$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc

$wtfc Overview Financials Valuation SEC Filings Company Website

2024 Q4 Form 10-Q Financial Statement

#000101532824000253 Filed on November 08, 2024

Income Statement

Concept	2024 Q4	2024 Q3
Revenue		$615.7M
YoY Change		7.11%
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		$25.74M
YoY Change		-6.73%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense		$406.0M
YoY Change		35.32%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income		$232.7M
YoY Change		3.49%
Income Tax		$62.71M
% Of Pretax Income		26.95%
Net Earnings		$163.0M
YoY Change		-0.72%
Net Earnings / Revenue		26.47%
Basic Earnings Per Share		$2.51
Diluted Earnings Per Share		$2.47
COMMON SHARES
Basic Shares Outstanding	66.49M shares	66.50M shares
Diluted Shares Outstanding		65.94M shares

Balance Sheet

Concept	2024 Q4	2024 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents		$731.1M
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		$772.0M
YoY Change		3.28%
Goodwill		$800.8M
YoY Change		22.05%
Intangibles		$123.9M
YoY Change		410.91%
Long-Term Investments
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets		$63.79B
YoY Change		14.82%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable		$1.614B
YoY Change		-14.44%
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt		$0.00
YoY Change		-100.0%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities		$1.614B
YoY Change		-15.07%
LONG-TERM LIABILITIES
Long-Term Debt		$1.199B
YoY Change		-9.25%
Other Long-Term Liabilities
YoY Change
Total Long-Term Liabilities		$1.199B
YoY Change		-9.25%
TOTAL LIABILITIES
Total Short-Term Liabilities		$1.614B
Total Long-Term Liabilities		$1.199B
Total Liabilities		$57.39B
YoY Change		13.55%
SHAREHOLDERS EQUITY
Retained Earnings		$3.749B
YoY Change		15.23%
Common Stock		$66.55M
YoY Change		8.66%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity		$6.400B
YoY Change
Total Liabilities & Shareholders Equity		$63.79B
YoY Change		14.82%

Cashflow Statement

Concept	2024 Q4	2024 Q3
OPERATING ACTIVITIES
Net Income		$163.0M
YoY Change		-0.72%
Depreciation, Depletion And Amortization		$25.74M
YoY Change		-6.73%
Cash From Operating Activities		-$61.63M
YoY Change		-169.87%
INVESTING ACTIVITIES
Capital Expenditures		$16.70M
YoY Change		-16.09%
Acquisitions
YoY Change
Other Investing Activities		-$646.7M
YoY Change		-53.02%
Cash From Investing Activities		-$663.4M
YoY Change		-52.5%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities		1.041B
YoY Change		-14.17%
NET CHANGE
Cash From Operating Activities		-61.63M
Cash From Investing Activities		-663.4M
Cash From Financing Activities		1.041B
Net Change In Cash		315.6M
YoY Change		-429.1%
FREE CASH FLOW
Cash From Operating Activities		-$61.63M
Capital Expenditures		$16.70M
Free Cash Flow		-$78.32M
YoY Change		-214.68%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Entity Central Index Key EntityCentralIndexKey	0001015328
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2024-09-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity Registrant Name EntityRegistrantName	WINTRUST FINANCIAL CORP
	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	IL
	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	36-3873352
	dei	Entity Address Address Line1 EntityAddressAddressLine1	9700 W. Higgins Road, Suite 800
	dei	Entity Address City Or Town EntityAddressCityOrTown	Rosemont
	dei	Entity Address State Or Province EntityAddressStateOrProvince	IL
	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	60018
	dei	City Area Code CityAreaCode	847
	dei	Local Phone Number LocalPhoneNumber	939-9000
	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
CY2024Q4	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	66492204	shares
CY2024Q3	us-gaap	Cash And Due From Banks CashAndDueFromBanks	725465000	usd
CY2023Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	423404000	usd
CY2023Q3	us-gaap	Cash And Due From Banks CashAndDueFromBanks	418088000	usd
CY2024Q3	us-gaap	Federal Funds Sold And Securities Purchased Under Agreements To Resell FederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	5663000	usd
CY2023Q4	us-gaap	Federal Funds Sold And Securities Purchased Under Agreements To Resell FederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	60000	usd
CY2023Q3	us-gaap	Federal Funds Sold And Securities Purchased Under Agreements To Resell FederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	60000	usd
CY2024Q3	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	3648117000	usd
CY2023Q3	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	2448570000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3856916000	usd
CY2023Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3909150000	usd
CY2024Q3	us-gaap	Trading Securities Debt TradingSecuritiesDebt	3472000	usd
CY2023Q4	us-gaap	Trading Securities Debt TradingSecuritiesDebt	4707000	usd
CY2023Q3	us-gaap	Trading Securities Debt TradingSecuritiesDebt	1663000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	125310000	usd
CY2023Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	139268000	usd
CY2023Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	134310000	usd
CY2024Q3	us-gaap	Federal Home Loan Bank Stock And Federal Reserve Bank Stock FederalHomeLoanBankStockAndFederalReserveBankStock	266908000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Stock And Federal Reserve Bank Stock FederalHomeLoanBankStockAndFederalReserveBankStock	205003000	usd
CY2023Q3	us-gaap	Federal Home Loan Bank Stock And Federal Reserve Bank Stock FederalHomeLoanBankStockAndFederalReserveBankStock	204040000	usd
CY2024Q3	us-gaap	Receivables From Brokers Dealers And Clearing Organizations ReceivablesFromBrokersDealersAndClearingOrganizations	16662000	usd
CY2023Q4	us-gaap	Receivables From Brokers Dealers And Clearing Organizations ReceivablesFromBrokersDealersAndClearingOrganizations	10592000	usd
CY2023Q3	us-gaap	Receivables From Brokers Dealers And Clearing Organizations ReceivablesFromBrokersDealersAndClearingOrganizations	14042000	usd
CY2024Q3	us-gaap	Loans Receivable Held For Sale Net Not Part Of Disposal Group LoansReceivableHeldForSaleNetNotPartOfDisposalGroup	461067000	usd
CY2023Q4	us-gaap	Loans Receivable Held For Sale Net Not Part Of Disposal Group LoansReceivableHeldForSaleNetNotPartOfDisposalGroup	292722000	usd
CY2023Q3	us-gaap	Loans Receivable Held For Sale Net Not Part Of Disposal Group LoansReceivableHeldForSaleNetNotPartOfDisposalGroup	304808000	usd
CY2024Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	772002000	usd
CY2023Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	748966000	usd
CY2023Q3	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	747501000	usd
CY2024Q3	us-gaap	Net Investment In Lease NetInvestmentInLease	270171000	usd
CY2023Q4	us-gaap	Net Investment In Lease NetInvestmentInLease	281280000	usd
CY2024Q3	us-gaap	Assets Assets	63788424000	usd
CY2023Q4	us-gaap	Assets Assets	56259934000	usd
CY2023Q3	us-gaap	Assets Assets	55555246000	usd
CY2024Q3	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10739132000	usd
CY2023Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10420401000	usd
CY2023Q3	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10347006000	usd
CY2024Q3	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	40665834000	usd
CY2023Q4	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	34976769000	usd
CY2023Q3	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	34645680000	usd
CY2024Q3	us-gaap	Deposits Deposits	51404966000	usd
CY2023Q4	us-gaap	Deposits Deposits	45397170000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	2326071000	usd
CY2023Q3	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	2326071000	usd
CY2024Q3	us-gaap	Other Borrowings OtherBorrowings	647043000	usd
CY2023Q4	us-gaap	Other Borrowings OtherBorrowings	645813000	usd
CY2023Q3	us-gaap	Other Borrowings OtherBorrowings	643999000	usd
CY2024Q3	us-gaap	Subordinated Debt SubordinatedDebt	298188000	usd
CY2023Q4	us-gaap	Subordinated Debt SubordinatedDebt	437866000	usd
CY2023Q3	us-gaap	Subordinated Debt SubordinatedDebt	437731000	usd
CY2024Q3	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	253566000	usd
CY2023Q4	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	253566000	usd
CY2023Q3	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	253566000	usd
CY2024Q3	us-gaap	Accounts Payable And Other Accrued Liabilities AccountsPayableAndOtherAccruedLiabilities	1613638000	usd
CY2023Q3	us-gaap	Accounts Payable And Other Accrued Liabilities AccountsPayableAndOtherAccruedLiabilities	1885580000	usd
CY2024Q3	us-gaap	Liabilities Liabilities	57388710000	usd
CY2023Q4	us-gaap	Liabilities Liabilities	50860408000	usd
CY2023Q3	us-gaap	Liabilities Liabilities	50539633000	usd
CY2023Q3	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2023Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2024Q3	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2023Q3	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1.00
CY2024Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2023Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2024Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	66546351	shares
CY2023Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	61268566	shares
CY2023Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	61243622	shares
CY2024Q3	us-gaap	Common Stock Value CommonStockValue	66546000	usd
CY2023Q4	us-gaap	Common Stock Value CommonStockValue	61269000	usd
CY2023Q3	us-gaap	Common Stock Value CommonStockValue	61244000	usd
CY2024Q3	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	2470228000	usd
CY2023Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	1943806000	usd
CY2023Q3	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	1933226000	usd
CY2024Q3	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	64808	shares
CY2023Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	24940	shares
CY2023Q3	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	21564	shares
CY2024Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	3748715000	usd
CY2023Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	3345399000	usd
CY2023Q3	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	3253332000	usd
CY2024Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-292177000	usd
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-361231000	usd
CY2023Q3	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-642723000	usd
CY2024Q3	us-gaap	Stockholders Equity StockholdersEquity	6399714000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	5399526000	usd
CY2023Q3	us-gaap	Stockholders Equity StockholdersEquity	5015613000	usd
CY2023Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	56259934000	usd
CY2023Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	55555246000	usd
CY2024Q3	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	794163000	usd
CY2023Q3	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	666260000	usd
	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	2254316000	usd
	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	1846009000	usd
CY2024Q3	us-gaap	Interest And Fee Income Loans Held For Sale Mortgages InterestAndFeeIncomeLoansHeldForSaleMortgages	6233000	usd
	us-gaap	Interest And Fee Income Loans Held For Sale Mortgages InterestAndFeeIncomeLoansHeldForSaleMortgages	15813000	usd
	us-gaap	Interest And Fee Income Loans Held For Sale Mortgages InterestAndFeeIncomeLoansHeldForSaleMortgages	12473000	usd
CY2024Q3	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	32608000	usd
CY2023Q3	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	26866000	usd
	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	68997000	usd
	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	57216000	usd
CY2024Q3	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	277000	usd
CY2023Q3	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	1157000	usd
	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	313000	usd
	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	1228000	usd
CY2024Q3	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	69592000	usd
CY2023Q3	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	59164000	usd
	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	209049000	usd
	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	170350000	usd
CY2024Q3	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	11000	usd
CY2023Q3	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	6000	usd
	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	42000	usd
	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	26000	usd
	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	14903000	usd
	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	11120000	usd
CY2024Q3	wtfc	Interest Income Brokerage Customer Receivables InterestIncomeBrokerageCustomerReceivables	269000	usd
CY2023Q3	wtfc	Interest Income Brokerage Customer Receivables InterestIncomeBrokerageCustomerReceivables	284000	usd
	wtfc	Interest Income Brokerage Customer Receivables InterestIncomeBrokerageCustomerReceivables	663000	usd
	wtfc	Interest Income Brokerage Customer Receivables InterestIncomeBrokerageCustomerReceivables	844000	usd
CY2024Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	22334000	usd
CY2023Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	19923000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	84068000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	71482000	usd
CY2024Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	480249000	usd
CY2023Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	442435000	usd
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	1353319000	usd
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	1296408000	usd
CY2024Q3	wtfc	Marketable Securities Gain Loss Including Other Than Temporary Impairment Loss MarketableSecuritiesGainLossIncludingOtherThanTemporaryImpairmentLoss	3189000	usd
CY2023Q3	wtfc	Marketable Securities Gain Loss Including Other Than Temporary Impairment Loss MarketableSecuritiesGainLossIncludingOtherThanTemporaryImpairmentLoss	-2357000	usd
	wtfc	Marketable Securities Gain Loss Including Other Than Temporary Impairment Loss MarketableSecuritiesGainLossIncludingOtherThanTemporaryImpairmentLoss	233000	usd
	wtfc	Marketable Securities Gain Loss Including Other Than Temporary Impairment Loss MarketableSecuritiesGainLossIncludingOtherThanTemporaryImpairmentLoss	-959000	usd
CY2024Q3	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	988000	usd
CY2023Q3	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	4215000	usd
	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	7891000	usd
	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	17184000	usd
CY2024Q3	us-gaap	Trading Gains Losses TradingGainsLosses	-130000	usd
CY2023Q3	us-gaap	Trading Gains Losses TradingGainsLosses	728000	usd
	us-gaap	Trading Gains Losses TradingGainsLosses	617000	usd
	us-gaap	Trading Gains Losses TradingGainsLosses	1647000	usd
CY2024Q3	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	15335000	usd
CY2023Q3	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	13863000	usd
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	43383000	usd
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	39136000	usd
CY2024Q3	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	24137000	usd
CY2023Q3	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	20888000	usd
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	95750000	usd
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	62569000	usd
CY2024Q3	us-gaap	Noninterest Income NoninterestIncome	113147000	usd
CY2023Q3	us-gaap	Noninterest Income NoninterestIncome	112478000	usd
	us-gaap	Noninterest Income NoninterestIncome	374874000	usd
	us-gaap	Noninterest Income NoninterestIncome	333277000	usd
CY2024Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	211261000	usd
CY2023Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	192338000	usd
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	604975000	usd
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	554042000	usd
CY2024Q3	us-gaap	Equipment Expense EquipmentExpense	31574000	usd
CY2023Q3	us-gaap	Equipment Expense EquipmentExpense	25951000	usd
	us-gaap	Equipment Expense EquipmentExpense	76853000	usd
CY2024Q3	wtfc	Lessor Operating Lease Depreciation And Impairment Expense LessorOperatingLeaseDepreciationAndImpairmentExpense	10518000	usd
CY2023Q3	wtfc	Lessor Operating Lease Depreciation And Impairment Expense LessorOperatingLeaseDepreciationAndImpairmentExpense	12020000	usd
	wtfc	Lessor Operating Lease Depreciation And Impairment Expense LessorOperatingLeaseDepreciationAndImpairmentExpense	31669000	usd
CY2024Q3	us-gaap	Occupancy Net OccupancyNet	19945000	usd
CY2023Q3	us-gaap	Occupancy Net OccupancyNet	21304000	usd
	us-gaap	Occupancy Net OccupancyNet	58616000	usd
	us-gaap	Occupancy Net OccupancyNet	58966000	usd
CY2024Q3	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	9984000	usd
CY2023Q3	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	10773000	usd
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	28779000	usd
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	29908000	usd
CY2024Q3	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	18239000	usd
CY2023Q3	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	18169000	usd
	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	48715000	usd
	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	47909000	usd
CY2024Q3	us-gaap	Professional Fees ProfessionalFees	9783000	usd
CY2023Q3	us-gaap	Professional Fees ProfessionalFees	8887000	usd
	us-gaap	Professional Fees ProfessionalFees	29303000	usd
	us-gaap	Professional Fees ProfessionalFees	25990000	usd
CY2024Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	4042000	usd
CY2023Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1408000	usd
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6322000	usd
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	4142000	usd
CY2024Q3	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	10512000	usd
CY2024Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	6991000	usd
CY2023Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	6991000	usd
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	20973000	usd
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	20973000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	478173000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	168166000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-178080000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	69510000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-177271000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	43688000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-47458000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	17594000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-47243000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	124478000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-130622000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	51916000	usd
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-130028000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	45000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	158000	usd
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	1223000	usd
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	720000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	6000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	40000	usd
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	318000	usd
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	192000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	39000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	118000	usd
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	905000	usd
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	528000	usd
CY2024Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	14000	usd
CY2023Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	31000	usd
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	102000	usd
CY2024Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	4000	usd
CY2023Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	8000	usd
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	21000	usd
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	27000	usd
CY2024Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	10000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	347000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3856916000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Restricted DebtSecuritiesAvailableForSaleRestricted	7200000000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Restricted DebtSecuritiesAvailableForSaleRestricted	6900000000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	47067447000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	42131831000	usd
CY2024Q3	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2023Q4	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2024Q3	us-gaap	Financing Receivable Unamortized Loan Commitment Origination Fee And Premium Discount FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount	79400000	usd
CY2023Q4	us-gaap	Financing Receivable Unamortized Loan Commitment Origination Fee And Premium Discount FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount	84200000	usd
CY2024Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	22334000	usd
CY2023Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	19923000	usd
CY2024Q3	wtfc	Change In Contribution Provision For Loan Lease And Other Losses ChangeInContributionProvisionForLoanLeaseAndOtherLosses	2411000	usd
CY2024Q3	wtfc	Change In Contribution Provision For Loan Lease And Other Losses Percentage ChangeInContributionProvisionForLoanLeaseAndOtherLossesPercentage	0.12
CY2023Q3	us-gaap	Noninterest Income NoninterestIncome	112478000	usd
CY2024Q3	wtfc	Change In Contribution Non Interest Income ChangeInContributionNonInterestIncome	669000	usd
CY2024Q3	wtfc	Non Interest Income Percentage NonInterestIncomePercentage	0.01
CY2024Q3	us-gaap	Revenues Revenues	615730000	usd
CY2023Q3	us-gaap	Revenues Revenues	574836000	usd
CY2024Q3	wtfc	Change In Contribution Revenues ChangeInContributionRevenues	40894000	usd
CY2024Q3	wtfc	Revenues Percentage RevenuesPercentage	0.07
CY2024Q3	us-gaap	Net Income Loss NetIncomeLoss	170001000	usd
CY2023Q3	us-gaap	Net Income Loss NetIncomeLoss	164198000	usd
CY2024Q3	wtfc	Change In Contribution Operating Income Loss ChangeInContributionOperatingIncomeLoss	5803000	usd
CY2024Q3	wtfc	Operating Income Loss Percentage OperatingIncomeLossPercentage	0.04
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2024
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q3
CY2024Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3912232000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3502915000	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3611835000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	479000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	347000	usd
CY2023Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	381000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3100000000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3200000000	usd
CY2023Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3100000000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3677420000	usd
CY2023Q3	us-gaap	Net Investment In Lease NetInvestmentInLease	275152000	usd
CY2024Q3	us-gaap	Interest Receivable And Other Assets InterestReceivableAndOtherAssets	1721090000	usd
CY2023Q4	us-gaap	Interest Receivable And Other Assets InterestReceivableAndOtherAssets	1551899000	usd
CY2023Q3	us-gaap	Interest Receivable And Other Assets InterestReceivableAndOtherAssets	1674681000	usd
CY2024Q3	wtfc	Trade Date Securities Receivable TradeDateSecuritiesReceivable	551031000	usd
CY2023Q4	wtfc	Trade Date Securities Receivable TradeDateSecuritiesReceivable	690722000	usd
CY2023Q3	wtfc	Trade Date Securities Receivable TradeDateSecuritiesReceivable	0	usd
CY2024Q3	us-gaap	Goodwill Goodwill	800780000	usd
CY2023Q4	us-gaap	Goodwill Goodwill	656672000	usd
CY2023Q3	us-gaap	Goodwill Goodwill	656109000	usd
CY2024Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	123866000	usd
CY2023Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	22889000	usd
CY2023Q3	us-gaap	Deposits Deposits	44992686000	usd
CY2024Q3	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	3171309000	usd
CY2023Q4	us-gaap	Accounts Payable And Other Accrued Liabilities AccountsPayableAndOtherAccruedLiabilities	1799922000	usd
CY2023Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1.00
CY2024Q3	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1.00
CY2024Q3	us-gaap	Treasury Stock Common Value TreasuryStockCommonValue	6098000	usd
CY2023Q4	us-gaap	Treasury Stock Common Value TreasuryStockCommonValue	2217000	usd
CY2023Q3	us-gaap	Treasury Stock Common Value TreasuryStockCommonValue	1966000	usd
CY2024Q3	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	63788424000	usd
CY2023Q3	us-gaap	Interest And Fee Income Loans Held For Sale Mortgages InterestAndFeeIncomeLoansHeldForSaleMortgages	4767000	usd
CY2024Q3	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	5451000	usd
CY2023Q3	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	3896000	usd
CY2023Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	762400000	usd
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	2564096000	usd
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	2099266000	usd
CY2024Q3	us-gaap	Interest Expense Deposits InterestExpenseDeposits	362019000	usd
CY2023Q3	us-gaap	Interest Expense Deposits InterestExpenseDeposits	262783000	usd
	us-gaap	Interest Expense Deposits InterestExpenseDeposits	997254000	usd
	us-gaap	Interest Expense Deposits InterestExpenseDeposits	621080000	usd
CY2024Q3	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	26254000	usd
CY2023Q3	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	17436000	usd
	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	73099000	usd
	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	53970000	usd
CY2023Q3	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	9384000	usd
	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	26961000	usd
	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	25723000	usd
CY2024Q3	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	3712000	usd
	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	14384000	usd
	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	16502000	usd
CY2024Q3	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	5023000	usd
	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	15011000	usd
	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	14101000	usd
CY2024Q3	us-gaap	Interest Expense InterestExpense	406021000	usd
CY2023Q3	us-gaap	Interest Expense InterestExpense	300042000	usd
	us-gaap	Interest Expense InterestExpense	1126709000	usd
	us-gaap	Interest Expense InterestExpense	731376000	usd
	us-gaap	Equipment Expense EquipmentExpense	88536000	usd
	wtfc	Lessor Operating Lease Depreciation And Impairment Expense LessorOperatingLeaseDepreciationAndImpairmentExpense	32035000	usd
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	35478000	usd
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	27425000	usd
CY2024Q3	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	938000	usd
CY2023Q3	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	-120000	usd
	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	805000	usd
	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	-31000	usd
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	102231000	usd
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	92912000	usd
CY2024Q3	us-gaap	Noninterest Expense NoninterestExpense	360687000	usd
CY2023Q3	us-gaap	Noninterest Expense NoninterestExpense	330055000	usd
	us-gaap	Noninterest Expense NoninterestExpense	1034185000	usd
	us-gaap	Noninterest Expense NoninterestExpense	949847000	usd
CY2024Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	232709000	usd
CY2023Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	224858000	usd
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	694008000	usd
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	679838000	usd
CY2024Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	62708000	usd
CY2023Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	60660000	usd
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	184325000	usd
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	180692000	usd
CY2023Q3	us-gaap	Net Income Loss NetIncomeLoss	164198000	usd
	us-gaap	Net Income Loss NetIncomeLoss	509683000	usd
	us-gaap	Net Income Loss NetIncomeLoss	499146000	usd
CY2024Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	163010000	usd
CY2023Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	157207000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	488710000	usd
CY2024Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.51
CY2023Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.57
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.79
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.82
CY2024Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.47
CY2023Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.53
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.67
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.71
CY2024Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.45
CY2023Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.35
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.20
CY2023Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	61213000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	62743000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	61119000	shares
CY2024Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1053000	shares
CY2023Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	964000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	934000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	888000	shares
CY2024Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	65941000	shares
CY2023Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	62177000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	63677000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	62007000	shares
CY2024Q3	us-gaap	Net Income Loss NetIncomeLoss	170001000	usd
CY2023Q3	us-gaap	Net Income Loss NetIncomeLoss	164198000	usd
	us-gaap	Net Income Loss NetIncomeLoss	509683000	usd
	us-gaap	Net Income Loss NetIncomeLoss	499146000	usd
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	78000	usd
CY2023Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	23000	usd
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	57000	usd
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	75000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	124429000	usd
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	50954000	usd
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-130631000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	124848000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-43082000	usd
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	31914000	usd
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-114847000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	32460000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-11482000	usd
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	7879000	usd
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-30607000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	92388000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-31600000	usd
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	24035000	usd
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-84240000	usd
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-7323000	usd
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-942000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	680000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-2089000	usd
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-1388000	usd
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-726000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	3204000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-6270000	usd
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-5935000	usd
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-216000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	220021000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-168633000	usd
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	69054000	usd
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-215087000	usd
CY2024Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	390022000	usd
CY2023Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-4435000	usd
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	578737000	usd
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	284059000	usd
CY2023Q2	us-gaap	Stockholders Equity StockholdersEquity	5041912000	usd
CY2023Q3	us-gaap	Net Income Loss NetIncomeLoss	164198000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-168633000	usd
CY2023Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2023Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	24501000	usd
CY2023Q3	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	6991000	usd
CY2023Q3	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	8130000	usd
	us-gaap	Net Income Loss NetIncomeLoss	499146000	usd
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-215087000	usd
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.20
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	73304000	usd
	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	20973000	usd
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	24532000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	84068000	usd
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	70884000	usd
	us-gaap	Share Based Compensation ShareBasedCompensation	27568000	usd
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	1380000	usd
	us-gaap	Mortgage Servicing Rights Msr Impairment Recovery MortgageServicingRightsMSRImpairmentRecovery	26106000	usd
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-54507000	usd
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	1964576000	usd
	wtfc	Early Buyout Exercises Of Guaranteed Mortgage Loans Held For Sale EarlyBuyoutExercisesOfGuaranteedMortgageLoansHeldForSale	22558000	usd
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	1824513000	usd
	wtfc	Gain Loss On Bank Owned Life Insurance Net Of Claims GainLossOnBankOwnedLifeInsuranceNetOfClaims	4519000	usd
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-1235000	usd
	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	47978000	usd
	us-gaap	Premiums Receivable Gain Loss On Sale Of Receivables PremiumsReceivableGainLossOnSaleOfReceivables	4575000	usd
	us-gaap	Gain Loss On Investments GainLossOnInvestments	233000	usd
	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	93000	usd
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	1234000	usd
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	46711000	usd
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-256022000	usd
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	230739000	usd
	us-gaap	Proceeds From Payments For In Interest Bearing Deposits In Banks ProceedsFromPaymentsForInInterestBearingDepositsInBanks	-1566241000	usd
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	4361365000	usd
	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	304000	usd
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	66457000	usd
	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	7352000	usd
	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	57000	usd
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	3881000	usd
	us-gaap	Payments Of Dividends PaymentsOfDividends	106367000	usd
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	4304855000	usd
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	307664000	usd
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	423464000	usd
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	490966000	usd
CY2024Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	731128000	usd
	dei	Amendment Flag AmendmentFlag	false
CY2023Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	2084323000	usd
CY2023Q3	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2022	us-gaap	Accounting Standards Update Extensible List AccountingStandardsUpdateExtensibleList	http://fasb.org/us-gaap/2024#AccountingStandardsUpdate202202Member
CY2024Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	908604000	usd
CY2024Q3	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	9013000	usd
CY2023Q3	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	5491000	usd
CY2023Q3	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	4948000	usd
CY2024Q3	wtfc	Revenues Wealth Management RevenuesWealthManagement	37224000	usd
CY2023Q3	wtfc	Revenues Wealth Management RevenuesWealthManagement	33529000	usd
	wtfc	Revenues Wealth Management RevenuesWealthManagement	107452000	usd
	wtfc	Revenues Wealth Management RevenuesWealthManagement	97332000	usd
CY2024Q3	wtfc	Revenues Mortgage Banking RevenuesMortgageBanking	15974000	usd
CY2023Q3	wtfc	Revenues Mortgage Banking RevenuesMortgageBanking	27395000	usd
	wtfc	Revenues Mortgage Banking RevenuesMortgageBanking	72761000	usd
	wtfc	Revenues Mortgage Banking RevenuesMortgageBanking	75640000	usd
CY2024Q3	wtfc	Revenues Service Charges RevenuesServiceCharges	16430000	usd
CY2023Q3	wtfc	Revenues Service Charges RevenuesServiceCharges	14217000	usd
	wtfc	Revenues Service Charges RevenuesServiceCharges	46787000	usd
	wtfc	Revenues Service Charges RevenuesServiceCharges	40728000	usd
CY2023Q3	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	9748000	usd
CY2024Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	35767000	usd
CY2023Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	29337000	usd
CY2024Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	64888000	shares
CY2023Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-130763000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	3884000	usd
CY2023Q3	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	usd
CY2023Q3	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	816000	usd
CY2023Q3	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	682000	usd
CY2023Q3	us-gaap	Stockholders Equity StockholdersEquity	5015613000	usd
CY2022Q4	us-gaap	Stockholders Equity StockholdersEquity	4796838000	usd
	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	2216000	usd
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-1662000	usd
	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2418000	usd
	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	2033000	usd
CY2024Q2	us-gaap	Stockholders Equity StockholdersEquity	5536628000	usd
CY2024Q3	us-gaap	Net Income Loss NetIncomeLoss	170001000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	220021000	usd
CY2024Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.45
CY2024Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	29911000	usd
CY2024Q3	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	6991000	usd
CY2024Q3	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	9461000	usd
CY2023Q3	us-gaap	Financing Receivable Modification To Total Financing Receivables Excluding Accrued Interest Percent FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent	0.000
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023Q3	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss Statement Of Financial Position Extensible List FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLossStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2024#InterestReceivableAndOtherAssets
CY2023Q4	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss Statement Of Financial Position Extensible List FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLossStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2024#InterestReceivableAndOtherAssets
CY2024Q3	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss Statement Of Financial Position Extensible List FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLossStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2024#InterestReceivableAndOtherAssets
CY2023Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	24244000	usd
CY2024Q3	us-gaap	Interest Revenue Expense Net InterestRevenueExpenseNet	502583000	usd
CY2023Q3	us-gaap	Interest Revenue Expense Net InterestRevenueExpenseNet	462358000	usd
	us-gaap	Interest Revenue Expense Net InterestRevenueExpenseNet	1437387000	usd
	us-gaap	Interest Revenue Expense Net InterestRevenueExpenseNet	1367890000	usd
CY2024Q3	us-gaap	Net Income Loss NetIncomeLoss	170001000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-8359000	usd
CY2023Q3	us-gaap	Stockholders Equity StockholdersEquity	5015613000	usd
CY2024Q3	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	499239000	usd
CY2024Q3	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-338000	usd
CY2024Q3	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	797000	usd
CY2024Q3	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	807000	usd
CY2024Q3	us-gaap	Stockholders Equity StockholdersEquity	6399714000	usd
CY2023Q4	us-gaap	Stockholders Equity StockholdersEquity	5399526000	usd
	us-gaap	Net Income Loss NetIncomeLoss	509683000	usd
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	69054000	usd
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.35
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	85394000	usd
	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	20973000	usd
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	27568000	usd
	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	499239000	usd
	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	25000	usd
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-3877000	usd
	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2440000	usd
	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	2423000	usd
CY2024Q3	us-gaap	Stockholders Equity StockholdersEquity	6399714000	usd
	us-gaap	Net Income Loss NetIncomeLoss	509683000	usd
	us-gaap	Net Income Loss NetIncomeLoss	499146000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	71482000	usd
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	62591000	usd
	us-gaap	Share Based Compensation ShareBasedCompensation	24532000	usd
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-1201000	usd
	wtfc	Accretion Amortization Of Discounts And Premiums On Loans AccretionAmortizationOfDiscountsAndPremiumsOnLoans	11876000	usd
	wtfc	Accretion Amortization Of Discounts And Premiums On Loans AccretionAmortizationOfDiscountsAndPremiumsOnLoans	13105000	usd
	us-gaap	Mortgage Servicing Rights Msr Impairment Recovery MortgageServicingRightsMSRImpairmentRecovery	13065000	usd
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	271000	usd
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	1532325000	usd
	wtfc	Early Buyout Exercises Of Guaranteed Mortgage Loans Held For Sale EarlyBuyoutExercisesOfGuaranteedMortgageLoansHeldForSale	-9323000	usd
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	1500870000	usd
	wtfc	Gain Loss On Bank Owned Life Insurance Net Of Claims GainLossOnBankOwnedLifeInsuranceNetOfClaims	2849000	usd
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	536000	usd
	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	6070000	usd
	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	-2345000	usd
	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	27777000	usd
	us-gaap	Premiums Receivable Gain Loss On Sale Of Receivables PremiumsReceivableGainLossOnSaleOfReceivables	890000	usd
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-959000	usd
	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-1547000	usd
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-121000	usd
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	269677000	usd
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	156697000	usd
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	496449000	usd
	wtfc	Proceeds From Sale And Calls Of Debt Securities Available For Sale ProceedsFromSaleAndCallsOfDebtSecuritiesAvailableForSale	1218695000	usd
	wtfc	Proceeds From Sale And Calls Of Debt Securities Available For Sale ProceedsFromSaleAndCallsOfDebtSecuritiesAvailableForSale	1879682000	usd
	wtfc	Proceeds From Maturities Of Debt Securities Available For Sale ProceedsFromMaturitiesOfDebtSecuritiesAvailableForSale	360773000	usd
	wtfc	Proceeds From Maturities Of Debt Securities Available For Sale ProceedsFromMaturitiesOfDebtSecuritiesAvailableForSale	227519000	usd
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	178553000	usd
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	138154000	usd
	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	51792000	usd
	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	23592000	usd
	wtfc	Proceeds From Sales And Capital Distributions Of Equity Securities Without Readily Determinable Fair Value ProceedsFromSalesAndCapitalDistributionsOfEquitySecuritiesWithoutReadilyDeterminableFairValue	2226000	usd
	wtfc	Proceeds From Sales And Capital Distributions Of Equity Securities Without Readily Determinable Fair Value ProceedsFromSalesAndCapitalDistributionsOfEquitySecuritiesWithoutReadilyDeterminableFairValue	67000	usd
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1116875000	usd
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1731266000	usd
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	usd
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	407527000	usd
	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	33322000	usd
	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	45954000	usd
	wtfc	Payments To Acquire Equity Securities Without Readily Determinable Fair Value PaymentsToAcquireEquitySecuritiesWithoutReadilyDeterminableFairValue	6933000	usd
	wtfc	Payments To Acquire Equity Securities Without Readily Determinable Fair Value PaymentsToAcquireEquitySecuritiesWithoutReadilyDeterminableFairValue	9350000	usd
	wtfc	Payments For Proceeds From Federal Home Loan And Federal Reserve Bank Stock PaymentsForProceedsFromFederalHomeLoanAndFederalReserveBankStock	61905000	usd
	wtfc	Payments For Proceeds From Federal Home Loan And Federal Reserve Bank Stock PaymentsForProceedsFromFederalHomeLoanAndFederalReserveBankStock	-20719000	usd
	us-gaap	Payments For Proceeds From Limited Partnership PaymentsForProceedsFromLimitedPartnership	-2586000	usd
	us-gaap	Payments For Proceeds From Limited Partnership PaymentsForProceedsFromLimitedPartnership	-5540000	usd
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	-531308000	usd
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	5147000	usd
	us-gaap	Premiums Receivable Proceeds From Sale Of Receivables PremiumsReceivableProceedsFromSaleOfReceivables	627450000	usd
	us-gaap	Premiums Receivable Proceeds From Sale Of Receivables PremiumsReceivableProceedsFromSaleOfReceivables	405560000	usd
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	11481000	usd
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	1635000	usd
	us-gaap	Proceeds From Payments For In Interest Bearing Deposits In Banks ProceedsFromPaymentsForInInterestBearingDepositsInBanks	-458115000	usd
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	2644535000	usd
	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	553000	usd
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	29218000	usd
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-4227930000	usd
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-2628091000	usd
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	3697621000	usd
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	2090137000	usd
	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	48016000	usd
	us-gaap	Increase Decrease In Loans From Other Federal Home Loan Banks IncreaseDecreaseInLoansFromOtherFederalHomeLoanBanks	845238000	usd
	us-gaap	Increase Decrease In Loans From Other Federal Home Loan Banks IncreaseDecreaseInLoansFromOtherFederalHomeLoanBanks	10000000	usd
	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	0	usd
	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	140000000	usd
	us-gaap	Repayments Of Subordinated Debt RepaymentsOfSubordinatedDebt	0	usd
	wtfc	Issuance Of Common Shares Resulting From Exercise Of Share Based Compensation Awards IssuanceOfCommonSharesResultingFromExerciseOfShareBasedCompensationAwards	4892000	usd
	wtfc	Issuance Of Common Shares Resulting From Exercise Of Share Based Compensation Awards IssuanceOfCommonSharesResultingFromExerciseOfShareBasedCompensationAwards	6667000	usd
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1662000	usd
	us-gaap	Payments Of Dividends PaymentsOfDividends	94277000	usd
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	2058824000	usd
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-72818000	usd
CY2023Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	418148000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	4320843000	usd
CY2024Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	11552000	usd
CY2024Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	420163000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3912232000	usd
CY2024Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	3677899000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	7526000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	563605000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3121820000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	479000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3677420000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	127700000	usd
CY2024Q3	wtfc	Equity Securities Fvni Accumulated Unrealized Gain EquitySecuritiesFVNIAccumulatedUnrealizedGain	4313000	usd
CY2024Q3	wtfc	Equity Securities Fvni Accumulated Unrealized Loss EquitySecuritiesFVNIAccumulatedUnrealizedLoss	6703000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	125310000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	3979814000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	3525000	usd
CY2023Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	480424000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3502915000	usd
CY2023Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	3857263000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	3472000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	645267000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3215468000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	347000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3856916000	usd
CY2023Q4	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	143312000	usd
CY2023Q4	wtfc	Equity Securities Fvni Accumulated Unrealized Gain EquitySecuritiesFVNIAccumulatedUnrealizedGain	3500000	usd
CY2023Q4	wtfc	Equity Securities Fvni Accumulated Unrealized Loss EquitySecuritiesFVNIAccumulatedUnrealizedLoss	7544000	usd
CY2023Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	139268000	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	4315723000	usd
CY2023Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	50000	usd
CY2023Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	703938000	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3611835000	usd
CY2023Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	3909531000	usd
CY2023Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	123000	usd
CY2023Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	851695000	usd
CY2023Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3057959000	usd
CY2023Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	381000	usd
CY2023Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3909150000	usd
CY2023Q3	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	140749000	usd
CY2023Q3	wtfc	Equity Securities Fvni Accumulated Unrealized Gain EquitySecuritiesFVNIAccumulatedUnrealizedGain	3290000	usd
CY2023Q3	wtfc	Equity Securities Fvni Accumulated Unrealized Loss EquitySecuritiesFVNIAccumulatedUnrealizedLoss	9729000	usd
CY2023Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	134310000	usd
CY2024Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Amount EquitySecuritiesWithoutReadilyDeterminableFairValueAmount	64100000	usd
	us-gaap	Equity Securities Without Readily Determinable Fair Value Downward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentAnnualAmount	0	usd
CY2024Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Upward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount	0	usd
CY2023Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Upward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount	0	usd
	us-gaap	Equity Securities Without Readily Determinable Fair Value Upward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount	0	usd
	us-gaap	Equity Securities Without Readily Determinable Fair Value Downward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentAnnualAmount	0	usd
	us-gaap	Equity Securities Without Readily Determinable Fair Value Upward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentAnnualAmount	0	usd
CY2024Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Downward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentAnnualAmount	0	usd
CY2023Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Downward Price Adjustment Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentAnnualAmount	0	usd
CY2024Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Impairment Loss Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount	0	usd
	us-gaap	Equity Securities Without Readily Determinable Fair Value Impairment Loss Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount	3700000	usd
	us-gaap	Equity Securities Without Readily Determinable Fair Value Impairment Loss Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount	489000	usd
CY2023Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Impairment Loss Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount	489000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	111475000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	1326000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	2563051000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	418837000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	2674526000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	420163000	usd
CY2024Q3	wtfc	Marketable Securities Gross Realized Gains Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedGainsExcludingOtherThanTemporaryImpairments	222000	usd
CY2023Q3	wtfc	Marketable Securities Gross Realized Gains Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedGainsExcludingOtherThanTemporaryImpairments	225000	usd
	wtfc	Marketable Securities Gross Realized Gains Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedGainsExcludingOtherThanTemporaryImpairments	2582000	usd
	wtfc	Marketable Securities Gross Realized Gains Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedGainsExcludingOtherThanTemporaryImpairments	836000	usd
CY2024Q3	wtfc	Marketable Securities Gross Realized Losses Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments	144000	usd
CY2023Q3	wtfc	Marketable Securities Gross Realized Losses Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments	9000	usd
	wtfc	Marketable Securities Gross Realized Losses Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments	273000	usd
	wtfc	Marketable Securities Gross Realized Losses Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments	60000	usd
CY2024Q3	us-gaap	Marketable Securities Realized Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments	78000	usd
CY2023Q3	us-gaap	Marketable Securities Realized Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments	216000	usd
	us-gaap	Marketable Securities Realized Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments	2309000	usd
	us-gaap	Marketable Securities Realized Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments	776000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain EquitySecuritiesFvNiUnrealizedGain	3126000	usd
CY2023Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain EquitySecuritiesFvNiUnrealizedGain	10000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Gain EquitySecuritiesFvNiUnrealizedGain	4234000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Gain EquitySecuritiesFvNiUnrealizedGain	2984000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni Unrealized Loss EquitySecuritiesFvNiUnrealizedLoss	15000	usd
CY2023Q3	us-gaap	Equity Securities Fv Ni Unrealized Loss EquitySecuritiesFvNiUnrealizedLoss	2094000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Loss EquitySecuritiesFvNiUnrealizedLoss	2579000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Loss EquitySecuritiesFvNiUnrealizedLoss	4230000	usd
CY2024Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	3111000	usd
CY2023Q3	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-2084000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	1655000	usd
	us-gaap	Equity Securities Fv Ni Unrealized Gain Loss EquitySecuritiesFvNiUnrealizedGainLoss	-1246000	usd
CY2024Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Impairment Loss Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount	0	usd
CY2023Q3	us-gaap	Equity Securities Without Readily Determinable Fair Value Impairment Loss Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount	489000	usd
	us-gaap	Equity Securities Without Readily Determinable Fair Value Impairment Loss Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount	3731000	usd
	us-gaap	Equity Securities Without Readily Determinable Fair Value Impairment Loss Annual Amount EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLossAnnualAmount	489000	usd
CY2024Q3	wtfc	Marketable Securities Gain Loss Including Other Than Temporary Impairment Loss MarketableSecuritiesGainLossIncludingOtherThanTemporaryImpairmentLoss	3189000	usd
CY2023Q3	wtfc	Marketable Securities Gain Loss Including Other Than Temporary Impairment Loss MarketableSecuritiesGainLossIncludingOtherThanTemporaryImpairmentLoss	-2357000	usd
	wtfc	Marketable Securities Gain Loss Including Other Than Temporary Impairment Loss MarketableSecuritiesGainLossIncludingOtherThanTemporaryImpairmentLoss	233000	usd
	wtfc	Marketable Securities Gain Loss Including Other Than Temporary Impairment Loss MarketableSecuritiesGainLossIncludingOtherThanTemporaryImpairmentLoss	-959000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	150539000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	150627000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	53162000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	52945000	usd
CY2023Q3	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	99892000	usd
CY2023Q3	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	99525000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	168856000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	164650000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	132348000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	123985000	usd
CY2023Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	139623000	usd
CY2023Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	130036000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	91620000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	89220000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	82040000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	76869000	usd
CY2023Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	43199000	usd
CY2023Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	38074000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	23834000	usd
CY2024Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	21809000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	18705000	usd
CY2023Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	15782000	usd
CY2023Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	64419000	usd
CY2023Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	54855000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	4320843000	usd
CY2024Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3912232000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	3979814000	usd
CY2023Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3502915000	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	4315723000	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3611835000	usd
CY2024Q3	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	12026000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	11883000	usd
CY2023Q4	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	5169000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	5142000	usd
CY2023Q3	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	2248000	usd
CY2023Q3	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	2241000	usd
CY2024Q3	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	110330000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	108416000	usd
CY2023Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	109602000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	105835000	usd
CY2023Q3	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	103104000	usd
CY2023Q3	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	96546000	usd
CY2024Q3	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	84580000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	83918000	usd
CY2023Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	99700000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	98718000	usd
CY2023Q3	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	106042000	usd
CY2023Q3	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	100215000	usd
CY2024Q3	us-gaap	Heldtomaturity Securities Debt Maturities Rolling After Ten Years Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost	329808000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	271954000	usd
CY2023Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling After Ten Years Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost	352474000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	283506000	usd
CY2023Q3	us-gaap	Heldtomaturity Securities Debt Maturities Rolling After Ten Years Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost	362183000	usd
CY2023Q3	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	270722000	usd
CY2024Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	3677899000	usd
CY2024Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3121820000	usd
CY2023Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	3857263000	usd
CY2023Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3215468000	usd
CY2023Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	3909531000	usd
CY2023Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3057959000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	479000	usd
CY2023Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	381000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3677420000	usd
CY2023Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3909150000	usd
CY2023Q3	us-gaap	Debt Securities Available For Sale Restricted DebtSecuritiesAvailableForSaleRestricted	7100000000	usd
CY2024Q3	wtfc	Securities By A Single Non Government Sponsored Issuer Exceeding Ten Percent Of Shareholders Equity SecuritiesByASingleNonGovernmentSponsoredIssuerExceedingTenPercentOfShareholdersEquity	0	security
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	41446032000	usd
CY2023Q3	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2023Q3	us-gaap	Financing Receivable Unamortized Loan Commitment Origination Fee And Premium Discount FinancingReceivableUnamortizedLoanCommitmentOriginationFeeAndPremiumDiscount	67600000	usd
CY2024Q3	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLoss	351500000	usd
CY2023Q4	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLoss	304500000	usd
CY2023Q3	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLoss	290900000	usd
CY2024Q3	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	161059000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	47067447000	usd
CY2023Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	42131831000	usd
CY2023Q3	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	104967000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	41446032000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	12511611000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	12102441000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	5803751000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	3950457000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	1773105000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	4871250000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	6031596000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Converted To Term Loan FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan	23236000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	47067447000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff	8223000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff	30985000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff	5797000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff	20094000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff	2206000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year Writeoff FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff	22310000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Writeoff FinancingReceivableExcludingAccruedInterestRevolvingWriteoff	0	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Converted To Term Loan Writeoff FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoanWriteoff	0	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	89615000	usd
CY2024Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	3677899000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	479000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	3677420000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	479000	usd
CY2023Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	347000	usd
CY2023Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	381000	usd
CY2024Q3	wtfc	Allowance For Credit Loss Excluding Accrued Interest AllowanceForCreditLossExcludingAccruedInterest	436193000	usd
CY2023Q4	wtfc	Allowance For Credit Loss Excluding Accrued Interest AllowanceForCreditLossExcludingAccruedInterest	427612000	usd
CY2023Q3	wtfc	Allowance For Credit Loss Excluding Accrued Interest AllowanceForCreditLossExcludingAccruedInterest	399531000	usd
CY2024Q3	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	62700000	usd
CY2024Q2	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	437069000	usd
CY2024Q3	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	-30000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	31018000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	4283000	usd
CY2024Q3	wtfc	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal Other FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversalOther	6799000	usd
CY2024Q3	wtfc	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal Acquisition FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversalAcquisition	15547000	usd
CY2024Q3	us-gaap	Financing Receivable Purchased With Credit Deterioration Allowance For Credit Loss At Acquisition Date FinancingReceivablePurchasedWithCreditDeteriorationAllowanceForCreditLossAtAcquisitionDate	3004000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	435714000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	27630000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	408084000	usd
CY2024Q3	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	124586000	usd
CY2024Q3	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	46804823000	usd
CY2024Q3	wtfc	Loans Held For Investment Fair Value Disclosure LoansHeldForInvestmentFairValueDisclosure	138038000	usd
CY2023Q2	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	387380000	usd
CY2023Q3	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	60000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	10477000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	2359000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	19948000	usd
CY2023Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	399150000	usd
CY2023Q3	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	15302000	usd
CY2023Q3	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	383848000	usd
CY2023Q3	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	77937000	usd
CY2023Q3	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	41196917000	usd
CY2023Q3	wtfc	Loans Held For Investment Fair Value Disclosure LoansHeldForInvestmentFairValueDisclosure	171178000	usd
CY2023Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	427265000	usd
	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	20000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	89615000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	11144000	usd
	wtfc	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal Other FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversalOther	68389000	usd
	wtfc	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal Acquisition FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversalAcquisition	15547000	usd
	us-gaap	Financing Receivable Purchased With Credit Deterioration Allowance For Credit Loss At Acquisition Date FinancingReceivablePurchasedWithCreditDeteriorationAllowanceForCreditLossAtAcquisitionDate	3004000	usd
CY2024Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	435714000	usd
CY2022Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	357448000	usd
	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	15000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff	36344000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery	5731000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	71589000	usd
CY2023Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	399150000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	22300000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Credit Loss Expense Reversal FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal	83900000	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff After Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery	26700000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Allowance For Credit Loss Writeoff After Recovery FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery	78500000	usd
CY2024Q3	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	12000	usd
	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-132000	usd
CY2024Q3	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	0	usd
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	3209000	usd
CY2024Q3	us-gaap	Financing Receivable Modification To Total Financing Receivables Excluding Accrued Interest Percent FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent	0.000
CY2024Q3	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	3209000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	1437000	usd
CY2023Q3	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	1437000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	8274000	usd
	us-gaap	Financing Receivable Modification To Total Financing Receivables Excluding Accrued Interest Percent FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent	0.000
	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	8274000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	47229000	usd
	us-gaap	Financing Receivable Modification To Total Financing Receivables Excluding Accrued Interest Percent FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent	0.001
	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	47229000	usd
CY2024Q3	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	8600000	usd
CY2023Q3	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	45000000	usd
CY2024	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	14696000	usd
	us-gaap	Financing Receivable Excluding Accrued Interest Modified Period FinancingReceivableExcludingAccruedInterestModifiedPeriod	47229000	usd
CY2023Q4	us-gaap	Goodwill Goodwill	656672000	usd
	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	144586000	usd
	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	usd
	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	-478000	usd
CY2024Q3	us-gaap	Goodwill Goodwill	800780000	usd
CY2024Q3	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	196898000	usd
CY2023Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	89599000	usd
CY2023Q3	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	89598000	usd
CY2024Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	73032000	usd
CY2023Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	66710000	usd
CY2023Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	65354000	usd
CY2024Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	123866000	usd
CY2023Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	22889000	usd
CY2023Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	24244000	usd
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6322000	usd
CY2024Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Remainder Of Fiscal Year FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear	5501000	usd
CY2024Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	20784000	usd
CY2024Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	18268000	usd
CY2024Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	15848000	usd
CY2024Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	13477000	usd
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	6300000	usd
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	4100000	usd
CY2024Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	204610000	usd
CY2023Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	200692000	usd
CY2023Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	192456000	usd
CY2022Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	230225000	usd
CY2024Q3	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	6357000	usd
CY2023Q3	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	9706000	usd
	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	19959000	usd
	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	23533000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	0	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	0	usd
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	0	usd
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	30170000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-7328000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-4597000	usd
	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-17248000	usd
	us-gaap	Servicing Asset At Fair Value Other Changes In Fair Value ServicingAssetAtFairValueOtherChangesInFairValue	-13549000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-17331000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	4723000	usd
	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-8859000	usd
	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	485000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	186308000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	210524000	usd
CY2024Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	186308000	usd
CY2023Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	210524000	usd
CY2024Q3	us-gaap	Principal Amount Outstanding On Loans Managed And Securitized PrincipalAmountOutstandingOnLoansManagedAndSecuritized	12253361000	usd
CY2023Q3	us-gaap	Principal Amount Outstanding On Loans Managed And Securitized PrincipalAmountOutstandingOnLoansManagedAndSecuritized	11885531000	usd
CY2024Q3	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10739132000	usd
CY2023Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10420401000	usd
CY2023Q3	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10347006000	usd
CY2024Q3	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	5466932000	usd
CY2023Q4	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	5797649000	usd
CY2023Q3	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	6006114000	usd
CY2024Q3	wtfc	Wealth Management Deposits WealthManagementDeposits	1303354000	usd
CY2023Q4	wtfc	Wealth Management Deposits WealthManagementDeposits	1614499000	usd
CY2023Q3	wtfc	Wealth Management Deposits WealthManagementDeposits	1788099000	usd
CY2024Q3	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	17713726000	usd
CY2023Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	15149215000	usd
CY2023Q3	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	14478504000	usd
CY2024Q3	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	6183249000	usd
CY2023Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	5790334000	usd
CY2023Q3	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	5584294000	usd
CY2024Q3	us-gaap	Time Deposits TimeDeposits	9998573000	usd
CY2023Q4	us-gaap	Time Deposits TimeDeposits	6625072000	usd
CY2023Q3	us-gaap	Time Deposits TimeDeposits	6788669000	usd
CY2024Q3	us-gaap	Deposits Deposits	51404966000	usd
CY2023Q4	us-gaap	Deposits Deposits	45397170000	usd
CY2023Q3	us-gaap	Deposits Deposits	44992686000	usd
CY2024Q3	wtfc	Non Interest Bearing Deposits Percentage NonInterestBearingDepositsPercentage	0.21
CY2023Q4	wtfc	Non Interest Bearing Deposits Percentage NonInterestBearingDepositsPercentage	0.23
CY2023Q3	wtfc	Non Interest Bearing Deposits Percentage NonInterestBearingDepositsPercentage	0.23
CY2024Q3	wtfc	Negotiable Order Of Withdrawal And Interest Bearing Demand Deposits Percentage NegotiableOrderOfWithdrawalAndInterestBearingDemandDepositsPercentage	0.11
CY2023Q4	wtfc	Negotiable Order Of Withdrawal And Interest Bearing Demand Deposits Percentage NegotiableOrderOfWithdrawalAndInterestBearingDemandDepositsPercentage	0.13
CY2023Q3	wtfc	Negotiable Order Of Withdrawal And Interest Bearing Demand Deposits Percentage NegotiableOrderOfWithdrawalAndInterestBearingDemandDepositsPercentage	0.13
CY2024Q3	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.03
CY2023Q4	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.04
CY2023Q3	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.04
CY2024Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.34
CY2023Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.33
CY2023Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.32
CY2024Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.12
CY2023Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.13
CY2023Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.13
CY2024Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.19
CY2023Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.14
CY2023Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.15
CY2024Q3	wtfc	Deposits Percentage DepositsPercentage	1
CY2023Q4	wtfc	Deposits Percentage DepositsPercentage	1
CY2023Q3	wtfc	Deposits Percentage DepositsPercentage	1
CY2024Q3	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	3171309000	usd
CY2023Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	2326071000	usd
CY2023Q3	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	2326071000	usd
CY2024Q3	us-gaap	Notes Payable NotesPayable	149894000	usd
CY2023Q4	us-gaap	Notes Payable NotesPayable	171282000	usd
CY2023Q3	us-gaap	Notes Payable NotesPayable	178411000	usd
CY2024Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	0	usd
CY2023Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	13430000	usd
CY2023Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	14183000	usd
CY2024Q3	us-gaap	Secured Debt SecuredDebt	439513000	usd
CY2023Q4	us-gaap	Secured Debt SecuredDebt	401897000	usd
CY2023Q3	us-gaap	Secured Debt SecuredDebt	391681000	usd
CY2024Q3	us-gaap	Other Long Term Debt OtherLongTermDebt	57636000	usd
CY2023Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	59204000	usd
CY2023Q3	us-gaap	Other Long Term Debt OtherLongTermDebt	59724000	usd
CY2024Q3	us-gaap	Other Borrowings OtherBorrowings	647043000	usd
CY2023Q4	us-gaap	Other Borrowings OtherBorrowings	645813000	usd
CY2023Q3	us-gaap	Other Borrowings OtherBorrowings	643999000	usd
CY2024Q3	us-gaap	Subordinated Debt SubordinatedDebt	298188000	usd
CY2023Q4	us-gaap	Subordinated Debt SubordinatedDebt	437866000	usd
CY2023Q3	us-gaap	Subordinated Debt SubordinatedDebt	437731000	usd
CY2024Q3	wtfc	Debt Current And Noncurrent DebtCurrentAndNoncurrent	4116540000	usd
CY2023Q4	wtfc	Debt Current And Noncurrent DebtCurrentAndNoncurrent	3409750000	usd
CY2023Q3	wtfc	Debt Current And Noncurrent DebtCurrentAndNoncurrent	3407801000	usd
CY2024Q3	us-gaap	Subordinated Debt SubordinatedDebt	298200000	usd
CY2023Q4	us-gaap	Subordinated Debt SubordinatedDebt	437900000	usd
CY2023Q3	us-gaap	Subordinated Debt SubordinatedDebt	437700000	usd
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2024Q3	wtfc	Number Of Subsidiaries NumberOfSubsidiaries	16	subsidiary
CY2024Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	502583000	usd
CY2023Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	462358000	usd
CY2024Q3	wtfc	Change In Contribution Interest Income Expense Net ChangeInContributionInterestIncomeExpenseNet	40225000	usd
CY2024Q3	wtfc	Interest Income Expense Net Percentage InterestIncomeExpenseNetPercentage	0.09
CY2024Q3	us-gaap	Noninterest Income NoninterestIncome	113147000	usd
CY2024Q3	us-gaap	Assets Assets	63788424000	usd
CY2023Q3	us-gaap	Assets Assets	55555246000	usd
CY2024Q3	wtfc	Change In Contribution Assets ChangeInContributionAssets	8233178000	usd
CY2024Q3	wtfc	Assets Percentage AssetsPercentage	0.15
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1437387000	usd
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1367890000	usd
	wtfc	Change In Contribution Interest Income Expense Net ChangeInContributionInterestIncomeExpenseNet	69497000	usd
	wtfc	Interest Income Expense Net Percentage InterestIncomeExpenseNetPercentage	0.05
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	84068000	usd
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	71482000	usd
	wtfc	Change In Contribution Provision For Loan Lease And Other Losses ChangeInContributionProvisionForLoanLeaseAndOtherLosses	12586000	usd
	wtfc	Change In Contribution Provision For Loan Lease And Other Losses Percentage ChangeInContributionProvisionForLoanLeaseAndOtherLossesPercentage	0.18
	us-gaap	Noninterest Income NoninterestIncome	374874000	usd
	us-gaap	Noninterest Income NoninterestIncome	333277000	usd
	wtfc	Change In Contribution Non Interest Income ChangeInContributionNonInterestIncome	41597000	usd
	wtfc	Non Interest Income Percentage NonInterestIncomePercentage	0.12
	us-gaap	Revenues Revenues	1812261000	usd
	us-gaap	Revenues Revenues	1701167000	usd
	wtfc	Change In Contribution Revenues ChangeInContributionRevenues	111094000	usd
	wtfc	Revenues Percentage RevenuesPercentage	0.07
	us-gaap	Net Income Loss NetIncomeLoss	509683000	usd
	us-gaap	Net Income Loss NetIncomeLoss	499146000	usd
	wtfc	Change In Contribution Operating Income Loss ChangeInContributionOperatingIncomeLoss	10537000	usd
	wtfc	Operating Income Loss Percentage OperatingIncomeLossPercentage	0.15
CY2024Q3	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	255662000	usd
CY2023Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	275726000	usd
CY2023Q3	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	323705000	usd
CY2024Q3	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	199339000	usd
CY2023Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	267255000	usd
CY2023Q3	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	458706000	usd
	us-gaap	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths	-13900000	usd
CY2024Q3	us-gaap	Credit Risk Derivatives At Fair Value Net CreditRiskDerivativesAtFairValueNet	97500000	usd
CY2024Q3	wtfc	Impaired Loans Fair Value Losses Recognized ImpairedLoansFairValueLossesRecognized	22908000	usd
	wtfc	Impaired Loans Fair Value Losses Recognized ImpairedLoansFairValueLossesRecognized	64747000	usd
CY2024Q3	wtfc	Real Estate Acquired Through Foreclosure Fair Value Losses Recognized RealEstateAcquiredThroughForeclosureFairValueLossesRecognized	0	usd
	wtfc	Real Estate Acquired Through Foreclosure Fair Value Losses Recognized RealEstateAcquiredThroughForeclosureFairValueLossesRecognized	207000	usd
CY2024Q3	wtfc	Assets Nonrecurring Fair Value Losses Recognized AssetsNonrecurringFairValueLossesRecognized	22908000	usd
	wtfc	Assets Nonrecurring Fair Value Losses Recognized AssetsNonrecurringFairValueLossesRecognized	64954000	usd
CY2024Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	659000	shares
CY2024Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	9500000	usd
CY2023Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	8100000	usd
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	27600000	usd
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	24500000	usd
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	13100	shares
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.76
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	0
	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	775	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	32.26
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	0	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	0
CY2024Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	12325	shares
CY2024Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	43.42
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P3Y8M12D
CY2024Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	802000	usd
CY2024Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	12325	shares
CY2024Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	43.42
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P3Y8M12D
CY2024Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	802000	usd
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	68093	shares
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	41.14
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	0
	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	54218	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	40.87
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	0	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	0
CY2023Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	13875	shares
CY2023Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.18
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P4Y2M12D
CY2023Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	462000	usd
CY2023Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	13875	shares
CY2023Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	42.18
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P4Y2M12D
CY2023Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	462000	usd
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	50000	usd
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	2500000	usd
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	25000	usd
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	2200000	usd
CY2024Q3	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	204990000	usd
CY2024Q3	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-15041000	usd
CY2024Q3	wtfc	Reclassification From Aoci Amortization Of Unrealized Gains Losses On Investment Securities Transferred To Held To Maturity From Available For Sale Net Of Tax Attributable To Parent ReclassificationFromAOCIAmortizationOfUnrealizedGainsLossesOnInvestmentSecuritiesTransferredToHeldToMaturityFromAvailableForSaleNetOfTaxAttributableToParent	10000	usd
CY2024Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	220021000	usd
	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	25266000	usd
	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-43845000	usd
	wtfc	Reclassification From Aoci Amortization Of Unrealized Gains Losses On Investment Securities Transferred To Held To Maturity From Available For Sale Net Of Tax Attributable To Parent ReclassificationFromAOCIAmortizationOfUnrealizedGainsLossesOnInvestmentSecuritiesTransferredToHeldToMaturityFromAvailableForSaleNetOfTaxAttributableToParent	57000	usd
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	69054000	usd
CY2023Q3	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-181970000	usd
CY2023Q3	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-13360000	usd
CY2023Q3	wtfc	Reclassification From Aoci Amortization Of Unrealized Gains Losses On Investment Securities Transferred To Held To Maturity From Available For Sale Net Of Tax Attributable To Parent ReclassificationFromAOCIAmortizationOfUnrealizedGainsLossesOnInvestmentSecuritiesTransferredToHeldToMaturityFromAvailableForSaleNetOfTaxAttributableToParent	23000	usd
CY2023Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-168633000	usd
	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-241175000	usd
	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-26163000	usd
	wtfc	Reclassification From Aoci Amortization Of Unrealized Gains Losses On Investment Securities Transferred To Held To Maturity From Available For Sale Net Of Tax Attributable To Parent ReclassificationFromAOCIAmortizationOfUnrealizedGainsLossesOnInvestmentSecuritiesTransferredToHeldToMaturityFromAvailableForSaleNetOfTaxAttributableToParent	75000	usd
	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-215087000	usd
CY2024Q3	us-gaap	Net Income Loss NetIncomeLoss	170001000	usd
CY2023Q3	us-gaap	Net Income Loss NetIncomeLoss	164198000	usd
	us-gaap	Net Income Loss NetIncomeLoss	509683000	usd
	us-gaap	Net Income Loss NetIncomeLoss	499146000	usd
CY2024Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	6991000	usd
CY2023Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	6991000	usd
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	20973000	usd
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	20973000	usd
CY2024Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	163010000	usd
CY2023Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	157207000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	488710000	usd
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	478173000	usd
CY2024Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	64888000	shares
CY2023Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	61213000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	62743000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	61119000	shares
CY2024Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1053000	shares
CY2023Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	964000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	934000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	888000	shares
CY2024Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	65941000	shares
CY2023Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	62177000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	63677000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	62007000	shares
CY2024Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.51
CY2023Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.57
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.79
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.82
CY2024Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.47
CY2023Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.53
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.67
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.71
CY2024Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.45
CY2024Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.45
CY2024Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.45
CY2024Q3	ecd	Rule10b51 Arr Adopted Flag Rule10b51ArrAdoptedFlag	false
CY2024Q3	ecd	Rule10b51 Arr Trmntd Flag Rule10b51ArrTrmntdFlag	false
CY2024Q3	ecd	Non Rule10b51 Arr Adopted Flag NonRule10b51ArrAdoptedFlag	false
CY2024Q3	ecd	Non Rule10b51 Arr Trmntd Flag NonRule10b51ArrTrmntdFlag	false

Files In Submission

Name	View Source	Status
FilingSummary.xml	Edgar Link	unprocessable
wtfc-20240930_cal.xml	Edgar Link	unprocessable
0001015328-24-000253-index-headers.html	Edgar Link	pending
0001015328-24-000253-index.html	Edgar Link	pending
0001015328-24-000253.txt	Edgar Link	pending
0001015328-24-000253-xbrl.zip	Edgar Link	pending
exhibit3112024q3.htm	Edgar Link	pending
exhibit3122024q3.htm	Edgar Link	pending
exhibit3212024q3.htm	Edgar Link	pending
Financial_Report.xlsx	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R69.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R70.htm	Edgar Link	pending
R71.htm	Edgar Link	pending
R72.htm	Edgar Link	pending
R73.htm	Edgar Link	pending
R74.htm	Edgar Link	pending
R75.htm	Edgar Link	pending
R76.htm	Edgar Link	pending
R77.htm	Edgar Link	pending
R78.htm	Edgar Link	pending
R79.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R82.htm	Edgar Link	pending
R83.htm	Edgar Link	pending
R84.htm	Edgar Link	pending
R85.htm	Edgar Link	pending
R86.htm	Edgar Link	pending
R87.htm	Edgar Link	pending
R88.htm	Edgar Link	pending
R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
R90.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending
wtfc-20240930.htm	Edgar Link	pending
wtfc-20240930.xsd	Edgar Link	pending
wtfc-20240930_def.xml	Edgar Link	unprocessable
wtfc-20240930_lab.xml	Edgar Link	unprocessable
wtfc-20240930_htm.xml	Edgar Link	completed
wtfc-20240930_pre.xml	Edgar Link	unprocessable

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc

2024 Q4 Form 10-Q Financial Statement

#000101532824000253 Filed on November 08, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WTFC WINTRUST FINANCIAL CORP Stock $wtfc

2024 Q4 Form 10-Q Financial Statement

#000101532824000253 Filed on November 08, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc