$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal

$wal Overview Financials Valuation SEC Filings Company Website

2024 Q4 Form 10-Q Financial Statement

#000121254524000293 Filed on October 31, 2024

Income Statement

Concept	2024 Q4	2024 Q3
Revenue		$15.20M
YoY Change		-98.52%
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		$22.40M
YoY Change		126.26%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense
YoY Change
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income		$252.1M
YoY Change		-9.28%
Income Tax		$52.30M
% Of Pretax Income		20.75%
Net Earnings		$196.6M
YoY Change		-9.23%
Net Earnings / Revenue		1293.42%
Basic Earnings Per Share		$1.81
Diluted Earnings Per Share		$1.80
COMMON SHARES
Basic Shares Outstanding	110.1M shares	110.1M shares
Diluted Shares Outstanding		109.5M shares

Balance Sheet

Concept	2024 Q4	2024 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$4.096B	$2.592B
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	$361.0M	$481.0M
YoY Change	-25.41%	47.09%
Goodwill	$527.0M
YoY Change	0.0%
Intangibles
YoY Change
Long-Term Investments		$117.0M
YoY Change		-3.31%
Other Assets		$254.0M
YoY Change		-30.41%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$80.93B	$80.08B
YoY Change	14.21%	12.96%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable		$1.311B
YoY Change
Accrued Expenses		$159.0M
YoY Change		-11.67%
Deferred Revenue
YoY Change
Short-Term Debt	$3.151B	$1.567B
YoY Change	-53.55%	-80.37%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities		$1.470B
YoY Change		-57.54%
LONG-TERM LIABILITIES
Long-Term Debt		$3.893B
YoY Change		135.51%
Other Long-Term Liabilities		$1.311B
YoY Change		25.7%
Total Long-Term Liabilities		$3.893B
YoY Change		44.4%
TOTAL LIABILITIES
Total Short-Term Liabilities		$1.470B
Total Long-Term Liabilities		$3.893B
Total Liabilities	$74.23B	$73.40B
YoY Change	14.58%	12.68%
SHAREHOLDERS EQUITY
Retained Earnings	$4.826B	$4.654B
YoY Change	14.5%	13.21%
Common Stock		$2.235B
YoY Change		2.1%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$125.0M	$125.0M
YoY Change	7.76%	7.76%
Treasury Stock Shares
Shareholders Equity	$6.707B	$6.677B
YoY Change
Total Liabilities & Shareholders Equity	$80.93B	$80.08B
YoY Change	14.21%	12.96%

Cashflow Statement

Concept	2024 Q4	2024 Q3
OPERATING ACTIVITIES
Net Income		$196.6M
YoY Change		-9.23%
Depreciation, Depletion And Amortization		$22.40M
YoY Change		126.26%
Cash From Operating Activities		-$1.068B
YoY Change		87.47%
INVESTING ACTIVITIES
Capital Expenditures		$22.10M
YoY Change		-15.65%
Acquisitions
YoY Change
Other Investing Activities		-$372.8M
YoY Change		-39.81%
Cash From Investing Activities		-$394.9M
YoY Change		-38.83%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities		-22.50M
YoY Change		-100.88%
NET CHANGE
Cash From Operating Activities		-1.068B
Cash From Investing Activities		-394.9M
Cash From Financing Activities		-22.50M
Net Change In Cash		-1.485B
YoY Change		-210.54%
FREE CASH FLOW
Cash From Operating Activities		-$1.068B
Capital Expenditures		$22.10M
Free Cash Flow		-$1.090B
YoY Change		82.93%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2024
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2024-09-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	88-0365922
	dei	Entity Small Business EntitySmallBusiness	false
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
	dei	Entity Shell Company EntityShellCompany	false
CY2024Q4	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	110069292	shares
CY2024Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	400000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	1400000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	10000000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	8000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1371000000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1251000000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	117000000	usd
CY2023Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	126000000	usd
CY2024Q3	us-gaap	Restricted Investments RestrictedInvestments	171000000	usd
CY2023Q4	us-gaap	Restricted Investments RestrictedInvestments	281000000	usd
CY2024Q3	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	2327000000	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	1402000000	usd
CY2023Q4	us-gaap	Servicing Asset ServicingAsset	1124000000	usd
CY2024Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	354000000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	339000000	usd
CY2024Q3	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	127000000	usd
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	145000000	usd
CY2024Q3	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	1000000000	usd
CY2023Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	186000000	usd
CY2023Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	12000000	shares
CY2023Q3	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	860800000	usd
CY2024Q3	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	195400000	usd
CY2023Q3	us-gaap	Interest Expense Deposits InterestExpenseDeposits	316200000	usd
CY2024Q3	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	9500000	usd
CY2023Q3	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	9500000	usd
CY2024Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	696900000	usd
CY2024Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	33600000	usd
CY2023Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	12100000	usd
CY2024Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	663300000	usd
CY2023Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	574900000	usd
CY2023Q3	wal	Net Gain On Loan Origination And Sale Activities NetGainOnLoanOriginationAndSaleActivities	52000000.0	usd
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	32200000	usd
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	19200000	usd
	us-gaap	Noninterest Income NoninterestIncome	371300000	usd
	us-gaap	Noninterest Income NoninterestIncome	190200000	usd
CY2024Q3	us-gaap	General Insurance Expense GeneralInsuranceExpense	35400000	usd
CY2023Q3	us-gaap	General Insurance Expense GeneralInsuranceExpense	33100000	usd
	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	80700000	usd
	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	77800000	usd
	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	50300000	usd
	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	44100000	usd
	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	13400000	usd
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	61200000	usd
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	65500000	usd
	us-gaap	Noninterest Expense NoninterestExpense	1506000000	usd
	us-gaap	Noninterest Expense NoninterestExpense	1161500000	usd
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	161000000.0	usd
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	148100000	usd
	us-gaap	Net Income Loss NetIncomeLoss	570800000	usd
	us-gaap	Net Income Loss NetIncomeLoss	574500000	usd
	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	9600000	usd
	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	9600000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	561200000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	564900000	usd
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.17
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.22
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.14
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.21
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	108600000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	108300000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	109200000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	108400000	shares
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.11
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.08
	us-gaap	Net Income Loss NetIncomeLoss	570800000	usd
	us-gaap	Net Income Loss NetIncomeLoss	574500000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-46100000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	31700000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	140500000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-94300000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	53300000	usd
	us-gaap	Amortization Of Deferred Loan Origination Fees Net AmortizationOfDeferredLoanOriginationFeesNet	64800000	usd
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	32403800000	usd
	us-gaap	Proceeds From Sale And Collection Of Loans Heldforsale ProceedsFromSaleAndCollectionOfLoansHeldforsale	31552200000	usd
	wal	Assets Fair Value Adjustment Non Cash AssetsFairValueAdjustmentNonCash	122200000	usd
	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	-26000000.0	usd
	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	13400000	usd
	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	8100000	usd
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-94900000	usd
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-669800000	usd
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	6853500000	usd
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	3559200000	usd
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	777800000	usd
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	163200000	usd
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	us-gaap	Payments To Acquire Equity Securities Fv Ni PaymentsToAcquireEquitySecuritiesFvNi	500000	usd
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	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	87000000.0	usd
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-279000000.0	usd
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	642900000	usd
	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	9900000	usd
	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	538400000	usd
	us-gaap	Proceeds From Short Term Debt Maturing In More Than Three Months ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths	2661800000	usd
	us-gaap	Repayments Of Short Term Debt Maturing In More Than Three Months RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths	2198000000	usd
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	10900000	usd
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CY2023Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	5100000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	5900000	usd
	dei	Entity Registrant Name EntityRegistrantName	WESTERN ALLIANCE BANCORPORATION
	dei	Entity Address Address Line1 EntityAddressAddressLine1	One E. Washington Street, Suite 1400
	dei	Entity Address City Or Town EntityAddressCityOrTown	Phoenix
	dei	Entity Address State Or Province EntityAddressStateOrProvince	AZ
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	85004
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
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CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	11849000000	usd
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	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	2713900000	usd
	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	2550700000	usd
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	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	526200000	usd
	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	325600000	usd
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	us-gaap	Dividend Income Securities Operating Taxable DividendIncomeSecuritiesOperatingTaxable	162400000	usd
	us-gaap	Dividend Income Securities Operating Taxable DividendIncomeSecuritiesOperatingTaxable	120000000.0	usd
CY2024Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	1200000000	usd
CY2023Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	1026600000	usd
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	3402500000	usd
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	2996300000	usd
CY2024Q3	us-gaap	Interest Expense Deposits InterestExpenseDeposits	422100000	usd
	us-gaap	Interest Expense Deposits InterestExpenseDeposits	1213000000	usd
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CY2023Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Allowance For Credit Loss Not Previously Recorded DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossNotPreviouslyRecorded	300000	usd
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CY2023Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	108500000	shares
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CY2024Q3	us-gaap	Stockholders Equity StockholdersEquity	6677100000	usd
	us-gaap	Net Income Loss NetIncomeLoss	570800000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	85900000	usd
	us-gaap	Depreciation And Amortization DepreciationAndAmortization	64600000	usd
	us-gaap	Share Based Compensation ShareBasedCompensation	37000000.0	usd
	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	-10000000.0	usd
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	170600000	usd
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	55300000	usd
	us-gaap	Operating Lease Expense OperatingLeaseExpense	18000000.0	usd
	us-gaap	Amortization Of Deferred Loan Origination Fees Net AmortizationOfDeferredLoanOriginationFeesNet	66800000	usd
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	35134200000	usd
	us-gaap	Proceeds From Sale And Collection Of Loans Heldforsale ProceedsFromSaleAndCollectionOfLoansHeldforsale	32872900000	usd
	wal	Capitalization Of Mortgage Servicing Rights Ms Rs CapitalizationOfMortgageServicingRightsMSRs	625900000	usd
	wal	Increase Decrease In Loans Held For Sale Mortgage Servicing Rights And Derivatives IncreaseDecreaseInLoansHeldForSaleMortgageServicingRightsAndDerivatives	-83000000.0	usd
	wal	Assets Fair Value Adjustment Non Cash AssetsFairValueAdjustmentNonCash	-11500000	usd
	us-gaap	Gain Loss On Sale Of Investments GainLossOnSaleOfInvestments	10200000	usd
	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	usd
	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-16600000	usd
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-138000000.0	usd
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-2120300000	usd
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	14325200000	usd
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	7219500000	usd
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	4020700000	usd
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	121500000	usd
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	26000000.0	usd
	us-gaap	Payments To Acquire Equity Securities Fv Ni PaymentsToAcquireEquitySecuritiesFvNi	600000	usd
	wal	Proceeds From Redemptions Of Equity Securities Fvni ProceedsFromRedemptionsOfEquitySecuritiesFVNI	15000000.0	usd
	us-gaap	Proceeds From Sale Of Equity Securities Fv Ni ProceedsFromSaleOfEquitySecuritiesFvNi	0	usd
	us-gaap	Proceeds From Sale Of Mortgage Servicing Rights Msr ProceedsFromSaleOfMortgageServicingRightsMSR	653800000	usd
	wal	Purchase Sale Of Other Investments PurchaseSaleOfOtherInvestments	-33900000	usd
	wal	Purchase Sale Of Other Investments PurchaseSaleOfOtherInvestments	116600000	usd
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	3218700000	usd
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	-1926500000	usd
	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	57100000	usd
	us-gaap	Payments To Acquire Life Insurance Policies PaymentsToAcquireLifeInsurancePolicies	800000000.0	usd
	us-gaap	Payments To Acquire Life Insurance Policies PaymentsToAcquireLifeInsurancePolicies	0	usd
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-6554200000	usd
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	12707300000	usd
	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	1000000000	usd
	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	19100000	usd
	us-gaap	Proceeds From Other Short Term Debt ProceedsFromOtherShortTermDebt	-3857200000	usd
	us-gaap	Proceeds From Other Short Term Debt ProceedsFromOtherShortTermDebt	2962900000	usd
	us-gaap	Proceeds From Short Term Debt Maturing In More Than Three Months ProceedsFromShortTermDebtMaturingInMoreThanThreeMonths	0	usd
	us-gaap	Repayments Of Short Term Debt Maturing In More Than Three Months RepaymentsOfShortTermDebtMaturingInMoreThanThreeMonths	0	usd
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	8700000	usd
	us-gaap	Payments Of Dividends PaymentsOfDividends	131800000	usd
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	9690500000	usd
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	3402400000	usd
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	1016000000	usd
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	2453600000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1576100000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1043400000	usd
CY2024Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	2592100000	usd
CY2023Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	3497000000	usd
	us-gaap	Interest Paid Net InterestPaidNet	1435700000	usd
	us-gaap	Interest Paid Net InterestPaidNet	1108500000	usd
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	-27500000	usd
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	57000000.0	usd
	wal	Transfers Of Mortgage Backed Securities In Settlement Of Secured Borrowings TransfersOfMortgageBackedSecuritiesInSettlementOfSecuredBorrowings	1369300000	usd
	wal	Transfers Of Mortgage Backed Securities In Settlement Of Secured Borrowings TransfersOfMortgageBackedSecuritiesInSettlementOfSecuredBorrowings	461200000	usd
	wal	Transfers Of Securitized Lhfs To Afs Securities TransfersOfSecuritizedLHFSToAFSSecurities	123000000.0	usd
	wal	Transfers Of Securitized Lhfs To Afs Securities TransfersOfSecuritizedLHFSToAFSSecurities	182000000.0	usd
	wal	Loan And Lease Transfer From Held In Portfolio To Held For Sale Net Of Fair Value Adjustments LoanAndLeaseTransferFromHeldInPortfolioToHeldForSaleNetOfFairValueAdjustments	207800000	usd
	wal	Loan And Lease Transfer From Held In Portfolio To Held For Sale Net Of Fair Value Adjustments LoanAndLeaseTransferFromHeldInPortfolioToHeldForSaleNetOfFairValueAdjustments	6646800000	usd
	us-gaap	Transfer Of Loans Held For Sale To Portfolio Loans1 TransferOfLoansHeldForSaleToPortfolioLoans1	1800000	usd
	us-gaap	Transfer Of Loans Held For Sale To Portfolio Loans1 TransferOfLoansHeldForSaleToPortfolioLoans1	2357200000	usd
	wal	Loan And Lease Transfer From Held In Portfolio To Held For Sale Operating Activity LoanAndLeaseTransferFromHeldInPortfolioToHeldForSaleOperatingActivity	333300000	usd
	wal	Loan And Lease Transfer From Held In Portfolio To Held For Sale Operating Activity LoanAndLeaseTransferFromHeldInPortfolioToHeldForSaleOperatingActivity	426400000	usd
	us-gaap	Use Of Estimates UseOfEstimates	<div style="margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Use of estimates</span></div>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 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 relate to: 1) the determination of the ACL; 2) certain assets and liabilities carried at or evaluated using fair value measurements; 3) goodwill impairment; and 4) accounting for income taxes.
	wal	Number Of Unconsolidated Subsidiaries NumberOfUnconsolidatedSubsidiaries	8	subsidiary
	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	<div style="margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">Reclassifications</span></div>Certain amounts in the Consolidated Income Statements and Note 4. Loans, Leases and Allowance for Credit Losses for the prior periods have been reclassified to conform to the current presentation. The reclassifications had no effect on net income or stockholders’ equity as previously reported.
CY2024Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	1525000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	3000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	157000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1371000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	15258000000	usd
CY2024Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	77000000	usd
CY2024Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	585000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	14750000000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	1429000000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	1000000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	179000000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1251000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	11849000000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	18000000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	702000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	11165000000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	117000000	usd
CY2023Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	126000000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-3300000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	13000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	2819000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	572000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	3814000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	585000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	6633000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	7000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	2449000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	695000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	4655000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	702000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	7104000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	658	security
CY2023Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	708	security
CY2024Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Transfer To Held To Maturity Allowance For Credit Loss Expense Reversal DebtSecuritiesAvailableForSaleExcludingAccruedInterestTransferToHeldToMaturityAllowanceForCreditLossExpenseReversal	400000	usd
	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Transfer To Held To Maturity Allowance For Credit Loss Expense Reversal DebtSecuritiesAvailableForSaleExcludingAccruedInterestTransferToHeldToMaturityAllowanceForCreditLossExpenseReversal	1000000.0	usd
	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Allowance For Credit Loss Not Previously Recorded DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossNotPreviouslyRecorded	21800000	usd
	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Allowance For Credit Loss Writeoff DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossWriteoff	17100000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Transfer To Held To Maturity Allowance For Credit Loss Expense Reversal DebtSecuritiesAvailableForSaleExcludingAccruedInterestTransferToHeldToMaturityAllowanceForCreditLossExpenseReversal	400000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	1400000	usd
	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Transfer To Held To Maturity Allowance For Credit Loss Expense Reversal DebtSecuritiesAvailableForSaleExcludingAccruedInterestTransferToHeldToMaturityAllowanceForCreditLossExpenseReversal	1000000.0	usd
	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Allowance For Credit Loss Writeoff DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossWriteoff	0	usd
	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Allowance For Credit Loss Recovery DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossRecovery	0	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	400000	usd
CY2023Q2	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	4400000	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Allowance For Credit Loss Recovery DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossRecovery	0	usd
CY2022Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	usd
	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Allowance For Credit Loss Not Previously Recorded DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossNotPreviouslyRecorded	21800000	usd
	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Allowance For Credit Loss Writeoff DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossWriteoff	17100000	usd
	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest Allowance For Credit Loss Recovery DebtSecuritiesAvailableForSaleExcludingAccruedInterestAllowanceForCreditLossRecovery	0	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	4700000	usd
CY2024Q3	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	5000000	usd
CY2023Q4	us-gaap	Accrued Investment Income Receivable AccruedInvestmentIncomeReceivable	5000000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	1525000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	14750000000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	117000000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	1429000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	11165000000	usd
CY2023Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	126000000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date Year One DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateYearOne	34000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue	34000000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year One Through Five DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYearOneThroughFive	7000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	7000000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year5 Through10 DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear5Through10	97000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	89000000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Allocated And Single Maturity Date After Year10 DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityAllocatedAndSingleMaturityDateAfterYear10	1208000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	1094000000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss Maturity Without Single Maturity Date DebtSecuritiesHeldToMaturityAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLossMaturityWithoutSingleMaturityDate	179000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	147000000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	1525000000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1371000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	5079000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	5081000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	697000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	692000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	567000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	544000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	1175000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	1109000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	7740000000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	7324000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss	15258000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	14750000000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	8800000	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	500000	usd
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	12400000	usd
	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	4000000.0	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	0	usd
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	2200000	usd
	us-gaap	Debt Securities Available For Sale Realized Loss DebtSecuritiesAvailableForSaleRealizedLoss	29600000	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	500000	usd
	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	10200000	usd
	us-gaap	Debt Securities Available For Sale Realized Gain Loss DebtSecuritiesAvailableForSaleRealizedGainLoss	-25600000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni Realized Gain EquitySecuritiesFvNiRealizedGain	0	usd
CY2023Q3	us-gaap	Equity Securities Fv Ni Realized Gain EquitySecuritiesFvNiRealizedGain	0	usd
	us-gaap	Equity Securities Fv Ni Realized Gain EquitySecuritiesFvNiRealizedGain	0	usd
	us-gaap	Equity Securities Fv Ni Realized Gain EquitySecuritiesFvNiRealizedGain	0	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni Realized Loss EquitySecuritiesFvNiRealizedLoss	0	usd
CY2023Q3	us-gaap	Equity Securities Fv Ni Realized Loss EquitySecuritiesFvNiRealizedLoss	400000	usd
	us-gaap	Equity Securities Fv Ni Realized Loss EquitySecuritiesFvNiRealizedLoss	0	usd
	us-gaap	Equity Securities Fv Ni Realized Loss EquitySecuritiesFvNiRealizedLoss	400000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	0	usd
CY2023Q3	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	-400000	usd
	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	0	usd
	us-gaap	Equity Securities Fv Ni Realized Gain Loss EquitySecuritiesFvNiRealizedGainLoss	-400000	usd
CY2024Q3	wal	Debt And Equity Securities Sold During Period Carrying Value DebtAndEquitySecuritiesSoldDuringPeriodCarryingValue	2300000000	usd
	wal	Debt And Equity Securities Sold During Period Carrying Value DebtAndEquitySecuritiesSoldDuringPeriodCarryingValue	4000000000	usd
CY2024Q3	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	8800000	usd
	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	10200000	usd
CY2023Q3	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	100000	usd
	us-gaap	Debt And Equity Securities Realized Gain Loss DebtAndEquitySecuritiesRealizedGainLoss	-26000000	usd
CY2024Q3	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	2327000000	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	1402000000	usd
CY2024Q3	wal	Msr Capitalized Upon Sale Of Loan MSRCapitalizedUponSaleOfLoan	222500000	usd
	wal	Msr Capitalized Upon Sale Of Loan MSRCapitalizedUponSaleOfLoan	653000000.0	usd
CY2023Q3	wal	Proceeds From Sale Loan Mortgage Held For Sale Net Of Loan Basis ProceedsFromSaleLoanMortgageHeldForSaleNetOfLoanBasis	-274700000	usd
	wal	Proceeds From Sale Loan Mortgage Held For Sale Net Of Loan Basis ProceedsFromSaleLoanMortgageHeldForSaleNetOfLoanBasis	-467700000	usd
	wal	Proceeds From Sale Loan Mortgage Held For Sale Net Of Loan Basis ProceedsFromSaleLoanMortgageHeldForSaleNetOfLoanBasis	-612700000	usd
CY2024Q3	wal	Provision For And Change In Estimate Of Liability For Losses Under Representations And Warranties ProvisionForAndChangeInEstimateOfLiabilityForLossesUnderRepresentationsAndWarranties	0	usd
CY2023Q3	wal	Provision For And Change In Estimate Of Liability For Losses Under Representations And Warranties ProvisionForAndChangeInEstimateOfLiabilityForLossesUnderRepresentationsAndWarranties	100000	usd
	wal	Provision For And Change In Estimate Of Liability For Losses Under Representations And Warranties ProvisionForAndChangeInEstimateOfLiabilityForLossesUnderRepresentationsAndWarranties	4200000	usd
	wal	Provision For And Change In Estimate Of Liability For Losses Under Representations And Warranties ProvisionForAndChangeInEstimateOfLiabilityForLossesUnderRepresentationsAndWarranties	2800000	usd
CY2024Q3	wal	Change In Fair Value Of Loans Held For Sale ChangeInFairValueOfLoansHeldForSale	4000000.0	usd
CY2023Q3	wal	Change In Fair Value Of Loans Held For Sale ChangeInFairValueOfLoansHeldForSale	-10100000	usd
	wal	Change In Fair Value Of Loans Held For Sale ChangeInFairValueOfLoansHeldForSale	-1300000	usd
	wal	Change In Fair Value Of Loans Held For Sale ChangeInFairValueOfLoansHeldForSale	-13200000	usd
CY2024Q3	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	-2900000	usd
CY2023Q3	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	10300000	usd
	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	14200000	usd
	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	25300000	usd
CY2024Q3	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet	-76300000	usd
CY2023Q3	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet	44500000	usd
	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet	-79700000	usd
	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet	47000000.0	usd
CY2024Q3	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-79200000	usd
CY2023Q3	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	54800000	usd
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-65500000	usd
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	72300000	usd
CY2024Q3	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	30900000	usd
CY2023Q3	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	35900000	usd
	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	95600000	usd
	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	102200000	usd
CY2024Q3	wal	Loan Acquisition And Origination Fees LoanAcquisitionAndOriginationFees	15400000	usd
CY2023Q3	wal	Loan Acquisition And Origination Fees LoanAcquisitionAndOriginationFees	16100000	usd
	wal	Loan Acquisition And Origination Fees LoanAcquisitionAndOriginationFees	42800000	usd
	wal	Loan Acquisition And Origination Fees LoanAcquisitionAndOriginationFees	43500000	usd
CY2024Q3	wal	Net Gain On Loan Origination And Sale Activities NetGainOnLoanOriginationAndSaleActivities	46300000	usd
CY2023Q3	wal	Net Gain On Loan Origination And Sale Activities NetGainOnLoanOriginationAndSaleActivities	52000000.0	usd
	wal	Net Gain On Loan Origination And Sale Activities NetGainOnLoanOriginationAndSaleActivities	138400000	usd
	wal	Net Gain On Loan Origination And Sale Activities NetGainOnLoanOriginationAndSaleActivities	145700000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	53346000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	50297000000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	357000000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	337000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	52989000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	49960000000	usd
CY2024Q3	us-gaap	Financing Receivable Unamortized Loan Fee Cost FinancingReceivableUnamortizedLoanFeeCost	-107000000	usd
CY2023Q4	us-gaap	Financing Receivable Unamortized Loan Fee Cost FinancingReceivableUnamortizedLoanFeeCost	-108000000	usd
CY2024Q3	us-gaap	Financing Receivable Unamortized Purchase Premium Discount FinancingReceivableUnamortizedPurchasePremiumDiscount	173000000	usd
CY2023Q4	us-gaap	Financing Receivable Unamortized Purchase Premium Discount FinancingReceivableUnamortizedPurchasePremiumDiscount	177000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual No Allowance FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance	214000000	usd
CY2024Q3	wal	Financing Receivable Nonaccrual With Allowance FinancingReceivableNonaccrualWithAllowance	135000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual FinancingReceivableExcludingAccruedInterestNonaccrual	349000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest90 Days Or More Past Due Still Accruing FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing	317000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest90 Days Or More Past Due Still Accruing FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing	317000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual No Allowance FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance	151000000	usd
CY2023Q4	wal	Financing Receivable Nonaccrual With Allowance FinancingReceivableNonaccrualWithAllowance	122000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual FinancingReceivableExcludingAccruedInterestNonaccrual	273000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest90 Days Or More Past Due Still Accruing FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing	441000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest90 Days Or More Past Due Still Accruing FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing	441000000	usd
CY2024Q3	us-gaap	Financing Receivable Nonaccrual Interest Income FinancingReceivableNonaccrualInterestIncome	6600000	usd
CY2023Q3	us-gaap	Financing Receivable Nonaccrual Interest Income FinancingReceivableNonaccrualInterestIncome	4500000	usd
	us-gaap	Financing Receivable Nonaccrual Interest Income FinancingReceivableNonaccrualInterestIncome	18400000	usd
	us-gaap	Financing Receivable Nonaccrual Interest Income FinancingReceivableNonaccrualInterestIncome	8100000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual FinancingReceivableExcludingAccruedInterestNonaccrual	349000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	53346000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Nonaccrual FinancingReceivableExcludingAccruedInterestNonaccrual	273000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	50297000000	usd
CY2024Q3	wal	Financing Receivable Increase Decrease From Cumulative Fair Value Hedging Adjustment FinancingReceivableIncreaseDecreaseFromCumulativeFairValueHedgingAdjustment	44000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	5940000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	5849000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	10973000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	10220000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	2433000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	3192000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	14695000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	53346000000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff	100000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff	18800000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff	6800000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff	28700000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff	3500000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff	2200000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Writeoff FinancingReceivableExcludingAccruedInterestRevolvingWriteoff	800000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	60900000	usd
CY2023Q4	wal	Financing Receivable Increase Decrease From Cumulative Fair Value Hedging Adjustment FinancingReceivableIncreaseDecreaseFromCumulativeFairValueHedgingAdjustment	19000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	7504000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	12434000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	11544000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	2876000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	1568000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	2523000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	11829000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	50297000000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff	2600000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff	3400000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff	15100000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff	3900000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff	100000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff	400000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Writeoff FinancingReceivableExcludingAccruedInterestRevolvingWriteoff	400000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	25900000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	89000000	usd
CY2024Q3	us-gaap	Financing Receivable Modification To Total Financing Receivables Excluding Accrued Interest Percent FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent	0.002
	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	223000000	usd
	us-gaap	Financing Receivable Modification To Total Financing Receivables Excluding Accrued Interest Percent FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent	0.004
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	63000000	usd
CY2023Q3	us-gaap	Financing Receivable Modification To Total Financing Receivables Excluding Accrued Interest Percent FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent	0.001
	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	143000000	usd
	us-gaap	Financing Receivable Modification To Total Financing Receivables Excluding Accrued Interest Percent FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent	0.003
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CY2024Q3	wal	Financing Receivable Excluding Accrued Interest Modified Nonaccrual FinancingReceivableExcludingAccruedInterestModifiedNonaccrual	136000000	usd
CY2023Q4	wal	Financing Receivable Excluding Accrued Interest Modified Accrual Status FinancingReceivableExcludingAccruedInterestModifiedAccrualStatus	95000000	usd
CY2023Q4	wal	Financing Receivable Excluding Accrued Interest Modified Nonaccrual FinancingReceivableExcludingAccruedInterestModifiedNonaccrual	111000000	usd
CY2024Q2	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	351800000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	31400000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	27800000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	1200000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	356600000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	336700000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	79100000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	60900000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	1700000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	356600000	usd
CY2023Q2	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	321100000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	14300000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	8500000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	500000	usd
CY2023Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	327400000	usd
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	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	39100000	usd
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CY2023Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	327400000	usd
CY2024Q3	us-gaap	Interest Receivable InterestReceivable	271000000	usd
CY2023Q4	us-gaap	Interest Receivable InterestReceivable	281000000	usd
CY2024Q2	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	35900000	usd
CY2023Q2	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	41100000	usd
CY2023Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	31600000	usd
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	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	6000000.0	usd
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CY2024Q3	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	37600000	usd
CY2023Q3	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	37900000	usd
CY2024Q3	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	37600000	usd
CY2023Q3	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	37900000	usd
CY2024Q3	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	52606000000	usd
CY2024Q3	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	740000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	53346000000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	318500000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	38100000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	356600000	usd
CY2023Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	49723000000	usd
CY2023Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	574000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	50297000000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	315100000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	21600000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	336700000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Purchase FinancingReceivableExcludingAccruedInterestPurchase	360000000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Purchase FinancingReceivableExcludingAccruedInterestPurchase	875000000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Purchase FinancingReceivableExcludingAccruedInterestPurchase	329000000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Purchase FinancingReceivableExcludingAccruedInterestPurchase	1400000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Sale FinancingReceivableExcludingAccruedInterestSale	161000000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Sale FinancingReceivableExcludingAccruedInterestSale	550000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Loan Sold FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossLoanSold	400000	usd
CY2024Q3	us-gaap	Gain Loss On Sale Of Notes Receivable GainLossOnSaleOfNotesReceivable	-100000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Loan Sold FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossLoanSold	1800000	usd
	us-gaap	Gain Loss On Sale Of Notes Receivable GainLossOnSaleOfNotesReceivable	-5700000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Reclassification To Held For Sale FinancingReceivableExcludingAccruedInterestReclassificationToHeldForSale	442000000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Reclassification To Held For Sale FinancingReceivableExcludingAccruedInterestReclassificationToHeldForSale	7700000000	usd
CY2023Q3	us-gaap	Gain Loss On Sale Of Notes Receivable GainLossOnSaleOfNotesReceivable	-21400000	usd
	us-gaap	Gain Loss On Sale Of Notes Receivable GainLossOnSaleOfNotesReceivable	-237200000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Sale FinancingReceivableExcludingAccruedInterestSale	904000000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Sale FinancingReceivableExcludingAccruedInterestSale	4700000000	usd
CY2023Q3	us-gaap	Transfer Of Loans Held For Sale To Portfolio Loans1 TransferOfLoansHeldForSaleToPortfolioLoans1	1400000000	usd
	us-gaap	Transfer Of Loans Held For Sale To Portfolio Loans1 TransferOfLoansHeldForSaleToPortfolioLoans1	2400000000	usd
CY2024Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1145000000	usd
CY2023Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1007000000	usd
CY2023Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1124000000	usd
CY2022Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1148000000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	223000000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	266000000	usd
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	626000000	usd
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	653000000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	258000000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	112000000	usd
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	655000000	usd
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	611000000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-62000000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	98000000	usd
	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	30000000	usd
	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	114000000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Other Changes That Affect Balance ServicingAssetAtFairValueOtherChangesThatAffectBalance	0	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Other Changes That Affect Balance ServicingAssetAtFairValueOtherChangesThatAffectBalance	0	usd
	us-gaap	Servicing Asset At Fair Value Other Changes That Affect Balance ServicingAssetAtFairValueOtherChangesThatAffectBalance	0	usd
	us-gaap	Servicing Asset At Fair Value Other Changes That Affect Balance ServicingAssetAtFairValueOtherChangesThatAffectBalance	4000000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-37000000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-26000000	usd
	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-114000000	usd
	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-75000000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1011000000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1233000000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1011000000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1233000000	usd
CY2024Q3	us-gaap	Continuing Involvement With Transferred Financial Assets Principal Amount Outstanding ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding	63773000000	usd
CY2023Q3	us-gaap	Continuing Involvement With Transferred Financial Assets Principal Amount Outstanding ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding	70261000000	usd
CY2024Q3	wal	Msr Sales Upb Of Underlying Loans MSRSalesUPBOfUnderlyingLoans	15500000000	usd
	wal	Msr Sales Upb Of Underlying Loans MSRSalesUPBOfUnderlyingLoans	42800000000	usd
CY2023Q3	wal	Msr Sales Upb Of Underlying Loans MSRSalesUPBOfUnderlyingLoans	16000000000.0	usd
	wal	Msr Sales Upb Of Underlying Loans MSRSalesUPBOfUnderlyingLoans	44300000000	usd
CY2023Q4	wal	Msr Loan Sales Receivable MSRLoanSalesReceivable	41000000	usd
CY2024Q3	wal	Msr Loan Sales Receivable MSRLoanSalesReceivable	41000000	usd
CY2024Q3	us-gaap	Contractually Specified Servicing Fees Late Fees And Ancillary Fees Earned In Exchange For Servicing Financial Assets ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets	59800000	usd
	us-gaap	Contractually Specified Servicing Fees Late Fees And Ancillary Fees Earned In Exchange For Servicing Financial Assets ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets	196900000	usd
CY2023Q3	us-gaap	Contractually Specified Servicing Fees Late Fees And Ancillary Fees Earned In Exchange For Servicing Financial Assets ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets	56400000	usd
	us-gaap	Contractually Specified Servicing Fees Late Fees And Ancillary Fees Earned In Exchange For Servicing Financial Assets ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets	173300000	usd
CY2024Q3	wal	Servicing Advances Net ServicingAdvancesNet	48000000	usd
CY2023Q4	wal	Servicing Advances Net ServicingAdvancesNet	87000000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1011000000	usd
CY2024Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Adverse Interest Rate Change SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointAdverseInterestRateChange	84000000	usd
CY2024Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Favorable Interest Rate Change SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointFavorableInterestRateChange	81000000	usd
CY2024Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Discount Rate Increase SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointDiscountRateIncrease	21000000	usd
CY2024Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Discount Rate Decrease SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointDiscountRateDecrease	21000000	usd
CY2024Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of1 Percent Increase In Prepayment Speed SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf1PercentIncreaseInPrepaymentSpeed	33000000	usd
CY2024Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of1 Percent Decrease In Prepayment Speed SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf1PercentDecreaseInPrepaymentSpeed	36000000	usd
CY2024Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of10 Percent Increase Cost Of Service SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf10PercentIncreaseCostOfService	12000000	usd
CY2024Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of10 Percent Decrease Cost Of Service SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf10PercentDecreaseCostOfService	12000000	usd
CY2024Q3	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	24965000000	usd
CY2023Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	14520000000	usd
CY2024Q3	us-gaap	Interest Bearing Domestic Deposit Demand InterestBearingDomesticDepositDemand	13846000000	usd
CY2023Q4	us-gaap	Interest Bearing Domestic Deposit Demand InterestBearingDomesticDepositDemand	15916000000	usd
CY2024Q3	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	19575000000	usd
CY2023Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	14791000000	usd
CY2024Q3	us-gaap	Time Deposit Liability Above Us Insurance Limit TimeDepositLiabilityAboveUsInsuranceLimit	1567000000	usd
CY2023Q4	us-gaap	Time Deposit Liability Above Us Insurance Limit TimeDepositLiabilityAboveUsInsuranceLimit	1478000000	usd
CY2024Q3	wal	Time Deposits Lessthan250000 TimeDepositsLessthan250000	8087000000	usd
CY2023Q4	wal	Time Deposits Lessthan250000 TimeDepositsLessthan250000	8628000000	usd
CY2024Q3	us-gaap	Deposits Deposits	68040000000	usd
CY2023Q4	us-gaap	Deposits Deposits	55333000000	usd
CY2024Q3	wal	Time Deposits250000ormore TimeDeposits250000ormore	4900000000	usd
CY2023Q4	wal	Time Deposits250000ormore TimeDeposits250000ormore	5800000000	usd
CY2024Q3	us-gaap	Time Deposit Maturities Remainder Of Fiscal Year TimeDepositMaturitiesRemainderOfFiscalYear	3911000000	usd
CY2024Q3	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	5521000000	usd
CY2024Q3	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	211000000	usd
CY2024Q3	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	8000000	usd
CY2024Q3	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	1000000	usd
CY2024Q3	wal	Time Deposit Maturities After Year Four TimeDepositMaturitiesAfterYearFour	2000000	usd
CY2024Q3	us-gaap	Time Deposits TimeDeposits	9654000000	usd
CY2024Q3	us-gaap	Deposits Wholesale DepositsWholesale	6000000000.0	usd
CY2023Q4	us-gaap	Deposits Wholesale DepositsWholesale	6600000000	usd
CY2024Q3	wal	Reciprocal Deposits ReciprocalDeposits	13100000000	usd
CY2023Q4	wal	Reciprocal Deposits ReciprocalDeposits	13300000000	usd
CY2024Q3	wal	Deposits Earnings Credit DepositsEarningsCredit	26100000000	usd
CY2023Q4	wal	Deposits Earnings Credit DepositsEarningsCredit	17800000000	usd
CY2024Q3	wal	Depositscostsdepositswithearningscredits Depositscostsdepositswithearningscredits	201700000	usd
CY2023Q3	wal	Depositscostsdepositswithearningscredits Depositscostsdepositswithearningscredits	123700000	usd
	wal	Depositscostsdepositswithearningscredits Depositscostsdepositswithearningscredits	500400000	usd
	wal	Depositscostsdepositswithearningscredits Depositscostsdepositswithearningscredits	297100000	usd
CY2024Q3	us-gaap	Federal Funds Purchased FederalFundsPurchased	0	usd
CY2023Q4	us-gaap	Federal Funds Purchased FederalFundsPurchased	175000000	usd
CY2024Q3	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	1500000000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	6200000000	usd
CY2024Q3	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	5000000	usd
CY2023Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	382000000	usd
CY2024Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	1567000000	usd
CY2023Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	6784000000	usd
CY2024Q3	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1000000000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	0	usd
CY2024Q3	us-gaap	Notes Payable NotesPayable	428000000	usd
CY2023Q4	us-gaap	Notes Payable NotesPayable	446000000	usd
CY2024Q3	us-gaap	Long Term Debt LongTermDebt	1428000000	usd
CY2023Q4	us-gaap	Long Term Debt LongTermDebt	446000000	usd
CY2024Q3	us-gaap	Other Borrowings OtherBorrowings	2995000000	usd
CY2023Q4	us-gaap	Other Borrowings OtherBorrowings	7230000000	usd
CY2024Q3	us-gaap	Federal Home Loan Bank Advances Weighted Average Interest Rate Maturing In Next Twelve Rolling Months FederalHomeLoanBankAdvancesWeightedAverageInterestRateMaturingInNextTwelveRollingMonths	0.0521
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Weighted Average Interest Rate Maturing In Next Twelve Rolling Months FederalHomeLoanBankAdvancesWeightedAverageInterestRateMaturingInNextTwelveRollingMonths	0.0567
CY2024Q3	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1000000000.0	usd
CY2024Q3	us-gaap	Federal Home Loan Bank Advances Weighted Average Interest Rate FederalHomeLoanBankAdvancesWeightedAverageInterestRate	0.0531
	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	13400000	usd
CY2024Q3	us-gaap	Subordinated Long Term Debt SubordinatedLongTermDebt	819000000	usd
CY2023Q4	us-gaap	Subordinated Long Term Debt SubordinatedLongTermDebt	818000000	usd
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CY2024Q3	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	79000000	usd
CY2023Q4	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	77000000	usd
	us-gaap	Preferred Stock Dividend Rate Percentage PreferredStockDividendRatePercentage	0.04250
CY2024Q3	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.0001
CY2024Q3	us-gaap	Preferred Stock Liquidation Preference PreferredStockLiquidationPreference	25
	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0.27
CY2024Q3	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0.27
	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0.27
CY2023Q3	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0.27
CY2024Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.37
CY2024Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.37
CY2024Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.37
CY2023Q2	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.36
CY2023Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.36
CY2023Q1	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.36
CY2024Q3	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	1042	shares
	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	141525	shares
CY2024Q3	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	75.27
	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	61.34
CY2023Q3	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	139	shares
	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	151358	shares
CY2023Q3	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	48.56
	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	72.47
CY2024Q3	us-gaap	Hedged Asset Fair Value Hedge HedgedAssetFairValueHedge	4836000000	usd
CY2024Q3	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	38000000	usd
CY2023Q4	us-gaap	Hedged Asset Fair Value Hedge HedgedAssetFairValueHedge	3875000000	usd
CY2023Q4	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	6000000	usd
CY2024Q3	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	33702000000	usd
CY2024Q3	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Asset At Fair Value DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue	363000000	usd
CY2024Q3	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Liability At Fair Value DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue	65000000	usd
CY2023Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	29912000000	usd
CY2023Q4	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Asset At Fair Value DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue	271000000	usd
CY2023Q4	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Liability At Fair Value DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue	67000000	usd
CY2023Q3	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	28604000000	usd
CY2023Q3	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Asset At Fair Value DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAssetAtFairValue	137000000	usd
CY2023Q3	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Liability At Fair Value DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsLiabilityAtFairValue	72000000	usd
CY2024Q3	wal	Derivative Asset Subject To Master Netting Arrangement Collateral Obligation To Return Cash Offset Against Derivative Asset Net Of Adjustments DerivativeAssetSubjectToMasterNettingArrangementCollateralObligationToReturnCashOffsetAgainstDerivativeAssetNetOfAdjustments	-280000000	usd
CY2024Q3	wal	Derivative Asset Subject To Master Netting Arrangement Collateral Obligation To Return Cash Offset Against Derivative Asset Net Of Adjustments DerivativeAssetSubjectToMasterNettingArrangementCollateralObligationToReturnCashOffsetAgainstDerivativeAssetNetOfAdjustments	-280000000	usd
CY2023Q4	wal	Derivative Asset Subject To Master Netting Arrangement Collateral Obligation To Return Cash Offset Against Derivative Asset Net Of Adjustments DerivativeAssetSubjectToMasterNettingArrangementCollateralObligationToReturnCashOffsetAgainstDerivativeAssetNetOfAdjustments	-202000000	usd
CY2023Q4	wal	Derivative Asset Subject To Master Netting Arrangement Collateral Obligation To Return Cash Offset Against Derivative Asset Net Of Adjustments DerivativeAssetSubjectToMasterNettingArrangementCollateralObligationToReturnCashOffsetAgainstDerivativeAssetNetOfAdjustments	-202000000	usd
CY2023Q3	wal	Derivative Asset Subject To Master Netting Arrangement Collateral Obligation To Return Cash Offset Against Derivative Asset Net Of Adjustments DerivativeAssetSubjectToMasterNettingArrangementCollateralObligationToReturnCashOffsetAgainstDerivativeAssetNetOfAdjustments	-66000000	usd
CY2023Q3	wal	Derivative Asset Subject To Master Netting Arrangement Collateral Obligation To Return Cash Offset Against Derivative Asset Net Of Adjustments DerivativeAssetSubjectToMasterNettingArrangementCollateralObligationToReturnCashOffsetAgainstDerivativeAssetNetOfAdjustments	-66000000	usd
CY2024Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	94000000	usd
CY2024Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	94000000	usd
CY2023Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	67000000	usd
CY2023Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	67000000	usd
CY2023Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	43000000	usd
CY2024Q3	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	319000000	usd
CY2024Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	94000000	usd
CY2024Q3	us-gaap	Derivative Asset After Offset Subject To Master Netting Arrangement DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement	225000000	usd
CY2023Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	260000000	usd
CY2023Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	67000000	usd
CY2023Q4	us-gaap	Derivative Asset After Offset Subject To Master Netting Arrangement DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement	193000000	usd
CY2023Q3	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	257000000	usd
CY2023Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	43000000	usd
CY2023Q3	us-gaap	Derivative Asset After Offset Subject To Master Netting Arrangement DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement	214000000	usd
CY2024Q3	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	-4000000	usd
CY2024Q3	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	-4000000	usd
CY2023Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	-9000000	usd
CY2023Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	-9000000	usd
CY2023Q3	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	25000000	usd
CY2023Q3	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	25000000	usd
CY2024Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	94000000	usd
CY2024Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	94000000	usd
CY2023Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	67000000	usd
CY2023Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	67000000	usd
CY2023Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	43000000	usd
CY2023Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	43000000	usd
CY2024Q3	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	103000000	usd
CY2024Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	94000000	usd
CY2024Q3	us-gaap	Derivative Liability After Offset Subject To Master Netting Arrangement DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement	9000000	usd
CY2023Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	78000000	usd
CY2023Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	67000000	usd
CY2023Q4	us-gaap	Derivative Liability After Offset Subject To Master Netting Arrangement DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement	11000000	usd
CY2023Q3	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	46000000	usd
CY2023Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	43000000	usd
CY2023Q3	us-gaap	Derivative Liability After Offset Subject To Master Netting Arrangement DerivativeLiabilityAfterOffsetSubjectToMasterNettingArrangement	3000000	usd
CY2024Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	58000000	usd
CY2024Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	58000000	usd
CY2023Q4	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	30000000	usd
CY2023Q4	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	30000000	usd
CY2023Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	8000000	usd
CY2023Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	8000000	usd
CY2024Q3	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	13000000	usd
CY2024Q3	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	13000000	usd
CY2023Q4	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	13000000	usd
CY2023Q4	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	13000000	usd
CY2023Q3	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	26000000	usd
CY2023Q3	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	26000000	usd
CY2024Q3	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	377000000	usd
CY2024Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	94000000	usd
CY2024Q3	us-gaap	Derivative Asset Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	283000000	usd
CY2023Q4	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	290000000	usd
CY2023Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	67000000	usd
CY2023Q4	us-gaap	Derivative Asset Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	223000000	usd
CY2023Q3	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	265000000	usd
CY2023Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	43000000	usd
CY2023Q3	us-gaap	Derivative Asset Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	222000000	usd
CY2024Q3	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	116000000	usd
CY2024Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	94000000	usd
CY2024Q3	us-gaap	Derivative Liability Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	22000000	usd
CY2023Q4	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	91000000	usd
CY2023Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	67000000	usd
CY2023Q4	us-gaap	Derivative Liability Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	24000000	usd
CY2023Q3	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	72000000	usd
CY2023Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	43000000	usd
CY2023Q3	us-gaap	Derivative Liability Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	29000000	usd
CY2024Q3	us-gaap	Collateral Already Posted Aggregate Fair Value CollateralAlreadyPostedAggregateFairValue	292000000	usd
CY2023Q4	us-gaap	Collateral Already Posted Aggregate Fair Value CollateralAlreadyPostedAggregateFairValue	216000000	usd
CY2023Q3	us-gaap	Collateral Already Posted Aggregate Fair Value CollateralAlreadyPostedAggregateFairValue	72000000	usd
CY2024Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	108700000	shares
CY2023Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	108300000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	108600000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	108300000	shares
CY2024Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	800000	shares
CY2023Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	200000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	600000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	100000	shares
CY2024Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	109500000	shares
CY2023Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	108500000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	109200000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	108400000	shares
CY2024Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	196600000	usd
CY2023Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	213400000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	561200000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	564900000	usd
CY2024Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.81
CY2023Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.97
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.17
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.22
CY2024Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.80
CY2023Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.97
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.14
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.21
CY2024Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.207
CY2023Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.221
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.220
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.205
CY2024Q3	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	254000000	usd
	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	-33000000	usd
CY2023Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	287000000	usd
CY2024Q3	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	254000000	usd
CY2024Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	usd
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	usd
CY2024Q3	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	560000000	usd
CY2023Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	573000000	usd
CY2024Q3	us-gaap	Investment Related Liabilities InvestmentRelatedLiabilities	305000000	usd
CY2023Q4	us-gaap	Investment Related Liabilities InvestmentRelatedLiabilities	322000000	usd
CY2024Q3	us-gaap	Investment Program Proportional Amortization Method Elected Income Tax Credit InvestmentProgramProportionalAmortizationMethodElectedIncomeTaxCredit	21000000.0	usd
CY2023Q3	us-gaap	Investment Program Proportional Amortization Method Elected Income Tax Credit InvestmentProgramProportionalAmortizationMethodElectedIncomeTaxCredit	25600000	usd
	us-gaap	Investment Program Proportional Amortization Method Elected Income Tax Credit InvestmentProgramProportionalAmortizationMethodElectedIncomeTaxCredit	59700000	usd
	us-gaap	Investment Program Proportional Amortization Method Elected Income Tax Credit InvestmentProgramProportionalAmortizationMethodElectedIncomeTaxCredit	65900000	usd
CY2024Q3	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	19600000	usd
CY2023Q3	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	27900000	usd
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	55300000	usd
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	66900000	usd
	us-gaap	Line Of Credit Facility Expiration Period LineOfCreditFacilityExpirationPeriod	P1Y
CY2024Q3	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Face Amount Liability FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability	14083000000	usd
CY2023Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Face Amount Liability FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability	13931000000	usd
CY2024Q3	us-gaap	Other Commitment OtherCommitment	20000000	usd
CY2023Q4	us-gaap	Other Commitment OtherCommitment	32000000	usd
CY2024Q3	wal	Percentage Of Commercial Real Estate Loans Occupied By Owners PercentageOfCommercialRealEstateLoansOccupiedByOwners	0.16
CY2023Q4	wal	Percentage Of Commercial Real Estate Loans Occupied By Owners PercentageOfCommercialRealEstateLoansOccupiedByOwners	0.16
CY2024Q3	us-gaap	Lease Cost LeaseCost	7100000	usd
	us-gaap	Lease Cost LeaseCost	21200000	usd
CY2023Q3	us-gaap	Lease Cost LeaseCost	7000000.0	usd
	us-gaap	Lease Cost LeaseCost	21500000	usd
CY2024Q3	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	1700000	usd
	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	4800000	usd
CY2023Q3	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	1500000	usd
	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	4000000.0	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-300000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-1200000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-1300000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	2700000	usd
CY2024Q3	us-gaap	Fair Value Liabilities Measured On Recurring Basis Subordinated Debt Obligations FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations	65000000	usd
CY2024Q3	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	38000000	usd
CY2023Q4	us-gaap	Fair Value Liabilities Measured On Recurring Basis Subordinated Debt Obligations FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations	63000000	usd
CY2023Q4	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	6000000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-300000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-1200000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-1300000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	2700000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Other Changes That Affect Balance ServicingAssetAtFairValueOtherChangesThatAffectBalance	0	usd
	us-gaap	Servicing Asset At Fair Value Other Changes That Affect Balance ServicingAssetAtFairValueOtherChangesThatAffectBalance	4000000	usd
CY2024Q3	wal	Fair Value Option Loans Held As Assets Current Through89 Days FairValueOptionLoansHeldAsAssetsCurrentThrough89Days	2292000000	usd
CY2024Q3	wal	Fair Value Option Loans Held As Assets Upb Current Through89 Days FairValueOptionLoansHeldAsAssetsUPBCurrentThrough89Days	2210000000	usd
CY2024Q3	wal	Fair Value Option Loans Held As Assets Current Through89 Days Aggregate Difference FairValueOptionLoansHeldAsAssetsCurrentThrough89DaysAggregateDifference	82000000	usd
CY2023Q4	wal	Fair Value Option Loans Held As Assets Current Through89 Days FairValueOptionLoansHeldAsAssetsCurrentThrough89Days	1379000000	usd
CY2023Q4	wal	Fair Value Option Loans Held As Assets Upb Current Through89 Days FairValueOptionLoansHeldAsAssetsUPBCurrentThrough89Days	1319000000	usd
CY2023Q4	wal	Fair Value Option Loans Held As Assets Current Through89 Days Aggregate Difference FairValueOptionLoansHeldAsAssetsCurrentThrough89DaysAggregateDifference	60000000	usd
CY2024Q3	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due FairValueOptionLoansHeldAsAssets90DaysOrMorePastDue	0	usd
CY2024Q3	wal	Fair Value Option Loans Held As Assets Upb90 Days Or More Past Due FairValueOptionLoansHeldAsAssetsUPB90DaysOrMorePastDue	0	usd
CY2024Q3	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due Aggregate Difference FairValueOptionLoansHeldAsAssets90DaysOrMorePastDueAggregateDifference	0	usd
CY2023Q4	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due FairValueOptionLoansHeldAsAssets90DaysOrMorePastDue	1000000	usd
CY2023Q4	wal	Fair Value Option Loans Held As Assets Upb90 Days Or More Past Due FairValueOptionLoansHeldAsAssetsUPB90DaysOrMorePastDue	2000000	usd
CY2023Q4	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due Aggregate Difference FairValueOptionLoansHeldAsAssets90DaysOrMorePastDueAggregateDifference	-1000000	usd
CY2024Q3	wal	Fair Value Option Loans Held As Assets FairValueOptionLoansHeldAsAssets	2292000000	usd
CY2024Q3	wal	Fair Value Option Loans Held As Assets Upb FairValueOptionLoansHeldAsAssetsUPB	2210000000	usd
CY2024Q3	us-gaap	Fair Value Option Loans Held As Assets Aggregate Difference FairValueOptionLoansHeldAsAssetsAggregateDifference	82000000	usd
CY2023Q4	wal	Fair Value Option Loans Held As Assets FairValueOptionLoansHeldAsAssets	1380000000	usd
CY2023Q4	wal	Fair Value Option Loans Held As Assets Upb FairValueOptionLoansHeldAsAssetsUPB	1321000000	usd
CY2023Q4	us-gaap	Fair Value Option Loans Held As Assets Aggregate Difference FairValueOptionLoansHeldAsAssetsAggregateDifference	59000000	usd
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	reportable_business_segments
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CY2024Q3	wal	Cash Cash Equivalentsand Investment Securities CashCashEquivalentsandInvestmentSecurities	18974000000	usd
CY2024Q3	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	2327000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	53346000000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	357000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	52989000000	usd
CY2024Q3	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	661000000	usd
CY2024Q3	wal	Other Assets Segment OtherAssetsSegment	5129000000	usd
CY2024Q3	us-gaap	Assets Assets	80080000000	usd
CY2024Q3	us-gaap	Deposits Deposits	68040000000	usd
CY2024Q3	wal	Borrowingsand Qualifying Debt BorrowingsandQualifyingDebt	3893000000	usd
CY2024Q3	wal	Other Liabilities Segment OtherLiabilitiesSegment	1470000000	usd
CY2024Q3	us-gaap	Liabilities Liabilities	73403000000	usd
CY2024Q3	us-gaap	Stockholders Equity StockholdersEquity	6677000000	usd
CY2024Q3	wal	Liabilities And Equity Excluding Excess Funds Provided Used LiabilitiesAndEquityExcludingExcessFundsProvidedUsed	80080000000	usd
CY2024Q3	wal	Excess Funds Providedby Usedin Segment Basis ExcessFundsProvidedbyUsedinSegmentBasis	0	usd
CY2024Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	696900000	usd
CY2024Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	33600000	usd
CY2024Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	663300000	usd
CY2024Q3	us-gaap	Noninterest Income NoninterestIncome	126200000	usd
CY2024Q3	us-gaap	Noninterest Expense NoninterestExpense	537400000	usd
CY2024Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	252100000	usd
CY2024Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	52300000	usd
CY2024Q3	us-gaap	Net Income Loss NetIncomeLoss	199800000	usd
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1952400000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	85900000	usd
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	1866500000	usd
	us-gaap	Noninterest Income NoninterestIncome	371300000	usd
	us-gaap	Noninterest Expense NoninterestExpense	1506000000	usd
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	731800000	usd
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	161000000.0	usd
	us-gaap	Net Income Loss NetIncomeLoss	570800000	usd
CY2023Q4	wal	Cash Cash Equivalentsand Investment Securities CashCashEquivalentsandInvestmentSecurities	14288000000	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	1402000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	50297000000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	337000000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	49960000000	usd
CY2023Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	669000000	usd
CY2023Q4	wal	Other Assets Segment OtherAssetsSegment	4543000000	usd
CY2023Q4	us-gaap	Assets Assets	70862000000	usd
CY2023Q4	us-gaap	Deposits Deposits	55333000000	usd
CY2023Q4	wal	Borrowingsand Qualifying Debt BorrowingsandQualifyingDebt	8125000000	usd
CY2023Q4	wal	Other Liabilities Segment OtherLiabilitiesSegment	1326000000	usd
CY2023Q4	us-gaap	Liabilities Liabilities	64784000000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	6078000000	usd
CY2023Q4	wal	Liabilities And Equity Excluding Excess Funds Provided Used LiabilitiesAndEquityExcludingExcessFundsProvidedUsed	70862000000	usd
CY2023Q4	wal	Excess Funds Providedby Usedin Segment Basis ExcessFundsProvidedbyUsedinSegmentBasis	0	usd
CY2023Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	587000000.0	usd
CY2023Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	12100000	usd
CY2023Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	574900000	usd
CY2023Q3	us-gaap	Noninterest Income NoninterestIncome	129200000	usd
CY2023Q3	us-gaap	Noninterest Expense NoninterestExpense	426200000	usd
CY2023Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	277900000	usd
CY2023Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	61300000	usd
CY2023Q3	us-gaap	Net Income Loss NetIncomeLoss	216600000	usd
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1747200000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	53300000	usd
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	1693900000	usd
	us-gaap	Noninterest Income NoninterestIncome	190200000	usd
	us-gaap	Noninterest Expense NoninterestExpense	1161500000	usd
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	722600000	usd
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	148100000	usd
	us-gaap	Net Income Loss NetIncomeLoss	574500000	usd
CY2024Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	15200000	usd
CY2023Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	29600000	usd
CY2024Q3	ecd	Non Rule10b51 Arr Adopted Flag NonRule10b51ArrAdoptedFlag	false
CY2024Q3	ecd	Rule10b51 Arr Trmntd Flag Rule10b51ArrTrmntdFlag	false
CY2024Q3	ecd	Non Rule10b51 Arr Trmntd Flag NonRule10b51ArrTrmntdFlag	false
CY2024Q3	ecd	Rule10b51 Arr Adopted Flag Rule10b51ArrAdoptedFlag	false

Files In Submission

Name	View Source	Status
0001212545-24-000293-index-headers.html	Edgar Link	pending
0001212545-24-000293-index.html	Edgar Link	pending
0001212545-24-000293.txt	Edgar Link	pending
0001212545-24-000293-xbrl.zip	Edgar Link	pending
Financial_Report.xlsx	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
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wal-20240930.htm	Edgar Link	pending
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walex3119302024.htm	Edgar Link	pending
walex3129302024.htm	Edgar Link	pending
walex329302024.htm	Edgar Link	pending
wal-20240930_htm.xml	Edgar Link	completed
wal-20240930_def.xml	Edgar Link	unprocessable
wal-20240930_lab.xml	Edgar Link	unprocessable
wal-20240930_pre.xml	Edgar Link	unprocessable
wal-20240930_cal.xml	Edgar Link	unprocessable

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$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal

2024 Q4 Form 10-Q Financial Statement

#000121254524000293 Filed on October 31, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WAL WESTERN ALLIANCE BANCORPORATION Stock $wal

2024 Q4 Form 10-Q Financial Statement

#000121254524000293 Filed on October 31, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal