the activity in the balance of foreclosed assets follows (in thousands): Six months ended Six months ended June 30, 2017 Total Noncovered Covered Total Beginning balance, net $ 3,226 $ 3,763 $ 223 $ 3,986 Additions/transfers from loans — 684 — 684 Dispositions/sales (1,762 ) (930 ) (223 ) (1,153 ) Valuation adjustments (90 ) (28 ) — (28 ) Ending balance, net $ 1,374 $ 3,489 — $ 3,489 Ending valuation allowance $ (152 ) $ (179 ) — $ (179 ) Ending number of foreclosed assets 8 12 — 12 Proceeds from sale of foreclosed assets $ 2,150 $ 1,424 $ — $ 1,424 Gain on sale of foreclosed assets $ 388 $ 271 $ — $ 271 As of June 30, 2018, $837,000 of foreclosed residential real estate properties, all of which the Company has obtained physical possession of, are included in foreclosed assets. At June 30, 2018, the recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are underway is $743,000.

Premises and Equipment

Premises and Equipment	6 Months Ended
	Jun. 30, 2018
Property, Plant and Equipment [Abstract]
Premises and Equipment	Note 7 – Premises and Equipment Premises and equipment were comprised of: June 30, December 31, 2018 2017 (In thousands) Land & land improvements $ 9,973 $ 9,959 Buildings 51,065 50,340 Furniture and equipment 38,172 35,939 99,210 96,238 Less: Accumulated depreciation (42,066 ) (40,644 ) 57,144 55,594 Construction in progress 1,870 2,148 Total premises and equipment $ 59,014 $ 57,742 Depreciation expense for premises and equipment amounted to $1,386,000 and $1,394,000 for the three months ended June 30, 2018 and 2017, respectively, and $2,757,000 and $2,705,000 for the six months ended June 30, 2018 and 2017, respectively.

Cash Value of Life Insurance

Cash Value of Life Insurance	6 Months Ended
	Jun. 30, 2018
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 (in thousands): Six months ended June 30, 2018 2017 Beginning balance $ 97,783 $ 95,912 Increase in cash value of life insurance 1,264 1,311 Gain on death benefit — 108 Insurance proceeds receivable reclassified to other assets — (921 ) Ending balance $ 99,047 $ 96,410 End of period death benefit $ 164,649 $ 166,318 Number of policies owned 182 183 Insurance companies used 13 14 Current and former employees and directors covered 57 57 As of June 30, 2018, the Bank was the owner and beneficiary of 182 life insurance policies, issued by 13 life insurance companies, covering 57 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

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 30, 2018
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: (in thousands) June 30, Additions Reductions December 31, Goodwill $ 64,311 — — $ 64,311 The following table summarizes the Company’s core deposit intangibles as of the dates indicated: (in thousands) June 30, Additions Reductions/ December 31, Core deposit intangibles $ 9,558 — — $ 9,558 Accumulated amortization (5,062 ) — $ (678 ) (4,384 ) Core deposit intangibles, net $ 4,496 — $ (678 ) $ 5,174 The Company recorded additions to its CDI of $2,046,000 in conjunction with the acquisition of three branch offices from Bank of America on March 18, 2016, $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 remaining estimated core deposit intangible amortization at December 31, 2017 (dollars in thousands): Years Ended Estimated Core Deposit 2018 $ 1,324 2019 1,228 2020 1,228 2021 969 2022 280 Thereafter 145

Mortgage Servicing Rights

Mortgage Servicing Rights	6 Months Ended
	Jun. 30, 2018
Text Block [Abstract]
Mortgage Servicing Rights	Note 10 - Mortgage Servicing Rights The following tables summarize the activity in, and the main assumptions used to determine the fair value of mortgage servicing rights (“MSRs”) for the periods indicated (dollars in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Balance at beginning of period $ 6,953 $ 6,860 $ 6,687 $ 6,595 Additions 104 193 259 471 Change in fair value (36 ) (457 ) 75 (470 ) Balance at end of period $ 7,021 $ 6,596 $ 7,021 $ 6,596 Contractually specified servicing fees, late fees and ancillary fees earned $ 511 $ 526 $ 1,028 $ 1,047 Balance of loans serviced at: Beginning of period $ 806,178 $ 822,506 $ 811,065 $ 816,623 End of period $ 801,817 $ 822,549 $ 801,817 $ 822,549 Period end: Weighted-average prepayment speed (CPR) 7.4 % 8.7 % Weighted-average discount rate 12.5 % 14 % The changes in fair value of MSRs that occurred during the three and six months ended June 30, 2018 and 2017 were mainly due to changes in principal balances, changes in mortgage prepayment speeds, and changes in investor required rate of return, or discount rate, of the MSRs.

Indemnification Asset

Indemnification Asset	6 Months Ended
	Jun. 30, 2018
Text Block [Abstract]
Indemnification Asset	Note 11 - Indemnification Asset A summary of the activity in the balance of indemnification asset (liability) follows (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Beginning balance — $ (895 ) — $ (744 ) Effect of actual and estimated future covered losses and recoveries — (1 ) — (224 ) Payments made to (received from) FDIC — 184 — 256 Gain on termination of loss share agreement — 712 — 712 Ending balance — $ — — $ — During May 2015, the indemnification portion of the Company’s agreement with the FDIC related to the Company’s acquisition of certain nonresidential real estate loans of Granite in May 2010 expired. The indemnification portion of the Company’s agreement with the FDIC related to the Company’s acquisition of certain residential real estate loans of Granite in May 2010 was set to expire in May 2018. The agreement specified that recoveries of losses that are claimed by the Company and indemnified by the FDIC under the agreement that are recovered by the Company through May 2020 are to be shared with the FDIC in the same proportion as they were indemnified by the FDIC. In addition, the agreement specified that at the end of the agreement in May 2020, to the extent that total claimed losses plus servicing expenses, net of recoveries, claimed under the agreement over the entire ten year period of the agreement did not meet a certain threshold, the Company would have been required to pay to the FDIC a “true up” amount equal to fifty percent of the difference of the threshold and actual claimed losses plus servicing expenses, net of recoveries. The Company continually estimated, updated and recorded this “true up” amount, at its estimated present value, since the inception of the agreement in May 2010. On May 9, 2017, the Company and the FDIC terminated their loss sharing agreements. As part of the termination agreement, the Company paid the FDIC $184,000, and recorded a $712,000 gain representing the difference between the Company’s payment to the FDIC and the recorded payable balance on May 9, 2017.

Other Assets

Other Assets	6 Months Ended
	Jun. 30, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	Note 12 – Other Assets Other assets were comprised of (in thousands): June 30, December 31, Deferred tax asset, net $ 27,665 $ 21,697 Investment in low income housing tax credit funds 16,672 16,854 Prepaid expense 4,097 4,111 Tax refund receivable 4,754 4,754 Capital trusts 1,710 1,706 Software 793 1,126 Life insurance proceeds receivable — 2,242 Miscellaneous other assets 1,718 2,561 Total other assets $ 57,409 $ 55,051

Deposits

Deposits	6 Months Ended
	Jun. 30, 2018
Banking and Thrift [Abstract]
Deposits	Note 13 - Deposits A summary of the balances of deposits follows (in thousands): June 30, December 31, Noninterest-bearing demand $ 1,369,834 $ 1,368,218 Interest-bearing demand 1,006,331 971,459 Savings 1,385,268 1,364,518 Time certificates, over $250,000 84,015 73,596 Other time certificates 231,774 231,340 Total deposits $ 4,077,222 $ 4,009,131 Certificate of deposit balances of $50,000,000 from the State of California were included in time certificates, $250,000 and over, at each of June 30, 2018 and December 31, 2017. 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 $1,533,000 and $1,366,000 were classified as consumer loans at June 30, 2018 and December 31, 2017, respectively.

Reserve for Unfunded Commitment

Reserve for Unfunded Commitments	6 Months Ended
	Jun. 30, 2018
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): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Balance at beginning of period $ 3,864 $ 2,734 $ 3,164 $ 2,719 Provision (reversal of provision) for losses – unfunded commitments (137 ) (135 ) 563 (120 ) Balance at end of period $ 3,727 $ 2,599 $ 3,727 $ 2,599

Other Liabilities

Other Liabilities	6 Months Ended
	Jun. 30, 2018
Other Liabilities Disclosure [Abstract]
Other Liabilities	Note 15 – Other Liabilities Other liabilities were comprised of (in thousands): June 30, December 31, Pension liability $ 28,880 $ 28,472 Low income housing tax credit fund commitments 5,969 8,554 Deferred compensation 6,932 6,605 Taxes payable 1,267 — Accrued salaries and benefits expense 5,014 6,619 Joint beneficiary agreements 3,494 3,365 Loan escrow and servicing payable 2,295 1,958 Deferred revenue 1,449 1,228 Litigation contingency — 1,450 Miscellaneous other liabilities 3,596 5,007 Total other liabilities $ 58,896 $ 63,258

Other Borrowings

Other Borrowings	6 Months Ended
	Jun. 30, 2018
Text Block [Abstract]
Other Borrowings	Note 16 - Other Borrowings A summary of the balances of other borrowings follows: June 30, December 31, (in thousands) FHLB collateralized borrowing, fixed rate, as of June 30, 2018 of 2.05%, payable on July 2, 2018 $ 136,020 $ — FHLB collateralized borrowing, fixed rate, as of December 31, 2017 of 1.38%, payable on January 2, 2018 — 104,729 Other collateralized borrowings, fixed rate, as of June 30, 2018 and December 31, 2017 of 0.05%, payable on July 2, 2018 and January 2, 2018, respectively 16,819 17,437 Total other borrowings $ 152,839 $ 122,166 The Company did not enter into any repurchase agreements during the six months ended June 30, 2018 or the year ended December 31, 2017. The Company maintains a collateralized line of credit with the Federal Home Loan Bank of San Francisco. Based on the FHLB stock requirements at June 30, 2018, this line provided for maximum borrowings of $1,622,655,000 of which $136,020,000 was outstanding as of June 30, 2018, leaving $1,486,635,000 available. As of June 30, 2018, the Company has designated investment securities with fair value of $198,309,000 and loans totaling $2,183,416,000 as potential collateral under this collateralized line of credit with the FHLB. The Company had $16,819,000 and $17,437,000 of other collateralized borrowings at June 30, 2018 and December 31, 2017, respectively. Other collateralized borrowings are generally overnight maturity borrowings from non-financial The Company maintains a collateralized line of credit with the San Francisco Federal Reserve Bank. As of June 30, 2018, this line provided for maximum borrowings of $141,993,000 of which none was outstanding, leaving $141,993,000 available. As of June 30, 2018, the Company has designated investment securities with fair value of $14,000 and loans totaling $267,570,000 as potential collateral under this collateralized line of credit with the San Francisco Federal Reserve Bank. The Company had available unused correspondent banking lines of credit from commercial banks totaling $20,000,000 for federal funds transactions at June 30, 2018.

Junior Subordinated Debt

Junior Subordinated Debt	6 Months Ended
	Jun. 30, 2018
Text Block [Abstract]
Junior Subordinated Debt	Note 17 – Junior Subordinated Debt At June 30, 2018, the Company had five wholly-owned subsidiary business trusts that had issued $62.9 million of trust preferred securities (the “Capital Trusts”). Trust preferred securities accrue and pay distributions periodically at specified annual rates as provided in the indentures. The trusts used the net proceeds from the offering to purchase a like amount of subordinated debentures (the “Debentures”) of the Company. The Debentures are the sole assets of the trusts. The Company’s obligations under the subordinated debentures and related documents, taken together, constitute a full and unconditional guarantee by the Company of the obligations of the trusts. The trust preferred securities are mandatorily redeemable upon the maturity of the Debentures, or upon earlier redemption as provided in the indentures. The Company has the right to redeem the Debentures in whole (but not in part) on or after specific dates, at a redemption price specified in the indentures plus any accrued but unpaid interest to the redemption date. The Company also has a right to defer consecutive payments of interest on the debentures for up to five years. The Company organized two of the Capital Trusts. The Company acquired its three other Capital Trusts and assumed their related Debentures as a result of its acquisition of North Valley Bancorp. At the acquisition date of October 3, 2014, the Debentures associated with North Valley Bancorp’s three Capital Trusts 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 interests in each of the acquired Capital Trusts and these discounts will be proportionally amortized over the remaining time to maturity for each related debenture. The recorded book values of the 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): Coupon Rate As of June 30, 2018 December 31, 2017 Maturity Face (Variable) Current Recorded Recorded Subordinated Debt Series Date Value 3 mo. LIBOR + Coupon Rate Book Value Book Value TriCo Cap Trust I 10/7/2033 $ 20,619 3.05 % 5.40 % $ 20,619 $ 20,619 TriCo Cap Trust II 7/23/2034 20,619 2.55 % 4.91 % 20,619 20,619 North Valley Trust II 4/24/2033 6,186 3.25 % 5.61 % 5,154 5,135 North Valley Trust III 4/24/2034 5,155 2.80 % 5.16 % 4,060 4,041 North Valley Trust IV 3/15/2036 10,310 1.33 % 3.67 % 6,498 6,444 $ 62,889 $ 56,950 $ 56,858 During the six months ended June 30, 2018, the balance of Junior Subordinated Debt increased $92,000 to $56,950,000 due to purchase fair value discount amortization.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 18 - Commitments and Contingencies Restricted Cash Balances Lease Commitments non-cancelable At December 31, 2017, future minimum commitments under non-cancelable Operating Leases (in thousands) 2018 $ 3,278 2019 2,499 2020 1,847 2021 1,488 2022 757 Thereafter 798 Future minimum lease payments $ 10,667 Rent expense under operating leases was $949,000 and $1,048,000 during the three months ended June 30, 2018 and 2017, respectively. Rent expense was offset by rent income of $10,000 and $10,000 during the three months ended June 30, 2018 and 2017, respectively. Rent expense under operating leases was $1,869,000 and $2,095,000 during the six months ended June 30, 2018 and 2017, respectively. Rent expense was offset by rent income of $21,000 and $23,000 during the six months ended June 30, 2018 and 2017, respectively. Financial Instruments with Off-Balance-Sheet off-balance 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 The following table presents a summary of the Bank’s commitments and contingent liabilities: (in thousands) June 30, December 31, Financial instruments whose amounts represent risk: Commitments to extend credit: Commercial loans $ 266,538 $ 257,220 Consumer loans 443,265 422,958 Real estate mortgage loans 61,185 66,267 Real estate construction loans 223,956 187,097 Standby letters of credit 11,535 13,075 Deposit account overdraft privilege 97,670 98,260 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 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 Other Commitments and Contingencies 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. Other Commitments and Contingencies (continued)

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2018
Federal Home Loan Banks [Abstract]
Shareholders' Equity	Note 19 – Shareholders’ Equity Dividends Paid The Bank paid to the Company cash dividends in the aggregate amounts of $4,770,000 and $5,167,000 during the three months ended June 30, 2018 and 2017, respectively, and $9,142,000 and $9,209,000 during the six months ended June 30, 2018 and 2017, 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 the 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, 2017, the Bank could have paid dividends of $85,254,000 to the Company without the approval of the Commissioner of the Department of Business Oversight. 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 June 30, 2018, the Company had repurchased 166,600 shares under this plan. Stock Repurchased Under Equity Compensation Plans During the three months ended June 30, 2018 and 2017, employees tendered 17,086 and 69,401 shares, respectively, of the Company’s common stock with market value of $667,000, and $2,488,000, respectively, in lieu of cash to exercise options to purchase shares of the Company’s stock and to pay income taxes related to equity compensation plan instruments 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 included in the total of stock repurchased under the stock repurchase plan announced on August 21, 2007. During the six months ended June 30, 2018 and 2017 employees tendered 17,220 and 85,652 shares, respectively, of the Company’s common stock with market value of $671,000 and $3,092,000, respectively, in lieu of cash to exercise options to purchase shares of the Company’s stock and to satisfy tax withholding requirements related to such exercises and the release of RSUs 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 included in the total of stock repurchased under the stock repurchase plan announced on August 21, 2007.

Stock Options and Other Equity-

Stock Options and Other Equity-Based Incentive Instruments	6 Months Ended
	Jun. 30, 2018
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 June 30, 2018, 408,900 options for the purchase of common shares, and 121,428 restricted stock units were outstanding, and 376,144 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 June 30, 2018, 20,000 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 during the six months ended June 30, 2018 is summarized in the following table: Number Option Price Weighted Value on Weighted Outstanding at December 31, 2017 446,400 $12.63 to $23.21 $ 16.84 Options granted — — to — — Options exercised (14,500 ) $15.40 to $15.40 $ 15.40 Options forfeited (3,000 ) $23.21 to $23.21 $ 23.21 Outstanding at June 30, 2018 428,900 $12.63 to $23.21 $ 16.85 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 June 30, 2018: Currently Currently Not Total Number of options 425,900 3,000 428,900 Weighted average exercise price $ 16.80 $ 23.21 $ 16.85 Intrinsic value (in thousands) $ 8,794 $ 43 $ 8,837 Weighted average remaining contractual term (yrs.) 3.5 6.3 3.5 The 3,000 options that are currently not exercisable as of June 30, 2018 are expected to vest, on a weighted-average basis, over the next 1.3 years, and the Company is expected to recognize $20,000 of pre-tax 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 Outstanding at December 31, 2017 68,457 52,829 RSUs granted 26,939 $ 39.31 16,939 $ 36.40 Additional market plus service condition RSUs vested — 8,506 RSUs added through dividend credits 545 — RSUs released through vesting (25,398 ) (25,512 ) RSUs forfeited/expired (907 ) (970 ) Outstanding at June 30, 2018 69,636 51,792 The 69,636 of service condition vesting RSUs outstanding as of June 30, 2018 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 69,636 of service condition vesting RSUs outstanding as of June 30, 2018 are expected to vest, and be released, on a weighted-average basis, over the next 1.5 years. The Company expects to recognize $2,018,000 of pre-tax The 51,792 of market plus service condition vesting RSUs outstanding as of June 30, 2018 are expected to vest, and be released, on a weighted-average basis, over the next 1.9 years. The Company expects to recognize $1,116,000 of pre-tax

Noninterest Income and Expense

Noninterest Income and Expense	6 Months Ended
	Jun. 30, 2018
Other Income and Expenses [Abstract]
Noninterest Income and Expense	Note 21 - Noninterest Income and Expense The following table summarizes the Company’s noninterest income for the periods indicated (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Service charges on deposit accounts $ 3,613 $ 4,323 $ 7,392 $ 7,942 ATM and interchange fees 4,510 4,248 8,745 8,263 Other service fees 630 839 1,344 1,604 Mortgage banking service fees 511 526 1,028 1,047 Change in value of mortgage servicing rights (36 ) (457 ) 75 (470 ) Total service charges and fees 9,228 9,479 18,584 18,386 Commissions on sale of non-deposit 810 705 1,686 1,312 Gain on sale of loans 666 777 1,292 1,687 Increase in cash value of life insurance 656 626 1,264 1,311 Gain on sale of foreclosed assets 17 153 388 271 Lease brokerage income 200 161 328 367 Sale of customer checks 138 94 239 198 Change in indemnification asset — 711 — 490 Life insurance proceeds in excess of cash value — — — 108 Loss on disposal of fixed assets (41 ) (28 ) (54 ) (28 ) Loss on marketable equity securities (23 ) — (70 ) — Other 523 232 807 511 Total other noninterest income 2,946 3,431 5,880 6,227 Total noninterest income $ 12,174 $ 12,910 $ 24,464 $ 24,613 The components of noninterest expense were as follows (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Base salaries, net of deferred loan origination costs $ 14,429 $ 13,657 $ 28,391 $ 27,047 Incentive compensation 2,159 2,173 4,611 4,371 Benefits and other compensation costs 4,865 4,664 10,103 9,969 Total salaries and benefits expense 21,453 20,494 43,105 41,387 Occupancy 2,720 2,705 5,401 5,397 Data processing and software 2,679 2,441 5,193 4,837 Equipment 1,637 1,805 3,188 3,528 ATM and POS network charges 1,437 1,075 2,663 1,928 Advertising 1,035 1,167 1,873 2,134 Professional fees 774 690 1,546 1,456 Telecommunications 681 668 1,382 1,311 Change in reserve for unfunded commitments (137 ) (135 ) 563 (120 ) Merger and acquisition expense 601 — 1,077 — Assessments 417 420 847 825 Postage 301 329 659 733 Intangible amortization 339 352 678 711 Operational losses 252 430 546 865 Courier service 224 263 491 517 Provision for foreclosed asset losses — 94 90 28 Foreclosed assets expense 180 38 204 76 Other miscellaneous expense 3,277 3,068 6,526 6,113 Total other noninterest expense 16,417 15,410 32,927 30,339 Total noninterest expense $ 37,870 $ 35,904 $ 76,032 $ 71,726 Merger and acquisition expense: Occupancy $ 49 $ — $ 49 $ — Equipment 11 — 11 — Professional fees 196 — 552 — Advertising and marketing 164 — 172 — Postage 7 — 7 — Other miscellaneous expense 174 — 286 — Total merger and acquisition expense $ 601 $ — $ 1,077 $ —

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 22 - Income Taxes The provisions for income taxes applicable to income before taxes 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 for the periods indicated as follows: Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Federal statutory income tax rate 21.0 % 35.0 % 21.0 % 35.0 % State income taxes, net of federal tax benefit 8.8 6.6 8.9 6.7 Tax-exempt (1.0 ) (1.7 ) (1.1 ) (1.8 ) Increase in cash value of insurance policies (0.7 ) (1.0 ) (0.7 ) (1.2 ) Low income housing tax credits (0.6 ) (0.7 ) (0.8 ) (0.7 ) Equity compensation (0.4 ) (2.1 ) (0.2 ) (1.3 ) Nondeductible merger expenses 0.3 — 0.3 — Other 0.4 (0.1 ) 0.5 0.2 Effective Tax Rate 27.8 % 36.0 % 27.9 % 36.9 %

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Note 23 – Earnings Per Share Basic earnings per share represent income available to common shareholders divided by the weighted-average number of common shares outstanding during the period. Diluted earnings per share reflect 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: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 Net income $ 15,029 $ 13,589 $ 28,939 $ 25,668 Average number of common shares outstanding 22,983 22,900 22,970 22,885 Effect of dilutive stock options and restricted stock 293 340 310 351 Average number of common shares outstanding used to calculate diluted earnings per share 23,276 23,240 23,280 23,236 Options excluded from diluted earnings per share because the effect of these options was antidilutive — — — —

Comprehensive Income

Comprehensive Income	6 Months Ended
	Jun. 30, 2018
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 The components of accumulated other comprehensive loss, included in shareholders’ equity, are as follows: (in thousands) June 30, December 31, Net unrealized loss on available for sale securities $ (24,651 ) (3,409 ) Tax effect 7,288 1,433 Unrealized holding loss on available for sale securities, net of tax (17,363 ) (1,976 ) Unfunded status of the supplemental retirement plans (5,124 ) (5,352 ) Tax effect 1,514 2,250 Unfunded status of the supplemental retirement plans, net of tax (3,610 ) (3,102 ) Joint beneficiary agreement liability (150 ) (150 ) Tax effect — Joint beneficiary agreement liability, net of tax (150 ) (150 ) Accumulated other comprehensive loss $ (21,123 ) $ (5,228 ) The components of other comprehensive income (loss) and related tax effects are as follows: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 Unrealized holding gains (losses) on available for sale securities before reclassifications $ (5,676 ) $ 4,911 $ (20,941 ) $ 5,698 Amounts reclassified out of accumulated other comprehensive income: Adoption ASU 2016-01 — — 62 — Adoption ASU 2018-02 — — (425 ) — Total amounts reclassified out of accumulated other comprehensive income — — (363 ) — Unrealized holding gains (losses) on available for sale securities after reclassifications (5,676 ) 4,911 (21,304 ) 5,698 Tax effect 1,678 (2,065 ) 6,280 (2,395 ) Unrealized holding gains (losses) on available for sale securities, net of tax (3,998 ) 2,846 (15,024 ) 3,303 Change in unfunded status of the supplemental retirement plans before reclassifications — — 668 — Amounts reclassified out of accumulated other comprehensive income: Amortization of prior service cost (13 ) (1 ) (27 ) (4 ) Amortization of actuarial losses 127 96 254 192 Adoption ASU 2018-02 — — (668 ) — Total amounts reclassified out of accumulated other comprehensive income 114 95 (441 ) 188 Change in unfunded status of the supplemental retirement plans after reclassifications 114 95 227 188 Tax effect (34 ) (40 ) (67 ) (79 ) Change in unfunded status of the supplemental retirement plans, net of tax 80 55 160 109 Change in joint beneficiary agreement liability before reclassifications — — — — Amounts reclassified out of accumulated other comprehensive income — — — — Change in joint beneficiary agreement liability after reclassifications — — — Tax effect — — — — Change in joint beneficiary agreement liability, net of tax — — — — Total other comprehensive income (loss) $ (3,918 ) $ 2,901 $ (14,864 ) $ 3,412

Retirement Plans

Retirement Plans	6 Months Ended
	Jun. 30, 2018
Retirement Benefits [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. Prior to July 1, 2015, the Company did not contribute to the 401(k) Plan. Effective July 1, 2015, the Company initiated a discretionary matching contribution equal to 50% of participant’s elective deferrals each quarter, up to 4% of eligible compensation. The following table sets forth the benefit expense attributable to the 401(k) Plan matching contributions, and the contributions made by the Company to the 401(k) Plan during the periods indicated: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 401(k) Plan benefits expense $ 251 $ 194 $ 454 $ 380 401(k) Plan contributions made by the Company $ 247 $ 192 $ 446 $ 371 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. Company shares owned by the ESOP are paid dividends and included in the calculation of earnings per share exactly as other common shares outstanding. The following table sets forth the benefit expense attributable to the ESOP, and the contributions made by the Company to the ESOP during the periods indicated: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 ESOP benefits expense $ 475 $ 540 $ 940 $ 1,065 ESOP contributions made by the Company $ 940 $ 1,073 $ 1,479 $ 1,536 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 $6,932,000 and $6,605,000 at June 30, 2018 and December 31, 2017, respectively. The following table sets forth the earnings credits on deferred balances included in noninterest expense during the periods indicated: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 Deferred compensation earnings credits included in noninterest expense $ 121 $ 109 $ 245 $ 254 Supplemental Retirement Plans The Company has supplemental retirement plans for current and former directors and key executives. These plans are non-qualified Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 Net pension cost included the following components: Service cost-benefits earned during the period $ 243 $ 235 $ 486 $ 470 Interest cost on projected benefit obligation 237 248 475 496 Amortization of net obligation at transition — 1 1 1 Amortization of prior service cost (13 ) (3 ) (27 ) (6 ) Recognized net actuarial loss 127 97 254 195 Net periodic pension cost $ 594 $ 578 $ 1,189 $ 1,156 Company contributions to pension plans $ 287 $ 329 $ 554 $ 588 Pension plan payouts to participants $ 287 $ 329 $ 554 $ 588 For the year ending December 31, 2018, the Company expects to contribute and pay out as benefits $1,106,000 to participants under the plans.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2018
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 periods indicated (in thousands): Balance December 31, 2016 $ 2,432 Advances/new loans 437 Removed/payments (721 ) Balance December 31, 2017 2,148 Advances/new loans 145 Removed/payments (480 ) Balance June 30, 2018 $ 1,813 Deposits of directors, officers and other related parties to the Bank totaled $28,910,000 and $46,025,000 at June 30, 2018 and December 31, 2017, respectively.

Fair Value Measurement

Fair Value Measurement	6 Months Ended
	Jun. 30, 2018
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 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 over-the-counter Loans held for sale Impaired originated and PNCI loans Foreclosed assets Mortgage servicing rights The table below presents the recorded amount of assets and liabilities measured at fair value on a recurring basis (in thousands): Fair value at June 30, 2018 Total Level 1 Level 2 Level 3 Marketable equity securities $ 2,868 $ 2,868 $ — $ — Debt securities available for sale: Obligations of U.S. government corporations and agencies 635,428 — 635,428 — Obligations of states and political subdivisions 118,779 — 118,779 — Mortgage servicing rights 7,021 — — 7,021 Total assets measured at fair value $ 764,096 $ 2,868 $ 754,207 $ 7,021 Fair value at December 31, 2017 Total Level 1 Level 2 Level 3 Marketable equity securities $ 2,938 $ 2,938 $ — $ — Debt securities available for sale: Obligations of U.S. government corporations and agencies 604,789 — 604,789 — Obligations of states and political subdivisions 123,156 — 123,156 — Mortgage servicing rights 6,687 — — 6,687 Total assets measured at fair value $ 737,570 $ 2,938 $ 727,945 $ 6,687 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 the six months ended June 30, 2018 or the year ended December 31, 2017. 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 time periods indicated. Had there been any transfer into or out of Level 3 during the time periods indicated, 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): Three months ended June 30, Beginning Transfers Change Issuances Ending 2018: Mortgage servicing rights $ 6,953 — $ (36 ) $ 104 $ 7,021 2017: Mortgage servicing rights $ 6,860 — $ (457 ) $ 193 $ 6,596 Six months ended June 30, Beginning Transfers Change Issuances Ending 2018: Mortgage servicing rights $ 6,687 — $ 75 $ 259 $ 7,021 2017: Mortgage servicing rights $ 6,595 — $ (470 ) $ 471 $ 6,596 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 June 30, 2018: Fair Value Valuation Unobservable Inputs Range, Mortgage Servicing Rights $ 7,021 Discounted Constant 4.9%-27.7%, 7.4% Discount rate 12.5%-13.5%, 12.5% The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2017: Fair Value Valuation Unobservable Inputs Range, Mortgage Servicing Rights $ 6,687 Discounted Constant 6.2%-22.0%, 8.9% Discount rate 13.0%-15.0%, 13.0% The tables below present the recorded investment in assets and liabilities measured at fair value on a nonrecurring basis, as of the dates indicated (in thousands): Six months ended June 30, 2018 Total Level 1 Level 2 Level 3 Total Gains Fair value: Impaired Originated & PNCI loans $ 1,647 — — $ 1,647 $ (505 ) Foreclosed assets 584 — — 584 (90 ) Total assets measured at fair value $ 2,231 — — $ 2,231 $ (595 ) Year ended December 31, 2017 Total Level 1 Level 2 Level 3 Total Gains Fair value: Impaired Originated & PNCI loans $ 2,767 — — $ 2,767 $ (1,452 ) Foreclosed assets 2,217 — — 2,217 (135 ) Total assets measured at fair value $ 4,984 — — $ 4,984 $ (1,587 ) Six months ended June 30, 2017 Total Level 1 Level 2 Level 3 Total Gains Fair value: Impaired Originated & PNCI loans $ 686 — — $ 686 $ (456 ) Foreclosed assets 1,103 — — 1,103 (28 ) Total assets measured at fair value $ 1,789 — — $ 1,789 $ (484 ) 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 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 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 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 June 30, 2018: June 30, 2018 Fair Value Valuation Unobservable Inputs Range, Impaired Originated & PNCI loans $ 1,647 Sales comparison Income approach Adjustment for differences (70%) - 60%; (7.41%) N/A Foreclosed assets (Land & construction) $ 492 Sales comparison Adjustment for differences (47%) - 39%; 3.64% Foreclosed assets (Residential real estate) $ 92 Sales comparison Adjustment for differences (65%) - 20%; (45%) 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, 2017: December 31, 2017 Fair Value Valuation Unobservable Inputs Range, Impaired Originated & PNCI loans $ 2,767 Sales comparison Adjustment for differences (74%) - 23%; N/A Foreclosed assets (Land & construction) $ 1,341 Sales comparison Adjustment for differences (53%) - 283%; 167% Foreclosed assets (Residential real estate) $ 622 Sales comparison Adjustment for differences (47%) - 39%; (3.13%) Foreclosed assets (Commercial real estate) $ 254 Sales comparison Adjustment for differences (84%) - 19%; (84%) 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 Securities held to maturity over-the-counter Restricted Equity Securities Originated and PNCI loans PCI Loans FDIC Indemnification Asset - Deposit Liabilities Other Borrowings Junior Subordinated Debentures Commitments to Extend Credit and Standby Letters of Credit 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. In January 2018, the Company adopted the provisions of Accounting Standard Update 2016-01 “ Recognition and Measurement of Financial Assets and Financial Liabilities June 30, 2018 December 31, 2017 Carrying Fair Carrying Fair Financial assets: Level 1 inputs: Cash and due from banks $ 94,661 $ 94,661 $ 105,968 $ 105,968 Cash at Federal Reserve and other banks 89,401 89,401 99,460 99,460 Level 2 inputs: Securities held to maturity 477,745 468,621 514,844 518,165 Restricted equity securities 16,956 N/A 16,956 N/A Loans held for sale 3,601 3,601 4,616 4,616 Level 3 inputs: Loans, net 3,116,789 3,091,134 2,984,842 2,992,225 Financial liabilities: Level 2 inputs: Deposits 4,077,222 4,073,628 4,009,131 4,006,620 Other borrowings 152,839 152,839 122,166 122,166 Level 3 inputs: Junior subordinated debt 56,950 58,930 56,858 58,466 Contract Fair Contract Fair Off-balance Level 3 inputs: Commitments $ 994,944 $ 9,949 $ 933,542 $ 9,335 Standby letters of credit 11,535 115 13,075 131 Overdraft privilege commitments 97,670 977 98,260 983

TriCo Bancshares Condensed Fina

TriCo Bancshares Condensed Financial Statements (Parent Only)	6 Months Ended
	Jun. 30, 2018
Condensed Financial Information Disclosure [Abstract]
TriCo Bancshares Condensed Financial Statements (Parent Only)	Note 28 - TriCo Bancshares Condensed Financial Statements (Parent Only) Condensed Balance Sheets June 30, December 31, 2018 2017 (In thousands) Assets Cash and cash equivalents $ 3,069 $ 3,924 Investment in Tri Counties Bank 565,047 557,538 Other assets 1,742 1,721 Total assets $ 569,858 $ 563,183 Liabilities and shareholders’ equity Other liabilities $ 564 $ 517 Junior subordinated debt 56,950 56,858 Total liabilities 57,514 57,375 Shareholders’ equity: Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at June 30, 2018 and December 31, 2017 — — Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 23,004,153 and 22,955,963 shares, respectively 256,590 255,836 Retained earnings 276,877 255,200 Accumulated other comprehensive loss, net (21,123 ) (5,228 ) Total shareholders’ equity 512,344 505,808 Total liabilities and shareholders’ equity $ 569,858 $ 563,183 Condensed Statements of Income Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 (In thousands) (In thousands) Interest expense $ (789 ) $ (623 ) $ (1,486 ) $ (1,218 ) Administration expense (511 ) (218 ) (937 ) (377 ) Loss before equity in net income of Tri Counties Bank (1,300 ) (841 ) (2,423 ) (1,595 ) Equity in net income of Tri Counties Bank: Distributed 4,770 5,167 9,142 9,209 Undistributed 11,253 8,909 21,650 17,383 Income tax benefit 306 354 570 671 Net income $ 15,029 $ 13,589 $ 28,939 $ 25,668 Condensed Statements of Comprehensive Income Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 (In thousands) (In thousands) Net income $ 15,029 $ 13,589 $ 28,939 $ 25,668 Other comprehensive income (loss), net of tax: Increase (decrease) in unrealized gains on available for sale securities arising during the period (3,998 ) 2,846 (15,024 ) 3,303 Change in minimum pension liability 80 55 160 109 Other comprehensive income (loss) (3,918 ) 2,901 (14,864 ) 3,412 Comprehensive income $ 11,111 $ 16,490 $ 14,075 $ 29,080 Condensed Statements of Cash Flows Six months ended June 30, 2018 2017 (In thousands) Operating activities: Net income $ 28,939 $ 25,668 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed equity in earnings of Tri Counties Bank (21,650 ) (17,383 ) Equity compensation vesting expense 722 774 Net change in other assets and liabilities (605 ) (672 ) Net cash provided by operating activities 7,406 8,387 Investing activities: None Financing activities: Issuance of common stock through option exercise 185 192 Repurchase of common stock (633 ) (1,121 ) Cash dividends paid — common (7,813 ) (7,328 ) Net cash used for financing activities (8,261 ) (8,257 ) Net change in cash and cash equivalents (855 ) 130 Cash and cash equivalents at beginning of year 3,924 2,802 Cash and cash equivalents at end of year $ 3,069 $ 2,932

Regulatory Matters

Regulatory Matters	6 Months Ended
	Jun. 30, 2018
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 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, Tier 1, and common equity Tier 1capital to risk-weighted assets, and of Tier 1 capital to average assets. The following tables present actual and required capital ratios as of June 30, 2018 and December 31, 2017 for the Company and the Bank under Basel III Capital Rules. The minimum capital amounts presented include the minimum required capital levels as of June 30, 2018 and December 31, 2017 based on the then phased-in phased-in. Actual Minimum Capital Phase-in Minimum Capital Required to be Amount Ratio Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) As of June 30, 2018: Total Capital (to Risk Weighted Assets): Consolidated $ 550,769 13.91 % $ 390,991 9.875 % $ 415,737 10.50 % N/A N/A Tri Counties Bank $ 548,232 13.85 % $ 390,819 9.875 % $ 415,554 10.50 % $ 395,766 10.00 % Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 517,518 13.07 % $ 311,803 7.875 % $ 336,549 8.50 % N/A N/A Tri Counties Bank $ 514,981 13.01 % $ 311,666 7.875 % $ 336,401 8.50 % $ 316,613 8.00 % Common equity Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 462,278 11.68 % $ 252,412 6.375 % $ 277,158 7.00 % N/A N/A Tri Counties Bank $ 514,981 13.01 % $ 252,301 6.375 % $ 277,036 7.00 % $ 257,248 6.50 % Tier 1 Capital (to Average Assets): Consolidated $ 517,518 10.92 % $ 189,647 4.000 % $ 189,647 4.00 % N/A N/A Tri Counties Bank $ 514,981 10.86 % $ 189,643 4.000 % $ 189,643 4.00 % $ 237,054 5.00 % Actual Minimum Capital Phase-in Minimum Capital Required to be Amount Ratio Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) As of December 31, 2017: Total Capital (to Risk Weighted Assets): Consolidated $ 528,805 14.07 % $ 347,694 9.25 % $ 394,679 10.50 % N/A N/A Tri Counties Bank $ 525,384 13.98 % $ 347,535 9.25 % $ 394,499 10.50 % $ 375,713 10.00 % Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 495,318 13.18 % $ 272,517 7.25 % $ 319,502 8.50 % N/A N/A Tri Counties Bank $ 491,897 13.09 % $ 272,392 7.25 % $ 319,356 8.50 % $ 300,570 8.00 % Common equity Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 440,643 11.72 % $ 216,134 5.75 % $ 263,120 7.00 % N/A N/A Tri Counties Bank $ 491,897 13.09 % $ 216,035 5.75 % $ 262,999 7.00 % $ 244,214 6.50 % Tier 1 Capital (to Average Assets): Consolidated $ 495,318 10.80 % $ 183,400 4.00 % $ 183,400 4.00 % N/A N/A Tri Counties Bank $ 491,897 10.73 % $ 183,394 4.00 % $ 183,394 4.00 % $ 229,243 5.00 % As of June 30, 2018, capital levels at the Company and the Bank exceed all capital adequacy requirements under the Basel III Capital Rules on a fully phased-in Beginning January 1, 2016, the Basel III Capital Rules implemented a requirement for all banking organizations to maintain a capital conservation buffer above the minimum risk-based capital requirements in order to avoid certain limitations on capital distributions, stock repurchases and discretionary bonus payments to executive officers. The capital conservation buffer is exclusively composed of common equity tier 1 capital, and it applies to each of the risk-based capital ratios but not the leverage ratio. At June 30, 2018, the Company and the Bank are in compliance with the capital conservation buffer requirement. The three risk-based capital ratios will increase by 0.625% each year through 2019, at which point, the common equity tier 1 risk-based, tier 1 risk-based and total risk-based capital ratio minimums will be 7.0%, 8.5% and 10.5%, respectively. The following table sets forth the results of operations for the periods indicated, 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. 2018 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 $ 180 $ 246 Discount accretion PCI – other 95 60 Discount accretion PNCI 284 326 All other loan interest income 38,745 37,417 Total loan interest income 39,304 38,049 Debt securities, dividends and interest bearing cash at banks (not FTE) 9,174 9,072 Total interest income 48,478 47,121 Interest expense 2,609 2,135 Net interest income 45,869 44,986 (Benefit from reversal of) provision for loan losses (638 ) (236 ) Net interest income after provision for loan losses 46,507 45,222 Noninterest income 12,174 12,290 Noninterest expense 37,870 38,162 Income before income taxes 20,811 19,350 Income tax expense 5,782 5,440 Net income $ 15,029 $ 13,910 Per common share: Net income (diluted) $ 0.65 $ 0.60 Dividends $ 0.17 $ 0.17 2017 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 $ 516 $ 398 $ 386 $ 112 Discount accretion PCI – other 445 407 797 631 Discount accretion PNCI 528 559 987 798 All other loan interest income 36,705 35,904 34,248 33,373 Total loan interest income 38,194 37,268 36,418 34,914 Debt securities, dividends and interest bearing cash at banks (not FTE) 8,767 8,645 8,626 8,570 Total interest income 46,961 45,913 45,044 43,484 Interest expense 1,868 1,829 1,610 1,491 Net interest income 45,093 44,084 43,434 41,993 Provision for (benefit from reversal of provision for) loan losses 1,677 765 (796 ) (1,557 ) Net interest income after provision for loan losses 43,416 43,319 44,230 43,550 Noninterest income 12,478 12,930 12,910 11,703 Noninterest expense 38,076 37,222 35,904 35,822 Income before income taxes 17,818 19,027 21,236 19,431 Income tax expense 14,829 7,130 7,647 7,352 Net income $ 2,989 $ 11,897 $ 13,589 $ 12,079 Per common share: Net income (diluted) $ 0.13 $ 0.51 $ 0.58 $ 0.52 Dividends $ 0.17 $ 0.17 $ 0.17 $ 0.15

Summary of Significant Accoun38

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation TriCo Bancshares (the “Company” or “we”) 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. The Bank operates from 57 traditional branches, 9 in-store 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 $1,710,000 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. 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.
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.
Marketable Equity Securities	Marketable Equity Securities As of December 31, 2017, marketable equity securities with a fair value of $2,938,000 were recorded within investment securities available for sale on the consolidated balance sheets with changes in the fair value recorded through other comprehensive income and accumulated other comprehensive income (loss). As of January 1, 2018, the Company adopted Accounting Standard Update (“ASU”) 2016-01
Debt Securities	Debt Securities The Company classifies its debt 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 six months ended June 30, 2018 and throughout 2017, the Company did not have any debt 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 more likely than not 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
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 Bank 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 Bank 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, based on evaluations of the collectability, impairment and prior loss experience of loans. 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 original 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 specific reserve allocation within the allowance for loan losses. 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 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 probable incurred 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 re-graded Re-grading The Company’s method for assessing the appropriateness of the allowance for originated loan losses includes specific allowances for impaired originated loans, 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. 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 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality 310-30, 310-30 310-30 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, 310-20, 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 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.
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. Physical possession of residential real estate property collateralizing a consumer mortgage loan occurs when legal title is obtained upon completion of foreclosure or when the borrower conveys all interest in the property to satisfy the loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. Any write-downs based on the asset’s fair value less costs to sell at the date of acquisition are charged to the allowance for loan and lease losses. Any recoveries based on the asset’s fair value less estimated costs to sell in excess of the recorded value of the loan at the date of acquisition are recorded to the allowance for loan and lease losses. These assets are subsequently accounted for at lower of cost or fair value less estimated costs to sell. If fair value declines subsequent to foreclosure, a valuation allowance is recorded through expense. Operating costs after acquisition are expensed. 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. On May 9, 2017, the Company and the FDIC terminated their loss sharing agreements.
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 shorter of the estimated useful lives of the related assets or lease terms. Asset lives range from 3-10 15-40
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
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
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.
Low Income Housing Tax Credits	Low Income Housing Tax Credits The Company accounts for low income housing tax credits and the related qualified affordable housing projects using the proportional amortization method. Under the proportional amortization method, the Company amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). Upon entering into a qualified affordable housing project, the Company records, in other liabilities, the entire amount that it has agreed to invest in the project, and an equal amount, in other assets, representing its investment in the project. As the Company disburses cash to satisfy its investment obligation, other liabilities are reduced. Over time, as the tax credits and other tax benefits of the project are realized by the Company, the investment recorded in other assets is reduced using the proportional amortization method.
Revenue Recognition	Revenue Recognition The Company records revenue from contracts with customers in accordance with Accounting Standards Codification Topic 606, “Revenue from Contracts with Customers” (“Topic 606”). Under Topic 606, the Company must identify the contract with a customer, identify the performance obligations in the contract, determine the transaction price, allocate the transaction price to the performance obligations in the contract, and recognize revenue when (or as) the Company satisfies a performance obligation. Significant revenue has not been recognized in the current reporting period that results from performance obligations satisfied in previous periods. Most of our revenue-generating transactions are not subject to ASC 606, including revenue generated from financial instruments, such as our loans and investment securities. In addition, certain noninterest income streams such as fees associated with mortgage servicing rights, financial guarantees, derivatives, and certain credit card fees are also not in scope of the new guidance. The Company’s noninterest revenue streams are largely based on transactional activity, or standard month-end month-end
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 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 During the three months ended September 30, 2017, the Company changed its classification of 1st lien and 2nd lien non-owner 1-4
Recent Accounting Pronouncements	Recent Accounting Pronouncements FASB Accounting Standards Update (ASU) No.2014-09, Revenue from Contracts with Customers (Topic 606): 2014-09 2014-09 2014-09 2014-09 In January 2016, the FASB issued ASU No. 2016-01, “Recognition and Measurement of Financial Assets and Financial Liabilities.” available-for-sale No. 2016-01 Fair Value Measurement FASB issued ASU No. 2016-02 , Leases (Topic 842) ASU 2016-2, on-balance ASU 2016-02 No. 2018-10 2018-11. FASB issued ASU No. 2016-13, 2016-13 2016-13, 2016-13 available-for-sale 2016-13 2016-13 2016-13 2016-13 one-time FASB issued ASU No. 2016-18, Statement of Cash Flows - Restricted Cash (Topic 230). ASU 2016-18 beginning-of-period end-of-period ASU 2016-18 FASB issued ASU No. 2017-01, Business Combinations - Clarifying the Definition of a Business (Topic 805). ASU 2017-01 ASU 2017-01 ASU 2017-01 FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other: Simplifying the Test for Goodwill Impairment (Topic 350): 2017-04 ASU 2017-04 FASB issued ASU No. 2017-07, Compensation - Retirement Benefits (Topic 715). 2017-07 ASU 2017-07 FASB issued ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Topic 310). ASU 2017-08 non-pooled ASU 2017-08 ASU 2017-08 FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718). ASU 2017-09 ASU 2017-09, ASU 2017-09 FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220). 2018-02 2018-02 2018-02

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Jun. 30, 2018
Investments Schedule [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: June 30, 2018 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value (in thousands) Debt Securities Available for Sale Obligations of U.S. government corporations and agencies $ 657,335 $ 257 $ (22,164 ) $ 635,428 Obligations of states and political subdivisions 121,523 359 (3,103 ) 118,779 Total debt securities available for sale $ 778,858 $ 616 $ (25,267 ) $ 754,207 Debt Securities Held to Maturity Obligations of U.S. government corporations and agencies $ 463,162 $ 291 $ (9,211 ) $ 454,242 Obligations of states and political subdivisions 14,583 77 (281 ) 14,379 Total debt securities held to maturity $ 477,745 $ 368 $ (9,492 ) $ 468,621 December 31, 2017 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value (in thousands) Debt Securities Available for Sale Obligations of U.S. government corporations and agencies $ 609,695 $ 695 $ (5,601 ) $ 604,789 Obligations of states and political subdivisions 121,597 1,888 (329 ) 123,156 Total debt securities available for sale $ 731,292 $ 2,583 $ (5,930 ) $ 727,945 Debt Securities Held to Maturity Obligations of U.S. government corporations and agencies $ 500,271 $ 5,101 $ (1,889 ) $ 503,483 Obligations of states and political subdivisions 14,573 146 (37 ) 14,682 Total debt securities held to maturity $ 514,844 $ 5,247 $ (1,926 ) $ 518,165
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. Debt Securities Available for Sale Held to Maturity (In thousands) Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value Due in one year $ 1 $ 1 $ — $ — Due after one year through five years 233 234 1,223 1,239 Due after five years through ten years 3,229 3,331 27,400 26,800 Due after ten years 775,395 750,641 449,122 440,582 Totals $ 778,858 $ 754,207 $ 477,745 $ 468,621
Gross Unrealized Losses on Debt Securities	Gross unrealized losses on debt 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 (in thousands) June 30, 2018 Debt Securities Available for Sale Obligations of U.S. government corporations and agencies $ 437,859 $ (14,490 ) $ 152,004 $ (7,674 ) $ 589,863 $ (22,164 ) Obligations of states and political subdivisions 66,052 (1,785 ) 16,556 (1,318 ) 82,608 (3,103 ) Total debt securities available for sale $ 503,911 $ (16,275 ) $ 168,560 $ (8,992 ) $ 672,471 $ (25,267 ) Debt Securities Held to Maturity Obligations of U.S. government corporations and agencies $ 326,966 $ (5,578 ) $ 91,801 $ (3,633 ) $ 418,767 $ (9,211 ) Obligations of states and political subdivisions 8,884 (152 ) 2,536 (129 ) 11,420 (281 ) Total debt securities held to maturity $ 335,850 $ (5,730 ) $ 94,337 $ (3,762 ) $ 430,187 $ (9,492 ) Less than 12 months 12 months or more Total Fair Unrealized Fair Unrealized Fair Unrealized Value Loss Value Loss Value Loss (in thousands) December 31, 2017 Debt Securities Available for Sale Obligations of U.S. government corporations and agencies $ 284,367 $ (2,176 ) $ 166,338 $ (3,425 ) $ 450,705 $ (5,601 ) Obligations of states and political subdivisions 4,904 (35 ) 17,085 (294 ) 21,989 (329 ) Total securities available for sale $ 289,271 $ (2,211 ) $ 183,423 $ (3,719 ) $ 472,694 $ (5,930 ) Debt Securities Held to Maturity Obligations of U.S. government corporations and agencies $ 93,017 $ (567 ) $ 95,367 $ (1,322 ) $ 188,384 $ (1,889 ) Obligations of states and political subdivisions 1,488 (7 ) 2,637 (30 ) 4,125 (37 ) Total debt securities held to maturity $ 94,505 $ (574 ) $ 98,004 $ (1,352 ) $ 192,509 $ (1,926 )

Loans (Tables)

Loans (Tables)	6 Months Ended
	Jun. 30, 2018
Receivables [Abstract]
Summary of Loan Balances	A summary of loan balances follows (in thousands): June 30, 2018 Originated PNCI PCI - PCI - Total Cash basis Other Mortgage loans on real estate: Residential 1-4 $ 326,149 $ 56,823 $ — $ 1,720 $ 384,692 Commercial 1,805,830 202,923 — 7,595 2,016,348 Total mortgage loans on real estate 2,131,979 259,746 — 9,315 2,401,040 Consumer: Home equity lines of credit 270,283 14,578 1,530 45 286,436 Home equity loans 38,082 2,449 — 455 40,986 Other 21,421 2,039 — 43 23,503 Total consumer loans 329,786 19,066 1,530 543 350,925 Commercial 227,591 7,555 — 2,473 237,619 Construction: Residential 73,570 8 — — 73,578 Commercial 82,912 239 — — 83,151 Total construction 156,482 247 — — 156,729 Total loans, net of deferred loan fees and discounts $ 2,845,838 $ 286,614 $ 1,530 $ 12,331 $ 3,146,313 Total principal balance of loans owed, net of charge-offs $ 2,855,594 $ 293,151 $ 4,898 $ 16,032 $ 3,169,675 Unamortized net deferred loan fees (9,756 ) — — — (9,756 ) Discounts to principal balance of loans owed, net of charge-offs — (6,537 ) (3,368 ) (3,701 ) (13,606 ) Total loans, net of unamortized deferred loan fees and discounts $ 2,845,838 $ 286,614 $ 1,530 $ 12,331 $ 3,146,313 Allowance for loan losses $ (28,761 ) $ (624 ) $ (7 ) $ (132 ) $ (29,524 ) December 31, 2017 Originated PNCI PCI - PCI - Total Mortgage loans on real estate: Residential 1-4 $ 320,522 $ 63,519 $ — $ 1,385 $ 385,426 Commercial 1,690,510 215,823 — 8,563 1,914,896 Total mortgage loan on real estate 2,011,032 279,342 — 9,948 2,300,322 Consumer: Home equity lines of credit 269,942 16,248 2,069 429 288,688 Home equity loans 39,848 2,698 — 485 43,031 Other 22,859 2,251 — 45 25,155 Total consumer loans 332,649 21,197 2,069 959 356,874 Commercial 209,437 8,391 — 2,584 220,412 Construction: Residential 67,920 10 — — 67,930 Commercial 69,364 263 — — 69,627 Total construction 137,284 273 — — 137,557 Total loans, net of deferred loan fees and discounts $ 2,690,402 $ 309,203 $ 2,069 $ 13,491 $ 3,015,165 Total principal balance of loans owed, net of charge-offs $ 2,699,053 $ 316,238 $ 5,863 $ 17,318 $ 3,038,472 Unamortized net deferred loan fees (8,651 ) — — — (8,651 ) Discounts to principal balance of loans owed, net of charge-offs — (7,035 ) (3,794 ) (3,827 ) (14,656 ) Total loans, net of unamortized deferred loan fees and discounts $ 2,690,402 $ 309,203 $ 2,069 $ 13,491 $ 3,015,165 Allowance for loan losses $ (29,122 ) $ (929 ) $ (17 ) $ (255 ) $ (30,323 )
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): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Change in accretable yield: Balance at beginning of period $ 4,147 $ 9,560 $ 4,262 $ 10,348 Accretion to interest income (261 ) (1,058 ) (516 ) (1,960 ) Reclassification (to) from nonaccretable difference 110 (546 ) 250 (432 ) Balance at end of period $ 3,996 $ 7,956 $ 3,996 $ 7,956

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	6 Months Ended
	Jun. 30, 2018
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 – Three Months Ended June 30, 2018 (in thousands) Beginning Charge-offs Recoveries Provision Ending Mortgage loans on real estate: Residential 1-4 $ 2,170 $ (51 ) $ — $ (128 ) $ 1,991 Commercial 11,495 (15 ) 21 106 11,607 Total mortgage loans on real estate 13,665 (66 ) 21 (22 ) 13,598 Consumer: Home equity lines of credit 5,412 (24 ) 317 (657 ) 5,048 Home equity loans 1,736 — 23 (227 ) 1,532 Other 570 (174 ) 66 95 557 Total consumer loans 7,718 (198 ) 406 (789 ) 7,137 Commercial 6,392 (54 ) 80 (40 ) 6,378 Construction: Residential 1,351 — — 83 1,434 Commercial 847 — — 130 977 Total construction 2,198 — — 213 2,411 Total $ 29,973 $ (318 ) $ 507 $ (638 ) $ 29,524 Allowance for Loan Losses – Six Months Ended June 30, 2018 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,317 $ (52 ) $ — $ (274 ) $ 1,991 Commercial 11,441 (15 ) 36 145 11,607 Total mortgage loans on real estate 13,758 (67 ) 36 (129 ) 13,598 Consumer: Home equity lines of credit 5,800 (104 ) 526 (1,174 ) 5,048 Home equity loans 1,841 — 37 (346 ) 1,532 Other 586 (368 ) 144 195 557 Total consumer loans 8,227 (472 ) 707 (1,325 ) 7,137 Commercial 6,512 (259 ) 130 (5 ) 6,378 Construction: Residential 1,184 — — 250 1,434 Commercial 642 — — 335 977 Total construction 1,826 — — 585 2,411 Total $ 30,323 $ (798 ) $ 873 $ (874 ) $ 29,524 Allowance for Loan Losses – As of June 30, 2018 (in thousands) Individually Loans pooled Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 147 $ 1,794 $ 50 $ 1,991 Commercial 82 11,466 59 11,607 Total mortgage loans on real estate 229 13,260 109 13,598 Consumer: Home equity lines of credit 287 4,754 7 5,048 Home equity loans 192 1,340 — 1,532 Other 54 503 — 557 Total consumer loans 533 6,597 7 7,137 Commercial 2,127 4,228 23 6,378 Construction: Residential — 1,434 — 1,434 Commercial — 977 — 977 Total construction — 2,411 — 2,411 Total $ 2,889 $ 26,496 $ 139 $ 29,524 Loans, Net of Unearned fees – As of June 30, 2018 (in thousands) Individually Loans pooled Loans acquired Total loans, net Mortgage loans on real estate: Residential 1-4 $ 6,344 $ 376,628 $ 1,720 $ 384,692 Commercial 11,162 1,997,591 7,595 2,016,348 Total mortgage loans on real estate 17,506 2,374,219 9,315 2,401,040 Consumer: Home equity lines of credit 2,250 282,611 1,575 286,436 Home equity loans 2,457 38,074 455 40,986 Other 247 23,213 43 23,503 Total consumer loans 4,954 343,898 2,073 350,925 Commercial 4,751 230,395 2,473 237,619 Construction: Residential — 73,578 — 73,578 Commercial — 83,151 — 83,151 Total construction — 156,729 — 156,729 Total $ 27,211 $ 3,105,241 $ 13,861 $ 3,146,313 Allowance for Loan Losses – Year Ended December 31, 2017 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,748 $ (60 ) $ — $ (371 ) $ 2,317 Commercial 11,517 (186 ) 397 (287 ) 11,441 Total mortgage loans on real estate 14,265 (246 ) 397 (658 ) 13,758 Consumer: Home equity lines of credit 7,044 (98 ) 698 (1,844 ) 5,800 Home equity loans 2,644 (332 ) 242 (713 ) 1,841 Other 622 (1,186 ) 375 775 586 Total consumer loans 10,310 (1,616 ) 1,315 (1,782 ) 8,227 Commercial 5,831 (1,444 ) 428 1,697 6,512 Construction: Residential 1,417 (1,104 ) — 871 1,184 Commercial 680 — 1 (39 ) 642 Total construction 2,097 (1,104 ) 1 832 1,826 Total $ 32,503 $ (4,410 ) $ 2,141 $ 89 $ 30,323 Allowance for Loan Losses – As of December 31, 2017 (in thousands) Individually Loans pooled Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 230 $ 1,932 $ 155 $ 2,317 Commercial 30 11,351 60 11,441 Total mortgage loans on real estate 260 13,283 215 13,758 Consumer: Home equity lines of credit 427 5,356 17 5,800 Home equity loans 107 1,734 — 1,841 Other 57 529 — 586 Total consumer loans 591 7,619 17 8,227 Commercial 1,848 4,624 40 6,512 Construction: Residential — 1,184 — 1,184 Commercial — 642 — 642 Total construction — 1,826 — 1,826 Total $ 2,699 $ 27,352 $ 272 $ 30,323 Loans, Net of Unearned fees – As of December 31, 2017 (in thousands) Individually Loans pooled Loans acquired Total loans, net Mortgage loans on real estate: Residential 1-4 $ 5,298 $ 378,743 $ 1,385 $ 385,426 Commercial 13,911 1,892,422 8,563 1,914,896 Total mortgage loans on real estate 19,209 2,271,165 9,948 2,300,322 Consumer: Home equity lines of credit 2,688 283,502 2,498 288,688 Home equity loans 1,470 41,076 485 43,031 Other 257 24,853 45 25,155 Total consumer loans 4,415 349,431 3,028 356,874 Commercial 4,470 213,358 2,584 220,412 Construction: Residential 140 67,790 — 67,930 Commercial — 69,627 — 69,627 Total construction 140 137,417 — 137,557 Total $ 28,234 $ 2,971,371 $ 15,560 $ 3,015,165 Allowance for Loan Losses – Three Months Ended June 30, 2017 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,662 $ — $ — $ (151 ) $ 2,511 Commercial 11,542 (150 ) 17 (1,307 ) 10,102 Total mortgage loans on real estate 14,204 (150 ) 17 (1,458 ) 12,613 Consumer: Home equity lines of credit 6,530 (13 ) 252 (613 ) 6,156 Home equity loans 2,451 (206 ) 13 98 2,356 Other 595 (308 ) 68 290 645 Total consumer loans 9,576 (527 ) 333 (225 ) 9,157 Commercial 5,326 (764 ) 84 83 4,729 Construction: Residential 1,339 (1,071 ) — 910 1,178 Commercial 572 — — (106 ) 466 Total construction 1,911 (1,071 ) — 804 1,644 Total $ 31,017 $ (2,512 ) $ 434 $ (796 ) $ 28,143 Allowance for Loan Losses – Six Months Ended June 30, 2017 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,748 $ — $ $ (237 ) $ 2,511 Commercial 11,517 (150 ) 127 (1,392 ) 10,102 Total mortgage loans on real estate 14,265 (150 ) 127 (1,629 ) 12,613 Consumer: Home equity lines of credit 7,044 (84 ) 298 (1,102 ) 6,156 Home equity loans 2,644 (237 ) 25 (76 ) 2,356 Other 622 (482 ) 209 296 645 Total consumer loans 10,310 (803 ) 532 (882 ) 9,157 Commercial 5,831 (897 ) 254 (459 ) 4,729 Construction: Residential 1,417 (1,071 ) — 832 1,178 Commercial 680 — 1 (215 ) 466 Total construction 2,097 (1,071 ) 1 617 1,644 Total $ 32,503 $ (2,921 ) $ 914 $ (2,353 ) $ 28,143 Allowance for Loan Losses – As of June 30, 2017 (in thousands) Individually Loans pooled Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 249 $ 2,037 $ 225 $ 2,511 Commercial 124 8,531 1,447 10,102 Total mortgage loans on real estate 373 10,568 1,672 12,613 Consumer: Home equity lines of credit 400 5,748 8 6,156 Home equity loans 57 2,233 66 2,356 Other 31 614 — 645 Total consumer loans 488 8,595 74 9,157 Commercial 811 3,276 642 4,729 Construction: Residential 14 1,121 43 1,178 Commercial — 466 — 466 Total construction 14 1,587 43 1,644 Total $ 1,686 $ 24,026 $ 2,431 $ 28,143 Loans, Net of Unearned fees – As of June 30, 2017 (in thousands) Individually Loans pooled Loans acquired Total Loans Mortgage loans on real estate: Residential 1-4 $ 4,726 $ 375,217 $ 1,362 $ 381,305 Commercial 14,524 1,700,046 10,692 1,725,262 Total mortgage loans on real estate 19,250 2,075,263 12,054 2,106,567 Consumer: Home equity lines of credit 2,633 280,672 3,171 286,476 Home equity loans 1,285 43,515 1,136 45,936 Other 323 27,981 66 28,370 Total consumer loans 4,241 352,168 4,373 360,782 Commercial 2,744 219,658 3,341 225,743 Construction: Residential — 62,626 524 63,150 Commercial — 70,151 — 70,151 Total construction — 132,777 524 133,301 Total $ 26,235 $ 2,779,866 $ 20,292 $ 2,826,393
Schedule Credit Quality Indicators	The following tables present ending loan balances by loan category and risk grade for the periods indicated: Credit Quality Indicators Originated Loans– As of June 30, 2018 (in thousands) Pass Special Substandard Loss Total Originated Mortgage loans on real estate: Residential 1-4 $ 323,576 $ 292 $ 2,281 $ — $ 326,149 Commercial 1,760,898 27,717 17,215 — 1,805,830 Total mortgage loans on real estate 2,084,474 28,009 19,496 — 2,131,979 Consumer: Home equity lines of credit 265,724 1,828 2,731 — 270,283 Home equity loans 37,441 163 478 — 38,082 Other 21,083 158 180 — 21,421 Total consumer loans 324,248 2,149 3,389 — 329,786 Commercial 221,108 3,568 2,915 — 227,591 Construction: Residential 70,471 2,953 146 — 73,570 Commercial 82,912 — — — 82,912 Total construction 153,383 2,953 146 — 156,482 Total loans $ 2,783,213 $ 36,679 $ 25,946 $ — $ 2,845,838 Credit Quality Indicators PNCI Loans – As of June 30, 2018 (in thousands) Pass Special Substandard Loss Total PNCI Mortgage loans on real estate: Residential 1-4 $ 55,039 $ — $ 1,784 $ — $ 56,823 Commercial 198,353 2,935 1,635 — 202,923 Total mortgage loans on real estate 253,392 2,935 3,419 — 259,746 Consumer: Home equity lines of credit 13,675 903 — 14,578 Home equity loans 2,220 161 68 — 2,449 Other 2,030 4 5 — 2,039 Total consumer loans 17,925 165 976 — 19,066 Commercial 7,555 — — 7,555 Construction: Residential 8 — — — 8 Commercial 239 — — — 239 Total construction 247 — — — 247 Total loans $ 279,119 $ 3,100 $ 4,395 $ — $ 286,614 Credit Quality Indicators Originated Loans – As of December 31, 2017 (in thousands) Pass Special Substandard Loss Total Originated Mortgage loans on real estate: Residential 1-4 $ 315,120 $ 2,234 $ 3,168 $ — $ 320,522 Commercial 1,649,333 18,434 22,743 — 1,690,510 Total mortgage loans on real estate 1,964,453 20,668 25,911 — 2,011,032 Consumer: Home equity lines of credit 265,345 2,558 2,039 — 269,942 Home equity loans 37,428 800 1,620 — 39,848 Other 22,432 272 155 — 22,859 Total consumer loans 325,205 3,630 3,814 — 332,649 Commercial 195,208 9,492 4,737 — 209,437 Construction: Residential 67,813 — 107 — 67,920 Commercial 64,492 4,872 — — 69,364 Total construction 132,305 4,872 107 — 137,284 Total loans $ 2,617,171 $ 38,662 $ 34,569 $ — $ 2,690,402 Credit Quality Indicators PNCI Loans – As of December 31, 2017 (in thousands) Pass Special Substandard Loss Total PNCI Mortgage loans on real estate: Residential 1-4 $ 61,411 $ 218 $ 1,890 $ — $ 63,519 Commercial 203,751 11,513 559 — 215,823 Total mortgage loans on real estate 265,162 11,731 2,449 — 279,342 Consumer: Home equity lines of credit 14,866 450 932 — 16,248 Home equity loans 2,433 188 77 — 2,698 Other 2,207 38 6 — 2,251 Total consumer loans 19,506 676 1,015 — 21,197 Commercial 8,390 1 — — 8,391 Construction: Residential 10 — — — 10 Commercial 263 — — — 263 Total construction 273 — — — 273 Total $ 293,331 $ 12,408 $ 3,464 $ — $ 309,203
Analysis of Current and Past Due Loans	The following table shows the ending balance of current and past due originated loans by loan category as of the date indicated: Analysis of Originated Past Due Loans - As of June 30, 2018 (in thousands) 30-59 days 60-89 days > 90 days Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 271 $ 64 $ 1,219 $ 324,595 $ 326,149 $ — Commercial 1,281 577 792 1,803,180 1,805,830 — Total mortgage loans on real estate 1,552 641 2,011 2,127,775 2,131,979 — Consumer: Home equity lines of credit 158 37 47 270,041 270,283 — Home equity loans 358 150 486 37,088 38,082 — Other 33 26 — 21,362 21,421 — Total consumer loans 549 213 533 328,491 329,786 — Commercial 506 766 1,778 224,541 227,591 — Construction: Residential — — — 73,570 73,570 — Commercial 1,249 831 — 80,832 82,912 — Total construction 1,249 831 — 154,402 156,482 — Total originated loans $ 3,856 $ 2,451 $ 4,322 $ 2,835,209 $ 2,845,838 $ — The following table shows the ending balance of current and past due PNCI loans by loan category as of the date indicated: Analysis of PNCI Past Due Loans - As of June 30, 2018 (in thousands) 30-59 days 60-89 days > 90 days Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 59 $ 78 $ 36 $ 56,650 $ 56,823 $ — Commercial 356 164 — 202,403 202,923 — Total mortgage loans on real estate 415 242 36 259,053 259,746 — Consumer: Home equity lines of credit 182 — 77 14,319 14,578 — Home equity loans — 43 — 2,406 2,449 — Other 2 — — 2,037 2,039 — Total consumer loans 184 43 77 18,762 19,066 — Commercial — — — 7,555 7,555 — Construction: Residential — — — 8 8 — Commercial — — — 239 239 — Total construction — — — 247 247 — Total PNCI loans $ 599 $ 285 $ 113 $ 285,617 $ 286,614 $ — The following table shows the ending balance of current and past due originated loans by loan category as of the date indicated: Analysis of Originated Past Due Loans - As of December 31, 2017 (in thousands) 30-59 days 60-89 days > 90 days Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,740 $ 510 $ 243 $ 318,029 $ 320,522 $ — Commercial 158 987 — 1,689,365 1,690,510 — Total mortgage loans on real estate 1,898 1,497 243 2,007,394 2,011,032 — Consumer: Home equity lines of credit 528 48 372 268,994 269,942 — Home equity loans 511 107 373 38,857 39,848 — Other 56 36 3 22,764 22,859 — Total consumer loans 1,095 191 748 330,615 332,649 — Commercial 956 738 1,527 206,216 209,437 — Construction: Residential 34 — — 67,886 67,920 — Commercial — — — 69,364 69,364 — Total construction 34 — — 137,250 137,284 — Total loans $ 3,983 $ 2,426 $ 2,518 $ 2,681,475 $ 2,690,402 $ — The following table shows the ending balance of current and past due PNCI loans by loan category as of the date indicated: Analysis of PNCI Past Due Loans - As of December 31, 2017 (in thousands) 30-59 days 60-89 days > 90 days Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,495 $ 90 $ 109 $ 61,825 $ 63,519 $ 81 Commercial 70 — — 215,753 215,823 — Total mortgage loans on real estate 1,565 90 109 277,578 279,342 81 Consumer: Home equity lines of credit 298 228 330 15,392 16,248 200 Home equity loans 30 — — 2,668 2,698 — Other 6 26 — 2,219 2,251 — Total consumer loans 334 254 330 20,279 21,197 200 Commercial — — — 8,391 8,391 — Construction: Residential — — — 10 10 — Commercial — — — 263 263 — Total construction — — — 273 273 — Total loans $ 1,899 $ 344 $ 439 $ 306,521 $ 309,203 $ 281
Schedule of Non Accrual Loans	The following table shows the ending balance of nonaccrual originated and PNCI loans by loan category as of the date indicated: Non Accrual Loans As of June 30, 2018 As of December 31, 2017 (in thousands) Originated PNCI Total Originated PNCI Total Mortgage loans on real estate: Residential 1-4 $ 3,027 $ 1,082 $ 4,109 $ 1,725 $ 1,012 $ 2,737 Commercial 5,494 323 5,817 8,144 — 8,144 Total mortgage loans on real estate 8,521 1,405 9,926 9,869 1,012 10,881 Consumer: Home equity lines of credit 1,457 574 2,031 811 402 1,213 Home equity loans 4,419 36 4,455 1,106 44 1,150 Other 341 5 346 7 5 12 Total consumer loans 6,217 615 6,832 1,924 451 2,375 Commercial 2,339 — 2,339 3,669 — 3,669 Construction: Residential — — — — — — Commercial — — — — — — Total construction — — — — Total non accrual loans $ 17,077 $ 2,020 $ 19,097 $ 15,462 $ 1,463 $ 16,925
Impaired Loans	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, or for the Six Months Ended, June 30, 2018 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 5,656 $ 3,947 $ 1,050 $ 4,997 $ 147 $ 4,600 $ 76 Commercial 11,280 9,763 1,076 10,839 82 10,975 107 Total mortgage loans on real estate 16,936 13,710 2,126 15,836 229 15,575 183 Consumer: Home equity lines of credit 1,244 1,108 106 1,214 29 1,315 19 Home equity loans 2,558 1,828 351 2,179 38 1,784 20 Other 3 — 3 3 3 3 — Total consumer loans 3,805 2,936 460 3,396 70 3,102 39 Commercial 4,952 809 3,942 4,751 2,127 4,686 48 Construction: Residential — — — — — 68 — Commercial — — — — — — — Total construction — — — — — 68 — Total $ 25,693 $ 17,455 $ 6,528 $ 23,983 $ 2,426 $ 23,431 $ 270 Impaired PNCI Loans – As of, or for the Six Months Ended, June 30, 2018 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 family $ 1,417 $ 1,348 $ — $ 1,348 $ — $ 1,339 $ 10 Commercial 323 323 — 323 — 161 14 Total mortgage loans on real estate 1,740 1,671 — 1,671 — 1,500 24 Consumer: Home equity lines of credit 1,098 529 506 1,035 258 1,035 13 Home equity loans 293 36 242 278 154 281 6 Other 244 — 244 244 51 259 5 Total consumer loans 1,635 565 992 1,557 463 1,575 24 Commercial — — — — — — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total $ 3,375 $ 2,236 $ 992 $ 3,228 $ 463 $ 3,075 $ 48 Impaired Originated Loans – As of, or for the Twelve Months Ended, December 31, 2017 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 4,023 $ 2,058 $ 1,881 $ 3,939 $ 230 $ 3,501 $ 143 Commercial 14,186 13,101 810 13,911 30 13,851 645 Total mortgage loans on real estate 18,209 15,159 2,691 17,850 260 17,352 788 Consumer: Home equity lines of credit 1,581 1,093 401 1,494 111 1,702 47 Home equity loans 1,627 1,107 198 1,305 10 1,193 24 Other 52 4 3 7 3 20 — Total consumer loans 3,260 2,204 602 2,806 124 2,915 71 Commercial 4,566 575 3,895 4,470 1,848 4,283 184 Construction: Residential 140 140 — 140 — 76 9 Commercial — — — — — — — Total construction 140 140 — 140 — 76 9 Total $ 26,175 $ 18,078 $ 7,188 $ 25,266 $ 2,232 $ 24,626 $ 1,052 Impaired PNCI Loans – As of, or for the Twelve Months Ended, December 31, 2017 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 1,404 $ 1,359 $ — $ 1,359 $ $ 1,041 $ 24 Commercial — — — — 979 — Total mortgage loans on real estate 1,404 1,359 — 1,359 — 2,020 24 Consumer: Home equity lines of credit 1,216 591 603 1,194 316 1,240 48 Home equity loans 178 44 121 165 97 117 6 Other 250 — 250 250 54 186 11 Total consumer loans 1,644 635 974 1,609 467 1,543 65 Commercial — — — — — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total $ 3,048 $ 1,994 $ 974 $ 2,968 $ 467 $ 3,563 $ 89 Impaired Originated Loans – As of, or for the Six Months Ended, June 30, 2017 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 3,108 $ 1,623 $ 1,463 $ 3,086 $ 179 $ 1,417 $ 23 Commercial 13,203 11,864 803 12,667 45 724 18 Total mortgage loans on real estate 16,311 13,487 2,266 15,753 224 2,141 41 Consumer: Home equity lines of credit 1,746 1,305 331 1,636 66 380 — Home equity loans 1,633 836 395 1,231 68 440 10 Other 73 22 50 72 23 34 1 Total consumer loans 3,452 2,163 776 2,939 157 854 11 Commercial 3,053 1,007 1,737 2,744 863 2,536 27 Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total $ 22,816 $ 16,657 $ 4,779 $ 21,436 $ 1,244 $ 5,531 $ 79 Impaired PNCI Loans – As of, or for the Six Months Ended, June 30, 2017 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 1,665 $ 1,387 $ 253 $ 1,640 $ 75 $ 256 $ 5 Commercial 2,121 1,728 129 1,857 104 131 3 Total mortgage loans on real estate 3,786 3,115 382 3,497 179 387 8 Consumer: Home equity lines of credit 1,012 387 610 997 332 580 13 Home equity loans 64 54 — 54 — — — Other 251 — 251 251 68 185 5 Total consumer loans 1,327 441 861 1,302 400 765 18 Commercial — — — — — — — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total $ 5,113 $ 3,556 $ 1,243 $ 4,799 $ 579 $ 1,152 $ 26
Troubled Debt Restructurings	The following tables show certain information regarding Troubled Debt Restructurings (TDRs) that occurred during the periods indicated: TDR Information for the Three Months Ended June 30, 2018 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial Mortgage loans on real estate: Residential 1-4 — $ — $ — $ — — $ — $ — Commercial 1 34 34 34 — Total mortgage loans on real estate 1 34 34 34 — — — Consumer: Home equity lines of credit — — — — — — — Home equity loans — — — — — — — Other — — — — — — — Total consumer loans — — — — — — — Commercial 2 416 422 (2 ) 4 340 (2 ) Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total 3 $ 450 $ 456 $ 32 4 $ 340 $ (2 ) TDR Information for the Six Months Ended June 30, 2018 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial Mortgage loans on real estate: Residential 1-4 — $ $ — $ — $ $ Commercial 2 417 418 46 1 169 — Total mortgage loans on real estate 2 417 418 46 1 169 — Consumer: Home equity lines of credit 1 133 138 — — — — Home equity loans 1 121 121 — — — — Other — — — — — — — Total consumer loans 2 254 259 — — — — Commercial 2 416 422 (2 ) 4 340 (2 ) Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total 6 $ 1,087 $ 1,099 $ 44 5 $ 509 $ (2 ) The following tables show certain information regarding TDRs that occurred during the periods indicated: TDR Information for the Three Months Ended June 30, 2017 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial Mortgage loans on real estate: Residential 1-4 — $ $ — $ — — $ — $ — Commercial 3 623 596 (125 ) — — — Total mortgage loans on real estate 3 623 596 (125 ) — — — Consumer: Home equity lines of credit 2 167 167 27 — — — Home equity loans — — — — — — — Other — — — — — — — Total consumer loans 2 167 167 27 — — — Commercial 2 645 539 (84 ) — — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — Total 7 $ 1,435 $ 1,302 $ (182 ) — $ — $ — TDR Information for the Six Months Ended June 30, 2017 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial Mortgage loans on real estate: Residential 1-4 — $ — $ — $ — — $ — $ — Commercial 3 623 596 (125 ) 1 124 — Total mortgage loans on real estate 3 623 596 (125 ) 1 124 — Consumer: Home equity lines of credit 3 187 187 27 — — — Home equity loans — — — — — — — Other 1 14 14 11 — — — Total consumer loans 4 201 201 38 — — — Commercial 3 745 639 10 — Construction: Residential — — — — — — — Commercial — — — — — — Total construction — — — — — — Total 10 $ 1,569 $ 1,436 $ (77 ) 1 $ 124 $ —

Foreclosed Assets (Tables)

Foreclosed Assets (Tables)	6 Months Ended
	Jun. 30, 2018
Text Block [Abstract]
Summary of Activity in Balance of Foreclosed Assets	A summary of the activity in the balance of foreclosed assets follows (in thousands): Six months ended Six months ended June 30, 2017 Total Noncovered Covered Total Beginning balance, net $ 3,226 $ 3,763 $ 223 $ 3,986 Additions/transfers from loans — 684 — 684 Dispositions/sales (1,762 ) (930 ) (223 ) (1,153 ) Valuation adjustments (90 ) (28 ) — (28 ) Ending balance, net $ 1,374 $ 3,489 — $ 3,489 Ending valuation allowance $ (152 ) $ (179 ) — $ (179 ) Ending number of foreclosed assets 8 12 — 12 Proceeds from sale of foreclosed assets $ 2,150 $ 1,424 $ — $ 1,424 Gain on sale of foreclosed assets $ 388 $ 271 $ — $ 271

Premises and Equipment (Tables)

Premises and Equipment (Tables)	6 Months Ended
	Jun. 30, 2018
Property, Plant and Equipment [Abstract]
Summary of Premises and Equipment	Premises and equipment were comprised of: June 30, December 31, 2018 2017 (In thousands) Land & land improvements $ 9,973 $ 9,959 Buildings 51,065 50,340 Furniture and equipment 38,172 35,939 99,210 96,238 Less: Accumulated depreciation (42,066 ) (40,644 ) 57,144 55,594 Construction in progress 1,870 2,148 Total premises and equipment $ 59,014 $ 57,742

Cash Value of Life Insurance (T

Cash Value of Life Insurance (Tables)	6 Months Ended
	Jun. 30, 2018
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 (in thousands): Six months ended June 30, 2018 2017 Beginning balance $ 97,783 $ 95,912 Increase in cash value of life insurance 1,264 1,311 Gain on death benefit — 108 Insurance proceeds receivable reclassified to other assets — (921 ) Ending balance $ 99,047 $ 96,410 End of period death benefit $ 164,649 $ 166,318 Number of policies owned 182 183 Insurance companies used 13 14 Current and former employees and directors covered 57 57

Goodwill and Other Intangible45

Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill Intangible	The following table summarizes the Company’s goodwill intangible as of the dates indicated: (in thousands) June 30, Additions Reductions December 31, Goodwill $ 64,311 — — $ 64,311
Summary of Core Deposit Intangibles	The following table summarizes the Company’s core deposit intangibles as of the dates indicated: (in thousands) June 30, Additions Reductions/ December 31, Core deposit intangibles $ 9,558 — — $ 9,558 Accumulated amortization (5,062 ) — $ (678 ) (4,384 ) Core deposit intangibles, net $ 4,496 — $ (678 ) $ 5,174
Remaining Estimated Core Deposit Intangible Amortization	The following table summarizes the Company’s remaining estimated core deposit intangible amortization at December 31, 2017 (dollars in thousands): Years Ended Estimated Core Deposit 2018 $ 1,324 2019 1,228 2020 1,228 2021 969 2022 280 Thereafter 145

Mortgage Servicing Rights (Tabl

Mortgage Servicing Rights (Tables)	6 Months Ended
	Jun. 30, 2018
Text Block [Abstract]
Fair Value of Mortgage Servicing Rights	The following tables summarize the activity in, and the main assumptions used to determine the fair value of mortgage servicing rights (“MSRs”) for the periods indicated (dollars in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Balance at beginning of period $ 6,953 $ 6,860 $ 6,687 $ 6,595 Additions 104 193 259 471 Change in fair value (36 ) (457 ) 75 (470 ) Balance at end of period $ 7,021 $ 6,596 $ 7,021 $ 6,596 Contractually specified servicing fees, late fees and ancillary fees earned $ 511 $ 526 $ 1,028 $ 1,047 Balance of loans serviced at: Beginning of period $ 806,178 $ 822,506 $ 811,065 $ 816,623 End of period $ 801,817 $ 822,549 $ 801,817 $ 822,549 Period end: Weighted-average prepayment speed (CPR) 7.4 % 8.7 % Weighted-average discount rate 12.5 % 14 %

Indemnification Asset (Tables)

Indemnification Asset (Tables)	6 Months Ended
	Jun. 30, 2018
Text Block [Abstract]
Summary of Activity in Balance of Indemnification Asset (Liability)	A summary of the activity in the balance of indemnification asset (liability) follows (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Beginning balance — $ (895 ) — $ (744 ) Effect of actual and estimated future covered losses and recoveries — (1 ) — (224 ) Payments made to (received from) FDIC — 184 — 256 Gain on termination of loss share agreement — 712 — 712 Ending balance — $ — — $ —

Other Assets (Tables)

Other Assets (Tables)	6 Months Ended
	Jun. 30, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Other Assets	Other assets were comprised of (in thousands): June 30, December 31, Deferred tax asset, net $ 27,665 $ 21,697 Investment in low income housing tax credit funds 16,672 16,854 Prepaid expense 4,097 4,111 Tax refund receivable 4,754 4,754 Capital trusts 1,710 1,706 Software 793 1,126 Life insurance proceeds receivable — 2,242 Miscellaneous other assets 1,718 2,561 Total other assets $ 57,409 $ 55,051

Deposits (Tables)

Deposits (Tables)	6 Months Ended
	Jun. 30, 2018
Banking and Thrift [Abstract]
Summary of Balances of Deposits	A summary of the balances of deposits follows (in thousands): June 30, December 31, Noninterest-bearing demand $ 1,369,834 $ 1,368,218 Interest-bearing demand 1,006,331 971,459 Savings 1,385,268 1,364,518 Time certificates, over $250,000 84,015 73,596 Other time certificates 231,774 231,340 Total deposits $ 4,077,222 $ 4,009,131

Reserve for Unfunded Commitme50

Reserve for Unfunded Commitments (Tables)	6 Months Ended
	Jun. 30, 2018
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): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Balance at beginning of period $ 3,864 $ 2,734 $ 3,164 $ 2,719 Provision (reversal of provision) for losses – unfunded commitments (137 ) (135 ) 563 (120 ) Balance at end of period $ 3,727 $ 2,599 $ 3,727 $ 2,599

Other Liabilities (Tables)

Other Liabilities (Tables)	6 Months Ended
	Jun. 30, 2018
Other Liabilities Disclosure [Abstract]
Components of Other Liabilities	Other liabilities were comprised of (in thousands): June 30, December 31, Pension liability $ 28,880 $ 28,472 Low income housing tax credit fund commitments 5,969 8,554 Deferred compensation 6,932 6,605 Taxes payable 1,267 — Accrued salaries and benefits expense 5,014 6,619 Joint beneficiary agreements 3,494 3,365 Loan escrow and servicing payable 2,295 1,958 Deferred revenue 1,449 1,228 Litigation contingency — 1,450 Miscellaneous other liabilities 3,596 5,007 Total other liabilities $ 58,896 $ 63,258

Other Borrowings (Tables)

Other Borrowings (Tables)	6 Months Ended
	Jun. 30, 2018
Text Block [Abstract]
Summary of Balances of Other Borrowings	A summary of the balances of other borrowings follows: June 30, December 31, (in thousands) FHLB collateralized borrowing, fixed rate, as of June 30, 2018 of 2.05%, payable on July 2, 2018 $ 136,020 $ — FHLB collateralized borrowing, fixed rate, as of December 31, 2017 of 1.38%, payable on January 2, 2018 — 104,729 Other collateralized borrowings, fixed rate, as of June 30, 2018 and December 31, 2017 of 0.05%, payable on July 2, 2018 and January 2, 2018, respectively 16,819 17,437 Total other borrowings $ 152,839 $ 122,166

Junior Subordinated Debt (Table

Junior Subordinated Debt (Tables)	6 Months Ended
	Jun. 30, 2018
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): Coupon Rate As of June 30, 2018 December 31, 2017 Maturity Face (Variable) Current Recorded Recorded Subordinated Debt Series Date Value 3 mo. LIBOR + Coupon Rate Book Value Book Value TriCo Cap Trust I 10/7/2033 $ 20,619 3.05 % 5.40 % $ 20,619 $ 20,619 TriCo Cap Trust II 7/23/2034 20,619 2.55 % 4.91 % 20,619 20,619 North Valley Trust II 4/24/2033 6,186 3.25 % 5.61 % 5,154 5,135 North Valley Trust III 4/24/2034 5,155 2.80 % 5.16 % 4,060 4,041 North Valley Trust IV 3/15/2036 10,310 1.33 % 3.67 % 6,498 6,444 $ 62,889 $ 56,950 $ 56,858

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2018
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, 2017, future minimum commitments under non-cancelable Operating Leases (in thousands) 2018 $ 3,278 2019 2,499 2020 1,847 2021 1,488 2022 757 Thereafter 798 Future minimum lease payments $ 10,667
Summary of Bank's Commitments and Contingent Liabilities	The following table presents a summary of the Bank’s commitments and contingent liabilities: (in thousands) June 30, December 31, Financial instruments whose amounts represent risk: Commitments to extend credit: Commercial loans $ 266,538 $ 257,220 Consumer loans 443,265 422,958 Real estate mortgage loans 61,185 66,267 Real estate construction loans 223,956 187,097 Standby letters of credit 11,535 13,075 Deposit account overdraft privilege 97,670 98,260

Stock Options and Other Equit55

Stock Options and Other Equity-Based Incentive Instruments (Tables)	6 Months Ended
	Jun. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Activity	Stock option activity during the six months ended June 30, 2018 is summarized in the following table: Number Option Price Weighted Value on Weighted Outstanding at December 31, 2017 446,400 $12.63 to $23.21 $ 16.84 Options granted — — to — — Options exercised (14,500 ) $15.40 to $15.40 $ 15.40 Options forfeited (3,000 ) $23.21 to $23.21 $ 23.21 Outstanding at June 30, 2018 428,900 $12.63 to $23.21 $ 16.85
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 June 30, 2018: Currently Currently Not Total Number of options 425,900 3,000 428,900 Weighted average exercise price $ 16.80 $ 23.21 $ 16.85 Intrinsic value (in thousands) $ 8,794 $ 43 $ 8,837 Weighted average remaining contractual term (yrs.) 3.5 6.3 3.5
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 Outstanding at December 31, 2017 68,457 52,829 RSUs granted 26,939 $ 39.31 16,939 $ 36.40 Additional market plus service condition RSUs vested — 8,506 RSUs added through dividend credits 545 — RSUs released through vesting (25,398 ) (25,512 ) RSUs forfeited/expired (907 ) (970 ) Outstanding at June 30, 2018 69,636 51,792

Noninterest Income and Expense

Noninterest Income and Expense (Tables)	6 Months Ended
	Jun. 30, 2018
Other Income and Expenses [Abstract]
Components of Other Noninterest Income	The following table summarizes the Company’s noninterest income for the periods indicated (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Service charges on deposit accounts $ 3,613 $ 4,323 $ 7,392 $ 7,942 ATM and interchange fees 4,510 4,248 8,745 8,263 Other service fees 630 839 1,344 1,604 Mortgage banking service fees 511 526 1,028 1,047 Change in value of mortgage servicing rights (36 ) (457 ) 75 (470 ) Total service charges and fees 9,228 9,479 18,584 18,386 Commissions on sale of non-deposit 810 705 1,686 1,312 Gain on sale of loans 666 777 1,292 1,687 Increase in cash value of life insurance 656 626 1,264 1,311 Gain on sale of foreclosed assets 17 153 388 271 Lease brokerage income 200 161 328 367 Sale of customer checks 138 94 239 198 Change in indemnification asset — 711 — 490 Life insurance proceeds in excess of cash value — — — 108 Loss on disposal of fixed assets (41 ) (28 ) (54 ) (28 ) Loss on marketable equity securities (23 ) — (70 ) — Other 523 232 807 511 Total other noninterest income 2,946 3,431 5,880 6,227 Total noninterest income $ 12,174 $ 12,910 $ 24,464 $ 24,613
Components of Noninterest Expense	The components of noninterest expense were as follows (in thousands): Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Base salaries, net of deferred loan origination costs $ 14,429 $ 13,657 $ 28,391 $ 27,047 Incentive compensation 2,159 2,173 4,611 4,371 Benefits and other compensation costs 4,865 4,664 10,103 9,969 Total salaries and benefits expense 21,453 20,494 43,105 41,387 Occupancy 2,720 2,705 5,401 5,397 Data processing and software 2,679 2,441 5,193 4,837 Equipment 1,637 1,805 3,188 3,528 ATM and POS network charges 1,437 1,075 2,663 1,928 Advertising 1,035 1,167 1,873 2,134 Professional fees 774 690 1,546 1,456 Telecommunications 681 668 1,382 1,311 Change in reserve for unfunded commitments (137 ) (135 ) 563 (120 ) Merger and acquisition expense 601 — 1,077 — Assessments 417 420 847 825 Postage 301 329 659 733 Intangible amortization 339 352 678 711 Operational losses 252 430 546 865 Courier service 224 263 491 517 Provision for foreclosed asset losses — 94 90 28 Foreclosed assets expense 180 38 204 76 Other miscellaneous expense 3,277 3,068 6,526 6,113 Total other noninterest expense 16,417 15,410 32,927 30,339 Total noninterest expense $ 37,870 $ 35,904 $ 76,032 $ 71,726 Merger and acquisition expense: Occupancy $ 49 $ — $ 49 $ — Equipment 11 — 11 — Professional fees 196 — 552 — Advertising and marketing 164 — 172 — Postage 7 — 7 — Other miscellaneous expense 174 — 286 — Total merger and acquisition expense $ 601 $ — $ 1,077 $ —

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Reconciliation of Effective Tax Rate and Statutory Federal Income Tax Rate	The effective tax rate and the statutory federal income tax rate are reconciled for the periods indicated as follows: Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 Federal statutory income tax rate 21.0 % 35.0 % 21.0 % 35.0 % State income taxes, net of federal tax benefit 8.8 6.6 8.9 6.7 Tax-exempt (1.0 ) (1.7 ) (1.1 ) (1.8 ) Increase in cash value of insurance policies (0.7 ) (1.0 ) (0.7 ) (1.2 ) Low income housing tax credits (0.6 ) (0.7 ) (0.8 ) (0.7 ) Equity compensation (0.4 ) (2.1 ) (0.2 ) (1.3 ) Nondeductible merger expenses 0.3 — 0.3 — Other 0.4 (0.1 ) 0.5 0.2 Effective Tax Rate 27.8 % 36.0 % 27.9 % 36.9 %

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Computation of Earnings Per Share	Earnings per share have been computed based on the following: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 Net income $ 15,029 $ 13,589 $ 28,939 $ 25,668 Average number of common shares outstanding 22,983 22,900 22,970 22,885 Effect of dilutive stock options and restricted stock 293 340 310 351 Average number of common shares outstanding used to calculate diluted earnings per share 23,276 23,240 23,280 23,236 Options excluded from diluted earnings per share because the effect of these options was antidilutive — — — —

Comprehensive Income (Tables)

Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Components of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive loss, included in shareholders’ equity, are as follows: (in thousands) June 30, December 31, Net unrealized loss on available for sale securities $ (24,651 ) (3,409 ) Tax effect 7,288 1,433 Unrealized holding loss on available for sale securities, net of tax (17,363 ) (1,976 ) Unfunded status of the supplemental retirement plans (5,124 ) (5,352 ) Tax effect 1,514 2,250 Unfunded status of the supplemental retirement plans, net of tax (3,610 ) (3,102 ) Joint beneficiary agreement liability (150 ) (150 ) Tax effect — Joint beneficiary agreement liability, net of tax (150 ) (150 ) Accumulated other comprehensive loss $ (21,123 ) $ (5,228 )
Components of Other Comprehensive Income (Loss) and Related Tax Effects	The components of other comprehensive income (loss) and related tax effects are as follows: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 Unrealized holding gains (losses) on available for sale securities before reclassifications $ (5,676 ) $ 4,911 $ (20,941 ) $ 5,698 Amounts reclassified out of accumulated other comprehensive income: Adoption ASU 2016-01 — — 62 — Adoption ASU 2018-02 — — (425 ) — Total amounts reclassified out of accumulated other comprehensive income — — (363 ) — Unrealized holding gains (losses) on available for sale securities after reclassifications (5,676 ) 4,911 (21,304 ) 5,698 Tax effect 1,678 (2,065 ) 6,280 (2,395 ) Unrealized holding gains (losses) on available for sale securities, net of tax (3,998 ) 2,846 (15,024 ) 3,303 Change in unfunded status of the supplemental retirement plans before reclassifications — — 668 — Amounts reclassified out of accumulated other comprehensive income: Amortization of prior service cost (13 ) (1 ) (27 ) (4 ) Amortization of actuarial losses 127 96 254 192 Adoption ASU 2018-02 — — (668 ) — Total amounts reclassified out of accumulated other comprehensive income 114 95 (441 ) 188 Change in unfunded status of the supplemental retirement plans after reclassifications 114 95 227 188 Tax effect (34 ) (40 ) (67 ) (79 ) Change in unfunded status of the supplemental retirement plans, net of tax 80 55 160 109 Change in joint beneficiary agreement liability before reclassifications — — — — Amounts reclassified out of accumulated other comprehensive income — — — — Change in joint beneficiary agreement liability after reclassifications — — — Tax effect — — — — Change in joint beneficiary agreement liability, net of tax — — — — Total other comprehensive income (loss) $ (3,918 ) $ 2,901 $ (14,864 ) $ 3,412

Retirement Plans (Tables)

Retirement Plans (Tables)	6 Months Ended
	Jun. 30, 2018
Retirement Benefits [Abstract]
Summary of 401(k) Contribution Plan	The following table sets forth the benefit expense attributable to the 401(k) Plan matching contributions, and the contributions made by the Company to the 401(k) Plan during the periods indicated: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 401(k) Plan benefits expense $ 251 $ 194 $ 454 $ 380 401(k) Plan contributions made by the Company $ 247 $ 192 $ 446 $ 371
Summary of ESOP Activities	The following table sets forth the benefit expense attributable to the ESOP, and the contributions made by the Company to the ESOP during the periods indicated: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 ESOP benefits expense $ 475 $ 540 $ 940 $ 1,065 ESOP contributions made by the Company $ 940 $ 1,073 $ 1,479 $ 1,536
Schedule of Deferred Compensation Earnings Credits Included in Noninterest Expense	The following table sets forth the earnings credits on deferred balances included in noninterest expense during the periods indicated: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 Deferred compensation earnings credits included in noninterest expense $ 121 $ 109 $ 245 $ 254
Net Periodic Benefit Cost Recognized for Supplemental Retirement Plans	The following table sets forth the net periodic benefit cost recognized for the plans: Three months ended June 30, Six months ended June 30, (in thousands) 2018 2017 2018 2017 Net pension cost included the following components: Service cost-benefits earned during the period $ 243 $ 235 $ 486 $ 470 Interest cost on projected benefit obligation 237 248 475 496 Amortization of net obligation at transition — 1 1 1 Amortization of prior service cost (13 ) (3 ) (27 ) (6 ) Recognized net actuarial loss 127 97 254 195 Net periodic pension cost $ 594 $ 578 $ 1,189 $ 1,156 Company contributions to pension plans $ 287 $ 329 $ 554 $ 588 Pension plan payouts to participants $ 287 $ 329 $ 554 $ 588

Related Party Transactions (Tab

Related Party Transactions (Tables)	6 Months Ended
	Jun. 30, 2018
Related Party Transactions [Abstract]
Summary of Activity in Lending Transactions	The following table summarizes the activity in these loans for periods indicated (in thousands): Balance December 31, 2016 $ 2,432 Advances/new loans 437 Removed/payments (721 ) Balance December 31, 2017 2,148 Advances/new loans 145 Removed/payments (480 ) Balance June 30, 2018 $ 1,813

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	6 Months Ended
	Jun. 30, 2018
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 June 30, 2018 Total Level 1 Level 2 Level 3 Marketable equity securities $ 2,868 $ 2,868 $ — $ — Debt securities available for sale: Obligations of U.S. government corporations and agencies 635,428 — 635,428 — Obligations of states and political subdivisions 118,779 — 118,779 — Mortgage servicing rights 7,021 — — 7,021 Total assets measured at fair value $ 764,096 $ 2,868 $ 754,207 $ 7,021 Fair value at December 31, 2017 Total Level 1 Level 2 Level 3 Marketable equity securities $ 2,938 $ 2,938 $ — $ — Debt securities available for sale: Obligations of U.S. government corporations and agencies 604,789 — 604,789 — Obligations of states and political subdivisions 123,156 — 123,156 — Mortgage servicing rights 6,687 — — 6,687 Total assets measured at fair value $ 737,570 $ 2,938 $ 727,945 $ 6,687
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 time periods indicated. Had there been any transfer into or out of Level 3 during the time periods indicated, 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): Three months ended June 30, Beginning Transfers Change Issuances Ending 2018: Mortgage servicing rights $ 6,953 — $ (36 ) $ 104 $ 7,021 2017: Mortgage servicing rights $ 6,860 — $ (457 ) $ 193 $ 6,596 Six months ended June 30, Beginning Transfers Change Issuances Ending 2018: Mortgage servicing rights $ 6,687 — $ 75 $ 259 $ 7,021 2017: Mortgage servicing rights $ 6,595 — $ (470 ) $ 471 $ 6,596
Quantitative Information about Recurring Level 3 Fair Value Measurements	The following table presents quantitative information about recurring Level 3 fair value measurements at June 30, 2018: Fair Value Valuation Unobservable Inputs Range, Mortgage Servicing Rights $ 7,021 Discounted Constant 4.9%-27.7%, 7.4% Discount rate 12.5%-13.5%, 12.5% The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2017: Fair Value Valuation Unobservable Inputs Range, Mortgage Servicing Rights $ 6,687 Discounted Constant 6.2%-22.0%, 8.9% Discount rate 13.0%-15.0%, 13.0%
Assets and Liabilities Measured at Fair Value on Nonrecurring Basis	The tables below present the recorded investment in assets and liabilities measured at fair value on a nonrecurring basis, as of the dates indicated (in thousands): Six months ended June 30, 2018 Total Level 1 Level 2 Level 3 Total Gains Fair value: Impaired Originated & PNCI loans $ 1,647 — — $ 1,647 $ (505 ) Foreclosed assets 584 — — 584 (90 ) Total assets measured at fair value $ 2,231 — — $ 2,231 $ (595 ) Year ended December 31, 2017 Total Level 1 Level 2 Level 3 Total Gains Fair value: Impaired Originated & PNCI loans $ 2,767 — — $ 2,767 $ (1,452 ) Foreclosed assets 2,217 — — 2,217 (135 ) Total assets measured at fair value $ 4,984 — — $ 4,984 $ (1,587 ) Six months ended June 30, 2017 Total Level 1 Level 2 Level 3 Total Gains Fair value: Impaired Originated & PNCI loans $ 686 — — $ 686 $ (456 ) Foreclosed assets 1,103 — — 1,103 (28 ) Total assets measured at fair value $ 1,789 — — $ 1,789 $ (484 )
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 June 30, 2018: June 30, 2018 Fair Value Valuation Unobservable Inputs Range, Impaired Originated & PNCI loans $ 1,647 Sales comparison Income approach Adjustment for differences (70%) - 60%; (7.41%) N/A Foreclosed assets (Land & construction) $ 492 Sales comparison Adjustment for differences (47%) - 39%; 3.64% Foreclosed assets (Residential real estate) $ 92 Sales comparison Adjustment for differences (65%) - 20%; (45%) 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, 2017: December 31, 2017 Fair Value Valuation Unobservable Inputs Range, Impaired Originated & PNCI loans $ 2,767 Sales comparison Adjustment for differences (74%) - 23%; N/A Foreclosed assets (Land & construction) $ 1,341 Sales comparison Adjustment for differences (53%) - 283%; 167% Foreclosed assets (Residential real estate) $ 622 Sales comparison Adjustment for differences (47%) - 39%; (3.13%) Foreclosed assets (Commercial real estate) $ 254 Sales comparison Adjustment for differences (84%) - 19%; (84%)
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): June 30, 2018 December 31, 2017 Carrying Fair Carrying Fair Financial assets: Level 1 inputs: Cash and due from banks $ 94,661 $ 94,661 $ 105,968 $ 105,968 Cash at Federal Reserve and other banks 89,401 89,401 99,460 99,460 Level 2 inputs: Securities held to maturity 477,745 468,621 514,844 518,165 Restricted equity securities 16,956 N/A 16,956 N/A Loans held for sale 3,601 3,601 4,616 4,616 Level 3 inputs: Loans, net 3,116,789 3,091,134 2,984,842 2,992,225 Financial liabilities: Level 2 inputs: Deposits 4,077,222 4,073,628 4,009,131 4,006,620 Other borrowings 152,839 152,839 122,166 122,166 Level 3 inputs: Junior subordinated debt 56,950 58,930 56,858 58,466 Contract Fair Contract Fair Off-balance Level 3 inputs: Commitments $ 994,944 $ 9,949 $ 933,542 $ 9,335 Standby letters of credit 11,535 115 13,075 131 Overdraft privilege commitments 97,670 977 98,260 983

TriCo Bancshares Condensed Fi63

TriCo Bancshares Condensed Financial Statements (Parent Only) (Tables)	6 Months Ended
	Jun. 30, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets June 30, December 31, 2018 2017 (In thousands) Assets Cash and cash equivalents $ 3,069 $ 3,924 Investment in Tri Counties Bank 565,047 557,538 Other assets 1,742 1,721 Total assets $ 569,858 $ 563,183 Liabilities and shareholders’ equity Other liabilities $ 564 $ 517 Junior subordinated debt 56,950 56,858 Total liabilities 57,514 57,375 Shareholders’ equity: Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at June 30, 2018 and December 31, 2017 — — Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 23,004,153 and 22,955,963 shares, respectively 256,590 255,836 Retained earnings 276,877 255,200 Accumulated other comprehensive loss, net (21,123 ) (5,228 ) Total shareholders’ equity 512,344 505,808 Total liabilities and shareholders’ equity $ 569,858 $ 563,183
Condensed Statements of Income	Condensed Statements of Income Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 (In thousands) (In thousands) Interest expense $ (789 ) $ (623 ) $ (1,486 ) $ (1,218 ) Administration expense (511 ) (218 ) (937 ) (377 ) Loss before equity in net income of Tri Counties Bank (1,300 ) (841 ) (2,423 ) (1,595 ) Equity in net income of Tri Counties Bank: Distributed 4,770 5,167 9,142 9,209 Undistributed 11,253 8,909 21,650 17,383 Income tax benefit 306 354 570 671 Net income $ 15,029 $ 13,589 $ 28,939 $ 25,668
Condensed Statements of Comprehensive Income	Condensed Statements of Comprehensive Income Three months ended June 30, Six months ended June 30, 2018 2017 2018 2017 (In thousands) (In thousands) Net income $ 15,029 $ 13,589 $ 28,939 $ 25,668 Other comprehensive income (loss), net of tax: Increase (decrease) in unrealized gains on available for sale securities arising during the period (3,998 ) 2,846 (15,024 ) 3,303 Change in minimum pension liability 80 55 160 109 Other comprehensive income (loss) (3,918 ) 2,901 (14,864 ) 3,412 Comprehensive income $ 11,111 $ 16,490 $ 14,075 $ 29,080
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows Six months ended June 30, 2018 2017 (In thousands) Operating activities: Net income $ 28,939 $ 25,668 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed equity in earnings of Tri Counties Bank (21,650 ) (17,383 ) Equity compensation vesting expense 722 774 Net change in other assets and liabilities (605 ) (672 ) Net cash provided by operating activities 7,406 8,387 Investing activities: None Financing activities: Issuance of common stock through option exercise 185 192 Repurchase of common stock (633 ) (1,121 ) Cash dividends paid — common (7,813 ) (7,328 ) Net cash used for financing activities (8,261 ) (8,257 ) Net change in cash and cash equivalents (855 ) 130 Cash and cash equivalents at beginning of year 3,924 2,802 Cash and cash equivalents at end of year $ 3,069 $ 2,932

Regulatory Matters (Tables)

Regulatory Matters (Tables)	6 Months Ended
	Jun. 30, 2018
Banking and Thrift [Abstract]
Actual and Required Capital Ratios of Bank	The following tables present actual and required capital ratios as of June 30, 2018 and December 31, 2017 for the Company and the Bank under Basel III Capital Rules. The minimum capital amounts presented include the minimum required capital levels as of June 30, 2018 and December 31, 2017 based on the then phased-in phased-in. Actual Minimum Capital Phase-in Minimum Capital Required to be Amount Ratio Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) As of June 30, 2018: Total Capital (to Risk Weighted Assets): Consolidated $ 550,769 13.91 % $ 390,991 9.875 % $ 415,737 10.50 % N/A N/A Tri Counties Bank $ 548,232 13.85 % $ 390,819 9.875 % $ 415,554 10.50 % $ 395,766 10.00 % Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 517,518 13.07 % $ 311,803 7.875 % $ 336,549 8.50 % N/A N/A Tri Counties Bank $ 514,981 13.01 % $ 311,666 7.875 % $ 336,401 8.50 % $ 316,613 8.00 % Common equity Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 462,278 11.68 % $ 252,412 6.375 % $ 277,158 7.00 % N/A N/A Tri Counties Bank $ 514,981 13.01 % $ 252,301 6.375 % $ 277,036 7.00 % $ 257,248 6.50 % Tier 1 Capital (to Average Assets): Consolidated $ 517,518 10.92 % $ 189,647 4.000 % $ 189,647 4.00 % N/A N/A Tri Counties Bank $ 514,981 10.86 % $ 189,643 4.000 % $ 189,643 4.00 % $ 237,054 5.00 % Actual Minimum Capital Phase-in Minimum Capital Required to be Amount Ratio Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) As of December 31, 2017: Total Capital (to Risk Weighted Assets): Consolidated $ 528,805 14.07 % $ 347,694 9.25 % $ 394,679 10.50 % N/A N/A Tri Counties Bank $ 525,384 13.98 % $ 347,535 9.25 % $ 394,499 10.50 % $ 375,713 10.00 % Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 495,318 13.18 % $ 272,517 7.25 % $ 319,502 8.50 % N/A N/A Tri Counties Bank $ 491,897 13.09 % $ 272,392 7.25 % $ 319,356 8.50 % $ 300,570 8.00 % Common equity Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 440,643 11.72 % $ 216,134 5.75 % $ 263,120 7.00 % N/A N/A Tri Counties Bank $ 491,897 13.09 % $ 216,035 5.75 % $ 262,999 7.00 % $ 244,214 6.50 % Tier 1 Capital (to Average Assets): Consolidated $ 495,318 10.80 % $ 183,400 4.00 % $ 183,400 4.00 % N/A N/A Tri Counties Bank $ 491,897 10.73 % $ 183,394 4.00 % $ 183,394 4.00 % $ 229,243 5.00 %
Results of Operations	The following table sets forth the results of operations for the periods indicated, 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. 2018 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 $ 180 $ 246 Discount accretion PCI – other 95 60 Discount accretion PNCI 284 326 All other loan interest income 38,745 37,417 Total loan interest income 39,304 38,049 Debt securities, dividends and interest bearing cash at banks (not FTE) 9,174 9,072 Total interest income 48,478 47,121 Interest expense 2,609 2,135 Net interest income 45,869 44,986 (Benefit from reversal of) provision for loan losses (638 ) (236 ) Net interest income after provision for loan losses 46,507 45,222 Noninterest income 12,174 12,290 Noninterest expense 37,870 38,162 Income before income taxes 20,811 19,350 Income tax expense 5,782 5,440 Net income $ 15,029 $ 13,910 Per common share: Net income (diluted) $ 0.65 $ 0.60 Dividends $ 0.17 $ 0.17 2017 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 $ 516 $ 398 $ 386 $ 112 Discount accretion PCI – other 445 407 797 631 Discount accretion PNCI 528 559 987 798 All other loan interest income 36,705 35,904 34,248 33,373 Total loan interest income 38,194 37,268 36,418 34,914 Debt securities, dividends and interest bearing cash at banks (not FTE) 8,767 8,645 8,626 8,570 Total interest income 46,961 45,913 45,044 43,484 Interest expense 1,868 1,829 1,610 1,491 Net interest income 45,093 44,084 43,434 41,993 Provision for (benefit from reversal of provision for) loan losses 1,677 765 (796 ) (1,557 ) Net interest income after provision for loan losses 43,416 43,319 44,230 43,550 Noninterest income 12,478 12,930 12,910 11,703 Noninterest expense 38,076 37,222 35,904 35,822 Income before income taxes 17,818 19,027 21,236 19,431 Income tax expense 14,829 7,130 7,647 7,352 Net income $ 2,989 $ 11,897 $ 13,589 $ 12,079 Per common share: Net income (diluted) $ 0.13 $ 0.51 $ 0.58 $ 0.52 Dividends $ 0.17 $ 0.17 $ 0.17 $ 0.15

Summary of Significant Accoun65

Summary of Significant Accounting Policies - Additional Information (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018USD ($)Office	Jun. 30, 2017	Jun. 30, 2018USD ($)OfficeSegmentLocationTrustBranchBusiness	Jun. 30, 2017	Dec. 31, 2017USD ($)	Jan. 01, 2018USD ($)
Significant Of Accounting Policies [Line Items]
Number of subsidiary business trusts | Trust			5
Number of loan production offices | Office	2		2
Company's investments in the trusts	$ 1,710,000		$ 1,710,000
Number of business segment | Segment			1
Marketable securities recorded	$ 2,868,000		$ 2,868,000		$ 2,938,000
Unrealized losses recognized in condensed consolidated statements of income			70,000
OTTI losses due to debt securities			$ 0		$ 0
Loans contractual past due			90 days
TDR loans payment period in nonaccrual status			6 months
Federal statutory income tax rate	21.00%	35.00%	21.00%	35.00%	35.00%
Tri Counties Bank [Member]
Significant Of Accounting Policies [Line Items]
Number of locations acquired | Location			3
Number of traditional operating branches | Branch			57
Number of in-store operating branches | Branch			9
California [Member]
Significant Of Accounting Policies [Line Items]
Number of counties | Business			26
ASU 2016-02 [Member] | Assets, Total [Member]
Significant Of Accounting Policies [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification			$ 24,000,000
ASU 2016-02 [Member] | Liabilities, Total [Member]
Significant Of Accounting Policies [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification			24,000,000
ASU 2016-01 [Member] | Deferred Tax Assets [Member]
Significant Of Accounting Policies [Line Items]
New accounting pronouncement or change in accounting principle cumulative effect of change on equity or net assets						$ (18,000)
ASU 2016-01 [Member] | Retained Earnings [Member]
Significant Of Accounting Policies [Line Items]
New accounting pronouncement or change in accounting principle cumulative effect of change on equity or net assets						(62,000)
ASU 2018-02 [Member] | Retained Earnings [Member]
Significant Of Accounting Policies [Line Items]
New accounting pronouncement or change in accounting principle cumulative effect of change on equity or net assets						1,093,000
ASU 2018-02 [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Significant Of Accounting Policies [Line Items]
New accounting pronouncement or change in accounting principle cumulative effect of change on equity or net assets						$ (1,093,000)
Trading Debt Securities [Member]
Significant Of Accounting Policies [Line Items]
Trading debt securities	$ 0		$ 0		$ 0
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 - Additio

Business Combinations - Additional Information (Detail)	Jul. 10, 2018USD ($)	Jul. 06, 2018USD ($)$ / sharesshares	Jun. 30, 2018USD ($)shares	Jun. 30, 2017USD ($)shares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016shares	Aug. 21, 2007shares
Business Acquisition [Line Items]
Common stock, shares outstanding | shares			23,004,153		22,955,963		15,814,662
Total asset			$ 4,863,153,000		$ 4,761,315,000
Investment securities			410,073,000		285,596,000
Loan			3,146,313,000	$ 2,826,393,000	3,015,165,000
Deposits			4,077,222,000		$ 4,009,131,000
Sale of Investment securities			$ 0	$ 0
Common Stock [Member]
Business Acquisition [Line Items]
Common stock, shares outstanding | shares			23,004,153	22,925,069	22,955,963	22,867,802
FNBB [Member]
Business Acquisition [Line Items]
Total asset			$ 1,300,000,000
Investment securities			344,000,000
Loan			868,000,000
Deposits			995,000,000
FNBB [Member] | Federal Home Loan Bank of San Francisco [Member]
Business Acquisition [Line Items]
Proceeds from security sales			$ 165,000,000
Subsequent Event [Member]
Business Acquisition [Line Items]
Common stock, closing price | $ / shares		$ 38.41
Common stock, shares outstanding | shares		30,409,430
Total asset		$ 6,100,000,000
Sale of Investment securities	$ 292,000,000
Gain or Loss on sale of investment securities	0
Payment of FHLB	136,000,000
Subsequent Event [Member] | FNBB [Member]
Business Acquisition [Line Items]
Issue of common stock shares | shares		7,405,277
Value in lieu of fractional share | shares		6,000
Amount paid in exchange for the outstanding options		$ 6,690,000
Total consideration value		$ 284,400,000
Ownership percentage of combined entity post merger		24.40%
Subsequent Event [Member] | FNBB [Member] | Federal Home Loan Bank of San Francisco [Member]
Business Acquisition [Line Items]
Payment of FHLB	$ 165,000,000
Subsequent Event [Member] | FNBB [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Shares exchange ratio		0.98

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Estimated Fair Values of Investments in Debt and Equity Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 778,858	$ 731,292
Gross Unrealized Gains	616	2,583
Gross Unrealized Losses	(25,267)	(5,930)
Estimated Fair Value	754,207	727,945
Amortized Cost, Held to Maturity	477,745	514,844
Gross Unrealized Gains, Held to Maturity	368	5,247
Gross Unrealized Losses, Held to Maturity	(9,492)	(1,926)
Estimated Fair Value, Held to Maturity	468,621	518,165
Obligations of U.S. Government Corporations and Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	657,335	609,695
Gross Unrealized Gains	257	695
Gross Unrealized Losses	(22,164)	(5,601)
Estimated Fair Value	635,428	604,789
Amortized Cost, Held to Maturity	463,162	500,271
Gross Unrealized Gains, Held to Maturity	291	5,101
Gross Unrealized Losses, Held to Maturity	(9,211)	(1,889)
Estimated Fair Value, Held to Maturity	454,242	503,483
Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	121,523	121,597
Gross Unrealized Gains	359	1,888
Gross Unrealized Losses	(3,103)	(329)
Estimated Fair Value	118,779	123,156
Amortized Cost, Held to Maturity	14,583	14,573
Gross Unrealized Gains, Held to Maturity	77	146
Gross Unrealized Losses, Held to Maturity	(281)	(37)
Estimated Fair Value, Held to Maturity	$ 14,379	$ 14,682

Investment Securities - Additio

Investment Securities - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2018USD ($)Investmentsecurities	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Investment Securities [Line Items]
Investment securities sold	$ 0	$ 0
Investment securities carrying value	410,073,000		$ 285,596,000
Residential real estate mortgage-backed securities	$ 1,120,497,000
Life of mortgage-backed securities	6 years 1 month 6 days
Obligations of U.S. Government Corporations and Agencies [Member]
Investment Securities [Line Items]
Debt securities | Investmentsecurities	143
Percentage of aggregate depreciation in unrealized losses	3.02%
Obligations of States and Political Subdivisions [Member]
Investment Securities [Line Items]
Debt securities | Investmentsecurities	98
Percentage of aggregate depreciation in unrealized losses	3.47%

Investment Securities - Amort69

Investment Securities - Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Due in one year, Amortized Cost	$ 1
Due after one year through five years, Amortized Cost	233
Due after five years through ten years, Amortized Cost	3,229
Due after ten years, Amortized Cost	775,395
Totals, Amortized Cost	778,858
Due in one year, Estimated Fair Value	1
Due after one year through five years, Estimated Fair Value	234
Due after five years through ten years, Estimated Fair Value	3,331
Due after ten years, Estimated Fair Value	750,641
Totals, Estimated Fair Value	754,207
Due in one year, Amortized Cost, Held to Maturity	0
Due after one year through five years, Amortized Cost, Held to Maturity	1,223
Due after five years through ten years, Amortized Cost, Held to Maturity	27,400
Due after ten years, Amortized Cost, Held to Maturity	449,122
Totals, Amortized Cost, Held to Maturity	477,745	$ 514,844
Due in one year, Estimated Fair Value, Held to Maturity	0
Due after one year through five years, Estimated Fair Value, Held to Maturity	1,239
Due after five years through ten years, Estimated Fair Value, Held to Maturity	26,800
Due after ten years, Estimated Fair Value, Held to Maturity	440,582
Estimated Fair Value, Held to Maturity	$ 468,621	$ 518,165

Investment Securities - Gross U

Investment Securities - Gross Unrealized Losses on Debt Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	$ 503,911	$ 289,271
Less than 12 months, Unrealized Loss	(16,275)	(2,211)
12 months or more, Fair Value	168,560	183,423
12 months or more, Unrealized Loss	(8,992)	(3,719)
Total Fair Value	672,471	472,694
Total Unrealized Loss	(25,267)	(5,930)
Less than 12 months, Fair Value, held to maturity	335,850	94,505
Less than 12 months, Unrealized Loss, held to maturity	(5,730)	(574)
12 months or more, Fair Value, held to maturity	94,337	98,004
12 months or more, Unrealized Loss, held to maturity	(3,762)	(1,352)
Total Fair Value, held to maturity	430,187	192,509
Total Unrealized Loss, held to maturity	(9,492)	(1,926)
Obligations of U.S. Government Corporations and Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	437,859	284,367
Less than 12 months, Unrealized Loss	(14,490)	(2,176)
12 months or more, Fair Value	152,004	166,338
12 months or more, Unrealized Loss	(7,674)	(3,425)
Total Fair Value	589,863	450,705
Total Unrealized Loss	(22,164)	(5,601)
Less than 12 months, Fair Value, held to maturity	326,966	93,017
Less than 12 months, Unrealized Loss, held to maturity	(5,578)	(567)
12 months or more, Fair Value, held to maturity	91,801	95,367
12 months or more, Unrealized Loss, held to maturity	(3,633)	(1,322)
Total Fair Value, held to maturity	418,767	188,384
Total Unrealized Loss, held to maturity	(9,211)	(1,889)
Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Fair Value	66,052	4,904
Less than 12 months, Unrealized Loss	(1,785)	(35)
12 months or more, Fair Value	16,556	17,085
12 months or more, Unrealized Loss	(1,318)	(294)
Total Fair Value	82,608	21,989
Total Unrealized Loss	(3,103)	(329)
Less than 12 months, Fair Value, held to maturity	8,884	1,488
Less than 12 months, Unrealized Loss, held to maturity	(152)	(7)
12 months or more, Fair Value, held to maturity	2,536	2,637
12 months or more, Unrealized Loss, held to maturity	(129)	(30)
Total Fair Value, held to maturity	11,420	4,125
Total Unrealized Loss, held to maturity	$ (281)	$ (37)

Loans - Summary of Loan Balance

Loans - Summary of Loan Balances (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable Disclosure [Line Items]
Commercial	$ 3,169,675		$ 3,038,472
Unamortized net deferred loan fees	(9,756)		(8,651)
Discounts to principal balance of loans owed, net of charge-offs	(13,606)		(14,656)
Total loans, net of unamortized deferred loan fees and discounts	3,146,313		3,015,165	$ 2,826,393
Allowance for loan losses	(29,524)	$ (29,973)	(30,323)	(28,143)	$ (31,017)	$ (32,503)
Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,401,040		2,300,322	2,106,567
Allowance for loan losses	(13,598)	(13,665)	(13,758)	(12,613)	(14,204)	(14,265)
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	350,925		356,874	360,782
Allowance for loan losses	(7,137)	(7,718)	(8,227)	(9,157)	(9,576)	(10,310)
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	237,619		220,412	225,743
Allowance for loan losses	(6,378)	(6,392)	(6,512)	(4,729)	(5,326)	(5,831)
Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	156,729		137,557	133,301
Allowance for loan losses	(2,411)	(2,198)	(1,826)	(1,644)	(1,911)	(2,097)
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	384,692		385,426	381,305
Allowance for loan losses	(1,991)	(2,170)	(2,317)	(2,511)	(2,662)	(2,748)
Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	40,986		43,031	45,936
Allowance for loan losses	(1,532)	(1,736)	(1,841)	(2,356)	(2,451)	(2,644)
Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	23,503		25,155	28,370
Allowance for loan losses	(557)	(570)	(586)	(645)	(595)	(622)
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,016,348		1,914,896	1,725,262
Allowance for loan losses	(11,607)	(11,495)	(11,441)	(10,102)	(11,542)	(11,517)
Commercial [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	83,151		69,627	70,151
Allowance for loan losses	(977)	(847)	(642)	(466)	(572)	(680)
Home Equity Lines of Credit [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	286,436		288,688	286,476
Allowance for loan losses	(5,048)	(5,412)	(5,800)	(6,156)	(6,530)	(7,044)
Residential [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	73,578		67,930	63,150
Allowance for loan losses	(1,434)	$ (1,351)	(1,184)	$ (1,178)	$ (1,339)	$ (1,417)
Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Commercial	2,855,594		2,699,053
Unamortized net deferred loan fees	(9,756)		(8,651)
Total loans, net of unamortized deferred loan fees and discounts	2,845,838		2,690,402
Allowance for loan losses	(28,761)		(29,122)
Originated [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,131,979		2,011,032
Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	329,786		332,649
Originated [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	227,591		209,437
Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	156,482		137,284
Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	326,149		320,522
Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	38,082		39,848
Originated [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	21,421		22,859
Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,805,830		1,690,510
Originated [Member] | Commercial [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	82,912		69,364
Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	270,283		269,942
Originated [Member] | Residential [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	73,570		67,920
PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Commercial	293,151		316,238
Discounts to principal balance of loans owed, net of charge-offs	(6,537)		(7,035)
Total loans, net of unamortized deferred loan fees and discounts	286,614		309,203
Allowance for loan losses	(624)		(929)
PNCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	259,746		279,342
PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	19,066		21,197
PNCI [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	7,555		8,391
PNCI [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	247		273
PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	56,823		63,519
PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,449		2,698
PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,039		2,251
PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	202,923		215,823
PNCI [Member] | Commercial [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	239		263
PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	14,578		16,248
PNCI [Member] | Residential [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	8		10
PCI - Cash Basis [Member]
Loans and Leases Receivable Disclosure [Line Items]
Commercial	4,898		5,863
Discounts to principal balance of loans owed, net of charge-offs	(3,368)		(3,794)
Total loans, net of unamortized deferred loan fees and discounts	1,530		2,069
Allowance for loan losses	(7)		(17)
PCI - Cash Basis [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,530		2,069
PCI - Cash Basis [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,530		2,069
PCI - Other [Member]
Loans and Leases Receivable Disclosure [Line Items]
Commercial	16,032		17,318
Discounts to principal balance of loans owed, net of charge-offs	(3,701)		(3,827)
Total loans, net of unamortized deferred loan fees and discounts	12,331		13,491
Allowance for loan losses	(132)		(255)
PCI - Other [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	9,315		9,948
PCI - Other [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	543		959
PCI - Other [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,473		2,584
PCI - Other [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,720		1,385
PCI - Other [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	455		485
PCI - Other [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	43		45
PCI - Other [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	7,595		8,563
PCI - Other [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	$ 45		$ 429

Loans - Change in Accretable Yi

Loans - Change in Accretable Yield for PCI (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Change in accretable yield:
Balance at beginning of period	$ 4,147	$ 9,560	$ 4,262	$ 10,348
Accretion to interest income	(261)	(1,058)	(516)	(1,960)
Reclassification (to) from nonaccretable difference	110	(546)	250	(432)
Balance at end of period	$ 3,996	$ 7,956	$ 3,996	$ 7,956

Allowance for Loan Losses - Sum

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 ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	$ 29,973	$ 31,017	$ 30,323	$ 32,503	$ 32,503
Charge-offs	(318)	(2,512)	(798)	(2,921)	(4,410)
Recoveries	507	434	873	914	2,141
Provision (benefit)	(638)	(796)	(874)	(2,353)	89
Ending Balance	29,524	28,143	29,524	28,143	30,323
Allowance for Loan Losses, Individually evaluated for impairment						$ 2,889	$ 2,699	$ 1,686
Allowance for Loan Losses, Loans pooled for evaluation						26,496	27,352	24,026
Total allowance for loan losses	29,973	31,017	29,524	28,143	32,503	29,524	30,323	28,143
Loans, Net of Unearned fees , Individually evaluated for impairment						27,211	28,234	26,235
Loans, Net of Unearned fees , Loans pooled for evaluation						3,105,241	2,971,371	2,779,866
Total loans, net of unamortized deferred loan fees and discounts						3,146,313	3,015,165	2,826,393
Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	13,665	14,204	13,758	14,265	14,265
Charge-offs	(66)	(150)	(67)	(150)	(246)
Recoveries	21	17	36	127	397
Provision (benefit)	(22)	(1,458)	(129)	(1,629)	(658)
Ending Balance	13,598	12,613	13,598	12,613	13,758
Allowance for Loan Losses, Individually evaluated for impairment						229	260	373
Allowance for Loan Losses, Loans pooled for evaluation						13,260	13,283	10,568
Total allowance for loan losses	13,665	14,204	13,598	12,613	14,265	13,598	13,758	12,613
Loans, Net of Unearned fees , Individually evaluated for impairment						17,506	19,209	19,250
Loans, Net of Unearned fees , Loans pooled for evaluation						2,374,219	2,271,165	2,075,263
Total loans, net of unamortized deferred loan fees and discounts						2,401,040	2,300,322	2,106,567
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	7,718	9,576	8,227	10,310	10,310
Charge-offs	(198)	(527)	(472)	(803)	(1,616)
Recoveries	406	333	707	532	1,315
Provision (benefit)	(789)	(225)	(1,325)	(882)	(1,782)
Ending Balance	7,137	9,157	7,137	9,157	8,227
Allowance for Loan Losses, Individually evaluated for impairment						533	591	488
Allowance for Loan Losses, Loans pooled for evaluation						6,597	7,619	8,595
Total allowance for loan losses	7,718	9,576	7,137	9,157	10,310	7,137	8,227	9,157
Loans, Net of Unearned fees , Individually evaluated for impairment						4,954	4,415	4,241
Loans, Net of Unearned fees , Loans pooled for evaluation						343,898	349,431	352,168
Total loans, net of unamortized deferred loan fees and discounts						350,925	356,874	360,782
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	6,392	5,326	6,512	5,831	5,831
Charge-offs	(54)	(764)	(259)	(897)	(1,444)
Recoveries	80	84	130	254	428
Provision (benefit)	(40)	83	(5)	(459)	1,697
Ending Balance	6,378	4,729	6,378	4,729	6,512
Allowance for Loan Losses, Individually evaluated for impairment						2,127	1,848	811
Allowance for Loan Losses, Loans pooled for evaluation						4,228	4,624	3,276
Total allowance for loan losses	6,392	5,326	6,378	4,729	5,831	6,378	6,512	4,729
Loans, Net of Unearned fees , Individually evaluated for impairment						4,751	4,470	2,744
Loans, Net of Unearned fees , Loans pooled for evaluation						230,395	213,358	219,658
Total loans, net of unamortized deferred loan fees and discounts						237,619	220,412	225,743
Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	2,198	1,911	1,826	2,097	2,097
Charge-offs		(1,071)		(1,071)	(1,104)
Recoveries				1	1
Provision (benefit)	213	804	585	617	832
Ending Balance	2,411	1,644	2,411	1,644	1,826
Allowance for Loan Losses, Individually evaluated for impairment								14
Allowance for Loan Losses, Loans pooled for evaluation						2,411	1,826	1,587
Total allowance for loan losses	2,198	1,911	2,411	1,644	2,097	2,411	1,826	1,644
Loans, Net of Unearned fees , Individually evaluated for impairment							140
Loans, Net of Unearned fees , Loans pooled for evaluation						156,729	137,417	132,777
Total loans, net of unamortized deferred loan fees and discounts						156,729	137,557	133,301
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	2,170	2,662	2,317	2,748	2,748
Charge-offs	(51)		(52)		(60)
Provision (benefit)	(128)	(151)	(274)	(237)	(371)
Ending Balance	1,991	2,511	1,991	2,511	2,317
Allowance for Loan Losses, Individually evaluated for impairment						147	230	249
Allowance for Loan Losses, Loans pooled for evaluation						1,794	1,932	2,037
Total allowance for loan losses	2,170	2,662	1,991	2,511	2,748	1,991	2,317	2,511
Loans, Net of Unearned fees , Individually evaluated for impairment						6,344	5,298	4,726
Loans, Net of Unearned fees , Loans pooled for evaluation						376,628	378,743	375,217
Total loans, net of unamortized deferred loan fees and discounts						384,692	385,426	381,305
Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	1,736	2,451	1,841	2,644	2,644
Charge-offs		(206)		(237)	(332)
Recoveries	23	13	37	25	242
Provision (benefit)	(227)	98	(346)	(76)	(713)
Ending Balance	1,532	2,356	1,532	2,356	1,841
Allowance for Loan Losses, Individually evaluated for impairment						192	107	57
Allowance for Loan Losses, Loans pooled for evaluation						1,340	1,734	2,233
Total allowance for loan losses	1,736	2,451	1,532	2,356	2,644	1,532	1,841	2,356
Loans, Net of Unearned fees , Individually evaluated for impairment						2,457	1,470	1,285
Loans, Net of Unearned fees , Loans pooled for evaluation						38,074	41,076	43,515
Total loans, net of unamortized deferred loan fees and discounts						40,986	43,031	45,936
Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	570	595	586	622	622
Charge-offs	(174)	(308)	(368)	(482)	(1,186)
Recoveries	66	68	144	209	375
Provision (benefit)	95	290	195	296	775
Ending Balance	557	645	557	645	586
Allowance for Loan Losses, Individually evaluated for impairment						54	57	31
Allowance for Loan Losses, Loans pooled for evaluation						503	529	614
Total allowance for loan losses	570	595	557	645	622	557	586	645
Loans, Net of Unearned fees , Individually evaluated for impairment						247	257	323
Loans, Net of Unearned fees , Loans pooled for evaluation						23,213	24,853	27,981
Total loans, net of unamortized deferred loan fees and discounts						23,503	25,155	28,370
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	11,495	11,542	11,441	11,517	11,517
Charge-offs	(15)	(150)	(15)	(150)	(186)
Recoveries	21	17	36	127	397
Provision (benefit)	106	(1,307)	145	(1,392)	(287)
Ending Balance	11,607	10,102	11,607	10,102	11,441
Allowance for Loan Losses, Individually evaluated for impairment						82	30	124
Allowance for Loan Losses, Loans pooled for evaluation						11,466	11,351	8,531
Total allowance for loan losses	11,495	11,542	11,607	10,102	11,517	11,607	11,441	10,102
Loans, Net of Unearned fees , Individually evaluated for impairment						11,162	13,911	14,524
Loans, Net of Unearned fees , Loans pooled for evaluation						1,997,591	1,892,422	1,700,046
Total loans, net of unamortized deferred loan fees and discounts						2,016,348	1,914,896	1,725,262
Commercial [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	847	572	642	680	680
Recoveries				1	1
Provision (benefit)	130	(106)	335	(215)	(39)
Ending Balance	977	466	977	466	642
Allowance for Loan Losses, Loans pooled for evaluation						977	642	466
Total allowance for loan losses	847	572	977	466	680	977	642	466
Loans, Net of Unearned fees , Loans pooled for evaluation						83,151	69,627	70,151
Total loans, net of unamortized deferred loan fees and discounts						83,151	69,627	70,151
Home Equity Lines of Credit [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	5,412	6,530	5,800	7,044	7,044
Charge-offs	(24)	(13)	(104)	(84)	(98)
Recoveries	317	252	526	298	698
Provision (benefit)	(657)	(613)	(1,174)	(1,102)	(1,844)
Ending Balance	5,048	6,156	5,048	6,156	5,800
Allowance for Loan Losses, Individually evaluated for impairment						287	427	400
Allowance for Loan Losses, Loans pooled for evaluation						4,754	5,356	5,748
Total allowance for loan losses	5,412	6,530	5,048	6,156	7,044	5,048	5,800	6,156
Loans, Net of Unearned fees , Individually evaluated for impairment						2,250	2,688	2,633
Loans, Net of Unearned fees , Loans pooled for evaluation						282,611	283,502	280,672
Total loans, net of unamortized deferred loan fees and discounts						286,436	288,688	286,476
Residential [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	1,351	1,339	1,184	1,417	1,417
Charge-offs		(1,071)		(1,071)	(1,104)
Provision (benefit)	83	910	250	832	871
Ending Balance	1,434	1,178	1,434	1,178	1,184
Allowance for Loan Losses, Individually evaluated for impairment								14
Allowance for Loan Losses, Loans pooled for evaluation						1,434	1,184	1,121
Total allowance for loan losses	$ 1,351	$ 1,339	$ 1,434	$ 1,178	$ 1,417	1,434	1,184	1,178
Loans, Net of Unearned fees , Individually evaluated for impairment							140
Loans, Net of Unearned fees , Loans pooled for evaluation						73,578	67,790	62,626
Total loans, net of unamortized deferred loan fees and discounts						73,578	67,930	63,150
Financial Asset Acquired with Credit Deterioration [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality						139	272	2,431
Total loans, net of unamortized deferred loan fees and discounts						13,861	15,560	20,292
Financial Asset Acquired with Credit Deterioration [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality						109	215	1,672
Total loans, net of unamortized deferred loan fees and discounts						9,315	9,948	12,054
Financial Asset Acquired with Credit Deterioration [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality						7	17	74
Total loans, net of unamortized deferred loan fees and discounts						2,073	3,028	4,373
Financial Asset Acquired with Credit Deterioration [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality						23	40	642
Total loans, net of unamortized deferred loan fees and discounts						2,473	2,584	3,341
Financial Asset Acquired with Credit Deterioration [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality								43
Total loans, net of unamortized deferred loan fees and discounts								524
Financial Asset Acquired with Credit Deterioration [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality						50	155	225
Total loans, net of unamortized deferred loan fees and discounts						1,720	1,385	1,362
Financial Asset Acquired with Credit Deterioration [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality								66
Total loans, net of unamortized deferred loan fees and discounts						455	485	1,136
Financial Asset Acquired with Credit Deterioration [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts						43	45	66
Financial Asset Acquired with Credit Deterioration [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality						59	60	1,447
Total loans, net of unamortized deferred loan fees and discounts						7,595	8,563	10,692
Financial Asset Acquired with Credit Deterioration [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality						7	17	8
Total loans, net of unamortized deferred loan fees and discounts						$ 1,575	$ 2,498	3,171
Financial Asset Acquired with Credit Deterioration [Member] | Residential [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality								43
Total loans, net of unamortized deferred loan fees and discounts								$ 524

Allowance for Loan Losses - Sch

Allowance for Loan Losses - Schedule Credit Quality Indicators (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	$ 3,146,313	$ 3,015,165	$ 2,826,393
Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,401,040	2,300,322	2,106,567
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	350,925	356,874	360,782
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	237,619	220,412	225,743
Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	156,729	137,557	133,301
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	384,692	385,426	381,305
Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	40,986	43,031	45,936
Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	23,503	25,155	28,370
Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,845,838	2,690,402
Originated [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,131,979	2,011,032
Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	329,786	332,649
Originated [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	227,591	209,437
Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	156,482	137,284
Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	326,149	320,522
Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	38,082	39,848
Originated [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	21,421	22,859
PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	286,614	309,203
PNCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	259,746	279,342
PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	19,066	21,197
PNCI [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	7,555	8,391
PNCI [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	247	273
PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	56,823	63,519
PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,449	2,698
PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,039	2,251
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,016,348	1,914,896	1,725,262
Commercial [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	83,151	69,627	70,151
Commercial [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,805,830	1,690,510
Commercial [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	82,912	69,364
Commercial [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	202,923	215,823
Commercial [Member] | PNCI [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	239	263
Home Equity Lines of Credit [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	286,436	288,688	286,476
Home Equity Lines of Credit [Member] | Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	270,283	269,942
Home Equity Lines of Credit [Member] | PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	14,578	16,248
Residential [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	73,578	67,930	$ 63,150
Residential [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	73,570	67,920
Residential [Member] | PNCI [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	8	10
Pass [Member] | Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,783,213	2,617,171
Pass [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,084,474	1,964,453
Pass [Member] | Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	324,248	325,205
Pass [Member] | Originated [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	221,108	195,208
Pass [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	153,383	132,305
Pass [Member] | Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	323,576	315,120
Pass [Member] | Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	37,441	37,428
Pass [Member] | Originated [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	21,083	22,432
Pass [Member] | PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	279,119	293,331
Pass [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	253,392	265,162
Pass [Member] | PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	17,925	19,506
Pass [Member] | PNCI [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	7,555	8,390
Pass [Member] | PNCI [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	247	273
Pass [Member] | PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	55,039	61,411
Pass [Member] | PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,220	2,433
Pass [Member] | PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,030	2,207
Pass [Member] | Commercial [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,760,898	1,649,333
Pass [Member] | Commercial [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	82,912	64,492
Pass [Member] | Commercial [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	198,353	203,751
Pass [Member] | Commercial [Member] | PNCI [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	239	263
Pass [Member] | Home Equity Lines of Credit [Member] | Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	265,724	265,345
Pass [Member] | Home Equity Lines of Credit [Member] | PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	13,675	14,866
Pass [Member] | Residential [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	70,471	67,813
Pass [Member] | Residential [Member] | PNCI [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	8	10
Special Mention [Member] | Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	36,679	38,662
Special Mention [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	28,009	20,668
Special Mention [Member] | Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,149	3,630
Special Mention [Member] | Originated [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	3,568	9,492
Special Mention [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,953	4,872
Special Mention [Member] | Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	292	2,234
Special Mention [Member] | Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	163	800
Special Mention [Member] | Originated [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	158	272
Special Mention [Member] | PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	3,100	12,408
Special Mention [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,935	11,731
Special Mention [Member] | PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	165	676
Special Mention [Member] | PNCI [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts		1
Special Mention [Member] | PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts		218
Special Mention [Member] | PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	161	188
Special Mention [Member] | PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	4	38
Special Mention [Member] | Commercial [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	27,717	18,434
Special Mention [Member] | Commercial [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts		4,872
Special Mention [Member] | Commercial [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,935	11,513
Special Mention [Member] | Home Equity Lines of Credit [Member] | Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,828	2,558
Special Mention [Member] | Home Equity Lines of Credit [Member] | PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts		450
Special Mention [Member] | Residential [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,953
Substandard [Member] | Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	25,946	34,569
Substandard [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	19,496	25,911
Substandard [Member] | Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	3,389	3,814
Substandard [Member] | Originated [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,915	4,737
Substandard [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	146	107
Substandard [Member] | Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,281	3,168
Substandard [Member] | Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	478	1,620
Substandard [Member] | Originated [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	180	155
Substandard [Member] | PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	4,395	3,464
Substandard [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	3,419	2,449
Substandard [Member] | PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	976	1,015
Substandard [Member] | PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,784	1,890
Substandard [Member] | PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	68	77
Substandard [Member] | PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	5	6
Substandard [Member] | Commercial [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	17,215	22,743
Substandard [Member] | Commercial [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,635	559
Substandard [Member] | Home Equity Lines of Credit [Member] | Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,731	2,039
Substandard [Member] | Home Equity Lines of Credit [Member] | PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	903	932
Substandard [Member] | Residential [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	$ 146	$ 107

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2018USD ($)Category	Dec. 31, 2017USD ($)	Jun. 30, 2017USD ($)
Loans and Leases Receivable Disclosure [Line Items]
Number of categories occupied under commercial real estate loans | Category	2
Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Impaired TDR Loans	$ 9,450,000	$ 12,517,000	$ 12,802,000
Obligations to lend additional funds on TDR	0	1,000	0
PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Impaired TDR Loans	1,459,000	1,352,000	1,627,000
Obligations to lend additional funds on TDR	$ 0	$ 0	$ 2,000
Minimum [Member]
Loans and Leases Receivable Disclosure [Line Items]
Period of collateral payment of loan	3 months
Maximum [Member]
Loans and Leases Receivable Disclosure [Line Items]
Period of collateral payment of loan	12 months

Allowance for Loan Losses - Ana

Allowance for Loan Losses - Analysis of Current and Past Due Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	$ 3,146,313	$ 3,015,165	$ 2,826,393
Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,401,040	2,300,322	2,106,567
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	350,925	356,874	360,782
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	237,619	220,412	225,743
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	156,729	137,557	133,301
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	384,692	385,426	381,305
Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	40,986	43,031	45,936
Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	23,503	25,155	28,370
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,016,348	1,914,896	1,725,262
Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	83,151	69,627	70,151
Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	286,436	288,688	286,476
Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	73,578	67,930	$ 63,150
Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,835,209	2,681,475
Total	2,845,838	2,690,402
Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,127,775	2,007,394
Total	2,131,979	2,011,032
Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	328,491	330,615
Total	329,786	332,649
Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	224,541	206,216
Total	227,591	209,437
Originated [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	154,402	137,250
Total	156,482	137,284
Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	324,595	318,029
Total	326,149	320,522
Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	37,088	38,857
Total	38,082	39,848
Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	21,362	22,764
Total	21,421	22,859
Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,803,180	1,689,365
Total	1,805,830	1,690,510
Originated [Member] | Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	80,832	69,364
Total	82,912	69,364
Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	270,041	268,994
Total	270,283	269,942
Originated [Member] | Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	73,570	67,886
Total	73,570	67,920
PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	285,617	306,521
Total	286,614	309,203
> 90 Days and Still Accruing		281
PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	259,053	277,578
Total	259,746	279,342
> 90 Days and Still Accruing		81
PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	18,762	20,279
Total	19,066	21,197
> 90 Days and Still Accruing		200
PNCI [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7,555	8,391
Total	7,555	8,391
PNCI [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	247	273
Total	247	273
PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	56,650	61,825
Total	56,823	63,519
> 90 Days and Still Accruing		81
PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,406	2,668
Total	2,449	2,698
PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,037	2,219
Total	2,039	2,251
PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	202,403	215,753
Total	202,923	215,823
PNCI [Member] | Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	239	263
Total	239	263
PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	14,319	15,392
Total	14,578	16,248
> 90 Days and Still Accruing		200
PNCI [Member] | Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	8	10
Total	8	10
30-59 Days [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	3,856	3,983
30-59 Days [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,552	1,898
30-59 Days [Member] | Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	549	1,095
30-59 Days [Member] | Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	506	956
30-59 Days [Member] | Originated [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,249	34
30-59 Days [Member] | Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	271	1,740
30-59 Days [Member] | Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	358	511
30-59 Days [Member] | Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	33	56
30-59 Days [Member] | Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,281	158
30-59 Days [Member] | Originated [Member] | Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,249
30-59 Days [Member] | Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	158	528
30-59 Days [Member] | Originated [Member] | Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due		34
30-59 Days [Member] | PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	599	1,899
30-59 Days [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	415	1,565
30-59 Days [Member] | PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	184	334
30-59 Days [Member] | PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	59	1,495
30-59 Days [Member] | PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due		30
30-59 Days [Member] | PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2	6
30-59 Days [Member] | PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	356	70
30-59 Days [Member] | PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	182	298
60-89 Days [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,451	2,426
60-89 Days [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	641	1,497
60-89 Days [Member] | Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	213	191
60-89 Days [Member] | Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	766	738
60-89 Days [Member] | Originated [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	831
60-89 Days [Member] | Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	64	510
60-89 Days [Member] | Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	150	107
60-89 Days [Member] | Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	26	36
60-89 Days [Member] | Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	577	987
60-89 Days [Member] | Originated [Member] | Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	831
60-89 Days [Member] | Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	37	48
60-89 Days [Member] | PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	285	344
60-89 Days [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	242	90
60-89 Days [Member] | PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	43	254
60-89 Days [Member] | PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	78	90
60-89 Days [Member] | PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	43
60-89 Days [Member] | PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due		26
60-89 Days [Member] | PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	164
60-89 Days [Member] | PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due		228
> 90 Days [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	4,322	2,518
> 90 Days [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,011	243
> 90 Days [Member] | Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	533	748
> 90 Days [Member] | Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,778	1,527
> 90 Days [Member] | Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,219	243
> 90 Days [Member] | Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	486	373
> 90 Days [Member] | Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due		3
> 90 Days [Member] | Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	792
> 90 Days [Member] | Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	47	372
> 90 Days [Member] | PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	113	439
> 90 Days [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	36	109
> 90 Days [Member] | PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	77	330
> 90 Days [Member] | PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	36	109
> 90 Days [Member] | PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	$ 77	$ 330

Allowance for Loan Losses - S77

Allowance for Loan Losses - Schedule of Non Accrual Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 19,097	$ 16,925
Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	9,926	10,881
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	6,832	2,375
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	2,339	3,669
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	4,109	2,737
Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	4,455	1,150
Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	346	12
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	5,817	8,144
Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	2,031	1,213
Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	17,077	15,462
Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	8,521	9,869
Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	6,217	1,924
Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	2,339	3,669
Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	3,027	1,725
Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	4,419	1,106
Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	341	7
Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	5,494	8,144
Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,457	811
PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	2,020	1,463
PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,405	1,012
PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	615	451
PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,082	1,012
PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	36	44
PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	5	5
PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	323
PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 574	$ 402

Allowance for Loan Losses - Imp

Allowance for Loan Losses - Impaired Loans (Detail) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Originated [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	$ 25,693	$ 22,816	$ 26,175
Recorded investment with no related allowance	17,455	16,657	18,078
Recorded investment with related allowance	6,528	4,779	7,188
Total recorded investment	23,983	21,436	25,266
Related Allowance	2,426	1,244	2,232
Average recorded investment	23,431	5,531	24,626
Interest income recognized	270	79	1,052
Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	16,936	16,311	18,209
Recorded investment with no related allowance	13,710	13,487	15,159
Recorded investment with related allowance	2,126	2,266	2,691
Total recorded investment	15,836	15,753	17,850
Related Allowance	229	224	260
Average recorded investment	15,575	2,141	17,352
Interest income recognized	183	41	788
Originated [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	3,805	3,452	3,260
Recorded investment with no related allowance	2,936	2,163	2,204
Recorded investment with related allowance	460	776	602
Total recorded investment	3,396	2,939	2,806
Related Allowance	70	157	124
Average recorded investment	3,102	854	2,915
Interest income recognized	39	11	71
Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	4,952	3,053	4,566
Recorded investment with no related allowance	809	1,007	575
Recorded investment with related allowance	3,942	1,737	3,895
Total recorded investment	4,751	2,744	4,470
Related Allowance	2,127	863	1,848
Average recorded investment	4,686	2,536	4,283
Interest income recognized	48	27	184
Originated [Member] | Construction [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance			140
Recorded investment with no related allowance			140
Total recorded investment			140
Average recorded investment	68		76
Interest income recognized			9
Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	5,656	3,108	4,023
Recorded investment with no related allowance	3,947	1,623	2,058
Recorded investment with related allowance	1,050	1,463	1,881
Total recorded investment	4,997	3,086	3,939
Related Allowance	147	179	230
Average recorded investment	4,600	1,417	3,501
Interest income recognized	76	23	143
Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	2,558	1,633	1,627
Recorded investment with no related allowance	1,828	836	1,107
Recorded investment with related allowance	351	395	198
Total recorded investment	2,179	1,231	1,305
Related Allowance	38	68	10
Average recorded investment	1,784	440	1,193
Interest income recognized	20	10	24
Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	3	73	52
Recorded investment with no related allowance		22	4
Recorded investment with related allowance	3	50	3
Total recorded investment	3	72	7
Related Allowance	3	23	3
Average recorded investment	3	34	20
Interest income recognized		1
Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	11,280	13,203	14,186
Recorded investment with no related allowance	9,763	11,864	13,101
Recorded investment with related allowance	1,076	803	810
Total recorded investment	10,839	12,667	13,911
Related Allowance	82	45	30
Average recorded investment	10,975	724	13,851
Interest income recognized	107	18	645
Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	1,244	1,746	1,581
Recorded investment with no related allowance	1,108	1,305	1,093
Recorded investment with related allowance	106	331	401
Total recorded investment	1,214	1,636	1,494
Related Allowance	29	66	111
Average recorded investment	1,315	380	1,702
Interest income recognized	19		47
Originated [Member] | Residential [Member] | Construction [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance			140
Recorded investment with no related allowance			140
Total recorded investment			140
Average recorded investment	68		76
Interest income recognized			9
PNCI [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	3,375	5,113	3,048
Recorded investment with no related allowance	2,236	3,556	1,994
Recorded investment with related allowance	992	1,243	974
Total recorded investment	3,228	4,799	2,968
Related Allowance	463	579	467
Average recorded investment	3,075	1,152	3,563
Interest income recognized	48	26	89
PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	1,740	3,786	1,404
Recorded investment with no related allowance	1,671	3,115	1,359
Recorded investment with related allowance		382
Total recorded investment	1,671	3,497	1,359
Related Allowance		179
Average recorded investment	1,500	387	2,020
Interest income recognized	24	8	24
PNCI [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	1,635	1,327	1,644
Recorded investment with no related allowance	565	441	635
Recorded investment with related allowance	992	861	974
Total recorded investment	1,557	1,302	1,609
Related Allowance	463	400	467
Average recorded investment	1,575	765	1,543
Interest income recognized	24	18	65
PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	1,417	1,665	1,404
Recorded investment with no related allowance	1,348	1,387	1,359
Recorded investment with related allowance		253
Total recorded investment	1,348	1,640	1,359
Related Allowance		75
Average recorded investment	1,339	256	1,041
Interest income recognized	10	5	24
PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	293	64	178
Recorded investment with no related allowance	36	54	44
Recorded investment with related allowance	242		121
Total recorded investment	278	54	165
Related Allowance	154		97
Average recorded investment	281		117
Interest income recognized	6		6
PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	244	251	250
Recorded investment with related allowance	244	251	250
Total recorded investment	244	251	250
Related Allowance	51	68	54
Average recorded investment	259	185	186
Interest income recognized	5	5	11
PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	323	2,121
Recorded investment with no related allowance	323	1,728
Recorded investment with related allowance		129
Total recorded investment	323	1,857
Related Allowance		104
Average recorded investment	161	131	979
Interest income recognized	14	3
PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	1,098	1,012	1,216
Recorded investment with no related allowance	529	387	591
Recorded investment with related allowance	506	610	603
Total recorded investment	1,035	997	1,194
Related Allowance	258	332	316
Average recorded investment	1,035	580	1,240
Interest income recognized	$ 13	$ 13	$ 48

Allowance for Loan Losses - Tro

Allowance for Loan Losses - Troubled Debt Restructurings (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)SecurityLoan	Jun. 30, 2017USD ($)SecurityLoan	Jun. 30, 2018USD ($)SecurityLoan	Jun. 30, 2017USD ($)SecurityLoan
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	3	7	6	10
Pre-mod outstanding principal balance	$ 450	$ 1,435	$ 1,087	$ 1,569
Post-mod outstanding principal balance	456	1,302	1,099	1,436
Financial impact due to TDR taken as additional provision	$ 32	$ (182)	$ 44	$ (77)
Number that defaulted during the period | SecurityLoan	4		5	1
Recorded investment of TDRs that defaulted during the period	$ 340		$ 509	$ 124
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions	$ (2)		$ (2)
Mortgage Loans on Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	1	3	2	3
Pre-mod outstanding principal balance	$ 34	$ 623	$ 417	$ 623
Post-mod outstanding principal balance	34	596	418	596
Financial impact due to TDR taken as additional provision	$ 34	$ (125)	$ 46	$ (125)
Number that defaulted during the period | SecurityLoan			1	1
Recorded investment of TDRs that defaulted during the period			$ 169	$ 124
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan		2	2	4
Pre-mod outstanding principal balance		$ 167	$ 254	$ 201
Post-mod outstanding principal balance		167	$ 259	201
Financial impact due to TDR taken as additional provision		$ 27		$ 38
Commercial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	2	2	2	3
Pre-mod outstanding principal balance	$ 416	$ 645	$ 416	$ 745
Post-mod outstanding principal balance	422	539	422	639
Financial impact due to TDR taken as additional provision	$ (2)	$ (84)	$ (2)	$ 10
Number that defaulted during the period | SecurityLoan	4		4
Recorded investment of TDRs that defaulted during the period	$ 340		$ 340
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions	$ (2)		$ (2)
Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan			1
Pre-mod outstanding principal balance			$ 121
Post-mod outstanding principal balance			$ 121
Other Consumer [Member] | Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan				1
Pre-mod outstanding principal balance				$ 14
Post-mod outstanding principal balance				14
Financial impact due to TDR taken as additional provision				$ 11
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	1	3	2	3
Pre-mod outstanding principal balance	$ 34	$ 623	$ 417	$ 623
Post-mod outstanding principal balance	34	596	418	596
Financial impact due to TDR taken as additional provision	$ 34	$ (125)	$ 46	$ (125)
Number that defaulted during the period | SecurityLoan			1	1
Recorded investment of TDRs that defaulted during the period			$ 169	$ 124
Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan		2	1	3
Pre-mod outstanding principal balance		$ 167	$ 133	$ 187
Post-mod outstanding principal balance		167	$ 138	187
Financial impact due to TDR taken as additional provision		$ 27		$ 27

Foreclosed Assets - Summary of

Foreclosed Assets - Summary of Activity in Balance of Foreclosed Assets (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)Assets	Jun. 30, 2017USD ($)Assets
Schedule Of Foreclosed Assets Activity [Line Items]
Beginning balance, net			$ 3,226	$ 3,986
Additions/transfers from loans				684
Dispositions/sales			(1,762)	(1,153)
Valuation adjustments			(90)	(28)
Ending balance, net	$ 1,374	$ 3,489	1,374	3,489
Ending valuation allowance			$ (152)	$ (179)
Ending number of foreclosed assets | Assets			8	12
Proceeds from sale of foreclosed assets			$ 2,150	$ 1,424
Gain on sale of foreclosed assets	$ 17	153	$ 388	271
Noncovered [Member]
Schedule Of Foreclosed Assets Activity [Line Items]
Beginning balance, net				3,763
Additions/transfers from loans				684
Dispositions/sales				(930)
Valuation adjustments				(28)
Ending balance, net		$ 3,489		3,489
Ending valuation allowance				$ (179)
Ending number of foreclosed assets | Assets				12
Proceeds from sale of foreclosed assets				$ 1,424
Gain on sale of foreclosed assets				271
Covered [Member]
Schedule Of Foreclosed Assets Activity [Line Items]
Beginning balance, net				223
Dispositions/sales				$ (223)

Foreclosed Assets - Additional

Foreclosed Assets - Additional Information (Detail) - USD ($)	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Schedule Of Foreclosed Assets Activity [Line Items]
Foreclosed assets	$ 1,374,000	$ 3,226,000	$ 3,489,000	$ 3,986,000
Residential Real Estate [Member]
Schedule Of Foreclosed Assets Activity [Line Items]
Foreclosed assets	837,000
Formal foreclosure proceedings	$ 743,000

Premises and Equipment - Summar

Premises and Equipment - Summary of Premises and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment, Net, by Type [Abstract]
Land & land improvements	$ 9,973	$ 9,959
Buildings	51,065	50,340
Furniture and equipment	38,172	35,939
Premises and equipment, gross	99,210	96,238
Less: Accumulated depreciation	(42,066)	(40,644)
Premises and equipment less depreciation, gross	57,144	55,594
Construction in progress	1,870	2,148
Total premises and equipment	$ 59,014	$ 57,742

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Property, Plant and Equipment [Abstract]
Depreciation expense for premises and equipment	$ 1,386,000	$ 1,394,000	$ 2,757,000	$ 2,705,000

Cash Value of Life Insurance -

Cash Value of Life Insurance - Summary of Activity in Balance of Cash Value of Life Insurance (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)PoliciesCompanyEmployees	Jun. 30, 2017USD ($)PoliciesCompanyEmployees
Increase (Decrease) in Insurance Liabilities [Abstract]
Beginning balance			$ 97,783	$ 95,912
Increase in cash value of life insurance	$ 656	$ 626	1,264	1,311
Gain on death benefit				108
Insurance proceeds receivable reclassified to other assets				(921)
Ending balance	$ 99,047	$ 96,410	99,047	96,410
End of period death benefit			$ 164,649	$ 166,318
Number of policies owned | Policies			182	183
Insurance companies used | Company			13	14
Current and former employees and directors covered | Employees			57	57

Cash Value of Life Insurance 85

Cash Value of Life Insurance - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2018PoliciesCompany	Jun. 30, 2017Company
Insurance [Abstract]
Number of life insurance policies owned by the Company	182
Insurance companies used | Company	13	14
Policies covering current and former employees and directors	57

Goodwill and Other Intangible86

Goodwill and Other Intangible Assets - Summary of Goodwill Intangible (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Ending Balance	$ 64,311
Goodwill, Additions	0
Goodwill, Reductions	0
Goodwill, Beginning Balance	$ 64,311

Goodwill and Other Intangible87

Goodwill and Other Intangible Assets - Summary of Core Deposit Intangibles (Detail) - Core Deposit Intangibles [Member] $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)
Finite-Lived Intangible Assets [Line Items]
Core deposit intangibles, Beginning balance	$ 9,558
Core deposit intangibles, Reductions/Amortization	0
Core deposit intangibles, Additions	0
Core deposit intangibles, Ending balance	9,558
Accumulated amortization, Beginning balance	(4,384)
Accumulated amortization, Reductions/Amortization	(678)
Accumulated amortization, Additions	0
Accumulated amortization, Ending balance	(5,062)
Core deposit intangibles, net, Beginning balance	5,174
Core deposit intangibles, net, Reductions/Amortization	(678)
Core deposit intangibles, net, Additions	0
Core deposit intangibles, net, Ending balance	$ 4,496

Goodwill and Other Intangible88

Goodwill and Other Intangible Assets - Additional Information (Detail)	Mar. 18, 2016USD ($)Branches	Oct. 03, 2014USD ($)	Sep. 23, 2011USD ($)	May 28, 2010USD ($)
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
Bank of America [Member]
Finite-Lived Intangible Assets [Line Items]
Additions to core deposit intangibles	$ 2,046,000
Number of branches | Branches	3
Granite [Member]
Finite-Lived Intangible Assets [Line Items]
Additions to core deposit intangibles				$ 562,000

Goodwill and Other Intangible89

Goodwill and Other Intangible Assets - Remaining Estimated Core Deposit Intangible Amortization (Detail) - Core Deposit Intangibles [Member] $ in Thousands	Dec. 31, 2017USD ($)
Finite-Lived Intangible Assets [Line Items]
2,018	$ 1,324
2,019	1,228
2,020	1,228
2,021	969
2,022	280
Thereafter	$ 145

Mortgage Servicing Rights - Fai

Mortgage Servicing Rights - Fair Value of Mortgage Servicing Rights (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Servicing Assets at Fair Value [Line Items]
Contractually specified servicing fees, late fees and ancillary fees earned	$ 511	$ 526	$ 1,028	$ 1,047
Mortgage Servicing Rights [Member]
Servicing Assets at Fair Value [Line Items]
Balance at beginning of period	6,953	6,860	6,687	6,595
Additions	104	193	259	471
Change in fair value	(36)	(457)	75	(470)
Balance at end of period	7,021	6,596	$ 7,021	$ 6,596
Measurement Input, Constant Prepayment Rate [Member]
Servicing Assets at Fair Value [Line Items]
Fair Value Of Mortgage Servicing Rights Weighted Average			7.40%	8.70%
Measurement Input, Discount Rate [Member]
Servicing Assets at Fair Value [Line Items]
Fair Value Of Mortgage Servicing Rights Weighted Average			12.50%	14.00%
Loans [Member]
Servicing Assets at Fair Value [Line Items]
Balance at beginning of period	806,178	822,506	$ 811,065	$ 816,623
Balance at end of period	$ 801,817	$ 822,549	$ 801,817	$ 822,549

Indemnification Asset - Summary

Indemnification Asset - Summary of Activity in Balance of Indemnification Asset (Liability) (Detail) - USD ($) $ in Thousands	May 09, 2017	Jun. 30, 2017	Jun. 30, 2017
FDIC Indemnification Asset [Roll Forward]
Beginning balance		$ (895)	$ (744)
Effect of actual and estimated future covered losses and recoveries		(1)	(224)
Payments made to (received from) FDIC	$ (184)	184	256
Gain on termination of loss share agreement	$ (712)	$ 712	$ 712

Indemnification Asset - Additio

Indemnification Asset - Additional Information (Detail) - USD ($) $ in Thousands	May 09, 2017	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Fdic Agreements And Fdic Indemnification Asset [Line Items]
FDIC indemnification agreement expiry month and year			2020-05
Term of FDIC indemnification agreement			10 years
True up amount payable to FDIC, description			In addition, the agreement specified that at the end of the agreement in May 2020, to the extent that total claimed losses plus servicing expenses, net of recoveries, claimed under the agreement over the entire ten year period of the agreement did not meet a certain threshold, the Company would have been required to pay to the FDIC a “true up” amount equal to fifty percent of the difference of the threshold and actual claimed losses plus servicing expenses, net of recoveries. The Company continually estimated, updated and recorded this “true up” amount, at its estimated present value, since the inception of the agreement in May 2010.
Percentage of true up amount payable to FDIC			50.00%
Payment made to FDIC	$ 184	$ (184)		$ (256)
Gain on termination of loss share agreement	$ 712	$ (712)		$ (712)
Residential Real Estate Loans [Member]
Fdic Agreements And Fdic Indemnification Asset [Line Items]
FDIC indemnification agreement expiry month and year			2018-05
Nonresidential Real Estate Loans [Member]
Fdic Agreements And Fdic Indemnification Asset [Line Items]
FDIC indemnification agreement expiry month and year			2010-05

Other Assets - Summary of Other

Other Assets - Summary of Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred tax asset, net	$ 27,665	$ 21,697
Investment in low income housing tax credit funds	16,672	16,854
Prepaid expense	4,097	4,111
Tax refund receivable	4,754	4,754
Capital trusts	1,710	1,706
Software	793	1,126
Life insurance proceeds receivable		2,242
Miscellaneous other assets	1,718	2,561
Total other assets	$ 57,409	$ 55,051

Deposits - Summary of Balances

Deposits - Summary of Balances of Deposits (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Deposits [Abstract]
Noninterest-bearing demand	$ 1,369,834	$ 1,368,218
Interest-bearing demand	1,006,331	971,459
Savings	1,385,268	1,364,518
Time certificates, over $250,000	84,015	73,596
Other time certificates	231,774	231,340
Total deposits	$ 4,077,222	$ 4,009,131

Deposits - Additional Informati

Deposits - Additional Information (Detail) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Schedule Of Deposits [Line Items]
Overdrawn deposit balances classified as consumer loans	$ 1,533,000	$ 1,366,000
California [Member]
Schedule Of Deposits [Line Items]
Certificate of deposits, included in time certificates $250,000 and over	$ 50,000,000	$ 50,000,000

Reserve for Unfunded Commitme96

Reserve for Unfunded Commitments - Summary of Activity in Reserve for Unfunded Commitments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Balance at beginning of period	$ 3,864	$ 2,734	$ 3,164	$ 2,719
Provision (reversal of provision) for losses - unfunded commitments	(137)	(135)	563	(120)
Balance at end of period	$ 3,727	$ 2,599	$ 3,727	$ 2,599

Other Liabilities - Components

Other Liabilities - Components of Other Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Pension liability	$ 28,880	$ 28,472
Low income housing tax credit fund commitments	5,969	8,554
Deferred compensation	6,932	6,605
Taxes payable	1,267
Accrued salaries and benefits expense	5,014	6,619
Joint beneficiary agreements	3,494	3,365
Loan escrow and servicing payable	2,295	1,958
Deferred revenue	1,449	1,228
Litigation contingency		1,450
Miscellaneous other liabilities	3,596	5,007
Total other liabilities	$ 58,896	$ 63,258

Other Borrowings - Summary of B

Other Borrowings - Summary of Balances of Other Borrowings (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total other borrowings	$ 152,839	$ 122,166
2.05% Fixed Rate FHLB Collateralized Borrowings [Member]
Debt Instrument [Line Items]
Collateralized borrowings	136,020
1.38% Fixed Rate FHLB Collateralized Borrowings [Member]
Debt Instrument [Line Items]
Collateralized borrowings		104,729
0.05% Fixed Rate Collateralized Borrowings [Member]
Debt Instrument [Line Items]
Collateralized borrowings	$ 16,819	$ 17,437

Other Borrowings - Summary of99

Other Borrowings - Summary of Balances of Other Borrowings (Parenthetical) (Detail)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
2.05% Fixed Rate FHLB Collateralized Borrowings [Member]
Debt Instrument [Line Items]
Collateralized borrowing, fixed rate	2.05%
Collateralized borrowing, maturity date	Jul. 2, 2018
1.38% Fixed Rate FHLB Collateralized Borrowings [Member]
Debt Instrument [Line Items]
Collateralized borrowing, fixed rate		1.38%
Collateralized borrowing, maturity date		Jan. 2, 2018
0.05% Fixed Rate Collateralized Borrowings [Member]
Debt Instrument [Line Items]
Collateralized borrowing, fixed rate	0.05%	0.05%
Collateralized borrowing, maturity date	Jul. 2, 2018	Jan. 2, 2018

Other Borrowings - Additional I

Other Borrowings - Additional Information (Detail) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Schedule Of Borrowings [Line Items]
Security repurchase agreement	$ 0	$ 0
FHLB collateral line of credit, maximum borrowings capacity	1,622,655,000
FHLB collateral line of credit, outstanding balance	136,020,000
FHLB collateral line of credit, remaining borrowing capacity	1,486,635,000
Loans designated as potential collateral under collateralized line of credit with FHLB	198,309,000
Investment securities designated as potential collateral under collateral line of credit	2,183,416,000
Repurchase investment securities sold and pledged as collateral under securities repurchase agreement	39,957,000
Collateralized line of credit with San Francisco Federal Reserve Bank, maximum borrowings capacity	141,993,000
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	141,993,000
Investment securities designated as potential collateral under collateral line of credit with San Francisco Federal Reserve Bank	14,000
Loans designated as potential collateral under collateral line of credit with San Francisco Federal Reserve Bank	267,570,000
Unused correspondent banking lines of credit from commercial banks for federal funds	20,000,000
0.05% Fixed Rate Collateralized Borrowings [Member]
Schedule Of Borrowings [Line Items]
Collateralized borrowings	$ 16,819,000	$ 17,437,000

Junior Subordinated Debt - Addi

Junior Subordinated Debt - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2018USD ($)LocationTrust	Dec. 31, 2017USD ($)	Oct. 03, 2014USD ($)
Class of Stock [Line Items]
Number of subsidiary business trusts | Trust	5
Trust preferred securities amount	$ 62,889,000
Subordinated debenture, recorded fair value	$ 56,950,000	$ 56,858,000
Number of locations organized | Location	2
Change in junior subordinated debt	$ 92,000
Capital Trusts [Member]
Class of Stock [Line Items]
Trust preferred securities amount	62,900,000
North Valley Trust II [Member]
Class of Stock [Line Items]
Trust preferred securities amount	6,186,000
Subordinated debenture, recorded fair value	5,154,000	5,135,000	$ 5,006,000
North Valley Trust III [Member]
Class of Stock [Line Items]
Trust preferred securities amount	5,155,000
Subordinated debenture, recorded fair value	4,060,000	4,041,000	3,918,000
North Valley Trust IV [Member]
Class of Stock [Line Items]
Trust preferred securities amount	10,310,000
Subordinated debenture, recorded fair value	$ 6,498,000	$ 6,444,000	$ 6,063,000
North Valley Bancorp [Member]
Class of Stock [Line Items]
Number of locations acquired | Location	3
Acquisition, completion date	Oct. 3, 2014
Maximum [Member]
Class of Stock [Line Items]
Consecutive payments of interest on debenture defer Period	5 years

Junior Subordinated Debt - Summ

Junior Subordinated Debt - Summary of Terms and Recorded Balance of Subordinated Debenture (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Oct. 03, 2014
Subordinated Borrowing [Line Items]
Subordinated debenture, Face Value	$ 62,889,000
Subordinated debenture, Recorded Book Value	$ 56,950,000	$ 56,858,000
TriCo Capital Trust I [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Oct. 7, 2033
Subordinated debenture, Face Value	$ 20,619,000
Subordinated debenture, Current Coupon Rate	5.40%
Subordinated debenture, Recorded Book Value	$ 20,619,000	20,619,000
TriCo Capital Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Jul. 23, 2034
Subordinated debenture, Face Value	$ 20,619,000
Subordinated debenture, Current Coupon Rate	4.91%
Subordinated debenture, Recorded Book Value	$ 20,619,000	20,619,000
North Valley Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Apr. 24, 2033
Subordinated debenture, Face Value	$ 6,186,000
Subordinated debenture, Current Coupon Rate	5.61%
Subordinated debenture, Recorded Book Value	$ 5,154,000	5,135,000	$ 5,006,000
North Valley Trust III [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Apr. 24, 2034
Subordinated debenture, Face Value	$ 5,155,000
Subordinated debenture, Current Coupon Rate	5.16%
Subordinated debenture, Recorded Book Value	$ 4,060,000	4,041,000	3,918,000
North Valley Trust IV [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Mar. 15, 2036
Subordinated debenture, Face Value	$ 10,310,000
Subordinated debenture, Current Coupon Rate	3.67%
Subordinated debenture, Recorded Book Value	$ 6,498,000	$ 6,444,000	$ 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 -

Commitments and Contingencies - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)$ / sharesshares	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)site$ / sharesshares	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)shares	Aug. 21, 2007shares
Conversion of Stock [Line Items]
Reserves to satisfy Federal regulatory requirements	$ 85,078,000		$ 85,078,000		$ 82,068,000
Number of sites leased under non-cancelable operating leases | site			44
Rent expense under operating leases	949,000	$ 1,048,000	$ 1,869,000	$ 2,095,000
Rent expense offset by rent income	$ 10,000	$ 10,000	$ 21,000	$ 23,000
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. | shares	23,004,153		23,004,153		22,955,963	15,814,662
Conversion ratio			1.648265
Common Class B [Member]
Conversion of Stock [Line Items]
Class B common stock of Visa Inc. | shares	13,396		13,396
Common Class A [Member]
Conversion of Stock [Line Items]
The value of the Class A shares | $ / shares	$ 132.45		$ 132.45
Value of unredeemed Class A equivalent shares	$ 2,925,000		$ 2,925,000

Commitments and Contingencie104

Commitments and Contingencies - Future Minimum Commitments under Non-Cancelable Operating Leases with Initial or Remaining Terms of One Year or More (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Leases [Abstract]
2,018	$ 3,278
2,019	2,499
2,020	1,847
2,021	1,488
2,022	757
Thereafter	798
Future minimum lease payments	$ 10,667

Commitments and Contingencie105

Commitments and Contingencies - Summary of Bank's Commitments and Contingent Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit
Construction [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	223,956	187,097
RE Mortgage [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	61,185	66,267
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	11,535	13,075
Commercial [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	266,538	257,220
Consumer Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	443,265	422,958
Deposit Account Overdraft Privilege [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	$ 97,670	$ 98,260

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Aug. 21, 2007
Class of Stock [Line Items]
Repurchase of common stock							500,000
Stock repurchase plan percentage of common stock							3.20%
Common stock, shares outstanding	23,004,153		23,004,153		22,955,963		15,814,662
Repurchased shares outstanding	166,600		166,600
Market value of common stock			$ 671,000	$ 3,092,000
Maximum [Member]
Class of Stock [Line Items]
Cash dividend payable by bank					$ 85,254,000
Tri Counties Bank [Member]
Class of Stock [Line Items]
Cash dividends received	$ 4,770,000	$ 5,167,000	$ 9,142,000	$ 9,209,000
Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares outstanding	23,004,153	22,925,069	23,004,153	22,925,069	22,955,963	22,867,802
Company's common stock in lieu of cash to exercise options to purchase shares	17,086	69,401	17,220	85,652
Market value of common stock	$ 667,000	$ 2,488,000	$ 671,000	$ 3,092,000

Stock Options and Other Equi107

Stock Options and Other Equity-Based Incentive Instruments - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding options under the plan	428,900	446,400
Options currently not exercisable yet expected to vest	3,000
Weighted-average remaining contractual term	1 year 3 months 18 days
Pre-tax compensation costs expected to recognize	$ 20,000
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	69,636	68,457
Weighted-average remaining contractual term	1 year 6 months
Pre-tax compensation costs	$ 2,018,000
Number of units released	25,398
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	51,792	52,829
Weighted-average remaining contractual term	1 year 10 months 24 days
Pre-tax compensation costs	$ 1,116,000
Number of units released	25,512
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
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
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	77,689
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
Number of shares to be reduced pursuant to restricted stock award for computation of available number of shares for issuance	2
Outstanding options under the plan	408,900
Options available for grant under the plan	376,144
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	121,428
2001 Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding options under the plan	20,000
Options available for grant under the plan	0
Share based compensation grant expiry period	10 years

Stock Options and Other Equi108

Stock Options and Other Equity-Based Incentive Instruments - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Number of Shares, beginning balance	446,400
Options granted, Number of Shares	0
Options exercised, Number of Shares	(14,500)
Options forfeited, Number of Shares	(3,000)
Options outstanding, Number of Shares, ending balance	428,900
Options outstanding, Weighted Average Exercise Price, beginning balance	$ 16.84
Options granted, Weighted Average Exercise Price	0
Options exercised, Weighted Average Exercise Price	15.40
Options forfeited, Weighted Average Exercise Price	23.21
Options outstanding, Weighted Average Exercise Price, ending balance	$ 16.85
Options Outstanding, Value on Date of Grant	$ 0	$ 0
Options granted, Weighted Average Fair Value	$ 0
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	0
Options exercised, Option Price per Share	15.40
Options forfeited, Option Price per Share	23.21
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	23.21
Options granted, Option Price per Share	0
Options exercised, Option Price per Share	15.40
Options forfeited, Option Price per Share	23.21
Options outstanding, Option Price per Share, ending balance	$ 23.21

Stock Options and Other Equi109

Stock Options and Other Equity-Based Incentive Instruments - Summary of Options Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options	428,900	446,400
Weighted average exercise price	$ 16.85	$ 16.84
Intrinsic value (in thousands)	$ 8,837
Weighted average remaining contractual term (yrs.)	3 years 6 months
Currently Exercisable [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options	425,900
Weighted average exercise price	$ 16.80
Intrinsic value (in thousands)	$ 8,794
Weighted average remaining contractual term (yrs.)	3 years 6 months
Currently Not Exercisable [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options	3,000
Weighted average exercise price	$ 23.21
Intrinsic value (in thousands)	$ 43
Weighted average remaining contractual term (yrs.)	6 years 3 months 18 days

Stock Options and Other Equi110

Stock Options and Other Equity-Based Incentive Instruments - Restricted Stock Unit (RSU) Activity (Detail) - Restricted Stock Units (RSUs) [Member]	6 Months Ended
	Jun. 30, 2018$ / sharesshares
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	52,829
RSUs granted, Number of RSUs	16,939
Additional market plus service condition RSUs vested, Number of RSUs	8,506
RSUs released through vesting, Number of RSUs	(25,512)
RSUs forfeited/expired, Number of RSUs	(970)
RSUs outstanding, Number of RSUs, ending balance	51,792
RSUs granted, Weighted Average Fair Value on Date of Grant | $ / shares	$ 36.40
Service Condition Vesting RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs outstanding, Number of RSUs, beginning balance	68,457
RSUs granted, Number of RSUs	26,939
RSUs added through dividend credits, Number of RSUs	545
RSUs released through vesting, Number of RSUs	(25,398)
RSUs forfeited/expired, Number of RSUs	(907)
RSUs outstanding, Number of RSUs, ending balance	69,636
RSUs granted, Weighted Average Fair Value on Date of Grant | $ / shares	$ 39.31

Noninterest Income and Expen111

Noninterest Income and Expense - Components of Other Noninterest Income (Detail) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Schedule Of Other Noninterest Income And Expense [Line Items]
Commissions on sale of non-deposit investment products	$ 810				$ 705		$ 1,686	$ 1,312
Gain on sale of loans	666				777		1,292	1,687
Increase in cash value of life insurance	656				626		1,264	1,311
Gain on sale of foreclosed assets	17				153		388	271
Lease brokerage income	200				161		328	367
Sale of customer checks	138				94		239	198
Change in indemnification asset					711			490
Life insurance proceeds in excess of cash value								108
Loss on disposal of fixed assets	(41)				(28)		(54)	(28)
Loss on marketable equity securities	(23)						(70)
Other	523				232		807	511
Total other noninterest income	2,946				3,431		5,880	6,227
Total noninterest income	12,174	$ 12,290	$ 12,478	$ 12,930	12,910	$ 11,703	24,464	24,613
Service Charges on Deposit Accounts [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees	3,613				4,323		7,392	7,942
ATM and Interchange Fees [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees	4,510				4,248		8,745	8,263
Other Service Fees [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees	630				839		1,344	1,604
Mortgage Banking Service Fees [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees	511				526		1,028	1,047
Change in Value of Mortgage Servicing Rights [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees	(36)				(457)		75	(470)
Financial Service [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees	$ 9,228				$ 9,479		$ 18,584	$ 18,386

Noninterest Income and Expen112

Noninterest Income and Expense - Components of Noninterest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Schedule Of Other Noninterest Income And Expense [Line Items]
Base salaries, net of deferred loan origination costs	$ 14,429				$ 13,657		$ 28,391	$ 27,047
Incentive compensation	2,159				2,173		4,611	4,371
Benefits and other compensation costs	4,865				4,664		10,103	9,969
Total salaries and benefits expense	21,453				20,494		43,105	41,387
Occupancy	2,720				2,705		5,401	5,397
Data processing and software	2,679				2,441		5,193	4,837
Equipment	1,637				1,805		3,188	3,528
ATM and POS network charges	1,437				1,075		2,663	1,928
Advertising	1,035				1,167		1,873	2,134
Professional fees	774				690		1,546	1,456
Telecommunications	681				668		1,382	1,311
Reserve for unfunded commitments	(137)				(135)		563	(120)
Merger and acquisition expense	601						1,077
Assessments	417				420		847	825
Postage	301				329		659	733
Intangible amortization	339				352		678	711
Operational losses	252				430		546	865
Courier service	224				263		491	517
Provision for foreclosed asset losses					94		90	28
Foreclosed assets expense	180				38		204	76
Other miscellaneous expense	3,277				3,068		6,526	6,113
Total other noninterest expense	16,417				15,410		32,927	30,339
Total noninterest expense	37,870	$ 38,162	$ 38,076	$ 37,222	$ 35,904	$ 35,822	76,032	$ 71,726
Total merger and acquisition expense	601						1,077
North Valley Bancorp [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Occupancy	49						49
Equipment	11						11
Professional fees	196						552
Advertising and marketing	164						172
Postage	7						7
Other miscellaneous expense	$ 174						$ 286

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Tax Rate and Statutory Federal Income Tax Rate (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%	35.00%	21.00%	35.00%	35.00%
State income taxes, net of federal tax benefit	8.80%	6.60%	8.90%	6.70%
Tax-exempt interest on municipal obligations	(1.00%)	(1.70%)	(1.10%)	(1.80%)
Increase in cash value of insurance policies	(0.70%)	(1.00%)	(0.70%)	(1.20%)
Low income housing tax credits	(0.60%)	(0.70%)	(0.80%)	(0.70%)
Equity compensation	(0.40%)	(2.10%)	(0.20%)	(1.30%)
Nondeductible merger expenses	0.30%		0.30%
Other	0.40%	(0.10%)	0.50%	0.20%
Effective Tax Rate	27.80%	36.00%	27.90%	36.90%

Earnings Per Share - Computatio

Earnings Per Share - Computation of Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Net income	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	$ 28,939	$ 25,668
Average number of common shares outstanding	22,983				22,900		22,970	22,885
Effect of dilutive stock options and restricted stock	293				340		310	351
Average number of common shares outstanding used to calculate diluted earnings per share	23,276				23,240		23,280	23,236
Options excluded from diluted earnings per share because the effect of these options was antidilutive	0				0		0	0

Comprehensive Income - Componen

Comprehensive Income - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ (21,123)	$ (5,228)
Net Unrealized Loss on Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, before tax	(24,651)	(3,409)
Accumulated other comprehensive loss, tax effect	7,288	1,433
Accumulated other comprehensive loss	(17,363)	(1,976)
Unfunded Status of Supplemental Retirement Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, before tax	(5,124)	(5,352)
Accumulated other comprehensive loss, tax effect	1,514	2,250
Accumulated other comprehensive loss	(3,610)	(3,102)
Joint Beneficiary Agreement Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, before tax	(150)	(150)
Accumulated other comprehensive loss	$ (150)	$ (150)

Comprehensive Income - Compo116

Comprehensive Income - Components of Other Comprehensive Income (Loss) and Related Tax Effects (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized holding gains (losses) on available for sale securities before reclassifications	$ (5,676)	$ 4,911	$ (20,941)	$ 5,698
Amounts reclassified out of accumulated other comprehensive income:
Total amounts reclassified out of accumulated other comprehensive income			(363)
Unrealized holding gains (losses) on available for sale securities after reclassifications	(5,676)	4,911	(21,304)	5,698
Tax effect	1,678	(2,065)	6,280	(2,395)
Unrealized holding gains (losses) on available for sale securities, net of tax	(3,998)	2,846	(15,024)	3,303
Change in unfunded status of the supplemental retirement plans before reclassifications			668
Amounts reclassified out of accumulated other comprehensive income:
Amortization of prior service cost	(13)	(1)	(27)	(4)
Amortization of actuarial losses	127	96	254	192
Total amounts reclassified out of accumulated other comprehensive income	114	95	(441)	188
Change in unfunded status of the supplemental retirement plans after reclassifications	114	95	227	188
Tax effect	(34)	(40)	(67)	(79)
Change in unfunded status of the supplemental retirement plans, net of tax	80	55	160	109
Change in joint beneficiary agreement liability before reclassifications	0	0	0	0
Amounts reclassified out of accumulated other comprehensive income	0	0	0	0
Change in joint beneficiary agreement liability after reclassifications	0	0	0	0
Tax effect	0	0	0	0
Change in joint beneficiary agreement liability, net of tax	0	0	0	0
Other comprehensive income (loss)	$ (3,918)	$ 2,901	(14,864)	$ 3,412
ASU 2016-01 [Member]
Amounts reclassified out of accumulated other comprehensive income:
Total amounts reclassified out of accumulated other comprehensive income			62
ASU 2018-02 [Member]
Amounts reclassified out of accumulated other comprehensive income:
Total amounts reclassified out of accumulated other comprehensive income			(425)
Amounts reclassified out of accumulated other comprehensive income:
Total amounts reclassified out of accumulated other comprehensive income			$ (668)

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation obligations	$ 6,932,000		$ 6,932,000			$ 6,605,000
401(k) Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum age for employees			21 years
Minimum period for employees to participate			90 days
Discretionary matching contribution equal to percentage of participant's contribution			50.00%
Discretionary matching contribution maximum percentage of eligible compensation			4.00%
Employer's contribution to retirement plan	$ 247,000	$ 192,000	$ 446,000	$ 371,000
Supplemental Retirement Plans [Member] | Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer's contribution to retirement plan					$ 1,106,000

Retirement Plans - Summary of 4

Retirement Plans - Summary of 401(k) Contribution Plan (Detail) - 401(k) Plan [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
401(k) Plan benefits expense	$ 251	$ 194	$ 454	$ 380
401(k) Plan contributions made by the Company	$ 247	$ 192	$ 446	$ 371

Retirement Plans - Summary of E

Retirement Plans - Summary of ESOP Activities (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Retirement Benefits [Abstract]
ESOP benefits expense	$ 475	$ 540	$ 940	$ 1,065
ESOP contributions made by the Company	$ 940	$ 1,073	$ 1,479	$ 1,536

Retirement Plans - Schedule of

Retirement Plans - Schedule of Deferred Compensation Earnings Credits Included in Noninterest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Retirement Benefits [Abstract]
Deferred compensation earnings credits included in noninterest expense	$ 121	$ 109	$ 245	$ 254

Retirement Plans - Net Periodic

Retirement Plans - Net Periodic Benefit Cost Recognized for Supplemental Retirement Plans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net pension cost included the following components:
Service cost-benefits earned during the period	$ 243	$ 235	$ 486	$ 470
Interest cost on projected benefit obligation	237	248	475	496
Amortization of net obligation at transition		1	1	1
Amortization of prior service cost	(13)	(3)	(27)	(6)
Recognized net actuarial loss	127	97	254	195
Net periodic pension cost	594	578	1,189	1,156
Company contributions to pension plans	287	329	554	588
Pension plan payouts to participants	$ 287	$ 329	$ 554	$ 588

Related Party Transactions - Su

Related Party Transactions - Summary of Activity in Lending Transactions (Detail) - Directors and Officers [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Beginning balance	$ 2,148	$ 2,432
Advances/new loans	145	437
Removed/payments	(480)	(721)
Ending balance	$ 1,813	$ 2,148

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Related Party Transactions [Abstract]
Bank deposits of directors, officers and other related parties	$ 28,910,000	$ 46,025,000

Fair Value Measurement - Record

Fair Value Measurement - Recorded Amount of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value Measurements on Recurring Basis [Member] - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 764,096	$ 737,570
Marketable Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,868	2,938
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	635,428	604,789
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	118,779	123,156
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	7,021	6,687
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,868	2,938
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	2,868	2,938
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	754,207	727,945
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	635,428	604,789
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	118,779	123,156
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	7,021	6,687
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	$ 7,021	$ 6,687

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Transfers between level 1 to level 2, Assets	$ 0	$ 0
Transfers between level 2 to level 1, Assets	0	0
Transfers between level 1 to level 2, Liabilities	0	0
Transfers between level 2 to level 1, Liabilities	0	0
Transfer into level 3	0	0
Transfer out of level 3	0	$ 0
Carrying value of loans fully charged-off	$ 0

Fair Value Measurement - Reconc

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 ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 6,953	$ 6,860	$ 6,687	$ 6,595
Transfers into (out of) Level 3	0	0	0	0
Change Included in Earnings	(36)	(457)	75	(470)
Issuances	104	193	259	471
Ending Balance	$ 7,021	$ 6,596	$ 7,021	$ 6,596

Fair Value Measurement - Quanti

Fair Value Measurement - Quantitative Information about Recurring Level 3 Fair Value Measurements (Detail) - Mortgage Servicing Rights [Member] $ in Thousands	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgages Servicing Rights, Fair Value	$ 7,021	$ 6,953	$ 6,687	$ 6,596	$ 6,860	$ 6,595
Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Constant Prepayment Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Constant prepayment rate	0.049		0.062
Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Constant prepayment rate	0.125		0.130
Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Constant Prepayment Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Constant prepayment rate	0.277		0.220
Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Constant prepayment rate	0.135		0.150
Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Constant Prepayment Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Constant prepayment rate	0.074		0.089
Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Constant prepayment rate	0.125		0.130

Fair Value Measurement - Assets

Fair Value Measurement - Assets and Liabilities Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Impaired Originated & PNCI Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 1,647		$ 2,767
Fair Value Nonrecurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,231	$ 1,789	4,984
Total Gains/(Losses)	(595)	(484)	(1,587)
Fair Value Nonrecurring Basis [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	1,647	686	2,767
Total Gains/(Losses)	(505)	(456)	(1,452)
Fair Value Nonrecurring Basis [Member] | Foreclosed Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	584	1,103	2,217
Total Gains/(Losses)	(90)	(28)	(135)
Fair Value Nonrecurring Basis [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,231	1,789	4,984
Fair Value Nonrecurring Basis [Member] | 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	1,647	686	2,767
Fair Value Nonrecurring Basis [Member] | 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	$ 584	$ 1,103	$ 2,217

Fair Value Measurement - Qua129

Fair Value Measurement - Quantitative Information about Level 3 Fair Value Measurements for Financial Instruments Measured at Fair Value on Nonrecurring Basis (Detail) $ in Thousands	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Impaired Originated & PNCI Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 1,647	$ 2,767
Foreclosed Assets [Member] | Land & Construction [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	492	1,341
Foreclosed Assets [Member] | Residential Real Estate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 92	622
Foreclosed Assets [Member] | Commercial Real Estate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value		$ 254
Level 3 [Member] | Sales Comparison Approach [Member] | Minimum [Member] | Impaired Originated & PNCI Loans [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average	(0.7000)	(0.7400)
Level 3 [Member] | Sales Comparison Approach [Member] | Minimum [Member] | Foreclosed Assets [Member] | Land & Construction [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average	(0.4700)	(0.53)
Level 3 [Member] | Sales Comparison Approach [Member] | Minimum [Member] | Foreclosed Assets [Member] | Residential Real Estate [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average	(0.65)	(0.4700)
Level 3 [Member] | Sales Comparison Approach [Member] | Minimum [Member] | Foreclosed Assets [Member] | Commercial Real Estate [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average		(0.84)
Level 3 [Member] | Sales Comparison Approach [Member] | Maximum [Member] | Impaired Originated & PNCI Loans [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average	0.6000	0.2300
Level 3 [Member] | Sales Comparison Approach [Member] | Maximum [Member] | Foreclosed Assets [Member] | Land & Construction [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average	0.3900	2.83
Level 3 [Member] | Sales Comparison Approach [Member] | Maximum [Member] | Foreclosed Assets [Member] | Residential Real Estate [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average	0.20	0.3900
Level 3 [Member] | Sales Comparison Approach [Member] | Maximum [Member] | Foreclosed Assets [Member] | Commercial Real Estate [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average		0.19
Level 3 [Member] | Sales Comparison Approach [Member] | Weighted Average [Member] | Impaired Originated & PNCI Loans [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average	(0.0741)	(0.1976)
Level 3 [Member] | Sales Comparison Approach [Member] | Weighted Average [Member] | Foreclosed Assets [Member] | Land & Construction [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average	0.0364	1.67
Level 3 [Member] | Sales Comparison Approach [Member] | Weighted Average [Member] | Foreclosed Assets [Member] | Residential Real Estate [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average	(0.45)	(0.0313)
Level 3 [Member] | Sales Comparison Approach [Member] | Weighted Average [Member] | Foreclosed Assets [Member] | Commercial Real Estate [Member] | Adjustment for Differences between Comparable Sales [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average		(0.84)

Fair Value Measurement - Estima

Fair Value Measurement - Estimated Fair Values of Financial Instruments that are Reported at Amortized Cost in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financial assets:
Cash and due from banks	$ 94,661	$ 105,968
Cash at Federal Reserve and other banks	89,401	99,460
Securities held to maturity	477,745	514,844
Financial liabilities:
Other borrowings	152,839	122,166
Junior subordinated debt	56,950	56,858
Level 3 [Member] | Overdraft Privilege Commitments [Member]
Off-balance sheet:
Contract amount, Off-balance sheet	97,670	98,260
Level 3 [Member] | Standby Letters of Credit [Member]
Off-balance sheet:
Contract amount, Off-balance sheet	11,535	13,075
Level 3 [Member] | Commitments [Member]
Off-balance sheet:
Contract amount, Off-balance sheet	994,944	933,542
Fair Value [Member] | Level 3 [Member]
Financial assets:
Loans, net	3,091,134	2,992,225
Financial liabilities:
Junior subordinated debt	58,930	58,466
Fair Value [Member] | Level 3 [Member] | Overdraft Privilege Commitments [Member]
Off-balance sheet:
Fair value, Off-balance sheet	977	983
Fair Value [Member] | Level 3 [Member] | Standby Letters of Credit [Member]
Off-balance sheet:
Fair value, Off-balance sheet	115	131
Fair Value [Member] | Level 3 [Member] | Commitments [Member]
Off-balance sheet:
Fair value, Off-balance sheet	9,949	9,335
Fair Value [Member] | Level 1 [Member]
Financial assets:
Cash and due from banks	94,661	105,968
Cash at Federal Reserve and other banks	89,401	99,460
Fair Value [Member] | Level 2 [Member]
Financial assets:
Securities held to maturity	468,621	518,165
Loans held for sale	3,601	4,616
Financial liabilities:
Deposits	4,073,628	4,006,620
Other borrowings	152,839	122,166
Carrying Amount [Member] | Level 3 [Member]
Financial assets:
Loans, net	3,116,789	2,984,842
Financial liabilities:
Junior subordinated debt	56,950	56,858
Carrying Amount [Member] | Level 1 [Member]
Financial assets:
Cash and due from banks	94,661	105,968
Cash at Federal Reserve and other banks	89,401	99,460
Carrying Amount [Member] | Level 2 [Member]
Financial assets:
Securities held to maturity	477,745	514,844
Restricted equity securities	16,956	16,956
Loans held for sale	3,601	4,616
Financial liabilities:
Deposits	4,077,222	4,009,131
Other borrowings	$ 152,839	$ 122,166

TriCo Bancshares Condensed F131

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 184,062	$ 205,428
Other assets	57,409	55,051
Total assets	4,863,153	4,761,315
Liabilities and shareholders' equity
Other liabilities	58,896	63,258
Junior subordinated debt	56,950	56,858
Total liabilities	4,350,809	4,255,507
Shareholders' equity:
Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at June 30, 2018 and December 31, 2017
Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 23,004,153 and 22,955,963 shares, respectively	256,590	255,836
Retained earnings	276,877	255,200
Accumulated other comprehensive loss, net	(21,123)	(5,228)
Total shareholders' equity	512,344	505,808	$ 498,944	$ 477,347
Total liabilities and shareholders' equity	4,863,153	4,761,315
Parent [Member]
Assets
Cash and cash equivalents	3,069	3,924
Investment in Tri Counties Bank	565,047	557,538
Other assets	1,742	1,721
Total assets	569,858	563,183
Liabilities and shareholders' equity
Other liabilities	564	517
Junior subordinated debt	56,950	56,858
Total liabilities	57,514	57,375
Shareholders' equity:
Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at June 30, 2018 and December 31, 2017
Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 23,004,153 and 22,955,963 shares, respectively	256,590	255,836
Retained earnings	276,877	255,200
Accumulated other comprehensive loss, net	(21,123)	(5,228)
Total shareholders' equity	512,344	505,808
Total liabilities and shareholders' equity	$ 569,858	$ 563,183

TriCo Bancshares Condensed F132

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Balance Sheets (Parenthetical) (Detail) - $ / shares	Jun. 30, 2018	Dec. 31, 2017	Aug. 21, 2007
Condensed Financial Statements, Captions [Line Items]
Preferred stock, par value	$ 0	$ 0
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	23,004,153	22,955,963
Common stock, shares outstanding	23,004,153	22,955,963	15,814,662
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Preferred stock, par value	$ 0	$ 0
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	23,004,153	22,955,963
Common stock, shares outstanding	23,004,153	22,955,963

TriCo Bancshares Condensed F133

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Condensed Financial Statements, Captions [Line Items]
Interest expense	$ (2,609)	$ (2,135)	$ (1,868)	$ (1,829)	$ (1,610)	$ (1,491)	$ (4,744)	$ (3,101)
Income before income taxes	20,811	19,350	17,818	19,027	21,236	19,431	40,161	40,667
Equity in net income of Tri Counties Bank:
Income tax benefit	(5,782)	(5,440)	(14,829)	(7,130)	(7,647)	(7,352)	(11,222)	(14,999)
Net income	15,029	$ 13,910	$ 2,989	$ 11,897	13,589	$ 12,079	28,939	25,668
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Interest expense	(789)				(623)		(1,486)	(1,218)
Administration expense	(511)				(218)		(937)	(377)
Income before income taxes	(1,300)				(841)		(2,423)	(1,595)
Equity in net income of Tri Counties Bank:
Distributed	4,770				5,167		9,142	9,209
Undistributed	11,253				8,909		21,650	17,383
Income tax benefit	306				354		570	671
Net income	$ 15,029				$ 13,589		$ 28,939	$ 25,668

TriCo Bancshares Condensed F134

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Condensed Financial Statements, Captions [Line Items]
Net income	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	$ 28,939	$ 25,668
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) on available for sale securities arising during the period	(3,998)				2,846		(15,024)	3,303
Change in minimum pension liability	80				55		160	109
Other comprehensive income (loss)	(3,918)				2,901		(14,864)	3,412
Comprehensive income	11,111				16,490		14,075	29,080
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	15,029				13,589		28,939	25,668
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) on available for sale securities arising during the period	(3,998)				2,846		(15,024)	3,303
Change in minimum pension liability	80				55		160	109
Other comprehensive income (loss)	(3,918)				2,901		(14,864)	3,412
Comprehensive income	$ 11,111				$ 16,490		$ 14,075	$ 29,080

TriCo Bancshares Condensed F135

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net income	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	$ 28,939	$ 25,668
Adjustments to reconcile net income to net cash provided by operating activities:
Equity compensation vesting expense							722	774
Net cash from operating activities							32,944	27,556
Financing activities:
Issuance of common stock through option exercise							185	193
Repurchase of common stock							(633)	(1,122)
Cash dividends paid - common							(7,813)	(7,328)
Net cash from financing activities							90,503	(20,328)
Net change in cash and cash equivalents							(21,366)	(137,963)
Cash and cash equivalents at beginning of year		205,428		167,649		305,612	205,428	305,612
Cash and cash equivalents at end of year	184,062		205,428		167,649		184,062	167,649
Parent [Member]
Operating activities:
Net income	15,029				13,589		28,939	25,668
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed equity in earnings of Tri Counties Bank	(11,253)				(8,909)		(21,650)	(17,383)
Equity compensation vesting expense							722	774
Net change in other assets and liabilities							(605)	(672)
Net cash from operating activities							7,406	8,387
Financing activities:
Issuance of common stock through option exercise							185	192
Repurchase of common stock							(633)	(1,121)
Cash dividends paid - common							(7,813)	(7,328)
Net cash from financing activities							(8,261)	(8,257)
Net change in cash and cash equivalents							(855)	130
Cash and cash equivalents at beginning of year		$ 3,924		$ 2,932		$ 2,802	3,924	2,802
Cash and cash equivalents at end of year	$ 3,069		$ 3,924		$ 2,932		$ 3,069	$ 2,932

Regulatory Matters - Actual and

Regulatory Matters - Actual and Required Capital Ratios of Bank (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Schedule of Capitalization [Line Items]
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	8.00%	8.00%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.50%	6.50%
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	$ 550,769	$ 528,805
Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	517,518	495,318
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	462,278	440,643
Tier 1 Capital (to Average Assets), Actual, Amount	$ 517,518	$ 495,318
Total Capital (to Risk Weighted Assets), Actual, Ratio	13.91%	14.07%
Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	13.07%	13.18%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	11.68%	11.72%
Tier 1 Capital (to Average Assets), Actual, Ratio	10.92%	10.80%
Parent [Member] | Basel III Phase-in Schedule [Member]
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	$ 390,991	$ 347,694
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	311,803	272,517
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	252,412	216,134
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$ 189,647	$ 183,400
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	9.875%	9.25%
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	7.875%	7.25%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	6.375%	5.75%
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%
Parent [Member] | Basel III Fully Phased In [Member]
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	$ 415,737	$ 394,679
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	336,549	319,502
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	277,158	263,120
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$ 189,647	$ 183,400
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	10.50%	10.50%
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	8.50%	8.50%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	7.00%	7.00%
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	$ 548,232	$ 525,384
Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	514,981	491,897
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	514,981	491,897
Tier 1 Capital (to Average Assets), Actual, Amount	$ 514,981	$ 491,897
Total Capital (to Risk Weighted Assets), Actual, Ratio	13.85%	13.98%
Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	13.01%	13.09%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	13.01%	13.09%
Tier 1 Capital (to Average Assets), Actual, Ratio	10.86%	10.73%
Total Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 395,766	$ 375,713
Tier 1 Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	316,613	300,570
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	257,248	244,214
Tier 1 Capital (to Average Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	237,054	229,243
Tri Countries Bank [Member] | Basel III Phase-in Schedule [Member]
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	390,819	347,535
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	311,666	272,392
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	252,301	216,035
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$ 189,643	$ 183,394
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	9.875%	9.25%
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	7.875%	7.25%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	6.375%	5.75%
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%
Tri Countries Bank [Member] | Basel III Fully Phased In [Member]
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	$ 415,554	$ 394,499
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	336,401	319,356
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	277,036	262,999
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$ 189,643	$ 183,394
Total Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	10.50%	10.50%
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	8.50%	8.50%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Ratio	7.00%	7.00%
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Ratio	4.00%	4.00%

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Detail)	Dec. 31, 2019	Jun. 30, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Increase in risk-based capital ratios		0.625%
Scenario, Forecast [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Minimum capital level requirements, Tier 1 capital ratio	8.50%
Minimum capital level requirements, Total capital ratio	10.50%
Scenario, Forecast [Member] | Common Stock [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Minimum capital level requirements, Tier 1 capital ratio	7.00%

Summary of Quarterly Results of

Summary of Quarterly Results of Operations (Unaudited) - Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Loans:
Discount accretion PCI - cash basis	$ 180	$ 246	$ 516	$ 398	$ 386	$ 112
Discount accretion PCI - other	95	60	445	407	797	631
Discount accretion PNCI	284	326	528	559	987	798
All other loan interest income	38,745	37,417	36,705	35,904	34,248	33,373
Total loan interest income	39,304	38,049	38,194	37,268	36,418	34,914	$ 77,353	$ 71,332
Debt securities, dividends and interest bearing cash at banks (not FTE)	9,174	9,072	8,767	8,645	8,626	8,570
Total interest and dividend income	48,478	47,121	46,961	45,913	45,044	43,484	95,599	88,528
Interest expense	2,609	2,135	1,868	1,829	1,610	1,491	4,744	3,101
Net interest income	45,869	44,986	45,093	44,084	43,434	41,993	90,855	85,427
Provision for (benefit from reversal of provision for) loan losses	(638)	(236)	1,677	765	(796)	(1,557)	(874)	(2,353)
Net interest income after provision for loan losses	46,507	45,222	43,416	43,319	44,230	43,550	91,729	87,780
Noninterest income	12,174	12,290	12,478	12,930	12,910	11,703	24,464	24,613
Noninterest expense	37,870	38,162	38,076	37,222	35,904	35,822	76,032	71,726
Income before income taxes	20,811	19,350	17,818	19,027	21,236	19,431	40,161	40,667
Income tax expense	5,782	5,440	14,829	7,130	7,647	7,352	11,222	14,999
Net income	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	$ 28,939	$ 25,668
Per common share:
Net income (diluted)	$ 0.65	$ 0.60	$ 0.13	$ 0.51	$ 0.58	$ 0.52	$ 1.24	$ 1.10
Dividends	$ 0.17	$ 0.17	$ 0.17	$ 0.17	$ 0.17	$ 0.15