XML 82 R72.htm IDEA: XBRL DOCUMENT
v3.25.2

Derivative Financial Instruments - Narrative (Details) | 3 Months Ended | 6 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Mar. 31, 2022 USD ($) | Jun. 30, 2025 USD ($) derivativeInstrument | Dec. 31, 2024 USD ($) derivativeInstrument | Jun. 30, 2024 derivativeInstrument | Jun. 30, 2022 USD ($) derivativeInstrument
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Gain (loss) to be reclassified from accumulated other comprehensive income during the next 12 months |  | $ 2,200,000 |  |  |
Net derivative liability position, aggregate fair value |  | 45,000 |  |  |
Interest Rate Swap Terminated |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Gain (loss) to be reclassified from accumulated other comprehensive income during the next 12 months |  | 13,300,000 |  |  |
Interest Rate Swap And Collar |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Gain (loss) to be reclassified from accumulated other comprehensive income during the next 12 months |  | (15,500,000) |  |  |
Mortgage banking derivatives |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount |  | $ 330,000,000.0 | $ 295,000,000.0 |  |
Number of derivative instruments held | derivativeInstrument |  | 8 | 10 |  |
Not designated as hedging instrument | Interest rate contract |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount |  | $ 0 |  |  |
Not designated as hedging instrument | Interest rate contract, qualified borrowers |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount |  | 13,700,000,000 | $ 13,300,000,000 |  |
Not designated as hedging instrument | Interest rate lock commitments |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount |  | 201,000,000.0 | 120,700,000 |  |
Not designated as hedging instrument | Forward commitments to sell mortgage loans |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount |  | 467,900,000 | 377,500,000 |  |
Not designated as hedging instrument | Commodity forward contracts |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount |  | 2,100,000 | 5,200,000 |  |
Not designated as hedging instrument | Foreign exchange contracts |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount |  | $ 117,500,000 | $ 97,100,000 |  |
Not designated as hedging instrument | Covered call options |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Number of derivative instruments held | derivativeInstrument |  | 0 | 0 | 0 |
Interest rate derivatives designated as Cash Flow Hedges | Designated as hedging instrument |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount |  | $ 7,950,000,000 |  |  |
Interest rate derivatives designated as Cash Flow Hedges | Designated as hedging instrument | Interest Rate Swap Terminated |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount | $ 1,000,000,000 |  |  |  | $ 500,000,000
Derivative term | 5 years |  |  |  |
Fair value of derivative contracts | $ 66,500,000 |  |  |  |
Number of derivative instruments held | derivativeInstrument |  |  |  |  | 1
Interest rate derivatives designated as Cash Flow Hedges | Designated as hedging instrument | Interest Rate Swap Terminated, Original Swap Maturing April 2024 |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Fair value of derivative contracts |  |  |  |  | $ 10,700,000
Interest rate derivatives designated as Fair Value Hedges | Designated as hedging instrument | Interest rate swaps |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Notional amount |  | $ 143,100,000 |  |  |
Number of interest rate derivatives | derivativeInstrument |  | 13 |  |  |

X
- Definition The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480870/815-30-50-1 + Details
Name: | us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-10 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4C -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 182 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480401/815-10-55-182 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (a)(5) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4D Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (a)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4D Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4D Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4D Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4A -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (a)(6) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4D Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4D Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4A -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4A Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4C -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4CCC -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4CCC Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4CCC -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4CCC Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4CCC -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4CCC Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4CC -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4CC Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4C -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4C -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4C -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4C -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4C -Subparagraph (bb) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4C Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4D Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4E -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4E + Details
Name: | us-gaap_DerivativeInstrumentsGainLossLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 185 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480401/815-10-55-185 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4H -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4H + Details
Name: | us-gaap_DerivativeNetLiabilityPositionAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 181 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480401/815-10-55-181 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of derivative instruments of a particular group held by the entity. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478795/946-210-50-6 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section 55 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477439/946-210-55-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5 -Subparagraph (SX 210.12-13(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5 -Subparagraph (SX 210.12-13(Column C)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 5A -Subparagraph (SX 210.12-13A(Column B)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-5A + Details
Name: | us-gaap_DerivativeNumberOfInstrumentsHeld
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DerivativeTermOfContract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of interest rate derivative instruments held by the entity at the reporting date. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A + Details
Name: | us-gaap_NumberOfInterestRateDerivativesHeld
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wtfc_InterestRateSwapTerminatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wtfc_InterestRateSwapAndCollarMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wtfc_MortgageBankingDerivativesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wtfc_InterestRateContractQualifiedBorrowersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateLockCommitmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wtfc_ForwardCommitmentsToSellMortgageLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CallOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=wtfc_InterestRateSwapTerminatedOriginalSwapMaturingApril2024Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_FairValueHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |