Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations.	Nature of Operations. Webster Financial Corporation (collectively, with its consolidated subsidiaries, “Webster” or the “Company”), is a bank holding company and financial holding company under the Bank Holding Company Act of 1956, as amended, headquartered in Waterbury, Connecticut and incorporated under the laws of Delaware in 1986. At June 30, 2013, Webster Financial Corporation's principal asset was all of the outstanding capital stock of Webster Bank, National Association (“Webster Bank”). Webster, through Webster Bank and various non-banking financial services subsidiaries, delivers financial services to individuals, families and businesses throughout southern New England and into Westchester County, New York. Webster provides business and consumer banking, mortgage lending, financial planning, trust and investment services through banking offices, ATMs, telephone banking, mobile banking and its Internet website (www.websterbank.com). Webster Bank offers, through its HSA Bank division, health savings accounts on a nationwide basis. Webster also offers equipment financing, commercial real estate lending, and asset-based lending.
Basis of Presentation	Basis of Presentation. The Condensed Consolidated Financial Statements include the accounts of Webster Financial Corporation and all other entities in which it has a controlling financial interest. All significant intercompany balances and transactions have been eliminated in consolidation. The accounting and financial reporting policies Webster follows conform, in all material respects, to accounting principles generally accepted in the United States (“GAAP”) and to general practices within the financial services industry. The Company determines whether it has a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a variable interest entity (“VIE”) under GAAP. Voting interest entities are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holder with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. The Company consolidates voting interest entities in which it has all or at least a majority of, the voting interest. VIEs are entities that lack one or more of the characteristics of a voting interest entity. A controlling financial interest in a VIE is present when the Company has both the power and ability to direct the activities of the VIE that most significantly impact the VIE's economic performance and an obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The Company owns the common stock of a trust which has issued trust preferred securities. The trust is a VIE in which the Company is not the primary beneficiary and therefore is not consolidated. The trust's only assets are junior subordinated debentures issued by the Company, which were acquired by the trust using the proceeds from the issuance of the trust preferred securities and common stock. The junior subordinated debentures are included in long-term debt and the Company’s equity interests in the trust is included in other assets in the accompanying Condensed Consolidated Balance Sheets. Interest expense on the junior subordinated debentures is reported in interest expense on long-term debt in the accompanying Condensed Consolidated Statements of Income. See Note 9 - Long-Term Debt. Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications had no impact on the Company's consolidated financial position, results of operations or net change in cash or cash equivalents.
Use of Estimates	Use of Estimates. The preparation of the Condensed Consolidated Financial Statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the Condensed Consolidated Financial Statements. Actual results could differ from those estimates. The allowance for loan and lease losses, the fair value measurements of financial instruments and valuation of investments for other-than-temporary impairment (“OTTI”), the valuation of goodwill, the deferred tax asset valuation allowance and pension and other postretirement benefits, as well as the status of contingencies are particularly subject to change.
Cash and Cash Equivalents	Cash Equivalents and Cash Flows. For the purposes of the Condensed Consolidated Statements of Cash Flows, cash equivalents include cash on hand and due from banks, interest-bearing deposits in the Federal Reserve Bank or other short-term money market investments.
Interest-bearing Deposits	Webster classifies financial instruments with maturities of one year or less at the date of purchase as interest-bearing deposits. These deposits are carried at cost, which approximates fair value.
Investment Securities	Investment Securities. Investment securities are classified at the time of purchase as “available for sale”, or “held-to-maturity”. Classification is re-evaluated each quarter to ensure appropriate classification and to maintain consistency with corporate objectives. Debt securities held-to-maturity are those which Webster has the ability and intent to hold to maturity. Securities held-to-maturity are recorded at amortized cost. Amortized cost includes the amortization of premiums or accretion of discounts. Such amortization and accretion is included in interest income from securities. Securities classified as available for sale are recorded at fair value. Unrealized gains and losses, net of taxes, are calculated each reporting period and presented as a separate component of other comprehensive income (“OCI”). Securities transferred from available for sale to held-to-maturity are recorded at fair value at the time of transfer. The respective gain or loss is reclassified as a separate component of OCI and amortized as an adjustment to interest income over the remaining life of the security. Investment securities are reviewed quarterly for OTTI. All securities classified as available for sale or held-to-maturity that are in an unrealized loss position are evaluated for OTTI. The evaluation considers several qualitative factors including the amount of the unrealized loss and the period of time the security has been in a loss position. If the Company intends to sell the security or, if it is more than likely the Company will be required to sell the security prior to recovery of its amortized cost basis, the security is written down to fair value and the loss is recorded in non-interest income in the accompanying Condensed Consolidated Statements of Income. If the Company does not intend to sell the security and if it is more likely than not that the Company will not be required to sell the security prior to recovery of its amortized cost basis, only the credit component of any impairment charge of a debt security would be recognized as a loss in non-interest income in the accompanying Condensed Consolidated Statements of Income. The remaining loss component would be recorded in OCI. A decline in the value of an equity security that is considered OTTI is recorded as a loss in non-interest income in the accompanying Condensed Consolidated Statements of Income. The specific identification method is used to determine realized gains and losses on sales of securities.
Loans Held for Sale	Loans Held for Sale. Loans held for sale are primarily residential real estate mortgage loans. Loans typically are assigned this classification upon origination based on management's intent to sell when the loans are underwritten. Loans held for sale are carried at the lower of cost or fair value. Non-residential mortgage loans held for sale are carried at lower of cost or fair value and are valued on individual asset basis. Any cost amount in excess of fair value is recorded as a valuation allowance and recognized as a reduction of other income. Gains or losses on the sale of loans held for sale are included in non-interest income in the accompanying Condensed Consolidated Statements of Income. Direct loan origination costs and fees are deferred and are recognized at the time of sale.
Loans	Loans. Loans are stated at the principal amounts outstanding, net of charged off amounts and unamortized premiums and discounts and net of deferred loan fees and/or costs which are recognized as a yield adjustment using the interest method. These yield adjustments are amortized over the contractual life of the related loans adjusted for estimated prepayments when applicable. Interest on loans is credited to interest income as earned based on the interest rate applied to principal amounts outstanding. Loans are placed on non-accrual status when timely collection of principal and interest in accordance with contractual terms is doubtful. A loan is transferred to a non-accrual basis generally when principal or interest payments become 90 days delinquent, unless the loan is well secured and in process of collection, or sooner if management concludes circumstances indicate that the borrower may be unable to meet contractual principal or interest payments. Residential real estate and consumer loans are placed on non-accrual status at 90 days past due and a charge-off is recorded at 180 days if the loan balance exceeds the fair value of the collateral less costs to sell. Commercial, commercial real estate and equipment finance loans are subject to a loan by loan review at 90 days past due to determine accrual status. Accrual of interest is discontinued if the loan is placed on non-accrual status. When a loan is put on non-accrual status, unpaid accrued interest is reversed and charged against interest income. If ultimate repayment of a non-accrual loan is expected, any payments received are applied in accordance with contractual terms. If ultimate repayment is not expected on commercial, commercial real estate and equipment finance loans, any payment received on a non-accrual loan is applied to principal until the unpaid balance has been fully recovered. Any excess is then credited to interest income when received. If the Company determines, through a current valuation analysis, that principal can be repaid on residential real estate and consumer loans, interest payments may be taken into income as received or on a cash basis. Loans are removed from non-accrual status when they become current as to principal and interest or demonstrate a period of performance under contractual terms and, in the opinion of management, are fully collectible as to principal and interest.
Allowance for Credit Losses	Allowance for Credit Losses. The allowance for credit losses includes the allowance for loan and lease losses and the reserve for unfunded credit commitments. Allowance for Loan and Lease Losses (“ALLL”). The allowance for loan and lease losses is a reserve established through a provision for loan and lease losses charged to expense, and represents management’s best estimate of probable losses that may be incurred within the existing loan and lease portfolio as of the balance sheet date. The level of the allowance reflects management’s view of trends in loss activity, current portfolio quality and present economic, political and regulatory conditions. Portions of the allowance may be allocated for specific loans and leases; however, the entire allowance is available for any loan or lease that is charged off. A charge-off is recorded on a case-by-case basis when all or a portion of the loan or lease is deemed to be uncollectible. Back-testing is performed to compare original estimated losses and actual observed losses, resulting in ongoing refinements. While management utilizes its best judgment based on the information available at the time, the ultimate adequacy of the allowance is dependent upon a variety of factors that are beyond the Company’s control, which include the performance of the Company’s portfolio, economic conditions, interest rate sensitivity and the view of the regulatory authorities regarding loan classifications. The Company’s allowance for loan and lease losses consists of three elements: (i) specific valuation allowances established for probable losses on impaired loans and leases; (ii) quantitative valuation allowances calculated using loss experience for like loans and leases with similar characteristics and trends, adjusted, as necessary, to reflect the impact of current conditions; and (iii) qualitative factors determined based on general economic conditions and other factors that may be internal or external to the Company. Loans and leases are considered impaired when, based on current information and events, it is probable the Company will be unable to collect all amounts due in accordance with the original contractual terms of the loan agreement, including scheduled principal and interest payments. Impairment is evaluated on a pooled basis for smaller-balance homogeneous residential and consumer loans. Commercial, commercial real estate and equipment financing loans and leases over a specific dollar amount and all troubled debt restructurings are evaluated individually for impairment. A loan identified as a Troubled Debt Restructuring ("TDR") is considered an impaired loan for the entire term of the loan, with few exceptions. If a loan is impaired, a specific valuation allowance may be established, and the loan is reported net, at the present value of estimated future cash flows using the loan’s original interest rate or at the fair value of collateral less cost to sell if repayment is expected from collateral liquidation. Interest payments on non-accruing impaired loans are typically applied to principal unless collectability of the principal amount is reasonably assured, in which case interest is recognized on a cash basis. Impaired loans, or portions thereof, are charged off when deemed uncollectible. Factors considered by management in determining impairment include payment status, collateral value, discharged bankruptcy and the likelihood of collecting scheduled principal and interest payments. Consumer modified loans are analyzed for re-default probability which is considered when determining the impaired reserve for ALLL. The current or weighted average (for multiple notes within a commercial borrowing arrangement) interest rate of the loan is used as the discount rate when the interest rate floats with a specified index. A change in terms or payments would be included in the impairment calculation. Reserve for Unfunded Commitments. The reserve for unfunded commitments provides for probable losses inherent with funding the unused portion of legal commitments available to lend. The unfunded reserve calculation includes factors that are consistent with ALLL methodology for funded loans using the loss given default, probability of default and a draw down factor applied to the underlying borrower risk and facility risk grades. The changes in the reserve for unfunded credit commitments is reported as a component of other expense and the reserve is recorded within other liabilities.
Troubled Debt Restructurings	Troubled Debt Restructurings. A modified loan is considered a TDR when two conditions are met: (1) the borrower is experiencing financial difficulties and (2) the modification constitutes a concession. The Company considers all aspects of the restructuring in determining whether a concession has been granted, including the debtor's ability to access funds at a market rate. In general, a concession exists when the modified terms of the loan are more attractive to the borrower than standard market terms. Modified terms are dependent upon the financial position and needs of the individual borrower. The Company does not employ modification programs for temporary or trial periods. The most common types of modifications include covenant modifications, forbearance and/or other concessions. If the modification agreement is violated, the loan is reevaluated to determine if it should be handled by the Company’s Restructuring and Recovery group for resolution, which may result in foreclosure. Loans for which the borrower has been discharged under Chapter 7 bankruptcy are considered collateral dependent TDRs, impaired at the date of discharge, and charged down to the fair value of collateral less cost to sell. The Company’s policy is to place all consumer loan TDRs on non-accrual status for a minimum period of 6 months. Commercial TDRs are evaluated on a case-by-case basis for determination of whether or not to place on non-accrual status. Loans qualify for return to accrual status once they have demonstrated performance with the restructured terms of the loan agreement for a minimum of 6 months. Initially, all TDRs are reported as impaired. Generally, TDRs are classified as impaired loans and reported as TDRs for the remaining life of the loan. Impaired and TDR classification may be removed if the borrower demonstrates compliance with the modified terms for a minimum of 6 months and through 1 fiscal year-end and the restructuring agreement specifies a market rate of interest equal to that which would be provided to a borrower with similar credit at the time of restructuring. In the limited circumstances that a loan is removed from TDR classification it is the Company’s policy to continue to base its measure of loan impairment on the contractual terms specified by the loan agreement.
Transfers and Servicing of Financial Assets	Transfers and Servicing of Financial Assets. Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is generally considered to have been surrendered when (1) the transferred assets are legally isolated from the Company or its consolidated affiliates, even in bankruptcy or other receivership, (2) the transferee has the right to pledge or exchange the assets with no conditions that constrain the transferee and provide more than a trivial benefit to the Company, and (3) the Company does not maintain the obligation or unilateral ability to reclaim or repurchase the assets. The Company sells financial assets in the normal course of business, the majority of which are residential mortgage loans sales primarily to government-sponsored enterprises through established programs, commercial loan sales through participation agreements, and other individual or portfolio loan and securities sales. In accordance with accounting guidance for asset transfers, the Company considers any ongoing involvement with transferred assets in determining whether the assets can be derecognized from the balance sheet. With the exception of servicing and certain performance-based guarantees, the Company’s continuing involvement with financial assets sold is minimal and generally limited to market customary representation and warranty clauses. When the Company sells financial assets, it may retain servicing rights and/or other interests in the financial assets. The gain or loss on sale depends on the previous carrying amount of the transferred financial assets and the consideration received and any liabilities incurred in exchange for the transferred assets. Upon transfer, any servicing assets and other interests held by the Company are initially recognized at fair value.
Recently Issued Accounting Standards Update	Recently Adopted Accounting Standards Updates ASU No. 2011-11, “Balance Sheet (Topic 210): Disclosures about Offsetting Assets and Liabilities”. The ASU expands required disclosures of information related to the nature of an entity’s rights of setoff and related arrangements associated with its financial instruments and derivative instruments, in an effort to enhance comparability between financial statements prepared with GAAP and IFRS. The requirements include disclosure of net and gross positions in covered financial instruments and derivative instruments which are either (1) offset in accordance with ASC Sections 210-20-45 or 815-10-45, or (2) subject to an enforceable netting or other similar arrangement. The disclosures required by this amendment were applied retrospectively for all comparative periods presented. The amendments did not have a material impact on the Company's financial statements. ASU 2013-01- Balance Sheet (Topic 210): "Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities". The ASU amends Update 2011-11 to clarify that the scope applies to derivatives, repurchase and reverse repurchase agreements, and securities borrowing and lending transactions that are either offset in accordance with Section 210-20-45 or Section 815-10-45 or subject to master netting or similar arrangements. Other types of financial assets and liabilities subject to master netting or similar arrangements are not subject to the disclosure requirements in Update 2011-11. The amendments are effective for fiscal years beginning on or after January 1, 2013, and interim periods within those annual periods. The amendments did not have a material impact on the Company's financial statements. ASU 2013-02- Comprehensive Income (Topic 220): "Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income". The ASU requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the statement where net income is presented or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income but only if the amount reclassified is required under U.S. GAAP to be reclassified to net income in its entirety in the same reporting period. The amendments are effective prospectively for reporting periods beginning after December 15, 2012. The amendments did not have a material impact on the Company's financial statements.