$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc

$wtfc Overview Financials Valuation SEC Filings Company Website

2019 Q2 Form 10-Q Financial Statement

#000101532820000165 Filed on August 07, 2020

Income Statement

Concept	2019 Q2	2019 Q1
Revenue	$364.4M	$343.6M
YoY Change	9.29%	10.58%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$22.10M	$21.20M
YoY Change	37.27%	33.33%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense	$80.61M	$71.98M
YoY Change	75.71%	99.27%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$110.2M	$118.6M
YoY Change	-9.39%	9.79%
Income Tax	$28.71M	$29.50M
% Of Pretax Income	26.06%	24.86%
Net Earnings	$81.47M	$89.15M
YoY Change	-9.06%	8.74%
Net Earnings / Revenue	22.36%	25.94%
Basic Earnings Per Share	$1.40	$1.54
Diluted Earnings Per Share	$1.38	$1.52
COMMON SHARES
Basic Shares Outstanding	56.66M shares	56.53M shares
Diluted Shares Outstanding	57.36M shares	57.23M shares

Balance Sheet

Concept	2019 Q2	2019 Q1
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$301.0M	$270.8M
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	$711.2M	$676.0M
YoY Change	11.24%	7.87%
Goodwill	$584.9M	$573.7M
YoY Change	14.7%	12.15%
Intangibles	$46.59M	$46.57M
YoY Change	117.56%	107.76%
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	$33.64B	$32.36B
YoY Change	14.18%	13.71%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$798.0M	$644.0M
YoY Change	17.87%	8.97%
Accrued Expenses	$195.0M	$197.0M
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$10.20M	$16.20M
YoY Change	-52.34%	-9.88%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$993.0M	$841.0M
YoY Change	46.68%	42.3%
LONG-TERM LIABILITIES
Long-Term Debt	$1.097B	$749.0M
YoY Change	74.96%	20.42%
Other Long-Term Liabilities
YoY Change
Total Long-Term Liabilities	$1.097B	$749.0M
YoY Change	74.96%	20.42%
TOTAL LIABILITIES
Total Short-Term Liabilities	$993.0M	$841.0M
Total Long-Term Liabilities	$1.097B	$749.0M
Total Liabilities	$30.19B	$28.99B
YoY Change	14.56%	14.01%
SHAREHOLDERS EQUITY
Retained Earnings	$1.747B	$1.682B
YoY Change	19.31%	21.21%
Common Stock	$56.79M	$56.77M
YoY Change	0.63%	0.71%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$6.650M	$6.650M
YoY Change	24.18%	24.18%
Treasury Stock Shares	126.5K shares	126.5K shares
Shareholders Equity	$3.447B	$3.372B
YoY Change
Total Liabilities & Shareholders Equity	$33.64B	$32.36B
YoY Change	14.18%	13.71%

Cashflow Statement

Concept	2019 Q2	2019 Q1
OPERATING ACTIVITIES
Net Income	$81.47M	$89.15M
YoY Change	-9.06%	8.74%
Depreciation, Depletion And Amortization	$22.10M	$21.20M
YoY Change	37.27%	33.33%
Cash From Operating Activities	-$65.50M	$87.69M
YoY Change	-181.88%	294.52%
INVESTING ACTIVITIES
Capital Expenditures	-$17.70M	$13.61M
YoY Change	-14.49%	17.51%
Acquisitions		$0.00
YoY Change		-100.0%
Other Investing Activities	-$761.0M	-$1.018B
YoY Change	-7.88%	108.91%
Cash From Investing Activities	-$778.7M	-$1.032B
YoY Change	-8.05%	106.78%
FINANCING ACTIVITIES
Cash Dividend Paid		$16.17M
YoY Change		27.22%
Common Stock Issuance & Retirement, Net		$0.00
YoY Change		-100.0%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	874.4M	$822.5M
YoY Change	4.08%	91.05%
NET CHANGE
Cash From Operating Activities	-65.50M	$87.69M
Cash From Investing Activities	-778.7M	-$1.032B
Cash From Financing Activities	874.4M	$822.5M
Net Change In Cash	30.20M	-$121.4M
YoY Change	-58.74%	163.14%
FREE CASH FLOW
Cash From Operating Activities	-$65.50M	$87.69M
Capital Expenditures	-$17.70M	$13.61M
Free Cash Flow	-$47.80M	$74.08M
YoY Change	-147.47%	595.82%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2019Q4	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	253600000	USD
CY2019Q2	us-gaap	Preferred Stock Dividends Per Share Declared PreferredStockDividendsPerShareDeclared	0.41
	us-gaap	Preferred Stock Dividends Per Share Declared PreferredStockDividendsPerShareDeclared	0.82
	dei	Amendment Flag AmendmentFlag	false
	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	Q2
	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
	dei	Entity Central Index Key EntityCentralIndexKey	0001015328
	us-gaap	Accounting Standards Update Extensible List AccountingStandardsUpdateExtensibleList	us-gaap:AccountingStandardsUpdate201708Member
	us-gaap	Accounting Standards Update Extensible List AccountingStandardsUpdateExtensibleList	us-gaap:AccountingStandardsUpdate201613Member
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.50
CY2019Q2	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1
CY2020Q2	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	1
CY2019Q2	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2020Q2	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2019Q2	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	56794328	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	57950803	shares
CY2020Q2	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	58294456	shares
CY2019Q2	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1200000000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1100000000	USD
CY2020Q2	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	744300000	USD
CY2020Q2	us-gaap	Preferred Stock Dividends Per Share Declared PreferredStockDividendsPerShareDeclared	0.41
	us-gaap	Preferred Stock Dividends Per Share Declared PreferredStockDividendsPerShareDeclared	0.82
CY2019Q2	us-gaap	Preferred Stock Liquidation Preference PreferredStockLiquidationPreference	25
CY2019Q4	us-gaap	Preferred Stock Liquidation Preference PreferredStockLiquidationPreference	25
CY2020Q2	us-gaap	Preferred Stock Liquidation Preference PreferredStockLiquidationPreference	25
CY2019Q2	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2020Q2	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2019Q2	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	5000000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	5000000	shares
CY2020Q2	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	5000000	shares
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	7006000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	4915000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	118552000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	34081000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	31443000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	4782000	USD
	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	202055000	USD
CY2019Q2	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	2050000	USD
	wtfc	Weighted Average Decrease Stated Interest Rate Basis Points WeightedAverageDecreaseStatedInterestRateBasisPoints	0.0158
CY2020Q2	wtfc	Weighted Average Decrease Stated Interest Rate Basis Points WeightedAverageDecreaseStatedInterestRateBasisPoints	0.0142
	dei	Document Type DocumentType	10-Q
CY2019Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	286167000	USD
CY2019Q2	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	5000000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	5000000	shares
CY2020Q2	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	5000000	shares
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CY2020Q2	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2020Q2	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2020Q2	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P1Y
CY2019Q2	us-gaap	Treasury Stock Shares TreasuryStockShares	126482	shares
CY2019Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	128912	shares
CY2020Q2	us-gaap	Treasury Stock Shares TreasuryStockShares	720784	shares
	wtfc	Debt Instrument Interest Payment Deferral Period DebtInstrumentInterestPaymentDeferralPeriod	P60M
CY2019Q2	wtfc	Loan Forgiveness LoanForgiveness	0	USD
CY2019Q2	wtfc	Weighted Average Decrease Stated Interest Rate Basis Points WeightedAverageDecreaseStatedInterestRateBasisPoints	0.0219
	wtfc	Weighted Average Decrease Stated Interest Rate Basis Points WeightedAverageDecreaseStatedInterestRateBasisPoints	0.0216
	dei	Document Quarterly Report DocumentQuarterlyReport	true
	dei	Document Period End Date DocumentPeriodEndDate	2020-06-30
	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
	dei	Entity Shell Company EntityShellCompany	false
CY2020Q3	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	57600765	shares
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CY2019Q2	us-gaap	Cash And Due From Banks CashAndDueFromBanks	300934000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	81466000	USD
CY2020Q2	wtfc	Debt Securities Held To Maturity Net Of Allowance For Credit Losses DebtSecuritiesHeldToMaturityNetOfAllowanceForCreditLosses	728465000	USD
CY2019Q2	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	1437105000	USD
CY2020Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	3194961000	USD
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CY2020Q2	us-gaap	Federal Funds Sold And Securities Purchased Under Agreements To Resell FederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	58000	USD
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CY2019Q2	us-gaap	Common Stock Value CommonStockValue	56794000	USD
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CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	3990218000	USD
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CY2019Q2	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	33641769000	USD
CY2020Q2	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	294746000	USD
CY2019Q2	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	309161000	USD
	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	596585000	USD
	us-gaap	Interest And Fee Income Loans And Leases Held In Portfolio InterestAndFeeIncomeLoansAndLeasesHeldInPortfolio	606148000	USD
CY2020Q2	us-gaap	Interest And Fee Income Loans Held For Sale Mortgages InterestAndFeeIncomeLoansHeldForSaleMortgages	4764000	USD
CY2019Q2	us-gaap	Interest And Fee Income Loans Held For Sale Mortgages InterestAndFeeIncomeLoansHeldForSaleMortgages	3104000	USD
	us-gaap	Interest And Fee Income Loans Held For Sale Mortgages InterestAndFeeIncomeLoansHeldForSaleMortgages	7929000	USD
	us-gaap	Interest And Fee Income Loans Held For Sale Mortgages InterestAndFeeIncomeLoansHeldForSaleMortgages	5313000	USD
CY2020Q2	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	1310000	USD
CY2019Q2	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	5206000	USD
	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	6078000	USD
	us-gaap	Interest Income Deposits With Financial Institutions InterestIncomeDepositsWithFinancialInstitutions	10506000	USD
CY2020Q2	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	16000	USD
CY2019Q2	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	0	USD
	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	102000	USD
	us-gaap	Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell InterestIncomeFederalFundsSoldAndSecuritiesPurchasedUnderAgreementsToResell	0	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	4915000	USD
CY2019Q2	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	86381000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	124000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	358000	USD
CY2020Q2	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	12000	USD
CY2020Q2	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	5506000	USD
CY2019Q2	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	2806000	USD
CY2019Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	14166000	USD
	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	10978000	USD
	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	4581000	USD
CY2020Q2	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	2752000	USD
CY2019Q2	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	3064000	USD
	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	5563000	USD
	wtfc	Interest Income On Brokerage Customer Receivables InterestIncomeOnBrokerageCustomerReceivables	255000	USD
	wtfc	Interest Income On Brokerage Customer Receivables InterestIncomeOnBrokerageCustomerReceivables	333000	USD
CY2020Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	329816000	USD
	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	7158000	USD
CY2020Q2	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	27105000	USD
CY2019Q2	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	27721000	USD
	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	59572000	USD
	us-gaap	Interest And Dividend Income Securities Other InterestAndDividendIncomeSecuritiesOther	55677000	USD
CY2020Q2	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	13000	USD
CY2019Q2	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	5000	USD
	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	20000	USD
	us-gaap	Interest Income Debt Securities Trading Operating InterestIncomeDebtSecuritiesTradingOperating	13000	USD
CY2020Q2	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	1765000	USD
CY2019Q2	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	1439000	USD
	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	3342000	USD
	wtfc	Interest Income Federal Home Loan Banks And Federal Reserve Bank Stock InterestIncomeFederalHomeLoanBanksAndFederalReserveBankStock	2794000	USD
CY2020Q2	wtfc	Interest Income On Brokerage Customer Receivables InterestIncomeOnBrokerageCustomerReceivables	97000	USD
CY2019Q2	wtfc	Interest Income On Brokerage Customer Receivables InterestIncomeOnBrokerageCustomerReceivables	178000	USD
CY2019Q2	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	346814000	USD
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	673883000	USD
	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	680784000	USD
CY2020Q2	us-gaap	Interest Expense Deposits InterestExpenseDeposits	50057000	USD
CY2019Q2	us-gaap	Interest Expense Deposits InterestExpenseDeposits	67024000	USD
	us-gaap	Interest Expense Deposits InterestExpenseDeposits	117492000	USD
	us-gaap	Interest Expense Deposits InterestExpenseDeposits	128000000	USD
CY2020Q2	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	4934000	USD
CY2019Q2	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	4193000	USD
	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	8294000	USD
	us-gaap	Interest Expense Federal Home Loan Bank And Federal Reserve Bank Advances Long Term InterestExpenseFederalHomeLoanBankAndFederalReserveBankAdvancesLongTerm	6643000	USD
CY2020Q2	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	3436000	USD
CY2019Q2	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	3525000	USD
	us-gaap	Interest Expense Other Long Term Debt InterestExpenseOtherLongTermDebt	6982000	USD
	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	6214000	USD
CY2020Q2	us-gaap	Interest Expense InterestExpense	66685000	USD
CY2019Q1	us-gaap	Stockholders Equity StockholdersEquity	3371972000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	336560000	USD
	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	492984000	USD
CY2020Q2	wtfc	Fees And Commissions Mortgage Banking1 FeesAndCommissionsMortgageBanking1	102324000	USD
CY2019Q2	wtfc	Fees And Commissions Mortgage Banking1 FeesAndCommissionsMortgageBanking1	37411000	USD
CY2019Q2	us-gaap	Interest Expense InterestExpense	80612000	USD
	us-gaap	Interest Expense InterestExpense	149309000	USD
	us-gaap	Interest Expense InterestExpense	152596000	USD
CY2020Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	263131000	USD
CY2019Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	266202000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	524574000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	528188000	USD
CY2020Q2	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	135053000	USD
CY2019Q2	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	24580000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	188014000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	35204000	USD
CY2020Q2	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	128078000	USD
CY2019Q2	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	241622000	USD
	wtfc	Fees And Commissions Mortgage Banking1 FeesAndCommissionsMortgageBanking1	150650000	USD
	wtfc	Fees And Commissions Mortgage Banking1 FeesAndCommissionsMortgageBanking1	55569000	USD
CY2020Q2	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	808000	USD
CY2019Q2	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	864000	USD
	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	-3551000	USD
	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	2228000	USD
CY2020Q2	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	0	USD
CY2019Q2	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	643000	USD
	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	2292000	USD
	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	2427000	USD
CY2020Q2	us-gaap	Trading Gains Losses TradingGainsLosses	-634000	USD
CY2019Q2	us-gaap	Trading Gains Losses TradingGainsLosses	-44000	USD
	us-gaap	Trading Gains Losses TradingGainsLosses	-1085000	USD
	us-gaap	Trading Gains Losses TradingGainsLosses	-215000	USD
CY2020Q2	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	11785000	USD
CY2019Q2	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	11733000	USD
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	23769000	USD
	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	22529000	USD
CY2020Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	14654000	USD
CY2019Q2	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	14135000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	32898000	USD
	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	31036000	USD
CY2020Q2	us-gaap	Noninterest Income NoninterestIncome	161993000	USD
CY2019Q2	us-gaap	Noninterest Income NoninterestIncome	98158000	USD
CY2019Q2	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	57000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	33000	USD
CY2019Q2	us-gaap	Occupancy Net OccupancyNet	15921000	USD
	us-gaap	Occupancy Net OccupancyNet	34440000	USD
	us-gaap	Occupancy Net OccupancyNet	32166000	USD
CY2020Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	10406000	USD
CY2019Q2	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	6204000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	18779000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	98000	USD
	us-gaap	Noninterest Income NoninterestIncome	275235000	USD
	us-gaap	Noninterest Income NoninterestIncome	179815000	USD
CY2020Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	154156000	USD
CY2019Q2	us-gaap	Labor And Related Expense LaborAndRelatedExpense	133732000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	290918000	USD
	us-gaap	Labor And Related Expense LaborAndRelatedExpense	259455000	USD
CY2020Q2	us-gaap	Equipment Expense EquipmentExpense	15846000	USD
CY2019Q2	us-gaap	Equipment Expense EquipmentExpense	12759000	USD
	us-gaap	Equipment Expense EquipmentExpense	30680000	USD
	us-gaap	Equipment Expense EquipmentExpense	24529000	USD
CY2020Q2	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	9292000	USD
CY2019Q2	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	8768000	USD
	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	18552000	USD
	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	17087000	USD
CY2020Q2	us-gaap	Occupancy Net OccupancyNet	16893000	USD
	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	13729000	USD
CY2020Q2	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	7704000	USD
CY2019Q2	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	12845000	USD
	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	18566000	USD
	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	22703000	USD
CY2020Q2	us-gaap	Professional Fees ProfessionalFees	7687000	USD
CY2019Q2	us-gaap	Professional Fees ProfessionalFees	6228000	USD
	us-gaap	Professional Fees ProfessionalFees	14408000	USD
	us-gaap	Professional Fees ProfessionalFees	11784000	USD
CY2020Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2820000	USD
CY2019Q2	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2957000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5683000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5899000	USD
CY2020Q2	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	7081000	USD
CY2019Q2	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	4127000	USD
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	11216000	USD
	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	7703000	USD
CY2020Q2	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	-237000	USD
CY2019Q2	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	-1290000	USD
	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	-639000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	70524000	USD
	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	46562000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-2867000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-22168000	USD
CY2020Q2	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	34000	USD
CY2019Q2	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	157000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	91000	USD
	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	260000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	3933000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	18660000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-41560000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-27164000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-773000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-5918000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-11095000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-7263000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-2094000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-16250000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-30465000	USD
	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-19901000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	6677000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	3232000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	-7655000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	6123000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	1510000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	727000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	-1677000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	1341000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	5167000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	2505000	USD
	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	-5978000	USD
	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	1922000	USD
CY2020Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	27246000	USD
CY2019Q2	us-gaap	Other Noninterest Expense OtherNoninterestExpense	24776000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	51406000	USD
	us-gaap	Other Noninterest Expense OtherNoninterestExpense	47004000	USD
CY2020Q2	us-gaap	Noninterest Expense NoninterestExpense	259368000	USD
CY2019Q2	us-gaap	Noninterest Expense NoninterestExpense	229607000	USD
	us-gaap	Noninterest Expense NoninterestExpense	494009000	USD
	us-gaap	Noninterest Expense NoninterestExpense	443981000	USD
CY2020Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	30703000	USD
CY2019Q2	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	110173000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	117786000	USD
	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	228818000	USD
CY2020Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	9044000	USD
CY2019Q2	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	28707000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	33315000	USD
	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	58206000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	21659000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	81466000	USD
	us-gaap	Net Income Loss NetIncomeLoss	84471000	USD
	us-gaap	Net Income Loss NetIncomeLoss	170612000	USD
CY2020Q2	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	2050000	USD
CY2019Q2	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	2050000	USD
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	4100000	USD
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	4100000	USD
CY2020Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	19609000	USD
CY2019Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	79416000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	80371000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	166512000	USD
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.34
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.40
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.40
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.94
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.34
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.38
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.38
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.91
CY2020Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
CY2019Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.25
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.56
	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.50
CY2020Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57567000	shares
CY2019Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56662000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57593000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56596000	shares
CY2020Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	414000	shares
CY2019Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	699000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	481000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	700000	shares
CY2020Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57981000	shares
CY2019Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57361000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58074000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57296000	shares
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	21659000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	81466000	USD
	us-gaap	Net Income Loss NetIncomeLoss	84471000	USD
	us-gaap	Net Income Loss NetIncomeLoss	170612000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	5068000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	26177000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	96422000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	64452000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	1350000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	6977000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	25697000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	17296000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	3718000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	19200000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	70725000	USD
	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	47156000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	-341000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	523000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	150000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	456000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	-92000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	140000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	40000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	122000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	-249000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	383000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	110000	USD
	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	334000	USD
CY2020Q2	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	46000	USD
CY2019Q2	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	214000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	188014000	USD
CY2019Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	2965000	USD
CY2019Q2	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	659000	USD
CY2019Q2	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	666000	USD
CY2019Q2	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	523000	USD
CY2019Q2	us-gaap	Stockholders Equity StockholdersEquity	3446950000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	3267570000	USD
	us-gaap	Net Income Loss NetIncomeLoss	170612000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	31443000	USD
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	28289000	USD
	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	4100000	USD
	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	6283000	USD
	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	3027000	USD
	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-441000	USD
	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	1349000	USD
	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	1027000	USD
CY2019Q2	us-gaap	Stockholders Equity StockholdersEquity	3446950000	USD
CY2020Q1	us-gaap	Stockholders Equity StockholdersEquity	3700393000	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	21659000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	7006000	USD
CY2020Q2	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	16119000	USD
CY2020Q2	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	2050000	USD
CY2020Q2	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	541000	USD
CY2020Q2	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	277375000	USD
CY2020Q2	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	161000	USD
CY2020Q2	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	676000	USD
CY2020Q2	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	576000	USD
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	3990218000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	3691250000	USD
	us-gaap	Net Income Loss NetIncomeLoss	84471000	USD
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	34081000	USD
	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	32236000	USD
	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	4100000	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	-2278000	USD
	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	277375000	USD
	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	3707000	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	1385000	USD
	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	1148000	USD
CY2020Q2	us-gaap	Stockholders Equity StockholdersEquity	3990218000	USD
	us-gaap	Net Income Loss NetIncomeLoss	84471000	USD
	us-gaap	Net Income Loss NetIncomeLoss	170612000	USD
	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	960000	USD
	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	155108000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	35204000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	47138000	USD
	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	43322000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	-2278000	USD
	us-gaap	Share Based Compensation ShareBasedCompensation	6283000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-4694000	USD
	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-2971000	USD
	wtfc	Accretion Amortization Of Discount Premium On Loans AccretionAmortizationOfDiscountPremiumOnLoans	41304000	USD
	wtfc	Accretion Amortization Of Discount Premium On Loans AccretionAmortizationOfDiscountPremiumOnLoans	11746000	USD
	us-gaap	Mortgage Servicing Rights Msr Impairment Recovery MortgageServicingRightsMSRImpairmentRecovery	35509000	USD
	us-gaap	Mortgage Servicing Rights Msr Impairment Recovery MortgageServicingRightsMSRImpairmentRecovery	19122000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	3426911000	USD
	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	1832264000	USD
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	3035641000	USD
	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	1736063000	USD
	wtfc	Bank Owned Life Insurance Net Of Claims BankOwnedLifeInsuranceNetOfClaims	666000	USD
	wtfc	Bank Owned Life Insurance Net Of Claims BankOwnedLifeInsuranceNetOfClaims	2740000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-178000	USD
	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	738000	USD
	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	-1950000	USD
	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	51086000	USD
	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	-3551000	USD
	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	2228000	USD
	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-3000	USD
	us-gaap	Gain Loss On Sale Of Property Plant Equipment GainLossOnSaleOfPropertyPlantEquipment	-37000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	694000	USD
	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-1115000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	171099000	USD
	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	139971000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	27244000	USD
	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	49233000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-369667000	USD
	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	22229000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	549981000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	231198000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	529974000	USD
	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	51393000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	502676000	USD
	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	667918000	USD
	wtfc	Proceedsfrom Saleof Equity Securities With Readily Determinable Fair Value ProceedsfromSaleofEquitySecuritiesWithReadilyDeterminableFairValue	4030000	USD
	wtfc	Proceedsfrom Saleof Equity Securities With Readily Determinable Fair Value ProceedsfromSaleofEquitySecuritiesWithReadilyDeterminableFairValue	11000000	USD
	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	18677000	USD
	wtfc	Paymentsto Acquire Equity Securitieswithout Readily Determinable Fair Value PaymentstoAcquireEquitySecuritieswithoutReadilyDeterminableFairValue	3166000	USD
	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	0	USD
	wtfc	Paymentsto Acquire Equity Securitieswithout Readily Determinable Fair Value PaymentstoAcquireEquitySecuritieswithoutReadilyDeterminableFairValue	1072000	USD
	wtfc	Proceedsfrom Salesand Capital Distributionsof Equity Securities Without Readily Determinable Fair Value ProceedsfromSalesandCapitalDistributionsofEquitySecuritiesWithoutReadilyDeterminableFairValue	444000	USD
	wtfc	Proceedsfrom Salesand Capital Distributionsof Equity Securities Without Readily Determinable Fair Value ProceedsfromSalesandCapitalDistributionsofEquitySecuritiesWithoutReadilyDeterminableFairValue	609000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1048539000	USD
	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	871269000	USD
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	124802000	USD
	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	178331000	USD
	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	7659000	USD
	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	34832000	USD
	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	672000	USD
	us-gaap	Payments For Proceeds From Limited Partnership PaymentsForProceedsFromLimitedPartnership	355000	USD
	us-gaap	Payments For Proceeds From Limited Partnership PaymentsForProceedsFromLimitedPartnership	-772000	USD
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	-748000	USD
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	5405000	USD
	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	5155000	USD
	us-gaap	Proceeds From Payments For In Interest Bearing Deposits In Banks ProceedsFromPaymentsForInInterestBearingDepositsInBanks	-1852194000	USD
	us-gaap	Proceeds From Payments For In Interest Bearing Deposits In Banks ProceedsFromPaymentsForInInterestBearingDepositsInBanks	-337581000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	4460325000	USD
	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	1340204000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	38132000	USD
	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	31297000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-5977494000	USD
	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1810310000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	5545133000	USD
	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	1262941000	USD
	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	98974000	USD
	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	16243000	USD
	wtfc	Proceeds From Payments To Federal Home Loan Bank Borrowings ProceedsFromPaymentsToFederalHomeLoanBankBorrowings	553500000	USD
	wtfc	Proceeds From Payments To Federal Home Loan Bank Borrowings ProceedsFromPaymentsToFederalHomeLoanBankBorrowings	148441000	USD
	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	USD
	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	296741000	USD
	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	277375000	USD
	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	1276000	USD
	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	66000	USD
	wtfc	Issuance Of Common Shares Resulting From Exercise Of Stock Options Employee Stock Purchase Plan And Conversion Of Common Stock Warrants IssuanceOfCommonSharesResultingFromExerciseOfStockOptionsEmployeeStockPurchasePlanAndConversionOfCommonStockWarrants	6332000	USD
	wtfc	Issuance Of Common Shares Resulting From Exercise Of Stock Options Employee Stock Purchase Plan And Conversion Of Common Stock Warrants IssuanceOfCommonSharesResultingFromExerciseOfStockOptionsEmployeeStockPurchasePlanAndConversionOfCommonStockWarrants	5978000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	37116000	USD
	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	844000	USD
	us-gaap	Payments Of Dividends PaymentsOfDividends	32389000	USD
	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1016000	USD
	us-gaap	Payments Of Dividends PaymentsOfDividends	36336000	USD
CY2020Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	345057000	USD
CY2019Q2	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	300992000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	6405742000	USD
	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	1696873000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	58581000	USD
	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-91208000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	286476000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	392200000	USD
CY2020Q2	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLoss	109100000	USD
CY2020Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	3079299000	USD
CY2020Q2	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	121321000	USD
CY2020Q2	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	5659000	USD
CY2020Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	3194961000	USD
CY2020Q2	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	728530000	USD
CY2020Q2	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	15913000	USD
CY2020Q2	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	157000	USD
CY2019Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	1134400000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	9695000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	5699000	USD
CY2019Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	1138396000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni Cost EquitySecuritiesFvNiCost	48044000	USD
CY2019Q4	wtfc	Equity Securities Fvni Accumulated Unrealized Gain EquitySecuritiesFVNIAccumulatedUnrealizedGain	3511000	USD
CY2019Q4	wtfc	Equity Securities Fvni Accumulated Unrealized Loss EquitySecuritiesFVNIAccumulatedUnrealizedLoss	715000	USD
CY2019Q4	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	50840000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	3086824000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	30467000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	11077000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	3106214000	USD
CY2020Q2	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	744286000	USD
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CY2019Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	2186154000	USD
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CY2019Q2	wtfc	Equity Securities Fvni Accumulated Unrealized Loss EquitySecuritiesFVNIAccumulatedUnrealizedLoss	752000	USD
CY2019Q2	us-gaap	Equity Securities Fv Ni EquitySecuritiesFvNi	44319000	USD
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CY2019Q2	wtfc	Marketable Securities Gross Realized Gains Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedGainsExcludingOtherThanTemporaryImpairments	530000	USD
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CY2019Q2	wtfc	Marketable Securities Gross Realized Losses Excluding Other Than Temporary Impairments MarketableSecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments	7000	USD
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CY2020Q2	us-gaap	Marketable Securities Realized Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments	-341000	USD
CY2019Q2	us-gaap	Marketable Securities Realized Gain Loss Excluding Other Than Temporary Impairments MarketableSecuritiesRealizedGainLossExcludingOtherThanTemporaryImpairments	523000	USD
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CY2019Q2	wtfc	Proceedsfrom Salesand Capital Distributionsof Equity Securities Without Readily Determinable Fair Value ProceedsfromSalesandCapitalDistributionsofEquitySecuritiesWithoutReadilyDeterminableFairValue	396000	USD
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CY2020Q2	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	121023000	USD
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CY2019Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	185035000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	114853000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	115231000	USD
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CY2019Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	64064000	USD
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CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	109246000	USD
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CY2019Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	292924000	USD
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CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	172296000	USD
CY2020Q2	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	2476384000	USD
CY2020Q2	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	2587157000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	2361158000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	2379525000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateAmortizedCost	1646323000	USD
CY2019Q2	us-gaap	Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithoutSingleMaturityDateFairValue	1649423000	USD
CY2020Q2	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	3079299000	USD
CY2020Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	3194961000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	3086824000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	3106214000	USD
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CY2019Q2	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	2186154000	USD
CY2020Q2	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	6988000	USD
CY2020Q2	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	7028000	USD
CY2019Q4	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	6061000	USD
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CY2019Q2	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	7573000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	7566000	USD
CY2020Q2	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	21818000	USD
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CY2019Q2	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	27768000	USD
CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	27952000	USD
CY2020Q2	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	146937000	USD
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CY2019Q2	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	325009000	USD
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CY2020Q2	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	561232000	USD
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CY2020Q2	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	31402903000	USD
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CY2019Q2	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	25304659000	USD
CY2020Q2	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2019Q4	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2019Q2	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2020Q2	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	-61700000	USD
CY2019Q4	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	9100000	USD
CY2019Q2	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	5600000	USD
CY2019Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Outstanding Balance CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesOutstandingBalance	455784000	USD
CY2019Q4	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount Net CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesCarryingAmountNet	425372000	USD
CY2019Q1	us-gaap	Certain Loans Acquired In Transfer Accretable Yield CertainLoansAcquiredInTransferAccretableYield	34092000	USD
CY2018Q4	us-gaap	Certain Loans Acquired In Transfer Accretable Yield CertainLoansAcquiredInTransferAccretableYield	34876000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Additions CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAdditions	1874000	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	7913000	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsFromNonaccretableDifference	2006000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications From Nonaccretable Difference CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReclassificationsFromNonaccretableDifference	432000	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Additions CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAdditions	1874000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion	4084000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Period Increase Decrease CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldPeriodIncreaseDecrease	1975000	USD
	us-gaap	Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Period Increase Decrease CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldPeriodIncreaseDecrease	3446000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Accretable Yield CertainLoansAcquiredInTransferAccretableYield	34289000	USD
CY2020Q2	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	31402903000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	105908000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	34376000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	26361332000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	26800290000	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	105847000	USD
CY2019Q2	us-gaap	Certain Loans Acquired In Transfer Accretable Yield CertainLoansAcquiredInTransferAccretableYield	34289000	USD
CY2020Q2	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	151116000	USD
CY2020Q2	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	37168000	USD
CY2020Q2	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	30968939000	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	16105000	USD
CY2019Q2	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	24998685000	USD
CY2019Q2	us-gaap	Loans And Leases Receivable Net Of Deferred Income LoansAndLeasesReceivableNetOfDeferredIncome	25304659000	USD
CY2020Q2	us-gaap	Financing Receivable Originated In Current Fiscal Year FinancingReceivableOriginatedInCurrentFiscalYear	8884430000	USD
CY2020Q2	us-gaap	Financing Receivable Originated In Fiscal Year Before Latest Fiscal Year FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear	4699039000	USD
CY2020Q2	us-gaap	Financing Receivable Originated Two Years Before Latest Fiscal Year FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear	3417530000	USD
CY2020Q2	us-gaap	Financing Receivable Originated Three Years Before Latest Fiscal Year FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear	2753167000	USD
CY2020Q2	us-gaap	Financing Receivable Originated Four Years Before Latest Fiscal Year FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear	2261808000	USD
CY2020Q2	us-gaap	Financing Receivable Originated Five Or More Years Before Latest Fiscal Year FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear	6073037000	USD
CY2020Q2	us-gaap	Financing Receivable Revolving FinancingReceivableRevolving	3305341000	USD
CY2020Q2	us-gaap	Financing Receivable Revolving Converted To Term Loan FinancingReceivableRevolvingConvertedToTermLoan	8551000	USD
CY2020Q2	us-gaap	Notes Receivable Gross NotesReceivableGross	31402903000	USD
CY2020Q2	wtfc	Financing Receivable Before Allowance For Credit Loss Modifications Related To Covid19 FinancingReceivableBeforeAllowanceForCreditLossModificationsRelatedToCOVID19	702700000	USD
CY2020Q2	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	728530000	USD
CY2020Q2	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	65000	USD
CY2020Q2	wtfc	Debt Securities Held To Maturity Net Of Allowance For Credit Losses DebtSecuritiesHeldToMaturityNetOfAllowanceForCreditLosses	728465000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	373109000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	158461000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	354626000	USD
CY2020Q2	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	183365000	USD
CY2020Q2	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	30964924000	USD
CY2020Q2	wtfc	Loans Heldfor Investment Fair Value Disclosure LoansHeldforInvestmentFairValueDisclosure	254614000	USD
CY2019Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	159622000	USD
CY2019Q2	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	11000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	23828000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	1538000	USD
CY2019Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	24580000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	161901000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	15206000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	146164000	USD
CY2019Q2	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	137514000	USD
CY2020Q2	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	135058000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	373109000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	18483000	USD
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	161901000	USD
CY2020Q2	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	65000	USD
CY2019Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	0	USD
CY2019Q2	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss DebtSecuritiesHeldToMaturityAllowanceForCreditLoss	0	USD
CY2020Q2	wtfc	Allowance For Credit Loss AllowanceForCreditLoss	373174000	USD
CY2019Q4	wtfc	Allowance For Credit Loss AllowanceForCreditLoss	158461000	USD
CY2019Q2	wtfc	Allowance For Credit Loss AllowanceForCreditLoss	161901000	USD
CY2020Q2	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	83400000	USD
	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	4400000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	253412000	USD
CY2020Q2	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	-42000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	16975000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	1572000	USD
CY2019Q2	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	24750279000	USD
CY2019Q2	wtfc	Loans Heldfor Investment Fair Value Disclosure LoansHeldforInvestmentFairValueDisclosure	106081000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	158461000	USD
	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	31000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	24412000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	3724000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	188023000	USD
CY2020Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	373109000	USD
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	154164000	USD
	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	38000	USD
	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	35204000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	3039000	USD
	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	30468000	USD
CY2020Q2	wtfc	Loan Forgiveness LoanForgiveness	0	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	67
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	32814000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	60
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	33207000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	67
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	32800000	USD
	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	60
	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	14012000	USD
CY2020Q2	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P18M
CY2019Q2	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P15M
CY2020Q2	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P8M
CY2019Q2	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P6M
CY2019Q2	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	161901000	USD
CY2020Q2	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	135100000	USD
	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	188000000.0	USD
CY2020Q2	us-gaap	Allowance For Loan And Lease Losses Writeoffs Net AllowanceForLoanAndLeaseLossesWriteoffsNet	15400000	USD
	us-gaap	Allowance For Loan And Lease Losses Writeoffs Net AllowanceForLoanAndLeaseLossesWriteoffsNet	20700000	USD
CY2020Q2	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-5000	USD
	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	-9000	USD
CY2020Q2	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	1400000	USD
CY2020Q2	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	29
CY2020Q2	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	9017000	USD
CY2019Q2	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	30
CY2019Q2	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	9489000	USD
CY2020Q2	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	29
CY2020Q2	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	9000000.0	USD
CY2019Q2	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	30
CY2019Q2	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	9500000	USD
	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	33200000	USD
	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P10M
	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P14M
	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P13M
	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P3M
	wtfc	Loan Forgiveness LoanForgiveness	453000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	183
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	53173000	USD
CY2020Q2	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	25
CY2020Q2	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	12940000	USD
	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	27
CY2019	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	112
CY2019	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	41854000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	7692000	USD
CY2019Q2	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	17
CY2019Q2	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	14304000	USD
	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	18
	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	14433000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	645220000	USD
	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	0	USD
	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	-1007000	USD
CY2020Q2	us-gaap	Goodwill Goodwill	644213000	USD
CY2020Q2	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	83395000	USD
CY2019Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	83401000	USD
CY2019Q2	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	86617000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	42027000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	36344000	USD
CY2019Q2	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	40029000	USD
CY2020Q2	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	41368000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	47057000	USD
CY2019Q2	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	46588000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5683000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	6135000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Remainder Of Fiscal Year FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear	5335000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	4670000	USD
CY2020Q2	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	3263000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5700000	USD
	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	5900000	USD
CY2020Q1	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	73504000	USD
CY2019Q1	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	71022000	USD
CY2019Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	85638000	USD
CY2018Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	75183000	USD
CY2020Q2	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	20351000	USD
CY2019Q2	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	9802000	USD
	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	29798000	USD
	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	16382000	USD
CY2020Q2	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	0	USD
CY2019Q2	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	407000	USD
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	0	USD
	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	407000	USD
CY2020Q2	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	8670000	USD
CY2019Q2	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	4076000	USD
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	15694000	USD
	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	6073000	USD
CY2020Q2	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-7982000	USD
CY2019Q2	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-4305000	USD
	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-22539000	USD
	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-13049000	USD
CY2020Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	77203000	USD
CY2019Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	72850000	USD
CY2020Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	77203000	USD
CY2019Q2	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	72850000	USD
CY2020Q2	us-gaap	Principal Amount Outstanding On Loans Managed And Securitized PrincipalAmountOutstandingOnLoansManagedAndSecuritized	9188285000	USD
CY2019Q2	us-gaap	Principal Amount Outstanding On Loans Managed And Securitized PrincipalAmountOutstandingOnLoansManagedAndSecuritized	7515186000	USD
CY2019Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.26
CY2019Q2	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.24
CY2020Q2	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10204791000	USD
CY2019Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	7216758000	USD
CY2019Q2	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	6719958000	USD
CY2020Q2	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	3440348000	USD
CY2019Q4	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	3093159000	USD
CY2019Q2	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	2788976000	USD
CY2020Q2	wtfc	Wealth Management Deposits WealthManagementDeposits	4433020000	USD
CY2019Q4	wtfc	Wealth Management Deposits WealthManagementDeposits	3123063000	USD
CY2019Q2	wtfc	Wealth Management Deposits WealthManagementDeposits	3220256000	USD
CY2020Q2	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	9288976000	USD
CY2019Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	7854189000	USD
CY2019Q2	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	6460098000	USD
CY2020Q2	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3447352000	USD
CY2019Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3196698000	USD
CY2019Q2	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	2823904000	USD
CY2020Q2	us-gaap	Time Deposits TimeDeposits	4837387000	USD
CY2019Q4	us-gaap	Time Deposits TimeDeposits	5623271000	USD
CY2019Q2	us-gaap	Time Deposits TimeDeposits	5505623000	USD
CY2020Q2	us-gaap	Deposits Deposits	35651874000	USD
CY2019Q4	us-gaap	Deposits Deposits	30107138000	USD
CY2019Q2	us-gaap	Deposits Deposits	27518815000	USD
CY2020Q2	wtfc	Non Interest Bearing Percentage NonInterestBearingPercentage	0.29
CY2019Q4	wtfc	Non Interest Bearing Percentage NonInterestBearingPercentage	0.24
CY2019Q2	wtfc	Non Interest Bearing Percentage NonInterestBearingPercentage	0.24
CY2020Q2	wtfc	No Wand Interest Bearing Demand Deposits Percentage NOWandInterestBearingDemandDepositsPercentage	0.10
CY2019Q4	wtfc	No Wand Interest Bearing Demand Deposits Percentage NOWandInterestBearingDemandDepositsPercentage	0.10
CY2019Q2	wtfc	No Wand Interest Bearing Demand Deposits Percentage NOWandInterestBearingDemandDepositsPercentage	0.10
CY2020Q2	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.12
CY2019Q4	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.10
CY2019Q2	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.12
CY2020Q2	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.25
CY2020Q2	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.10
CY2019Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	40065000	USD
CY2019Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.11
CY2019Q2	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.10
CY2020Q2	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.14
CY2019Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.19
CY2019Q2	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.20
CY2020Q2	wtfc	Deposits Percentage DepositsPercentage	1
CY2019Q4	wtfc	Deposits Percentage DepositsPercentage	1
CY2019Q2	wtfc	Deposits Percentage DepositsPercentage	1
CY2020Q2	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1228416000	USD
CY2019Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	674870000	USD
CY2019Q2	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	574823000	USD
CY2020Q2	us-gaap	Notes Payable NotesPayable	112401000	USD
CY2019Q4	us-gaap	Notes Payable NotesPayable	123090000	USD
CY2019Q2	us-gaap	Notes Payable NotesPayable	133776000	USD
CY2020Q2	us-gaap	Short Term Borrowings ShortTermBorrowings	8458000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	20520000	USD
CY2019Q2	us-gaap	Short Term Borrowings ShortTermBorrowings	10182000	USD
CY2020Q2	us-gaap	Other Long Term Debt OtherLongTermDebt	65980000	USD
CY2019Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	46447000	USD
CY2019Q2	us-gaap	Other Long Term Debt OtherLongTermDebt	47072000	USD
CY2020Q2	us-gaap	Secured Debt SecuredDebt	321696000	USD
CY2019Q4	us-gaap	Secured Debt SecuredDebt	228117000	USD
CY2019Q2	us-gaap	Secured Debt SecuredDebt	227027000	USD
CY2020Q2	us-gaap	Other Borrowings OtherBorrowings	508535000	USD
CY2019Q4	us-gaap	Other Borrowings OtherBorrowings	418174000	USD
CY2019Q2	us-gaap	Other Borrowings OtherBorrowings	418057000	USD
CY2020Q2	us-gaap	Subordinated Debt SubordinatedDebt	436298000	USD
CY2019Q4	us-gaap	Subordinated Debt SubordinatedDebt	436095000	USD
CY2019Q2	us-gaap	Subordinated Debt SubordinatedDebt	436021000	USD
CY2020Q2	wtfc	Debt Currentand Noncurrent DebtCurrentandNoncurrent	2173249000	USD
CY2019Q4	wtfc	Debt Currentand Noncurrent DebtCurrentandNoncurrent	1529139000	USD
CY2019Q2	wtfc	Debt Currentand Noncurrent DebtCurrentandNoncurrent	1428901000	USD
CY2018Q3	us-gaap	Notes Payable NotesPayable	150000000.0	USD
CY2020Q2	us-gaap	Short Term Borrowings ShortTermBorrowings	8500000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	20500000	USD
CY2019Q2	us-gaap	Short Term Borrowings ShortTermBorrowings	10200000	USD
CY2020Q2	us-gaap	Subordinated Debt SubordinatedDebt	436300000	USD
CY2019Q4	us-gaap	Subordinated Debt SubordinatedDebt	436100000	USD
CY2019Q2	us-gaap	Subordinated Debt SubordinatedDebt	436000000.0	USD
CY2020Q2	wtfc	Ownership Interest Percentage In Unconsolidated Subsidiary Trusts OwnershipInterestPercentageInUnconsolidatedSubsidiaryTrusts	1
CY2020Q2	wtfc	Number Of Unconsolidated Subsidiary Trusts NumberOfUnconsolidatedSubsidiaryTrusts	11	trust
CY2020Q2	wtfc	Common Securities Proportion To Junior Subordinated Debentures CommonSecuritiesProportionToJuniorSubordinatedDebentures	0.03
CY2020Q2	wtfc	Trust Preferred Securities Proportion To Junior Subordinated Debentures TrustPreferredSecuritiesProportionToJuniorSubordinatedDebentures	0.97
CY2020Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	38456000	USD
	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	79447000	USD
CY2020Q2	wtfc	Numberof Wealth Management Subsidiaries NumberofWealthManagementSubsidiaries	4	subsidiary
	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	82111000	USD
CY2020Q2	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2019Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2019Q2	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2020Q2	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	665000	USD
CY2019Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1356000	USD
CY2019Q2	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1540000	USD
CY2020Q2	wtfc	Mortgage Broker Fee Receivable MortgageBrokerFeeReceivable	59000	USD
CY2019Q4	wtfc	Mortgage Broker Fee Receivable MortgageBrokerFeeReceivable	19000	USD
CY2019Q2	wtfc	Mortgage Broker Fee Receivable MortgageBrokerFeeReceivable	16000	USD
CY2020Q2	wtfc	Administrative Services Receivable AdministrativeServicesReceivable	161000	USD
CY2019Q4	wtfc	Administrative Services Receivable AdministrativeServicesReceivable	194000	USD
CY2019Q2	wtfc	Administrative Services Receivable AdministrativeServicesReceivable	48000	USD
CY2020Q2	wtfc	Wealth Management Receivable WealthManagementReceivable	10297000	USD
CY2019Q4	wtfc	Wealth Management Receivable WealthManagementReceivable	9118000	USD
CY2019Q2	wtfc	Wealth Management Receivable WealthManagementReceivable	9909000	USD
CY2020Q2	wtfc	Card Related Fee Receivable CardRelatedFeeReceivable	0	USD
CY2019Q4	wtfc	Card Related Fee Receivable CardRelatedFeeReceivable	266000	USD
CY2019Q2	wtfc	Card Related Fee Receivable CardRelatedFeeReceivable	0	USD
CY2020Q2	us-gaap	Accounts Receivable Net AccountsReceivableNet	10517000	USD
CY2019Q4	us-gaap	Accounts Receivable Net AccountsReceivableNet	9597000	USD
CY2019Q2	us-gaap	Accounts Receivable Net AccountsReceivableNet	9973000	USD
	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	1100000	USD
	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	382000	USD
CY2020Q2	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	160000	USD
CY2020Q2	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	10000	USD
CY2019Q2	us-gaap	Noninterest Income NoninterestIncome	98158000	USD
CY2020Q2	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	0	USD
CY2020Q2	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	0	USD
CY2020Q2	wtfc	Change In Contribution Non Interest Income ChangeInContributionNonInterestIncome	63835000	USD
CY2020Q2	wtfc	Non Interest Income Percentage NonInterestIncomePercentage	0.65
CY2020Q2	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	665000	USD
CY2020Q2	us-gaap	Revenues Revenues	425124000	USD
CY2019Q2	us-gaap	Assets Assets	33641769000	USD
CY2020Q2	wtfc	Change In Contribution Interest Income Expense Net ChangeInContributionInterestIncomeExpenseNet	-3071000	USD
CY2020Q2	wtfc	Interest Income Expense Net Percentage InterestIncomeExpenseNetPercentage	-0.01
CY2020Q2	us-gaap	Noninterest Income NoninterestIncome	161993000	USD
CY2020Q2	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	495000	USD
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2020Q2	wtfc	Number Of Subsidiaries NumberOfSubsidiaries	15	subsidiary
CY2020Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	263131000	USD
CY2019Q2	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	266202000	USD
CY2019Q2	us-gaap	Revenues Revenues	364360000	USD
CY2020Q2	wtfc	Change In Contribution Revenues ChangeInContributionRevenues	60764000	USD
CY2020Q2	wtfc	Revenues Percentage RevenuesPercentage	0.17
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	21659000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	81466000	USD
CY2020Q2	wtfc	Change In Contribution Operating Income Loss ChangeInContributionOperatingIncomeLoss	-59807000	USD
	wtfc	Revenues Percentage RevenuesPercentage	0.13
CY2020Q2	wtfc	Operating Income Loss Percentage OperatingIncomeLossPercentage	-0.73
CY2020Q2	us-gaap	Assets Assets	43540017000	USD
	us-gaap	Net Income Loss NetIncomeLoss	84471000	USD
	us-gaap	Net Income Loss NetIncomeLoss	170612000	USD
	wtfc	Change In Contribution Operating Income Loss ChangeInContributionOperatingIncomeLoss	-86141000	USD
	wtfc	Operating Income Loss Percentage OperatingIncomeLossPercentage	-0.50
	us-gaap	Revenues Revenues	799809000	USD
	us-gaap	Revenues Revenues	708003000	USD
	wtfc	Change In Contribution Revenues ChangeInContributionRevenues	91806000	USD
CY2020Q2	wtfc	Assets Percentage AssetsPercentage	0.29
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	524574000	USD
	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	528188000	USD
	wtfc	Change In Contribution Interest Income Expense Net ChangeInContributionInterestIncomeExpenseNet	-3614000	USD
	wtfc	Interest Income Expense Net Percentage InterestIncomeExpenseNetPercentage	-0.01
	us-gaap	Noninterest Income NoninterestIncome	275235000	USD
	us-gaap	Noninterest Income NoninterestIncome	179815000	USD
	wtfc	Change In Contribution Non Interest Income ChangeInContributionNonInterestIncome	95420000	USD
	wtfc	Non Interest Income Percentage NonInterestIncomePercentage	0.53
CY2020Q2	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	327624000	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	103644000	USD
CY2019Q2	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	108784000	USD
CY2020Q2	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	355265000	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	129204000	USD
CY2019Q2	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	136312000	USD
	us-gaap	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths	-20100000	USD
CY2020Q2	us-gaap	Derivative Net Liability Position Aggregate Fair Value DerivativeNetLiabilityPositionAggregateFairValue	346500000	USD
CY2020Q2	wtfc	Assets Nonrecurring Fair Value Losses Recognized AssetsNonrecurringFairValueLossesRecognized	13631000	USD
	wtfc	Assets Nonrecurring Fair Value Losses Recognized AssetsNonrecurringFairValueLossesRecognized	17997000	USD
CY2020Q2	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	183400000	USD
CY2020Q2	wtfc	Impaired Loans Fair Value Losses Recognized ImpairedLoansFairValueLossesRecognized	13414000	USD
	wtfc	Impaired Loans Fair Value Losses Recognized ImpairedLoansFairValueLossesRecognized	17474000	USD
CY2020Q2	wtfc	Real Estate Acquired Through Foreclosure Fair Value Losses Recognized RealEstateAcquiredThroughForeclosureFairValueLossesRecognized	217000	USD
	wtfc	Real Estate Acquired Through Foreclosure Fair Value Losses Recognized RealEstateAcquiredThroughForeclosureFairValueLossesRecognized	523000	USD
CY2020Q2	us-gaap	Impaired Financing Receivable Recorded Investment ImpairedFinancingReceivableRecordedInvestment	183400000	USD
CY2015Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	5485000	shares
CY2020Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	2100000	shares
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
CY2020Q2	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	540000	USD
CY2020Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	656025	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	0
CY2019Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	700247	shares
CY2020Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.98
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P2Y2M12D
CY2019Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.83
CY2019Q2	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	3000000.0	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	-2300000	USD
	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	6300000	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	98659	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	38.75
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	648	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	46.86
CY2020Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	970000	USD
CY2020Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	648124	shares
CY2020Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	42.97
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P2Y2M12D
CY2020Q2	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	957000	USD
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	795014	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.25
	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	94767	shares
	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	38.00
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	0	shares
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P2Y8M12D
CY2019Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	21239000	USD
CY2019Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	685127	shares
CY2019Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	42.80
	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P2Y8M12D
CY2019Q2	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	20802000	USD
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	2700000	USD
	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	3300000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	3800000	USD
	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	3600000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	37642000	USD
CY2020Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
CY2020Q1	wtfc	Common Stock Dividends Per Share Declared Annualized CommonStockDividendsPerShareDeclaredAnnualized	1.12
CY2019Q2	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	157000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	2793000	USD
CY2020Q2	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-4247000	USD
CY2020Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.28
CY2019Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	4915000	USD
CY2020Q2	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	34000	USD
CY2020Q2	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	7006000	USD
CY2020Q2	wtfc	Common Stock Dividends Per Share Declared Annualized CommonStockDividendsPerShareDeclaredAnnualized	1.12
CY2019Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	699000	shares
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	5939000	USD
	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	29485000	USD
CY2019Q2	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	3376000	USD
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	481000	shares
	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	700000	shares
CY2020Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57981000	shares
	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-4687000	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	91000	USD
CY2019Q2	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57361000	shares
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	34081000	USD
CY2019Q2	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	8448000	USD
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58074000	shares
	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57296000	shares
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.34
	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	260000	USD
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.40
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.40
	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	31443000	USD
	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	2.94
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56596000	shares
CY2020Q2	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	414000	shares
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	21659000	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	81466000	USD
	us-gaap	Net Income Loss NetIncomeLoss	84471000	USD
	us-gaap	Net Income Loss NetIncomeLoss	170612000	USD
CY2020Q2	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	2050000	USD
CY2019Q2	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	2050000	USD
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	4100000	USD
	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	4100000	USD
CY2020Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	19609000	USD
CY2019Q2	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	79416000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	80371000	USD
	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	166512000	USD
CY2020Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57567000	shares
CY2019Q2	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56662000	shares
	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57593000	shares
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.34
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.38
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.38
	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	2.91

Files In Submission

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0001015328-20-000165-index-headers.html	Edgar Link	pending
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exhibit3112020q2.htm	Edgar Link	pending
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wtfc-20200630_pre.xml	Edgar Link	unprocessable

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$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc

2019 Q2 Form 10-Q Financial Statement

#000101532820000165 Filed on August 07, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WTFC WINTRUST FINANCIAL CORP Stock $wtfc

2019 Q2 Form 10-Q Financial Statement

#000101532820000165 Filed on August 07, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc