$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal

$wal Overview Financials Valuation SEC Filings Company Website

2022 Q4 Form 10-Q Financial Statement

#000121254522000155 Filed on November 01, 2022

Income Statement

Concept	2022 Q4	2022 Q3
Revenue		$739.4M
YoY Change		66.98%
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	$16.30M	$13.30M
YoY Change	101.23%	25.47%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense		$137.3M
YoY Change		323.77%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$364.7M	$329.6M
YoY Change	17.65%	8.99%
Income Tax	$71.70M	$65.60M
% Of Pretax Income	19.66%	19.9%
Net Earnings	$289.8M	$264.0M
YoY Change	17.8%	11.44%
Net Earnings / Revenue		35.7%
Basic Earnings Per Share		$2.43
Diluted Earnings Per Share	$2.678M	$2.447M
COMMON SHARES
Basic Shares Outstanding	108.9M shares	108.3M shares
Diluted Shares Outstanding		107.9M shares

Balance Sheet

Concept	2022 Q4	2022 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$1.043B	$1.610B
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	$439.0M	$368.0M
YoY Change	141.21%	128.29%
Goodwill	$527.0M
YoY Change	7.27%
Intangibles
YoY Change
Long-Term Investments	$160.0M	$165.0M
YoY Change	0.63%	-7.3%
Other Assets	$311.0M	$302.0M
YoY Change	1380.95%	2645.45%
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$67.73B	$69.17B
YoY Change	20.99%	31.06%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$1.357B	$1.198B
YoY Change
Accrued Expenses	$185.0M	$149.0M
YoY Change	29.37%	29.57%
Deferred Revenue
YoY Change
Short-Term Debt	$4.992B	$5.096B
YoY Change	586.66%	1042.86%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$1.542B	$149.0M
YoY Change	978.32%	29.57%
LONG-TERM LIABILITIES
Long-Term Debt	$7.192B	$7.208B
YoY Change	330.4%	344.12%
Other Long-Term Liabilities	$1.357B	$1.198B
YoY Change	56.34%	50.69%
Total Long-Term Liabilities	$7.192B	$7.208B
YoY Change	183.26%	198.1%
TOTAL LIABILITIES
Total Short-Term Liabilities	$1.542B	$149.0M
Total Long-Term Liabilities	$7.192B	$7.208B
Total Liabilities	$62.38B	$64.14B
YoY Change	22.26%	32.91%
SHAREHOLDERS EQUITY
Retained Earnings	$3.664B	$3.413B
YoY Change	32.13%	32.96%
Common Stock	$2.163B	$2.154B
YoY Change	10.02%	27.02%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$105.0M	$105.0M
YoY Change	20.69%	22.24%
Treasury Stock Shares	2.551M shares	2.549M shares
Shareholders Equity	$5.356B	$5.021B
YoY Change
Total Liabilities & Shareholders Equity	$67.73B	$69.17B
YoY Change	20.99%	31.06%

Cashflow Statement

Concept	2022 Q4	2022 Q3
OPERATING ACTIVITIES
Net Income	$289.8M	$264.0M
YoY Change	17.8%	11.44%
Depreciation, Depletion And Amortization	$16.30M	$13.30M
YoY Change	101.23%	25.47%
Cash From Operating Activities	$794.4M	$490.9M
YoY Change	29.17%	-137.54%
INVESTING ACTIVITIES
Capital Expenditures	$56.80M	-$36.80M
YoY Change	-251.06%	102.2%
Acquisitions
YoY Change
Other Investing Activities	$547.7M	-$3.891B
YoY Change	-113.67%	-26.11%
Cash From Investing Activities	$490.9M	-$3.928B
YoY Change	-112.14%	-25.67%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-1.851B	3.161B
YoY Change	-161.15%	-23.17%
NET CHANGE
Cash From Operating Activities	794.4M	490.9M
Cash From Investing Activities	490.9M	-3.928B
Cash From Financing Activities	-1.851B	3.161B
Net Change In Cash	-566.1M	-276.3M
YoY Change	41.0%	-88.85%
FREE CASH FLOW
Cash From Operating Activities	$794.4M	$490.9M
Capital Expenditures	$56.80M	-$36.80M
Free Cash Flow	$737.6M	$527.7M
YoY Change	13.02%	-140.92%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Entity Central Index Key EntityCentralIndexKey	0001212545
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2022
	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 Type DocumentType	10-Q
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2022-09-30
	dei	Document Transition Report DocumentTransitionReport	false
	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
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	85004
	dei	City Area Code CityAreaCode	602
	dei	Local Phone Number LocalPhoneNumber	389-3500
	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
	dei	Entity Small Business EntitySmallBusiness	false
	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
	dei	Entity Shell Company EntityShellCompany	false
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CY2022Q3	wal	Incomefrom Equity Investments IncomefromEquityInvestments	4300000	usd
CY2021Q3	wal	Incomefrom Equity Investments IncomefromEquityInvestments	2500000	usd
	wal	Incomefrom Equity Investments IncomefromEquityInvestments	13600000	usd
	wal	Incomefrom Equity Investments IncomefromEquityInvestments	16900000	usd
CY2022Q3	wal	Gain On Recovery From Credit Guarantees GainOnRecoveryFromCreditGuarantees	400000	usd
CY2021Q3	wal	Gain On Recovery From Credit Guarantees GainOnRecoveryFromCreditGuarantees	0	usd
	wal	Gain On Recovery From Credit Guarantees GainOnRecoveryFromCreditGuarantees	11700000	usd
	wal	Gain On Recovery From Credit Guarantees GainOnRecoveryFromCreditGuarantees	0	usd
CY2022Q3	wal	Gain On Sales Of Investment Securities GainOnSalesOfInvestmentSecurities	0	usd
CY2021Q3	wal	Gain On Sales Of Investment Securities GainOnSalesOfInvestmentSecurities	0	usd
	wal	Gain On Sales Of Investment Securities GainOnSalesOfInvestmentSecurities	6700000	usd
	wal	Gain On Sales Of Investment Securities GainOnSalesOfInvestmentSecurities	100000	usd
CY2022Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-2800000	usd
CY2021Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-2200000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-19400000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-500000	usd
CY2022Q3	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	10800000	usd
CY2021Q3	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	2900000	usd
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	25300000	usd
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	9200000	usd
CY2022Q3	us-gaap	Noninterest Income NoninterestIncome	61800000	usd
CY2021Q3	us-gaap	Noninterest Income NoninterestIncome	138100000	usd
	us-gaap	Noninterest Income NoninterestIncome	263100000	usd
	us-gaap	Noninterest Income NoninterestIncome	293800000	usd
CY2022Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	136500000	usd
CY2021Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	133500000	usd
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	413800000	usd
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	346100000	usd
CY2022Q3	wal	Non Interest Expense Deposit Costs NonInterestExpenseDepositCosts	56200000	usd
CY2021Q3	wal	Non Interest Expense Deposit Costs NonInterestExpenseDepositCosts	7300000	usd
	wal	Non Interest Expense Deposit Costs NonInterestExpenseDepositCosts	83600000	usd
	wal	Non Interest Expense Deposit Costs NonInterestExpenseDepositCosts	20700000	usd
CY2022Q3	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	24800000	usd
CY2021Q3	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	13700000	usd
	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	73900000	usd
	wal	Legal Professional And Director Fees LegalProfessionalAndDirectorFees	37800000	usd
CY2022Q3	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	21800000	usd
CY2021Q3	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	15400000	usd
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	59100000	usd
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	40300000	usd
CY2022Q3	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	15200000	usd
CY2021Q3	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	15600000	usd
	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	40700000	usd
	us-gaap	Expense Related To Distribution Or Servicing And Underwriting Fees ExpenseRelatedToDistributionOrServicingAndUnderwritingFees	37900000	usd
CY2022Q3	us-gaap	Occupancy Net OccupancyNet	13900000	usd
CY2021Q3	us-gaap	Occupancy Net OccupancyNet	12400000	usd
	us-gaap	Occupancy Net OccupancyNet	39700000	usd
	us-gaap	Occupancy Net OccupancyNet	31400000	usd
CY2022Q3	us-gaap	General Insurance Expense GeneralInsuranceExpense	8100000	usd
CY2021Q3	us-gaap	General Insurance Expense GeneralInsuranceExpense	6200000	usd
	us-gaap	General Insurance Expense GeneralInsuranceExpense	22200000	usd
	us-gaap	General Insurance Expense GeneralInsuranceExpense	15900000	usd
CY2022Q3	us-gaap	Loan Processing Fee LoanProcessingFee	5800000	usd
CY2021Q3	us-gaap	Loan Processing Fee LoanProcessingFee	9700000	usd
	us-gaap	Loan Processing Fee LoanProcessingFee	18700000	usd
	us-gaap	Loan Processing Fee LoanProcessingFee	20200000	usd
CY2022Q3	us-gaap	Business Development BusinessDevelopment	5000000.0	usd
CY2021Q3	us-gaap	Business Development BusinessDevelopment	2800000	usd
	us-gaap	Business Development BusinessDevelopment	14800000	usd
	us-gaap	Business Development BusinessDevelopment	7400000	usd
CY2022Q3	wal	Net Loss Gain On Sales Valuations Of Repossessed Assets And Bank Premises Net NetLossGainOnSalesValuationsOfRepossessedAssetsAndBankPremisesNet	-200000	usd
CY2021Q3	wal	Net Loss Gain On Sales Valuations Of Repossessed Assets And Bank Premises Net NetLossGainOnSalesValuationsOfRepossessedAssetsAndBankPremisesNet	-1300000	usd
	wal	Net Loss Gain On Sales Valuations Of Repossessed Assets And Bank Premises Net NetLossGainOnSalesValuationsOfRepossessedAssetsAndBankPremisesNet	-400000	usd
	wal	Net Loss Gain On Sales Valuations Of Repossessed Assets And Bank Premises Net NetLossGainOnSalesValuationsOfRepossessedAssetsAndBankPremisesNet	-3100000	usd
CY2022Q3	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	0	usd
CY2021Q3	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	2400000	usd
	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	400000	usd
	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	18500000	usd
CY2022Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	18700000	usd
CY2021Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	16100000	usd
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	56800000	usd
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	40500000	usd
CY2022Q3	us-gaap	Noninterest Expense NoninterestExpense	305800000	usd
CY2021Q3	us-gaap	Noninterest Expense NoninterestExpense	233800000	usd
	us-gaap	Noninterest Expense NoninterestExpense	823300000	usd
	us-gaap	Noninterest Expense NoninterestExpense	613600000	usd
CY2022Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	329600000	usd
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	302400000	usd
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	951400000	usd
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	813000000.0	usd
CY2022Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	65600000	usd
CY2021Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	65500000	usd
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	187100000	usd
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	159800000	usd
CY2022Q3	us-gaap	Net Income Loss NetIncomeLoss	264000000.0	usd
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	236900000	usd
	us-gaap	Net Income Loss NetIncomeLoss	764300000	usd
	us-gaap	Net Income Loss NetIncomeLoss	653200000	usd
CY2022Q3	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	3200000	usd
CY2021Q3	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	0	usd
	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	9600000	usd
	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	0	usd
CY2022Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	260800000	usd
CY2021Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	236900000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	754700000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	653200000	usd
CY2022Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.43
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.29
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.06
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.39
CY2022Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.42
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.28
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.03
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.35
CY2022Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	107500000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	103300000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	107000000.0	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	102300000	shares
CY2022Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	107900000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	103900000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	107400000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	102900000	shares
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.35
CY2022Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.36
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.35
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.06
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.85
CY2022Q3	us-gaap	Net Income Loss NetIncomeLoss	264000000.0	usd
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	236900000	usd
	us-gaap	Net Income Loss NetIncomeLoss	764300000	usd
	us-gaap	Net Income Loss NetIncomeLoss	653200000	usd
CY2022Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-74200000	usd
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-7100000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-248200000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-16000000.0	usd
CY2022Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-219900000	usd
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-21800000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-752300000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-49000000.0	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	-500000	usd
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	-100000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	-1900000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodTax	-200000	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-1600000	usd
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-100000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	5800000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-600000	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-0.0	usd
CY2021Q3	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	-1800000	usd
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	0.0	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	0	usd
CY2021Q3	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	5400000	usd
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	100000	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-218300000	usd
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-21900000	usd
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-751900000	usd
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-49700000	usd
CY2022Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	45700000	usd
CY2021Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	215000000.0	usd
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	12400000	usd
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	603500000	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
CY2022Q2	us-gaap	Stockholders Equity StockholdersEquity	4958800000	usd
CY2022Q3	us-gaap	Net Income Loss NetIncomeLoss	264000000.0	usd
CY2022Q3	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	9400000	usd
CY2022Q3	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	900000	usd
CY2022Q3	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	50000000.0	usd
CY2022Q3	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	3200000	usd
CY2022Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	39000000.0	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-218300000	usd
CY2022Q3	us-gaap	Stockholders Equity StockholdersEquity	5020800000	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
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	4962600000	usd
	us-gaap	Net Income Loss NetIncomeLoss	764300000	usd
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	30300000	usd
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	18400000	usd
	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	157700000	usd
	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	9600000	usd
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	114200000	usd
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-751900000	usd
CY2022Q3	us-gaap	Stockholders Equity StockholdersEquity	5020800000	usd
	us-gaap	Net Income Loss NetIncomeLoss	764300000	usd
	us-gaap	Net Income Loss NetIncomeLoss	653200000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	65000000.0	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	34600000	usd
	us-gaap	Depreciation And Amortization DepreciationAndAmortization	36100000	usd
	us-gaap	Depreciation And Amortization DepreciationAndAmortization	25600000	usd
	us-gaap	Share Based Compensation ShareBasedCompensation	30300000	usd
	us-gaap	Share Based Compensation ShareBasedCompensation	25600000	usd
	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	47700000	usd
	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	43600000	usd
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-17100000	usd
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-30800000	usd
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	45600000	usd
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	36600000	usd
	us-gaap	Operating Lease Expense OperatingLeaseExpense	16400000	usd
	us-gaap	Operating Lease Expense OperatingLeaseExpense	11500000	usd
	us-gaap	Amortization Of Deferred Loan Origination Fees Net AmortizationOfDeferredLoanOriginationFeesNet	50600000	usd
	us-gaap	Amortization Of Deferred Loan Origination Fees Net AmortizationOfDeferredLoanOriginationFeesNet	53200000	usd
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	37064400000	usd
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	41336400000	usd
	us-gaap	Proceeds From Sale And Collection Of Loans Heldforsale ProceedsFromSaleAndCollectionOfLoansHeldforsale	38294500000	usd
	us-gaap	Proceeds From Sale And Collection Of Loans Heldforsale ProceedsFromSaleAndCollectionOfLoansHeldforsale	37810500000	usd
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	578100000	usd
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	512700000	usd
	us-gaap	Servicing Asset At Fair Value Period Increase Decrease ServicingAssetAtFairValuePeriodIncreaseDecrease	139300000	usd
	us-gaap	Servicing Asset At Fair Value Period Increase Decrease ServicingAssetAtFairValuePeriodIncreaseDecrease	-49500000	usd
	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-10100000	usd
	us-gaap	Other Operating Activities Cash Flow Statement OtherOperatingActivitiesCashFlowStatement	-2400000	usd
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	43800000	usd
	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	21400000	usd
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-1450900000	usd
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-3269000000	usd
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	2286400000	usd
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	3100700000	usd
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	511800000	usd
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1293200000	usd
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	124600000	usd
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	49800000	usd
CY2022Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.199
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	230300000	usd
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	494700000	usd
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	68100000	usd
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	14200000	usd
	us-gaap	Payments To Acquire Equity Securities Fv Ni PaymentsToAcquireEquitySecuritiesFvNi	35200000	usd
	us-gaap	Payments To Acquire Equity Securities Fv Ni PaymentsToAcquireEquitySecuritiesFvNi	36100000	usd
	us-gaap	Payments For Proceeds From Investments PaymentsForProceedsFromInvestments	1100000	usd
	us-gaap	Payments For Proceeds From Investments PaymentsForProceedsFromInvestments	21400000	usd
	us-gaap	Proceeds From Sale Of Equity Securities Fv Ni ProceedsFromSaleOfEquitySecuritiesFvNi	14100000	usd
	us-gaap	Proceeds From Sale Of Equity Securities Fv Ni ProceedsFromSaleOfEquitySecuritiesFvNi	2800000	usd
	us-gaap	Proceeds From Sale Of Mortgage Servicing Rights Msr ProceedsFromSaleOfMortgageServicingRightsMSR	382200000	usd
	us-gaap	Proceeds From Sale Of Mortgage Servicing Rights Msr ProceedsFromSaleOfMortgageServicingRightsMSR	1112100000	usd
	wal	Purchase Of Other Investments PurchaseOfOtherInvestments	300300000	usd
	wal	Purchase Of Other Investments PurchaseOfOtherInvestments	99400000	usd
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	11736500000	usd
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	8385400000	usd
CY2021Q3	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.217
	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	84200000	usd
	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	31800000	usd
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	50000000.0	usd
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	1013400000	usd
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	13621000000	usd
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-10668000000	usd
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	7976700000	usd
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	13352100000	usd
	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	485500000	usd
	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	831400000	usd
	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	24800000	usd
	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	75000000.0	usd
	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	4810300000	usd
	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-2396600000	usd
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	18400000	usd
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	14600000	usd
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.197
	us-gaap	Payments Of Dividends PaymentsOfDividends	123800000	usd
	us-gaap	Payments Of Dividends PaymentsOfDividends	87600000	usd
	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	157700000	usd
	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	279000000.0	usd
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	13263200000	usd
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	12183200000	usd
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	1093100000	usd
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-1753800000	usd
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	516400000	usd
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	2671700000	usd
CY2022Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1609500000	usd
CY2021Q3	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	917900000	usd
	us-gaap	Interest Paid Net InterestPaidNet	211400000	usd
	us-gaap	Interest Paid Net InterestPaidNet	70400000	usd
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	190700000	usd
	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	160200000	usd
	us-gaap	Transfer Of Loans Held For Sale To Portfolio Loans1 TransferOfLoansHeldForSaleToPortfolioLoans1	1505700000	usd
	us-gaap	Transfer Of Loans Held For Sale To Portfolio Loans1 TransferOfLoansHeldForSaleToPortfolioLoans1	0	usd
	wal	Transfers Of Mortgage Backed Securities In Settlement Of Secured Borrowings TransfersOfMortgageBackedSecuritiesInSettlementOfSecuredBorrowings	452900000	usd
	wal	Transfers Of Mortgage Backed Securities In Settlement Of Secured Borrowings TransfersOfMortgageBackedSecuritiesInSettlementOfSecuredBorrowings	495200000	usd
	wal	Net Increase Decrease In Unfunded Commitments And Obligations NetIncreaseDecreaseInUnfundedCommitmentsAndObligations	281100000	usd
	wal	Net Increase Decrease In Unfunded Commitments And Obligations NetIncreaseDecreaseInUnfundedCommitmentsAndObligations	152600000	usd
	wal	Net Increase In Unsettled Loans Hfi And Investment Securities Purchased NetIncreaseInUnsettledLoansHFIAndInvestmentSecuritiesPurchased	-33400000	usd
	wal	Net Increase In Unsettled Loans Hfi And Investment Securities Purchased NetIncreaseInUnsettledLoansHFIAndInvestmentSecuritiesPurchased	104300000	usd
	wal	Transfers Of Securitized Lhfs To Afs Securities TransfersOfSecuritizedLHFSToAFSSecurities	131000000.0	usd
	wal	Transfers Of Securitized Lhfs To Afs Securities TransfersOfSecuritizedLHFSToAFSSecurities	0	usd
	wal	Number Of Wholly Owned Subsidiaries Non Bank Subsidiaries NumberOfWhollyOwnedSubsidiariesNonBankSubsidiaries	2	subsidiary
CY2022Q1	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Intangibles BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles	20100000	usd
	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 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 in the Consolidated Income Statements for the prior periods have been reclassified to conform to the current presentation. The reclassifications have no effect on net income or stockholders’ equity as previously reported.
CY2022Q1	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Other Noncurrent Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets	100000	usd
CY2022Q1	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets	20800000	usd
CY2022Q1	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Other BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther	400000	usd
CY2022Q1	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Liabilities BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities	400000	usd
CY2022Q1	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Net BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet	20400000	usd
CY2022Q1	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	50600000	usd
CY2022Q1	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	6400000	usd
CY2022Q1	us-gaap	Business Acquisition Effective Date Of Acquisition1 BusinessAcquisitionEffectiveDateOfAcquisition1	2022-01-25
CY2022Q3	us-gaap	Business Combination Provisional Information Initial Accounting Incomplete Adjustment Intangibles BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentIntangibles	7400000	usd
CY2022Q3	us-gaap	Business Combination Provisional Information Initial Accounting Incomplete Adjustments Related To Previous Period BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentsRelatedToPreviousPeriod	500000	usd
CY2022Q1	us-gaap	Business Combination Consideration Transferred1 BusinessCombinationConsiderationTransferred1	57000000	usd
CY2022Q1	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	50600000	usd
CY2022Q1	us-gaap	Business Combination Contingent Consideration Liability BusinessCombinationContingentConsiderationLiability	6400000	usd
CY2022Q3	us-gaap	Business Combination Provisional Information Initial Accounting Incomplete Adjustment Consideration Transferred BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentConsiderationTransferred	10800000	usd
	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	400000	usd
CY2022Q3	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	0	usd
CY2022Q1	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Cash And Equivalents BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents	600000	usd
CY2022Q1	us-gaap	Business Combination Consideration Transferred1 BusinessCombinationConsiderationTransferred1	57000000.0	usd
CY2022Q1	us-gaap	Goodwill Goodwill	36600000	usd
CY2022Q1	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Intangibles BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles	20100000	usd
CY2022Q1	us-gaap	Goodwill Goodwill	36600000	usd
CY2021Q2	us-gaap	Business Acquisition Effective Date Of Acquisition1 BusinessAcquisitionEffectiveDateOfAcquisition1	2021-04-07
	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	1200000000	usd
CY2021Q3	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	2400000	usd
	wal	Acquisition And Restructure Expenses AcquisitionAndRestructureExpenses	18500000	usd
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	3552900000	usd
CY2021Q2	wal	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Servicing Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedServicingAssets	1347000000	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	236000000.0	usd
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets	8265600000	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	149500000	usd
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Liabilities BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities	6547000000	usd
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Net BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet	1718600000	usd
CY2021Q2	us-gaap	Payments To Acquire Businesses Gross PaymentsToAcquireBusinessesGross	1231600000	usd
CY2021Q2	wal	Business Combination Elimination Of Pre Existing Debt And Other BusinessCombinationEliminationOfPreExistingDebtAndOther	686800000	usd
CY2021Q2	us-gaap	Business Combination Consideration Transferred1 BusinessCombinationConsiderationTransferred1	1918400000	usd
CY2021Q2	us-gaap	Goodwill Goodwill	199800000	usd
CY2021Q2	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Intangibles BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles	141000000	usd
CY2021Q2	us-gaap	Goodwill Goodwill	199800000	usd
CY2021Q2	us-gaap	Business Acquisition Purchase Price Allocation Goodwill Expected Tax Deductible Amount BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount	185000000	usd
CY2021Q3	wal	Business Acquisition Pro Forma Interest Income BusinessAcquisitionProFormaInterestIncome	442800000	usd
	wal	Business Acquisition Pro Forma Interest Income BusinessAcquisitionProFormaInterestIncome	1196600000	usd
CY2021Q3	wal	Business Acquisition Pro Forma Non Interest Income BusinessAcquisitionProFormaNonInterestIncome	122800000	usd
	wal	Business Acquisition Pro Forma Non Interest Income BusinessAcquisitionProFormaNonInterestIncome	344800000	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
CY2022Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	1270000000	usd
CY2022Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	0	usd
CY2022Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	186000000	usd
CY2022Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1084000000	usd
CY2022Q3	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	7944000000	usd
CY2022Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	7000000	usd
CY2022Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	991000000	usd
CY2022Q3	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	6960000000	usd
CY2022Q3	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	177000000	usd
CY2022Q3	wal	Equitysecurities Fvni Accumulated Gross Unrealized Gain Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedGainBeforeTax	0	usd
CY2022Q3	wal	Equitysecurities Fvni Accumulated Gross Unrealized Loss Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedLossBeforeTax	12000000	usd
CY2022Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	165000000	usd
CY2021Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	1107000000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	43000000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	4000000	usd
CY2021Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1146000000	usd
CY2021Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	6167000000	usd
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	103000000	usd
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	81000000	usd
CY2021Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	6189000000	usd
CY2021Q4	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	152000000	usd
CY2021Q4	wal	Equitysecurities Fvni Accumulated Gross Unrealized Gain Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedGainBeforeTax	8000000	usd
CY2021Q4	wal	Equitysecurities Fvni Accumulated Gross Unrealized Loss Before Tax EquitysecuritiesFVNIAccumulatedGrossUnrealizedLossBeforeTax	1000000	usd
CY2021Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	159000000	usd
CY2022Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	603000000	usd
CY2022Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	5330000000	usd
CY2022Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	388000000	usd
CY2022Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	1499000000	usd
CY2022Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	991000000	usd
CY2022Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	6829000000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	68000000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	3046000000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	13000000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	170000000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	81000000	usd
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	3216000000	usd
CY2022Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	766	positions
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	179	positions
CY2022Q2	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	3200000	usd
CY2022Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityExcludingAccruedInterestCreditLossExpenseReversal	-1200000	usd
CY2022Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityExcludingAccruedInterestAllowanceForCreditLossWriteoff	0	usd
CY2022Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityExcludingAccruedInterestAllowanceForCreditLossRecovery	0	usd
CY2022Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	4400000	usd
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	5200000	usd
	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityExcludingAccruedInterestCreditLossExpenseReversal	800000	usd
	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityExcludingAccruedInterestAllowanceForCreditLossWriteoff	0	usd
	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityExcludingAccruedInterestAllowanceForCreditLossRecovery	0	usd
CY2022Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	4400000	usd
CY2021Q2	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	6000000.0	usd
CY2021Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityExcludingAccruedInterestCreditLossExpenseReversal	-1500000	usd
CY2021Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Allowance For Credit Loss Writeoff DebtSecuritiesHeldToMaturityExcludingAccruedInterestAllowanceForCreditLossWriteoff	0	usd
CY2021Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Allowance For Credit Loss Recovery DebtSecuritiesHeldToMaturityExcludingAccruedInterestAllowanceForCreditLossRecovery	0	usd
CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	4500000	usd
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	6800000	usd
	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityExcludingAccruedInterestCreditLossExpenseReversal	-2300000	usd
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CY2022Q3	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	285300000	usd
CY2022Q3	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	18800000	usd
CY2022Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	304100000	usd
CY2021Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	38812000000	usd
CY2021Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	263000000	usd
CY2021Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	39075000000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	236400000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	16100000	usd
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	252500000	usd
CY2022Q3	us-gaap	Financing Receivable Sale FinancingReceivableSale	210000000	usd
	us-gaap	Financing Receivable Sale FinancingReceivableSale	226000000	usd
CY2022Q3	us-gaap	Gain Loss On Sale Of Notes Receivable GainLossOnSaleOfNotesReceivable	-500000	usd
	us-gaap	Gain Loss On Sale Of Notes Receivable GainLossOnSaleOfNotesReceivable	-800000	usd
CY2022Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	826000000	usd
CY2021Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	726000000	usd
CY2021Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	698000000	usd
CY2021Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	0	usd
CY2021Q2	wal	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Servicing Assets Before Purchase Accounting Adjustments BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedServicingAssetsBeforePurchaseAccountingAdjustments	1376000000	usd
CY2022Q3	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	180000000	usd
CY2021Q3	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	230000000	usd
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	578000000	usd
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	513000000	usd
CY2022Q3	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	0	usd
CY2021Q3	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	327000000	usd
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	350000000	usd
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	1199000000	usd
CY2022Q3	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	63000000	usd
CY2021Q3	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	15000000	usd
	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	206000000	usd
	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	22000000	usd
CY2022Q3	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-25000000	usd
CY2021Q3	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-39000000	usd
	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-88000000	usd
	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-107000000	usd
CY2022Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1044000000	usd
CY2021Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	605000000	usd
CY2022Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1044000000	usd
CY2021Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	605000000	usd
CY2022Q3	us-gaap	Continuing Involvement With Transferred Financial Assets Principal Amount Outstanding ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding	62841000000	usd
CY2021Q3	us-gaap	Continuing Involvement With Transferred Financial Assets Principal Amount Outstanding ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding	47211000000	usd
	wal	Msr Sales Upb Of Underlying Loans MSRSalesUPBOfUnderlyingLoans	24100000000	usd
CY2021Q3	wal	Msr Sales Upb Of Underlying Loans MSRSalesUPBOfUnderlyingLoans	23300000000	usd
	wal	Msr Sales Upb Of Underlying Loans MSRSalesUPBOfUnderlyingLoans	88600000000	usd
CY2022Q3	wal	Msr Loan Sales Receivable MSRLoanSalesReceivable	49000000	usd
CY2022Q3	us-gaap	Contractually Specified Servicing Fees Late Fees And Ancillary Fees Earned In Exchange For Servicing Financial Assets ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets	48900000	usd
	us-gaap	Contractually Specified Servicing Fees Late Fees And Ancillary Fees Earned In Exchange For Servicing Financial Assets ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets	140700000	usd
CY2021Q3	us-gaap	Contractually Specified Servicing Fees Late Fees And Ancillary Fees Earned In Exchange For Servicing Financial Assets ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets	41500000	usd
	us-gaap	Contractually Specified Servicing Fees Late Fees And Ancillary Fees Earned In Exchange For Servicing Financial Assets ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets	102400000	usd
CY2022Q3	wal	Servicing Advances Net ServicingAdvancesNet	-76000000	usd
CY2021Q4	wal	Servicing Advances Net ServicingAdvancesNet	-82000000	usd
CY2022Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	1044000000	usd
CY2022Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Adverse Interest Rate Change SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointAdverseInterestRateChange	-36000000	usd
CY2022Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Favorable Interest Rate Change SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointFavorableInterestRateChange	28000000	usd
CY2022Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Discount Rate Increase SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointDiscountRateIncrease	21000000	usd
CY2022Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of50 Basis Point Discount Rate Decrease SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf50BasisPointDiscountRateDecrease	22000000	usd
CY2022Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of1 Percent Increase In Prepayment Speed SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf1PercentIncreaseInPrepaymentSpeed	26000000	usd
CY2022Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of1 Percent Decrease In Prepayment Speed SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf1PercentDecreaseInPrepaymentSpeed	29000000	usd
CY2022Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of10 Percent Increase Cost Of Service SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf10PercentIncreaseCostOfService	13000000	usd
CY2022Q3	wal	Sensitivity Analysis Of Fair Value Transferors Interests In Transferred Financial Assets Impact Of10 Percent Decrease Cost Of Service SensitivityAnalysisOfFairValueTransferorsInterestsInTransferredFinancialAssetsImpactOf10PercentDecreaseCostOfService	13000000	usd
CY2022Q3	us-gaap	Notes Payable NotesPayable	907000000	usd
CY2022Q3	us-gaap	Federal Funds Purchased FederalFundsPurchased	1010000000	usd
CY2021Q4	us-gaap	Federal Funds Purchased FederalFundsPurchased	675000000	usd
CY2022Q3	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	4000000000	usd
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	0	usd
CY2022Q3	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	26000000	usd
CY2021Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	17000000	usd
CY2022Q3	us-gaap	Other Short Term Borrowings OtherShortTermBorrowings	60000000	usd
CY2021Q4	us-gaap	Other Short Term Borrowings OtherShortTermBorrowings	35000000	usd
CY2022Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	5096000000	usd
CY2021Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	727000000	usd
CY2022Q3	us-gaap	Senior Notes SeniorNotes	316000000	usd
CY2021Q4	us-gaap	Senior Notes SeniorNotes	318000000	usd
CY2021Q4	us-gaap	Notes Payable NotesPayable	457000000	usd
CY2022Q3	us-gaap	Long Term Debt LongTermDebt	1223000000	usd
CY2021Q4	us-gaap	Long Term Debt LongTermDebt	775000000	usd
CY2022Q3	us-gaap	Other Borrowings OtherBorrowings	6319000000	usd
CY2021Q4	us-gaap	Other Borrowings OtherBorrowings	1502000000	usd
CY2022Q3	us-gaap	Subordinated Long Term Debt SubordinatedLongTermDebt	816000000	usd
CY2021Q4	us-gaap	Subordinated Long Term Debt SubordinatedLongTermDebt	815000000	usd
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CY2022Q3	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	73000000	usd
CY2021Q4	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	81000000	usd
CY2022Q3	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	0.27
CY2022Q3	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	600000	shares
	us-gaap	Stock Issued During Period Shares New Issues StockIssuedDuringPeriodSharesNewIssues	1900000	shares
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CY2022Q3	us-gaap	Adjustments To Additional Paid In Capital Stock Issued Issuance Costs AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts	300000	usd
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CY2022Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.36
	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.25
CY2021Q3	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.35
CY2022Q3	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	11039	shares
	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	199208	shares
CY2022Q3	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	77.36
	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	92.40
CY2021Q3	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	16858	shares
	us-gaap	Shares Paid For Tax Withholding For Share Based Compensation SharesPaidForTaxWithholdingForShareBasedCompensation	173277	shares
CY2021Q3	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	96.90
	us-gaap	Treasury Stock Acquired Average Cost Per Share TreasuryStockAcquiredAverageCostPerShare	85.15
CY2022Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-517900000	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-218300000	usd
CY2022Q3	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	0	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-218300000	usd
CY2022Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-736200000	usd
CY2021Q2	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	64500000	usd
CY2021Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-21900000	usd
CY2021Q3	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	0	usd
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-21900000	usd
CY2021Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	42600000	usd
CY2021Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	15700000	usd
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CY2022Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-736200000	usd
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-92300000	usd
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CY2021Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	42600000	usd
CY2022Q3	us-gaap	Hedged Asset Fair Value Hedge HedgedAssetFairValueHedge	447000000	usd
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CY2021Q4	us-gaap	Hedged Asset Fair Value Hedge HedgedAssetFairValueHedge	1391000000	usd
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CY2022Q3	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	100000000	usd
CY2022Q3	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	100000000	usd
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CY2021Q3	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	1000000	usd
CY2021Q3	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	1000000	usd
CY2022Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	-233000000	usd
CY2022Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	-233000000	usd
CY2021Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	-28000000	usd
CY2021Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	-28000000	usd
CY2021Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	-66000000	usd
CY2021Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	-66000000	usd
CY2022Q3	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	285000000	usd
CY2022Q3	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	-233000000	usd
CY2022Q3	us-gaap	Derivative Asset After Offset Subject To Master Netting Arrangement DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement	52000000	usd
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CY2021Q4	us-gaap	Derivative Asset After Offset Subject To Master Netting Arrangement DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement	10000000	usd
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CY2021Q3	us-gaap	Derivative Asset After Offset Subject To Master Netting Arrangement DerivativeAssetAfterOffsetSubjectToMasterNettingArrangement	12000000	usd
CY2022Q3	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	-11000000	usd
CY2022Q3	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	-11000000	usd
CY2021Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	6000000	usd
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CY2021Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	66000000	usd
CY2022Q3	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	237000000	usd
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CY2022Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	30000000	usd
CY2022Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	30000000	usd
CY2021Q4	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	12000000	usd
CY2021Q4	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	12000000	usd
CY2021Q3	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	19000000	usd
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CY2022Q3	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	44000000	usd
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CY2021Q4	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	4000000	usd
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CY2021Q3	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	6000000	usd
CY2021Q3	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	6000000	usd
CY2022Q3	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	315000000	usd
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CY2022Q3	us-gaap	Derivative Asset Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeAssetFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	82000000	usd
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CY2022Q3	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	281000000	usd
CY2022Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	233000000	usd
CY2022Q3	us-gaap	Derivative Liability Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	48000000	usd
CY2021Q4	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	100000000	usd
CY2021Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	28000000	usd
CY2021Q4	us-gaap	Derivative Liability Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	72000000	usd
CY2021Q3	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	141000000	usd
CY2021Q3	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	66000000	usd
CY2021Q3	us-gaap	Derivative Liability Fair Value Offset Against Collateral Net Of Not Subject To Master Netting Arrangement Policy Election DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection	75000000	usd
CY2022Q3	us-gaap	Derivative Liability Fair Value Of Collateral DerivativeLiabilityFairValueOfCollateral	5000000	usd
CY2021Q4	us-gaap	Derivative Liability Fair Value Of Collateral DerivativeLiabilityFairValueOfCollateral	67000000	usd
CY2021Q3	us-gaap	Derivative Liability Fair Value Of Collateral DerivativeLiabilityFairValueOfCollateral	98000000	usd
CY2022Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	107500000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	103300000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	107000000.0	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	102300000	shares
CY2022Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	400000	shares
CY2021Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	600000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	400000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	600000	shares
CY2022Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	107900000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	103900000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	107400000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	102900000	shares
CY2022Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	260800000	usd
CY2021Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	236900000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	754700000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	653200000	usd
CY2022Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.43
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.29
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.06
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.39
CY2022Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.42
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.28
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.03
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.35
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.197
CY2022Q3	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	302000000	usd
	us-gaap	Increase Decrease In Deferred Income Taxes IncreaseDecreaseInDeferredIncomeTaxes	281000000	usd
CY2021Q4	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	21000000	usd
CY2022Q3	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	302000000	usd
CY2022Q3	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	usd
CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	0	usd
CY2022Q3	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	727000000	usd
CY2021Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	631000000	usd
CY2022Q3	us-gaap	Investment Related Liabilities InvestmentRelatedLiabilities	431000000	usd
CY2021Q4	us-gaap	Investment Related Liabilities InvestmentRelatedLiabilities	361000000	usd
CY2022Q3	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	16800000	usd
CY2021Q3	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	12900000	usd
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	45600000	usd
	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	36600000	usd
	us-gaap	Line Of Credit Facility Expiration Period LineOfCreditFacilityExpirationPeriod	P1Y
CY2022Q3	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Face Amount Liability FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability	18867000000	usd
CY2021Q4	us-gaap	Fair Value Disclosure Offbalance Sheet Risks Face Amount Liability FairValueDisclosureOffbalanceSheetRisksFaceAmountLiability	13901000000	usd
	wal	Maximum Loan To Value Ratio MaximumLoanToValueRatio	0.75
CY2022Q3	wal	Percentage Of Commercial Real Estate Loans Occupied By Owners PercentageOfCommercialRealEstateLoansOccupiedByOwners	0.18
CY2021Q4	wal	Percentage Of Commercial Real Estate Loans Occupied By Owners PercentageOfCommercialRealEstateLoansOccupiedByOwners	0.23
CY2022Q3	us-gaap	Lease Cost LeaseCost	6200000	usd
	us-gaap	Lease Cost LeaseCost	18300000	usd
CY2021Q3	us-gaap	Lease Cost LeaseCost	5800000	usd
	us-gaap	Lease Cost LeaseCost	13900000	usd
CY2022Q3	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	1200000	usd
	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	3300000	usd
CY2021Q3	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	900000	usd
	wal	Lesseeoperatingleaseothercost Lesseeoperatingleaseothercost	2800000	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-1600000	usd
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-100000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	5800000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-600000	usd
CY2022Q3	us-gaap	Fair Value Liabilities Measured On Recurring Basis Subordinated Debt Obligations FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations	60000000	usd
CY2022Q3	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	22000000	usd
CY2021Q4	us-gaap	Fair Value Liabilities Measured On Recurring Basis Subordinated Debt Obligations FairValueLiabilitiesMeasuredOnRecurringBasisSubordinatedDebtObligations	67000000	usd
CY2021Q4	us-gaap	Hedged Asset Fair Value Hedge Cumulative Increase Decrease HedgedAssetFairValueHedgeCumulativeIncreaseDecrease	39000000	usd
CY2022Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-1600000	usd
CY2021Q3	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-100000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	5800000	usd
	us-gaap	Other Comprehensive Income Loss Financial Liability Fair Value Option Unrealized Gain Loss Arising During Period After Tax OtherComprehensiveIncomeLossFinancialLiabilityFairValueOptionUnrealizedGainLossArisingDuringPeriodAfterTax	-600000	usd
CY2022Q3	wal	Fair Value Option Loans Held As Assets Current Through89 Days FairValueOptionLoansHeldAsAssetsCurrentThrough89Days	2053000000	usd
CY2022Q3	wal	Fair Value Option Loans Held As Assets Upb Current Through89 Days FairValueOptionLoansHeldAsAssetsUPBCurrentThrough89Days	2098000000	usd
CY2022Q3	wal	Fair Value Option Loans Held As Assets Current Through89 Days Aggregate Difference FairValueOptionLoansHeldAsAssetsCurrentThrough89DaysAggregateDifference	-45000000	usd
CY2021Q4	wal	Fair Value Option Loans Held As Assets Current Through89 Days FairValueOptionLoansHeldAsAssetsCurrentThrough89Days	3938000000	usd
CY2021Q4	wal	Fair Value Option Loans Held As Assets Upb Current Through89 Days FairValueOptionLoansHeldAsAssetsUPBCurrentThrough89Days	3808000000	usd
CY2021Q4	wal	Fair Value Option Loans Held As Assets Current Through89 Days Aggregate Difference FairValueOptionLoansHeldAsAssetsCurrentThrough89DaysAggregateDifference	130000000	usd
CY2022Q3	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due FairValueOptionLoansHeldAsAssets90DaysOrMorePastDue	1000000	usd
CY2022Q3	wal	Fair Value Option Loans Held As Assets Upb90 Days Or More Past Due FairValueOptionLoansHeldAsAssetsUPB90DaysOrMorePastDue	1000000	usd
CY2022Q3	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due Aggregate Difference FairValueOptionLoansHeldAsAssets90DaysOrMorePastDueAggregateDifference	0	usd
CY2021Q4	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due FairValueOptionLoansHeldAsAssets90DaysOrMorePastDue	2000000	usd
CY2021Q4	wal	Fair Value Option Loans Held As Assets Upb90 Days Or More Past Due FairValueOptionLoansHeldAsAssetsUPB90DaysOrMorePastDue	2000000	usd
CY2021Q4	us-gaap	Fair Value Option Loans Held As Assets90 Days Or More Past Due Aggregate Difference FairValueOptionLoansHeldAsAssets90DaysOrMorePastDueAggregateDifference	0	usd
CY2022Q3	wal	Fair Value Option Loans Held As Assets FairValueOptionLoansHeldAsAssets	2054000000	usd
CY2022Q3	us-gaap	Fair Value Option Loans Held As Assets Aggregate Difference FairValueOptionLoansHeldAsAssetsAggregateDifference	-45000000	usd
CY2021Q4	wal	Fair Value Option Loans Held As Assets FairValueOptionLoansHeldAsAssets	3940000000	usd
CY2021Q4	us-gaap	Fair Value Option Loans Held As Assets Aggregate Difference FairValueOptionLoansHeldAsAssetsAggregateDifference	130000000	usd
CY2022Q3	wal	Cash Cash Equivalentsand Investment Securities CashCashEquivalentsandInvestmentSecurities	10213000000	usd
CY2022Q3	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	2204000000	usd
CY2022Q3	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	52201000000	usd
CY2022Q3	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	304000000	usd
CY2022Q3	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	51897000000	usd
CY2022Q3	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	11000000	usd
CY2022Q3	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	682000000	usd
CY2022Q3	wal	Other Assets Segment OtherAssetsSegment	4158000000	usd
CY2022Q3	us-gaap	Assets Assets	69165000000	usd
CY2022Q3	us-gaap	Deposits Deposits	55589000000	usd
CY2022Q3	wal	Borrowingsand Qualifying Debt BorrowingsandQualifyingDebt	7208000000	usd
CY2022Q3	wal	Other Liabilities Segment OtherLiabilitiesSegment	1347000000	usd
CY2022Q3	us-gaap	Liabilities Liabilities	64144000000	usd
CY2022Q3	us-gaap	Stockholders Equity StockholdersEquity	5021000000	usd
CY2022Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	69165000000	usd
CY2022Q3	wal	Excess Funds Providedby Usedin Segment Basis ExcessFundsProvidedbyUsedinSegmentBasis	0	usd
CY2022Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	602100000	usd
CY2022Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	28500000	usd
CY2022Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	573600000	usd
CY2022Q3	us-gaap	Noninterest Income NoninterestIncome	61800000	usd
CY2022Q3	us-gaap	Noninterest Expense NoninterestExpense	305800000	usd
CY2022Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	329600000	usd
CY2022Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	65600000	usd
CY2022Q3	us-gaap	Net Income Loss NetIncomeLoss	264000000.0	usd
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1576600000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	65000000.0	usd
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	1511600000	usd
	us-gaap	Noninterest Income NoninterestIncome	263100000	usd
	us-gaap	Noninterest Expense NoninterestExpense	823300000	usd
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	951400000	usd
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	187100000	usd
	us-gaap	Net Income Loss NetIncomeLoss	764300000	usd
CY2021Q4	wal	Cash Cash Equivalentsand Investment Securities CashCashEquivalentsandInvestmentSecurities	8057000000	usd
CY2021Q4	us-gaap	Loans Receivable Held For Sale Amount LoansReceivableHeldForSaleAmount	5635000000	usd
CY2021Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	39075000000	usd
CY2021Q4	us-gaap	Loans And Leases Receivable Allowance LoansAndLeasesReceivableAllowance	252000000	usd
CY2021Q4	us-gaap	Loans And Leases Receivable Net Reported Amount LoansAndLeasesReceivableNetReportedAmount	38823000000	usd
CY2021Q4	us-gaap	Other Foreclosed Assets OtherForeclosedAssets	12000000	usd
CY2021Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	635000000	usd
CY2021Q4	wal	Other Assets Segment OtherAssetsSegment	2821000000	usd
CY2021Q4	us-gaap	Assets Assets	55983000000	usd
CY2021Q4	us-gaap	Deposits Deposits	47612000000	usd
CY2021Q4	wal	Borrowingsand Qualifying Debt BorrowingsandQualifyingDebt	2398000000	usd
CY2021Q4	wal	Other Liabilities Segment OtherLiabilitiesSegment	1010000000	usd
CY2021Q4	us-gaap	Liabilities Liabilities	51020000000	usd
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	4963000000	usd
CY2021Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	55983000000	usd
CY2021Q4	wal	Excess Funds Providedby Usedin Segment Basis ExcessFundsProvidedbyUsedinSegmentBasis	0	usd
CY2021Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	410400000	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
CY2022Q3	wal	Revenue From Contracts With Customers RevenueFromContractsWithCustomers	9000000	usd
CY2021Q3	wal	Revenue From Contracts With Customers RevenueFromContractsWithCustomers	9000000	usd
	wal	Revenue From Contracts With Customers RevenueFromContractsWithCustomers	34600000	usd
	wal	Revenue From Contracts With Customers RevenueFromContractsWithCustomers	27600000	usd

Files In Submission

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$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal

2022 Q4 Form 10-Q Financial Statement

#000121254522000155 Filed on November 01, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WAL WESTERN ALLIANCE BANCORPORATION Stock $wal

2022 Q4 Form 10-Q Financial Statement

#000121254522000155 Filed on November 01, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WAL
WESTERN ALLIANCE BANCORPORATION Stock $wal