$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal

$wal Overview Financials Valuation SEC Filings Company Website

2021 Q4 Form 10-Q Financial Statement

#000121254521000170 Filed on November 03, 2021

Income Statement

Concept	2021 Q4	2021 Q3	2020 Q4
Revenue		$442.8M	$331.6M
YoY Change		45.28%	5.14%
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	$8.100M	$10.60M	$5.800M
YoY Change	39.66%	39.47%	16.0%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense		$32.40M	$16.80M
YoY Change		61.19%	-61.29%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$310.0M	$302.4M	$240.6M
YoY Change	28.84%	81.51%	55.93%
Income Tax	$64.00M	$65.50M	$47.00M
% Of Pretax Income	20.65%	21.66%	19.53%
Net Earnings	$246.0M	$236.9M	$193.6M
YoY Change	27.07%	74.45%	51.13%
Net Earnings / Revenue		53.5%	58.38%
Basic Earnings Per Share		$2.29	$1.94
Diluted Earnings Per Share	$2.354M	$2.28	$1.93
COMMON SHARES
Basic Shares Outstanding	104.2M shares	103.3M shares	100.8M shares
Diluted Shares Outstanding		103.9M shares

Balance Sheet

Concept	2021 Q4	2021 Q3	2020 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$516.4M	$917.9M	$2.672B
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	$182.0M	$161.2M	$134.1M
YoY Change	35.72%	25.69%	6.6%
Goodwill	$491.3M		$289.9M
YoY Change	69.47%		0.0%
Intangibles
YoY Change
Long-Term Investments	$159.0M	$178.0M	$167.0M
YoY Change	-4.79%	10.56%	20.14%
Other Assets	$21.00M	$11.00M	$31.00M
YoY Change	-32.26%	-76.6%	72.22%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$55.98B	$52.78B	$36.46B
YoY Change	53.54%	58.32%	35.94%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$143.0M	$115.0M	$80.00M
YoY Change	78.75%	45.57%	2.56%
Deferred Revenue
YoY Change
Short-Term Debt	$727.0M	$445.9M	$21.00M
YoY Change	3361.9%	4359.0%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$143.0M	$115.0M	$80.00M
YoY Change	78.75%	45.57%	2.56%
LONG-TERM LIABILITIES
Long-Term Debt	$1.671B	$1.623B	$549.0M
YoY Change	204.37%	158.03%	39.34%
Other Long-Term Liabilities	$868.0M	$795.0M	$467.0M
YoY Change	85.87%	46.95%	-10.19%
Total Long-Term Liabilities	$2.539B	$2.418B	$1.016B
YoY Change	149.9%	106.67%	11.16%
TOTAL LIABILITIES
Total Short-Term Liabilities	$143.0M	$115.0M	$80.00M
Total Long-Term Liabilities	$2.539B	$2.418B	$1.016B
Total Liabilities	$51.02B	$48.26B	$33.05B
YoY Change	54.38%	60.27%	38.82%
SHAREHOLDERS EQUITY
Retained Earnings	$2.773B	$2.567B	$2.001B
YoY Change	38.55%	40.04%	19.11%
Common Stock	$1.966B	$1.696B	$1.391B
YoY Change	41.35%	16957900.0%	13908900.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$87.00M	$85.90M	$71.10M
YoY Change	22.36%	20.82%	13.4%
Treasury Stock Shares	2.350M shares	2.343M shares	2.169M shares
Shareholders Equity	$4.963B	$4.514B	$3.414B
YoY Change
Total Liabilities & Shareholders Equity	$55.98B	$52.78B	$36.46B
YoY Change	53.54%	58.32%	35.94%

Cashflow Statement

Concept	2021 Q4	2021 Q3	2020 Q4
OPERATING ACTIVITIES
Net Income	$246.0M	$236.9M	$193.6M
YoY Change	27.07%	74.45%	51.13%
Depreciation, Depletion And Amortization	$8.100M	$10.60M	$5.800M
YoY Change	39.66%	39.47%	16.0%
Cash From Operating Activities	$615.0M	-$1.308B	$220.1M
YoY Change	179.42%	-884.52%	20.08%
INVESTING ACTIVITIES
Capital Expenditures	-$37.60M	-$18.20M	$6.300M
YoY Change	-696.83%	35.82%	-131.82%
Acquisitions
YoY Change
Other Investing Activities	-$4.006B	-$5.266B	-$1.952B
YoY Change	105.25%	246.37%	110.33%
Cash From Investing Activities	-$4.044B	-$5.284B	-$1.946B
YoY Change	107.85%	244.53%	105.28%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	3.027B	4.114B	2.978B
YoY Change	1.65%	224.63%	810.55%
NET CHANGE
Cash From Operating Activities	615.0M	-1.308B	220.1M
Cash From Investing Activities	-4.044B	-5.284B	-1.946B
Cash From Financing Activities	3.027B	4.114B	2.978B
Net Change In Cash	-401.5M	-2.478B	1.253B
YoY Change	-132.05%	2385.36%	-386.44%
FREE CASH FLOW
Cash From Operating Activities	$615.0M	-$1.308B	$220.1M
Capital Expenditures	-$37.60M	-$18.20M	$6.300M
Free Cash Flow	$652.6M	-$1.290B	$213.8M
YoY Change	205.24%	-816.05%	5.27%

Facts In Submission

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	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q3
	dei	Amendment Flag AmendmentFlag	false
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
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	dei	Document Period End Date DocumentPeriodEndDate	2021-09-30
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	dei	Entity File Number EntityFileNumber	001-32550
	dei	Entity Registrant Name EntityRegistrantName	WESTERN ALLIANCE BANCORPORATION
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	88-0365922
	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
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	dei	City Area Code CityAreaCode	602
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	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	1132800000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	694300000	USD
CY2021Q3	wal	Net Gain On Loan Origination And Sale Activities NetGainOnLoanOriginationAndSaleActivities	121000000.0	USD
CY2020Q3	wal	Net Gain On Loan Origination And Sale Activities NetGainOnLoanOriginationAndSaleActivities	0	USD
	wal	Net Gain On Loan Origination And Sale Activities NetGainOnLoanOriginationAndSaleActivities	253000000.0	USD
	wal	Net Gain On Loan Origination And Sale Activities NetGainOnLoanOriginationAndSaleActivities	0	USD
CY2021Q3	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	7100000	USD
CY2020Q3	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	5900000	USD
	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	21200000	USD
	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	17400000	USD
CY2021Q3	wal	Commercial Banking Related Income CommercialBankingRelatedIncome	4600000	USD
CY2020Q3	wal	Commercial Banking Related Income CommercialBankingRelatedIncome	4500000	USD
	wal	Commercial Banking Related Income CommercialBankingRelatedIncome	12500000	USD
	wal	Commercial Banking Related Income CommercialBankingRelatedIncome	10700000	USD
CY2021Q3	wal	Incomefrom Equity Investments IncomefromEquityInvestments	2500000	USD
CY2020Q3	wal	Incomefrom Equity Investments IncomefromEquityInvestments	1200000	USD
	wal	Incomefrom Equity Investments IncomefromEquityInvestments	16900000	USD
	wal	Incomefrom Equity Investments IncomefromEquityInvestments	6300000	USD
CY2021Q3	wal	Loan Servicing Fees Net LoanServicingFeesNet	2200000	USD
CY2020Q3	wal	Loan Servicing Fees Net LoanServicingFeesNet	0	USD
	wal	Loan Servicing Fees Net LoanServicingFeesNet	-18600000	USD
	wal	Loan Servicing Fees Net LoanServicingFeesNet	0	USD
CY2021Q3	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet	1900000	USD
CY2020Q3	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet	1800000	USD
	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet	5600000	USD
	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet	4300000	USD
CY2021Q3	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1000000.0	USD
CY2020Q3	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	1300000	USD
	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	2900000	USD
	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	9000000.0	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-2200000	USD
CY2020Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	5900000	USD
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-500000	USD
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-1000000.0	USD
CY2021Q3	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	0	USD
CY2020Q3	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	0	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	800000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	300000	USD
CY2021Q3	us-gaap	Noninterest Income NoninterestIncome	138100000	USD
CY2020Q3	us-gaap	Noninterest Income NoninterestIncome	20600000	USD
	us-gaap	Noninterest Income NoninterestIncome	293800000	USD
	us-gaap	Noninterest Income NoninterestIncome	47000000.0	USD
CY2021Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	133500000	USD
CY2020Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	78800000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	346100000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	220500000	USD
CY2021Q3	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	15600000	USD
CY2020Q3	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	0	USD
	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	37900000	USD
	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	0	USD
CY2021Q3	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	15400000	USD
CY2020Q3	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	8900000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	40300000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	26100000	USD
CY2021Q3	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	13700000	USD
CY2020Q3	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	10000000.0	USD
	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	37800000	USD
	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	31100000	USD
CY2021Q3	us-gaap	Occupancy Net OccupancyNet	12400000	USD
CY2020Q3	us-gaap	Occupancy Net OccupancyNet	9400000	USD
	us-gaap	Occupancy Net OccupancyNet	31400000	USD
	us-gaap	Occupancy Net OccupancyNet	25700000	USD
CY2021Q3	us-gaap	Loan Processing Fee LoanProcessingFee	9700000	USD
CY2020Q3	us-gaap	Loan Processing Fee LoanProcessingFee	0	USD
	us-gaap	Loan Processing Fee LoanProcessingFee	20200000	USD
	us-gaap	Loan Processing Fee LoanProcessingFee	0	USD
CY2021Q3	wal	Non Interest Expense Deposit Costs NonInterestExpenseDepositCosts	7300000	USD
CY2020Q3	wal	Non Interest Expense Deposit Costs NonInterestExpenseDepositCosts	3200000	USD
	wal	Non Interest Expense Deposit Costs NonInterestExpenseDepositCosts	20700000	USD
	wal	Non Interest Expense Deposit Costs NonInterestExpenseDepositCosts	14000000.0	USD
CY2021Q3	us-gaap	General Insurance Expense GeneralInsuranceExpense	6200000	USD
CY2020Q3	us-gaap	General Insurance Expense GeneralInsuranceExpense	3100000	USD
	us-gaap	General Insurance Expense GeneralInsuranceExpense	15900000	USD
	us-gaap	General Insurance Expense GeneralInsuranceExpense	9500000	USD
CY2021Q3	wal	Loan And Repossessed Asset Expense LoanAndRepossessedAssetExpense	2500000	USD
CY2020Q3	wal	Loan And Repossessed Asset Expense LoanAndRepossessedAssetExpense	1800000	USD
	wal	Loan And Repossessed Asset Expense LoanAndRepossessedAssetExpense	7200000	USD
	wal	Loan And Repossessed Asset Expense LoanAndRepossessedAssetExpense	5300000	USD
CY2021Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1900000	USD
CY2020Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	400000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	4200000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1200000	USD
CY2021Q3	us-gaap	Business Development BusinessDevelopment	1900000	USD
CY2020Q3	us-gaap	Business Development BusinessDevelopment	1000000.0	USD
	us-gaap	Business Development BusinessDevelopment	4200000	USD
	us-gaap	Business Development BusinessDevelopment	4100000	USD
CY2021Q3	us-gaap	Marketing Expense MarketingExpense	900000	USD
CY2020Q3	us-gaap	Marketing Expense MarketingExpense	800000	USD
	us-gaap	Marketing Expense MarketingExpense	3200000	USD
	us-gaap	Marketing Expense MarketingExpense	2600000	USD
CY2021Q3	wal	Cardexpense Cardexpense	600000	USD
CY2020Q3	wal	Cardexpense Cardexpense	500000	USD
	wal	Cardexpense Cardexpense	1800000	USD
	wal	Cardexpense Cardexpense	1600000	USD
CY2021Q3	wal	Net Loss Gain On Sales Valuations Of Repossessed Assets And Bank Premises Net NetLossGainOnSalesValuationsOfRepossessedAssetsAndBankPremisesNet	-1300000	USD
CY2020Q3	wal	Net Loss Gain On Sales Valuations Of Repossessed Assets And Bank Premises Net NetLossGainOnSalesValuationsOfRepossessedAssetsAndBankPremisesNet	100000	USD
	wal	Net Loss Gain On Sales Valuations Of Repossessed Assets And Bank Premises Net NetLossGainOnSalesValuationsOfRepossessedAssetsAndBankPremisesNet	-3100000	USD
	wal	Net Loss Gain On Sales Valuations Of Repossessed Assets And Bank Premises Net NetLossGainOnSalesValuationsOfRepossessedAssetsAndBankPremisesNet	-1300000	USD
CY2021Q3	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	2400000	USD
CY2020Q3	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	0	USD
	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	18500000	USD
	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	0	USD
CY2021Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	11100000	USD
CY2020Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	6100000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	27300000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	19000000.0	USD
CY2021Q3	us-gaap	Noninterest Expense NoninterestExpense	233800000	USD
CY2020Q3	us-gaap	Noninterest Expense NoninterestExpense	124100000	USD
	us-gaap	Noninterest Expense NoninterestExpense	613600000	USD
	us-gaap	Noninterest Expense NoninterestExpense	359400000	USD
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	302400000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	166600000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	813000000.0	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	381900000	USD
CY2021Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	65500000	USD
CY2020Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30800000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	159800000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	68900000	USD
CY2021Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	236900000	USD
CY2020Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	135800000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	653200000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	313000000.0	USD
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.29
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.36
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.39
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.12
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.28
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.36
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.35
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.11
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	103300000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	99900000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	102300000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	100300000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	103900000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	100100000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	102900000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	100600000	shares
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.35
CY2020Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.25
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.85
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.75
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	236900000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	135800000	USD
	us-gaap	Net Income Loss NetIncomeLoss	653200000	USD
	us-gaap	Net Income Loss NetIncomeLoss	313000000.0	USD
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-7100000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	2500000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-16000000.0	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	17300000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-21800000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	7600000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-49000000.0	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	53200000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	0.0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	0.0	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	0.0	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	100000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	0	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	0	USD
	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	300000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	100000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	-900000	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	-200000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	53600000	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	-300000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	100000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-2700000	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-600000	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-900000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0.0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0.0	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0.0	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	100000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	0	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	100000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	200000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-21900000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	4900000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-49700000	USD
CY2021Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	215000000.0	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	140700000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	603500000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	366600000	USD
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	3102400000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	135800000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	6700000	USD
CY2020Q3	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	500000	USD
CY2020Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	25300000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	4900000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	3224000000	USD
CY2021Q2	us-gaap	Stockholders Equity StockholdersEquity	4034500000	USD
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	236900000	USD
CY2021Q3	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	8200000	USD
CY2021Q3	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	1700000	USD
CY2021Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	36500000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-21900000	USD
CY2021Q3	us-gaap	Stockholders Equity StockholdersEquity	4514000000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	3016700000	USD
CY2020Q1	us-gaap	Stockholders Equity StockholdersEquity	2991800000	USD
	us-gaap	Net Income Loss NetIncomeLoss	313000000.0	USD
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	21700000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	8400000	USD
	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	71600000	USD
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	76100000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	53600000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	3224000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	3413500000	USD
	us-gaap	Net Income Loss NetIncomeLoss	653200000	USD
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	25900000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	14800000	USD
	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	279000000.0	USD
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	87600000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-49700000	USD
CY2021Q3	us-gaap	Stockholders Equity StockholdersEquity	4514000000	USD
	us-gaap	Net Income Loss NetIncomeLoss	653200000	USD
	us-gaap	Net Income Loss NetIncomeLoss	313000000.0	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	34600000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	157800000	USD
	us-gaap	Depreciation And Amortization DepreciationAndAmortization	25600000	USD
	us-gaap	Depreciation And Amortization DepreciationAndAmortization	17100000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	25600000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	21600000	USD
	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	43600000	USD
	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	-37400000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-30800000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-19000000.0	USD
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	36600000	USD
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	34200000	USD
	us-gaap	Operating Lease Expense OperatingLeaseExpense	11500000	USD
	us-gaap	Operating Lease Expense OperatingLeaseExpense	8900000	USD
	us-gaap	Amortization Of Deferred Loan Origination Fees Net AmortizationOfDeferredLoanOriginationFeesNet	53200000	USD
	us-gaap	Amortization Of Deferred Loan Origination Fees Net AmortizationOfDeferredLoanOriginationFeesNet	34100000	USD
	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	2900000	USD
	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	3400000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	41336400000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	0	USD
	us-gaap	Proceeds From Sale And Collection Of Loans Heldforsale ProceedsFromSaleAndCollectionOfLoansHeldforsale	37810500000	USD
	us-gaap	Proceeds From Sale And Collection Of Loans Heldforsale ProceedsFromSaleAndCollectionOfLoansHeldforsale	0	USD
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	512700000	USD
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	0	USD
	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	-5200000	USD
	us-gaap	Increase Decrease In Loans Held For Sale IncreaseDecreaseInLoansHeldForSale	0	USD
	us-gaap	Servicing Asset At Fair Value Period Increase Decrease ServicingAssetAtFairValuePeriodIncreaseDecrease	-85200000	USD
	us-gaap	Servicing Asset At Fair Value Period Increase Decrease ServicingAssetAtFairValuePeriodIncreaseDecrease	0	USD
	us-gaap	Increase Decrease In Derivative Assets And Liabilities IncreaseDecreaseInDerivativeAssetsAndLiabilities	40900000	USD
	us-gaap	Increase Decrease In Derivative Assets And Liabilities IncreaseDecreaseInDerivativeAssetsAndLiabilities	0	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	16900000	USD
	wal	Paymentsto Acquire Securities Equity PaymentstoAcquireSecuritiesEquity	36100000	USD
	wal	Gain Loss On Sale And Valuation Of Investment Securities And Other Assets Net GainLossOnSaleAndValuationOfInvestmentSecuritiesAndOtherAssetsNet	-5300000	USD
	wal	Gain Loss On Sale And Valuation Of Investment Securities And Other Assets Net GainLossOnSaleAndValuationOfInvestmentSecuritiesAndOtherAssetsNet	600000	USD
	wal	Bank Owned Life Insurance Enhancement BankOwnedLifeInsuranceEnhancement	0	USD
	wal	Bank Owned Life Insurance Enhancement BankOwnedLifeInsuranceEnhancement	5600000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	21400000	USD
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	40400000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	3269000000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	450100000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	3100700000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1720600000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1293200000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1014400000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	49800000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	156600000	USD
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	494700000	USD
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	106800000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	14200000	USD
	wal	Paymentsto Acquire Securities Equity PaymentstoAcquireSecuritiesEquity	31100000	USD
	us-gaap	Payments For Proceeds From Investments PaymentsForProceedsFromInvestments	21400000	USD
	us-gaap	Payments For Proceeds From Investments PaymentsForProceedsFromInvestments	7000000.0	USD
	us-gaap	Proceeds From Sale Of Equity Securities Fv Ni ProceedsFromSaleOfEquitySecuritiesFvNi	2800000	USD
	us-gaap	Proceeds From Sale Of Equity Securities Fv Ni ProceedsFromSaleOfEquitySecuritiesFvNi	0	USD
	wal	Purchase Of Investment Tax Credits PurchaseOfInvestmentTaxCredits	69000000.0	USD
	wal	Purchase Of Investment Tax Credits PurchaseOfInvestmentTaxCredits	103400000	USD
	us-gaap	Proceeds From Sale Of Mortgage Servicing Rights Msr ProceedsFromSaleOfMortgageServicingRightsMSR	1112100000	USD
	us-gaap	Proceeds From Sale Of Mortgage Servicing Rights Msr ProceedsFromSaleOfMortgageServicingRightsMSR	0	USD
	wal	Purchaseof Sbic Investments PurchaseofSBICInvestments	30400000	USD
	wal	Purchaseof Sbic Investments PurchaseofSBICInvestments	1200000	USD
	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	0	USD
	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	6000000.0	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	8385400000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	4806100000	USD
	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	31800000	USD
	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	26000000.0	USD
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	1013400000	USD
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	10668000000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-5591900000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	13352100000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	6046900000	USD
	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	591900000	USD
	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	221900000	USD
	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	75000000.0	USD
	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	USD
	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	-2157100000	USD
	us-gaap	Proceeds From Repayments Of Debt ProceedsFromRepaymentsOfDebt	13000000.0	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	14600000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	8200000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	71600000	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	87600000	USD
	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	279000000.0	USD
	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	76100000	USD
	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	12183200000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	6125900000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	-1753800000	USD
	us-gaap	Cash And Cash Equivalents Period Increase Decrease CashAndCashEquivalentsPeriodIncreaseDecrease	984100000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2671700000	USD
CY2019Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	434600000	USD
CY2021Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	917900000	USD
CY2020Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1418700000	USD
	us-gaap	Interest Paid Net InterestPaidNet	70400000	USD
	us-gaap	Interest Paid Net InterestPaidNet	87100000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	160200000	USD
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	37100000	USD
CY2020Q3	us-gaap	Business Acquisitions Pro Forma Net Income Loss BusinessAcquisitionsProFormaNetIncomeLoss	271500000	USD
	wal	Number Of Wholly Owned Subsidiaries Non Bank Subsidiaries NumberOfWhollyOwnedSubsidiariesNonBankSubsidiaries	2	Subsidiary
	us-gaap	Use Of Estimates UseOfEstimates	Use of estimatesThe preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management's estimates and judgments are ongoing and are based on experience, current and expected future conditions, third-party evaluations and various other assumptions that management believes are reasonable under the circumstances. The results of these estimates form the basis for making judgments about the carrying values of assets and liabilities, as well as identifying and assessing the accounting treatment with respect to commitments and contingencies. Actual results may differ from those estimates and assumptions used in the Consolidated Financial Statements and related notes. Material estimates that are susceptible to significant changes in the near term, particularly to the extent that economic conditions worsen or persist longer than expected in an adverse state, relate to: 1) the determination of the allowance for credit losses; 2) certain assets and liabilities carried at fair value; and 3) accounting for income taxes.
	wal	Number Of Unconsolidated Subsidiaries NumberOfUnconsolidatedSubsidiaries	8	Subsidiary
	us-gaap	Prior Period Reclassification Adjustment Description PriorPeriodReclassificationAdjustmentDescription	ReclassificationsCertain amounts reported in prior periods may have been reclassified in the Consolidated Financial Statements to conform to the current presentation. The reclassifications have no effect on net income or stockholders’ equity as previously reported. Certain amounts previously reported in the Company’s June 30, 2021 Statement of Cash Flows have been adjusted in the current period. This adjustment, totaling $837.7 million, relates to classification between operating and investing activities. The cash outflow for residential loans originated through AmeriHome that were originally treated as held for sale in the Statement of Cash Flows should have been treated as held for investment. As a result of this change, purchases and originations of loans held for sale and the net increase in loans held for investment line items for the six months ended June 30, 2021, as adjusted, would have been $21.8 billion and $3.5 billion, respectively, and net cash used in operating and investing activities, as adjusted, would have been $1.1 billion and $6.2 billion, respectively.
CY2021Q2	us-gaap	Business Acquisition Effective Date Of Acquisition1 BusinessAcquisitionEffectiveDateOfAcquisition1	2021-04-07
	wal	Payments To Acquire Business Premium Amount PaymentsToAcquireBusinessPremiumAmount	275000000	USD
	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	1200000000	USD
	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	18500000	USD
	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	3400000	USD
CY2021Q2	us-gaap	Business Acquisition Effective Date Of Acquisition1 BusinessAcquisitionEffectiveDateOfAcquisition1	2021-04-07
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Cash And Equivalents BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents	207200000	USD
CY2021Q2	wal	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Loans Held For Sale BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansHeldForSale	3553700000	USD
CY2021Q2	wal	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Servicing Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedServicingAssets	1376300000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Property Plant And Equipment BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment	11300000	USD
CY2021Q2	wal	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Operating Right Of Use Asset BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOperatingRightOfUseAsset	18900000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Intangibles BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles	141000000.0	USD
CY2021Q2	wal	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Loans Eligible For Repurchase BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLoansEligibleForRepurchase	2744700000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Deferred Tax Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxAssets	6600000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Other Noncurrent Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets	240900000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets	8300600000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Long Term Debt BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt	3633900000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Capital Lease Obligation BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCapitalLeaseObligation	18900000	USD
CY2021Q2	wal	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Liability For Loans Eligible For Repurchase BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilityForLoansEligibleForRepurchase	2744700000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Other BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther	157400000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Liabilities BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities	6554900000	USD
CY2021Q3	wal	Business Acquisition Pro Forma Non Interest Income BusinessAcquisitionProFormaNonInterestIncome	122800000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Net BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet	1745700000	USD
	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	1220600000	USD
CY2021Q3	wal	Business Combination Elimination Of Pre Existing Debt And Other BusinessCombinationEliminationOfPreExistingDebtAndOther	698200000	USD
	us-gaap	Business Combination Consideration Transferred1 BusinessCombinationConsiderationTransferred1	1918800000	USD
CY2021Q2	us-gaap	Goodwill Goodwill	173100000	USD
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Intangibles BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles	141000000	USD
CY2021Q2	us-gaap	Goodwill Goodwill	173100000	USD
CY2021Q2	us-gaap	Business Acquisition Purchase Price Allocation Goodwill Expected Tax Deductible Amount BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount	150000000	USD
CY2021Q3	wal	Business Acquisition Pro Forma Interest Income BusinessAcquisitionProFormaInterestIncome	442800000	USD
CY2020Q3	wal	Business Acquisition Pro Forma Interest Income BusinessAcquisitionProFormaInterestIncome	315100000	USD
	wal	Business Acquisition Pro Forma Interest Income BusinessAcquisitionProFormaInterestIncome	1196600000	USD
	wal	Business Acquisition Pro Forma Interest Income BusinessAcquisitionProFormaInterestIncome	976900000	USD
CY2020Q3	wal	Business Acquisition Pro Forma Non Interest Income BusinessAcquisitionProFormaNonInterestIncome	269000000.0	USD
	wal	Business Acquisition Pro Forma Non Interest Income BusinessAcquisitionProFormaNonInterestIncome	344800000	USD
	wal	Business Acquisition Pro Forma Non Interest Income BusinessAcquisitionProFormaNonInterestIncome	694900000	USD
CY2021Q3	us-gaap	Business Acquisitions Pro Forma Net Income Loss BusinessAcquisitionsProFormaNetIncomeLoss	236900000	USD
	us-gaap	Business Acquisitions Pro Forma Net Income Loss BusinessAcquisitionsProFormaNetIncomeLoss	660900000	USD
	us-gaap	Business Acquisitions Pro Forma Net Income Loss BusinessAcquisitionsProFormaNetIncomeLoss	661300000	USD
CY2021Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	1046900000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	47500000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	2400000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1092000000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	6326500000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	116900000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	59800000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	6383600000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	171300000	USD
CY2021Q3	wal	Equitysecurities Fvni Accumulated Gross Unrealized Gain Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedGainBeforeTax	7900000	USD
CY2021Q3	wal	Equitysecurities Fvni Accumulated Gross Unrealized Loss Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedLossBeforeTax	800000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	178400000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	4586400000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	137600000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	15500000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	4708500000	USD
CY2020Q4	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	160100000	USD
CY2020Q4	wal	Equitysecurities Fvni Accumulated Gross Unrealized Gain Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedGainBeforeTax	7600000	USD
CY2020Q4	wal	Equitysecurities Fvni Accumulated Gross Unrealized Loss Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedLossBeforeTax	400000	USD
CY2020Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	167300000	USD
CY2021Q3	us-gaap	Pledged Financial Instruments Not Separately Reported Other Debt Securities Available For Sale Or Held For Investment PledgedFinancialInstrumentsNotSeparatelyReportedOtherDebtSecuritiesAvailableForSaleOrHeldForInvestment	2300000000	USD
CY2020Q4	us-gaap	Pledged Financial Instruments Not Separately Reported Other Debt Securities Available For Sale Or Held For Investment PledgedFinancialInstrumentsNotSeparatelyReportedOtherDebtSecuritiesAvailableForSaleOrHeldForInvestment	778000000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	2400000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue	314900000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	0	USD
CY2021Q3	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue	0	USD
CY2021Q3	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Accumulated Loss HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss	2400000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Continuous Unrealized Loss Position Fair Value HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue	314900000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	54700000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	2156500000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	5100000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	70800000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	59800000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	2227300000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	4400000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	398900000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	11100000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	120800000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	15500000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	519700000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	130	positions
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	49	positions
CY2021Q2	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	6000000.0	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	1500000	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityAllowanceForCreditLossWriteoff	0	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityAllowanceForCreditLossRecovery	0	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	4500000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	6800000	USD
	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-2300000	USD
	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityAllowanceForCreditLossWriteoff	0	USD
	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityAllowanceForCreditLossRecovery	0	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	4500000	USD
CY2020Q2	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	7600000	USD
CY2020Q3	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-1600000	USD
CY2020Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityAllowanceForCreditLossWriteoff	0	USD
CY2020Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityAllowanceForCreditLossRecovery	0	USD
CY2020Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	6000000.0	USD
CY2019Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	2600000	USD
	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	3400000	USD
	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityAllowanceForCreditLossWriteoff	0	USD
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CY2020Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	6000000.0	USD
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CY2021Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	1046900000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	6383600000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	178400000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	4708500000	USD
CY2020Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	167300000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount	45400000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue	45400000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount	17800000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	17700000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount	757800000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	803300000	USD
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CY2021Q3	us-gaap	Held To Maturity Securities Debt Maturities Without Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	225600000	USD
CY2021Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	1046900000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1092000000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	10000000.0	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	10000000.0	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	58000000.0	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	57900000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	791900000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	795900000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	1789500000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	1865100000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	3677100000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	3654700000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	6326500000	USD
CY2021Q3	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	6383600000	USD
CY2021Q3	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	6534300000	USD
CY2021Q3	us-gaap	Pledged Assets Separately Reported Loans Pledged As Collateral At Fair Value PledgedAssetsSeparatelyReportedLoansPledgedAsCollateralAtFairValue	0	USD
CY2021Q3	wal	Msr Capitalized Upon Sale Of Loan MSRCapitalizedUponSaleOfLoan	230400000	USD
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CY2021Q3	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	107400000	USD
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	251000000.0	USD
CY2021Q3	wal	Provision For And Change In Estimate Of Liability For Losses Under Representations And Warranties ProvisionForAndChangeInEstimateOfLiabilityForLossesUnderRepresentationsAndWarranties	-1100000	USD
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CY2021Q3	wal	Change In Fair Value Of Loans Held For Sale ChangeInFairValueOfLoansHeldForSale	-18400000	USD
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CY2021Q3	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	-24000000.0	USD
	us-gaap	Unrealized Gain Loss On Derivatives UnrealizedGainLossOnDerivatives	31200000	USD
CY2021Q3	us-gaap	Derivative Instruments Not Designated As Hedging Instruments Gain DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGain	35900000	USD
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CY2021Q3	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	93800000	USD
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CY2021Q3	wal	Loan Acquisition And Origination Fees LoanAcquisitionAndOriginationFees	27200000	USD
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CY2021Q3	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	246900000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	278900000	USD
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CY2021Q3	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	78900000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Deferred Income LoansAndLeasesReceivableDeferredIncome	75400000	USD
CY2021Q3	us-gaap	Receivable With Imputed Interest Premium ReceivableWithImputedInterestPremium	135100000	USD
CY2020Q4	us-gaap	Receivable With Imputed Interest Premium ReceivableWithImputedInterestPremium	26000000	USD
CY2021Q3	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	48600000	USD
CY2021Q3	wal	Financing Receivable Nonaccrual With Allowance FinancingReceivableNonaccrualWithAllowance	29500000	USD
CY2021Q3	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	78100000	USD
CY2021Q3	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	0	USD
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CY2020Q4	wal	Financing Receivable Nonaccrual With Allowance FinancingReceivableNonaccrualWithAllowance	10300000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	115200000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	0	USD
CY2021Q3	us-gaap	Loans And Leases Receivable Impaired Interest Lost On Nonaccrual Loans LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans	1400000	USD
CY2020Q3	us-gaap	Loans And Leases Receivable Impaired Interest Lost On Nonaccrual Loans LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans	1700000	USD
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CY2021Q3	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	34801900000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	27053000000	USD
CY2021Q3	us-gaap	Financing Receivable Originated In Current Fiscal Year FinancingReceivableOriginatedInCurrentFiscalYear	10539500000	USD
CY2021Q3	us-gaap	Financing Receivable Originated In Fiscal Year Before Latest Fiscal Year FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear	4183400000	USD
CY2021Q3	us-gaap	Financing Receivable Originated Two Years Before Latest Fiscal Year FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear	3671500000	USD
CY2021Q3	us-gaap	Financing Receivable Originated Three Years Before Latest Fiscal Year FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear	1846700000	USD
CY2021Q3	us-gaap	Financing Receivable Originated Four Years Before Latest Fiscal Year FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear	1201300000	USD
CY2021Q3	us-gaap	Financing Receivable Originated Five Or More Years Before Latest Fiscal Year FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear	2048300000	USD
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CY2021Q3	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	34801900000	USD
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CY2020Q4	us-gaap	Financing Receivable Originated Two Years Before Latest Fiscal Year FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear	2939200000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Three Years Before Latest Fiscal Year FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear	1669000000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Four Years Before Latest Fiscal Year FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear	691400000	USD
CY2020Q4	us-gaap	Financing Receivable Originated Five Or More Years Before Latest Fiscal Year FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear	1892400000	USD
CY2020Q4	us-gaap	Financing Receivable Revolving FinancingReceivableRevolving	8919500000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	27053000000	USD
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CY2020Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	61600000	USD
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CY2021Q3	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	55100000	USD
CY2021Q3	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	0	SecurityLoan
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CY2020Q3	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	60800000	USD
CY2020Q3	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	20	SecurityLoan
CY2020Q3	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	25000000	USD
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CY2021Q3	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	0	SecurityLoan
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CY2021Q3	us-gaap	Financing Receivables Impaired Troubled Debt Restructuring Write Down FinancingReceivablesImpairedTroubledDebtRestructuringWriteDown	2000000	USD
CY2020Q3	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	1	SecurityLoan
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CY2021Q3	wal	Covid19 Related Loan Modifications COVID19RelatedLoanModifications	189700000	USD
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CY2021Q3	us-gaap	Loans And Leases Receivable Collateral For Secured Borrowings LoansAndLeasesReceivableCollateralForSecuredBorrowings	195900000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Collateral For Secured Borrowings LoansAndLeasesReceivableCollateralForSecuredBorrowings	196200000	USD
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CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	300000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	246900000	USD
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CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	246900000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	310500000	USD
CY2020Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	8200000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	8800000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	600000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	310500000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	186900000	USD
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CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	310500000	USD
CY2021Q3	us-gaap	Interest Receivable InterestReceivable	196400000	USD
CY2020Q4	us-gaap	Interest Receivable InterestReceivable	142100000	USD
CY2021Q2	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	31300000	USD
CY2020Q2	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	36300000	USD
CY2020Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	37000000.0	USD
CY2019Q4	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	9000000.0	USD
CY2021Q3	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	800000	USD
CY2020Q3	us-gaap	Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal	8100000	USD
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CY2021Q3	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	32100000	USD
CY2020Q3	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	44400000	USD
CY2021Q3	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	32100000	USD
CY2020Q3	us-gaap	Off Balance Sheet Credit Loss Liability OffBalanceSheetCreditLossLiability	44400000	USD
CY2021Q3	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	34554700000	USD
CY2021Q3	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	247200000	USD
CY2021Q3	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	34801900000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	218700000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	28200000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	246900000	USD
CY2020Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	26787400000	USD
CY2020Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	265600000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	27053000000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	267700000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	11200000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	278900000	USD
CY2021Q3	us-gaap	Financing Receivable Significant Purchases FinancingReceivableSignificantPurchases	4633400000	USD
CY2020Q3	us-gaap	Financing Receivable Significant Purchases FinancingReceivableSignificantPurchases	514400000	USD
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CY2021Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	726200000	USD
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CY2021Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	604800000	USD
CY2021Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	604800000	USD
CY2021Q3	us-gaap	Continuing Involvement With Transferred Financial Assets Principal Amount Outstanding ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding	47211400000	USD
CY2021Q3	wal	Msr Sales Upb Of Underlying Loans MSRSalesUPBOfUnderlyingLoans	23300000000	USD
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CY2021Q3	wal	Msr Loan Sales Receivable MSRLoanSalesReceivable	90000000	USD
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CY2021Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Favorable Interest Rate Change SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointFavorableInterestRateChange	31500000	USD
CY2021Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Discount Rate Increase SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointDiscountRateIncrease	10000000.0	USD
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CY2021Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of10 Percent Increase Cost Of Service SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf10PercentIncreaseCostOfService	7300000	USD
CY2021Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of10 Percent Decrease Cost Of Service SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf10PercentDecreaseCostOfService	7300000	USD
CY2021Q3	us-gaap	Federal Funds Purchased FederalFundsPurchased	400000000.0	USD
CY2020Q4	us-gaap	Federal Funds Purchased FederalFundsPurchased	0	USD
CY2021Q3	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	0	USD
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CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	16000000.0	USD
CY2021Q3	us-gaap	Other Short Term Borrowings OtherShortTermBorrowings	29800000	USD
CY2020Q4	us-gaap	Other Short Term Borrowings OtherShortTermBorrowings	0	USD
CY2021Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	445900000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	21000000.0	USD
CY2021Q3	us-gaap	Senior Notes SeniorNotes	318300000	USD
CY2020Q4	us-gaap	Senior Notes SeniorNotes	0	USD
CY2021Q3	us-gaap	Notes Payable NotesPayable	239300000	USD
CY2020Q4	us-gaap	Notes Payable NotesPayable	0	USD
CY2021Q3	us-gaap	Long Term Debt LongTermDebt	557600000	USD
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	0	USD
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CY2020Q4	us-gaap	Other Borrowings OtherBorrowings	21000000.0	USD
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CY2020Q4	us-gaap	Federal Funds Purchased FederalFundsPurchased	0	USD
CY2021Q3	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	0	USD
CY2021Q3	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	0	USD
CY2021Q3	us-gaap	Other Short Term Borrowings OtherShortTermBorrowings	29800000	USD
CY2021Q3	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	16100000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	16000000	USD
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CY2021Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.35
CY2021Q3	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	1300000	USD
CY2021Q3	us-gaap	Senior Notes SeniorNotes	318300000	USD
CY2021Q3	us-gaap	Notes Payable NotesPayable	239300000	USD
CY2021Q3	us-gaap	Subordinated Long Term Debt SubordinatedLongTermDebt	985000000	USD
CY2020Q4	us-gaap	Subordinated Long Term Debt SubordinatedLongTermDebt	469800000	USD
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CY2020Q4	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	78900000	USD
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CY2021Q1	us-gaap	Shares Issued Price Per Share SharesIssuedPricePerShare	91.00
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CY2021Q3	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	16858	shares
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CY2021Q3	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	96.90
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CY2020Q3	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	35.73
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CY2021Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-21900000	USD
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CY2020Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	73700000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	4900000	USD
CY2020Q3	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	0	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	4900000	USD
CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	78600000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	92300000	USD
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CY2020Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	78600000	USD
CY2021Q3	us-gaap	Hedged Asset Fair Value Hedge HedgedAssetFairValueHedge	1407300000	USD
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CY2020Q4	us-gaap	Hedged Asset Fair Value Hedge HedgedAssetFairValueHedge	1587100000	USD
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CY2021Q3	us-gaap	Hedged Asset Fair Value Hedge Last Of Layer Cumulative Increase Decrease HedgedAssetFairValueHedgeLastOfLayerCumulativeIncreaseDecrease	6400000	USD
CY2020Q4	us-gaap	Hedged Asset Fair Value Hedge Last Of Layer Cumulative Increase Decrease HedgedAssetFairValueHedgeLastOfLayerCumulativeIncreaseDecrease	600000	USD
CY2021Q3	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	37200000	USD
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CY2021Q3	wal	Derivative Netting Adjustments Liabilities DerivativeNettingAdjustmentsLiabilities	66400000	USD
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CY2020Q3	us-gaap	Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral	92400000	USD
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CY2021Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	18600000	USD
CY2020Q4	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	900000	USD
CY2020Q4	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	900000	USD
CY2020Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	700000	USD
CY2020Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	700000	USD
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CY2020Q4	wal	Derivative Netting Adjustments Assets DerivativeNettingAdjustmentsAssets	-600000	USD
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CY2020Q3	wal	Derivative Netting Adjustments Assets DerivativeNettingAdjustmentsAssets	0	USD
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CY2021Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	236900000	USD
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CY2021Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	USD
CY2021Q3	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	508800000	USD
CY2020Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	405600000	USD
CY2021Q3	us-gaap	Investment Related Liabilities InvestmentRelatedLiabilities	230300000	USD
CY2020Q4	us-gaap	Investment Related Liabilities InvestmentRelatedLiabilities	151700000	USD
CY2021Q3	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	12900000	USD
CY2020Q3	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	14500000	USD
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	36600000	USD
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	34200000	USD
	us-gaap	Line Of Credit Facility Expiration Period LineOfCreditFacilityExpirationPeriod	P1Y
CY2021Q3	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Face Amount Liability FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability	11625900000	USD
CY2020Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Face Amount Liability FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability	9903600000	USD
	wal	Maximum Loan To Value Ratio MaximumLoanToValueRatio	0.75
CY2021Q3	wal	Percentage Of Commercial Real Estate Loans Occupied By Owners PercentageOfCommercialRealEstateLoansOccupiedByOwners	0.25
CY2020Q4	wal	Percentage Of Commercial Real Estate Loans Occupied By Owners PercentageOfCommercialRealEstateLoansOccupiedByOwners	0.28
CY2021Q3	us-gaap	Lease Cost LeaseCost	5800000	USD
	us-gaap	Lease Cost LeaseCost	13900000	USD
CY2020Q3	us-gaap	Lease Cost LeaseCost	3900000	USD
	us-gaap	Lease Cost LeaseCost	10900000	USD
CY2021Q3	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	900000	USD
	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	2800000	USD
CY2020Q3	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	1000000	USD
	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	2900000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	100000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-2700000	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-600000	USD
CY2021Q3	wal	Cash Cash Equivalentsand Investment Securities CashCashEquivalentsandInvestmentSecurities	8613800000	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-900000	USD
CY2021Q3	us-gaap	Fair Value Liabilities Measured On Recurring Basis Subordinated Debt Obligations FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations	66700000	USD
CY2021Q3	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	48700000	USD
CY2021Q3	us-gaap	Hedged Liability Fair Value Hedge Cumulative Increase Decrease HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease	-200000	USD
CY2020Q4	us-gaap	Fair Value Liabilities Measured On Recurring Basis Subordinated Debt Obligations FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations	65900000	USD
CY2020Q4	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	85500000	USD
CY2020Q4	us-gaap	Hedged Liability Fair Value Hedge Cumulative Increase Decrease HedgedLiabilityFairValueHedgeCumulativeIncreaseDecrease	-2700000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	100000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-2700000	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-600000	USD
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-900000	USD
CY2020Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	0	USD
CY2020Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	0	USD
CY2020Q4	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue	0	USD
CY2021Q3	wal	Fair Value Option Loans Held As Assets Current Through89 Days FairValueOptionLoansHeldAsAssetsCurrentThrough89Days	4593400000	USD
CY2021Q3	wal	Fair Value Option Loans Held As Assets Upb Current Through89 Days FairValueOptionLoansHeldAsAssetsUPBCurrentThrough89Days	4422900000	USD
CY2021Q3	wal	Fair Value Option Loans Held As Assets Current Through89 Days Aggregate Difference FairValueOptionLoansHeldAsAssetsCurrentThrough89DaysAggregateDifference	170500000	USD
CY2021Q3	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due FairValueOptionLoansHeldAsAssets90DaysOrMorePastDue	700000	USD
CY2021Q3	wal	Fair Value Option Loans Held As Assets Upb90 Days Or More Past Due FairValueOptionLoansHeldAsAssetsUPB90DaysOrMorePastDue	800000	USD
CY2021Q3	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due Aggregate Difference FairValueOptionLoansHeldAsAssets90DaysOrMorePastDueAggregateDifference	-100000	USD
CY2021Q3	wal	Fair Value Option Loans Held As Assets FairValueOptionLoansHeldAsAssets	4594100000	USD
CY2021Q3	us-gaap	Fair Value Option Loans Held As Assets Aggregate Difference FairValueOptionLoansHeldAsAssetsAggregateDifference	170400000	USD
CY2021Q3	wal	Collateral Dependent Loans Allowance CollateralDependentLoansAllowance	17400000	USD
CY2021Q3	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	6534300000	USD
CY2021Q3	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	34801900000	USD
CY2021Q3	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	246900000	USD
CY2021Q3	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	34555000000	USD
CY2021Q3	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	11500000	USD
CY2021Q3	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	608400000	USD
CY2021Q3	wal	Other Assets Segment OtherAssetsSegment	2452100000	USD
CY2021Q3	us-gaap	Assets Assets	52775100000	USD
CY2021Q3	us-gaap	Deposits Deposits	45282600000	USD
CY2021Q3	wal	Borrowingsand Qualifying Debt BorrowingsandQualifyingDebt	2052300000	USD
CY2021Q3	wal	Other Liabilities Segment OtherLiabilitiesSegment	926200000	USD
CY2021Q3	us-gaap	Liabilities Liabilities	48261100000	USD
CY2021Q3	us-gaap	Stockholders Equity StockholdersEquity	4514000000	USD
CY2021Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	52775100000	USD
CY2021Q3	wal	Excess Funds Providedby Usedin Segment Basis ExcessFundsProvidedbyUsedinSegmentBasis	0	USD
CY2021Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	410400000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	27053000000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	278900000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	26774100000	USD
CY2020Q4	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	1400000	USD
CY2020Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	298500000	USD
CY2021Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	12300000	USD
CY2021Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	398100000	USD
CY2021Q3	us-gaap	Noninterest Income NoninterestIncome	138100000	USD
CY2021Q3	us-gaap	Noninterest Expense NoninterestExpense	233800000	USD
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	302400000	USD
CY2021Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	65500000	USD
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	236900000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1098200000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	34600000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	1132800000	USD
	us-gaap	Noninterest Income NoninterestIncome	293800000	USD
	us-gaap	Noninterest Expense NoninterestExpense	613600000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	813000000.0	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	159800000	USD
	us-gaap	Net Income Loss NetIncomeLoss	653200000	USD
CY2020Q4	wal	Cash Cash Equivalentsand Investment Securities CashCashEquivalentsandInvestmentSecurities	8176500000	USD
CY2020Q4	wal	Other Assets Segment OtherAssetsSegment	1210500000	USD
CY2020Q4	us-gaap	Assets Assets	36461000000	USD
CY2020Q4	us-gaap	Deposits Deposits	31930500000	USD
CY2020Q4	wal	Borrowingsand Qualifying Debt BorrowingsandQualifyingDebt	553700000	USD
CY2020Q4	wal	Other Liabilities Segment OtherLiabilitiesSegment	563300000	USD
CY2020Q4	us-gaap	Liabilities Liabilities	33047500000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	3413500000	USD
CY2020Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	36461000000	USD
CY2020Q4	wal	Excess Funds Providedby Usedin Segment Basis ExcessFundsProvidedbyUsedinSegmentBasis	0	USD
CY2020Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	284700000	USD
CY2020Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	14600000	USD
CY2020Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	270100000	USD
CY2020Q3	us-gaap	Noninterest Income NoninterestIncome	20600000	USD
CY2020Q3	us-gaap	Noninterest Expense NoninterestExpense	124100000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	166600000	USD
CY2020Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	30800000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	135800000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	852100000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	157800000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	694300000	USD
	us-gaap	Noninterest Income NoninterestIncome	47000000.0	USD
	us-gaap	Noninterest Expense NoninterestExpense	359400000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	381900000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	68900000	USD
	us-gaap	Net Income Loss NetIncomeLoss	313000000.0	USD
CY2021Q3	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	7100000	USD
CY2021Q3	wal	Debitandcreditcardinterchangefees Debitandcreditcardinterchangefees	1700000	USD
CY2021Q3	wal	Success Fees SuccessFees	0	USD
CY2021Q3	wal	Othernoninterestincome Othernoninterestincome	200000	USD
CY2021Q3	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	9000000.0	USD
CY2021Q3	wal	Otherrevenue Otherrevenue	129100000	USD
CY2021Q3	us-gaap	Noninterest Income NoninterestIncome	138100000	USD
	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	21200000	USD
	wal	Debitandcreditcardinterchangefees Debitandcreditcardinterchangefees	4800000	USD
	wal	Success Fees SuccessFees	1000000.0	USD
	wal	Othernoninterestincome Othernoninterestincome	600000	USD
	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	27600000	USD
	wal	Otherrevenue Otherrevenue	266200000	USD
	us-gaap	Noninterest Income NoninterestIncome	293800000	USD
CY2020Q3	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	5900000	USD
CY2020Q3	wal	Debitandcreditcardinterchangefees Debitandcreditcardinterchangefees	1600000	USD
CY2020Q3	wal	Success Fees SuccessFees	0	USD
CY2020Q3	wal	Othernoninterestincome Othernoninterestincome	100000	USD
CY2020Q3	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	7600000	USD
CY2020Q3	wal	Otherrevenue Otherrevenue	13000000.0	USD
CY2020Q3	us-gaap	Noninterest Income NoninterestIncome	20600000	USD
	us-gaap	Fees And Commissions Mortgage Banking And Servicing FeesAndCommissionsMortgageBankingAndServicing	17400000	USD
	wal	Debitandcreditcardinterchangefees Debitandcreditcardinterchangefees	4000000.0	USD
	wal	Success Fees SuccessFees	400000	USD
	wal	Othernoninterestincome Othernoninterestincome	200000	USD
	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	22000000.0	USD
	wal	Otherrevenue Otherrevenue	25000000.0	USD
	us-gaap	Noninterest Income NoninterestIncome	47000000.0	USD
CY2021Q3	us-gaap	Accounts Receivable Net AccountsReceivableNet	2000000	USD
CY2020Q4	us-gaap	Accounts Receivable Net AccountsReceivableNet	1600000	USD

Files In Submission

Name	View Source	Status
0001212545-21-000170-index-headers.html	Edgar Link	pending
0001212545-21-000170-index.html	Edgar Link	pending
0001212545-21-000170.txt	Edgar Link	pending
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wal-20210930_htm.xml	Edgar Link	completed
wal-20210930_lab.xml	Edgar Link	unprocessable
wal-20210930_pre.xml	Edgar Link	unprocessable
walex3119302021.htm	Edgar Link	pending
walex3129302021.htm	Edgar Link	pending
walex329302021.htm	Edgar Link	pending

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$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal

2021 Q4 Form 10-Q Financial Statement

#000121254521000170 Filed on November 03, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WAL WESTERN ALLIANCE BANCORPORATION Stock $wal

2021 Q4 Form 10-Q Financial Statement

#000121254521000170 Filed on November 03, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal