TriCo Bancshares (TCBK) 10-K 1 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 25, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	TCBK
Entity Registrant Name	TRICO BANCSHARES /
Entity Central Index Key	356,171
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		30,424,119
Entity Public Float			$ 748,354,000

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets:
Cash and due from banks	$ 119,781	$ 105,968
Cash at Federal Reserve and other banks	107,752	99,460
Cash and cash equivalents	227,533	205,428
Investment securities:
Marketable equity securities	2,874	2,938
Available for sale debt securities	1,115,036	727,945
Held to maturity debt securities	444,936	514,844
Restricted equity securities	17,250	16,956
Loans held for sale	3,687	4,616
Loans	4,022,014	3,015,165
Allowance for loan losses	(32,582)	(30,323)
Total loans, net	3,989,432	2,984,842
Foreclosed assets, net	2,280	3,226
Premises and equipment, net	89,347	57,742
Cash value of life insurance	117,318	97,783
Accrued interest receivable	19,412	13,772
Goodwill	220,972	64,311
Other intangible assets, net	29,280	5,174
Mortgage servicing rights	7,098	6,687
Other assets	65,986	55,051
Total assets	6,352,441	4,761,315
Deposits:
Noninterest-bearing demand	1,760,580	1,368,218
Interest-bearing	3,605,886	2,640,913
Total deposits	5,366,466	4,009,131
Accrued interest payable	1,997	930
Other liabilities	83,724	66,422
Other borrowings	15,839	122,166
Junior subordinated debt	57,042	56,858
Total liabilities	5,525,068	4,255,507
Commitments and contingencies (Note 14)
Shareholders' equity:
Preferred stock, no par value: 1,000,000 shares authorized; zero issued and outstanding at December 31, 2018 and 2017
Common stock, no par value: 50,000,000 shares authorized; issued and outstanding: 30,417,223 and 22,955,963 at December 31, 2018 and 2017, respectively	541,762	255,836
Retained earnings	303,490	255,200
Accumulated other comprehensive loss, net of tax	(17,879)	(5,228)
Total shareholders' equity	827,373	505,808
Total liabilities and shareholders' equity	$ 6,352,441	$ 4,761,315

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 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	30,417,223	22,955,963
Common stock, shares outstanding	30,417,223	22,955,963	15,814,662

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest and dividend income:
Loans, including fees	$ 186,117	$ 146,794	$ 141,086
Investments:
Taxable securities	33,997	27,772	25,397
Tax exempt securities	4,345	4,165	3,881
Dividends	1,705	1,324	2,181
Interest bearing cash at Federal Reserve and other banks	2,054	1,347	1,163
Total interest and dividend income	228,218	181,402	173,708
Interest expense:
Deposits	6,996	3,958	3,483
Other borrowings	2,745	305	9
Junior subordinated debt	3,131	2,535	2,229
Total interest expense	12,872	6,798	5,721
Net interest income	215,346	174,604	167,987
Provision for (benefit from) loan losses	2,583	89	(5,970)
Net interest income after provision for (benefit from) loan losses	212,763	174,515	173,957
Noninterest income:
Service charges and fees	38,460	37,423	33,226
Commissions on sale of non-deposit investment products	3,151	2,729	2,329
Increase in cash value of life insurance	2,718	2,685	2,717
Gain on sale of loans	2,371	3,109	4,037
Gain on sale of investment securities	207	961
Other	2,377	3,114	2,254
Total noninterest income	49,284	50,021	44,563
Noninterest expense:
Salaries and related benefits	93,942	82,930	80,724
Other	74,753	64,094	65,273
Total noninterest expense	168,695	147,024	145,997
Income before income taxes	93,352	77,512	72,523
Provision for income taxes	25,032	36,958	27,712
Net income	$ 68,320	$ 40,554	$ 44,811
Earnings per share:
Basic	$ 2.57	$ 1.77	$ 1.96
Diluted	$ 2.54	$ 1.74	$ 1.94

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 23,211	$ 16,170	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	$ 68,320	$ 40,554	$ 44,811
Other comprehensive (loss) income, net of tax:
Unrealized (losses) gains on available for sale securities arising during the period, after reclassifications									(12,434)	3,165	(6,384)
Change in minimum pension liability, after reclassifications									388	(370)	592
Change in joint beneficiary agreement liability									426	(110)	(343)
Other comprehensive (loss) income									(11,620)	2,685	(6,135)
Comprehensive income									$ 56,700	$ 43,239	$ 38,676

Consolidated Statements of Chan

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, 2015	$ 452,116	$ 247,587	$ 206,307	$ (1,778)
Beginning balance, shares at Dec. 31, 2015		22,775,173
Net income	44,811		44,811
Other comprehensive income (loss)	(6,135)			(6,135)
Stock option vesting	580	$ 580
Service condition RSU vesting	616	616
Market plus service condition RSU vesting	271	271
Stock options exercised	6,506	$ 6,506
Stock options exercised, shares		336,900
Tax effect of stock options exercised	154	$ 154
Service condition RSUs released	0	$ 0	0	0
Service condition RSUs released, shares		20,529
Tax benefit from release of service condition RSUs	1	$ 1
Repurchase of common stock, value	(7,878)	$ (2,895)	(4,983)
Repurchase of common stock, shares		(264,800)
Dividends paid	(13,695)		(13,695)
Ending balance at Dec. 31, 2016	477,347	$ 252,820	232,440	(7,913)
Ending balance, shares at Dec. 31, 2016		22,867,802
Net income	40,554		40,554
Other comprehensive income (loss)	2,685			2,685
Stock option vesting	259	$ 259
Service condition RSU vesting	895	895
Market plus service condition RSU vesting	432	432
Stock options exercised	2,621	$ 2,621
Stock options exercised, shares		145,850
Service condition RSUs released	0	$ 0	0	0
Service condition RSUs released, shares		30,896
Market plus service condition RSUs released	0	$ 0	0	0
Market plus service conditions RSUs released, shares		18,805
Repurchase of common stock, value	(3,854)	$ (1,191)	(2,663)
Repurchase of common stock, shares		(107,390)
Dividends paid	(15,131)		(15,131)
Ending balance at Dec. 31, 2017	$ 505,808	$ 255,836	255,200	(5,228)
Ending balance, shares at Dec. 31, 2017	22,955,963	22,955,963
Net income	$ 68,320		68,320
Adoption ASU | ASU 2016-01 [Member]			(62)	62
Adoption ASU | ASU 2018-02 [Member]			1,093	(1,093)
Other comprehensive income (loss)	(11,620)			(11,620)
Stock option vesting	75	$ 75
Service condition RSU vesting	1,017	1,017
Market plus service condition RSU vesting	370	370
Stock options exercised	$ 1,704	$ 1,704
Stock options exercised, shares	100,400	100,400
Service condition RSUs released	$ 0	$ 0	0	0
Service condition RSUs released, shares		35,060
Market plus service condition RSUs released	0	$ 0	0	0
Market plus service conditions RSUs released, shares		25,512
Issuance of common stock	284,437	$ 284,437
Issuance of common stock, shares		7,405,277
Repurchase of common stock, value	(3,969)	$ (1,677)	(2,292)
Repurchase of common stock, shares		(104,989)
Dividends paid	(18,769)		(18,769)
Ending balance at Dec. 31, 2018	$ 827,373	$ 541,762	$ 303,490	$ (17,879)
Ending balance, shares at Dec. 31, 2018	30,417,223	30,417,223

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retained Earnings [Member]
Dividends paid, per share	$ 0.70	$ 0.66	$ 0.60

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities:
Net income	$ 68,320	$ 40,554	$ 44,811
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of premises and equipment, and amortization	7,014	6,787	6,474
Amortization of intangible assets	3,499	1,389	1,377
Provision for (benefit from) loan losses	2,583	89	(5,970)
Amortization of investment securities premium, net	2,512	3,200	4,926
Gain on sale of investment securities	(207)	(961)
Originations of loans for resale	(84,245)	(114,107)	(142,619)
Proceeds from sale of loans originated for resale	86,988	114,788	144,062
Gain on sale of loans	(2,371)	(3,109)	(4,037)
Change in market value of mortgage servicing rights	146	718	2,184
Provision for losses on foreclosed assets	89	162	140
Gain on sale of foreclosed assets	(408)	(711)	(262)
Loss on disposal of fixed assets	185	142	929
Gain on sale of premises held for sale		(3)
Increase in cash value of life insurance	(2,718)	(2,685)	(2,717)
Life insurance proceeds in excess of cash value		(108)	(238)
Loss on marketable equity securities	64
Equity compensation vesting expense	1,462	1,586	1,467
Equity compensation tax effect			(155)
Deferred income tax expense	2,600	12,473	3,190
Change in:
Interest receivable	(5,640)	(1,745)	(1,241)
Interest payable	1,067	112	44
Other assets and liabilities, net	10,129	(3,190)	(4,139)
Net cash from operating activities	91,069	55,381	48,226
Investing activities:
Cash acquired in acquisition, net of consideration paid	30,613		156,316
Proceeds from maturities of securities available for sale	73,014	63,942	71,684
Proceeds from maturities of securities held to maturity	68,937	86,371	121,666
Proceeds from sale of available for sale securities	293,279	25,757
Purchases of securities available for sale	(436,678)	(265,806)	(247,717)
Net redemption of restricted equity securities	7,429
Loan origination and principal collections, net	(173,752)	(247,837)	(251,479)
Loans purchased		(11,567)	(22,503)
Proceeds from sale of loans other than loans originated for resale			37,880
Proceeds from sale of foreclosed assets	2,527	2,872	4,010
Proceeds from sale of premises held for sale		3,338
Proceeds from sale of premises and equipment	63		1,682
Purchases of premises and equipment	(7,435)	(15,164)	(10,930)
Life insurance proceeds		649
Net cash from investing activities	(142,003)	(357,445)	(139,391)
Financing activities:
Net change in deposits	365,400	113,571	103,063
Net change in other borrowings	(271,327)	104,673	5,165
Equity compensation tax effect			155
Repurchase of common stock	(2,483)	(1,629)	(1,890)
Dividends paid	(18,769)	(15,131)	(13,695)
Exercise of stock options	218	396	518
Net cash from financing activities	73,039	201,880	93,316
Net change in cash and cash equivalents	22,105	(100,184)	2,151
Cash and cash equivalents at beginning of year	205,428	305,612	303,461
Cash and cash equivalents at end of year	227,533	205,428	305,612
Supplemental disclosure of noncash activities:
Unrealized (loss) gain on securities available for sale	(17,627)	5,461	(11,015)
Loans transferred to foreclosed assets	1,262	1,563	2,505
Market value of shares tendered in-lieu of cash to pay for exercise of options and/or related taxes	1,486	2,225	5,988
Supplemental disclosure of cash flow activity:
Cash paid for interest expense	11,805	5,609	5,677
Cash paid for income taxes	14,525	$ 21,170	27,575
Assets acquired in acquisition and goodwill, net	1,463,200		161,231
Liabilities assumed in acquisition	$ 1,172,068		$ 161,231

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 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 29 California counties. The Company has five capital subsidiary business trusts (collectively, the “Capital Trusts”) that issued trust preferred securities, including two organized by the Company and three acquired with the acquisition of North Valley Bancorp. 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. All adjustments necessary for a fair presentation of these consolidated financial statements have been included and are of a normal and recurring nature. 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 $1,713,000 are accounted for under the equity method and, accordingly, are included in other assets on the consolidated balance sheets. 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 sheets. 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. Segment and Significant Group Concentration of Credit Risk The Company grants agribusiness, commercial, consumer, and residential loans to customers located throughout Northern and Central 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. Geographical Descriptions For the purpose of describing the geographical location of the Company’s operations, the Company has defined northern California as that area of California north of, and including, Stockton to the east and San Jose to the west; central California as that area of the state south of Stockton and San Jose, to and including, Bakersfield to the east and San Luis Obispo to the west; and southern California as that area of the state south of Bakersfield and San Luis Obispo. Business Combinations The Company accounts for acquisitions of businesses using the acquisition method of accounting. Under the acquisition method, assets acquired and liabilities assumed are recorded at their estimated fair values at the date of acquisition. Management utilizes various valuation techniques including discounted cash flow analyses to determine these fair values. Any excess of the purchase price over amounts allocated to the acquired assets, including identifiable intangible assets, and liabilities assumed is recorded as goodwill. 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 the new accounting standard for Financial Instruments using a prospective transition approach, which requires equity investments to be measured at fair value with changes in fair value recognized in net income. The adoption of this guidance resulted in a $62,000 decrease to beginning retained earnings and a decrease to the deferred tax of $18,000. During the twelve months ended December 31, 2018, the Company recognized $64,000 of unrealized losses in the consolidated statements of income related to changes in the fair value of marketable equity 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 and changes in the value of these securities are recorded through earnings. 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. The Company did not have any debt securities classified as trading during 2018, 2017 or 2016. 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. Both cash and stock dividends are reported as income when received. 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 to 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 considered 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, if any, certain repayment 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 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 are 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 measured and recorded at their fair value as of the acquisition date. Loans acquired with evidence of credit deterioration since origination for which it is probable that all contractually required payments will not be collected are referred to as purchased credit impaired (PCI) loans. PCI loans are recorded at fair value at acquisition date, factoring in credit losses expected to be incurred over the life of the loan. Accordingly, an allowance for loan losses is not carried over or recorded as of the acquisition date. Fair value is defined as the present value of the future estimated principal and interest payments of the loan, with the discount rate used in the present value calculation representing the estimated effective yield of the loan. Default rates, loss severity, and prepayment speed assumptions are periodically reassessed and our estimate of future payments is adjusted accordingly. The difference between contractual future payments and estimated future payments is referred to as the nonaccretable difference. The difference between estimated future payments and the present value of the estimated future payments is referred to as the accretable yield. The accretable yield represents the amount that is expected to be recorded as interest income over the remaining life of the loan. If after acquisition, the Company determines that the estimated future cash flows of a PCI loan are expected to be more than originally estimated, an increase in the discount rate (effective yield) would be made such that the newly increased accretable yield would be recognized, on a level yield basis, over the remaining estimated life of the loan. If, thereafter, the Company determines that the estimated future cash flows of a PCI loan are expected to be less than previously estimated, an allowance for loan loss would be established through a provision for loan losses charged to expense to decrease the present value to the required level. If the estimated cash flows improve after an allowance has been established for a loan, the allowance may be partially or fully reversed depending on the improvement in the estimated cash flows. Only after the allowance has been fully reversed may the discount rate be increased. PCI loans are put on nonaccrual status when cash flows cannot be reasonably estimated. PCI loans on nonaccrual status are accounted for using the cost recovery method or cash basis method of income recognition. PCI loans are charged off when evidence suggests cash flows are not recoverable. Foreclosed assets from PCI loans are recorded in foreclosed assets at fair value with the fair value at time of foreclosure representing estimated proceeds less selling costs from the collateral securing the loan. PCI loans with similar risk characteristics and acquisition time frame may be “pooled” and have their cash flows aggregated as if they were one loan or accounted for individually. Acquired loans that are not PCI loans are referred to as purchased not credit impaired (PNCI) loans and interest income is accrued on a level-yield basis. For income recognition purposes, this method assumes that all contractual cash flows will be collected, and no allowance for loan losses is established at the time of acquisition. Post-acquisition date, an allowance for loan losses may need to be established for acquired loans through a provision charged to earnings for credit losses incurred subsequent to acquisition. The loss estimate for acquired loans is measured based on the probable shortfall in relation to the contractual note requirements, consistent with our allowance for loan loss policy for similar loans. Throughout these financial statements, reference to “Loans” or “Allowance for loan losses” relates to all categories of loans, including Originated, PNCI, and PCI. When not referring to all categories of loans, specific reference to Originated, PNCI, or PCI is made. 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. 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 Company Owned Life Insurance The Company has purchased life insurance policies on certain key executives. Company owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement. Goodwill, Other Intangible and Long-Lived Assets Goodwill represents the excess of costs over fair value of net assets of businesses acquired from a business combination. The Company has an identifiable intangible asset consisting of core deposit intangibles (“CDI”). CDI are amortized over their respective estimated useful lives, and reviewed periodically for impairment. Goodwill and other intangible assets acquired in a business combination and determined to have an indefinite useful life are not amortized, but instead tested for impairment at least annually. Other intangible assets with estimable useful lives are amortized over their respective estimated useful lives to their estimated residual values, and reviewed periodically for impairment. As of September 30 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. 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. 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, when earned, and changes in fair value of the MSR, are recorded in noninterest income. 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. Reserve for Unfunded Commitments The reserve for unfunded commitments is established through a provision for losses – unfunded commitments, the changes of which are recorded in 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 credit and other loans, standby letters of credit, and unused deposit account overdraft privileges. 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. 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. 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. 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. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. Interest and/or penalties related to income taxes are reported as a component of noninterest income. Earnings per Share Basic earnings per share represents income available to common shareholders divided by the weighted-average number of common shares outstanding during the period. There are no unvested share-based payment awards that contain rights to nonforfeitable dividends (participating securities). Diluted earnings per share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued, as well as any adjustments to income that would result from assumed issuance. Potential common shares that may be issued by the Company relate solely from outstanding stock options and restricted stock units, and are determined using the treasury stock method. Revenue Recognition The Company records revenue from contracts with customers in accorda

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Business Combinations	Note 2 – Business Combinations Merger with FNB Bancorp On July 6, 2018, the Company completed the acquisition of FNB Bancorp (“FNBB”) for an aggregate transaction value of $291,132,000. FNBB was merged into the Company, and the Company issued 7,405,277 shares of common stock to the former shareholders of FNBB. FNBB’s subsidiary, First National Bank of Northern California, merged into the Bank on the same day. The Company also paid $6.7 million to settle and retire all FNBB stock options outstanding as of the acquisition date. Upon the consummation of the merger, the Company added 12 branches within San Mateo, San Francisco, and Santa Clara counties. In accordance with accounting for business combinations, the Company recorded $156,661,000 of goodwill and $27,605,000 of core deposit intangibles on the acquisition date. The core deposit intangibles will be amortized over the weighted average remaining life of 6.2 years with no significant residual value. For tax purposes, purchase prices accounting adjustments including goodwill are all non-taxable non-deductible. The acquisition was consistent with the Company’s strategy to expand into the Bay Area market. The acquisition offers the Company the opportunity to increase profitability by introducing existing products and services to the acquired customer base as well as add new customers in the expanded region. Goodwill arising from the acquisition consisted largely of the estimated cost savings resulting from the combined operations. The following table summarizes the consideration paid for FNBB and the amounts of assets acquired and liabilities assumed that were recorded at the acquisition date (in thousands). FNB Bancorp Fair value of consideration transferred: Fair value of shares issued $ 284,437 Cash consideration 6,695 Total fair value of consideration transferred 291,132 Assets acquired: Cash and cash equivalents 37,308 Securities available for sale 335,667 Restricted equity securities 7,723 Loans 834,683 Premises and equipment 30,522 Cash value of life insurance 16,817 Core deposit intangible 27,605 Other assets 16,214 Total assets acquired 1,306,539 Liabilities assumed: Deposits 991,935 Other liabilities 15,133 Short-term borrowings—Federal Home Loan Bank 165,000 Total liabilities assumed 1,172,068 Total net assets acquired 134,471 Goodwill recognized $ 156,661 A summary of the estimated fair value adjustments resulting in the goodwill recorded in the FNB Bancorp acquisition are presented below (in thousands): FNB Bancorp Value of stock consideration paid to FNB Bancorp Shareholders $ 284,437 Cash consideration 6,695 Less: Cost basis net assets acquired 114,030 Fair value adjustments: Investments (1,081 ) Loans (22,390 ) Premises and Equipment 21,590 Core deposit intangible 27,327 Deferred income taxes (6,394 ) Other 1,389 Goodwill $ 156,661 The fair value of net assets acquired includes fair value adjustments to certain loans that were not considered impaired (PNCI loans) as of the acquisition date. The fair value adjustments were determined using discounted contractual cash flows. As such, these loans were not considered impaired at the acquisition date and were not subject to the guidance relating to purchased credit impaired loans (PCI loans), which have shown evidence of credit deterioration since origination. The gross contractual amounts receivable and fair value for PNCI loans as of the acquisition date was $866,189,000 and $833,381,000, respectively. The gross contractual amounts receivable and fair value for PCI loans as of the acquisition date was $1,683,000 and $1,302,000, respectively. At the acquisition date, the Company was unable to estimate the expected contractual cash flows to be collected from the purchased credit impaired loans. The table below presents the unaudited proforma information as if the acquisition of FNB Bancorp had occurred on January 1, 2017 after giving effect to certain acquisition accounting adjustments. The proforma information for the years ended December 31, 2018 and 2017 includes acquisition adjustments for the amortization/accretion on loans, core deposit intangibles, and related income tax effects. The proforma financial information also includes one-time Year ended December 31, 2018 December 31, 2017 (in thousands, except per share data) Summarized proforma income statement data: Net interest income $ 242,793 $ 227,795 (Provision for) benefit from loan losses (2,180 ) 271 Noninterest income 51,152 53,881 Noninterest expense (180,884 ) (181,833 ) Income before taxes 110,881 100,114 Income taxes (30,337 ) (47,352 ) Net income $ 80,544 $ 52,762 Basic earnings per share $ 2.65 $ 1.74 Diluted earnings per share $ 2.63 $ 1.72 It is impracticable to separately provide information regarding the revenue and earnings of FNB Bancorp included in the Company’s consolidated income statement from the July 6, 2018 acquisition date to December 31, 2018 because the operations of FNBB were substantially comingled with the operations of the Company as of the system conversion date of July 22, 2018.

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2018
Investments Schedule [Abstract]
Investment Securities	Note 3 – Investment Securities The amortized cost and estimated fair values of investment securities classified as available for sale and held to maturity are summarized in the following tables: December 31, 2018 Amortized Gross Gross Estimated (in thousands) Debt Securities Available for Sale Obligations of U.S. government agencies $ 647,288 $ 771 $ (18,078 ) $ 629,981 Obligations of states and political subdivisions 128,890 294 (3,112 ) 126,072 Corporate bonds 4,381 97 — 4,478 Asset backed securities 355,451 73 (1,019 ) 354,505 Total debt securities available for sale $ 1,136,010 $ 1,235 $ (22,209 ) $ 1,115,036 Debt Securities Held to Maturity Obligations of U.S. government agencies $ 430,343 $ 327 $ (7,745 ) $ 422,925 Obligations of states and political subdivisions 14,593 82 (230 ) 14,445 Total debt securities held to maturity $ 444,936 $ 409 $ (7,975 ) $ 437,370 December 31, 2017 Amortized Gross Gross Estimated (in thousands) Debt Securities Available for Sale Obligations of U.S. government 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 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 During 2018, proceeds from sales of debt securities were $293,279,000, resulting in gross gains of $207,000. During 2017 investment securities with cost basis of $24,796,000 were sold for $25,757,000, resulting in a gain of $961,000 on sale. No investment securities were sold during 2016. Investment securities with an aggregate carrying value of $597,591,000 and $285,596,000 at December 31, 2018 and 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 December 31, 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 December 31, 2018, obligations of U.S. government and agencies with an amortized cost basis totaling $1,077,631 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 December 31, 2018, the Company estimates the average remaining life of these mortgage-backed securities issued by U.S. government corporations and agencies to be approximately 5.8 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 Due in one year $ 2,410 $ 2,413 $ — $ — Due after one year through five years 10,625 10,794 1,238 1,250 Due after five years through ten years 17,381 17,622 25,039 24,744 Due after ten years 1,105,594 1,084,207 418,659 411,376 Totals $ 1,136,010 $ 1,115,036 $ 444,936 $ 437,370 Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, were as follows: Less than 12 months 12 months or more Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2018 (in thousands) Debt Securities Available for Sale Obligations of U.S. government agencies $ 171,309 $ (3,588 ) $ 394,630 $ (14,490 ) $ 565,939 $ (18,078 ) Obligations of states and political subdivisions 63,738 (1,541 ) 20,719 (1,571 ) 84,457 (3,112 ) Asset backed securities 101,386 (1,019 ) — — 101,386 (1,019 ) Total debt securities available for sale $ 336,433 $ (6,148 ) $ 415,349 $ (16,061 ) $ 751,782 $ (22,209 ) Debt Securities Held to Maturity Obligations of U.S. government agencies $ 223,810 $ (2,619 ) $ 158,648 $ (5,126 ) $ 382,458 $ (7,745 ) Obligations of states and political subdivisions 5,786 (114 ) 4,042 (116 ) 9,828 (230 ) Total debt securities held to maturity $ 229,596 $ (2,733 ) $ 162,690 $ (5,242 ) $ 392,286 $ (7,975 ) Less than 12 months 12 months or more Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2017 (in thousands) Debt Securities Available for Sale Obligations of U.S. government 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 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 December 31, 2018, 145 debt securities representing obligations of U.S. government corporations and agencies had unrealized losses with aggregate depreciation of 2.65% from the Company’s amortized cost basis. Obligations of states and political subdivisions: The unrealized losses on investments in obligations of states and political subdivisions were caused by increases in required yields by investors in these types of securities. It is expected that the securities would not be settled at a price less than the amortized cost of the investment. Because the decline in fair value is attributable to changes in interest rates and not credit quality, and because the Company does not intend to sell and more likely than not will not be required to sell, these investments are not considered other-than-temporarily impaired. At December 31, 2018, 105 debt securities representing obligations of states and political subdivisions had unrealized losses with aggregate depreciation of 3.42% from the Company’s amortized cost basis. Asset backed securities: The unrealized losses on investments in asset backed securities were caused by increases in required yields by investors in these types of securities. At the time of purchase, each of these securities were rated AA or AAA and through December 31, 2018 have not experienced any deterioration in credit rating. The Company continues to monitor these securities for changes in credit rating or other indications of credit deterioration. Because management believes the decline in fair value is attributable to changes in interest rates and not credit quality, and because the Company does not intend to sell and more likely than not will not be required to sell, these investments are not considered other-than-temporarily impaired. At December 31, 2018, 6 asset backed securities had unrealized losses with aggregate depreciation of 1.0% 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 December 31, 2018.

Loans

Loans	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Loans	Note 4 – Loans A summary of loan balances follows (in thousands): December 31, 2018 Originated PNCI PCI Total Mortgage loans on real estate: Residential 1-4 $ 343,796 $ 169,792 $ 1,674 $ 515,262 Commercial 1,910,981 708,401 8,456 2,627,838 Total mortgage loans on real estate 2,254,777 878,193 10,130 3,143,100 Consumer: Home equity lines of credit 284,453 40,957 1,167 326,577 Home equity loans 32,660 3,585 439 36,684 Other 34,020 21,659 42 55,721 Total consumer loans 351,133 66,201 1,648 418,982 Commercial 228,635 45,468 2,445 276,548 Construction: Residential 90,703 30,593 — 121,296 Commercial 56,208 5,880 — 62,088 Total construction 146,911 36,473 — 183,384 Total loans, net of deferred loan fees and discounts $ 2,981,456 $ 1,026,335 $ 14,223 $ 4,022,014 Total principal balance of loans owed, net of charge-offs $ 2,991,324 $ 1,062,655 $ 21,265 $ 4,075,244 Unamortized net deferred loan fees (9,868 ) — — (9,868 ) Discounts to principal balance of loans owed, net of charge-offs — (36,320 ) (7,042 ) (43,362 ) Total loans, net of deferred loan fees and discounts $ 2,981,456 $ 1,026,335 $ 14,223 $ 4,022,014 Allowance for loan losses $ (31,793 ) $ (667 ) $ (122 ) $ (32,582 ) December 31, 2017 Originated PNCI 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 2,498 288,688 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 3,028 356,874 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 $ 15,560 $ 3,015,165 Total principal balance of loans owed, net of charge-offs $ 2,699,053 $ 316,238 $ 23,181 $ 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 ) (7,621 ) (14,656 ) Total loans, net of unamortized deferred loan fees and discounts $ 2,690,402 $ 309,203 $ 15,560 $ 3,015,165 Allowance for loan losses $ (29,122 ) $ (929 ) $ (272 ) $ (30,323 ) The following is a summary of the change in accretable yield for PCI loans during the periods indicated (in thousands): Year ended December 31, 2018 2017 2016 Change in accretable yield: Balance at beginning of period $ 6,137 $ 7,670 $ 13,255 Accretion to interest income (787 ) (2,809 ) (4,011 ) Reclassification (to) from nonaccretable difference 709 1,276 (1,574 ) Balance at end of period $ 6,059 $ 6,137 $ 7,670

Allowance for Loan Losses

Allowance for Loan Losses	12 Months Ended
	Dec. 31, 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 – Year Ended December 31, 2018 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,317 $ (77 ) $ — $ 436 $ 2,676 Commercial 11,441 (15 ) 68 1,450 12,944 Total mortgage loans on real estate 13,758 (92 ) 68 1,886 15,620 Consumer: Home equity lines of credit 5,800 (277 ) 846 (327 ) 6,042 Home equity loans 1,841 (24 ) 297 (574 ) 1,540 Other 586 (783 ) 288 702 793 Total consumer loans 8,227 (1,084 ) 1,431 (199 ) 8,375 Commercial 6,512 (1,188 ) 541 225 6,090 Construction: Residential 1,184 — — 650 1,834 Commercial 642 — — 21 663 Total construction 1,826 — — 671 2,497 Total $ 30,323 $ (2,364 ) $ 2,040 $ 2,583 $ 32,582 Allowance for Loan Losses – As of December 31, 2018 (in thousands) Loans pooled Individually Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 2,620 $ 56 $ — $ 2,676 Commercial 12,737 91 116 12,944 Total mortgage loans on real estate 15,357 147 116 15,620 Consumer: Home equity lines of credit 5,838 198 6 6,042 Home equity loans 1,486 54 — 1,540 Other 779 14 — 793 Total consumer loans 8,103 266 6 8,375 Commercial 4,309 1,781 — 6,090 Construction: Residential 1,834 — — 1,834 Commercial 663 — — 663 Total construction 2,497 — — 2,497 Total $ 30,266 $ 2,194 $ 122 $ 32,582 Loans, Net of Unearned fees – As of December 31, 2018 (in thousands) Loans pooled Individually Loans acquired Total loans, net Mortgage loans on real estate: Residential 1-4 $ 509,267 $ 4,321 $ 1,674 $ 515,262 Commercial 2,606,819 12,563 8,456 2,627,838 Total mortgage loans on real estate 3,116,086 16,884 10,130 3,143,100 Consumer: Home equity lines of credit 322,764 2,646 1,167 326,577 Home equity loans 33,142 3,103 439 36,684 Other 55,483 196 42 55,721 Total consumer loans 411,389 5,945 1,648 418,982 Commercial 268,885 5,218 2,445 276,548 Construction: Residential 121,296 — — 121,296 Commercial 62,088 — — 62,088 Total construction 183,384 — — 183,384 Total $ 3,979,744 $ 28,047 $ 14,223 $ 4,022,014 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) Loans Individually Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 1,932 $ 230 $ 155 $ 2,317 Commercial 11,351 30 60 11,441 Total mortgage loans on real estate 13,283 260 215 13,758 Consumer: Home equity lines of credit 5,356 427 17 5,800 Home equity loans 1,734 107 — 1,841 Other 529 57 — 586 Total consumer loans 7,619 591 17 8,227 Commercial 4,624 1,848 40 6,512 Construction: Residential 1,184 — — 1,184 Commercial 642 — — 642 Total construction 1,826 — — 1,826 Total $ 27,352 $ 2,699 $ 272 $ 30,323 Loans, Net of Unearned fees – As of December 31, 2017 (in thousands) Loans pooled Individually Loans acquired Total loans, Mortgage loans on real estate: Residential 1-4 $ 378,743 $ 5,298 $ 1,385 $ 385,426 Commercial 1,892,422 13,911 8,563 1,914,896 Total mortgage loans on real estate 2,271,165 19,209 9,948 2,300,322 Consumer: Home equity lines of credit 283,502 2,688 2,498 288,688 Home equity loans 41,076 1,470 485 43,031 Other 24,853 257 45 25,155 Total consumer loans 349,431 4,415 3,028 356,874 Commercial 213,358 4,470 2,584 220,412 Construction: Residential 67,790 140 — 67,930 Commercial 69,627 — — 69,627 Total construction 137,417 140 — 137,557 Total $ 2,971,371 $ 28,234 $ 15,560 $ 3,015,165 Allowance for Loan Losses – Year Ended December 31, 2016 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,896 $ (321 ) $ 880 $ (707 ) $ 2,748 Commercial 11,015 (827 ) 920 409 11,517 Total mortgage loans on real estate 13,911 (1,148 ) 1,800 (298 ) 14,265 Consumer: Home equity lines of credit 11,253 (585 ) 2,317 (5,941 ) 7,044 Home equity loans 3,177 (219 ) 590 (904 ) 2,644 Other 688 (823 ) 449 308 622 Total consumer loans 15,118 (1,627 ) 3,356 (6,537 ) 10,310 Commercial 5,271 (455 ) 404 611 5,831 Construction: Residential 899 — 54 464 1,417 Commercial 812 — 78 (210 ) 680 Total construction 1,711 — 132 254 2,097 Total $ 36,011 $ (3,230 ) $ 5,692 $ (5,970 ) $ 32,503 Allowance for Loan Losses – As of December 31, 2016 (in thousands) Loans Individually Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 2,304 $ 258 $ 186 $ 2,748 Commercial 10,064 4 1,449 11,517 Total mortgage loans on real estate 12,368 262 1,635 14,265 Consumer: Home equity lines of credit 6,616 411 17 7,044 Home equity loans 2,365 215 64 2,644 Other 594 28 — 622 Total consumer loans 9,575 654 81 10,310 Commercial 3,765 1,130 936 5,831 Construction: Residential 1,372 — 45 1,417 Commercial 680 — — 680 Total construction 2,052 — 45 2,097 Total $ 27,760 $ 2,046 $ 2,697 $ 32,503 Loans, Net of Unearned fees – As of December 31, 2016 (in thousands) Loans pooled Individually Loans acquired Total Loans Mortgage loans on real estate: Residential 1-4 $ 362,780 $ 4,094 $ 1,469 $ 368,343 Commercial 1,657,238 15,081 12,802 1,685,121 Total mortgage loans on real estate 2,020,018 19,175 14,271 2,053,464 Consumer: Home equity lines of credit 282,159 3,196 4,360 289,715 Home equity loans 42,992 1,508 1,682 46,182 Other 30,547 154 65 30,766 Total consumer loans 355,698 4,858 6,107 366,663 Commercial 208,960 4,096 3,991 217,047 Construction: Residential 54,743 11 675 55,429 Commercial 66,990 — — 66,990 Total construction 121,733 11 675 122,419 Total $ 2,706,409 $ 28,140 $ 25,044 $ 2,759,593 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 December 31, 2018 (in thousands) Pass Special Substandard Doubtful / Loss Total Originated Mortgage loans on real estate: Residential 1-4 $ 337,189 $ 1,724 $ 4,883 $ — $ 343,796 Commercial 1,861,627 33,483 15,871 — 1,910,981 Total mortgage loans on real estate 2,198,816 35,207 20,754 — 2,254,777 Consumer: Home equity lines of credit 279,491 2,309 2,653 — 284,453 Home equity loans 29,289 1,054 2,317 — 32,660 Other 33,606 341 73 — 34,020 Total consumer loans 342,386 3,704 5,043 — 351,133 Commercial 217,126 6,127 5,382 — 228,635 Construction: Residential 90,412 32 259 — 90,703 Commercial 55,863 345 — — 56,208 Total construction 146,275 377 259 — 146,911 Total loans $ 2,904,603 $ 45,415 $ 31,438 $ — $ 2,981,456 Credit Quality Indicators PNCI Loans – As of December 31, 2018 (in thousands) Pass Special Substandard Doubtful / Loss Total PNCI Mortgage loans on real estate: Residential 1-4 $ 167,908 $ 1,086 $ 798 $ — $ 169,792 Commercial 701,868 3,085 3,448 — 708,401 Total mortgage loans on real estate 869,776 4,171 4,246 — 878,193 Consumer: Home equity lines of credit 38,780 1,124 1,053 — 40,957 Home equity loans 3,413 74 98 — 3,585 Other 21,481 173 5 — 21,659 Total consumer loans 63,674 1,371 1,156 — 66,201 Commercial 45,027 321 120 — 45,468 Construction: Residential 30,593 — — — 30,593 Commercial 5,880 — — — 5,880 Total construction 36,473 — — — 36,473 Total loans $ 1,014,950 $ 5,863 $ 5,522 $ — $ 1,026,335 Credit Quality Indicators Originated Loans – As of December 31, 2017 (in thousands) Pass Special Substandard Doubtful / 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 Doubtful / 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 tables show the ending balance of current and past due originated and PNCI loans by loan category as of the date indicated: Analysis of Originated Past Due Loans - As of December 31, 2018 (in thousands) 30-59 days 60-89 days > 90 days Total Past Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,675 $ 132 $ 478 $ 2,285 $ 341,511 $ 343,796 $ — Commercial 431 1,200 296 1,927 1,909,054 1,910,981 — Total mortgage loans on real estate 2,106 1,332 774 4,212 2,250,565 2,254,777 — Consumer: Home equity lines of credit 908 47 609 1,564 282,889 284,453 — Home equity loans 1,043 24 214 1,281 31,379 32,660 — Other 298 17 — 315 33,705 34,020 — Total consumer loans 2,249 88 823 3,160 347,973 351,133 — Commercial 1,053 579 1,247 2,879 225,756 228,635 — Construction: Residential 209 — — 209 90,494 90,703 — Commercial — — — — 56,208 56,208 — Total construction 209 — — 209 146,702 146,911 — Total originated loans $ 5,617 $ 1,999 $ 2,844 $ 10,460 $ 2,970,996 $ 2,981,456 $ — Analysis of PNCI Past Due Loans - As of December 31, 2018 (in thousands) 30-59 days 60-89 days > 90 days Total Past Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,009 $ 133 $ 156 $ 1,298 $ 168,494 $ 169,792 $ — Commercial 1,646 1,136 1,082 3,864 704,537 708,401 Total mortgage loans on real estate 2,655 1,269 1,238 5,162 873,031 878,193 — Consumer: Home equity lines of credit 304 35 237 576 40,381 40,957 Home equity loans 74 — — 74 3,511 3,585 — Other 160 — — 160 21,499 21,659 — Total consumer loans 538 35 237 810 65,391 66,201 — Commercial 678 145 113 936 44,532 45,468 — Construction: Residential — — — — 30,593 30,593 — Commercial — — — — 5,880 5,880 — Total construction — — — — 36,473 36,473 — Total PNCI loans $ 3,871 $ 1,449 $ 1,588 $ 6,908 $ 1,019,427 $ 1,026,335 $ — Analysis of Originated Past Due Loans - As of December 31, 2017 (in thousands) 30-59 days 60-89 days > 90 days Total Past Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,740 $ 510 $ 243 $ 2,493 $ 318,029 $ 320,522 $ — Commercial 158 987 — 1,145 1,689,365 1,690,510 — Total mortgage loans on real estate 1,898 1,497 243 3,638 2,007,394 2,011,032 — Consumer: Home equity lines of credit 528 48 372 948 268,994 269,942 — Home equity loans 511 107 373 991 38,857 39,848 — Other 56 36 3 95 22,764 22,859 — Total consumer loans 1,095 191 748 2,034 330,615 332,649 — Commercial 956 738 1,527 3,221 206,216 209,437 — Construction: Residential 34 — — 34 67,886 67,920 — Commercial — — — — 69,364 69,364 — Total construction 34 — — 34 137,250 137,284 — Total loans $ 3,983 $ 2,426 $ 2,518 $ 8,927 $ 2,681,475 $ 2,690,402 $ — Analysis of PNCI Past Due Loans - As of December 31, 2017 (in thousands) 30-59 60-89 > 90 days Total Past Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,495 $ 90 $ 109 $ 1,694 $ 61,825 $ 63,519 $ 81 Commercial 70 — — 70 215,753 215,823 — Total mortgage loans on real estate 1,565 90 109 1,764 277,578 279,342 81 Consumer: Home equity lines of credit 298 228 330 856 15,392 16,248 200 Home equity loans 30 — — 30 2,668 2,698 — Other 6 26 — 32 2,219 2,251 — Total consumer loans 334 254 330 918 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 $ 2,682 $ 306,521 $ 309,203 $ 281 The following table shows the ending balance of nonaccrual loans by loan category as of the date indicated: Non Accrual Loans As of December 31, 2018 As of December 31, 2017 (in thousands) Originated PNCI Total Originated PNCI Total Mortgage loans on real estate: Residential 1-4 $ 3,244 $ 334 $ 3,578 $ 1,725 $ 1,012 $ 2,737 Commercial 9,263 1,468 10,731 8,144 — 8,144 Total mortgage loans on real estate 12,507 1,802 14,309 9,869 1,012 10,881 Consumer: Home equity lines of credit 1,429 885 2,314 811 402 1,213 Home equity loans 1,722 47 1,769 1,106 44 1,150 Other 3 4 7 7 5 12 Total consumer loans 3,154 936 4,090 1,924 451 2,375 Commercial 3,755 120 3,875 3,669 — 3,669 Construction: Residential — — — — — — Commercial — — — — — — Total construction — — — — — — Total non accrual loans $ 19,416 $ 2,858 $ 22,274 $ 15,462 $ 1,463 $ 16,925 Interest income on originated nonaccrual loans that would have been recognized during the years ended December 31, 2018, 2017, and 2016, if all such loans had been current in accordance with their original terms, totaled $1,584,000, $1,067,000, and $783,000, respectively. Interest income actually recognized on these originated loans during the years ended December 31, 2018, 2017, and 2016 was $486,000, $530,000, and $377,000, respectively. Interest income on PNCI nonaccrual loans that would have been recognized during the years ended December 31, 2018, 2017, and 2016, if all such loans had been current in accordance with their original terms, totaled $1,122,000, $73,000, and $178,000, respectively. Interest income actually recognized on these PNCI loans during the years ended December 31, 2018, 2017, and 2016 was $989,000, $18,000, and $11,000, respectively. Impaired originated loans are those where management has concluded that it is probable that the borrower will be unable to pay all amounts due under the contractual terms. The following tables show the recorded investment (financial statement balance), unpaid principal balance, average recorded investment, and interest income recognized for impaired Originated and PNCI loans, segregated by those with no related allowance recorded and those with an allowance recorded for the periods indicated. Impaired Originated Loans - As of, or for the Twelve Months Ended, December 31, 2018 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 4,594 $ 3,663 $ 308 $ 3,971 $ 56 $ 3,517 $ 90 Commercial 13,081 10,676 1,765 12,441 42 13,115 137 Total mortgage loans on real estate 17,675 14,339 2,073 16,412 98 16,632 227 Consumer: Home equity lines of credit 1,900 1,749 111 1,860 71 1,885 43 Home equity loans 2,374 1,892 65 1,957 2 1,520 23 Other 3 — 3 3 3 17 2 Total consumer loans 4,277 3,641 179 3,820 76 3,422 68 Commercial 5,433 2,924 2,287 5,211 1,774 4,654 91 Construction: Residential — — — — — 5 — Commercial — — — — — — — Total construction — — — — — 5 — Total $ 27,385 $ 20,904 $ 4,539 $ 25,443 $ 1,948 $ 24,713 $ 386 Impaired PNCI Loans - As of, or for the Twelve Months Ended, December 31, 2018 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 375 $ 334 $ — $ 334 $ — $ 529 $ 5 Commercial 3,110 1,468 — 1,468 — 1,713 183 Total mortgage loans on real estate 3,485 1,802 — 1,802 — 2,242 188 Consumer: Home equity lines of credit 1,027 587 367 954 127 1,120 18 Home equity loans 252 47 197 244 101 155 — Other 106 21 85 106 11 114 — Total consumer loans 1,385 655 649 1,304 239 1,389 18 Commercial 120 113 7 120 7 60 1 Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — — Total $ 4,990 $ 2,570 $ 656 $ 3,226 $ 246 $ 3,691 $ 207 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 55 4 3 7 3 20 — Total consumer loans 3,263 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 $ 26,178 $ 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 Twelve Months Ended, December 31, 2016 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 3,381 $ 1,820 $ 1,551 $ 3,371 $ 180 $ 4,632 $ 157 Commercial 13,503 12,898 357 13,255 4 20,891 592 Total mortgage loans on real estate 16,884 14,718 1,908 16,626 184 25,523 749 Consumer: Home equity lines of credit 2,001 1,480 430 1,910 110 3,297 49 Home equity loans 1,730 715 594 1,309 107 1,465 37 Other 48 15 19 34 13 26 3 Total consumer loans 3,779 2,210 1,043 3,253 230 4,788 89 Commercial 4,311 762 3,334 4,096 1,130 3,383 125 Construction: Residential 16 11 — 11 — 7 — Commercial — — — — — — — Total construction 16 11 — 11 — 7 — Total $ 24,990 $ 17,701 $ 6,285 $ 23,986 $ 1,544 $ 33,701 $ 963 Impaired PNCI Loans - As of, or for the Twelve Months Ended, December 31, 2016 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 745 $ 463 $ 259 $ 722 $ 79 $ 799 $ 17 Commercial 2,031 1,826 — 1,826 — 2,853 — Total mortgage loans on real estate 2,776 2,289 259 2,548 79 3,652 17 Consumer: Home equity lines of credit 1,297 735 551 1,286 300 1,173 36 Home equity loans 206 67 132 199 108 154 8 Other 122 3 118 121 15 194 5 Total consumer loans 1,625 805 801 1,606 423 1,521 49 Commercial — — — — — 1 — Construction: Residential — — — — — — — Commercial — — — — — 245 — Total construction — — — — — 245 — Total $ 4,401 $ 3,094 $ 1,060 $ 4,154 $ 502 $ 5,419 $ 66 Originated loans classified as TDRs and impaired were $10,253,000, $12,517,000 and $12,371,000 at December 31, 2018, 2017 and 2016, respectively. PNCI loans classified as TDRs and impaired were $615,000, $1,352,000 and $1,324,000 at December 31, 2018, 2017 and 2016, respectively. The Company had no significant obligations to lend additional funds on Originated or PNCI TDRs as of December 31, 2018, 2017, or 2016. The following tables show certain information regarding Troubled Debt Restructurings that occurred during the periods indicated: TDR Information for the Year Ended December 31, 2018 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial impact Mortgage loans on real estate: Residential 1-4 1 $ 156 $ 156 $ — — $ — $ — Commercial 7 1,782 1,779 491 1 169 — Total mortgage loans on real estate 8 1,938 1,935 491 1 169 — Consumer: Home equity lines of credit 1 133 138 — 2 248 — Home equity loans 2 599 599 (35 ) — — — Other — — — — — — — Total consumer loans 3 732 737 (35 ) 2 248 — Commercial 6 1,098 1,083 325 3 148 — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — — Total 17 $ 3,768 $ 3,755 $ 781 6 $ 565 $ — TDR Information for the Year Ended December 31, 2017 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial impact Mortgage loans on real estate: Residential 1-4 1 $ 939 $ 939 $ 169 2 $ 223 $ — Commercial 8 3,721 3,695 (111 ) 1 219 — Total mortgage loans on real estate 9 4,660 4,634 58 3 442 — Consumer: Home equity lines of credit 3 187 187 27 1 127 (5 ) Home equity loans 1 252 252 — 1 55 — Other 1 14 14 11 — — — Total consumer loans 5 453 453 38 2 182 (5 ) Commercial 11 1,854 1,747 37 — — — Construction: Residential 1 144 144 — — — — Commercial — — — — — — — Total construction 1 144 144 — — — — Total 26 $ 7,111 $ 6,978 $ 133 5 $ 624 $ (5 ) TDR Information for the Year Ended December 31, 2016 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial impact Mortgage loans on real estate: Residential 1-4 3 $ 650 $ 656 $ 50 2 $ 101 $ — Commercial 5 423 461 46 — — — Total mortgage loans on real estate 8 1,073 1,117 96 2 101 — Consumer: Home equity lines of credit 9 707 709 205 1 229 — Home equity loans 1 105 105 — — — — Other 2 27 27 2 — — — Total consumer loans 12 839 841 207 1 229 — Commercial 4 77 77 23 — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — — Total 24 $ 1,989 $ 2,035 $ 326 3 $ 330 $ — 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	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Foreclosed Assets	Note 6 – Foreclosed Assets A summary of the activity in the balance of foreclosed assets follows (dollars in thousands): Year ended December 31, 2018 2017 Beginning balance, net $ 3,226 $ 3,986 Additions/transfers from loans 1,262 1,563 Dispositions/sales (2,119 ) (2,161 ) Valuation adjustments (89 ) (162 ) Ending balance, net $ 2,280 $ 3,226 Ending valuation allowance $ (116 ) $ (200 ) Ending number of foreclosed assets 11 16 Proceeds from sale of foreclosed assets $ 2,527 $ 2,872 Gain on sale of foreclosed assets $ 408 $ 711 At December 31, 2018, the balance of real estate owned includes $1,218,000 of foreclosed residential real estate properties recorded as a result of obtaining physical possession of the property. At December 31, 2018, the recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are underway is $453,000.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Premises and Equipment	Note 7 – Premises and Equipment As of December 31, 2018 2017 (In thousands) Land & land improvements $ 29,065 $ 9,959 Buildings 64,478 50,340 Furniture and equipment 45,228 35,939 138,771 96,238 Less: Accumulated depreciation (50,125 ) (40,644 ) 88,646 55,594 Construction in progress 701 2,148 Total premises and equipment $ 89,347 $ 57,742 Depreciation expense for premises and equipment amounted to $6,104,000, $5,686,000, and $5,314,000 in 2018, 2017, and 2016, respectively.

Cash Value of Life Insurance

Cash Value of Life Insurance	12 Months Ended
	Dec. 31, 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 (dollars in thousands): Year ended December 31, 2018 2017 Beginning balance $ 97,783 $ 95,912 Acquired policies from business combination 16,817 — Increase in cash value of life insurance 2,718 2,685 Gain on death benefit — 108 Insurance proceeds receivable reclassified to other assets — (922 ) Ending balance $ 117,318 $ 97,783 End of period death benefit $ 200,249 $ 165,587 Number of policies owned 196 182 Insurance companies used 14 14 Current and former employees and directors covered 66 57 As of December 31, 2018, the Bank was the owner and beneficiary of 196 life insurance policies, issued by 14 life insurance companies, covering 66 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	12 Months Ended
	Dec. 31, 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) December 31, Additions Reductions December 31, Goodwill $ 220,972 $ 156,661 $ — $ 64,311 Impairment exists when a Company’s carrying value exceeds its fair value. Goodwill is evaluated for impairment annually. At September 30, 2018, the Company had positive equity and the Company elected to perform a qualitative assessment to determine if it was more likely than not that the fair value of the Company exceeded its carrying value, including goodwill. The qualitative assessment indicated that it was more likely than not that the fair value of the reporting unit exceeds its carrying value, resulting in no impairment. For each of the years in the three year period ended December 31, 2018, there were no impairment charges recognized. The following table summarizes the Company’s core deposit intangibles (“CDI”) as of the dates indicated: (in thousands) December 31, Additions Reductions/ December 31, Core deposit intangibles $ 37,163 $ 27,605 $ — $ 9,558 Accumulated amortization (7,883 ) — (3,499 ) (4,384 ) Core deposit intangibles, net $ 29,280 27,605 $ (3,499 ) $ 5,174 The Company recorded additions to its CDI of $27,605,000 in conjunction with the FNBB acquisition on July 6, 2018, $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, and $898,000 in conjunction with the Citizens acquisition on September 23, 2011. The following table summarizes the Company’s estimated core deposit intangible amortization (dollars in thousands): Years Ended Estimated Core Deposit 2019 $ 5,723 2020 5,723 2021 5,465 2022 4,776 2023 4,269 Thereafter 3,324

Mortgage Servicing Rights

Mortgage Servicing Rights	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Mortgage Servicing Rights	Note 10 – Mortgage Servicing Rights The following tables summarize the activity in, and the main assumptions we used to determine the fair value of mortgage servicing rights for the periods indicated (dollars in thousands): Year ended December 31, 2018 2017 2016 Balance at beginning of period $ 6,687 $ 6,595 $ 7,618 Additions 557 810 1,161 Change in fair value (146 ) (718 ) (2,184 ) Balance at end of period $ 7,098 $ 6,687 $ 6,595 Contractually specified servicing fees, late fees and ancillary fees earned $ 2,038 $ 2,076 $ 2,065 Balance of loans serviced at: Beginning of period $ 811,065 $ 816,623 $ 817,917 End of period $ 785,138 $ 811,065 $ 816,623 Period end: Weighted-average prepayment speed (CPR) 7.6 % 8.9 % 8.8 % Weighted-average discount rate 12.0 % 13.0 % 14.0 % The changes in fair value of MSRs during 2018 were primarily due to changes in principal balances and mortgage prepayment speeds of the MSRs. The changes in fair value of MSRs during 2017 were primarily due to changes in investor required rate of return, or discount rate, of the MSRs. The changes in fair value of MSRs during 2016 were primarily 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.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Deposits	Note 11 – Deposits A summary of the balances of deposits follows (in thousands): December 31, 2018 2017 Noninterest-bearing demand $ 1,760,580 $ 1,368,218 Interest-bearing demand 1,252,366 971,459 Savings 1,921,324 1,364,518 Time certificates, over $250,000 132,429 73,596 Other time certificates 299,767 231,340 Total deposits $ 5,366,466 $ 4,009,131 Certificate of deposit balances of $60,000,000 and $50,000,000 from the State of California were included in time certificates over $250,000 at December 31, 2018 and 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 $1,469,000 and $1,366,000 were classified as consumer loans at December 31, 2018 and 2017, respectively. At December 31, 2018, the scheduled maturities of time deposits were as follows (in thousands): Scheduled 2019 $ 298,855 2020 75,989 2021 36,267 2022 18,542 2023 2,537 Thereafter 6 Total $ 432,196

Other Borrowings

Other Borrowings	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Other Borrowings	Note 12 – Other Borrowings A summary of the balances of other borrowings follows: December 31, 2018 2017 (in thousands) 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 December 31, 2018 and December 31, 2017 of 0.05%, payable on January 2, 2019 and January 2, 2018, respectively 15,839 17,437 Total other borrowings $ 15,839 $ 122,166 The Company did not enter into any other borrowings or repurchase agreements during 2018 or 2017. The Company maintains a collateralized line of credit with the FHLB. Based on the FHLB stock requirements at December 31, 2018, this line provided for maximum borrowings of $2,063,815,000 of which zero was outstanding. As of December 31, 2018, the Company had designated investment securities with a fair value of $188,559,000 and loans totaling $2,832,945,000 as potential collateral under this collateralized line of credit with the FHLB. The Company had $15,839,000 and $17,437,000 of other collateralized borrowings at December 31, 2018 and 2017, respectively. Other collateralized borrowings are generally overnight maturity borrowings from non-financial The Company maintains a collateralized line of credit with the Federal Reserve Bank of San Francisco (“FRB”). As of December 31, 2018, this line provided for maximum borrowings of $142,272,000 of which none was outstanding. As of December 31, 2018, the Company has designated investment securities with fair value of $12,000 and loans totaling $256,364,000 as potential collateral under this collateralized line of credit with the FRB. The Company has available unused correspondent banking lines of credit from commercial banks totaling $20,000,000 for federal funds transactions at December 31, 2018.

Junior Subordinated Debt

Junior Subordinated Debt	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Junior Subordinated Debt	Note 13 – Junior Subordinated Debt At December 31, 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 in 2014. The acquired Debentures were recorded on the Company’s books at their fair values on the acquisition date. 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. 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 December 31, 2018 December 31, 2017 Subordinated Debt Series Maturity Face Current Recorded Recorded TriCo Cap Trust I 10/7/2033 $ 20,619 3.05 % 5.49 % $ 20,619 $ 20,619 TriCo Cap Trust II 7/23/2034 20,619 2.55 % 5.03 % 20,619 20,619 North Valley Trust II 4/24/2033 6,186 3.25 % 5.79 % 5,174 5,135 North Valley Trust III 4/24/2034 5,155 2.80 % 5.28 % 4,079 4,041 North Valley Trust IV 3/15/2036 10,310 1.33 % 4.12 % 6,551 6,444 $ 62,889 $ 57,042 $ 56,858

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 14 – Commitments and Contingencies Restricted Cash Balances Lease Commitments non-cancelable non-cancelable Operating Leases (in thousands) 2019 $ 4,639 2020 4,036 2021 3,644 2022 2,814 2023 1,831 Thereafter 2,636 Future minimum lease payments $ 19,600 Rent expense under operating leases was $6,348,000 in 2018, $5,885,000 in 2017, and $6,082,000 in 2016. Rent expense was offset by rent income of $42,000 in 2018, $44,000 in 2017, and $220,000 in 2016. 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: December 31, (in thousands) 2018 2017 Financial instruments whose amounts represent risk: Commitments to extend credit: Commercial loans $ 306,191 $ 257,220 Consumer loans 496,575 422,958 Real estate mortgage loans 140,292 66,267 Real estate construction loans 248,996 187,097 Standby letters of credit 11,346 13,075 Deposit account overdraft privilege 111,956 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 The Bank owns 13,396 shares of Class B common stock of Visa Inc. which are convertible into Class A common stock at a conversion ratio of 1.6298 per Class B share. As of December 31, 2018, the value of the Class A shares was $131.94 per share. Utilizing the conversion ratio, the value of unredeemed Class A equivalent shares owned by the Bank was $2,881,000 as of December 31, 2018, and has not been reflected in the accompanying consolidated financial statements. The shares of Visa Class B common stock are restricted and may not be transferred. Visa Member Banks are required to fund an escrow account to cover settlements, resolution of pending litigation and related claims. If the funds in the escrow account are insufficient to settle all the covered litigation, Visa may sell additional Class A shares, use the proceeds to settle litigation, and further reduce the conversion ratio. If funds remain in the escrow account after all litigation is settled, the Class B conversion ratio will be increased to reflect that surplus. Mortgage loans sold to investors may be sold with servicing rights retained, with only the standard legal representations and warranties regarding recourse to the Bank. Management believes that any liabilities that may result from such recourse provisions are not significant.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2018
Federal Home Loan Banks [Abstract]
Shareholders' Equity	Note 15 – Shareholders’ Equity Dividends Paid The Bank paid to the Company cash dividends in the aggregate amounts of $26,432,000, $19,236,000, and $16,758,000 in 2018, 2017, and 2016, 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, 2018, the Bank could have paid dividends of $98,438,000 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 December 31, 2018, the Company had repurchased 196,566 shares under this plan. During the year ended December 31, 2018, 26,966 shares of common stock with a fair value of $968,000 were repurchased under this plan. There were no shares of common stock repurchased during 2017 or 2016. Stock Repurchased Under Equity Compensation Plans During the years ended December 31, 2018, 2017, and 2016, employees tendered 78,023, 107,390, and 264,800 of the Company’s common stock with market value of $3,001,000, $3,854,000, and $7,879,000, respectively, in lieu of cash to exercise options to purchase shares of the Company’s stock and to pay income taxes related to such exercises as permitted by the Company’s shareholder-approved equity compensation plans. The tendered shares were retired. The market value of tendered shares is the last market trade price at closing on the day an option is exercised. Stock repurchased under equity incentive plans are not included in the total of stock repurchased under the stock repurchase plan announced August 21, 2007.

Stock Options and Other Equity-

Stock Options and Other Equity-Based Incentive Instruments	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Options and Other Equity-Based Incentive Instruments	Note 16 – 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 RSU. When Awards made under the 2009 Plan expire or are forfeited or cancelled, the underlying shares will become available for future Awards under the 2009 Plan. To the extent that a share of common stock pursuant to an Award that counted as two shares against the number of shares again becomes available for issuance under the 2009 Plan, the number of shares of common stock available for issuance under the 2009 Plan shall increase by two shares. Shares awarded and delivered under the 2009 Plan may be authorized but unissued, or reacquired shares. As of December 31, 2018, 343,000 options for the purchase of common shares, and 112,483 RSUs were outstanding, and 380,958 shares remain available for issuance, under the 2009 Plan. In May 2001, the Company adopted the TriCo Bancshares 2001 Stock Option Plan (2001 Plan) covering officers, employees, directors of, and consultants to, the Company. Under the 2001 Plan, the option exercise price cannot be less than the fair market value of the Common Stock at the date of grant except in the case of substitute options. Options for the 2001 Plan expire on the tenth anniversary of the grant date. Vesting schedules under the 2001 Plan are determined individually for each grant. As of December 31, 2018, 10,000 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 stock awards may be granted under the 2001 Plan. Stock option activity is summarized in the following table for the dates indicated: Number of Option Price Weighted Outstanding at January 1, 2018 446,400 $ 12.63 to $23.21 $ 16.84 Options granted — — to — — Options exercised (100,400 ) $ 12.63 to $23.21 $ 16.97 Options forfeited (3,000 ) $ 23.21 $ 23.21 Outstanding at December 31, 2018 343,000 $ 12.63 to $23.21 $ 16.67 The following table shows the number, weighted-average exercise price, intrinsic value, and weighted average remaining contractual life of options exercisable, options not yet exercisable and total options outstanding as of December 31, 2018: Currently Currently Not Total Number of options 341,875 1,125 343,000 Weighted average exercise price $ 16.65 $ 23.21 $ 16.67 Intrinsic value (in thousands) $ 5,860 $ 12 $ 5,872 Weighted average remaining contractual term (yrs.) 3.2 5.8 3.3 The 1,125 options that are currently not exercisable as of December 31, 2018 are expected to vest, on a weighted-average basis, over the next 0.8 years. The Company did not modify any option grants during 2018 or 2017. The following table shows the total intrinsic value of options exercised, the total fair value of options vested, total compensation costs for options recognized in income, total tax benefit and excess tax benefits recognized in income related to compensation costs for options during the periods indicated: Year Ended December 31, 2018 2017 2016 Intrinsic value of options exercised $ 2,109,000 $ 2,657,000 $ 3,483,000 Fair value of options that vested $ 75,000 $ 259,000 $ 580,000 Total compensation costs for options recognized in income $ 75,000 $ 259,000 $ 580,000 Total tax benefit recognized in income related to compensation costs for options $ 22,000 $ 109,000 $ 244,000 Excess tax benefit recognized in income $ 623,000 $ 600,000 $ — During 2018, 2017 and 2016, the Company granted no options. Restricted stock unit activity is summarized in the following table for the dates indicated: Service Condition Vesting RSUs Market Plus Service Condition Number Weighted Average Number Weighted Average Outstanding at January 1, 2018 68,457 52,829 RSUs granted 38,605 $ 39.08 16,939 $ 36.40 Additional market plus service condition RSUs vested — 8,506 RSUs added through dividend credits 1,188 — RSUs released through vesting (35,060 ) (25,512 ) RSUs forfeited/expired (6,243 ) (7,226 ) Outstanding at December 31, 2018 66,947 45,536 The 66,947 of service condition vesting RSUs outstanding as of December 31, 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. Additional RSUs credited through dividends are subject to the same vesting requirements as the original grant. The 66,947 of service condition vesting RSUs outstanding as of December 31, 2018 are expected to vest, and be released, on a weighted-average basis, over the next 1.4 years. The Company expects to recognize $2,319,000 of pre-tax The 45,536 of market plus service condition vesting RSUs outstanding as of December 31, 2018 are expected to vest, and be released, on a weighted-average basis, over the next 1.4 years. The Company expects to recognize $848,000 of pre-tax The following table shows the compensation costs and excess tax benefits for RSUs recognized in income for the periods indicated: Year Ended December 31, 2018 2017 2016 Total compensation costs recognized in income Service condition vesting RSUs $ 1,017,000 $ 895,000 $ 616,000 Market plus service condition vesting RSUs $ 370,000 $ 432,000 $ 271,000 Excess tax benefit recognized in income Service condition vesting RSUs $ 104,000 $ 131,000 $ — Market plus service condition vesting RSUs $ 191,000 $ 175,000 $ —

Noninterest Income and Expense

Noninterest Income and Expense	12 Months Ended
	Dec. 31, 2018
Other Income and Expenses [Abstract]
Noninterest Income and Expense	Note 17 – Noninterest Income and Expense The components of other noninterest income were as follows (in thousands): Year Ended December 31, 2018 2017 2016 ATM and interchange fees $ 18,249 $ 16,727 $ 15,859 Service charges on deposit accounts 15,467 16,056 14,365 Other service fees 2,852 3,282 3,121 Mortgage banking service fees 2,038 2,076 2,065 Change in value of mortgage loan servicing rights (146 ) (718 ) (2,184 ) Total service charges and fees 38,460 37,423 33,226 Commissions on sale of non-deposit 3,151 2,729 2,329 Increase in cash value of life insurance 2,718 2,685 2,717 Gain on sale of loans 2,371 3,109 4,037 Lease brokerage income 678 782 711 Sale of customer checks 449 372 408 Gain on sale of foreclosed assets 408 711 262 Gain on sale of investment securities 207 961 — Loss on disposal of fixed assets (185 ) (142 ) (147 ) Loss on marketable equity securities (64 ) — — Other 1,091 1,391 1,020 Total other noninterest income 10,824 12,598 11,337 Total noninterest income $ 49,284 $ 50,021 $ 44,563 Mortgage banking servicing fees, net of change in value of mortgage loan servicing rights, totaling $1,892,000, $1,358,000, and ($119,000) were recorded within service charges and fees for the years ended December 31, 2018, 2017, and 2016, respectively. The components of noninterest expense were as follows (in thousands): Year Ended December 31, 2018 2017 2016 Base salaries, net of deferred loan origination costs $ 62,422 $ 54,589 $ 53,169 Incentive compensation 11,147 9,227 8,872 Benefits and other compensation costs 20,373 19,114 18,683 Total salaries and benefits expense 93,942 82,930 80,724 Occupancy 12,139 10,894 10,139 Data processing and software 11,021 10,448 8,846 Equipment 6,651 7,141 6,597 ATM and POS network charges 5,271 4,752 4,999 Merger and acquisition expense 5,227 530 784 Advertising 4,578 4,101 3,829 Professional fees 3,546 3,745 5,409 Intangible amortization 3,499 1,389 1,377 Telecommunications 3,023 2,713 2,749 Regulatory assessments and insurance 1,906 1,676 2,105 Courier service 1,287 1,035 998 Operational losses 1,260 1,394 1,564 Postage 1,154 1,296 1,603 Legal settlement — — 1,450 Foreclosed assets expense 382 231 266 Provision for foreclosed asset losses 89 162 140 Other miscellaneous expense 13,720 12,587 12,418 Total other noninterest expense 74,753 64,094 65,273 Total noninterest expense $ 168,695 $ 147,024 $ 145,997

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 18 – Income Taxes The components of consolidated income tax expense are as follows (in thousands): Year Ended December 31, 2018 2017 2016 Current tax expense Federal $ 13,109 $ 17,835 $ 17,401 State 9,323 6,650 7,121 $ 22,432 24,485 24,522 Deferred tax expense Federal 1,842 11,418 2,735 State 758 1,055 455 2,600 12,473 3,190 Total tax expense $ 25,032 $ 36,958 $ 27,712 A deferred tax asset or liability is recognized for the tax consequences of temporary differences in the recognition of revenue and expense for financial and tax reporting purposes. The net change during the year in the deferred tax asset or liability results in a deferred tax expense or benefit. On December 22, 2017, President Donald Trump signed into law “H.R.1”, commonly known as the “Tax Cuts and Jobs Act”, which among other items reduced the Federal corporate tax rate from 35% to 21%. The Company’s deferred tax expense as of December 31, 2017 included $7,416,000 from the re-measurement The Company recognized, as components of tax expense, tax credits and other tax benefits, and amortization expense relating to our investments in Qualified Affordable Housing Projects as follows for the periods indicated (in thousands): Year Ended December 31, 2018 2017 2016 Tax credits and other tax benefits – decrease in tax expense $ (1,993 ) $ (1,753 ) $ (954 ) Amortization – increase in tax expense $ 1,814 $ 1,611 $ 757 The carrying value of Low Income Housing Tax Credit Funds was $23,885,000 and $16,854,000 as of December 31, 2018 and 2017, respectively. As of December 31, 2018, the Company has committed to make additional capital contributions to the Low Income Housing Tax Credit Funds in the amount of $9,032,000, and these contributions are expected to be made over the next several years. The provisions for income taxes applicable to income before taxes for the years ended December 31, 2018, 2017 and 2016 differ from amounts computed by applying the statutory Federal income tax rates to income before taxes. The effective tax rate and the statutory federal income tax rate are reconciled as follows: Year Ended December 31, 2018 2017 2016 Federal statutory income tax rate 21.0 % 35.0 % 35.0 % State income taxes, net of federal tax benefit 8.6 6.9 6.8 Tax Cuts and Jobs Act impact of federal rate change — 9.6 — Tax-exempt (1.0 ) (1.9 ) (1.8 ) Tax-exempt (0.6 ) (1.3 ) (1.3 ) Low income housing tax credits (2.2 ) (2.3 ) (1.3 ) Low income housing tax credit amortization 2.0 2.1 0.8 Equity compensation (0.5 ) (1.2 ) — Non-deductible 0.1 0.1 0.1 Non-deductible 0.2 0.2 — Other (0.8 ) 0.5 (0.1 ) Effective Tax Rate 26.8 % 47.7 % 38.2 % The temporary differences, tax effected, which give rise to the Company’s net deferred tax asset recorded in other assets are as follows as of December 31 for the years indicated (in thousands): December 31, 2018 2017 Deferred tax assets: Allowance for losses and reserve for unfunded commitments $ 10,394 $ 9,900 Deferred compensation 2,780 1,953 Accrued pension liability 9,734 6,835 Accrued bonus 709 171 Other accrued expenses 466 522 Additional unfunded status of the supplemental retirement plans 1,420 1,582 State taxes 1,864 1,397 Share based compensation 1,132 1,322 Nonaccrual interest 814 282 OREO write downs 34 59 Acquisition cost basis 6,714 2,187 Unrealized loss on securities 6,201 1,008 Tax credits 623 581 Net operating loss carryforwards 2,442 1,801 Other 389 508 Total deferred tax assets 45,716 30,108 Deferred tax liabilities: Securities income (1,020 ) (958 ) Depreciation (5,572 ) (1,987 ) Merger related fixed asset valuations (26 ) (30 ) Securities accretion (426 ) (315 ) Mortgage servicing rights valuation (2,073 ) (1,943 ) Core deposit intangible (8,234 ) (916 ) Junior subordinated debt (1,729 ) (1,783 ) Prepaid expenses and other (582 ) (479 ) Total deferred tax liability (19,662 ) (8,411 ) Net deferred tax asset $ 26,054 $ 21,697 As part of the merger with FNB Bancorp in 2018 and North Valley Bancorp in 2014, TriCo acquired federal and state net operating loss carryforwards, capital loss carryforwards, and tax credit carryforwards. These tax attribute carryforwards will be subject to provisions of the tax law that limit the use of such losses and credits generated by a company prior to the date certain ownership changes occur. The amount of the Company’s net operating loss carryforwards that would be subject to these limitations as of December 31, 2018 were $1,292,000 for federal and $23,877,000 for California. The amount of the Company’s tax credits that would be subject to these limitations as of December 31, 2018 are $123,000 and $648,000 for federal and California, respectively. Due to the limitation, a significant portion of the state tax credits will expire regardless of whether the Company generates future taxable income. As such, the Company has recorded the future benefit of these tax credits on the books at the value which is more likely than not to be realized. These tax loss and tax credit carryforwards expire at various dates beginning in 2019. The Company believes that a valuation allowance is not needed to reduce the deferred tax assets as it is more likely than not that the results of future operations will generate sufficient taxable income to realize the deferred tax assets, including the tax attribute carryforwards acquired as part of the FNB Bancorp and North Valley Bancorp merger. Disclosure of unrecognized tax benefits at December 31, 2018 and 2017 were not considered significant for disclosure purposes. Management does not expect the unrecognized tax benefit will materially change in the next 12 months. During the years ended December 31, 2018 and December 31, 2017 the Company recognized no interest and penalties related to taxes. The Company files income tax returns in the U.S. federal jurisdiction, and California. With few exceptions, the Company is no longer subject to U.S. federal and state/local income tax examinations by tax authorities for years before 2015 and 2014, respectively.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Note 19 – Earnings per Share Earnings per share have been computed based on the following: Year Ended December 31, (in thousands) 2018 2017 2016 Net income $ 68,320 $ 40,554 $ 44,811 Average number of common shares outstanding 26,593 22,912 22,814 Effect of dilutive stock options and restricted stock 287 338 273 Average number of common shares outstanding used to calculate diluted earnings per share 26,880 23,250 23,087 Options excluded from diluted earnings per share because the effect of these options was antidilutive 10,056 — 13,825

Comprehensive Income

Comprehensive Income	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Comprehensive Income	Note 20 – 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 Year Ended December 31, (in thousands) 2018 2017 2016 Unrealized holding (losses) gains on available for sale securities before reclassifications $ (17,057 ) $ 6,422 $ (11,015 ) Amounts reclassified out of accumulated other comprehensive income: Realized gains on debt securities (207 ) (961 ) — Adoption ASU 2016-01 62 — — Adoption ASU 2018-02 (425 ) — — Total amounts reclassified out of accumulated other comprehensive income (570 ) (961 ) — Unrealized holding (losses) gains on available for sale securities after reclassifications (17,627 ) 5,461 (11,015 ) Tax effect 5,193 (2,296 ) 4,631 Unrealized holding (losses) gains on available for sale securities, net of tax (12,434 ) 3,165 (6,384 ) Change in unfunded status of the supplemental retirement plans before reclassifications 762 (1,016 ) 511 Amounts reclassified out of accumulated other comprehensive income: Amortization of prior service cost (54 ) (12 ) (40 ) Amortization of actuarial losses 510 390 550 Adoption ASU 2018-02 (668 ) — — Total amounts reclassified out of accumulated other comprehensive income (212 ) 378 510 Change in unfunded status of the supplemental retirement plans after reclassifications 550 (638 ) 1,021 Tax effect (162 ) 268 (429 ) Change in unfunded status of the supplemental retirement plans, net of tax 388 (370 ) 592 Change in joint beneficiary agreement liability before reclassifications 426 (110 ) (343 ) Tax effect — — — Change in unfunded status of the supplemental retirement plans, net of tax 426 (110 ) (343 ) Total other comprehensive (loss) income $(11,620) $2,685 $ (6,135 ) The components of accumulated other comprehensive income, included in shareholders’ equity, are as follows: Year Ended December 31, (in thousands) 2018 2017 Net unrealized loss on available for sale securities $ (20,974 ) (3,409 ) Stranded OCI from tax rate change — 425 Tax effect 6,201 1,008 Unrealized holding loss on available for sale securities, net of tax (14,773 ) (1,976 ) Unfunded status of the supplemental retirement plans (4,802 ) (5,352 ) Stranded OCI from tax rate change — 668 Tax effect 1,420 1,582 Unfunded status of the supplemental retirement plans, net of tax (3,382 ) (3,102 ) Joint beneficiary agreement liability 276 (150 ) Tax effect — — Joint beneficiary agreement liability, net of tax 276 (150 ) Accumulated other comprehensive loss $ (17,879 ) $ (5,228 )

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Retirement Plans	Note 21 – 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 Company recorded salaries & benefits expense attributable to the 401(k) Plan matching contributions and 401(k) Plan matching contributions for the years ended: Year Ended December 31, (in thousands) 2018 2017 2016 401(k) Plan benefits expense $ 879 $ 776 $ 678 401(k) Plan contributions made by the Company $ 872 $ 767 $ 811 Employee Stock Ownership Plan Substantially all employees with at least one year of service are covered by a discretionary employee stock ownership plan (ESOP). Company shares owned by the ESOP are paid dividends and included in the calculation of earnings per share as common shares outstanding. Contributions are made to the plan at the discretion of the Board of Directors. Expenses related to the Company’s ESOP, included in benefits and other compensation costs under salaries and benefits expense, and contributions to the plan for the years ended were: Year Ended December 31, (in thousands) 2018 2017 2016 ESOP benefits expense $ 1,887 $ 2,149 $ 1,831 ESOP contributions made by the Company $ 1,952 $ 2,073 $ 1,368 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 $9,402,000 and $6,605,000 at December 31, 2018 and 2017, respectively. Earnings credits on deferred balances included in noninterest expense are included in the following table: Year Ended December 31, (in thousands) 2018 2017 2016 Deferred compensation earnings credits included in noninterest expense $ 462 $ 478 $ 487 Supplemental Retirement Plans The Company has supplemental retirement plans for certain directors and key executives. These plans are non-qualified The Company recorded in other liabilities the additional unfunded status of the supplemental retirement plans of $4,802,000 and $5,352,000 related to the supplemental retirement plans as of December 31, 2018 and 2017, respectively. These amounts represent the amount by which the projected benefit obligations for these retirement plans exceeded the fair value of plan assets plus amounts previously accrued related to the plans. The projected benefit obligation is recorded in other liabilities. At December 31, 2018 and 2017, the additional unfunded status of the supplemental retirement plans of $4,802,000 and $5,352,000 were offset by a reduction of shareholders’ equity accumulated other comprehensive loss of $3,382,000 and $3,102,000, respectively, representing the after-tax year-end December 31, (in thousands) 2018 2017 Transition obligation $ 3 $ 4 Prior service cost (194 ) (248 ) Net actuarial loss 4,993 5,596 Amount included in accumulated other comprehensive loss 4,802 5,352 Stranded OCI from tax rate change — (668 ) Deferred tax benefit (1,420 ) (1,582 ) Amount included in accumulated other comprehensive loss, net of tax $ 3,382 $ 3,102 Information pertaining to the activity in the supplemental retirement plans, using a measurement date of December 31, is as follows: December 31, (in thousands) 2018 2017 Change in benefit obligation: Benefit obligation at beginning of year $ (28,472 ) $ (26,645 ) Service cost (973 ) (941 ) Interest cost (949 ) (991 ) Actuarial (loss)/gain 92 (1,203 ) Plan amendments — 185 Benefits paid 1,106 1,123 Benefit obligation at end of year $ (29,196 ) $ (28,472 ) Change in plan assets: Fair value of plan assets at beginning of year $ — $ — Fair value of plan assets at end of year $ — $ — Funded status $ (29,196 ) $ (28,472 ) Unrecognized net obligation existing at January 1, 1986 3 4 Unrecognized net actuarial loss 4,993 5,596 Unrecognized prior service cost (194 ) (248 ) Accumulated other comprehensive income (4,802 ) (5,352 ) Accrued benefit cost $ (29,196 ) $ (28,472 ) Accumulated benefit obligation $ (27,544 ) $ (26,432 ) The following table sets forth the net periodic benefit cost recognized for the supplemental retirement plans: Year Ended December 31, (in thousands) 2018 2017 2016 Net pension cost included the following components: Service cost-benefits earned during the period $ 973 $ 941 $ 1,042 Interest cost on projected benefit obligation 949 991 1,025 Amortization of net obligation at transition 2 2 2 Amortization of prior service cost (54 ) (12 ) (41 ) Recognized net actuarial loss 510 390 549 Net periodic pension cost $ 2,380 $ 2,312 $ 2,577 The following table sets forth assumptions used in accounting for the plans: Year Ended December 31, 2018 2017 2016 Discount rate used to calculate benefit obligation 3.96 % 3.40 % 3.80 % Discount rate used to calculate net periodic pension cost 3.40 % 3.80 % 4.00 % Average annual increase in executive compensation 3.25 % 3.25 % 2.50 % Average annual increase in director compensation 0.00 % 0.00 % 2.50 % The following table sets forth the expected benefit payments to participants and estimated contributions to be made by the Company under the supplemental retirement plans for the years indicated: Expected Benefit Estimated (in thousands) 2019 $ 1,254 $ 1,254 2020 1,668 1,668 2021 2,192 2,192 2022 2,161 2,161 2023 2,153 2,153 2024-2028 10,928 10,928

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Note 22 – Related Party Transactions Certain directors, officers, and companies with which they are associated were customers of, and had banking transactions with, the Company or the Bank in the ordinary course of business. The following table summarizes the activity in these loans for the periods indicated (in thousands): Balance January 1, 2017 $ 2,432 Advances/new loans 437 Removed/payments (721 ) Balance December 31, 2017 2,148 Advances/new loans 8,854 Removed/payments (1,799 ) Balance December 31, 2018 $ 9,203 Deposits of directors, officers and other related parties to the Bank totaled $43,881,000 and $46,025,000 at December 31, 2018 and 2017, respectively.

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurement	Note 23 – 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 December 31, 2018 Total Level 1 Level 2 Level 3 Marketable equity securities $ 2,874 $ 2,874 $ — $ — Debt securities available for sale: Obligations of U.S. government agencies 629,981 — 629,981 — Obligations of states and political subdivisions 126,072 — 126,072 — Corporate bonds 4,478 — 4,478 — Asset backed securities 354,505 — 354,505 — Loans held for sale 3,687 — 3,687 — Mortgage servicing rights 7,098 — — 7,098 Total assets measured at fair value $ 1,128,695 $ 2,874 $ 1,118,723 $ 7,098 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 agencies 604,789 — 604,789 — Obligations of states and political subdivisions 123,156 — 123,156 — Loans held for sale 4,616 — 4,616 — Mortgage servicing rights 6,687 — — 6,687 Total assets measured at fair value $ 742,186 $ 2,938 $ 732,561 $ 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 2018 or 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 years ended December 31, 2018, 2017, and 2016. Had there been any transfer into or out of Level 3 during 2018, 2017, or 2016, the amount included in the “Transfers into (out of) Level 3” column would represent the beginning balance of an item in the period (interim quarter) during which it was transferred (in thousands): Year ended December 31, Beginning Transfers Change Issuances Ending 2018: Mortgage servicing rights $ 6,687 — $ (146 ) $ 557 $ 7,098 2017: Mortgage servicing rights $ 6,595 — $ (718 ) $ 810 $ 6,687 2016: Mortgage servicing rights $ 7,618 — $ (2,184 ) $ 1,161 $ 6,595 The Company’s method for determining the fair value of mortgage servicing rights is described in Note 1. The key unobservable inputs used in determining the fair value of mortgage servicing rights are mortgage prepayment speeds and the discount rate used to discount cash projected cash flows. Generally, any significant increases in the mortgage prepayment speed and discount rate utilized in the fair value measurement of the mortgage servicing rights will result in a negative fair value adjustments (and decrease in the fair value measurement). Conversely, a decrease in the mortgage prepayment speed and discount rate will result in a positive fair value adjustment (and increase in the fair value measurement). Note 10 contains additional information regarding mortgage servicing rights. The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2018 and 2017: December 31, 2018 Fair Value Valuation Unobservable Range, Mortgage Servicing Rights $7,098 Discounted Constant 5.0%-27.3%, 7.6% December 31, 2017 Discount rate 12%-13%, 12% 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 amount of assets and liabilities measured at fair value on a nonrecurring basis, as of the dates indicated, that had a write-down or an additional allowance provided during the periods indicated (in thousands): Year ended December 31, 2018 Total Level 1 Level 2 Level 3 Total Gains Fair value: Impaired Originated & PNCI loans $ 281 — — $ 281 $ (294 ) Foreclosed assets 1,311 — — 1,311 (8 ) Total assets measured at fair value $ 1,592 — — $ 1,592 $ (302 ) 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 ) 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 December 31, 2018 and 2017: December 31, 2018 Fair Value Valuation Technique Unobservable Inputs Range, Impaired Originated & PNCI loans $ 281 Sales comparison approach Income approach Adjustment for differences between comparable sales; Capitalization rate (16.3%)—35.14%; 10.45% N/A Foreclosed assets (Residential real estate) $ 693 Sales comparison approach Adjustment for differences between comparable sales (21.83%)—7.25%; (3.75%) Foreclosed assets (Commercial real estate) $ 618 Sales comparison approach Adjustment for differences between comparable sales (65%)—20%; December 31, 2017 Fair Value Valuation Technique Unobservable Inputs Range, Impaired Originated & PNCI loans $ 2,767 Sales comparison approach Income approach Adjustment for differences between comparable sales Capitalization rate (74%)—23%; Foreclosed assets (Land & construction) $ 1,341 Sales comparison approach Adjustment for differences between comparable sales (53%)—283%; Foreclosed assets (Residential real estate) $ 622 Sales comparison approach Adjustment for differences between comparable sales (47%)—39%; Foreclosed assets (Commercial real estate) $ 254 Sales comparison approach Adjustment for differences between comparable sales (84%)—19%; (84%) The estimated fair values of financial instruments that are reported at amortized cost in the Corporation’s consolidated balance sheets, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value, were as follows (in thousands): December 31, 2018 December 31, 2017 Carrying Fair Carrying Fair Financial assets: Level 1 inputs: Cash and due from banks $ 119,781 $ 119,781 $ 105,968 $ 105,968 Cash at Federal Reserve and other banks 107,752 107,752 99,460 99,460 Level 2 inputs: Securities held to maturity 444,936 437,370 514,844 518,165 Restricted equity securities 17,250 N/A 16,956 N/A Level 3 inputs: Loans, net (1) 3,989,432 4,006,986 2,984,842 2,992,225 Financial liabilities: Level 2 inputs: Deposits 5,366,466 5,362,173 4,009,131 4,006,620 Other borrowings 15,839 15,839 122,166 122,166 Level 3 inputs: Junior subordinated debt 57,042 62,610 56,858 58,466 Contract Fair Contract Fair Off-balance Level 3 inputs: Commitments $ 1,192,054 $ 11,921 $ 933,542 $ 9,335 Standby letters of credit 11,346 113 13,075 131 Overdraft privilege commitments 111,956 1,120 98,260 983 (1) The estimated fair value of loans for December 31, 2018 reflects an exit price assumption. The December 31, 2017 fair value estimate is not based on an exit price assumption.

TriCo Bancshares Condensed Fina

TriCo Bancshares Condensed Financial Statements (Parent Only)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
TriCo Bancshares Condensed Financial Statements (Parent Only)	Note 24 – TriCo Bancshares Condensed Financial Statements (Parent Only) Condensed Balance Sheets December 31, December 31, (In thousands) Assets Cash and cash equivalents $ 2,374 $ 3,924 Investment in Tri Counties Bank 880,907 557,538 Other assets 1,723 1,721 Total assets $ 885,004 $ 563,183 Liabilities and shareholders’ equity Other liabilities $ 589 $ 517 Junior subordinated debt 57,042 56,858 Total liabilities 57,631 57,375 Shareholders’ equity: Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at December 31, 2018 and 2017 — — Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 30,417,223 and 22,955,963 shares at December 31, 2018 and 2017, respectively 541,762 255,836 Retained earnings 303,490 255,200 Accumulated other comprehensive loss, net (17,879 ) (5,228 ) Total shareholders’ equity 827,373 505,808 Total liabilities and shareholders’ equity $ 885,004 $ 563,183 Condensed Statements of Income Year ended December 31, 2018 2017 2016 (In thousands) Interest expense $ (3,131 ) $ (2,535 ) $ (2,229 ) Administration expense (1,489 ) (915 ) (725 ) Loss before equity in net income of Tri Counties Bank (4,620 ) (3,450 ) (2,954 ) Equity in net income of Tri Counties Bank: Distributed 26,432 19,236 16,758 Undistributed 45,315 23,359 29,764 Income tax benefit 1,193 1,409 1,243 Net income $ 68,320 $ 40,554 $ 44,811 Condensed Statements of Comprehensive Income Year ended December 31, 2018 2017 2016 (In thousands) Net income $ 68,320 $ 40,554 $ 44,811 Other comprehensive income (loss), net of tax: Increase (decrease) in unrealized gains on available for sale securities arising during the period (12,434 ) 3,165 (6,384 ) Change in minimum pension liability 388 (370 ) 592 Change in joint beneficiary agreement liablity 426 (110 ) (343 ) Other comprehensive income (loss) (11,620 ) 2,685 (6,135 ) Comprehensive income $ 56,700 $ 43,239 $ 38,676 Condensed Statements of Cash Flows Year ended December 31, 2018 2017 2016 (In thousands) Operating activities: Net income $ 68,320 $ 40,554 $ 44,811 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed equity in earnings of Tri Counties Bank (45,315 ) (23,359 ) (29,764 ) Equity compensation vesting expense 1,462 1,586 1,467 Equity compensation tax effect — — (155 ) Net change in other assets and liabilities (4,983 ) (1,295 ) (1,210 ) Net cash provided by operating activities 19,484 17,486 15,149 Investing activities: None Financing activities: Issuance of common stock through option exercise 218 396 518 Equity compensation tax effect — — 155 Repurchase of common stock (2,483 ) (1,629 ) (1,890 ) Cash dividends paid — common (18,769 ) (15,131 ) (13,695 ) Net cash used for financing activities (21,034 ) (16,364 ) (14,912 ) Net change in cash and cash equivalents (1,550 ) 1,122 237 Cash and cash equivalents at beginning of year 3,924 2,802 2,565 Cash and cash equivalents at end of year $ 2,374 $ 3,924 $ 2,802

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Regulatory Matters	Note 25 – 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 The following tables present actual and required capital ratios as of December 31, 2018 and 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 December 31, 2018 and 2017 based on the phased-in phased-in. Actual Minimum Capital Phase-in Minimum Capital Required to be (dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) As of December 31, 2018: Total Capital (to Risk Weighted Assets): Consolidated $ 682,419 14.40 % $ 467,874 9.875 % $ 497,486 10.50 % N/A N/A Tri Counties Bank $ 680,624 14.37 % $ 467,704 9.875 % $ 497,305 10.50 % $ 473,624 10.00 % Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 647,262 13.66 % $ 373,115 7.875 % $ 402,727 8.50 % N/A N/A Tri Counties Bank $ 645,467 13.63 % $ 372,979 7.875 % $ 402,581 8.50 % $ 378,899 8.00 % Common equity Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 591,933 12.49 % $ 302,045 6.375 % $ 331,658 7.00 % N/A N/A Tri Counties Bank $ 645,467 13.63 % $ 301,935 6.375 % $ 331,537 7.00 % $ 307,856 6.50 % Tier 1 Capital (to Average Assets): Consolidated $ 647,262 10.68 % $ 242,452 4.000 % $ 242,452 4.00 % N/A N/A Tri Counties Bank $ 645,467 10.65 % $ 242,447 4.000 % $ 242,447 4.00 % $ 303,059 5.00 % Actual Minimum Capital Phase-in Schedule Minimum Capital Required to be (dollars in thousands) 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 9.250 % $ 394,679 10.50 % N/A N/A Tri Counties Bank $ 525,384 13.98 % $ 347,535 9.250 % $ 394,499 10.50 % $ 375,713 10.00 % Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 495,318 13.18 % $ 272,517 7.250 % $ 319,502 8.50 % N/A N/A Tri Counties Bank $ 491,897 13.09 % $ 272,392 7.250 % $ 319,356 8.50 % $ 300,570 8.00 % Common equity Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 440,643 11.72 % $ 216,134 5.750 % $ 263,120 7.00 % N/A N/A Tri Counties Bank $ 491,897 13.09 % $ 216,035 5.750 % $ 262,999 7.00 % $ 244,214 6.50 % Tier 1 Capital (to Average Assets): Consolidated $ 495,318 10.80 % $ 183,400 4.000 % $ 183,400 4.00 % N/A N/A Tri Counties Bank $ 491,897 10.73 % $ 183,394 4.000 % $ 183,394 4.00 % $ 229,243 5.00 % As of December 31, 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

Summary of Quarterly Results of

Summary of Quarterly Results of Operations (unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results of Operations (unaudited)	Note 26 – Summary of Quarterly Results of Operations (unaudited) The following table sets forth the results of operations for the four quarters of 2018 and 2017, 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 $ 1,982 $ 2,098 $ 559 $ 632 All other loan interest income 53,680 51,004 38,745 37,417 Total loan interest income 55,662 53,102 39,304 38,049 Debt securities, dividends and interest bearing cash at banks 12,403 11,452 9,174 9,072 Total interest income 68,065 64,554 48,478 47,121 Interest expense 4,063 4,065 2,609 2,135 Net interest income 64,002 60,489 45,869 44,986 (Benefit from reversal of) provision for loan losses 806 2,651 (638 ) (236 ) Net interest income after provision for loan losses 63,196 57,838 46,507 45,222 Noninterest income 12,634 12,186 12,174 12,290 Noninterest expense 45,285 47,378 37,870 38,162 Income before income taxes 30,545 22,646 20,811 19,350 Income tax expense 7,334 6,476 5,782 5,440 Net income $ 23,211 $ 16,170 $ 15,029 $ 13,910 Per common share: Net income (diluted) $ 0.76 $ 0.53 $ 0.65 $ 0.60 Dividends $ 0.19 $ 0.17 $ 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 $ 1,489 $ 1,364 $ 2,170 $ 1,541 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 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 Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 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 29 California counties. The Company has five capital subsidiary business trusts (collectively, the “Capital Trusts”) that issued trust preferred securities, including two organized by the Company and three acquired with the acquisition of North Valley Bancorp. 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. All adjustments necessary for a fair presentation of these consolidated financial statements have been included and are of a normal and recurring nature. 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 $1,713,000 are accounted for under the equity method and, accordingly, are included in other assets on the consolidated balance sheets. 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 sheets.
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.
Segment and Significant Group Concentration of Credit Risk	Segment and Significant Group Concentration of Credit Risk The Company grants agribusiness, commercial, consumer, and residential loans to customers located throughout Northern and Central 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.
Geographical Descriptions	Geographical Descriptions For the purpose of describing the geographical location of the Company’s operations, the Company has defined northern California as that area of California north of, and including, Stockton to the east and San Jose to the west; central California as that area of the state south of Stockton and San Jose, to and including, Bakersfield to the east and San Luis Obispo to the west; and southern California as that area of the state south of Bakersfield and San Luis Obispo.
Business Combinations	Business Combinations The Company accounts for acquisitions of businesses using the acquisition method of accounting. Under the acquisition method, assets acquired and liabilities assumed are recorded at their estimated fair values at the date of acquisition. Management utilizes various valuation techniques including discounted cash flow analyses to determine these fair values. Any excess of the purchase price over amounts allocated to the acquired assets, including identifiable intangible assets, and liabilities assumed is recorded as goodwill.
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 the new accounting standard for Financial Instruments using a prospective transition approach, which requires equity investments to be measured at fair value with changes in fair value recognized in net income. The adoption of this guidance resulted in a $62,000 decrease to beginning retained earnings and a decrease to the deferred tax of $18,000. During the twelve months ended December 31, 2018, the Company recognized $64,000 of unrealized losses in the consolidated statements of income related to changes in the fair value of marketable equity securities.
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 and changes in the value of these securities are recorded through earnings. 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. The Company did not have any debt securities classified as trading during 2018, 2017 or 2016. 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. Both cash and stock dividends are reported as income when received.
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 to 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 considered 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, if any, certain repayment 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 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 are 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 measured and recorded at their fair value as of the acquisition date. Loans acquired with evidence of credit deterioration since origination for which it is probable that all contractually required payments will not be collected are referred to as purchased credit impaired (PCI) loans. PCI loans are recorded at fair value at acquisition date, factoring in credit losses expected to be incurred over the life of the loan. Accordingly, an allowance for loan losses is not carried over or recorded as of the acquisition date. Fair value is defined as the present value of the future estimated principal and interest payments of the loan, with the discount rate used in the present value calculation representing the estimated effective yield of the loan. Default rates, loss severity, and prepayment speed assumptions are periodically reassessed and our estimate of future payments is adjusted accordingly. The difference between contractual future payments and estimated future payments is referred to as the nonaccretable difference. The difference between estimated future payments and the present value of the estimated future payments is referred to as the accretable yield. The accretable yield represents the amount that is expected to be recorded as interest income over the remaining life of the loan. If after acquisition, the Company determines that the estimated future cash flows of a PCI loan are expected to be more than originally estimated, an increase in the discount rate (effective yield) would be made such that the newly increased accretable yield would be recognized, on a level yield basis, over the remaining estimated life of the loan. If, thereafter, the Company determines that the estimated future cash flows of a PCI loan are expected to be less than previously estimated, an allowance for loan loss would be established through a provision for loan losses charged to expense to decrease the present value to the required level. If the estimated cash flows improve after an allowance has been established for a loan, the allowance may be partially or fully reversed depending on the improvement in the estimated cash flows. Only after the allowance has been fully reversed may the discount rate be increased. PCI loans are put on nonaccrual status when cash flows cannot be reasonably estimated. PCI loans on nonaccrual status are accounted for using the cost recovery method or cash basis method of income recognition. PCI loans are charged off when evidence suggests cash flows are not recoverable. Foreclosed assets from PCI loans are recorded in foreclosed assets at fair value with the fair value at time of foreclosure representing estimated proceeds less selling costs from the collateral securing the loan. PCI loans with similar risk characteristics and acquisition time frame may be “pooled” and have their cash flows aggregated as if they were one loan or accounted for individually. Acquired loans that are not PCI loans are referred to as purchased not credit impaired (PNCI) loans and interest income is accrued on a level-yield basis. For income recognition purposes, this method assumes that all contractual cash flows will be collected, and no allowance for loan losses is established at the time of acquisition. Post-acquisition date, an allowance for loan losses may need to be established for acquired loans through a provision charged to earnings for credit losses incurred subsequent to acquisition. The loss estimate for acquired loans is measured based on the probable shortfall in relation to the contractual note requirements, consistent with our allowance for loan loss policy for similar loans. Throughout these financial statements, reference to “Loans” or “Allowance for loan losses” relates to all categories of loans, including Originated, PNCI, and PCI. When not referring to all categories of loans, specific reference to Originated, PNCI, or PCI is made. 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.
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
Company Owned Life Insurance	Company Owned Life Insurance The Company has purchased life insurance policies on certain key executives. Company owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement.
Goodwill, Other Intangible and Long-Lived Assets	Goodwill, Other Intangible and Long-Lived Assets Goodwill represents the excess of costs over fair value of net assets of businesses acquired from a business combination. The Company has an identifiable intangible asset consisting of core deposit intangibles (“CDI”). CDI are amortized over their respective estimated useful lives, and reviewed periodically for impairment. Goodwill and other intangible assets acquired in a business combination and determined to have an indefinite useful life are not amortized, but instead tested for impairment at least annually. Other intangible assets with estimable useful lives are amortized over their respective estimated useful lives to their estimated residual values, and reviewed periodically for impairment. As of September 30 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. 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.
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, when earned, and changes in fair value of the MSR, are recorded in noninterest income. 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.
Reserve for Unfunded Commitments	Reserve for Unfunded Commitments The reserve for unfunded commitments is established through a provision for losses – unfunded commitments, the changes of which are recorded in 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 credit and other loans, standby letters of credit, and unused deposit account overdraft privileges. 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.
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.
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.
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. A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. Interest and/or penalties related to income taxes are reported as a component of noninterest income.
Earnings per Share	Earnings per Share Basic earnings per share represents income available to common shareholders divided by the weighted-average number of common shares outstanding during the period. There are no unvested share-based payment awards that contain rights to nonforfeitable dividends (participating securities). Diluted earnings per share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued, as well as any adjustments to income that would result from assumed issuance. Potential common shares that may be issued by the Company relate solely from outstanding stock options and restricted stock units, and are determined using the treasury stock 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. Most of our revenue-generating transactions are not subject to Topic 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 Deposit service charges The Company earns fees from its deposit customers for account maintenance, transaction-based and overdraft services. Account maintenance fees consist primarily of account fees and analyzed account fees charged on deposit accounts on a monthly basis. The performance obligation is satisfied and the fees are recognized on a monthly basis as the service period is completed. Transaction-based fees on deposit accounts are charged to deposit customers for specific services provided to the customer, such as non-sufficient funds fees, overdraft fees, and wire fees. The performance obligation is completed as the transaction occurs and the fees are recognized at the time each specific service is provided to the customer. Debit and ATM interchange fee income and expenses Debit and ATM interchange income represent fees earned when a debit card issued by the Company is used. The Company earns interchange fees from debit cardholder transactions through the Visa payment network. Interchange fees from cardholder transactions represent a percentage of the underlying transaction value and are recognized daily, concurrently with the transaction processing services provided to the cardholder. The performance obligation is satisfied and the fees are earned when the cost of the transaction is charged to the cardholders’ debit card. Certain expenses directly associated with the credit and debit card are recorded on a net basis with the interchange income. Commission on sale of non-deposit investment products Commissions on sale of non-deposit investment products consist of fees earned from advisory asset management, trade execution and administrative fees from investments. Advisory asset management fees are variable, since they are based on the underlying portfolio value, which is subject to market conditions and asset flows. Advisory asset management fees are recognized quarterly and are based on the portfolio values at the end of each quarter. Brokerage accounts are charged commissions at the time of a transaction and the commission schedule is based upon the type of security and quantity. In addition, revenues are earned from selling insurance and annuity policies. The amount of revenue earned is determined by the value and type of each instrument sold and is recognized at the time the policy or contract is written. Merchant fee income Merchant fee income represents fees earned by the Company for card payment services provided to its merchant customers. The Company outsources these services to a third party to provide card payment services to these merchants. The third party provider passes the payments made by the merchants through to the Company. The Company, in turn, pays the third party provider for the services it provides to the merchants. These payments to the third party provider are recorded as expenses as a net reduction against fee income. In addition, a portion of the payment received represents interchange fees which are passed through to the card issuing bank. Income is primarily earned based on the dollar volume and number of transactions processed. The performance obligation is satisfied and the related fee is earned when each payment is accepted by the processing network. Gain/loss on other real estate owned, net The Company records a gain or loss from the sale of other real estate owned when control of the property transfers to the buyer, which generally occurs at the time of an executed deed of trust. When the Company finances the sale of other real estate owned to the buyer, the Company assesses whether the buyer is committed to perform their obligations under the contract and whether collectability of the transaction price is probable. Once these criteria are met, the other real estate owned asset is derecognized and the gain or loss on sale is recorded upon the transfer of control of the property to the buyer. In determining the gain or loss on sale, the Company adjusts the transaction price and related gain or loss on sale if a significant financing component is present.
Reclassifications	Reclassifications Certain amounts reported in previous consolidated financial statements have been reclassified and recalculated to conform to the presentation in this report. These reclassifications did not affect previously reported net income, total assets or total shareholders’ equity.
Accounting Standards Adopted in 2018	Accounting Standards Adopted in 2018 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. 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. 2017-07, Compensation—Retirement Benefits (Topic 715). 2017-07 ASU 2017-07 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
Accounting Standards Pending Adoption	Accounting Standards Pending Adoption 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, Financial Instruments—Credit Losses (Topic 326) 2016-13 2016-13, 2016-13 available-for-sale 2016-13 2016-13 2016-13 2016-13 one-time one-time 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 2017-08, Receivables—Nonrefundable Fees and Other Costs (Topic 310). ASU 2017-08 non-pooled ASU 2017-08 ASU 2017-08

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Schedule of Fair Value of Consideration Transferred, Identifiable Net Assets Acquired and Resulting Goodwill	The following table summarizes the consideration paid for FNBB and the amounts of assets acquired and liabilities assumed that were recorded at the acquisition date (in thousands). FNB Bancorp Fair value of consideration transferred: Fair value of shares issued $ 284,437 Cash consideration 6,695 Total fair value of consideration transferred 291,132 Assets acquired: Cash and cash equivalents 37,308 Securities available for sale 335,667 Restricted equity securities 7,723 Loans 834,683 Premises and equipment 30,522 Cash value of life insurance 16,817 Core deposit intangible 27,605 Other assets 16,214 Total assets acquired 1,306,539 Liabilities assumed: Deposits 991,935 Other liabilities 15,133 Short-term borrowings—Federal Home Loan Bank 165,000 Total liabilities assumed 1,172,068 Total net assets acquired 134,471 Goodwill recognized $ 156,661
Summary of Estimated Fair Value Adjustments Resulting in Goodwill	A summary of the estimated fair value adjustments resulting in the goodwill recorded in the FNB Bancorp acquisition are presented below (in thousands): FNB Bancorp Value of stock consideration paid to FNB Bancorp Shareholders $ 284,437 Cash consideration 6,695 Less: Cost basis net assets acquired 114,030 Fair value adjustments: Investments (1,081 ) Loans (22,390 ) Premises and Equipment 21,590 Core deposit intangible 27,327 Deferred income taxes (6,394 ) Other 1,389 Goodwill $ 156,661
Schedule of Business Acquisition Pro-forma financial Information	The unaudited pro forma financial information is not necessarily indicative of the results of operations that would have occurred had the transaction been effected on the assumed date. Year ended December 31, 2018 December 31, 2017 (in thousands, except per share data) Summarized proforma income statement data: Net interest income $ 242,793 $ 227,795 (Provision for) benefit from loan losses (2,180 ) 271 Noninterest income 51,152 53,881 Noninterest expense (180,884 ) (181,833 ) Income before taxes 110,881 100,114 Income taxes (30,337 ) (47,352 ) Net income $ 80,544 $ 52,762 Basic earnings per share $ 2.65 $ 1.74 Diluted earnings per share $ 2.63 $ 1.72

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments Schedule [Abstract]
Amortized Cost and Estimated Fair Values of Investments Securities	The amortized cost and estimated fair values of investment securities classified as available for sale and held to maturity are summarized in the following tables: December 31, 2018 Amortized Gross Gross Estimated (in thousands) Debt Securities Available for Sale Obligations of U.S. government agencies $ 647,288 $ 771 $ (18,078 ) $ 629,981 Obligations of states and political subdivisions 128,890 294 (3,112 ) 126,072 Corporate bonds 4,381 97 — 4,478 Asset backed securities 355,451 73 (1,019 ) 354,505 Total debt securities available for sale $ 1,136,010 $ 1,235 $ (22,209 ) $ 1,115,036 Debt Securities Held to Maturity Obligations of U.S. government agencies $ 430,343 $ 327 $ (7,745 ) $ 422,925 Obligations of states and political subdivisions 14,593 82 (230 ) 14,445 Total debt securities held to maturity $ 444,936 $ 409 $ (7,975 ) $ 437,370 December 31, 2017 Amortized Gross Gross Estimated (in thousands) Debt Securities Available for Sale Obligations of U.S. government 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 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 Due in one year $ 2,410 $ 2,413 $ — $ — Due after one year through five years 10,625 10,794 1,238 1,250 Due after five years through ten years 17,381 17,622 25,039 24,744 Due after ten years 1,105,594 1,084,207 418,659 411,376 Totals $ 1,136,010 $ 1,115,036 $ 444,936 $ 437,370
Gross Unrealized Losses on Investment Securities	Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, were as follows: Less than 12 months 12 months or more Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2018 (in thousands) Debt Securities Available for Sale Obligations of U.S. government agencies $ 171,309 $ (3,588 ) $ 394,630 $ (14,490 ) $ 565,939 $ (18,078 ) Obligations of states and political subdivisions 63,738 (1,541 ) 20,719 (1,571 ) 84,457 (3,112 ) Asset backed securities 101,386 (1,019 ) — — 101,386 (1,019 ) Total debt securities available for sale $ 336,433 $ (6,148 ) $ 415,349 $ (16,061 ) $ 751,782 $ (22,209 ) Debt Securities Held to Maturity Obligations of U.S. government agencies $ 223,810 $ (2,619 ) $ 158,648 $ (5,126 ) $ 382,458 $ (7,745 ) Obligations of states and political subdivisions 5,786 (114 ) 4,042 (116 ) 9,828 (230 ) Total debt securities held to maturity $ 229,596 $ (2,733 ) $ 162,690 $ (5,242 ) $ 392,286 $ (7,975 ) Less than 12 months 12 months or more Total Fair Unrealized Fair Unrealized Fair Unrealized December 31, 2017 (in thousands) Debt Securities Available for Sale Obligations of U.S. government 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 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)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Summary of Loan Balances	A summary of loan balances follows (in thousands): December 31, 2018 Originated PNCI PCI Total Mortgage loans on real estate: Residential 1-4 $ 343,796 $ 169,792 $ 1,674 $ 515,262 Commercial 1,910,981 708,401 8,456 2,627,838 Total mortgage loans on real estate 2,254,777 878,193 10,130 3,143,100 Consumer: Home equity lines of credit 284,453 40,957 1,167 326,577 Home equity loans 32,660 3,585 439 36,684 Other 34,020 21,659 42 55,721 Total consumer loans 351,133 66,201 1,648 418,982 Commercial 228,635 45,468 2,445 276,548 Construction: Residential 90,703 30,593 — 121,296 Commercial 56,208 5,880 — 62,088 Total construction 146,911 36,473 — 183,384 Total loans, net of deferred loan fees and discounts $ 2,981,456 $ 1,026,335 $ 14,223 $ 4,022,014 Total principal balance of loans owed, net of charge-offs $ 2,991,324 $ 1,062,655 $ 21,265 $ 4,075,244 Unamortized net deferred loan fees (9,868 ) — — (9,868 ) Discounts to principal balance of loans owed, net of charge-offs — (36,320 ) (7,042 ) (43,362 ) Total loans, net of deferred loan fees and discounts $ 2,981,456 $ 1,026,335 $ 14,223 $ 4,022,014 Allowance for loan losses $ (31,793 ) $ (667 ) $ (122 ) $ (32,582 ) December 31, 2017 Originated PNCI 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 2,498 288,688 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 3,028 356,874 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 $ 15,560 $ 3,015,165 Total principal balance of loans owed, net of charge-offs $ 2,699,053 $ 316,238 $ 23,181 $ 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 ) (7,621 ) (14,656 ) Total loans, net of unamortized deferred loan fees and discounts $ 2,690,402 $ 309,203 $ 15,560 $ 3,015,165 Allowance for loan losses $ (29,122 ) $ (929 ) $ (272 ) $ (30,323 )
Change in Accretable Yield for PCI	The following is a summary of the change in accretable yield for PCI loans during the periods indicated (in thousands): Year ended December 31, 2018 2017 2016 Change in accretable yield: Balance at beginning of period $ 6,137 $ 7,670 $ 13,255 Accretion to interest income (787 ) (2,809 ) (4,011 ) Reclassification (to) from nonaccretable difference 709 1,276 (1,574 ) Balance at end of period $ 6,059 $ 6,137 $ 7,670

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 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 – Year Ended December 31, 2018 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,317 $ (77 ) $ — $ 436 $ 2,676 Commercial 11,441 (15 ) 68 1,450 12,944 Total mortgage loans on real estate 13,758 (92 ) 68 1,886 15,620 Consumer: Home equity lines of credit 5,800 (277 ) 846 (327 ) 6,042 Home equity loans 1,841 (24 ) 297 (574 ) 1,540 Other 586 (783 ) 288 702 793 Total consumer loans 8,227 (1,084 ) 1,431 (199 ) 8,375 Commercial 6,512 (1,188 ) 541 225 6,090 Construction: Residential 1,184 — — 650 1,834 Commercial 642 — — 21 663 Total construction 1,826 — — 671 2,497 Total $ 30,323 $ (2,364 ) $ 2,040 $ 2,583 $ 32,582 Allowance for Loan Losses – As of December 31, 2018 (in thousands) Loans pooled Individually Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 2,620 $ 56 $ — $ 2,676 Commercial 12,737 91 116 12,944 Total mortgage loans on real estate 15,357 147 116 15,620 Consumer: Home equity lines of credit 5,838 198 6 6,042 Home equity loans 1,486 54 — 1,540 Other 779 14 — 793 Total consumer loans 8,103 266 6 8,375 Commercial 4,309 1,781 — 6,090 Construction: Residential 1,834 — — 1,834 Commercial 663 — — 663 Total construction 2,497 — — 2,497 Total $ 30,266 $ 2,194 $ 122 $ 32,582 Loans, Net of Unearned fees – As of December 31, 2018 (in thousands) Loans pooled Individually Loans acquired Total loans, net Mortgage loans on real estate: Residential 1-4 $ 509,267 $ 4,321 $ 1,674 $ 515,262 Commercial 2,606,819 12,563 8,456 2,627,838 Total mortgage loans on real estate 3,116,086 16,884 10,130 3,143,100 Consumer: Home equity lines of credit 322,764 2,646 1,167 326,577 Home equity loans 33,142 3,103 439 36,684 Other 55,483 196 42 55,721 Total consumer loans 411,389 5,945 1,648 418,982 Commercial 268,885 5,218 2,445 276,548 Construction: Residential 121,296 — — 121,296 Commercial 62,088 — — 62,088 Total construction 183,384 — — 183,384 Total $ 3,979,744 $ 28,047 $ 14,223 $ 4,022,014 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) Loans Individually Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 1,932 $ 230 $ 155 $ 2,317 Commercial 11,351 30 60 11,441 Total mortgage loans on real estate 13,283 260 215 13,758 Consumer: Home equity lines of credit 5,356 427 17 5,800 Home equity loans 1,734 107 — 1,841 Other 529 57 — 586 Total consumer loans 7,619 591 17 8,227 Commercial 4,624 1,848 40 6,512 Construction: Residential 1,184 — — 1,184 Commercial 642 — — 642 Total construction 1,826 — — 1,826 Total $ 27,352 $ 2,699 $ 272 $ 30,323 Loans, Net of Unearned fees – As of December 31, 2017 (in thousands) Loans pooled Individually Loans acquired Total loans, Mortgage loans on real estate: Residential 1-4 $ 378,743 $ 5,298 $ 1,385 $ 385,426 Commercial 1,892,422 13,911 8,563 1,914,896 Total mortgage loans on real estate 2,271,165 19,209 9,948 2,300,322 Consumer: Home equity lines of credit 283,502 2,688 2,498 288,688 Home equity loans 41,076 1,470 485 43,031 Other 24,853 257 45 25,155 Total consumer loans 349,431 4,415 3,028 356,874 Commercial 213,358 4,470 2,584 220,412 Construction: Residential 67,790 140 — 67,930 Commercial 69,627 — — 69,627 Total construction 137,417 140 — 137,557 Total $ 2,971,371 $ 28,234 $ 15,560 $ 3,015,165 Allowance for Loan Losses – Year Ended December 31, 2016 (in thousands) Beginning Charge-offs Recoveries Provision Ending Balance Mortgage loans on real estate: Residential 1-4 $ 2,896 $ (321 ) $ 880 $ (707 ) $ 2,748 Commercial 11,015 (827 ) 920 409 11,517 Total mortgage loans on real estate 13,911 (1,148 ) 1,800 (298 ) 14,265 Consumer: Home equity lines of credit 11,253 (585 ) 2,317 (5,941 ) 7,044 Home equity loans 3,177 (219 ) 590 (904 ) 2,644 Other 688 (823 ) 449 308 622 Total consumer loans 15,118 (1,627 ) 3,356 (6,537 ) 10,310 Commercial 5,271 (455 ) 404 611 5,831 Construction: Residential 899 — 54 464 1,417 Commercial 812 — 78 (210 ) 680 Total construction 1,711 — 132 254 2,097 Total $ 36,011 $ (3,230 ) $ 5,692 $ (5,970 ) $ 32,503 Allowance for Loan Losses – As of December 31, 2016 (in thousands) Loans Individually Loans acquired Total allowance Mortgage loans on real estate: Residential 1-4 $ 2,304 $ 258 $ 186 $ 2,748 Commercial 10,064 4 1,449 11,517 Total mortgage loans on real estate 12,368 262 1,635 14,265 Consumer: Home equity lines of credit 6,616 411 17 7,044 Home equity loans 2,365 215 64 2,644 Other 594 28 — 622 Total consumer loans 9,575 654 81 10,310 Commercial 3,765 1,130 936 5,831 Construction: Residential 1,372 — 45 1,417 Commercial 680 — — 680 Total construction 2,052 — 45 2,097 Total $ 27,760 $ 2,046 $ 2,697 $ 32,503 Loans, Net of Unearned fees – As of December 31, 2016 (in thousands) Loans pooled Individually Loans acquired Total Loans Mortgage loans on real estate: Residential 1-4 $ 362,780 $ 4,094 $ 1,469 $ 368,343 Commercial 1,657,238 15,081 12,802 1,685,121 Total mortgage loans on real estate 2,020,018 19,175 14,271 2,053,464 Consumer: Home equity lines of credit 282,159 3,196 4,360 289,715 Home equity loans 42,992 1,508 1,682 46,182 Other 30,547 154 65 30,766 Total consumer loans 355,698 4,858 6,107 366,663 Commercial 208,960 4,096 3,991 217,047 Construction: Residential 54,743 11 675 55,429 Commercial 66,990 — — 66,990 Total construction 121,733 11 675 122,419 Total $ 2,706,409 $ 28,140 $ 25,044 $ 2,759,593
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 December 31, 2018 (in thousands) Pass Special Substandard Doubtful / Loss Total Originated Mortgage loans on real estate: Residential 1-4 $ 337,189 $ 1,724 $ 4,883 $ — $ 343,796 Commercial 1,861,627 33,483 15,871 — 1,910,981 Total mortgage loans on real estate 2,198,816 35,207 20,754 — 2,254,777 Consumer: Home equity lines of credit 279,491 2,309 2,653 — 284,453 Home equity loans 29,289 1,054 2,317 — 32,660 Other 33,606 341 73 — 34,020 Total consumer loans 342,386 3,704 5,043 — 351,133 Commercial 217,126 6,127 5,382 — 228,635 Construction: Residential 90,412 32 259 — 90,703 Commercial 55,863 345 — — 56,208 Total construction 146,275 377 259 — 146,911 Total loans $ 2,904,603 $ 45,415 $ 31,438 $ — $ 2,981,456 Credit Quality Indicators PNCI Loans – As of December 31, 2018 (in thousands) Pass Special Substandard Doubtful / Loss Total PNCI Mortgage loans on real estate: Residential 1-4 $ 167,908 $ 1,086 $ 798 $ — $ 169,792 Commercial 701,868 3,085 3,448 — 708,401 Total mortgage loans on real estate 869,776 4,171 4,246 — 878,193 Consumer: Home equity lines of credit 38,780 1,124 1,053 — 40,957 Home equity loans 3,413 74 98 — 3,585 Other 21,481 173 5 — 21,659 Total consumer loans 63,674 1,371 1,156 — 66,201 Commercial 45,027 321 120 — 45,468 Construction: Residential 30,593 — — — 30,593 Commercial 5,880 — — — 5,880 Total construction 36,473 — — — 36,473 Total loans $ 1,014,950 $ 5,863 $ 5,522 $ — $ 1,026,335 Credit Quality Indicators Originated Loans – As of December 31, 2017 (in thousands) Pass Special Substandard Doubtful / 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 Doubtful / 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 Past Due Loans	The following tables show the ending balance of current and past due originated and PNCI loans by loan category as of the date indicated: Analysis of Originated Past Due Loans - As of December 31, 2018 (in thousands) 30-59 days 60-89 days > 90 days Total Past Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,675 $ 132 $ 478 $ 2,285 $ 341,511 $ 343,796 $ — Commercial 431 1,200 296 1,927 1,909,054 1,910,981 — Total mortgage loans on real estate 2,106 1,332 774 4,212 2,250,565 2,254,777 — Consumer: Home equity lines of credit 908 47 609 1,564 282,889 284,453 — Home equity loans 1,043 24 214 1,281 31,379 32,660 — Other 298 17 — 315 33,705 34,020 — Total consumer loans 2,249 88 823 3,160 347,973 351,133 — Commercial 1,053 579 1,247 2,879 225,756 228,635 — Construction: Residential 209 — — 209 90,494 90,703 — Commercial — — — — 56,208 56,208 — Total construction 209 — — 209 146,702 146,911 — Total originated loans $ 5,617 $ 1,999 $ 2,844 $ 10,460 $ 2,970,996 $ 2,981,456 $ — Analysis of PNCI Past Due Loans - As of December 31, 2018 (in thousands) 30-59 days 60-89 days > 90 days Total Past Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,009 $ 133 $ 156 $ 1,298 $ 168,494 $ 169,792 $ — Commercial 1,646 1,136 1,082 3,864 704,537 708,401 Total mortgage loans on real estate 2,655 1,269 1,238 5,162 873,031 878,193 — Consumer: Home equity lines of credit 304 35 237 576 40,381 40,957 Home equity loans 74 — — 74 3,511 3,585 — Other 160 — — 160 21,499 21,659 — Total consumer loans 538 35 237 810 65,391 66,201 — Commercial 678 145 113 936 44,532 45,468 — Construction: Residential — — — — 30,593 30,593 — Commercial — — — — 5,880 5,880 — Total construction — — — — 36,473 36,473 — Total PNCI loans $ 3,871 $ 1,449 $ 1,588 $ 6,908 $ 1,019,427 $ 1,026,335 $ — Analysis of Originated Past Due Loans - As of December 31, 2017 (in thousands) 30-59 days 60-89 days > 90 days Total Past Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,740 $ 510 $ 243 $ 2,493 $ 318,029 $ 320,522 $ — Commercial 158 987 — 1,145 1,689,365 1,690,510 — Total mortgage loans on real estate 1,898 1,497 243 3,638 2,007,394 2,011,032 — Consumer: Home equity lines of credit 528 48 372 948 268,994 269,942 — Home equity loans 511 107 373 991 38,857 39,848 — Other 56 36 3 95 22,764 22,859 — Total consumer loans 1,095 191 748 2,034 330,615 332,649 — Commercial 956 738 1,527 3,221 206,216 209,437 — Construction: Residential 34 — — 34 67,886 67,920 — Commercial — — — — 69,364 69,364 — Total construction 34 — — 34 137,250 137,284 — Total loans $ 3,983 $ 2,426 $ 2,518 $ 8,927 $ 2,681,475 $ 2,690,402 $ — Analysis of PNCI Past Due Loans - As of December 31, 2017 (in thousands) 30-59 60-89 > 90 days Total Past Current Total > 90 Days and Mortgage loans on real estate: Residential 1-4 $ 1,495 $ 90 $ 109 $ 1,694 $ 61,825 $ 63,519 $ 81 Commercial 70 — — 70 215,753 215,823 — Total mortgage loans on real estate 1,565 90 109 1,764 277,578 279,342 81 Consumer: Home equity lines of credit 298 228 330 856 15,392 16,248 200 Home equity loans 30 — — 30 2,668 2,698 — Other 6 26 — 32 2,219 2,251 — Total consumer loans 334 254 330 918 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 $ 2,682 $ 306,521 $ 309,203 $ 281
Schedule of Non Accrual Loans	The following table shows the ending balance of nonaccrual loans by loan category as of the date indicated: Non Accrual Loans As of December 31, 2018 As of December 31, 2017 (in thousands) Originated PNCI Total Originated PNCI Total Mortgage loans on real estate: Residential 1-4 $ 3,244 $ 334 $ 3,578 $ 1,725 $ 1,012 $ 2,737 Commercial 9,263 1,468 10,731 8,144 — 8,144 Total mortgage loans on real estate 12,507 1,802 14,309 9,869 1,012 10,881 Consumer: Home equity lines of credit 1,429 885 2,314 811 402 1,213 Home equity loans 1,722 47 1,769 1,106 44 1,150 Other 3 4 7 7 5 12 Total consumer loans 3,154 936 4,090 1,924 451 2,375 Commercial 3,755 120 3,875 3,669 — 3,669 Construction: Residential — — — — — — Commercial — — — — — — Total construction — — — — — — Total non accrual loans $ 19,416 $ 2,858 $ 22,274 $ 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 Twelve Months Ended, December 31, 2018 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 4,594 $ 3,663 $ 308 $ 3,971 $ 56 $ 3,517 $ 90 Commercial 13,081 10,676 1,765 12,441 42 13,115 137 Total mortgage loans on real estate 17,675 14,339 2,073 16,412 98 16,632 227 Consumer: Home equity lines of credit 1,900 1,749 111 1,860 71 1,885 43 Home equity loans 2,374 1,892 65 1,957 2 1,520 23 Other 3 — 3 3 3 17 2 Total consumer loans 4,277 3,641 179 3,820 76 3,422 68 Commercial 5,433 2,924 2,287 5,211 1,774 4,654 91 Construction: Residential — — — — — 5 — Commercial — — — — — — — Total construction — — — — — 5 — Total $ 27,385 $ 20,904 $ 4,539 $ 25,443 $ 1,948 $ 24,713 $ 386 Impaired PNCI Loans - As of, or for the Twelve Months Ended, December 31, 2018 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 375 $ 334 $ — $ 334 $ — $ 529 $ 5 Commercial 3,110 1,468 — 1,468 — 1,713 183 Total mortgage loans on real estate 3,485 1,802 — 1,802 — 2,242 188 Consumer: Home equity lines of credit 1,027 587 367 954 127 1,120 18 Home equity loans 252 47 197 244 101 155 — Other 106 21 85 106 11 114 — Total consumer loans 1,385 655 649 1,304 239 1,389 18 Commercial 120 113 7 120 7 60 1 Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — — Total $ 4,990 $ 2,570 $ 656 $ 3,226 $ 246 $ 3,691 $ 207 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 55 4 3 7 3 20 — Total consumer loans 3,263 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 $ 26,178 $ 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 Twelve Months Ended, December 31, 2016 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 3,381 $ 1,820 $ 1,551 $ 3,371 $ 180 $ 4,632 $ 157 Commercial 13,503 12,898 357 13,255 4 20,891 592 Total mortgage loans on real estate 16,884 14,718 1,908 16,626 184 25,523 749 Consumer: Home equity lines of credit 2,001 1,480 430 1,910 110 3,297 49 Home equity loans 1,730 715 594 1,309 107 1,465 37 Other 48 15 19 34 13 26 3 Total consumer loans 3,779 2,210 1,043 3,253 230 4,788 89 Commercial 4,311 762 3,334 4,096 1,130 3,383 125 Construction: Residential 16 11 — 11 — 7 — Commercial — — — — — — — Total construction 16 11 — 11 — 7 — Total $ 24,990 $ 17,701 $ 6,285 $ 23,986 $ 1,544 $ 33,701 $ 963 Impaired PNCI Loans - As of, or for the Twelve Months Ended, December 31, 2016 (in thousands) Unpaid Recorded Recorded Total recorded Related Average Interest income Mortgage loans on real estate: Residential 1-4 $ 745 $ 463 $ 259 $ 722 $ 79 $ 799 $ 17 Commercial 2,031 1,826 — 1,826 — 2,853 — Total mortgage loans on real estate 2,776 2,289 259 2,548 79 3,652 17 Consumer: Home equity lines of credit 1,297 735 551 1,286 300 1,173 36 Home equity loans 206 67 132 199 108 154 8 Other 122 3 118 121 15 194 5 Total consumer loans 1,625 805 801 1,606 423 1,521 49 Commercial — — — — — 1 — Construction: Residential — — — — — — — Commercial — — — — — 245 — Total construction — — — — — 245 — Total $ 4,401 $ 3,094 $ 1,060 $ 4,154 $ 502 $ 5,419 $ 66
Troubled Debt Restructurings	The following tables show certain information regarding Troubled Debt Restructurings that occurred during the periods indicated: TDR Information for the Year Ended December 31, 2018 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial impact Mortgage loans on real estate: Residential 1-4 1 $ 156 $ 156 $ — — $ — $ — Commercial 7 1,782 1,779 491 1 169 — Total mortgage loans on real estate 8 1,938 1,935 491 1 169 — Consumer: Home equity lines of credit 1 133 138 — 2 248 — Home equity loans 2 599 599 (35 ) — — — Other — — — — — — — Total consumer loans 3 732 737 (35 ) 2 248 — Commercial 6 1,098 1,083 325 3 148 — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — — Total 17 $ 3,768 $ 3,755 $ 781 6 $ 565 $ — TDR Information for the Year Ended December 31, 2017 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial impact Mortgage loans on real estate: Residential 1-4 1 $ 939 $ 939 $ 169 2 $ 223 $ — Commercial 8 3,721 3,695 (111 ) 1 219 — Total mortgage loans on real estate 9 4,660 4,634 58 3 442 — Consumer: Home equity lines of credit 3 187 187 27 1 127 (5 ) Home equity loans 1 252 252 — 1 55 — Other 1 14 14 11 — — — Total consumer loans 5 453 453 38 2 182 (5 ) Commercial 11 1,854 1,747 37 — — — Construction: Residential 1 144 144 — — — — Commercial — — — — — — — Total construction 1 144 144 — — — — Total 26 $ 7,111 $ 6,978 $ 133 5 $ 624 $ (5 ) TDR Information for the Year Ended December 31, 2016 (dollars in thousands) Number Pre-mod Post-mod Financial Number that Recorded Financial impact Mortgage loans on real estate: Residential 1-4 3 $ 650 $ 656 $ 50 2 $ 101 $ — Commercial 5 423 461 46 — — — Total mortgage loans on real estate 8 1,073 1,117 96 2 101 — Consumer: Home equity lines of credit 9 707 709 205 1 229 — Home equity loans 1 105 105 — — — — Other 2 27 27 2 — — — Total consumer loans 12 839 841 207 1 229 — Commercial 4 77 77 23 — Construction: Residential — — — — — — — Commercial — — — — — — — Total construction — — — — — — — Total 24 $ 1,989 $ 2,035 $ 326 3 $ 330 $ —

Foreclosed Assets (Tables)

Foreclosed Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Summary of Activity in Balance of Foreclosed Assets	A summary of the activity in the balance of foreclosed assets follows (dollars in thousands): Year ended December 31, 2018 2017 Beginning balance, net $ 3,226 $ 3,986 Additions/transfers from loans 1,262 1,563 Dispositions/sales (2,119 ) (2,161 ) Valuation adjustments (89 ) (162 ) Ending balance, net $ 2,280 $ 3,226 Ending valuation allowance $ (116 ) $ (200 ) Ending number of foreclosed assets 11 16 Proceeds from sale of foreclosed assets $ 2,527 $ 2,872 Gain on sale of foreclosed assets $ 408 $ 711

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Summary of Premises and Equipment	As of December 31, 2018 2017 (In thousands) Land & land improvements $ 29,065 $ 9,959 Buildings 64,478 50,340 Furniture and equipment 45,228 35,939 138,771 96,238 Less: Accumulated depreciation (50,125 ) (40,644 ) 88,646 55,594 Construction in progress 701 2,148 Total premises and equipment $ 89,347 $ 57,742

Cash Value of Life Insurance (T

Cash Value of Life Insurance (Tables)	12 Months Ended
	Dec. 31, 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 (dollars in thousands): Year ended December 31, 2018 2017 Beginning balance $ 97,783 $ 95,912 Acquired policies from business combination 16,817 — Increase in cash value of life insurance 2,718 2,685 Gain on death benefit — 108 Insurance proceeds receivable reclassified to other assets — (922 ) Ending balance $ 117,318 $ 97,783 End of period death benefit $ 200,249 $ 165,587 Number of policies owned 196 182 Insurance companies used 14 14 Current and former employees and directors covered 66 57

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 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) December 31, Additions Reductions December 31, Goodwill $ 220,972 $ 156,661 $ — $ 64,311
Summary of Core Deposit Intangibles	The following table summarizes the Company’s core deposit intangibles (“CDI”) as of the dates indicated: (in thousands) December 31, Additions Reductions/ December 31, Core deposit intangibles $ 37,163 $ 27,605 $ — $ 9,558 Accumulated amortization (7,883 ) — (3,499 ) (4,384 ) Core deposit intangibles, net $ 29,280 27,605 $ (3,499 ) $ 5,174
Remaining Estimated Core Deposit Intangible Amortization	The following table summarizes the Company’s estimated core deposit intangible amortization (dollars in thousands): Years Ended Estimated Core Deposit 2019 $ 5,723 2020 5,723 2021 5,465 2022 4,776 2023 4,269 Thereafter 3,324

Mortgage Servicing Rights (Tabl

Mortgage Servicing Rights (Tables)	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Fair Value of Mortgage Servicing Rights	The following tables summarize the activity in, and the main assumptions we used to determine the fair value of mortgage servicing rights for the periods indicated (dollars in thousands): Year ended December 31, 2018 2017 2016 Balance at beginning of period $ 6,687 $ 6,595 $ 7,618 Additions 557 810 1,161 Change in fair value (146 ) (718 ) (2,184 ) Balance at end of period $ 7,098 $ 6,687 $ 6,595 Contractually specified servicing fees, late fees and ancillary fees earned $ 2,038 $ 2,076 $ 2,065 Balance of loans serviced at: Beginning of period $ 811,065 $ 816,623 $ 817,917 End of period $ 785,138 $ 811,065 $ 816,623 Period end: Weighted-average prepayment speed (CPR) 7.6 % 8.9 % 8.8 % Weighted-average discount rate 12.0 % 13.0 % 14.0 %

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Summary of Balances of Deposits	A summary of the balances of deposits follows (in thousands): December 31, 2018 2017 Noninterest-bearing demand $ 1,760,580 $ 1,368,218 Interest-bearing demand 1,252,366 971,459 Savings 1,921,324 1,364,518 Time certificates, over $250,000 132,429 73,596 Other time certificates 299,767 231,340 Total deposits $ 5,366,466 $ 4,009,131
Schedule of Maturities of Time Deposits	At December 31, 2018, the scheduled maturities of time deposits were as follows (in thousands): Scheduled 2019 $ 298,855 2020 75,989 2021 36,267 2022 18,542 2023 2,537 Thereafter 6 Total $ 432,196

Other Borrowings (Tables)

Other Borrowings (Tables)	12 Months Ended
	Dec. 31, 2018
Text Block [Abstract]
Summary of Balances of Other Borrowings	A summary of the balances of other borrowings follows: December 31, 2018 2017 (in thousands) 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 December 31, 2018 and December 31, 2017 of 0.05%, payable on January 2, 2019 and January 2, 2018, respectively 15,839 17,437 Total other borrowings $ 15,839 $ 122,166

Junior Subordinated Debt (Table

Junior Subordinated Debt (Tables)	12 Months Ended
	Dec. 31, 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 December 31, 2018 December 31, 2017 Subordinated Debt Series Maturity Face Current Recorded Recorded TriCo Cap Trust I 10/7/2033 $ 20,619 3.05 % 5.49 % $ 20,619 $ 20,619 TriCo Cap Trust II 7/23/2034 20,619 2.55 % 5.03 % 20,619 20,619 North Valley Trust II 4/24/2033 6,186 3.25 % 5.79 % 5,174 5,135 North Valley Trust III 4/24/2034 5,155 2.80 % 5.28 % 4,079 4,041 North Valley Trust IV 3/15/2036 10,310 1.33 % 4.12 % 6,551 6,444 $ 62,889 $ 57,042 $ 56,858

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 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, 2018, future minimum commitments under non-cancelable Operating Leases (in thousands) 2019 $ 4,639 2020 4,036 2021 3,644 2022 2,814 2023 1,831 Thereafter 2,636 Future minimum lease payments $ 19,600
Summary of Bank's Commitments and Contingent Liabilities	The following table presents a summary of the Bank’s commitments and contingent liabilities: December 31, (in thousands) 2018 2017 Financial instruments whose amounts represent risk: Commitments to extend credit: Commercial loans $ 306,191 $ 257,220 Consumer loans 496,575 422,958 Real estate mortgage loans 140,292 66,267 Real estate construction loans 248,996 187,097 Standby letters of credit 11,346 13,075 Deposit account overdraft privilege 111,956 98,260

Stock Options and Other Equit_2

Stock Options and Other Equity-Based Incentive Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Activity	Stock option activity is summarized in the following table for the dates indicated: Number of Option Price Weighted Outstanding at January 1, 2018 446,400 $ 12.63 to $23.21 $ 16.84 Options granted — — to — — Options exercised (100,400 ) $ 12.63 to $23.21 $ 16.97 Options forfeited (3,000 ) $ 23.21 $ 23.21 Outstanding at December 31, 2018 343,000 $ 12.63 to $23.21 $ 16.67
Summary of Options Outstanding	The following table shows the number, weighted-average exercise price, intrinsic value, and weighted average remaining contractual life of options exercisable, options not yet exercisable and total options outstanding as of December 31, 2018: Currently Currently Not Total Number of options 341,875 1,125 343,000 Weighted average exercise price $ 16.65 $ 23.21 $ 16.67 Intrinsic value (in thousands) $ 5,860 $ 12 $ 5,872 Weighted average remaining contractual term (yrs.) 3.2 5.8 3.3
Information about Options	The following table shows the total intrinsic value of options exercised, the total fair value of options vested, total compensation costs for options recognized in income, total tax benefit and excess tax benefits recognized in income related to compensation costs for options during the periods indicated: Year Ended December 31, 2018 2017 2016 Intrinsic value of options exercised $ 2,109,000 $ 2,657,000 $ 3,483,000 Fair value of options that vested $ 75,000 $ 259,000 $ 580,000 Total compensation costs for options recognized in income $ 75,000 $ 259,000 $ 580,000 Total tax benefit recognized in income related to compensation costs for options $ 22,000 $ 109,000 $ 244,000 Excess tax benefit recognized in income $ 623,000 $ 600,000 $ —
Restricted Stock Unit (RSU) Activity	Restricted stock unit activity is summarized in the following table for the dates indicated: Service Condition Vesting RSUs Market Plus Service Condition Number Weighted Average Number Weighted Average Outstanding at January 1, 2018 68,457 52,829 RSUs granted 38,605 $ 39.08 16,939 $ 36.40 Additional market plus service condition RSUs vested — 8,506 RSUs added through dividend credits 1,188 — RSUs released through vesting (35,060 ) (25,512 ) RSUs forfeited/expired (6,243 ) (7,226 ) Outstanding at December 31, 2018 66,947 45,536
Summary of Compensation Costs and Excess Tax Benefits for RSUs	The following table shows the compensation costs and excess tax benefits for RSUs recognized in income for the periods indicated: Year Ended December 31, 2018 2017 2016 Total compensation costs recognized in income Service condition vesting RSUs $ 1,017,000 $ 895,000 $ 616,000 Market plus service condition vesting RSUs $ 370,000 $ 432,000 $ 271,000 Excess tax benefit recognized in income Service condition vesting RSUs $ 104,000 $ 131,000 $ — Market plus service condition vesting RSUs $ 191,000 $ 175,000 $ —

Noninterest Income and Expense

Noninterest Income and Expense (Tables)	12 Months Ended
	Dec. 31, 2018
Other Income and Expenses [Abstract]
Components of Other Noninterest Income	The components of other noninterest income were as follows (in thousands): Year Ended December 31, 2018 2017 2016 ATM and interchange fees $ 18,249 $ 16,727 $ 15,859 Service charges on deposit accounts 15,467 16,056 14,365 Other service fees 2,852 3,282 3,121 Mortgage banking service fees 2,038 2,076 2,065 Change in value of mortgage loan servicing rights (146 ) (718 ) (2,184 ) Total service charges and fees 38,460 37,423 33,226 Commissions on sale of non-deposit 3,151 2,729 2,329 Increase in cash value of life insurance 2,718 2,685 2,717 Gain on sale of loans 2,371 3,109 4,037 Lease brokerage income 678 782 711 Sale of customer checks 449 372 408 Gain on sale of foreclosed assets 408 711 262 Gain on sale of investment securities 207 961 — Loss on disposal of fixed assets (185 ) (142 ) (147 ) Loss on marketable equity securities (64 ) — — Other 1,091 1,391 1,020 Total other noninterest income 10,824 12,598 11,337 Total noninterest income $ 49,284 $ 50,021 $ 44,563
Components of Noninterest Expense	The components of noninterest expense were as follows (in thousands): Year Ended December 31, 2018 2017 2016 Base salaries, net of deferred loan origination costs $ 62,422 $ 54,589 $ 53,169 Incentive compensation 11,147 9,227 8,872 Benefits and other compensation costs 20,373 19,114 18,683 Total salaries and benefits expense 93,942 82,930 80,724 Occupancy 12,139 10,894 10,139 Data processing and software 11,021 10,448 8,846 Equipment 6,651 7,141 6,597 ATM and POS network charges 5,271 4,752 4,999 Merger and acquisition expense 5,227 530 784 Advertising 4,578 4,101 3,829 Professional fees 3,546 3,745 5,409 Intangible amortization 3,499 1,389 1,377 Telecommunications 3,023 2,713 2,749 Regulatory assessments and insurance 1,906 1,676 2,105 Courier service 1,287 1,035 998 Operational losses 1,260 1,394 1,564 Postage 1,154 1,296 1,603 Legal settlement — — 1,450 Foreclosed assets expense 382 231 266 Provision for foreclosed asset losses 89 162 140 Other miscellaneous expense 13,720 12,587 12,418 Total other noninterest expense 74,753 64,094 65,273 Total noninterest expense $ 168,695 $ 147,024 $ 145,997

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Components of Consolidated Income Tax Expense	The components of consolidated income tax expense are as follows (in thousands): Year Ended December 31, 2018 2017 2016 Current tax expense Federal $ 13,109 $ 17,835 $ 17,401 State 9,323 6,650 7,121 $ 22,432 24,485 24,522 Deferred tax expense Federal 1,842 11,418 2,735 State 758 1,055 455 2,600 12,473 3,190 Total tax expense $ 25,032 $ 36,958 $ 27,712
Schedule of Components of Investments in Qualified Affordable Housing Projects	The Company recognized, as components of tax expense, tax credits and other tax benefits, and amortization expense relating to our investments in Qualified Affordable Housing Projects as follows for the periods indicated (in thousands): Year Ended December 31, 2018 2017 2016 Tax credits and other tax benefits – decrease in tax expense $ (1,993 ) $ (1,753 ) $ (954 ) Amortization – increase in tax expense $ 1,814 $ 1,611 $ 757
Reconciliation of Effective Tax Rate and Statutory Federal Income Tax Rate	The effective tax rate and the statutory federal income tax rate are reconciled as follows: Year Ended December 31, 2018 2017 2016 Federal statutory income tax rate 21.0 % 35.0 % 35.0 % State income taxes, net of federal tax benefit 8.6 6.9 6.8 Tax Cuts and Jobs Act impact of federal rate change — 9.6 — Tax-exempt (1.0 ) (1.9 ) (1.8 ) Tax-exempt (0.6 ) (1.3 ) (1.3 ) Low income housing tax credits (2.2 ) (2.3 ) (1.3 ) Low income housing tax credit amortization 2.0 2.1 0.8 Equity compensation (0.5 ) (1.2 ) — Non-deductible 0.1 0.1 0.1 Non-deductible 0.2 0.2 — Other (0.8 ) 0.5 (0.1 ) Effective Tax Rate 26.8 % 47.7 % 38.2 %
Company's Net Deferred Tax Asset Recorded in Other Assets	The temporary differences, tax effected, which give rise to the Company’s net deferred tax asset recorded in other assets are as follows as of December 31 for the years indicated (in thousands): December 31, 2018 2017 Deferred tax assets: Allowance for losses and reserve for unfunded commitments $ 10,394 $ 9,900 Deferred compensation 2,780 1,953 Accrued pension liability 9,734 6,835 Accrued bonus 709 171 Other accrued expenses 466 522 Additional unfunded status of the supplemental retirement plans 1,420 1,582 State taxes 1,864 1,397 Share based compensation 1,132 1,322 Nonaccrual interest 814 282 OREO write downs 34 59 Acquisition cost basis 6,714 2,187 Unrealized loss on securities 6,201 1,008 Tax credits 623 581 Net operating loss carryforwards 2,442 1,801 Other 389 508 Total deferred tax assets 45,716 30,108 Deferred tax liabilities: Securities income (1,020 ) (958 ) Depreciation (5,572 ) (1,987 ) Merger related fixed asset valuations (26 ) (30 ) Securities accretion (426 ) (315 ) Mortgage servicing rights valuation (2,073 ) (1,943 ) Core deposit intangible (8,234 ) (916 ) Junior subordinated debt (1,729 ) (1,783 ) Prepaid expenses and other (582 ) (479 ) Total deferred tax liability (19,662 ) (8,411 ) Net deferred tax asset $ 26,054 $ 21,697

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Computation of Earnings Per Share	Earnings per share have been computed based on the following: Year Ended December 31, (in thousands) 2018 2017 2016 Net income $ 68,320 $ 40,554 $ 44,811 Average number of common shares outstanding 26,593 22,912 22,814 Effect of dilutive stock options and restricted stock 287 338 273 Average number of common shares outstanding used to calculate diluted earnings per share 26,880 23,250 23,087 Options excluded from diluted earnings per share because the effect of these options was antidilutive 10,056 — 13,825

Comprehensive Income (Tables)

Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Components of Other Comprehensive Income (Loss) and Related Tax Effects	The components of other comprehensive income and related tax effects are as follows: Year Ended December 31, (in thousands) 2018 2017 2016 Unrealized holding (losses) gains on available for sale securities before reclassifications $ (17,057 ) $ 6,422 $ (11,015 ) Amounts reclassified out of accumulated other comprehensive income: Realized gains on debt securities (207 ) (961 ) — Adoption ASU 2016-01 62 — — Adoption ASU 2018-02 (425 ) — — Total amounts reclassified out of accumulated other comprehensive income (570 ) (961 ) — Unrealized holding (losses) gains on available for sale securities after reclassifications (17,627 ) 5,461 (11,015 ) Tax effect 5,193 (2,296 ) 4,631 Unrealized holding (losses) gains on available for sale securities, net of tax (12,434 ) 3,165 (6,384 ) Change in unfunded status of the supplemental retirement plans before reclassifications 762 (1,016 ) 511 Amounts reclassified out of accumulated other comprehensive income: Amortization of prior service cost (54 ) (12 ) (40 ) Amortization of actuarial losses 510 390 550 Adoption ASU 2018-02 (668 ) — — Total amounts reclassified out of accumulated other comprehensive income (212 ) 378 510 Change in unfunded status of the supplemental retirement plans after reclassifications 550 (638 ) 1,021 Tax effect (162 ) 268 (429 ) Change in unfunded status of the supplemental retirement plans, net of tax 388 (370 ) 592 Change in joint beneficiary agreement liability before reclassifications 426 (110 ) (343 ) Tax effect — — — Change in unfunded status of the supplemental retirement plans, net of tax 426 (110 ) (343 ) Total other comprehensive (loss) income $(11,620) $2,685 $ (6,135 )
Components of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive income, included in shareholders’ equity, are as follows: Year Ended December 31, (in thousands) 2018 2017 Net unrealized loss on available for sale securities $ (20,974 ) (3,409 ) Stranded OCI from tax rate change — 425 Tax effect 6,201 1,008 Unrealized holding loss on available for sale securities, net of tax (14,773 ) (1,976 ) Unfunded status of the supplemental retirement plans (4,802 ) (5,352 ) Stranded OCI from tax rate change — 668 Tax effect 1,420 1,582 Unfunded status of the supplemental retirement plans, net of tax (3,382 ) (3,102 ) Joint beneficiary agreement liability 276 (150 ) Tax effect — — Joint beneficiary agreement liability, net of tax 276 (150 ) Accumulated other comprehensive loss $ (17,879 ) $ (5,228 )

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Summary of 401(k) Contribution Plan	The Company recorded salaries & benefits expense attributable to the 401(k) Plan matching contributions and 401(k) Plan matching contributions for the years ended: Year Ended December 31, (in thousands) 2018 2017 2016 401(k) Plan benefits expense $ 879 $ 776 $ 678 401(k) Plan contributions made by the Company $ 872 $ 767 $ 811
Summary of ESOP Activities	Expenses related to the Company’s ESOP, included in benefits and other compensation costs under salaries and benefits expense, and contributions to the plan for the years ended were: Year Ended December 31, (in thousands) 2018 2017 2016 ESOP benefits expense $ 1,887 $ 2,149 $ 1,831 ESOP contributions made by the Company $ 1,952 $ 2,073 $ 1,368
Schedule of Deferred Compensation Earnings Credits Included in Noninterest Expense	Earnings credits on deferred balances included in noninterest expense are included in the following table: Year Ended December 31, (in thousands) 2018 2017 2016 Deferred compensation earnings credits included in noninterest expense $ 462 $ 478 $ 487
Defined Benefit Pension Plans	Amounts recognized as a component of accumulated other comprehensive loss as of year-end December 31, (in thousands) 2018 2017 Transition obligation $ 3 $ 4 Prior service cost (194 ) (248 ) Net actuarial loss 4,993 5,596 Amount included in accumulated other comprehensive loss 4,802 5,352 Stranded OCI from tax rate change — (668 ) Deferred tax benefit (1,420 ) (1,582 ) Amount included in accumulated other comprehensive loss, net of tax $ 3,382 $ 3,102
Information Pertaining to Activity in Supplemental Retirement Plans	Information pertaining to the activity in the supplemental retirement plans, using a measurement date of December 31, is as follows: December 31, (in thousands) 2018 2017 Change in benefit obligation: Benefit obligation at beginning of year $ (28,472 ) $ (26,645 ) Service cost (973 ) (941 ) Interest cost (949 ) (991 ) Actuarial (loss)/gain 92 (1,203 ) Plan amendments — 185 Benefits paid 1,106 1,123 Benefit obligation at end of year $ (29,196 ) $ (28,472 ) Change in plan assets: Fair value of plan assets at beginning of year $ — $ — Fair value of plan assets at end of year $ — $ — Funded status $ (29,196 ) $ (28,472 ) Unrecognized net obligation existing at January 1, 1986 3 4 Unrecognized net actuarial loss 4,993 5,596 Unrecognized prior service cost (194 ) (248 ) Accumulated other comprehensive income (4,802 ) (5,352 ) Accrued benefit cost $ (29,196 ) $ (28,472 ) Accumulated benefit obligation $ (27,544 ) $ (26,432 )
Net Periodic Benefit Cost Recognized for Supplemental Retirement Plans	The following table sets forth the net periodic benefit cost recognized for the supplemental retirement plans: Year Ended December 31, (in thousands) 2018 2017 2016 Net pension cost included the following components: Service cost-benefits earned during the period $ 973 $ 941 $ 1,042 Interest cost on projected benefit obligation 949 991 1,025 Amortization of net obligation at transition 2 2 2 Amortization of prior service cost (54 ) (12 ) (41 ) Recognized net actuarial loss 510 390 549 Net periodic pension cost $ 2,380 $ 2,312 $ 2,577
Assumptions Used in Accounting for Plans	The following table sets forth assumptions used in accounting for the plans: Year Ended December 31, 2018 2017 2016 Discount rate used to calculate benefit obligation 3.96 % 3.40 % 3.80 % Discount rate used to calculate net periodic pension cost 3.40 % 3.80 % 4.00 % Average annual increase in executive compensation 3.25 % 3.25 % 2.50 % Average annual increase in director compensation 0.00 % 0.00 % 2.50 %
Expected Benefit Payments to Participants and Estimated Contributions to be Made by Company	The following table sets forth the expected benefit payments to participants and estimated contributions to be made by the Company under the supplemental retirement plans for the years indicated: Expected Benefit Estimated (in thousands) 2019 $ 1,254 $ 1,254 2020 1,668 1,668 2021 2,192 2,192 2022 2,161 2,161 2023 2,153 2,153 2024-2028 10,928 10,928

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Summary of Activity in Lending Transactions	The following table summarizes the activity in these loans for the periods indicated (in thousands): Balance January 1, 2017 $ 2,432 Advances/new loans 437 Removed/payments (721 ) Balance December 31, 2017 2,148 Advances/new loans 8,854 Removed/payments (1,799 ) Balance December 31, 2018 $ 9,203

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 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 December 31, 2018 Total Level 1 Level 2 Level 3 Marketable equity securities $ 2,874 $ 2,874 $ — $ — Debt securities available for sale: Obligations of U.S. government agencies 629,981 — 629,981 — Obligations of states and political subdivisions 126,072 — 126,072 — Corporate bonds 4,478 — 4,478 — Asset backed securities 354,505 — 354,505 — Loans held for sale 3,687 — 3,687 — Mortgage servicing rights 7,098 — — 7,098 Total assets measured at fair value $ 1,128,695 $ 2,874 $ 1,118,723 $ 7,098 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 agencies 604,789 — 604,789 — Obligations of states and political subdivisions 123,156 — 123,156 — Loans held for sale 4,616 — 4,616 — Mortgage servicing rights 6,687 — — 6,687 Total assets measured at fair value $ 742,186 $ 2,938 $ 732,561 $ 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 years ended December 31, 2018, 2017, and 2016. Had there been any transfer into or out of Level 3 during 2018, 2017, or 2016, the amount included in the “Transfers into (out of) Level 3” column would represent the beginning balance of an item in the period (interim quarter) during which it was transferred (in thousands): Year ended December 31, Beginning Transfers Change Issuances Ending 2018: Mortgage servicing rights $ 6,687 — $ (146 ) $ 557 $ 7,098 2017: Mortgage servicing rights $ 6,595 — $ (718 ) $ 810 $ 6,687 2016: Mortgage servicing rights $ 7,618 — $ (2,184 ) $ 1,161 $ 6,595
Quantitative Information about Recurring Level 3 Fair Value Measurements	The following table presents quantitative information about recurring Level 3 fair value measurements at December 31, 2018 and 2017: December 31, 2018 Fair Value Valuation Unobservable Range, Mortgage Servicing Rights $7,098 Discounted Constant 5.0%-27.3%, 7.6% December 31, 2017 Discount rate 12%-13%, 12% 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 amount of assets and liabilities measured at fair value on a nonrecurring basis, as of the dates indicated, that had a write-down or an additional allowance provided during the periods indicated (in thousands): Year ended December 31, 2018 Total Level 1 Level 2 Level 3 Total Gains Fair value: Impaired Originated & PNCI loans $ 281 — — $ 281 $ (294 ) Foreclosed assets 1,311 — — 1,311 (8 ) Total assets measured at fair value $ 1,592 — — $ 1,592 $ (302 ) 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 )
Quantitative Information about Level 3 Fair Value Measurements for Financial Instruments Measured at Fair Value on Nonrecurring Basis	The following table presents quantitative information about Level 3 fair value measurements for financial instruments measured at fair value on a nonrecurring basis at December 31, 2018 and 2017: December 31, 2018 Fair Value Valuation Technique Unobservable Inputs Range, Impaired Originated & PNCI loans $ 281 Sales comparison approach Income approach Adjustment for differences between comparable sales; Capitalization rate (16.3%)—35.14%; 10.45% N/A Foreclosed assets (Residential real estate) $ 693 Sales comparison approach Adjustment for differences between comparable sales (21.83%)—7.25%; (3.75%) Foreclosed assets (Commercial real estate) $ 618 Sales comparison approach Adjustment for differences between comparable sales (65%)—20%; December 31, 2017 Fair Value Valuation Technique Unobservable Inputs Range, Impaired Originated & PNCI loans $ 2,767 Sales comparison approach Income approach Adjustment for differences between comparable sales Capitalization rate (74%)—23%; Foreclosed assets (Land & construction) $ 1,341 Sales comparison approach Adjustment for differences between comparable sales (53%)—283%; Foreclosed assets (Residential real estate) $ 622 Sales comparison approach Adjustment for differences between comparable sales (47%)—39%; Foreclosed assets (Commercial real estate) $ 254 Sales comparison approach Adjustment for differences between comparable sales (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): December 31, 2018 December 31, 2017 Carrying Fair Carrying Fair Financial assets: Level 1 inputs: Cash and due from banks $ 119,781 $ 119,781 $ 105,968 $ 105,968 Cash at Federal Reserve and other banks 107,752 107,752 99,460 99,460 Level 2 inputs: Securities held to maturity 444,936 437,370 514,844 518,165 Restricted equity securities 17,250 N/A 16,956 N/A Level 3 inputs: Loans, net (1) 3,989,432 4,006,986 2,984,842 2,992,225 Financial liabilities: Level 2 inputs: Deposits 5,366,466 5,362,173 4,009,131 4,006,620 Other borrowings 15,839 15,839 122,166 122,166 Level 3 inputs: Junior subordinated debt 57,042 62,610 56,858 58,466 Contract Fair Contract Fair Off-balance Level 3 inputs: Commitments $ 1,192,054 $ 11,921 $ 933,542 $ 9,335 Standby letters of credit 11,346 113 13,075 131 Overdraft privilege commitments 111,956 1,120 98,260 983 (1) The estimated fair value of loans for December 31, 2018 reflects an exit price assumption. The December 31, 2017 fair value estimate is not based on an exit price assumption.

TriCo Bancshares Condensed Fi_2

TriCo Bancshares Condensed Financial Statements (Parent Only) (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets December 31, December 31, (In thousands) Assets Cash and cash equivalents $ 2,374 $ 3,924 Investment in Tri Counties Bank 880,907 557,538 Other assets 1,723 1,721 Total assets $ 885,004 $ 563,183 Liabilities and shareholders’ equity Other liabilities $ 589 $ 517 Junior subordinated debt 57,042 56,858 Total liabilities 57,631 57,375 Shareholders’ equity: Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at December 31, 2018 and 2017 — — Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 30,417,223 and 22,955,963 shares at December 31, 2018 and 2017, respectively 541,762 255,836 Retained earnings 303,490 255,200 Accumulated other comprehensive loss, net (17,879 ) (5,228 ) Total shareholders’ equity 827,373 505,808 Total liabilities and shareholders’ equity $ 885,004 $ 563,183
Condensed Statements of Income	Condensed Statements of Income Year ended December 31, 2018 2017 2016 (In thousands) Interest expense $ (3,131 ) $ (2,535 ) $ (2,229 ) Administration expense (1,489 ) (915 ) (725 ) Loss before equity in net income of Tri Counties Bank (4,620 ) (3,450 ) (2,954 ) Equity in net income of Tri Counties Bank: Distributed 26,432 19,236 16,758 Undistributed 45,315 23,359 29,764 Income tax benefit 1,193 1,409 1,243 Net income $ 68,320 $ 40,554 $ 44,811
Condensed Statements of Comprehensive Income	Condensed Statements of Comprehensive Income Year ended December 31, 2018 2017 2016 (In thousands) Net income $ 68,320 $ 40,554 $ 44,811 Other comprehensive income (loss), net of tax: Increase (decrease) in unrealized gains on available for sale securities arising during the period (12,434 ) 3,165 (6,384 ) Change in minimum pension liability 388 (370 ) 592 Change in joint beneficiary agreement liablity 426 (110 ) (343 ) Other comprehensive income (loss) (11,620 ) 2,685 (6,135 ) Comprehensive income $ 56,700 $ 43,239 $ 38,676
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows Year ended December 31, 2018 2017 2016 (In thousands) Operating activities: Net income $ 68,320 $ 40,554 $ 44,811 Adjustments to reconcile net income to net cash provided by operating activities: Undistributed equity in earnings of Tri Counties Bank (45,315 ) (23,359 ) (29,764 ) Equity compensation vesting expense 1,462 1,586 1,467 Equity compensation tax effect — — (155 ) Net change in other assets and liabilities (4,983 ) (1,295 ) (1,210 ) Net cash provided by operating activities 19,484 17,486 15,149 Investing activities: None Financing activities: Issuance of common stock through option exercise 218 396 518 Equity compensation tax effect — — 155 Repurchase of common stock (2,483 ) (1,629 ) (1,890 ) Cash dividends paid — common (18,769 ) (15,131 ) (13,695 ) Net cash used for financing activities (21,034 ) (16,364 ) (14,912 ) Net change in cash and cash equivalents (1,550 ) 1,122 237 Cash and cash equivalents at beginning of year 3,924 2,802 2,565 Cash and cash equivalents at end of year $ 2,374 $ 3,924 $ 2,802

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Actual and Required Capital Ratios of Bank	The following tables present actual and required capital ratios as of December 31, 2018 and 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 December 31, 2018 and 2017 based on the phased-in phased-in. Actual Minimum Capital Phase-in Minimum Capital Required to be (dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) As of December 31, 2018: Total Capital (to Risk Weighted Assets): Consolidated $ 682,419 14.40 % $ 467,874 9.875 % $ 497,486 10.50 % N/A N/A Tri Counties Bank $ 680,624 14.37 % $ 467,704 9.875 % $ 497,305 10.50 % $ 473,624 10.00 % Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 647,262 13.66 % $ 373,115 7.875 % $ 402,727 8.50 % N/A N/A Tri Counties Bank $ 645,467 13.63 % $ 372,979 7.875 % $ 402,581 8.50 % $ 378,899 8.00 % Common equity Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 591,933 12.49 % $ 302,045 6.375 % $ 331,658 7.00 % N/A N/A Tri Counties Bank $ 645,467 13.63 % $ 301,935 6.375 % $ 331,537 7.00 % $ 307,856 6.50 % Tier 1 Capital (to Average Assets): Consolidated $ 647,262 10.68 % $ 242,452 4.000 % $ 242,452 4.00 % N/A N/A Tri Counties Bank $ 645,467 10.65 % $ 242,447 4.000 % $ 242,447 4.00 % $ 303,059 5.00 % Actual Minimum Capital Phase-in Schedule Minimum Capital Required to be (dollars in thousands) 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 9.250 % $ 394,679 10.50 % N/A N/A Tri Counties Bank $ 525,384 13.98 % $ 347,535 9.250 % $ 394,499 10.50 % $ 375,713 10.00 % Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 495,318 13.18 % $ 272,517 7.250 % $ 319,502 8.50 % N/A N/A Tri Counties Bank $ 491,897 13.09 % $ 272,392 7.250 % $ 319,356 8.50 % $ 300,570 8.00 % Common equity Tier 1 Capital (to Risk Weighted Assets): Consolidated $ 440,643 11.72 % $ 216,134 5.750 % $ 263,120 7.00 % N/A N/A Tri Counties Bank $ 491,897 13.09 % $ 216,035 5.750 % $ 262,999 7.00 % $ 244,214 6.50 % Tier 1 Capital (to Average Assets): Consolidated $ 495,318 10.80 % $ 183,400 4.000 % $ 183,400 4.00 % N/A N/A Tri Counties Bank $ 491,897 10.73 % $ 183,394 4.000 % $ 183,394 4.00 % $ 229,243 5.00 %

Summary of Quarterly Results _2

Summary of Quarterly Results of Operations (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Results of Operations	The following table sets forth the results of operations for the four quarters of 2018 and 2017, 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 $ 1,982 $ 2,098 $ 559 $ 632 All other loan interest income 53,680 51,004 38,745 37,417 Total loan interest income 55,662 53,102 39,304 38,049 Debt securities, dividends and interest bearing cash at banks 12,403 11,452 9,174 9,072 Total interest income 68,065 64,554 48,478 47,121 Interest expense 4,063 4,065 2,609 2,135 Net interest income 64,002 60,489 45,869 44,986 (Benefit from reversal of) provision for loan losses 806 2,651 (638 ) (236 ) Net interest income after provision for loan losses 63,196 57,838 46,507 45,222 Noninterest income 12,634 12,186 12,174 12,290 Noninterest expense 45,285 47,378 37,870 38,162 Income before income taxes 30,545 22,646 20,811 19,350 Income tax expense 7,334 6,476 5,782 5,440 Net income $ 23,211 $ 16,170 $ 15,029 $ 13,910 Per common share: Net income (diluted) $ 0.76 $ 0.53 $ 0.65 $ 0.60 Dividends $ 0.19 $ 0.17 $ 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 $ 1,489 $ 1,364 $ 2,170 $ 1,541 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 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 Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018USD ($)OfficeSegmentTrustBusiness	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jan. 01, 2018USD ($)
Significant Of Accounting Policies [Line Items]
Number of subsidiary business trusts | Trust	5
Number of loan production offices | Office	2
Company's investments in the trusts	$ 1,713,000
Number of business segment | Segment	1
Marketable securities recorded	$ 2,874,000	$ 2,938,000
Unrealized losses recognized in condensed consolidated statements of income	(64,000)
Trading securities	0	0	$ 0
Recognized OTTI losses	$ 0	$ 0	$ 0
Loans contractual past due	90 days
TDR loans payment period in nonaccrual status	6 months
California [Member]
Significant Of Accounting Policies [Line Items]
Number of counties | Business	29
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)
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 2016-02 [Member] | Assets, Total [Member]
Significant Of Accounting Policies [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 31,500,000
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	$ 31,500,000
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. 06, 2018USD ($)Branchesshares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Goodwill recognized		$ 220,972,000	$ 64,311,000
PNCI [Member]
Business Acquisition [Line Items]
Receivables gross contractual amount		866,189,000
Receivables fair value		833,381,000
PCI [Member]
Business Acquisition [Line Items]
Receivables gross contractual amount		1,683,000
Receivables fair value		1,302,000
FNBB [Member]
Business Acquisition [Line Items]
Total consideration value	$ 291,132,000
Issue of common stock shares | shares	7,405,277
Amount paid in exchange for the outstanding options	$ 6,700,000
Number of branches added | Branches	12
Goodwill recognized	$ 156,661,000
Recognized intangible related to acquisition	27,605,000
FNBB [Member] | Core Deposit Intangibles [Member]
Business Acquisition [Line Items]
Recognized intangible related to acquisition	$ 27,605,000
Finite lived intangible asset estimated useful life	6 years 2 months 12 days
Acquisition related costs		$ 5,227,000	$ 530,000	$ 784,000

Business Combinations - Schedul

Business Combinations - Schedule of Fair Value of Consideration Transferred, Identifiable Net Assets Acquired and Resulting Goodwill (Detail) - USD ($) $ in Thousands	Jul. 06, 2018	Dec. 31, 2018	Dec. 31, 2017
Liabilities assumed:
Goodwill recognized		$ 220,972	$ 64,311
FNBB [Member]
Fair value of consideration transferred:
Fair value of shares issued	$ 284,437
Cash consideration	6,695
Total fair value of consideration transferred	291,132
Assets acquired:
Cash and cash equivalents	37,308
Securities available for sale	335,667
Restricted equity securities	7,723
Loans	834,683
Premises and equipment	30,522
Cash value of life insurance	16,817	$ 16,817
Core deposit intangible	27,605
Other assets	16,214
Total assets acquired	1,306,539
Liabilities assumed:
Deposits	991,935
Other liabilities	15,133
Total liabilities assumed	1,172,068
Total net assets acquired	134,471
Goodwill recognized	156,661
FNBB [Member] | Federal Home Loan Bank of San Francisco [Member]
Liabilities assumed:
Short-term borrowings	$ 165,000

Business Combinations - Summary

Business Combinations - Summary of Estimated Fair Value Adjustments Resulting in Goodwill (Detail) - USD ($) $ in Thousands	Jul. 06, 2018	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill		$ 220,972	$ 64,311
FNBB [Member]
Business Acquisition [Line Items]
Value of stock consideration paid to FNB Bancorp Shareholders	$ 284,437
Cash consideration	6,695
Cost basis net assets acquired	114,030
Investments	(1,081)
Fair Value Adjustments, Premises and Equipment	21,590
Core deposit intangible	27,327
Deferred income taxes	(6,394)
Other	1,389
Goodwill	156,661
FNBB [Member] | Loans [Member]
Business Acquisition [Line Items]
Fair Value Adjustments	$ (22,390)

Business Combinations - Sched_2

Business Combinations - Schedule of Business Acquisition Pro-forma Financial Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Summarized proforma income statement data:
Net interest income	$ 242,793	$ 227,795
(Provision for) benefit from loan losses	(2,180)	271
Noninterest income	51,152	53,881
Noninterest expense	(180,884)	(181,833)
Income before taxes	110,881	100,114
Income taxes	(30,337)	(47,352)
Net income	$ 80,544	$ 52,762
Basic earnings per share	$ 2.65	$ 1.74
Diluted earnings per share	$ 2.63	$ 1.72

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Estimated Fair Values of Investments Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Debt Securities Available for Sale, Amortized Cost	$ 1,136,010	$ 731,292
Debt Securities Available for Sale, Gross Unrealized Gains	1,235	2,583
Debt Securities Available for Sale, Gross Unrealized Losses	(22,209)	(5,930)
Debt Securities Available for Sale, Estimated Fair Value	1,115,036	727,945
Debt Securities Held to Maturity, Amortized Cost	444,936	514,844
Debt Securities Held to Maturity, Gross Unrealized Gains	409	5,247
Debt Securities Held to Maturity, Gross Unrealized Losses	(7,975)	(1,926)
Debt Securities Held to Maturity, Estimated Fair Value	437,370	518,165
Obligations of U.S. Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities Available for Sale, Amortized Cost	647,288	609,695
Debt Securities Available for Sale, Gross Unrealized Gains	771	695
Debt Securities Available for Sale, Gross Unrealized Losses	(18,078)	(5,601)
Debt Securities Available for Sale, Estimated Fair Value	629,981	604,789
Debt Securities Held to Maturity, Amortized Cost	430,343	500,271
Debt Securities Held to Maturity, Gross Unrealized Gains	327	5,101
Debt Securities Held to Maturity, Gross Unrealized Losses	(7,745)	(1,889)
Debt Securities Held to Maturity, Estimated Fair Value	422,925	503,483
Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities Available for Sale, Amortized Cost	128,890	121,597
Debt Securities Available for Sale, Gross Unrealized Gains	294	1,888
Debt Securities Available for Sale, Gross Unrealized Losses	(3,112)	(329)
Debt Securities Available for Sale, Estimated Fair Value	126,072	123,156
Debt Securities Held to Maturity, Amortized Cost	14,593	14,573
Debt Securities Held to Maturity, Gross Unrealized Gains	82	146
Debt Securities Held to Maturity, Gross Unrealized Losses	(230)	(37)
Debt Securities Held to Maturity, Estimated Fair Value	14,445	$ 14,682
Corporate Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities Available for Sale, Amortized Cost	4,381
Debt Securities Available for Sale, Gross Unrealized Gains	97
Debt Securities Available for Sale, Estimated Fair Value	4,478
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities Available for Sale, Amortized Cost	355,451
Debt Securities Available for Sale, Gross Unrealized Gains	73
Debt Securities Available for Sale, Gross Unrealized Losses	(1,019)
Debt Securities Available for Sale, Estimated Fair Value	$ 354,505

Investment Securities - Additio

Investment Securities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018USD ($)Investmentsecurities	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Investment Securities [Line Items]
Proceeds from sales of debt securities	$ 293,279,000	$ 25,757,000
Gross realized gains	207,000	961,000
Investment securities sold		24,796,000	$ 0
Securities Pledged As Collateral	597,591,000	$ 285,596,000
Residential real estate mortgage-backed securities	$ 1,077,631
Life of mortgage-backed securities	5 years 9 months 18 days
Obligations of U.S. Government Agencies [Member]
Investment Securities [Line Items]
Available for sale securities in unrealized loss position | Investmentsecurities	145
Percentage of aggregate depreciation in unrealized losses	2.65%
Obligations of States and Political Subdivisions [Member]
Investment Securities [Line Items]
Available for sale securities in unrealized loss position | Investmentsecurities	105
Percentage of aggregate depreciation in unrealized losses	3.42%
Asset-backed Securities [Member]
Investment Securities [Line Items]
Available for sale securities in unrealized loss position | Investmentsecurities	6
Percentage of aggregate depreciation in unrealized losses	1.00%

Investment Securities - Amort_2

Investment Securities - Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Due in one year, Amortized Cost	$ 2,410
Due after one year through five years, Amortized Cost	10,625
Due after five years through ten years, Amortized Cost	17,381
Due after ten years, Amortized Cost	1,105,594
Totals, Amortized Cost	1,136,010
Due in one year, Estimated Fair Value	2,413
Due after one year through five years, Estimated Fair Value	10,794
Due after five years through ten years, Estimated Fair Value	17,622
Due after ten years, Estimated Fair Value	1,084,207
Totals, Estimated Fair Value	1,115,036
Due in one year, Amortized Cost, Held to Maturity	0
Due after one year through five years, Amortized Cost, Held to Maturity	1,238
Due after five years through ten years, Amortized Cost, Held to Maturity	25,039
Due after ten years, Amortized Cost, Held to Maturity	418,659
Totals, Amortized Cost, Held to Maturity	444,936	$ 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	1,250
Due after five years through ten years, Estimated Fair Value, Held to Maturity	24,744
Due after ten years, Estimated Fair Value, Held to Maturity	411,376
Estimated Fair Value, Held to Maturity	$ 437,370	$ 518,165

Investment Securities - Gross U

Investment Securities - Gross Unrealized Losses on Investment Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Debt Securities Available for Sale, Less than 12 months, Fair Value	$ 336,433	$ 289,271
Debt Securities Available for Sale, Less than 12 months, Unrealized Loss	(6,148)	(2,211)
Debt Securities Available for Sale, 12 months or more, Fair Value	415,349	183,423
Debt Securities Available for Sale, 12 months or more, Unrealized Loss	(16,061)	(3,719)
Debt Securities Available for Sale, Fair Value	751,782	472,694
Debt Securities Available for Sale, Unrealized Loss	(22,209)	(5,930)
Debt Securities Held to Maturity, Less than 12 months, Fair Value	229,596	94,505
Debt Securities Held to Maturity, Less than 12 months, Unrealized Loss	(2,733)	(574)
Debt Securities Held to Maturity, 12 months or more, Fair Value	162,690	98,004
Debt Securities Held to Maturity, 12 months or more, Unrealized Loss	(5,242)	(1,352)
Debt Securities Held to Maturity, Fair Value	392,286	192,509
Debt Securities Held to Maturity, Unrealized Loss	(7,975)	(1,926)
Obligations of U.S. Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities Available for Sale, Less than 12 months, Fair Value	171,309	284,367
Debt Securities Available for Sale, Less than 12 months, Unrealized Loss	(3,588)	(2,176)
Debt Securities Available for Sale, 12 months or more, Fair Value	394,630	166,338
Debt Securities Available for Sale, 12 months or more, Unrealized Loss	(14,490)	(3,425)
Debt Securities Available for Sale, Fair Value	565,939	450,705
Debt Securities Available for Sale, Unrealized Loss	(18,078)	(5,601)
Debt Securities Held to Maturity, Less than 12 months, Fair Value	223,810	93,017
Debt Securities Held to Maturity, Less than 12 months, Unrealized Loss	(2,619)	(567)
Debt Securities Held to Maturity, 12 months or more, Fair Value	158,648	95,367
Debt Securities Held to Maturity, 12 months or more, Unrealized Loss	(5,126)	(1,322)
Debt Securities Held to Maturity, Fair Value	382,458	188,384
Debt Securities Held to Maturity, Unrealized Loss	(7,745)	(1,889)
Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities Available for Sale, Less than 12 months, Fair Value	63,738	4,904
Debt Securities Available for Sale, Less than 12 months, Unrealized Loss	(1,541)	(35)
Debt Securities Available for Sale, 12 months or more, Fair Value	20,719	17,085
Debt Securities Available for Sale, 12 months or more, Unrealized Loss	(1,571)	(294)
Debt Securities Available for Sale, Fair Value	84,457	21,989
Debt Securities Available for Sale, Unrealized Loss	(3,112)	(329)
Debt Securities Held to Maturity, Less than 12 months, Fair Value	5,786	1,488
Debt Securities Held to Maturity, Less than 12 months, Unrealized Loss	(114)	(7)
Debt Securities Held to Maturity, 12 months or more, Fair Value	4,042	2,637
Debt Securities Held to Maturity, 12 months or more, Unrealized Loss	(116)	(30)
Debt Securities Held to Maturity, Fair Value	9,828	4,125
Debt Securities Held to Maturity, Unrealized Loss	(230)	$ (37)
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities Available for Sale, Less than 12 months, Fair Value	101,386
Debt Securities Available for Sale, Less than 12 months, Unrealized Loss	(1,019)
Debt Securities Available for Sale, Fair Value	101,386
Debt Securities Available for Sale, Unrealized Loss	$ (1,019)

Loans - Summary of Loan Balance

Loans - Summary of Loan Balances (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Leases Receivable Disclosure [Line Items]
Total principal balance of loans owed, net of charge-offs	$ 4,075,244	$ 3,038,472
Unamortized net deferred loan fees	(9,868)	(8,651)
Discounts to principal balance of loans owed, net of charge-offs	(43,362)	(14,656)
Total loans, net of unamortized deferred loan fees and discounts	4,022,014	3,015,165	$ 2,759,593
Allowance for loan losses	(32,582)	(30,323)	(32,503)	$ (36,011)
Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	3,143,100	2,300,322	2,053,464
Allowance for loan losses	(15,620)	(13,758)	(14,265)	(13,911)
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	418,982	356,874	366,663
Allowance for loan losses	(8,375)	(8,227)	(10,310)	(15,118)
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	276,548	220,412	217,047
Allowance for loan losses	(6,090)	(6,512)	(5,831)	(5,271)
Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	183,384	137,557	122,419
Allowance for loan losses	(2,497)	(1,826)	(2,097)	(1,711)
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	515,262	385,426	368,343
Allowance for loan losses	(2,676)	(2,317)	(2,748)	(2,896)
Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	36,684	43,031	46,182
Allowance for loan losses	(1,540)	(1,841)	(2,644)	(3,177)
Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	55,721	25,155	30,766
Allowance for loan losses	(793)	(586)	(622)	(688)
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	2,627,838	1,914,896	1,685,121
Allowance for loan losses	(12,944)	(11,441)	(11,517)	(11,015)
Commercial [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	62,088	69,627	66,990
Allowance for loan losses	(663)	(642)	(680)	(812)
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	326,577	288,688	289,715
Allowance for loan losses	(6,042)	(5,800)	(7,044)	(11,253)
Residential [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	121,296	67,930	55,429
Allowance for loan losses	(1,834)	(1,184)	$ (1,417)	$ (899)
Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total principal balance of loans owed, net of charge-offs	2,991,324	2,699,053
Unamortized net deferred loan fees	(9,868)	(8,651)
Total loans, net of unamortized deferred loan fees and discounts	2,981,456	2,690,402
Allowance for loan losses	(31,793)	(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	2,254,777	2,011,032
Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	351,133	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	228,635	209,437
Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	146,911	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	343,796	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	32,660	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	34,020	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	1,910,981	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	56,208	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	284,453	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	90,703	67,920
PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total principal balance of loans owed, net of charge-offs	1,062,655	316,238
Discounts to principal balance of loans owed, net of charge-offs	(36,320)	(7,035)
Total loans, net of unamortized deferred loan fees and discounts	1,026,335	309,203
Allowance for loan losses	(667)	(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	878,193	279,342
PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	66,201	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	45,468	8,391
PNCI [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	36,473	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	169,792	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	3,585	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	21,659	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	708,401	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	5,880	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	40,957	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	30,593	10
PCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total principal balance of loans owed, net of charge-offs	21,265	23,181
Discounts to principal balance of loans owed, net of charge-offs	(7,042)	(7,621)
Total loans, net of unamortized deferred loan fees and discounts	14,223	15,560
Allowance for loan losses	(122)	(272)
PCI [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	10,130	9,948
PCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,648	3,028
PCI [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,445	2,584
PCI [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	1,674	1,385
PCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	439	485
PCI [Member] | Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	42	45
PCI [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	8,456	8,563
PCI [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	$ 1,167	$ 2,498

Loans - Change in Accretable Yi

Loans - Change in Accretable Yield for PCI (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in accretable yield:
Balance at beginning of period	$ 6,137	$ 7,670	$ 13,255
Accretion to interest income	(787)	(2,809)	(4,011)
Reclassification (to) from nonaccretable difference	709	1,276	(1,574)
Balance at end of period	$ 6,059	$ 6,137	$ 7,670

Allowance for Loan Losses - Sum

Allowance for Loan Losses - Summary of Activity in Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	$ 30,323	$ 32,503	$ 36,011
Charge-offs	(2,364)	(4,410)	(3,230)
Recoveries	2,040	2,141	5,692
Provision (benefit)	2,583	89	(5,970)
Ending Balance	32,582	30,323	32,503
Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	13,758	14,265	13,911
Charge-offs	(92)	(246)	(1,148)
Recoveries	68	397	1,800
Provision (benefit)	1,886	(658)	(298)
Ending Balance	15,620	13,758	14,265
Mortgage Loans on Real Estate [Member] | Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	11,441	11,517	11,015
Charge-offs	(15)	(186)	(827)
Recoveries	68	397	920
Provision (benefit)	1,450	(287)	409
Ending Balance	12,944	11,441	11,517
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	8,227	10,310	15,118
Charge-offs	(1,084)	(1,616)	(1,627)
Recoveries	1,431	1,315	3,356
Provision (benefit)	(199)	(1,782)	(6,537)
Ending Balance	8,375	8,227	10,310
Consumer [Member] | Home Equity Lines of Credit [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	5,800	7,044	11,253
Charge-offs	(277)	(98)	(585)
Recoveries	846	698	2,317
Provision (benefit)	(327)	(1,844)	(5,941)
Ending Balance	6,042	5,800	7,044
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	6,512	5,831	5,271
Charge-offs	(1,188)	(1,444)	(455)
Recoveries	541	428	404
Provision (benefit)	225	1,697	611
Ending Balance	6,090	6,512	5,831
Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	1,826	2,097	1,711
Charge-offs		(1,104)
Recoveries		1	132
Provision (benefit)	671	832	254
Ending Balance	2,497	1,826	2,097
Construction [Member] | Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	642	680	812
Recoveries		1	78
Provision (benefit)	21	(39)	(210)
Ending Balance	663	642	680
Construction [Member] | Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	1,184	1,417	899
Charge-offs		(1,104)
Recoveries			54
Provision (benefit)	650	871	464
Ending Balance	1,834	1,184	1,417
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	2,317	2,748	2,896
Charge-offs	(77)	(60)	(321)
Recoveries			880
Provision (benefit)	436	(371)	(707)
Ending Balance	2,676	2,317	2,748
Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	1,841	2,644	3,177
Charge-offs	(24)	(332)	(219)
Recoveries	297	242	590
Provision (benefit)	(574)	(713)	(904)
Ending Balance	1,540	1,841	2,644
Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Beginning Balance	586	622	688
Charge-offs	(783)	(1,186)	(823)
Recoveries	288	375	449
Provision (benefit)	702	775	308
Ending Balance	$ 793	$ 586	$ 622

Allowance for Loan Losses - S_2

Allowance for Loan Losses - Summary of Activity in Allowance for Loan Losses, Net of Unearned Fees for Periods Indicated (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	$ 30,266	$ 27,352	$ 27,760
Allowance for Loan Losses, Individually evaluated for impairment	2,194	2,699	2,046
Total allowance for loan losses	32,582	30,323	32,503	$ 36,011
Loans, Net of Unearned fees , Loans pooled for evaluation	3,979,744	2,971,371	2,706,409
Loans, Net of Unearned fees , Individually evaluated for impairment	28,047	28,234	28,140
Total loans, net of unamortized deferred loan fees and discounts	4,022,014	3,015,165	2,759,593
Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	15,357	13,283	12,368
Allowance for Loan Losses, Individually evaluated for impairment	147	260	262
Total allowance for loan losses	15,620	13,758	14,265	13,911
Loans, Net of Unearned fees , Loans pooled for evaluation	3,116,086	2,271,165	2,020,018
Loans, Net of Unearned fees , Individually evaluated for impairment	16,884	19,209	19,175
Total loans, net of unamortized deferred loan fees and discounts	3,143,100	2,300,322	2,053,464
Mortgage Loans on Real Estate [Member] | Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	12,737	11,351	10,064
Allowance for Loan Losses, Individually evaluated for impairment	91	30	4
Total allowance for loan losses	12,944	11,441	11,517	11,015
Loans, Net of Unearned fees , Loans pooled for evaluation	2,606,819	1,892,422	1,657,238
Loans, Net of Unearned fees , Individually evaluated for impairment	12,563	13,911	15,081
Total loans, net of unamortized deferred loan fees and discounts	2,627,838	1,914,896	1,685,121
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	8,103	7,619	9,575
Allowance for Loan Losses, Individually evaluated for impairment	266	591	654
Total allowance for loan losses	8,375	8,227	10,310	15,118
Loans, Net of Unearned fees , Loans pooled for evaluation	411,389	349,431	355,698
Loans, Net of Unearned fees , Individually evaluated for impairment	5,945	4,415	4,858
Total loans, net of unamortized deferred loan fees and discounts	418,982	356,874	366,663
Consumer [Member] | Home Equity Lines of Credit [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	5,838	5,356	6,616
Allowance for Loan Losses, Individually evaluated for impairment	198	427	411
Total allowance for loan losses	6,042	5,800	7,044	11,253
Loans, Net of Unearned fees , Loans pooled for evaluation	322,764	283,502	282,159
Loans, Net of Unearned fees , Individually evaluated for impairment	2,646	2,688	3,196
Total loans, net of unamortized deferred loan fees and discounts	326,577	288,688	289,715
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	4,309	4,624	3,765
Allowance for Loan Losses, Individually evaluated for impairment	1,781	1,848	1,130
Total allowance for loan losses	6,090	6,512	5,831	5,271
Loans, Net of Unearned fees , Loans pooled for evaluation	268,885	213,358	208,960
Loans, Net of Unearned fees , Individually evaluated for impairment	5,218	4,470	4,096
Total loans, net of unamortized deferred loan fees and discounts	276,548	220,412	217,047
Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	2,497	1,826	2,052
Total allowance for loan losses	2,497	1,826	2,097	1,711
Loans, Net of Unearned fees , Loans pooled for evaluation	183,384	137,417	121,733
Loans, Net of Unearned fees , Individually evaluated for impairment		140	11
Total loans, net of unamortized deferred loan fees and discounts	183,384	137,557	122,419
Construction [Member] | Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	663	642	680
Total allowance for loan losses	663	642	680	812
Loans, Net of Unearned fees , Loans pooled for evaluation	62,088	69,627	66,990
Total loans, net of unamortized deferred loan fees and discounts	62,088	69,627	66,990
Construction [Member] | Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	1,834	1,184	1,372
Total allowance for loan losses	1,834	1,184	1,417	899
Loans, Net of Unearned fees , Loans pooled for evaluation	121,296	67,790	54,743
Loans, Net of Unearned fees , Individually evaluated for impairment		140	11
Total loans, net of unamortized deferred loan fees and discounts	121,296	67,930	55,429
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	2,620	1,932	2,304
Allowance for Loan Losses, Individually evaluated for impairment	56	230	258
Total allowance for loan losses	2,676	2,317	2,748	2,896
Loans, Net of Unearned fees , Loans pooled for evaluation	509,267	378,743	362,780
Loans, Net of Unearned fees , Individually evaluated for impairment	4,321	5,298	4,094
Total loans, net of unamortized deferred loan fees and discounts	515,262	385,426	368,343
Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	1,486	1,734	2,365
Allowance for Loan Losses, Individually evaluated for impairment	54	107	215
Total allowance for loan losses	1,540	1,841	2,644	3,177
Loans, Net of Unearned fees , Loans pooled for evaluation	33,142	41,076	42,992
Loans, Net of Unearned fees , Individually evaluated for impairment	3,103	1,470	1,508
Total loans, net of unamortized deferred loan fees and discounts	36,684	43,031	46,182
Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans pooled for evaluation	779	529	594
Allowance for Loan Losses, Individually evaluated for impairment	14	57	28
Total allowance for loan losses	793	586	622	$ 688
Loans, Net of Unearned fees , Loans pooled for evaluation	55,483	24,853	30,547
Loans, Net of Unearned fees , Individually evaluated for impairment	196	257	154
Total loans, net of unamortized deferred loan fees and discounts	55,721	25,155	30,766
Financial Asset Acquired with Credit Deterioration [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality	122	272	2,697
Total loans, net of unamortized deferred loan fees and discounts	14,223	15,560	25,044
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	116	215	1,635
Total loans, net of unamortized deferred loan fees and discounts	10,130	9,948	14,271
Financial Asset Acquired with Credit Deterioration [Member] | Mortgage Loans on Real Estate [Member] | Commercial [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality	116	60	1,449
Total loans, net of unamortized deferred loan fees and discounts	8,456	8,563	12,802
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	6	17	81
Total loans, net of unamortized deferred loan fees and discounts	1,648	3,028	6,107
Financial Asset Acquired with Credit Deterioration [Member] | Consumer [Member] | Home Equity Lines of Credit [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality	6	17	17
Total loans, net of unamortized deferred loan fees and discounts	1,167	2,498	4,360
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		40	936
Total loans, net of unamortized deferred loan fees and discounts	2,445	2,584	3,991
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			45
Total loans, net of unamortized deferred loan fees and discounts			675
Financial Asset Acquired with Credit Deterioration [Member] | Construction [Member] | Residential [Member]
Loans and Leases Receivable Disclosure [Line Items]
Allowance for Loan Losses, Loans acquired with deteriorated credit quality			45
Total loans, net of unamortized deferred loan fees and discounts			675
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		155	186
Total loans, net of unamortized deferred loan fees and discounts	1,674	1,385	1,469
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			64
Total loans, net of unamortized deferred loan fees and discounts	439	485	1,682
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	$ 42	$ 45	$ 65

Allowance for Loan Losses - Sch

Allowance for Loan Losses - Schedule Credit Quality Indicators (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	$ 4,022,014	$ 3,015,165	$ 2,759,593
Mortgage Loans on Real Estate [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	3,143,100	2,300,322	2,053,464
Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	418,982	356,874	366,663
Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	276,548	220,412	217,047
Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	183,384	137,557	122,419
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	515,262	385,426	368,343
Home Equity Loans [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	36,684	43,031	46,182
Other Consumer [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	55,721	25,155	30,766
Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,981,456	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	2,254,777	2,011,032
Originated [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	351,133	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	228,635	209,437
Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	146,911	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	343,796	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	32,660	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	34,020	22,859
PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,026,335	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	878,193	279,342
PNCI [Member] | Consumer [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	66,201	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	45,468	8,391
PNCI [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	36,473	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	169,792	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	3,585	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	21,659	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	2,627,838	1,914,896	1,685,121
Commercial [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	62,088	69,627	66,990
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	1,910,981	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	56,208	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	708,401	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	5,880	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	326,577	288,688	289,715
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	284,453	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	40,957	16,248
Residential [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	121,296	67,930	$ 55,429
Residential [Member] | Originated [Member] | Construction [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	90,703	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	30,593	10
Pass [Member] | Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	2,904,603	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	2,198,816	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	342,386	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	217,126	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	146,275	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	337,189	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	29,289	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	33,606	22,432
Pass [Member] | PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	1,014,950	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	869,776	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	63,674	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	45,027	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	36,473	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	167,908	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	3,413	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	21,481	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	1,861,627	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	55,863	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	701,868	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	5,880	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	279,491	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	38,780	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	90,412	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	30,593	10
Special Mention [Member] | Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	45,415	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	35,207	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	3,704	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	6,127	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	377	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	1,724	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	1,054	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	341	272
Special Mention [Member] | PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	5,863	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	4,171	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	1,371	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	321	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	1,086	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	74	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	173	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	33,483	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	345	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	3,085	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	2,309	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	1,124	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	32
Substandard [Member] | Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	31,438	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	20,754	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	5,043	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	5,382	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	259	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	4,883	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	2,317	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	73	155
Substandard [Member] | PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	5,522	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	4,246	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	1,156	1,015
Substandard [Member] | PNCI [Member] | Commercial Portfolio Segment [Member]
Loans and Leases Receivable Disclosure [Line Items]
Total loans, net of unamortized deferred loan fees and discounts	120
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	798	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	98	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	15,871	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	3,448	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	2,653	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	1,053	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	$ 259	$ 107

Allowance for Loan Losses - Ana

Allowance for Loan Losses - Analysis of Past Due and Nonaccrual Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	$ 4,022,014	$ 3,015,165	$ 2,759,593
Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	3,143,100	2,300,322	2,053,464
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	418,982	356,874	366,663
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	276,548	220,412	217,047
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	183,384	137,557	122,419
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	515,262	385,426	368,343
Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	36,684	43,031	46,182
Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	55,721	25,155	30,766
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	2,627,838	1,914,896	1,685,121
Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	62,088	69,627	66,990
Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	326,577	288,688	289,715
Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	121,296	67,930	$ 55,429
Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	10,460	8,927
Current	2,970,996	2,681,475
Total	2,981,456	2,690,402
Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	4,212	3,638
Current	2,250,565	2,007,394
Total	2,254,777	2,011,032
Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	3,160	2,034
Current	347,973	330,615
Total	351,133	332,649
Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,879	3,221
Current	225,756	206,216
Total	228,635	209,437
Originated [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	209	34
Current	146,702	137,250
Total	146,911	137,284
Originated [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,285	2,493
Current	341,511	318,029
Total	343,796	320,522
Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,281	991
Current	31,379	38,857
Total	32,660	39,848
Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	315	95
Current	33,705	22,764
Total	34,020	22,859
Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,927	1,145
Current	1,909,054	1,689,365
Total	1,910,981	1,690,510
Originated [Member] | Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	56,208	69,364
Total	56,208	69,364
Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,564	948
Current	282,889	268,994
Total	284,453	269,942
Originated [Member] | Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	209	34
Current	90,494	67,886
Total	90,703	67,920
PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	6,908	2,682
Current	1,019,427	306,521
Total	1,026,335	309,203
> 90 Days and Still Accruing		281
PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	5,162	1,764
Current	873,031	277,578
Total	878,193	279,342
> 90 Days and Still Accruing		81
PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	810	918
Current	65,391	20,279
Total	66,201	21,197
> 90 Days and Still Accruing		200
PNCI [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	936
Current	44,532	8,391
Total	45,468	8,391
PNCI [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	36,473	273
Total	36,473	273
PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,298	1,694
Current	168,494	61,825
Total	169,792	63,519
> 90 Days and Still Accruing		81
PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	74	30
Current	3,511	2,668
Total	3,585	2,698
PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	160	32
Current	21,499	2,219
Total	21,659	2,251
PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	3,864	70
Current	704,537	215,753
Total	708,401	215,823
PNCI [Member] | Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	5,880	263
Total	5,880	263
PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	576	856
Current	40,381	15,392
Total	40,957	16,248
> 90 Days and Still Accruing		200
PNCI [Member] | Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	30,593	10
Total	30,593	10
30-59 Days [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	5,617	3,983
30-59 Days [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,106	1,898
30-59 Days [Member] | Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,249	1,095
30-59 Days [Member] | Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,053	956
30-59 Days [Member] | Originated [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	209	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	1,675	1,740
30-59 Days [Member] | Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,043	511
30-59 Days [Member] | Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	298	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	431	158
30-59 Days [Member] | Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	908	528
30-59 Days [Member] | Originated [Member] | Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	209	34
30-59 Days [Member] | PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	3,871	1,899
30-59 Days [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,655	1,565
30-59 Days [Member] | PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	538	334
30-59 Days [Member] | PNCI [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	678
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	1,009	1,495
30-59 Days [Member] | PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	74	30
30-59 Days [Member] | PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	160	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	1,646	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	304	298
60-89 Days [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,999	2,426
60-89 Days [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,332	1,497
60-89 Days [Member] | Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	88	191
60-89 Days [Member] | Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	579	738
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	132	510
60-89 Days [Member] | Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	24	107
60-89 Days [Member] | Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	17	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	1,200	987
60-89 Days [Member] | Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	47	48
60-89 Days [Member] | PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,449	344
60-89 Days [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,269	90
60-89 Days [Member] | PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	35	254
60-89 Days [Member] | PNCI [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	145
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	133	90
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	1,136
60-89 Days [Member] | PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	35	228
> 90 Days [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,844	2,518
> 90 Days [Member] | Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	774	243
> 90 Days [Member] | Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	823	748
> 90 Days [Member] | Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,247	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	478	243
> 90 Days [Member] | Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	214	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	296
> 90 Days [Member] | Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	609	372
> 90 Days [Member] | PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,588	439
> 90 Days [Member] | PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,238	109
> 90 Days [Member] | PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	237	330
> 90 Days [Member] | PNCI [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	113
> 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	156	109
> 90 Days [Member] | PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,082
> 90 Days [Member] | PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	$ 237	$ 330

Allowance for Loan Losses - S_3

Allowance for Loan Losses - Schedule of Non Accrual Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 22,274	$ 16,925
Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	14,309	10,881
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	4,090	2,375
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	3,875	3,669
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	3,578	2,737
Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,769	1,150
Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	7	12
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	10,731	8,144
Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	2,314	1,213
Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	19,416	15,462
Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	12,507	9,869
Originated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	3,154	1,924
Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	3,755	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	3,244	1,725
Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,722	1,106
Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	3	7
Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	9,263	8,144
Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,429	811
PNCI [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	2,858	1,463
PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,802	1,012
PNCI [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	936	451
PNCI [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	120
PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	334	1,012
PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	47	44
PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	4	5
PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	1,468
PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	$ 885	$ 402

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Originated [Member]
Loans and Leases Receivable Disclosure [Line Items]
Interest income on non accrual loans	$ 1,584,000	$ 1,067,000	$ 783,000
Interest income on non accrual loans ,recognized	486,000	530,000	377,000
Impaired TDR Loans	10,253,000	12,517,000	12,371,000
Obligations to lend additional funds on TDR	0	0	0
PNCI [Member]
Loans and Leases Receivable Disclosure [Line Items]
Interest income on non accrual loans	1,122,000	73,000	178,000
Interest income on non accrual loans ,recognized	989,000	18,000	11,000
Impaired TDR Loans	615,000	1,352,000	1,324,000
Obligations to lend additional funds on TDR	$ 0	$ 0	$ 0

Allowance for Loan Losses - Imp

Allowance for Loan Losses - Impaired Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Originated [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	$ 27,385	$ 26,178	$ 24,990
Recorded investment with no related allowance	20,904	18,078	17,701
Recorded investment with related allowance	4,539	7,188	6,285
Total recorded investment	25,443	25,266	23,986
Related Allowance	1,948	2,232	1,544
Average recorded investment	24,713	24,626	33,701
Interest income recognized	386	1,052	963
Originated [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	17,675	18,209	16,884
Recorded investment with no related allowance	14,339	15,159	14,718
Recorded investment with related allowance	2,073	2,691	1,908
Total recorded investment	16,412	17,850	16,626
Related Allowance	98	260	184
Average recorded investment	16,632	17,352	25,523
Interest income recognized	227	788	749
Originated [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	4,277	3,263	3,779
Recorded investment with no related allowance	3,641	2,204	2,210
Recorded investment with related allowance	179	602	1,043
Total recorded investment	3,820	2,806	3,253
Related Allowance	76	124	230
Average recorded investment	3,422	2,915	4,788
Interest income recognized	68	71	89
Originated [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	5,433	4,566	4,311
Recorded investment with no related allowance	2,924	575	762
Recorded investment with related allowance	2,287	3,895	3,334
Total recorded investment	5,211	4,470	4,096
Related Allowance	1,774	1,848	1,130
Average recorded investment	4,654	4,283	3,383
Interest income recognized	91	184	125
Originated [Member] | Construction [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance		140	16
Recorded investment with no related allowance		140	11
Total recorded investment		140	11
Average recorded investment	5	76	7
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	4,594	4,023	3,381
Recorded investment with no related allowance	3,663	2,058	1,820
Recorded investment with related allowance	308	1,881	1,551
Total recorded investment	3,971	3,939	3,371
Related Allowance	56	230	180
Average recorded investment	3,517	3,501	4,632
Interest income recognized	90	143	157
Originated [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	2,374	1,627	1,730
Recorded investment with no related allowance	1,892	1,107	715
Recorded investment with related allowance	65	198	594
Total recorded investment	1,957	1,305	1,309
Related Allowance	2	10	107
Average recorded investment	1,520	1,193	1,465
Interest income recognized	23	24	37
Originated [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	3	55	48
Recorded investment with no related allowance		4	15
Recorded investment with related allowance	3	3	19
Total recorded investment	3	7	34
Related Allowance	3	3	13
Average recorded investment	17	20	26
Interest income recognized	2		3
Originated [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	13,081	14,186	13,503
Recorded investment with no related allowance	10,676	13,101	12,898
Recorded investment with related allowance	1,765	810	357
Total recorded investment	12,441	13,911	13,255
Related Allowance	42	30	4
Average recorded investment	13,115	13,851	20,891
Interest income recognized	137	645	592
Originated [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	1,900	1,581	2,001
Recorded investment with no related allowance	1,749	1,093	1,480
Recorded investment with related allowance	111	401	430
Total recorded investment	1,860	1,494	1,910
Related Allowance	71	111	110
Average recorded investment	1,885	1,702	3,297
Interest income recognized	43	47	49
Originated [Member] | Residential [Member] | Construction [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance		140	16
Recorded investment with no related allowance		140	11
Total recorded investment		140	11
Average recorded investment	5	76	7
Interest income recognized		9
PNCI [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	4,990	3,048	4,401
Recorded investment with no related allowance	2,570	1,994	3,094
Recorded investment with related allowance	656	974	1,060
Total recorded investment	3,226	2,968	4,154
Related Allowance	246	467	502
Average recorded investment	3,691	3,563	5,419
Interest income recognized	207	89	66
PNCI [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	3,485	1,404	2,776
Recorded investment with no related allowance	1,802	1,359	2,289
Recorded investment with related allowance			259
Total recorded investment	1,802	1,359	2,548
Related Allowance			79
Average recorded investment	2,242	2,020	3,652
Interest income recognized	188	24	17
PNCI [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	1,385	1,644	1,625
Recorded investment with no related allowance	655	635	805
Recorded investment with related allowance	649	974	801
Total recorded investment	1,304	1,609	1,606
Related Allowance	239	467	423
Average recorded investment	1,389	1,543	1,521
Interest income recognized	18	65	49
PNCI [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	120
Recorded investment with no related allowance	113
Recorded investment with related allowance	7
Total recorded investment	120
Related Allowance	7
Average recorded investment	60		1
Interest income recognized	1
PNCI [Member] | Construction [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment			245
PNCI [Member] | Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	375	1,404	745
Recorded investment with no related allowance	334	1,359	463
Recorded investment with related allowance			259
Total recorded investment	334	1,359	722
Related Allowance			79
Average recorded investment	529	1,041	799
Interest income recognized	5	24	17
PNCI [Member] | Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	252	178	206
Recorded investment with no related allowance	47	44	67
Recorded investment with related allowance	197	121	132
Total recorded investment	244	165	199
Related Allowance	101	97	108
Average recorded investment	155	117	154
Interest income recognized		6	8
PNCI [Member] | Other Consumer [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	106	250	122
Recorded investment with no related allowance	21		3
Recorded investment with related allowance	85	250	118
Total recorded investment	106	250	121
Related Allowance	11	54	15
Average recorded investment	114	186	194
Interest income recognized		11	5
PNCI [Member] | Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	3,110		2,031
Recorded investment with no related allowance	1,468		1,826
Total recorded investment	1,468		1,826
Average recorded investment	1,713	979	2,853
Interest income recognized	183
PNCI [Member] | Commercial [Member] | Construction [Member]
Financing Receivable, Impaired [Line Items]
Average recorded investment			245
PNCI [Member] | Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid principal balance	1,027	1,216	1,297
Recorded investment with no related allowance	587	591	735
Recorded investment with related allowance	367	603	551
Total recorded investment	954	1,194	1,286
Related Allowance	127	316	300
Average recorded investment	1,120	1,240	1,173
Interest income recognized	$ 18	$ 48	$ 36

Allowance for Loan Losses - Tro

Allowance for Loan Losses - Troubled Debt Restructurings (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)SecurityLoan	Dec. 31, 2017USD ($)SecurityLoan	Dec. 31, 2016USD ($)SecurityLoan
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	17	26	24
Pre-mod outstanding principal balance	$ 3,768	$ 7,111	$ 1,989
Post-mod outstanding principal balance	3,755	6,978	2,035
Financial impact due to TDR taken as additional provision	$ 781	$ 133	$ 326
Number that defaulted during the period | SecurityLoan	6	5	3
Recorded investment of TDRs that defaulted during the period	$ 565	$ 624	$ 330
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions		$ (5)
Mortgage Loans on Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	8	9	8
Pre-mod outstanding principal balance	$ 1,938	$ 4,660	$ 1,073
Post-mod outstanding principal balance	1,935	4,634	1,117
Financial impact due to TDR taken as additional provision	$ 491	$ 58	$ 96
Number that defaulted during the period | SecurityLoan	1	3	2
Recorded investment of TDRs that defaulted during the period	$ 169	$ 442	$ 101
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	3	5	12
Pre-mod outstanding principal balance	$ 732	$ 453	$ 839
Post-mod outstanding principal balance	737	453	841
Financial impact due to TDR taken as additional provision	$ (35)	$ 38	$ 207
Number that defaulted during the period | SecurityLoan	2	2	1
Recorded investment of TDRs that defaulted during the period	$ 248	$ 182	$ 229
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions		$ (5)
Commercial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	6	11	4
Pre-mod outstanding principal balance	$ 1,098	$ 1,854	$ 77
Post-mod outstanding principal balance	1,083	1,747	77
Financial impact due to TDR taken as additional provision	$ 325	$ 37	$ 23
Number that defaulted during the period | SecurityLoan	3
Recorded investment of TDRs that defaulted during the period	$ 148
Construction [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan		1
Pre-mod outstanding principal balance		$ 144
Post-mod outstanding principal balance		$ 144
Residential 1-4 Family [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	1	1	3
Pre-mod outstanding principal balance	$ 156	$ 939	$ 650
Post-mod outstanding principal balance	$ 156	939	656
Financial impact due to TDR taken as additional provision		$ 169	$ 50
Number that defaulted during the period | SecurityLoan		2	2
Recorded investment of TDRs that defaulted during the period		$ 223	$ 101
Home Equity Loans [Member] | Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	2	1	1
Pre-mod outstanding principal balance	$ 599	$ 252	$ 105
Post-mod outstanding principal balance	599	$ 252	$ 105
Financial impact due to TDR taken as additional provision	$ (35)
Number that defaulted during the period | SecurityLoan		1
Recorded investment of TDRs that defaulted during the period		$ 55
Other Consumer [Member] | Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan		1	2
Pre-mod outstanding principal balance		$ 14	$ 27
Post-mod outstanding principal balance		14	27
Financial impact due to TDR taken as additional provision		$ 11	$ 2
Commercial [Member] | Mortgage Loans on Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	7	8	5
Pre-mod outstanding principal balance	$ 1,782	$ 3,721	$ 423
Post-mod outstanding principal balance	1,779	3,695	461
Financial impact due to TDR taken as additional provision	$ 491	$ (111)	$ 46
Number that defaulted during the period | SecurityLoan	1	1
Recorded investment of TDRs that defaulted during the period	$ 169	$ 219
Home Equity Lines of Credit [Member] | Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan	1	3	9
Pre-mod outstanding principal balance	$ 133	$ 187	$ 707
Post-mod outstanding principal balance	$ 138	187	709
Financial impact due to TDR taken as additional provision		$ 27	$ 205
Number that defaulted during the period | SecurityLoan	2	1	1
Recorded investment of TDRs that defaulted during the period	$ 248	$ 127	$ 229
Financial impact due to the default of previous TDR taken as charge-offs or additional provisions		$ (5)
Residential [Member] | Construction [Member]
Financing Receivable, Modifications [Line Items]
Number | SecurityLoan		1
Pre-mod outstanding principal balance		$ 144
Post-mod outstanding principal balance		$ 144

Foreclosed Assets - Summary of

Foreclosed Assets - Summary of Activity in Balance of Foreclosed Assets (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)Assets	Dec. 31, 2017USD ($)Assets	Dec. 31, 2016USD ($)
Repossessed Assets [Abstract]
Beginning balance, net	$ 3,226	$ 3,986
Additions/transfers from loans	1,262	1,563
Dispositions/sales	(2,119)	(2,161)
Valuation adjustments	(89)	(162)
Ending balance, net	2,280	3,226	$ 3,986
Ending valuation allowance	$ (116)	$ (200)
Ending number of foreclosed assets | Assets	11	16
Proceeds from sale of foreclosed assets	$ 2,527	$ 2,872	4,010
Gain on sale of foreclosed assets	$ 408	$ 711	$ 262

Foreclosed Assets - Additional

Foreclosed Assets - Additional Information (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Foreclosed Assets Activity [Line Items]
Foreclosed assets	$ 2,280,000	$ 3,226,000	$ 3,986,000
Residential Real Estate [Member]
Schedule Of Foreclosed Assets Activity [Line Items]
Foreclosed assets	1,218,000
Formal foreclosure proceedings	$ 453,000

Premises and Equipment - Summar

Premises and Equipment - Summary of Premises and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment, Net, by Type [Abstract]
Land & land improvements	$ 29,065	$ 9,959
Buildings	64,478	50,340
Furniture and equipment	45,228	35,939
Premises and equipment, gross	138,771	96,238
Less: Accumulated depreciation	(50,125)	(40,644)
Premises and equipment less depreciation, gross	88,646	55,594
Construction in progress	701	2,148
Total premises and equipment	$ 89,347	$ 57,742

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Depreciation expense for premises and equipment	$ 6,104,000	$ 5,686,000	$ 5,314,000

Cash Value of Life Insurance -

Cash Value of Life Insurance - Summary of Activity in Balance of Cash Value of Life Insurance (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)PoliciesCompanyEmployees	Dec. 31, 2017USD ($)PoliciesCompanyEmployees	Dec. 31, 2016USD ($)	Jul. 06, 2018USD ($)
Insurance [Line Items]
Beginning balance	$ 97,783	$ 95,912
Increase in cash value of life insurance	2,718	2,685	$ 2,717
Gain on death benefit		108
Insurance proceeds receivable reclassified to other assets		(922)
Ending balance	117,318	97,783	$ 95,912
End of period death benefit	$ 200,249	$ 165,587
Number of policies owned | Policies	196	182
Insurance companies used | Company	14	14
Current and former employees and directors covered | Employees	66	57
FNBB [Member]
Insurance [Line Items]
Acquired policies from business combination	$ 16,817			$ 16,817

Cash Value of Life Insurance _2

Cash Value of Life Insurance - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018PoliciesCompany	Dec. 31, 2017Company
Insurance [Abstract]
Number of life insurance policies owned by the Company	196
Insurance companies used | Company	14	14
Policies covering current and former employees and directors	66

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Summary of Goodwill Intangible (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Ending Balance	$ 220,972
Goodwill, Additions	156,661
Goodwill, Reductions	0
Goodwill, Beginning Balance	$ 64,311

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Additional Information (Detail)	Mar. 18, 2016USD ($)Branches	Dec. 31, 2018USD ($)	Jul. 06, 2018USD ($)	Oct. 03, 2014USD ($)	Sep. 23, 2011USD ($)
Finite-Lived Intangible Assets [Line Items]
Impairment charges		$ 0
FNBB [Member]
Finite-Lived Intangible Assets [Line Items]
Additions to core deposit intangibles			$ 27,605,000
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

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Summary of Core Deposit Intangibles (Detail) - Core Deposit Intangibles [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Finite-Lived Intangible Assets [Line Items]
Core deposit intangibles, Beginning balance	$ 9,558
Core deposit intangibles, Reductions/Amortization	0
Core deposit intangibles, Additions	27,605
Core deposit intangibles, Ending balance	37,163
Accumulated amortization, Beginning balance	(4,384)
Accumulated amortization, Reductions/Amortization	(3,499)
Accumulated amortization, Additions	0
Accumulated amortization, Ending balance	(7,883)
Core deposit intangibles, net, Beginning balance	5,174
Core deposit intangibles, net, Reductions/Amortization	(3,499)
Core deposit intangibles, net, Additions	27,605
Core deposit intangibles, net, Ending balance	$ 29,280

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Remaining Estimated Core Deposit Intangible Amortization (Detail) - Core Deposit Intangibles [Member] $ in Thousands	Dec. 31, 2018USD ($)
Finite-Lived Intangible Assets [Line Items]
2,019	$ 5,723
2,020	5,723
2,021	5,465
2,022	4,776
2,023	4,269
Thereafter	$ 3,324

Mortgage Servicing Rights - Fai

Mortgage Servicing Rights - Fair Value of Mortgage Servicing Rights (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Servicing Assets at Fair Value [Line Items]
Contractually specified servicing fees, late fees and ancillary fees earned	$ 2,038	$ 2,076	$ 2,065
Mortgage Servicing Rights [Member]
Servicing Assets at Fair Value [Line Items]
Balance at beginning of period	6,687	6,595	7,618
Additions	557	810	1,161
Change in fair value	(146)	(718)	(2,184)
Balance at end of period	$ 7,098	$ 6,687	$ 6,595
Measurement Input, Constant Prepayment Rate [Member]
Servicing Assets at Fair Value [Line Items]
Fair Value Of Mortgage Servicing Rights Weighted Average	0.076	0.089	0.088
Measurement Input, Discount Rate [Member]
Servicing Assets at Fair Value [Line Items]
Fair Value Of Mortgage Servicing Rights Weighted Average	0.120	0.130	0.140
Loans [Member]
Servicing Assets at Fair Value [Line Items]
Balance at beginning of period	$ 811,065	$ 816,623	$ 817,917
Balance at end of period	$ 785,138	$ 811,065	$ 816,623

Deposits - Summary of Balances

Deposits - Summary of Balances of Deposits (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Noninterest-bearing demand	$ 1,760,580	$ 1,368,218
Interest-bearing demand	1,252,366	971,459
Savings	1,921,324	1,364,518
Time certificates, over $250,000	132,429	73,596
Other time certificates	299,767	231,340
Total deposits	$ 5,366,466	$ 4,009,131

Deposits - Additional Informati

Deposits - Additional Information (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Deposits [Line Items]
Overdrawn deposit balances classified as consumer loans	$ 1,469,000	$ 1,366,000
California [Member]
Schedule Of Deposits [Line Items]
Certificate of deposits, included in time certificates, over $250,000	$ 60,000,000	$ 50,000,000

Deposits - Schedule of Maturiti

Deposits - Schedule of Maturities of Time Deposits (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Summary of maturities of time deposits [Abstract]
2,019	$ 298,855
2,020	75,989
2,021	36,267
2,022	18,542
2,023	2,537
Thereafter	6
Total	$ 432,196

Other Borrowings - Summary of B

Other Borrowings - Summary of Balances of Other Borrowings (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total other borrowings	$ 15,839	$ 122,166
1.38% Fixed Rate FHLB Collateralized Borrowings [Member]
Debt Instrument [Line Items]
Collateralized borrowings, fixed rate, as of December 31, 2018 and December 31, 2017 of 1.38% & 0.05%, payable on January 2, 2019 and January 2, 2018, respectively		104,729
0.05% Fixed Rate Collateralized Borrowings [Member]
Debt Instrument [Line Items]
Collateralized borrowings, fixed rate, as of December 31, 2018 and December 31, 2017 of 1.38% & 0.05%, payable on January 2, 2019 and January 2, 2018, respectively	$ 15,839	$ 17,437

Other Borrowings - Summary of_2

Other Borrowings - Summary of Balances of Other Borrowings (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
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	Jan. 2, 2019	Jan. 2, 2018

Other Borrowings - Additional I

Other Borrowings - Additional Information (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Borrowings [Line Items]
Security repurchase agreement	$ 0	$ 0
FHLB collateral line of credit, maximum borrowings capacity	2,063,815,000
FHLB collateral line of credit, outstanding balance	0
Loans designated as potential collateral under collateralized line of credit with FHLB	188,559,000
Investment securities designated as potential collateral under collateral line of credit	2,832,945,000
Repurchase investment securities sold and pledged as collateral under securities repurchase agreement	37,688,000
Collateralized line of credit with San Francisco Federal Reserve Bank, maximum borrowings capacity	142,272,000
Collateralized line of credit with San Francisco Federal Reserve Bank, outstanding balance	0
Investment securities designated as potential collateral under collateral line of credit with San Francisco Federal Reserve Bank	12,000
Loans designated as potential collateral under collateral line of credit with San Francisco Federal Reserve Bank	256,364,000
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]
Other collateralized borrowings	$ 15,839,000	$ 17,437,000

Junior Subordinated Debt - Addi

Junior Subordinated Debt - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)LocationTrust	Dec. 31, 2017USD ($)
Class of Stock [Line Items]
Number of subsidiary business trusts | Trust	5
Trust preferred securities amount | $
Number of locations organized | Location	2
Wholly Owned Subsidiaries [Member]
Class of Stock [Line Items]
Trust preferred securities amount | $	$ 62.9
Maximum [Member]
Class of Stock [Line Items]
Consecutive payments of interest on debenture defer Period	5 years
North Valley Bancorp [Member]
Class of Stock [Line Items]
Number of locations acquired | Location	3

Junior Subordinated Debt - Summ

Junior Subordinated Debt - Summary of Terms and Recorded Balance of Subordinated Debenture (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Subordinated Borrowing [Line Items]
Subordinated debenture, Face Value	$ 62,889
Subordinated debenture, Recorded Book Value	$ 57,042	$ 56,858
TriCo Capital Trust I [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Oct. 7, 2033
Subordinated debenture, Face Value	$ 20,619
Subordinated debenture, Current Coupon Rate	5.49%
Subordinated debenture, Recorded Book Value	$ 20,619	20,619
TriCo Capital Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Jul. 23, 2034
Subordinated debenture, Face Value	$ 20,619
Subordinated debenture, Current Coupon Rate	5.03%
Subordinated debenture, Recorded Book Value	$ 20,619	20,619
North Valley Trust II [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Apr. 24, 2033
Subordinated debenture, Face Value	$ 6,186
Subordinated debenture, Current Coupon Rate	5.79%
Subordinated debenture, Recorded Book Value	$ 5,174	5,135
North Valley Trust III [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Apr. 24, 2034
Subordinated debenture, Face Value	$ 5,155
Subordinated debenture, Current Coupon Rate	5.28%
Subordinated debenture, Recorded Book Value	$ 4,079	4,041
North Valley Trust IV [Member]
Subordinated Borrowing [Line Items]
Subordinated debenture, Maturity Date	Mar. 15, 2036
Subordinated debenture, Face Value	$ 10,310
Subordinated debenture, Current Coupon Rate	4.12%
Subordinated debenture, Recorded Book Value	$ 6,551	$ 6,444
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)	12 Months Ended
	Dec. 31, 2018USD ($)site$ / sharesshares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)	Aug. 21, 2007shares
Conversion of Stock [Line Items]
Reserves to satisfy Federal regulatory requirements	$ 119,317,000	$ 82,068,000
Number of sites leased under non-cancelable operating leases | site	48
Rent expense under operating leases	$ 6,348,000	5,885,000	$ 6,082,000
Rent expense offset by rent income	$ 42,000	$ 44,000	$ 220,000
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	30,417,223	22,955,963		15,814,662
Conversion ratio	1.6298
Common Class B [Member]
Conversion of Stock [Line Items]
Class B common stock of Visa Inc. | shares	13,396
Common Class A [Member]
Conversion of Stock [Line Items]
The value of the Class A shares | $ / shares	$ 131.94
Value of unredeemed Class A equivalent shares	$ 2,881,000

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Commitments under Non-Cancelable Operating Leases with Initial or Remaining Terms of One Year or More (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2,019	$ 4,639
2,020	4,036
2,021	3,644
2,022	2,814
2,023	1,831
Thereafter	2,636
Future minimum lease payments	$ 19,600

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Bank's Commitments and Contingent Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 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	248,996	187,097
RE Mortgage [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	140,292	66,267
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	11,346	13,075
Commercial [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	306,191	257,220
Consumer Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	496,575	422,958
Deposit Account Overdraft Privilege [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to extend credit	$ 111,956	$ 98,260

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 21, 2007
Class of Stock [Line Items]
Cash dividends received	$ 26,432,000	$ 19,236,000	$ 16,758,000
Repurchase of common stock					500,000
Stock repurchase plan percentage of common stock					3.20%
Common stock, shares outstanding	30,417,223	22,955,963			15,814,662
Stock repurchase plan, amount of Share repurchased	$ 3,969,000	$ 3,854,000	7,878,000
Market value of shares repurchased under equity compensation plans	1,486,000	$ 2,225,000	$ 5,988,000
Maximum [Member]
Class of Stock [Line Items]
Amount available to dividend to holding company	$ 98,438,000
2007 Stock Repurchase Plan [Member]
Class of Stock [Line Items]
Cumulative number of shares repurchased	196,566
Stock repurchase plan, number of shares repurchased	26,966	0	0
Stock repurchase plan, amount of Share repurchased	$ 968,000
Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares outstanding	30,417,223	22,955,963	22,867,802	22,775,173
Stock repurchase plan, number of shares repurchased	104,989	107,390	264,800
Stock repurchase plan, amount of Share repurchased	$ 1,677,000	$ 1,191,000	$ 2,895,000
Company's common stock in lieu of cash to exercise options to purchase shares	78,023	107,390	264,800
Market value of shares repurchased under equity compensation plans	$ 3,001,000	$ 3,854,000	$ 7,879,000

Stock Options and Other Equit_3

Stock Options and Other Equity-Based Incentive Instruments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Aggregate number of shares of TriCo's common stock issued	1,650,000	650,000
Outstanding options under the plan	343,000	446,400
Options currently not exercisable yet expected to vest	1,125
Weighted-average remaining contractual term	9 months 18 days
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	45,536	52,829
Weighted-average remaining contractual term	1 year 4 months 24 days
Pre-tax compensation costs	$ 848,000
Number of units released	25,512
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	66,947	68,457
Weighted-average remaining contractual term	1 year 4 months 24 days
Pre-tax compensation costs	$ 2,319,000
Number of units released	35,060
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] | 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	68,304
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	343,000
Options available for grant under the plan	380,958
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	112,483
2001 Plan [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding options under the plan	10,000
Options available for grant under the plan	0
Share based compensation grant expiry period	10 years

Stock Options and Other Equit_4

Stock Options and Other Equity-Based Incentive Instruments - Stock Option Activity (Detail)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, Number of Shares, beginning balance | shares	446,400
Options granted, Number of Shares | shares	0
Options exercised, Number of Shares | shares	(100,400)
Options forfeited, Number of Shares | shares	(3,000)
Options outstanding, Number of Shares, ending balance | shares	343,000
Options outstanding, Weighted Average Exercise Price, beginning balance	$ 16.84
Options granted, Weighted Average Exercise Price	0
Options exercised, Weighted Average Exercise Price	16.97
Options forfeited, Weighted Average Exercise Price	23.21
Options outstanding, Weighted Average Exercise Price, ending balance	16.67
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	12.63
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	23.21
Options forfeited, Option Price per Share	23.21
Options outstanding, Option Price per Share, ending balance	$ 23.21

Stock Options and Other Equit_5

Stock Options and Other Equity-Based Incentive Instruments - Summary of Options Outstanding (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options	343,000	446,400
Weighted average exercise price	$ 16.67	$ 16.84
Intrinsic value (in thousands)	$ 5,872
Weighted average remaining contractual term (yrs.)	3 years 3 months 18 days
Currently Exercisable [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options	341,875
Weighted average exercise price	$ 16.65
Intrinsic value (in thousands)	$ 5,860
Weighted average remaining contractual term (yrs.)	3 years 2 months 12 days
Currently Not Exercisable [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of options	1,125
Weighted average exercise price	$ 23.21
Intrinsic value (in thousands)	$ 12
Weighted average remaining contractual term (yrs.)	5 years 9 months 18 days

Stock Options and Other Equit_6

Stock Options and Other Equity-Based Incentive Instruments - Information about Options (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Information about Options
Intrinsic value of options exercised	$ 2,109,000	$ 2,657,000	$ 3,483,000
Fair value of options that vested	75,000	259,000	580,000
Total compensation costs for options recognized in income	75,000	259,000	580,000
Excess tax benefit recognized in income	22,000	109,000	$ 244,000
ASU 2016-09 [Member]
Information about Options
Excess tax benefit recognized in income	$ 623,000	$ 600,000

Stock Options and Other Equit_7

Stock Options and Other Equity-Based Incentive Instruments - Restricted Stock Unit (RSU) Activity (Detail) - Restricted Stock Units (RSUs) [Member]	12 Months Ended
	Dec. 31, 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	(7,226)
RSUs outstanding, Number of RSUs, ending balance	45,536
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	38,605
RSUs added through dividend credits, Number of RSUs	1,188
RSUs released through vesting, Number of RSUs	(35,060)
RSUs forfeited/expired, Number of RSUs	(6,243)
RSUs outstanding, Number of RSUs, ending balance	66,947
RSUs granted, Weighted Average Fair Value on Date of Grant | $ / shares	$ 39.08

Stock Options and Other Equit_8

Stock Options and Other Equity-Based Incentive Instruments - Summary of Compensation Costs and Excess Tax Benefits for RSUs (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Service Condition Vesting RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation costs for RSUs recognized in income	$ 1,017,000	$ 895,000	$ 616,000
Excess tax benefit recognized in income Service condition vesting RSUs	104,000	131,000
Market Plus Service Condition Vesting RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation costs for RSUs recognized in income	370,000	432,000	$ 271,000
Excess tax benefit recognized in income Service condition vesting RSUs	$ 191,000	$ 175,000

Noninterest Income and Expens_2

Noninterest Income and Expense - Components of Other Noninterest Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees									$ 38,460	$ 37,423	$ 33,226
Commissions on sale of non-deposit investment products									3,151	2,729	2,329
Increase in cash value of life insurance									2,718	2,685	2,717
Gain on sale of loans									2,371	3,109	4,037
Lease brokerage income									678	782	711
Sale of customer checks									449	372	408
Gain on sale of foreclosed assets									408	711	262
Gain on sale of investment securities									207	961
Loss on disposal of fixed assets									(185)	(142)	(147)
Loss on marketable equity securities									(64)
Other									1,091	1,391	1,020
Total other noninterest income									10,824	12,598	11,337
Total noninterest income	$ 12,634	$ 12,186	$ 12,174	$ 12,290	$ 12,478	$ 12,930	$ 12,910	$ 11,703	49,284	50,021	44,563
ATM and Interchange Fees [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees									18,249	16,727	15,859
Service Charges on Deposit Accounts [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees									15,467	16,056	14,365
Other Service Fees [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees									2,852	3,282	3,121
Mortgage Banking Service Fees [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees									2,038	2,076	2,065
Change in Value of Mortgage Servicing Rights [Member]
Schedule Of Other Noninterest Income And Expense [Line Items]
Total service charges and fees									$ (146)	$ (718)	$ (2,184)

Noninterest Income and Expens_3

Noninterest Income and Expense - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Mortgage loan servicing fees, net of change in fair value of mortgage loan servicing rights	$ 1,892,000	$ 1,358,000	$ (119,000)

Noninterest Income and Expens_4

Noninterest Income and Expense - Components of Noninterest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Base salaries, net of deferred loan origination costs									$ 62,422	$ 54,589	$ 53,169
Incentive compensation									11,147	9,227	8,872
Benefits and other compensation costs									20,373	19,114	18,683
Total salaries and benefits expense									93,942	82,930	80,724
Occupancy									12,139	10,894	10,139
Data processing and software									11,021	10,448	8,846
Equipment									6,651	7,141	6,597
ATM and POS network charges									5,271	4,752	4,999
Merger and acquisition expense									5,227	530	784
Advertising									4,578	4,101	3,829
Professional fees									3,546	3,745	5,409
Intangible amortization									3,499	1,389	1,377
Telecommunications									3,023	2,713	2,749
Regulatory assessments and insurance									1,906	1,676	2,105
Courier service									1,287	1,035	998
Operational losses									1,260	1,394	1,564
Postage									1,154	1,296	1,603
Legal settlement											1,450
Foreclosed assets expense									382	231	266
Provision for foreclosed asset losses									89	162	140
Other miscellaneous expense									13,720	12,587	12,418
Total other noninterest expense									74,753	64,094	65,273
Total noninterest expense	$ 45,285	$ 47,378	$ 37,870	$ 38,162	$ 38,076	$ 37,222	$ 35,904	$ 35,822	$ 168,695	$ 147,024	$ 145,997

Income Taxes - Components of Co

Income Taxes - Components of Consolidated Income Tax Expense (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current tax expense
Federal									$ 13,109	$ 17,835	$ 17,401
State									9,323	6,650	7,121
Current tax expense, Total									22,432	24,485	24,522
Deferred tax expense
Federal									1,842	11,418	2,735
State									758	1,055	455
Deferred tax benefit, Total									2,600	12,473	3,190
Total tax expense	$ 7,334	$ 6,476	$ 5,782	$ 5,440	$ 14,829	$ 7,130	$ 7,647	$ 7,352	$ 25,032	$ 36,958	$ 27,712

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes (Textual) [Abstract]
Federal corporate tax rate	21.00%	35.00%	35.00%
Deferred tax expense for change in tax law		$ 7,416,000
Accelerated amortization expense due to change in tax law		226,000
Carrying value of low income housing tax credit funds	$ 23,885,000	$ 16,854,000
Low income housing tax credit fund commitments	9,032,000
Federal [Member]
Income Taxes (Textual) [Abstract]
Net operating loss carryforwards	1,292,000
Tax credit carryforwards	123,000
California [Member]
Income Taxes (Textual) [Abstract]
Net operating loss carryforwards	23,877,000
Tax credit carryforwards	$ 648,000

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Investments in Qualified Affordable Housing Projects (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax credits and other tax benefits - decrease in tax expense	$ (1,993)	$ (1,753)	$ (954)
Amortization - increase in tax expense	$ 1,814	$ 1,611	$ 757

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Tax Rate and Statutory Federal Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%	35.00%	35.00%
State income taxes, net of federal tax benefit	8.60%	6.90%	6.80%
Tax Cuts and Jobs Act impact of federal rate change		9.60%
Tax-exempt interest on municipal obligations	(1.00%)	(1.90%)	(1.80%)
Tax-exempt life insurance related income	(0.60%)	(1.30%)	(1.30%)
Low income housing tax credits	(2.20%)	(2.30%)	(1.30%)
Low income housing tax credit amortization	2.00%	2.10%	0.80%
Equity compensation	(0.50%)	(1.20%)
Non-deductible joint beneficiary agreement expense	0.10%	0.10%	0.10%
Non-deductible merger expenses	0.20%	0.20%
Other	(0.80%)	0.50%	(0.10%)
Effective Tax Rate	26.80%	47.70%	38.20%

Income Taxes - Company's Net De

Income Taxes - Company's Net Deferred Tax Asset Recorded in Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Allowance for losses and reserve for unfunded commitments	$ 10,394	$ 9,900
Deferred compensation	2,780	1,953
Accrued pension liability	9,734	6,835
Accrued bonus	709	171
Other accrued expenses	466	522
Additional unfunded status of the supplemental retirement plans	1,420	1,582
State taxes	1,864	1,397
Share based compensation	1,132	1,322
Nonaccrual interest	814	282
OREO write downs	34	59
Acquisition cost basis	6,714	2,187
Unrealized loss on securities	6,201	1,008
Tax credits	623	581
Net operating loss carryforwards	2,442	1,801
Other	389	508
Total deferred tax assets	45,716	30,108
Deferred tax liabilities:
Securities income	(1,020)	(958)
Depreciation	(5,572)	(1,987)
Merger related fixed asset valuations	(26)	(30)
Securities accretion	(426)	(315)
Mortgage servicing rights valuation	(2,073)	(1,943)
Core deposit intangible	(8,234)	(916)
Junior subordinated debt	(1,729)	(1,783)
Prepaid expenses and other	(582)	(479)
Total deferred tax liability	(19,662)	(8,411)
Net deferred tax asset	$ 26,054	$ 21,697

Earnings Per Share - Computatio

Earnings Per Share - Computation of Earnings Per Share (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income	$ 23,211	$ 16,170	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	$ 68,320	$ 40,554	$ 44,811
Average number of common shares outstanding									26,593	22,912	22,814
Effect of dilutive stock options and restricted stock									287	338	273
Average number of common shares outstanding used to calculate diluted earnings per share									26,880	23,250	23,087
Options excluded from diluted earnings per share because the effect of these options was antidilutive									10,056		13,825

Comprehensive Income - Componen

Comprehensive Income - Components of Other Comprehensive Income (Loss) and Related Tax Effects (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized holding (losses) gains on available for sale securities before reclassifications	$ (17,057)	$ 6,422	$ (11,015)
Amounts reclassified out of accumulated other comprehensive income:
Realized gains on debt securities	(207)	(961)
Total amounts reclassified out of accumulated other comprehensive income	(570)	(961)
Unrealized holding (losses) gains on available for sale securities after reclassifications	(17,627)	5,461	(11,015)
Tax effect	5,193	(2,296)	4,631
Unrealized holding (losses) gains on available for sale securities, net of tax	(12,434)	3,165	(6,384)
Change in unfunded status of the supplemental retirement plans before reclassifications	762	(1,016)	511
Amounts reclassified out of accumulated other comprehensive income:
Amortization of prior service cost	(54)	(12)	(40)
Amortization of actuarial losses	510	390	550
Total amounts reclassified out of accumulated other comprehensive income	(212)	378	510
Change in unfunded status of the supplemental retirement plans after reclassifications	550	(638)	1,021
Tax effect	(162)	268	(429)
Change in unfunded status of the supplemental retirement plans, net of tax	388	(370)	592
Change in joint beneficiary agreement liability before reclassifications	426	(110)	(343)
Tax effect	0	0	0
Change in unfunded status of the supplemental retirement plans, net of tax	426	(110)	(343)
Other comprehensive (loss) income	(11,620)	$ 2,685	$ (6,135)
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)

Comprehensive Income - Compon_2

Comprehensive Income - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ (5,228)	$ (17,879)
Net Unrealized Loss on Available for Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, before tax	(3,409)	(20,974)
Stranded OCI from tax rate change	425
Accumulated other comprehensive loss, tax effect	1,008	6,201
Accumulated other comprehensive loss	(1,976)	(14,773)
Unfunded Status of Supplemental Retirement Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, before tax	(5,352)	(4,802)
Stranded OCI from tax rate change	668
Accumulated other comprehensive loss, tax effect	1,582	1,420
Accumulated other comprehensive loss	(3,102)	(3,382)
Joint Beneficiary Agreement Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, before tax	(150)	276
Accumulated other comprehensive loss	$ (150)	$ 276

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Employee service period under ESOP	1 year
Deferred compensation obligations	$ 9,402,000	$ 6,605,000
Cash values of the insurance policies purchased to fund deferred compensation obligations	117,318,000	97,783,000	$ 95,912,000
Unfunded status of the supplemental retirement plans	(4,802,000)	(5,352,000)
Net actuarial loss	$ 408,000
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%
Supplemental Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Cash values of the insurance policies purchased to fund deferred compensation obligations	$ 117,318,000	97,783,000
Unfunded status of the supplemental retirement plans	4,802,000	5,352,000
Accumulated other comprehensive loss	3,382,000	3,102,000
Deferred tax asset	$ 1,420,000	$ 1,582,000

Retirement Plans - Summary of 4

Retirement Plans - Summary of 401(k) Contribution Plan (Detail) - 401(k) Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
401(k) Plan benefits expense	$ 879	$ 776	$ 678
401(k) Plan contributions made by the Company	$ 872	$ 767	$ 811

Retirement Plans - Summary of E

Retirement Plans - Summary of ESOP Activities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
ESOP benefits expense	$ 1,887	$ 2,149	$ 1,831
ESOP contributions made by the Company	$ 1,952	$ 2,073	$ 1,368

Retirement Plans - Schedule of

Retirement Plans - Schedule of Deferred Compensation Earnings Credits Included in Noninterest Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Deferred compensation earnings credits included in noninterest expense	$ 462	$ 478	$ 487

Retirement Plans - Defined Bene

Retirement Plans - Defined Benefit Pension Plans (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Transition obligation	$ 3	$ 4
Prior service cost	(194)	(248)
Net actuarial loss	4,993	5,596
Amount included in accumulated other comprehensive loss	4,802	5,352
Stranded OCI from tax rate change		(668)
Deferred tax benefit	(1,420)	(1,582)
Amount included in accumulated other comprehensive loss, net of tax	$ 3,382	$ 3,102

Retirement Plans - Information

Retirement Plans - Information Pertaining to Activity in Supplemental Retirement Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in benefit obligation:
Benefit obligation at beginning of year	$ (28,472)	$ (26,645)
Service cost	(973)	(941)	$ (1,042)
Interest cost	(949)	(991)	(1,025)
Actuarial (loss)/gain	92	(1,203)
Plan amendments		185
Benefits paid	1,106	1,123
Benefit obligation at end of year	(29,196)	(28,472)	(26,645)
Change in plan assets:
Fair value of plan assets at beginning of year	0	0
Fair value of plan assets at end of year	0	0	$ 0
Funded status	(29,196)	(28,472)
Unrecognized net obligation existing at January 1, 1986	3	4
Unrecognized net actuarial loss	4,993	5,596
Unrecognized prior service cost	(194)	(248)
Accumulated other comprehensive income	(4,802)	(5,352)
Accrued benefit cost	(29,196)	(28,472)
Accumulated benefit obligation	$ (27,544)	$ (26,432)

Retirement Plans - Net Periodic

Retirement Plans - Net Periodic Benefit Cost Recognized for Supplemental Retirement Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net pension cost included the following components:
Service cost-benefits earned during the period	$ 973	$ 941	$ 1,042
Interest cost on projected benefit obligation	949	991	1,025
Amortization of net obligation at transition	2	2	2
Amortization of prior service cost	(54)	(12)	(41)
Recognized net actuarial loss	510	390	549
Net periodic pension cost	$ 2,380	$ 2,312	$ 2,577

Retirement Plans - Assumptions

Retirement Plans - Assumptions Used in Accounting for Plans (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Discount rate used to calculate benefit obligation	3.96%	3.40%	3.80%
Discount rate used to calculate net periodic pension cost	3.40%	3.80%	4.00%
Executive Compensation [Member]
Defined Benefit Plan Disclosure [Line Items]
Average annual increase in compensation	3.25%	3.25%	2.50%
Director Compensation [Member]
Defined Benefit Plan Disclosure [Line Items]
Average annual increase in compensation	0.00%	0.00%	2.50%

Retirement Plans - Expected Ben

Retirement Plans - Expected Benefit Payments to Participants and Estimated Contributions to be Made by Company (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Retirement Benefits [Abstract]
Expected Benefit Payments to Participants, 2019	$ 1,254
Expected Benefit Payments to Participants, 2020	1,668
Expected Benefit Payments to Participants, 2021	2,192
Expected Benefit Payments to Participants, 2022	2,161
Expected Benefit Payments to Participants, 2023	2,153
Expected Benefit Payments to Participants, 2024-2028	10,928
Estimated Company Contributions, 2019	1,254
Estimated Company Contributions, 2020	1,668
Estimated Company Contributions, 2021	2,192
Estimated Company Contributions, 2022	2,161
Estimated Company Contributions, 2023	2,153
Estimated Company Contributions, 2024-2028	$ 10,928

Related Party Transactions - Su

Related Party Transactions - Summary of Activity in Lending Transactions (Detail) - Directors and Officers [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Beginning balance	$ 2,148	$ 2,432
Advances/new loans	8,854	437
Removed/payments	(1,799)	(721)
Ending balance	$ 9,203	$ 2,148

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Related Party Transactions [Abstract]
Bank deposits of directors, officers and other related parties	$ 43,881,000	$ 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	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 1,128,695	$ 742,186
Marketable Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,874	2,938
Obligations of U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	629,981	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	126,072	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	7,098	6,687
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	4,478
Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	354,505
Loans Held For Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	3,687	4,616
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	2,874	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	2,874	2,938
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	1,118,723	732,561
Level 2 [Member] | Obligations of U.S. Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	629,981	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	126,072	123,156
Level 2 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	4,478
Level 2 [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	354,505
Level 2 [Member] | Loans Held For Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	3,687	4,616
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	7,098	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	$ 7,098	$ 6,687

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 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	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 6,687	$ 6,595	$ 7,618
Transfers into (out of) Level 3	0	0	0
Change Included in Earnings	(146)	(718)	(2,184)
Issuances	557	810	1,161
Ending Balance	$ 7,098	$ 6,687	$ 6,595

Fair Value Measurement - Quanti

Fair Value Measurement - Quantitative Information about Recurring Level 3 Fair Value Measurements (Detail) - Mortgage Servicing Rights [Member] $ in Thousands	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgages Servicing Rights, Fair Value	$ 7,098	$ 6,687	$ 6,595	$ 7,618
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	0.050	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	0.12	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	0.273	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	0.13	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	0.076	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	0.12	0.130

Fair Value Measurement - Assets

Fair Value Measurement - Assets and Liabilities Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	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	$ 281	$ 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	1,592	4,984
Total Gains/(Losses)	(302)	(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	281	2,767
Total Gains/(Losses)	(294)	(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	1,311	2,217
Total Gains/(Losses)	(8)	(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	1,592	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	281	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	$ 1,311	$ 2,217

Fair Value Measurement - Quan_2

Fair Value Measurement - Quantitative Information about Level 3 Fair Value Measurements for Financial Instruments Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Impaired Originated & PNCI Loans [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 281	$ 2,767
Foreclosed Assets [Member] | Residential Real Estate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	693	622
Foreclosed Assets [Member] | Commercial Real Estate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value	$ 618	254
Foreclosed Assets [Member] | Land & Construction [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value		$ 1,341
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	(16.30%)	(74.00%)
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	(21.83%)	(47.00%)
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	(65.00%)	(84.00%)
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		(53.00%)
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	35.14%	23.00%
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	7.25%	39.00%
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	20.00%	19.00%
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		283.00%
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	10.45%	(19.76%)
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	(3.75%)	(3.13%)
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	(45.00%)	(84.00%)
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		167.00%

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		Dec. 31, 2018	Dec. 31, 2017
Financial assets:
Cash and due from banks		$ 119,781	$ 105,968
Cash at Federal Reserve and other banks		107,752	99,460
Securities held to maturity		444,936	514,844
Financial liabilities:
Other borrowings		15,839	122,166
Junior subordinated debt		57,042	56,858
Level 3 [Member] | Overdraft Privilege Commitments [Member]
Off-balance sheet:
Contract amount, Off-balance sheet		111,956	98,260
Level 3 [Member] | Standby Letters of Credit [Member]
Off-balance sheet:
Contract amount, Off-balance sheet		11,346	13,075
Level 3 [Member] | Commitments [Member]
Off-balance sheet:
Contract amount, Off-balance sheet		1,192,054	933,542
Fair Value [Member] | Level 3 [Member]
Financial assets:
Loans, net	[1]	4,006,986	2,992,225
Financial liabilities:
Junior subordinated debt		62,610	58,466
Fair Value [Member] | Level 3 [Member] | Overdraft Privilege Commitments [Member]
Off-balance sheet:
Fair value, Off-balance sheet		1,120	983
Fair Value [Member] | Level 3 [Member] | Standby Letters of Credit [Member]
Off-balance sheet:
Fair value, Off-balance sheet		113	131
Fair Value [Member] | Level 3 [Member] | Commitments [Member]
Off-balance sheet:
Fair value, Off-balance sheet		11,921	9,335
Fair Value [Member] | Level 1 [Member]
Financial assets:
Cash and due from banks		119,781	105,968
Cash at Federal Reserve and other banks		107,752	99,460
Fair Value [Member] | Level 2 [Member]
Financial assets:
Securities held to maturity		437,370	518,165
Financial liabilities:
Deposits		5,362,173	4,006,620
Other borrowings		15,839	122,166
Carrying Amount [Member] | Level 3 [Member]
Financial assets:
Loans, net	[1]	3,989,432	2,984,842
Financial liabilities:
Junior subordinated debt		57,042	56,858
Carrying Amount [Member] | Level 1 [Member]
Financial assets:
Cash and due from banks		119,781	105,968
Cash at Federal Reserve and other banks		107,752	99,460
Carrying Amount [Member] | Level 2 [Member]
Financial assets:
Securities held to maturity		444,936	514,844
Restricted equity securities		17,250	16,956
Financial liabilities:
Deposits		5,366,466	4,009,131
Other borrowings		$ 15,839	$ 122,166
[1]	The estimated fair value of loans for December 31, 2018 reflects an exit price assumption. The December 31, 2017 fair value estimate is not based on an exit price assumption.

TriCo Bancshares Condensed Fi_3

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents	$ 227,533	$ 205,428
Other assets	65,986	55,051
Total assets	6,352,441	4,761,315
Liabilities and shareholders' equity
Other liabilities	83,724	66,422
Junior subordinated debt	57,042	56,858
Total liabilities	5,525,068	4,255,507
Shareholders' equity:
Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at December 31, 2018 and 2017
Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 30,417,223 and 22,955,963 shares at December 31, 2018 and 2017, respectively	541,762	255,836
Retained earnings	303,490	255,200
Accumulated other comprehensive loss, net	(17,879)	(5,228)
Total shareholders' equity	827,373	505,808	$ 477,347	$ 452,116
Total liabilities and shareholders' equity	6,352,441	4,761,315
Parent [Member]
Assets
Cash and cash equivalents	2,374	3,924
Investment in Tri Counties Bank	880,907	557,538
Other assets	1,723	1,721
Total assets	885,004	563,183
Liabilities and shareholders' equity
Other liabilities	589	517
Junior subordinated debt	57,042	56,858
Total liabilities	57,631	57,375
Shareholders' equity:
Preferred stock, no par value: 1,000,000 shares authorized, zero issued and outstanding at December 31, 2018 and 2017
Common stock, no par value: authorized 50,000,000 shares; issued and outstanding 30,417,223 and 22,955,963 shares at December 31, 2018 and 2017, respectively	541,762	255,836
Retained earnings	303,490	255,200
Accumulated other comprehensive loss, net	(17,879)	(5,228)
Total shareholders' equity	827,373	505,808
Total liabilities and shareholders' equity	$ 885,004	$ 563,183

TriCo Bancshares Condensed Fi_4

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Balance Sheets (Parenthetical) (Detail) - $ / shares	Dec. 31, 2018	Dec. 31, 2017	Aug. 21, 2007
Condensed Financial Statements, Captions [Line Items]
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, par value	$ 0	$ 0
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	30,417,223	22,955,963
Common stock, shares outstanding	30,417,223	22,955,963	15,814,662
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
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, par value	$ 0	$ 0
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	30,417,223	22,955,963
Common stock, shares outstanding	30,417,223	22,955,963

TriCo Bancshares Condensed Fi_5

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Interest expense	$ (4,063)	$ (4,065)	$ (2,609)	$ (2,135)	$ (1,868)	$ (1,829)	$ (1,610)	$ (1,491)	$ (12,872)	$ (6,798)	$ (5,721)
Income before income taxes	30,545	22,646	20,811	19,350	17,818	19,027	21,236	19,431	93,352	77,512	72,523
Equity in net income of Tri Counties Bank:
Income tax benefit	(7,334)	(6,476)	(5,782)	(5,440)	(14,829)	(7,130)	(7,647)	(7,352)	(25,032)	(36,958)	(27,712)
Net income	$ 23,211	$ 16,170	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	68,320	40,554	44,811
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Interest expense									(3,131)	(2,535)	(2,229)
Administration expense									(1,489)	(915)	(725)
Income before income taxes									(4,620)	(3,450)	(2,954)
Equity in net income of Tri Counties Bank:
Distributed									26,432	19,236	16,758
Undistributed									45,315	23,359	29,764
Income tax benefit									1,193	1,409	1,243
Net income									$ 68,320	$ 40,554	$ 44,811

TriCo Bancshares Condensed Fi_6

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net income	$ 23,211	$ 16,170	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	$ 68,320	$ 40,554	$ 44,811
Other comprehensive income (loss), net of tax:
Increase (decrease) in unrealized gains on available for sale securities arising during the period									(12,434)	3,165	(6,384)
Change in minimum pension liability									388	(370)	592
Change in joint beneficiary agreement liablity									426	(110)	(343)
Other comprehensive income (loss)									(11,620)	2,685	(6,135)
Comprehensive income									56,700	43,239	38,676
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net income									68,320	40,554	44,811
Other comprehensive income (loss), net of tax:
Increase (decrease) in unrealized gains on available for sale securities arising during the period									(12,434)	3,165	(6,384)
Change in minimum pension liability									388	(370)	592
Change in joint beneficiary agreement liablity									426	(110)	(343)
Other comprehensive income (loss)									(11,620)	2,685	(6,135)
Comprehensive income									$ 56,700	$ 43,239	$ 38,676

TriCo Bancshares Condensed Fi_7

TriCo Bancshares Condensed Financial Statements (Parent Only) - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities:
Net income	$ 68,320	$ 40,554	$ 44,811
Adjustments to reconcile net income to net cash provided by operating activities:
Equity compensation vesting expense	1,462	1,586	1,467
Net cash from operating activities	91,069	55,381	48,226
Financing activities:
Issuance of common stock through option exercise	218	396	518
Equity compensation tax effect			155
Repurchase of common stock	(2,483)	(1,629)	(1,890)
Cash dividends paid - common	(18,769)	(15,131)	(13,695)
Net cash from financing activities	73,039	201,880	93,316
Net change in cash and cash equivalents	22,105	(100,184)	2,151
Cash and cash equivalents at beginning of year	205,428	305,612	303,461
Cash and cash equivalents at end of year	227,533	205,428	305,612
Parent [Member]
Operating activities:
Net income	68,320	40,554	44,811
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed equity in earnings of Tri Counties Bank	(45,315)	(23,359)	(29,764)
Equity compensation vesting expense	1,462	1,586	1,467
Equity compensation tax effect			(155)
Net change in other assets and liabilities	(4,983)	(1,295)	(1,210)
Net cash from operating activities	19,484	17,486	15,149
Financing activities:
Issuance of common stock through option exercise	218	396	518
Equity compensation tax effect			155
Repurchase of common stock	(2,483)	(1,629)	(1,890)
Cash dividends paid - common	(18,769)	(15,131)	(13,695)
Net cash from financing activities	(21,034)	(16,364)	(14,912)
Net change in cash and cash equivalents	(1,550)	1,122	237
Cash and cash equivalents at beginning of year	3,924	2,802	2,565
Cash and cash equivalents at end of year	$ 2,374	$ 3,924	$ 2,802

Regulatory Matters - Actual and

Regulatory Matters - Actual and Required Capital Ratios of Bank (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Parent [Member]
Schedule of Capitalization [Line Items]
Total Capital (to Risk Weighted Assets), Actual, Amount	$ 682,419	$ 528,805
Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	647,262	495,318
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	591,933	440,643
Tier 1 Capital (to Average Assets), Actual, Amount	$ 647,262	$ 495,318
Total Capital (to Risk Weighted Assets), Actual, Ratio	14.40%	14.07%
Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	13.66%	13.18%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	12.49%	11.72%
Tier 1 Capital (to Average Assets), Actual, Ratio	10.68%	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	$ 467,874	$ 347,694
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	373,115	272,517
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	302,045	216,134
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$ 242,452	$ 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	$ 497,486	$ 394,679
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	402,727	319,502
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	331,658	263,120
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$ 242,452	$ 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	$ 680,624	$ 525,384
Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	645,467	491,897
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual, Amount	645,467	491,897
Tier 1 Capital (to Average Assets), Actual, Amount	$ 645,467	$ 491,897
Total Capital (to Risk Weighted Assets), Actual, Ratio	14.37%	13.98%
Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	13.63%	13.09%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual, Ratio	13.63%	13.09%
Tier 1 Capital (to Average Assets), Actual, Ratio	10.65%	10.73%
Total Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 473,624	$ 375,713
Tier 1 Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	378,899	300,570
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	307,856	244,214
Tier 1 Capital (to Average Assets), Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 303,059	$ 229,243
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%
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	$ 467,704	$ 347,535
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	372,979	272,392
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	301,935	216,035
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$ 242,447	$ 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	$ 497,305	$ 394,499
Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	402,581	319,356
Common Equity Tier 1 Capital (to Risk Weighted Assets), Minimum Capital Requirement, Amount	331,537	262,999
Tier 1 Capital (to Average Assets), Minimum Capital Requirement, Amount	$ 242,447	$ 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	Dec. 31, 2018	Dec. 31, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Increase in risk-based capital ratios		0.625%
Capital conservation buffer ratio		1.875%	1.25%
Scenario, Forecast [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Minimum capital level requirements, Common equity tier 1 capital ratio	7.00%
Minimum capital level requirements, Common equity tier 1 capital ratio	8.50%
Minimum capital level requirements, Total capital ratio	10.50%

Summary of Quarterly Results _3

Summary of Quarterly Results of Operations (Unaudited) - Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans:
Discount accretion	$ 1,982	$ 2,098	$ 559	$ 632	$ 1,489	$ 1,364	$ 2,170	$ 1,541
All other loan interest income	53,680	51,004	38,745	37,417	36,705	35,904	34,248	33,373
Total loan interest income	55,662	53,102	39,304	38,049	38,194	37,268	36,418	34,914	$ 186,117	$ 146,794	$ 141,086
Debt securities, dividends and interest bearing cash at banks	12,403	11,452	9,174	9,072	8,767	8,645	8,626	8,570
Total interest and dividend income	68,065	64,554	48,478	47,121	46,961	45,913	45,044	43,484	228,218	181,402	173,708
Interest expense	4,063	4,065	2,609	2,135	1,868	1,829	1,610	1,491	12,872	6,798	5,721
Net interest income	64,002	60,489	45,869	44,986	45,093	44,084	43,434	41,993	215,346	174,604	167,987
Provision for (benefit from reversal of provision for) loan losses	806	2,651	(638)	(236)	1,677	765	(796)	(1,557)	2,583	89	(5,970)
Net interest income after provision for loan losses	63,196	57,838	46,507	45,222	43,416	43,319	44,230	43,550	212,763	174,515	173,957
Noninterest income	12,634	12,186	12,174	12,290	12,478	12,930	12,910	11,703	49,284	50,021	44,563
Noninterest expense	45,285	47,378	37,870	38,162	38,076	37,222	35,904	35,822	168,695	147,024	145,997
Income before income taxes	30,545	22,646	20,811	19,350	17,818	19,027	21,236	19,431	93,352	77,512	72,523
Income tax expense	7,334	6,476	5,782	5,440	14,829	7,130	7,647	7,352	25,032	36,958	27,712
Net income	$ 23,211	$ 16,170	$ 15,029	$ 13,910	$ 2,989	$ 11,897	$ 13,589	$ 12,079	$ 68,320	$ 40,554	$ 44,811
Per common share:
Net income (diluted)	$ 0.76	$ 0.53	$ 0.65	$ 0.60	$ 0.13	$ 0.51	$ 0.58	$ 0.52	$ 2.54	$ 1.74	$ 1.94
Dividends	$ 0.19	$ 0.17	$ 0.17	$ 0.17	$ 0.17	$ 0.17	$ 0.17	$ 0.15