$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc

$wtfc Overview Financials Valuation SEC Filings Company Website

2021 Q4 Form 10-Q Financial Statement

#000101532821000189 Filed on November 08, 2021

Income Statement

Concept	2021 Q4	2021 Q3	2020 Q3
Revenue		$424.0M	$426.5M
YoY Change		-0.6%	12.25%
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	$26.40M	$23.90M	$24.20M
YoY Change	5.18%	-1.24%	12.56%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense		$34.96M	$55.22M
YoY Change		-36.69%	-38.49%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$137.0M	$149.7M	$137.3M
YoY Change	1.7%	9.07%	1.99%
Income Tax	$38.30M	$40.61M	$29.97M
% Of Pretax Income	27.96%	27.12%	21.83%
Net Earnings	$98.80M	$109.1M	$107.3M
YoY Change	-2.38%	1.7%	8.27%
Net Earnings / Revenue		25.74%	25.16%
Basic Earnings Per Share		$1.79	$1.68
Diluted Earnings Per Share	$1.703M	$1.77	$1.67
COMMON SHARES
Basic Shares Outstanding	57.01M shares	57.00M shares	57.60M shares
Diluted Shares Outstanding		57.75M shares	58.05M shares

Balance Sheet

Concept	2021 Q4	2021 Q3	2020 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$411.2M	$462.3M	$308.7M
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	$766.4M	$748.9M	$774.3M
YoY Change	-0.31%	-3.28%	7.26%
Goodwill	$655.1M	$645.8M	$644.6M
YoY Change	1.46%	0.18%	10.32%
Intangibles	$28.31M	$30.12M	$38.67M
YoY Change	-21.46%	-22.12%	-11.42%
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	$50.14B	$47.83B	$43.73B
YoY Change	11.23%	9.38%	25.26%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$1.121B	$1.032B	$1.387B
YoY Change	-21.88%	-25.59%	74.69%
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$9.198M	$14.10M	$8.000M
YoY Change	-19.32%	76.25%	-17.53%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$1.121B	$1.032B	$1.387B
YoY Change	-21.88%	-25.59%	40.67%
LONG-TERM LIABILITIES
Long-Term Debt	$1.175B	$1.181B	$1.189B
YoY Change	-1.92%	-0.67%	9.08%
Other Long-Term Liabilities	$2.000M	$2.000M
YoY Change
Total Long-Term Liabilities	$1.177B	$1.183B	$1.189B
YoY Change	-1.75%	-0.5%	9.08%
TOTAL LIABILITIES
Total Short-Term Liabilities	$1.121B	$1.032B	$1.387B
Total Long-Term Liabilities	$1.177B	$1.183B	$1.189B
Total Liabilities	$45.64B	$43.42B	$39.66B
YoY Change	11.42%	9.49%	26.41%
SHAREHOLDERS EQUITY
Retained Earnings	$2.448B	$2.373B	$2.002B
YoY Change	17.67%	18.56%	9.39%
Common Stock	$58.89M	$58.79M	$58.32M
YoY Change	0.72%	0.81%	2.64%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$109.9M	$109.9M	$44.89M
YoY Change	9.51%	144.82%	560.26%
Treasury Stock Shares	1.838M shares	1.838M shares	720.8K shares
Shareholders Equity	$4.499B	$4.410B	$4.074B
YoY Change
Total Liabilities & Shareholders Equity	$50.14B	$47.83B	$43.73B
YoY Change	11.23%	9.38%	25.26%

Cashflow Statement

Concept	2021 Q4	2021 Q3	2020 Q3
OPERATING ACTIVITIES
Net Income	$98.80M	$109.1M	$107.3M
YoY Change	-2.38%	1.7%	8.27%
Depreciation, Depletion And Amortization	$26.40M	$23.90M	$24.20M
YoY Change	5.18%	-1.24%	12.56%
Cash From Operating Activities	$399.9M	$82.20M	-$53.50M
YoY Change	-519.62%	-253.64%	18.36%
INVESTING ACTIVITIES
Capital Expenditures	-$33.70M	-$11.30M	-$16.30M
YoY Change	266.3%	-30.67%	-19.31%
Acquisitions
YoY Change
Other Investing Activities	-$2.529B	-$1.153B	-$124.3M
YoY Change	139.65%	827.35%	-87.03%
Cash From Investing Activities	-$2.562B	-$1.164B	-$140.6M
YoY Change	140.74%	727.88%	-85.64%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	2.111B	1.109B	157.8M
YoY Change	79.91%	602.85%	-86.53%
NET CHANGE
Cash From Operating Activities	399.9M	82.20M	-53.50M
Cash From Investing Activities	-2.562B	-1.164B	-140.6M
Cash From Financing Activities	2.111B	1.109B	157.8M
Net Change In Cash	-51.20M	27.30M	-36.30M
YoY Change	-471.01%	-175.21%	-124.58%
FREE CASH FLOW
Cash From Operating Activities	$399.9M	$82.20M	-$53.50M
Capital Expenditures	-$33.70M	-$11.30M	-$16.30M
Free Cash Flow	$433.6M	$93.50M	-$37.20M
YoY Change	-603.6%	-351.34%	48.8%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
	dei	Entity Central Index Key EntityCentralIndexKey	0001015328
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q3
	dei	Amendment Flag AmendmentFlag	false
CY2019	us-gaap	Accounting Standards Update Extensible List AccountingStandardsUpdateExtensibleList	http://fasb.org/us-gaap/2021-01-31#AccountingStandardsUpdate201613Member
	wtfc	Debt Instrument Interest Payment Deferral Period DebtInstrumentInterestPaymentDeferralPeriod	P60M
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CY2021Q3	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2021Q3	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2021Q3	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
	dei	Document Type DocumentType	10-Q
	dei	Entity Shell Company EntityShellCompany	false
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2021-09-30
	dei	Document Transition Report DocumentTransitionReport	false
	dei	Entity File Number EntityFileNumber	001-35077
	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
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CY2020Q3	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	21819000	USD
	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	68076000	USD
	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	81391000	USD
CY2021Q3	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	3000	USD
CY2020Q3	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	6000	USD
	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	6000	USD
	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	26000	USD
CY2021Q3	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	1777000	USD
CY2020Q3	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	1774000	USD
	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	5291000	USD
	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	5116000	USD
CY2021Q3	wtfc	Interest Income On Brokerage Customer Receivables InterestIncomeOnBrokerageCustomerReceivables	185000	USD
CY2020Q3	wtfc	Interest Income On Brokerage Customer Receivables InterestIncomeOnBrokerageCustomerReceivables	106000	USD
	wtfc	Interest Income On Brokerage Customer Receivables InterestIncomeOnBrokerageCustomerReceivables	457000	USD
	wtfc	Interest Income On Brokerage Customer Receivables InterestIncomeOnBrokerageCustomerReceivables	361000	USD
CY2021Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	322457000	USD
CY2020Q3	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	311156000	USD
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	947505000	USD
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	985039000	USD
CY2021Q3	us-gaap	Interest Expense Deposits InterestExpenseDeposits	19305000	USD
CY2020Q3	us-gaap	Interest Expense Deposits InterestExpenseDeposits	39084000	USD
	us-gaap	Interest Expense Deposits InterestExpenseDeposits	71547000	USD
	us-gaap	Interest Expense Deposits InterestExpenseDeposits	156576000	USD
CY2021Q3	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	4931000	USD
CY2020Q3	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	4947000	USD
	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	14658000	USD
	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	13241000	USD
CY2021Q3	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	2501000	USD
CY2020Q3	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	3012000	USD
	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	7678000	USD
	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	9994000	USD
CY2021Q3	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	5480000	USD
CY2020Q3	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	5474000	USD
	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	16469000	USD
	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	16452000	USD
CY2021Q3	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	2744000	USD
CY2020Q3	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	2703000	USD
	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	8172000	USD
	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	8266000	USD
CY2021Q3	us-gaap	Interest Expense InterestExpense	34961000	USD
CY2020Q3	us-gaap	Interest Expense InterestExpense	55220000	USD
	us-gaap	Interest Expense InterestExpense	118524000	USD
	us-gaap	Interest Expense InterestExpense	204529000	USD
CY2021Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	287496000	USD
CY2020Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	255936000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	828981000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	780510000	USD
CY2021Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-7916000	USD
CY2020Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	25026000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-68562000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	213040000	USD
CY2021Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	295412000	USD
CY2020Q3	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	230910000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	897543000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	567470000	USD
CY2021Q3	wtfc	Fees And Commissions Mortgage Banking1 FeesAndCommissionsMortgageBanking1	55794000	USD
CY2020Q3	wtfc	Fees And Commissions Mortgage Banking1 FeesAndCommissionsMortgageBanking1	108544000	USD
	wtfc	Fees And Commissions Mortgage Banking1 FeesAndCommissionsMortgageBanking1	219872000	USD
	wtfc	Fees And Commissions Mortgage Banking1 FeesAndCommissionsMortgageBanking1	259194000	USD
CY2021Q3	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	-2431000	USD
CY2020Q3	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	411000	USD
	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	8000	USD
	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	-3140000	USD
CY2021Q3	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	1157000	USD
CY2020Q3	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	0	USD
	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	2545000	USD
	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	2292000	USD
CY2021Q3	us-gaap	Trading Gains Losses TradingGainsLosses	58000	USD
CY2020Q3	us-gaap	Trading Gains Losses TradingGainsLosses	183000	USD
	us-gaap	Trading Gains Losses TradingGainsLosses	39000	USD
	us-gaap	Trading Gains Losses TradingGainsLosses	-902000	USD
CY2021Q3	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	12807000	USD
CY2020Q3	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	11717000	USD
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	39487000	USD
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	35486000	USD
CY2021Q3	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	23409000	USD
CY2020Q3	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	13284000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	59438000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	46182000	USD
CY2021Q3	us-gaap	Noninterest Income NoninterestIncome	136474000	USD
CY2020Q3	us-gaap	Noninterest Income NoninterestIncome	170593000	USD
	us-gaap	Noninterest Income NoninterestIncome	452353000	USD
	us-gaap	Noninterest Income NoninterestIncome	445828000	USD
CY2021Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	170912000	USD
CY2020Q3	us-gaap	Labor And Related Expense LaborAndRelatedExpense	164042000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	524538000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	454960000	USD
CY2021Q3	us-gaap	Equipment Expense EquipmentExpense	22029000	USD
CY2020Q3	us-gaap	Equipment Expense EquipmentExpense	17251000	USD
	us-gaap	Equipment Expense EquipmentExpense	63807000	USD
	us-gaap	Equipment Expense EquipmentExpense	47931000	USD
CY2021Q3	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	10013000	USD
CY2020Q3	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	9425000	USD
	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	30733000	USD
	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	27977000	USD
CY2021Q3	us-gaap	Occupancy Net OccupancyNet	18158000	USD
CY2020Q3	us-gaap	Occupancy Net OccupancyNet	15830000	USD
	us-gaap	Occupancy Net OccupancyNet	55841000	USD
	us-gaap	Occupancy Net OccupancyNet	50270000	USD
CY2021Q3	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	7104000	USD
CY2020Q3	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	5689000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	20072000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	24468000	USD
CY2021Q3	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	13443000	USD
CY2020Q3	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	7880000	USD
	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	33294000	USD
	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	26446000	USD
CY2021Q3	us-gaap	Professional Fees ProfessionalFees	7052000	USD
CY2020Q3	us-gaap	Professional Fees ProfessionalFees	6488000	USD
	us-gaap	Professional Fees ProfessionalFees	21943000	USD
	us-gaap	Professional Fees ProfessionalFees	20896000	USD
CY2021Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	1877000	USD
CY2020Q3	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2701000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5923000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	8384000	USD
CY2021Q3	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	6750000	USD
CY2020Q3	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	6772000	USD
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	19713000	USD
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	17988000	USD
CY2021Q3	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	1531000	USD
CY2020Q3	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	168000	USD
	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	1013000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	74294000	USD
	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	807000	USD
CY2021Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	26337000	USD
CY2020Q3	us-gaap	Other Noninterest Expense OtherNoninterestExpense	28309000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	79715000	USD
CY2021Q3	us-gaap	Noninterest Expense NoninterestExpense	282144000	USD
CY2020Q3	us-gaap	Noninterest Expense NoninterestExpense	264219000	USD
	us-gaap	Noninterest Expense NoninterestExpense	849145000	USD
	us-gaap	Noninterest Expense NoninterestExpense	758228000	USD
CY2021Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	149742000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	137284000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	500751000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	255070000	USD
CY2021Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	40605000	USD
CY2020Q3	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	29969000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	133357000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	63284000	USD
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	109137000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	107315000	USD
	us-gaap	Net Income Loss NetIncomeLoss	367394000	USD
	us-gaap	Net Income Loss NetIncomeLoss	191786000	USD
CY2021Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	6991000	USD
CY2020Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	10286000	USD
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	20973000	USD
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	14386000	USD
CY2021Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	102146000	USD
CY2020Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	97029000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	346421000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	177400000	USD
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.79
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.68
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.08
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.08
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.77
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.67
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.00
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.06
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.31
CY2020Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.93
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.84
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57000000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57597000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56985000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57595000	shares
CY2021Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	753000	shares
CY2020Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	449000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	728000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	469000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57753000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58046000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57713000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58064000	shares
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	109137000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	107315000	USD
	us-gaap	Net Income Loss NetIncomeLoss	367394000	USD
	us-gaap	Net Income Loss NetIncomeLoss	191786000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-14141000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-14563000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-68555000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	81859000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-3767000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-3881000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-18290000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	21816000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-10374000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-10682000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-50265000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	60043000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	350000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	50000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	1144000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	200000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	94000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	14000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	307000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	54000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	256000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	36000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	837000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	146000	USD
CY2021Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	54000	USD
CY2020Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	54000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	158000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	178000	USD
CY2021Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	14000	USD
CY2020Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	14000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	42000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	47000	USD
CY2021Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	40000	USD
CY2020Q3	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	40000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	116000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	131000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-10670000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-10758000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-51218000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	59766000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	9004000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	10393000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	51008000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	2770000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	13594000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-31167000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	2400000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-8325000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	6604000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	7623000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	37414000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-22842000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-5858000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	3716000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-248000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-3939000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-1208000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	825000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-87000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-852000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-4650000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	2891000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-161000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-3087000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-8716000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-244000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-13965000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	33837000	USD
CY2021Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	100421000	USD
CY2020Q3	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	107071000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	353429000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	225623000	USD
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	3990218000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	107315000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-244000	USD
CY2020Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
CY2020Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	16128000	USD
CY2020Q3	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	10286000	USD
CY2020Q3	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	1255000	USD
CY2020Q3	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	497000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	847000	USD
CY2020Q3	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	615000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	4074089000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	3691250000	USD
	us-gaap	Net Income Loss NetIncomeLoss	191786000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	33837000	USD
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.84
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	48364000	USD
	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	14386000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	37116000	USD
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	-1023000	USD
	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	3936000	USD
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-752000	USD
	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2232000	USD
	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	1763000	USD
CY2020Q3	us-gaap	Stockholders Equity StockholdersEquity	4074089000	USD
CY2021Q2	us-gaap	Stockholders Equity StockholdersEquity	4339011000	USD
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	109137000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-8716000	USD
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.31
CY2021Q3	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	17668000	USD
CY2021Q3	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	6991000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	9540000	USD
CY2021Q3	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	3243000	USD
CY2021Q3	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	318000	USD
CY2021Q3	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
CY2021Q3	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	928000	USD
CY2021Q3	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	595000	USD
CY2021Q3	us-gaap	Stockholders Equity StockholdersEquity	4410317000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	4115995000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	71295000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	9437000	USD
	us-gaap	Net Income Loss NetIncomeLoss	367394000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-13965000	USD
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.93
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	52987000	USD
	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	20973000	USD
	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	9540000	USD
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	9437000	USD
	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	10559000	USD
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	0	USD
	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2548000	USD
	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	1849000	USD
CY2021Q3	us-gaap	Stockholders Equity StockholdersEquity	4410317000	USD
	us-gaap	Net Income Loss NetIncomeLoss	367394000	USD
	us-gaap	Net Income Loss NetIncomeLoss	191786000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-68562000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	213040000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	75389000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	-1023000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-5188000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-8079000	USD
	wtfc	Accretion Amortization Of Discount Premium On Loans AccretionAmortizationOfDiscountPremiumOnLoans	68413000	USD
	wtfc	Accretion Amortization Of Discount Premium On Loans AccretionAmortizationOfDiscountPremiumOnLoans	60451000	USD
	us-gaap	Mortgage Servicing Rights Msr Impairment Recovery MortgageServicingRightsMSRImpairmentRecovery	15685000	USD
	us-gaap	Mortgage Servicing Rights Msr Impairment Recovery MortgageServicingRightsMSRImpairmentRecovery	49097000	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	378000	USD
	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	600000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	5504906000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	5653486000	USD
	wtfc	Early Buyout Exercises Of Guaranteed Mortgage Loans Held For Sale EarlyBuyoutExercisesOfGuaranteedMortgageLoansHeldForSale	9747000	USD
	wtfc	Early Buyout Exercises Of Guaranteed Mortgage Loans Held For Sale EarlyBuyoutExercisesOfGuaranteedMortgageLoansHeldForSale	71625000	USD
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	6014689000	USD
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	5280587000	USD
	wtfc	Bank Owned Life Insurance Net Of Claims BankOwnedLifeInsuranceNetOfClaims	4620000	USD
	wtfc	Bank Owned Life Insurance Net Of Claims BankOwnedLifeInsuranceNetOfClaims	1884000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	432000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	652000	USD
	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	8942000	USD
	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	245000	USD
	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	178927000	USD
	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	260622000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	8000	USD
	us-gaap	Gain Loss On Investments GainLossOnInvestments	-3140000	USD
	wtfc	Gain Loss On Disposition Of Property Plant Equipment Net And Related Deposit Liabilities GainLossOnDispositionOfPropertyPlantEquipmentNetAndRelatedDepositLiabilities	3649000	USD
	wtfc	Gain Loss On Disposition Of Property Plant Equipment Net And Related Deposit Liabilities GainLossOnDispositionOfPropertyPlantEquipmentNetAndRelatedDepositLiabilities	-192000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	2134000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	933000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-121657000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	154912000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-27720000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-33935000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	731001000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-423152000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1101149000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1005968000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	177668000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	698305000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	192227000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	502676000	USD
	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	9759000	USD
	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	6530000	USD
	wtfc	Proceedsfrom Salesand Capital Distributionsof Equity Securities Without Readily Determinable Fair Value ProceedsfromSalesandCapitalDistributionsofEquitySecuritiesWithoutReadilyDeterminableFairValue	2467000	USD
	wtfc	Proceedsfrom Salesand Capital Distributionsof Equity Securities Without Readily Determinable Fair Value ProceedsfromSalesandCapitalDistributionsofEquitySecuritiesWithoutReadilyDeterminableFairValue	1691000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	682172000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1273798000	USD
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	2537242000	USD
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	125220000	USD
	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	6000000	USD
	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	11367000	USD
	wtfc	Paymentsto Acquire Equity Securitieswithout Readily Determinable Fair Value PaymentstoAcquireEquitySecuritieswithoutReadilyDeterminableFairValue	7295000	USD
	wtfc	Paymentsto Acquire Equity Securitieswithout Readily Determinable Fair Value PaymentstoAcquireEquitySecuritieswithoutReadilyDeterminableFairValue	3666000	USD
	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	-180000	USD
	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	34829000	USD
	us-gaap	Payments For Proceeds From Limited Partnership PaymentsForProceedsFromLimitedPartnership	2757000	USD
	us-gaap	Payments For Proceeds From Limited Partnership PaymentsForProceedsFromLimitedPartnership	606000	USD
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	7263000	USD
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	6937000	USD
	us-gaap	Proceeds From Payments For In Interest Bearing Deposits In Banks ProceedsFromPaymentsForInInterestBearingDepositsInBanks	-428917000	USD
	us-gaap	Proceeds From Payments For In Interest Bearing Deposits In Banks ProceedsFromPaymentsForInInterestBearingDepositsInBanks	-1662172000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	1169636000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	5174163000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	23434000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	54392000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-3366740000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-6118106000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	2863778000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	0	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	844000	USD
	us-gaap	Payments Of Dividends PaymentsOfDividends	73960000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	5737721000	USD
	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	-15716000	USD
	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	91823000	USD
	wtfc	Proceeds From Payments To Federal Home Loan Bank Borrowings ProceedsFromPaymentsToFederalHomeLoanBankBorrowings	12629000	USD
	wtfc	Proceeds From Payments To Federal Home Loan Bank Borrowings ProceedsFromPaymentsToFederalHomeLoanBankBorrowings	553500000	USD
	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	0	USD
	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	277643000	USD
	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	16583000	USD
	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	4523000	USD
	wtfc	Issuance Of Common Shares Resulting From Exercise Of Stock Options Employee Stock Purchase Plan And Conversion Of Common Stock Warrants IssuanceOfCommonSharesResultingFromExerciseOfStockOptionsEmployeeStockPurchasePlanAndConversionOfCommonStockWarrants	14956000	USD
	wtfc	Issuance Of Common Shares Resulting From Exercise Of Stock Options Employee Stock Purchase Plan And Conversion Of Common Stock Warrants IssuanceOfCommonSharesResultingFromExerciseOfStockOptionsEmployeeStockPurchasePlanAndConversionOfCommonStockWarrants	8023000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	9540000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	37116000	USD
	us-gaap	Payments Of Dividends PaymentsOfDividends	62750000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	2775564000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	6563477000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	139825000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	22219000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	322474000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	286476000	USD
CY2021Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	462299000	USD
CY2020Q3	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	308695000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	2347419000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	52948000	USD
CY2021Q3	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	26889000	USD
CY2021Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	2373478000	USD
CY2021Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	2736805000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	12727000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	50052000	USD
CY2021Q3	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	2699480000	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	83000	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	2736722000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	83909000	USD
CY2021Q3	wtfc	Equity Securities Fvni Accumulated Unrealized Gain EquitySecuritiesFVNIAccumulatedUnrealizedGain	5678000	USD
CY2021Q3	wtfc	Equity Securities Fvni Accumulated Unrealized Loss EquitySecuritiesFVNIAccumulatedUnrealizedLoss	1394000	USD
CY2021Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	88193000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	2960081000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	98578000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	2820000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3055839000	USD
CY2020Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	579197000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	14784000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	214000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	593767000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	59000	USD
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CY2020Q3	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	54398000	USD
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CY2020Q3	wtfc	Marketable Securities Gross Realized Gains Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedGainsExcludingOtherThanTemporaryImpairments	78000	USD
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CY2020Q3	us-gaap	Marketable Securities Realized Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments	50000	USD
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CY2020Q3	wtfc	Proceedsfrom Saleof Equity Securities With Readily Determinable Fair Value ProceedsfromSaleofEquitySecuritiesWithReadilyDeterminableFairValue	2500000	USD
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CY2020Q3	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	338702000	USD
CY2020Q3	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	338954000	USD
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CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	101441000	USD
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CY2020Q3	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	193339000	USD
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CY2020Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3055839000	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	2845410000	USD
CY2020Q3	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	2946459000	USD
CY2021Q3	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	5466000	USD
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CY2020Q4	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	7138000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	7186000	USD
CY2020Q3	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	6911000	USD
CY2020Q3	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	6942000	USD
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CY2020Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	22217000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	23068000	USD
CY2020Q3	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	21392000	USD
CY2020Q3	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	21999000	USD
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CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	83000	USD
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CY2020Q3	us-gaap	Debt Securities Available For Sale Restricted DebtSecuritiesAvailableForSaleRestricted	3000000000	USD
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CY2021Q3	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	47300000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	33264043000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	32079073000	USD
CY2020Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	32135555000	USD
CY2021Q3	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2020Q4	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2020Q3	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2021Q3	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	13100000	USD
CY2020Q4	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	-3200000	USD
CY2020Q3	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	-42300000	USD
CY2021Q3	wtfc	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums Paid By Small Business Administration Under Paycheck Protection Program UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiumsPaidBySmallBusinessAdministrationUnderPaycheckProtectionProgram	24800000	USD
CY2021Q3	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLoss	119200000	USD
CY2020Q4	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLoss	121900000	USD
CY2020Q3	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLoss	116900000	USD
CY2021Q3	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	83940000	USD
CY2021Q3	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	6101000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	33264043000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	114150000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	13363000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	32079073000	USD
CY2020Q3	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	160751000	USD
CY2020Q3	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	12352000	USD
CY2020Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	32135555000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	9593469000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	4641356000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	3465980000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	2582554000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	2244073000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	6726820000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	3984335000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Converted To Term Loan FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan	25456000	USD
CY2021Q3	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	33264043000	USD
CY2021Q3	wtfc	Financing Receivable Before Allowance For Credit Loss Modifications Related To Covid19 Migrated From Pass To Special Mention Or Substandard FinancingReceivableBeforeAllowanceForCreditLossModificationsRelatedToCOVID19MigratedFromPassToSpecialMentionOrSubstandard	37500000	USD
CY2021Q3	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	2736805000	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	83000	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	2736722000	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	83000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	59000	USD
CY2020Q3	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	63000	USD
CY2021Q3	wtfc	Allowance For Credit Loss Excluding Accrued Interest AllowanceForCreditLossExcludingAccruedInterest	296138000	USD
CY2020Q4	wtfc	Allowance For Credit Loss Excluding Accrued Interest AllowanceForCreditLossExcludingAccruedInterest	379969000	USD
CY2020Q3	wtfc	Allowance For Credit Loss Excluding Accrued Interest AllowanceForCreditLossExcludingAccruedInterest	388971000	USD
	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	335000	USD
CY2021Q2	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	304031000	USD
CY2021Q3	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	65000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	3329000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	3327000	USD
CY2021Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-7909000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	296055000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	10759000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	285296000	USD
CY2021Q3	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	109011000	USD
CY2021Q3	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	33124053000	USD
CY2021Q3	wtfc	Loans Heldfor Investment Fair Value Disclosure LoansHeldforInvestmentFairValueDisclosure	30979000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	373109000	USD
CY2020Q3	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	-55000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	11763000	USD
CY2021Q3	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P105M
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	2479000	USD
CY2020Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	25028000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	388908000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	16367000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	372541000	USD
CY2020Q3	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	183667000	USD
CY2020Q3	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	31698373000	USD
CY2020Q3	wtfc	Loans Heldfor Investment Fair Value Disclosure LoansHeldforInvestmentFairValueDisclosure	253515000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	379910000	USD
	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	2000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	26420000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	11151000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-68584000	USD
CY2021Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	296055000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	158461000	USD
	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	-24000	USD
CY2020Q3	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P26M
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	36175000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	6203000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	213051000	USD
CY2020Q3	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	388908000	USD
CY2021Q3	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-7900000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-68600000	USD
CY2021Q3	us-gaap	Allowance For Loan And Lease Losses Writeoffs Net AllowanceForLoanAndLeaseLossesWriteoffsNet	2000	USD
	us-gaap	Allowance For Loan And Lease Losses Writeoffs Net AllowanceForLoanAndLeaseLossesWriteoffsNet	15300000	USD
CY2021Q3	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-7000	USD
	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	22000	USD
CY2021Q3	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	2500000	USD
CY2021Q3	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	9	contract
CY2021Q3	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	559000	USD
CY2020Q3	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	36	contract
CY2020Q3	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	7596000	USD
CY2021Q3	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	9	contract
CY2021Q3	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	559000	USD
CY2020Q3	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	36	contract
CY2020Q3	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	7600000	USD
CY2021Q3	wtfc	Weighted Average Decrease Stated Interest Rate Basis Points WeightedAverageDecreaseStatedInterestRateBasisPoints	0.0129
CY2020Q3	wtfc	Weighted Average Decrease Stated Interest Rate Basis Points WeightedAverageDecreaseStatedInterestRateBasisPoints	0.0116
CY2020Q3	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P5M
CY2021Q3	wtfc	Loan Forgiveness LoanForgiveness	0	USD
CY2020Q3	wtfc	Loan Forgiveness LoanForgiveness	0	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	45	contract
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	6884000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	103	contract
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	40410000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	45	contract
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	6900000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	103	contract
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	40400000	USD
	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P108M
	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P14M
	wtfc	Weighted Average Decrease Stated Interest Rate Basis Points WeightedAverageDecreaseStatedInterestRateBasisPoints	0.0151
	wtfc	Weighted Average Decrease Stated Interest Rate Basis Points WeightedAverageDecreaseStatedInterestRateBasisPoints	0.0143
	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P6M
	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P13M
	wtfc	Loan Forgiveness LoanForgiveness	0	USD
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CY2021	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	66	contract
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	12345000	USD
CY2021Q3	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	6	contract
CY2021Q3	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	2590000	USD
	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	9	contract
	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	3915000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	152	contract
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	47173000	USD
CY2020Q3	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	31	contract
CY2020Q3	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	21333000	USD
	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	34	contract
	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	21784000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	645707000	USD
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	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	85000	USD
CY2021Q3	us-gaap	Goodwill Goodwill	645792000	USD
CY2021Q3	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	83403000	USD
CY2020Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	83402000	USD
CY2020Q3	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	83398000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	53285000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	47362000	USD
CY2020Q3	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	44728000	USD
CY2021Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	30118000	USD
CY2020Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	36040000	USD
CY2020Q3	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	38670000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5923000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Remainder Of Fiscal Year FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear	1809000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	6115000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	4658000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	3259000	USD
CY2021Q3	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	2552000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5900000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	8400000	USD
CY2021Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	127604000	USD
CY2020Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	77203000	USD
CY2020Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	92081000	USD
CY2019Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	85638000	USD
CY2021Q3	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	15546000	USD
CY2020Q3	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	20936000	USD
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	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	50734000	USD
CY2021Q3	wtfc	Servicing Assetat Fair Value Early Buyout Option ServicingAssetatFairValueEarlyBuyoutOption	116000	USD
CY2020Q3	wtfc	Servicing Assetat Fair Value Early Buyout Option ServicingAssetatFairValueEarlyBuyoutOption	367000	USD
	wtfc	Servicing Assetat Fair Value Early Buyout Option ServicingAssetatFairValueEarlyBuyoutOption	518000	USD
	wtfc	Servicing Assetat Fair Value Early Buyout Option ServicingAssetatFairValueEarlyBuyoutOption	367000	USD
CY2021Q3	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	8594000	USD
CY2020Q3	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	7863000	USD
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	27302000	USD
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	23557000	USD
CY2021Q3	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-888000	USD
CY2020Q3	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-3002000	USD
	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	11617000	USD
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CY2021Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	133552000	USD
CY2020Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	86907000	USD
CY2021Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	133552000	USD
CY2020Q3	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	86907000	USD
CY2021Q3	us-gaap	Principal Amount Outstanding On Loans Managed And Securitized PrincipalAmountOutstandingOnLoansManagedAndSecuritized	12720126000	USD
CY2020Q3	us-gaap	Principal Amount Outstanding On Loans Managed And Securitized PrincipalAmountOutstandingOnLoansManagedAndSecuritized	10139878000	USD
CY2021Q3	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	13255417000	USD
CY2020Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	11748455000	USD
CY2020Q3	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10409747000	USD
CY2021Q3	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	3769825000	USD
CY2020Q4	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	3349021000	USD
CY2020Q3	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	3294071000	USD
CY2021Q3	wtfc	Wealth Management Deposits WealthManagementDeposits	4177820000	USD
CY2020Q4	wtfc	Wealth Management Deposits WealthManagementDeposits	4138712000	USD
CY2020Q3	wtfc	Wealth Management Deposits WealthManagementDeposits	4235583000	USD
CY2021Q3	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	10757654000	USD
CY2020Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	9348806000	USD
CY2020Q3	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	9423653000	USD
CY2021Q3	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3861296000	USD
CY2020Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3531029000	USD
CY2020Q3	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3415073000	USD
CY2021Q3	us-gaap	Time Deposits TimeDeposits	4130546000	USD
CY2020Q4	us-gaap	Time Deposits TimeDeposits	4976628000	USD
CY2020Q3	us-gaap	Time Deposits TimeDeposits	5066295000	USD
CY2021Q3	us-gaap	Deposits Deposits	39952558000	USD
CY2020Q4	us-gaap	Deposits Deposits	37092651000	USD
CY2020Q3	us-gaap	Deposits Deposits	35844422000	USD
CY2021Q3	wtfc	Non Interest Bearing Percentage NonInterestBearingPercentage	0.33
CY2020Q4	wtfc	Non Interest Bearing Percentage NonInterestBearingPercentage	0.32
CY2020Q3	wtfc	Non Interest Bearing Percentage NonInterestBearingPercentage	0.29
CY2021Q3	wtfc	No Wand Interest Bearing Demand Deposits Percentage NOWandInterestBearingDemandDepositsPercentage	0.09
CY2020Q4	wtfc	No Wand Interest Bearing Demand Deposits Percentage NOWandInterestBearingDemandDepositsPercentage	0.09
CY2020Q3	wtfc	No Wand Interest Bearing Demand Deposits Percentage NOWandInterestBearingDemandDepositsPercentage	0.09
CY2021Q3	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.11
CY2020Q4	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.11
CY2020Q3	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.12
CY2021Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.27
CY2020Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.25
CY2020Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.26
CY2021Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.10
CY2020Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.10
CY2020Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.10
CY2021Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.10
CY2020Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.13
CY2020Q3	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.14
CY2021Q3	wtfc	Deposits Percentage DepositsPercentage	1
CY2020Q4	wtfc	Deposits Percentage DepositsPercentage	1
CY2020Q3	wtfc	Deposits Percentage DepositsPercentage	1
CY2021Q3	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1241071000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1228429000	USD
CY2020Q3	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1228422000	USD
CY2021Q3	us-gaap	Notes Payable NotesPayable	85668000	USD
CY2020Q4	us-gaap	Notes Payable NotesPayable	101710000	USD
CY2020Q3	us-gaap	Notes Payable NotesPayable	107056000	USD
CY2021Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	14051000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	11366000	USD
CY2020Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	7983000	USD
CY2021Q3	us-gaap	Other Long Term Debt OtherLongTermDebt	63770000	USD
CY2020Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	65108000	USD
CY2020Q3	us-gaap	Other Long Term Debt OtherLongTermDebt	65548000	USD
CY2021Q3	us-gaap	Secured Debt SecuredDebt	341038000	USD
CY2020Q4	us-gaap	Secured Debt SecuredDebt	340744000	USD
CY2020Q3	us-gaap	Secured Debt SecuredDebt	326808000	USD
CY2021Q3	us-gaap	Other Borrowings OtherBorrowings	504527000	USD
CY2020Q4	us-gaap	Other Borrowings OtherBorrowings	518928000	USD
CY2020Q3	us-gaap	Other Borrowings OtherBorrowings	507395000	USD
CY2021Q3	us-gaap	Subordinated Debt SubordinatedDebt	436811000	USD
CY2020Q4	us-gaap	Subordinated Debt SubordinatedDebt	436506000	USD
CY2020Q3	us-gaap	Subordinated Debt SubordinatedDebt	436385000	USD
CY2021Q3	wtfc	Debt Currentand Noncurrent DebtCurrentandNoncurrent	2182409000	USD
CY2020Q4	wtfc	Debt Currentand Noncurrent DebtCurrentandNoncurrent	2183863000	USD
CY2020Q3	wtfc	Debt Currentand Noncurrent DebtCurrentandNoncurrent	2172202000	USD
CY2021Q3	us-gaap	Notes Payable NotesPayable	85700000	USD
CY2021Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	14100000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	11400000	USD
CY2020Q3	us-gaap	Short Term Borrowings ShortTermBorrowings	8000000	USD
CY2021Q3	us-gaap	Subordinated Debt SubordinatedDebt	436800000	USD
CY2020Q4	us-gaap	Subordinated Debt SubordinatedDebt	436500000	USD
CY2020Q3	us-gaap	Subordinated Debt SubordinatedDebt	436400000	USD
CY2021Q3	wtfc	Ownership Interest Percentage In Unconsolidated Subsidiary Trusts OwnershipInterestPercentageInUnconsolidatedSubsidiaryTrusts	1
CY2021Q3	wtfc	Number Of Unconsolidated Subsidiary Trusts NumberOfUnconsolidatedSubsidiaryTrusts	11	trust
CY2021Q3	wtfc	Common Securities Proportion To Junior Subordinated Debentures CommonSecuritiesProportionToJuniorSubordinatedDebentures	0.03
CY2021Q3	wtfc	Trust Preferred Securities Proportion To Junior Subordinated Debentures TrustPreferredSecuritiesProportionToJuniorSubordinatedDebentures	0.97
CY2021Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	53219000	USD
CY2020Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	42797000	USD
	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	151720000	USD
	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	124908000	USD
CY2021Q3	wtfc	Numberof Wealth Management Subsidiaries NumberofWealthManagementSubsidiaries	4	subsidiary
CY2021Q3	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2020Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2020Q3	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2021Q3	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1632000	USD
CY2020Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1548000	USD
CY2020Q3	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1543000	USD
CY2021Q3	wtfc	Mortgage Broker Fee Receivable MortgageBrokerFeeReceivable	31000	USD
CY2020Q4	wtfc	Mortgage Broker Fee Receivable MortgageBrokerFeeReceivable	20000	USD
CY2020Q3	wtfc	Mortgage Broker Fee Receivable MortgageBrokerFeeReceivable	28000	USD
CY2021Q3	wtfc	Administrative Services Receivable AdministrativeServicesReceivable	185000	USD
CY2020Q4	wtfc	Administrative Services Receivable AdministrativeServicesReceivable	64000	USD
CY2020Q3	wtfc	Administrative Services Receivable AdministrativeServicesReceivable	191000	USD
CY2021Q3	wtfc	Wealth Management Receivable WealthManagementReceivable	12001000	USD
CY2020Q4	wtfc	Wealth Management Receivable WealthManagementReceivable	10144000	USD
CY2020Q3	wtfc	Wealth Management Receivable WealthManagementReceivable	10232000	USD
CY2021Q3	wtfc	Card Related Fee Receivable CardRelatedFeeReceivable	462000	USD
CY2020Q4	wtfc	Card Related Fee Receivable CardRelatedFeeReceivable	783000	USD
CY2020Q3	wtfc	Card Related Fee Receivable CardRelatedFeeReceivable	201000	USD
CY2021Q3	us-gaap	Accounts Receivable Net AccountsReceivableNet	12679000	USD
CY2020Q4	us-gaap	Accounts Receivable Net AccountsReceivableNet	11011000	USD
CY2020Q3	us-gaap	Accounts Receivable Net AccountsReceivableNet	10652000	USD
	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	798000	USD
	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	1300000	USD
CY2021Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	291000	USD
CY2021Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	591000	USD
CY2021Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	400000	USD
CY2021Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	250000	USD
CY2021Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	100000	USD
CY2021Q3	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	1632000	USD
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2021Q3	wtfc	Number Of Subsidiaries NumberOfSubsidiaries	15	subsidiary
CY2021Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	287496000	USD
CY2020Q3	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	255936000	USD
CY2021Q3	wtfc	Change In Contribution Interest Income Expense Net ChangeInContributionInterestIncomeExpenseNet	31560000	USD
CY2021Q3	wtfc	Interest Income Expense Net Percentage InterestIncomeExpenseNetPercentage	0.12
CY2021Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-7916000	USD
CY2020Q3	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	25026000	USD
CY2021Q3	wtfc	Change In Contribution Provision For Loan Lease And Other Losses ChangeInContributionProvisionForLoanLeaseAndOtherLosses	-32942000	USD
CY2021Q3	us-gaap	Noninterest Income NoninterestIncome	136474000	USD
CY2020Q3	us-gaap	Noninterest Income NoninterestIncome	170593000	USD
CY2021Q3	wtfc	Change In Contribution Non Interest Income ChangeInContributionNonInterestIncome	-34119000	USD
CY2021Q3	wtfc	Non Interest Income Percentage NonInterestIncomePercentage	-0.20
CY2021Q3	us-gaap	Revenues Revenues	423970000	USD
CY2020Q3	us-gaap	Revenues Revenues	426529000	USD
CY2021Q3	wtfc	Change In Contribution Revenues ChangeInContributionRevenues	-2559000	USD
CY2021Q3	wtfc	Revenues Percentage RevenuesPercentage	-0.01
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	109137000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	107315000	USD
CY2021Q3	wtfc	Change In Contribution Operating Income Loss ChangeInContributionOperatingIncomeLoss	1822000	USD
CY2021Q3	wtfc	Operating Income Loss Percentage OperatingIncomeLossPercentage	0.02
CY2021Q3	us-gaap	Assets Assets	47832271000	USD
CY2020Q3	us-gaap	Assets Assets	43731718000	USD
CY2021Q3	wtfc	Change In Contribution Assets ChangeInContributionAssets	4100553000	USD
CY2021Q3	wtfc	Assets Percentage AssetsPercentage	0.09
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	828981000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	780510000	USD
	wtfc	Change In Contribution Interest Income Expense Net ChangeInContributionInterestIncomeExpenseNet	48471000	USD
	wtfc	Interest Income Expense Net Percentage InterestIncomeExpenseNetPercentage	0.06
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-68562000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	213040000	USD
	wtfc	Change In Contribution Provision For Loan Lease And Other Losses ChangeInContributionProvisionForLoanLeaseAndOtherLosses	-281602000	USD
	us-gaap	Noninterest Income NoninterestIncome	452353000	USD
	us-gaap	Noninterest Income NoninterestIncome	445828000	USD
	wtfc	Change In Contribution Non Interest Income ChangeInContributionNonInterestIncome	6525000	USD
	wtfc	Non Interest Income Percentage NonInterestIncomePercentage	0.01
	us-gaap	Revenues Revenues	1281334000	USD
	us-gaap	Revenues Revenues	1226338000	USD
	wtfc	Change In Contribution Revenues ChangeInContributionRevenues	54996000	USD
	wtfc	Revenues Percentage RevenuesPercentage	0.04
	us-gaap	Net Income Loss NetIncomeLoss	367394000	USD
	us-gaap	Net Income Loss NetIncomeLoss	191786000	USD
	wtfc	Change In Contribution Operating Income Loss ChangeInContributionOperatingIncomeLoss	175608000	USD
	wtfc	Operating Income Loss Percentage OperatingIncomeLossPercentage	0.92
CY2021Q3	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	191612000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	278423000	USD
CY2020Q3	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	321488000	USD
CY2021Q3	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	161314000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	288465000	USD
CY2020Q3	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	326990000	USD
	us-gaap	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths	-14900000	USD
CY2021Q3	us-gaap	Derivative Net Liability Position Aggregate Fair Value DerivativeNetLiabilityPositionAggregateFairValue	115700000	USD
CY2021Q3	wtfc	Impaired Loans Fair Value Losses Recognized ImpairedLoansFairValueLossesRecognized	1425000	USD
	wtfc	Impaired Loans Fair Value Losses Recognized ImpairedLoansFairValueLossesRecognized	17956000	USD
CY2021Q3	wtfc	Real Estate Acquired Through Foreclosure Fair Value Losses Recognized RealEstateAcquiredThroughForeclosureFairValueLossesRecognized	93000	USD
	wtfc	Real Estate Acquired Through Foreclosure Fair Value Losses Recognized RealEstateAcquiredThroughForeclosureFairValueLossesRecognized	1012000	USD
CY2021Q3	wtfc	Assets Nonrecurring Fair Value Losses Recognized AssetsNonrecurringFairValueLossesRecognized	1518000	USD
	wtfc	Assets Nonrecurring Fair Value Losses Recognized AssetsNonrecurringFairValueLossesRecognized	18968000	USD
CY2021Q3	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	109000000	USD
CY2021Q3	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	109000000	USD
CY2015Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	5485000	shares
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	976000	shares
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
CY2021Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3200000	USD
CY2020Q3	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	1300000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	9400000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	-1000000.0	USD
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	520663	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.47
	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	245286	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	43.05
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	590	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	46.86
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	274787	shares
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	41.95
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P1Y4M24D
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	10557000	USD
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	273238	shares
CY2021Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	41.92
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P1Y4M24D
CY2021Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	10506000	USD
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	755332	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.43
	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	104703	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	38.71
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	5608	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	44.34
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	645021	shares
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	43.02
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P1Y10M24D
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	52000	USD
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	637120	shares
CY2020Q3	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	43.01
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P1Y9M18D
CY2020Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	52000	USD
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	7900000	USD
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	2700000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	10600000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	4100000	USD
CY2021Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.31
CY2021Q1	wtfc	Common Stock Dividends Per Share Declared Annualized CommonStockDividendsPerShareDeclaredAnnualized	1.24
CY2021Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.31
CY2021Q2	wtfc	Common Stock Dividends Per Share Declared Annualized CommonStockDividendsPerShareDeclaredAnnualized	1.24
CY2021Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.31
CY2021Q3	wtfc	Common Stock Dividends Per Share Declared Annualized CommonStockDividendsPerShareDeclaredAnnualized	1.24
CY2021Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-13393000	USD
CY2021Q3	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-4717000	USD
CY2021Q3	wtfc	Reclassification From Accumulated Other Comprehensive Income Amortization Of Unrealized Gains Losses On Investment Securities Transferred To Held To Maturity From Available For Sale Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeAmortizationOfUnrealizedGainsLossesOnInvestmentSecuritiesTransferredToHeldToMaturityFromAvailableForSaleNetOfTax	40000	USD
CY2021Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-8716000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-27933000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-14084000	USD
	wtfc	Reclassification From Accumulated Other Comprehensive Income Amortization Of Unrealized Gains Losses On Investment Securities Transferred To Held To Maturity From Available For Sale Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeAmortizationOfUnrealizedGainsLossesOnInvestmentSecuritiesTransferredToHeldToMaturityFromAvailableForSaleNetOfTax	116000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-13965000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-4325000	USD
CY2020Q3	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-4121000	USD
CY2020Q3	wtfc	Reclassification From Accumulated Other Comprehensive Income Amortization Of Unrealized Gains Losses On Investment Securities Transferred To Held To Maturity From Available For Sale Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeAmortizationOfUnrealizedGainsLossesOnInvestmentSecuritiesTransferredToHeldToMaturityFromAvailableForSaleNetOfTax	40000	USD
CY2020Q3	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-244000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	25160000	USD
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-8808000	USD
	wtfc	Reclassification From Accumulated Other Comprehensive Income Amortization Of Unrealized Gains Losses On Investment Securities Transferred To Held To Maturity From Available For Sale Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeAmortizationOfUnrealizedGainsLossesOnInvestmentSecuritiesTransferredToHeldToMaturityFromAvailableForSaleNetOfTax	131000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	33837000	USD
CY2021Q3	us-gaap	Net Income Loss NetIncomeLoss	109137000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	107315000	USD
	us-gaap	Net Income Loss NetIncomeLoss	367394000	USD
	us-gaap	Net Income Loss NetIncomeLoss	191786000	USD
CY2021Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	6991000	USD
CY2020Q3	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	10286000	USD
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	20973000	USD
CY2020Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	97029000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	346421000	USD
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	728000	shares
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	14386000	USD
CY2021Q3	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	102146000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	177400000	USD
CY2021Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57000000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57597000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56985000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57595000	shares
CY2021Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	753000	shares
CY2020Q3	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	449000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	469000	shares
CY2021Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57753000	shares
CY2020Q3	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58046000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57713000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58064000	shares
CY2021Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.79
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.68
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.08
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	3.08
CY2021Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.77
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.67
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.00
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	3.06

Files In Submission

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0001015328-21-000189-index-headers.html	Edgar Link	pending
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0001015328-21-000189.txt	Edgar Link	pending
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exhibit3112021q3.htm	Edgar Link	pending
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wtfc-20210930_htm.xml	Edgar Link	completed
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wtfc-20210930_pre.xml	Edgar Link	unprocessable

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$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc

2021 Q4 Form 10-Q Financial Statement

#000101532821000189 Filed on November 08, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WTFC WINTRUST FINANCIAL CORP Stock $wtfc

2021 Q4 Form 10-Q Financial Statement

#000101532821000189 Filed on November 08, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc