XML 172 R149.htm IDEA: XBRL DOCUMENT
v3.25.4

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions | 1 Months Ended |  |  |
--- | --- | --- | --- | ---
Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023 | Nov. 29, 2023
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |  |
Proposed annual rate | 0.0297% |  |  | 0.0336%
Accrual for special assessment charge | $ 5.9 | $ 10.3 | $ 47.2 |
Special deposit insurance assessment accrual released | 10.3 |  |  |
SEC Schedule, 12-09, Allowance, Credit Loss |  |  |  |
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |  |
ACL on unfunded loan commitments | $ 24.1 | $ 22.6 |  |

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 -Name Regulation S-X (SX) -Number 210 -Section 12 -Subsection 09 -Paragraph Column E -Publisher SEC Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-X (SX) -Number 210 -Section 12 -Subsection 09 -Paragraph Column D -Publisher SEC Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-X (SX) -Number 210 -Section 12 -Subsection 09 -Paragraph Column C -Subparagraph (1) -Publisher SEC Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-X (SX) -Number 210 -Section 12 -Subsection 09 -Paragraph Column C -Subparagraph (2) -Publisher SEC Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-X (SX) -Number 210 -Section 12 -Subsection 09 -Paragraph Column B -Publisher SEC Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-5 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column C)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-4 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column C)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-4 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column B)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-4 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column E)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-4 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column D)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-4 + Details
Name: | srt_ValuationAndQualifyingAccountsDisclosureLineItems
Namespace Prefix: | srt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column B)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-4 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column E)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-4 + Details
Name: | us-gaap_ValuationAllowancesAndReservesBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Deposit Liability, Uninsured, Proposed Annual Rate + References No definition available. + Details
Name: | wbs_DepositLiabilityUninsuredProposedAnnualRate
Namespace Prefix: | wbs_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Estimated Special Assessment Charge + References No definition available. + Details
Name: | wbs_EstimatedSpecialAssessmentCharge
Namespace Prefix: | wbs_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Released Special Assessment Accrual + References No definition available. + Details
Name: | wbs_ReleasedSpecialAssessmentAccrual
Namespace Prefix: | wbs_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForCreditLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |