$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal

$wal Overview Financials Valuation SEC Filings Company Website

2020 Q1 Form 10-Q Financial Statement

#000121254520000131 Filed on April 30, 2020

Income Statement

Concept	2020 Q1	2019 Q1
Revenue	$307.2M	$291.1M
YoY Change	5.53%	24.03%
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	$5.000M	$4.200M
YoY Change	19.05%	23.53%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$38.20M	$43.80M
YoY Change	-12.79%	113.9%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$102.4M	$146.3M
YoY Change	-30.01%	20.2%
Income Tax	$18.50M	$25.50M
% Of Pretax Income	18.07%	17.43%
Net Earnings	$83.90M	$120.8M
YoY Change	-30.55%	19.72%
Net Earnings / Revenue	27.31%	41.5%
Basic Earnings Per Share	$0.83	$1.16
Diluted Earnings Per Share	$0.83	$1.16
COMMON SHARES
Basic Shares Outstanding	101.3M shares	104.0M shares
Diluted Shares Outstanding	101.7M shares	104.5M shares

Balance Sheet

Concept	2020 Q1	2019 Q1
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$415.7M	$785.6M
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	$125.9M	$119.8M
YoY Change	5.06%	2.68%
Goodwill		$289.9M
YoY Change		0.0%
Intangibles		$8.873M
YoY Change		-15.13%
Long-Term Investments	$131.0M	$118.0M
YoY Change	11.02%
Other Assets	$28.00M	$22.00M
YoY Change	27.27%	-18.52%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$29.16B	$23.79B
YoY Change	22.55%	14.61%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$79.00M	$78.00M
YoY Change	1.28%
Deferred Revenue
YoY Change
Short-Term Debt	$308.0M	$0.00
YoY Change		-100.0%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$79.00M	$78.00M
YoY Change	1.28%	254.55%
LONG-TERM LIABILITIES
Long-Term Debt	$698.0M	$374.0M
YoY Change	86.63%	-43.67%
Other Long-Term Liabilities	$528.0M	$397.0M
YoY Change	33.0%	-7.03%
Total Long-Term Liabilities	$1.226B	$771.0M
YoY Change	59.01%	-29.33%
TOTAL LIABILITIES
Total Short-Term Liabilities	$79.00M	$78.00M
Total Long-Term Liabilities	$1.226B	$771.0M
Total Liabilities	$26.16B	$21.07B
YoY Change	24.14%	14.11%
SHAREHOLDERS EQUITY
Retained Earnings	$1.680B	$1.399B
YoY Change	20.09%	47.22%
Common Stock	$10.00K	$10.00K
YoY Change	0.0%	0.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$70.19M	$60.98M
YoY Change	15.09%	31.23%
Treasury Stock Shares
Shareholders Equity	$2.992B	$2.721B
YoY Change
Total Liabilities & Shareholders Equity	$29.16B	$23.79B
YoY Change	22.55%	14.61%

Cashflow Statement

Concept	2020 Q1	2019 Q1
OPERATING ACTIVITIES
Net Income	$83.90M	$120.8M
YoY Change	-30.55%	19.72%
Depreciation, Depletion And Amortization	$5.000M	$4.200M
YoY Change	19.05%	23.53%
Cash From Operating Activities	$124.0M	$151.3M
YoY Change	-18.05%	71.33%
INVESTING ACTIVITIES
Capital Expenditures	-$16.60M	-$3.200M
YoY Change	418.75%	433.33%
Acquisitions
YoY Change
Other Investing Activities	-$2.379B	-$348.3M
YoY Change	583.12%	0.46%
Cash From Investing Activities	-$2.396B	-$351.5M
YoY Change	581.65%	1.21%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net	$62.50M	$37.95M
YoY Change	64.69%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	$2.253B	$487.2M
YoY Change	362.43%	73.02%
NET CHANGE
Cash From Operating Activities	$124.0M	$151.3M
Cash From Investing Activities	-$2.396B	-$351.5M
Cash From Financing Activities	$2.253B	$487.2M
Net Change In Cash	-$18.90M	$287.0M
YoY Change	-106.58%	1169.92%
FREE CASH FLOW
Cash From Operating Activities	$124.0M	$151.3M
Capital Expenditures	-$16.60M	-$3.200M
Free Cash Flow	$140.6M	$154.5M
YoY Change	-9.01%	73.78%

Facts In Submission

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CY2020Q1	us-gaap	Noninterest Expense NoninterestExpense	120481000	USD
CY2019Q1	us-gaap	Noninterest Expense NoninterestExpense	111878000	USD
CY2020Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	102472000	USD
CY2019Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	146332000	USD
CY2020Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	18508000	USD
CY2019Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	25536000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	83964000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	120796000	USD
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.83
CY2020Q1	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	6557000	USD
CY2020Q1	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	7442000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-5928000	USD
CY2019Q1	wal	Gain Loss On Foreclosed Assets GainLossOnForeclosedAssets	0	USD
CY2020Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	101328000	shares
CY2019Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	104033000	shares
CY2020Q1	wal	Valuation Adjustments Of Other Repossessed Assets Net ValuationAdjustmentsOfOtherRepossessedAssetsNet	0	USD
CY2020Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	101675000	shares
CY2019Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	104475000	shares
CY2019Q1	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	10145000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	83964000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	120796000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	25431000	USD
CY2019Q1	us-gaap	Stockholders Equity StockholdersEquity	2720620000	USD
CY2020Q1	us-gaap	Operating Lease Expense OperatingLeaseExpense	2799000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	31377000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	290000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	54000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	0	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	12489000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	25431000	USD
CY2020Q1	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	96453000	USD
CY2019Q1	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	146227000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	2613734000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	120796000	USD
CY2019Q1	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	36000	USD
CY2019Q1	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	6472000	USD
CY2019Q1	us-gaap	Restricted Stock Award Forfeitures RestrictedStockAwardForfeitures	7900000	USD
CY2019Q1	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	-37949000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	3016748000	USD
CY2020Q1	us-gaap	Stockholders Equity StockholdersEquity	2991801000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	83964000	USD
CY2020Q1	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	70000	USD
CY2020Q1	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	6894000	USD
CY2020Q1	us-gaap	Restricted Stock Award Forfeitures RestrictedStockAwardForfeitures	7458000	USD
CY2020Q1	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	-62521000	USD
CY2020Q1	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	-25606000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	12489000	USD
CY2020Q1	us-gaap	Stockholders Equity StockholdersEquity	2999633000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	83964000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	120796000	USD
CY2020Q1	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	51176000	USD
CY2019Q1	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	4536000	USD
CY2020Q1	us-gaap	Depreciation And Amortization DepreciationAndAmortization	4995000	USD
CY2019Q1	us-gaap	Depreciation And Amortization DepreciationAndAmortization	4209000	USD
CY2020Q1	us-gaap	Share Based Compensation ShareBasedCompensation	6894000	USD
CY2019Q1	us-gaap	Share Based Compensation ShareBasedCompensation	6472000	USD
CY2020Q1	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	-4825000	USD
CY2019Q1	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	1398000	USD
CY2020Q1	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-5609000	USD
CY2019Q1	wal	Valuation Adjustments Of Other Repossessed Assets Net ValuationAdjustmentsOfOtherRepossessedAssetsNet	-99000	USD
CY2019Q1	us-gaap	Operating Lease Expense OperatingLeaseExpense	2601000	USD
CY2020Q1	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	962000	USD
CY2020Q1	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	0	USD
CY2020Q1	wal	Accretion And Amortization Fair Market Value Adjustments Relating To Acquisitionsof Loans AccretionAndAmortizationFairMarketValueAdjustmentsRelatingToAcquisitionsofLoans	1738000	USD
CY2019Q1	wal	Accretion And Amortization Fair Market Value Adjustments Relating To Acquisitionsof Loans AccretionAndAmortizationFairMarketValueAdjustmentsRelatingToAcquisitionsofLoans	2817000	USD
CY2019Q1	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	981000	USD
CY2020Q1	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	72000	USD
CY2019Q1	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	2000	USD
CY2019Q1	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	385497000	USD
CY2019Q1	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-3004000	USD
CY2020Q1	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	41602000	USD
CY2019Q1	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-3817000	USD
CY2020Q1	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	123979000	USD
CY2019Q1	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	0	USD
CY2019Q1	us-gaap	Payments To Acquire Restricted Investments PaymentsToAcquireRestrictedInvestments	155000	USD
CY2020Q1	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	1991131000	USD
CY2020Q1	wal	Accretionand Amortization Fair Market Value Adjustments Relatingto Acquisitionsof Other Assetsand Liabilities AccretionandAmortizationFairMarketValueAdjustmentsRelatingtoAcquisitionsofOtherAssetsandLiabilities	-451000	USD
CY2019Q1	wal	Accretionand Amortization Fair Market Value Adjustments Relatingto Acquisitionsof Other Assetsand Liabilities AccretionandAmortizationFairMarketValueAdjustmentsRelatingtoAcquisitionsofOtherAssetsandLiabilities	-463000	USD
CY2020Q1	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-11300000	USD
CY2019Q1	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	2834000	USD
CY2020Q1	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	0	USD
CY2019Q1	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	-408000	USD
CY2020Q1	wal	Gain Loss On Foreclosed Assets GainLossOnForeclosedAssets	1452000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	516261000	USD
CY2019Q1	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	151314000	USD
CY2020Q1	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	654501000	USD
CY2019Q1	us-gaap	Payments To Acquire Available For Sale Securities PaymentsToAcquireAvailableForSaleSecurities	26342000	USD
CY2020Q1	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	264639000	USD
CY2019Q1	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	97732000	USD
CY2020Q1	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	62310000	USD
CY2019Q1	us-gaap	Proceeds From Sale Of Available For Sale Securities ProceedsFromSaleOfAvailableForSaleSecurities	0	USD
CY2020Q1	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	24205000	USD
CY2019Q1	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	10825000	USD
CY2020Q1	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	1295000	USD
CY2019Q1	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	2868000	USD
CY2020Q1	wal	Paymentsto Acquire Securities Equity PaymentstoAcquireSecuritiesEquity	7487000	USD
CY2019Q1	wal	Paymentsto Acquire Securities Equity PaymentstoAcquireSecuritiesEquity	0	USD
CY2020Q1	us-gaap	Proceeds From Dividends Received ProceedsFromDividendsReceived	4216000	USD
CY2019Q1	us-gaap	Proceeds From Dividends Received ProceedsFromDividendsReceived	-151000	USD
CY2020Q1	wal	Purchase Of Investment Tax Credits PurchaseOfInvestmentTaxCredits	37389000	USD
CY2019Q1	wal	Purchase Of Investment Tax Credits PurchaseOfInvestmentTaxCredits	24400000	USD
CY2020Q1	wal	Purchaseof Sbic Investments PurchaseofSBICInvestments	1889000	USD
CY2019Q1	wal	Purchaseof Sbic Investments PurchaseofSBICInvestments	1570000	USD
CY2020Q1	wal	Proceedsfrom Sale Paymentsto Purchase Investment In Money Market ProceedsfromSalePaymentstoPurchaseInvestmentInMoneyMarket	0	USD
CY2019Q1	wal	Proceedsfrom Sale Paymentsto Purchase Investment In Money Market ProceedsfromSalePaymentstoPurchaseInvestmentInMoneyMarket	7000	USD
CY2020Q1	us-gaap	Payments To Acquire Restricted Investments PaymentsToAcquireRestrictedInvestments	200000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	3317928000	USD
CY2019Q4	wal	Equitysecurities Fvni Accumulated Gross Unrealized Loss Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedLossBeforeTax	499000	USD
CY2020Q1	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	16576000	USD
CY2019Q1	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	3152000	USD
CY2020Q1	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	5075000	USD
CY2019Q1	us-gaap	Proceeds From Sale Of Wholly Owned Real Estate And Real Estate Acquired In Settlement Of Loans ProceedsFromSaleOfWhollyOwnedRealEstateAndRealEstateAcquiredInSettlementOfLoans	0	USD
CY2020Q1	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2395843000	USD
CY2019Q1	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-351485000	USD
CY2020Q1	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	2034188000	USD
CY2019Q1	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	1031293000	USD
CY2020Q1	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	314305000	USD
CY2019Q1	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	-498270000	USD
CY2020Q1	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	70000	USD
CY2019Q1	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	36000	USD
CY2020Q1	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	7458000	USD
CY2019Q1	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	7900000	USD
CY2020Q1	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	62521000	USD
CY2019Q1	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	37949000	USD
CY2020Q1	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	25606000	USD
CY2019Q1	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	0	USD
CY2020Q1	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	2252978000	USD
CY2019Q1	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	487210000	USD
CY2020Q1	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-18886000	USD
CY2019Q1	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	287039000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	434596000	USD
CY2018Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	498572000	USD
CY2020Q1	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	415710000	USD
CY2019Q1	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	785611000	USD
CY2020Q1	us-gaap	Interest Paid InterestPaid	46291000	USD
CY2019Q1	us-gaap	Interest Paid InterestPaid	43832000	USD
CY2020Q1	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	1316000	USD
CY2019Q1	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	-34619000	USD
CY2020Q1	wal	Number Of Wholly Owned Subsidiaries Non Bank Subsidiaries NumberOfWhollyOwnedSubsidiariesNonBankSubsidiaries	2	Subsidiary
CY2019Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Other Debt Securities Available For Sale Or Held For Investment PledgedFinancialInstrumentsNotSeparatelyReportedOtherDebtSecuritiesAvailableForSaleOrHeldForInvestment	962500000	USD
CY2019Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	48252000	USD
CY2020Q1	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	0	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	-167797000	USD
CY2020Q1	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	18025000	USD
CY2020Q1	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	8955000	USD
CY2020Q1	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1680317000	USD
CY2019Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	799113000	USD
CY2019Q4	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	19870000	USD
CY2019Q4	us-gaap	Available For Sale Securities AvailableForSaleSecurities	3346310000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	135319000	USD
CY2019Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	15847000	USD
CY2019Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	585688000	USD
CY2019Q4	wal	Equitysecurities Fvni Accumulated Gross Unrealized Gain Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedGainBeforeTax	3881000	USD
CY2020Q1	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	-133000	USD
CY2020Q1	us-gaap	Use Of Estimates UseOfEstimates	<div style="line-height:120%;padding-top:12px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;font-weight:bold;">Use of estimates</span></div><div style="line-height:120%;padding-top:12px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management's estimates and judgments are ongoing and are based on experience, current and expected future conditions, third-party evaluations and various other assumptions that management believes are reasonable under the circumstances. The results of these estimates form the basis for making judgments about the carrying values of assets and liabilities, as well as identifying and assessing the accounting treatment with respect to commitments and contingencies. Actual results may differ from those estimates and assumptions used in the Consolidated Financial Statements and related notes. Material estimates that are susceptible to significant changes in the near term, </span><span style="font-family:inherit;font-size:10pt;text-decoration:underline;">particularly to the extent the impact of the pandemic is prolonged and economic conditions worsen or persist longer than expected,</span><span style="font-family:inherit;font-size:10pt;"> relate to: the determination of the allowance for credit losses; certain assets and liabilities carried at fair value; and accounting for income taxes. </span></div>
CY2020Q1	wal	Number Of Unconsolidated Subsidiaries NumberOfUnconsolidatedSubsidiaries	8	Subsidiary
CY2020Q1	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	<div style="line-height:120%;padding-top:12px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;font-weight:bold;">Reclassifications</span></div><div style="line-height:120%;padding-top:12px;text-align:justify;font-size:10pt;"><span style="font-family:inherit;font-size:10pt;">Certain amounts reported in prior periods may have been reclassified in the Consolidated Financial Statements to conform to the current presentation. The reclassifications have no effect on net income or stockholders’ equity as previously reported.</span></div>
CY2019Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	19870000	USD
CY2020Q1	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	83995000	USD
CY2020Q1	us-gaap	Available For Sale Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	47453000	USD
CY2020Q1	us-gaap	Available For Sale Securities AvailableForSaleSecurities	3676651000	USD
CY2020Q1	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	137940000	USD
CY2020Q1	wal	Equitysecurities Fvni Accumulated Gross Unrealized Gain Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedGainBeforeTax	267000	USD
CY2020Q1	wal	Equitysecurities Fvni Accumulated Gross Unrealized Loss Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedLossBeforeTax	7049000	USD
CY2020Q1	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	131158000	USD
CY2020Q1	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	166234000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	163505000	USD
CY2020Q1	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	483775000	USD
CY2020Q1	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	46287000	USD
CY2020Q1	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	0	USD
CY2020Q1	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	530062000	USD
CY2020Q1	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	3640109000	USD
CY2019Q1	us-gaap	Available For Sale Securities Gross Realized Losses AvailableForSaleSecuritiesGrossRealizedLosses	0	USD
CY2019Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	485107000	USD
CY2020Q1	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	47453000	USD
CY2020Q1	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	1168991000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	31303000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	149000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	147247000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	717221000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	737128000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	2746644000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	138701000	USD
CY2020Q1	us-gaap	Pledged Financial Instruments Not Separately Reported Other Debt Securities Available For Sale Or Held For Investment PledgedFinancialInstrumentsNotSeparatelyReportedOtherDebtSecuritiesAvailableForSaleOrHeldForInvestment	1000000000.0	USD
CY2020Q1	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	20011000	USD
CY2020Q1	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	1002757000	USD
CY2020Q1	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	27442000	USD
CY2019Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	4023000	USD
CY2019Q4	us-gaap	Available For Sale Securities Continuous Unrealized Loss Position Fair Value AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue	1384801000	USD
CY2020Q1	us-gaap	Availableforsale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions1 AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1	134	positions
CY2019Q4	us-gaap	Availableforsale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Positions1 AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1	158	positions
CY2020Q1	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	335000	USD
CY2020Q1	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityAllowanceForCreditLossWriteoff	0	USD
CY2020Q1	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityAllowanceForCreditLossRecovery	0	USD
CY2020Q1	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	2981000	USD
CY2020Q1	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	1700000	USD
CY2020Q1	us-gaap	Available For Sale Securities AvailableForSaleSecurities	3676651000	USD
CY2020Q1	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	131158000	USD
CY2019Q4	us-gaap	Available For Sale Securities AvailableForSaleSecurities	3346310000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	138701000	USD
CY2020Q1	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount	24649000	USD
CY2020Q1	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	25222000	USD
CY2020Q1	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount	459126000	USD
CY2020Q1	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	504840000	USD
CY2020Q1	us-gaap	Realized Gain Loss On Marketable Securities Cost Method Investments And Other Investments RealizedGainLossOnMarketableSecuritiesCostMethodInvestmentsAndOtherInvestments	72000	USD
CY2020Q1	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	483775000	USD
CY2019Q1	us-gaap	Realized Gain Loss On Marketable Securities Cost Method Investments And Other Investments RealizedGainLossOnMarketableSecuritiesCostMethodInvestmentsAndOtherInvestments	0	USD
CY2020Q1	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	530062000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	6011000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	6045000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	6728000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	6777000	USD
CY2020Q1	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	2779454000	USD
CY2020Q1	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	3640109000	USD
CY2020Q1	us-gaap	Available For Sale Securities AvailableForSaleSecurities	3676651000	USD
CY2019Q1	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	0	USD
CY2020Q1	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	0	USD
CY2020Q1	us-gaap	Available For Sale Securities Gross Realized Gains AvailableForSaleSecuritiesGrossRealizedGains	205000	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	23145268000	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	235329000	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	22909939000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	21101493000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	167797000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	20933696000	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	53100000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	47700000	USD
CY2020Q1	us-gaap	Receivable With Imputed Interest Premium ReceivableWithImputedInterestPremium	30300000	USD
CY2019Q4	us-gaap	Receivable With Imputed Interest Premium ReceivableWithImputedInterestPremium	29900000	USD
CY2020Q1	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	20900000	USD
CY2019Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	21800000	USD
CY2020Q1	us-gaap	Financing Receivable Originated In Current Fiscal Year FinancingReceivableOriginatedInCurrentFiscalYear	1200887000	USD
CY2020Q1	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	49401000	USD
CY2020Q1	us-gaap	Financing Receivable Originated In Fiscal Year Before Latest Fiscal Year FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear	5720668000	USD
CY2020Q1	wal	Financing Receivable Nonaccrual With Allowance FinancingReceivableNonaccrualWithAllowance	16299000	USD
CY2020Q1	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	65700000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	55968000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	0	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Impaired Interest Lost On Nonaccrual Loans LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans	700000	USD
CY2019Q1	us-gaap	Loans And Leases Receivable Impaired Interest Lost On Nonaccrual Loans LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans	300000	USD
CY2020Q1	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	23080481000	USD
CY2020Q1	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	64787000	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	23145268000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	21065187000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	36306000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	21101493000	USD
CY2020Q1	us-gaap	Financing Receivable Originated Two Years Before Latest Fiscal Year FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear	3693329000	USD
CY2020Q1	us-gaap	Financing Receivable Originated Three Years Before Latest Fiscal Year FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear	2207850000	USD
CY2020Q1	us-gaap	Financing Receivable Originated Four Years Before Latest Fiscal Year FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear	857384000	USD
CY2020Q1	us-gaap	Financing Receivable Originated Five Or More Years Before Latest Fiscal Year FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear	2229278000	USD
CY2020Q1	us-gaap	Financing Receivable Revolving FinancingReceivableRevolving	7235872000	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	23145268000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	21101493000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	21065187000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	21101493000	USD
CY2020Q1	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	26500000	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	200000	USD
CY2020Q1	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	7
CY2020Q1	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	26525000	USD
CY2019Q1	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	2
CY2019Q1	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	27100000	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Collateral For Secured Borrowings LoansAndLeasesReceivableCollateralForSecuredBorrowings	161387000	USD
CY2019Q1	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	2313000	USD
CY2019Q1	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	-1083000	USD
CY2019Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	3500000	USD
CY2019Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	154987000	USD
CY2019Q1	us-gaap	Loans And Leases Receivable Gain Loss On Sales Net LoansAndLeasesReceivableGainLossOnSalesNet	-400000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	200000	USD
CY2020Q1	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	29600000	USD
CY2019Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	9000000.0	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	186925000	USD
CY2020Q1	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	45241000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	97000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	-3260000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	235329000	USD
CY2020Q1	us-gaap	Interest Receivable InterestReceivable	88100000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	152717000	USD
CY2020Q1	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	22861511000	USD
CY2020Q1	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	283757000	USD
CY2020Q1	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	23145268000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	228478000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	6851000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	235329000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With Related Allowance Recorded Investment ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment	20979000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Recorded Investment ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment	95324000	USD
CY2019Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	116303000	USD
CY2019Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	20932161000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	21101493000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance	24055000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance	99440000	USD
CY2019Q4	wal	Impaired Financing Receivable Unpaid Principal Balance Individually Evaluated For Impairment ImpairedFinancingReceivableUnpaidPrincipalBalanceIndividuallyEvaluatedForImpairment	123495000	USD
CY2019Q4	wal	Financing Receivable Unpaid Principal Balance Collectively Evaluated For Impairment FinancingReceivableUnpaidPrincipalBalanceCollectivelyEvaluatedForImpairment	20921137000	USD
CY2019Q4	wal	Financing Receivable Unpaid Principal Balance FinancingReceivableUnpaidPrincipalBalance	21108472000	USD
CY2019Q4	us-gaap	Impaired Financing Receivable Related Allowance ImpairedFinancingReceivableRelatedAllowance	2776000	USD
CY2019Q4	wal	Impaired Financing Receivable With No Related Allowance ImpairedFinancingReceivableWithNoRelatedAllowance	0	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	2776000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	164923000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	167797000	USD
CY2020Q1	us-gaap	Financing Receivable Significant Purchases FinancingReceivableSignificantPurchases	667624000	USD
CY2020Q1	us-gaap	Financing Receivable Purchased With Credit Deterioration Amount At Purchase Price FinancingReceivablePurchasedWithCreditDeteriorationAmountAtPurchasePrice	0	USD
CY2019Q1	us-gaap	Financing Receivable Significant Purchases FinancingReceivableSignificantPurchases	530497000	USD
CY2019Q1	us-gaap	Financing Receivable Significant Sales FinancingReceivableSignificantSales	15500000	USD
CY2019Q4	us-gaap	Federal Funds Purchased FederalFundsPurchased	0	USD
CY2019Q1	wal	Weighted Average Selling Price Per Share WeightedAverageSellingPricePerShare	40.30
CY2020Q1	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	0	USD
CY2019Q1	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	-37900000	USD
CY2020Q1	us-gaap	Federal Funds Purchased FederalFundsPurchased	308000000.0	USD
CY2020Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.25
CY2020Q1	us-gaap	Federal Funds Purchased FederalFundsPurchased	308000000	USD
CY2019Q4	us-gaap	Federal Funds Purchased FederalFundsPurchased	0	USD
CY2020Q1	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	0	USD
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	0	USD
CY2020Q1	us-gaap	Short Term Borrowings ShortTermBorrowings	308000000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	0	USD
CY2020Q1	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	23000000.0	USD
CY2019Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	16700000	USD
CY2020Q1	us-gaap	Subordinated Debt SubordinatedDebt	324100000	USD
CY2019Q4	us-gaap	Subordinated Debt SubordinatedDebt	319200000	USD
CY2020Q1	wal	Numberof Statutory Business Trusts Formedor Acquired NumberofStatutoryBusinessTrustsFormedorAcquired	8	Trust
CY2020Q1	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	65700000	USD
CY2019Q4	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	74400000	USD
CY2020Q1	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod	136334	shares
CY2020Q1	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	250000000.0	USD
CY2020Q1	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	1769479	shares
CY2020Q1	wal	Weighted Average Selling Price Per Share WeightedAverageSellingPricePerShare	35.30
CY2020Q1	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	-62500000	USD
CY2020Q1	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	139111	shares
CY2019Q1	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	940915	shares
CY2020Q1	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	6404000	USD
CY2018Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-33622000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	25431000	USD
CY2019Q1	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	0	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	25431000	USD
CY2020Q1	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	53.61
CY2019Q1	us-gaap	Treasury Stock Shares Acquired TreasuryStockSharesAcquired	173007	shares
CY2019Q1	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	45.66
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	25008000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	12543000	USD
CY2020Q1	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	54000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	12489000	USD
CY2020Q1	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	37497000	USD
CY2019Q1	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-8191000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	72000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	0	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-18000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	54000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	0	USD
CY2020Q1	us-gaap	Hedged Asset Fair Value Hedge HedgedAssetFairValueHedge	615890000	USD
CY2020Q1	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	95128000	USD
CY2019Q4	us-gaap	Hedged Asset Fair Value Hedge HedgedAssetFairValueHedge	578063000	USD
CY2019Q4	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	53292000	USD
CY2020Q1	us-gaap	Hedged Liability Fair Value Hedge HedgedLiabilityFairValueHedge	-324145000	USD
CY2020Q1	us-gaap	Hedged Liability Fair Value Hedge Cumulative Increase Decrease HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease	-4416000	USD
CY2019Q4	us-gaap	Hedged Liability Fair Value Hedge HedgedLiabilityFairValueHedge	-319197000	USD
CY2019Q4	us-gaap	Hedged Liability Fair Value Hedge Cumulative Increase Decrease HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease	401000	USD
CY2020Q1	us-gaap	Derivative Fair Value Amount Offset Against Collateral Net DerivativeFairValueAmountOffsetAgainstCollateralNet	95100000	USD
CY2019Q4	us-gaap	Derivative Fair Value Amount Offset Against Collateral Net DerivativeFairValueAmountOffsetAgainstCollateralNet	55500000	USD
CY2019Q1	us-gaap	Derivative Fair Value Amount Offset Against Collateral Net DerivativeFairValueAmountOffsetAgainstCollateralNet	48300000	USD
CY2020Q1	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	27500000	USD
CY2019Q1	us-gaap	Noninterest Income NoninterestIncome	15410000	USD
CY2019Q1	us-gaap	Noninterest Expense NoninterestExpense	111878000	USD
CY2019Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	146332000	USD
CY2020Q1	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.1806
CY2020Q1	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	0	USD
CY2020Q1	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	416300000	USD
CY2019Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	25536000	USD
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CY2019Q1	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.1745
CY2020Q1	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	27500000	USD
CY2020Q1	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	9500000	USD
CY2020Q1	us-gaap	Derivative Collateral Right To Reclaim Securities DerivativeCollateralRightToReclaimSecurities	22400000	USD
CY2020Q1	us-gaap	Collateral Already Posted Aggregate Fair Value CollateralAlreadyPostedAggregateFairValue	117500000	USD
CY2019Q4	us-gaap	Derivative Collateral Right To Reclaim Securities DerivativeCollateralRightToReclaimSecurities	29200000	USD
CY2019Q1	us-gaap	Collateral Already Posted Aggregate Fair Value CollateralAlreadyPostedAggregateFairValue	14200000	USD
CY2020Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	101328000	shares
CY2019Q1	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	104033000	shares
CY2020Q1	wal	Dilutive Effect Of Stock Options Restricted Stock And Equity Settled Awards DilutiveEffectOfStockOptionsRestrictedStockAndEquitySettledAwards	347000	shares
CY2019Q1	wal	Dilutive Effect Of Stock Options Restricted Stock And Equity Settled Awards DilutiveEffectOfStockOptionsRestrictedStockAndEquitySettledAwards	442000	shares
CY2020Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	101675000	shares
CY2019Q1	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	104475000	shares
CY2020Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	83964000	USD
CY2019Q1	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	120796000	USD
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.83
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.16
CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.83
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.16
CY2020Q1	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
CY2019Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	409400000	USD
CY2020Q1	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	18508000	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	83964000	USD
CY2019Q4	wal	Cash Cash Equivalentsand Investment Securities CashCashEquivalentsandInvestmentSecurities	4471200000	USD
CY2019Q4	wal	Loansand Leases Receivable Including Heldfor Sale Net LoansandLeasesReceivableIncludingHeldforSaleNet	20955500000	USD
CY2020Q1	us-gaap	Variable Interest Entity Nonconsolidated Carrying Amount Liabilities VariableInterestEntityNonconsolidatedCarryingAmountLiabilities	182100000	USD
CY2019Q4	us-gaap	Variable Interest Entity Nonconsolidated Carrying Amount Liabilities VariableInterestEntityNonconsolidatedCarryingAmountLiabilities	191000000.0	USD
CY2020Q1	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	7400000	USD
CY2019Q1	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	10100000	USD
CY2020Q1	us-gaap	Line Of Credit Facility Expiration Period LineOfCreditFacilityExpirationPeriod	P1Y
CY2020Q1	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Face Amount Liability FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability	7848971000	USD
CY2019Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Face Amount Liability FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability	8827108000	USD
CY2020Q1	wal	Maximum Loan To Value Ratio MaximumLoanToValueRatio	0.75
CY2020Q1	wal	Percentage Of Commercial Real Estate Loans Occupied By Owners PercentageOfCommercialRealEstateLoansOccupiedByOwners	0.30
CY2019Q4	wal	Percentage Of Commercial Real Estate Loans Occupied By Owners PercentageOfCommercialRealEstateLoansOccupiedByOwners	0.31
CY2020Q1	us-gaap	Lease Cost LeaseCost	3400000	USD
CY2019Q1	us-gaap	Lease Cost LeaseCost	3300000	USD
CY2020Q1	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	1100000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	6557000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-5928000	USD
CY2020Q1	us-gaap	Fair Value Liabilities Measured On Recurring Basis Subordinated Debt Obligations FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations	52990000	USD
CY2020Q1	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	95128000	USD
CY2020Q1	us-gaap	Hedged Liability Fair Value Hedge Cumulative Increase Decrease HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease	-4416000	USD
CY2019Q4	us-gaap	Fair Value Liabilities Measured On Recurring Basis Subordinated Debt Obligations FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations	61685000	USD
CY2019Q4	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	53292000	USD
CY2019Q4	us-gaap	Hedged Liability Fair Value Hedge Cumulative Increase Decrease HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease	401000	USD
CY2019Q4	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	13900000	USD
CY2019Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	297600000	USD
CY2019Q4	wal	Other Assets Segment OtherAssetsSegment	1083700000	USD
CY2019Q4	us-gaap	Assets Assets	26821900000	USD
CY2020Q1	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	6600000	USD
CY2019Q1	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-5900000	USD
CY2020Q1	wal	Collateral Dependent Loans Allowance CollateralDependentLoansAllowance	-6400000	USD
CY2020Q1	wal	Cash Cash Equivalentsand Investment Securities CashCashEquivalentsandInvestmentSecurities	4771000000.0	USD
CY2020Q1	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	10600000	USD
CY2020Q1	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	297200000	USD
CY2020Q1	wal	Other Assets Segment OtherAssetsSegment	1148500000	USD
CY2020Q1	us-gaap	Assets Assets	29158200000	USD
CY2020Q1	us-gaap	Deposits Deposits	24830700000	USD
CY2020Q1	wal	Borrowingsand Qualifying Debt BorrowingsandQualifyingDebt	697900000	USD
CY2020Q1	wal	Other Liabilities Segment OtherLiabilitiesSegment	630000000.0	USD
CY2020Q1	us-gaap	Liabilities Liabilities	26158600000	USD
CY2020Q1	us-gaap	Stockholders Equity StockholdersEquity	2999600000	USD
CY2020Q1	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	29158200000	USD
CY2020Q1	wal	Excess Funds Providedby Usedin Segment Basis ExcessFundsProvidedbyUsedinSegmentBasis	0	USD
CY2020Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	269020000	USD
CY2020Q1	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	51176000	USD
CY2020Q1	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	217844000	USD
CY2020Q1	us-gaap	Noninterest Income NoninterestIncome	5109000	USD
CY2020Q1	us-gaap	Noninterest Expense NoninterestExpense	120481000	USD
CY2020Q1	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	102472000	USD
CY2019Q4	us-gaap	Deposits Deposits	22796500000	USD
CY2019Q4	wal	Borrowingsand Qualifying Debt BorrowingsandQualifyingDebt	393600000	USD
CY2019Q4	wal	Other Liabilities Segment OtherLiabilitiesSegment	615100000	USD
CY2019Q4	us-gaap	Liabilities Liabilities	23805200000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	3016700000	USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	26821900000	USD
CY2019Q4	wal	Excess Funds Providedby Usedin Segment Basis ExcessFundsProvidedbyUsedinSegmentBasis	0	USD
CY2019Q1	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	247336000	USD
CY2019Q1	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	4536000	USD
CY2019Q1	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	242800000	USD
CY2020Q1	wal	Debitandcreditcardinterchangefees Debitandcreditcardinterchangefees	1411000	USD
CY2020Q1	wal	Success Fees SuccessFees	135000	USD
CY2020Q1	wal	Othernoninterestincome Othernoninterestincome	95000	USD
CY2020Q1	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	8045000	USD
CY2020Q1	wal	Otherrevenue Otherrevenue	-2936000	USD
CY2020Q1	us-gaap	Noninterest Income NoninterestIncome	5109000	USD
CY2019Q1	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	5412000	USD
CY2019Q1	wal	Debitandcreditcardinterchangefees Debitandcreditcardinterchangefees	1865000	USD
CY2019Q1	wal	Success Fees SuccessFees	435000	USD
CY2019Q1	wal	Othernoninterestincome Othernoninterestincome	119000	USD
CY2019Q1	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	7831000	USD
CY2019Q1	wal	Otherrevenue Otherrevenue	7579000	USD
CY2019Q1	us-gaap	Noninterest Income NoninterestIncome	15410000	USD
CY2020Q1	us-gaap	Accounts Receivable Net AccountsReceivableNet	1700000	USD
CY2019Q4	us-gaap	Accounts Receivable Net AccountsReceivableNet	1600000	USD

Files In Submission

Name	View Source	Status
0001212545-20-000131-index-headers.html	Edgar Link	pending
0001212545-20-000131-index.html	Edgar Link	pending
0001212545-20-000131.txt	Edgar Link	pending
0001212545-20-000131-xbrl.zip	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
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report.css	Edgar Link	pending
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wal-20200331.xsd	Edgar Link	pending
wal-20200331_cal.xml	Edgar Link	unprocessable
wal-20200331_def.xml	Edgar Link	unprocessable
wal-20200331_lab.xml	Edgar Link	unprocessable
wal-20200331_pre.xml	Edgar Link	unprocessable
wal331202010-q.htm	Edgar Link	pending
wal331202010-q_htm.xml	Edgar Link	completed
walex3113312020.htm	Edgar Link	pending
walex3123312020.htm	Edgar Link	pending
walex323312020.htm	Edgar Link	pending

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$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal

2020 Q1 Form 10-Q Financial Statement

#000121254520000131 Filed on April 30, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WAL WESTERN ALLIANCE BANCORPORATION Stock $wal

2020 Q1 Form 10-Q Financial Statement

#000121254520000131 Filed on April 30, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal