XML 61 R51.htm IDEA: XBRL DOCUMENT
v3.25.2

Allowance for Credit Losses - Schedule of Aging of the Company's Loan Portfolio (Details) - USD ($) $ in Thousands | Jun. 30, 2025 | Dec. 31, 2024 | Jun. 30, 2024
--- | --- | --- | ---
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | $ 173,977 | $ 154,641 | $ 151,399
Loans, net of unearned income | 51,041,679 | 48,055,037 | 44,675,531
Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 0 | 0 | 0
Loans, net of unearned income | 134,067 | 156,756 | 134,178
Commercial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 80,877 | 73,490 | 51,087
Loans, net of unearned income | 16,387,431 | 15,574,551 | 14,154,462
Commercial real estate |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 13,292,010 | 12,903,944 | 11,947,197
Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 3,200 | 2,282 | 2,528
Loans, net of unearned income | 2,529,117 | 2,434,081 | 2,260,551
Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 29,628 | 18,760 | 45,761
Loans, net of unearned income | 10,762,893 | 10,469,863 | 9,686,646
Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 1,780 | 1,117 | 1,100
Loans, net of unearned income | 466,815 | 445,028 | 356,313
Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 3,948,782 | 3,612,765 | 3,067,335
Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 28,047 | 23,762 | 18,198
Loans, net of unearned income | 3,814,715 | 3,456,009 | 2,933,157
Premium finance receivables | Premium finance receivables—property & casualty |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 30,404 | 28,797 | 32,722
Loans, net of unearned income | 8,323,176 | 7,272,042 | 7,100,753
Premium finance receivables | Premium finance receivables—life insurance |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 0 | 6,431 | 0
Loans, net of unearned income | 8,506,960 | 8,147,145 | 7,962,115
Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 41 | 2 | 3
Loans, net of unearned income | 116,505 | 99,562 | 87,356
Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Nonaccrual | 173,977 | 154,641 | 151,399
Loans, net of unearned income | 50,907,612 | 47,898,281 | 44,541,353
90+ days and still accruing |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 65,500 | 50,134 | 68,640
90+ days and still accruing | Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 50,639 | 33,952 | 45,788
90+ days and still accruing | Commercial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 104 | 304
90+ days and still accruing | Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 0 | 0
90+ days and still accruing | Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 0 | 0
90+ days and still accruing | Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 0 | 0
90+ days and still accruing | Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 0 | 0
90+ days and still accruing | Premium finance receivables | Premium finance receivables—property & casualty |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 14,350 | 16,031 | 22,427
90+ days and still accruing | Premium finance receivables | Premium finance receivables—life insurance |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 327 | 0 | 0
90+ days and still accruing | Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 184 | 47 | 121
90+ days and still accruing | Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 14,861 | 16,182 | 22,852
60-89 days past due |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 92,108 | 164,988 | 59,416
60-89 days past due | Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 618 | 0
60-89 days past due | Commercial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 34,855 | 54,844 | 16,485
60-89 days past due | Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 3,271 | 1,339 | 1,699
60-89 days past due | Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 7,986 | 9,182 | 4,856
60-89 days past due | Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 138 | 1,233 | 275
60-89 days past due | Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 8,954 | 5,708 | 1,977
60-89 days past due | Premium finance receivables | Premium finance receivables—property & casualty |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 25,641 | 19,042 | 29,925
60-89 days past due | Premium finance receivables | Premium finance receivables—life insurance |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 11,202 | 72,963 | 4,118
60-89 days past due | Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 61 | 59 | 81
60-89 days past due | Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 92,108 | 164,370 | 59,416
30-59 days past due |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 163,323 | 252,223 | 139,768
30-59 days past due | Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 0 | 2,335 | 0
30-59 days past due | Commercial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 45,103 | 92,551 | 36,358
30-59 days past due | Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 1,721 | 4,634 | 6,539
30-59 days past due | Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 49,452 | 26,132 | 31,526
30-59 days past due | Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 2,971 | 2,148 | 1,229
30-59 days past due | Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 38 | 18,917 | 130
30-59 days past due | Premium finance receivables | Premium finance receivables—property & casualty |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 29,460 | 68,219 | 45,927
30-59 days past due | Premium finance receivables | Premium finance receivables—life insurance |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 34,403 | 36,405 | 17,693
30-59 days past due | Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 175 | 882 | 366
30-59 days past due | Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 163,323 | 249,888 | 139,768
Current |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 50,546,771 | 47,433,051 | 44,256,308
Current | Early buy-out loans guaranteed by U.S. government agencies |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 83,428 | 119,851 | 88,390
Current | Commercial |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 16,226,596 | 15,353,562 | 14,050,228
Current | Commercial real estate | Construction and development |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 2,520,925 | 2,425,826 | 2,249,785
Current | Commercial real estate | Non-construction |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 10,675,827 | 10,415,789 | 9,604,503
Current | Home equity |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 461,926 | 440,530 | 353,709
Current | Residential real estate, excluding early buy-out loans | Residential real estate, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 3,777,676 | 3,407,622 | 2,912,852
Current | Premium finance receivables | Premium finance receivables—property & casualty |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 8,223,321 | 7,139,953 | 6,969,752
Current | Premium finance receivables | Premium finance receivables—life insurance |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 8,461,028 | 8,031,346 | 7,940,304
Current | Consumer and other |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | 116,044 | 98,572 | 86,785
Current | Total loans, net of unearned income, excluding early buy-out loans |  |  |
Financing Receivable, Past Due [Line Items] |  |  |
Loans, net of unearned income | $ 50,463,343 | $ 47,313,200 | $ 44,167,918

X
- Definition Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3B -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-5 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of financing receivable on nonaccrual status. Excludes net investment in lease. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph a -Subparagraph (3) -Publisher SEC Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph a -Subparagraph (2) -Publisher SEC Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 16 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-16 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
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/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (d)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 8: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 9: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 10: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-14 Reference 12: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (e)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 13: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (e)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 14: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 15: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 16: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-12 Reference 17: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 80 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479294/326-20-55-80 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wtfc_EarlyBuyOutLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wtfc_NonConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=wtfc_HomeEquityPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wtfc_ResidentialRealEstateLoansExcludingEarlyBuyOutLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=wtfc_PremiumFinanceReceivablePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wtfc_PropertyAndCasualtyInsuranceLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wtfc_LifeInsuranceLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=wtfc_ConsumerAndOtherPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=wtfc_TotalFinancingReceivablePortfolioSegmentExcludingEarlyBuyOutLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables60To89DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetNotPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |