XML 67 R57.htm IDEA: XBRL DOCUMENT v3.24.2.u1

Allowance for Credit Losses - Schedule of Modification of Loans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		13 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 2,588	$ 5,063	$ 5,065	$ 45,792	$ 10,836
Percentage of Total Class of Loan	0.00%	0.00%	0.00%	0.10%
Extension of Term
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 2,115	$ 143	$ 3,455	$ 4,007
Duration of Extension of Term (months)	7 months	43 months	11 months	36 months
Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 3	$ 0	$ 171	$ 1,319
Reduction of  Interest Rate (bps)	1.40%	2.07%	1.56%	2.23%
Interest Only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 319		$ 319
Delay in Contractual Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	97	$ 0	954	$ 35,304
Extended of Term and Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 54	$ 4,920	$ 166	$ 5,162
Payment Deferral, Quarterly (QTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	34 months	0 months	34 months	0 months	34 months
Payment Deferral, Year-to-Date (YTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	18 months	17 months	18 months	17 months	18 months
Commercial | Commercial, industrial and other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 2,161	$ 423	$ 3,219	$ 37,897	$ 4,685
Percentage of Total Class of Loan	0.00%	0.00%	0.00%	0.30%
Commercial | Commercial, industrial and other | Extension of Term
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 2,010	$ 0	$ 2,956	$ 1,938
Duration of Extension of Term (months)	5 months	41 months	8 months	15 months
Commercial | Commercial, industrial and other | Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 0	$ 0	$ 221
Reduction of  Interest Rate (bps)	1.43%	1.44%	1.13%	1.08%
Commercial | Commercial, industrial and other | Interest Only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0		$ 0
Commercial | Commercial, industrial and other | Delay in Contractual Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	97	$ 0	97	$ 35,265
Commercial | Commercial, industrial and other | Extended of Term and Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 54	$ 423	$ 166	$ 473
Commercial | Commercial, industrial and other | Payment Deferral, Quarterly (QTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	34 months	0 months	34 months	0 months	34 months
Commercial | Commercial, industrial and other | Payment Deferral, Year-to-Date (YTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	34 months	16 months	34 months	16 months	34 months
Commercial real estate | Non-construction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 340	$ 4,376	$ 1,469	$ 5,709	$ 2,644
Percentage of Total Class of Loan	0.00%	0.00%	0.00%	0.10%
Commercial real estate | Non-construction | Extension of Term
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 21	$ 0	$ 293	$ 467
Duration of Extension of Term (months)	13 months	39 months	29 months	40 months
Commercial real estate | Non-construction | Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 0	$ 0	$ 827
Reduction of  Interest Rate (bps)	0.00%	2.12%	0.00%	2.32%
Commercial real estate | Non-construction | Interest Only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 319		$ 319
Commercial real estate | Non-construction | Delay in Contractual Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	0	$ 0	857	$ 39
Commercial real estate | Non-construction | Extended of Term and Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 4,376	$ 0	$ 4,376
Commercial real estate | Non-construction | Payment Deferral, Quarterly (QTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	0 months	0 months	0 months	0 months	0 months
Commercial real estate | Non-construction | Payment Deferral, Year-to-Date (YTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	16 months	101 months	16 months	101 months	16 months
Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 0	$ 89	$ 203	$ 586
Percentage of Total Class of Loan	0.00%	0.00%	0.00%	0.10%
Home equity | Extension of Term
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 0	$ 89	$ 203
Duration of Extension of Term (months)	0 months	0 months	12 months	12 months
Home equity | Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 0	$ 0	$ 0
Reduction of  Interest Rate (bps)	0.00%	0.00%	0.00%	0.00%
Home equity | Interest Only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0		$ 0
Home equity | Delay in Contractual Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	0	$ 0	0	$ 0
Home equity | Extended of Term and Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 0	$ 0	$ 0
Home equity | Payment Deferral, Quarterly (QTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	0 months		0 months		0 months
Home equity | Payment Deferral, Year-to-Date (YTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	0 months	0 months	0 months	0 months	0 months
Home equity | Non-construction | Payment Deferral, Quarterly (QTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)		0 months		0 months
Residential real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 81	$ 264	$ 282	$ 1,972	$ 417
Percentage of Total Class of Loan	0.00%	0.00%	0.00%	0.10%
Residential real estate | Extension of Term
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 81	$ 143	$ 114	$ 1,396
Duration of Extension of Term (months)	12 months	123 months	19 months	57 months
Residential real estate | Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 0	$ 168	$ 271
Reduction of  Interest Rate (bps)	0.00%	2.62%	2.01%	2.84%
Residential real estate | Interest Only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0		$ 0
Residential real estate | Delay in Contractual Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	0	$ 0	0	$ 0
Residential real estate | Extended of Term and Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 121	$ 0	$ 305
Residential real estate | Payment Deferral, Quarterly (QTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	0 months		0 months		0 months
Residential real estate | Payment Deferral, Year-to-Date (YTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	0 months	0 months	0 months	0 months	0 months
Residential real estate | Non-construction | Payment Deferral, Quarterly (QTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)		0 months		0 months
Premium finance receivables | Property and casualty insurance loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 6	$ 0	$ 6	$ 11	$ 18
Percentage of Total Class of Loan	0.00%	0.00%	0.00%	0.00%
Premium finance receivables | Property and casualty insurance loans | Extension of Term
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 3	$ 0	$ 3	$ 3
Duration of Extension of Term (months)	2 months	0 months	2 months	0 months
Premium finance receivables | Property and casualty insurance loans | Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 3	$ 0	$ 3	$ 0
Reduction of  Interest Rate (bps)	0.86%	0.00%	0.86%	0.50%
Premium finance receivables | Property and casualty insurance loans | Interest Only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0		$ 0
Premium finance receivables | Property and casualty insurance loans | Delay in Contractual Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	0	$ 0	0	$ 0
Premium finance receivables | Property and casualty insurance loans | Extended of Term and Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-modification loan balances	$ 0	$ 0	$ 0	$ 8
Premium finance receivables | Property and casualty insurance loans | Payment Deferral, Quarterly (QTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	0 months	0 months	0 months	0 months	0 months
Premium finance receivables | Property and casualty insurance loans | Payment Deferral, Year-to-Date (YTD)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Duration of Delay in Contractual Payments (months)	0 months	0 months	0 months	0 months	0 months

X

- Definition

Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Percentage, excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

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://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-34

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-33

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Period of payment deferral of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableModifiedPaymentDeferralPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Percentage of decrease in weighted average contractual interest rate of financing receivable modified for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

+ Details

Name:	us-gaap_FinancingReceivableModifiedWeightedAverageInterestRateDecreaseFromModification
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Period of increase in weighted average maturity of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

+ Details

Name:	us-gaap_FinancingReceivableModifiedWeightedAverageTermIncreaseFromModification
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ContractualInterestRateReductionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=wtfc_InterestOnlyPaymentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_PaymentDeferralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=wtfc_ExtendedMaturityAndContractualInterestRateReductionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=wtfc_PaymentDeferralReportedPeriodOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=wtfc_PaymentDeferralReportedPeriodTwoMember
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_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=wtfc_CommercialIndustrialAndOtherLoansMember
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=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_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: