v3.25.3

Document and Entity Information Statement	Oct. 17, 2025
Entity Information [Line Items]
Amendment Flag	false
Document Type	8-K
Document Period End Date	Oct. 17, 2025
Entity Registrant Name	WEBSTER FINANCIAL CORPORATION
Entity Incorporation, State or Country Code	DE
Entity File Number	001-31486
Entity Tax Identification Number	06-1187536
Entity Address, Address Line One	200 Elm Street
Entity Address, City or Town	Stamford
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06902
City Area Code	203
Local Phone Number	578-2202
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Entity Emerging Growth Company	false
Entity Central Index Key	0000801337
NEW YORK STOCK EXCHANGE, INC. [Member]
Entity Information [Line Items]
Security Exchange Name	NYSE
Common Class A [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	WBS
Series F Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Depositary Shares, each representing 1/1000th interest in a share of 5.25% Series F Non-Cumulative Perpetual Preferred Stock
Trading Symbol	WBS-PrF
Series G Preferred Stock
Entity Information [Line Items]
Title of 12(b) Security	Depositary Shares, each representing 1/40th interest in a share of 6.50% Series G Non-Cumulative Perpetual Preferred Stock
Trading Symbol	WBS-PrG

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Area code of city

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For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

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The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

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Address Line 1 such as Attn, Building Name, Street Name

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Name of the City or Town

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Code for the postal or zip code

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Name of the state or province.

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- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
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Indicate if registrant meets the emerging growth company criteria.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

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Two-character EDGAR code representing the state or country of incorporation.

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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.

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The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b-2

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- Definition

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
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Local phone number for entity.

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No definition available.

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- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Name of the Exchange on which a security is registered.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Exchange Act
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-Subsection 12

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Trading symbol of an instrument as listed on an exchange.

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No definition available.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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WEBSTER FINANCIAL CORP 8-K