Webster Financial (WBS) 10-Q 7 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 31, 2016
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Trading Symbol	WBS
Entity Registrant Name	WEBSTER FINANCIAL CORPORATION
Entity Central Index Key	801,337
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		91,726,376

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Assets:
Cash and due from banks		$ 199,989	$ 199,693
Interest-bearing deposits		21,938	155,907
Securities available-for-sale		3,040,111	2,984,631
Securities held-to-maturity (fair value of $4,109,943 and $3,961,534)		4,022,332	3,923,052
Federal Home Loan Bank and Federal Reserve Bank stock		185,104	188,347
Loans held for sale (valued under fair value option $66,400 and $0)		66,578	37,091
Loans and leases	[1],[2]	16,623,401	15,671,735
Allowance for loan and lease losses		(187,925)	(174,990)
Loans and leases, net		16,435,476	15,496,745
Deferred tax asset, net		73,228	101,578
Premises and equipment, net		137,067	129,426
Goodwill		538,373	538,373
Other intangible assets, net		34,756	39,326
Cash surrender value of life insurance policies		514,153	503,093
Accrued interest receivable and other assets		364,512	343,856
Total assets		25,633,617	24,641,118
Liabilities and shareholders' equity:
Noninterest-bearing Deposit Liabilities		3,993,750	3,713,063
Interest-bearing Deposit Liabilities		15,207,158	14,239,715
Total deposits		19,200,908	17,952,778
Securities sold under agreements to repurchase and other borrowings		800,705	1,151,400
Federal Home Loan Bank advances		2,587,983	2,664,139
Long-term debt		225,450	225,260
Accrued expenses and other liabilities		306,942	233,581
Total liabilities		23,121,988	22,227,158
Shareholders’ equity:
Preferred stock, $.01 par value; Authorized - 3,000,000 shares: Series E issued and outstanding (5,060 shares)		122,710	122,710
Common stock, $.01 par value: Authorized - 200,000,000 shares: Issued (93,651,601 shares)		937	937
Paid-in capital		1,125,377	1,124,325
Retained earnings		1,392,500	1,315,948
Treasury stock, at cost (2,125,891 and 2,090,409 shares)		(76,742)	(71,854)
Accumulated other comprehensive loss, net of tax		(53,153)	(78,106)
Total shareholders' equity		2,511,629	2,413,960
Total liabilities and shareholders' equity		$ 25,633,617	$ 24,641,118
[1]	At September 30, 2016, the Company had pledged $6.4 billion of eligible residential and consumer loans as collateral to support borrowing capacity at the FHLB Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums/discounts of $19.7 million and $18.0 million at September 30, 2016 and December 31, 2015, respectively.

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Securities held-to-maturity ,fair value	$ 4,109,943	$ 3,961,534
Originated loans held for sale	$ 66,400	$ 0
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	3,000,000	3,000,000
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	93,651,601	93,651,601
Treasury stock ,shares (in shares)	2,125,891	2,090,409
Series E Preferred Stock [Member]
Preferred stock, shares issued (in shares)	5,060	5,060
Preferred stock, shares outstanding (in shares)	5,060	5,060

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest Income:
Interest and fees on loans and leases	$ 157,071	$ 140,520	$ 459,050	$ 406,937
Taxable interest and dividends on securities	43,384	47,230	136,734	141,739
Non-taxable interest on securities	4,820	3,891	13,691	11,905
Loans held for sale	440	357	1,006	1,299
Total interest income	205,715	191,998	610,481	561,880
Interest Expense:
Deposits	12,594	11,480	37,267	34,555
Securities sold under agreements to repurchase and other borrowings	3,447	4,138	10,999	12,711
Federal Home Loan Bank advances	6,979	5,949	21,517	16,099
Long-term debt	2,498	2,421	7,444	7,230
Total interest expense	25,518	23,988	77,227	70,595
Net interest income	180,197	168,010	533,254	491,285
Provision for loan and lease losses	14,250	13,000	43,850	35,500
Net interest income after provision for loan and lease losses	165,947	155,010	489,404	455,785
Non-interest Income:
Deposit service fees	35,734	35,164	105,553	101,382
Loan and lease related fees	10,299	8,305	23,048	19,713
Wealth and investment services	7,593	7,761	21,992	24,434
Mortgage banking activities	3,276	1,441	8,850	5,519
Increase in cash surrender value of life insurance policies	3,743	3,288	11,060	9,637
Gain on sale of investment securities, net	0	0	414	529
Impairment loss on securities recognized in earnings	0	(82)	(149)	(82)
Other income	5,767	5,415	23,093	16,966
Total non-interest income	66,412	61,292	193,861	178,098
Non-interest Expense:
Compensation and benefits	83,148	73,378	243,688	218,285
Occupancy	15,004	11,987	44,099	37,263
Technology and equipment	19,753	21,419	59,067	60,979
Intangible assets amortization	1,493	1,621	4,570	4,752
Marketing	4,622	4,099	14,215	12,520
Professional and outside services	4,795	2,896	11,360	8,224
Deposit insurance	6,177	6,067	19,596	17,800
Other expense	21,105	18,470	64,725	51,738
Total non-interest expense	156,097	139,937	461,320	411,561
Income (loss) before income tax expense	76,262	76,365	221,945	222,322
Income tax expense	24,445	24,995	72,478	69,405
Net of tax	51,817	51,370	149,467	152,917
Preferred stock dividends and other	(2,183)	(2,194)	(6,540)	(7,202)
Earnings applicable to common shareholders	$ 49,634	$ 49,176	$ 142,927	$ 145,715
Earnings per common share:
Basic (in dollars per share)	$ 0.54	$ 0.54	$ 1.57	$ 1.61
Diluted (in dollars per share)	$ 0.54	$ 0.53	$ 1.56	$ 1.60

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 51,817	$ 51,370	$ 149,467	$ 152,917
Other comprehensive income (loss), net of tax:
Total available-for-sale and transferred securities	1,218	712	19,988	(6,248)
Total derivative instruments	2,015	(519)	1,589	42
Total defined benefit pension and other postretirement benefit plans	1,125	983	3,376	2,948
Other comprehensive income (loss), net of tax	4,358	1,176	24,953	(3,258)
Comprehensive income	$ 56,175	$ 52,546	$ 174,420	$ 149,659

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Series A Preferred Stock [Member]	Series E Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Paid-In Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Series A Preferred Stock [Member]	Retained Earnings [Member]Series E Preferred Stock [Member]	Treasury Stock, at cost [Member]	Accumulated Other Comprehensive Loss, Net of Tax [Member]
Beginning Balance at Dec. 31, 2014	$ 2,322,815			$ 151,649	$ 936	$ 1,127,534	$ 1,202,251			$ (103,294)	$ (56,261)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	152,917						152,917
Other comprehensive income, net of tax	(3,258)										(3,258)
Dividends and dividend equivalents declared on common stock $0.48 and $0.43 per share during the 6 months ended June 30, 2016 and 2015, respectively	(60,149)					87	(60,236)
Dividends on Series E preferred stock $800.00 per share for the 6 months ended June 30, 2016 and 2015 and Series A preferred stock $21.25 per share for the 6 months ended June 30, 2015		$ (615)	$ (6,072)					$ (615)	$ (6,072)
Preferred stock conversion	0			(28,939)		(3,429)				32,368
Stock-based compensation, net of tax impact	10,404					2,778	(828)			8,454
Exercise of stock options	2,562					(2,124)				4,686
Common shares acquired related to stock compensation plan activity	(4,316)									(4,316)
Common stock repurchase program	(12,564)									(12,564)
Common stock warrants repurchased	(23)					(23)
Ending Balance at Sep. 30, 2015	2,401,701			122,710	936	1,124,823	1,287,417			(74,666)	(59,519)
Beginning Balance at Dec. 31, 2015	2,413,960			122,710	937	1,124,325	1,315,948			(71,854)	(78,106)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	149,467						149,467
Other comprehensive income, net of tax	24,953										24,953
Dividends and dividend equivalents declared on common stock $0.48 and $0.43 per share during the 6 months ended June 30, 2016 and 2015, respectively	(66,979)					109	(67,088)
Dividends on Series E preferred stock $800.00 per share for the 6 months ended June 30, 2016 and 2015 and Series A preferred stock $21.25 per share for the 6 months ended June 30, 2015			$ (6,072)						$ (6,072)
Stock-based compensation, net of tax impact	10,689					2,413	245			8,031
Exercise of stock options	2,372					(1,307)				3,679
Common shares acquired related to stock compensation plan activity	(5,392)									(5,392)
Common stock repurchase program	(11,206)									(11,206)
Common stock warrants repurchased	(163)					(163)
Ending Balance at Sep. 30, 2016	$ 2,511,629			$ 122,710	$ 937	$ 1,125,377	$ 1,392,500			$ (76,742)	$ (53,153)

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Dividends on common stock and dividend equivalents declared (in dollars per share)	$ 0.73	$ 0.66
Series A Preferred Stock [Member]
Dividends on preferred stock (in dollars per share)		21.25
Series E Preferred Stock [Member]
Dividends on preferred stock (in dollars per share)	$ 1,200	$ 1,200

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating Activities:
Net income	$ 149,467	$ 152,917
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	43,850	35,500
Deferred tax expense (benefit)	14,425	(7,272)
Depreciation and amortization	27,342	25,991
Amortization of earning assets and funding, premiums/discounts, net	42,855	41,704
Stock-based compensation	8,558	8,283
Gain on sale, net of write-down, on foreclosed and repossessed assets	(744)	(69)
Gain on sale, net of write-down, on premises and equipment	(713)	(249)
Impairment loss on securities recognized in earnings	149	82
Gain on the sale of investment securities, net	(414)	(529)
Increase in cash surrender value of life insurance policies	(11,060)	(9,637)
Mortgage banking activities	(8,850)	(5,519)
Proceeds from sale of loans held for sale	298,840	352,300
Origination of loans held for sale	(320,739)	(351,236)
Derivative contract assets and liabilities	(73,765)	(33,775)
Net decrease (increase) in accrued interest receivable and other assets	48,136	(23,338)
Net decrease in accrued expenses and other liabilities	(30,419)	(2,801)
Net cash provided by operating activities	186,918	182,352
Investing Activities:
Net decrease in interest-bearing deposits	133,969	113,438
Purchases of available for sale securities	(615,174)	(737,184)
Proceeds from maturities and principal payments of available for sale securities	430,099	452,397
Proceeds from sales of available for sale securities	259,283	65,643
Purchases of held-to-maturity securities	(640,218)	(639,699)
Proceeds from maturities and principal payments of held-to-maturity securities	517,513	538,772
Net proceeds of Federal Home Loan Bank stock	3,243	9,010
Net increase in loans	(1,010,423)	(1,345,816)
Proceeds from sale of loans not originated for sale	20,764	33,100
Proceeds from life insurance policies	0	3,912
Proceeds from the sale of foreclosed and repossessed assets	6,900	7,783
Proceeds from the sale of premises and equipment	1,550	650
Purchases of premises and equipment	(31,250)	(26,801)
Acquisition of business, net cash acquired	0	1,396,414
Net cash used for investing activities	(923,744)	(128,381)
Financing Activities:
Net increase in deposits	1,248,710	484,568
Proceeds from Federal Home Loan Bank advances	14,150,000	9,100,000
Repayments of Federal Home Loan Bank advances	(14,226,147)	(9,350,209)
Net decrease in securities sold under agreements to repurchase and other borrowings	(350,695)	(248,738)
Dividends paid to common shareholders	(66,648)	(59,890)
Dividends paid to preferred shareholders	(6,072)	(6,687)
Exercise of stock options	2,372	2,562
Excess tax benefits from stock-based compensation	2,363	2,131
Common shares acquired related to stock compensation plan activity	(5,392)	(4,316)
Common stock repurchase program	(11,206)	(12,564)
Common stock warrants repurchased	(163)	(23)
Net cash provided by (used for) financing activities	737,122	(93,166)
Net increase (decrease) in cash and due from banks	296	(39,195)
Cash and due from banks at beginning of period	199,693	213,914
Cash and due from banks at end of period	199,989	174,719
Supplemental disclosure of cash flow information:
Interest paid	79,054	73,283
Income taxes paid	61,639	79,564
Noncash investing and financing activities:
Transfer of loans from portfolio to loans-held-for-sale	20,547	186
Transfer of loans and leases to foreclosed properties and repossessed assets	4,917	6,582
Deposits assumed in business acquisition	0	1,446,899
Preferred stock conversion	$ 0	$ 28,939

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations Webster Financial Corporation is a bank holding company and financial holding company under the Bank Holding Company Act of 1956, as amended, incorporated under the laws of Delaware in 1986 and headquartered in Waterbury, Connecticut. At September 30, 2016 , Webster Financial Corporation's principal asset is all of the outstanding capital stock of Webster Bank. Webster, through Webster Bank and various non-banking financial services subsidiaries, delivers financial services to individuals, families, and businesses primarily from New York to Massachusetts. 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 or www.wbst.com ). Webster also offers equipment financing, commercial real estate lending, and asset-based lending primarily across the Northeast. HSA Bank, offers and administers health savings accounts, flexible spending accounts, health reimbursement accounts, and commuter benefits on a nationwide basis. Basis of Presentation The accounting and reporting policies of the Company that materially affect its financial statements conform with GAAP. The accompanying unaudited Condensed Consolidated Financial Statements of the Company have been prepared in conformity with the instructions for Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all the information and notes required by GAAP for complete financial statements and should be read in conjunction with the Company's Consolidated Financial Statements, and notes thereto, for the year ended December 31, 2015 , included in the Company's Annual Report on Form 10-K filed with the SEC on February 29, 2016. The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the amounts of assets and liabilities as of the date of the financial statements as well as income and expense during the period. Actual results could differ from those estimates. Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for the full year or any future period. Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications had an immaterial effect on total assets, total liabilities, net cash provided by operating activities, net cash used for investing activities, and net cash provided by financing activities. Correction of Immaterial Error Related to Prior Periods The Company identified an immaterial error relating to the accounting for cash collateral associated with derivative instruments, as previously reported in the Company's March 31, 2016 Form 10-Q quarterly report, filed with the SEC on May 9, 2016. The impact of this previously reported error to the net cash provided by operating activities within the Condensed Consolidated Statements of Cash Flows was a $29.5 million decrease for the nine months ended September 30, 2015. The Company identified an immaterial error relating to the reporting of certain fee accruals and certain expenses within the Company's HSA Bank segment, as previously reported in the Company's June 30, 2016 Form 10-Q quarterly report, filed with the SEC on August 9, 2016. The impact of this previously reported error to net income within the Condensed Consolidated Statements of Income was a $0.8 million decrease for the nine months ended September 30, 2015. Significant Accounting Policy Updates Loans Held For Sale. Effective January 1, 2016, on a loan by loan election, residential mortgage loans that are classified as held for sale are accounted for under either the fair value option method of accounting or the lower of cost or fair value method of accounting with the election being made at the time the asset is first recognized. The Company has elected the fair value option to mitigate accounting mismatches between held for sale derivative commitments and loan valuations. Prior to January 1, 2016, residential mortgage loans that were classified as held for sale were accounted for at the lower of cost or fair value method of accounting and were valued on an individual asset basis. Loans not originated for sale but subsequently transferred to held for sale continue to be valued at the lower of cost or fair value method of accounting and are valued on an individual asset basis. Accounting Standards Adopted during 2016 Effective January 1, 2016, the following new accounting guidance was adopted by the Company: • ASU No. 2015-02, Consolidation (Topic 810) - Amendments to the Consolidation Analysis; • ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs; • ASU No. 2015-07, Fair Value Measurement (Topic 820) - Disclosures for investments in Certain Entities That Calculate Net Asset Value per Share (or its Equivalent) (a consensus of the FASB Emerging Issues Task Force); and • ASU No. 2015-16, Business Combinations (Topic 805) - Simplifying the Accounting for Measurement - Period Adjustments. The adoption of these accounting standards did not have a material impact on the Company's financial statements; however, additional disclosures of VIEs are included in Note 3: Variable Interest Entities . The Company did not identify any additional investments requiring consolidation as a result of ASU No. 2015-02. Accounting Standards Issued but not yet Adopted The following table identifies ASUs applicable to the Company that have been issued by the FASB but are not yet effective: ASU Description Effective Date and Financial Statement Impact ASU No. 2016-16 - Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The update addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The Update addresses the following eight issues: Debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The Company intends to adopt the Update for the first quarter of 2019. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. Current GAAP requires an "incurred loss" methodology for recognizing credit losses that delays recognition until it is probable a loss has been incurred. Both financial institutions and users of their financial statements expressed concern that current GAAP restricts the ability to record credit losses that are expected, but do not yet meet the "probable" threshold. The main objective of this Update is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this Update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. The Change from an "incurred loss" method to an "expected loss" method represents a fundamental shift from existing GAAP, and may result in material changes to the Company's accounting for credit losses on financial instruments. The Company is evaluating the effect that this ASU will have on its financial statements and related disclosures. The ASU will be effective for the Company as of January 1, 2020. ASU No. 2016-09, Compensation - Stock Compensation (Topic 718) - Improvements to Employee Share Based Payment Accounting. The Update impacts the accounting for employee share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. In addition, the amendments in this Update eliminates the guidance in Topic 718 that was indefinitely deferred shortly after the issuance of FASB Statement No. 123 (revised 2004), Share-Based Payment. The Company intends to adopt the Update for the first quarter of 2017 and is in the process of assessing the impact on its financial statements. ASU No. 2016-06, Derivatives and Hedging (Topic 815) - Contingent Put and Call Options in Debt Instruments. The Update clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. The Update requires the assessment of embedded call (put) options solely in accordance with the four-step decision sequence. The Company intends to adopt the Update for the first quarter of 2017. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2016-02, Leases (Topic 842). The Update introduces a lessee model that brings most leases on the balance sheet. The Update also aligns certain of the underlying principles of the new lessor model with those in ASC 606 "Revenue from Contracts with Customers", the FASB’s new revenue recognition standard (e.g., evaluating how collectability should be considered and determining when profit can be recognized). Furthermore, the Update addresses other concerns including the elimination of the required use of bright-line tests for determining lease classification. Lessors are required to provide additional transparency into the exposure to the changes in value of their residual assets and how they manage that exposure. The Company intends to adopt the Update for the first quarter of 2019 and is in the process of assessing the impact on its financial statements. ASU Description Effective Date and Financial Statement Impact ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities. Equity investments not accounted for under the equity method or those that do not result in consolidation of the investee are to be measured at fair value with changes in the fair value recognized through net income. Entities are to present separately in other comprehensive income, the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when an election to measure the liability at fair value in accordance with the fair value option for financial instruments has been made. Also, the requirement to disclose the method(s) and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost on the balance sheet has been eliminated. The Company intends to adopt the Update for the first quarter of 2018 and is in the process of assessing the impact on its financial statements. ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) and ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606) A single comprehensive model has been established for an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled, and will supersede nearly all existing revenue recognition guidance, and clarify and converge revenue recognition principles under GAAP and International Financial Reporting Standards. The five steps to recognizing revenue: (i) identify the contracts with the customer; (ii) identify the separate performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the separate performance obligations; and (v) recognize revenue when each performance obligation is satisfied. The most significant potential impact to banking entities relates to less prescriptive derecognition requirements on the sale of owned real estate properties. An entity may elect either a full retrospective or a modified retrospective application. ASU No. 2015-14 - Revenue from Contracts with Customers (Topic 606), defers the effective date to annual and interim periods beginning after December 15, 2017. The Company intends to adopt the Update for the first quarter of 2018. Adoption is not anticipated to have a material impact on the Company's financial statements.

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities A summary of the amortized cost and fair value of investment securities is presented below: At September 30, 2016 At December 31, 2015 (In thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Available-for-sale: U.S. Treasury Bills $ 985 $ — $ — $ 985 $ 924 $ — $ — $ 924 Agency CMO 457,768 7,453 (1,491 ) 463,730 546,168 5,532 (2,946 ) 548,754 Agency MBS 992,742 11,051 (2,779 ) 1,001,014 1,075,941 6,459 (17,291 ) 1,065,109 Agency CMBS 481,079 3,435 (106 ) 484,408 215,670 639 (959 ) 215,350 CMBS 465,120 4,794 (1,553 ) 468,361 574,686 7,485 (2,905 ) 579,266 CLO 481,555 3,132 (451 ) 484,236 431,837 592 (3,270 ) 429,159 Single issuer trust preferred securities 42,312 63 (4,264 ) 38,111 42,168 — (4,998 ) 37,170 Corporate debt securities 97,149 2,117 — 99,266 104,031 2,290 — 106,321 Equities - financial services — — — — 3,499 — (921 ) 2,578 Securities available-for-sale $ 3,018,710 $ 32,045 $ (10,644 ) $ 3,040,111 $ 2,994,924 $ 22,997 $ (33,290 ) $ 2,984,631 Held-to-maturity: Agency CMO $ 371,700 $ 4,353 $ (890 ) $ 375,163 $ 407,494 $ 3,717 $ (2,058 ) $ 409,153 Agency MBS 2,072,481 48,397 (1,544 ) 2,119,334 2,030,176 38,813 (19,908 ) 2,049,081 Agency CMBS 624,403 14,449 — 638,852 686,086 4,253 (325 ) 690,014 Municipal bonds and notes 610,690 13,658 (1,682 ) 622,666 435,905 12,019 (417 ) 447,507 CMBS 341,019 10,935 (80 ) 351,874 360,018 5,046 (2,704 ) 362,360 Private Label MBS 2,039 15 — 2,054 3,373 46 — 3,419 Securities held-to-maturity $ 4,022,332 $ 91,807 $ (4,196 ) $ 4,109,943 $ 3,923,052 $ 63,894 $ (25,412 ) $ 3,961,534 Other-Than-Temporary Impairment The balance of OTTI, included in the amortized cost columns above, is related to certain CLO positions that were previously considered Covered Funds as defined by Section 619 of the Dodd-Frank Act, commonly known as the Volcker Rule. The Company has taken certain legal measures intended to bring CLO into conformance with the Volcker rule. To the extent that changes occur in interest rates, credit movements, and other factors that impact fair value and expected recovery of amortized cost of its investment securities, the Company may be required to recognize OTTI in earnings, in future periods. The following table presents the changes in OTTI: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Beginning balance $ 3,437 $ 3,178 $ 3,288 $ 3,696 Reduction for securities sold or called (30 ) — (30 ) (518 ) Additions for OTTI not previously recognized in earnings — 82 149 82 Ending balance $ 3,407 $ 3,260 $ 3,407 $ 3,260 Fair Value and Unrealized Losses The following tables provide information on fair value and unrealized losses for the individual securities with an unrealized loss, aggregated by investment security type and length of time that the individual securities have been in a continuous unrealized loss position: At September 30, 2016 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses # of Holdings Fair Value Unrealized Losses Available-for-sale: Agency CMO $ 22,888 $ (337 ) $ 71,140 $ (1,154 ) 7 $ 94,028 $ (1,491 ) Agency MBS 26,917 (48 ) 274,866 (2,731 ) 48 301,783 (2,779 ) Agency CMBS 78,572 (106 ) — — 6 78,572 (106 ) CMBS 34,741 (382 ) 126,244 (1,171 ) 24 160,985 (1,553 ) CLO 9,780 (28 ) 69,708 (423 ) 4 79,488 (451 ) Single issuer trust preferred securities — — 33,812 (4,264 ) 7 33,812 (4,264 ) Equities - financial services — — — — — — — Total available-for-sale in an unrealized loss position $ 172,898 $ (901 ) $ 575,770 $ (9,743 ) 96 $ 748,668 $ (10,644 ) Held-to-maturity: Agency CMO $ 77,555 $ (661 ) $ 18,814 $ (229 ) 8 $ 96,369 $ (890 ) Agency MBS 86,133 (88 ) 297,018 (1,456 ) 30 383,151 (1,544 ) Agency CMBS — — — — — — — Municipal bonds and notes 106,453 (1,663 ) 3,359 (19 ) 45 109,812 (1,682 ) CMBS 27,773 (80 ) — — 5 27,773 (80 ) Total held-to-maturity in an unrealized loss position $ 297,914 $ (2,492 ) $ 319,191 $ (1,704 ) 88 $ 617,105 $ (4,196 ) At December 31, 2015 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses # of Holdings Fair Value Unrealized Losses Available-for-sale: Agency CMO $ 195,369 $ (2,195 ) $ 26,039 $ (751 ) 14 $ 221,408 $ (2,946 ) Agency MBS 481,839 (6,386 ) 351,911 (10,905 ) 84 833,750 (17,291 ) Agency CMBS 124,241 (959 ) — — 7 124,241 (959 ) CMBS 276,330 (2,879 ) 19,382 (26 ) 29 295,712 (2,905 ) CLO 211,515 (2,709 ) 15,708 (561 ) 13 227,223 (3,270 ) Single issuer trust preferred securities 4,087 (128 ) 33,083 (4,870 ) 8 37,170 (4,998 ) Equities - financial services 2,578 (921 ) — — 1 2,578 (921 ) Total available-for-sale in an unrealized loss position $ 1,295,959 $ (16,177 ) $ 446,123 $ (17,113 ) 156 $ 1,742,082 $ (33,290 ) Held-to-maturity: Agency CMO $ 143,364 $ (1,304 ) $ 27,928 $ (754 ) 13 $ 171,292 $ (2,058 ) Agency MBS 551,918 (7,089 ) 470,828 (12,819 ) 87 1,022,746 (19,908 ) Agency CMBS 110,864 (325 ) — — 7 110,864 (325 ) Municipal bonds and notes 29,034 (130 ) 13,829 (287 ) 27 42,863 (417 ) CMBS 142,382 (1,983 ) 30,129 (721 ) 18 172,511 (2,704 ) Total held-to-maturity in an unrealized loss position $ 977,562 $ (10,831 ) $ 542,714 $ (14,581 ) 152 $ 1,520,276 $ (25,412 ) Impairment Analysis The following impairment analysis by investment security type, summarizes the basis for evaluating if investment securities within the Company’s available-for-sale and held-to-maturity portfolios have been impacted by OTTI. Unless otherwise noted for an investment security type, management does not intend to sell these investments and has determined, based upon available evidence, that it is more likely than not that the Company will not be required to sell these securities before the recovery of their amortized cost. As such, based on the following impairment analysis, the Company does not consider these securities, in unrealized loss positions, to exhibit OTTI at September 30, 2016 . Available-for-Sale Securities Agency CMO. There were unrealized losses of $1.5 million on the Company’s investment in Agency CMO at September 30, 2016 compared to $2.9 million at December 31, 2015 . Unrealized losses decreased due to lower market rates which resulted in higher security prices at September 30, 2016 compared to December 31, 2015 . These investments are issued by a government agency or a government-sponsored agency and, therefore, are backed by certain government guarantees, either direct or indirect. The contractual cash flows for these investments are performing as expected, and there has been no change in the underlying credit quality. Agency MBS. There were unrealized losses of $2.8 million on the Company’s investment in Agency MBS at September 30, 2016 compared to $17.3 million at December 31, 2015 . Unrealized losses decreased due to lower market rates which resulted in higher security prices at September 30, 2016 compared to December 31, 2015 . These investments are issued by a government agency or a government-sponsored agency and, therefore, are backed by certain government guarantees, either direct or indirect. The contractual cash flows for these investments are performing as expected, and there has been no change in the underlying credit quality. Agency CMBS. There were unrealized losses of $106 thousand on the Company's investment in commercial mortgage-backed securities issued by government agencies at September 30, 2016 , compared to $1.0 million at December 31, 2015 . Unrealized losses decreased due to lower market rates which resulted in higher security prices since December 31, 2015 . CMBS. There were unrealized losses of $1.6 million on the Company’s investment in CMBS at September 30, 2016 compared to $2.9 million at December 31, 2015 . The portfolio of mainly floating rate CMBS experienced decreased market spreads which resulted in higher market prices and smaller unrealized losses at September 30, 2016 compared to December 31, 2015 . Internal and external metrics are considered when evaluating potential OTTI. Internal stress tests are performed on individual bonds to monitor potential losses under stress scenarios. Contractual cash flows for these investments are performing as expected. CLO. There were unrealized losses of $0.5 million on the Company's investment in CLO at September 30, 2016 compared to $3.3 million at December 31, 2015 . Unrealized losses decreased due to lower market spreads for the CLO portfolio at September 30, 2016 compared to December 31, 2015 . Contractual cash flows for these investments are performing as expected. The Company has taken certain legal measures intended to bring CLO into conformance with the Volcker rule. Single Issuer Trust Preferred Securities. There were unrealized losses of $4.3 million on the Company's investment in single issuer trust preferred securities at September 30, 2016 compared to $5.0 million at December 31, 2015 . Unrealized losses decreased due to lower market spreads for this asset class, which resulted in higher security prices compared to December 31, 2015 . The single issuer trust preferred securities portfolio consists of four floating rate investments issued by three large capitalization money center financial institutions, which continue to service the debt. The Company performs periodic credit reviews of the issuer to assess the likelihood for ultimate recovery of amortized cost. Held-to-Maturity Securities Agency CMO. There were unrealized losses of $0.9 million on the Company’s investment in Agency CMO at September 30, 2016 compared to $2.1 million at December 31, 2015 . Unrealized losses decreased due to lower market rates which resulted in higher security prices at September 30, 2016 compared to December 31, 2015 . These investments are issued by a government agency or a government-sponsored agency and, therefore, are backed by certain government guarantees, either direct or indirect. The contractual cash flows for these investments are performing as expected, and there has been no change in the underlying credit quality. Agency MBS. There were unrealized losses of $1.5 million on the Company’s investment in Agency MBS at September 30, 2016 compared to $19.9 million at December 31, 2015 . Unrealized losses decreased due to lower market rates which resulted in higher security prices at September 30, 2016 compared to December 31, 2015 . These investments are issued by a government agency or a government-sponsored agency and, therefore, are backed by certain government guarantees, either direct or indirect. There has been no change in the underlying credit quality, and the contractual cash flows are performing as expected. Municipal Bonds and Notes. There were unrealized losses of $1.7 million on the Company’s investment in municipal bonds and notes at September 30, 2016 , compared to $417 thousand at December 31, 2015 . Unrealized losses increased due to higher market rates primarily on current year to date purchases. The Company performs periodic credit reviews of the issuers and the securities are currently performing as expected. CMBS. There were unrealized losses of $80 thousand on the Company’s investment in CMBS at September 30, 2016 compared to $2.7 million at December 31, 2015 . Unrealized losses decreased due to lower market rates on mainly seasoned fixed rate conduit transactions, which resulted in higher security prices at September 30, 2016 compared to December 31, 2015 . Internal and external metrics are considered when evaluating potential OTTI. Internal stress tests are performed on individual bonds to monitor potential losses under stress scenarios. The contractual cash flows for these investments are performing as expected. Sales of Available-for Sale Securities The following table provides information on sales of available-for-sale securities: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Proceeds from sales $ — $ 2,500 $ 259,273 $ 37,465 Gross realized gains on sales $ — $ — $ 2,891 $ 529 Less: Gross realized losses on sales — — 2,477 — Gain on sale of investment securities, net $ — $ — $ 414 $ 529 Contractual Maturities The amortized cost and fair value of debt securities by contractual maturity are set forth below: At September 30, 2016 Available-for-Sale Held-to-Maturity (In thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 60,737 $ 61,771 $ 7,988 $ 8,034 Due after one year through five years 37,397 38,479 19,980 20,376 Due after five through ten years 572,461 575,465 36,758 37,932 Due after ten years 2,348,115 2,364,396 3,957,606 4,043,601 Total debt securities $ 3,018,710 $ 3,040,111 $ 4,022,332 $ 4,109,943 For the maturity schedule above, mortgage-backed securities and CLO, which are not due at a single maturity date, have been categorized based on the maturity date of the underlying collateral. Actual principal cash flows may differ from this maturity date presentation as borrowers have the right to prepay obligations with or without prepayment penalties. At September 30, 2016 , the Company had a carrying value of $1.2 billion in callable securities in its CMBS, CLO, and municipal bond portfolios. The Company considers prepayment risk in the evaluation of its interest rate risk profile. These maturities do not reflect actual durations which are impacted by prepayments. Securities with a carrying value totaling $2.7 billion at September 30, 2016 and $2.6 billion at December 31, 2015 were pledged to secure public funds, trust deposits, repurchase agreements, and for other purposes, as required or permitted by law.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities A VIE is an entity that has either a total equity investment that is insufficient to finance its activities without additional subordinated financial support or whose equity investors lack the ability to control the entity’s activities or lack the ability to receive expected benefits or absorb obligations in a manner that’s consistent with their investment in the entity. The Company evaluates each VIE to understand the purpose and design of the entity, and its involvement in the ongoing activities of the VIE. The Company will consolidate the VIE if it has: • the power to direct the activities of the VIE that most significantly affect the VIE's economic performance; and • an obligation to absorb losses of the VIE, or the right to receive benefits from the VIE, that could potentially be significant to the VIE. Consolidated Rabbi Trust. The Company has established a Rabbi Trust related to a deferred compensation plan offered to certain employees. Investments held in the Rabbi Trust primarily consist of mutual funds that invest in equity and fixed income securities. The Company is considered the primary beneficiary of the Rabbi Trust as it has the power to direct the underlying investments made by the trust as well as make funding decisions related to the trust and it has the obligation to absorb losses of the VIE that could potentially be significant to the VIE. The Company consolidates the invested assets of the trust along with the total deferred compensation obligations and includes them in accrued interest receivable and other assets and accrued expenses and other liabilities, respectively, in the accompanying Condensed Consolidated Balance Sheets. Earnings in the Rabbi Trust, including appreciation or depreciation, are reflected as other non-interest income, and changes in the corresponding liability are reflected as compensation and benefits, in the accompanying Condensed Consolidated Statements of Income. The cost and fair value associated with the assets and liabilities of this trust are not significant. Refer to Note 13: Fair Value Measurements for additional information. Non-Consolidated Securitized Investments. The Company, through normal investment activities, makes passive investments in securities issued by a VIE for which the Company is not the manager. These securities consist of Agency CMO, Agency MBS, Agency CMBS, CLO and single issuer trust preferred securities. The Company has not provided financial or other support with respect to these investments other than its original investment. For these investments, the Company determined it is not the primary beneficiary due to the relative size of the Company’s investment in comparison to the principal amount of the structured securities issued by the VIE, the level of credit subordination which reduces the Company’s obligation to absorb losses or right to receive benefits and the Company’s inability to direct the activities that most significantly impact the economic performance of the VIE. The Company’s maximum exposure to loss on these investments is limited to the amount of the Company’s investment. Refer to Note 2: Investment Securities for additional information. Tax Credit - Finance Investments. The Company makes equity investments in entities that finance affordable housing and other community development projects and provide a return primarily through the realization of tax benefits. In most instances the investments require the funding of capital commitments in the future. While the Company's investment in an entity may exceed 50% of its outstanding equity interests, the entity is not consolidated as Webster is not involved in its management. For these investments, the Company determined it is not the primary beneficiary due to its inability to direct the activities that most significantly impact the economic performance of the VIE. The Company's tax credit-finance investments had an aggregate carrying value of $23.5 million and $25.9 million at September 30, 2016 and December 31, 2015 , respectively. At September 30, 2016 and December 31, 2015 , unfunded obligations, which are recognized as a component of accrued expenses and other liabilities, were $14.4 million and $16.5 million , respectively. Webster Statutory Trust. The Company owns all of the outstanding common stock of Webster Statutory Trust, which is a financial vehicle that has issued, and may issue in the future, 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 interest in the trust is included in accrued interest receivable and other assets in the accompanying Condensed Consolidated Balance Sheets. Interest expense on the junior subordinated debentures is reported as interest expense on long-term debt in the accompanying Condensed Consolidated Statements of Income. Other Investments. The Company invests in various alternative investments in which it holds a variable interest. Alternative investments are non-public entities which cannot be redeemed since the Company’s investment is distributed as the underlying investments are liquidated. For these investments, the Company has determined it is not the primary beneficiary due to its inability to direct the activities that most significantly impacts the economic performance of the VIE. The Company's other investments in VIEs had an aggregate carrying value of $12.5 million and $12.1 million at September 30, 2016 and December 31, 2015 , respectively, and the total exposure of the Company's other investments in VIEs, including unfunded commitments, were $20.6 million and $19.0 million , respectively. For a further description of the Company's accounting policies regarding the consolidation of a VIE, refer to Note 1 to the Consolidated Financial Statements for the year ended December 31, 2015 included in its 2015 Form 10-K.

Loans and Leases

Loans and Leases	9 Months Ended
	Sep. 30, 2016
Loans and Leases Receivable Disclosure [Abstract]
Loans and Leases	Loans and Leases The following table summarizes loans and leases: (In thousands) At September 30, At December 31, 2015 Residential $ 4,234,047 $ 4,061,001 Consumer 2,707,343 2,702,560 Commercial 4,779,802 4,315,999 Commercial Real Estate 4,280,513 3,991,649 Equipment Financing 621,696 600,526 Loans and leases (1) (2) $ 16,623,401 $ 15,671,735 (1) Loans and leases include net deferred fees and net premiums/discounts of $19.7 million and $18.0 million at September 30, 2016 and December 31, 2015 , respectively. (2) At September 30, 2016 , the Company had pledged $6.4 billion of eligible residential and consumer loans as collateral to support borrowing capacity at the FHLB Boston and the FRB of Boston. Loans and Leases Portfolio Aging The following tables summarize the aging of loans and leases: At September 30, 2016 (In thousands) 30-59 Days Past Due and Accruing 60-89 Days 90 or More Days Past Due and Accruing Non-accrual Total Past Due and Non-accrual Current Total Loans Residential $ 7,547 $ 3,547 $ — $ 49,197 $ 60,291 $ 4,173,756 $ 4,234,047 Consumer: Home equity 7,627 4,746 — 35,597 47,970 2,371,700 2,419,670 Other consumer 1,757 1,354 — 1,571 4,682 282,991 287,673 Commercial: Commercial non-mortgage 1,949 576 23 27,397 29,945 3,946,986 3,976,931 Asset-based — — — — — 802,871 802,871 Commercial real estate: Commercial real estate 1,082 148 5,444 10,957 17,631 3,933,588 3,951,219 Commercial construction — — — 3,438 3,438 325,856 329,294 Equipment financing 3,164 313 — 202 3,679 618,017 621,696 Total $ 23,126 $ 10,684 $ 5,467 $ 128,359 $ 167,636 $ 16,455,765 $ 16,623,401 At December 31, 2015 (In thousands) 30-59 Days 60-89 Days Past Due and Accruing 90 or More Days Past Due Non-accrual Total Past Due and Non-accrual Current Total Loans Residential $ 10,365 $ 4,703 $ 2,029 $ 54,201 $ 71,298 $ 3,989,703 $ 4,061,001 Consumer: Home equity 9,061 4,242 — 37,337 50,640 2,402,758 2,453,398 Other consumer 1,390 615 — 560 2,565 246,597 249,162 Commercial: Commercial non-mortgage 768 3,288 22 27,037 31,115 3,531,669 3,562,784 Asset-based — — — — — 753,215 753,215 Commercial real estate: Commercial real estate 1,624 625 — 16,767 19,016 3,673,408 3,692,424 Commercial construction — — — 3,461 3,461 295,764 299,225 Equipment financing 543 59 — 706 1,308 599,218 600,526 Total $ 23,751 $ 13,532 $ 2,051 $ 140,069 $ 179,403 $ 15,492,332 $ 15,671,735 Interest on non-accrual loans and leases that would have been recorded as additional interest income for the three and nine months ended September 30, 2016 and 2015 , had the loans and leases been current in accordance with their original terms, totaled $3.7 million , $8.4 million , $2.6 million and $6.3 million , respectively. Allowance for Loan and Lease Losses The following tables summarize the ALLL: At or for the three months ended September 30, 2016 Residential Consumer Commercial Commercial Real Estate Equipment Financing Total ALLL: Balance, beginning of period $ 24,413 $ 42,956 $ 73,822 $ 33,622 $ 5,615 $ 180,428 Provision (benefit) charged to expense 1,076 4,985 4,351 2,953 885 14,250 Charge-offs (1,304 ) (5,259 ) (2,561 ) — (300 ) (9,424 ) Recoveries 554 1,313 370 194 240 2,671 Balance, end of period $ 24,739 $ 43,995 $ 75,982 $ 36,769 $ 6,440 $ 187,925 At or for the three months ended September 30, 2015 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total ALLL: Balance, beginning of period $ 24,463 $ 40,807 $ 66,241 $ 30,768 $ 5,581 $ 167,860 Provision (benefit) charged to expense 1,150 6,864 3,089 1,961 (64 ) 13,000 Charge-offs (1,588 ) (4,831 ) (2,204 ) (1,346 ) — (9,969 ) Recoveries 281 1,004 715 69 32 2,101 Balance, end of period $ 24,306 $ 43,844 $ 67,841 $ 31,452 $ 5,549 $ 172,992 At or for the nine months ended September 30, 2016 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total ALLL: Balance, beginning of period $ 25,876 $ 42,052 $ 66,686 $ 34,889 $ 5,487 $ 174,990 Provision (benefit) charged to expense 991 12,458 25,447 3,921 1,033 43,850 Charge-offs (3,536 ) (14,236 ) (17,294 ) (2,521 ) (521 ) (38,108 ) Recoveries 1,408 3,721 1,143 480 441 7,193 Balance, end of period $ 24,739 $ 43,995 $ 75,982 $ 36,769 $ 6,440 $ 187,925 Individually evaluated for impairment $ 9,443 $ 3,005 $ 6,579 $ 467 $ 9 $ 19,503 Collectively evaluated for impairment $ 15,296 $ 40,990 $ 69,403 $ 36,302 $ 6,431 $ 168,422 Loan and lease balances: Individually evaluated for impairment $ 122,020 $ 46,208 $ 58,197 $ 24,423 $ 6,863 $ 257,711 Collectively evaluated for impairment 4,112,027 2,661,135 4,721,605 4,256,090 614,833 16,365,690 Loans and leases $ 4,234,047 $ 2,707,343 $ 4,779,802 $ 4,280,513 $ 621,696 $ 16,623,401 At or for the nine months ended September 30, 2015 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total ALLL: Balance, beginning of period $ 25,452 $ 43,518 $ 52,114 $ 32,102 $ 6,078 $ 159,264 Provision (benefit) charged to expense 3,100 10,091 18,468 4,617 (776 ) 35,500 Charge-offs (5,004 ) (12,980 ) (5,000 ) (5,590 ) (30 ) (28,604 ) Recoveries 758 3,215 2,259 323 277 6,832 Balance, end of period $ 24,306 $ 43,844 $ 67,841 $ 31,452 $ 5,549 $ 172,992 Individually evaluated for impairment $ 10,773 $ 3,540 $ 11,478 $ 4,527 $ 5 $ 30,323 Collectively evaluated for impairment $ 13,533 $ 40,304 $ 56,363 $ 26,925 $ 5,544 $ 142,669 Loan and lease balances: Individually evaluated for impairment $ 138,227 $ 46,455 $ 54,522 $ 41,598 $ 102 $ 280,904 Collectively evaluated for impairment 3,877,612 2,604,247 4,085,457 3,815,557 552,748 14,935,621 Loans and leases $ 4,015,839 $ 2,650,702 $ 4,139,979 $ 3,857,155 $ 552,850 $ 15,216,525 Impaired Loans and Leases The following tables summarize impaired loans and leases: At September 30, 2016 (In thousands) Unpaid Principal Balance Total Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Residential $ 134,026 $ 122,020 $ 21,404 $ 100,616 $ 9,443 Consumer 52,516 46,208 23,612 22,596 3,005 Commercial 64,537 58,197 25,720 32,477 6,579 Commercial real estate: Commercial real estate 20,823 20,044 9,156 10,888 467 Commercial construction 4,911 4,379 4,379 — — Equipment financing 6,901 6,863 6,638 225 9 Total $ 283,714 $ 257,711 $ 90,909 $ 166,802 $ 19,503 At December 31, 2015 (In thousands) Unpaid Principal Balance Total Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Residential $ 148,144 $ 134,448 $ 23,024 $ 111,424 $ 10,364 Consumer 56,680 48,425 25,130 23,295 3,477 Commercial 67,116 56,581 31,600 24,981 5,197 Commercial real estate: Commercial real estate 36,980 33,333 9,204 24,129 3,160 Commercial construction 7,010 5,962 5,939 23 3 Equipment financing 612 422 328 94 3 Total $ 316,542 $ 279,171 $ 95,225 $ 183,946 $ 22,204 The following table summarizes the average recorded investment and interest income recognized for impaired loans and leases: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 (In thousands) Average Recorded Investment Accrued Interest Income Cash Basis Interest Income Average Accrued Cash Basis Interest Income Average Recorded Investment Accrued Cash Basis Interest Income Average Recorded Investment Accrued Cash Basis Interest Income Residential $ 124,993 $ 1,070 $ 304 $ 138,519 $ 1,114 $ 290 $ 128,234 $ 3,309 $ 918 $ 140,105 $ 3,322 $ 847 Consumer 46,892 336 238 47,787 371 271 47,317 1,029 754 48,352 1,094 827 Commercial 58,874 352 — 54,667 262 — 57,389 1,299 — 45,349 936 — Commercial real estate: Commercial real estate 23,930 77 — 44,222 137 — 26,689 374 — 65,640 1,024 — Commercial construction 4,386 12 — 6,059 33 — 5,171 81 — 6,068 99 — Equipment financing 3,642 107 — 111 2 — 3,642 109 — 367 15 — Total $ 262,717 $ 1,954 $ 542 $ 291,365 $ 1,919 $ 561 $ 268,442 $ 6,201 $ 1,672 $ 305,881 $ 6,490 $ 1,674 Credit Quality Indicators. To measure credit risk for the commercial, commercial real estate, and equipment financing portfolios, the Company employs a dual grade credit risk grading system for estimating the probability of borrower default and the loss given default. The credit risk grade system assigns a rating to each borrower and to the facility, which together form a CCRP. The credit risk grade system categorizes borrowers by common financial characteristics that measure the credit strength of borrowers and facilities by common structural characteristics. The CCRP has 10 grades, with each grade corresponding to a progressively greater risk of default. Grades 1 through 6 are considered pass ratings, and 7 through 10 are considered criticized, as defined by the regulatory agencies. Risk ratings, assigned to differentiate risk within the portfolio, are reviewed on an ongoing basis and revised to reflect changes in the borrowers’ current financial positions and outlooks, risk profiles, and the related collateral and structural positions. Loan officers review updated financial information on at least an annual basis for all pass rated loans to assess the accuracy of the risk grade. Criticized loans undergo more frequent reviews and enhanced monitoring. A "Special Mention" (7) credit has the potential weakness that, if left uncorrected, may result in deterioration of the repayment prospects for the asset. "Substandard" (8) assets have a well defined weakness that jeopardizes the full repayment of the debt. An asset rated "Doubtful" (9) has all of the same weaknesses as a substandard credit with the added characteristic that the weakness makes collection or liquidation in full, given current facts, conditions, and values, improbable. Assets classified as "Loss" (10) in accordance with regulatory guidelines are considered uncollectible and charged off. The following table summarizes commercial, commercial real estate and equipment financing loans and leases segregated by risk rating exposure: Commercial Commercial Real Estate Equipment Financing (In thousands) At September 30, At December 31, At September 30, At December 31, At September 30, At December 31, (1) - (6) Pass $ 4,474,603 $ 4,023,255 $ 4,152,199 $ 3,857,019 $ 598,526 $ 586,445 (7) Special Mention 93,767 70,904 36,588 55,030 25 1,628 (8) Substandard 207,059 220,389 91,726 79,289 23,145 12,453 (9) Doubtful 4,373 1,451 — 311 — — Total $ 4,779,802 $ 4,315,999 $ 4,280,513 $ 3,991,649 $ 621,696 $ 600,526 For residential and consumer loans, the Company considers factors such as past due status, updated FICO scores, employment status, collateral, geography, loans discharged in bankruptcy, and the status of first lien position loans on second lien position loans as credit quality indicators. On an ongoing basis for portfolio monitoring purposes, the Company estimates the current value of property secured as collateral for both home equity and residential first mortgage lending products. The estimate is based on home price indices compiled by the S&P/Case-Shiller Home Price Indices. The trend data is applied to the loan portfolios taking into account the age of the most recent valuation and geographic area. Troubled Debt Restructurings The following table summarizes information for TDRs: (Dollars in thousands) At September 30, 2016 At December 31, 2015 Accrual status $ 161,853 $ 171,784 Non-accrual status 74,147 100,906 Total recorded investment of TDRs (1) $ 236,000 $ 272,690 Accruing TDRs performing under modified terms more than one year 54.1 % 55.0 % Specific reserves for TDRs included in the balance of ALLL $ 16,302 $ 21,405 Additional funds committed to borrowers in TDR status 1,316 1,133 (1) Total recorded investment of TDRs excludes $0.8 million and $1.1 million of accrued interest receivable at September 30, 2016 and December 31, 2015 , respectively. In the three and nine months ended September 30, 2016 and 2015 , Webster charged off $3.0 million , $17.9 million , $1.7 million and $7.6 million , respectively, for the portion of TDRs deemed to be uncollectible. A TDR may be modified by means of extended maturity, below market adjusted interest rates, a combination of rate and maturity, or other means, including covenant modifications, forbearance, loans discharged under Chapter 7 bankruptcy, or other concessions. The following table provides information on the type of concession for loans and leases modified as TDRs: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Number of Post- (1) Number of Post- (1) Number of Post- (1) Number of Post- (1) (Dollars in thousands) Residential: Extended Maturity 4 $ 967 4 $ 998 11 $ 1,969 19 $ 3,301 Adjusted Interest Rate 1 292 1 160 2 528 2 464 Maturity/Rate Combined 3 290 4 1,006 10 1,185 18 3,138 Other (2) 3 299 9 1,594 18 3,190 23 3,387 Consumer: Extended Maturity 2 89 4 296 9 381 9 935 Adjusted Interest Rate — — — — — — — — Maturity/Rate Combined 3 264 — — 11 923 8 444 Other (2) 8 270 20 1,357 37 1,447 50 3,087 Commercial: Extended Maturity 2 213 — — 11 14,862 3 256 Adjusted Interest Rate — — — — — 1 24 Maturity/Rate Combined — — 1 74 2 648 5 371 Other (2) 4 1,265 5 1,772 11 1,639 9 8,062 Commercial real estate: Extended Maturity 1 109 1 315 1 109 1 315 Maturity/Rate Combined 1 291 — — 2 335 1 43 Other (2) — — 1 405 1 509 1 405 Equipment Financing Extended Maturity 6 6,638 — — 7 6,642 — — Total TDRs 38 $ 10,987 50 $ 7,977 133 $ 34,367 150 $ 24,232 (1) Post-modification balances approximate pre-modification balances. The aggregate amount of charge-offs as a result of the restructurings was not significant. (2) Other includes covenant modifications, forbearance, loans discharged under Chapter 7 bankruptcy, or other concessions. The following table provides information on loans and leases modified as TDRs within the previous 12 months and for which there was a payment default during the periods presented: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Residential — $ — — $ — — $ — — $ — Consumer — — 1 3 — — 2 326 Commercial — — 1 9 — — 1 9 Commercial real estate — — — — — — — — Total — $ — 2 $ 12 — $ — 3 $ 335 The recorded investment of TDRs in commercial, commercial real estate, and equipment financing segregated by risk rating exposure is as follows: (In thousands) At September 30, 2016 At December 31, 2015 (1) - (6) Pass $ 11,510 $ 12,970 (7) Special Mention 7 2,999 (8) Substandard 52,658 72,132 (9) Doubtful 3,597 1,717 Total $ 67,772 $ 89,818

Transfers of Financial Assets

Transfers of Financial Assets	9 Months Ended
	Sep. 30, 2016
Transfers and Servicing [Abstract]
Transfers of Financial Assets	Transfers of Financial Assets The Company sells financial assets in the normal course of business, primarily residential mortgage loans sold to government-sponsored enterprises through established programs and securitizations. The gain or loss on residential mortgage loans sold and the fair value adjustment to loans held-for-sale are included as mortgage banking activities in the accompanying Condensed Consolidated Statements of Income. The Company may be required to repurchase a loan in the event of certain breaches of the representations and warranties, or in the event of default of the borrower within 90 days of sale, as provided for in the sale agreements. A reserve for loan repurchases provides for estimated losses pertaining to the potential repurchase of loans associated with the Company’s mortgage banking activities. The reserve reflects management’s evaluation of the identity of the counterparty, the vintage of the loans sold, the amount of open repurchase requests, specific loss estimates for each open request, the current level of loan losses in similar vintages held in the residential loan portfolio, and estimated recoveries on the underlying collateral. The reserve also reflects management’s expectation of losses from repurchase requests for which the Company has not yet been notified, as the performance of loans sold and the quality of the servicing provided by the acquirer also may impact the reserve. The provision recorded at the time of the loan sale is netted from the gain or loss recorded in mortgage banking activities, while any incremental provision, post loan sale, is recorded in other non-interest expense in the accompanying Condensed Consolidated Statements of Income. The following table provides a summary of activity in the reserve for loan repurchases: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Beginning balance $ 992 $ 1,120 $ 1,192 $ 1,059 Provision (benefit) charged to expense 37 43 (64 ) 104 Repurchased loans and settlements charged off — — (99 ) — Ending balance $ 1,029 $ 1,163 $ 1,029 $ 1,163 The following table provides information for mortgage banking activities: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Residential mortgage loans held for sale: Proceeds from sale $ 128,268 $ 143,801 $ 298,840 $ 352,300 Net gain on sale 3,324 1,441 6,749 5,519 Fair value option adjustment (48 ) — 2,101 — Loans sold with servicing rights retained 115,822 132,920 273,827 327,030 The Company has retained servicing rights on residential mortgage loans totaling $2.5 billion at both September 30, 2016 and December 31, 2015 . Loan servicing fees, net of mortgage servicing rights amortization, were $0.3 million for both the three months ended September 30, 2016 and 2015 , and $0.9 million and $1.1 million for the nine months ended September 30, 2016 and 2015 , respectively, and are included as a component of loan related fees in the accompanying Condensed Consolidated Statements of Income. See Note 13: Fair Value Measurements for a further discussion on the fair value of loans held for sale and mortgage servicing assets. Additionally, loans not originated for sale were sold at carrying value, for cash proceeds of $20.8 million for certain commercial loans and $33.1 million for certain consumer loans for the nine months ended September 30, 2016 and 2015 , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets There was no change in the carrying amounts for goodwill since December 31, 2015. See Note 7 - Goodwill and Other Intangible Assets in Notes to Consolidated Financial Statements contained in the Company's Annual Report on Form 10-K for the year ended December 31, 2015 , for information related to goodwill allocated by reportable segment. The gross carrying amount and accumulated amortization of CDI and customer relationships included in reportable segments are as follows: At September 30, 2016 At December 31, 2015 (In thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Community Banking CDI $ 49,420 $ (49,420 ) $ — $ 49,420 $ (48,277 ) $ 1,143 HSA Bank: CDI 22,000 (5,484 ) 16,516 22,000 (3,269 ) 18,731 Customer relationships 21,000 (2,760 ) 18,240 21,000 (1,548 ) 19,452 Total HSA Bank 43,000 (8,244 ) 34,756 43,000 (4,817 ) 38,183 Total other intangible assets $ 92,420 $ (57,664 ) $ 34,756 $ 92,420 $ (53,094 ) $ 39,326 As of September 30, 2016 , the remaining estimated aggregate future amortization expense for intangible assets is as follows: (In thousands) Remainder of 2016 $ 1,082 2017 4,062 2018 3,847 2019 3,847 2020 3,847 Thereafter 18,071

Deposits

Deposits	9 Months Ended
	Sep. 30, 2016
Banking and Thrift [Abstract]
Deposits	Deposits A summary of deposits by type follows: (In thousands) At September 30, At December 31, Non-interest-bearing: Demand $ 3,993,750 $ 3,713,063 Interest-bearing: Checking 2,429,222 2,369,971 Health savings accounts 4,187,823 3,802,313 Money market 2,342,236 1,933,460 Savings 4,226,934 4,047,817 Time deposits 2,020,943 2,086,154 Total interest-bearing 15,207,158 14,239,715 Total deposits $ 19,200,908 $ 17,952,778 Time deposits and interest-bearing checking, included in above balances, obtained through brokers $ 852,014 $ 910,304 Time deposits, included in above balance, that meet or exceed the FDIC limit 481,884 542,206 Deposit overdrafts reclassified as loan balances 1,936 1,356 The scheduled maturities of time deposits are as follows: (In thousands) At September 30, Remainder of 2016 $ 267,114 2017 670,946 2018 342,507 2019 473,697 2020 180,741 Thereafter 85,938 Total time deposits $ 2,020,943

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Borrowings	Borrowings Total borrowings of $3.6 billion at September 30, 2016 and $4.0 billion at December 31, 2015 are described in detail below. The following table summarizes securities sold under agreements to repurchase and other borrowings: (In thousands) At September 30, At December 31, Securities sold under agreements to repurchase: Original maturity of one year or less $ 353,705 $ 334,400 Original maturity of greater than one year, non-callable 400,000 500,000 Total securities sold under agreements to repurchase 753,705 834,400 Fed funds purchased 47,000 317,000 Securities sold under agreements to repurchase and other borrowings $ 800,705 $ 1,151,400 Repurchase agreements are used as a source of borrowed funds and are collateralized by U.S. Government agency mortgage-backed securities. Repurchase agreement counterparties are limited to primary dealers in government securities and commercial/municipal customers through Webster’s Treasury Unit. Dealer counterparties have the right to pledge, transfer, or hypothecate purchased securities during the term of the transaction. The Company has right of offset with respect to all repurchase agreement assets and liabilities. Total securities sold under agreements to repurchase represents the gross amount for these transactions, as only liabilities are outstanding for the periods presented. The following table provides information for FHLB advances: At September 30, 2016 At December 31, 2015 (Dollars in thousands) Amount Weighted- Average Contractual Coupon Rate Amount Weighted- Average Contractual Coupon Rate Maturing within 1 year $ 1,875,000 0.50 % $ 2,025,934 0.55 % After 1 but within 2 years 100,500 1.49 500 5.66 After 2 but within 3 years 133,731 1.34 200,000 1.36 After 3 but within 4 years 244,295 1.70 103,026 1.54 After 4 but within 5 years 75,000 1.51 175,000 1.77 After 5 years 159,442 1.82 159,655 1.60 2,587,968 0.81 % 2,664,115 0.79 % Premiums on advances 15 24 Federal Home Loan Bank advances $ 2,587,983 $ 2,664,139 Aggregate carrying value of assets pledged as collateral $ 5,919,426 $ 5,719,746 Remaining borrowing capacity 1,386,310 1,203,057 Webster Bank is in compliance with FHLB collateral requirements for the periods presented. Eligible collateral, primarily certain residential and commercial loans, has been pledged to secure FHLB advances. The following table summarizes long-term debt: (Dollars in thousands) At September 30, At December 31, 4.375% Senior fixed-rate notes due February 15, 2024 $ 150,000 $ 150,000 Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (1) 77,320 77,320 Total notes and subordinated debt 227,320 227,320 Discount on senior fixed-rate notes (875 ) (964 ) Debt issuance cost on senior fixed-rate notes (2) (995 ) (1,096 ) Long-term debt $ 225,450 $ 225,260 (1) The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95% , was 3.81% at September 30, 2016 and 3.48% at December 31, 2015 . (2) In accordance with the adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, debt issuance cost is accounted for as a reduction to long-term debt. Previously debt issuance cost was included in accrued interest receivable and other assets within the accompanying Condensed Consolidated Balance Sheets.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss, Net of Tax	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Accumulated Other Comprehensive Loss, Net of Tax	Accumulated Other Comprehensive Loss, Net of Tax The following tables summarize the changes in AOCL by component: Three months ended September 30, 2016 Nine months ended September 30, 2016 (In thousands) Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Beginning balance $ 12,363 $ (23,406 ) $ (46,468 ) $ (57,511 ) $ (6,407 ) $ (22,980 ) $ (48,719 ) $ (78,106 ) OCI/OCL before reclassifications 1,218 794 — 2,012 20,156 (2,416 ) — 17,740 Amounts reclassified from AOCL — 1,221 1,125 2,346 (168 ) 4,005 3,376 7,213 Net current-period OCI/OCL 1,218 2,015 1,125 4,358 19,988 1,589 3,376 24,953 Ending balance $ 13,581 $ (21,391 ) $ (45,343 ) $ (53,153 ) $ 13,581 $ (21,391 ) $ (45,343 ) $ (53,153 ) Three months ended September 30, 2015 Nine months ended September 30, 2015 (In thousands) Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Beginning balance $ 9,461 $ (24,969 ) $ (45,187 ) $ (60,695 ) $ 16,421 $ (25,530 ) $ (47,152 ) $ (56,261 ) OCI/OCL before reclassifications 660 (1,998 ) — (1,338 ) (5,964 ) (4,154 ) — (10,118 ) Amounts reclassified from AOCL 52 1,479 983 2,514 (284 ) 4,196 2,948 6,860 Net current-period OCI/OCL 712 (519 ) 983 1,176 (6,248 ) 42 2,948 (3,258 ) Ending balance $ 10,173 $ (25,488 ) $ (44,204 ) $ (59,519 ) $ 10,173 $ (25,488 ) $ (44,204 ) $ (59,519 ) The following tables provide information for the items reclassified from AOCL: (In thousands) Three months ended September 30, Nine months ended September 30, Associated Line Item in the Condensed Consolidated Statements of Income AOCL Components 2016 2015 2016 2015 Available-for-sale and transferred securities: Unrealized gains (losses) on investment securities $ — $ — $ 414 $ 529 Gain on sale of investment securities, net Unrealized gains (losses) on investment securities — (82 ) (149 ) (82 ) Impairment loss recognized in earnings Total before tax — (82 ) 265 447 Tax benefit (expense) — 30 (97 ) (163 ) Income tax expense Net of tax $ — $ (52 ) $ 168 $ 284 Derivative instruments: Cash flow hedges $ (1,925 ) $ (2,332 ) $ (6,314 ) $ (6,616 ) Total interest expense Tax benefit 704 853 2,309 2,420 Income tax expense Net of tax $ (1,221 ) $ (1,479 ) $ (4,005 ) $ (4,196 ) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (1,780 ) $ (1,540 ) $ (5,343 ) $ (4,621 ) Compensation and benefits (1) Prior service costs (4 ) (19 ) (11 ) (55 ) Compensation and benefits (1) Total before tax (1,784 ) (1,559 ) (5,354 ) (4,676 ) Tax benefit 659 576 1,978 1,728 Income tax expense Net of tax $ (1,125 ) $ (983 ) $ (3,376 ) $ (2,948 ) (1) These accumulated other comprehensive income components are included in the computation of net periodic benefit cost (see Retirement Benefit note 14 for further details).

Regulatory Matters

Regulatory Matters	9 Months Ended
	Sep. 30, 2016
Regulatory Capital Requirements [Abstract]
Regulatory Matters	Regulatory Matters Capital Requirements Webster Financial Corporation is subject to regulatory capital requirements administered by the Federal Reserve System, while Webster Bank is subject to regulatory capital requirements administered by the OCC. Regulatory authorities can initiate certain mandatory actions if Webster Financial Corporation or Webster Bank fail to meet minimum capital requirements, which could have a direct material effect on the Company’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, both Webster Financial Corporation and Webster Bank must meet specific capital guidelines that involve quantitative measures of assets, liabilities, and certain off-balance sheet items calculated under regulatory accounting practices. These quantitative measures require minimum amounts and ratios to ensure capital adequacy. Basel III total risk-based capital is comprised of three categories: CET1 capital, additional Tier 1 capital, and Tier 2 capital. CET1 capital includes common shareholders' equity, less deductions for goodwill, other intangibles, and certain deferred tax liabilities. Common shareholders' equity, for purposes of CET1 capital, excludes AOCL components as permitted by the opt-out election taken by Webster upon adoption of Basel III. Tier 1 capital is comprised of CET1 capital plus perpetual preferred stock, while Tier 2 capital includes qualifying subordinated debt and qualifying allowance for credit losses, that together equal total capital. The following table provides information on the capital ratios for Webster Financial Corporation and Webster Bank: Capital Requirements Actual Minimum Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio At September 30, 2016 Webster Financial Corporation CET1 risk-based capital $ 1,892,244 10.5 % $ 812,420 4.5 % $ 1,173,495 6.5 % Total risk-based capital 2,282,690 12.6 1,444,302 8.0 1,805,377 10.0 Tier 1 risk-based capital 2,014,954 11.2 1,083,226 6.0 1,444,302 8.0 Tier 1 leverage capital 2,014,954 8.2 987,561 4.0 1,234,452 5.0 Webster Bank CET1 risk-based capital $ 1,919,417 10.6 % $ 811,487 4.5 % $ 1,172,148 6.5 % Total risk-based capital 2,109,833 11.7 1,442,643 8.0 1,803,304 10.0 Tier 1 risk-based capital 1,919,417 10.6 1,081,983 6.0 1,442,643 8.0 Tier 1 leverage capital 1,919,417 7.8 986,708 4.0 1,233,385 5.0 At December 31, 2015 Webster Financial Corporation CET1 risk-based capital $ 1,824,106 10.7 % $ 766,848 4.5 % $ 1,107,670 6.5 % Total risk-based capital 2,201,245 12.9 1,363,286 8.0 1,704,107 10.0 Tier 1 risk-based capital 1,966,146 11.5 1,022,464 6.0 1,363,286 8.0 Tier 1 leverage capital 1,966,146 8.2 954,369 4.0 1,192,962 5.0 Webster Bank CET1 risk-based capital $ 1,869,241 11.0 % $ 765,152 4.5 % $ 1,105,220 6.5 % Total risk-based capital 2,046,350 12.0 1,360,271 8.0 1,700,338 10.0 Tier 1 risk-based capital 1,869,241 11.0 1,020,203 6.0 1,360,271 8.0 Tier 1 leverage capital 1,869,241 7.8 953,300 4.0 1,191,626 5.0 Dividend Restrictions Webster Financial Corporation is dependent upon dividends from Webster Bank to provide funds for its cash requirements,including payments of dividends to shareholders. Banking regulations may limit the amount of dividends that may be paid. Approval by regulatory authorities is required if the effect of dividends declared would cause the regulatory capital of Webster Bank to fall below specified minimum levels, or if dividends declared exceed the net income for that year combined with the undistributed net income for the preceding two years. In addition, the OCC has discretion to prohibit any otherwise permitted capital distribution on general safety and soundness grounds. Dividends paid by Webster Bank to Webster Financial Corporation totaled $115 million during the nine months ended September 30, 2016 compared to $80 million during the nine months ended September 30, 2015 . Cash Restrictions Webster Bank is required by Federal Reserve System regulations to hold cash reserve balances on hand or with the Federal Reserve Bank. Pursuant to this requirement, Webster Bank held $63.8 million and $109.4 million at September 30, 2016 and December 31, 2015 , respectively.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share Reconciliation of the calculation of basic and diluted earnings per common share follows: Three months ended September 30, Nine months ended September 30, (In thousands, except per share data) 2016 2015 2016 2015 Earnings for basic and diluted earnings per common share: Net income $ 51,817 $ 51,370 $ 149,467 $ 152,917 Less: Preferred stock dividends 2,024 2,024 6,072 6,687 Net income available to common shareholders 49,793 49,346 143,395 146,230 Less: Earnings applicable to participating securities 159 170 468 515 Earnings applicable to common shareholders $ 49,634 $ 49,176 $ 142,927 $ 145,715 Shares: Weighted-average common shares outstanding - basic 91,365 91,458 91,298 90,816 Effect of dilutive securities: Stock options and restricted stock 465 512 452 532 Warrants 27 37 26 43 Weighted-average common shares outstanding - diluted 91,857 92,007 91,776 91,391 Earnings per common share: Basic $ 0.54 $ 0.54 $ 1.57 $ 1.61 Diluted 0.54 0.53 1.56 1.60 Potential common shares excluded from the effect of dilutive securities because they would have been anti-dilutive, are as follows: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Stock options (shares with exercise price greater than market price) 172 305 172 305 Restricted stock (due to performance conditions on non-participating shares) — 52 161 93 Basic weighted-average common shares outstanding includes the effect of 1.1 million common shares issued from treasury stock on June 1, 2015, representing the conversion of the Series A Preferred Stock. Prior to conversion, the Series A Preferred Stock was considered to be anti-dilutive. Refer to Note 15: Share-Based Plans for further information relating to potential common shares excluded from the effect of dilutive securities.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments Risk Management Objective of Using Derivatives Webster manages economic risks, including interest rate, liquidity, and credit risk by managing the amount, sources, and duration of its debt funding along with the use of interest rate derivative financial instruments. Webster enters into interest rate derivative financial instruments to manage exposure related to business activities that result in the receipt or payment of both future known and uncertain cash amounts determined by interest rates. Webster’s primary objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish these objectives, Webster uses interest rate swaps and interest rate caps as part of its interest rate risk management strategy. Interest rate swaps and caps designated as cash flow hedges are designed to manage the risk associated with a forecasted event or an uncertain variable-rate cash flow. Forward-settle interest rate swaps protect the Company against adverse fluctuations in interest rates by reducing its exposure to variability in cash flows relating to interest payments on forecasted debt issuances. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. Interest rate caps designated as cash flow hedges involve the receipt of variable amounts from a counterparty if interest rates rise above the strike rate on the contract in exchange for payment of an up-front premium. Derivative instruments designated as cash flow hedges are recorded on the balance sheet at fair value. The effective portion of the change in the fair value of derivatives which are designated as cash flow hedges, and that qualify for hedge accounting, is recorded to AOCL and is reclassified into earnings in the subsequent periods that the hedged forecasted transaction affects earnings. During the periods presented, such derivatives were used to hedge the variable cash flows associated with existing variable-rate debt and forecasted issuances of debt. The ineffective portion of the change in the fair value of the derivatives is recognized directly in earnings. For the nine months ended September 30, 2016 and 2015 , the Company recorded no ineffectiveness in earnings attributable to the difference in the effective date of the hedge and the effective date of the debt issuance. Webster is also exposed to changes in the fair value of certain of its fixed-rate obligations due to changes in benchmark interest rates. Webster, on occasion, uses interest rate swaps to manage its exposure to changes in fair value on these obligations attributable to changes in the benchmark interest rates. Interest rate swaps designated as fair value hedges involve the receipt of fixed-rate amounts from a counterparty in exchange for Webster making variable-rate payments over the life of the agreements without the exchange of the underlying notional amount. For a qualifying derivative designated as a fair value hedge, the gain or loss on the derivative, as well as the gain or loss on the hedged item, is recognized in interest expense. Webster did not have interest rate derivative financial instruments designated as fair value hedges at September 30, 2016 and December 31, 2015 . As a result, there was no impact to interest expense during the periods presented. Additionally, in order to address certain other risk management matters, the Company utilizes the following derivative instruments that do not qualify for hedge accounting. These derivative instruments are recorded on the balance sheet at fair value, with changes in fair value recognized each period as other non-interest income in the accompanying Condensed Consolidated Statements of Income. Interest rate swap and cap contracts are sold to commercial and other customers who wish to modify loan interest rate sensitivity. These contracts are offset with dealer counterparty transactions structured with matching terms. As a result, there is minimal impact on earnings, except for fee income earned in such transactions. RPAs are entered into as financial guarantees of performance on interest rate swap derivatives. The purchased (asset) or sold (liability) guarantee allows the Company to participate-in (for a fee received) or participate-out (for a fee paid) the risk associated with certain derivative positions executed with the borrower by a lead bank. Other derivatives include foreign currency forward contracts related to lending arrangements, a VISA equity swap transaction, and mortgage banking derivatives such as mortgage-backed securities related to residential loan commitments and loans held for sale. Mortgage banking derivatives are utilized by Webster in its efforts to manage risk of loss associated with its mortgage loan commitments and mortgage loans held for sale. Prior to closing and funding certain single-family residential mortgage loans interest rate lock commitments are generally extended to the borrowers. During the period from commitment date to closing date, Webster is subject to the risk that market rates of interest may change. If market rates rise, investors generally will pay less to purchase such loans causing a reduction in the anticipated gain on sale of the loans and possibly resulting in a loss. In an effort to mitigate such risk, forward delivery sales commitments are established under which Webster agrees to deliver whole mortgage loans to various investors or issue mortgage-backed securities. Mandatory forward commitments establish the price to be received upon the sale of the related mortgage loan, thereby mitigating certain interest rate risk. There is, however, still certain execution risk specifically related to Webster’s ability to close and deliver to its investors the mortgage loans it has committed to sell. Fair Value of Derivative Instruments The following table presents the notional amounts and fair values of derivative positions: At September 30, 2016 At December 31, 2015 Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives (In thousands) Notional Fair Notional Fair Notional Fair Notional Fair Designated as hedging instruments: Positions subject to a master netting agreement (1) Interest rate derivatives $ 175,000 $ 768 $ 150,000 $ 3,433 $ 200,000 $ 2,507 $ 100,000 $ 1,359 Not designated as hedging instruments: Positions subject to a master netting agreement (1) Interest rate derivatives 472,750 236 2,320,222 91,262 989,695 2,255 1,543,479 40,302 Other 22,634 66 8,517 37 8,237 183 4,561 66 Positions not subject to a master netting agreement (2) Interest rate derivatives 2,388,726 116,645 404,272 125 2,050,460 58,304 482,738 571 RPAs 75,250 320 106,633 337 41,798 153 92,985 245 Mortgage banking derivatives (3) 110,015 1,874 132,529 698 62,514 819 — — Other — — 60 10 — — 60 9 Total not designated as hedging instruments 3,069,375 119,141 2,972,233 92,469 3,152,704 61,714 2,123,823 41,193 Gross derivative instruments, before netting $ 3,244,375 119,909 $ 3,122,233 95,902 $ 3,352,704 64,221 $ 2,223,823 42,552 Less: Legally enforceable master netting agreements 1,070 1,070 4,945 4,945 Less: Cash collateral posted — 93,662 — 31,330 Total derivative instruments, after netting $ 118,839 $ 1,170 $ 59,276 $ 6,277 (1) The Company has elected to report derivative positions subject to a legally enforceable master netting agreement on a net basis, net of cash collateral. Refer to the Offsetting Derivatives section of this footnote for additional information. (2) Derivative positions not subject to a legally enforceable master netting agreement are reported on a gross basis in the accompanying Condensed Consolidated Balance Sheets. (3) Notional amounts include mandatory forward commitments of $133.1 million , while notional amounts do not include approved floating rate commitments of $29.3 million , at September 30, 2016 . Changes in Fair Value Changes in the fair value of derivatives not qualifying for hedge accounting treatment were recognized as follows: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Interest rate derivatives $ 608 $ 955 $ 6,515 $ 3,375 RPAs 110 — (143 ) (118 ) Mortgage banking derivatives 720 (1,331 ) 357 215 Other (285 ) 29 (582 ) (37 ) Total impact on other non-interest income $ 1,153 $ (347 ) $ 6,147 $ 3,435 Amounts for the effective portion of changes in the fair value of derivatives qualifying for hedge accounting treatment are reclassified to interest expense as interest payments are made on Webster's variable-rate debt. Over the next twelve months, the Company estimates that $2.1 million will be reclassified from AOCL as an increase to interest expense. Webster records gains and losses related to hedge terminations to AOCL. These balances are subsequently amortized into interest expense over the respective terms of the hedged debt instruments. At September 30, 2016 , the remaining unamortized loss on the termination of cash flow hedges is $22.9 million . Over the next twelve months, the Company estimates that $6.4 million will be reclassified from AOCL as an increase to interest expense. Additional information about cash flow hedge activity impacting AOCL, and the related amounts reclassified to interest expense is provided in Note 9: Accumulated Other Comprehensive Loss, Net of Tax . Information about the valuation methods used to measure the fair value of derivatives is provided in Note 13: Fair Value Measurements . Offsetting Derivatives Webster has entered into transactions with counterparties that are subject to a legally enforceable master netting agreement. Derivatives subject to a legally enforceable master netting agreement are reported on a net basis, net of cash collateral. Net positions are recorded in other assets for a net gain position and in other liabilities for a net loss position in the accompanying Condensed Consolidated Balance Sheets. The following table is presented on a gross basis, prior to the application of counterparty netting agreements. Derivative assets and liabilities are shown net of cash collateral: At September 30, 2016 At December 31, 2015 (In thousands) Gross Amount Amount Offset Net Amount (1) (2) Gross Amount Amount Offset Net Amount (1) (2) Derivative instrument assets: Hedged Accounting Positions $ 768 $ (768 ) $ — $ 2,507 $ (2,507 ) $ — Non-Hedged Accounting Positions 302 (302 ) — 2,438 (2,438 ) — Total $ 1,070 $ (1,070 ) $ — $ 4,945 $ (4,945 ) $ — Derivative instrument liabilities: Hedged Accounting Positions $ 3,433 $ (3,433 ) $ — $ 1,359 $ (1,359 ) $ — Non-Hedged Accounting Positions 91,299 (91,299 ) — 40,368 (34,916 ) 5,452 Total $ 94,732 $ (94,732 ) $ — $ 41,727 $ (36,275 ) $ 5,452 (1) Net amount is net of $93.7 million and $31.3 million of cash collateral at September 30, 2016 and December 31, 2015 , respectively, as presented in the accompanying Condensed Consolidated Balance Sheets. (2) Net amount excludes $29.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at September 30, 2016 and December 31, 2015 , respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Condensed Consolidated Balance Sheets. Counterparty Credit Risk Use of derivative contracts may expose the bank to counterparty credit risk. The Company has ISDA master agreements, including a Credit Support Annex, with all derivative counterparties. The ISDA master agreements provide that on each payment date, all amounts otherwise owing the same currency under the same transaction are netted so that only a single amount is owed in that currency. The ISDA provides, if the parties so elect, for such netting of amounts in the same currency among all transactions identified as being subject to such election that have common payment dates and booking offices. Under the Credit Support Annex, daily net exposure in excess of a negotiated threshold is secured by posted cash collateral. The Company has negotiated a zero threshold with the majority of its approved financial institution counterparties. In accordance with Webster policies, institutional counterparties must be analyzed and approved through the Company’s credit approval process. The Company’s credit exposure on interest rate derivatives with non-dealer counterparties is limited to the net favorable value, including accrued interest, of all such instruments, reduced by the amount of collateral pledged by the counterparties. The Company's credit exposure related to derivatives with dealer counterparties is significantly mitigated with cash collateral equal to, or in excess of, the market value of the instrument updated daily. In accordance with counterparty credit agreements and derivative clearing rules, the Company had approximately $125.8 million in net margin collateral posted with financial counterparties at September 30, 2016 , comprised of $29.5 million in initial margin and $96.3 million in variation margin collateral posted to financial counterparties or the derivative clearing organization. Collateral levels for approved financial institution counterparties are monitored daily and adjusted as necessary. In the event of default, should the collateral not be returned, the exposure would be offset by terminating the transaction. The Company regularly evaluates the credit risk of its counterparties, taking into account the likelihood of default, net exposures, and remaining contractual life, among other related factors. The Company's net current credit exposure relating to interest rate derivatives with Webster Bank customers was $116.9 million at September 30, 2016 . In addition, the Company monitors potential future exposure, representing its best estimate of exposure to remaining contractual maturity. The potential future exposure relating to interest rate derivatives with Webster Bank customers totaled $24.8 million at September 30, 2016 . The credit exposures are mitigated as transactions with customers are generally secured by the same collateral of the underlying transactions being hedged.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is best determined using quoted market prices. However, in many instances, quoted market prices are not available. In such instances, fair values are determined using appropriate valuation techniques. Various assumptions and observable inputs must be relied upon in applying these techniques. Accordingly, categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. As such, the fair value estimates may not be realized in an immediate transfer of the respective asset or liability. Fair Value Hierarchy The three levels within the fair value hierarchy are as follows: • Level 1: Valuation is based upon unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2: Fair value is calculated using significant inputs other than quoted market prices that are directly or indirectly observable for the asset or liability. The valuation may rely on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatilities, prepayment speeds, credit ratings, etc.), or inputs that are derived principally or corroborated by market data, by correlation, or other means. • Level 3: Inputs for determining the fair value of the respective assets or liabilities are not observable. Level 3 valuations are reliant upon pricing models and techniques that require significant management judgment or estimation. Assets and Liabilities Measured at Fair Value on a Recurring Basis Available-for-Sale Investment Securities. When quoted prices are available in an active market, the Company classifies securities within Level 1 of the valuation hierarchy. Equity securities in financial services and U.S. Treasury Bills are classified within Level 1 of the fair value hierarchy. When quoted market prices are not available, the Company employs an independent pricing service that utilizes matrix pricing to calculate fair value. Such fair value measurements consider observable data such as dealer quotes, market spreads, cash flows, yield curves, live trading levels, trade execution data, market consensus prepayments speeds, credit information, and respective terms and conditions for debt instruments. Management maintains procedures to monitor the pricing service's assumptions and establishes processes to challenge the pricing service's valuations that appear unusual or unexpected. Available-for-Sale investment securities which include Agency CMO, Agency MBS, Agency CMBS, CMBS, CLO, single-issuer trust preferred securities, and corporate debt securities, are classified within Level 2 of the fair value hierarchy. Derivative Instruments. Foreign exchange contracts are valued based on unadjusted quoted prices in active markets and classified within Level 1 of the fair value hierarchy. Derivative instruments are valued using third-party valuation software, which considers the present value of cash flows discounted using observable forward rate assumptions. The resulting fair values are validated against valuations performed by independent third parties and are classified within Level 2 of the fair value hierarchy. In determining if any fair value adjustment related to credit risk is required, Webster evaluates the credit risk of its counterparties by considering factors such as the likelihood of default by the counterparties, its net exposures, the remaining contractual life, as well as the amount of collateral securing the position. Webster reviews its counterparty exposure on a regular basis, and, when necessary, appropriate business actions are taken to adjust the exposure. When determining fair value, Webster applies the portfolio exception with respect to measuring counterparty credit risk for all of its derivative transactions subject to a master netting arrangement. The change in value of derivative assets and liabilities attributable to credit risk was not significant during the reported periods. Mortgage Banking Derivatives. Forward sales of mortgage loans and mortgage-backed securities are utilized by the Company in its efforts to manage risk of loss associated with its mortgage loan commitments and mortgage loans held for sale. Prior to closing and funding certain single-family residential mortgage loans, an interest rate lock commitment is generally extended to the borrower. During the period from commitment date to closing date, the Company is subject to the risk that market rates of interest may change. If market rates rise, investors generally will pay less to purchase such loans resulting in a reduction in the gain on sale of the loans or, possibly, a loss. In an effort to mitigate such risk, forward delivery sales commitments are established, under which the Company agrees to deliver whole mortgage loans to various investors or issue mortgage-backed securities. The fair value of mortgage banking derivatives is determined based on current market prices for similar assets in the secondary market and, therefore, classified within Level 2 of the fair value hierarchy. Investments Held in Rabbi Trust. Investments held in the Rabbi Trust primarily include mutual funds that invest in equity and fixed income securities. Shares of mutual funds are valued based on net asset value, which represents quoted market prices for the underlying shares held in the mutual funds. Therefore, investments held in the Rabbi Trust are classified within Level 1 of the fair value hierarchy. Webster has elected to measure the investments held in the Rabbi Trust at fair value. The Company consolidates the invested assets of the trust along with the total deferred compensation obligations and includes them in other assets and other liabilities, respectively, in the accompanying Condensed Consolidated Balance Sheets. Earnings in the Rabbi Trust, including appreciation or depreciation, are reflected as other non-interest income, and changes in the corresponding liability are reflected as compensation and benefits in the accompanying Condensed Consolidated Statements of Income. The cost basis of the investments held in the Rabbi Trust is $3.3 million as of September 30, 2016 . Alternative Investments. The Company generally records alternative investments at cost, subject to impairment testing. The alternative investments that are carried at cost are considered to be measured at fair value on a non-recurring basis when there is impairment. There are certain funds in which the ownership percentage is greater than 3% and are, therefore, recorded at fair value on a recurring basis based upon the net asset value of the respective fund. Alternative investments are non-public entities that cannot be redeemed since the Company’s investment is distributed as the underlying investments are liquidated. As such, these investments are classified within Level 3 of the fair value hierarchy. The Company has $22.4 million in unfunded commitments remaining for its alternative investments, including tax credit deals, as of September 30, 2016 . See the "Investment Securities Portfolio" section of Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations for additional discussion of the Company's alternative investments. Originated Loans Held For Sale. Residential mortgage loans typically are classified as held for sale upon origination based on management's intent to sell such loans. The Company generally records residential mortgage loans held for sale under the fair value option of ASC 820 "Fair Value Measurement" . The fair value of residential mortgage loans held for sale is based on quoted market prices of similar loans sold in conjunction with securitization transactions. Accordingly, such loans are classified within Level 2 of the fair value hierarchy. Contingent Consideration. As part of the health savings accounts acquisition, the contingent consideration arrangement entitles the Company to receive a rebate of the purchase price relating to the premium paid, for account attrition that occurs during the eighteen-month period beginning on the acquisition date of January 13, 2015. In periods subsequent to the initial valuation the fair value is adjusted for measurable attrition milestones. This valuation is based on a contractual obligation that is reliant upon calculation inputs, and as such could be subject to miscalculation. Therefore, the contingent consideration is classified within Level 3 of the fair value hierarchy. Contingent Liability. As part of the health savings accounts acquisition, Webster assumed a pre-existing liability as part of the transaction. The liability valuation was based upon unobservable inputs. Therefore, the contingent liability was classified within Level 3 of the fair value hierarchy. The fair value of the contingency represented the estimated price to transfer the liability between market participants at the measurement date under current market conditions. Webster settled the liability during the quarter ended September 30, 2016 . Summaries of the fair values of assets and liabilities measured at fair value on a recurring basis are as follows: At September 30, 2016 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: U.S. Treasury Bills $ 985 $ — $ — $ 985 Agency CMO — 463,730 — 463,730 Agency MBS — 1,001,014 — 1,001,014 Agency CMBS — 484,408 — 484,408 CMBS — 468,361 — 468,361 CLO — 484,236 — 484,236 Single issuer trust preferred securities — 38,111 — 38,111 Corporate debt securities — 99,266 — 99,266 Equities - financial services — — — — Total available-for-sale investment securities 985 3,039,126 — 3,040,111 Gross derivative instruments, before netting (1) 66 119,843 — 119,909 Investments held in Rabbi Trust 5,020 — — 5,020 Alternative investments — — 5,464 5,464 Originated loans held for sale (2) — 66,400 — 66,400 Contingent consideration — — 8,035 8,035 Total financial assets held at fair value $ 6,071 $ 3,225,369 $ 13,499 $ 3,244,939 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 37 $ 95,865 $ — $ 95,902 Contingent liability — — — — Total financial liabilities held at fair value $ 37 $ 95,865 $ — $ 95,902 At December 31, 2015 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: U.S. Treasury Bills $ 924 $ — $ — $ 924 Agency CMO — 548,754 — 548,754 Agency MBS — 1,065,109 — 1,065,109 Agency CMBS — 215,350 — 215,350 CMBS — 579,266 — 579,266 CLO — 429,159 — 429,159 Single issuer trust preferred securities — 37,170 — 37,170 Corporate debt securities — 106,321 — 106,321 Equities - financial services 2,578 — — 2,578 Total available-for-sale investment securities 3,502 2,981,129 — 2,984,631 Gross derivative instruments, before netting (1) 183 64,038 — 64,221 Investments held in Rabbi Trust 5,372 — — 5,372 Alternative investments — — 3,471 3,471 Originated loans held for sale — — — — Contingent Consideration — — 5,331 5,331 Total financial assets held at fair value $ 9,057 $ 3,045,167 $ 8,802 $ 3,063,026 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 66 $ 42,486 $ — $ 42,552 Contingent liability — — 6,000 6,000 Total financial liabilities held at fair value $ 66 $ 42,486 $ 6,000 $ 48,552 (1) For information relating to the impact of netting derivative assets and derivative liabilities as well as the impact from offsetting cash collateral paid to the same derivative counterparties see Note 12: Derivative Financial Instruments . (2) Loans held for sale accounted for under the fair value option of ASC 825 "Financial Instruments" at September 30, 2016 . The Company made this policy election on loans originated for sale. See Note 1: Summary of Significant Accounting Policies . The following table presents the changes in Level 3 assets and liabilities that are measured at fair value on a recurring basis: (In thousands) Alternative Investments Contingent Consideration Total Financial Assets Contingent Liability Balance at January 1, 2016 $ 3,471 $ 5,331 $ 8,802 $ 6,000 Unrealized gain included in net income 311 2,704 3,015 — Purchases/capital funding 1,682 — 1,682 — Payments — — — (6,000 ) Balance at September 30, 2016 $ 5,464 $ 8,035 $ 13,499 $ — Assets Measured at Fair Value on a Non-Recurring Basis Certain assets are measured at fair value on a non-recurring basis; that is, the assets are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances, for example, when there is evidence of impairment. The following is a description of valuation methodologies used for assets measured on a non-recurring basis. Transferred Loans Held For Sale. Certain loans are transferred to loans held for sale once a decision has been made to sell such loans. These loans are accounted for at the lower of cost or market and are considered to be recognized at fair value when they are recorded at below cost. This activity is primarily commercial loans with observable inputs and is classified within Level 2. On the occasion should these loans include adjustments for changes in loan characteristics using unobservable inputs, the loans would be classified within Level 3. Collateral Dependent Impaired Loans and Leases. Impaired loans and leases for which repayment is expected to be provided solely by the value of the underlying collateral are considered collateral dependent and are valued based on the estimated fair value of such collateral using customized discounting criteria. As such, collateral dependent impaired loans and leases are classified as Level 3 of the fair value hierarchy. Other Real Estate Owned and Repossessed Assets. The total book value of OREO and repossessed assets was $4.1 million at September 30, 2016 . OREO and repossessed assets are accounted for at the lower of cost or market and are considered to be recognized at fair value when they are recorded at below cost. The fair value of OREO is based on independent appraisals or internal valuation methods, less estimated selling costs. The valuation may consider available pricing guides, auction results, and price opinions. Certain assets require assumptions about factors that are not observable in an active market in the determination of fair value; as such, OREO and repossessed assets are classified within Level 3 of the fair value hierarchy. Mortgage Servicing Assets. Mortgage servicing assets are accounted for at cost, subject to impairment testing. When the carrying cost exceeds fair value, a valuation allowance is established to reduce the carrying cost to fair value. Changes in fair value are included as a component of other non-interest income in the accompanying Condensed Consolidated Statements of Income. Fair value is calculated as the present value of estimated future net servicing income and relies on market based assumptions for loan prepayment speeds, servicing costs, discount rates, and other economic factors; as such, the primary risk inherent in valuing mortgage servicing assets is the impact of fluctuating interest rates on the servicing revenue stream. Mortgage servicing assets are classified within Level 3 of the fair value hierarchy. The following table presents the changes in fair value for mortgage servicing assets: Nine months ended September 30, (In thousands) 2016 2015 Beginning balance $ 33,568 $ 28,690 Originations of servicing assets 8,198 6,335 Changes in fair value: Due to payoffs/paydowns (3,026 ) (1,918 ) Due to market changes (3,119 ) (754 ) Ending balance $ 35,621 $ 32,353 The table below presents the valuation methodology and unobservable inputs for Level 3 assets measured at fair value on a non-recurring basis as of September 30, 2016 : (Dollars in thousands) Asset Fair Value Valuation Methodology Unobservable Inputs Range of Inputs Collateral dependent impaired loans and leases $ 1,974 Real Estate Appraisals Discount for appraisal type 0% Discount for costs to sell 0% OREO $ 195 Real Estate Appraisals Discount for appraisal type 0% - 10.0% Discount for costs to sell 8% Mortgage servicing assets $ 35,621 Discounted cash flow Constant prepayment rate 7.9% - 32.6% Discount rates 1.5% - 2.1% Fair Value of Financial Instruments The Company is required to disclose the estimated fair value of financial instruments, both assets and liabilities, for which it is practicable to estimate fair value. The following is a description of valuation methodologies used for those assets and liabilities. Cash, Due from Banks, and Interest-bearing Deposits. The carrying amount of cash, due from banks, and interest-bearing deposits is used to approximate fair value, given the short time frame to maturity and, as such, these assets do not present unanticipated credit concerns. Cash, due from banks, and interest-bearing deposits are classified within Level 1 of the fair value hierarchy. Held-to-Maturity Investment Securities. When quoted market prices are not available, the Company employs an independent pricing service that utilizes matrix pricing to calculate fair value. Such fair value measurements consider observable data such as dealer quotes, market spreads, cash flows, yield curves, live trading levels, trade execution data, market consensus prepayments speeds, credit information, and respective terms and conditions for debt instruments. Management maintains procedures to monitor the pricing service's assumptions and establishes processes to challenge the pricing service's valuations that appear unusual or unexpected. Held-to-Maturity investment securities, which include Agency CMO, Agency MBS, Agency CMBS, CMBS, municipal bonds and notes, and private label MBS securities, are classified within Level 2 of the fair value hierarchy. Loans and Leases, net. The estimated fair value of loans and leases held for investment is calculated using a discounted cash flow method, using future prepayments and market interest rates inclusive of an illiquidity premium for comparable loans and leases. The associated cash flows are adjusted for credit and other potential losses. Fair value for impaired loans and leases is estimated using the net present value of the expected cash flows. Loans and leases are classified within Level 3 of the fair value hierarchy. Deposit Liabilities. The fair value of demand deposits, savings accounts, and certain money market deposits is the amount payable on demand at the reporting date. The fair value of fixed-maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. Deposit liabilities are classified within Level 2 of the fair value hierarchy. Securities Sold Under Agreements to Repurchase and Other Borrowings. The carrying value is an estimate of fair value for those securities sold under agreements to repurchase and other borrowings that mature within 90 days. The fair values of all other borrowings are estimated using discounted cash flow analysis based on current market rates adjusted, as appropriate, for associated credit risks. Securities sold under agreements to repurchase and other borrowings are classified within Level 2 of the fair value hierarchy. Federal Home Loan Bank Advances and Long-Term Debt. The fair value of FHLB advances and long-term debt is estimated using a discounted cash flow technique. Discount rates are matched with the time period of the expected cash flow and are adjusted, as appropriate, to reflect credit risk. FHLB advances and long-term debt are classified within Level 2 of the fair value hierarchy. The estimated fair values of selected financial instruments and servicing assets are as follows: At September 30, 2016 At December 31, 2015 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Value Assets: Level 2 Held-to-maturity investment securities $ 4,022,332 $ 4,109,943 $ 3,923,052 $ 3,961,534 Loans held for sale (1) 178 178 37,091 37,457 Level 3 Loans and leases, net 16,435,476 16,450,034 15,496,745 15,543,892 Mortgage servicing assets 23,384 35,621 20,698 33,568 Alternative investments 11,303 12,867 12,900 14,294 Liabilities: Level 2 Deposit liabilities, other than time deposits $ 17,179,965 $ 17,179,965 $ 15,866,624 $ 15,866,624 Time deposits 2,020,943 2,037,577 2,086,154 2,095,357 Securities sold under agreements to repurchase and other borrowings 800,705 811,273 1,151,400 1,163,974 FHLB advances (2) 2,587,983 2,576,651 2,664,139 2,647,872 Long-term debt (2) 225,450 222,694 226,356 218,143 (1) Loans held for sale accounted for at the lower of cost or market includes commercial loans at September 30, 2016 and both commercial and residential loans at December 31, 2015 . (2) The following adjustments to the carrying amount are not included for determination of fair value, see Note 8: Borrowings : • FHLB advances - unamortized premiums on advances • Long-term debt - unamortized discount and debt issuance cost on senior fixed-rate notes Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the entire holdings or any part of a particular financial instrument. Fair value estimates are based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments, and other factors. These factors are subjective in nature and involve uncertainties and matters of significant judgment and, therefore, cannot be determined with precision. Changes in assumptions could significantly affect the estimates.

Retirement Benefit Plans

Retirement Benefit Plans	9 Months Ended
	Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Retirement Benefit Plans	Retirement Benefit Plans Defined benefit pension and other postretirement benefits The following table summarizes the components of net periodic benefit cost: Three months ended September 30, 2016 2015 (In thousands) Webster Bank Pension Plan Webster Other Postretirement Benefits Webster Bank Pension Plan Webster Other Postretirement Benefits Service cost $ 11 $ — $ — $ 11 $ — $ — Interest cost on benefit obligations 2,110 98 32 2,002 86 31 Expected return on plan assets (3,067 ) — — (2,968 ) — — Amortization of prior service cost — — 4 — — 18 Recognized net loss 1,666 106 8 1,431 98 11 Net periodic benefit cost $ 720 $ 204 $ 44 $ 476 $ 184 $ 60 Nine months ended September 30, 2016 2015 (In thousands) Webster Bank Pension Plan Webster Other Postretirement Benefits Webster Bank Pension Plan Webster Other Postretirement Benefits Service cost $ 34 $ — $ — $ 34 $ — $ — Interest cost on benefit obligations 6,331 292 94 6,006 259 93 Expected return on plan assets (8,596 ) — — (8,905 ) — — Amortization of prior service cost — — 11 — — 54 Recognized net loss 4,998 319 26 4,293 293 35 Net periodic benefit cost $ 2,767 $ 611 $ 131 $ 1,428 $ 552 $ 182 The Company made a discretionary $20.0 million contribution to the Webster Bank Pension Plan in September 2016 . Additional contributions may be made as deemed appropriate by management in conjunction with information provided by the Plan’s actuarial firm.

Share-Based Plans

Share-Based Plans	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Plans	Share-Based Plans Stock compensation plans Webster maintains stock compensation plans under which non-qualified stock options, incentive stock options, restricted stock, restricted stock units, or stock appreciation rights may be granted to employees and directors. The Company believes these share awards better align the interests of its employees with those of its shareholders. Stock compensation cost is recognized over the required service vesting period for the awards, based on the grant-date fair value, net of estimated forfeitures, and is included as a component of compensation and benefits reflected in non-interest expense. The following table provides a summary of stock compensation expense recognized in the accompanying Condensed Consolidated Statements of Income: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Stock options $ — $ 73 $ 43 $ 305 Restricted stock 2,944 2,934 8,515 7,978 Total stock compensation expense $ 2,944 $ 3,007 $ 8,558 $ 8,283 At September 30, 2016 there was $16.9 million of unrecognized stock compensation expense for restricted stock expected to be recognized over a weighted-average period of 1.7 years . The following table provides a summary of the activity under the stock compensation plans for the nine months ended September 30, 2016 : Restricted Stock Awards Outstanding Stock Options Outstanding Time-Based Performance-Based Number of Shares Weighted-Average Grant Date Fair Value Number of Units Weighted-Average Grant Date Fair Value Number of Shares Weighted-Average Grant Date Fair Value Number of Shares Weighted-Average Exercise Price Outstanding, at January 1, 2016 236,145 $ 32.58 2,088 $ 34.45 115,721 $ 34.14 1,527,074 $ 23.92 Granted 222,610 32.93 12,946 32.89 150,392 32.75 — — Exercised options — — — — — — 116,694 20.19 Vested restricted stock awards (1) 166,988 31.81 9,638 33.23 104,419 33.17 — — Forfeited 11,628 32.73 — — 3,401 33.59 41,562 47.92 Outstanding and exercisable, at September 30, 2016 280,139 $ 33.28 5,396 $ 32.89 158,293 $ 33.47 1,368,818 $ 23.51 (1) Vested for purposes of recording compensation expense. Time-based restricted stock. Time-based restricted stock awards vest over the applicable service period ranging from 1 to 5 years. The number of time-based awards that may be granted to an eligible individual in a calendar year is limited to 100,000 shares. Compensation expense is recorded over the vesting period based on a fair value, which is measured using the Company's common stock closing price at the date of grant. Performance-based restricted stock. Performance-based restricted stock awards vest after a 3 year performance period. The awards vest with a share quantity dependent on that performance, in a range from 0 to 150% . The performance criteria for 50% of the shares granted in 2016 is based upon Webster's ranking for total shareholder return versus Webster's compensation peer group companies and the remaining 50% is based upon upon Webster's average of return on equity during the three year vesting period. The compensation peer group companies are utilized because they represent the financial institutions that best compare with Webster. The Company records compensation expense over the vesting period, based on a fair value calculated using the Monte-Carlo simulation model, which allows for the incorporation of the performance condition for the 50% of the performance-based shares tied to total shareholder return versus the compensation peer group, and based on a fair value of the market price on the date of grant for the remaining 50% of the performance-based shares tied to Webster's return on equity. Compensation expense is subject to adjustment based on management's assessment of Webster's return on equity performance relative to the target number of shares condition. Stock options. Stock option awards have an exercise price equal to the market price of Webster Financial Corporation's stock on the date of grant. Each option grants the holder the right to acquire a share of Webster Financial Corporation common stock over a contractual life of up to 10 years. All awarded options have vested. There were 1,269,249 non-qualified stock options and 99,569 incentive stock options outstanding at September 30, 2016 .

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting Webster’s operations are organized into four reportable segments that represent its primary businesses - Commercial Banking, Community Banking, HSA Bank, and Private Banking. Community Banking consists of the operating segments - Personal Banking and Business Banking. These four segments reflect how executive management responsibilities are assigned by the chief operating decision maker for each of the primary businesses, the products and services provided, the type of customer served, and reflects how discrete financial information is currently evaluated. The Company’s Treasury unit and consumer liquidating portfolio are included in the Corporate and Reconciling category along with the amounts required to reconcile profitability metrics to GAAP reported amounts. Webster’s reportable segment results are intended to reflect each segment as if it were a stand-alone business. Webster uses an internal profitability reporting system to generate information by operating segment, which is based on a series of management estimates and allocations regarding funds transfer pricing, provision for loan and lease losses, non-interest expense, income taxes, and equity capital. These estimates and allocations, certain of which are subjective in nature, are periodically reviewed and refined. Changes in estimates and allocations that affect the reported results of any operating segment do not affect the consolidated financial position or results of operations of Webster as a whole. The full profitability measurement reports, which are prepared for each operating segment, reflect non-GAAP reporting methodologies. The differences between full profitability and GAAP results are reconciled in the Corporate and Reconciling category. Webster allocates interest income and interest expense to each business, while also transferring the primary interest rate risk exposures to the Corporate and Reconciling category, using a matched maturity funding concept called Funds Transfer Pricing. The allocation process considers the specific interest rate risk and liquidity risk of financial instruments and other assets and liabilities in each line of business. The matched maturity funding concept considers the origination date and the earlier of the maturity date or the repricing date of a financial instrument to assign an FTP rate for loans and deposits originated each day. Loans are assigned an FTP rate for funds used and deposits are assigned an FTP rate for funds provided. This process is executed by the Company’s Financial Planning and Analysis division and is overseen by ALCO. Webster allocates the provision for loan and lease losses to each segment based on management’s estimate of the inherent loss content in each of the specific loan and lease portfolios. Provision expense for certain elements of risk that are not deemed specifically attributable to a reportable segment, such as the provision for the consumer liquidating portfolio, is shown as part of the Corporate and Reconciling category. Webster allocates a majority of non-interest expense to each reportable segment using a full-absorption costing process. Costs, including corporate overhead, are analyzed, pooled by process, and assigned to the appropriate reportable segment. Income tax expense is allocated to each reportable segment based on the consolidated effective income tax rate for the period shown. The following tables present the operating results, including all appropriate allocations, for Webster’s reportable segments and the Corporate and Reconciling category: Three months ended September 30, 2016 (In thousands) Commercial Banking Community Banking HSA Bank Private Banking Corporate and Reconciling Consolidated Total Net interest income (loss) $ 71,454 $ 91,522 $ 20,560 $ 2,811 $ (6,150 ) $ 180,197 Provision (benefit) for loan and lease losses 7,459 6,939 — 417 (565 ) 14,250 Net interest income (loss) after provision for loan and lease losses 63,995 84,583 20,560 2,394 (5,585 ) 165,947 Non-interest income 13,515 29,121 16,900 2,401 4,475 66,412 Non-interest expense 30,477 91,463 23,021 5,316 5,820 156,097 Income (loss) before income tax expense 47,033 22,241 14,439 (521 ) (6,930 ) 76,262 Income tax expense (benefit) 15,128 7,121 4,624 (171 ) (2,257 ) 24,445 Net income (loss) $ 31,905 $ 15,120 $ 9,815 $ (350 ) $ (4,673 ) $ 51,817 Three months ended September 30, 2015 (In thousands) Commercial Banking Community Banking HSA Bank Private Banking Corporate and Reconciling Consolidated Total Net interest income (loss) $ 64,769 $ 90,370 $ 18,852 $ 2,575 $ (8,556 ) $ 168,010 Provision (benefit) for loan and lease losses 3,992 8,953 — 76 (21 ) 13,000 Net interest income (loss) after provision for loan and lease losses 60,777 81,417 18,852 2,499 (8,535 ) 155,010 Non-interest income 10,970 26,928 16,386 2,215 4,793 61,292 Non-interest expense 27,474 82,919 21,273 5,026 3,245 139,937 Income (loss) before income tax expense 44,273 25,426 13,965 (312 ) (6,987 ) 76,365 Income tax expense (benefit) 14,387 8,366 4,561 (96 ) (2,223 ) 24,995 Net income (loss) $ 29,886 $ 17,060 $ 9,404 $ (216 ) $ (4,764 ) $ 51,370 Nine months ended September 30, 2016 (In thousands) Commercial Banking Community Banking HSA Bank Private Banking Corporate and Reconciling Consolidated Total Net interest income (loss) $ 203,012 $ 272,725 $ 60,484 $ 8,410 $ (11,377 ) $ 533,254 Provision (benefit) for loan and lease losses 29,247 15,572 — 518 (1,487 ) 43,850 Net interest income (loss) after provision for loan and lease losses 173,765 257,153 60,484 7,892 (9,890 ) 489,404 Non-interest income 34,374 83,219 54,969 7,445 13,854 193,861 Non-interest expense 87,781 272,823 71,966 15,555 13,195 461,320 Income (loss) before income tax expense 120,358 67,549 43,487 (218 ) (9,231 ) 221,945 Income tax expense (benefit) 39,304 22,059 14,201 (71 ) (3,015 ) 72,478 Net income (loss) $ 81,054 $ 45,490 $ 29,286 $ (147 ) $ (6,216 ) $ 149,467 Nine months ended September 30, 2015 (In thousands) Commercial Banking Community Banking HSA Bank Private Banking Corporate and Reconciling Consolidated Total Net interest income (loss) $ 188,539 $ 262,214 $ 53,080 $ 7,471 $ (20,019 ) $ 491,285 Provision (benefit) for loan and lease losses 19,951 16,383 — (158 ) (676 ) 35,500 Net interest income (loss) after provision for loan and lease losses 168,588 245,831 53,080 7,629 (19,343 ) 455,785 Non-interest income 28,321 80,748 46,885 6,891 15,253 178,098 Non-interest expense 81,144 247,070 60,476 14,502 8,369 411,561 Income (loss) before income tax expense 115,765 79,509 39,489 18 (12,459 ) 222,322 Income tax expense (benefit) 36,139 24,821 12,327 5 (3,887 ) 69,405 Net income (loss) $ 79,626 $ 54,688 $ 27,162 $ 13 $ (8,572 ) $ 152,917 The following table presents total assets for Webster's reportable segments and the Corporate and Reconciling category: Total Assets (In thousands) Commercial Banking Community HSA Bank Private Corporate and Reconciling Consolidated Total At September 30, 2016 $ 8,174,174 $ 8,638,736 $ 92,128 $ 521,877 $ 8,206,702 $ 25,633,617 At December 31, 2015 7,505,513 8,441,950 95,815 493,571 8,104,269 24,641,118

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Credit-Related Financial Instruments The Company offers credit-related financial instruments in the normal course of business to meet certain financing needs of its customers, that involve off-balance sheet risk. These transactions may include an unused commitment to extend credit, standby letter of credit, or commercial letter of credit. Such transactions involve, to varying degrees, elements of credit risk. The following table summarizes the outstanding amounts of credit-related financial instruments with off-balance sheet risk: (In thousands) At September 30, 2016 At December 31, 2015 Commitments to extend credit $ 5,239,513 $ 4,851,994 Standby letter of credit 141,200 133,294 Commercial letter of credit 46,344 45,742 Total credit-related financial instruments with off-balance sheet risk $ 5,427,057 $ 5,031,030 Commitments to Extend Credit . The Company makes commitments under various terms to lend funds to customers at a future point in time. These commitments include revolving credit arrangements, term loan commitments, and short-term borrowing agreements. Most of these loans have fixed expiration dates or other termination clauses where a fee may be required. Since commitments routinely expire without being funded, or after required availability of collateral occurs, the total commitment amount does not necessarily represent future liquidity requirements. Standby Letter of Credit . A standby letter of credit commits the Company to make payments on behalf of customers if certain specified future events occur. The Company has recourse against the customer for any amount required to be paid to a third party under a standby letter of credit, which is often part of a larger credit agreement under which security is provided. Historically, a large percentage of standby letters of credit expire without being funded. The contractual amount of a standby letter of credit represents the maximum amount of potential future payments the Company could be required to make, and is the Company's maximum credit risk. Commercial Letter of Credit . A commercial letter of credit is issued to facilitate either domestic or foreign trade arrangements for customers. As a general rule, drafts are committed to be drawn when the goods underlying the transaction are in transit. Similar to a standby letter of credit, a commercial letter of credit is often secured by an underlying security agreement including the assets or inventory to which they relate. These commitments subject the Company to potential exposure in excess of the amounts recorded in the financial statements, and therefore, management maintains a specific reserve for unfunded credit commitments. This reserve is reported as a component of accrued expenses and other liabilities in the accompanying Condensed Consolidated Balance Sheets. The following table provides a summary of activity in the reserve for unfunded credit commitments: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Beginning balance $ 2,319 $ 2,007 $ 2,119 $ 5,151 Provision (benefit) 172 16 372 (3,128 ) Ending balance $ 2,491 $ 2,023 $ 2,491 $ 2,023 Litigation Webster is involved in routine legal proceedings occurring in the ordinary course of business and is subject to loss contingencies related to such litigation and claims arising therefrom. Webster evaluates these contingencies based on information currently available, including advice of counsel and assessment of available insurance coverage. Webster establishes an accrual for litigation and claims when a loss contingency is considered probable and the related amount is reasonably estimable. This accrual is periodically reviewed and may be adjusted as circumstances change. Webster also estimates certain loss contingencies for possible litigation and claims, whether or not there is an accrued probable loss. Webster believes it has defenses to all the claims asserted against it in existing litigation matters and intends to defend itself in all matters. Based upon its current knowledge, after consultation with counsel and after taking into consideration its current litigation accrual, Webster believes that at September 30, 2016 any reasonably possible losses, in addition to amounts accrued, are not material to Webster’s consolidated financial condition. However, in light of the uncertainties involved in such actions and proceedings, there is no assurance that the ultimate resolution of these matters will not significantly exceed the amounts currently accrued by Webster or that the Company’s litigation accrual will not need to be adjusted in future periods. Such an outcome could be material to the Company’s operating results in a particular period, depending on, among other factors, the size of the loss or liability imposed and the level of the Company’s income for that period.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accounting and reporting policies of the Company that materially affect its financial statements conform with GAAP. The accompanying unaudited Condensed Consolidated Financial Statements of the Company have been prepared in conformity with the instructions for Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all the information and notes required by GAAP for complete financial statements and should be read in conjunction with the Company's Consolidated Financial Statements, and notes thereto, for the year ended December 31, 2015 , included in the Company's Annual Report on Form 10-K filed with the SEC on February 29, 2016. The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the amounts of assets and liabilities as of the date of the financial statements as well as income and expense during the period. Actual results could differ from those estimates. Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for the full year or any future period.
Reclassification	Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications had an immaterial effect on total assets, total liabilities, net cash provided by operating activities, net cash used for investing activities, and net cash provided by financing activities.
Loans Held For Sale	Loans Held For Sale. Effective January 1, 2016, on a loan by loan election, residential mortgage loans that are classified as held for sale are accounted for under either the fair value option method of accounting or the lower of cost or fair value method of accounting with the election being made at the time the asset is first recognized. The Company has elected the fair value option to mitigate accounting mismatches between held for sale derivative commitments and loan valuations. Prior to January 1, 2016, residential mortgage loans that were classified as held for sale were accounted for at the lower of cost or fair value method of accounting and were valued on an individual asset basis. Loans not originated for sale but subsequently transferred to held for sale continue to be valued at the lower of cost or fair value method of accounting and are valued on an individual asset basis.
Financial Accounting Standards Board (FASB) Standards Adopted during 2016 and FASB Standards Issued but not yet Adopted	Accounting Standards Adopted during 2016 Effective January 1, 2016, the following new accounting guidance was adopted by the Company: • ASU No. 2015-02, Consolidation (Topic 810) - Amendments to the Consolidation Analysis; • ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs; • ASU No. 2015-07, Fair Value Measurement (Topic 820) - Disclosures for investments in Certain Entities That Calculate Net Asset Value per Share (or its Equivalent) (a consensus of the FASB Emerging Issues Task Force); and • ASU No. 2015-16, Business Combinations (Topic 805) - Simplifying the Accounting for Measurement - Period Adjustments. The adoption of these accounting standards did not have a material impact on the Company's financial statements; however, additional disclosures of VIEs are included in Note 3: Variable Interest Entities . The Company did not identify any additional investments requiring consolidation as a result of ASU No. 2015-02. Accounting Standards Issued but not yet Adopted The following table identifies ASUs applicable to the Company that have been issued by the FASB but are not yet effective: ASU Description Effective Date and Financial Statement Impact ASU No. 2016-16 - Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The update addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The Update addresses the following eight issues: Debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The Company intends to adopt the Update for the first quarter of 2019. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. Current GAAP requires an "incurred loss" methodology for recognizing credit losses that delays recognition until it is probable a loss has been incurred. Both financial institutions and users of their financial statements expressed concern that current GAAP restricts the ability to record credit losses that are expected, but do not yet meet the "probable" threshold. The main objective of this Update is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this Update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. The Change from an "incurred loss" method to an "expected loss" method represents a fundamental shift from existing GAAP, and may result in material changes to the Company's accounting for credit losses on financial instruments. The Company is evaluating the effect that this ASU will have on its financial statements and related disclosures. The ASU will be effective for the Company as of January 1, 2020. ASU No. 2016-09, Compensation - Stock Compensation (Topic 718) - Improvements to Employee Share Based Payment Accounting. The Update impacts the accounting for employee share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. In addition, the amendments in this Update eliminates the guidance in Topic 718 that was indefinitely deferred shortly after the issuance of FASB Statement No. 123 (revised 2004), Share-Based Payment. The Company intends to adopt the Update for the first quarter of 2017 and is in the process of assessing the impact on its financial statements. ASU No. 2016-06, Derivatives and Hedging (Topic 815) - Contingent Put and Call Options in Debt Instruments. The Update clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. The Update requires the assessment of embedded call (put) options solely in accordance with the four-step decision sequence. The Company intends to adopt the Update for the first quarter of 2017. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2016-02, Leases (Topic 842). The Update introduces a lessee model that brings most leases on the balance sheet. The Update also aligns certain of the underlying principles of the new lessor model with those in ASC 606 "Revenue from Contracts with Customers", the FASB’s new revenue recognition standard (e.g., evaluating how collectability should be considered and determining when profit can be recognized). Furthermore, the Update addresses other concerns including the elimination of the required use of bright-line tests for determining lease classification. Lessors are required to provide additional transparency into the exposure to the changes in value of their residual assets and how they manage that exposure. The Company intends to adopt the Update for the first quarter of 2019 and is in the process of assessing the impact on its financial statements. ASU Description Effective Date and Financial Statement Impact ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities. Equity investments not accounted for under the equity method or those that do not result in consolidation of the investee are to be measured at fair value with changes in the fair value recognized through net income. Entities are to present separately in other comprehensive income, the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when an election to measure the liability at fair value in accordance with the fair value option for financial instruments has been made. Also, the requirement to disclose the method(s) and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost on the balance sheet has been eliminated. The Company intends to adopt the Update for the first quarter of 2018 and is in the process of assessing the impact on its financial statements. ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) and ASU No. 2015-14, Revenue from Contracts with Customers (Topic 606) A single comprehensive model has been established for an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled, and will supersede nearly all existing revenue recognition guidance, and clarify and converge revenue recognition principles under GAAP and International Financial Reporting Standards. The five steps to recognizing revenue: (i) identify the contracts with the customer; (ii) identify the separate performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the separate performance obligations; and (v) recognize revenue when each performance obligation is satisfied. The most significant potential impact to banking entities relates to less prescriptive derecognition requirements on the sale of owned real estate properties. An entity may elect either a full retrospective or a modified retrospective application. ASU No. 2015-14 - Revenue from Contracts with Customers (Topic 606), defers the effective date to annual and interim periods beginning after December 15, 2017. The Company intends to adopt the Update for the first quarter of 2018. Adoption is not anticipated to have a material impact on the Company's financial statements.

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Summary of Investment Securities	A summary of the amortized cost and fair value of investment securities is presented below: At September 30, 2016 At December 31, 2015 (In thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Available-for-sale: U.S. Treasury Bills $ 985 $ — $ — $ 985 $ 924 $ — $ — $ 924 Agency CMO 457,768 7,453 (1,491 ) 463,730 546,168 5,532 (2,946 ) 548,754 Agency MBS 992,742 11,051 (2,779 ) 1,001,014 1,075,941 6,459 (17,291 ) 1,065,109 Agency CMBS 481,079 3,435 (106 ) 484,408 215,670 639 (959 ) 215,350 CMBS 465,120 4,794 (1,553 ) 468,361 574,686 7,485 (2,905 ) 579,266 CLO 481,555 3,132 (451 ) 484,236 431,837 592 (3,270 ) 429,159 Single issuer trust preferred securities 42,312 63 (4,264 ) 38,111 42,168 — (4,998 ) 37,170 Corporate debt securities 97,149 2,117 — 99,266 104,031 2,290 — 106,321 Equities - financial services — — — — 3,499 — (921 ) 2,578 Securities available-for-sale $ 3,018,710 $ 32,045 $ (10,644 ) $ 3,040,111 $ 2,994,924 $ 22,997 $ (33,290 ) $ 2,984,631 Held-to-maturity: Agency CMO $ 371,700 $ 4,353 $ (890 ) $ 375,163 $ 407,494 $ 3,717 $ (2,058 ) $ 409,153 Agency MBS 2,072,481 48,397 (1,544 ) 2,119,334 2,030,176 38,813 (19,908 ) 2,049,081 Agency CMBS 624,403 14,449 — 638,852 686,086 4,253 (325 ) 690,014 Municipal bonds and notes 610,690 13,658 (1,682 ) 622,666 435,905 12,019 (417 ) 447,507 CMBS 341,019 10,935 (80 ) 351,874 360,018 5,046 (2,704 ) 362,360 Private Label MBS 2,039 15 — 2,054 3,373 46 — 3,419 Securities held-to-maturity $ 4,022,332 $ 91,807 $ (4,196 ) $ 4,109,943 $ 3,923,052 $ 63,894 $ (25,412 ) $ 3,961,534
Summary of Changes in OTTI	The following table presents the changes in OTTI: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Beginning balance $ 3,437 $ 3,178 $ 3,288 $ 3,696 Reduction for securities sold or called (30 ) — (30 ) (518 ) Additions for OTTI not previously recognized in earnings — 82 149 82 Ending balance $ 3,407 $ 3,260 $ 3,407 $ 3,260
Summary of Gross Unrealized Losses not Considered OTTI	The following tables provide information on fair value and unrealized losses for the individual securities with an unrealized loss, aggregated by investment security type and length of time that the individual securities have been in a continuous unrealized loss position: At September 30, 2016 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses # of Holdings Fair Value Unrealized Losses Available-for-sale: Agency CMO $ 22,888 $ (337 ) $ 71,140 $ (1,154 ) 7 $ 94,028 $ (1,491 ) Agency MBS 26,917 (48 ) 274,866 (2,731 ) 48 301,783 (2,779 ) Agency CMBS 78,572 (106 ) — — 6 78,572 (106 ) CMBS 34,741 (382 ) 126,244 (1,171 ) 24 160,985 (1,553 ) CLO 9,780 (28 ) 69,708 (423 ) 4 79,488 (451 ) Single issuer trust preferred securities — — 33,812 (4,264 ) 7 33,812 (4,264 ) Equities - financial services — — — — — — — Total available-for-sale in an unrealized loss position $ 172,898 $ (901 ) $ 575,770 $ (9,743 ) 96 $ 748,668 $ (10,644 ) Held-to-maturity: Agency CMO $ 77,555 $ (661 ) $ 18,814 $ (229 ) 8 $ 96,369 $ (890 ) Agency MBS 86,133 (88 ) 297,018 (1,456 ) 30 383,151 (1,544 ) Agency CMBS — — — — — — — Municipal bonds and notes 106,453 (1,663 ) 3,359 (19 ) 45 109,812 (1,682 ) CMBS 27,773 (80 ) — — 5 27,773 (80 ) Total held-to-maturity in an unrealized loss position $ 297,914 $ (2,492 ) $ 319,191 $ (1,704 ) 88 $ 617,105 $ (4,196 ) At December 31, 2015 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses # of Holdings Fair Value Unrealized Losses Available-for-sale: Agency CMO $ 195,369 $ (2,195 ) $ 26,039 $ (751 ) 14 $ 221,408 $ (2,946 ) Agency MBS 481,839 (6,386 ) 351,911 (10,905 ) 84 833,750 (17,291 ) Agency CMBS 124,241 (959 ) — — 7 124,241 (959 ) CMBS 276,330 (2,879 ) 19,382 (26 ) 29 295,712 (2,905 ) CLO 211,515 (2,709 ) 15,708 (561 ) 13 227,223 (3,270 ) Single issuer trust preferred securities 4,087 (128 ) 33,083 (4,870 ) 8 37,170 (4,998 ) Equities - financial services 2,578 (921 ) — — 1 2,578 (921 ) Total available-for-sale in an unrealized loss position $ 1,295,959 $ (16,177 ) $ 446,123 $ (17,113 ) 156 $ 1,742,082 $ (33,290 ) Held-to-maturity: Agency CMO $ 143,364 $ (1,304 ) $ 27,928 $ (754 ) 13 $ 171,292 $ (2,058 ) Agency MBS 551,918 (7,089 ) 470,828 (12,819 ) 87 1,022,746 (19,908 ) Agency CMBS 110,864 (325 ) — — 7 110,864 (325 ) Municipal bonds and notes 29,034 (130 ) 13,829 (287 ) 27 42,863 (417 ) CMBS 142,382 (1,983 ) 30,129 (721 ) 18 172,511 (2,704 ) Total held-to-maturity in an unrealized loss position $ 977,562 $ (10,831 ) $ 542,714 $ (14,581 ) 152 $ 1,520,276 $ (25,412 )
Summary of Sale Proceeds of Available for Sale Securities	The following table provides information on sales of available-for-sale securities: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Proceeds from sales $ — $ 2,500 $ 259,273 $ 37,465 Gross realized gains on sales $ — $ — $ 2,891 $ 529 Less: Gross realized losses on sales — — 2,477 — Gain on sale of investment securities, net $ — $ — $ 414 $ 529
Summary of Debt Securities by Contractual Maturity	The amortized cost and fair value of debt securities by contractual maturity are set forth below: At September 30, 2016 Available-for-Sale Held-to-Maturity (In thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 60,737 $ 61,771 $ 7,988 $ 8,034 Due after one year through five years 37,397 38,479 19,980 20,376 Due after five through ten years 572,461 575,465 36,758 37,932 Due after ten years 2,348,115 2,364,396 3,957,606 4,043,601 Total debt securities $ 3,018,710 $ 3,040,111 $ 4,022,332 $ 4,109,943

Loans and Leases (Tables)

Loans and Leases (Tables)	9 Months Ended
	Sep. 30, 2016
Loans and Leases Receivable Disclosure [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The following table summarizes loans and leases: (In thousands) At September 30, At December 31, 2015 Residential $ 4,234,047 $ 4,061,001 Consumer 2,707,343 2,702,560 Commercial 4,779,802 4,315,999 Commercial Real Estate 4,280,513 3,991,649 Equipment Financing 621,696 600,526 Loans and leases (1) (2) $ 16,623,401 $ 15,671,735 (1) Loans and leases include net deferred fees and net premiums/discounts of $19.7 million and $18.0 million at September 30, 2016 and December 31, 2015 , respectively. (2) At September 30, 2016 , the Company had pledged $6.4 billion of eligible residential and consumer loans as collateral to support borrowing capacity at the FHLB Boston and the FRB of Boston.
Past Due Financing Receivables	The following tables summarize the aging of loans and leases: At September 30, 2016 (In thousands) 30-59 Days Past Due and Accruing 60-89 Days 90 or More Days Past Due and Accruing Non-accrual Total Past Due and Non-accrual Current Total Loans Residential $ 7,547 $ 3,547 $ — $ 49,197 $ 60,291 $ 4,173,756 $ 4,234,047 Consumer: Home equity 7,627 4,746 — 35,597 47,970 2,371,700 2,419,670 Other consumer 1,757 1,354 — 1,571 4,682 282,991 287,673 Commercial: Commercial non-mortgage 1,949 576 23 27,397 29,945 3,946,986 3,976,931 Asset-based — — — — — 802,871 802,871 Commercial real estate: Commercial real estate 1,082 148 5,444 10,957 17,631 3,933,588 3,951,219 Commercial construction — — — 3,438 3,438 325,856 329,294 Equipment financing 3,164 313 — 202 3,679 618,017 621,696 Total $ 23,126 $ 10,684 $ 5,467 $ 128,359 $ 167,636 $ 16,455,765 $ 16,623,401 At December 31, 2015 (In thousands) 30-59 Days 60-89 Days Past Due and Accruing 90 or More Days Past Due Non-accrual Total Past Due and Non-accrual Current Total Loans Residential $ 10,365 $ 4,703 $ 2,029 $ 54,201 $ 71,298 $ 3,989,703 $ 4,061,001 Consumer: Home equity 9,061 4,242 — 37,337 50,640 2,402,758 2,453,398 Other consumer 1,390 615 — 560 2,565 246,597 249,162 Commercial: Commercial non-mortgage 768 3,288 22 27,037 31,115 3,531,669 3,562,784 Asset-based — — — — — 753,215 753,215 Commercial real estate: Commercial real estate 1,624 625 — 16,767 19,016 3,673,408 3,692,424 Commercial construction — — — 3,461 3,461 295,764 299,225 Equipment financing 543 59 — 706 1,308 599,218 600,526 Total $ 23,751 $ 13,532 $ 2,051 $ 140,069 $ 179,403 $ 15,492,332 $ 15,671,735
Activity In Allowance For Losses	The following tables summarize the ALLL: At or for the three months ended September 30, 2016 Residential Consumer Commercial Commercial Real Estate Equipment Financing Total ALLL: Balance, beginning of period $ 24,413 $ 42,956 $ 73,822 $ 33,622 $ 5,615 $ 180,428 Provision (benefit) charged to expense 1,076 4,985 4,351 2,953 885 14,250 Charge-offs (1,304 ) (5,259 ) (2,561 ) — (300 ) (9,424 ) Recoveries 554 1,313 370 194 240 2,671 Balance, end of period $ 24,739 $ 43,995 $ 75,982 $ 36,769 $ 6,440 $ 187,925 At or for the three months ended September 30, 2015 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total ALLL: Balance, beginning of period $ 24,463 $ 40,807 $ 66,241 $ 30,768 $ 5,581 $ 167,860 Provision (benefit) charged to expense 1,150 6,864 3,089 1,961 (64 ) 13,000 Charge-offs (1,588 ) (4,831 ) (2,204 ) (1,346 ) — (9,969 ) Recoveries 281 1,004 715 69 32 2,101 Balance, end of period $ 24,306 $ 43,844 $ 67,841 $ 31,452 $ 5,549 $ 172,992 At or for the nine months ended September 30, 2016 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total ALLL: Balance, beginning of period $ 25,876 $ 42,052 $ 66,686 $ 34,889 $ 5,487 $ 174,990 Provision (benefit) charged to expense 991 12,458 25,447 3,921 1,033 43,850 Charge-offs (3,536 ) (14,236 ) (17,294 ) (2,521 ) (521 ) (38,108 ) Recoveries 1,408 3,721 1,143 480 441 7,193 Balance, end of period $ 24,739 $ 43,995 $ 75,982 $ 36,769 $ 6,440 $ 187,925 Individually evaluated for impairment $ 9,443 $ 3,005 $ 6,579 $ 467 $ 9 $ 19,503 Collectively evaluated for impairment $ 15,296 $ 40,990 $ 69,403 $ 36,302 $ 6,431 $ 168,422 Loan and lease balances: Individually evaluated for impairment $ 122,020 $ 46,208 $ 58,197 $ 24,423 $ 6,863 $ 257,711 Collectively evaluated for impairment 4,112,027 2,661,135 4,721,605 4,256,090 614,833 16,365,690 Loans and leases $ 4,234,047 $ 2,707,343 $ 4,779,802 $ 4,280,513 $ 621,696 $ 16,623,401 At or for the nine months ended September 30, 2015 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total ALLL: Balance, beginning of period $ 25,452 $ 43,518 $ 52,114 $ 32,102 $ 6,078 $ 159,264 Provision (benefit) charged to expense 3,100 10,091 18,468 4,617 (776 ) 35,500 Charge-offs (5,004 ) (12,980 ) (5,000 ) (5,590 ) (30 ) (28,604 ) Recoveries 758 3,215 2,259 323 277 6,832 Balance, end of period $ 24,306 $ 43,844 $ 67,841 $ 31,452 $ 5,549 $ 172,992 Individually evaluated for impairment $ 10,773 $ 3,540 $ 11,478 $ 4,527 $ 5 $ 30,323 Collectively evaluated for impairment $ 13,533 $ 40,304 $ 56,363 $ 26,925 $ 5,544 $ 142,669 Loan and lease balances: Individually evaluated for impairment $ 138,227 $ 46,455 $ 54,522 $ 41,598 $ 102 $ 280,904 Collectively evaluated for impairment 3,877,612 2,604,247 4,085,457 3,815,557 552,748 14,935,621 Loans and leases $ 4,015,839 $ 2,650,702 $ 4,139,979 $ 3,857,155 $ 552,850 $ 15,216,525
Impaired Loans	The following tables summarize impaired loans and leases: At September 30, 2016 (In thousands) Unpaid Principal Balance Total Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Residential $ 134,026 $ 122,020 $ 21,404 $ 100,616 $ 9,443 Consumer 52,516 46,208 23,612 22,596 3,005 Commercial 64,537 58,197 25,720 32,477 6,579 Commercial real estate: Commercial real estate 20,823 20,044 9,156 10,888 467 Commercial construction 4,911 4,379 4,379 — — Equipment financing 6,901 6,863 6,638 225 9 Total $ 283,714 $ 257,711 $ 90,909 $ 166,802 $ 19,503 At December 31, 2015 (In thousands) Unpaid Principal Balance Total Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Residential $ 148,144 $ 134,448 $ 23,024 $ 111,424 $ 10,364 Consumer 56,680 48,425 25,130 23,295 3,477 Commercial 67,116 56,581 31,600 24,981 5,197 Commercial real estate: Commercial real estate 36,980 33,333 9,204 24,129 3,160 Commercial construction 7,010 5,962 5,939 23 3 Equipment financing 612 422 328 94 3 Total $ 316,542 $ 279,171 $ 95,225 $ 183,946 $ 22,204 The following table summarizes the average recorded investment and interest income recognized for impaired loans and leases: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 (In thousands) Average Recorded Investment Accrued Interest Income Cash Basis Interest Income Average Accrued Cash Basis Interest Income Average Recorded Investment Accrued Cash Basis Interest Income Average Recorded Investment Accrued Cash Basis Interest Income Residential $ 124,993 $ 1,070 $ 304 $ 138,519 $ 1,114 $ 290 $ 128,234 $ 3,309 $ 918 $ 140,105 $ 3,322 $ 847 Consumer 46,892 336 238 47,787 371 271 47,317 1,029 754 48,352 1,094 827 Commercial 58,874 352 — 54,667 262 — 57,389 1,299 — 45,349 936 — Commercial real estate: Commercial real estate 23,930 77 — 44,222 137 — 26,689 374 — 65,640 1,024 — Commercial construction 4,386 12 — 6,059 33 — 5,171 81 — 6,068 99 — Equipment financing 3,642 107 — 111 2 — 3,642 109 — 367 15 — Total $ 262,717 $ 1,954 $ 542 $ 291,365 $ 1,919 $ 561 $ 268,442 $ 6,201 $ 1,672 $ 305,881 $ 6,490 $ 1,674
Financing Receivable Credit Quality Indicators	The following table summarizes commercial, commercial real estate and equipment financing loans and leases segregated by risk rating exposure: Commercial Commercial Real Estate Equipment Financing (In thousands) At September 30, At December 31, At September 30, At December 31, At September 30, At December 31, (1) - (6) Pass $ 4,474,603 $ 4,023,255 $ 4,152,199 $ 3,857,019 $ 598,526 $ 586,445 (7) Special Mention 93,767 70,904 36,588 55,030 25 1,628 (8) Substandard 207,059 220,389 91,726 79,289 23,145 12,453 (9) Doubtful 4,373 1,451 — 311 — — Total $ 4,779,802 $ 4,315,999 $ 4,280,513 $ 3,991,649 $ 621,696 $ 600,526
Troubled Debt Restructurings on Financing Receivables	Troubled Debt Restructurings The following table summarizes information for TDRs: (Dollars in thousands) At September 30, 2016 At December 31, 2015 Accrual status $ 161,853 $ 171,784 Non-accrual status 74,147 100,906 Total recorded investment of TDRs (1) $ 236,000 $ 272,690 Accruing TDRs performing under modified terms more than one year 54.1 % 55.0 % Specific reserves for TDRs included in the balance of ALLL $ 16,302 $ 21,405 Additional funds committed to borrowers in TDR status 1,316 1,133 (1) Total recorded investment of TDRs excludes $0.8 million and $1.1 million of accrued interest receivable at September 30, 2016 and December 31, 2015 , respectively. In the three and nine months ended September 30, 2016 and 2015 , Webster charged off $3.0 million , $17.9 million , $1.7 million and $7.6 million , respectively, for the portion of TDRs deemed to be uncollectible. A TDR may be modified by means of extended maturity, below market adjusted interest rates, a combination of rate and maturity, or other means, including covenant modifications, forbearance, loans discharged under Chapter 7 bankruptcy, or other concessions. The following table provides information on the type of concession for loans and leases modified as TDRs: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Number of Post- (1) Number of Post- (1) Number of Post- (1) Number of Post- (1) (Dollars in thousands) Residential: Extended Maturity 4 $ 967 4 $ 998 11 $ 1,969 19 $ 3,301 Adjusted Interest Rate 1 292 1 160 2 528 2 464 Maturity/Rate Combined 3 290 4 1,006 10 1,185 18 3,138 Other (2) 3 299 9 1,594 18 3,190 23 3,387 Consumer: Extended Maturity 2 89 4 296 9 381 9 935 Adjusted Interest Rate — — — — — — — — Maturity/Rate Combined 3 264 — — 11 923 8 444 Other (2) 8 270 20 1,357 37 1,447 50 3,087 Commercial: Extended Maturity 2 213 — — 11 14,862 3 256 Adjusted Interest Rate — — — — — 1 24 Maturity/Rate Combined — — 1 74 2 648 5 371 Other (2) 4 1,265 5 1,772 11 1,639 9 8,062 Commercial real estate: Extended Maturity 1 109 1 315 1 109 1 315 Maturity/Rate Combined 1 291 — — 2 335 1 43 Other (2) — — 1 405 1 509 1 405 Equipment Financing Extended Maturity 6 6,638 — — 7 6,642 — — Total TDRs 38 $ 10,987 50 $ 7,977 133 $ 34,367 150 $ 24,232 (1) Post-modification balances approximate pre-modification balances. The aggregate amount of charge-offs as a result of the restructurings was not significant. (2) Other includes covenant modifications, forbearance, loans discharged under Chapter 7 bankruptcy, or other concessions. The following table provides information on loans and leases modified as TDRs within the previous 12 months and for which there was a payment default during the periods presented: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 (Dollars in thousands) Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Residential — $ — — $ — — $ — — $ — Consumer — — 1 3 — — 2 326 Commercial — — 1 9 — — 1 9 Commercial real estate — — — — — — — — Total — $ — 2 $ 12 — $ — 3 $ 335 The recorded investment of TDRs in commercial, commercial real estate, and equipment financing segregated by risk rating exposure is as follows: (In thousands) At September 30, 2016 At December 31, 2015 (1) - (6) Pass $ 11,510 $ 12,970 (7) Special Mention 7 2,999 (8) Substandard 52,658 72,132 (9) Doubtful 3,597 1,717 Total $ 67,772 $ 89,818

Transfers of Financial Assets (

Transfers of Financial Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Transfers and Servicing [Abstract]
Schedule Of Reserve For Loan Repurchases Table	The following table provides a summary of activity in the reserve for loan repurchases: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Beginning balance $ 992 $ 1,120 $ 1,192 $ 1,059 Provision (benefit) charged to expense 37 43 (64 ) 104 Repurchased loans and settlements charged off — — (99 ) — Ending balance $ 1,029 $ 1,163 $ 1,029 $ 1,163
Schedule of Loan Sale Activity	The following table provides information for mortgage banking activities: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Residential mortgage loans held for sale: Proceeds from sale $ 128,268 $ 143,801 $ 298,840 $ 352,300 Net gain on sale 3,324 1,441 6,749 5,519 Fair value option adjustment (48 ) — 2,101 — Loans sold with servicing rights retained 115,822 132,920 273,827 327,030

Goodwill and Other Intangible30

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The gross carrying amount and accumulated amortization of CDI and customer relationships included in reportable segments are as follows: At September 30, 2016 At December 31, 2015 (In thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Community Banking CDI $ 49,420 $ (49,420 ) $ — $ 49,420 $ (48,277 ) $ 1,143 HSA Bank: CDI 22,000 (5,484 ) 16,516 22,000 (3,269 ) 18,731 Customer relationships 21,000 (2,760 ) 18,240 21,000 (1,548 ) 19,452 Total HSA Bank 43,000 (8,244 ) 34,756 43,000 (4,817 ) 38,183 Total other intangible assets $ 92,420 $ (57,664 ) $ 34,756 $ 92,420 $ (53,094 ) $ 39,326
Schedule Of Expected Amortization Expense, Next Four Years	As of September 30, 2016 , the remaining estimated aggregate future amortization expense for intangible assets is as follows: (In thousands) Remainder of 2016 $ 1,082 2017 4,062 2018 3,847 2019 3,847 2020 3,847 Thereafter 18,071

Deposits (Tables)

Deposits (Tables)	9 Months Ended
	Sep. 30, 2016
Banking and Thrift [Abstract]
Schedule of Deposits	A summary of deposits by type follows: (In thousands) At September 30, At December 31, Non-interest-bearing: Demand $ 3,993,750 $ 3,713,063 Interest-bearing: Checking 2,429,222 2,369,971 Health savings accounts 4,187,823 3,802,313 Money market 2,342,236 1,933,460 Savings 4,226,934 4,047,817 Time deposits 2,020,943 2,086,154 Total interest-bearing 15,207,158 14,239,715 Total deposits $ 19,200,908 $ 17,952,778 Time deposits and interest-bearing checking, included in above balances, obtained through brokers $ 852,014 $ 910,304 Time deposits, included in above balance, that meet or exceed the FDIC limit 481,884 542,206 Deposit overdrafts reclassified as loan balances 1,936 1,356
Scheduled Maturities of Time Deposits	The scheduled maturities of time deposits are as follows: (In thousands) At September 30, Remainder of 2016 $ 267,114 2017 670,946 2018 342,507 2019 473,697 2020 180,741 Thereafter 85,938 Total time deposits $ 2,020,943

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Schedule of Repurchase Agreements	The following table summarizes securities sold under agreements to repurchase and other borrowings: (In thousands) At September 30, At December 31, Securities sold under agreements to repurchase: Original maturity of one year or less $ 353,705 $ 334,400 Original maturity of greater than one year, non-callable 400,000 500,000 Total securities sold under agreements to repurchase 753,705 834,400 Fed funds purchased 47,000 317,000 Securities sold under agreements to repurchase and other borrowings $ 800,705 $ 1,151,400
Federal Home Loan Bank, Advances	The following table provides information for FHLB advances: At September 30, 2016 At December 31, 2015 (Dollars in thousands) Amount Weighted- Average Contractual Coupon Rate Amount Weighted- Average Contractual Coupon Rate Maturing within 1 year $ 1,875,000 0.50 % $ 2,025,934 0.55 % After 1 but within 2 years 100,500 1.49 500 5.66 After 2 but within 3 years 133,731 1.34 200,000 1.36 After 3 but within 4 years 244,295 1.70 103,026 1.54 After 4 but within 5 years 75,000 1.51 175,000 1.77 After 5 years 159,442 1.82 159,655 1.60 2,587,968 0.81 % 2,664,115 0.79 % Premiums on advances 15 24 Federal Home Loan Bank advances $ 2,587,983 $ 2,664,139 Aggregate carrying value of assets pledged as collateral $ 5,919,426 $ 5,719,746 Remaining borrowing capacity 1,386,310 1,203,057
Schedule of Long-term Debt Instruments	The following table summarizes long-term debt: (Dollars in thousands) At September 30, At December 31, 4.375% Senior fixed-rate notes due February 15, 2024 $ 150,000 $ 150,000 Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (1) 77,320 77,320 Total notes and subordinated debt 227,320 227,320 Discount on senior fixed-rate notes (875 ) (964 ) Debt issuance cost on senior fixed-rate notes (2) (995 ) (1,096 ) Long-term debt $ 225,450 $ 225,260 (1) The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95% , was 3.81% at September 30, 2016 and 3.48% at December 31, 2015 . (2) In accordance with the adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, debt issuance cost is accounted for as a reduction to long-term debt. Previously debt issuance cost was included in accrued interest receivable and other assets within the accompanying Condensed Consolidated Balance Sheets.

Accumulated Other Comprehensi33

Accumulated Other Comprehensive Loss, Net of Tax (Tables)	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Loss by Component	The following tables summarize the changes in AOCL by component: Three months ended September 30, 2016 Nine months ended September 30, 2016 (In thousands) Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Beginning balance $ 12,363 $ (23,406 ) $ (46,468 ) $ (57,511 ) $ (6,407 ) $ (22,980 ) $ (48,719 ) $ (78,106 ) OCI/OCL before reclassifications 1,218 794 — 2,012 20,156 (2,416 ) — 17,740 Amounts reclassified from AOCL — 1,221 1,125 2,346 (168 ) 4,005 3,376 7,213 Net current-period OCI/OCL 1,218 2,015 1,125 4,358 19,988 1,589 3,376 24,953 Ending balance $ 13,581 $ (21,391 ) $ (45,343 ) $ (53,153 ) $ 13,581 $ (21,391 ) $ (45,343 ) $ (53,153 ) Three months ended September 30, 2015 Nine months ended September 30, 2015 (In thousands) Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Beginning balance $ 9,461 $ (24,969 ) $ (45,187 ) $ (60,695 ) $ 16,421 $ (25,530 ) $ (47,152 ) $ (56,261 ) OCI/OCL before reclassifications 660 (1,998 ) — (1,338 ) (5,964 ) (4,154 ) — (10,118 ) Amounts reclassified from AOCL 52 1,479 983 2,514 (284 ) 4,196 2,948 6,860 Net current-period OCI/OCL 712 (519 ) 983 1,176 (6,248 ) 42 2,948 (3,258 ) Ending balance $ 10,173 $ (25,488 ) $ (44,204 ) $ (59,519 ) $ 10,173 $ (25,488 ) $ (44,204 ) $ (59,519 )
Schedule of Accumulated Other Comprehensive Loss	The following tables provide information for the items reclassified from AOCL: (In thousands) Three months ended September 30, Nine months ended September 30, Associated Line Item in the Condensed Consolidated Statements of Income AOCL Components 2016 2015 2016 2015 Available-for-sale and transferred securities: Unrealized gains (losses) on investment securities $ — $ — $ 414 $ 529 Gain on sale of investment securities, net Unrealized gains (losses) on investment securities — (82 ) (149 ) (82 ) Impairment loss recognized in earnings Total before tax — (82 ) 265 447 Tax benefit (expense) — 30 (97 ) (163 ) Income tax expense Net of tax $ — $ (52 ) $ 168 $ 284 Derivative instruments: Cash flow hedges $ (1,925 ) $ (2,332 ) $ (6,314 ) $ (6,616 ) Total interest expense Tax benefit 704 853 2,309 2,420 Income tax expense Net of tax $ (1,221 ) $ (1,479 ) $ (4,005 ) $ (4,196 ) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (1,780 ) $ (1,540 ) $ (5,343 ) $ (4,621 ) Compensation and benefits (1) Prior service costs (4 ) (19 ) (11 ) (55 ) Compensation and benefits (1) Total before tax (1,784 ) (1,559 ) (5,354 ) (4,676 ) Tax benefit 659 576 1,978 1,728 Income tax expense Net of tax $ (1,125 ) $ (983 ) $ (3,376 ) $ (2,948 ) (1) These accumulated other comprehensive income components are included in the computation of net periodic benefit cost (see Retirement Benefit note 14 for further details).

Regulatory Matters (Tables)

Regulatory Matters (Tables)	9 Months Ended
	Sep. 30, 2016
Regulatory Capital Requirements [Abstract]
Information On The Capital Ratios	The following table provides information on the capital ratios for Webster Financial Corporation and Webster Bank: Capital Requirements Actual Minimum Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio At September 30, 2016 Webster Financial Corporation CET1 risk-based capital $ 1,892,244 10.5 % $ 812,420 4.5 % $ 1,173,495 6.5 % Total risk-based capital 2,282,690 12.6 1,444,302 8.0 1,805,377 10.0 Tier 1 risk-based capital 2,014,954 11.2 1,083,226 6.0 1,444,302 8.0 Tier 1 leverage capital 2,014,954 8.2 987,561 4.0 1,234,452 5.0 Webster Bank CET1 risk-based capital $ 1,919,417 10.6 % $ 811,487 4.5 % $ 1,172,148 6.5 % Total risk-based capital 2,109,833 11.7 1,442,643 8.0 1,803,304 10.0 Tier 1 risk-based capital 1,919,417 10.6 1,081,983 6.0 1,442,643 8.0 Tier 1 leverage capital 1,919,417 7.8 986,708 4.0 1,233,385 5.0 At December 31, 2015 Webster Financial Corporation CET1 risk-based capital $ 1,824,106 10.7 % $ 766,848 4.5 % $ 1,107,670 6.5 % Total risk-based capital 2,201,245 12.9 1,363,286 8.0 1,704,107 10.0 Tier 1 risk-based capital 1,966,146 11.5 1,022,464 6.0 1,363,286 8.0 Tier 1 leverage capital 1,966,146 8.2 954,369 4.0 1,192,962 5.0 Webster Bank CET1 risk-based capital $ 1,869,241 11.0 % $ 765,152 4.5 % $ 1,105,220 6.5 % Total risk-based capital 2,046,350 12.0 1,360,271 8.0 1,700,338 10.0 Tier 1 risk-based capital 1,869,241 11.0 1,020,203 6.0 1,360,271 8.0 Tier 1 leverage capital 1,869,241 7.8 953,300 4.0 1,191,626 5.0

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Share Basic And Diluted	Reconciliation of the calculation of basic and diluted earnings per common share follows: Three months ended September 30, Nine months ended September 30, (In thousands, except per share data) 2016 2015 2016 2015 Earnings for basic and diluted earnings per common share: Net income $ 51,817 $ 51,370 $ 149,467 $ 152,917 Less: Preferred stock dividends 2,024 2,024 6,072 6,687 Net income available to common shareholders 49,793 49,346 143,395 146,230 Less: Earnings applicable to participating securities 159 170 468 515 Earnings applicable to common shareholders $ 49,634 $ 49,176 $ 142,927 $ 145,715 Shares: Weighted-average common shares outstanding - basic 91,365 91,458 91,298 90,816 Effect of dilutive securities: Stock options and restricted stock 465 512 452 532 Warrants 27 37 26 43 Weighted-average common shares outstanding - diluted 91,857 92,007 91,776 91,391 Earnings per common share: Basic $ 0.54 $ 0.54 $ 1.57 $ 1.61 Diluted 0.54 0.53 1.56 1.60
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Potential common shares excluded from the effect of dilutive securities because they would have been anti-dilutive, are as follows: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Stock options (shares with exercise price greater than market price) 172 305 172 305 Restricted stock (due to performance conditions on non-participating shares) — 52 161 93

Derivative Financial Instrume36

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value Of Derivative Financial Instruments Designated As Cash Flow Hedges	The following table presents the notional amounts and fair values of derivative positions: At September 30, 2016 At December 31, 2015 Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives (In thousands) Notional Fair Notional Fair Notional Fair Notional Fair Designated as hedging instruments: Positions subject to a master netting agreement (1) Interest rate derivatives $ 175,000 $ 768 $ 150,000 $ 3,433 $ 200,000 $ 2,507 $ 100,000 $ 1,359 Not designated as hedging instruments: Positions subject to a master netting agreement (1) Interest rate derivatives 472,750 236 2,320,222 91,262 989,695 2,255 1,543,479 40,302 Other 22,634 66 8,517 37 8,237 183 4,561 66 Positions not subject to a master netting agreement (2) Interest rate derivatives 2,388,726 116,645 404,272 125 2,050,460 58,304 482,738 571 RPAs 75,250 320 106,633 337 41,798 153 92,985 245 Mortgage banking derivatives (3) 110,015 1,874 132,529 698 62,514 819 — — Other — — 60 10 — — 60 9 Total not designated as hedging instruments 3,069,375 119,141 2,972,233 92,469 3,152,704 61,714 2,123,823 41,193 Gross derivative instruments, before netting $ 3,244,375 119,909 $ 3,122,233 95,902 $ 3,352,704 64,221 $ 2,223,823 42,552 Less: Legally enforceable master netting agreements 1,070 1,070 4,945 4,945 Less: Cash collateral posted — 93,662 — 31,330 Total derivative instruments, after netting $ 118,839 $ 1,170 $ 59,276 $ 6,277 (1) The Company has elected to report derivative positions subject to a legally enforceable master netting agreement on a net basis, net of cash collateral. Refer to the Offsetting Derivatives section of this footnote for additional information. (2) Derivative positions not subject to a legally enforceable master netting agreement are reported on a gross basis in the accompanying Condensed Consolidated Balance Sheets. (3) Notional amounts include mandatory forward commitments of $133.1 million , while notional amounts do not include approved floating rate commitments of $29.3 million , at September 30, 2016 .
Other Derivatives Not Designated For Hedge Accounting	Changes in the fair value of derivatives not qualifying for hedge accounting treatment were recognized as follows: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Interest rate derivatives $ 608 $ 955 $ 6,515 $ 3,375 RPAs 110 — (143 ) (118 ) Mortgage banking derivatives 720 (1,331 ) 357 215 Other (285 ) 29 (582 ) (37 ) Total impact on other non-interest income $ 1,153 $ (347 ) $ 6,147 $ 3,435
Offsetting Liabilities	The following table is presented on a gross basis, prior to the application of counterparty netting agreements. Derivative assets and liabilities are shown net of cash collateral: At September 30, 2016 At December 31, 2015 (In thousands) Gross Amount Amount Offset Net Amount (1) (2) Gross Amount Amount Offset Net Amount (1) (2) Derivative instrument assets: Hedged Accounting Positions $ 768 $ (768 ) $ — $ 2,507 $ (2,507 ) $ — Non-Hedged Accounting Positions 302 (302 ) — 2,438 (2,438 ) — Total $ 1,070 $ (1,070 ) $ — $ 4,945 $ (4,945 ) $ — Derivative instrument liabilities: Hedged Accounting Positions $ 3,433 $ (3,433 ) $ — $ 1,359 $ (1,359 ) $ — Non-Hedged Accounting Positions 91,299 (91,299 ) — 40,368 (34,916 ) 5,452 Total $ 94,732 $ (94,732 ) $ — $ 41,727 $ (36,275 ) $ 5,452 (1) Net amount is net of $93.7 million and $31.3 million of cash collateral at September 30, 2016 and December 31, 2015 , respectively, as presented in the accompanying Condensed Consolidated Balance Sheets. (2) Net amount excludes $29.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at September 30, 2016 and December 31, 2015 , respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Condensed Consolidated Balance Sheets.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Of Assets And Liabilities Measured On Recurring Basis	Summaries of the fair values of assets and liabilities measured at fair value on a recurring basis are as follows: At September 30, 2016 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: U.S. Treasury Bills $ 985 $ — $ — $ 985 Agency CMO — 463,730 — 463,730 Agency MBS — 1,001,014 — 1,001,014 Agency CMBS — 484,408 — 484,408 CMBS — 468,361 — 468,361 CLO — 484,236 — 484,236 Single issuer trust preferred securities — 38,111 — 38,111 Corporate debt securities — 99,266 — 99,266 Equities - financial services — — — — Total available-for-sale investment securities 985 3,039,126 — 3,040,111 Gross derivative instruments, before netting (1) 66 119,843 — 119,909 Investments held in Rabbi Trust 5,020 — — 5,020 Alternative investments — — 5,464 5,464 Originated loans held for sale (2) — 66,400 — 66,400 Contingent consideration — — 8,035 8,035 Total financial assets held at fair value $ 6,071 $ 3,225,369 $ 13,499 $ 3,244,939 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 37 $ 95,865 $ — $ 95,902 Contingent liability — — — — Total financial liabilities held at fair value $ 37 $ 95,865 $ — $ 95,902 At December 31, 2015 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: U.S. Treasury Bills $ 924 $ — $ — $ 924 Agency CMO — 548,754 — 548,754 Agency MBS — 1,065,109 — 1,065,109 Agency CMBS — 215,350 — 215,350 CMBS — 579,266 — 579,266 CLO — 429,159 — 429,159 Single issuer trust preferred securities — 37,170 — 37,170 Corporate debt securities — 106,321 — 106,321 Equities - financial services 2,578 — — 2,578 Total available-for-sale investment securities 3,502 2,981,129 — 2,984,631 Gross derivative instruments, before netting (1) 183 64,038 — 64,221 Investments held in Rabbi Trust 5,372 — — 5,372 Alternative investments — — 3,471 3,471 Originated loans held for sale — — — — Contingent Consideration — — 5,331 5,331 Total financial assets held at fair value $ 9,057 $ 3,045,167 $ 8,802 $ 3,063,026 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 66 $ 42,486 $ — $ 42,552 Contingent liability — — 6,000 6,000 Total financial liabilities held at fair value $ 66 $ 42,486 $ 6,000 $ 48,552 (1) For information relating to the impact of netting derivative assets and derivative liabilities as well as the impact from offsetting cash collateral paid to the same derivative counterparties see Note 12: Derivative Financial Instruments . (2) Loans held for sale accounted for under the fair value option of ASC 825 "Financial Instruments" at September 30, 2016 . The Company made this policy election on loans originated for sale. See Note 1: Summary of Significant Accounting Policies .
Schedule Of Quantitative Inputs And Assumptions For Items Categorized In Level 3 Of The Fair Value Hierarchy	The following table presents the changes in Level 3 assets and liabilities that are measured at fair value on a recurring basis: (In thousands) Alternative Investments Contingent Consideration Total Financial Assets Contingent Liability Balance at January 1, 2016 $ 3,471 $ 5,331 $ 8,802 $ 6,000 Unrealized gain included in net income 311 2,704 3,015 — Purchases/capital funding 1,682 — 1,682 — Payments — — — (6,000 ) Balance at September 30, 2016 $ 5,464 $ 8,035 $ 13,499 $ —
Schedule of Servicing Assets at Fair Value	The following table presents the changes in fair value for mortgage servicing assets: Nine months ended September 30, (In thousands) 2016 2015 Beginning balance $ 33,568 $ 28,690 Originations of servicing assets 8,198 6,335 Changes in fair value: Due to payoffs/paydowns (3,026 ) (1,918 ) Due to market changes (3,119 ) (754 ) Ending balance $ 35,621 $ 32,353
Schedule Of Valuation Methodology And Unobservable Inputs	The table below presents the valuation methodology and unobservable inputs for Level 3 assets measured at fair value on a non-recurring basis as of September 30, 2016 : (Dollars in thousands) Asset Fair Value Valuation Methodology Unobservable Inputs Range of Inputs Collateral dependent impaired loans and leases $ 1,974 Real Estate Appraisals Discount for appraisal type 0% Discount for costs to sell 0% OREO $ 195 Real Estate Appraisals Discount for appraisal type 0% - 10.0% Discount for costs to sell 8% Mortgage servicing assets $ 35,621 Discounted cash flow Constant prepayment rate 7.9% - 32.6% Discount rates 1.5% - 2.1%
Summary Of Estimated Fair Values Of Significant Financial Instruments	The estimated fair values of selected financial instruments and servicing assets are as follows: At September 30, 2016 At December 31, 2015 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Value Assets: Level 2 Held-to-maturity investment securities $ 4,022,332 $ 4,109,943 $ 3,923,052 $ 3,961,534 Loans held for sale (1) 178 178 37,091 37,457 Level 3 Loans and leases, net 16,435,476 16,450,034 15,496,745 15,543,892 Mortgage servicing assets 23,384 35,621 20,698 33,568 Alternative investments 11,303 12,867 12,900 14,294 Liabilities: Level 2 Deposit liabilities, other than time deposits $ 17,179,965 $ 17,179,965 $ 15,866,624 $ 15,866,624 Time deposits 2,020,943 2,037,577 2,086,154 2,095,357 Securities sold under agreements to repurchase and other borrowings 800,705 811,273 1,151,400 1,163,974 FHLB advances (2) 2,587,983 2,576,651 2,664,139 2,647,872 Long-term debt (2) 225,450 222,694 226,356 218,143 (1) Loans held for sale accounted for at the lower of cost or market includes commercial loans at September 30, 2016 and both commercial and residential loans at December 31, 2015 . (2) The following adjustments to the carrying amount are not included for determination of fair value, see Note 8: Borrowings : • FHLB advances - unamortized premiums on advances • Long-term debt - unamortized discount and debt issuance cost on senior fixed-rate notes

Reitrement Benefit Plans (Table

Reitrement Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Summary of Net Periodic Benefit Cost	The following table summarizes the components of net periodic benefit cost: Three months ended September 30, 2016 2015 (In thousands) Webster Bank Pension Plan Webster Other Postretirement Benefits Webster Bank Pension Plan Webster Other Postretirement Benefits Service cost $ 11 $ — $ — $ 11 $ — $ — Interest cost on benefit obligations 2,110 98 32 2,002 86 31 Expected return on plan assets (3,067 ) — — (2,968 ) — — Amortization of prior service cost — — 4 — — 18 Recognized net loss 1,666 106 8 1,431 98 11 Net periodic benefit cost $ 720 $ 204 $ 44 $ 476 $ 184 $ 60 Nine months ended September 30, 2016 2015 (In thousands) Webster Bank Pension Plan Webster Other Postretirement Benefits Webster Bank Pension Plan Webster Other Postretirement Benefits Service cost $ 34 $ — $ — $ 34 $ — $ — Interest cost on benefit obligations 6,331 292 94 6,006 259 93 Expected return on plan assets (8,596 ) — — (8,905 ) — — Amortization of prior service cost — — 11 — — 54 Recognized net loss 4,998 319 26 4,293 293 35 Net periodic benefit cost $ 2,767 $ 611 $ 131 $ 1,428 $ 552 $ 182

Share-Based Plans (Tables)

Share-Based Plans (Tables)	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Allocation of Share-based Compensation Costs by Plan	The following table provides a summary of stock compensation expense recognized in the accompanying Condensed Consolidated Statements of Income: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Stock options $ — $ 73 $ 43 $ 305 Restricted stock 2,944 2,934 8,515 7,978 Total stock compensation expense $ 2,944 $ 3,007 $ 8,558 $ 8,283
Schedule of Share-based Compensation, Activity	The following table provides a summary of the activity under the stock compensation plans for the nine months ended September 30, 2016 : Restricted Stock Awards Outstanding Stock Options Outstanding Time-Based Performance-Based Number of Shares Weighted-Average Grant Date Fair Value Number of Units Weighted-Average Grant Date Fair Value Number of Shares Weighted-Average Grant Date Fair Value Number of Shares Weighted-Average Exercise Price Outstanding, at January 1, 2016 236,145 $ 32.58 2,088 $ 34.45 115,721 $ 34.14 1,527,074 $ 23.92 Granted 222,610 32.93 12,946 32.89 150,392 32.75 — — Exercised options — — — — — — 116,694 20.19 Vested restricted stock awards (1) 166,988 31.81 9,638 33.23 104,419 33.17 — — Forfeited 11,628 32.73 — — 3,401 33.59 41,562 47.92 Outstanding and exercisable, at September 30, 2016 280,139 $ 33.28 5,396 $ 32.89 158,293 $ 33.47 1,368,818 $ 23.51 (1) Vested for purposes of recording compensation expense.

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Operating Results And Total Assets Reportable Segments	The following tables present the operating results, including all appropriate allocations, for Webster’s reportable segments and the Corporate and Reconciling category: Three months ended September 30, 2016 (In thousands) Commercial Banking Community Banking HSA Bank Private Banking Corporate and Reconciling Consolidated Total Net interest income (loss) $ 71,454 $ 91,522 $ 20,560 $ 2,811 $ (6,150 ) $ 180,197 Provision (benefit) for loan and lease losses 7,459 6,939 — 417 (565 ) 14,250 Net interest income (loss) after provision for loan and lease losses 63,995 84,583 20,560 2,394 (5,585 ) 165,947 Non-interest income 13,515 29,121 16,900 2,401 4,475 66,412 Non-interest expense 30,477 91,463 23,021 5,316 5,820 156,097 Income (loss) before income tax expense 47,033 22,241 14,439 (521 ) (6,930 ) 76,262 Income tax expense (benefit) 15,128 7,121 4,624 (171 ) (2,257 ) 24,445 Net income (loss) $ 31,905 $ 15,120 $ 9,815 $ (350 ) $ (4,673 ) $ 51,817 Three months ended September 30, 2015 (In thousands) Commercial Banking Community Banking HSA Bank Private Banking Corporate and Reconciling Consolidated Total Net interest income (loss) $ 64,769 $ 90,370 $ 18,852 $ 2,575 $ (8,556 ) $ 168,010 Provision (benefit) for loan and lease losses 3,992 8,953 — 76 (21 ) 13,000 Net interest income (loss) after provision for loan and lease losses 60,777 81,417 18,852 2,499 (8,535 ) 155,010 Non-interest income 10,970 26,928 16,386 2,215 4,793 61,292 Non-interest expense 27,474 82,919 21,273 5,026 3,245 139,937 Income (loss) before income tax expense 44,273 25,426 13,965 (312 ) (6,987 ) 76,365 Income tax expense (benefit) 14,387 8,366 4,561 (96 ) (2,223 ) 24,995 Net income (loss) $ 29,886 $ 17,060 $ 9,404 $ (216 ) $ (4,764 ) $ 51,370 Nine months ended September 30, 2016 (In thousands) Commercial Banking Community Banking HSA Bank Private Banking Corporate and Reconciling Consolidated Total Net interest income (loss) $ 203,012 $ 272,725 $ 60,484 $ 8,410 $ (11,377 ) $ 533,254 Provision (benefit) for loan and lease losses 29,247 15,572 — 518 (1,487 ) 43,850 Net interest income (loss) after provision for loan and lease losses 173,765 257,153 60,484 7,892 (9,890 ) 489,404 Non-interest income 34,374 83,219 54,969 7,445 13,854 193,861 Non-interest expense 87,781 272,823 71,966 15,555 13,195 461,320 Income (loss) before income tax expense 120,358 67,549 43,487 (218 ) (9,231 ) 221,945 Income tax expense (benefit) 39,304 22,059 14,201 (71 ) (3,015 ) 72,478 Net income (loss) $ 81,054 $ 45,490 $ 29,286 $ (147 ) $ (6,216 ) $ 149,467 Nine months ended September 30, 2015 (In thousands) Commercial Banking Community Banking HSA Bank Private Banking Corporate and Reconciling Consolidated Total Net interest income (loss) $ 188,539 $ 262,214 $ 53,080 $ 7,471 $ (20,019 ) $ 491,285 Provision (benefit) for loan and lease losses 19,951 16,383 — (158 ) (676 ) 35,500 Net interest income (loss) after provision for loan and lease losses 168,588 245,831 53,080 7,629 (19,343 ) 455,785 Non-interest income 28,321 80,748 46,885 6,891 15,253 178,098 Non-interest expense 81,144 247,070 60,476 14,502 8,369 411,561 Income (loss) before income tax expense 115,765 79,509 39,489 18 (12,459 ) 222,322 Income tax expense (benefit) 36,139 24,821 12,327 5 (3,887 ) 69,405 Net income (loss) $ 79,626 $ 54,688 $ 27,162 $ 13 $ (8,572 ) $ 152,917 The following table presents total assets for Webster's reportable segments and the Corporate and Reconciling category: Total Assets (In thousands) Commercial Banking Community HSA Bank Private Corporate and Reconciling Consolidated Total At September 30, 2016 $ 8,174,174 $ 8,638,736 $ 92,128 $ 521,877 $ 8,206,702 $ 25,633,617 At December 31, 2015 7,505,513 8,441,950 95,815 493,571 8,104,269 24,641,118

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Outstanding Financial Instruments Contract Amounts Represent Credit Risk	The following table summarizes the outstanding amounts of credit-related financial instruments with off-balance sheet risk: (In thousands) At September 30, 2016 At December 31, 2015 Commitments to extend credit $ 5,239,513 $ 4,851,994 Standby letter of credit 141,200 133,294 Commercial letter of credit 46,344 45,742 Total credit-related financial instruments with off-balance sheet risk $ 5,427,057 $ 5,031,030
Reserve For Unfunded Credit Commitments	The following table provides a summary of activity in the reserve for unfunded credit commitments: Three months ended September 30, Nine months ended September 30, (In thousands) 2016 2015 2016 2015 Beginning balance $ 2,319 $ 2,007 $ 2,119 $ 5,151 Provision (benefit) 172 16 372 (3,128 ) Ending balance $ 2,491 $ 2,023 $ 2,491 $ 2,023

Summary of Significant Accoun42

Summary of Significant Accounting Policies (Correction of Immaterial Error Related to Prior Periods) (Details) - USD ($) $ in Thousands	6 Months Ended	9 Months Ended
	Jun. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities		$ 186,918	$ 182,352
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities	$ (29,500)
HSA Bank [Member] | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net cash provided by operating activities	$ (800)

Investment Securities (Summary

Investment Securities (Summary Of Investment Securities) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Available-for-sale Securities [Abstract]
Amortized Cost	$ 3,018,710	$ 2,994,924
Unrealized Gains	32,045	22,997
Unrealized Losses	(10,644)	(33,290)
Fair Value	3,040,111	2,984,631
Held-to-maturity Securities [Abstract]
Amortized Cost	4,022,332	3,923,052
Unrealized Gains	91,807	63,894
Unrealized Losses	(4,196)	(25,412)
Fair Value	4,109,943	3,961,534
U.S. Treasury Bills [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	985	924
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	985	924
Agency collateralized mortgage obligations (CMOs) [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	457,768	546,168
Unrealized Gains	7,453	5,532
Unrealized Losses	(1,491)	(2,946)
Fair Value	463,730	548,754
Held-to-maturity Securities [Abstract]
Amortized Cost	371,700	407,494
Unrealized Gains	4,353	3,717
Unrealized Losses	(890)	(2,058)
Fair Value	375,163	409,153
Agency mortgage-backed securities (MBS) [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	992,742	1,075,941
Unrealized Gains	11,051	6,459
Unrealized Losses	(2,779)	(17,291)
Fair Value	1,001,014	1,065,109
Held-to-maturity Securities [Abstract]
Amortized Cost	2,072,481	2,030,176
Unrealized Gains	48,397	38,813
Unrealized Losses	(1,544)	(19,908)
Fair Value	2,119,334	2,049,081
Agency commercial mortgage-backed securities (ACMBS) [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	481,079	215,670
Unrealized Gains	3,435	639
Unrealized Losses	(106)	(959)
Fair Value	484,408	215,350
Held-to-maturity Securities [Abstract]
Amortized Cost	624,403	686,086
Unrealized Gains	14,449	4,253
Unrealized Losses	0	(325)
Fair Value	638,852	690,014
Non-agency Commercial mortgage-backed securities (CMBS) [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	465,120	574,686
Unrealized Gains	4,794	7,485
Unrealized Losses	(1,553)	(2,905)
Fair Value	468,361	579,266
Held-to-maturity Securities [Abstract]
Amortized Cost	341,019	360,018
Unrealized Gains	10,935	5,046
Unrealized Losses	(80)	(2,704)
Fair Value	351,874	362,360
CLO [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	481,555	431,837
Unrealized Gains	3,132	592
Unrealized Losses	(451)	(3,270)
Fair Value	484,236	429,159
Single issuer trust preferred securities [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	42,312	42,168
Unrealized Gains	63	0
Unrealized Losses	(4,264)	(4,998)
Fair Value	38,111	37,170
Corporate debt securities [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	97,149	104,031
Unrealized Gains	2,117	2,290
Unrealized Losses	0	0
Fair Value	99,266	106,321
Equities - financial services [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	0	3,499
Unrealized Gains	0	0
Unrealized Losses	0	(921)
Fair Value	0	2,578
Municipal bonds and notes [Member]
Held-to-maturity Securities [Abstract]
Amortized Cost	610,690	435,905
Unrealized Gains	13,658	12,019
Unrealized Losses	(1,682)	(417)
Fair Value	622,666	447,507
Private Label MBS [Member]
Held-to-maturity Securities [Abstract]
Amortized Cost	2,039	3,373
Unrealized Gains	15	46
Unrealized Losses	0	0
Fair Value	$ 2,054	$ 3,419

Investment Securities (Other Th

Investment Securities (Other Than Temporary Impairment Credit Losses Recognized In Earnings) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance of OTTI, beginning of period	$ 3,437	$ 3,178	$ 3,288	$ 3,696
Reduction for securities sold, called	(30)	0	(30)	(518)
Additions for OTTI not previously recognized in earnings	0	82	149	82
Balance of OTTI, end of period	$ 3,407	$ 3,260	$ 3,407	$ 3,260

Investment Securities (Summar45

Investment Securities (Summary Of Gross Unrealized Losses Not Considered OTTI) (Detail) $ in Thousands	Sep. 30, 2016USD ($)holding	Dec. 31, 2015USD ($)holding
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 172,898	$ 1,295,959
Available for sale, Unrealized Losses - Less Than Twelve Months	(901)	(16,177)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	575,770	446,123
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (9,743)	$ (17,113)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | holding	96	156
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 748,668	$ 1,742,082
Available for sale, Unrealized Losses - Total	(10,644)	(33,290)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	297,914	977,562
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(2,492)	(10,831)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	319,191	542,714
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	$ (1,704)	$ (14,581)
Held-to-maturity, Number of Holdings - Total | holding	88	152
Held-to-maturity, Fair Value - Total	$ 617,105	$ 1,520,276
Held-to-maturity, Unrealized Losses - Total	(4,196)	(25,412)
Agency CMO [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	22,888	195,369
Available for sale, Unrealized Losses - Less Than Twelve Months	(337)	(2,195)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	71,140	26,039
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (1,154)	$ (751)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | holding	7	14
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 94,028	$ 221,408
Available for sale, Unrealized Losses - Total	(1,491)	(2,946)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	77,555	143,364
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(661)	(1,304)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	18,814	27,928
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	$ (229)	$ (754)
Held-to-maturity, Number of Holdings - Total | holding	8	13
Held-to-maturity, Fair Value - Total	$ 96,369	$ 171,292
Held-to-maturity, Unrealized Losses - Total	(890)	(2,058)
Agency MBS [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	26,917	481,839
Available for sale, Unrealized Losses - Less Than Twelve Months	(48)	(6,386)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	274,866	351,911
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (2,731)	$ (10,905)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | holding	48	84
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 301,783	$ 833,750
Available for sale, Unrealized Losses - Total	(2,779)	(17,291)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	86,133	551,918
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(88)	(7,089)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	297,018	470,828
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	$ (1,456)	$ (12,819)
Held-to-maturity, Number of Holdings - Total | holding	30	87
Held-to-maturity, Fair Value - Total	$ 383,151	$ 1,022,746
Held-to-maturity, Unrealized Losses - Total	(1,544)	(19,908)
Agency CMBS [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	78,572	124,241
Available for sale, Unrealized Losses - Less Than Twelve Months	$ (106)	$ (959)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | holding	6	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 78,572	$ 124,241
Available for sale, Unrealized Losses - Total	$ (106)	(959)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		110,864
Held-to-maturity, Unrealized Losses - Less Than Twelve Months		$ (325)
Held-to-maturity, Number of Holdings - Total | holding	0	7
Held-to-maturity, Fair Value - Total		$ 110,864
Held-to-maturity, Unrealized Losses - Total		(325)
Non-agency CMBS [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 34,741	276,330
Available for sale, Unrealized Losses - Less Than Twelve Months	(382)	(2,879)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	126,244	19,382
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (1,171)	$ (26)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | holding	24	29
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 160,985	$ 295,712
Available for sale, Unrealized Losses - Total	(1,553)	(2,905)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	27,773	142,382
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	$ (80)	(1,983)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		30,129
Held-to-maturity, Unrealized Losses, Twelve Months or Longer		$ (721)
Held-to-maturity, Number of Holdings - Total | holding	5	18
Held-to-maturity, Fair Value - Total	$ 27,773	$ 172,511
Held-to-maturity, Unrealized Losses - Total	(80)	(2,704)
CLO [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	9,780	211,515
Available for sale, Unrealized Losses - Less Than Twelve Months	(28)	(2,709)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	69,708	15,708
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (423)	$ (561)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | holding	4	13
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 79,488	$ 227,223
Available for sale, Unrealized Losses - Total	(451)	(3,270)
Single issuer trust preferred securities [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		4,087
Available for sale, Unrealized Losses - Less Than Twelve Months		(128)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	33,812	33,083
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (4,264)	$ (4,870)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | holding	7	8
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 33,812	$ 37,170
Available for sale, Unrealized Losses - Total	(4,264)	(4,998)
Equities - financial services [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		2,578
Available for sale, Unrealized Losses - Less Than Twelve Months		$ (921)
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | holding		1
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		$ 2,578
Available for sale, Unrealized Losses - Total		(921)
Municipal bonds and notes [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	106,453	29,034
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(1,663)	(130)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	3,359	13,829
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	$ (19)	$ (287)
Held-to-maturity, Number of Holdings - Total | holding	45	27
Held-to-maturity, Fair Value - Total	$ 109,812	$ 42,863
Held-to-maturity, Unrealized Losses - Total	$ (1,682)	$ (417)

Investment Securities (Narrativ

Investment Securities (Narrative) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Available-for-sale - Accumulated Gross Unrealized Losses Before Tax	$ (10,644)	$ (33,290)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(4,196)	(25,412)
Securities available-for-sale	3,040,111	2,984,631
Pledged Financial Instruments, Not Separately Reported, Securities	2,700,000	2,600,000
Agency collateralized mortgage obligations (CMOs) [Member]
Schedule of Investments [Line Items]
Available-for-sale - Accumulated Gross Unrealized Losses Before Tax	(1,491)	(2,946)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(890)	(2,058)
Securities available-for-sale	463,730	548,754
Agency MBS [Member]
Schedule of Investments [Line Items]
Available-for-sale - Accumulated Gross Unrealized Losses Before Tax	(2,779)	(17,291)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(1,544)	(19,908)
Securities available-for-sale	1,001,014	1,065,109
Agency CMBS [Member]
Schedule of Investments [Line Items]
Available-for-sale - Accumulated Gross Unrealized Losses Before Tax	(106)	(959)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	(325)
Securities available-for-sale	484,408	215,350
Non-agency Commercial mortgage-backed securities (CMBS) [Member]
Schedule of Investments [Line Items]
Available-for-sale - Accumulated Gross Unrealized Losses Before Tax	(1,553)	(2,905)
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(80)	(2,704)
Securities available-for-sale	468,361	579,266
CLO [Member]
Schedule of Investments [Line Items]
Available-for-sale - Accumulated Gross Unrealized Losses Before Tax	(451)	(3,270)
Securities available-for-sale	484,236	429,159
Single issuer trust preferred securities [Member]
Schedule of Investments [Line Items]
Available-for-sale - Accumulated Gross Unrealized Losses Before Tax	(4,264)	(4,998)
Securities available-for-sale	38,111	37,170
Municipal bonds and notes [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(1,682)	$ (417)
Callable at the option of the counterparty [Member]
Schedule of Investments [Line Items]
Securities available-for-sale	$ 1,200,000

Investment Securities (Summar47

Investment Securities (Summary Of Realized Gain (Loss) on Investments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Gain (Loss) on Investments [Line Items]
Proceeds from sales	$ 0	$ 2,500	$ 259,273	$ 37,465
Gross realized gains on sales	0	0	2,891	529
Less: Gross realized losses on sales	0	0	2,477	0
Gain on sale of investment securities, net	$ 0	$ 0	$ 414	$ 529

Investment Securities (Summar48

Investment Securities (Summary Of Debt Securities By Contractual Maturity) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Available-for-sale, Amortized Cost - Due in one year or less	$ 60,737
Available-for-sale, Amortized Cost - Due after one year through five years	37,397
Available-for-sale, Amortized Cost - Due after five through ten years	572,461
Available-for-sale, Amortized Cost - Due after ten years	2,348,115
Available-for-sale, Amortized Cost - Total debt securities	3,018,710
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Available-for-sale, Fair Value - Due in one year or less	61,771
Available-for-sale, Fair Value - Due after one year through five years	38,479
Available-for-sale, Fair Value - Due after five through ten years	575,465
Available-for-sale, Fair Value - Due after ten years	2,364,396
Available-for-sale, Fair Value - Total debt securities	3,040,111
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis [Abstract]
Held-to-maturity, Amortized Cost - Due in one year or less	7,988
Held-to-maturity, Amortized Cost - Due after one year through five years	19,980
Held-to-maturity, Amortized Cost - Due after five through ten years	36,758
Held-to-maturity, Amortized Cost - Due after ten years	3,957,606
Amortized Cost	4,022,332	$ 3,923,052
Held-to-maturity Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Held to maturity, Fair Value - Due in one year or less	8,034
Held-to-maturity, Fair Value - Due after one year through five years	20,376
Held to maturity, Fair Value - Due after five through ten years	37,932
Held to maturity, Fair Value - Due after ten years	4,043,601
Fair Value	$ 4,109,943	$ 3,961,534

Variable Interest Entities (Var

Variable Interest Entities (Variable Interest Entity, Consolidated, Carrying Amount, Assets) (Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	$ 20.6	$ 19
Other Assets [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	23.5	25.9
Accounts Payable and Accrued Liabilities [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	14.4	16.5
Other Investments [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 12.5	$ 12.1

Loans and Leases (Detail)

Loans and Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2016		Dec. 31, 2015		Sep. 30, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 16,623,401	[1],[2]	$ 15,671,735	[1],[2]	$ 15,216,525
Unamortized premiums	19,700		18,000
Pledged Financial Instruments, Not Separately Reported, Loans Receivable Pledged as Collateral	6,400,000
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	4,234,047		4,061,001		4,015,839
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	2,707,343		2,702,560		2,650,702
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	4,779,802		4,315,999		4,139,979
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	4,280,513		3,991,649		3,857,155
Finance Leases Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 621,696		$ 600,526		$ 552,850
[1]	At September 30, 2016, the Company had pledged $6.4 billion of eligible residential and consumer loans as collateral to support borrowing capacity at the FHLB Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums/discounts of $19.7 million and $18.0 million at September 30, 2016 and December 31, 2015, respectively.

Loans and Leases (Summary Of Lo

Loans and Leases (Summary Of Loan And Lease Portfolio Aging By Class Of Loan) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016		Dec. 31, 2015		Sep. 30, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	$ 167,636		$ 179,403
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	5,467		2,051
Financing Receivable, Recorded Investment, Nonaccrual Status	128,359		140,069
Financing Receivable, Recorded Investment, Current	16,455,765		15,492,332
Loans and leases	16,623,401	[1],[2]	15,671,735	[1],[2]	$ 15,216,525
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	23,126		23,751
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	10,684		13,532
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	60,291		71,298
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0		2,029
Financing Receivable, Recorded Investment, Nonaccrual Status	49,197		54,201
Financing Receivable, Recorded Investment, Current	4,173,756		3,989,703
Loans and leases	4,234,047		4,061,001		4,015,839
Residential Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	7,547		10,365
Residential Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	3,547		4,703
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases	2,707,343		2,702,560		2,650,702
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	47,970		50,640
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	35,597		37,337
Financing Receivable, Recorded Investment, Current	2,371,700		2,402,758
Loans and leases	2,419,670		2,453,398
Consumer Portfolio Segment [Member] | Home Equity Loan [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	7,627		9,061
Consumer Portfolio Segment [Member] | Home Equity Loan [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	4,746		4,242
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases	4,779,802		4,315,999		4,139,979
Commercial Portfolio Segment [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	29,945		31,115
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	23		22
Financing Receivable, Recorded Investment, Nonaccrual Status	27,397		27,037
Financing Receivable, Recorded Investment, Current	3,946,986		3,531,669
Loans and leases	3,976,931		3,562,784
Commercial Portfolio Segment [Member] | Asset Based Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0		0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	0		0
Financing Receivable, Recorded Investment, Current	802,871		753,215
Loans and leases	802,871		753,215
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,949		768
Commercial Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Asset Based Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0		0
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	576		3,288
Commercial Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Asset Based Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0		0
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans and leases	4,280,513		3,991,649		3,857,155
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	17,631		19,016
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	5,444		0
Financing Receivable, Recorded Investment, Nonaccrual Status	10,957		16,767
Financing Receivable, Recorded Investment, Current	3,933,588		3,673,408
Loans and leases	3,951,219		3,692,424
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,082		1,624
Commercial Real Estate Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	148		625
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	3,438		3,461
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	3,438		3,461
Financing Receivable, Recorded Investment, Current	325,856		295,764
Loans and leases	329,294		299,225
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0		0
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0		0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	3,679		1,308
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	202		706
Financing Receivable, Recorded Investment, Current	618,017		599,218
Loans and leases	621,696		600,526		$ 552,850
Finance Leases Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	3,164		543
Finance Leases Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	313		59
Consumer Borrower [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	4,682		2,565
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	1,571		560
Financing Receivable, Recorded Investment, Current	282,991		246,597
Loans and leases	287,673		249,162
Consumer Borrower [Member] | Consumer Portfolio Segment [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,757		1,390
Consumer Borrower [Member] | Consumer Portfolio Segment [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	$ 1,354		$ 615
[1]	At September 30, 2016, the Company had pledged $6.4 billion of eligible residential and consumer loans as collateral to support borrowing capacity at the FHLB Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums/discounts of $19.7 million and $18.0 million at September 30, 2016 and December 31, 2015, respectively.

Loans and Leases (Narrative) (D

Loans and Leases (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Loans and Leases Receivable Disclosure [Abstract]
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	$ 3.7	$ 2.6	$ 8.4	$ 6.3
Write-down of TDR's	$ 3	$ 1.7	$ 17.9	$ 7.6

Loans and Leases (Allowance For

Loans and Leases (Allowance For Loan And Lease Losses By Portfolio Segment) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016		Dec. 31, 2015		Sep. 30, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	$ 180,428	$ 167,860	$ 174,990	$ 159,264
Provision (benefit) charged to expense	14,250	13,000	43,850	35,500
Charge-offs	(9,424)	(9,969)	(38,108)	(28,604)
Recoveries	2,671	2,101	7,193	6,832
Balance, end of period	180,428	167,860	174,990	159,264	$ 187,925		$ 174,990		$ 172,992
ALLL, Individually evaluated for impairment					19,503				30,323
ALLL, Collectively evaluated for impairment					168,422				142,669
Loan and lease balances, Individually evaluated for impairment					257,711				280,904
Loan and lease balances, Collectively evaluated for impairment					16,365,690				14,935,621
Loans and leases					16,623,401	[1],[2]	15,671,735	[1],[2]	15,216,525
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	24,413	24,463	25,876	25,452
Provision (benefit) charged to expense	1,076	1,150	991	3,100
Charge-offs	(1,304)	(1,588)	(3,536)	(5,004)
Recoveries	554	281	1,408	758
Balance, end of period	24,413	24,463	25,876	25,452	24,739		25,876		24,306
ALLL, Individually evaluated for impairment					9,443				10,773
ALLL, Collectively evaluated for impairment					15,296				13,533
Loan and lease balances, Individually evaluated for impairment					122,020				138,227
Loan and lease balances, Collectively evaluated for impairment					4,112,027				3,877,612
Loans and leases					4,234,047		4,061,001		4,015,839
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	42,956	40,807	42,052	43,518
Provision (benefit) charged to expense	4,985	6,864	12,458	10,091
Charge-offs	(5,259)	(4,831)	(14,236)	(12,980)
Recoveries	1,313	1,004	3,721	3,215
Balance, end of period	42,956	40,807	42,052	43,518	43,995		42,052		43,844
ALLL, Individually evaluated for impairment					3,005				3,540
ALLL, Collectively evaluated for impairment					40,990				40,304
Loan and lease balances, Individually evaluated for impairment					46,208				46,455
Loan and lease balances, Collectively evaluated for impairment					2,661,135				2,604,247
Loans and leases					2,707,343		2,702,560		2,650,702
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	73,822	66,241	66,686	52,114
Provision (benefit) charged to expense	4,351	3,089	25,447	18,468
Charge-offs	(2,561)	(2,204)	(17,294)	(5,000)
Recoveries	370	715	1,143	2,259
Balance, end of period	73,822	66,241	66,686	52,114	75,982		66,686		67,841
ALLL, Individually evaluated for impairment					6,579				11,478
ALLL, Collectively evaluated for impairment					69,403				56,363
Loan and lease balances, Individually evaluated for impairment					58,197				54,522
Loan and lease balances, Collectively evaluated for impairment					4,721,605				4,085,457
Loans and leases					4,779,802		4,315,999		4,139,979
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	33,622	30,768	34,889	32,102
Provision (benefit) charged to expense	2,953	1,961	3,921	4,617
Charge-offs	0	(1,346)	(2,521)	(5,590)
Recoveries	194	69	480	323
Balance, end of period	33,622	30,768	34,889	32,102	36,769		34,889		31,452
ALLL, Individually evaluated for impairment					467				4,527
ALLL, Collectively evaluated for impairment					36,302				26,925
Loan and lease balances, Individually evaluated for impairment					24,423				41,598
Loan and lease balances, Collectively evaluated for impairment					4,256,090				3,815,557
Loans and leases					4,280,513		3,991,649		3,857,155
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	5,615	5,581	5,487	6,078
Provision (benefit) charged to expense	885	(64)	1,033	(776)
Charge-offs	(300)	0	(521)	(30)
Recoveries	240	32	441	277
Balance, end of period	$ 5,615	$ 5,581	$ 5,487	$ 6,078	6,440		5,487		5,549
ALLL, Individually evaluated for impairment					9				5
ALLL, Collectively evaluated for impairment					6,431				5,544
Loan and lease balances, Individually evaluated for impairment					6,863				102
Loan and lease balances, Collectively evaluated for impairment					614,833				552,748
Loans and leases					$ 621,696		$ 600,526		$ 552,850
[1]	At September 30, 2016, the Company had pledged $6.4 billion of eligible residential and consumer loans as collateral to support borrowing capacity at the FHLB Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums/discounts of $19.7 million and $18.0 million at September 30, 2016 and December 31, 2015, respectively.

Loans and Leases (Impaired Loan

Loans and Leases (Impaired Loans And Leases By Class) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	$ 283,714	$ 316,542
Total Recorded Investment	257,711	279,171
Recorded Investment No Allowance	90,909	95,225
Recorded Investment With Allowance	166,802	183,946
Related Valuation Allowance	19,503	22,204
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	134,026	148,144
Total Recorded Investment	122,020	134,448
Recorded Investment No Allowance	21,404	23,024
Recorded Investment With Allowance	100,616	111,424
Related Valuation Allowance	9,443	10,364
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	52,516	56,680
Total Recorded Investment	46,208	48,425
Recorded Investment No Allowance	23,612	25,130
Recorded Investment With Allowance	22,596	23,295
Related Valuation Allowance	3,005	3,477
Commercial Portfolio Segment [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	64,537	67,116
Total Recorded Investment	58,197	56,581
Recorded Investment No Allowance	25,720	31,600
Recorded Investment With Allowance	32,477	24,981
Related Valuation Allowance	6,579	5,197
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	20,823	36,980
Total Recorded Investment	20,044	33,333
Recorded Investment No Allowance	9,156	9,204
Recorded Investment With Allowance	10,888	24,129
Related Valuation Allowance	467	3,160
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	4,911	7,010
Total Recorded Investment	4,379	5,962
Recorded Investment No Allowance	4,379	5,939
Recorded Investment With Allowance	0	23
Related Valuation Allowance	0	3
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	6,901	612
Total Recorded Investment	6,863	422
Recorded Investment No Allowance	6,638	328
Recorded Investment With Allowance	225	94
Related Valuation Allowance	$ 9	$ 3

Loans and Leases (Interest Inco

Loans and Leases (Interest Income From Impaired Loans And Leases, By Class) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 262,717	$ 291,365	$ 268,442	$ 305,881
Accrued Interest Income	1,954	1,919	6,201	6,490
Cash Basis Interest Income	542	561	1,672	1,674
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	124,993	138,519	128,234	140,105
Accrued Interest Income	1,070	1,114	3,309	3,322
Cash Basis Interest Income	304	290	918	847
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	46,892	47,787	47,317	48,352
Accrued Interest Income	336	371	1,029	1,094
Cash Basis Interest Income	238	271	754	827
Commercial Portfolio Segment [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	58,874	54,667	57,389	45,349
Accrued Interest Income	352	262	1,299	936
Cash Basis Interest Income	0	0	0	0
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,386	6,059	5,171	6,068
Accrued Interest Income	12	33	81	99
Cash Basis Interest Income	0	0	0	0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	23,930	44,222	26,689	65,640
Accrued Interest Income	77	137	374	1,024
Cash Basis Interest Income	0	0	0	0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	3,642	111	3,642	367
Accrued Interest Income	107	2	109	15
Cash Basis Interest Income	$ 0	$ 0	$ 0	$ 0

Loans and Leases (Commercial, C

Loans and Leases (Commercial, Commercial Real Estate Loans And Equipment Financing Loans Segregated By Risk Rating Exposure) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016		Dec. 31, 2015		Sep. 30, 2015
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 16,623,401	[1],[2]	$ 15,671,735	[1],[2]	$ 15,216,525
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	4,779,802		4,315,999		4,139,979
Commercial Portfolio Segment [Member] | (1) - (6) Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	4,474,603		4,023,255
Commercial Portfolio Segment [Member] | (7) Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	93,767		70,904
Commercial Portfolio Segment [Member] | (8) Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	207,059		220,389
Commercial Portfolio Segment [Member] | (9) Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	4,373		1,451
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	4,280,513		3,991,649		3,857,155
Commercial Real Estate Portfolio Segment [Member] | (1) - (6) Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	4,152,199		3,857,019
Commercial Real Estate Portfolio Segment [Member] | (7) Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	36,588		55,030
Commercial Real Estate Portfolio Segment [Member] | (8) Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	91,726		79,289
Commercial Real Estate Portfolio Segment [Member] | (9) Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	0		311
Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	621,696		600,526		$ 552,850
Finance Leases Portfolio Segment [Member] | (1) - (6) Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	598,526		586,445
Finance Leases Portfolio Segment [Member] | (7) Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	25		1,628
Finance Leases Portfolio Segment [Member] | (8) Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	23,145		12,453
Finance Leases Portfolio Segment [Member] | (9) Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 0		$ 0
[1]	At September 30, 2016, the Company had pledged $6.4 billion of eligible residential and consumer loans as collateral to support borrowing capacity at the FHLB Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums/discounts of $19.7 million and $18.0 million at September 30, 2016 and December 31, 2015, respectively.

Loans and Leases (Summary Of Th

Loans and Leases (Summary Of The Recorded Investment Of Company's TDRs) (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs	[1]	$ 236,000		$ 272,690
Accruing TDRs performing under modified terms more than one year (as a percent)		54.10%		55.00%
Specific reserves for TDRs included in the balance of ALLL		$ 187,925	$ 180,428	$ 174,990	$ 172,992	$ 167,860	$ 159,264
Additional funds committed to borrowers in TDR status		1,316		1,133
Troubled Debt Restructures [Member]
Financing Receivable, Modifications [Line Items]
Interest Receivable		800		1,100
Performing Financial Instruments [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		161,853		171,784
Nonperforming Financial Instruments [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		74,147		100,906
Nonperforming Financial Instruments [Member] | Troubled Debt Restructures [Member]
Financing Receivable, Modifications [Line Items]
Specific reserves for TDRs included in the balance of ALLL		$ 16,302		$ 21,405
[1]	Total recorded investment of TDRs excludes $0.8 million and $1.1 million of accrued interest receivable at September 30, 2016 and December 31, 2015, respectively.

Loans and Leases (Information o

Loans and Leases (Information on How Loans and Leases were Modified as a TDR) (Detail) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016USD ($)loan	Sep. 30, 2015USD ($)loan	Sep. 30, 2016USD ($)loan	Sep. 30, 2015USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		38	50	133	150
Post-Modification Recorded Investment | $	[1]	$ 10,987	$ 7,977	$ 34,367	$ 24,232
Residential Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		4	4	11	19
Post-Modification Recorded Investment | $	[1]	$ 967	$ 998	$ 1,969	$ 3,301
Residential Portfolio Segment [Member] | Adjusted Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		1	1	2	2
Post-Modification Recorded Investment | $	[1]	$ 292	$ 160	$ 528	$ 464
Residential Portfolio Segment [Member] | Maturity/Rate Combined [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		3	4	10	18
Post-Modification Recorded Investment | $	[1]	$ 290	$ 1,006	$ 1,185	$ 3,138
Residential Portfolio Segment [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	[2]	3	9	18	23
Post-Modification Recorded Investment | $	[1],[2]	$ 299	$ 1,594	$ 3,190	$ 3,387
Consumer Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		2	4	9	9
Post-Modification Recorded Investment | $	[1]	$ 89	$ 296	$ 381	$ 935
Consumer Portfolio Segment [Member] | Adjusted Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		0	0	0	0
Post-Modification Recorded Investment | $	[1]	$ 0	$ 0	$ 0	$ 0
Consumer Portfolio Segment [Member] | Maturity/Rate Combined [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		3	0	11	8
Post-Modification Recorded Investment | $	[1]	$ 264	$ 0	$ 923	$ 444
Consumer Portfolio Segment [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	[2]	8	20	37	50
Post-Modification Recorded Investment | $	[1],[2]	$ 270	$ 1,357	$ 1,447	$ 3,087
Commercial Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		2	0	11	3
Post-Modification Recorded Investment | $	[1]	$ 213	$ 0	$ 14,862	$ 256
Commercial Portfolio Segment [Member] | Adjusted Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		0	0	0	1
Post-Modification Recorded Investment | $	[1]	$ 0	$ 0		$ 24
Commercial Portfolio Segment [Member] | Maturity/Rate Combined [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		0	1	2	5
Post-Modification Recorded Investment | $	[1]	$ 0	$ 74	$ 648	$ 371
Commercial Portfolio Segment [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	[2]	4	5	11	9
Post-Modification Recorded Investment | $	[1],[2]	$ 1,265	$ 1,772	$ 1,639	$ 8,062
Commercial Real Estate Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		1	1	1	1
Post-Modification Recorded Investment | $	[1]	$ 109	$ 315	$ 109	$ 315
Commercial Real Estate Portfolio Segment [Member] | Maturity/Rate Combined [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		1	0	2	1
Post-Modification Recorded Investment | $	[1]	$ 291	$ 0	$ 335	$ 43
Commercial Real Estate Portfolio Segment [Member] | Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	[2]	0	1	1	1
Post-Modification Recorded Investment | $	[1],[2]	$ 0	$ 405	$ 509	$ 405
Finance Leases Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		6	0	7	0
Post-Modification Recorded Investment | $	[1]	$ 6,638	$ 0	$ 6,642	$ 0
[1]	Post-modification balances approximate pre-modification balances. The aggregate amount of charge-offs as a result of the restructurings was not significant.
[2]	Other includes covenant modifications, forbearance, loans discharged under Chapter 7 bankruptcy, or other concessions.

Loans and Leases (Information59

Loans and Leases (Information on Loans and Leases Modified as TDR within the Previous 12 Months) (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)loan	Sep. 30, 2015USD ($)loan	Sep. 30, 2016USD ($)loan	Sep. 30, 2015USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	0	2	0	3
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $	$ 0	$ 12	$ 0	$ 335
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	0	0	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	0	1	0	2
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $	$ 0	$ 3	$ 0	$ 326
Commercial Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	0	1	0	1
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $	$ 0	$ 9	$ 0	$ 9
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	0	0	0	0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $	$ 0	$ 0	$ 0	$ 0

Loans and Leases (Investments i

Loans and Leases (Investments in TDRs, Segregated by Risk Rating Exposure) (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs	[1]	$ 236,000	$ 272,690
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		67,772	89,818
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (1) - (6) Pass [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		11,510	12,970
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (7) Special Mention [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		7	2,999
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (8) Substandard [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		52,658	72,132
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (9) Doubtful [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		$ 3,597	$ 1,717
[1]	Total recorded investment of TDRs excludes $0.8 million and $1.1 million of accrued interest receivable at September 30, 2016 and December 31, 2015, respectively.

Transfers of Financial Assets61

Transfers of Financial Assets (Reserve for loan repurchases) (Detail) - Loan Purchase Commitments [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 992	$ 1,120	$ 1,192	$ 1,059
Provision (benefit) charged to expense	37	43	(64)	104
Repurchased loans and settlements charged off	0	0	(99)	0
Ending balance	$ 1,029	$ 1,163	$ 1,029	$ 1,163

Transfers of Financial Assets62

Transfers of Financial Assets (Loans sold) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net gain on sale	$ 3,276	$ 1,441	$ 8,850	$ 5,519
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale	128,268	143,801	298,840	352,300
Net gain on sale	3,324	1,441	6,749	5,519
Fair value option adjustment	(48)	0	2,101	0
Loans sold with servicing rights retained	$ 115,822	$ 132,920	$ 273,827	$ 327,030

Transfers of Financial Assets63

Transfers of Financial Assets (Mortgage Servicing Assets) (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds from sale of loans not originated for sale			$ 20,764	$ 33,100
Residential Mortgage [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Retained servicing rights					$ 2,500,000
Bank servicing fees	$ 300	$ 300	900	$ 1,100
Commercial Loan [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds from sale of loans not originated for sale			20,800
Consumer Loan [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds from sale of loans not originated for sale			$ 33,100

Goodwill and Other Intangible64

Goodwill and Other Intangible Assets (Gross Carrying Value And Accumulated Amortization Of Other Intangible Assets) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 92,420	$ 92,420
Accumulated Amortization	(57,664)	(53,094)
Net Carrying Amount	34,756	39,326
HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	43,000	43,000
Accumulated Amortization	(8,244)	(4,817)
Net Carrying Amount	34,756	38,183
Core Deposits [Member] | Community Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	49,420	49,420
Accumulated Amortization	(49,420)	(48,277)
Net Carrying Amount	0	1,143
Core Deposits [Member] | HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	22,000	22,000
Accumulated Amortization	(5,484)	(3,269)
Net Carrying Amount	16,516	18,731
Customer Relationships [Member] | HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	21,000	21,000
Accumulated Amortization	(2,760)	(1,548)
Net Carrying Amount	$ 18,240	$ 19,452

Goodwill and Other Intangible65

Goodwill and Other Intangible Assets (Schedule Of Expected Future Amortization Expense) (Detail) $ in Thousands	Sep. 30, 2016USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2016	$ 1,082
2,017	4,062
2,018	3,847
2,019	3,847
2,020	3,847
Thereafter	$ 18,071

Deposits (Summary Of Deposits)

Deposits (Summary Of Deposits) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Non-interest-bearing:
Demand	$ 3,993,750	$ 3,713,063
Interest-bearing:
Checking	2,429,222	2,369,971
Health savings accounts	4,187,823	3,802,313
Money market	2,342,236	1,933,460
Savings	4,226,934	4,047,817
Time deposits	2,020,943	2,086,154
Total interest-bearing	15,207,158	14,239,715
Total deposits	19,200,908	17,952,778
Time deposits and interest-bearing checking, included in above balances, obtained through brokers	852,014	910,304
Time deposits, included in above balance, that meet or exceed the FDIC limit	481,884	542,206
Deposit overdrafts reclassified as loan balances	$ 1,936	$ 1,356

Deposits (Scheduled Maturities

Deposits (Scheduled Maturities Of Time Deposits) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Banking and Thrift [Abstract]
Remainder of 2016	$ 267,114
2,017	670,946
2,018	342,507
2,019	473,697
2,020	180,741
Thereafter	85,938
Total time deposits	$ 2,020,943	$ 2,086,154

Borrowings Borrowings - (Narrat

Borrowings Borrowings - (Narrative) (Details) - USD ($) $ in Billions	Sep. 30, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
Total borrowings	$ 3.6	$ 4

Borrowings (Summary Of Securiti

Borrowings (Summary Of Securities Sold Under Agreements To Repurchase And Other Borrowings) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under agreements to repurchase	$ 753,705	$ 834,400
Fed funds purchased	47,000	317,000
Securities sold under agreements to repurchase and other borrowings	800,705	1,151,400
Original maturity of one year or less [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under agreements to repurchase	353,705	334,400
Original maturity of greater than one year, non-callable [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under agreements to repurchase	$ 400,000	$ 500,000

Borrowings (Federal Home Loan A

Borrowings (Federal Home Loan Advances) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Federal Home Loan Bank, Advances, Maturity, Rolling Year [Abstract]
FHLB advances maturing within 1 year, Total Outstanding	$ 1,875,000	$ 2,025,934
FHLB advances maturing after 1 but within 2 years, Total Outstanding	100,500	500
FHLB advances maturing after 2 but within 3 years, Total Outstanding	133,731	200,000
FHLB advances maturing after 3 but within 4 years, Total Outstanding	244,295	103,026
FHLB advances maturing after 4 but within 5 years, Total Outstanding	75,000	175,000
FHLB advances maturing after 5 years, Total Outstanding	159,442	159,655
Federal Home Loan Bank, Advances	2,587,968	2,664,115
Premiums on advances	15	24
Federal Home Loan Bank advances	$ 2,587,983	$ 2,664,139
Federal Home Loan Bank, Advances, Weighted Average Interest Rate [Abstract]
FHLB advances maturing within 1 year, Weighted Average Contractual Coupon Rate (as a percent)	0.50%	0.55%
FHLB advances maturing after 1 but within 2 years, Weighted Average Contractual Coupon Rate (as a percent)	1.49%	5.66%
FHLB advances maturing after 2 but within 3 years, Weighted Average Contractual Coupon Rate (as a percent)	1.34%	1.36%
FHLB advances maturing after 3 but within 4 years, Weighted Average Contractual Coupon Rate (as a percent)	1.70%	1.54%
FHLB advances maturing after 4 but within 5 years, Weighted Average Contractual Coupon Rate (as a percent)	1.51%	1.77%
FHLB advances maturing after 5 years, Weighted Average Contractual Coupon Rate (as a percent)	1.82%	1.60%
Federal Home Loan Bank, Advances, Weighted Average Contractual Coupon Rate (as a percent)	0.81%	0.79%
Aggregate carrying value of assets pledged as collateral	$ 5,919,426	$ 5,719,746
Remaining borrowing capacity	$ 1,386,310	$ 1,203,057

Borrowings (Long Term Debt) (De

Borrowings (Long Term Debt) (Details) - USD ($)		Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Notes and subordinated debt		$ 227,320,000	$ 227,320,000
Debt issuance cost on senior fixed-rates	[1]	(995,000)	(1,096,000)
Long-term debt		$ 225,450,000	$ 225,260,000
Variable interest rate		3.81%	3.48%
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Basis spread on variable rate		2.95%
Long-term Debt [Member]
Debt Instrument [Line Items]
Discount on senior fixed-rate notes		$ (875,000)	$ (964,000)
4.375% Senior fixed-rate notes due February 15, 2024 [Member]
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)		4.375%
Notes and subordinated debt		$ 150,000,000	150,000,000
Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	[2]	$ 77,320,000	$ 77,320,000
[1]	In accordance with the adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, debt issuance cost is accounted for as a reduction to long-term debt. Previously debt issuance cost was included in accrued interest receivable and other assets within the accompanying Condensed Consolidated Balance Sheets.
[2]	The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95%, was 3.81% at September 30, 2016 and 3.48% at December 31, 2015.

Accumulated Other Comprehensi72

Accumulated Other Comprehensive Loss, Net of Tax (Schedule of Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (57,511)	$ (60,695)	$ (78,106)	$ (56,261)
OCI/OCL before reclassifications	2,012	(1,338)	17,740	(10,118)
Amounts reclassified from AOCL	2,346	2,514	7,213	6,860
Other comprehensive income (loss), net of tax	4,358	1,176	24,953	(3,258)
Ending balance	(53,153)	(59,519)	(53,153)	(59,519)
Available For Sale and Transferred Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	12,363	9,461	(6,407)	16,421
OCI/OCL before reclassifications	1,218	660	20,156	(5,964)
Amounts reclassified from AOCL	0	52	(168)	(284)
Other comprehensive income (loss), net of tax	1,218	712	19,988	(6,248)
Ending balance	13,581	10,173	13,581	10,173
Derivative Instruments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(23,406)	(24,969)	(22,980)	(25,530)
OCI/OCL before reclassifications	794	(1,998)	(2,416)	(4,154)
Amounts reclassified from AOCL	1,221	1,479	4,005	4,196
Other comprehensive income (loss), net of tax	2,015	(519)	1,589	42
Ending balance	(21,391)	(25,488)	(21,391)	(25,488)
Defined Benefit Pension and Other Postretirement Benefit Plans [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(46,468)	(45,187)	(48,719)	(47,152)
OCI/OCL before reclassifications	0	0	0	0
Amounts reclassified from AOCL	1,125	983	3,376	2,948
Other comprehensive income (loss), net of tax	1,125	983	3,376	2,948
Ending balance	$ (45,343)	$ (44,204)	$ (45,343)	$ (44,204)

Accumulated Other Comprehensi73

Accumulated Other Comprehensive Loss, Net of Tax (Schedule of Accumulated Other Comprehensive Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Impairment loss recognized in earnings	$ 0	$ (82)	$ (149)	$ (82)
Income (loss) before income tax expense	76,262	76,365	221,945	222,322
Income tax expense	(24,445)	(24,995)	(72,478)	(69,405)
Earnings applicable to common shareholders	49,634	49,176	142,927	145,715
Net of tax	(2,346)	(2,514)	(7,213)	(6,860)
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] | Reclassification out of accumualted comprehensive income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of investment securities, net	0	0	414	529
Impairment loss recognized in earnings	0	(82)	(149)	(82)
Income (loss) before income tax expense	0	(82)	265	447
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	0	(52)	168	284
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] | Reclassification out of accumualted comprehensive income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	0	30	(97)	(163)
Earnings applicable to common shareholders	0	(52)	168	284
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	(1,221)	(1,479)	(4,005)	(4,196)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] | Reclassification out of accumualted comprehensive income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total interest expense	(1,925)	(2,332)	(6,314)	(6,616)
Income tax expense	704	853	2,309	2,420
Earnings applicable to common shareholders	(1,221)	(1,479)	(4,005)	(4,196)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(1,780)	(1,540)	(5,343)	(4,621)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Cost (Credit) [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(4)	(19)	(11)	(55)
Defined benefit pension and postretirement benefit plans [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(1,784)	(1,559)	(5,354)	(4,676)
Income tax expense	659	576	1,978	1,728
Net of tax	$ (1,125)	$ (983)	$ (3,376)	$ (2,948)

Regulatory Matters (Information

Regulatory Matters (Information On The Capital Ratios) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier 1, Actual Amount	$ 1,892,244		$ 1,824,106
Common equity tier 1, Actual Ratio	10.50%		10.70%
Common equity tier 1, Capital Requirements, Minimum Amount	$ 812,420		$ 766,848
Common equity tier 1, Capital Requirements, Minimum Ratio	4.50%		4.50%
Common equity tier 1, Capital Requirements, Well Capitalized Amount	$ 1,173,495		$ 1,107,670
Common equity tier 1, Capital Requirements, Well Capitalized Ratio	6.50%		6.50%
Total risk-based capital, Actual Amount	$ 2,282,690		$ 2,201,245
Total risk-based capital, Actual Ratio	12.60%		12.90%
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,444,302		$ 1,363,286
Total risk-based capital, Capital Requirements, Minimum Ratio	8.00%		8.00%
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 1,805,377		$ 1,704,107
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	10.00%		10.00%
Tier 1 capital, Actual Amount	$ 2,014,954		$ 1,966,146
Tier 1 capital, Actual Ratio	11.20%		11.50%
Tier 1 capital, Capital Requirements, Minimum Amount	$ 1,083,226		$ 1,022,464
Tier 1 capital, Capital Requirements, Minimum Ratio	6.00%		6.00%
Tier 1 capital, Capital Requirements, Well Capitalized Amount	$ 1,444,302		$ 1,363,286
Tier 1 capital, Capital Requirements, Well Capitalized Ratio	8.00%		8.00%
Tier 1 leverage capital ratio, Actual Amount	$ 2,014,954		$ 1,966,146
Tier 1 leverage capital ratio, Actual Ratio	8.20%		8.20%
Tier 1 leverage capital ratio, Capital Requirements, Minimum Amount	$ 987,561		$ 954,369
Tier 1 leverage capital ratio, Capital Requirements, Minimum Ratio	4.00%		4.00%
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Amount	$ 1,234,452		$ 1,192,962
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Ratio	5.00%		5.00%
Dividends paid	$ 115,000	$ 80,000
Cash Pass-through Reserve, Federal Home Loan Bank	63,800		$ 109,400
Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier 1, Actual Amount	$ 1,919,417		$ 1,869,241
Common equity tier 1, Actual Ratio	10.60%		11.00%
Common equity tier 1, Capital Requirements, Minimum Amount	$ 811,487		$ 765,152
Common equity tier 1, Capital Requirements, Minimum Ratio	4.50%		4.50%
Common equity tier 1, Capital Requirements, Well Capitalized Amount	$ 1,172,148		$ 1,105,220
Common equity tier 1, Capital Requirements, Well Capitalized Ratio	6.50%		6.50%
Total risk-based capital, Actual Amount	$ 2,109,833		$ 2,046,350
Total risk-based capital, Actual Ratio	11.70%		12.00%
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,442,643		$ 1,360,271
Total risk-based capital, Capital Requirements, Minimum Ratio	8.00%		8.00%
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 1,803,304		$ 1,700,338
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	10.00%		10.00%
Tier 1 capital, Actual Amount	$ 1,919,417		$ 1,869,241
Tier 1 capital, Actual Ratio	10.60%		11.00%
Tier 1 capital, Capital Requirements, Minimum Amount	$ 1,081,983		$ 1,020,203
Tier 1 capital, Capital Requirements, Minimum Ratio	6.00%		6.00%
Tier 1 capital, Capital Requirements, Well Capitalized Amount	$ 1,442,643		$ 1,360,271
Tier 1 capital, Capital Requirements, Well Capitalized Ratio	8.00%		8.00%
Tier 1 leverage capital ratio, Actual Amount	$ 1,919,417		$ 1,869,241
Tier 1 leverage capital ratio, Actual Ratio	7.80%		7.80%
Tier 1 leverage capital ratio, Capital Requirements, Minimum Amount	$ 986,708		$ 953,300
Tier 1 leverage capital ratio, Capital Requirements, Minimum Ratio	4.00%		4.00%
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Amount	$ 1,233,385		$ 1,191,626
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Ratio	5.00%		5.00%

Earnings Per Common Share (Earn

Earnings Per Common Share (Earnings Per Share Basic And Diluted) (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings for basic and diluted earnings per common share:
Net income	$ 51,817	$ 51,370	$ 149,467	$ 152,917
Less: Preferred stock dividends	2,024	2,024	6,072	6,687
Net income available to common shareholders	49,793	49,346	143,395	146,230
Net income available to common shareholders	49,793	49,346	143,395	146,230
Less: Earnings applicable to participating securities	159	170	468	515
Less: Earnings applicable to participating securities	159	170	468	515
Earnings applicable to common shareholders	49,634	49,176	142,927	145,715
Earnings applicable to common shareholders	$ 49,634	$ 49,176	$ 142,927	$ 145,715
Shares:
Weighted average common shares outstanding - basic (in shares)	91,365	91,458	91,298	90,816
Effect of dilutive securities:
Stock options and restricted stock (in shares)	465	512	452	532
Warrants (in shares)	27	37	26	43
Weighted-average common shares outstanding - diluted (in shares)	91,857	92,007	91,776	91,391
Earnings per common share:
Basic (in dollars per share)	$ 0.54	$ 0.54	$ 1.57	$ 1.61
Diluted (in dollars per share)	$ 0.54	$ 0.53	$ 1.56	$ 1.60

Earnings Per Common Share Sched

Earnings Per Common Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock options (shares with exercise price greater than market price) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	172	305	172	305
Restricted stock (due to performance conditions on non-participating shares) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	52	161	93

Earnings Per Common Share (Narr

Earnings Per Common Share (Narrative) (Detail) shares in Millions	9 Months Ended
	Sep. 30, 2016shares
Employee Stock Option [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	(1.1)

Derivative Financial Instrume78

Derivative Financial Instruments (Risk Management Objective of Using Derivatives) (Narrative) (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Derivative [Line Items]
Interest expense related to previous fair value hedges	$ 1,153,000	$ (347,000)	$ 6,147,000	$ 3,435,000
Designated as Hedging Instrument [Member] | Interest Expense [Member] | Fair Value Hedging [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Interest expense related to previous fair value hedges			$ 0		$ 0

Derivative Financial Instrume79

Derivative Financial Instruments (Schedule fair value of derivative instruments) (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value, Less: Cash collateral posted		$ 29,500	$ 20,200
Liability Derivatives, Fair Value, Less: Cash collateral posted		96,300
Mandatory Forward Commitment		133,100
Floating rate Commitments		29,300
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value, Gross Asset		1,070	4,945
Asset Derivatives, Fair Value, Less: Legally enforceable master netting agreements		1,070	4,945
Derivative Asset	[1],[2]	0	0
Liability Derivatives, Fair Value, Gross Liability		94,732	41,727
Liability Derivatives, Fair Value, Less: Legally enforceable master netting agreements		94,732	36,275
Liability Derivatives	[1],[2]	0	5,452
Subject to and not subject to Master Netting Agreements [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts		3,244,375	3,352,704
Asset Derivatives, Fair Value, Gross Asset		119,909	64,221
Asset Derivatives, Fair Value, Less: Legally enforceable master netting agreements		1,070	4,945
Asset Derivatives, Fair Value, Less: Cash collateral posted		0	0
Derivative Asset		118,839	59,276
Liability Derivatives, Notional Amount		3,122,233	2,223,823
Liability Derivatives, Fair Value, Gross Liability		95,902	42,552
Liability Derivatives, Fair Value, Less: Legally enforceable master netting agreements		1,070	4,945
Liability Derivatives, Fair Value, Less: Cash collateral posted		93,662	31,330
Liability Derivatives		1,170	6,277
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value, Gross Asset		768	2,507
Asset Derivatives, Fair Value, Less: Cash collateral posted		768	2,507
Derivative Asset	[1],[2]	0	0
Liability Derivatives, Fair Value, Gross Liability		3,433	1,359
Liability Derivatives, Fair Value, Less: Cash collateral posted		3,433	1,359
Liability Derivatives	[1],[2]	0	0
Designated as Hedging Instrument [Member] | Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member] | Interest rate derivatives [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	[3]	175,000	200,000
Asset Derivatives, Fair Value, Gross Asset	[3]	768	2,507
Liability Derivatives, Notional Amount	[3]	150,000	100,000
Liability Derivatives, Fair Value, Gross Liability	[3]	3,433	1,359
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value, Gross Asset		302	2,438
Asset Derivatives, Fair Value, Less: Cash collateral posted		302	2,438
Derivative Asset	[1],[2]	0	0
Liability Derivatives, Fair Value, Gross Liability		91,299	40,368
Liability Derivatives, Fair Value, Less: Cash collateral posted		91,299	34,916
Liability Derivatives	[1],[2]	0	5,452
Not Designated as Hedging Instrument [Member] | Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member] | Interest rate derivatives [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	[3]	472,750	989,695
Asset Derivatives, Fair Value, Gross Asset	[3]	236	2,255
Liability Derivatives, Notional Amount	[3]	2,320,222	1,543,479
Liability Derivatives, Fair Value, Gross Liability	[3]	91,262	40,302
Not Designated as Hedging Instrument [Member] | Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member] | Other [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	[3]	22,634	8,237
Asset Derivatives, Fair Value, Gross Asset	[3]	66	183
Liability Derivatives, Notional Amount	[3]	8,517	4,561
Liability Derivatives, Fair Value, Gross Liability	[3]	37	66
Not Designated as Hedging Instrument [Member] | Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	[4]	3,069,375	3,152,704
Asset Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	119,141	61,714
Liability Derivatives, Notional Amount	[4]	2,972,233	2,123,823
Liability Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	92,469	41,193
Not Designated as Hedging Instrument [Member] | Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Interest rate derivatives [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	[4]	2,388,726	2,050,460
Asset Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	116,645	58,304
Liability Derivatives, Notional Amount	[4]	404,272	482,738
Liability Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	125	571
Not Designated as Hedging Instrument [Member] | Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | RPAs [Member] | RPA-Out [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	[4]	75,250	41,798
Asset Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	320	153
Not Designated as Hedging Instrument [Member] | Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | RPAs [Member] | RPA-In [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Notional Amount	[4]	106,633	92,985
Liability Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	337	245
Not Designated as Hedging Instrument [Member] | Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Mortgage Banking Derivatives [Member] | RPA-Out [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	[4]	110,015	62,514
Asset Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	1,874	819
Not Designated as Hedging Instrument [Member] | Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Mortgage Banking Derivatives [Member] | RPA-In [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Notional Amount	[4]	132,529	0
Liability Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	698	0
Not Designated as Hedging Instrument [Member] | Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Other [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	[4]	0	0
Asset Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	0	0
Liability Derivatives, Notional Amount	[4]	60	60
Liability Derivatives, Fair Value, Positions not subject to master netting agreement	[4]	$ 10	$ 9
[1]	Net amount excludes $29.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at September 30, 2016 and December 31, 2015, respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Condensed Consolidated Balance Sheets.
[2]	Net amount is net of $93.7 million and $31.3 million of cash collateral at September 30, 2016 and December 31, 2015, respectively, as presented in the accompanying Condensed Consolidated Balance Sheets.
[3]	The Company has elected to report derivative positions subject to a legally enforceable master netting agreement on a net basis, net of cash collateral. Refer to the Offsetting Derivatives section of this footnote for additional information.
[4]	Derivative positions not subject to a legally enforceable master netting agreement are reported on a gross basis in the accompanying Condensed Consolidated Balance Sheets.

Derivative Financial Instrume80

Derivative Financial Instruments (Schedule of the changes in the fair value of non-hedge accounting derivatives) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 1,153	$ (347)	$ 6,147	$ 3,435
Interest Rate Derivatives [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	608	955	6,515	3,375
RPA [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	110	0	(143)	(118)
Mortgage Banking Derivatives [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	720	(1,331)	357	215
Other [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ (285)	$ 29	$ (582)	$ (37)

Derivative Financial Instrume81

Derivative Financial Instruments (AOCI Related to Cash Flow Hedges) (Narrative) (Detail) - Cash Flow Hedging [Member] $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Estimate of amount to be reclassified from AOCL	$ 6.4
Remaining unamortized gain (loss) on termination of cash flow hedges	(22.9)
Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Estimate of amount to be reclassified from AOCL	$ 2.1

Derivative Financial Instrume82

Derivative Financial Instruments (Offsetting Derivatives) (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative instrument asset, Amount Offset		$ (29,500)	$ (20,200)
Derivative instrument liability, Amount Offset		(96,300)
Hedge Accounting Positions [Member]
Derivative [Line Items]
Derivative instrument assets, Gross Amount		768	2,507
Derivative instrument asset, Amount Offset		(768)	(2,507)
Derivative Asset	[1],[2]	0	0
Derivative instrument liability, Gross Amount		3,433	1,359
Derivative instrument liability, Amount Offset		(3,433)	(1,359)
Derivative instrument liability, Net Amount	[1],[2]	0	0
Non-Hedged Accounting Positions [Member]
Derivative [Line Items]
Derivative instrument assets, Gross Amount		302	2,438
Derivative instrument asset, Amount Offset		(302)	(2,438)
Derivative Asset	[1],[2]	0	0
Derivative instrument liability, Gross Amount		91,299	40,368
Derivative instrument liability, Amount Offset		(91,299)	(34,916)
Derivative instrument liability, Net Amount	[1],[2]	0	5,452
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member]
Derivative [Line Items]
Derivative instrument assets, Gross Amount		1,070	4,945
Derivative Asset	[1],[2]	0	0
Derivative instrument asset, Amount Offset, Total		(1,070)	(4,945)
Derivative instrument liability, Gross Amount		94,732	41,727
Derivative instrument liability, Net Amount	[1],[2]	0	5,452
Derivative instrument liability, Amount Offset, Total		(94,732)	(36,275)
Subject to and not subject to Master Netting Agreements [Member]
Derivative [Line Items]
Derivative instrument assets, Gross Amount		119,909	64,221
Derivative instrument asset, Amount Offset		0	0
Derivative Asset		118,839	59,276
Derivative instrument asset, Amount Offset, Total		(1,070)	(4,945)
Derivative instrument liability, Gross Amount		95,902	42,552
Derivative instrument liability, Amount Offset		(93,662)	(31,330)
Derivative instrument liability, Net Amount		1,170	6,277
Derivative instrument liability, Amount Offset, Total		$ (1,070)	$ (4,945)
[1]	Net amount excludes $29.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at September 30, 2016 and December 31, 2015, respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Condensed Consolidated Balance Sheets.
[2]	Net amount is net of $93.7 million and $31.3 million of cash collateral at September 30, 2016 and December 31, 2015, respectively, as presented in the accompanying Condensed Consolidated Balance Sheets.

Derivative Financial Instrume83

Derivative Financial Instruments (Counterparty Credit Risk Narrative) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative, Collateral, Right to Reclaim Cash	$ 125,800
Derivative Asset, Collateral, Obligation to Return Cash, Offset	29,500	$ 20,200
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	96,300
Credit Derivative, Maximum Exposure, Undiscounted	116,900
Market Approach Valuation Technique [Member]
Derivative [Line Items]
Credit Derivative, Maximum Exposure, Undiscounted	24,800
Subject to and not subject to Master Netting Agreements [Member]
Derivative [Line Items]
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0	0
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	$ 93,662	$ 31,330

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 5,427,057	$ 5,031,030
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Book value of other real estate owned (OREO) and repossessed assets	4,100
Rabbi Trust [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	3,300
Alternative investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 22,400

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Assets And Liabilities Measured On Recurring Basis) (Detail) - USD ($) $ in Thousands		Sep. 30, 2016		Dec. 31, 2015
Financial assets held at fair value:
Originated loans held for sale		$ 66,400		$ 0
Fair Value, Measurements, Recurring [Member]
Financial assets held at fair value:
Originated loans held for sale	[1]	66,400
Total financial assets held at fair value		3,244,939		3,063,026
Financial liabilities held at fair value:
Derivative liability	[2]	95,902		42,552
Contingent liability				6,000
Total financial liabilities held at fair value		95,902		48,552
Fair Value, Measurements, Recurring [Member] | Contingent Consideration [Member]
Financial assets held at fair value:
Other assets		8,035		5,331
Fair Value, Measurements, Recurring [Member] | Derivative instruments [Member]
Financial assets held at fair value:
Derivative Asset	[2]	119,909		64,221
Fair Value, Measurements, Recurring [Member] | Available-for-sale Investment Securities [Member]
Financial assets held at fair value:
Available for sale investment securities		3,040,111		2,984,631
Fair Value, Measurements, Recurring [Member] | U.S. Treasury Bills [Member]
Financial assets held at fair value:
Available for sale investment securities		985		924
Fair Value, Measurements, Recurring [Member] | Agency CMO [Member]
Financial assets held at fair value:
Available for sale investment securities		463,730		548,754
Fair Value, Measurements, Recurring [Member] | Agency MBS [Member]
Financial assets held at fair value:
Available for sale investment securities		1,001,014		1,065,109
Fair Value, Measurements, Recurring [Member] | Agency CMBS [Member]
Financial assets held at fair value:
Available for sale investment securities		484,408		215,350
Fair Value, Measurements, Recurring [Member] | CMBS [Member]
Financial assets held at fair value:
Available for sale investment securities		468,361		579,266
Fair Value, Measurements, Recurring [Member] | CLO [Member]
Financial assets held at fair value:
Available for sale investment securities		484,236		429,159
Fair Value, Measurements, Recurring [Member] | Single issuer trust preferred securities [Member]
Financial assets held at fair value:
Available for sale investment securities		38,111		37,170
Fair Value, Measurements, Recurring [Member] | Corporate debt securities [Member]
Financial assets held at fair value:
Available for sale investment securities		99,266		106,321
Fair Value, Measurements, Recurring [Member] | Equity securities [Member]
Financial assets held at fair value:
Available for sale investment securities				2,578
Fair Value, Measurements, Recurring [Member] | Investments held In Rabbi Trust [Member]
Financial assets held at fair value:
Other assets		5,020		5,372
Fair Value, Measurements, Recurring [Member] | Alternative investments [Member]
Financial assets held at fair value:
Other assets		5,464		3,471
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member]
Financial assets held at fair value:
Originated loans held for sale		0	[1]	0
Total financial assets held at fair value		6,071		9,057
Financial liabilities held at fair value:
Derivative liability	[2]	37		66
Total financial liabilities held at fair value		37		66
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member] | Contingent Consideration [Member]
Financial assets held at fair value:
Other assets		0		0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member] | Derivative instruments [Member]
Financial assets held at fair value:
Derivative Asset	[2]	66		183
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member] | Available-for-sale Investment Securities [Member]
Financial assets held at fair value:
Available for sale investment securities		985		3,502
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member] | U.S. Treasury Bills [Member]
Financial assets held at fair value:
Available for sale investment securities		985		924
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member] | Agency CMBS [Member]
Financial assets held at fair value:
Available for sale investment securities		0		0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member] | CMBS [Member]
Financial assets held at fair value:
Available for sale investment securities		0		0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member] | Equity securities [Member]
Financial assets held at fair value:
Available for sale investment securities				2,578
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member] | Investments held In Rabbi Trust [Member]
Financial assets held at fair value:
Other assets		5,020		5,372
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets For Identical Assets (Level 1) [Member] | Alternative investments [Member]
Financial assets held at fair value:
Other assets		0		0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Originated loans held for sale		66,400	[1]	0
Total financial assets held at fair value		3,225,369		3,045,167
Financial liabilities held at fair value:
Derivative liability	[2]	95,865		42,486
Total financial liabilities held at fair value		95,865		42,486
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Contingent Consideration [Member]
Financial assets held at fair value:
Other assets		0		0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Derivative instruments [Member]
Financial assets held at fair value:
Derivative Asset	[2]	119,843		64,038
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale Investment Securities [Member]
Financial assets held at fair value:
Available for sale investment securities		3,039,126		2,981,129
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Agency CMO [Member]
Financial assets held at fair value:
Available for sale investment securities		463,730		548,754
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Agency MBS [Member]
Financial assets held at fair value:
Available for sale investment securities		1,001,014		1,065,109
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Agency CMBS [Member]
Financial assets held at fair value:
Available for sale investment securities		484,408		215,350
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | CMBS [Member]
Financial assets held at fair value:
Available for sale investment securities		468,361		579,266
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | CLO [Member]
Financial assets held at fair value:
Available for sale investment securities		484,236		429,159
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Single issuer trust preferred securities [Member]
Financial assets held at fair value:
Available for sale investment securities		38,111		37,170
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate debt securities [Member]
Financial assets held at fair value:
Available for sale investment securities		99,266		106,321
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Alternative investments [Member]
Financial assets held at fair value:
Other assets		0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets held at fair value:
Total financial assets held at fair value		13,499		8,802
Financial liabilities held at fair value:
Contingent liability				6,000
Total financial liabilities held at fair value				6,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Contingent Consideration [Member]
Financial assets held at fair value:
Other assets		8,035		5,331
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Derivative instruments [Member]
Financial assets held at fair value:
Derivative Asset	[2]			0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Agency CMBS [Member]
Financial assets held at fair value:
Available for sale investment securities		0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | CMBS [Member]
Financial assets held at fair value:
Available for sale investment securities		0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Alternative investments [Member]
Financial assets held at fair value:
Other assets		$ 5,464		$ 3,471
[1]	Loans held for sale accounted for under the fair value option of ASC 825 "Financial Instruments" at September 30, 2016. The Company made this policy election on loans originated for sale. See Note 1: Summary of Significant Accounting Policies.
[2]	For information relating to the impact of netting derivative assets and derivative liabilities as well as the impact from offsetting cash collateral paid to the same derivative counterparties see Note 12: Derivative Financial Instruments.

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3, beginning of period, Financial Assets	$ 8,802
Level 3, beginning of period, Contingent Liability	6,000
Unrealized gain included in net income	3,015
Purchases/capital funding	1,682
Payments	(6,000)
Level 3, end of period, Financial Assets	13,499
Level 3, end of period, Contingent Liability	0
Contingent Consideration [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3, beginning of period, Financial Assets	5,331
Unrealized gain included in net income	2,704
Level 3, end of period, Financial Assets	8,035
Equity Method Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3, beginning of period, Financial Assets	3,471
Unrealized gain included in net income	311
Purchases/capital funding	1,682
Level 3, end of period, Financial Assets	$ 5,464

Fair Value Measurements Schedul

Fair Value Measurements Schedule of Servicing Assets at Fair Value (Details) - Residential Mortgage [Member] - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 33,568	$ 28,690
Originations of servicing assets	8,198	6,335
Due to payoffs/paydowns	(3,026)	(1,918)
Due to market changes	(3,119)	(754)
Ending balance	$ 35,621	$ 32,353

Fair Value Measurements (Sche88

Fair Value Measurements (Schedule Of Valuation Methodology And Unobservable Inputs) (Detail) - Significant Unobservable Inputs (Level 3) [Member] - Fair Value, Measurements, Nonrecurring [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Other Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
OREO	$ 195
Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortgage servicing assets	$ 35,621
Market Approach Valuation Technique [Member] | Other Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	8.00%
Market Approach Valuation Technique [Member] | Maximum [Member] | Other Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	10.00%
Income Approach Valuation Technique [Member] | Minimum [Member] | Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	1.50%
Income Approach Valuation Technique [Member] | Minimum [Member] | Mortgage Servicing Rights [Member] | Interest Rate Risk [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate (as a percent)	7.90%
Income Approach Valuation Technique [Member] | Maximum [Member] | Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	2.10%
Income Approach Valuation Technique [Member] | Maximum [Member] | Mortgage Servicing Rights [Member] | Interest Rate Risk [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate (as a percent)	32.60%
Impaired Loans and Leases [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Collateral dependent impaired loans and leases	$ 1,974
Impaired Loans and Leases [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	0.00%
Impaired Loans and Leases [Member] | Market Approach Valuation Technique - Discount for cost to sell [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	0.00%
Other Real Estate Owned [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	0.00%

Fair Value Measurements (Summar

Fair Value Measurements (Summary Of Estimated Fair Values Of Significant Financial Instruments) (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale		$ 66,400	$ 0
Fair Value, Measurements, Nonrecurring [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale	[1]	178		$ 37,091
Loans and leases, net		16,435,476		15,496,745
Securities sold under agreements to repurchase and other borrowings		800,705		1,151,400
FHLB advances	[2]	2,587,983		2,664,139
Long-term debt	[2]	225,450		226,356
Fair Value, Measurements, Nonrecurring [Member] | Reported Value Measurement [Member] | Deposits Liabilities, other than time deposits [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		17,179,965		15,866,624
Fair Value, Measurements, Nonrecurring [Member] | Reported Value Measurement [Member] | Time Deposits [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		2,020,943		2,086,154
Fair Value, Measurements, Nonrecurring [Member] | Reported Value Measurement [Member] | Alternative investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative investments		11,303		12,900
Fair Value, Measurements, Nonrecurring [Member] | Reported Value Measurement [Member] | Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage servicing assets, Carrying Amount		23,384		20,698
Fair Value, Measurements, Nonrecurring [Member] | Reported Value Measurement [Member] | Held-to-maturity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		4,022,332		3,923,052
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale	[1]	178		37,457
Securities sold under agreements to repurchase and other borrowings		811,273		1,163,974
FHLB advances	[2]	2,576,651		2,647,872
Long-term debt	[2]	222,694		218,143
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases, net		16,450,034		15,543,892
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Deposits Liabilities, other than time deposits [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		17,179,965		15,866,624
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Time Deposits [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		2,037,577		2,095,357
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Alternative investments [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative investments		12,867		14,294
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Residential Mortgage [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage servicing assets, Fair value		35,621		33,568
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member] | Held-to-maturity Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		$ 4,109,943		$ 3,961,534
[1]	Loans held for sale accounted for at the lower of cost or market includes commercial loans at September 30, 2016 and both commercial and residential loans at December 31, 2015.
[2]	The following adjustments to the carrying amount are not included for determination of fair value, see Note 8: Borrowings:•FHLB advances - unamortized premiums on advances•Long-term debt - unamortized discount and debt issuance cost on senior fixed-rate notes

Retirement Benefit Plans (Detai

Retirement Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Webster Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 11	$ 11	$ 34	$ 34
Interest cost on benefit obligations	2,110	2,002	6,331	6,006
Expected return on plan assets	(3,067)	(2,968)	(8,596)	(8,905)
Amortization of prior service cost	0	0	0	0
Recognized net loss	1,666	1,431	4,998	4,293
Net periodic benefit cost	720	476	2,767	1,428
Webster SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost on benefit obligations	98	86	292	259
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	0	0	0	0
Recognized net loss	106	98	319	293
Net periodic benefit cost	204	184	611	552
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost on benefit obligations	32	31	94	93
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	4	18	11	54
Recognized net loss	8	11	26	35
Net periodic benefit cost	$ 44	$ 60	$ 131	$ 182

Retirement Benefit Plans Retire

Retirement Benefit Plans Retirement Benefits Plan Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Webster Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer	$ 20

Share-Based Plans (Summary of S

Share-Based Plans (Summary of Stock-based compensation expense recognized) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock compensation expense	$ 2,944	$ 3,007	$ 8,558	$ 8,283
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock compensation expense	0	73	43	305
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock compensation expense	$ 2,944	$ 2,934	$ 8,515	$ 7,978

Share-Based Plans (Narrative) (

Share-Based Plans (Narrative) (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock compensation expense	$ 16.9
Weighted average recognition period	1 year 8 months 18 days
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant	100,000
Time Based Restricted Stock Awards [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Time Based Restricted Stock Awards [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	5 years
Performance-Based Restricted Stock Awards Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Vesting range (as a percent)	50.00%
Performance-Based Restricted Stock Awards Shares [Member] | Minimum [Member] | Share-based Compensation Award, Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting range (as a percent)	0.00%
Performance-Based Restricted Stock Awards Shares [Member] | Maximum [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting range (as a percent)	150.00%
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding (in shares)	1,368,818	1,527,074
Employee Stock Option [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award (in years)	P10Y0M
Non-Qualified Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding (in shares)	1,269,249
Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding (in shares)	99,569

Share-Based Plans (Summary of R

Share-Based Plans (Summary of Restricted Stock and Stock Option Activity) (Detail)	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options exercisable, Number of Shares	0
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock, Outstanding at beginning of period (in shares)	236,145
Restricted stock, Granted (in shares)	222,610
Restricted stock, Vested restricted stock awards (in shares)	166,988	[1]
Restricted stock, Forfeited (in shares)	11,628
Restricted stock, Outstanding at end of period (in shares)	280,139
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted stock, at beginning of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 32.58
Restricted stock, Granted (in dollars per share) | $ / shares	32.93
Restricted stock, Vested restricted stock awards (in dollars per share) | $ / shares	31.81	[1]
Restricted stock, Forfeited (in dollars per share) | $ / shares	32.73
Restricted stock, at end of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 33.28
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock, Outstanding at beginning of period (in shares)	2,088
Restricted stock, Granted (in shares)	12,946
Restricted stock, Vested restricted stock awards (in shares)	9,638	[1]
Restricted stock, Forfeited (in shares)	0
Restricted stock, Outstanding at end of period (in shares)	5,396
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted stock, at beginning of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 34.45
Restricted stock, Granted (in dollars per share) | $ / shares	32.89
Restricted stock, Vested restricted stock awards (in dollars per share) | $ / shares	33.23	[1]
Restricted stock, Forfeited (in dollars per share) | $ / shares	0
Restricted stock, at end of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 32.89
Performance-Based Restricted Stock Awards Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock, Outstanding at beginning of period (in shares)	115,721
Restricted stock, Granted (in shares)	150,392
Restricted stock, Vested restricted stock awards (in shares)	104,419	[1]
Restricted stock, Forfeited (in shares)	3,401
Restricted stock, Outstanding at end of period (in shares)	158,293
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted stock, at beginning of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 34.14
Restricted stock, Granted (in dollars per share) | $ / shares	32.75
Restricted stock, Vested restricted stock awards (in dollars per share) | $ / shares	33.17	[1]
Restricted stock, Forfeited (in dollars per share) | $ / shares	33.59
Restricted stock, at end of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 33.47
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, at beginning of period, Number of Shares	1,527,074
Options granted, Number of Shares	0
Exercised options, Number of Shares	116,694
Options forfeited, Number of Shares	41,562
Options outstanding, at end of period, Number of Shares	1,368,818
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Options, at beginning of period, Weighted-average Exercise Price (in dollars per share) | $ / shares	$ 23.92
Options granted, Weighted-Average Exercise Price (in dollars per share) | $ / shares	0
Exercised options, Weighted-Average Exercise Price (in dollars per share) | $ / shares	20.19
Options forfeited, Weighted-Average Exercise Price (in dollars per share) | $ / shares	47.92
Options, at end of period, Weighted-average Exercise Price (in dollars per share) | $ / shares	$ 23.51
[1]	Vested for purposes of recording compensation expense.

Segment Reporting (Operating Re

Segment Reporting (Operating Results and Total Assets Reportable Segments) (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)Segment	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | Segment			4
Net interest income (loss)	$ 180,197	$ 168,010	$ 533,254	$ 491,285
Provision (benefit) for loan and lease losses	14,250	13,000	43,850	35,500
Net interest income after provision for loan and lease losses	165,947	155,010	489,404	455,785
Non-interest income	66,412	61,292	193,861	178,098
Non-interest expense	156,097	139,937	461,320	411,561
Income (loss) before income tax expense	76,262	76,365	221,945	222,322
Income tax expense (benefit)	24,445	24,995	72,478	69,405
Net of tax	51,817	51,370	149,467	152,917
Total Assets	25,633,617		25,633,617		$ 24,641,118
Operating Segments [Member] | Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	71,454	64,769	203,012	188,539
Provision (benefit) for loan and lease losses	7,459	3,992	29,247	19,951
Net interest income after provision for loan and lease losses	63,995	60,777	173,765	168,588
Non-interest income	13,515	10,970	34,374	28,321
Non-interest expense	30,477	27,474	87,781	81,144
Income (loss) before income tax expense	47,033	44,273	120,358	115,765
Income tax expense (benefit)	15,128	14,387	39,304	36,139
Net of tax	31,905	29,886	81,054	79,626
Total Assets	8,174,174		8,174,174		7,505,513
Operating Segments [Member] | Community Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	91,522	90,370	272,725	262,214
Provision (benefit) for loan and lease losses	6,939	8,953	15,572	16,383
Net interest income after provision for loan and lease losses	84,583	81,417	257,153	245,831
Non-interest income	29,121	26,928	83,219	80,748
Non-interest expense	91,463	82,919	272,823	247,070
Income (loss) before income tax expense	22,241	25,426	67,549	79,509
Income tax expense (benefit)	7,121	8,366	22,059	24,821
Net of tax	15,120	17,060	45,490	54,688
Total Assets	8,638,736		8,638,736		8,441,950
Operating Segments [Member] | HSA Bank [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	20,560	18,852	60,484	53,080
Provision (benefit) for loan and lease losses	0	0	0	0
Net interest income after provision for loan and lease losses	20,560	18,852	60,484	53,080
Non-interest income	16,900	16,386	54,969	46,885
Non-interest expense	23,021	21,273	71,966	60,476
Income (loss) before income tax expense	14,439	13,965	43,487	39,489
Income tax expense (benefit)	4,624	4,561	14,201	12,327
Net of tax	9,815	9,404	29,286	27,162
Total Assets	92,128		92,128		95,815
Operating Segments [Member] | Private Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	2,811	2,575	8,410	7,471
Provision (benefit) for loan and lease losses	417	76	518	(158)
Net interest income after provision for loan and lease losses	2,394	2,499	7,892	7,629
Non-interest income	2,401	2,215	7,445	6,891
Non-interest expense	5,316	5,026	15,555	14,502
Income (loss) before income tax expense	(521)	(312)	(218)	18
Income tax expense (benefit)	(171)	(96)	(71)	5
Net of tax	(350)	(216)	(147)	13
Total Assets	521,877		521,877		493,571
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)	(6,150)	(8,556)	(11,377)	(20,019)
Provision (benefit) for loan and lease losses	(565)	(21)	(1,487)	(676)
Net interest income after provision for loan and lease losses	(5,585)	(8,535)	(9,890)	(19,343)
Non-interest income	4,475	4,793	13,854	15,253
Non-interest expense	5,820	3,245	13,195	8,369
Income (loss) before income tax expense	(6,930)	(6,987)	(9,231)	(12,459)
Income tax expense (benefit)	(2,257)	(2,223)	(3,015)	(3,887)
Net of tax	(4,673)	$ (4,764)	(6,216)	$ (8,572)
Total Assets	$ 8,206,702		$ 8,206,702		$ 8,104,269

Commitments and Contingencies96

Commitments and Contingencies (Outstanding Financial Instruments Contract Amounts Represent Credit Risk) (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 5,427,057	$ 5,031,030
Standby letter of credit [Member]
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	141,200	133,294
Commercial letter of credit [Member]
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	46,344	45,742
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 5,239,513	$ 4,851,994

(Reserve for Unfunded Commitmen

(Reserve for Unfunded Commitments) (Detail) - Reserve for Off-balance Sheet Activities [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 2,319	$ 2,007	$ 2,119	$ 5,151
Provision (benefit)	172	16	372	(3,128)
Ending balance	$ 2,491	$ 2,023	$ 2,491	$ 2,023