Westamerica Bancorporation (WABC) 10-K 28 Feb 19 2018 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 20, 2019	Jun. 30, 2018
Document Information [Line Items]
Entity Registrant Name	WESTAMERICA BANCORPORATION
Entity Central Index Key	311,094
Trading Symbol	wabc
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding (in shares)		26,889,495
Entity Public Float			$ 1,072,647,598
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Shell Company	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets:
Cash and due from banks	$ 420,284	$ 575,002
Equity securities	1,747	1,800
Debt securities available for sale	2,654,670	2,191,707
Debt securities held to maturity, with fair values of: $971,445 at December 31, 2018 and $1,155,342 at December 31, 2017	984,609	1,158,864
Loans	1,207,202	1,287,982
Allowance for loan losses	(21,351)	(23,009)
Loans, net of allowance for loan losses	1,185,851	1,264,973
Other real estate owned	350	1,426
Premises and equipment, net	34,507	35,301
Identifiable intangibles, net	1,929	3,850
Goodwill	121,673	121,673
Other assets	162,906	158,450
Total Assets	5,568,526	5,513,046
Liabilities:
Noninterest-bearing deposits	2,243,251	2,197,526
Interest-bearing deposits	2,623,588	2,630,087
Total deposits	4,866,839	4,827,613
Short-term borrowed funds	51,247	58,471
Other liabilities	34,849	36,723
Total Liabilities	4,952,935	4,922,807
Contingencies (Note 13)
Shareholders' Equity:
Common stock (no par value), authorized - 150,000 shares Issued and outstanding: 26,730 at December 31, 2018 and 26,425 at December 31, 2017	448,351	431,734
Deferred compensation	1,395	1,533
Accumulated other comprehensive loss	(39,996)	(16,832)
Retained earnings	205,841	173,804
Total Shareholders' Equity	615,591	590,239
Total Liabilities and Shareholders' Equity	$ 5,568,526	$ 5,513,046

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Thousands, $ / shares in Thousands, $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt securities held to maturity, fair values	$ 971,445	$ 1,155,342
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, authorized (in shares)	150,000	150,000
Common stock, issued (in shares)	26,730	26,425
Common stock, outstanding (in shares)	26,730	26,425

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest and Loan Fee Income:
Loans	$ 59,030	$ 61,740	$ 69,139
Equity securities	354	293	267
Debt securities available for sale	60,383	44,371	34,009
Debt securities held to maturity	24,031	27,432	30,636
Interest bearing cash	7,925	4,476	1,868
Total Interest and Loan Fee Income	151,723	138,312	135,919
Interest Expense:
Deposits	1,922	1,856	2,077
Short-term borrowed funds	37	44	39
Total Interest Expense	1,959	1,900	2,116
Net Interest and Loan Fee Income	149,764	136,412	133,803
Reversal of Provision for Loan Losses		(1,900)	(3,200)
Net Interest and Loan Fee Income After Reversal of Provision For Loan Losses	149,764	138,312	137,003
Noninterest Income:
Life insurance gains	585
Equity securities (losses) gains	(52)	7,955
Other noninterest income	4,079	5,506	4,817
Total Noninterest Income	48,149	56,628	46,574
Noninterest Expense:
Salaries and related benefits	53,007	51,519	51,507
Occupancy and equipment	19,679	19,430	19,017
Outsourced data processing services	9,229	9,035	8,505
Loss contingency	3,500	5,542	3
Professional fees	2,842	2,161	3,980
Amortization of identifiable intangibles	1,921	3,077	3,504
Courier service	1,779	1,732	1,952
Impairment of tax credit investments		625
Other noninterest expense	14,959	14,647	15,152
Total Noninterest Expense	106,916	107,768	103,620
Income Before Income Taxes	90,997	87,172	79,957
Provision for income taxes	19,433	37,147	21,104
Net Income	$ 71,564	$ 50,025	$ 58,853
Average Common Shares Outstanding (in shares)	26,649	26,291	25,612
Diluted Average Common Shares Outstanding (in shares)	26,756	26,419	25,678
Per Common Share Data:
Basic earnings (in dollars per share)	$ 2.69	$ 1.90	$ 2.30
Diluted earnings (in dollars per share)	2.67	1.89	2.29
Dividends paid (in dollars per share)	$ 1.60	$ 1.57	$ 1.56
Deposit Account [Member]
Noninterest Income:
Noninterest income revenue	$ 18,508	$ 19,612	$ 20,854
Credit Card, Merchant Discount [Member]
Noninterest Income:
Noninterest income revenue	9,630	8,426	6,377
Debit Card [Member]
Noninterest Income:
Noninterest income revenue	6,643	6,421	6,290
Fiduciary and Trust [Member]
Noninterest Income:
Noninterest income revenue	2,938	2,875	2,686
ATM Processing Fees [Member]
Noninterest Income:
Noninterest income revenue	2,752	2,610	2,411
Financial Service, Other [Member]
Noninterest Income:
Noninterest income revenue	2,567	2,584	2,571
Financial Services Commission [Member]
Noninterest Income:
Noninterest income revenue	$ 499	$ 639	$ 568

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Income	$ 71,564	$ 50,025	$ 58,853
Other comprehensive loss:
Changes in net unrealized losses on debt securities available for sale	(27,939)	(3,767)	(18,610)
Deferred tax benefit	8,258	1,585	7,825
Reclassification of gains included in net income		(7,955)
Deferred tax expense on gains included in net income		3,345
Changes in unrealized losses on debt securities available for sale, net of tax	(19,681)	(6,792)	(10,785)
Post-retirement benefit transition obligation amortization		59	61
Deferred tax expense		(25)	(25)
Post-retirement benefit transition obligation amortization, net of tax		34	36
Total Other Comprehensive Loss	(19,681)	(6,758)	(10,749)
Total Comprehensive Income	$ 51,883	$ 43,267	$ 48,104

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Accumulated Deferred Compensation [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2015	25,528,000
Balance at Dec. 31, 2015	$ 378,858	$ 2,578	$ 675	$ 150,094	$ 532,205
Net income for the period				58,853	58,853
Other comprehensive loss			(10,749)		(10,749)
Exercise of stock options (in shares)	499,000
Exercise of stock options	$ 24,031				24,031
Tax benefit increase upon exercise and expiration of stock options	$ 394				394
Restricted stock activity (in shares)	15,000
Restricted stock activity	$ 1,798	(1,045)			753
Stock based compensation	$ 1,494				1,494
Stock awarded to employees (in shares)	2,000
Stock awarded to employees	$ 90				90
Retirement of common stock (in shares)	(137,000)
Retirement of common stock	$ (2,059)			(3,721)	(5,780)
Dividends				(39,924)	(39,924)
Other comprehensive loss			(10,749)		(10,749)
Balance (in shares) at Dec. 31, 2016	25,907,000
Balance at Dec. 31, 2016	$ 404,606	1,533	(10,074)	165,302	561,367
Net income for the period				50,025	50,025
Other comprehensive loss			(6,758)		$ (6,758)
Exercise of stock options (in shares)	509,000				509,000
Exercise of stock options	$ 24,583				$ 24,583
Restricted stock activity (in shares)	13,000
Restricted stock activity	$ 707				707
Stock based compensation	$ 1,824				1,824
Stock awarded to employees (in shares)	2,000
Stock awarded to employees	$ 104				104
Retirement of common stock (in shares)	(6,000)
Retirement of common stock	$ (90)			(224)	(314)
Dividends				(41,299)	(41,299)
Other comprehensive loss			(6,758)		(6,758)
Balance (in shares) at Dec. 31, 2017	26,425,000
Balance at Dec. 31, 2017	$ 431,734	1,533	(16,832)	173,804	590,239
Net income for the period				71,564	$ 71,564
Exercise of stock options (in shares)	292,000				292,000
Exercise of stock options	$ 13,373				$ 13,373
Restricted stock activity (in shares)	20,000
Restricted stock activity	$ 1,281	(138)			1,143
Stock based compensation	$ 1,988				1,988
Stock awarded to employees (in shares)	2,000
Stock awarded to employees	$ 124				124
Retirement of common stock (in shares)	(9,000)
Retirement of common stock	$ (149)			(375)	(524)
Dividends				(42,635)	(42,635)
Cumulative effect of equity securities losses reclassified at Dec. 31, 2017			142	(142)
Balance at Dec. 31, 2017	$ 431,734	1,533	(16,690)	173,662	590,239
Reclass stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017			(3,625)	3,625
Other comprehensive loss			(19,681)		(19,681)
Balance (in shares) at Dec. 31, 2018	26,730,000
Balance at Dec. 31, 2018	$ 448,351	$ 1,395	$ (39,996)	$ 205,841	$ 615,591

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retained Earnings [Member]
Dividends per share (in dollars per share)	$ 1.60	$ 1.57	$ 1.56

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net income		$ 71,564	$ 50,025	$ 58,853
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization/accretion		24,402	26,082	19,939
Reversal of Provision for Loan Losses			(1,900)	(3,200)
Net amortization of deferred loan fees		(203)	(46)	(340)
Increase in interest income receivable		(2,277)	(2,068)	(1,316)
(Increase) decrease in net deferred tax asset		(943)	27,018	4,380
Increase in other assets		(4,017)	(1,732)	(3,321)
Stock option compensation expense		1,988	1,824	1,494
Tax benefit increase upon exercise and expiration of stock options				(394)
Increase (decrease) in income taxes payable		7,554	(6,650)	(40)
Decrease in interest expense payable		(27)	(31)	(52)
(Decrease) increase in other liabilities		(580)	(3,016)	2,026
Life insurance gains		(585)
Equity securities losses		52
Gain on sale of other assets			(1,004)
Gain on sale of securities			(7,955)
(Gain) loss on disposal of premises and equipment		(216)	60	30
Net (gain) loss on sale of or write-down of foreclosed assets		(83)	147	(422)
Net Cash Provided by Operating Activities		96,629	80,754	77,637
Investing Activities:
Net repayments of loans		80,985	66,065	183,506
Net payments under FDIC(1) indemnification agreements	[1]		(63)	(127)
Proceeds from life insurance		1,169
Purchases of debt securities available for sale		(854,555)	(635,814)	(1,080,959)
Proceeds from sale/maturity/calls of debt securities available for sale		353,327	319,324	737,625
Purchases of debt securities held to maturity				(246,956)
Proceeds from maturity/calls of debt securities held to maturity		167,029	178,429	204,054
Purchases of premises and equipment		(3,123)	(2,720)	(1,818)
Proceeds from sale of premises and equipment		446
Proceeds from sale of foreclosed assets		1,159	1,521	7,412
Net Cash Used in Investing Activities		(253,563)	(73,258)	(197,263)
Financing Activities:
Net change in deposits		39,226	122,872	164,082
Net change in short-term borrowings		(7,224)	(607)	6,050
Exercise of stock options		13,373	24,583	24,031
Taxes paid by withholding shares for tax purposes				(356)
Tax benefit increase upon exercise and expiration of stock options				394
Retirement of common stock		(524)	(314)	(5,424)
Common stock dividends paid		(42,635)	(41,299)	(39,924)
Net Cash Provided by Financing Activities		2,216	105,235	148,853
Net Change In Cash and Due from Banks		(154,718)	112,731	29,227
Cash and Due from Banks at Beginning of Period		575,002	462,271	433,044
Cash and Due from Banks at End of Period		420,284	575,002	462,271
Supplemental disclosure of noncash activities:
Loan collateral transferred to other real estate owned				821
Supplemental disclosure of cash flow activities:
Interest paid for the period		1,932	1,931	2,202
Income tax payments for the period		$ 13,627	$ 17,351	$ 19,264
[1]	Federal Deposit Insurance Corporation ("FDIC")

Note 1 - Business and Accountin

Note 1 - Business and Accounting Policies	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Note 1: Westamerica Bancorporation, a registered bank holding company (the “Company”), provides a full range of banking services to corporate and individual customers in Northern and Central California through its wholly-owned subsidiary bank, Westamerica Bank (the “Bank”). The Bank is subject to competition from both financial and nonfinancial institutions and to the regulations of certain agencies and undergoes periodic examinations by those regulatory authorities. All of the financial service operations are considered by management to be aggregated in one The Company has evaluated events and transactions subsequent to the balance sheet date. Based on this evaluation, the Company is not Summary of Significant Accounting Policies The consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States of America. The following is a summary of significant policies used in the preparation of the accompanying financial statements. Accounting Estimates. Certain accounting policies underlying the preparation of these financial statements require Management to make estimates, assumptions, and judgments that affect the amounts reported in the financial statements and accompanying notes. These estimates, assumptions, and judgments are based on information available as of the date of the financial statements; accordingly, as this information changes, the financial statements could reflect different estimates, assumptions, and judgments and as such have a greater possibility of producing results that could be materially different than originally reported. Estimates, assumptions, and judgments are necessary when assets and liabilities are required to be recorded at fair value, when a decline in fair value of an asset not third may 2019 Principles of Consolidation. The consolidated financial statements include the accounts of the Company and all the Company’s subsidiaries. Significant intercompany transactions have been eliminated in consolidation. The Company does not Cash. Cash includes Due From Banks balances which are readily convertible to known amounts of cash and are generally 90 Equity Securities. Equity securities consist of marketable equity securities and mutual funds which are recorded at fair value. Unrealized gains and losses are included in net income effective January 1, 2018 Debt Securities. Debt securities consist of securities of the U.S. Treasury, government sponsored entities, states, counties, municipalities, corporations, agency and non-agency mortgage-backed securities and asset-backed securities. Securities transactions are recorded on a trade date basis. The Company classifies its debt securities in one three not The Company utilizes third 1 2 third one third third not 3 A decline in the market value of any available for sale or held to maturity security below amortized cost that is deemed other than temporary results in a charge to earnings and the establishment of a new cost basis for the security. Unrealized investment securities losses are evaluated at least quarterly to determine whether such declines in value should be considered “other than temporary” and therefore be subject to immediate loss recognition in income. Although these evaluations involve significant judgment, an unrealized loss in the fair value of a debt security is generally deemed to be temporary when the fair value of the security is below the carrying value primarily due to changes in risk-free interest rates, there has not not not not may The Company follows the guidance issued by the Board of Governors of the Federal Reserve System, “Investing in Securities without Reliance on Nationally Recognized Statistical Rating Agencies” (SR 12 15 Purchase premiums are amortized and purchase discounts are accreted over the estimated life of the related investment security as an adjustment to yield using the effective interest method. Unamortized premiums, unaccreted discounts, and early payment premiums are recognized as a component of gain or loss on sale upon disposition of the related security. Interest and dividend income are recognized when earned. Realized gains and losses from the sale of available for sale securities are included in earnings using the specific identification method. Nonmarketable Equity Securities. Nonmarketable equity securities include securities that are not Loans. Loans are stated at the principal amount outstanding, net of unearned discount and unamortized deferred fees and costs. Interest is accrued daily on the outstanding principal balances. Loans which are more than 90 120 The Company evaluates all classified loans and nonaccrual loans with outstanding principal balances in excess of $500 310 40, not Nonrefundable fees and certain costs associated with originating or acquiring loans are deferred and amortized as an adjustment to interest income over the contractual loan lives. Upon prepayment, unamortized loan fees, net of costs, are immediately recognized in interest income. Other fees, including those collected upon principal prepayments, are included in interest income when received. Loans held for sale are identified upon origination and are reported at the lower of cost or market value on an aggregate loan basis. Purchased Loans. Purchased loans are recorded at estimated fair value on the date of purchase. Impaired purchased loans are accounted for under FASB ASC 310 30, not may 310 30. 310 30 not 310 30 Covered Loans. Loans covered under loss-sharing or similar credit protection agreements with the FDIC are reported in loans exclusive of the expected reimbursement cash flows from the FDIC. Covered loans are initially recorded at fair value at the acquisition date. Subsequent decreases in the amount expected to be collected results in a provision for loan losses and a corresponding increase in the estimated FDIC reimbursement, with the estimated net loss impacting earnings. Interest previously accrued on covered loans placed on nonaccrual status is charged against interest income, net of estimated FDIC reimbursements of such accrued interest. The FDIC reimburses the Company up to 80% 90 February 6, 2019. Allowance for Credit Losses. The Company extends loans to commercial and consumer customers primarily in Northern and Central California. These lending activities expose the Company to the risk borrowers will default, causing loan losses. The Company’s lending activities are exposed to various qualitative risks. All loan segments are exposed to risks inherent in the economy and market conditions. Significant risk characteristics related to the commercial loan segment include the borrowers’ business performance and financial condition, and the value of collateral for secured loans. Significant risk characteristics related to the commercial real estate segment include the borrowers’ business performance and the value of properties collateralizing the loans. Significant risk characteristics related to the construction loan segment include the borrowers’ performance in successfully developing the real estate into the intended purpose and the value of the property collateralizing the loans. Significant risk characteristics related to the residential real estate segment include the borrowers’ financial wherewithal to service the mortgages and the value of the property collateralizing the loans. Significant risk characteristics related to the consumer loan segment include the financial condition of the borrowers and the value of collateral securing the loans. The preparation of these financial statements requires Management to estimate the amount of probable incurred losses inherent in the loan portfolio and establish an allowance for credit losses. In estimating credit losses, Management must exercise significant judgment in evaluating information deemed relevant. The amount of ultimate losses on the loan portfolio can vary from the estimated amounts. Management follows a systematic methodology to estimate loss potential in an effort to reduce the differences between estimated and actual losses. The allowance for credit losses is established through provisions for credit losses charged to income. Losses on loans, including impaired loans, are charged to the allowance for loan losses when all or a portion of the recorded amount of a loan is deemed to be uncollectible. Recoveries of loans previously charged off are credited to the allowance when realized. The Company’s allowance for credit losses is maintained at a level considered adequate to provide for losses that can be estimated based upon specific and general conditions. These include conditions unique to individual borrowers, as well as overall credit loss experience, the amount of past due, nonperforming and classified loans, recommendations of regulatory authorities, prevailing economic conditions, FDIC loss-sharing or similar credit protection agreements and other factors. A portion of the allowance is specifically allocated to impaired loans whose full collectability is uncertain. Such allocations are determined by Management based on loan-by-loan analyses. The Company evaluates all classified loans and nonaccrual loans with outstanding principal balances in excess of $500 second not not not not Liability for Off-Balance Sheet Credit Exposures. A liability for off-balance sheet credit exposures is established through expense recognition. Off-balance sheet credit exposures relate to letters of credit and unfunded loan commitments for commercial, construction and consumer loans. Historical credit loss factors for commercial, construction and consumer loans are applied to the amount of these off-balance sheet credit exposures to estimate inherent losses. Other Real Estate Owned. Other real estate owned is comprised of property acquired through foreclosure proceedings, acceptances of deeds-in-lieu of foreclosure and, if applicable, vacated bank properties. Losses recognized at the time of acquiring property in full or partial satisfaction of debt are charged against the allowance for credit losses. Other real estate owned is recorded at the fair value of the collateral, generally based upon an independent property appraisal, less estimated disposition costs. Losses incurred subsequent to acquisition due to any decline in annual independent property appraisals are recognized as noninterest expense. Routine holding costs, such as property taxes, insurance and maintenance, and losses from sales and dispositions, are recognized as noninterest expense. Premises and Equipment. Premises and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is computed substantially on the straight-line method over the estimated useful life of each type of asset. Estimated useful lives of premises and equipment range from 20 50 3 20 Revenue Recognition. The Company recognizes revenue as it is earned based on contractual terms, as transactions occur, or as services are provided and collectability is reasonably assured. In certain circumstances, noninterest income is reported net of associated expenses that are directly related to variable volume-based sales or revenue sharing arrangements or when the Company acts on an agency basis for others. Life Insurance Cash Surrender Value. The Company has purchased life insurance policies on certain directors and officers as well as acquired such assets as part of the acquisition of other banks. 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. These assets are included in other assets on the consolidated balance sheets. Intangible Assets. Intangible assets are comprised of goodwill, core deposit intangibles and other identifiable intangibles acquired in business combinations. Intangible assets with definite useful lives are amortized on an accelerated basis over their respective estimated useful lives not 15 may not not first 2011 08, Testing for Goodwill Impairment. first Impairment of Long-Lived Assets. The Company reviews its long-lived and certain intangible assets for impairment whenever events or changes indicate that the carrying amount of an asset may not Income Taxes. The Company and its subsidiaries file consolidated tax returns. The Company accounts for income taxes in accordance with FASB ASC 740, two not. not fifty Stock Options. The Company applies FASB ASC 718 no Extinguishment of Debt. Gains and losses, including fees, incurred in connection with the early extinguishment of debt are charged to current earnings as reductions in noninterest income. Postretirement Benefits. The Company uses an actuarial-based accrual method of accounting for post-retirement benefits. Other. Securities and other property held by the Bank in a fiduciary or agency capacity are not not Recently Adopted Accounting Standards In 2018, FASB Accounting Standard Update (ASU) 2014 09 Revenue (Topic 606 May 2014. not 606 not All of the Company’s net interest income and a portion of its noninterest income are out of scope of the guidance. The contracts that are in scope of the guidance are primarily related to service charges and fees on deposit accounts, merchant processing fees, debit card fees, ATM processing fees, trust fees and other service charges, commissions and fees. The Company’s revenue recognition practices within the scope of the ASU as described below did not Service Charges on Deposit Accounts, ATM Processing Fees and Other Service Fees Merchant Processing Services and Debit Card Fees Trust Fees Gains/Losses on Sales of OREO not $110 $72 $1,185 twelve December 31, 2018 2017 2016, The Company adopted the ASU on January 1, 2018 no FASB ASU 2016 01 Financial Instruments – Overall (Subtopic 825 10 January 2016. 11 The Company was required to adopt the ASU provisions on January 1, 2018, not January 1, 2018, $142 FASB ASU 2018 02 Income Statement – Reporting Comprehensive Income (Topic 220 February 2018. 2017 2017. January 1, 2018, $3,625 Recently Issued Accounting Standards FASB ASU 2016 02, Leases (Topic 842 February 25, 2016. January 1, 2019, $15.3 $15.3 not FASB ASU 2016 13, Financial Instruments – Credit Losses (Topic 326 June 16, 2016. The Company will be required to adopt the ASU provisions on January 1, 2020. September 30, 2019. FASB ASU 2017 08 Receivables – Non-Refundable Fees and Other Costs (Subtopic 310 20 March 2017. not January 1, 2019. $3.1 $2.8 not FASB ASU 2017 12 Derivatives and Hedging (Topic 815 August 2017. one The Company will be required to adopt the ASU provisions on January 1, 2019. not may not one FASB ASU 2018 13 Fair Value Measurements (Topic 820 August 2018. The provisions of the ASU are effective January 1, 2020 11 January 1, 2020. not

Note 2 - Investment Securities

Note 2 - Investment Securities	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]	Note 2: Effective January 1, 2018, 2016 01, $1,800 $ 142 At December 31, 2018, $1,747 twelve December 31, 2018, $52 An analysis of the amortized cost and fair value by major categories of debt securities available for sale, which are carried at fair value with net unrealized gains (losses) reported on an after-tax basis as a component of cumulative other comprehensive income, and debt securities held to maturity, which are carried at amortized cost, follows: Amortized Gross Gross Fair At December 31, 2018 (In thousands) Debt securities available for sale U.S. Treasury securities $ 139,572 $ 5 $ (3 ) $ 139,574 Securities of U.S. Government sponsored entities 167,228 65 (3,275 ) 164,018 Agency residential mortgage-backed securities (MBS) 883,715 595 (30,439 ) 853,871 Non-agency residential MBS 113 1 - 114 Agency commercial MBS 1,869 - (27 ) 1,842 Securities of U.S. Government entities 1,128 - (9 ) 1,119 Obligations of states and political subdivisions 180,220 1,856 (2,985 ) 179,091 Corporate securities 1,337,608 1,075 (23,642 ) 1,315,041 Total debt securities available for sale 2,711,453 3,597 (60,380 ) 2,654,670 Debt securities held to maturity Agency residential MBS 447,332 249 (14,129 ) 433,452 Non-agency residential MBS 3,387 40 - 3,427 Obligations of states and political subdivisions 533,890 3,403 (2,727 ) 534,566 Total debt securities held to maturity 984,609 3,692 (16,856 ) 971,445 Total $ 3,696,062 $ 7,289 $ (77,236 ) $ 3,626,115 Amortized Gross Gross Fair At December 31, 2017 (In thousands) Debt securities available for sale Securities of U.S. Government sponsored entities $ 122,285 $ 1 $ (2,967 ) $ 119,319 Agency residential MBS 787,679 522 (20,495 ) 767,706 Non-agency residential MBS 153 1 - 154 Agency commercial MBS 2,244 - (25 ) 2,219 Securities of U.S. Government entities 1,612 - (22 ) 1,590 Obligations of states and political subdivisions 182,907 3,796 (1,482 ) 185,221 Corporate securities 1,123,671 1,104 (9,277 ) 1,115,498 Total debt securities available for sale 2,220,551 5,424 (34,268 ) 2,191,707 Debt securities held to maturity Agency residential MBS 545,883 606 (9,850 ) 536,639 Non-agency residential MBS 4,462 70 - 4,532 Agency commercial MBS 9,041 - (66 ) 8,975 Obligations of states and political subdivisions 599,478 7,736 (2,018 ) 605,196 Total debt securities held to maturity 1,158,864 8,412 (11,934 ) 1,155,342 Total $ 3,379,415 $ 13,836 $ (46,202 ) $ 3,347,049 The amortized cost and fair value of debt At December 31, 2018 Debt Securities Available Debt Securities Held Amortized Fair Amortized Fair (In thousands) Maturity in years: 1 year or less $ 262,418 $ 261,976 $ 86,172 $ 86,148 Over 1 to 5 years 1,438,849 1,414,020 214,137 213,829 Over 5 to 10 years 85,817 85,877 232,544 233,515 Over 10 years 38,672 36,970 1,037 1,074 Subtotal 1,825,756 1,798,843 533,890 534,566 MBS 885,697 855,827 450,719 436,879 Total $ 2,711,453 $ 2,654,670 $ 984,609 $ 971,445 At December 31, 2017 Debt Securities Available Debt Securities Held Amortized Fair Amortized Fair (In thousands) Maturity in years: 1 year or less $ 193,337 $ 193,385 $ 50,295 $ 51,105 Over 1 to 5 years 1,031,807 1,023,047 269,050 269,471 Over 5 to 10 years 159,266 160,042 277,170 281,546 Over 10 years 46,065 45,154 2,963 3,074 Subtotal 1,430,475 1,421,628 599,478 605,196 MBS 790,076 770,079 559,386 550,146 Total $ 2,220,551 $ 2,191,707 $ 1,158,864 $ 1,155,342 Expected maturities of mortgage-related securities can differ from contractual maturities because borrowers have the right to call or prepay obligations with or without call or prepayment penalties. In addition, such factors as prepayments and interest rates may December 31, 2018 December 31, 2017, no An analysis of the gross unrealized losses of the debt securities available for sale portfolio follows: Debt Securities Available for Sale No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrealized Investment Unrealized Investment Unrealized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) U.S. Treasury securities 2 $ 54,805 $ (3 ) - $ - $ - 2 $ 54,805 $ (3 ) Securities of U.S. Government sponsored entities 1 990 (5 ) 9 117,963 (3,270 ) 10 118,953 (3,275 ) Agency residential MBS 8 107,497 (507 ) 58 640,210 (29,932 ) 66 747,707 (30,439 ) Agency commercial MBS 1 1,842 (27 ) - - - 1 1,842 (27 ) Securities of U.S. Government entities - - - 2 1,119 (9 ) 2 1,119 (9 ) Obligations of states and political 32 26,452 (166 ) 71 67,121 (2,819 ) 103 93,573 (2,985 ) Corporate securities 38 308,157 (3,403 ) 79 722,740 (20,239 ) 117 1,030,897 (23,642 ) Total 82 $ 499,743 $ (4,111 ) 219 $ 1,549,153 $ (56,269 ) 301 $ 2,048,896 $ (60,380 ) An analysis of gross unrecognized losses of the debt securities held to maturity portfolio follows: Debt Securities Held to Maturity No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrecognized Investment Unrecognized Investment Unrecognized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Agency residential MBS 16 $ 8,495 $ (34 ) 78 $ 412,574 $ (14,095 ) 94 $ 421,069 $ (14,129 ) Non-agency residential MBS 1 26 - - - - 1 26 - Obligations of states and political 97 83,633 (271 ) 142 151,546 (2,456 ) 239 235,179 (2,727 ) Total 114 $ 92,154 $ (305 ) 220 $ 564,120 $ (16,551 ) 334 $ 656,274 $ (16,856 ) The unrealized losses on the Company’s debt securities were caused by market conditions for these types of investments, particularly changes in risk-free interest rates. The Company evaluates debt securities on a quarterly basis including changes in security ratings issued by rating agencies, changes in the financial condition of the issuer, and, for mortgage-backed and asset-backed securities, delinquency and loss information with respect to the underlying collateral, changes in the levels of subordination for the Company’s particular position within the repayment structure and remaining credit enhancement as compared to expected credit losses of the security. Substantially all of these securities continue to be investment grade rated by a major rating agency. One $15.0 $13.8 December 31, 2018, The Company does not not not not December 31, 2018. The fair values of the debt securities could decline in the future if the general economy deteriorates, inflation increases, credit ratings decline, the issuer’s financial condition deteriorates, or the liquidity for debt securities declines. As a result, other than temporary impairments may As of December 31, 2018 December 31, 2017, $728,161 $715,774 An analysis of gross unrealized losses of debt securities available for sale follows: Debt Securities Available for Sale At December 31, 2017 No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrealized Investment Unrealized Investment Unrealized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Securities of U.S. Government 1 $ 996 $ (2 ) 8 $ 117,252 $ (2,965 ) 9 $ 118,248 $ (2,967 ) Agency residential MBS 7 238,554 (1,501 ) 51 516,711 (18,994 ) 58 755,265 (20,495 ) Non-agency residential MBS 1 1 - - - - 1 1 - Agency commercial MBS 2 2,219 (25 ) - - - 2 2,219 (25 ) Securities of U.S. Government entities - - - 3 1,590 (22 ) 3 1,590 (22 ) Obligations of states and political 50 21,453 (228 ) 35 52,071 (1,254 ) 85 73,524 (1,482 ) Corporate securities 64 571,112 (4,047 ) 38 282,924 (5,230 ) 102 854,036 (9,277 ) Total 125 $ 834,335 $ (5,803 ) 135 $ 970,548 $ (28,465 ) 260 $ 1,804,883 $ (34,268 ) An analysis of gross unrecognized losses of the debt securities held to maturity portfolio follows: Debt Securities Held to Maturity At December 31, 2017 No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrecognized Investment Unrecognized Investment Unrecognized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Agency residential MBS 15 $ 30,218 $ (201 ) 65 $ 479,775 $ (9,649 ) 80 $ 509,993 $ (9,850 ) Agency commercial MBS 1 1,913 (4 ) 1 7,062 (62 ) 2 8,975 (66 ) Obligations of states and political subdivisions 146 131,032 (553 ) 59 58,979 (1,465 ) 205 190,011 (2,018 ) Total 162 $ 163,163 $ (758 ) 125 $ 545,816 $ (11,176 ) 287 $ 708,979 $ (11,934 ) The following table provides information about the amount of interest income earned on investment securities which is fully taxable and which is exempt from regular federal income tax: For the Years Ended December 31, 2018 2017 2016 (In thousands) Taxable $ 65,330 $ 51,445 $ 42,718 Tax-exempt from regular federal income tax 19,438 20,651 22,194 Total interest income from investment securities $ 84,768 $ 72,096 $ 64,912

Note 3 - Loans and Allowance fo

Note 3 - Loans and Allowance for Credit Losses	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]	Note 3: At December 31, 2018, $5.7 eighty February 6, 2019. A summary of the major categories of loans outstanding is shown in the following tables at the dates indicated. At Decmber 31, 2018 2017 (In thousands) Commercial $ 275,080 $ 335,996 Commercial Real Estate 580,480 568,584 Construction 3,982 5,649 Residential Real Estate 44,866 65,183 Consumer Installment & Other 302,794 312,570 Total $ 1,207,202 $ 1,287,982 Total loans outstanding reported above include loans purchased from the FDIC of $58,247 $83,478 December 31, 2018 December 31, 2017, Changes in the accretable yield for purchased loans were as follows: For the Years Ended December 31, 2018 2017 Accretable yield: (In thousands) Balance at the beginning of the period $ 738 $ 1,237 Reclassification from nonaccretable difference 1,119 1,852 Accretion (1,675 ) (2,351 ) Balance at the end of the period $ 182 $ 738 Accretion $ (1,675 ) $ (2,351 ) Change in FDIC indemnification 2 192 (Increase) in interest income $ (1,673 ) $ (2,159 ) The following summarizes activity in the allowance for loan losses: Allowance for Loan Losses Commercial Commercial Construction Residential Consumer Unallocated Total (In thousands) Allowance for loan losses: Balance at beginning of period $ 7,746 $ 3,849 $ 335 $ 995 $ 6,418 $ 3,666 $ 23,009 (Reversal) provision (2,369 ) 275 1,130 (126 ) 1,579 (489 ) - Chargeoffs (513 ) (240 ) - - (4,124 ) - (4,877 ) Recoveries 1,447 - - - 1,772 - 3,219 Total allowance for loan losses $ 6,311 $ 3,884 $ 1,465 $ 869 $ 5,645 $ 3,177 $ 21,351 Allowance for Loan Losses Commercial Commercial Construction Residential Consumer Unallocated Total (In thousands) Allowance for loan losses: Balance at beginning of period $ 8,327 $ 3,330 $ 152 $ 1,330 $ 7,980 $ 4,835 $ 25,954 (Reversal) provision (382 ) 431 (1,716 ) (335 ) 1,271 (1,169 ) (1,900 ) Chargeoffs (961 ) - - - (4,957 ) - (5,918 ) Recoveries 762 88 1,899 - 2,124 - 4,873 Total allowance for loan losses $ 7,746 $ 3,849 $ 335 $ 995 $ 6,418 $ 3,666 $ 23,009 Allowance for Credit Losses Commercial Commercial Construction Residential Consumer Unallocated Total (In thousands) Allowance for loan losses: Balance at beginning of period $ 9,559 $ 4,212 $ 235 $ 1,801 $ 8,001 $ 5,963 $ 29,771 (Reversal) provision (3,237 ) (1,436 ) (83 ) (471 ) 3,155 (1,128 ) (3,200 ) Chargeoffs (2,023 ) - - - (4,749 ) - (6,772 ) Recoveries 4,028 554 - - 1,573 - 6,155 Total allowance for loan losses $ 8,327 $ 3,330 $ 152 $ 1,330 $ 7,980 $ 4,835 $ 25,954 The allowance for loan losses and recorded investment in loans evaluated for impairment were as follows: Allowance for Loan Losses and Recorded Investment in Loans Evaluated for Impairment Commercial Commercial Real Estate Construction Residential Real Estate Consumer Installment and Other Unallocated Total (In thousands) Allowance for loan losses: Individually evaluated for impairment $ 2,752 $ - $ - $ - $ - $ - $ 2,752 Collectively evaluated for impairment 3,559 3,884 1,465 869 5,645 3,177 18,599 Purchased loans with evidence of credit deterioration - - - - - - - Total $ 6,311 $ 3,884 $ 1,465 $ 869 $ 5,645 $ 3,177 $ 21,351 Carrying value of loans: Individually evaluated for impairment $ 9,921 $ 8,217 $ - $ 717 $ - $ - $ 18,855 Collectively evaluated for impairment 265,136 572,042 3,982 44,149 302,651 - 1,187,960 Purchased loans with evidence of credit deterioration 23 221 - - 143 - 387 Total $ 275,080 $ 580,480 $ 3,982 $ 44,866 $ 302,794 $ - $ 1,207,202 Allowance for Loan Losses and Recorded Investment in Loans Evaluated for Impairment Commercial Commercial Real Estate Construction Residential Real Estate Consumer Installment and Other Unallocated Total (In thousands) Allowance for loan losses: Individually evaluated for impairment $ 4,814 $ 171 $ - $ - $ - $ - $ 4,985 Collectively evaluated for impairment 2,932 3,678 335 995 6,418 3,666 18,024 Purchased loans with evidence of credit deterioration - - - - - - - Total $ 7,746 $ 3,849 $ 335 $ 995 $ 6,418 $ 3,666 $ 23,009 Carrying value of loans: Individually evaluated for impairment $ 10,675 $ 14,234 $ - $ 208 $ - $ - $ 25,117 Collectively evaluated for impairment 325,291 553,769 5,649 64,975 312,406 - 1,262,090 Purchased loans with evidence of credit deterioration 30 581 - - 164 - 775 Total $ 335,996 $ 568,584 $ 5,649 $ 65,183 $ 312,570 $ - $ 1,287,982 The Company’s customers are small businesses, professionals and consumers. Given the scale of these borrowers, corporate credit rating agencies do not The following summarizes the credit risk profile by internally assigned grade: Credit Risk Profile by Internally Assigned Grade Commercial Commercial Real Estate Construction Residential Real Estate Consumer Installment and Other Total (In thousands) Grade: Pass $ 264,634 $ 567,578 $ 3,982 $ 43,112 $ 300,553 $ 1,179,859 Substandard 10,446 12,902 - 1,754 1,556 26,658 Doubtful - - - - 135 135 Loss - - - - 550 550 Total $ 275,080 $ 580,480 $ 3,982 $ 44,866 $ 302,794 $ 1,207,202 Credit risk profile reflects internally assigned grades of purchased covered loans without regard to FDIC indemnification on $5,713 December 31, 2018. February 6, 2019. Credit Risk Profile by Internally Assigned Grade Commercial Commercial Real Estate Construction Residential Real Estate Consumer Installment and Other Total (In thousands) Grade: Pass $ 324,185 $ 548,853 $ 5,649 $ 62,253 $ 310,429 $ 1,251,369 Substandard 11,811 19,731 - 2,930 1,370 35,842 Doubtful - - - - 1 1 Loss - - - - 770 770 Total $ 335,996 $ 568,584 $ 5,649 $ 65,183 $ 312,570 $ 1,287,982 Credit risk profile reflects internally assigned grades of purchased covered loans without regard to FDIC indemnification on $7,766 December 31, 2017. The following tables summarize loans by delinquency and nonaccrual status: Summary of Loans by Delinquency and Nonaccrual Status Current and Accruing 30-59 Days Past Due and Accruing 60-89 Days Past Due and Accruing Past Due 90 Days or More and Accruing Nonaccrual Total Loans (In thousands) Commercial $ 274,045 $ 781 $ 254 $ - $ - $ 275,080 Commercial real estate 574,853 617 785 - 4,225 580,480 Construction 3,982 - - - - 3,982 Residential real estate 43,372 789 189 - 516 44,866 Consumer installment and other 297,601 3,408 1,107 551 127 302,794 Total $ 1,193,853 $ 5,595 $ 2,335 $ 551 $ 4,868 $ 1,207,202 Summary of Loans by Delinquency and Nonaccrual Status Current and Accruing 30-59 Days Past Due and Accruing 60-89 Days Past Due and Accruing Past Due 90 Days or More and Accruing Nonaccrual Total Loans (In thousands) Commercial $ 334,908 $ 627 $ 164 $ - $ 297 $ 335,996 Commercial real estate 561,883 1,143 125 - 5,433 568,584 Construction 5,649 - - - - 5,649 Residential real estate 65,183 - - - - 65,183 Consumer installment and other 307,445 3,321 1,077 531 196 312,570 Total $ 1,275,068 $ 5,091 $ 1,366 $ 531 $ 5,926 $ 1,287,982 There were no December 31, 2018 December 31, 2017. The following summarizes impaired loans: Impaired Loans 2018 2017 Recorded Unpaid Related Recorded Unpaid Related (In thousands) With no related allowance recorded: Commercial $ 755 $ 759 $ - $ 1,212 $ 1,271 $ - Commercial real estate 8,438 10,373 - 13,169 14,985 - Residential real estate 717 747 - 208 239 - Consumer installment and other 270 377 - 360 466 - Total with no related allowance recorded 10,180 12,256 - 14,949 16,961 - With an allowance recorded: Commercial 9,189 9,189 2,752 9,764 9,764 4,814 Commercial real estate - - - 1,790 1,792 171 Total with an allowance recorded 9,189 9,189 2,752 11,554 11,556 4,985 Total $ 19,369 $ 21,445 $ 2,752 $ 26,503 $ 28,517 $ 4,985 Impaired loans include troubled debt restructured loans. Impaired loans at December 31, 2018, $8,579 $4,225 December 31, 2017, $12,081 $4,285 Impaired Loans 2018 2017 2016 Average Recognized Average Recognized Average Recognized (In thousands) Commercial $ 10,532 $ 667 $ 11,156 $ 508 $ 12,923 $ 512 Commercial real estate 11,703 758 14,806 884 16,701 725 Construction - - - - 102 - Residential real estate 269 19 423 17 746 19 Consumer installment and other 254 14 415 20 473 25 Total $ 22,758 $ 1,458 $ 26,800 $ 1,429 $ 30,945 $ 1,281 The following tables provide information on troubled debt restructurings: Troubled Debt Restructurings Number of Pre-Modification Period-End Period-End ($ in thousands) Commercial 4 $ 2,274 $ 811 $ 19 Commercial real estate 8 9,237 7,568 - Residential real estate 1 241 200 - Total 13 $ 11,752 $ 8,579 $ 19 Troubled Debt Restructurings Number of Pre-Modification Period-End Period-End ($ in thousands) Commercial 7 $ 2,393 $ 1,085 $ 43 Commercial real estate 10 11,528 10,788 - Residential real estate 1 241 208 - Total 18 $ 14,162 $ 12,081 $ 43 Troubled Debt Restructurings Number of Pre-Modification Period-End Period-End ($ in thousands) Commercial 7 $ 2,719 $ 1,489 $ 113 Commercial real estate 10 11,257 10,673 - Residential real estate 1 241 219 - Total 18 $ 14,217 $ 12,381 $ 113 During the year ended December 31, 2018, not During the year ended December 31, 2017, four $699 four 2017 During the year ended December 31, 2016, four $4,731 four 2016 three one During the year ended December 31, 2018, one $41 December 31, 2017, one $58 no December 31, 2016. December 31, 2018, 2017 2016, no 12 ninety There were no December 31, 2018 December 31, 2017. There were no December 31, 2018 December 31, 2017. At December 31, 2018 December 31, 2017, $350 0 thousand and $1,426 $1,905 0 $516 December 31, 2018 $196 December 31, 2017.

Note 4 - Concentration of Credi

Note 4 - Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Concentration Risk Disclosure [Text Block]	Note 4: Under the California Financial Code, credit extended to any one one not not 15 not 25 December 31, 2018, not one December 31, 2018, 37 $5 3, $53,891 $53,874 December 31, 2018 December 31, 2017, no 75% no 80% December 31, 2018, 78 $5

Note 5 - Premises, Equipment an

Note 5 - Premises, Equipment and Other Assets	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Other Assets Disclosure [Text Block]	Note 5: Premises and equipment consisted of the following: At December 31, Cost Accumulated Depreciation and Amortization Net Book Value (In thousands) 2018 Land $ 11,691 $ - $ 11,691 Building and improvements 41,912 (27,178 ) 14,734 Leasehold improvements 6,174 (4,968 ) 1,206 Furniture and equipment 23,845 (16,969 ) 6,876 Total $ 83,622 $ (49,115 ) $ 34,507 2017 Land $ 11,796 $ - $ 11,796 Building and improvements 41,641 (26,249 ) 15,392 Leasehold improvements 5,817 (4,790 ) 1,027 Furniture and equipment 22,284 (15,198 ) 7,086 Total $ 81,538 $ (46,237 ) $ 35,301 Depreciation and amortization of premises and equipment included in noninterest expense amounted to $3,677 2018, $3,925 2017 $3,959 2016. Other assets consisted of the following: At December 31, 2018 2017 (In thousands) Cost method equity investments: Federal Reserve Bank stock (1) $ 14,069 $ 14,069 Other investments 158 158 Total cost method equity investments 14,227 14,227 Life insurance cash surrender value 56,083 54,101 Net deferred tax asset 42,256 33,112 Limited partnership investments 10,219 10,119 Interest receivable 25,834 23,557 Prepaid assets 4,658 4,906 Other assets 9,629 18,428 Total other assets $ 162,906 $ 158,450 ( 1 A bank applying for membership in the Federal Reserve System is required to subscribe to stock in the Federal Reserve Bank (FRB) in its district in a sum equal to six The Company owns 211 0 July 5, 2018, June 28, 2018 1.6483 1.6298. $131.94 December 31, 2018, fourth 2018. The Company invests in flow-through limited liability entities that manage or invest in affordable housing projects that qualify for low-income housing tax credits. At December 31, 2018, $10,219 $4,799 December 31, 2017, $10,119 $2,299 December 31, 2018, $4,799 $627 2019, $2,026 2020, $138 2021, $261 2022, $134 2023, $1,041 2024 $572 2025 The amounts recognized in net income for these investments include: For the Years Ended December 31, 2018 2017 2016 (In thousands) Investment loss included in pre-tax income $ 2,900 $ 1,800 $ 2,475 Valuation impairment included in pre-tax income - 625 - Tax credits recognized in provision for income taxes 1,121 1,850 2,286 The $625 2017 2017.

Note 6 - Goodwill and Identifia

Note 6 - Goodwill and Identifiable Intangible Assets	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Goodwill and Intangible Assets Disclosure [Text Block]	Note 6: The Company has recorded goodwill and other identifiable intangibles associated with purchase business combinations. Goodwill is not not December 31, 2018, 2017 2016. December 31, 2018, 2017 2016 no The carrying values of goodwill were: At December 31, 2018 2017 (In thousands) Goodwill $ 121,673 $ 121,673 The gross carrying amount of identifiable intangible assets and accumulated amortization was: At December 31, 2018 2017 Gross Accumulated Gross Accumulated (In thousands) Core Deposit Intangibles $ 56,808 $ (54,879 ) $ 56,808 $ (52,987 ) Merchant Draft Processing Intangible 10,300 (10,300 ) 10,300 (10,271 ) Total Identifiable Intangible Assets $ 67,108 $ (65,179 ) $ 67,108 $ (63,258 ) As of December 31, 2018, Core Merchant Total (In thousands) For the Year Ended December 31, 2018 (actual) $ 1,892 $ 29 $ 1,921 Estimate for the Year Ended December 31, 2019 538 - 538 2020 287 - 287 2021 269 - 269 2022 252 - 252 2023 236 - 236

Note 7 - Deposits and Borrowed

Note 7 - Deposits and Borrowed Funds	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Deposits and Borrowed Funds [Text Block]	Note 7: The following table provides additional detail regarding deposits. Deposits At December 31, 2018 2017 (In thousands) Noninterest-bearing $ 2,243,251 $ 2,197,526 Interest-bearing: Transaction 929,346 904,245 Savings 1,498,991 1,494,024 Time deposits less than $100 thousand 102,654 117,848 Time deposits $100 thousand through $250 thousand 64,512 76,578 Time deposits more than $250 thousand 28,085 37,392 Total deposits $ 4,866,839 $ 4,827,613 Demand deposit overdrafts of $980 $2,786 December 31, 2018 2017, $100 $368 2018, $415 2017 $509 2016. The following table provides additional detail regarding short-term borrowed funds. Repurchase Agreements (Sweep) Remaining Contractual Maturity of the Agreements At December 31, 2018 2017 Repurchase agreements: (In thousands) Collateral securing borrowings: Securities of U.S. Government sponsored entities $ 73,803 $ 74,173 Agency residential MBS 58,380 58,251 Corporate securities 91,837 105,113 Total collateral carrying value $ 224,020 $ 237,537 Total short-term borrowed funds $ 51,247 $ 58,471 For the Years Ended December 31, 2018 2017 Highest Balance at Any Month-end (In thousands) Securities sold under repurchase agreements $ 68,894 $ 82,126

Note 8 - Shareholders' Equity

Note 8 - Shareholders' Equity	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	Note 8: The Company grants stock options and restricted performance shares to employees in exchange for employee services, pursuant to the shareholder-approved 1995 2012. three ten three three The following table summarizes information about stock options granted under the Plan as of December 31, 2018. December 31, 2018 December 31, 2018 $55.68 Options Outstanding Options Exercisable At December 31, 2018 For the Year Ended December 31, 2018 At December 31, 2018 For the Year Ended December 31, 2018 Range of Exercise Price Number Outstanding Aggregate Intrinsic Value Weighted Average Remaining Contractual Life Weighted Average Exercise Price Number Exercisable Aggregate Intrinsic Value Weighted Average Remaining Contractual Life Weighted Average Exercise Price (In thousands) (Years) (In thousands) (Years) $40 - 45 176 $ 2,309 6.6 $ 43 87 $ 1,122 6.1 $ 43 45 - 50 11 106 3.1 46 11 106 3.1 46 50 - 55 286 1,297 0.7 51 286 1,297 0.7 51 55 - 60 229 - 7.7 57 73 - 6.9 57 60 - 65 244 - 9.1 62 - N/A N/A N/A $40 - 65 946 $ 3,712 5.7 54 457 $ 2,525 2.8 50 The Company applies the Roll-Geske option pricing model (Modified Roll) to determine grant date fair value of stock option grants. This model modifies the Black-Scholes Model to take into account dividends and American options. During the year ended December 31, 2018, 2017 2016, 249 266 325 For the Years Ended December 31, 2018 2017 2016 Expected volatility (1) 20 % 20 % 22 % Expected life in years (2) 4.8 4.8 4.8 Risk-free interest rate (3) 2.50 % 1.97 % 1.41 % Expected dividend yield 2.65 % 3.28 % 4.49 % Fair value per award $ 9.98 $ 8.27 $ 5.97 ( 1 Measured using daily price changes of Company’s stock over respective expected term of the option and the implied volatility derived from the market prices of the Company’s stock and traded options. ( 2 The number of years that the Company estimates that the options will be outstanding prior to exercise. ( 3 The risk-free rate over the expected life based on the US Treasury yield curve in effect at the time of the grant. Employee stock option grants are being expensed by the Company over the grants’ three December 31, 2018 713 A summary of option activity during the year ended December 31, 2018 Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (In thousands) (Years) Outstanding at January 1, 2018 1,030 $ 49.44 Granted 249 62.16 Exercised (292 ) 45.76 Forfeited or expired (41 ) 52.54 Outstanding at December 31, 2018 946 $ 53.78 5.7 Exercisable at December 31, 2018 457 $ 50.38 2.8 A summary of the Company’s nonvested option activity during the year ended December 31, 2018 Shares Weighted Average Grant Date Fair Value (In thousands) Nonvested at January 1, 2018 561 $ 6.98 Granted 249 9.98 Vested (280 ) 6.54 Forfeited (41 ) 7.66 Nonvested at December 31, 2018 489 8.71 The weighted average estimated grant date fair value for options granted under the Company’s stock option plan during the twelve December 31, 2018, 2017 2016 $9.98, $8.27 $5.97 December 31, 2018 $2,871 1.8 The total intrinsic value of options exercised during the twelve December 31, 2018, 2017 2016 $4,264 $4,642 $3,242 twelve December 31, 2018, 2017 2016 $1,143 $708 $753 twelve December 31, 2018, 2017 2016 $1,835 $1,493 $1,269 2016 09 January 1, 2017, twelve 2018, 292 $2,516 twelve 2017, 509 $1,667 $737 2018 $698 2017 2016 09. $394 twelve December 31, 2016. A summary of the status of the Company’s restricted performance shares as of December 31, 2018 2017 twelve 2018 2017 (In thousands) Outstanding at January 1, 49 48 Granted 11 14 Issued upon vesting (19 ) (13 ) Forfeited (2 ) - Outstanding at December 31, 39 49 As of December 31, 2018 2017, 1.2 $660 $827 $1,228 twelve December 31, 2018, 2017 2016, no twelve December 31, 2018 2017. On February 13, 2009, 246,640 $50.92 may not December 31, 2018. January 29, 2019, 50,788 The Company repurchases and retires its common stock in accordance with Board of Directors approved share repurchase programs. At December 31, 2018, 1,750 Shareholders have authorized two one million 150 December 31, 2018, no

Note 9 - Regulatory Capital

Note 9 - Regulatory Capital	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Regulatory Capital Requirements under Banking Regulations [Text Block]	Note 9: Banks and bank holding companies are subject to regulatory capital requirements administered by federal banking agencies. Capital adequacy guidelines and, additionally for banks, prompt corrective action regulations, involve quantitative measures of assets, liabilities, and certain off-balance-sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgments by regulators. Failure to meet capital requirements can result in regulatory action. The final rules implementing Basel Committee on Banking Supervision’s capital guidelines for U.S. banks (Basel III rules) became effective for the Company on January 1, 2015 January 1, 2019. 0.0% 2015 2.50% 2019. 1.875% 2018 1.25% 2017. not December 31, 2018, Prompt corrective action regulations provide five not 2018 2017, no The capital ratios for the Company and the Bank under the new capital framework as of the dates indicated are presented in the table below. At December 31, 2018 Required To Be Well-capitalized Amount Ratio Amount Ratio Amount Ratio ($ in thousands) Common Equity Tier 1 Capital Company $ 528,042 16.30 % $ 206,576 6.375 % (1) N/A N/A Bank 415,575 13.01 % 203,664 6.375 % (1) $ 207,658 6.50 % Tier 1 Capital Company 528,042 16.30 % 255,182 7.875 % (1) N/A N/A Bank 415,575 13.01 % 251,585 7.875 % (1) 255,579 8.00 % Total Capital Company 551,701 17.03 % 319,990 9.875 % (1) N/A N/A Bank 445,234 13.94 % 315,480 9.875 % (1) 319,474 10.00 % Leverage Ratio (2) Company 528,042 9.51 % 222,111 4.000 % N/A N/A Bank 415,575 7.55 % 220,312 4.000 % 275,390 5.00 % ( 1 1.875% ( 2 1 At December 31, 2017 Required To Be Well-capitalized Amount Ratio Amount Ratio Amount Ratio ($ in thousands) Common Equity Tier 1 Capital Company $ 479,259 15.36 % $ 179,377 5.75 % (3) N/A N/A Bank 383,796 12.50 % 176,568 5.75 % (3) $ 199,599 6.50 % Tier 1 Capital Company 479,259 15.36 % 226,170 7.25 % (3) N/A N/A Bank 383,796 12.50 % 222,630 7.25 % (3) 245,660 8.00 % Total Capital Company 504,576 16.17 % 288,562 9.25 % (3) N/A N/A Bank 415,113 13.52 % 284,045 9.25 % (3) 307,076 10.00 % Leverage Ratio (2) Company 479,259 8.86 % 216,280 4.000 % N/A N/A Bank 383,796 7.16 % 214,468 4.000 % 268,085 5.00 % ( 2 1capital ( 3 1.25%

Note 10 - Income Taxes

Note 10 - Income Taxes	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Income Tax Disclosure [Text Block]	Note 10: Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the amounts reported in the financial statements of existing assets and liabilities and their respective tax basis and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Amounts for the current year are based upon estimates and assumptions as of the date of these financial statements and could vary significantly from amounts shown on the tax returns as filed. The components of the net deferred tax asset are as follows: At December 31, 2018 2017 (In thousands) Deferred tax asset Allowance for credit losses $ 6,868 $ 7,349 State franchise taxes 3,026 1,871 AMT carryforward - 1,752 Securities available for sale 16,787 8,586 Deferred compensation 5,229 5,279 Real estate owned 553 553 Purchased assets and assumed liabilities 935 1,111 Post-retirement benefits 555 526 Employee benefit accruals 2,104 2,066 VISA Class B shares 167 96 Limited partnership investments 708 57 Impaired capital assets 3,070 3,056 Accrued liabilities 2,554 1,609 Premises and equipment 31 299 Other 721 520 Total deferred tax asset 43,308 34,730 Deferred tax liability Net deferred loan fees 291 281 Intangible assets 761 1,247 Other - 90 Total deferred tax liability 1,052 1,618 Net deferred tax asset $ 42,256 $ 33,112 At December 31, 2018 December 31, 2017, $3,070 $3,056 five five At December 31, 2017, no $1,752 2018. Based on Management’s judgment, a valuation allowance is not not The provision for federal and state income taxes consists of amounts currently payable and amounts deferred are as follows: For the Years Ended December 31, 2018 2017 2016 (In thousands) Current income tax expense: Federal $ 10,560 $ 1,778 $ 16,258 State 9,816 7,810 7,292 Total current 20,376 9,588 23,550 Deferred income tax (benefit) expense: Federal (206 ) 14,461 (2,604 ) State (737 ) 783 158 Total deferred (943 ) 15,244 (2,446 ) Adjustment of net deferred tax asset for enacted changes in tax rates: Federal - 12,315 - State - - - Total adjustments - 12,315 - Provision for income taxes $ 19,433 $ 37,147 $ 21,104 The provision for income taxes differs from the provision computed by applying the statutory federal income tax rate to income before taxes, as follows: For the Years Ended December 31, 2018 2017 2016 (In thousands) Federal income taxes due at statutory rate $ 19,109 $ 30,509 $ 27,985 Reductions in income taxes resulting from: Interest on state and municipal securities and loans not taxable for federal income tax purposes (4,375 ) (7,794 ) (8,382 ) State franchise taxes, net of federal income tax benefit 7,173 5,586 4,843 Re-measurement of net deferred tax asset due to enactment of new federal tax rate - 12,315 - Stock compensation deduction in excess of book expense (528 ) (583 ) - Tax credits (1,291 ) (1,850 ) (2,286 ) Dividend received deduction (32 ) (60 ) (52 ) Cash value life insurance (490 ) (603 ) (607 ) Other (133 ) (373 ) (397 ) Provision for income taxes $ 19,433 $ 37,147 $ 21,104 The 2017 $12.3 2017. A reconciliation of the beginning and ending amounts of unrecognized tax benefits follow: 2018 2017 (In thousands) Balance at January 1, $ 909 $ 1,099 Additions for tax positions taken in the current period - - Reductions for tax positions taken in the current period - - Additions for tax positions taken in prior years - - Reductions for tax positions taken in prior years - - Decrease related to settlements with taxing authorities - (190 ) Decrease as a result of a lapse in statute of limitations - - Balance at December 31, $ 909 $ 909 The Company’s uncertain tax positions relate to positions taken on tax returns which are under examination. The timing of concluding the examinations is dependent on the taxing authorities. The examinations could conclude in 2019. December 31, 2018 2017 $13 $13 The Company classifies interest and penalties as a component of the provision for income taxes. At December 31, 2018, December 31, 2017, 2016 2015 December 31, 2017, 2016, 2015, 2014, 2013, 2012 2011

Note 11 - Fair Value Measuremen

Note 11 - Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Fair Value Disclosures [Text Block]	Note 11: The Company uses fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. Equity securities and debt securities available for sale are recorded at fair value on a recurring basis. Additionally, from time to time, the Company may In accordance with the Fair Value Measurement and Disclosure topic of the FASB Accounting Standards Codification, the Company bases its fair values on the price that would be received to sell an asset or paid to transfer a liability in the principal market or most advantageous market for an asset or liability in an orderly transaction between market participants on the measurement date under current market conditions. A fair value measurement reflects all of the assumptions that market participants would use in pricing the 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. The Company groups its assets and liabilities measured at fair value into a three Level 1 1 Level 2 not 2 Level 3 not The Company relies on independent vendor pricing services to measure fair value for equity securities, debt securities available for sale and debt securities held to maturity. The Company employs three 95 may not The Company regularly reviews the valuation techniques and assumptions used by its vendors and determines which valuation techniques are utilized based on observable market inputs for the type of securities being measured. The Company uses the information to determine the placement in the fair value hierarchy as level 1, 2 3. Assets Recorded at Fair Value on a Recurring Basis The tables below present assets measured at fair value on a recurring basis on the dates indicated. At December 31, 2018 Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs (1) (In thousands) Equity securities Mutual funds $ 1,747 $ - $ 1,747 $ - Total equity securities 1,747 - 1,747 - Debt securities available for sale U.S. Treasury securities 139,574 139,574 - - Securities of U.S. Government sponsored entities 164,018 - 164,018 - Agency residential MBS 853,871 - 853,871 - Non-agency residential MBS 114 - 114 - Agency commercial MBS 1,842 - 1,842 - Securities of U.S. Government entities 1,119 - 1,119 - Obligations of states and political subdivisions 179,091 - 179,091 - Corporate securities 1,315,041 - 1,315,041 - Total debt securities available for sale 2,654,670 139,574 2,515,096 - Total $ 2,656,417 $ 139,574 $ 2,516,843 $ - ( 1 no 3 December 31, 2018. At December 31, 2017 Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs (1) (In thousands) Equity securities Mutual funds $ 1,800 $ - $ 1,800 $ - Total equity securities 1,800 - 1,800 - Debt securities available for sale Securities of U.S. Government sponsored entities 119,319 - 119,319 - Agency residential MBS 767,706 - 767,706 - Non-agency residential MBS 154 - 154 - Agency commercial MBS 2,219 - 2,219 - Securities of U.S. Government entities 1,590 - 1,590 - Obligations of states and political subdivisions 185,221 - 185,221 - Corporate securities 1,115,498 - 1,115,498 - Total debt securities available for sale 2,191,707 - 2,191,707 - Total $ 2,193,507 $ - $ 2,193,507 $ - ( 1 no 3 December 31, 2017. Assets Recorded at Fair Value on a Nonrecurring Basis The Company may December 31, 2018 December 31, 2017, For the Year Ended At December 31, 2018 December 31, 2018 Carrying Value Level 1 Level 2 Level 3 Total Losses (In thousands) Other real estate owned $ 350 $ - $ - $ 350 $ - Impaired loans: Commercial 6,437 - - 6,437 - Commercial real estate 3,870 - - 3,870 (240 ) Total assets measured at fair value on a nonrecurring basis $ 10,657 $ - $ - $ 10,657 $ (240 ) For the Year Ended At December 31, 2017 December 31, 2017 Carrying Value Level 1 Level 2 Level 3 Total Losses (In thousands) Other real estate owned $ 1,426 $ - $ - $ 1,426 $ (219 ) Impaired loans: Commercial 4,950 - - 4,950 - Commercial real estate 5,904 - - 5,904 - Total assets measured at fair value on a nonrecurring basis $ 12,280 $ - $ - $ 12,280 $ (219 ) Level 3 third 10% 3 not not Disclosures about Fair Value of Financial Instruments The following section describes the valuation methodologies used by the Company for estimating fair value of financial instruments not 2016 01, Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities January 1, 2018. Cash and Due from Banks Equity Securities 2 Debt Securities Held to Maturity 1 2 Loans Prior to adoption of ASU 2016 01, two $23,009 December 31, 2017 Deposit Liabilities no no Prior to adoption of ASU 2016 01, Short-Term Borrowed Funds The tables below are a summary of fair value estimates for financial instruments and the level of the fair value hierarchy within which the fair value measurements are categorized, excluding financial instruments recorded at fair value on a recurring basis. The values assigned do not may not may The Company has not not not not At December 31, 2018 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Financial Assets: (In thousands) Cash and due from banks $ 420,284 $ 420,284 $ 420,284 $ - $ - Debt securities held to maturity 984,609 971,445 - 971,445 - Loans 1,185,851 1,184,770 - - 1,184,770 Financial Liabilities: Deposits $ 4,866,839 $ 4,862,668 $ - $ 4,671,588 $ 191,080 Short-term borrowed funds 51,247 51,247 - 51,247 - At December 31, 2017 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Financial Assets: (In thousands) Cash and due from banks $ 575,002 $ 575,002 $ 575,002 $ - $ - Debt securities held to maturity 1,158,864 1,155,342 - 1,155,342 - Loans 1,264,973 1,257,811 - - 1,257,811 Financial Liabilities: Deposits $ 4,827,613 $ 4,824,586 $ - $ 4,595,795 $ 228,791 Short-term borrowed funds 58,471 58,471 - 58,471 - The majority of the Company’s standby letters of credit and other commitments to extend credit carry current market interest rates if converted to loans. No

Note 12 - Lease Commitments

Note 12 - Lease Commitments	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Leases of Lessee Disclosure [Text Block]	Note 12: Twenty eight 58 Minimum future rental payments under noncancelable operating leases as of December 31, 2018 Minimum (In thousands) 2019 $ 5,996 2020 4,409 2021 2,741 2022 1,921 2023 1,223 Thereafter 1,044 Total minimum lease payments $ 17,334 The total minimum future rental payments have not $1,319 $6,794 2018, $6,695 2017 $6,823 2016. $397 2018, $406 2017 $435 2016. $6,397 2018, $6,289 2017 $6,388 2016.

Note 13 - Commitments and Conti

Note 13 - Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	Note 13: Loan commitments are agreements to lend to a customer provided there is no not $278,598 $272,646 December 31, 2018 December 31, 2017, $2,772 $19,263 December 31, 2018 December 31, 2017, no December 31, 2018 December 31, 2017. $75 3 rd December 31, 2018. $ 2,308 December 31, 2018 2017, Due to the nature of its business, the Company is subject to various threatened or filed legal cases. Based on the advice of legal counsel, the Company does not third 2018, $3,500 The Company has determined that it will be obligated to provide refunds of revenue recognized in years prior to 2017 $5,542 2017;

Note 14 - Retirement Benefit Pl

Note 14 - Retirement Benefit Plans	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Pension and Other Postretirement Benefits Disclosure [Text Block]	Note 14: The Company sponsors a qualified defined contribution Deferred Profit-Sharing Plan covering substantially all of its salaried employees with one $1,057 2018, $944 2017 $1,000 2016. The Company also sponsors a qualified defined contribution Tax Deferred Savings/Retirement Plan (ESOP) covering salaried employees who become eligible to participate upon completion of a 90 may one $1,052 2018, $1,098 2017 $1,075 2016. The Company offers a continuation of group insurance coverage to eligible employees electing early retirement, for the period from the date of retirement until age 65. 65 February 1, 2006 January 1, 2019. December 31 The following tables set forth the net periodic post-retirement benefit cost and the change in the benefit obligation for the years ended December 31 December 31: Net Periodic Benefit Cost At December 31, 2018 2017 2016 (In thousands) Service benefit $ 24 $ (311 ) $ (153 ) Interest cost 72 95 108 Amortization of unrecognized transition obligation - 61 61 Net periodic (benefit) cost $ 96 $ (155 ) $ 16 Other Changes in Benefit Obligations Recognized in Other Comprehensive Income Amortization of unrecognized transition obligation, net of tax - (34 ) (36 ) Total recognized in net periodic (benefit) cost and accumulated other comprehensive income $ 96 $ (189 ) $ (20 ) The transition obligation for this post-retirement benefit plan became fully amortized during the twelve December 31, 2017. Obligation and Funded Status At December 31, 2018 2017 2016 Change in benefit obligation (In thousands) Benefit obligation at beginning of year $ 1,958 $ 2,319 $ 2,522 Service benefit 24 (311 ) (153 ) Interest cost 72 95 108 Benefits paid (141 ) (145 ) (158 ) Benefit obligation at end of year $ 1,913 $ 1,958 $ 2,319 Accumulated post-retirement benefit obligation attributable to: Retirees $ 1,913 $ 1,575 $ 1,705 Fully eligible participants - 382 606 Other - 1 8 Total $ 1,913 $ 1,958 $ 2,319 Fair value of plan assets - - - Accumulated post-retirement benefit obligation in excess of plan assets $ 1,913 $ 1,958 $ 2,319 Additional Information Assumptions At December 31, 2018 2017 2016 Weighted-average assumptions used to determine benefit obligations Discount rate 3.76 % 3.70 % 4.10 % Weighted-average assumptions used to determine net periodic benefit cost Discount rate 3.70 % 4.10 % 4.30 % The above discount rate is based on the Corporate Aa 25 zero 2018 Assumed benefit inflation rates are not Estimated future benefit payments (In thousands) 2019 $ 143 2020 143 2021 143 2022 140 2023 138 Years 2024-2028 624

Note 15 - Related Party Transac

Note 15 - Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Related Party Transactions Disclosure [Text Block]	Note 15: Certain of the Directors, executive officers and their associates have had banking transactions with subsidiaries of the Company in the ordinary course of business. The table below reflects information concerning loans to certain directors and executive officers and/or family members during 2018 2017: 2018 2017 (In thousands) Balance at January 1, $ 622 $ 867 Originations - - Principal reductions (45 ) (245 ) Balance at December 31, $ 577 $ 622 Percent of total loans outstanding. 0.05 % 0.05 %

Note 16 - Regulatory Matters

Note 16 - Regulatory Matters	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Regulatory Matters [Text Block]	Note 16: Payment of dividends to the Company by the Bank is limited under regulations for state chartered banks. The amount that can be paid in any calendar year, without prior approval from regulatory agencies, cannot exceed the net profits (as defined) for the preceding three 1972. The Bank is required to maintain reserves with the Federal Reserve Bank equal to a percentage of its reservable deposits. The Bank’s daily average on deposit at the Federal Reserve Bank was $473,250 2018 $458,186 2017,

Note 17 - Other Comprehensive I

Note 17 - Other Comprehensive Income	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Comprehensive Income (Loss) Note [Text Block]	Note 17: The components of other comprehensive (loss) income and other related tax effects were: 2018 Before tax Tax effect Net of tax (In thousands) Debt securities available for sale: Net unrealized losses arising during the year $ (27,939 ) $ 8,258 $ (19,681 ) Reclassification of losses included in net income - - - Net unrealized losses arising during the year (27,939 ) 8,258 (19,681 ) Post-retirement benefit obligation - - - Other comprehensive loss $ (27,939 ) $ 8,258 $ (19,681 ) 2017 Before tax Tax effect Net of tax (In thousands) Debt securities available for sale: Net unrealized losses arising during the year $ (3,767 ) $ 1,585 $ (2,182 ) Reclassification of gains included in net income (7,955 ) 3,345 (4,610 ) Net unrealized losses arising during the year (11,722 ) 4,930 (6,792 ) Post-retirement benefit obligation 59 (25 ) 34 Other comprehensive loss $ (11,663 ) $ 4,905 $ (6,758 ) 2016 Before tax Tax effect Net of tax (In thousands) Debt securities available for sale: Net unrealized losses arising during the year $ (18,610 ) $ 7,825 $ (10,785 ) Reclassification of (gains) losses included in net income - - - Net unrealized losses arising during the year (18,610 ) 7,825 (10,785 ) Post-retirement benefit obligation 61 (25 ) 36 Other comprehensive loss $ (18,549 ) $ 7,800 $ (10,749 ) Accumulated other comprehensive income (loss) balances were: Post-retirement Benefit Obligation Net Unrealized Gains (losses) on Securities Accumulated Other Comprehensive Income (loss) (In thousands) Balance, December 31, 2015 $ (70 ) $ 745 $ 675 Net change 36 (10,785 ) (10,749 ) Balance, December 31, 2016 (34 ) (10,040 ) (10,074 ) Net change 34 (6,792 ) (6,758 ) Balance, December 31, 2017 - (16,832 ) (16,832 ) Cumulative effect of equity securities losses reclassified - 142 142 Adjusted Balance, January 1, 2018 - (16,690 ) (16,690 ) Reclass stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 - (3,625 ) (3,625 ) Net change - (19,681 ) (19,681 ) Balance, December 31, 2018 $ - $ (39,996 ) $ (39,996 ) The transition obligation for this post-retirement benefit plan became fully amortized during the twelve December 31, 2017.

Note 18 - Earnings Per Common S

Note 18 - Earnings Per Common Share	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Earnings Per Share [Text Block]	Note 18: The table below shows earnings per common share and diluted earnings per common share. Basic earnings per common share are computed by dividing net income by the average number of common shares outstanding during the period. Diluted earnings per common share are computed by dividing net income by the average number of common shares outstanding during the period plus the impact of common stock equivalents. For the Years Ended December 31, 2018 2017 2016 (In thousands, except per share data) Net income (numerator) $ 71,564 $ 50,025 $ 58,853 Basic earnings per common share Weighted average number of common shares outstanding - basic (denominator) 26,649 26,291 25,612 Basic earnings per common share $ 2.69 $ 1.90 $ 2.30 Diluted earnings per common share Weighted average number of common shares outstanding - basic 26,649 26,291 25,612 Add common stock equivalents for options 107 128 66 Weighted average number of common shares outstanding - diluted (denominator) 26,756 26,419 25,678 Diluted earnings per common share $ 2.67 $ 1.89 $ 2.29 For the years ended December 31, 2018, 2017 2016, 423 323 773 not

Note 19 - Westamerica Bancorpor

Note 19 - Westamerica Bancorporation (Parent Company Only Condensed Financial Information)	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Condensed Financial Information of Parent Company Only Disclosure [Text Block]	Note 19: Statements of Income and Comprehensive Income For the Years Ended December 31, 2018 2017 2016 (In thousands) Dividends from subsidiaries $ 43,892 $ 12,728 $ 56,824 Interest income 33 43 25 Other income 9,447 8,590 8,315 Total income 53,372 21,361 65,164 Interest on borrowings - - - Salaries and benefits 7,575 7,163 7,079 Other expense 3,181 3,416 3,290 Total expense 10,756 10,579 10,369 Income before taxes and equity in undistributed income of subsidiaries 42,616 10,782 54,795 Income tax benefit 919 241 1,025 Earnings of subsidiaries greater than subsidiary dividends 28,029 39,002 3,033 Net income 71,564 50,025 58,853 Other comprehensive loss, net of tax (19,681 ) (6,758 ) (10,749 ) Comprehensive income $ 51,883 $ 43,267 $ 48,104 Balance Sheets At December 31, 2018 2017 (In thousands) Assets Cash $ 72,878 $ 53,409 Investment securities available for sale - - Investment in Westamerica Bank 509,125 500,776 Investment in non-bank subsidiaries 455 455 Premises and equipment, net 10,400 9,639 Accounts receivable from Westamerica Bank 580 538 Other assets 36,990 40,547 Total assets $ 630,428 $ 605,364 Liabilities Accounts payable to Westamerica Bank $ 46 $ 92 Other liabilities 14,791 15,033 Total liabilities 14,837 15,125 Shareholders' equity 615,591 590,239 Total liabilities and shareholders' equity $ 630,428 $ 605,364 Statements of Cash Flows For the Years Ended December 31, 2018 2017 2016 (In thousands) Operating Activities Net income $ 71,564 $ 50,025 $ 58,853 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 361 319 305 (Increase) decrease in accounts receivable from affiliates (43 ) (16 ) 299 Increase in other assets (2,638 ) (2,203 ) (1,940 ) Stock option compensation expense 1,988 1,824 1,494 Tax benefit increase upon exercise of stock options and expiration of stock options - - (394 ) Provision (benefit) for deferred income tax 5,028 (3,971 ) 1,983 Increase in other liabilities 978 202 1,392 Earnings of subsidiaries greater than subsidiary dividends (28,029 ) (39,002 ) (3,033 ) Life insurance gains (585 ) - - Gain on sales of premises and equipment (538 ) (793 ) (79 ) Net Cash Provided by Operating Activities 48,086 6,385 58,880 Investing Activities Proceeds from life insurance 1,169 - - Net Cash Provided by Investing Activities 1,169 - - Financing Activities Exercise of stock options/issuance of shares 13,373 24,583 24,031 Taxes paid by withholding shares for tax purposes - - (356 ) Tax benefit increase (decrease) upon exercise of stock options and expiration of stock options - - 394 Retirement of common stock (524 ) (314 ) (5,424 ) Dividends (42,635 ) (41,299 ) (39,924 ) Net Cash Used in Financing Activities (29,786 ) (17,030 ) (21,279 ) Net change in cash 19,469 (10,645 ) 37,601 Cash at Beginning of Period 53,409 64,054 26,453 Cash at End of Period $ 72,878 $ 53,409 $ 64,054 Supplemental Cash Flow Disclosures: Supplemental disclosure of cash flow activities: Interest paid for the period $ - $ - $ - Income tax payments for the period 13,627 17,351 19,264

Note 20 - Quarterly Financial I

Note 20 - Quarterly Financial Information	12 Months Ended
	Dec. 31, 2018
Notes to Financial Statements
Quarterly Financial Information [Text Block]	Note 20: (Unaudited) For the Three Months Ended March 31, June 30, September 30, December 31, (In thousands, expect per share data and 2018 Interest and loan fee income $ 36,315 $ 37,346 $ 38,614 $ 39,448 Net interest income 35,856 36,887 38,087 38,934 Provision for loan losses - - - - Noninterest income 11,955 11,769 12,528 11,897 Noninterest expense 26,022 25,741 29,366 25,787 Income before taxes 21,789 22,915 21,249 25,044 Net income 17,506 18,010 16,993 19,055 Basic earnings per common share 0.66 0.68 0.64 0.71 Diluted earnings per common share 0.66 0.67 0.63 0.71 Dividends paid per common share 0.40 0.40 0.40 0.40 Price range, common stock 55.72 - 62.52 55.81 - 60.68 57.56 - 64.52 52.75 - 63.20 2017 Interest and loan fee income $ 34,128 $ 34,083 $ 34,623 $ 35,478 Net interest income 33,648 33,607 34,150 35,007 (Reversal of) provision for loan losses - (1,900 ) - - Noninterest income 11,657 12,123 12,548 20,300 Noninterest expense 25,419 25,316 25,592 31,441 Income before taxes 19,886 22,314 21,106 23,866 Net income 15,049 15,799 15,017 4,160 Basic earnings per common share 0.58 0.60 0.57 0.16 Diluted earnings per common share 0.57 0.60 0.57 0.16 Dividends paid per common share 0.39 0.39 0.39 0.40 Price range, common stock 54.12 - 64.07 51.31 - 57.78 49.54 - 59.54 53.96 - 63.03 2016 Interest and loan fee income $ 34,001 $ 34,248 $ 33,955 $ 33,715 Net interest income 33,449 33,707 33,432 33,215 (Reversal of) provision for loan losses - - (3,200 ) - Noninterest income 11,729 11,702 11,598 11,545 Noninterest expense 26,212 25,750 26,575 25,083 Income before taxes 18,966 19,659 21,655 19,677 Net income 14,226 14,546 15,628 14,453 Basic earnings per common share 0.56 0.57 0.61 0.56 Diluted earnings per common share 0.56 0.57 0.61 0.56 Dividends paid per common share 0.39 0.39 0.39 0.39 Price range, common stock 40.72 - 49.63 45.86 - 51.53 46.61 - 50.96 48.20 - 65.34

Significant Accounting Policies

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Use of Estimates, Policy [Policy Text Block]	Accounting Estimates. Certain accounting policies underlying the preparation of these financial statements require Management to make estimates, assumptions, and judgments that affect the amounts reported in the financial statements and accompanying notes. These estimates, assumptions, and judgments are based on information available as of the date of the financial statements; accordingly, as this information changes, the financial statements could reflect different estimates, assumptions, and judgments and as such have a greater possibility of producing results that could be materially different than originally reported. Estimates, assumptions, and judgments are necessary when assets and liabilities are required to be recorded at fair value, when a decline in fair value of an asset not third may 2019
Consolidation, Policy [Policy Text Block]	Principles of Consolidation. The consolidated financial statements include the accounts of the Company and all the Company’s subsidiaries. Significant intercompany transactions have been eliminated in consolidation. The Company does not
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash. Cash includes Due From Banks balances which are readily convertible to known amounts of cash and are generally 90
Marketable Securities, Policy [Policy Text Block]	quity Securities. Equity securities consist of marketable equity securities and mutual funds which are recorded at fair value. Unrealized gains and losses are included in net income effective January 1, 2018 Debt Securities. Debt securities consist of securities of the U.S. Treasury, government sponsored entities, states, counties, municipalities, corporations, agency and non-agency mortgage-backed securities and asset-backed securities. Securities transactions are recorded on a trade date basis. The Company classifies its debt securities in one three not The Company utilizes third 1 2 third one third third not 3 A decline in the market value of any available for sale or held to maturity security below amortized cost that is deemed other than temporary results in a charge to earnings and the establishment of a new cost basis for the security. Unrealized investment securities losses are evaluated at least quarterly to determine whether such declines in value should be considered “other than temporary” and therefore be subject to immediate loss recognition in income. Although these evaluations involve significant judgment, an unrealized loss in the fair value of a debt security is generally deemed to be temporary when the fair value of the security is below the carrying value primarily due to changes in risk-free interest rates, there has not not not not may The Company follows the guidance issued by the Board of Governors of the Federal Reserve System, “Investing in Securities without Reliance on Nationally Recognized Statistical Rating Agencies” (SR 12 15 Purchase premiums are amortized and purchase discounts are accreted over the estimated life of the related investment security as an adjustment to yield using the effective interest method. Unamortized premiums, unaccreted discounts, and early payment premiums are recognized as a component of gain or loss on sale upon disposition of the related security. Interest and dividend income are recognized when earned. Realized gains and losses from the sale of available for sale securities are included in earnings using the specific identification method.
Cost Method Investments, Policy [Policy Text Block]	Nonmarketable Equity Securities. Nonmarketable equity securities include securities that are not
Finance, Loans and Leases Receivable, Policy [Policy Text Block]	Loans. Loans are stated at the principal amount outstanding, net of unearned discount and unamortized deferred fees and costs. Interest is accrued daily on the outstanding principal balances. Loans which are more than 90 120 The Company evaluates all classified loans and nonaccrual loans with outstanding principal balances in excess of $500 310 40, not Nonrefundable fees and certain costs associated with originating or acquiring loans are deferred and amortized as an adjustment to interest income over the contractual loan lives. Upon prepayment, unamortized loan fees, net of costs, are immediately recognized in interest income. Other fees, including those collected upon principal prepayments, are included in interest income when received. Loans held for sale are identified upon origination and are reported at the lower of cost or market value on an aggregate loan basis. Purchased Loans. Purchased loans are recorded at estimated fair value on the date of purchase. Impaired purchased loans are accounted for under FASB ASC 310 30, not may 310 30. 310 30 not 310 30 Covered Loans. Loans covered under loss-sharing or similar credit protection agreements with the FDIC are reported in loans exclusive of the expected reimbursement cash flows from the FDIC. Covered loans are initially recorded at fair value at the acquisition date. Subsequent decreases in the amount expected to be collected results in a provision for loan losses and a corresponding increase in the estimated FDIC reimbursement, with the estimated net loss impacting earnings. Interest previously accrued on covered loans placed on nonaccrual status is charged against interest income, net of estimated FDIC reimbursements of such accrued interest. The FDIC reimburses the Company up to 80% 90 February 6, 2019.
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]	Allowance for Credit Losses. The Company extends loans to commercial and consumer customers primarily in Northern and Central California. These lending activities expose the Company to the risk borrowers will default, causing loan losses. The Company’s lending activities are exposed to various qualitative risks. All loan segments are exposed to risks inherent in the economy and market conditions. Significant risk characteristics related to the commercial loan segment include the borrowers’ business performance and financial condition, and the value of collateral for secured loans. Significant risk characteristics related to the commercial real estate segment include the borrowers’ business performance and the value of properties collateralizing the loans. Significant risk characteristics related to the construction loan segment include the borrowers’ performance in successfully developing the real estate into the intended purpose and the value of the property collateralizing the loans. Significant risk characteristics related to the residential real estate segment include the borrowers’ financial wherewithal to service the mortgages and the value of the property collateralizing the loans. Significant risk characteristics related to the consumer loan segment include the financial condition of the borrowers and the value of collateral securing the loans. The preparation of these financial statements requires Management to estimate the amount of probable incurred losses inherent in the loan portfolio and establish an allowance for credit losses. In estimating credit losses, Management must exercise significant judgment in evaluating information deemed relevant. The amount of ultimate losses on the loan portfolio can vary from the estimated amounts. Management follows a systematic methodology to estimate loss potential in an effort to reduce the differences between estimated and actual losses. The allowance for credit losses is established through provisions for credit losses charged to income. Losses on loans, including impaired loans, are charged to the allowance for loan losses when all or a portion of the recorded amount of a loan is deemed to be uncollectible. Recoveries of loans previously charged off are credited to the allowance when realized. The Company’s allowance for credit losses is maintained at a level considered adequate to provide for losses that can be estimated based upon specific and general conditions. These include conditions unique to individual borrowers, as well as overall credit loss experience, the amount of past due, nonperforming and classified loans, recommendations of regulatory authorities, prevailing economic conditions, FDIC loss-sharing or similar credit protection agreements and other factors. A portion of the allowance is specifically allocated to impaired loans whose full collectability is uncertain. Such allocations are determined by Management based on loan-by-loan analyses. The Company evaluates all classified loans and nonaccrual loans with outstanding principal balances in excess of $500 second not not not not
Off-Balance-Sheet Credit Exposure, Policy [Policy Text Block]	Liability for Off-Balance Sheet Credit Exposures. A liability for off-balance sheet credit exposures is established through expense recognition. Off-balance sheet credit exposures relate to letters of credit and unfunded loan commitments for commercial, construction and consumer loans. Historical credit loss factors for commercial, construction and consumer loans are applied to the amount of these off-balance sheet credit exposures to estimate inherent losses.
Loans and Leases Receivable, Real Estate Acquired Through Foreclosure, Policy [Policy Text Block]	Other Real Estate Owned. Other real estate owned is comprised of property acquired through foreclosure proceedings, acceptances of deeds-in-lieu of foreclosure and, if applicable, vacated bank properties. Losses recognized at the time of acquiring property in full or partial satisfaction of debt are charged against the allowance for credit losses. Other real estate owned is recorded at the fair value of the collateral, generally based upon an independent property appraisal, less estimated disposition costs. Losses incurred subsequent to acquisition due to any decline in annual independent property appraisals are recognized as noninterest expense. Routine holding costs, such as property taxes, insurance and maintenance, and losses from sales and dispositions, are recognized as noninterest expense.
Property, Plant and Equipment, Policy [Policy Text Block]	Premises and Equipment. Premises and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation is computed substantially on the straight-line method over the estimated useful life of each type of asset. Estimated useful lives of premises and equipment range from 20 50 3 20
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition. The Company recognizes revenue as it is earned based on contractual terms, as transactions occur, or as services are provided and collectability is reasonably assured. In certain circumstances, noninterest income is reported net of associated expenses that are directly related to variable volume-based sales or revenue sharing arrangements or when the Company acts on an agency basis for others.
Life Insurance Cash Surrender Value [Policy Text Block]	Life Insurance Cash Surrender Value. The Company has purchased life insurance policies on certain directors and officers as well as acquired such assets as part of the acquisition of other banks. 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. These assets are included in other assets on the consolidated balance sheets.
Goodwill and Intangible Assets, Policy [Policy Text Block]	Intangible Assets. Intangible assets are comprised of goodwill, core deposit intangibles and other identifiable intangibles acquired in business combinations. Intangible assets with definite useful lives are amortized on an accelerated basis over their respective estimated useful lives not 15 may not not first 2011 08, Testing for Goodwill Impairment. first
Impairment of Long Lived Assets [Policy Text Block]	Impairment of Long-Lived Assets. The Company reviews its long-lived and certain intangible assets for impairment whenever events or changes indicate that the carrying amount of an asset may not
Income Tax, Policy [Policy Text Block]	Income Taxes. The Company and its subsidiaries file consolidated tax returns. The Company accounts for income taxes in accordance with FASB ASC 740, two not. not fifty
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	Stock Options. The Company applies FASB ASC 718 no
Extinguishment of Debt [Policy Text Block]	Extinguishment of Debt. Gains and losses, including fees, incurred in connection with the early extinguishment of debt are charged to current earnings as reductions in noninterest income.
Postemployment Benefit Plans, Policy [Policy Text Block]	Postretirement Benefits. The Company uses an actuarial-based accrual method of accounting for post-retirement benefits.
Fiduciary [Policy Text Block]	Other. Securities and other property held by the Bank in a fiduciary or agency capacity are not not
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Accounting Standards In 2018, FASB Accounting Standard Update (ASU) 2014 09 Revenue (Topic 606 May 2014. not 606 not All of the Company’s net interest income and a portion of its noninterest income are out of scope of the guidance. The contracts that are in scope of the guidance are primarily related to service charges and fees on deposit accounts, merchant processing fees, debit card fees, ATM processing fees, trust fees and other service charges, commissions and fees. The Company’s revenue recognition practices within the scope of the ASU as described below did not Service Charges on Deposit Accounts, ATM Processing Fees and Other Service Fees Merchant Processing Services and Debit Card Fees Trust Fees Gains/Losses on Sales of OREO not $110 $72 $1,185 twelve December 31, 2018 2017 2016, The Company adopted the ASU on January 1, 2018 no FASB ASU 2016 01 Financial Instruments – Overall (Subtopic 825 10 January 2016. 11 The Company was required to adopt the ASU provisions on January 1, 2018, not January 1, 2018, $142 FASB ASU 2018 02 Income Statement – Reporting Comprehensive Income (Topic 220 February 2018. 2017 2017. January 1, 2018, $3,625 Recently Issued Accounting Standards FASB ASU 2016 02, Leases (Topic 842 February 25, 2016. January 1, 2019, $15.3 $15.3 not FASB ASU 2016 13, Financial Instruments – Credit Losses (Topic 326 June 16, 2016. The Company will be required to adopt the ASU provisions on January 1, 2020. September 30, 2019. FASB ASU 2017 08 Receivables – Non-Refundable Fees and Other Costs (Subtopic 310 20 March 2017. not January 1, 2019. $3.1 $2.8 not FASB ASU 2017 12 Derivatives and Hedging (Topic 815 August 2017. one The Company will be required to adopt the ASU provisions on January 1, 2019. not may not one FASB ASU 2018 13 Fair Value Measurements (Topic 820 August 2018. The provisions of the ASU are effective January 1, 2020 11 January 1, 2020. not

Note 2 - Investment Securities

Note 2 - Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Debt Securities, Available-for-sale and Held-to-maturity [Table Text Block]	Amortized Gross Gross Fair At December 31, 2018 (In thousands) Debt securities available for sale U.S. Treasury securities $ 139,572 $ 5 $ (3 ) $ 139,574 Securities of U.S. Government sponsored entities 167,228 65 (3,275 ) 164,018 Agency residential mortgage-backed securities (MBS) 883,715 595 (30,439 ) 853,871 Non-agency residential MBS 113 1 - 114 Agency commercial MBS 1,869 - (27 ) 1,842 Securities of U.S. Government entities 1,128 - (9 ) 1,119 Obligations of states and political subdivisions 180,220 1,856 (2,985 ) 179,091 Corporate securities 1,337,608 1,075 (23,642 ) 1,315,041 Total debt securities available for sale 2,711,453 3,597 (60,380 ) 2,654,670 Debt securities held to maturity Agency residential MBS 447,332 249 (14,129 ) 433,452 Non-agency residential MBS 3,387 40 - 3,427 Obligations of states and political subdivisions 533,890 3,403 (2,727 ) 534,566 Total debt securities held to maturity 984,609 3,692 (16,856 ) 971,445 Total $ 3,696,062 $ 7,289 $ (77,236 ) $ 3,626,115 Amortized Gross Gross Fair At December 31, 2017 (In thousands) Debt securities available for sale Securities of U.S. Government sponsored entities $ 122,285 $ 1 $ (2,967 ) $ 119,319 Agency residential MBS 787,679 522 (20,495 ) 767,706 Non-agency residential MBS 153 1 - 154 Agency commercial MBS 2,244 - (25 ) 2,219 Securities of U.S. Government entities 1,612 - (22 ) 1,590 Obligations of states and political subdivisions 182,907 3,796 (1,482 ) 185,221 Corporate securities 1,123,671 1,104 (9,277 ) 1,115,498 Total debt securities available for sale 2,220,551 5,424 (34,268 ) 2,191,707 Debt securities held to maturity Agency residential MBS 545,883 606 (9,850 ) 536,639 Non-agency residential MBS 4,462 70 - 4,532 Agency commercial MBS 9,041 - (66 ) 8,975 Obligations of states and political subdivisions 599,478 7,736 (2,018 ) 605,196 Total debt securities held to maturity 1,158,864 8,412 (11,934 ) 1,155,342 Total $ 3,379,415 $ 13,836 $ (46,202 ) $ 3,347,049
Investments Classified by Contractual Maturity Date [Table Text Block]	At December 31, 2018 Debt Securities Available Debt Securities Held Amortized Fair Amortized Fair (In thousands) Maturity in years: 1 year or less $ 262,418 $ 261,976 $ 86,172 $ 86,148 Over 1 to 5 years 1,438,849 1,414,020 214,137 213,829 Over 5 to 10 years 85,817 85,877 232,544 233,515 Over 10 years 38,672 36,970 1,037 1,074 Subtotal 1,825,756 1,798,843 533,890 534,566 MBS 885,697 855,827 450,719 436,879 Total $ 2,711,453 $ 2,654,670 $ 984,609 $ 971,445 At December 31, 2017 Debt Securities Available Debt Securities Held Amortized Fair Amortized Fair (In thousands) Maturity in years: 1 year or less $ 193,337 $ 193,385 $ 50,295 $ 51,105 Over 1 to 5 years 1,031,807 1,023,047 269,050 269,471 Over 5 to 10 years 159,266 160,042 277,170 281,546 Over 10 years 46,065 45,154 2,963 3,074 Subtotal 1,430,475 1,421,628 599,478 605,196 MBS 790,076 770,079 559,386 550,146 Total $ 2,220,551 $ 2,191,707 $ 1,158,864 $ 1,155,342
Schedule of Unrealized Loss on Investments [Table Text Block]	Debt Securities Available for Sale No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrealized Investment Unrealized Investment Unrealized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) U.S. Treasury securities 2 $ 54,805 $ (3 ) - $ - $ - 2 $ 54,805 $ (3 ) Securities of U.S. Government sponsored entities 1 990 (5 ) 9 117,963 (3,270 ) 10 118,953 (3,275 ) Agency residential MBS 8 107,497 (507 ) 58 640,210 (29,932 ) 66 747,707 (30,439 ) Agency commercial MBS 1 1,842 (27 ) - - - 1 1,842 (27 ) Securities of U.S. Government entities - - - 2 1,119 (9 ) 2 1,119 (9 ) Obligations of states and political 32 26,452 (166 ) 71 67,121 (2,819 ) 103 93,573 (2,985 ) Corporate securities 38 308,157 (3,403 ) 79 722,740 (20,239 ) 117 1,030,897 (23,642 ) Total 82 $ 499,743 $ (4,111 ) 219 $ 1,549,153 $ (56,269 ) 301 $ 2,048,896 $ (60,380 ) Debt Securities Held to Maturity No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrecognized Investment Unrecognized Investment Unrecognized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Agency residential MBS 16 $ 8,495 $ (34 ) 78 $ 412,574 $ (14,095 ) 94 $ 421,069 $ (14,129 ) Non-agency residential MBS 1 26 - - - - 1 26 - Obligations of states and political 97 83,633 (271 ) 142 151,546 (2,456 ) 239 235,179 (2,727 ) Total 114 $ 92,154 $ (305 ) 220 $ 564,120 $ (16,551 ) 334 $ 656,274 $ (16,856 ) Debt Securities Available for Sale At December 31, 2017 No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrealized Investment Unrealized Investment Unrealized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Securities of U.S. Government 1 $ 996 $ (2 ) 8 $ 117,252 $ (2,965 ) 9 $ 118,248 $ (2,967 ) Agency residential MBS 7 238,554 (1,501 ) 51 516,711 (18,994 ) 58 755,265 (20,495 ) Non-agency residential MBS 1 1 - - - - 1 1 - Agency commercial MBS 2 2,219 (25 ) - - - 2 2,219 (25 ) Securities of U.S. Government entities - - - 3 1,590 (22 ) 3 1,590 (22 ) Obligations of states and political 50 21,453 (228 ) 35 52,071 (1,254 ) 85 73,524 (1,482 ) Corporate securities 64 571,112 (4,047 ) 38 282,924 (5,230 ) 102 854,036 (9,277 ) Total 125 $ 834,335 $ (5,803 ) 135 $ 970,548 $ (28,465 ) 260 $ 1,804,883 $ (34,268 ) Debt Securities Held to Maturity At December 31, 2017 No. of Less than 12 months No. of 12 months or longer No. of Total Investment Unrecognized Investment Unrecognized Investment Unrecognized Positions Fair Value Losses Positions Fair Value Losses Positions Fair Value Losses ($ in thousands) Agency residential MBS 15 $ 30,218 $ (201 ) 65 $ 479,775 $ (9,649 ) 80 $ 509,993 $ (9,850 ) Agency commercial MBS 1 1,913 (4 ) 1 7,062 (62 ) 2 8,975 (66 ) Obligations of states and political subdivisions 146 131,032 (553 ) 59 58,979 (1,465 ) 205 190,011 (2,018 ) Total 162 $ 163,163 $ (758 ) 125 $ 545,816 $ (11,176 ) 287 $ 708,979 $ (11,934 )
Interest Income from Investments [Table Text Block]	For the Years Ended December 31, 2018 2017 2016 (In thousands) Taxable $ 65,330 $ 51,445 $ 42,718 Tax-exempt from regular federal income tax 19,438 20,651 22,194 Total interest income from investment securities $ 84,768 $ 72,096 $ 64,912

Note 3 - Loans and Allowance _2

Note 3 - Loans and Allowance for Credit Losses (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Loans Receivable [Table Text Block]	At Decmber 31, 2018 2017 (In thousands) Commercial $ 275,080 $ 335,996 Commercial Real Estate 580,480 568,584 Construction 3,982 5,649 Residential Real Estate 44,866 65,183 Consumer Installment & Other 302,794 312,570 Total $ 1,207,202 $ 1,287,982
Accretable Yield Reconciliation Schedule [Table Text Block]	For the Years Ended December 31, 2018 2017 Accretable yield: (In thousands) Balance at the beginning of the period $ 738 $ 1,237 Reclassification from nonaccretable difference 1,119 1,852 Accretion (1,675 ) (2,351 ) Balance at the end of the period $ 182 $ 738 Accretion $ (1,675 ) $ (2,351 ) Change in FDIC indemnification 2 192 (Increase) in interest income $ (1,673 ) $ (2,159 )
Schedule of Credit Losses Related to Financing Receivables, Current and Noncurrent [Table Text Block]	Allowance for Loan Losses Commercial Commercial Construction Residential Consumer Unallocated Total (In thousands) Allowance for loan losses: Balance at beginning of period $ 7,746 $ 3,849 $ 335 $ 995 $ 6,418 $ 3,666 $ 23,009 (Reversal) provision (2,369 ) 275 1,130 (126 ) 1,579 (489 ) - Chargeoffs (513 ) (240 ) - - (4,124 ) - (4,877 ) Recoveries 1,447 - - - 1,772 - 3,219 Total allowance for loan losses $ 6,311 $ 3,884 $ 1,465 $ 869 $ 5,645 $ 3,177 $ 21,351 Allowance for Loan Losses Commercial Commercial Construction Residential Consumer Unallocated Total (In thousands) Allowance for loan losses: Balance at beginning of period $ 8,327 $ 3,330 $ 152 $ 1,330 $ 7,980 $ 4,835 $ 25,954 (Reversal) provision (382 ) 431 (1,716 ) (335 ) 1,271 (1,169 ) (1,900 ) Chargeoffs (961 ) - - - (4,957 ) - (5,918 ) Recoveries 762 88 1,899 - 2,124 - 4,873 Total allowance for loan losses $ 7,746 $ 3,849 $ 335 $ 995 $ 6,418 $ 3,666 $ 23,009 Allowance for Credit Losses Commercial Commercial Construction Residential Consumer Unallocated Total (In thousands) Allowance for loan losses: Balance at beginning of period $ 9,559 $ 4,212 $ 235 $ 1,801 $ 8,001 $ 5,963 $ 29,771 (Reversal) provision (3,237 ) (1,436 ) (83 ) (471 ) 3,155 (1,128 ) (3,200 ) Chargeoffs (2,023 ) - - - (4,749 ) - (6,772 ) Recoveries 4,028 554 - - 1,573 - 6,155 Total allowance for loan losses $ 8,327 $ 3,330 $ 152 $ 1,330 $ 7,980 $ 4,835 $ 25,954
Schedule of Recorded Investment in Loans Evaluated for Impairment [Table Text Block]	Allowance for Loan Losses and Recorded Investment in Loans Evaluated for Impairment Commercial Commercial Real Estate Construction Residential Real Estate Consumer Installment and Other Unallocated Total (In thousands) Allowance for loan losses: Individually evaluated for impairment $ 2,752 $ - $ - $ - $ - $ - $ 2,752 Collectively evaluated for impairment 3,559 3,884 1,465 869 5,645 3,177 18,599 Purchased loans with evidence of credit deterioration - - - - - - - Total $ 6,311 $ 3,884 $ 1,465 $ 869 $ 5,645 $ 3,177 $ 21,351 Carrying value of loans: Individually evaluated for impairment $ 9,921 $ 8,217 $ - $ 717 $ - $ - $ 18,855 Collectively evaluated for impairment 265,136 572,042 3,982 44,149 302,651 - 1,187,960 Purchased loans with evidence of credit deterioration 23 221 - - 143 - 387 Total $ 275,080 $ 580,480 $ 3,982 $ 44,866 $ 302,794 $ - $ 1,207,202 Allowance for Loan Losses and Recorded Investment in Loans Evaluated for Impairment Commercial Commercial Real Estate Construction Residential Real Estate Consumer Installment and Other Unallocated Total (In thousands) Allowance for loan losses: Individually evaluated for impairment $ 4,814 $ 171 $ - $ - $ - $ - $ 4,985 Collectively evaluated for impairment 2,932 3,678 335 995 6,418 3,666 18,024 Purchased loans with evidence of credit deterioration - - - - - - - Total $ 7,746 $ 3,849 $ 335 $ 995 $ 6,418 $ 3,666 $ 23,009 Carrying value of loans: Individually evaluated for impairment $ 10,675 $ 14,234 $ - $ 208 $ - $ - $ 25,117 Collectively evaluated for impairment 325,291 553,769 5,649 64,975 312,406 - 1,262,090 Purchased loans with evidence of credit deterioration 30 581 - - 164 - 775 Total $ 335,996 $ 568,584 $ 5,649 $ 65,183 $ 312,570 $ - $ 1,287,982
Financing Receivable Credit Quality Indicators [Table Text Block]	Credit Risk Profile by Internally Assigned Grade Commercial Commercial Real Estate Construction Residential Real Estate Consumer Installment and Other Total (In thousands) Grade: Pass $ 264,634 $ 567,578 $ 3,982 $ 43,112 $ 300,553 $ 1,179,859 Substandard 10,446 12,902 - 1,754 1,556 26,658 Doubtful - - - - 135 135 Loss - - - - 550 550 Total $ 275,080 $ 580,480 $ 3,982 $ 44,866 $ 302,794 $ 1,207,202 Credit Risk Profile by Internally Assigned Grade Commercial Commercial Real Estate Construction Residential Real Estate Consumer Installment and Other Total (In thousands) Grade: Pass $ 324,185 $ 548,853 $ 5,649 $ 62,253 $ 310,429 $ 1,251,369 Substandard 11,811 19,731 - 2,930 1,370 35,842 Doubtful - - - - 1 1 Loss - - - - 770 770 Total $ 335,996 $ 568,584 $ 5,649 $ 65,183 $ 312,570 $ 1,287,982
Past Due Financing Receivables [Table Text Block]	Summary of Loans by Delinquency and Nonaccrual Status Current and Accruing 30-59 Days Past Due and Accruing 60-89 Days Past Due and Accruing Past Due 90 Days or More and Accruing Nonaccrual Total Loans (In thousands) Commercial $ 274,045 $ 781 $ 254 $ - $ - $ 275,080 Commercial real estate 574,853 617 785 - 4,225 580,480 Construction 3,982 - - - - 3,982 Residential real estate 43,372 789 189 - 516 44,866 Consumer installment and other 297,601 3,408 1,107 551 127 302,794 Total $ 1,193,853 $ 5,595 $ 2,335 $ 551 $ 4,868 $ 1,207,202 Summary of Loans by Delinquency and Nonaccrual Status Current and Accruing 30-59 Days Past Due and Accruing 60-89 Days Past Due and Accruing Past Due 90 Days or More and Accruing Nonaccrual Total Loans (In thousands) Commercial $ 334,908 $ 627 $ 164 $ - $ 297 $ 335,996 Commercial real estate 561,883 1,143 125 - 5,433 568,584 Construction 5,649 - - - - 5,649 Residential real estate 65,183 - - - - 65,183 Consumer installment and other 307,445 3,321 1,077 531 196 312,570 Total $ 1,275,068 $ 5,091 $ 1,366 $ 531 $ 5,926 $ 1,287,982
Impaired Financing Receivables [Table Text Block]	Impaired Loans 2018 2017 Recorded Unpaid Related Recorded Unpaid Related (In thousands) With no related allowance recorded: Commercial $ 755 $ 759 $ - $ 1,212 $ 1,271 $ - Commercial real estate 8,438 10,373 - 13,169 14,985 - Residential real estate 717 747 - 208 239 - Consumer installment and other 270 377 - 360 466 - Total with no related allowance recorded 10,180 12,256 - 14,949 16,961 - With an allowance recorded: Commercial 9,189 9,189 2,752 9,764 9,764 4,814 Commercial real estate - - - 1,790 1,792 171 Total with an allowance recorded 9,189 9,189 2,752 11,554 11,556 4,985 Total $ 19,369 $ 21,445 $ 2,752 $ 26,503 $ 28,517 $ 4,985
Impaired Financing Receivables Supplemental Schedule [Table Text Block]	Impaired Loans 2018 2017 2016 Average Recognized Average Recognized Average Recognized (In thousands) Commercial $ 10,532 $ 667 $ 11,156 $ 508 $ 12,923 $ 512 Commercial real estate 11,703 758 14,806 884 16,701 725 Construction - - - - 102 - Residential real estate 269 19 423 17 746 19 Consumer installment and other 254 14 415 20 473 25 Total $ 22,758 $ 1,458 $ 26,800 $ 1,429 $ 30,945 $ 1,281
Troubled Debt Restructurings on Financing Receivables [Table Text Block]	Troubled Debt Restructurings Number of Pre-Modification Period-End Period-End ($ in thousands) Commercial 4 $ 2,274 $ 811 $ 19 Commercial real estate 8 9,237 7,568 - Residential real estate 1 241 200 - Total 13 $ 11,752 $ 8,579 $ 19 Troubled Debt Restructurings Number of Pre-Modification Period-End Period-End ($ in thousands) Commercial 7 $ 2,393 $ 1,085 $ 43 Commercial real estate 10 11,528 10,788 - Residential real estate 1 241 208 - Total 18 $ 14,162 $ 12,081 $ 43 Troubled Debt Restructurings Number of Pre-Modification Period-End Period-End ($ in thousands) Commercial 7 $ 2,719 $ 1,489 $ 113 Commercial real estate 10 11,257 10,673 - Residential real estate 1 241 219 - Total 18 $ 14,217 $ 12,381 $ 113

Note 5 - Premises, Equipment _2

Note 5 - Premises, Equipment and Other Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Premises and Equipment [Table Text Block]	At December 31, Cost Accumulated Depreciation and Amortization Net Book Value (In thousands) 2018 Land $ 11,691 $ - $ 11,691 Building and improvements 41,912 (27,178 ) 14,734 Leasehold improvements 6,174 (4,968 ) 1,206 Furniture and equipment 23,845 (16,969 ) 6,876 Total $ 83,622 $ (49,115 ) $ 34,507 2017 Land $ 11,796 $ - $ 11,796 Building and improvements 41,641 (26,249 ) 15,392 Leasehold improvements 5,817 (4,790 ) 1,027 Furniture and equipment 22,284 (15,198 ) 7,086 Total $ 81,538 $ (46,237 ) $ 35,301
Schedule of Other Assets [Table Text Block]	At December 31, 2018 2017 (In thousands) Cost method equity investments: Federal Reserve Bank stock (1) $ 14,069 $ 14,069 Other investments 158 158 Total cost method equity investments 14,227 14,227 Life insurance cash surrender value 56,083 54,101 Net deferred tax asset 42,256 33,112 Limited partnership investments 10,219 10,119 Interest receivable 25,834 23,557 Prepaid assets 4,658 4,906 Other assets 9,629 18,428 Total other assets $ 162,906 $ 158,450
Schedule of Amounts Recognized in Net Income [Table Text Block]	For the Years Ended December 31, 2018 2017 2016 (In thousands) Investment loss included in pre-tax income $ 2,900 $ 1,800 $ 2,475 Valuation impairment included in pre-tax income - 625 - Tax credits recognized in provision for income taxes 1,121 1,850 2,286

Note 6 - Goodwill and Identif_2

Note 6 - Goodwill and Identifiable Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Goodwill [Table Text Block]	At December 31, 2018 2017 (In thousands) Goodwill $ 121,673 $ 121,673
Schedule of Finite-Lived Intangible Assets [Table Text Block]	At December 31, 2018 2017 Gross Accumulated Gross Accumulated (In thousands) Core Deposit Intangibles $ 56,808 $ (54,879 ) $ 56,808 $ (52,987 ) Merchant Draft Processing Intangible 10,300 (10,300 ) 10,300 (10,271 ) Total Identifiable Intangible Assets $ 67,108 $ (65,179 ) $ 67,108 $ (63,258 )
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	Core Merchant Total (In thousands) For the Year Ended December 31, 2018 (actual) $ 1,892 $ 29 $ 1,921 Estimate for the Year Ended December 31, 2019 538 - 538 2020 287 - 287 2021 269 - 269 2022 252 - 252 2023 236 - 236

Note 7 - Deposits and Borrowe_2

Note 7 - Deposits and Borrowed Funds (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Deposit Liabilities, Type [Table Text Block]	Deposits At December 31, 2018 2017 (In thousands) Noninterest-bearing $ 2,243,251 $ 2,197,526 Interest-bearing: Transaction 929,346 904,245 Savings 1,498,991 1,494,024 Time deposits less than $100 thousand 102,654 117,848 Time deposits $100 thousand through $250 thousand 64,512 76,578 Time deposits more than $250 thousand 28,085 37,392 Total deposits $ 4,866,839 $ 4,827,613
Schedule of Repurchase Agreements [Table Text Block]	Repurchase Agreements (Sweep) Remaining Contractual Maturity of the Agreements At December 31, 2018 2017 Repurchase agreements: (In thousands) Collateral securing borrowings: Securities of U.S. Government sponsored entities $ 73,803 $ 74,173 Agency residential MBS 58,380 58,251 Corporate securities 91,837 105,113 Total collateral carrying value $ 224,020 $ 237,537 Total short-term borrowed funds $ 51,247 $ 58,471
Borrowed Funds Highest Month End Balance [Table Text Block]	For the Years Ended December 31, 2018 2017 Highest Balance at Any Month-end (In thousands) Securities sold under repurchase agreements $ 68,894 $ 82,126

Note 8 - Shareholders' Equity (

Note 8 - Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]	Options Outstanding Options Exercisable At December 31, 2018 For the Year Ended December 31, 2018 At December 31, 2018 For the Year Ended December 31, 2018 Range of Exercise Price Number Outstanding Aggregate Intrinsic Value Weighted Average Remaining Contractual Life Weighted Average Exercise Price Number Exercisable Aggregate Intrinsic Value Weighted Average Remaining Contractual Life Weighted Average Exercise Price (In thousands) (Years) (In thousands) (Years) $40 - 45 176 $ 2,309 6.6 $ 43 87 $ 1,122 6.1 $ 43 45 - 50 11 106 3.1 46 11 106 3.1 46 50 - 55 286 1,297 0.7 51 286 1,297 0.7 51 55 - 60 229 - 7.7 57 73 - 6.9 57 60 - 65 244 - 9.1 62 - N/A N/A N/A $40 - 65 946 $ 3,712 5.7 54 457 $ 2,525 2.8 50
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	For the Years Ended December 31, 2018 2017 2016 Expected volatility (1) 20 % 20 % 22 % Expected life in years (2) 4.8 4.8 4.8 Risk-free interest rate (3) 2.50 % 1.97 % 1.41 % Expected dividend yield 2.65 % 3.28 % 4.49 % Fair value per award $ 9.98 $ 8.27 $ 5.97
Share-based Compensation, Stock Options, Activity [Table Text Block]	Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (In thousands) (Years) Outstanding at January 1, 2018 1,030 $ 49.44 Granted 249 62.16 Exercised (292 ) 45.76 Forfeited or expired (41 ) 52.54 Outstanding at December 31, 2018 946 $ 53.78 5.7 Exercisable at December 31, 2018 457 $ 50.38 2.8
Schedule of Nonvested Share Activity [Table Text Block]	Shares Weighted Average Grant Date Fair Value (In thousands) Nonvested at January 1, 2018 561 $ 6.98 Granted 249 9.98 Vested (280 ) 6.54 Forfeited (41 ) 7.66 Nonvested at December 31, 2018 489 8.71
Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]	2018 2017 (In thousands) Outstanding at January 1, 49 48 Granted 11 14 Issued upon vesting (19 ) (13 ) Forfeited (2 ) - Outstanding at December 31, 39 49

Note 9 - Regulatory Capital (Ta

Note 9 - Regulatory Capital (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]	At December 31, 2018 Required To Be Well-capitalized Amount Ratio Amount Ratio Amount Ratio ($ in thousands) Common Equity Tier 1 Capital Company $ 528,042 16.30 % $ 206,576 6.375 % (1) N/A N/A Bank 415,575 13.01 % 203,664 6.375 % (1) $ 207,658 6.50 % Tier 1 Capital Company 528,042 16.30 % 255,182 7.875 % (1) N/A N/A Bank 415,575 13.01 % 251,585 7.875 % (1) 255,579 8.00 % Total Capital Company 551,701 17.03 % 319,990 9.875 % (1) N/A N/A Bank 445,234 13.94 % 315,480 9.875 % (1) 319,474 10.00 % Leverage Ratio (2) Company 528,042 9.51 % 222,111 4.000 % N/A N/A Bank 415,575 7.55 % 220,312 4.000 % 275,390 5.00 % At December 31, 2017 Required To Be Well-capitalized Amount Ratio Amount Ratio Amount Ratio ($ in thousands) Common Equity Tier 1 Capital Company $ 479,259 15.36 % $ 179,377 5.75 % (3) N/A N/A Bank 383,796 12.50 % 176,568 5.75 % (3) $ 199,599 6.50 % Tier 1 Capital Company 479,259 15.36 % 226,170 7.25 % (3) N/A N/A Bank 383,796 12.50 % 222,630 7.25 % (3) 245,660 8.00 % Total Capital Company 504,576 16.17 % 288,562 9.25 % (3) N/A N/A Bank 415,113 13.52 % 284,045 9.25 % (3) 307,076 10.00 % Leverage Ratio (2) Company 479,259 8.86 % 216,280 4.000 % N/A N/A Bank 383,796 7.16 % 214,468 4.000 % 268,085 5.00 %

Note 10 - Income Taxes (Tables)

Note 10 - Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	At December 31, 2018 2017 (In thousands) Deferred tax asset Allowance for credit losses $ 6,868 $ 7,349 State franchise taxes 3,026 1,871 AMT carryforward - 1,752 Securities available for sale 16,787 8,586 Deferred compensation 5,229 5,279 Real estate owned 553 553 Purchased assets and assumed liabilities 935 1,111 Post-retirement benefits 555 526 Employee benefit accruals 2,104 2,066 VISA Class B shares 167 96 Limited partnership investments 708 57 Impaired capital assets 3,070 3,056 Accrued liabilities 2,554 1,609 Premises and equipment 31 299 Other 721 520 Total deferred tax asset 43,308 34,730 Deferred tax liability Net deferred loan fees 291 281 Intangible assets 761 1,247 Other - 90 Total deferred tax liability 1,052 1,618 Net deferred tax asset $ 42,256 $ 33,112
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	For the Years Ended December 31, 2018 2017 2016 (In thousands) Current income tax expense: Federal $ 10,560 $ 1,778 $ 16,258 State 9,816 7,810 7,292 Total current 20,376 9,588 23,550 Deferred income tax (benefit) expense: Federal (206 ) 14,461 (2,604 ) State (737 ) 783 158 Total deferred (943 ) 15,244 (2,446 ) Adjustment of net deferred tax asset for enacted changes in tax rates: Federal - 12,315 - State - - - Total adjustments - 12,315 - Provision for income taxes $ 19,433 $ 37,147 $ 21,104
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	For the Years Ended December 31, 2018 2017 2016 (In thousands) Federal income taxes due at statutory rate $ 19,109 $ 30,509 $ 27,985 Reductions in income taxes resulting from: Interest on state and municipal securities and loans not taxable for federal income tax purposes (4,375 ) (7,794 ) (8,382 ) State franchise taxes, net of federal income tax benefit 7,173 5,586 4,843 Re-measurement of net deferred tax asset due to enactment of new federal tax rate - 12,315 - Stock compensation deduction in excess of book expense (528 ) (583 ) - Tax credits (1,291 ) (1,850 ) (2,286 ) Dividend received deduction (32 ) (60 ) (52 ) Cash value life insurance (490 ) (603 ) (607 ) Other (133 ) (373 ) (397 ) Provision for income taxes $ 19,433 $ 37,147 $ 21,104
Summary of Income Tax Contingencies [Table Text Block]	2018 2017 (In thousands) Balance at January 1, $ 909 $ 1,099 Additions for tax positions taken in the current period - - Reductions for tax positions taken in the current period - - Additions for tax positions taken in prior years - - Reductions for tax positions taken in prior years - - Decrease related to settlements with taxing authorities - (190 ) Decrease as a result of a lapse in statute of limitations - - Balance at December 31, $ 909 $ 909

Note 11 - Fair Value Measurem_2

Note 11 - Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	At December 31, 2018 Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs (1) (In thousands) Equity securities Mutual funds $ 1,747 $ - $ 1,747 $ - Total equity securities 1,747 - 1,747 - Debt securities available for sale U.S. Treasury securities 139,574 139,574 - - Securities of U.S. Government sponsored entities 164,018 - 164,018 - Agency residential MBS 853,871 - 853,871 - Non-agency residential MBS 114 - 114 - Agency commercial MBS 1,842 - 1,842 - Securities of U.S. Government entities 1,119 - 1,119 - Obligations of states and political subdivisions 179,091 - 179,091 - Corporate securities 1,315,041 - 1,315,041 - Total debt securities available for sale 2,654,670 139,574 2,515,096 - Total $ 2,656,417 $ 139,574 $ 2,516,843 $ - At December 31, 2017 Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs (1) (In thousands) Equity securities Mutual funds $ 1,800 $ - $ 1,800 $ - Total equity securities 1,800 - 1,800 - Debt securities available for sale Securities of U.S. Government sponsored entities 119,319 - 119,319 - Agency residential MBS 767,706 - 767,706 - Non-agency residential MBS 154 - 154 - Agency commercial MBS 2,219 - 2,219 - Securities of U.S. Government entities 1,590 - 1,590 - Obligations of states and political subdivisions 185,221 - 185,221 - Corporate securities 1,115,498 - 1,115,498 - Total debt securities available for sale 2,191,707 - 2,191,707 - Total $ 2,193,507 $ - $ 2,193,507 $ -
Fair Value Measurements, Nonrecurring [Table Text Block]	For the Year Ended At December 31, 2018 December 31, 2018 Carrying Value Level 1 Level 2 Level 3 Total Losses (In thousands) Other real estate owned $ 350 $ - $ - $ 350 $ - Impaired loans: Commercial 6,437 - - 6,437 - Commercial real estate 3,870 - - 3,870 (240 ) Total assets measured at fair value on a nonrecurring basis $ 10,657 $ - $ - $ 10,657 $ (240 ) For the Year Ended At December 31, 2017 December 31, 2017 Carrying Value Level 1 Level 2 Level 3 Total Losses (In thousands) Other real estate owned $ 1,426 $ - $ - $ 1,426 $ (219 ) Impaired loans: Commercial 4,950 - - 4,950 - Commercial real estate 5,904 - - 5,904 - Total assets measured at fair value on a nonrecurring basis $ 12,280 $ - $ - $ 12,280 $ (219 )
Fair Value, by Balance Sheet Grouping [Table Text Block]	At December 31, 2018 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Financial Assets: (In thousands) Cash and due from banks $ 420,284 $ 420,284 $ 420,284 $ - $ - Debt securities held to maturity 984,609 971,445 - 971,445 - Loans 1,185,851 1,184,770 - - 1,184,770 Financial Liabilities: Deposits $ 4,866,839 $ 4,862,668 $ - $ 4,671,588 $ 191,080 Short-term borrowed funds 51,247 51,247 - 51,247 - At December 31, 2017 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Financial Assets: (In thousands) Cash and due from banks $ 575,002 $ 575,002 $ 575,002 $ - $ - Debt securities held to maturity 1,158,864 1,155,342 - 1,155,342 - Loans 1,264,973 1,257,811 - - 1,257,811 Financial Liabilities: Deposits $ 4,827,613 $ 4,824,586 $ - $ 4,595,795 $ 228,791 Short-term borrowed funds 58,471 58,471 - 58,471 -

Note 12 - Lease Commitments (Ta

Note 12 - Lease Commitments (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Minimum (In thousands) 2019 $ 5,996 2020 4,409 2021 2,741 2022 1,921 2023 1,223 Thereafter 1,044 Total minimum lease payments $ 17,334

Note 14 - Retirement Benefit _2

Note 14 - Retirement Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Net Benefit Costs [Table Text Block]	At December 31, 2018 2017 2016 (In thousands) Service benefit $ 24 $ (311 ) $ (153 ) Interest cost 72 95 108 Amortization of unrecognized transition obligation - 61 61 Net periodic (benefit) cost $ 96 $ (155 ) $ 16 Amortization of unrecognized transition obligation, net of tax - (34 ) (36 ) Total recognized in net periodic (benefit) cost and accumulated other comprehensive income $ 96 $ (189 ) $ (20 )
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]	At December 31, 2018 2017 2016 Change in benefit obligation (In thousands) Benefit obligation at beginning of year $ 1,958 $ 2,319 $ 2,522 Service benefit 24 (311 ) (153 ) Interest cost 72 95 108 Benefits paid (141 ) (145 ) (158 ) Benefit obligation at end of year $ 1,913 $ 1,958 $ 2,319 Accumulated post-retirement benefit obligation attributable to: Retirees $ 1,913 $ 1,575 $ 1,705 Fully eligible participants - 382 606 Other - 1 8 Total $ 1,913 $ 1,958 $ 2,319 Fair value of plan assets - - - Accumulated post-retirement benefit obligation in excess of plan assets $ 1,913 $ 1,958 $ 2,319
Schedule of Assumptions Used [Table Text Block]	At December 31, 2018 2017 2016 Weighted-average assumptions used to determine benefit obligations Discount rate 3.76 % 3.70 % 4.10 % Weighted-average assumptions used to determine net periodic benefit cost Discount rate 3.70 % 4.10 % 4.30 %
Schedule of Expected Benefit Payments [Table Text Block]	Estimated future benefit payments (In thousands) 2019 $ 143 2020 143 2021 143 2022 140 2023 138 Years 2024-2028 624

Note 15 - Related Party Trans_2

Note 15 - Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Related Party Transactions [Table Text Block]	2018 2017 (In thousands) Balance at January 1, $ 622 $ 867 Originations - - Principal reductions (45 ) (245 ) Balance at December 31, $ 577 $ 622 Percent of total loans outstanding. 0.05 % 0.05 %

Note 17 - Other Comprehensive_2

Note 17 - Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Comprehensive Income (Loss) [Table Text Block]	2018 Before tax Tax effect Net of tax (In thousands) Debt securities available for sale: Net unrealized losses arising during the year $ (27,939 ) $ 8,258 $ (19,681 ) Reclassification of losses included in net income - - - Net unrealized losses arising during the year (27,939 ) 8,258 (19,681 ) Post-retirement benefit obligation - - - Other comprehensive loss $ (27,939 ) $ 8,258 $ (19,681 ) 2017 Before tax Tax effect Net of tax (In thousands) Debt securities available for sale: Net unrealized losses arising during the year $ (3,767 ) $ 1,585 $ (2,182 ) Reclassification of gains included in net income (7,955 ) 3,345 (4,610 ) Net unrealized losses arising during the year (11,722 ) 4,930 (6,792 ) Post-retirement benefit obligation 59 (25 ) 34 Other comprehensive loss $ (11,663 ) $ 4,905 $ (6,758 ) 2016 Before tax Tax effect Net of tax (In thousands) Debt securities available for sale: Net unrealized losses arising during the year $ (18,610 ) $ 7,825 $ (10,785 ) Reclassification of (gains) losses included in net income - - - Net unrealized losses arising during the year (18,610 ) 7,825 (10,785 ) Post-retirement benefit obligation 61 (25 ) 36 Other comprehensive loss $ (18,549 ) $ 7,800 $ (10,749 )
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Post-retirement Benefit Obligation Net Unrealized Gains (losses) on Securities Accumulated Other Comprehensive Income (loss) (In thousands) Balance, December 31, 2015 $ (70 ) $ 745 $ 675 Net change 36 (10,785 ) (10,749 ) Balance, December 31, 2016 (34 ) (10,040 ) (10,074 ) Net change 34 (6,792 ) (6,758 ) Balance, December 31, 2017 - (16,832 ) (16,832 ) Cumulative effect of equity securities losses reclassified - 142 142 Adjusted Balance, January 1, 2018 - (16,690 ) (16,690 ) Reclass stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 - (3,625 ) (3,625 ) Net change - (19,681 ) (19,681 ) Balance, December 31, 2018 $ - $ (39,996 ) $ (39,996 )

Note 18 - Earnings Per Common_2

Note 18 - Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	For the Years Ended December 31, 2018 2017 2016 (In thousands, except per share data) Net income (numerator) $ 71,564 $ 50,025 $ 58,853 Basic earnings per common share Weighted average number of common shares outstanding - basic (denominator) 26,649 26,291 25,612 Basic earnings per common share $ 2.69 $ 1.90 $ 2.30 Diluted earnings per common share Weighted average number of common shares outstanding - basic 26,649 26,291 25,612 Add common stock equivalents for options 107 128 66 Weighted average number of common shares outstanding - diluted (denominator) 26,756 26,419 25,678 Diluted earnings per common share $ 2.67 $ 1.89 $ 2.29

Note 19 - Westamerica Bancorp_2

Note 19 - Westamerica Bancorporation (Parent Company Only Condensed Financial Information) (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Statements of Income and Comprehensive Income, Parent Only [Table Text Block]	For the Years Ended December 31, 2018 2017 2016 (In thousands) Dividends from subsidiaries $ 43,892 $ 12,728 $ 56,824 Interest income 33 43 25 Other income 9,447 8,590 8,315 Total income 53,372 21,361 65,164 Interest on borrowings - - - Salaries and benefits 7,575 7,163 7,079 Other expense 3,181 3,416 3,290 Total expense 10,756 10,579 10,369 Income before taxes and equity in undistributed income of subsidiaries 42,616 10,782 54,795 Income tax benefit 919 241 1,025 Earnings of subsidiaries greater than subsidiary dividends 28,029 39,002 3,033 Net income 71,564 50,025 58,853 Other comprehensive loss, net of tax (19,681 ) (6,758 ) (10,749 ) Comprehensive income $ 51,883 $ 43,267 $ 48,104
Balance Sheets Parent Only [Table Text Block]	At December 31, 2018 2017 (In thousands) Assets Cash $ 72,878 $ 53,409 Investment securities available for sale - - Investment in Westamerica Bank 509,125 500,776 Investment in non-bank subsidiaries 455 455 Premises and equipment, net 10,400 9,639 Accounts receivable from Westamerica Bank 580 538 Other assets 36,990 40,547 Total assets $ 630,428 $ 605,364 Liabilities Accounts payable to Westamerica Bank $ 46 $ 92 Other liabilities 14,791 15,033 Total liabilities 14,837 15,125 Shareholders' equity 615,591 590,239 Total liabilities and shareholders' equity $ 630,428 $ 605,364
Statement of Cash Flows Parent Only [Table Text Block]	For the Years Ended December 31, 2018 2017 2016 (In thousands) Operating Activities Net income $ 71,564 $ 50,025 $ 58,853 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 361 319 305 (Increase) decrease in accounts receivable from affiliates (43 ) (16 ) 299 Increase in other assets (2,638 ) (2,203 ) (1,940 ) Stock option compensation expense 1,988 1,824 1,494 Tax benefit increase upon exercise of stock options and expiration of stock options - - (394 ) Provision (benefit) for deferred income tax 5,028 (3,971 ) 1,983 Increase in other liabilities 978 202 1,392 Earnings of subsidiaries greater than subsidiary dividends (28,029 ) (39,002 ) (3,033 ) Life insurance gains (585 ) - - Gain on sales of premises and equipment (538 ) (793 ) (79 ) Net Cash Provided by Operating Activities 48,086 6,385 58,880 Investing Activities Proceeds from life insurance 1,169 - - Net Cash Provided by Investing Activities 1,169 - - Financing Activities Exercise of stock options/issuance of shares 13,373 24,583 24,031 Taxes paid by withholding shares for tax purposes - - (356 ) Tax benefit increase (decrease) upon exercise of stock options and expiration of stock options - - 394 Retirement of common stock (524 ) (314 ) (5,424 ) Dividends (42,635 ) (41,299 ) (39,924 ) Net Cash Used in Financing Activities (29,786 ) (17,030 ) (21,279 ) Net change in cash 19,469 (10,645 ) 37,601 Cash at Beginning of Period 53,409 64,054 26,453 Cash at End of Period $ 72,878 $ 53,409 $ 64,054 Supplemental Cash Flow Disclosures: Supplemental disclosure of cash flow activities: Interest paid for the period $ - $ - $ - Income tax payments for the period 13,627 17,351 19,264

Note 20 - Quarterly Financial_2

Note 20 - Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2018
Notes Tables
Quarterly Financial Information [Table Text Block]	For the Three Months Ended March 31, June 30, September 30, December 31, (In thousands, expect per share data and 2018 Interest and loan fee income $ 36,315 $ 37,346 $ 38,614 $ 39,448 Net interest income 35,856 36,887 38,087 38,934 Provision for loan losses - - - - Noninterest income 11,955 11,769 12,528 11,897 Noninterest expense 26,022 25,741 29,366 25,787 Income before taxes 21,789 22,915 21,249 25,044 Net income 17,506 18,010 16,993 19,055 Basic earnings per common share 0.66 0.68 0.64 0.71 Diluted earnings per common share 0.66 0.67 0.63 0.71 Dividends paid per common share 0.40 0.40 0.40 0.40 Price range, common stock 55.72 - 62.52 55.81 - 60.68 57.56 - 64.52 52.75 - 63.20 2017 Interest and loan fee income $ 34,128 $ 34,083 $ 34,623 $ 35,478 Net interest income 33,648 33,607 34,150 35,007 (Reversal of) provision for loan losses - (1,900 ) - - Noninterest income 11,657 12,123 12,548 20,300 Noninterest expense 25,419 25,316 25,592 31,441 Income before taxes 19,886 22,314 21,106 23,866 Net income 15,049 15,799 15,017 4,160 Basic earnings per common share 0.58 0.60 0.57 0.16 Diluted earnings per common share 0.57 0.60 0.57 0.16 Dividends paid per common share 0.39 0.39 0.39 0.40 Price range, common stock 54.12 - 64.07 51.31 - 57.78 49.54 - 59.54 53.96 - 63.03 2016 Interest and loan fee income $ 34,001 $ 34,248 $ 33,955 $ 33,715 Net interest income 33,449 33,707 33,432 33,215 (Reversal of) provision for loan losses - - (3,200 ) - Noninterest income 11,729 11,702 11,598 11,545 Noninterest expense 26,212 25,750 26,575 25,083 Income before taxes 18,966 19,659 21,655 19,677 Net income 14,226 14,546 15,628 14,453 Basic earnings per common share 0.56 0.57 0.61 0.56 Diluted earnings per common share 0.56 0.57 0.61 0.56 Dividends paid per common share 0.39 0.39 0.39 0.39 Price range, common stock 40.72 - 49.63 45.86 - 51.53 46.61 - 50.96 48.20 - 65.34

Note 1 - Business and Account_2

Note 1 - Business and Accounting Policies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019	Jan. 01, 2018
Loans and Leases Receivable, Days Before Nonaccrual Status		90 days
Loans and Leases Receivable, Certain Consumer Loans and Auto Receivables, Days Before Chargeoff		120 days
Financing Receivable, Impairment Evaluation Criterion, Minimum Outstanding Principal Balance	$ 500	$ 500
FDIC Indemnification Rate	80.00%
FDIC Indemnification Rate, Duration of Interest Covered	90 days
Gains (Losses) on Sales of Other Real Estate	$ 110	72	$ 1,185
Debt Securities, Available-for-sale, Total	2,654,670	2,191,707
Retained Earnings (Accumulated Deficit), Ending Balance	205,841	173,804
Accounting Standards Update 2016-02 [Member] | Subsequent Event [Member]
Operating Lease, Liability, Total				$ 15,300
Operating Lease, Right-of-Use Asset				15,300
Accounting Standards Update 2017-08 [Member] | Subsequent Event [Member]
Debt Securities, Available-for-sale, Total				(3,100)
Retained Earnings (Accumulated Deficit), Ending Balance				$ (2,800)
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ (142)
Tax Cuts and Jobs Act of 2017, Reclassification From Aoci to Retained Earnings	3,625
Retained Earnings [Member] | Accounting Standards Update 2016-01 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	142				$ (142)
Retained Earnings [Member] | Accounting Standards Update 2018-02 [Member]
Tax Cuts and Jobs Act of 2017, Reclassification From Aoci to Retained Earnings	$ 3,625
Maximum [Member]
Finite-Lived Intangible Asset, Useful Life	15 years
Land and Land Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	20 years
Land and Land Improvements [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	50 years
Equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life	3 years
Equipment [Member] | Maximum [Member]
Property, Plant and Equipment, Useful Life	20 years

Note 2 - Investment Securitie_2

Note 2 - Investment Securities (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jan. 01, 2018USD ($)
Equity Securities, FV-NI	$ 1,747	$ 1,800		$ 1,800
Unrealized Gain (Loss) on Securities	(52)
High Risk Collateralized Mortgage Obligations	0	0
Debt Securities, Available-for-sale, Amortized Cost, Total	2,711,453	2,220,551
Debt Securities, Available-for-sale, Total	2,654,670	2,191,707
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Total	0
Pledged Financial Instruments, Not Separately Reported, Securities, Total	728,161	715,774
Debt Security, Corporate, US [Member]
Debt Securities, Available-for-sale, Amortized Cost, Total	1,337,608	1,123,671
Debt Securities, Available-for-sale, Total	$ 1,315,041	1,115,498
Debt Security, Corporate, US [Member] | External Credit Rating, Non Investment Grade [Member]
Available-for-sale Debt Securities, Number Below Investment Grade	1
Debt Securities, Available-for-sale, Amortized Cost, Total	$ 15,000
Debt Securities, Available-for-sale, Total	13,800
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption		(142)
Retained Earnings [Member] | Accounting Standards Update 2016-01 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 142			(142)
AOCI Attributable to Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ 142
AOCI Attributable to Parent [Member] | Accounting Standards Update 2016-01 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 142

Note 2 - Investment Securitie_3

Note 2 - Investment Securities - Amortized Cost, Unrealized Gains and Losses, and Estimated Fair Value of Investment Securities Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt securities available for sale, amortized cost	$ 2,711,453	$ 2,220,551
Debt securities available for sale, gross unrealized gains	3,597	5,424
Debt securities available for sale, gross unrealized losses	(60,380)	(34,268)
Debt securities available for sale	2,654,670	2,191,707
Debt securities held to maturity, amortized cost	984,609	1,158,864
Debt securities held to maturity, gross unrecognized gains	3,692	8,412
Debt securities held to maturity, gross unrecognized losses	(16,856)	(11,934)
Debt securities held to maturity, fair values	971,445	1,155,342
Debt securities, amortized cost	3,696,062	3,379,415
Debt securities, gross unrecognized gains	7,289	13,836
Debt securities, gross unrecognized losses	(77,236)	(46,202)
Debt securities, fair value	3,626,115	3,347,049
US Treasury Securities [Member]
Debt securities available for sale, amortized cost	139,572
Debt securities available for sale, gross unrealized gains	5
Debt securities available for sale, gross unrealized losses	(3)
Debt securities available for sale	139,574
US Government-sponsored Enterprises Debt Securities [Member]
Debt securities available for sale, amortized cost	167,228	122,285
Debt securities available for sale, gross unrealized gains	65	1
Debt securities available for sale, gross unrealized losses	(3,275)	(2,967)
Debt securities available for sale	164,018	119,319
Agency Residential MBS [Member]
Debt securities available for sale, amortized cost	883,715	787,679
Debt securities available for sale, gross unrealized gains	595	522
Debt securities available for sale, gross unrealized losses	(30,439)	(20,495)
Debt securities available for sale	853,871	767,706
Debt securities held to maturity, amortized cost	447,332	545,883
Debt securities held to maturity, gross unrecognized gains	249	606
Debt securities held to maturity, gross unrecognized losses	(14,129)	(9,850)
Debt securities held to maturity, fair values	433,452	536,639
Non-agency Residential MBS [Member]
Debt securities available for sale, amortized cost	113	153
Debt securities available for sale, gross unrealized gains	1	1
Debt securities available for sale, gross unrealized losses
Debt securities available for sale	114	154
Debt securities held to maturity, amortized cost	3,387	4,462
Debt securities held to maturity, gross unrecognized gains	40	70
Debt securities held to maturity, gross unrecognized losses
Debt securities held to maturity, fair values	3,427	4,532
Agency Commercial MBS [Member]
Debt securities available for sale, amortized cost	1,869	2,244
Debt securities available for sale, gross unrealized gains
Debt securities available for sale, gross unrealized losses	(27)	(25)
Debt securities available for sale	1,842	2,219
Debt securities held to maturity, amortized cost		9,041
Debt securities held to maturity, gross unrecognized gains
Debt securities held to maturity, gross unrecognized losses		(66)
Debt securities held to maturity, fair values		8,975
US Government Agencies Debt Securities [Member]
Debt securities available for sale, amortized cost	1,128	1,612
Debt securities available for sale, gross unrealized gains
Debt securities available for sale, gross unrealized losses	(9)	(22)
Debt securities available for sale	1,119	1,590
US States and Political Subdivisions Debt Securities [Member]
Debt securities available for sale, amortized cost	180,220	182,907
Debt securities available for sale, gross unrealized gains	1,856	3,796
Debt securities available for sale, gross unrealized losses	(2,985)	(1,482)
Debt securities available for sale	179,091	185,221
Debt securities held to maturity, amortized cost	533,890	599,478
Debt securities held to maturity, gross unrecognized gains	3,403	7,736
Debt securities held to maturity, gross unrecognized losses	(2,727)	(2,018)
Debt securities held to maturity, fair values	534,566	605,196
Debt Security, Corporate, US [Member]
Debt securities available for sale, amortized cost	1,337,608	1,123,671
Debt securities available for sale, gross unrealized gains	1,075	1,104
Debt securities available for sale, gross unrealized losses	(23,642)	(9,277)
Debt securities available for sale	$ 1,315,041	$ 1,115,498

Note 2 - Investment Securitie_4

Note 2 - Investment Securities - Amortized Cost and Estimated Market Value of Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Investment securities available for sale, amortized cost, 1 year or less	$ 262,418	$ 193,337
Investment securities available for sale, fair value, 1 year or less	261,976	193,385
Investment securities held to maturity, amortized cost, 1 year or less	86,172	50,295
Investment securities held to maturity, fair value, 1 year or less	86,148	51,105
Investment securities available for sale, amortized cost, over 1 to 5 years	1,438,849	1,031,807
Investment securities available for sale, fair value, over 1 to 5 years	1,414,020	1,023,047
Investment securities held to maturity, amortized cost, over 1 to 5 years	214,137	269,050
Investment securities held to maturity, fair value, over 1 to 5 years	213,829	269,471
Investment securities available for sale, amortized cost, over 5 to 10 years	85,817	159,266
Investment securities available for sale, fair value, over 5 to 10 years	85,877	160,042
Investment securities held to maturity, amortized cost, over 5 to 10 years	232,544	277,170
Investment securities held to maturity, fair value, over 5 to 10 years	233,515	281,546
Investment securities available for sale, amortized cost, over 10 years	38,672	46,065
Investment securities available for sale, fair value, over 10 years	36,970	45,154
Investment securities held to maturity, amortized cost, over 10 years	1,037	2,963
Investment securities held to maturity, fair value, over 10 years	1,074	3,074
Investment securities available for sale, amortized cost, subtotal	1,825,756	1,430,475
Investment securities available for sale, fair value, subtotal	1,798,843	1,421,628
Investment securities held to maturity, amortized cost, subtotal	533,890	599,478
Investment securities held to maturity, fair value, subtotal	534,566	605,196
Investment securities available for sale, amortized cost	885,697	790,076
Investment securities available for sale, fair value	855,827	770,079
Investment securities held to maturity, amortized cost	450,719	559,386
Investment securities held to maturity, fair value	436,879	550,146
Investment securities available for sale, amortized cost	2,711,453	2,220,551
Investment securities available for sale, fair value	2,654,670	2,191,707
Investment securities held to maturity, amortized cost	984,609	1,158,864
Investment securities held to maturity, fair value	$ 971,445	$ 1,155,342

Note 2 - Investment Securitie_5

Note 2 - Investment Securities - Gross Unrealized Losses, Investment Securities Portfolio (Details) $ in Thousands	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Available for sale securities, less than 12 months, number of investment positions	82	125
Available for sale securities, less than 12 months, fair value	$ 499,743	$ 834,335
Available for sale securities, less than 12 months, unrealized losses	$ (4,111)	$ (5,803)
Available for sale securities, 12 months or longer, number of investment positions	219	135
Available for sale securities, 12 months or longer, fair value	$ 1,549,153	$ 970,548
Available for sale securities, 12 months or longer, unrealized losses	$ (56,269)	$ (28,465)
Available for sale securities, total, number of investment positions	301	260
Available for sale securities, total, fair value	$ 2,048,896	$ 1,804,883
Available for sale securities, total, unrealized losses	$ (60,380)	$ (34,268)
Held to Maturity securities, less than 12 months, number of investment positions	114	162
Held to Maturity securities, less than 12 months, fair value	$ 92,154	$ 163,163
Held to Maturity securities, less than 12 months, unrecognized losses	$ (305)	$ (758)
Held to Maturity securities, 12 months or longer, number of investment positions	220	125
Held to Maturity securities, 12 months or longer, fair value	$ 564,120	$ 545,816
Held to Maturity securities, 12 months or longer, unrecognized losses	$ (16,551)	$ (11,176)
Held to Maturity securities, total, number of investment positions	334	287
Held to Maturity securities, total, fair value	$ 656,274	$ 708,979
Held to Maturity securities, total, unrecognized losses	$ (16,856)	$ (11,934)
US Treasury Securities [Member]
Available for sale securities, less than 12 months, number of investment positions	2
Available for sale securities, less than 12 months, fair value	$ 54,805
Available for sale securities, less than 12 months, unrealized losses	$ (3)
Available for sale securities, 12 months or longer, number of investment positions
Available for sale securities, 12 months or longer, fair value
Available for sale securities, 12 months or longer, unrealized losses
Available for sale securities, total, number of investment positions	2
Available for sale securities, total, fair value	$ 54,805
Available for sale securities, total, unrealized losses	$ (3)
Agency Residential MBS [Member]
Available for sale securities, less than 12 months, number of investment positions	8	7
Available for sale securities, less than 12 months, fair value	$ 107,497	$ 238,554
Available for sale securities, less than 12 months, unrealized losses	$ (507)	$ (1,501)
Available for sale securities, 12 months or longer, number of investment positions	58	51
Available for sale securities, 12 months or longer, fair value	$ 640,210	$ 516,711
Available for sale securities, 12 months or longer, unrealized losses	$ (29,932)	$ (18,994)
Available for sale securities, total, number of investment positions	66	58
Available for sale securities, total, fair value	$ 747,707	$ 755,265
Available for sale securities, total, unrealized losses	$ (30,439)	$ (20,495)
Held to Maturity securities, less than 12 months, number of investment positions	16	15
Held to Maturity securities, less than 12 months, fair value	$ 8,495	$ 30,218
Held to Maturity securities, less than 12 months, unrecognized losses	$ (34)	$ (201)
Held to Maturity securities, 12 months or longer, number of investment positions	78	65
Held to Maturity securities, 12 months or longer, fair value	$ 412,574	$ 479,775
Held to Maturity securities, 12 months or longer, unrecognized losses	$ (14,095)	$ (9,649)
Held to Maturity securities, total, number of investment positions	94	80
Held to Maturity securities, total, fair value	$ 421,069	$ 509,993
Held to Maturity securities, total, unrecognized losses	$ (14,129)	$ (9,850)
US Government-sponsored Enterprises Debt Securities [Member]
Available for sale securities, less than 12 months, number of investment positions	1	1
Available for sale securities, less than 12 months, fair value	$ 990	$ 996
Available for sale securities, less than 12 months, unrealized losses	$ (5)	$ (2)
Available for sale securities, 12 months or longer, number of investment positions	9	8
Available for sale securities, 12 months or longer, fair value	$ 117,963	$ 117,252
Available for sale securities, 12 months or longer, unrealized losses	$ (3,270)	$ (2,965)
Available for sale securities, total, number of investment positions	10	9
Available for sale securities, total, fair value	$ 118,953	$ 118,248
Available for sale securities, total, unrealized losses	$ (3,275)	$ (2,967)
Non-agency Residential MBS [Member]
Available for sale securities, less than 12 months, number of investment positions		1
Available for sale securities, less than 12 months, fair value		$ 1
Available for sale securities, less than 12 months, unrealized losses
Available for sale securities, 12 months or longer, number of investment positions
Available for sale securities, 12 months or longer, fair value
Available for sale securities, 12 months or longer, unrealized losses
Available for sale securities, total, number of investment positions		1
Available for sale securities, total, fair value		$ 1
Available for sale securities, total, unrealized losses
Held to Maturity securities, less than 12 months, number of investment positions	1
Held to Maturity securities, less than 12 months, fair value	$ 26
Held to Maturity securities, less than 12 months, unrecognized losses
Held to Maturity securities, 12 months or longer, number of investment positions
Held to Maturity securities, 12 months or longer, fair value
Held to Maturity securities, 12 months or longer, unrecognized losses
Held to Maturity securities, total, number of investment positions	1
Held to Maturity securities, total, fair value	$ 26
Held to Maturity securities, total, unrecognized losses
Agency Commercial MBS [Member]
Available for sale securities, less than 12 months, number of investment positions	1	2
Available for sale securities, less than 12 months, fair value	$ 1,842	$ 2,219
Available for sale securities, less than 12 months, unrealized losses	$ (27)	$ (25)
Available for sale securities, 12 months or longer, number of investment positions
Available for sale securities, 12 months or longer, fair value
Available for sale securities, 12 months or longer, unrealized losses
Available for sale securities, total, number of investment positions	1	2
Available for sale securities, total, fair value	$ 1,842	$ 2,219
Available for sale securities, total, unrealized losses	$ (27)	$ (25)
Held to Maturity securities, less than 12 months, number of investment positions		1
Held to Maturity securities, less than 12 months, fair value		$ 1,913
Held to Maturity securities, less than 12 months, unrecognized losses		$ (4)
Held to Maturity securities, 12 months or longer, number of investment positions		1
Held to Maturity securities, 12 months or longer, fair value		$ 7,062
Held to Maturity securities, 12 months or longer, unrecognized losses		$ (62)
Held to Maturity securities, total, number of investment positions		2
Held to Maturity securities, total, fair value		$ 8,975
Held to Maturity securities, total, unrecognized losses		$ (66)
US States and Political Subdivisions Debt Securities [Member]
Available for sale securities, less than 12 months, number of investment positions	32	50
Available for sale securities, less than 12 months, fair value	$ 26,452	$ 21,453
Available for sale securities, less than 12 months, unrealized losses	$ (166)	$ (228)
Available for sale securities, 12 months or longer, number of investment positions	71	35
Available for sale securities, 12 months or longer, fair value	$ 67,121	$ 52,071
Available for sale securities, 12 months or longer, unrealized losses	$ (2,819)	$ (1,254)
Available for sale securities, total, number of investment positions	103	85
Available for sale securities, total, fair value	$ 93,573	$ 73,524
Available for sale securities, total, unrealized losses	$ (2,985)	$ (1,482)
Held to Maturity securities, less than 12 months, number of investment positions	97	146
Held to Maturity securities, less than 12 months, fair value	$ 83,633	$ 131,032
Held to Maturity securities, less than 12 months, unrecognized losses	$ (271)	$ (553)
Held to Maturity securities, 12 months or longer, number of investment positions	142	59
Held to Maturity securities, 12 months or longer, fair value	$ 151,546	$ 58,979
Held to Maturity securities, 12 months or longer, unrecognized losses	$ (2,456)	$ (1,465)
Held to Maturity securities, total, number of investment positions	239	205
Held to Maturity securities, total, fair value	$ 235,179	$ 190,011
Held to Maturity securities, total, unrecognized losses	$ (2,727)	$ (2,018)
US Government Agencies Debt Securities [Member]
Available for sale securities, less than 12 months, number of investment positions
Available for sale securities, less than 12 months, fair value
Available for sale securities, less than 12 months, unrealized losses
Available for sale securities, 12 months or longer, number of investment positions	2	3
Available for sale securities, 12 months or longer, fair value	$ 1,119	$ 1,590
Available for sale securities, 12 months or longer, unrealized losses	$ (9)	$ (22)
Available for sale securities, total, number of investment positions	2	3
Available for sale securities, total, fair value	$ 1,119	$ 1,590
Available for sale securities, total, unrealized losses	$ (9)	$ (22)
Debt Security, Corporate, US [Member]
Available for sale securities, less than 12 months, number of investment positions	38	64
Available for sale securities, less than 12 months, fair value	$ 308,157	$ 571,112
Available for sale securities, less than 12 months, unrealized losses	$ (3,403)	$ (4,047)
Available for sale securities, 12 months or longer, number of investment positions	79	38
Available for sale securities, 12 months or longer, fair value	$ 722,740	$ 282,924
Available for sale securities, 12 months or longer, unrealized losses	$ (20,239)	$ (5,230)
Available for sale securities, total, number of investment positions	117	102
Available for sale securities, total, fair value	$ 1,030,897	$ 854,036
Available for sale securities, total, unrealized losses	$ (23,642)	$ (9,277)

Note 2 - Investment Securitie_6

Note 2 - Investment Securities - Interest Income From Investment Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Taxable	$ 65,330	$ 51,445	$ 42,718
Tax-exempt from regular federal income tax	19,438	20,651	22,194
Total interest income from investment securities	$ 84,768	$ 72,096	$ 64,912

Note 3 - Loans and Allowance _3

Note 3 - Loans and Allowance for Credit Losses (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
FDIC Indemnification Asset, Ending Balance	$ 5,713	$ 7,766
Percent of Principal Covered by FDIC	80.00%
Purchased Loans	$ 58,247	83,478
Loans and Leases Receivable, Nonaccrual, Commitment to Lend	0	0
Financing Receivable, Modifications, Recorded Investment	$ 8,579	$ 12,081	$ 12,381
Troubled Debt Restructurings During Period	0	4	4
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	$ 41	$ 58	$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	0	0
Pledged Financial Instruments, Not Separately Reported, Loans Receivable Pledged as Collateral, Total	$ 0	$ 0
Loans Receivable Held-for-sale, Amount	0	0
Other Real Estate, Ending Balance	350	1,426
Other Real Estate, Reserve	0	1,905
Mortgage Loans in Process of Foreclosure, Amount	516	196
Residential Real Estate Included in OREO [Member]
Real Estate Acquired Through Foreclosure	0	$ 0
Under-market Modification to Payment Terms and Extended Maturity Date [Member]
Troubled Debt Restructurings During Period		4	3
Under-Market Terms, Extended Maturity Date and Court Orders [Member]
Financing Receivable, Modifications, Recorded Investment			$ 4,731
Court Order [Member]
Troubled Debt Restructurings During Period			1
Restructured Loans [Member]
Financing Receivable, Modifications, Recorded Investment	8,579	$ 12,081
Impaired Loans, Restructured, Nonaccrual Status	$ 4,225	4,285
Four Concessions With Modifications of Extended Maturity and Under-market Terms [Member]
Financing Receivable, Recorded Investment, Modifications in Period		$ 699

Note 3 - Loans and Allowance _4

Note 3 - Loans and Allowance for Credit Losses - Loans Receivable at Carrying Amount (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans	$ 1,207,202	$ 1,287,982
Commercial Portfolio Segment [Member]
Loans	275,080	335,996
Commercial Real Estate Portfolio Segment [Member]
Loans	580,480	568,584
Construction Portfolio Segment [Member]
Loans	3,982	5,649
Residential Portfolio Segment [Member]
Loans	44,866	65,183
Consumer Portfolio Segment [Member]
Loans	$ 302,794	$ 312,570

Note 3 - Loans and Allowance _5

Note 3 - Loans and Allowance for Credit Losses - Changes in the Accretable Yield for Purchased Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Balance at the beginning of the period	$ 738	$ 1,237
Reclassification from nonaccretable difference	1,119	1,852
Accretion	(1,675)	(2,351)
Balance at the end of the period	182	738
Change in FDIC indemnification	2	192
(Increase) in interest income	$ (1,673)	$ (2,159)

Note 3 - Loans and Allowance _6

Note 3 - Loans and Allowance for Credit Losses - Allowance for Loan Losses (Details) - 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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Balance at beginning of period				$ 23,009				$ 25,954				$ 29,771	$ 23,009	$ 25,954	$ 29,771
(Reversal) provision							$ (1,900)			$ (3,200)				(1,900)	(3,200)
Chargeoffs													(4,877)	(5,918)	(6,772)
Recoveries													3,219	4,873	6,155
Total allowance for loan losses	21,351				23,009				25,954				21,351	23,009	25,954
Unallocated Financing Receivable [Member]
Balance at beginning of period				3,666				4,835				5,963	3,666	4,835	5,963
(Reversal) provision													(489)	(1,169)	(1,128)
Chargeoffs
Recoveries
Total allowance for loan losses	3,177				3,666				4,835				3,177	3,666	4,835
Commercial Portfolio Segment [Member]
Balance at beginning of period				7,746				8,327				9,559	7,746	8,327	9,559
(Reversal) provision													(2,369)	(382)	(3,237)
Chargeoffs													(513)	(961)	(2,023)
Recoveries													1,447	762	4,028
Total allowance for loan losses	6,311				7,746				8,327				6,311	7,746	8,327
Commercial Real Estate Portfolio Segment [Member]
Balance at beginning of period				3,849				3,330				4,212	3,849	3,330	4,212
(Reversal) provision													275	431	(1,436)
Chargeoffs													(240)
Recoveries														88	554
Total allowance for loan losses	3,884				3,849				3,330				3,884	3,849	3,330
Construction Portfolio Segment [Member]
Balance at beginning of period				335				152				235	335	152	235
(Reversal) provision													1,130	(1,716)	(83)
Chargeoffs
Recoveries														1,899
Total allowance for loan losses	1,465				335				152				1,465	335	152
Residential Portfolio Segment [Member]
Balance at beginning of period				995				1,330				1,801	995	1,330	1,801
(Reversal) provision													(126)	(335)	(471)
Chargeoffs
Recoveries
Total allowance for loan losses	869				995				1,330				869	995	1,330
Consumer Portfolio Segment [Member]
Balance at beginning of period				$ 6,418				$ 7,980				$ 8,001	6,418	7,980	8,001
(Reversal) provision													1,579	1,271	3,155
Chargeoffs													(4,124)	(4,957)	(4,749)
Recoveries													1,772	2,124	1,573
Total allowance for loan losses	$ 5,645				$ 6,418				$ 7,980				$ 5,645	$ 6,418	$ 7,980

Note 3 - Loans and Allowance _7

Note 3 - Loans and Allowance for Credit Losses - Recorded Investment in Loans Evaluated for Impairment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
wabc_AllowanceForLoanLossesAbstract
Individually evaluated for impairment	$ 2,752	$ 4,985
Collectively evaluated for impairment	18,599	18,024
Total allowance for loan losses	21,351	23,009	$ 25,954	$ 29,771
wabc_CarryingValueOfLoansAbstract
Individually evaluated for impairment	18,855	25,117
Collectively evaluated for impairment	1,187,960	1,262,090
Loans	1,207,202	1,287,982
Financial Asset Acquired with Credit Deterioration [Member]
wabc_AllowanceForLoanLossesAbstract
Total allowance for loan losses	0	0
wabc_CarryingValueOfLoansAbstract
Loans	387	775
Unallocated Financing Receivable [Member]
wabc_AllowanceForLoanLossesAbstract
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	3,177	3,666
Total allowance for loan losses	3,177	3,666	4,835	5,963
wabc_CarryingValueOfLoansAbstract
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	0	0
Loans	0	0
Unallocated Financing Receivable [Member] | Financial Asset Acquired with Credit Deterioration [Member]
wabc_AllowanceForLoanLossesAbstract
Total allowance for loan losses	0	0
wabc_CarryingValueOfLoansAbstract
Loans	0	0
Commercial Portfolio Segment [Member]
wabc_AllowanceForLoanLossesAbstract
Individually evaluated for impairment	2,752	4,814
Collectively evaluated for impairment	3,559	2,932
Total allowance for loan losses	6,311	7,746	8,327	9,559
wabc_CarryingValueOfLoansAbstract
Individually evaluated for impairment	9,921	10,675
Collectively evaluated for impairment	265,136	325,291
Loans	275,080	335,996
Commercial Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
wabc_AllowanceForLoanLossesAbstract
Total allowance for loan losses	0	0
wabc_CarryingValueOfLoansAbstract
Loans	23	30
Commercial Real Estate Portfolio Segment [Member]
wabc_AllowanceForLoanLossesAbstract
Individually evaluated for impairment		171
Collectively evaluated for impairment	3,884	3,678
Total allowance for loan losses	3,884	3,849	3,330	4,212
wabc_CarryingValueOfLoansAbstract
Individually evaluated for impairment	8,217	14,234
Collectively evaluated for impairment	572,042	553,769
Loans	580,480	568,584
Commercial Real Estate Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
wabc_AllowanceForLoanLossesAbstract
Total allowance for loan losses	0	0
wabc_CarryingValueOfLoansAbstract
Loans	221	581
Construction Portfolio Segment [Member]
wabc_AllowanceForLoanLossesAbstract
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	1,465	335
Total allowance for loan losses	1,465	335	152	235
wabc_CarryingValueOfLoansAbstract
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	3,982	5,649
Loans	3,982	5,649
Construction Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
wabc_AllowanceForLoanLossesAbstract
Total allowance for loan losses	0	0
wabc_CarryingValueOfLoansAbstract
Loans	0	0
Residential Portfolio Segment [Member]
wabc_AllowanceForLoanLossesAbstract
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	869	995
Total allowance for loan losses	869	995	1,330	1,801
wabc_CarryingValueOfLoansAbstract
Individually evaluated for impairment	717	208
Collectively evaluated for impairment	44,149	64,975
Loans	44,866	65,183
Residential Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
wabc_AllowanceForLoanLossesAbstract
Total allowance for loan losses	0	0
wabc_CarryingValueOfLoansAbstract
Loans	0	0
Consumer Portfolio Segment [Member]
wabc_AllowanceForLoanLossesAbstract
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	5,645	6,418
Total allowance for loan losses	5,645	6,418	$ 7,980	$ 8,001
wabc_CarryingValueOfLoansAbstract
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	302,651	312,406
Loans	302,794	312,570
Consumer Portfolio Segment [Member] | Financial Asset Acquired with Credit Deterioration [Member]
wabc_AllowanceForLoanLossesAbstract
Total allowance for loan losses	0	0
wabc_CarryingValueOfLoansAbstract
Loans	$ 143	$ 164

Note 3 - Loans and Allowance _8

Note 3 - Loans and Allowance for Credit Losses - Credit Risk Profile by Internally Assigned Grade (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans	$ 1,207,202	$ 1,287,982
Pass [Member]
Loans	1,179,859	1,251,369
Substandard [Member]
Loans	26,658	35,842
Doubtful [Member]
Loans	135	1
Unlikely to be Collected Financing Receivable [Member]
Loans	550	770
Commercial Portfolio Segment [Member]
Loans	275,080	335,996
Commercial Portfolio Segment [Member] | Pass [Member]
Loans	264,634	324,185
Commercial Portfolio Segment [Member] | Substandard [Member]
Loans	10,446	11,811
Commercial Portfolio Segment [Member] | Doubtful [Member]
Loans	0	0
Commercial Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Commercial Real Estate Portfolio Segment [Member]
Loans	580,480	568,584
Commercial Real Estate Portfolio Segment [Member] | Pass [Member]
Loans	567,578	548,853
Commercial Real Estate Portfolio Segment [Member] | Substandard [Member]
Loans	12,902	19,731
Commercial Real Estate Portfolio Segment [Member] | Doubtful [Member]
Loans	0	0
Commercial Real Estate Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Construction Portfolio Segment [Member]
Loans	3,982	5,649
Construction Portfolio Segment [Member] | Pass [Member]
Loans	3,982	5,649
Construction Portfolio Segment [Member] | Substandard [Member]
Loans	0	0
Construction Portfolio Segment [Member] | Doubtful [Member]
Loans	0	0
Construction Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Residential Portfolio Segment [Member]
Loans	44,866	65,183
Residential Portfolio Segment [Member] | Pass [Member]
Loans	43,112	62,253
Residential Portfolio Segment [Member] | Substandard [Member]
Loans	1,754	2,930
Residential Portfolio Segment [Member] | Doubtful [Member]
Loans	0	0
Residential Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	0	0
Consumer Portfolio Segment [Member]
Loans	302,794	312,570
Consumer Portfolio Segment [Member] | Pass [Member]
Loans	300,553	310,429
Consumer Portfolio Segment [Member] | Substandard [Member]
Loans	1,556	1,370
Consumer Portfolio Segment [Member] | Doubtful [Member]
Loans	135	1
Consumer Portfolio Segment [Member] | Unlikely to be Collected Financing Receivable [Member]
Loans	$ 550	$ 770

Note 3 - Loans and Allowance _9

Note 3 - Loans and Allowance for Credit Losses - Loans by Delinquency and Nonaccrual Status (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current and accruing	$ 1,193,853	$ 1,275,068
Nonaccrual	4,868	5,926
Loans	1,207,202	1,287,982
Financing Receivables, 30 to 59 Days Past Due [Member]
Past due and accruing	5,595	5,091
Financing Receivables, 60 to 89 Days Past Due [Member]
Past due and accruing	2,335	1,366
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due and accruing	551	531
Commercial Portfolio Segment [Member]
Current and accruing	274,045	334,908
Nonaccrual		297
Loans	275,080	335,996
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due and accruing	781	627
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due and accruing	254	164
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due and accruing	0	0
Commercial Real Estate Portfolio Segment [Member]
Current and accruing	574,853	561,883
Nonaccrual	4,225	5,433
Loans	580,480	568,584
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due and accruing	617	1,143
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due and accruing	785	125
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due and accruing	0	0
Construction Portfolio Segment [Member]
Current and accruing	3,982	5,649
Nonaccrual	0	0
Loans	3,982	5,649
Construction Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due and accruing	0	0
Construction Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due and accruing	0	0
Construction Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due and accruing	0	0
Residential Portfolio Segment [Member]
Current and accruing	43,372	65,183
Nonaccrual	516	0
Loans	44,866	65,183
Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due and accruing	789	0
Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due and accruing	189	0
Residential Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due and accruing	0	0
Consumer Portfolio Segment [Member]
Current and accruing	297,601	307,445
Nonaccrual	127	196
Loans	302,794	312,570
Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Past due and accruing	3,408	3,321
Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Past due and accruing	1,107	1,077
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Past due and accruing	$ 551	$ 531

Note 3 - Loans and Allowance_10

Note 3 - Loans and Allowance for Credit Losses - Impaired Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Impaired loans with no related allowance recorded, recorded investment	$ 10,180	$ 14,949
Impaired loans with no related allowance recorded, unpaid principal balance	12,256	16,961
Impaired loans with an allowance recorded, recorded investment	9,189	11,554
Impaired loans with an allowance recorded, unpaid principal balance	9,189	11,556
Impaired loans with an allowance recorded, related allowance	2,752	4,985
Total impaired loans, recorded investment	19,369	26,503
Total impaired loans, unpaid principal balance	21,445	28,517
Commercial Portfolio Segment [Member]
Impaired loans with no related allowance recorded, recorded investment	755	1,212
Impaired loans with no related allowance recorded, unpaid principal balance	759	1,271
Impaired loans with an allowance recorded, recorded investment	9,189	9,764
Impaired loans with an allowance recorded, unpaid principal balance	9,189	9,764
Impaired loans with an allowance recorded, related allowance	2,752	4,814
Commercial Real Estate Portfolio Segment [Member]
Impaired loans with no related allowance recorded, recorded investment	8,438	13,169
Impaired loans with no related allowance recorded, unpaid principal balance	10,373	14,985
Impaired loans with an allowance recorded, recorded investment		1,790
Impaired loans with an allowance recorded, unpaid principal balance		1,792
Impaired loans with an allowance recorded, related allowance		171
Residential Portfolio Segment [Member]
Impaired loans with no related allowance recorded, recorded investment	717	208
Impaired loans with no related allowance recorded, unpaid principal balance	747	239
Consumer Portfolio Segment [Member]
Impaired loans with no related allowance recorded, recorded investment	270	360
Impaired loans with no related allowance recorded, unpaid principal balance	$ 377	$ 466

Note 3 - Loans and Allowance_11

Note 3 - Loans and Allowance for Credit Losses - Impaired Loans, Supplemental Schedule (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Average Recorded Investment	$ 22,758	$ 26,800	$ 30,945
Recognized Interest Income	1,458	1,429	1,281
Commercial Portfolio Segment [Member]
Average Recorded Investment	10,532	11,156	12,923
Recognized Interest Income	667	508	512
Commercial Real Estate Portfolio Segment [Member]
Average Recorded Investment	11,703	14,806	16,701
Recognized Interest Income	758	884	725
Construction Portfolio Segment [Member]
Average Recorded Investment			102
Recognized Interest Income
Residential Portfolio Segment [Member]
Average Recorded Investment	269	423	746
Recognized Interest Income	19	17	19
Consumer Portfolio Segment [Member]
Average Recorded Investment	254	415	473
Recognized Interest Income	$ 14	$ 20	$ 25

Note 3 - Loans and Allowance_12

Note 3 - Loans and Allowance for Credit Losses - Troubled Debt Restructurings (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Number of Contracts	13	18	18
Pre-Modification Carrying Value	$ 11,752	$ 14,162	$ 14,217
Financing Receivable, Modifications, Recorded Investment	8,579	12,081	12,381
Period-End Individual Impairment Allowance	$ 19	$ 43	$ 113
Commercial Portfolio Segment [Member]
Number of Contracts	4	7	7
Pre-Modification Carrying Value	$ 2,274	$ 2,393	$ 2,719
Financing Receivable, Modifications, Recorded Investment	811	1,085	1,489
Period-End Individual Impairment Allowance	$ 19	$ 43	$ 113
Commercial Real Estate Portfolio Segment [Member]
Number of Contracts	8	10	10
Pre-Modification Carrying Value	$ 9,237	$ 11,528	$ 11,257
Financing Receivable, Modifications, Recorded Investment	7,568	10,788	10,673
Period-End Individual Impairment Allowance		$ 0	$ 0
Residential Portfolio Segment [Member]
Number of Contracts	1	1	1
Pre-Modification Carrying Value	$ 241	$ 241	$ 241
Financing Receivable, Modifications, Recorded Investment	200	208	219
Period-End Individual Impairment Allowance		$ 0	$ 0

Note 4 - Concentration of Cre_2

Note 4 - Concentration of Credit Risk (Details Textual) $ in Thousands	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Unsecured Loan Limit, Percentage of Shareholders' Equity, California Financial Code	15.00%
Secured and Unsecured Loan Limit Percentage, California Financial Code	25.00%
Concentration Risk, Issuer Relationships	78
Loan Commitments and Standby Letters of Credit Related to Real Estate Loans	$ 53,891	$ 53,874
Concentration Risk, Aggregate Securities Amount	$ 5,000
Commercial Real Estate Loans [Member]
Loan To Value Ratio Requirement	75.00%
Residential Real Estate Loans [Member]
Loan To Value Ratio Requirement	80.00%
Aggregate Loans [Member] | Customer Concentration Risk [Member]
Concentration Risk, Issuer Relationships	37
Concentration Risk, Aggregate Loans Amount	$ 5,000

Note 5 - Premises, Equipment _3

Note 5 - Premises, Equipment and Other Assets (Details Textual) $ / shares in Units, shares in Thousands, $ in Thousands	Jun. 28, 2018	Jun. 27, 2018	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Depreciation, Depletion and Amortization, Nonproduction, Total			$ 3,677	$ 3,925	$ 3,959
FRB Membership, Stock Subscription, Percent of Paid-Up Capital Stock and Surplus Requirement			6.00%
Share Price | $ / shares			$ 55.68
LIHTC Investments			$ 10,219	10,119
Qualified Affordable Housing Project Investments, Commitment			4,799	2,299
Affordable Housing Project Investment, Write-down, Amount				$ 625
Contingent Commitment, Year 1 [Member]
Qualified Affordable Housing Project Investments, Commitment			627
Contingent Commitment, Year 2 [Member]
Qualified Affordable Housing Project Investments, Commitment			2,026
Contingent Commitment, Year 3 [Member]
Qualified Affordable Housing Project Investments, Commitment			138
Contingent Commitment, Year 4 [Member]
Qualified Affordable Housing Project Investments, Commitment			261
Contingent Commitment, Year 5 [Member]
Qualified Affordable Housing Project Investments, Commitment			134
Contingent Commitment, Year 6 [Member]
Qualified Affordable Housing Project Investments, Commitment			1,041
Contingent Commitment, Year 7 or Thereafter [Member]
Qualified Affordable Housing Project Investments, Commitment			$ 572
VISA Class B Common Stock [Member]
Investment Owned, Balance, Shares | shares			211
Conversion Rate of Class B Common Stock into Class A Common Stock	1.6298	1.6483
Share Price | $ / shares			$ 131.94
VISA Class B Common Stock [Member] | Reported Value Measurement [Member]
Investment Owned, at Fair Value			$ 0

Note 5 - Premises, Equipment _4

Note 5 - Premises, Equipment and Other Assets - Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Cost	$ 83,622	$ 81,538
Accumulated Depreciation and Amortization	(49,115)	(46,237)
Premises and equipment, net	34,507	35,301
Land [Member]
Cost	11,691	11,796
Accumulated Depreciation and Amortization
Premises and equipment, net	11,691	11,796
Building and Building Improvements [Member]
Cost	41,912	41,641
Accumulated Depreciation and Amortization	(27,178)	(26,249)
Premises and equipment, net	14,734	15,392
Leasehold Improvements [Member]
Cost	6,174	5,817
Accumulated Depreciation and Amortization	(4,968)	(4,790)
Premises and equipment, net	1,206	1,027
Furniture and Fixtures [Member]
Cost	23,845	22,284
Accumulated Depreciation and Amortization	(16,969)	(15,198)
Premises and equipment, net	$ 6,876	$ 7,086

Note 5 - Premises, Equipment _5

Note 5 - Premises, Equipment and Other Assets - Other Assets (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Cost method equity investments:
Federal Reserve Bank stock (1)	[1]	$ 14,069	$ 14,069
Other investments		158	158
Total cost method equity investments		14,227	14,227
Life insurance cash surrender value		56,083	54,101
Net deferred tax asset		42,256	33,112
Limited partnership investments		10,219	10,119
Interest receivable		25,834	23,557
Prepaid assets		4,658	4,906
Other assets		9,629	18,428
Total other assets		$ 162,906	$ 158,450
[1]	A bank applying for membership in the Federal Reserve System is required to subscribe to stock in the Federal Reserve Bank (FRB) in its district in a sum equal to six percent of the bank's paid-up capital stock and surplus. One-half of the amount of the bank's subscription shall be paid to the FRB and the remaining half will be subject to call when deemed necessary by the Board of Governors of the Federal Reserve System.

Note 5 - Premises, Equipment _6

Note 5 - Premises, Equipment and Other Assets - Amounts Recognized in Net Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investment loss included in pre-tax income	$ 2,900	$ 1,800	$ 2,475
Valuation impairment included in pre-tax income		625
Tax credits recognized in provision for income taxes	$ 1,121	$ 1,850	$ 2,286

Note 6 - Goodwill and Identif_3

Note 6 - Goodwill and Identifiable Intangible Assets (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Asset Impairment, Total	$ 0	$ 0	$ 0
Amortization Expense, Adjustment Resulting from a Change in Estimates of Useful Lives or Residual Values	$ 0	$ 0	$ 0

Note 6 - Goodwill and Identif_4

Note 6 - Goodwill and Identifiable Intangible Assets - Carrying Values of Goodwill (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Goodwill	$ 121,673	$ 121,673

Note 6 - Goodwill and Identif_5

Note 6 - Goodwill and Identifiable Intangible Assets - Gross Carrying Amount of Intangible Assets and Accumulated Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Gross Carrying Amount	$ 67,108	$ 67,108
Accumulated Amortization	(65,179)	(63,258)
Core Deposits [Member]
Gross Carrying Amount	56,808	56,808
Accumulated Amortization	(54,879)	(52,987)
Mechant Draft Processing [Member]
Gross Carrying Amount	10,300	10,300
Accumulated Amortization	$ (10,300)	$ (10,271)

Note 6 - Goodwill and Identif_6

Note 6 - Goodwill and Identifiable Intangible Assets - Estimated Future Amortization Expense for Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
For the Year Ended December 31, 2018 (actual)	$ 1,921	$ 3,077	$ 3,504
Estimate for the Year Ended December 31, 2019	538
2,020	287
2,021	269
2,022	252
2,023	236
Core Deposits [Member]
For the Year Ended December 31, 2018 (actual)	1,892
Estimate for the Year Ended December 31, 2019	538
2,020	287
2,021	269
2,022	252
2,023	236
Mechant Draft Processing [Member]
For the Year Ended December 31, 2018 (actual)	29
Estimate for the Year Ended December 31, 2019
2,020
2,021
2,022
2,023

Note 7 - Deposits and Borrowe_3

Note 7 - Deposits and Borrowed Funds (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Demand Deposit Overdrafts	$ 980	$ 2,786
Interest Expense, Time Deposits, $100,000 or More	$ 368	$ 415	$ 509

Note 7 - Deposits and Borrowe_4

Note 7 - Deposits and Borrowed Funds - Deposits Detail (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Noninterest-bearing deposits	$ 2,243,251	$ 2,197,526
Interest-bearing:
Transaction	929,346	904,245
Savings	1,498,991	1,494,024
Time deposits less than $100 thousand	102,654	117,848
Time deposits $100 thousand through $250 thousand	64,512	76,578
Time deposits more than $250 thousand	28,085	37,392
Total deposits	$ 4,866,839	$ 4,827,613

Note 7 - Deposits and Borrowe_5

Note 7 - Deposits and Borrowed Funds - Short-term Borrowed Funds (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Collateral Carrying Value	$ 224,020	$ 237,537
Short-term borrowed funds	51,247	58,471
US Government-sponsored Enterprises Debt Securities [Member]
Collateral Carrying Value	73,803	74,173
Agency Residential MBS [Member]
Collateral Carrying Value	58,380	58,251
Corporate Debt Securities [Member]
Collateral Carrying Value	$ 91,837	$ 105,113

Note 7 - Deposits and Borrowe_6

Note 7 - Deposits and Borrowed Funds - Borrowed Funds, Highest Month End Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Securities Sold under Agreements to Repurchase [Member]
Securities sold under repurchase agreements	$ 68,894	$ 82,126

Note 8 - Shareholders' Equity_2

Note 8 - Shareholders' Equity (Details Textual) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Feb. 13, 2009$ / sharesshares
Share Price | $ / shares	$ 55.68	$ 55.68
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross		249,000	266,000	325,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares		$ 9.98	$ 8.27	$ 5.97
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options | $	$ 2,871	$ 2,871
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value | $		4,264	$ 4,642	$ 3,242
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value | $		$ 1,835	$ 1,493	1,269
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period		292,000	509,000
Excess Tax Deduction Exceeding Related Share-based Compensation, Operating Activities | $		$ 2,516	$ 1,667
Income Tax Expense (Benefit), Total | $		$ 19,433	$ 37,147	21,104
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense | $				394
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		11,000	14,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					246,640
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares					$ 50.92
Stock Issued During Period, Shares, Warrants Exercised		50,788
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	1,750,000	1,750,000
Additional Classes of Stock Authorized	2	2
Additional Classes of Stock Authorized, Shares Authorized, Per Class	1,000,000	1,000,000
Common Stock, Shares Authorized	150,000,000	150,000,000	150,000,000
Common Stock, Shares, Outstanding, Ending Balance	26,730,000	26,730,000	26,425,000
Common Class B [Member]
Common Stock, Shares, Outstanding, Ending Balance	0	0
Accounting Standards Update 2016-09 [Member]
Income Tax Expense (Benefit), Total | $	$ (737)		$ (698)
NQSO [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		10 years
Restricted Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value | $		$ 1,143	708	753
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms		1 year 73 days
Allocated Share-based Compensation Expense, Total | $		$ 660	$ 827	$ 1,228
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	713,000	713,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition		1 year 292 days
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period		0	0

Note 8 - Shareholders' Equity -

Note 8 - Shareholders' Equity - Information About Stock Options Granted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Options outstanding, range of exercise price, lower range (in dollars per share)	$ 40
Options outstanding, range of exercise price, upper range (in dollars per share)	$ 65
Options outstanding, number outstanding (in shares)	946	1,030
Options outstanding, aggregate intrinsic value	$ 3,712
Options outstanding, weighted average remaining contractual life (Year)	5 years 255 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 54
Options exercisable, number outstanding (in shares)	457
Options exercisable, aggregate intrinsic value	$ 2,525
Options exercisable, weighted average remaining contractual life (Year)	2 years 292 days
Options exercisable, weighted average exercise price (in dollars per share)	$ 50
Range 1 [Member]
Options outstanding, range of exercise price, lower range (in dollars per share)	40
Options outstanding, range of exercise price, upper range (in dollars per share)	$ 45
Options outstanding, number outstanding (in shares)	176
Options outstanding, aggregate intrinsic value	$ 2,309
Options outstanding, weighted average remaining contractual life (Year)	6 years 219 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 43
Options exercisable, number outstanding (in shares)	87
Options exercisable, aggregate intrinsic value	$ 1,122
Options exercisable, weighted average remaining contractual life (Year)	6 years 36 days
Options exercisable, weighted average exercise price (in dollars per share)	$ 43
Range 2 [Member]
Options outstanding, range of exercise price, lower range (in dollars per share)	45
Options outstanding, range of exercise price, upper range (in dollars per share)	$ 50
Options outstanding, number outstanding (in shares)	11
Options outstanding, aggregate intrinsic value	$ 106
Options outstanding, weighted average remaining contractual life (Year)	3 years 36 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 46
Options exercisable, number outstanding (in shares)	11
Options exercisable, aggregate intrinsic value	$ 106
Options exercisable, weighted average remaining contractual life (Year)	3 years 36 days
Options exercisable, weighted average exercise price (in dollars per share)	$ 46
Range 3 [Member]
Options outstanding, range of exercise price, lower range (in dollars per share)	50
Options outstanding, range of exercise price, upper range (in dollars per share)	$ 55
Options outstanding, number outstanding (in shares)	286
Options outstanding, aggregate intrinsic value	$ 1,297
Options outstanding, weighted average remaining contractual life (Year)	255 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 51
Options exercisable, number outstanding (in shares)	286
Options exercisable, aggregate intrinsic value	$ 1,297
Options exercisable, weighted average remaining contractual life (Year)	255 days
Options exercisable, weighted average exercise price (in dollars per share)	$ 51
Range 4 [Member]
Options outstanding, range of exercise price, lower range (in dollars per share)	55
Options outstanding, range of exercise price, upper range (in dollars per share)	$ 60
Options outstanding, number outstanding (in shares)	229
Options outstanding, aggregate intrinsic value
Options outstanding, weighted average remaining contractual life (Year)	7 years 255 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 57
Options exercisable, number outstanding (in shares)	73
Options exercisable, aggregate intrinsic value
Options exercisable, weighted average remaining contractual life (Year)	6 years 328 days
Options exercisable, weighted average exercise price (in dollars per share)	$ 57
Range 5 [Member]
Options outstanding, range of exercise price, lower range (in dollars per share)	60
Options outstanding, range of exercise price, upper range (in dollars per share)	$ 65
Options outstanding, number outstanding (in shares)	244
Options outstanding, aggregate intrinsic value
Options outstanding, weighted average remaining contractual life (Year)	9 years 36 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 62

Note 8 - Shareholders' Equity_3

Note 8 - Shareholders' Equity - Weighted Average Assumptions Used in the Option Pricing to Value Stock Options Granted (Details) - $ / shares		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Expected volatility (1)	[1]	20.00%	20.00%	22.00%
Expected life in years (2) (Year)	[2]	4 years 292 days	4 years 292 days	4 years 292 days
Risk-free interest rate (3)	[3]	2.50%	1.97%	1.41%
Expected dividend yield		2.65%	3.28%	4.49%
Fair value per award (in dollars per share)		$ 9.98	$ 8.27	$ 5.97
[1]	Measured using daily price changes of Company's stock over respective expected term of the option and the implied volatility derived from the market prices of the Company's stock and traded options.
[2]	The number of years that the Company estimates that the options will be outstanding prior to exercise.
[3]	The risk-free rate over the expected life based on the US Treasury yield curve in effect at the time of the grant.

Note 8 - Shareholders' Equity_4

Note 8 - Shareholders' Equity - Summary of Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Outstanding at January 1, 2018 (in shares)	1,030,000
Outstanding at January 1, 2018 (in dollars per share)	$ 49.44
Granted (in shares)	249,000	266,000	325,000
Granted (in dollars per share)	$ 62.16
Exercised (in shares)	(292,000)	(509,000)
Exercised (in dollars per share)	$ 45.76
Forfeited or expired (in shares)	(41,000)
Forfeited or expired (in dollars per share)	$ 52.54
Outstanding at December 31, 2018 (in shares)	946,000	1,030,000
Outstanding at December 31, 2018 (in dollars per share)	$ 53.78	$ 49.44
Outstanding at December 31, 2018 (Year)	5 years 255 days
Exercisable at December 31, 2018 (in shares)	457,000
Exercisable at December 31, 2018 (in dollars per share)	$ 50.38
Exercisable at December 31, 2018 (Year)	2 years 292 days

Note 8 - Shareholders' Equity_5

Note 8 - Shareholders' Equity - Summary of Nonvested Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Nonvested at January 1, 2018 (in shares)	561,000
Nonvested at January 1, 2018 (in dollars per share)	$ 6.98
Granted (in shares)	249,000	266,000	325,000
Granted (in dollars per share)	$ 9.98
Vested (in shares)	(280,000)
Vested (in dollars per share)	$ 6.54
Forfeited (in shares)	(41,000)
Forfeited (in dollars per share)	$ 7.66
Nonvested at December 31, 2018 (in shares)	489,000	561,000
Nonvested at December 31, 2018 (in dollars per share)	$ 8.71

Note 8 - Shareholders' Equity_6

Note 8 - Shareholders' Equity - Summary of the Status of Restricted Performance Shares (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Outstanding at January 1, (in shares)	49	48
Granted (in shares)	11	14
Issued upon vesting (in shares)	(19)	(13)
Forfeited (in shares)	(2)
Outstanding at December 31, (in shares)	39	49

Note 9 - Regulatory Capital (De

Note 9 - Regulatory Capital (Details Textual)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2015
Capital Conservation Buffer		1.875%	1.25%	0.00%
Scenario, Forecast [Member]
Capital Conservation Buffer	2.50%

Note 9 - Regulatory Capital - C

Note 9 - Regulatory Capital - Capital Ratios for the Company and the Bank (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Common Equity Tier 1 Capital		$ 528,042	$ 479,259
Common Equity Tier 1 Capital, ratio		16.30%	15.36%
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 206,576	$ 179,377
Common Equity Tier 1 Capital Required for Capital Adequacy, ratio	[1]	6.375%	5.75%
Common Equity Tier 1 Capital To Be Well-capitalized
Common Equity Tier 1 Capital To Be Well-capitalized, ratio
Tier 1 Capital		$ 528,042	$ 479,259
Tier 1 Capital, raio		16.30%	15.36%
Tier 1 Capital Required for Capital Adequacy		$ 255,182	$ 226,170
Tier 1 Capital Required for Capital Adequacy, ratio	[1]	7.875%	7.25%
Tier 1 Capital To Be Well-capitalized
Tier 1 Capital To Be Well-capitalized, ratio
Total Capital		$ 551,701	$ 504,576
Total Capital, ratio		17.03%	16.17%
Total Capital Required for Capital Adequacy		$ 319,990	$ 288,562
Total Capital Required for Capital Adequacy, ratio	[1]	9.875%	9.25%
Total Capital To Be Well-capitalized
Total Capital To Be Well-capitalized, ratio
Leverage Ratio, amount	[2]	$ 528,042	$ 479,259
Leverage Ratio	[2]	9.51%	8.86%
Leverage Ratio Required for Capital Adequacy, amount	[2]	$ 222,111	$ 216,280
Leverage Ratio Required for Capital Adequacy	[2]	4.00%	4.00%
Leverage Ratio To Be Well-capitalized, amount	[2]
Leverage Ratio To Be Well-capitalized	[2]
Westamerica Bank [Member]
Common Equity Tier 1 Capital		$ 415,575	$ 383,796
Common Equity Tier 1 Capital, ratio		13.01%	12.50%
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 203,664	$ 176,568
Common Equity Tier 1 Capital Required for Capital Adequacy, ratio	[1]	6.375%	5.75%
Common Equity Tier 1 Capital To Be Well-capitalized		$ 207,658	$ 199,599
Common Equity Tier 1 Capital To Be Well-capitalized, ratio		6.50%	6.50%
Tier 1 Capital		$ 415,575	$ 383,796
Tier 1 Capital, raio		13.01%	12.50%
Tier 1 Capital Required for Capital Adequacy		$ 251,585	$ 222,630
Tier 1 Capital Required for Capital Adequacy, ratio	[1]	7.875%	7.25%
Tier 1 Capital To Be Well-capitalized		$ 255,579	$ 245,660
Tier 1 Capital To Be Well-capitalized, ratio		8.00%	8.00%
Total Capital		$ 445,234	$ 415,113
Total Capital, ratio		13.94%	13.52%
Total Capital Required for Capital Adequacy		$ 315,480	$ 284,045
Total Capital Required for Capital Adequacy, ratio	[1]	9.875%	9.25%
Total Capital To Be Well-capitalized		$ 319,474	$ 307,076
Total Capital To Be Well-capitalized, ratio		10.00%	10.00%
Leverage Ratio, amount	[2]	$ 415,575	$ 383,796
Leverage Ratio	[2]	7.55%	7.16%
Leverage Ratio Required for Capital Adequacy, amount	[2]	$ 220,312	$ 214,468
Leverage Ratio Required for Capital Adequacy	[2]	4.00%	4.00%
Leverage Ratio To Be Well-capitalized, amount	[2]	$ 275,390	$ 268,085
Leverage Ratio To Be Well-capitalized	[2]	5.00%	5.00%
[1]	Includes 1.25% capital conservation buffer.
[2]	The leverage ratio consists of Tier 1capital divided by the most recent quarterly average total assets, excluding certain intangible assets.

Note 10 - Income Taxes (Details

Note 10 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards, Total	$ 0	$ 0
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax			$ 1,752
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			12,315
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	13	13	13
State and Local Jurisdiction [Member]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability
California Franchise Tax Board [Member]
Open Tax Year		2011 2012 2013 2014 2015 2016 2017
California Franchise Tax Board [Member] | State and Local Jurisdiction [Member]
Deferred Tax Assets, Tax Credit Carryforwards, Total	$ 3,070	$ 3,070	$ 3,056
Operating Loss Carryforwards, Expiration Period	5 years		5 years
Internal Revenue Service (IRS) [Member]
Open Tax Year		2015 2016 2017

Note 10 - Income Taxes - Compon

Note 10 - Income Taxes - Components of Net Deferred Tax Asset (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax asset
Allowance for credit losses	$ 6,868	$ 7,349
State franchise taxes	3,026	1,871
AMT carryforward		1,752
Securities available for sale	16,787	8,586
Deferred compensation	5,229	5,279
Real estate owned	553	553
Purchased assets and assumed liabilities	935	1,111
Post-retirement benefits	555	526
Employee benefit accruals	2,104	2,066
VISA Class B shares	167	96
Limited partnership investments	708	57
Impaired capital assets	3,070	3,056
Accrued liabilities	2,554	1,609
Premises and equipment	31	299
Other	721	520
Total deferred tax asset	43,308	34,730
Deferred tax liability
Net deferred loan fees	291	281
Intangible assets	761	1,247
Other		90
Total deferred tax liability	1,052	1,618
Net deferred tax asset	$ 42,256	$ 33,112

Note 10 - Income Taxes - Provis

Note 10 - Income Taxes - Provision for Federal and State Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Federal	$ 10,560	$ 1,778	$ 16,258
State	9,816	7,810	7,292
Total current	20,376	9,588	23,550
Federal	(206)	14,461	(2,604)
State	(737)	783	158
Total deferred	(943)	15,244	(2,446)
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability		12,315
Provision for income taxes	19,433	37,147	21,104
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability		12,315
State and Local Jurisdiction [Member]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability

Note 10 - Income Taxes - Reconc

Note 10 - Income Taxes - Reconciliation of Income Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Federal income taxes due at statutory rate	$ 19,109	$ 30,509	$ 27,985
Reductions in income taxes resulting from:
Interest on state and municipal securities and loans not taxable for federal income tax purposes	(4,375)	(7,794)	(8,382)
State franchise taxes, net of federal income tax benefit	7,173	5,586	4,843
Re-measurement of net deferred tax asset due to enactment of new federal tax rate		12,315
Stock compensation deduction in excess of book expense	(528)	(583)
Tax credits	(1,291)	(1,850)	(2,286)
Dividend received deduction	(32)	(60)	(52)
Cash value life insurance	(490)	(603)	(607)
Other	(133)	(373)	(397)
Provision for income taxes	$ 19,433	$ 37,147	$ 21,104

Note 10 - Income Taxes - Reco_2

Note 10 - Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Balance	$ 909	$ 1,099
Additions for tax positions taken in the current period
Reductions for tax positions taken in the current period
Additions for tax positions taken in prior years
Reductions for tax positions taken in prior years
Decrease related to settlements with taxing authorities		(190)
Decrease as a result of a lapse in statute of limitations
Balance	$ 909	$ 909

Note 11 - Fair Value Measurem_3

Note 11 - Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Securities Selected for OTTI Analysis, Market Price, Threshold	95.00%
Loans and Leases Receivable, Allowance, Ending Balance	$ 21,351	$ 23,009
Fair Value, Inputs, Level 3 [Member]
Fair Value Inputs, Appraisal Rate	10.00%

Note 11 - Fair Value Measurem_4

Note 11 - Fair Value Measurements - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Equity securities		$ 1,747	$ 1,800	$ 1,800
Debt securities available for sale		2,654,670		2,191,707
US Treasury Securities [Member]
Debt securities available for sale		139,574
US Government-sponsored Enterprises Debt Securities [Member]
Debt securities available for sale		164,018		119,319
Agency Residential MBS [Member]
Debt securities available for sale		853,871		767,706
Non-agency Residential MBS [Member]
Debt securities available for sale		114		154
Agency Commercial MBS [Member]
Debt securities available for sale		1,842		2,219
US Government Agencies Debt Securities [Member]
Debt securities available for sale		1,119		1,590
US States and Political Subdivisions Debt Securities [Member]
Debt securities available for sale		179,091		185,221
Debt Security, Corporate, US [Member]
Debt securities available for sale		1,315,041		1,115,498
Fair Value, Measurements, Recurring [Member]
Equity securities		1,747		1,800
Debt securities available for sale		2,654,670		2,191,707
Total		2,656,417		2,193,507
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Equity securities
Debt securities available for sale		139,574
Total		139,574
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Equity securities		1,747		1,800
Debt securities available for sale		2,515,096		2,191,707
Total		2,516,843		2,193,507
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Equity securities	[1]
Debt securities available for sale	[1]
Total	[1]
Fair Value, Measurements, Recurring [Member] | Mutual Fund [Member]
Equity securities		1,747		1,800
Fair Value, Measurements, Recurring [Member] | Mutual Fund [Member] | Fair Value, Inputs, Level 1 [Member]
Equity securities
Fair Value, Measurements, Recurring [Member] | Mutual Fund [Member] | Fair Value, Inputs, Level 2 [Member]
Equity securities		1,747		1,800
Fair Value, Measurements, Recurring [Member] | Mutual Fund [Member] | Fair Value, Inputs, Level 3 [Member]
Equity securities	[1]
Fair Value, Measurements, Recurring [Member] | US Treasury Securities [Member]
Debt securities available for sale		139,574
Fair Value, Measurements, Recurring [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Debt securities available for sale		139,574
Fair Value, Measurements, Recurring [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Debt securities available for sale
Fair Value, Measurements, Recurring [Member] | US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Debt securities available for sale	[1]
Fair Value, Measurements, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Debt securities available for sale		164,018		119,319
Fair Value, Measurements, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Debt securities available for sale
Fair Value, Measurements, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Debt securities available for sale		164,018		119,319
Fair Value, Measurements, Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Debt securities available for sale	[1]
Fair Value, Measurements, Recurring [Member] | Agency Residential MBS [Member]
Debt securities available for sale		853,871		767,706
Fair Value, Measurements, Recurring [Member] | Agency Residential MBS [Member] | Fair Value, Inputs, Level 1 [Member]
Debt securities available for sale
Fair Value, Measurements, Recurring [Member] | Agency Residential MBS [Member] | Fair Value, Inputs, Level 2 [Member]
Debt securities available for sale		853,871		767,706
Fair Value, Measurements, Recurring [Member] | Agency Residential MBS [Member] | Fair Value, Inputs, Level 3 [Member]
Debt securities available for sale	[1]
Fair Value, Measurements, Recurring [Member] | Non-agency Residential MBS [Member]
Debt securities available for sale		114		154
Fair Value, Measurements, Recurring [Member] | Non-agency Residential MBS [Member] | Fair Value, Inputs, Level 1 [Member]
Debt securities available for sale
Fair Value, Measurements, Recurring [Member] | Non-agency Residential MBS [Member] | Fair Value, Inputs, Level 2 [Member]
Debt securities available for sale		114		154
Fair Value, Measurements, Recurring [Member] | Non-agency Residential MBS [Member] | Fair Value, Inputs, Level 3 [Member]
Debt securities available for sale	[1]
Fair Value, Measurements, Recurring [Member] | Agency Commercial MBS [Member]
Debt securities available for sale		1,842		2,219
Fair Value, Measurements, Recurring [Member] | Agency Commercial MBS [Member] | Fair Value, Inputs, Level 1 [Member]
Debt securities available for sale
Fair Value, Measurements, Recurring [Member] | Agency Commercial MBS [Member] | Fair Value, Inputs, Level 2 [Member]
Debt securities available for sale		1,842		2,219
Fair Value, Measurements, Recurring [Member] | Agency Commercial MBS [Member] | Fair Value, Inputs, Level 3 [Member]
Debt securities available for sale	[1]
Fair Value, Measurements, Recurring [Member] | US Government Agencies Debt Securities [Member]
Debt securities available for sale		1,119		1,590
Fair Value, Measurements, Recurring [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Debt securities available for sale
Fair Value, Measurements, Recurring [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Debt securities available for sale		1,119		1,590
Fair Value, Measurements, Recurring [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Debt securities available for sale	[1]
Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Debt securities available for sale		179,091		185,221
Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Debt securities available for sale
Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Debt securities available for sale		179,091		185,221
Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Debt securities available for sale	[1]
Fair Value, Measurements, Recurring [Member] | Debt Security, Corporate, US [Member]
Debt securities available for sale		1,315,041		1,115,498
Fair Value, Measurements, Recurring [Member] | Debt Security, Corporate, US [Member] | Fair Value, Inputs, Level 1 [Member]
Debt securities available for sale
Fair Value, Measurements, Recurring [Member] | Debt Security, Corporate, US [Member] | Fair Value, Inputs, Level 2 [Member]
Debt securities available for sale		1,315,041		1,115,498
Fair Value, Measurements, Recurring [Member] | Debt Security, Corporate, US [Member] | Fair Value, Inputs, Level 3 [Member]
Debt securities available for sale	[1]
[1]	There were no transfers in to or out of level 3 during the year ended December 31, 2017.

Note 11 - Fair Value Measurem_5

Note 11 - Fair Value Measurements - Assets Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value	$ 10,657	$ 12,280
Total Losses	(240)	(219)
Fair Value, Inputs, Level 1 [Member]
Fair Value
Fair Value, Inputs, Level 2 [Member]
Fair Value
Fair Value, Inputs, Level 3 [Member]
Fair Value	10,657	12,280
Other Real Estate Owned [Member]
Fair Value	350	1,426
Total Losses		(219)
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value
Other Real Estate Owned [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value	350	1,426
Impaired Loans [Member] | Commercial Portfolio Segment [Member]
Fair Value	6,437	4,950
Total Losses
Impaired Loans [Member] | Commercial Real Estate Portfolio Segment [Member]
Fair Value	3,870	5,904
Total Losses	(240)
Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Portfolio Segment [Member]
Fair Value
Impaired Loans [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Real Estate Portfolio Segment [Member]
Fair Value
Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Portfolio Segment [Member]
Fair Value
Impaired Loans [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Real Estate Portfolio Segment [Member]
Fair Value
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Portfolio Segment [Member]
Fair Value	6,437	4,950
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Real Estate Portfolio Segment [Member]
Fair Value	$ 3,870	$ 5,904

Note 11 - Fair Value Measurem_6

Note 11 - Fair Value Measurements - Fair Value Estimates for Financial Instruments, Excluding Financial Instruments Recorded at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Reported Value Measurement [Member]
Cash and due from banks	$ 420,284	$ 575,002
Debt securities held to maturity	984,609	1,158,864
Loans	1,185,851	1,264,973
Deposits	4,866,839	4,827,613
Short-term borrowed funds	51,247	58,471
Estimate of Fair Value Measurement [Member]
Cash and due from banks	420,284	575,002
Debt securities held to maturity	971,445	1,155,342
Loans	1,184,770	1,257,811
Deposits	4,862,668	4,824,586
Short-term borrowed funds	51,247	58,471
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and due from banks	420,284	575,002
Debt securities held to maturity
Loans
Deposits
Short-term borrowed funds
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and due from banks
Debt securities held to maturity	971,445	1,155,342
Loans
Deposits	4,671,588	4,595,795
Short-term borrowed funds	51,247	58,471
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and due from banks
Debt securities held to maturity
Loans	1,184,770	1,257,811
Deposits	191,080	228,791
Short-term borrowed funds

Note 12 - Lease Commitments (De

Note 12 - Lease Commitments (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Facilities Leased	58
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals	$ 1,319
Operating Leases, Rent Expense, Minimum Rentals	6,794	$ 6,695	$ 6,823
Operating Leases, Rent Expense, Sublease Rentals	397	406	435
Operating Leases, Rent Expense, Net, Total	$ 6,397	$ 6,289	$ 6,388

Note 12 - Lease Commitments - M

Note 12 - Lease Commitments - Minimum Future Rental Payments Under Noncancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2018USD ($)
2,019	$ 5,996
2,020	4,409
2,021	2,741
2,022	1,921
2,023	1,223
Thereafter	1,044
Total minimum lease payments	$ 17,334

Note 13 - Commitments and Con_2

Note 13 - Commitments and Contingent Liabilities (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Unfunded Loan Commitments	$ 278,598	$ 272,646
Guarantor Obligations, Current Carrying Value	75
Other Liabilities [Member]
Reserve for Unfunded Commitments	2,308	2,308
Financial Standby Letter of Credit [Member]
Letters of Credit Outstanding, Amount	2,772	19,263
Commercial Standby Letters of Credit [Member]
Letters of Credit Outstanding, Amount	0	$ 0
Settlement to Dismiss Lawsuit [Member]
Loss Contingency Accrual, Ending Balance	3,500
Customer Refunds [Member]
Loss Contingency Accrual, Ending Balance	$ 5,542

Note 14 - Retirement Benefit _3

Note 14 - Retirement Benefit Plans (Details Textual) - USD ($) xbrli-pure in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Contribution Plan, Cost	$ 1,057	$ 944	$ 1,000
Employee Stock Ownership Plan (ESOP), Compensation Expense	$ 1,052	$ 1,098	$ 1,075
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	0.00%

Note 14 - Retirement Benefit _4

Note 14 - Retirement Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Service benefit	$ 24	$ (311)	$ (153)
Interest cost	72	95	108
Amortization of unrecognized transition obligation		61	61
Net periodic (benefit) cost	96	(155)	16
Amortization of unrecognized transition obligation, net of tax		(34)	(36)
Total recognized in net periodic (benefit) cost and accumulated other comprehensive income	$ 96	$ (189)	$ (20)

Note 14 - Retirement Benefit _5

Note 14 - Retirement Benefit Plans - Obligation and Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Benefit obligation at beginning of year	$ 1,958	$ 2,319	$ 2,522
Service benefit	24	(311)	(153)
Interest cost	72	95	108
Benefits paid	(141)	(145)	(158)
Benefit obligation at end of year	1,913	1,958	2,319
Accumulated post-retirement benefit obligation	1,958	1,958	2,319	$ 1,913	$ 1,958	$ 2,319
Fair value of plan assets
Accumulated post-retirement benefit obligation in excess of plan assets				1,913	1,958	2,319
Retirees [Member]
Benefit obligation at beginning of year	1,575	1,705
Benefit obligation at end of year	1,913	1,575	1,705
Accumulated post-retirement benefit obligation	1,913	1,575	1,705	1,913	1,575	1,705
Fully Eligible Participants [Member]
Benefit obligation at beginning of year	382	606
Benefit obligation at end of year		382	606
Accumulated post-retirement benefit obligation		382	606		382	606
Other Participants [Member]
Benefit obligation at beginning of year	1	8
Benefit obligation at end of year		1	8
Accumulated post-retirement benefit obligation		$ 1	$ 8		$ 1	$ 8

Note 14 - Retirement Benefit _6

Note 14 - Retirement Benefit Plans - Assumptions (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Discount rate	3.76%	3.70%	4.10%
Discount rate	3.70%	4.10%	4.30%

Note 14 - Retirement Benefit _7

Note 14 - Retirement Benefit Plans - Estimated Future Benefit Payments (Details) $ in Thousands	Dec. 31, 2018USD ($)
2,019	$ 143
2,020	143
2,021	143
2,022	140
2,023	138
Years 2024-2028	$ 624

Note 15 - Related Party Trans_3

Note 15 - Related Party Transactions - Related Party Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Balance at January 1,	$ 622	$ 867
Originations
Principal reductions	(45)	(245)
Balance at December 31,	$ 577	$ 622
Percent of total loans outstanding.	0.05%	0.05%

Note 16 - Regulatory Matters (D

Note 16 - Regulatory Matters (Details Textual) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Federal Reserve Bank Average Balance Deposit	$ 473,250	$ 458,186

Note 17 - Other Comprehensive_3

Note 17 - Other Comprehensive Income - Components of Other Comprehensive Income (Loss) and Other Related Tax Effects (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net unrealized gains (losses) arising during the year, before tax	$ (27,939)	$ (3,767)	$ (18,610)
Net unrealized gains (losses) arising during the year, tax	8,258	1,585	7,825
Net unrealized gains (losses) arising during the year, net of tax	(19,681)	(2,182)	(10,785)
Net unrealized losses arising during the year, before tax	(27,939)	(11,722)	(18,610)
Net unrealized gains (losses) arising during the year, tax	8,258	4,930	7,825
Changes in unrealized losses on debt securities available for sale, net of tax	(19,681)	(6,792)	(10,785)
Post-retirement benefit obligation, before tax		59	61
Post-retirement benefit obligation, tax		(25)	(25)
Post-retirement benefit obligation, net of tax		34	36
Other comprehensive income (loss), before tax	(27,939)	(11,663)	(18,549)
Other comprehensive income (loss), tax	8,258	4,905	7,800
Other comprehensive loss	(19,681)	(6,758)	(10,749)
Reclassification of gains (losses) included in net income, before tax		(7,955)
Reclassification of gains (losses) included in net income, tax		3,345
Reclassification of gains (losses) included in net income, net of tax		$ (4,610)

Note 17 - Other Comprehensive_4

Note 17 - Other Comprehensive Income - Cumulative Other Comprehensive Income (Loss) Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Balance	$ 590,239	$ 561,367	$ 532,205
Net change	(19,681)	(6,758)	(10,749)
Balance	590,239
Balance	615,591	590,239	561,367
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance		(34)	(70)
Net change		34	36
Cumulative effect of equity securities losses reclassified
Balance
Reclass stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017
Balance			(34)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Balance	(16,832)	(10,040)	745
Net change	(19,681)	(6,792)	(10,785)
Cumulative effect of equity securities losses reclassified	142
Balance	(16,690)
Reclass stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017	(3,625)
Balance	(39,996)	(16,832)	(10,040)
AOCI Attributable to Parent [Member]
Balance	(16,832)	(10,074)	675
Net change	(19,681)	(6,758)	(10,749)
Cumulative effect of equity securities losses reclassified	142
Balance	(16,690)
Reclass stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017	(3,625)
Balance	$ (39,996)	$ (16,832)	$ (10,074)

Note 18 - Earnings Per Common_3

Note 18 - Earnings Per Common Share (Details Textual) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	423	323	773

Note 18 - Earnings Per Common_4

Note 18 - Earnings Per Common Share - Earnings Per Common Share and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, 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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net Income	$ 19,055	$ 16,993	$ 18,010	$ 17,506	$ 4,160	$ 15,017	$ 15,799	$ 15,049	$ 14,453	$ 15,628	$ 14,546	$ 14,226	$ 71,564	$ 50,025	$ 58,853
Weighted average number of common shares outstanding - basic (in shares)													26,649	26,291	25,612
Basic earnings per common share (in dollars per share)	$ 0.71	$ 0.64	$ 0.68	$ 0.66	$ 0.16	$ 0.57	$ 0.60	$ 0.58	$ 0.56	$ 0.61	$ 0.57	$ 0.56	$ 2.69	$ 1.90	$ 2.30
Add common stock equivalents for options (in shares)													107	128	66
Weighted average number of common shares outstanding - diluted (denominator) (in shares)													26,756	26,419	25,678
Diluted earnings per common share (in dollars per share)	$ 0.71	$ 0.63	$ 0.67	$ 0.66	$ 0.16	$ 0.57	$ 0.60	$ 0.57	$ 0.56	$ 0.61	$ 0.57	$ 0.56	$ 2.67	$ 1.89	$ 2.29

Note 19 - Westamerica Bancorp_3

Note 19 - Westamerica Bancorporation (Parent Company Only Condensed Financial Information) - Statements of Income and Comprehensive Income (Details) - 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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Salaries and related benefits													$ 53,007	$ 51,519	$ 51,507
Income before taxes and equity in undistributed income of subsidiaries	$ 25,044	$ 21,249	$ 22,915	$ 21,789	$ 23,866	$ 21,106	$ 22,314	$ 19,886	$ 19,677	$ 21,655	$ 19,659	$ 18,966	90,997	87,172	79,957
Income tax benefit													(19,433)	(37,147)	(21,104)
Earnings of subsidiaries greater than subsidiary dividends													28,029	39,002	3,033
Net income for the period	$ 19,055	$ 16,993	$ 18,010	$ 17,506	$ 4,160	$ 15,017	$ 15,799	$ 15,049	$ 14,453	$ 15,628	$ 14,546	$ 14,226	71,564	50,025	58,853
Other comprehensive loss, net of tax														(6,758)	(10,749)
Comprehensive income													51,883	43,267	48,104
Parent Company [Member]
Dividends from subsidiaries													43,892	12,728	56,824
Interest income													33	43	25
Other income													9,447	8,590	8,315
Total income													53,372	21,361	65,164
Interest on borrowings
Salaries and related benefits													7,575	7,163	7,079
Other expense													3,181	3,416	3,290
Total expense													10,756	10,579	10,369
Income before taxes and equity in undistributed income of subsidiaries													42,616	10,782	54,795
Income tax benefit													919	241	1,025
Earnings of subsidiaries greater than subsidiary dividends													28,029	39,002	3,033
Net income for the period													71,564	50,025	58,853
Other comprehensive loss, net of tax													(19,681)	(6,758)	(10,749)
Comprehensive income													$ 51,883	$ 43,267	$ 48,104

Note 19 - Westamerica Bancorp_4

Note 19 - Westamerica Bancorporation (Parent Company Only Condensed Financial Information) - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Premises and equipment, net	$ 34,507	$ 35,301
Other assets	162,906	158,450
Total assets	5,568,526	5,513,046
Other liabilities	34,849	36,723
Total liabilities	4,952,935	4,922,807
Shareholders' equity	615,591	590,239	$ 561,367	$ 532,205
Total liabilities and shareholders' equity	5,568,526	5,513,046
Parent Company [Member]
Cash	72,878	53,409	$ 64,054	$ 26,453
Investment securities available for sale
Premises and equipment, net	10,400	9,639
Accounts receivable from Westamerica Bank	580	538
Other assets	36,990	40,547
Total assets	630,428	605,364
Accounts payable to Westamerica Bank	46	92
Other liabilities	14,791	15,033
Total liabilities	14,837	15,125
Shareholders' equity	615,591	590,239
Total liabilities and shareholders' equity	630,428	605,364
Parent Company [Member] | Westamerica Bank [Member]
Investment	509,125	500,776
Parent Company [Member] | Non-bank Subsidiaries [Member]
Investment	$ 455	$ 455

Note 19 - Westamerica Bancorp_5

Note 19 - Westamerica Bancorporation (Parent Company Only Condensed Financial Information) - Cash Flows Statement (Details) - 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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net income for the period	$ 19,055	$ 16,993	$ 18,010	$ 17,506	$ 4,160	$ 15,017	$ 15,799	$ 15,049	$ 14,453	$ 15,628	$ 14,546	$ 14,226	$ 71,564	$ 50,025	$ 58,853
Depreciation and amortization/accretion													24,402	26,082	19,939
Increase in other assets													(4,017)	(1,732)	(3,321)
Stock option compensation expense													1,988	1,824	1,494
Provision (benefit) for deferred income tax													(943)	15,244	(2,446)
(Decrease) increase in other liabilities													(580)	(3,016)	2,026
Earnings of subsidiaries greater than subsidiary dividends													(28,029)	(39,002)	(3,033)
Life insurance gains													(585)
Gain on sales of premises and equipment													(538)	(793)	(79)
Net Cash Provided by Operating Activities													96,629	80,754	77,637
Proceeds from life insurance													1,169
Net Cash Provided by Investing Activities													(253,563)	(73,258)	(197,263)
Financing Activities:
Exercise of stock options													13,373	24,583	24,031
Taxes paid by withholding shares for tax purposes															(356)
Tax benefit increase (decrease) upon exercise of stock options and expiration of stock options															394
Retirement of common stock													(524)	(314)	(5,424)
Common stock dividends paid													(42,635)	(41,299)	(39,924)
Net Cash Used in Financing Activities													2,216	105,235	148,853
Net change in cash													(154,718)	112,731	29,227
Interest paid for the period													1,932	1,931	2,202
Income tax payments for the period													13,627	17,351	19,264
Parent Company [Member]
Net income for the period													71,564	50,025	58,853
Depreciation and amortization/accretion													361	319	305
(Increase) decrease in accounts receivable from affiliates													(43)	(16)	299
Increase in other assets													(2,638)	(2,203)	(1,940)
Stock option compensation expense													1,988	1,824	1,494
Tax benefit increase upon exercise of stock options and expiration of stock options															(394)
Provision (benefit) for deferred income tax													5,028	(3,971)	1,983
(Decrease) increase in other liabilities													978	202	1,392
Earnings of subsidiaries greater than subsidiary dividends													(28,029)	(39,002)	(3,033)
Net Cash Provided by Operating Activities													48,086	6,385	58,880
Net Cash Provided by Investing Activities													1,169
Financing Activities:
Exercise of stock options													13,373	24,583	24,031
Taxes paid by withholding shares for tax purposes															(356)
Retirement of common stock													(524)	(314)	(5,424)
Common stock dividends paid													(42,635)	(41,299)	(39,924)
Net Cash Used in Financing Activities													(29,786)	(17,030)	(21,279)
Net change in cash													19,469	(10,645)	37,601
Cash at Beginning of Period				$ 53,409				$ 64,054				$ 26,453	53,409	64,054	26,453
Cash at End of Period	$ 72,878				$ 53,409				$ 64,054				72,878	53,409	64,054
Interest paid for the period
Income tax payments for the period													$ 13,627	$ 17,351	$ 19,264

Note 20 - Quarterly Financial_3

Note 20 - Quarterly Financial Information - Quarterly Financial Information (Unaudited) (Details) - 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, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest and loan fee income	$ 39,448	$ 38,614	$ 37,346	$ 36,315	$ 35,478	$ 34,623	$ 34,083	$ 34,128	$ 33,715	$ 33,955	$ 34,248	$ 34,001	$ 151,723	$ 138,312	$ 135,919
Net interest income	38,934	38,087	36,887	35,856	35,007	34,150	33,607	33,648	33,215	33,432	33,707	33,449	149,764	136,412	133,803
Provision for loan losses							(1,900)			(3,200)				(1,900)	(3,200)
Total Noninterest Income	11,897	12,528	11,769	11,955	20,300	12,548	12,123	11,657	11,545	11,598	11,702	11,729	48,149	56,628	46,574
Noninterest expense	25,787	29,366	25,741	26,022	31,441	25,592	25,316	25,419	25,083	26,575	25,750	26,212	106,916	107,768	103,620
Income before taxes and equity in undistributed income of subsidiaries	25,044	21,249	22,915	21,789	23,866	21,106	22,314	19,886	19,677	21,655	19,659	18,966	90,997	87,172	79,957
Net income for the period	$ 19,055	$ 16,993	$ 18,010	$ 17,506	$ 4,160	$ 15,017	$ 15,799	$ 15,049	$ 14,453	$ 15,628	$ 14,546	$ 14,226	$ 71,564	$ 50,025	$ 58,853
Basic earnings per common share (in dollars per share)	$ 0.71	$ 0.64	$ 0.68	$ 0.66	$ 0.16	$ 0.57	$ 0.60	$ 0.58	$ 0.56	$ 0.61	$ 0.57	$ 0.56	$ 2.69	$ 1.90	$ 2.30
Diluted earnings per common share (in dollars per share)	0.71	0.63	0.67	0.66	0.16	0.57	0.60	0.57	0.56	0.61	0.57	0.56	2.67	1.89	2.29
Dividends paid (in dollars per share)	0.40	0.40	0.40	0.40	0.40	0.39	0.39	0.39	0.39	0.39	0.39	0.39	1.60	1.57	1.56
Share price, common stock (in dollars per share)	55.68												55.68
Minimum [Member]
Share price, common stock (in dollars per share)	52.75	57.56	55.81	55.72	53.96	49.54	51.31	54.12	48.20	46.61	45.86	40.72	52.75	53.96	48.20
Maximum [Member]
Share price, common stock (in dollars per share)	$ 63.20	$ 64.52	$ 60.68	$ 62.52	$ 63.03	$ 59.54	$ 57.78	$ 64.07	$ 65.34	$ 50.96	$ 51.53	$ 49.63	$ 63.20	$ 63.03	$ 65.34