$WABC
WESTAMERICA BANCORPORATION Stock $wabc

$wabc Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000117184324001054 Filed on February 29, 2024

Income Statement

Concept	2024 Q1	2023 Q4	2023
Revenue	$68.75M	$71.05M	$284.0M
YoY Change	-1.26%	2.68%	28.07%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$2.962M	$2.974M	$11.77M
YoY Change	-2.69%	5.13%	-28.92%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$3.001M		$3.890M
YoY Change	537.15%		102.08%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$49.44M	$54.85M	$221.6M
YoY Change	-10.17%	1.39%	33.81%
Income Tax	$13.03M	$15.38M	$59.81M
% Of Pretax Income	26.35%	28.04%	26.99%
Net Earnings	$36.42M	$39.47M	$161.8M
YoY Change	-9.97%	0.32%	32.56%
Net Earnings / Revenue	52.97%	55.55%	56.96%
Basic Earnings Per Share	$1.37	$1.48	$6.06
Diluted Earnings Per Share	$1.37	$1.48	$6.06
COMMON SHARES
Basic Shares Outstanding	26.67M	26.65M	26.70M
Diluted Shares Outstanding	26.68M		26.71M

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$434.3M	$190.3M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$26.46M	$27.02M	$27.02M
YoY Change	-6.61%	-6.26%	-6.26%
Goodwill	$121.7M	$121.7M
YoY Change	0.0%	0.0%
Intangibles
YoY Change
Long-Term Investments	$158.0K	$14.23M	$14.23M
YoY Change	-98.88%	19.54%	19.54%
Other Assets	$100.4M	$99.51M	$99.51M
YoY Change	-12.42%	-20.48%	-20.48%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$6.465B	$6.365B	$6.365B
YoY Change	-3.52%	-8.43%	-8.43%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$19.98M	$18.81M	$18.81M
YoY Change	29.31%	19.48%	19.48%
Deferred Revenue
YoY Change
Short-Term Debt	$50.33M	$58.16M	$58.16M
YoY Change	-39.42%	0.64%	0.64%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$50.33M	$58.16M	$58.16M
YoY Change	-48.92%	269.38%	269.38%
LONG-TERM LIABILITIES
Long-Term Debt	$200.0M	$0.00	$0.00
YoY Change
Other Long-Term Liabilities	$67.74M	$59.27M	$59.27M
YoY Change	13.47%	-8.99%	-8.99%
Total Long-Term Liabilities	$267.7M	$59.27M	$59.27M
YoY Change	348.5%	-8.99%	-8.99%
TOTAL LIABILITIES
Total Short-Term Liabilities	$50.33M	$58.16M	$58.16M
Total Long-Term Liabilities	$267.7M	$59.27M	$59.27M
Total Liabilities	$5.673B	$5.592B	$5.592B
YoY Change	-6.35%	-11.92%	-11.92%
SHAREHOLDERS EQUITY
Retained Earnings	$514.6M	$490.0M
YoY Change	27.57%	27.91%
Common Stock	$474.0M	$473.1M
YoY Change	0.6%	-0.41%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$791.7M	$772.9M	$772.9M
YoY Change
Total Liabilities & Shareholders Equity	$6.465B	$6.365B	$6.365B
YoY Change	-3.52%	-8.43%	-8.43%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	$36.42M	$39.47M	$161.8M
YoY Change	-9.97%	0.32%	32.56%
Depreciation, Depletion And Amortization	$2.962M	$2.974M	$11.77M
YoY Change	-2.69%	5.13%	-28.92%
Cash From Operating Activities	$52.21M	-$7.992M	$158.2M
YoY Change	-5.21%	-119.11%	39.14%
INVESTING ACTIVITIES
Capital Expenditures	$122.0K	$261.0K	$1.161M
YoY Change	-76.13%	-26200.0%	43.16%
Acquisitions
YoY Change
Other Investing Activities	$131.0M	$70.73M	$548.4M
YoY Change	-23.91%	-49.12%	-186.99%
Cash From Investing Activities	$130.8M	$70.47M	$547.3M
YoY Change	-23.76%	-49.31%	-186.69%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	$60.89M	-292.7M	-$809.4M
YoY Change	-118.69%	-2.52%	152.73%
NET CHANGE
Cash From Operating Activities	$52.21M	-7.992M	$158.2M
Cash From Investing Activities	$130.8M	70.47M	$547.3M
Cash From Financing Activities	$60.89M	-292.7M	-$809.4M
Net Change In Cash	$243.9M	-230.2M	-$103.9M
YoY Change	-346.32%	92.77%	-87.6%
FREE CASH FLOW
Cash From Operating Activities	$52.21M	-$7.992M	$158.2M
Capital Expenditures	$122.0K	$261.0K	$1.161M
Free Cash Flow	$52.09M	-$8.253M	$157.0M
YoY Change	-4.55%	-119.73%	39.11%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2023	dei	Amendment Flag AmendmentFlag	false
CY2023	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2023	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2023
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	1000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	1000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	849562000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	873511000	usd
CY2023Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		usd
CY2022Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		usd
CY2023Q4	us-gaap	Common Stock No Par Value CommonStockNoParValue	0
CY2022Q4	us-gaap	Common Stock No Par Value CommonStockNoParValue	0
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	150000000
CY2022Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	150000000
CY2023Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	26671000
CY2023Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	26671000
CY2022Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	26913000
CY2022Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	26913000
CY2021	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.65
CY2022	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.68
CY2023	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.72
CY2023	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	1	pure
CY2022Q4	us-gaap	Equity Securities Fv Ni Current And Noncurrent EquitySecuritiesFvNiCurrentAndNoncurrent	0	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	1000	usd
CY2022Q4	wabc	Loans And Leases Receivable Nonaccrual Commitment To Lend LoansAndLeasesReceivableNonaccrualCommitmentToLend	0	usd
CY2022	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	0	usd
CY2022Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	0	usd
CY2022Q4	us-gaap	Other Real Estate OtherRealEstate	0	usd
CY2023Q4	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	0	usd
CY2023Q4	us-gaap	Lessee Operating Lease Term Of Contract LesseeOperatingLeaseTermOfContract	P5Y
CY2023Q4	us-gaap	Lessee Operating Lease Renewal Term LesseeOperatingLeaseRenewalTerm	P5Y
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	18814000	usd
CY2023	us-gaap	Goodwill And Intangible Asset Impairment GoodwillAndIntangibleAssetImpairment	0	usd
CY2022	us-gaap	Goodwill And Intangible Asset Impairment GoodwillAndIntangibleAssetImpairment	0	usd
CY2022	wabc	Amortization Expense Adjustment Resulting From A Change In Estimates Of Useful Lives Or Residual Values AmortizationExpenseAdjustmentResultingFromAChangeInEstimatesOfUsefulLivesOrResidualValues	0	usd
CY2023	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Lower Range Limit ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit	40
CY2023Q4	wabc	Additional Classes Of Stock Authorized Shares Authorized Per Class AdditionalClassesOfStockAuthorizedSharesAuthorizedPerClass	1000000
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	usd
CY2022	us-gaap	Income Tax Examination Penalties And Interest Expense IncomeTaxExaminationPenaltiesAndInterestExpense	0	usd
CY2023Q4	us-gaap	Defined Benefit Plan Health Care Cost Trend Rate Assumed Next Fiscal Year DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear	0	pure
CY2023	ecd	Non Rule10b51 Arr Trmntd Flag NonRule10b51ArrTrmntdFlag	false
CY2023	ecd	Rule10b51 Arr Trmntd Flag Rule10b51ArrTrmntdFlag	false
CY2023	ecd	Non Rule10b51 Arr Adopted Flag NonRule10b51ArrAdoptedFlag	false
CY2023	ecd	Rule10b51 Arr Adopted Flag Rule10b51ArrAdoptedFlag	false
CY2023	dei	Document Type DocumentType	10-K
CY2023	dei	Document Annual Report DocumentAnnualReport	true
CY2023	dei	Document Period End Date DocumentPeriodEndDate	2023-12-31
CY2023	dei	Document Transition Report DocumentTransitionReport	false
CY2023	dei	Entity File Number EntityFileNumber	001-09383
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	CA
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	94-2156203
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	1108 FIFTH AVENUE
CY2023	dei	Entity Address City Or Town EntityAddressCityOrTown	SAN RAFAEL
CY2023	dei	Entity Address State Or Province EntityAddressStateOrProvince	CA
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	94901
CY2023	dei	City Area Code CityAreaCode	707
CY2023	dei	Local Phone Number LocalPhoneNumber	863-6000
CY2023	dei	Security12b Title Security12bTitle	Common Stock, no par value
CY2023	dei	Trading Symbol TradingSymbol	WABC
CY2023	dei	Security Exchange Name SecurityExchangeName	NASDAQ
CY2023	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2023	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2023	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2023	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2023	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2023	dei	Entity Small Business EntitySmallBusiness	false
CY2023	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2023	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2023	dei	Document Fin Stmt Error Correction Flag DocumentFinStmtErrorCorrectionFlag	false
CY2023	dei	Entity Shell Company EntityShellCompany	false
CY2023Q2	dei	Entity Public Float EntityPublicFloat	687093519	usd
CY2024Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	26671215
CY2023	dei	Auditor Firm AuditorFirmId	173
CY2023Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	190314000	usd
CY2022Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	294236000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	3999801000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	4331743000	usd
CY2023Q4	wabc	Held To Maturity Securities Net HeldToMaturitySecuritiesNet	878396000	usd
CY2022Q4	wabc	Held To Maturity Securities Net HeldToMaturitySecuritiesNet	915913000	usd
CY2023Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	866602000	usd
CY2022Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	958488000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	16867000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	20284000	usd
CY2023Q4	us-gaap	Notes Receivable Net NotesReceivableNet	849735000	usd
CY2022Q4	us-gaap	Notes Receivable Net NotesReceivableNet	938204000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	27016000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	28819000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	347000	usd
CY2022Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	583000	usd
CY2023Q4	us-gaap	Goodwill Goodwill	121673000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	121673000	usd
CY2023Q4	us-gaap	Other Assets OtherAssets	297310000	usd
CY2022Q4	us-gaap	Other Assets OtherAssets	319146000	usd
CY2023Q4	us-gaap	Assets Assets	6364592000	usd
CY2022Q4	us-gaap	Assets Assets	6950317000	usd
CY2023Q4	us-gaap	Noninterest Bearing Deposit Liabilities Domestic NoninterestBearingDepositLiabilitiesDomestic	2605844000	usd
CY2022Q4	us-gaap	Noninterest Bearing Deposit Liabilities Domestic NoninterestBearingDepositLiabilitiesDomestic	2947277000	usd
CY2023Q4	us-gaap	Interest Bearing Deposit Liabilities Domestic InterestBearingDepositLiabilitiesDomestic	2868423000	usd
CY2022Q4	us-gaap	Interest Bearing Deposit Liabilities Domestic InterestBearingDepositLiabilitiesDomestic	3278013000	usd
CY2023Q4	us-gaap	Deposits Deposits	5474267000	usd
CY2022Q4	us-gaap	Deposits Deposits	6225290000	usd
CY2023Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	58162000	usd
CY2022Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	57792000	usd
CY2023Q4	us-gaap	Other Liabilities OtherLiabilities	59269000	usd
CY2022Q4	us-gaap	Other Liabilities OtherLiabilities	65125000	usd
CY2023Q4	us-gaap	Liabilities Liabilities	5591698000	usd
CY2022Q4	us-gaap	Liabilities Liabilities	6348207000	usd
CY2023Q4	us-gaap	Common Stock Value CommonStockValue	473136000	usd
CY2022Q4	us-gaap	Common Stock Value CommonStockValue	475086000	usd
CY2023Q4	wabc	Deferred Compensation DeferredCompensation	35000	usd
CY2022Q4	wabc	Deferred Compensation DeferredCompensation	35000	usd
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-190282000	usd
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-256105000	usd
CY2023Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	490005000	usd
CY2022Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	383094000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	772894000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	602110000	usd
CY2023Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	6364592000	usd
CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	6950317000	usd
CY2023	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	47116000	usd
CY2022	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	49682000	usd
CY2021	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	57558000	usd
CY2023	wabc	Interest And Dividend Income Equity Securities Operating InterestAndDividendIncomeEquitySecuritiesOperating	630000	usd
CY2022	wabc	Interest And Dividend Income Equity Securities Operating InterestAndDividendIncomeEquitySecuritiesOperating	537000	usd
CY2021	wabc	Interest And Dividend Income Equity Securities Operating InterestAndDividendIncomeEquitySecuritiesOperating	458000	usd
CY2023	us-gaap	Interest Income Debt Securities Available For Sale Operating InterestIncomeDebtSecuritiesAvailableForSaleOperating	190039000	usd
CY2022	us-gaap	Interest Income Debt Securities Available For Sale Operating InterestIncomeDebtSecuritiesAvailableForSaleOperating	144646000	usd
CY2021	us-gaap	Interest Income Debt Securities Available For Sale Operating InterestIncomeDebtSecuritiesAvailableForSaleOperating	105420000	usd
CY2023	us-gaap	Interest And Dividend Income Securities Held To Maturity InterestAndDividendIncomeSecuritiesHeldToMaturity	35557000	usd
CY2022	us-gaap	Interest And Dividend Income Securities Held To Maturity InterestAndDividendIncomeSecuritiesHeldToMaturity	19101000	usd
CY2021	us-gaap	Interest And Dividend Income Securities Held To Maturity InterestAndDividendIncomeSecuritiesHeldToMaturity	8875000	usd
CY2023	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	10671000	usd
CY2022	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	7790000	usd
CY2021	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	1132000	usd
CY2023	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	284013000	usd
CY2022	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	221756000	usd
CY2021	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	173443000	usd
CY2023	us-gaap	Interest Expense Deposits InterestExpenseDeposits	3770000	usd
CY2022	us-gaap	Interest Expense Deposits InterestExpenseDeposits	1846000	usd
CY2021	us-gaap	Interest Expense Deposits InterestExpenseDeposits	1877000	usd
CY2023	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	120000	usd
CY2022	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	79000	usd
CY2021	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	78000	usd
CY2023	us-gaap	Interest Expense InterestExpense	3890000	usd
CY2022	us-gaap	Interest Expense InterestExpense	1925000	usd
CY2021	us-gaap	Interest Expense InterestExpense	1955000	usd
CY2023	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	280123000	usd
CY2022	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	219831000	usd
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	171488000	usd
CY2023	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-1150000	usd
CY2022	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2023	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	281273000	usd
CY2022	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	219831000	usd
CY2021	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	171488000	usd
CY2023	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	279000	usd
CY2022	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	930000	usd
CY2021	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	0	usd
CY2023	us-gaap	Debt Securities Available For Sale Gain Loss DebtSecuritiesAvailableForSaleGainLoss	-125000	usd
CY2022	us-gaap	Debt Securities Available For Sale Gain Loss DebtSecuritiesAvailableForSaleGainLoss	0	usd
CY2021	us-gaap	Debt Securities Available For Sale Gain Loss DebtSecuritiesAvailableForSaleGainLoss	34000	usd
CY2023	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	2893000	usd
CY2022	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	2598000	usd
CY2021	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	2926000	usd
CY2023	us-gaap	Noninterest Income NoninterestIncome	43522000	usd
CY2022	us-gaap	Noninterest Income NoninterestIncome	45121000	usd
CY2021	us-gaap	Noninterest Income NoninterestIncome	43345000	usd
CY2023	us-gaap	Labor And Related Expense LaborAndRelatedExpense	47871000	usd
CY2022	us-gaap	Labor And Related Expense LaborAndRelatedExpense	46125000	usd
CY2021	us-gaap	Labor And Related Expense LaborAndRelatedExpense	48011000	usd
CY2023	us-gaap	Occupancy Net OccupancyNet	20520000	usd
CY2022	us-gaap	Occupancy Net OccupancyNet	19884000	usd
CY2021	us-gaap	Occupancy Net OccupancyNet	19139000	usd
CY2023	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	9846000	usd
CY2022	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	9684000	usd
CY2021	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	9601000	usd
CY2023	us-gaap	Income Loss From Affordable Housing Projects Equity Method Investments IncomeLossFromAffordableHousingProjectsEquityMethodInvestments	-5754000	usd
CY2022	us-gaap	Income Loss From Affordable Housing Projects Equity Method Investments IncomeLossFromAffordableHousingProjectsEquityMethodInvestments	-5724000	usd
CY2021	us-gaap	Income Loss From Affordable Housing Projects Equity Method Investments IncomeLossFromAffordableHousingProjectsEquityMethodInvestments	-2620000	usd
CY2023	wabc	Contract Courier Expense ContractCourierExpense	2652000	usd
CY2022	wabc	Contract Courier Expense ContractCourierExpense	2614000	usd
CY2021	wabc	Contract Courier Expense ContractCourierExpense	2177000	usd
CY2023	us-gaap	Professional Fees ProfessionalFees	1751000	usd
CY2022	us-gaap	Professional Fees ProfessionalFees	2628000	usd
CY2021	us-gaap	Professional Fees ProfessionalFees	3253000	usd
CY2023	us-gaap	Other Noninterest Expense OtherNoninterestExpense	14822000	usd
CY2022	us-gaap	Other Noninterest Expense OtherNoninterestExpense	12702000	usd
CY2021	us-gaap	Other Noninterest Expense OtherNoninterestExpense	13005000	usd
CY2023	us-gaap	Noninterest Expense NoninterestExpense	103216000	usd
CY2022	us-gaap	Noninterest Expense NoninterestExpense	99361000	usd
CY2021	us-gaap	Noninterest Expense NoninterestExpense	97806000	usd
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	221579000	usd
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	165591000	usd
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	117027000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	59811000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	43557000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30518000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	161768000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	122034000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	86509000	usd
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26703000
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26895000
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26855000
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	26706000
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	26907000
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	26870000
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.06
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.54
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.22
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.06
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.54
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.22
CY2023	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.72
CY2022	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.68
CY2021	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.65
CY2023	us-gaap	Net Income Loss NetIncomeLoss	161768000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	122034000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	86509000	usd
CY2023	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	93326000	usd
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-434107000	usd
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-91891000	usd
CY2023	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	27591000	usd
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-128338000	usd
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-27167000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-125000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-0	usd
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	34000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-37000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0	usd
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	10000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	65823000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-305769000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-64748000	usd
CY2023	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	227591000	usd
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-183735000	usd
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	21761000	usd
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	844809000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	86509000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-64748000	usd
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	3017000	usd
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	526000	usd
CY2021	us-gaap	Stock Issued During Period Value Share Based Compensation Gross StockIssuedDuringPeriodValueShareBasedCompensationGross	1419000	usd
CY2021	us-gaap	Stock Granted During Period Value Sharebased Compensation StockGrantedDuringPeriodValueSharebasedCompensation	106000	usd
CY2021	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	232000	usd
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	44304000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	827102000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	122034000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-305769000	usd
CY2022	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2255000	usd
CY2022	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	492000	usd
CY2022	us-gaap	Stock Issued During Period Value Share Based Compensation Gross StockIssuedDuringPeriodValueShareBasedCompensationGross	1309000	usd
CY2022	us-gaap	Stock Granted During Period Value Sharebased Compensation StockGrantedDuringPeriodValueSharebasedCompensation	87000	usd
CY2022	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	218000	usd
CY2022	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	45182000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	602110000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	161768000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	65823000	usd
CY2023	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	950000	usd
CY2023	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	508000	usd
CY2023	us-gaap	Stock Issued During Period Value Share Based Compensation Gross StockIssuedDuringPeriodValueShareBasedCompensationGross	1356000	usd
CY2023	us-gaap	Stock Granted During Period Value Sharebased Compensation StockGrantedDuringPeriodValueSharebasedCompensation	80000	usd
CY2023	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	13747000	usd
CY2023	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	45954000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	772894000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	161768000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	122034000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	86509000	usd
CY2023	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	11774000	usd
CY2022	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	16565000	usd
CY2021	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	16617000	usd
CY2023	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-1150000	usd
CY2022	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2023	us-gaap	Amortization Of Deferred Loan Origination Fees Net AmortizationOfDeferredLoanOriginationFeesNet	573000	usd
CY2022	us-gaap	Amortization Of Deferred Loan Origination Fees Net AmortizationOfDeferredLoanOriginationFeesNet	1704000	usd
CY2021	us-gaap	Amortization Of Deferred Loan Origination Fees Net AmortizationOfDeferredLoanOriginationFeesNet	5576000	usd
CY2023	us-gaap	Stock Option Plan Expense StockOptionPlanExpense	1356000	usd
CY2022	us-gaap	Stock Option Plan Expense StockOptionPlanExpense	1309000	usd
CY2021	us-gaap	Stock Option Plan Expense StockOptionPlanExpense	1419000	usd
CY2023	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	279000	usd
CY2022	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	930000	usd
CY2021	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	-0	usd
CY2023	us-gaap	Debt Securities Available For Sale Gain Loss DebtSecuritiesAvailableForSaleGainLoss	-125000	usd
CY2022	us-gaap	Debt Securities Available For Sale Gain Loss DebtSecuritiesAvailableForSaleGainLoss	-0	usd
CY2021	us-gaap	Debt Securities Available For Sale Gain Loss DebtSecuritiesAvailableForSaleGainLoss	34000	usd
CY2023	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	1010000	usd
CY2022	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	18037000	usd
CY2021	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	2499000	usd
CY2023	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	1995000	usd
CY2022	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-697000	usd
CY2021	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-3899000	usd
CY2023	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	3443000	usd
CY2022	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	2415000	usd
CY2021	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	3534000	usd
CY2023	us-gaap	Increase Decrease In Income Taxes Receivable IncreaseDecreaseInIncomeTaxesReceivable	869000	usd
CY2022	us-gaap	Increase Decrease In Income Taxes Receivable IncreaseDecreaseInIncomeTaxesReceivable	-3020000	usd
CY2021	us-gaap	Increase Decrease In Income Taxes Receivable IncreaseDecreaseInIncomeTaxesReceivable	1054000	usd
CY2023	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-12000	usd
CY2022	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-10000	usd
CY2021	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-72000	usd
CY2023	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-7484000	usd
CY2022	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-6827000	usd
CY2021	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-6940000	usd
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	158208000	usd
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	113702000	usd
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	88735000	usd
CY2023	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-90192000	usd
CY2022	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-108107000	usd
CY2021	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-193755000	usd
CY2023	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	604000	usd
CY2022	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	3041000	usd
CY2021	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	usd
CY2023	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	-0	usd
CY2022	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	636228000	usd
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1909370000	usd
CY2023	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	416447000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	500160000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1204455000	usd
CY2023	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	-0	usd
CY2022	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	718940000	usd
CY2021	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	-0	usd
CY2023	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	43518000	usd
CY2022	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	111059000	usd
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	206400000	usd
CY2023	us-gaap	Payments To Acquire Federal Reserve Stock PaymentsToAcquireFederalReserveStock	2326000	usd
CY2022	us-gaap	Payments To Acquire Federal Reserve Stock PaymentsToAcquireFederalReserveStock	-0	usd
CY2021	us-gaap	Payments To Acquire Federal Reserve Stock PaymentsToAcquireFederalReserveStock	-0	usd
CY2023	us-gaap	Proceeds From Sale Of Federal Reserve Stock ProceedsFromSaleOfFederalReserveStock	0	usd
CY2022	us-gaap	Proceeds From Sale Of Federal Reserve Stock ProceedsFromSaleOfFederalReserveStock	2326000	usd
CY2021	us-gaap	Proceeds From Sale Of Federal Reserve Stock ProceedsFromSaleOfFederalReserveStock	0	usd
CY2023	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1161000	usd
CY2022	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	811000	usd
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	1324000	usd
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	547274000	usd
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-631286000	usd
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-306084000	usd
CY2023	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	-751023000	usd
CY2022	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	-188666000	usd
CY2021	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	725977000	usd
CY2023	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	370000	usd
CY2022	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	-88454000	usd
CY2021	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	43701000	usd
CY2023	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	950000	usd
CY2022	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2255000	usd
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	3017000	usd
CY2023	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	13747000	usd
CY2022	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	218000	usd
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	232000	usd
CY2023	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	45954000	usd
CY2022	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	45182000	usd
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	44304000	usd
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-809404000	usd
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-320265000	usd
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	728159000	usd
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-103922000	usd
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-837849000	usd
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	510810000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	294236000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	1132085000	usd
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	621275000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	190314000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	294236000	usd
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	1132085000	usd
CY2023	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	8866000	usd
CY2022	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	3533000	usd
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	5105000	usd
CY2023	us-gaap	Operating Lease Payments OperatingLeasePayments	6217000	usd
CY2022	us-gaap	Operating Lease Payments OperatingLeasePayments	6037000	usd
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	6309000	usd
CY2023	us-gaap	Interest Paid Net InterestPaidNet	3902000	usd
CY2022	us-gaap	Interest Paid Net InterestPaidNet	1935000	usd
CY2021	us-gaap	Interest Paid Net InterestPaidNet	2027000	usd
CY2023	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	64017000	usd
CY2022	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	39840000	usd
CY2021	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	27673000	usd
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<p style="font-family: "Times New Roman"; font-size: 10pt; font-variant: normal; text-align: justify; margin: 0pt;">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 <em style="font: inherit;">not</em> carried on the financial statements at fair value warrants an impairment writedown or valuation reserve to be established, or when an asset or liability needs to be recorded contingent upon a future event. The allowance for credit losses accounting is an area requiring the most subjective or complex judgments, and as such could be most subject to revision as new information becomes available. A discussion of the factors affecting the accounting for the allowance for credit losses on loans is included in the following “Loans” and “Allowance for Credit Losses” sections. Carrying assets and liabilities at fair value inherently results in financial statement volatility. The fair values and the information used to record valuation adjustments for certain assets and liabilities are based either on quoted market prices or are provided by other <em style="font: inherit;">third</em> party sources, when available. The “Securities” section discusses the factors that <em style="font: inherit;"> may </em>affect the valuation of the Company’s securities. Although the estimates contemplate current conditions actual results can change.</p> <p style="font-family:'Times New Roman';font-size:10pt;font-variant:normal;margin:0pt;"> </p> <p style="font-family: "Times New Roman"; font-size: 10pt; font-variant: normal; text-align: justify; margin: 0pt;"></p>
CY2023Q4	us-gaap	Equity Securities Fv Ni Current And Noncurrent EquitySecuritiesFvNiCurrentAndNoncurrent	0	usd
CY2023	wabc	Loans And Leases Receivable Days Before Nonaccrual Status LoansAndLeasesReceivableDaysBeforeNonaccrualStatus	P90D
CY2023Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	878397000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	148000	usd
CY2023	wabc	Loans And Leases Receivable Certain Consumer Loans And Auto Receivables Days Before Chargeoff LoansAndLeasesReceivableCertainConsumerLoansAndAutoReceivablesDaysBeforeChargeoff	P120D
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	28983000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	849562000	usd
CY2023Q4	wabc	Debt Securities Availableforsale And Heldtomaturity Amortized Cost DebtSecuritiesAvailableforsaleAndHeldtomaturityAmortizedCost	5148345000	usd
CY2023Q4	wabc	Debt Securities Gross Unrecognized Gains DebtSecuritiesGrossUnrecognizedGains	1508000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	1000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	4269948000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1360000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	271507000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	3999801000	usd
CY2023Q4	wabc	Debt Securities Gross Unrecognized Losses DebtSecuritiesGrossUnrecognizedLosses	300490000	usd
CY2023Q4	wabc	Debt Securities Availableforsale And Heldtomaturity Before Allowance For Credit Loss DebtSecuritiesAvailableforsaleAndHeldtomaturityBeforeAllowanceForCreditLoss	4849363000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	4695341000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1625000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	365223000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	4331743000	usd
CY2022Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	915914000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	86000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	42489000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	873511000	usd
CY2022Q4	wabc	Debt Securities Availableforsale And Heldtomaturity Amortized Cost DebtSecuritiesAvailableforsaleAndHeldtomaturityAmortizedCost	5611255000	usd
CY2022Q4	wabc	Debt Securities Gross Unrecognized Gains DebtSecuritiesGrossUnrecognizedGains	1711000	usd
CY2022Q4	wabc	Debt Securities Gross Unrecognized Losses DebtSecuritiesGrossUnrecognizedLosses	407712000	usd
CY2022Q4	wabc	Debt Securities Availableforsale And Heldtomaturity Before Allowance For Credit Loss DebtSecuritiesAvailableforsaleAndHeldtomaturityBeforeAllowanceForCreditLoss	5205254000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	52703000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	52357000	usd
CY2023Q4	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	15117000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue	15095000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	756658000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	721179000	usd
CY2023Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	312847000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	307557000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	1701189000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	1502214000	usd
CY2023Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	471868000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	453598000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	2510550000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	2275750000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Amortized Cost Basis HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	799832000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue	776250000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	4269948000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	3999801000	usd
CY2023Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	878397000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	849562000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	251578000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	250317000	usd
CY2022Q4	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	12676000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue	12659000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	578886000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	548787000	usd
CY2022Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	161653000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	158409000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	1966462000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	1673708000	usd
CY2022Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	636733000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	605081000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	2796926000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	2472812000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Amortized Cost Basis HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	811062000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue	776149000	usd
CY2022Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	4695341000	usd
CY2022Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	4331743000	usd
CY2022Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	915914000	usd
CY2022Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	873511000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions	39	pure
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	440504000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	8946000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	394	pure
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	3047766000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	262561000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	433	pure
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	3488270000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	271507000	usd
CY2023Q4	wabc	Heldtomaturity Securities Less Than12 Months Number Of Positions HeldtomaturitySecuritiesLessThan12MonthsNumberOfPositions	27	pure
CY2023Q4	wabc	Debt Securities Heldtomaturity Continuous Unrealized Loss Position Less Than12 Months Fair Value Without Allowance For Credit Loss DebtSecuritiesHeldtomaturityContinuousUnrealizedLossPositionLessThan12MonthsFairValueWithoutAllowanceForCreditLoss	45166000	usd
CY2023Q4	wabc	Debt Securities Heldtomaturity Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss1 DebtSecuritiesHeldtomaturityContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss1	1274000	usd
CY2023Q4	wabc	Heldtomaturity Securities12 Months Or Longer Number Of Positions HeldtomaturitySecurities12MonthsOrLongerNumberOfPositions	165	pure
CY2023Q4	wabc	Debt Securities Heldtomaturity Continuous Unrealized Loss Position12 Months Or Longer Fair Value1 DebtSecuritiesHeldtomaturityContinuousUnrealizedLossPosition12MonthsOrLongerFairValue1	739440000	usd
CY2023Q4	wabc	Debt Securities Heldtomaturity Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss1 DebtSecuritiesHeldtomaturityContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss1	27709000	usd
CY2023Q4	wabc	Heldtomaturity Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions1 HeldtomaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1	192	pure
CY2023Q4	wabc	Debt Securities Heldtomaturity Unrealized Loss Position Fair Value1 DebtSecuritiesHeldtomaturityUnrealizedLossPositionFairValue1	784606000	usd
CY2023Q4	wabc	Debt Securities Heldtomaturity Unrealized Loss Position Accumulated Loss DebtSecuritiesHeldtomaturityUnrealizedLossPositionAccumulatedLoss	28983000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions	376	pure
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	2673207000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	225835000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	93	pure
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	757794000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	139388000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	469	pure
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	3431001000	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	365223000	usd
CY2022Q4	wabc	Heldtomaturity Securities Less Than12 Months Number Of Positions HeldtomaturitySecuritiesLessThan12MonthsNumberOfPositions	200	pure
CY2022Q4	wabc	Debt Securities Heldtomaturity Continuous Unrealized Loss Position Less Than12 Months Fair Value Without Allowance For Credit Loss DebtSecuritiesHeldtomaturityContinuousUnrealizedLossPositionLessThan12MonthsFairValueWithoutAllowanceForCreditLoss	821756000	usd
CY2022Q4	wabc	Debt Securities Heldtomaturity Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss1 DebtSecuritiesHeldtomaturityContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss1	42390000	usd
CY2022Q4	wabc	Heldtomaturity Securities12 Months Or Longer Number Of Positions HeldtomaturitySecurities12MonthsOrLongerNumberOfPositions	2	pure
CY2022Q4	wabc	Debt Securities Heldtomaturity Continuous Unrealized Loss Position12 Months Or Longer Fair Value1 DebtSecuritiesHeldtomaturityContinuousUnrealizedLossPosition12MonthsOrLongerFairValue1	682000	usd
CY2022Q4	wabc	Debt Securities Heldtomaturity Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss1 DebtSecuritiesHeldtomaturityContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss1	99000	usd
CY2022Q4	wabc	Heldtomaturity Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions1 HeldtomaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1	202	pure
CY2022Q4	wabc	Debt Securities Heldtomaturity Unrealized Loss Position Fair Value1 DebtSecuritiesHeldtomaturityUnrealizedLossPositionFairValue1	822438000	usd
CY2022Q4	wabc	Debt Securities Heldtomaturity Unrealized Loss Position Accumulated Loss DebtSecuritiesHeldtomaturityUnrealizedLossPositionAccumulatedLoss	42489000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	1000	usd
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	7000	usd
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	9000	usd
CY2023	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	0	usd
CY2022	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-6000	usd
CY2021	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-2000	usd
CY2023	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityAllowanceForCreditLossWriteoff	0	usd
CY2022	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityAllowanceForCreditLossWriteoff	0	usd
CY2021	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityAllowanceForCreditLossWriteoff	0	usd
CY2023	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityAllowanceForCreditLossRecovery	0	usd
CY2022	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityAllowanceForCreditLossRecovery	0	usd
CY2021	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityAllowanceForCreditLossRecovery	0	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	23514000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	1000	usd
CY2022Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	1000	usd
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	7000	usd
CY2023	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	221742000	usd
CY2022	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	158465000	usd
CY2021	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	106329000	usd
CY2023	us-gaap	Interest Income Securities Tax Exempt InterestIncomeSecuritiesTaxExempt	4484000	usd
CY2022	us-gaap	Interest Income Securities Tax Exempt InterestIncomeSecuritiesTaxExempt	5819000	usd
CY2021	us-gaap	Interest Income Securities Tax Exempt InterestIncomeSecuritiesTaxExempt	8424000	usd
CY2023	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	226226000	usd
CY2022	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	164284000	usd
CY2021	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	114753000	usd
CY2023Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	866602000	usd
CY2022Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	958488000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	20284000	usd
CY2023	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	-1150000	usd
CY2023	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	7954000	usd
CY2023	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	5687000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	16867000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	23514000	usd
CY2022	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	6000	usd
CY2022	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	6225000	usd
CY2022	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	2989000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	20284000	usd
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	23854000	usd
CY2021	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	2000	usd
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	3248000	usd
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	2906000	usd
CY2023Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	866602000	usd
CY2022Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	958488000	usd
CY2023Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	403000	usd
CY2023Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	866602000	usd
CY2022Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	146000	usd
CY2022Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	958488000	usd
CY2023Q4	wabc	Loans And Leases Receivable Nonaccrual Commitment To Lend LoansAndLeasesReceivableNonaccrualCommitmentToLend	0	usd
CY2023	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	0	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	0	usd
CY2023Q4	us-gaap	Other Real Estate OtherRealEstate	0	usd
CY2022Q4	us-gaap	Mortgage Loans In Process Of Foreclosure Amount MortgageLoansInProcessOfForeclosureAmount	0	usd
CY2023Q4	wabc	Unsecured Loan Limit Percentage Of Shareholders Equity California Financial Code UnsecuredLoanLimitPercentageOfShareholdersEquityCaliforniaFinancialCode	0.15	pure
CY2023Q4	wabc	Secured And Unsecured Loan Limit Percentage California Financial Code SecuredAndUnsecuredLoanLimitPercentageCaliforniaFinancialCode	0.25	pure
CY2023Q4	wabc	Loan Commitments Related To Real Estate Loans LoanCommitmentsRelatedToRealEstateLoans	30888000	usd
CY2022Q4	wabc	Loan Commitments Related To Real Estate Loans LoanCommitmentsRelatedToRealEstateLoans	34790000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	88846000	usd
CY2023Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	61830000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	27016000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	88904000	usd
CY2022Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	60085000	usd
CY2022Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	28819000	usd
CY2023	us-gaap	Depreciation And Amortization DepreciationAndAmortization	2942000	usd
CY2022	us-gaap	Depreciation And Amortization DepreciationAndAmortization	2899000	usd
CY2021	us-gaap	Depreciation And Amortization DepreciationAndAmortization	2978000	usd
CY2023Q4	us-gaap	Federal Reserve Bank Stock FederalReserveBankStock	14069000	usd
CY2022Q4	us-gaap	Federal Reserve Bank Stock FederalReserveBankStock	11743000	usd
CY2023Q4	us-gaap	Other Investments And Securities At Cost OtherInvestmentsAndSecuritiesAtCost	158000	usd
CY2022Q4	us-gaap	Other Investments And Securities At Cost OtherInvestmentsAndSecuritiesAtCost	158000	usd
CY2023Q4	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	14227000	usd
CY2022Q4	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	11901000	usd
CY2023Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	66611000	usd
CY2022Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	63816000	usd
CY2023Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	99507000	usd
CY2022Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	125140000	usd
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	18814000	usd
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	15746000	usd
CY2023Q4	wabc	Lihtc Investments LIHTCInvestments	28667000	usd
CY2022Q4	wabc	Lihtc Investments LIHTCInvestments	34421000	usd
CY2023Q4	us-gaap	Interest Receivable Current InterestReceivableCurrent	54568000	usd
CY2022Q4	us-gaap	Interest Receivable Current InterestReceivableCurrent	53558000	usd
CY2023Q4	us-gaap	Prepaid Expense Current And Noncurrent PrepaidExpenseCurrentAndNoncurrent	5200000	usd
CY2022Q4	us-gaap	Prepaid Expense Current And Noncurrent PrepaidExpenseCurrentAndNoncurrent	4894000	usd
CY2023Q4	us-gaap	Other Assets Miscellaneous OtherAssetsMiscellaneous	9716000	usd
CY2022Q4	us-gaap	Other Assets Miscellaneous OtherAssetsMiscellaneous	9670000	usd
CY2023Q4	us-gaap	Other Assets OtherAssets	297310000	usd
CY2022Q4	us-gaap	Other Assets OtherAssets	319146000	usd
CY2023Q4	wabc	Lihtc Investments LIHTCInvestments	28667000	usd
CY2023Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	15561000	usd
CY2022Q4	wabc	Lihtc Investments LIHTCInvestments	34421000	usd
CY2022Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	22647000	usd
CY2023Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	15561000	usd
CY2023	us-gaap	Income Loss From Affordable Housing Projects Equity Method Investments IncomeLossFromAffordableHousingProjectsEquityMethodInvestments	-5754000	usd
CY2022	us-gaap	Income Loss From Affordable Housing Projects Equity Method Investments IncomeLossFromAffordableHousingProjectsEquityMethodInvestments	-5724000	usd
CY2021	us-gaap	Income Loss From Affordable Housing Projects Equity Method Investments IncomeLossFromAffordableHousingProjectsEquityMethodInvestments	-2620000	usd
CY2023	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	3435000	usd
CY2022	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	3250000	usd
CY2021	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	2300000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	18814000	usd
CY2022Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	15746000	usd
CY2023Q4	wabc	Other Liabilities Excluding Operating Lease Liability OtherLiabilitiesExcludingOperatingLeaseLiability	40455000	usd
CY2022Q4	wabc	Other Liabilities Excluding Operating Lease Liability OtherLiabilitiesExcludingOperatingLeaseLiability	49379000	usd
CY2023Q4	us-gaap	Other Liabilities OtherLiabilities	59269000	usd
CY2022Q4	us-gaap	Other Liabilities OtherLiabilities	65125000	usd
CY2023Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	18814000	usd
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P3Y8M12D
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0294	pure
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	6067000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	5178000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	3518000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	2621000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	1865000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	818000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	20067000	usd
CY2023Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	1253000	usd
CY2023	wabc	Amortization Expense Adjustment Resulting From A Change In Estimates Of Useful Lives Or Residual Values AmortizationExpenseAdjustmentResultingFromAChangeInEstimatesOfUsefulLivesOrResidualValues	0	usd
CY2023Q4	us-gaap	Goodwill Goodwill	121673000	usd
CY2022Q4	us-gaap	Goodwill Goodwill	121673000	usd
CY2023Q4	us-gaap	Noninterest Bearing Deposit Liabilities Domestic NoninterestBearingDepositLiabilitiesDomestic	2605844000	usd
CY2022Q4	us-gaap	Noninterest Bearing Deposit Liabilities Domestic NoninterestBearingDepositLiabilitiesDomestic	2947277000	usd
CY2023Q4	us-gaap	Demand Deposit Accounts DemandDepositAccounts	1072233000	usd
CY2022Q4	us-gaap	Demand Deposit Accounts DemandDepositAccounts	1273143000	usd
CY2023Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	1699388000	usd
CY2022Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	1874115000	usd
CY2023Q4	us-gaap	Time Deposits Less Than100000 TimeDepositsLessThan100000	56100000	usd
CY2022Q4	us-gaap	Time Deposits Less Than100000 TimeDepositsLessThan100000	65962000	usd
CY2023Q4	wabc	Time Deposits100 Thousand Through250 Thousand TimeDeposits100ThousandThrough250Thousand	31107000	usd
CY2022Q4	wabc	Time Deposits100 Thousand Through250 Thousand TimeDeposits100ThousandThrough250Thousand	42733000	usd
CY2023Q4	wabc	Time Deposits More Than250 Thousand TimeDepositsMoreThan250Thousand	9595000	usd
CY2022Q4	wabc	Time Deposits More Than250 Thousand TimeDepositsMoreThan250Thousand	22060000	usd
CY2023Q4	us-gaap	Deposits Deposits	5474267000	usd
CY2022Q4	us-gaap	Deposits Deposits	6225290000	usd
CY2023Q4	wabc	Demand Deposit Overdrafts DemandDepositOverdrafts	620000	usd
CY2022Q4	wabc	Demand Deposit Overdrafts DemandDepositOverdrafts	995000	usd
CY2023	us-gaap	Interest Expense Time Deposits100000 Or More InterestExpenseTimeDeposits100000OrMore	116000	usd
CY2022	us-gaap	Interest Expense Time Deposits100000 Or More InterestExpenseTimeDeposits100000OrMore	156000	usd
CY2021	us-gaap	Interest Expense Time Deposits100000 Or More InterestExpenseTimeDeposits100000OrMore	265000	usd
CY2023	us-gaap	Schedule Of Repurchase Agreements ScheduleOfRepurchaseAgreements	<table border="0" cellpadding="0" cellspacing="0" class="finTable" style="margin-right: 20%; width: 80%; font-size: 10pt; font-family: "Times New Roman", Times, serif; text-indent: 0px;"><tbody><tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt;"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td colspan="6" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;">Repurchase Agreements (Sweep)<br/> Accounted for as Secured Borrowings</p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 1px solid rgb(0, 0, 0);"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt;"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td colspan="6" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;">Remaining Contractual Maturity of the Agreements</p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt;"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td colspan="6" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;">Overnight and Continuous</p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 1px solid rgb(0, 0, 0);"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt;"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;">At December 31,</p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;">At December 31,</p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt;"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;">2023</p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 1px solid rgb(0, 0, 0);"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td colspan="2" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;">2022</p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 1px solid rgb(0, 0, 0);"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt;"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt; width: 62%;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">Repurchase agreements:</p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td colspan="6" style="text-align: center; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; text-align: center; margin: 0pt;"><em style="font: inherit;"><em style="font: inherit;">(In thousands)</em></em></p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt; background-color: rgb(204, 238, 255);"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">Collateral securing borrowings:</p> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt; background-color: rgb(255, 255, 255);"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">Agency residential MBS</p> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td><td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">25,669</td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td><td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">30,108</td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt; background-color: rgb(204, 238, 255);"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">Corporate securities</p> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 1px solid rgb(0, 0, 0);"> </td><td style="width: 16%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; text-align: right; border-bottom: 1px solid rgb(0, 0, 0);">233,947</td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 1px solid rgb(0, 0, 0);"> </td><td style="width: 16%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; text-align: right; border-bottom: 1px solid rgb(0, 0, 0);">203,774</td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 1px solid rgb(0, 0, 0);"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt; background-color: rgb(255, 255, 255);"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">Total collateral carrying value</p> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 3px double rgb(0, 0, 0);">$</td><td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 3px double rgb(0, 0, 0);">259,616</td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 3px double rgb(0, 0, 0); margin-left: 0pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 3px double rgb(0, 0, 0);">$</td><td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt; border-bottom: 3px double rgb(0, 0, 0);">233,882</td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; border-bottom: 3px double rgb(0, 0, 0); margin-left: 0pt;"> </td></tr> <tr style="vertical-align: bottom; font-family: "Times New Roman", Times, serif; font-size: 10pt; background-color: rgb(204, 238, 255);"><td style="font-family: "Times New Roman", Times, serif; font-size: 10pt;"> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; font-variant: normal; margin: 0pt;">Total short-term borrowed funds</p> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td><td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">58,162</td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt;"> </td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">$</td><td style="width: 16%; text-align: right; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;">57,792</td><td style="width: 1%; font-family: "Times New Roman", Times, serif; font-size: 10pt; margin-left: 0pt;"> </td></tr> </tbody></table>
CY2023Q4	us-gaap	Carrying Value Of Securities Sold Under Repurchase Agreements And Deposits Received For Securities Loaned CarryingValueOfSecuritiesSoldUnderRepurchaseAgreementsAndDepositsReceivedForSecuritiesLoaned	259616000	usd
CY2022Q4	us-gaap	Carrying Value Of Securities Sold Under Repurchase Agreements And Deposits Received For Securities Loaned CarryingValueOfSecuritiesSoldUnderRepurchaseAgreementsAndDepositsReceivedForSecuritiesLoaned	233882000	usd
CY2023Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	58162000	usd
CY2022Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	57792000	usd
CY2023Q4	us-gaap	Share Price SharePrice	56.41
CY2023	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Upper Range Limit ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit	70
CY2023Q4	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Outstanding Options ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions	973000
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	157000	usd
CY2023	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Remaining Contractual Term2 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2	P6Y6M
CY2023Q4	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Exercise Price Beginning Balance1 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1	60
CY2023Q4	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Exercisable Options ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions	614000
CY2023Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	157000	usd
CY2023	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Exercisable Options Weighted Average Remaining Contractual Term2 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageRemainingContractualTerm2	P5Y4M24D
CY2023Q4	us-gaap	Sharebased Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Exercisable Options Weighted Average Exercise Price1 SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1	61
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	225000
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	229000
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	193000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.20	pure
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.19	pure
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.20	pure
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P4Y8M12D
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P4Y7M6D
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P4Y8M12D
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.036	pure
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0173	pure
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.0046	pure
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0366	pure
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0302	pure
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.0279	pure
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	8.5
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	7.9
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	7.5
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	854000
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	60.02
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	225000
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	55.47
CY2023	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	22000
CY2023	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	43.3
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod	84000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures And Expirations In Period Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriodWeightedAverageExercisePrice	55.26
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	973000
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	59.5
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P6Y6M
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	614000
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	61.17
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P5Y4M24D
CY2023Q4	wabc	Capital Conservation Buffer CapitalConservationBuffer	0.025	pure
CY2023Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	841611000	usd
CY2023Q4	us-gaap	Common Equity Tier One Capital Ratio CommonEquityTierOneCapitalRatio	0.1876	pure
CY2023Q4	wabc	Banking Regulation Common Equity Tier One Riskbased Capital Capital Adequacy Minimum Including Capital Conservation Buffer BankingRegulationCommonEquityTierOneRiskbasedCapitalCapitalAdequacyMinimumIncludingCapitalConservationBuffer	313959000	usd
CY2022Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Number Of Shares SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares	346000
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue	7.88
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	225000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	8.5
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested Number Of Shares SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares	164000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue	7.99
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Options Forfeited Number Of Shares SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares	48000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeitures Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue	8.18
CY2023Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Number Of Shares SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares	359000
CY2023Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Weighted Average Grant Date Fair Value SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue	8.18
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	8.5
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	7.9
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Weighted Average Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue	7.5
CY2023Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Stock Options EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions	1581000	usd
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	113000	usd
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	165000	usd
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	454000	usd
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	1309000	usd
CY2022	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	1464000	usd
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested In Period Fair Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1	1783000	usd
CY2023	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	22000
CY2023	wabc	Excess Tax Deduction Exceeding Related Sharebased Compensation Operating Activities ExcessTaxDeductionExceedingRelatedSharebasedCompensationOperatingActivities	16000	usd
CY2022	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	40000
CY2022	wabc	Excess Tax Deduction Exceeding Related Sharebased Compensation Operating Activities ExcessTaxDeductionExceedingRelatedSharebasedCompensationOperatingActivities	143000	usd
CY2022	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	30000	usd
CY2021	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	53000
CY2023	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	5000	usd
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	31000
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	30000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	12000
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod	12000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	9000
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	8000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	2000
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod	3000
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	32000
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	31000
CY2023Q4	us-gaap	Stock Repurchase Program Remaining Number Of Shares Authorized To Be Repurchased StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased	0
CY2023Q4	wabc	Additional Classes Of Stock Authorized AdditionalClassesOfStockAuthorized	2	pure
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	150000000
CY2023Q4	wabc	Common Equity Tier1 Capital Required For Capital Adequacy To Risk Weighted Assets CommonEquityTier1CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.07	pure
CY2023Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	841611000	usd
CY2023Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.1876	pure
CY2023Q4	wabc	Banking Regulation Tier One Riskbased Capital Capital Adequacy Minimum Including Capital Conservation Buffer BankingRegulationTierOneRiskbasedCapitalCapitalAdequacyMinimumIncludingCapitalConservationBuffer	381236000	usd
CY2023Q4	wabc	Banking Regulation Tier One Riskbased Capital Ratio Capital Adequacy Minimum Including Capital Conservation Buffe BankingRegulationTierOneRiskbasedCapitalRatioCapitalAdequacyMinimumIncludingCapitalConservationBuffe	0.085	pure
CY2023Q4	us-gaap	Capital Capital	858680000	usd
CY2023Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1915	pure
CY2023Q4	wabc	Banking Regulation Total Riskbased Capital Capital Adequacy Minimum Including Capital Conservation Buffer BankingRegulationTotalRiskbasedCapitalCapitalAdequacyMinimumIncludingCapitalConservationBuffer	470939000	usd
CY2023Q4	wabc	Banking Regulation Total Riskbased Capital Ratio Capital Adequacy Minimum Including Capital Conservation Buffer BankingRegulationTotalRiskbasedCapitalRatioCapitalAdequacyMinimumIncludingCapitalConservationBuffer	0.105	pure
CY2023Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	841611000	usd
CY2023Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.1286	pure
CY2023Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	261739000	usd
CY2023Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.04	pure
CY2022Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	736414000	usd
CY2022Q4	us-gaap	Common Equity Tier One Capital Ratio CommonEquityTierOneCapitalRatio	0.1522	pure
CY2022Q4	wabc	Banking Regulation Common Equity Tier One Riskbased Capital Capital Adequacy Minimum Including Capital Conservation Buffer BankingRegulationCommonEquityTierOneRiskbasedCapitalCapitalAdequacyMinimumIncludingCapitalConservationBuffer	338748000	usd
CY2022Q4	wabc	Common Equity Tier1 Capital Required For Capital Adequacy To Risk Weighted Assets CommonEquityTier1CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.07	pure
CY2022Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	736414000	usd
CY2022Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.1522	pure
CY2022Q4	wabc	Banking Regulation Tier One Riskbased Capital Capital Adequacy Minimum Including Capital Conservation Buffer BankingRegulationTierOneRiskbasedCapitalCapitalAdequacyMinimumIncludingCapitalConservationBuffer	411337000	usd
CY2022Q4	wabc	Banking Regulation Tier One Riskbased Capital Ratio Capital Adequacy Minimum Including Capital Conservation Buffe BankingRegulationTierOneRiskbasedCapitalRatioCapitalAdequacyMinimumIncludingCapitalConservationBuffe	0.085	pure
CY2022Q4	us-gaap	Capital Capital	756900000	usd
CY2022Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1564	pure
CY2022Q4	wabc	Banking Regulation Total Riskbased Capital Capital Adequacy Minimum Including Capital Conservation Buffer BankingRegulationTotalRiskbasedCapitalCapitalAdequacyMinimumIncludingCapitalConservationBuffer	508123000	usd
CY2022Q4	wabc	Banking Regulation Total Riskbased Capital Ratio Capital Adequacy Minimum Including Capital Conservation Buffer BankingRegulationTotalRiskbasedCapitalRatioCapitalAdequacyMinimumIncludingCapitalConservationBuffer	0.105	pure
CY2022Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	736414000	usd
CY2022Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.1018	pure
CY2022Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	289259000	usd
CY2022Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.04	pure
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	4853000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	5858000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	79865000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	107493000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	4816000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	3805000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	3828000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	4091000	usd
CY2023Q4	wabc	Deferred Tax Assets Purchased Assets And Assumed Liabilities DeferredTaxAssetsPurchasedAssetsAndAssumedLiabilities	321000	usd
CY2022Q4	wabc	Deferred Tax Assets Purchased Assets And Assumed Liabilities DeferredTaxAssetsPurchasedAssetsAndAssumedLiabilities	229000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	367000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Postretirement Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits	405000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	3454000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	3096000	usd
CY2023Q4	wabc	Deferred Tax Assets Visa Class B Shares DeferredTaxAssetsVISAClassBShares	343000	usd
CY2022Q4	wabc	Deferred Tax Assets Visa Class B Shares DeferredTaxAssetsVISAClassBShares	507000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	1172000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Accrued Liabilities DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	840000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	59811000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	43557000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30518000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	1175000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	1193000	usd
CY2023Q4	wabc	Deferred Tax Assets Lease Liability DeferredTaxAssetsLeaseLiability	5413000	usd
CY2022Q4	wabc	Deferred Tax Assets Lease Liability DeferredTaxAssetsLeaseLiability	4548000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	69000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	99000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	105676000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	132164000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Deferred Financing Costs DeferredTaxLiabilitiesDeferredExpenseDeferredFinancingCosts	0	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Deferred Expense Deferred Financing Costs DeferredTaxLiabilitiesDeferredExpenseDeferredFinancingCosts	193000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	5413000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	4548000	usd
CY2023Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	451000	usd
CY2022Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	453000	usd
CY2023Q4	wabc	Deferred Tax Liabilities Limited Partnership Investments DeferredTaxLiabilitiesLimitedPartnershipInvestments	305000	usd
CY2022Q4	wabc	Deferred Tax Liabilities Limited Partnership Investments DeferredTaxLiabilitiesLimitedPartnershipInvestments	1830000	usd
CY2023Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	6169000	usd
CY2022Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	7024000	usd
CY2023Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	99507000	usd
CY2022Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	125140000	usd
CY2023	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	38075000	usd
CY2022	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	26785000	usd
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	15299000	usd
CY2023	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	23731000	usd
CY2022	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	16075000	usd
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	11320000	usd
CY2023	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	61806000	usd
CY2022	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	42860000	usd
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	26619000	usd
CY2023	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-1197000	usd
CY2022	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-1349000	usd
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	1281000	usd
CY2023	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-798000	usd
CY2022	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	2046000	usd
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	842000	usd
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-1995000	usd
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	697000	usd
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2123000	usd
CY2023	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	-0	usd
CY2022	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	-0	usd
CY2021	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	-1776000	usd
CY2023	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	46532000	usd
CY2022	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	34774000	usd
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	24576000	usd
CY2023	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	1188000	usd
CY2022	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	1484000	usd
CY2021	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	2070000	usd
CY2023	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	18117000	usd
CY2022	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	14315000	usd
CY2021	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	9757000	usd
CY2023	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	-0	usd
CY2022	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	-0	usd
CY2021	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	-1776000	usd
CY2023	wabc	Income Tax Rate Reconciliation Deduction Stock Compensation IncomeTaxRateReconciliationDeductionStockCompensation	-3000	usd
CY2022	wabc	Income Tax Rate Reconciliation Deduction Stock Compensation IncomeTaxRateReconciliationDeductionStockCompensation	-30000	usd
CY2021	wabc	Income Tax Rate Reconciliation Deduction Stock Compensation IncomeTaxRateReconciliationDeductionStockCompensation	-0	usd
CY2023	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	2943000	usd
CY2022	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	3439000	usd
CY2021	us-gaap	Income Tax Reconciliation Tax Credits IncomeTaxReconciliationTaxCredits	2621000	usd
CY2023	us-gaap	Income Tax Reconciliation Deductions Dividends IncomeTaxReconciliationDeductionsDividends	66000	usd
CY2022	us-gaap	Income Tax Reconciliation Deductions Dividends IncomeTaxReconciliationDeductionsDividends	56000	usd
CY2021	us-gaap	Income Tax Reconciliation Deductions Dividends IncomeTaxReconciliationDeductionsDividends	48000	usd
CY2023	wabc	Income Tax Reconciliation Cash Value Life Insurance IncomeTaxReconciliationCashValueLifeInsurance	597000	usd
CY2022	wabc	Income Tax Reconciliation Cash Value Life Insurance IncomeTaxReconciliationCashValueLifeInsurance	421000	usd
CY2021	wabc	Income Tax Reconciliation Cash Value Life Insurance IncomeTaxReconciliationCashValueLifeInsurance	389000	usd
CY2023	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-47000	usd
CY2022	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-162000	usd
CY2021	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-463000	usd
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	59811000	usd
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	43557000	usd
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30518000	usd
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	usd
CY2023	us-gaap	Income Tax Examination Penalties And Interest Expense IncomeTaxExaminationPenaltiesAndInterestExpense	0	usd
CY2023Q4	wabc	Loan Commitments Not Unconditionally Cancellable LoanCommitmentsNotUnconditionallyCancellable	29958000	usd
CY2022Q4	wabc	Loan Commitments Not Unconditionally Cancellable LoanCommitmentsNotUnconditionallyCancellable	31889000	usd
CY2023Q4	wabc	Unfunded Loan Commitments UnfundedLoanCommitments	206028000	usd
CY2022Q4	wabc	Unfunded Loan Commitments UnfundedLoanCommitments	202696000	usd
CY2023Q4	us-gaap	Guarantee Obligations Current Carrying Value GuaranteeObligationsCurrentCarryingValue	1000000	usd
CY2022Q4	us-gaap	Guarantee Obligations Current Carrying Value GuaranteeObligationsCurrentCarryingValue	950000	usd
CY2023	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	1090000	usd
CY2022	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	1030000	usd
CY2021	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	1028000	usd
CY2023	us-gaap	Employee Stock Ownership Plan Esop Compensation Expense EmployeeStockOwnershipPlanESOPCompensationExpense	873000	usd
CY2022	us-gaap	Employee Stock Ownership Plan Esop Compensation Expense EmployeeStockOwnershipPlanESOPCompensationExpense	921000	usd
CY2021	us-gaap	Employee Stock Ownership Plan Esop Compensation Expense EmployeeStockOwnershipPlanESOPCompensationExpense	972000	usd
CY2023	wabc	Defined Benefit Plan Service Cost Benefit DefinedBenefitPlanServiceCostBenefit	-56000	usd
CY2022	wabc	Defined Benefit Plan Service Cost Benefit DefinedBenefitPlanServiceCostBenefit	-19000	usd
CY2021	wabc	Defined Benefit Plan Service Cost Benefit DefinedBenefitPlanServiceCostBenefit	-15000	usd
CY2023	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	70000	usd
CY2022	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	38000	usd
CY2021	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	30000	usd
CY2023	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	14000	usd
CY2022	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	19000	usd
CY2021	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	15000	usd
CY2022Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	1401000	usd
CY2021Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	1527000	usd
CY2020Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	1654000	usd
CY2023	wabc	Defined Benefit Plan Service Cost Benefit DefinedBenefitPlanServiceCostBenefit	-56000	usd
CY2022	wabc	Defined Benefit Plan Service Cost Benefit DefinedBenefitPlanServiceCostBenefit	-19000	usd
CY2021	wabc	Defined Benefit Plan Service Cost Benefit DefinedBenefitPlanServiceCostBenefit	-15000	usd
CY2023	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	70000	usd
CY2022	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	38000	usd
CY2021	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	30000	usd
CY2023	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	139000	usd
CY2022	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	145000	usd
CY2021	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	142000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	1276000	usd
CY2022Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	1401000	usd
CY2021Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	1527000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	1276000	usd
CY2022Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	1401000	usd
CY2021Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	1527000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	0	usd
CY2022Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	0	usd
CY2021Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	0	usd
CY2023Q4	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	-1276000	usd
CY2022Q4	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	-1401000	usd
CY2021Q4	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	-1527000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.0475	pure
CY2022Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.0501	pure
CY2021Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.0246	pure
CY2023	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0501	pure
CY2022	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0246	pure
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.018	pure
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	133000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	133000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	133000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	127000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	118000	usd
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	424000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	400000	usd
CY2021Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	454000	usd
CY2023	us-gaap	Loans And Leases Receivable Related Parties Additions LoansAndLeasesReceivableRelatedPartiesAdditions	0	usd
CY2022	us-gaap	Loans And Leases Receivable Related Parties Additions LoansAndLeasesReceivableRelatedPartiesAdditions	0	usd
CY2023	us-gaap	Loans And Leases Receivable Related Parties Proceeds LoansAndLeasesReceivableRelatedPartiesProceeds	51000	usd
CY2022	us-gaap	Loans And Leases Receivable Related Parties Proceeds LoansAndLeasesReceivableRelatedPartiesProceeds	54000	usd
CY2023Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	349000	usd
CY2022Q4	us-gaap	Loans And Leases Receivable Related Parties LoansAndLeasesReceivableRelatedParties	400000	usd
CY2023Q4	wabc	Loans And Leases Receivable Percent Outstanding Related Parties LoansAndLeasesReceivablePercentOutstandingRelatedParties	0.0004	pure
CY2022Q4	wabc	Loans And Leases Receivable Percent Outstanding Related Parties LoansAndLeasesReceivablePercentOutstandingRelatedParties	0.0004	pure
CY2023	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	93326000	usd
CY2023	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	27591000	usd
CY2023	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	65735000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-125000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-37000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-88000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	93451000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	27628000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	65823000	usd
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-434107000	usd
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-128338000	usd
CY2022	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-305769000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-434107000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-128338000	usd
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-305769000	usd
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-91891000	usd
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-27167000	usd
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-64724000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	34000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	10000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	24000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-91925000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-27177000	usd
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-64748000	usd
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	65823000	usd
CY2023	us-gaap	Net Income Loss NetIncomeLoss	161768000	usd
CY2022	us-gaap	Net Income Loss NetIncomeLoss	122034000	usd
CY2021	us-gaap	Net Income Loss NetIncomeLoss	86509000	usd
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26703000
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26895000
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26855000
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.06
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.54
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.22
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26703000
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26895000
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26855000
CY2023	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	3000
CY2022	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	12000
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	15000
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	26706000
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	26907000
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	26870000
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.06
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.54
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.22
CY2023Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	69624000	usd
CY2023Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	70489000	usd
CY2023Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	72848000	usd
CY2023Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	71052000	usd
CY2023Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	69153000	usd
CY2023Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	69882000	usd
CY2023Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	71715000	usd
CY2023Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	69373000	usd
CY2023Q1	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-1550000	usd
CY2023Q2	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2023Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	400000	usd
CY2023Q4	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2023Q1	us-gaap	Noninterest Income NoninterestIncome	10549000	usd
CY2023Q2	us-gaap	Noninterest Income NoninterestIncome	10700000	usd
CY2023Q3	us-gaap	Noninterest Income NoninterestIncome	11281000	usd
CY2023Q4	us-gaap	Noninterest Income NoninterestIncome	10992000	usd
CY2023Q1	us-gaap	Noninterest Expense NoninterestExpense	26210000	usd
CY2023Q2	us-gaap	Noninterest Expense NoninterestExpense	25839000	usd
CY2023Q3	us-gaap	Noninterest Expense NoninterestExpense	25650000	usd
CY2023Q4	us-gaap	Noninterest Expense NoninterestExpense	25517000	usd
CY2023Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	55042000	usd
CY2023Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	54743000	usd
CY2023Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	56946000	usd
CY2023Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	54848000	usd
CY2023Q1	us-gaap	Net Income Loss NetIncomeLoss	40451000	usd
CY2023Q2	us-gaap	Net Income Loss NetIncomeLoss	40248000	usd
CY2023Q3	us-gaap	Net Income Loss NetIncomeLoss	41601000	usd
CY2023Q4	us-gaap	Net Income Loss NetIncomeLoss	39468000	usd
CY2023Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.51
CY2023Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.51
CY2023Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.56
CY2023Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.48
CY2023Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.51
CY2023Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.51
CY2023Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.56
CY2023Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.48
CY2023Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.42
CY2023Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.42
CY2023Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.44
CY2023Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.44
CY2022Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	43759000	usd
CY2022Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	47997000	usd
CY2022Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	60802000	usd
CY2022Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	69198000	usd
CY2022Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	43279000	usd
CY2022Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	47514000	usd
CY2022Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	60315000	usd
CY2022Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	68723000	usd
CY2022Q1	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2022Q2	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2022Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2022Q4	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2022Q1	us-gaap	Noninterest Income NoninterestIncome	11576000	usd
CY2022Q2	us-gaap	Noninterest Income NoninterestIncome	11264000	usd
CY2022Q3	us-gaap	Noninterest Income NoninterestIncome	11818000	usd
CY2022Q4	us-gaap	Noninterest Income NoninterestIncome	10463000	usd
CY2022Q1	us-gaap	Noninterest Expense NoninterestExpense	24875000	usd
CY2022Q2	us-gaap	Noninterest Expense NoninterestExpense	24629000	usd
CY2022Q3	us-gaap	Noninterest Expense NoninterestExpense	24767000	usd
CY2022Q4	us-gaap	Noninterest Expense NoninterestExpense	25090000	usd
CY2022Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	29980000	usd
CY2022Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	34149000	usd
CY2022Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	47366000	usd
CY2022Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	54096000	usd
CY2022Q1	us-gaap	Net Income Loss NetIncomeLoss	22616000	usd
CY2022Q2	us-gaap	Net Income Loss NetIncomeLoss	25314000	usd
CY2022Q3	us-gaap	Net Income Loss NetIncomeLoss	34760000	usd
CY2022Q4	us-gaap	Net Income Loss NetIncomeLoss	39344000	usd
CY2022Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.84
CY2022Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.94
CY2022Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.29
CY2022Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.46
CY2022Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.84
CY2022Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.94
CY2022Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.29
CY2022Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.46
CY2022Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.42
CY2022Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.42
CY2022Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.42
CY2022Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.42
CY2021Q1	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	42316000	usd
CY2021Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	44276000	usd
CY2021Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	43810000	usd
CY2021Q4	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	43041000	usd
CY2021Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	41841000	usd
CY2021Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	43792000	usd
CY2021Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	43318000	usd
CY2021Q4	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	42537000	usd
CY2021Q1	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2021Q2	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2021Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2021Q4	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	0	usd
CY2021Q1	us-gaap	Noninterest Income NoninterestIncome	10189000	usd
CY2021Q2	us-gaap	Noninterest Income NoninterestIncome	11032000	usd
CY2021Q3	us-gaap	Noninterest Income NoninterestIncome	11282000	usd
CY2021Q4	us-gaap	Noninterest Income NoninterestIncome	10842000	usd
CY2021Q1	us-gaap	Noninterest Expense NoninterestExpense	24906000	usd
CY2021Q2	us-gaap	Noninterest Expense NoninterestExpense	24291000	usd
CY2021Q3	us-gaap	Noninterest Expense NoninterestExpense	24697000	usd
CY2021Q4	us-gaap	Noninterest Expense NoninterestExpense	23912000	usd
CY2021Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	27124000	usd
CY2021Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	30533000	usd
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	29903000	usd
CY2021Q4	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	29467000	usd
CY2021Q1	us-gaap	Net Income Loss NetIncomeLoss	20147000	usd
CY2021Q2	us-gaap	Net Income Loss NetIncomeLoss	22579000	usd
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	22063000	usd
CY2021Q4	us-gaap	Net Income Loss NetIncomeLoss	21720000	usd
CY2021Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.75
CY2021Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.84
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.82
CY2021Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.81
CY2021Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.75
CY2021Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.84
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.82
CY2021Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.81
CY2021Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.41
CY2021Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.41
CY2021Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.41
CY2021Q4	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.42
CY2023	dei	Auditor Name AuditorName	Crowe LLP
CY2023	dei	Auditor Location AuditorLocation	Sacramento, California

Files In Submission

Name	View Source	Status
0001171843-24-001054-index-headers.html	Edgar Link	pending
0001171843-24-001054-index.html	Edgar Link	pending
0001171843-24-001054.txt	Edgar Link	pending
0001171843-24-001054-xbrl.zip	Edgar Link	pending
ex_628056.htm	Edgar Link	pending
ex_628057.htm	Edgar Link	pending
ex_628058.htm	Edgar Link	pending
ex_628059.htm	Edgar Link	pending
ex_628060.htm	Edgar Link	pending
ex_628061.htm	Edgar Link	pending
ex_628062.htm	Edgar Link	pending
Financial_Report.xlsx	Edgar Link	pending
fiveyearperformance.jpg	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R100.htm	Edgar Link	pending
R101.htm	Edgar Link	pending
R102.htm	Edgar Link	pending
R103.htm	Edgar Link	pending
R104.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R69.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R70.htm	Edgar Link	pending
R71.htm	Edgar Link	pending
R72.htm	Edgar Link	pending
R73.htm	Edgar Link	pending
R74.htm	Edgar Link	pending
R75.htm	Edgar Link	pending
R76.htm	Edgar Link	pending
R77.htm	Edgar Link	pending
R78.htm	Edgar Link	pending
R79.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R82.htm	Edgar Link	pending
R83.htm	Edgar Link	pending
R84.htm	Edgar Link	pending
R85.htm	Edgar Link	pending
R86.htm	Edgar Link	pending
R87.htm	Edgar Link	pending
R88.htm	Edgar Link	pending
R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
R90.htm	Edgar Link	pending
R91.htm	Edgar Link	pending
R92.htm	Edgar Link	pending
R93.htm	Edgar Link	pending
R94.htm	Edgar Link	pending
R95.htm	Edgar Link	pending
R96.htm	Edgar Link	pending
R97.htm	Edgar Link	pending
R98.htm	Edgar Link	pending
R99.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending
tenyearperformance.jpg	Edgar Link	pending
wabc-20231231.xsd	Edgar Link	pending
wabc20231231_10k.htm	Edgar Link	pending
wabc-20231231_def.xml	Edgar Link	unprocessable
wabc-20231231_lab.xml	Edgar Link	unprocessable
wabc20231231_10k_htm.xml	Edgar Link	completed
FilingSummary.xml	Edgar Link	unprocessable
wabc-20231231_pre.xml	Edgar Link	unprocessable
wabc-20231231_cal.xml	Edgar Link	unprocessable

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$WABC
WESTAMERICA BANCORPORATION Stock $wabc

2024 Q1 Form 10-K Financial Statement

#000117184324001054 Filed on February 29, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WABC WESTAMERICA BANCORPORATION Stock $wabc

2024 Q1 Form 10-K Financial Statement

#000117184324001054 Filed on February 29, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WABC
WESTAMERICA BANCORPORATION Stock $wabc