$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc

$wtfc Overview Financials Valuation SEC Filings Company Website

2021 Q4 Form 10-K Financial Statement

#000101532822000057 Filed on February 25, 2022

Income Statement

Concept	2021 Q4	2021	2020 Q4
Revenue		$1.275B	$308.0M
YoY Change		-1.36%	-11.94%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$26.40M	$54.00M	$25.10M
YoY Change	5.18%	16.38%	6.36%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense		$150.5M	$48.58M
YoY Change		-40.53%	-44.7%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$137.0M	$637.8M	$134.7M
YoY Change	1.7%	63.63%	15.45%
Income Tax	$38.30M	$171.6M	$33.51M
% Of Pretax Income	27.96%	26.91%	24.87%
Net Earnings	$98.80M	$466.2M	$101.2M
YoY Change	-2.38%	59.1%	17.73%
Net Earnings / Revenue		36.55%	32.86%
Basic Earnings Per Share		$7.69	$1.64
Diluted Earnings Per Share	$1.703M	$7.58	$1.63
COMMON SHARES
Basic Shares Outstanding	57.01M shares	56.99M shares	57.64M shares
Diluted Shares Outstanding		57.79M shares

Balance Sheet

Concept	2021 Q4	2021	2020 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$411.2M		$322.5M
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$766.4M	$766.0M	$768.8M
YoY Change	-0.31%	-0.39%	1.92%
Goodwill	$655.1M		$645.7M
YoY Change	1.46%		0.08%
Intangibles	$28.31M		$36.04M
YoY Change	-21.46%		-23.41%
Long-Term Investments
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$50.14B	$50.14B	$45.08B
YoY Change	11.23%	11.23%	23.1%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$1.121B	$1.121B	$1.435B
YoY Change	-21.88%	-21.77%	70.43%
Accrued Expenses
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$9.198M	$9.000M	$11.40M
YoY Change	-19.32%	-18.18%	-44.39%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$1.121B	$1.121B	$1.435B
YoY Change	-21.88%	-21.77%	37.98%
LONG-TERM LIABILITIES
Long-Term Debt	$1.175B	$1.175B	$1.198B
YoY Change	-1.92%	-1.92%	10.21%
Other Long-Term Liabilities	$2.000M	$2.000M
YoY Change		0.0%
Total Long-Term Liabilities	$1.177B	$1.177B	$1.198B
YoY Change	-1.75%	-1.92%	10.21%
TOTAL LIABILITIES
Total Short-Term Liabilities	$1.121B	$1.121B	$1.435B
Total Long-Term Liabilities	$1.177B	$1.177B	$1.198B
Total Liabilities	$45.64B	$45.64B	$40.96B
YoY Change	11.42%	11.42%	24.4%
SHAREHOLDERS EQUITY
Retained Earnings	$2.448B		$2.080B
YoY Change	17.67%		9.5%
Common Stock	$58.89M		$58.47M
YoY Change	0.72%		0.9%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$109.9M		$100.4M
YoY Change	9.51%		1348.03%
Treasury Stock Shares	1.838M shares		1.704M shares
Shareholders Equity	$4.499B	$4.499B	$4.116B
YoY Change
Total Liabilities & Shareholders Equity	$50.14B	$50.14B	$45.08B
YoY Change	11.23%	11.23%	23.1%

Cashflow Statement

Concept	2021 Q4	2021	2020 Q4
OPERATING ACTIVITIES
Net Income	$98.80M	$466.2M	$101.2M
YoY Change	-2.38%	59.1%	17.73%
Depreciation, Depletion And Amortization	$26.40M	$54.00M	$25.10M
YoY Change	5.18%	16.38%	6.36%
Cash From Operating Activities	$399.9M	$1.131B	-$95.30M
YoY Change	-519.62%	-318.12%	-132.98%
INVESTING ACTIVITIES
Capital Expenditures	-$33.70M	$57.08M	-$9.200M
YoY Change	266.3%	-10.32%	-69.84%
Acquisitions		$585.4M
YoY Change
Other Investing Activities	-$2.529B	-$5.872B	-$1.055B
YoY Change	139.65%	-17.52%	-12.02%
Cash From Investing Activities	-$2.562B	-$5.929B	-$1.064B
YoY Change	140.74%	-17.45%	-13.45%
FINANCING ACTIVITIES
Cash Dividend Paid		$98.63M
YoY Change		14.83%
Common Stock Issuance & Retirement, Net		$9.540M
YoY Change		-89.64%
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	2.111B	$4.887B	1.173B
YoY Change	79.91%	-36.84%	50.73%
NET CHANGE
Cash From Operating Activities	399.9M	$1.131B	-95.30M
Cash From Investing Activities	-2.562B	-$5.929B	-1.064B
Cash From Financing Activities	2.111B	$4.887B	1.173B
Net Change In Cash	-51.20M	$88.73M	13.80M
YoY Change	-471.01%	146.49%	-108.51%
FREE CASH FLOW
Cash From Operating Activities	$399.9M	$1.131B	-$95.30M
Capital Expenditures	-$33.70M	$57.08M	-$9.200M
Free Cash Flow	$433.6M	$1.074B	-$86.10M
YoY Change	-603.6%	-284.47%	-126.95%

Facts In Submission

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CY2021	dei	Entity File Number EntityFileNumber	001-35077
CY2021	dei	Entity Registrant Name EntityRegistrantName	Wintrust Financial Corp
CY2021	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	IL
CY2021	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	36-3873352
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CY2021	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	21983000	USD
CY2020	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	21961000	USD
CY2019	us-gaap	Interest Expense Subordinated Notes And Debentures InterestExpenseSubordinatedNotesAndDebentures	15555000	USD
CY2021	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	10916000	USD
CY2020	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	11008000	USD
CY2019	us-gaap	Interest Expense Junior Subordinated Debentures InterestExpenseJuniorSubordinatedDebentures	12001000	USD
CY2021	us-gaap	Interest Expense InterestExpense	150527000	USD
CY2020	us-gaap	Interest Expense InterestExpense	253113000	USD
CY2019	us-gaap	Interest Expense InterestExpense	330223000	USD
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1124957000	USD
CY2020	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1039907000	USD
CY2019	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1054919000	USD
CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-59263000	USD
CY2020	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	214220000	USD
CY2019	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	53864000	USD
CY2021	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	1184220000	USD
CY2020	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	825687000	USD
CY2019	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	1001055000	USD
CY2020	wtfc	Fees And Commissions Mortgage Banking FeesAndCommissionsMortgageBanking	346013000	USD
CY2021	wtfc	Fees And Commissions Mortgage Banking FeesAndCommissionsMortgageBanking	273010000	USD
CY2019	wtfc	Fees And Commissions Mortgage Banking FeesAndCommissionsMortgageBanking	154293000	USD
CY2021	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	-1059000	USD
CY2020	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	-1926000	USD
CY2019	us-gaap	Marketable Securities Gain Loss MarketableSecuritiesGainLoss	3525000	USD
CY2021	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	3673000	USD
CY2020	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	2292000	USD
CY2019	wtfc	Fees From Covered Call Options FeesFromCoveredCallOptions	3670000	USD
CY2021	us-gaap	Trading Gains Losses TradingGainsLosses	245000	USD
CY2020	us-gaap	Trading Gains Losses TradingGainsLosses	-1004000	USD
CY2019	us-gaap	Trading Gains Losses TradingGainsLosses	-158000	USD
CY2021	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	53691000	USD
CY2020	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	47604000	USD
CY2019	us-gaap	Operating Lease Lease Income OperatingLeaseLeaseIncome	47041000	USD
CY2021	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	78373000	USD
CY2020	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	65851000	USD
CY2019	us-gaap	Noninterest Income Other Operating Income NoninterestIncomeOtherOperatingIncome	62617000	USD
CY2021	us-gaap	Noninterest Income NoninterestIncome	586120000	USD
CY2020	us-gaap	Noninterest Income NoninterestIncome	604189000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	407172000	USD
CY2021	us-gaap	Labor And Related Expense LaborAndRelatedExpense	691669000	USD
CY2020	us-gaap	Labor And Related Expense LaborAndRelatedExpense	626076000	USD
CY2019	us-gaap	Labor And Related Expense LaborAndRelatedExpense	546420000	USD
CY2021	us-gaap	Equipment Expense EquipmentExpense	87515000	USD
CY2020	us-gaap	Equipment Expense EquipmentExpense	68496000	USD
CY2019	us-gaap	Equipment Expense EquipmentExpense	52328000	USD
CY2021	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	40880000	USD
CY2020	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	37915000	USD
CY2019	wtfc	Lessor Operating Lease Depreciation Expense LessorOperatingLeaseDepreciationExpense	35760000	USD
CY2021	us-gaap	Occupancy Net OccupancyNet	74184000	USD
CY2020	us-gaap	Occupancy Net OccupancyNet	69957000	USD
CY2019	us-gaap	Occupancy Net OccupancyNet	64289000	USD
CY2021	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	27279000	USD
CY2020	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	30196000	USD
CY2019	us-gaap	Information Technology And Data Processing InformationTechnologyAndDataProcessing	27820000	USD
CY2021	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	47275000	USD
CY2020	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	36296000	USD
CY2019	us-gaap	Marketing And Advertising Expense MarketingAndAdvertisingExpense	48595000	USD
CY2021	us-gaap	Professional Fees ProfessionalFees	29494000	USD
CY2020	us-gaap	Professional Fees ProfessionalFees	27426000	USD
CY2019	us-gaap	Professional Fees ProfessionalFees	27471000	USD
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	7734000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	11018000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	11844000	USD
CY2021	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	27030000	USD
CY2020	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	25004000	USD
CY2019	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	9199000	USD
CY2021	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	1654000	USD
CY2020	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	921000	USD
CY2019	us-gaap	Other Revenue Expense From Real Estate Operations OtherRevenueExpenseFromRealEstateOperations	-3628000	USD
CY2021	us-gaap	Other Noninterest Expense OtherNoninterestExpense	101138000	USD
CY2020	us-gaap	Other Noninterest Expense OtherNoninterestExpense	108632000	USD
CY2019	us-gaap	Other Noninterest Expense OtherNoninterestExpense	100772000	USD
CY2021	us-gaap	Noninterest Expense NoninterestExpense	1132544000	USD
CY2020	us-gaap	Noninterest Expense NoninterestExpense	1040095000	USD
CY2019	us-gaap	Noninterest Expense NoninterestExpense	928126000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	637796000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	389781000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	480101000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	171645000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	96791000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	124404000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	466151000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	292990000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	355697000	USD
CY2021	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	27964000	USD
CY2020	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	21377000	USD
CY2019	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	8200000	USD
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	438187000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	271613000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	347497000	USD
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.69
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.72
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.11
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.58
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.68
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.03
CY2021	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.24
CY2020	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.12
CY2019	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.00
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56994000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57523000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56857000	shares
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	792000	shares
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	496000	shares
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	1079000	USD
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	762000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57786000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58019000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57619000	shares
CY2021	us-gaap	Net Income Loss NetIncomeLoss	466151000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	292990000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	355697000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	-83199000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	76464000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax	79702000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-22152000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	20378000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	21361000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-61047000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	56086000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	58341000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	221000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax	899000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	290000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	59000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax	241000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	789000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	162000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci For Sale Of Securities Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax	658000	USD
CY2021	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	241000	USD
CY2020	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	231000	USD
CY2019	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Before Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentBeforeTax	479000	USD
CY2021	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	64000	USD
CY2020	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	62000	USD
CY2019	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Tax Effect OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentTaxEffect	131000	USD
CY2021	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	177000	USD
CY2020	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	169000	USD
CY2019	wtfc	Other Comprehensive Income Loss Securities Transferred From Available For Sale To Held To Maturity Adjustment Net Of Tax OtherComprehensiveIncomeLossSecuritiesTransferredFromAvailableForSaleToHeldToMaturityAdjustmentNetOfTax	348000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-62013000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	55755000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	57335000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	68441000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-13591000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Before Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationBeforeTax	-28685000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	18240000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-3642000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationTax	-7687000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	50201000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-9949000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax	-20998000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	620000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	5367000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Before Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentBeforeTax	7483000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	98000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	1113000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Translation Adjustment Tax OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax	1626000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	522000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	4254000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	5857000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-11290000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	50060000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	42194000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	454861000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	343050000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	397891000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	3267570000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	355697000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	42194000	USD
CY2019	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.00
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	56910000	USD
CY2019	us-gaap	Preferred Stock Dividends Per Share Declared PreferredStockDividendsPerShareDeclared	1.64
CY2019	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	8200000	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	11304000	USD
CY2019	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	71756000	USD
CY2019	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	4843000	USD
CY2019	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-453000	USD
CY2019	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2819000	USD
CY2019	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	2161000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	3691250000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	292990000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	50060000	USD
CY2020	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.12
CY2020	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	64513000	USD
CY2020	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	21377000	USD
CY2020	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	92055000	USD
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	-4938000	USD
CY2020	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	9038000	USD
CY2020	us-gaap	Stock Issued During Period Value Restricted Stock Award Net Of Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures	-752000	USD
CY2020	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	2978000	USD
CY2020	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	2418000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	4115995000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	466151000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-11290000	USD
CY2021	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	1.24
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	70663000	USD
CY2021	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	27966000	USD
CY2021	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	9540000	USD
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	16177000	USD
CY2021	wtfc	Stock Issued During Period Value Stock Options And Warrants Exercised StockIssuedDuringPeriodValueStockOptionsAndWarrantsExercised	14035000	USD
CY2021	us-gaap	Stock Issued During Period Value Employee Stock Purchase Plan StockIssuedDuringPeriodValueEmployeeStockPurchasePlan	3325000	USD
CY2021	us-gaap	Stock Issued During Period Value Issued For Services StockIssuedDuringPeriodValueIssuedForServices	2464000	USD
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	4498688000	USD
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	16177000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	466151000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	292990000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	355697000	USD
CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-59263000	USD
CY2020	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	214220000	USD
CY2019	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	53864000	USD
CY2021	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	101797000	USD
CY2020	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	96369000	USD
CY2019	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	88362000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-2861000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-4058000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	44557000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	-4938000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	11304000	USD
CY2021	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-6391000	USD
CY2020	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-10881000	USD
CY2019	us-gaap	Accretion Amortization Of Discounts And Premiums Investments AccretionAmortizationOfDiscountsAndPremiumsInvestments	-6605000	USD
CY2021	wtfc	Accretion Amortization Of Discount Premium On Loans AccretionAmortizationOfDiscountPremiumOnLoans	83434000	USD
CY2020	wtfc	Accretion Amortization Of Discount Premium On Loans AccretionAmortizationOfDiscountPremiumOnLoans	81604000	USD
CY2019	wtfc	Accretion Amortization Of Discount Premium On Loans AccretionAmortizationOfDiscountPremiumOnLoans	26624000	USD
CY2021	us-gaap	Mortgage Servicing Rights Msr Impairment Recovery MortgageServicingRightsMSRImpairmentRecovery	16515000	USD
CY2020	us-gaap	Mortgage Servicing Rights Msr Impairment Recovery MortgageServicingRightsMSRImpairmentRecovery	63343000	USD
CY2019	us-gaap	Mortgage Servicing Rights Msr Impairment Recovery MortgageServicingRightsMSRImpairmentRecovery	34896000	USD
CY2021	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	569000	USD
CY2020	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	484000	USD
CY2019	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	-640000	USD
CY2021	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	6803777000	USD
CY2020	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	8004730000	USD
CY2019	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	4497921000	USD
CY2021	wtfc	Early Buyout Exercises Of Guaranteed Mortgage Loans Held For Sale EarlyBuyoutExercisesOfGuaranteedMortgageLoansHeldForSale	-88000	USD
CY2020	wtfc	Early Buyout Exercises Of Guaranteed Mortgage Loans Held For Sale EarlyBuyoutExercisesOfGuaranteedMortgageLoansHeldForSale	297599000	USD
CY2019	wtfc	Early Buyout Exercises Of Guaranteed Mortgage Loans Held For Sale EarlyBuyoutExercisesOfGuaranteedMortgageLoansHeldForSale	0	USD
CY2021	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	7441705000	USD
CY2020	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	7624799000	USD
CY2019	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	4484838000	USD
CY2021	wtfc	Bank Owned Life Insurance Net Of Claims BankOwnedLifeInsuranceNetOfClaims	5812000	USD
CY2020	wtfc	Bank Owned Life Insurance Net Of Claims BankOwnedLifeInsuranceNetOfClaims	4488000	USD
CY2019	wtfc	Bank Owned Life Insurance Net Of Claims BankOwnedLifeInsuranceNetOfClaims	4846000	USD
CY2021	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	390000	USD
CY2020	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-397000	USD
CY2019	us-gaap	Increase Decrease In Trading Securities IncreaseDecreaseInTradingSecurities	-624000	USD
CY2021	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	8632000	USD
CY2020	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	863000	USD
CY2019	us-gaap	Increase Decrease In Broker Dealer Related Receivables Payables Net IncreaseDecreaseInBrokerDealerRelatedReceivablesPayablesNet	3964000	USD
CY2021	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	214085000	USD
CY2020	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	339127000	USD
CY2019	us-gaap	Gain Loss On Sale Of Mortgage Loans GainLossOnSaleOfMortgageLoans	135607000	USD
CY2021	us-gaap	Gain Loss On Investments GainLossOnInvestments	-1059000	USD
CY2020	us-gaap	Gain Loss On Investments GainLossOnInvestments	-2373000	USD
CY2019	us-gaap	Gain Loss On Investments GainLossOnInvestments	3525000	USD
CY2021	wtfc	Gain Loss On Disposition Of Property Plant Equipment Net And Related Deposit Liabilities GainLossOnDispositionOfPropertyPlantEquipmentNetAndRelatedDepositLiabilities	3614000	USD
CY2020	wtfc	Gain Loss On Disposition Of Property Plant Equipment Net And Related Deposit Liabilities GainLossOnDispositionOfPropertyPlantEquipmentNetAndRelatedDepositLiabilities	-421000	USD
CY2019	wtfc	Gain Loss On Disposition Of Property Plant Equipment Net And Related Deposit Liabilities GainLossOnDispositionOfPropertyPlantEquipmentNetAndRelatedDepositLiabilities	-92000	USD
CY2021	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	2792000	USD
CY2020	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	1421000	USD
CY2019	us-gaap	Gains Losses On Sales Of Other Real Estate GainsLossesOnSalesOfOtherRealEstate	-1921000	USD
CY2021	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-187743000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	131870000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	133022000	USD
CY2021	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	78475000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	46924000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-11898000	USD
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	1130872000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-518465000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	265993000	USD
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1290126000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1613143000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	718345000	USD
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	307971000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	879713000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	422959000	USD
CY2021	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	192227000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	502250000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	972253000	USD
CY2021	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	9759000	USD
CY2020	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	6530000	USD
CY2019	us-gaap	Proceeds From Sale Of Trading Securities Heldforinvestment ProceedsFromSaleOfTradingSecuritiesHeldforinvestment	19200000	USD
CY2021	wtfc	Proceedsfrom Salesand Capital Distributionsof Equity Securities Without Readily Determinable Fair Value ProceedsfromSalesandCapitalDistributionsofEquitySecuritiesWithoutReadilyDeterminableFairValue	2685000	USD
CY2020	wtfc	Proceedsfrom Salesand Capital Distributionsof Equity Securities Without Readily Determinable Fair Value ProceedsfromSalesandCapitalDistributionsofEquitySecuritiesWithoutReadilyDeterminableFairValue	1857000	USD
CY2019	wtfc	Proceedsfrom Salesand Capital Distributionsof Equity Securities Without Readily Determinable Fair Value ProceedsfromSalesandCapitalDistributionsofEquitySecuritiesWithoutReadilyDeterminableFairValue	1764000	USD
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	842170000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1998380000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	2226834000	USD
CY2021	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	2873691000	USD
CY2020	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	125220000	USD
CY2019	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	493389000	USD
CY2021	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	9060000	USD
CY2020	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	45735000	USD
CY2019	us-gaap	Payments To Acquire Marketable Securities PaymentsToAcquireMarketableSecurities	32729000	USD
CY2021	wtfc	Paymentsto Acquire Equity Securitieswithout Readily Determinable Fair Value PaymentstoAcquireEquitySecuritieswithoutReadilyDeterminableFairValue	9265000	USD
CY2020	wtfc	Paymentsto Acquire Equity Securitieswithout Readily Determinable Fair Value PaymentstoAcquireEquitySecuritieswithoutReadilyDeterminableFairValue	5118000	USD
CY2019	wtfc	Paymentsto Acquire Equity Securitieswithout Readily Determinable Fair Value PaymentstoAcquireEquitySecuritieswithoutReadilyDeterminableFairValue	4394000	USD
CY2021	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	-210000	USD
CY2020	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	34849000	USD
CY2019	us-gaap	Payments For Proceeds From Federal Home Loan Bank Stock PaymentsForProceedsFromFederalHomeLoanBankStock	9385000	USD
CY2021	us-gaap	Payments For Proceeds From Limited Partnership PaymentsForProceedsFromLimitedPartnership	2107000	USD
CY2020	us-gaap	Payments For Proceeds From Limited Partnership PaymentsForProceedsFromLimitedPartnership	-76000	USD
CY2019	us-gaap	Payments For Proceeds From Limited Partnership PaymentsForProceedsFromLimitedPartnership	-1955000	USD
CY2021	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	585402000	USD
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	0	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	108365000	USD
CY2021	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	16927000	USD
CY2020	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	10776000	USD
CY2019	us-gaap	Proceeds From Sale Of Foreclosed Assets ProceedsFromSaleOfForeclosedAssets	14516000	USD
CY2021	us-gaap	Proceeds From Payments For Securities Purchased Under Agreements To Resell ProceedsFromPaymentsForSecuritiesPurchasedUnderAgreementsToResell	-700000000	USD
CY2020	us-gaap	Proceeds From Payments For Securities Purchased Under Agreements To Resell ProceedsFromPaymentsForSecuritiesPurchasedUnderAgreementsToResell	0	USD
CY2019	us-gaap	Proceeds From Payments For Securities Purchased Under Agreements To Resell ProceedsFromPaymentsForSecuritiesPurchasedUnderAgreementsToResell	0	USD
CY2021	us-gaap	Proceeds From Payments For In Interest Bearing Deposits In Banks ProceedsFromPaymentsForInInterestBearingDepositsInBanks	-569205000	USD
CY2020	us-gaap	Proceeds From Payments For In Interest Bearing Deposits In Banks ProceedsFromPaymentsForInInterestBearingDepositsInBanks	-2636581000	USD
CY2019	us-gaap	Proceeds From Payments For In Interest Bearing Deposits In Banks ProceedsFromPaymentsForInInterestBearingDepositsInBanks	-983513000	USD
CY2021	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	2101121000	USD
CY2020	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	5290668000	USD
CY2019	us-gaap	Payments For Proceeds From Loans And Leases PaymentsForProceedsFromLoansAndLeases	2229637000	USD
CY2021	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	332000	USD
CY2020	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	3428000	USD
CY2019	us-gaap	Proceeds From Life Insurance Policies ProceedsFromLifeInsurancePolicies	326000	USD
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	57075000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	63646000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	82021000	USD
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-5928859000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-7182424000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-4018949000	USD
CY2021	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	5006801000	USD
CY2020	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	6985964000	USD
CY2019	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	3142499000	USD
CY2021	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	-27784000	USD
CY2020	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	88596000	USD
CY2019	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	15480000	USD
CY2021	wtfc	Proceeds From Payments To Federal Home Loan Bank Borrowings ProceedsFromPaymentsToFederalHomeLoanBankBorrowings	12629000	USD
CY2020	wtfc	Proceeds From Payments To Federal Home Loan Bank Borrowings ProceedsFromPaymentsToFederalHomeLoanBankBorrowings	553500000	USD
CY2019	wtfc	Proceeds From Payments To Federal Home Loan Bank Borrowings ProceedsFromPaymentsToFederalHomeLoanBankBorrowings	248442000	USD
CY2021	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	16583000	USD
CY2020	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	4523000	USD
CY2019	us-gaap	Payment For Contingent Consideration Liability Financing Activities PaymentForContingentConsiderationLiabilityFinancingActivities	66000	USD
CY2021	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	0	USD
CY2020	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	277613000	USD
CY2019	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	0	USD
CY2021	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	USD
CY2020	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Subordinated Long Term Debt ProceedsFromIssuanceOfSubordinatedLongTermDebt	296617000	USD
CY2021	wtfc	Issuance Of Common Shares Resulting From Exercise Of Stock Options And Employee Stock Purchase Plan IssuanceOfCommonSharesResultingFromExerciseOfStockOptionsAndEmployeeStockPurchasePlan	19824000	USD
CY2020	wtfc	Issuance Of Common Shares Resulting From Exercise Of Stock Options And Employee Stock Purchase Plan IssuanceOfCommonSharesResultingFromExerciseOfStockOptionsAndEmployeeStockPurchasePlan	15059000	USD
CY2019	wtfc	Issuance Of Common Shares Resulting From Exercise Of Stock Options And Employee Stock Purchase Plan IssuanceOfCommonSharesResultingFromExerciseOfStockOptionsAndEmployeeStockPurchasePlan	10667000	USD
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	9540000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	92055000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2021	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	0	USD
CY2020	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1377000	USD
CY2019	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1297000	USD
CY2021	us-gaap	Payments Of Dividends PaymentsOfDividends	98629000	USD
CY2020	us-gaap	Payments Of Dividends PaymentsOfDividends	85890000	USD
CY2019	us-gaap	Payments Of Dividends PaymentsOfDividends	65110000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	3647232000	USD
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	88731000	USD
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	4886718000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	7736887000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	35998000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-105724000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	322474000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	286476000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	392200000	USD
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	411205000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	322474000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	286476000	USD
CY2021	us-gaap	Interest Paid Net InterestPaidNet	156868000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	257408000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	327329000	USD
CY2021	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	178575000	USD
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	105268000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	60845000	USD
CY2021	us-gaap	Fair Value Of Assets Acquired FairValueOfAssetsAcquired	591409000	USD
CY2020	us-gaap	Fair Value Of Assets Acquired FairValueOfAssetsAcquired	0	USD
CY2019	us-gaap	Fair Value Of Assets Acquired FairValueOfAssetsAcquired	1093254000	USD
CY2021	wtfc	Value Ascribed To Goodwill And Other Intangible Assets ValueAscribedToGoodwillAndOtherIntangibleAssets	9275000	USD
CY2020	wtfc	Value Ascribed To Goodwill And Other Intangible Assets ValueAscribedToGoodwillAndOtherIntangibleAssets	0	USD
CY2019	wtfc	Value Ascribed To Goodwill And Other Intangible Assets ValueAscribedToGoodwillAndOtherIntangibleAssets	80581000	USD
CY2021	us-gaap	Liabilities Assumed1 LiabilitiesAssumed1	6007000	USD
CY2020	us-gaap	Liabilities Assumed1 LiabilitiesAssumed1	0	USD
CY2019	us-gaap	Liabilities Assumed1 LiabilitiesAssumed1	896686000	USD
CY2021	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	5837000	USD
CY2020	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	13239000	USD
CY2019	us-gaap	Transfer To Other Real Estate TransferToOtherRealEstate	5722000	USD
CY2021	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	0	USD
CY2020	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	0	USD
CY2019	us-gaap	Stock Issued During Period Value Acquisitions StockIssuedDuringPeriodValueAcquisitions	71756000	USD
CY2021Q4	us-gaap	Assets Sold Under Agreements To Repurchase Carrying Amounts AssetsSoldUnderAgreementsToRepurchaseCarryingAmounts	700000000	USD
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Policy For Uncollectible Amounts FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts	<div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%">Allowance for Credit Losses</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:107%">In accordance with ASC 326, “Financial Instruments – Credit Losses” (“ASC 326”), the Company measures the allowance for credit losses at the time of origination or purchase of a financial asset, representing an estimate of lifetime expected credit losses on the related asset. Financial assets include assets measured under the amortized cost basis, including loans, net investments in leases recognized by a lessor, held-to-maturity debt securities and purchased credit deteriorated (“PCD”) assets at the time of and subsequent to acquisition, and off-balance-sheet credit exposures considered not unconditionally cancellable. In addition to financial assets measured at amortized cost, credit losses related to available-for-sale debt securities are recorded through the allowance for credit losses and not as a direct adjustment to the amortized cost of the securities. The Company elects the collateral maintenance practical expedient under ASC 326 and applies this approach to securities sold under agreements to repurchase and brokerage customer receivables. In accordance with contractual terms, these assets require underlying collateral to be monitored continuously and replenished when collateral is less than required levels. The Company measures an allowance for credit losses if the carrying balance of such assets exceeds the amount of underlying collateral.</span></div><div style="text-align:justify"><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance for credit losses on financial assets held at amortized cost is measured on a collective or pooled basis when similar risk characteristics exist. The Company utilizes modeling methodologies that estimate lifetime credit loss rates on each pool, including methodologies estimating the probability of default and loss given default on specific segments. Credit quality indicators, specifically the Company's internal risk rating systems, reflect how the Company monitors credit losses and represent factors used by the Company when measuring the allowance for credit losses. Historical credit loss history is adjusted for reasonable and supportable forecasts developed by the Company and incorporates third party economic forecasts on a quantitative or qualitative basis. Reasonable and supportable forecasts consider the macroeconomic factors that are most relevant to evaluating and predicting expected credit losses in the Company's financial assets. For periods beyond the ability to develop reasonable and supportable forecasts, the Company reverts to historical loss rates. Qualitative factors assessed by Management include the following:</span></div><div style="padding-left:36pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:14.5pt">Changes in the nature and volume of the institution’s financial assets;</span></div><div style="padding-left:36pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:14.5pt">Changes in the existence, growth, and effect of any concentrations of credit;</span></div><div style="padding-left:36pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:14.5pt">Changes in the volume and severity of past due financial assets, the volume of non-accrual assets, and the volume and severity of adversely classified or graded assets;</span></div><div style="padding-left:36pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:14.5pt">Changes in the value of the underlying collateral for loans that are not collateral-dependent;</span></div><div style="padding-left:36pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:14.5pt">Changes in the institution’s lending policies and procedures, including changes in underwriting standards and practices for collections, write-offs, and recoveries;</span></div><div style="padding-left:36pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:14.5pt">Changes in the quality of the institution’s credit review function;</span></div><div style="padding-left:36pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:14.5pt">Changes in the experience, ability, and depth of the institution’s lending, investment, collection, and other relevant management and staff;</span></div><div style="padding-left:36pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:14.5pt">The effect of changes in other external factors such as the regulatory, legal and technological environments; competition; and events such as natural disasters; and</span></div><div style="padding-left:36pt;text-align:justify;text-indent:-18pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">•</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%;padding-left:14.5pt">Actual and expected changes in international, national, regional, and local economic and business conditions and developments in which the institution operates that affect the collectability of financial assets.</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Expected credit losses are measured over the contractual term of the financial asset with consideration of expected prepayments. Expected extensions, renewals or modifications of the financial asset are considered when either 1) the expected extension, renewal or modification is contained within the existing agreement and is not unconditionally cancellable, or 2) the expected extension, renewal or modification is reasonably expected to result in a troubled debt restructuring (“TDR”).</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Financial assets that do not share similar risk characteristics with any pool are assessed for the allowance for credit losses on an individual basis. These typically include assets experiencing financial difficulties, including substandard non-accrual assets and assets currently classified or expected to be classified as TDRs. If an individual asset is removed from a pool, the allowance for credit losses for such pool will be measured without considering the removed asset. If foreclosure is probable or the asset is considered collateral-dependent, expected credit losses are measured based upon the fair value of the underlying collateral adjusted for selling costs, if appropriate. For certain accruing current and expected TDRs, expected credit losses are measured based upon the present value of future cash flows of the modified asset terms compared to the amortized cost of the asset. </span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">For purchased financial assets that have experienced more-than-insignificant deterioration in credit quality since origination (“PCD assets”), the Company recognizes the sum of the purchase price and estimate of the allowance for credit losses as of the date of acquisition as the initial amortized cost basis. If the estimated allowance for credit losses is recognized under a methodology that is not a discounted cash flow methodology, such allowance for credit losses will be estimated based upon the unpaid principal balance of the financial asset.</span></div><div><span><br/></span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The Company does not measure an allowance for credit losses on accrued interest receivable balances if these balances are written off in a timely manner. Write-offs of accrued interest receivable balances are recorded as a reduction to interest income.</span></div>Recoveries of financial assets previously written off are recognized when received and recorded as a component of the allowance for credit losses. When measuring the allowance for credit losses, the Company incorporates an estimate of expected recoveries provided the estimate is reasonable and supportable. Write-offs of financial assets are charged-off or deducted from the allowance for credit losses and recorded in the period when the Company concludes that all or a portion of a financial asset is no longer collectible. A provision for credit losses is charged to income based on Management’s periodic evaluation of the factors previously described. Evaluations are conducted at least quarterly and more frequently if deemed necessary.
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CY2020Q4	us-gaap	Heldtomaturity Securities Debt Maturities Next Rolling Twelve Months Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCost	7138000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Debt Maturities Next Rolling Twelve Months Fair Value HeldToMaturitySecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	7186000	USD
CY2021Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	79422000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	79705000	USD
CY2020Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Two Through Five Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCost	22217000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Two Through Five Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	23068000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	4306793000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Restricted DebtSecuritiesAvailableForSaleRestricted	2600000000	USD
CY2021Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	106713000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	112667000	USD
CY2020Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCost	150621000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling Year Six Through Ten Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	159293000	USD
CY2021Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling After Ten Years Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost	222522000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	221358000	USD
CY2020Q4	us-gaap	Heldtomaturity Securities Debt Maturities Rolling After Ten Years Amortized Cost HeldtomaturitySecuritiesDebtMaturitiesRollingAfterTenYearsAmortizedCost	198690000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Debt Maturities Rolling After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesRollingAfterTenYearsFairValue	203689000	USD
CY2021Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	2942363000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	2900694000	USD
CY2020Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	579197000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	593767000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	78000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	59000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	2942285000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	579138000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Restricted DebtSecuritiesAvailableForSaleRestricted	2400000000	USD
CY2021Q4	wtfc	Securities By A Single Non Government Sponsored Issuer Exceeding Ten Percent Of Shareholders Equity SecuritiesByASingleNonGovernmentSponsoredIssuerExceedingTenPercentOfShareholdersEquity	0	security
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	34789104000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	32079073000	USD
CY2021Q4	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2020Q4	wtfc	Percentage Of Loans And Leases Receivable Gross Carrying Amount PercentageOfLoansAndLeasesReceivableGrossCarryingAmount	1
CY2021Q4	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	50800000	USD
CY2020Q4	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	-3200000	USD
CY2021Q4	wtfc	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums Paid By Small Business Administration Under Paycheck Protection Program UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiumsPaidBySmallBusinessAdministrationUnderPaycheckProtectionProgram	12700000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1200000000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1200000000	USD
CY2021Q4	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLoss	117400000	USD
CY2020Q4	us-gaap	Financial Asset Amortized Cost Accrued Interest After Allowance For Credit Loss FinancialAssetAmortizedCostAccruedInterestAfterAllowanceForCreditLoss	121900000	USD
CY2021Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	67069000	USD
CY2021Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	7369000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	34789104000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	114150000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	13363000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	32079073000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	11520155000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	4412264000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	3363987000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	2442541000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	2121979000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	6575664000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	78000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving Converted To Term Loan FinancingReceivableExcludingAccruedInterestRevolvingConvertedToTermLoan	45721000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	34789104000	USD
CY2021Q4	wtfc	Financing Receivable Before Allowance For Credit Loss Modifications Related To Covid19 Migrated From Pass To Special Mention Or Substandard FinancingReceivableBeforeAllowanceForCreditLossModificationsRelatedToCOVID19MigratedFromPassToSpecialMentionOrSubstandard	31700000	USD
CY2021Q4	us-gaap	Held To Maturity Securities HeldToMaturitySecurities	2942363000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest After Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestAfterAllowanceForCreditLoss	2942285000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	78000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	59000	USD
CY2021Q4	wtfc	Allowance For Credit Loss Excluding Accrued Interest AllowanceForCreditLossExcludingAccruedInterest	299731000	USD
CY2020Q4	wtfc	Allowance For Credit Loss Excluding Accrued Interest AllowanceForCreditLossExcludingAccruedInterest	379969000	USD
CY2021Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	37000000	USD
CY2021	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	148000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	379910000	USD
CY2021	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	-3000	USD
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	35019000	USD
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	13569000	USD
CY2021	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-59280000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	299653000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	8552000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	291101000	USD
CY2021Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	93270000	USD
CY2021Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	34657236000	USD
CY2021Q4	wtfc	Loans Heldfor Investment Fair Value Disclosure LoansHeldforInvestmentFairValueDisclosure	38598000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	158461000	USD
CY2020	wtfc	Financing Receivable Allowance For Credit Losses Other Adjustments Expense Benefit FinancingReceivableAllowanceForCreditLossesOtherAdjustmentsExpenseBenefit	-179000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	53205000	USD
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	12896000	USD
CY2020	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	214235000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	379910000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1	8026000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment	371884000	USD
CY2020Q4	us-gaap	Financing Receivable Individually Evaluated For Impairment FinancingReceivableIndividuallyEvaluatedForImpairment	139662000	USD
CY2020Q4	us-gaap	Financing Receivable Collectively Evaluated For Impairment FinancingReceivableCollectivelyEvaluatedForImpairment	31884277000	USD
CY2020Q4	wtfc	Loans Heldfor Investment Fair Value Disclosure LoansHeldforInvestmentFairValueDisclosure	55134000	USD
CY2021	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	-59300000	USD
CY2020	us-gaap	Allowance For Loan And Lease Losses Writeoffs Net AllowanceForLoanAndLeaseLossesWriteoffsNet	21500000	USD
CY2021	us-gaap	Debt Securities Held To Maturity Credit Loss Expense Reversal DebtSecuritiesHeldToMaturityCreditLossExpenseReversal	17000	USD
CY2021Q4	us-gaap	Real Estate Acquired Through Foreclosure RealEstateAcquiredThroughForeclosure	1300000	USD
CY2021	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	64	contract
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	13869000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	124	contract
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	45872000	USD
CY2019	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	176	contract
CY2019	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	53565000	USD
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	13900000	USD
CY2021	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	64	contract
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	45900000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	124	contract
CY2019	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	53600000	USD
CY2019	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	176	contract
CY2021	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P83M
CY2020	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P14M
CY2019	wtfc	Financing Receivables Modifications Weighted Average Extension Term FinancingReceivablesModificationsWeightedAverageExtensionTerm	P18M
CY2021	wtfc	Weighted Average Decrease In Stated Interest Rate Basis Points WeightedAverageDecreaseInStatedInterestRateBasisPoints	0.0137
CY2020	wtfc	Weighted Average Decrease In Stated Interest Rate Basis Points WeightedAverageDecreaseInStatedInterestRateBasisPoints	0.0129
CY2019	wtfc	Weighted Average Decrease In Stated Interest Rate Basis Points WeightedAverageDecreaseInStatedInterestRateBasisPoints	0.0218
CY2021	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P3M
CY2020	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P12M
CY2019	wtfc	Financing Receivables Modifications Weighted Average Interest Only Term FinancingReceivablesModificationsWeightedAverageInterestOnlyTerm	P5M
CY2021	wtfc	Loan Forgiveness LoanForgiveness	0	USD
CY2020	wtfc	Loan Forgiveness LoanForgiveness	453000	USD
CY2019	wtfc	Loan Forgiveness LoanForgiveness	0	USD
CY2021	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	64	contract
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	13869000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	124	contract
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	45872000	USD
CY2019	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	176	contract
CY2019	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	53565000	USD
CY2020Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	92081000	USD
CY2019Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	85638000	USD
CY2018Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	75183000	USD
CY2021	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	72754000	USD
CY2020	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	71077000	USD
CY2019	wtfc	Servicing Assets At Fair Value Additions From Loans Sold With Servicing Retained ServicingAssetsAtFairValueAdditionsFromLoansSoldWithServicingRetained	44943000	USD
CY2021	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	0	USD
CY2019Q4	us-gaap	Principal Amount Outstanding On Loans Managed And Securitized PrincipalAmountOutstandingOnLoansManagedAndSecuritized	8243251000	USD
CY2019	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	20118000	USD
CY2020	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	0	USD
CY2019	us-gaap	Servicing Asset At Fair Value Additions ServicingAssetAtFairValueAdditions	408000	USD
CY2021	wtfc	Servicing Asset At Fair Value Early Buyout Option ServicingAssetAtFairValueEarlyBuyoutOption	749000	USD
CY2020	wtfc	Servicing Asset At Fair Value Early Buyout Option ServicingAssetAtFairValueEarlyBuyoutOption	1291000	USD
CY2019	wtfc	Servicing Asset At Fair Value Early Buyout Option ServicingAssetAtFairValueEarlyBuyoutOption	0	USD
CY2021	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	34788000	USD
CY2020	us-gaap	Servicing Asset At Fair Value Disposals ServicingAssetAtFairValueDisposals	32579000	USD
CY2021	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	18273000	USD
CY2020	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-30764000	USD
CY2019	us-gaap	Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions ServicingAssetAtFairValueChangesInFairValueResultingFromChangesInValuationInputsOrChangesInAssumptions	-14778000	USD
CY2021Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	147571000	USD
CY2020Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	92081000	USD
CY2019Q4	us-gaap	Servicing Asset At Fair Value Amount ServicingAssetAtFairValueAmount	85638000	USD
CY2021Q4	us-gaap	Principal Amount Outstanding On Loans Managed And Securitized PrincipalAmountOutstandingOnLoansManagedAndSecuritized	13126254000	USD
CY2020Q4	us-gaap	Principal Amount Outstanding On Loans Managed And Securitized PrincipalAmountOutstandingOnLoansManagedAndSecuritized	10833135000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	645707000	USD
CY2021	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	9275000	USD
CY2021	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	0	USD
CY2021	us-gaap	Goodwill Translation And Purchase Accounting Adjustments GoodwillTranslationAndPurchaseAccountingAdjustments	167000	USD
CY2021Q4	us-gaap	Goodwill Goodwill	655149000	USD
CY2021Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	83403000	USD
CY2020Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	83402000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	55096000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	47362000	USD
CY2021Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	28307000	USD
CY2020Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	36040000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	6115000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	4658000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	3259000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	2552000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	1954000	USD
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	7700000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	11000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	11800000	USD
CY2021Q4	wtfc	Non Interest Bearing Percentage NonInterestBearingPercentage	0.34
CY2020Q4	wtfc	Non Interest Bearing Percentage NonInterestBearingPercentage	0.32
CY2021Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1182793000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1139686000	USD
CY2021Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	416388000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	370878000	USD
CY2021Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	766405000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	768808000	USD
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	54000000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	46400000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	38000000	USD
CY2021Q4	wtfc	Negotiable Order Of Withdrawal And Interest Bearing Demand Deposits Percentage NegotiableOrderOfWithdrawalAndInterestBearingDemandDepositsPercentage	0.10
CY2020Q4	wtfc	Negotiable Order Of Withdrawal And Interest Bearing Demand Deposits Percentage NegotiableOrderOfWithdrawalAndInterestBearingDemandDepositsPercentage	0.09
CY2021Q4	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.11
CY2021Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	14179980000	USD
CY2020Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	11748455000	USD
CY2021Q4	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	4158871000	USD
CY2020Q4	us-gaap	Deposits Negotiable Order Of Withdrawal Now DepositsNegotiableOrderOfWithdrawalNOW	3349021000	USD
CY2021Q4	wtfc	Wealth Management Deposits WealthManagementDeposits	4491795000	USD
CY2020Q4	wtfc	Wealth Management Deposits WealthManagementDeposits	4138712000	USD
CY2021Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	11449469000	USD
CY2020Q4	us-gaap	Deposits Money Market Deposits DepositsMoneyMarketDeposits	9348806000	USD
CY2021Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3846681000	USD
CY2020Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3531029000	USD
CY2021Q4	us-gaap	Time Deposits TimeDeposits	3968789000	USD
CY2020Q4	us-gaap	Time Deposits TimeDeposits	4976628000	USD
CY2021Q4	us-gaap	Deposits Deposits	42095585000	USD
CY2020Q4	us-gaap	Deposits Deposits	37092651000	USD
CY2020Q4	wtfc	Wealth Management Deposits Percentage WealthManagementDepositsPercentage	0.11
CY2021Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.27
CY2020Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Money Market PercentageOfInterestBearingDomesticDepositsToDepositsMoneyMarket	0.25
CY2021Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.09
CY2021Q4	wtfc	Deposits Percentage DepositsPercentage	1
CY2020Q4	wtfc	Deposits Percentage DepositsPercentage	1
CY2020Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Savings PercentageOfInterestBearingDomesticDepositsToDepositsSavings	0.10
CY2021Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.09
CY2020Q4	us-gaap	Percentage Of Interest Bearing Domestic Deposits To Deposits Time Deposits PercentageOfInterestBearingDomesticDepositsToDepositsTimeDeposits	0.13
CY2021Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	14286000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	15233000	USD
CY2021Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	255000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	225733000	USD
CY2020Q4	us-gaap	Time Deposits TimeDeposits	4976628000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Next Rolling Twelve Months TimeDepositMaturitiesNextRollingTwelveMonths	2810669000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Next Rolling Twelve Months TimeDepositMaturitiesNextRollingTwelveMonths	3907724000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	899765000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	853915000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	170052000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	18081000	USD
CY2020Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	28896000	USD
CY2020Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	808000	USD
CY2021Q4	us-gaap	Time Deposits TimeDeposits	3968789000	USD
CY2021Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Three Months Or Less ContractualMaturitiesTimeDeposits100000OrMoreThreeMonthsOrLess	576918000	USD
CY2020Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Three Months Or Less ContractualMaturitiesTimeDeposits100000OrMoreThreeMonthsOrLess	584956000	USD
CY2021Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Three Months Through Six Months ContractualMaturitiesTimeDeposits100000OrMoreThreeMonthsThroughSixMonths	450418000	USD
CY2020Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Three Months Through Six Months ContractualMaturitiesTimeDeposits100000OrMoreThreeMonthsThroughSixMonths	913216000	USD
CY2021Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Six Months Through12 Months ContractualMaturitiesTimeDeposits100000OrMoreSixMonthsThrough12Months	838040000	USD
CY2020Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More Six Months Through12 Months ContractualMaturitiesTimeDeposits100000OrMoreSixMonthsThrough12Months	1156401000	USD
CY2021Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More After12 Months ContractualMaturitiesTimeDeposits100000OrMoreAfter12Months	754062000	USD
CY2020Q4	us-gaap	Contractual Maturities Time Deposits100000 Or More After12 Months ContractualMaturitiesTimeDeposits100000OrMoreAfter12Months	701993000	USD
CY2021Q4	us-gaap	Time Deposits100000 Or More TimeDeposits100000OrMore	2619438000	USD
CY2020Q4	us-gaap	Time Deposits100000 Or More TimeDeposits100000OrMore	3356566000	USD
CY2021Q4	wtfc	Time Deposits250000 Or More TimeDeposits250000OrMore	1200000000	USD
CY2020Q4	wtfc	Time Deposits250000 Or More TimeDeposits250000OrMore	1600000000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1241071000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	1228429000	USD
CY2021Q4	wtfc	Federal Home Loan Bank Advances Having Varying Put Dates FederalHomeLoanBankAdvancesHavingVaryingPutDates	1100000000	USD
CY2021Q4	us-gaap	Subordinated Debt SubordinatedDebt	436900000	USD
CY2020Q4	us-gaap	Subordinated Debt SubordinatedDebt	436500000	USD
CY2019	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	3300000	USD
CY2014	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	1300000	USD
CY2020Q4	us-gaap	Notes Payable NotesPayable	101710000	USD
CY2021Q4	us-gaap	Notes Payable NotesPayable	80319000	USD
CY2021Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	9198000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	11366000	USD
CY2021Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	63292000	USD
CY2020Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	65108000	USD
CY2021Q4	us-gaap	Secured Debt SecuredDebt	341327000	USD
CY2020Q4	us-gaap	Secured Debt SecuredDebt	340744000	USD
CY2021Q4	us-gaap	Other Borrowings OtherBorrowings	494136000	USD
CY2020Q4	us-gaap	Other Borrowings OtherBorrowings	518928000	USD
CY2021Q4	us-gaap	Notes Payable NotesPayable	80300000	USD
CY2021Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	9200000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	11400000	USD
CY2021Q4	wtfc	Ownership Interest Percentage In Unconsolidated Subsidiary Trusts OwnershipInterestPercentageInUnconsolidatedSubsidiaryTrusts	1
CY2021Q4	wtfc	Number Of Unconsolidated Subsidiary Trusts NumberOfUnconsolidatedSubsidiaryTrusts	11	trust
CY2021Q4	wtfc	Common Securities Proportion To Junior Subordinated Debentures CommonSecuritiesProportionToJuniorSubordinatedDebentures	0.03
CY2021Q4	wtfc	Trust Preferred Securities Proportion To Junior Subordinated Debentures TrustPreferredSecuritiesProportionToJuniorSubordinatedDebentures	0.97
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	207172000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	170130000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	161465000	USD
CY2021Q4	wtfc	Numberof Wealth Management Subsidiaries NumberofWealthManagementSubsidiaries	4	subsidiary
CY2020Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1548000	USD
CY2021Q4	wtfc	Mortgage Broker Fee Receivable MortgageBrokerFeeReceivable	73000	USD
CY2020Q4	wtfc	Mortgage Broker Fee Receivable MortgageBrokerFeeReceivable	20000	USD
CY2021Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2020Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	0	USD
CY2021Q4	us-gaap	Contract With Customer Liability ContractWithCustomerLiability	1588000	USD
CY2021Q4	wtfc	Administrative Services Receivable AdministrativeServicesReceivable	68000	USD
CY2020Q4	wtfc	Administrative Services Receivable AdministrativeServicesReceivable	64000	USD
CY2021Q4	wtfc	Wealth Management Receivable WealthManagementReceivable	11748000	USD
CY2020Q4	wtfc	Wealth Management Receivable WealthManagementReceivable	10144000	USD
CY2021Q4	wtfc	Card Related Fee Receivable CardRelatedFeeReceivable	921000	USD
CY2020Q4	wtfc	Card Related Fee Receivable CardRelatedFeeReceivable	783000	USD
CY2021Q4	us-gaap	Accounts Receivable Net AccountsReceivableNet	12810000	USD
CY2020Q4	us-gaap	Accounts Receivable Net AccountsReceivableNet	11011000	USD
CY2021	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	898000	USD
CY2020	us-gaap	Contract With Customer Liability Revenue Recognized ContractWithCustomerLiabilityRevenueRecognized	1400000	USD
CY2021Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	838000	USD
CY2021Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	400000	USD
CY2021Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	250000	USD
CY2021Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	100000	USD
CY2021Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	1588000	USD
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	22938000	USD
CY2021	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	164000	USD
CY2021	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	234000	USD
CY2021	us-gaap	Short Term Lease Cost ShortTermLeaseCost	321000	USD
CY2021	us-gaap	Variable Lease Cost VariableLeaseCost	3806000	USD
CY2021	us-gaap	Sublease Income SubleaseIncome	72000	USD
CY2021	us-gaap	Lease Cost LeaseCost	27391000	USD
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	23650000	USD
CY2021	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	164000	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	8262000	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	5343000	USD
CY2021Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P12Y1M6D
CY2021Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P39Y
CY2021Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0403
CY2021Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.0343
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	24582000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	24582000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	21625000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	21625000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	20461000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	20461000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	19203000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	19203000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	17820000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	17820000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	132417000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	132417000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	236108000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	236108000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	58069000	USD
CY2021Q4	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	58069000	USD
CY2021Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	178039000	USD
CY2021Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	178039000	USD
CY2021Q4	us-gaap	Lessor Operating Lease Payments To Be Received Next Twelve Months LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths	5452000	USD
CY2021Q4	us-gaap	Lessor Operating Lease Payments To Be Received Two Years LessorOperatingLeasePaymentsToBeReceivedTwoYears	3178000	USD
CY2021Q4	us-gaap	Lessor Operating Lease Payments To Be Received Three Years LessorOperatingLeasePaymentsToBeReceivedThreeYears	1957000	USD
CY2021Q4	us-gaap	Lessor Operating Lease Payments To Be Received Four Years LessorOperatingLeasePaymentsToBeReceivedFourYears	1390000	USD
CY2021Q4	us-gaap	Lessor Operating Lease Payments To Be Received Five Years LessorOperatingLeasePaymentsToBeReceivedFiveYears	986000	USD
CY2021Q4	us-gaap	Lessor Operating Lease Payments To Be Received Thereafter LessorOperatingLeasePaymentsToBeReceivedThereafter	511000	USD
CY2021Q4	us-gaap	Lessor Operating Lease Payments To Be Received LessorOperatingLeasePaymentsToBeReceived	13474000	USD
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	118723000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	75154000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	55664000	USD
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	48847000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	19194000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	18270000	USD
CY2021	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	6936000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	6501000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	5913000	USD
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	174506000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	100849000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	79847000	USD
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	794000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	284000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	33345000	USD
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-3597000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-2834000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	13099000	USD
CY2021	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-58000	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-1508000	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-1887000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-2861000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-4058000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	44557000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	171645000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	96791000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	124404000	USD
CY2021	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	133937000	USD
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	81854000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	100821000	USD
CY2021	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	2605000	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	2970000	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	3958000	USD
CY2021	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	35747000	USD
CY2020	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	20098000	USD
CY2019	us-gaap	Income Tax Reconciliation State And Local Income Taxes IncomeTaxReconciliationStateAndLocalIncomeTaxes	24600000	USD
CY2021	wtfc	Increase Decrease In Tax Resulting From Income Earned On Bank Owned Life Insurance IncreaseDecreaseInTaxResultingFromIncomeEarnedOnBankOwnedLifeInsurance	-1169000	USD
CY2020	wtfc	Increase Decrease In Tax Resulting From Income Earned On Bank Owned Life Insurance IncreaseDecreaseInTaxResultingFromIncomeEarnedOnBankOwnedLifeInsurance	-956000	USD
CY2019	wtfc	Increase Decrease In Tax Resulting From Income Earned On Bank Owned Life Insurance IncreaseDecreaseInTaxResultingFromIncomeEarnedOnBankOwnedLifeInsurance	-959000	USD
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-1906000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	466000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Share Based Compensation Excess Tax Benefit Amount EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount	-1447000	USD
CY2021	us-gaap	Income Tax Reconciliation Nondeductible Expense Meals And Entertainment IncomeTaxReconciliationNondeductibleExpenseMealsAndEntertainment	1208000	USD
CY2020	us-gaap	Income Tax Reconciliation Nondeductible Expense Meals And Entertainment IncomeTaxReconciliationNondeductibleExpenseMealsAndEntertainment	992000	USD
CY2019	us-gaap	Income Tax Reconciliation Nondeductible Expense Meals And Entertainment IncomeTaxReconciliationNondeductibleExpenseMealsAndEntertainment	2148000	USD
CY2021	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	5676000	USD
CY2020	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	4605000	USD
CY2019	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	1274000	USD
CY2021	wtfc	Effective Income Tax Rate Reconciliation Nondeductible Expense Compensation Amount EffectiveIncomeTaxRateReconciliationNondeductibleExpenseCompensationAmount	1799000	USD
CY2020	wtfc	Effective Income Tax Rate Reconciliation Nondeductible Expense Compensation Amount EffectiveIncomeTaxRateReconciliationNondeductibleExpenseCompensationAmount	398000	USD
CY2019	wtfc	Effective Income Tax Rate Reconciliation Nondeductible Expense Compensation Amount EffectiveIncomeTaxRateReconciliationNondeductibleExpenseCompensationAmount	1019000	USD
CY2021	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	2011000	USD
CY2020	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	2080000	USD
CY2019	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	1979000	USD
CY2021	us-gaap	Income Tax Reconciliation Tax Credits Investment IncomeTaxReconciliationTaxCreditsInvestment	1145000	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Credits Investment IncomeTaxReconciliationTaxCreditsInvestment	1902000	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Credits Investment IncomeTaxReconciliationTaxCreditsInvestment	513000	USD
CY2021	us-gaap	Income Tax Reconciliation Tax Contingencies State And Local IncomeTaxReconciliationTaxContingenciesStateAndLocal	0	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Contingencies State And Local IncomeTaxReconciliationTaxContingenciesStateAndLocal	-7173000	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Contingencies State And Local IncomeTaxReconciliationTaxContingenciesStateAndLocal	0	USD
CY2021	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-1908000	USD
CY2020	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-701000	USD
CY2019	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-560000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	171645000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	96791000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	124404000	USD
CY2021Q4	wtfc	Deferred Tax Assets Allowance For Credit Losses DeferredTaxAssetsAllowanceForCreditLosses	79879000	USD
CY2020Q4	wtfc	Deferred Tax Assets Allowance For Credit Losses DeferredTaxAssetsAllowanceForCreditLosses	101021000	USD
CY2021Q4	wtfc	Deferred Tax Assets Right Of Use Liability DeferredTaxAssetsRightOfUseLiability	47312000	USD
CY2020Q4	wtfc	Deferred Tax Assets Right Of Use Liability DeferredTaxAssetsRightOfUseLiability	47895000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	26301000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	23975000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	5762000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	3363000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	1870000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards Domestic DeferredTaxAssetsOperatingLossCarryforwardsDomestic	2722000	USD
CY2021Q4	wtfc	Deferred Tax Asset Discount On Purchased Loans DeferredTaxAssetDiscountOnPurchasedLoans	1344000	USD
CY2020Q4	wtfc	Deferred Tax Asset Discount On Purchased Loans DeferredTaxAssetDiscountOnPurchasedLoans	1196000	USD
CY2021Q4	wtfc	Deferred Tax Assets Nonaccrued Interest DeferredTaxAssetsNonaccruedInterest	1098000	USD
CY2020Q4	wtfc	Deferred Tax Assets Nonaccrued Interest DeferredTaxAssetsNonaccruedInterest	1949000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	0	USD
CY2020Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	8404000	USD
CY2021Q4	wtfc	Deferred Tax Assets Tax Deferred Expense Loan Fees And Costs DeferredTaxAssetsTaxDeferredExpenseLoanFeesAndCosts	0	USD
CY2020Q4	wtfc	Deferred Tax Assets Tax Deferred Expense Loan Fees And Costs DeferredTaxAssetsTaxDeferredExpenseLoanFeesAndCosts	3821000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	4652000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	7013000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	168218000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	201359000	USD
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CY2020Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	146393000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	56377000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	62278000	USD
CY2021Q4	wtfc	Deferred Tax Liabilities Right Of Use Asset DeferredTaxLiabilitiesRightOfUseAsset	38973000	USD
CY2020Q4	wtfc	Deferred Tax Liabilities Right Of Use Asset DeferredTaxLiabilitiesRightOfUseAsset	39568000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	37528000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	22367000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssets	10577000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssets	8227000	USD
CY2021Q4	wtfc	Deferred Tax Liabilities Net Unrealized Losses On Derivatives Included In Other Comprehensive Income DeferredTaxLiabilitiesNetUnrealizedLossesOnDerivativesIncludedInOtherComprehensiveIncome	9836000	USD
CY2020Q4	wtfc	Deferred Tax Liabilities Net Unrealized Losses On Derivatives Included In Other Comprehensive Income DeferredTaxLiabilitiesNetUnrealizedLossesOnDerivativesIncludedInOtherComprehensiveIncome	0	USD
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CY2020Q4	wtfc	Deferred Tax Liabilities Net Unrealized Losses On Investments Included In Other Comprehensive Income DeferredTaxLiabilitiesNetUnrealizedLossesOnInvestmentsIncludedInOtherComprehensiveIncome	25700000	USD
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CY2020Q4	wtfc	Deferred Tax Liabilities Fair Value Adjustment On Loans DeferredTaxLiabilitiesFairValueAdjustmentOnLoans	12042000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	3835000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	7599000	USD
CY2021Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	283973000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	324174000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	115755000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	122815000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	10840000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	11538000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	USD
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CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	10571000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	698000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	269000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	0	USD
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	0	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	10840000	USD
CY2021Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	0	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	0	USD
CY2015Q2	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	5485000	shares
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	963000000	shares
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CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	16200000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	-4900000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	11300000	USD
CY2021	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	3700000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	-914000000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	2600000	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
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CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	0
CY2019	wtfc	Share Based Compensation Arrangement By Share Based Payment Award Options Increase In Period For Acquired Plans ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIncreaseInPeriodForAcquiredPlans	106748	shares
CY2019	wtfc	Share Based Compensation Arrangements By Share Based Payment Award Options Increase In Period For Acquired Plans Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsIncreaseInPeriodForAcquiredPlansWeightedAverageExercisePrice	38.83
CY2019	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	146430	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	38.84
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CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	0
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	5608	shares
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CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.43
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P2Y9M18D
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CY2019Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	20947000	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
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	0
CY2020	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	229061	shares
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	42.29
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	520663	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.47
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P1Y10M24D
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	9694000	USD
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	512762	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	42.46
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P1Y9M18D
CY2020Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	9555000	USD
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	520663	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	42.47
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross	0	shares
CY2021	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Grants In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice	0
CY2021	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	326626	shares
CY2021	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	42.97
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CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P1Y3M18D
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	41.62
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P1Y4M24D
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	9518000	USD
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber	191898	shares
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	41.57
CY2021Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	9451000	USD
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Exercisable Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber	193447	shares
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice	41.62
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Vested And Expected To Vest Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageRemainingContractualTerm1	P1Y4M24D
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding Aggregate Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue	9518000	USD
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	11700000	USD
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	4100000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	4700000	USD
CY2021	us-gaap	Employee Service Share Based Compensation Tax Benefit From Exercise Of Stock Options EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions	3100000	USD
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Exercise Of Stock Options EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions	1100000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Exercise Of Stock Options EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions	1300000	USD
CY2021	wtfc	Excess Tax Benefit Deficit Over Estimate ExcessTaxBenefitDeficitOverEstimate	40000	USD
CY2020	wtfc	Excess Tax Benefit Deficit Over Estimate ExcessTaxBenefitDeficitOverEstimate	-848000	USD
CY2021	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	14000000	USD
CY2020	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	9700000	USD
CY2019	us-gaap	Proceeds From Stock Options Exercised ProceedsFromStockOptionsExercised	5700000	USD
CY2019	wtfc	Excess Tax Benefit Deficit Over Estimate ExcessTaxBenefitDeficitOverEstimate	870000	USD
CY2021Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	26100000	USD
CY2021	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P2Y
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue	1500000	USD
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue	14700000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Total Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue	9800000	USD
CY2021	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	15600000	USD
CY2020	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	13800000	USD
CY2019	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	12300000	USD
CY2021	us-gaap	Pension Expense PensionExpense	0	USD
CY2020	us-gaap	Pension Expense PensionExpense	0	USD
CY2019	us-gaap	Pension Expense PensionExpense	487000	USD
CY2021	us-gaap	Cash Dividends Paid To Parent Company By Consolidated Subsidiaries CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries	145000000	USD
CY2020	us-gaap	Cash Dividends Paid To Parent Company By Consolidated Subsidiaries CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries	253000000	USD
CY2019	us-gaap	Cash Dividends Paid To Parent Company By Consolidated Subsidiaries CashDividendsPaidToParentCompanyByConsolidatedSubsidiaries	139000000	USD
CY2021Q4	us-gaap	Statutory Accounting Practices Statutory Amount Available For Dividend Payments Without Regulatory Approval StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPaymentsWithoutRegulatoryApproval	431900000	USD
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CY2020Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.126
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CY2021Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.080
CY2021Q4	us-gaap	Tier One Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.080
CY2020Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.081
CY2021Q4	us-gaap	Capital Required To Be Well Capitalized To Risk Weighted Assets CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.100
CY2021Q4	us-gaap	Banking Regulation Common Equity Tier One Risk Based Capital Ratio Well Capitalized Minimum BankingRegulationCommonEquityTierOneRiskBasedCapitalRatioWellCapitalizedMinimum	0.065
CY2021Q4	us-gaap	Tier One Leverage Capital Required To Be Well Capitalized To Average Assets TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets	0.050
CY2021Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	351100000	USD
CY2020Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	348200000	USD
CY2021	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	7400000000	USD
CY2020	us-gaap	Proceeds From Sale Of Mortgage Loans Held For Sale ProceedsFromSaleOfMortgageLoansHeldForSale	7600000000	USD
CY2021Q4	wtfc	Liability For Loss Indemnification Claims On Residential Mortgage Loans Previously Sold To Investors LiabilityForLossIndemnificationClaimsOnResidentialMortgageLoansPreviouslySoldToInvestors	675000	USD
CY2020Q4	wtfc	Liability For Loss Indemnification Claims On Residential Mortgage Loans Previously Sold To Investors LiabilityForLossIndemnificationClaimsOnResidentialMortgageLoansPreviouslySoldToInvestors	779000	USD
CY2021	wtfc	Losses Charged Against Indemnification Liability LossesChargedAgainstIndemnificationLiability	219000	USD
CY2020	wtfc	Losses Charged Against Indemnification Liability LossesChargedAgainstIndemnificationLiability	187000	USD
CY2021Q4	wtfc	Unfunded Commitments To Invest In Partnerships UnfundedCommitmentsToInvestInPartnerships	40300000	USD
CY2021Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	7100000	USD
CY2021Q4	wtfc	Customer Balances Maintained By Clearing Broker And Subject To Indemnification CustomerBalancesMaintainedByClearingBrokerAndSubjectToIndemnification	22500000	USD
CY2021Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	165008000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset DerivativeFairValueOfDerivativeAsset	278423000	USD
CY2021Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	123000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Liability DerivativeFairValueOfDerivativeLiability	288465000	USD
CY2021	us-gaap	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths	-11300000	USD
CY2021Q4	us-gaap	Derivative Net Liability Position Aggregate Fair Value DerivativeNetLiabilityPositionAggregateFairValue	58800000	USD
CY2021	wtfc	Impaired Loans Fair Value Losses Recognized ImpairedLoansFairValueLossesRecognized	26341000	USD
CY2021	wtfc	Real Estate Acquired Through Foreclosure Fair Value Losses Recognized RealEstateAcquiredThroughForeclosureFairValueLossesRecognized	1197000	USD
CY2021	wtfc	Assets Nonrecurring Fair Value Losses Recognized AssetsNonrecurringFairValueLossesRecognized	27538000	USD
CY2021Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2020Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	100000000	shares
CY2021Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	58891780	shares
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	58473252	shares
CY2021Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	57054091	shares
CY2020Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	56769625	shares
CY2021	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.24
CY2020	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	1.12
CY2021Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2020Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2021Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	5011500	shares
CY2020Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	5011500	shares
CY2021Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	5011500	shares
CY2020Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	5011500	shares
CY2021	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-30043000	USD
CY2021	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-18930000	USD
CY2021	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	177000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-11290000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	36843000	USD
CY2020	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-13386000	USD
CY2020	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	169000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	50060000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	50717000	USD
CY2019	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	8175000	USD
CY2019	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	348000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	42194000	USD
CY2021	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2021	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2021Q4	wtfc	Number Of Subsidiaries NumberOfSubsidiaries	15	subsidiary
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1124957000	USD
CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	-59263000	USD
CY2021	us-gaap	Noninterest Income NoninterestIncome	586120000	USD
CY2021	us-gaap	Noninterest Expense NoninterestExpense	1132544000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	171645000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	466151000	USD
CY2021Q4	us-gaap	Assets Assets	50142143000	USD
CY2020	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1039907000	USD
CY2020	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	214220000	USD
CY2020	us-gaap	Noninterest Income NoninterestIncome	604189000	USD
CY2020	us-gaap	Noninterest Expense NoninterestExpense	1040095000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	96791000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	292990000	USD
CY2020Q4	us-gaap	Assets Assets	45080768000	USD
CY2019	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	1054919000	USD
CY2019	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	53864000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	407172000	USD
CY2019	us-gaap	Noninterest Expense NoninterestExpense	928126000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	124404000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	355697000	USD
CY2019Q4	us-gaap	Assets Assets	36620583000	USD
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	762000	shares
CY2021	us-gaap	Net Income Loss NetIncomeLoss	466151000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	292990000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	355697000	USD
CY2021	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	27964000	USD
CY2020	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	21377000	USD
CY2019	us-gaap	Preferred Stock Dividends And Other Adjustments PreferredStockDividendsAndOtherAdjustments	8200000	USD
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	438187000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	271613000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	347497000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56994000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	57523000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	56857000	shares
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	792000	shares
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	496000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57786000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	58019000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	57619000	shares
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.69
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.72
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	6.11
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.58
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.68
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	6.03
CY2021	dei	Auditor Firm AuditorFirmId	42

Files In Submission

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$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc

2021 Q4 Form 10-K Financial Statement

#000101532822000057 Filed on February 25, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WTFC WINTRUST FINANCIAL CORP Stock $wtfc

2021 Q4 Form 10-K Financial Statement

#000101532822000057 Filed on February 25, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$WTFC
WINTRUST FINANCIAL CORP Stock $wtfc