Webster Financial (WBS) 10-Q1 Nov 192019 Q3 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	9 Months Ended
Cover Page - shares	Sep. 30, 2019	Oct. 31, 2019
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Entity File Number	001-31486
Entity Registrant Name	WEBSTER FINANCIAL CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	06-1187536
Entity Address, Address Line One	145 Bank Street
Entity Address, City or Town	Waterbury
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06702
City Area Code	203
Local Phone Number	578-2202
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		92,031,914
Entity Central Index Key	0000801337
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Document Transition Report	false
NEW YORK STOCK EXCHANGE, INC. [Member] \| Common Class A [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	WBS
Security Exchange Name	NYSE
NEW YORK STOCK EXCHANGE, INC. [Member] \| Series F Preferred Stock [Member]
Entity Information [Line Items]
Title of 12(b) Security	Depository Shares, each representing 1/1000th interest in a share
Trading Symbol	WBS-F
Security Exchange Name	NYSE

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Cash and Due from Banks	$ 227,966	$ 260,422
Assets:
Interest-bearing deposits	74,865	69,077
Fair Value	2,960,103	2,898,730
Debt Securities, Held-to-maturity	5,193,521	4,325,420
Federal Home Loan Bank and Federal Reserve Bank stock	116,984	149,286
Loans held for sale (valued under fair value option $27,061 and $7,908)	27,061	11,869
Loans and leases	19,551,646	18,465,489
Allowance for loan and lease losses	(209,152)	(212,353)
Loans and leases, net	19,342,494	18,253,136
Deferred tax assets, net	59,956	96,516
Premises and equipment, net	278,642	124,850
Goodwill	538,373	538,373
Other intangible assets, net	22,879	25,764
Cash surrender value of life insurance policies	549,335	543,616
Accrued interest receivable and other assets	502,921	313,256
Total assets	29,895,100	27,610,315
Liabilities and shareholders' equity:
Noninterest-bearing Deposit Liabilities	4,291,659	4,162,446
Interest-bearing Deposit Liabilities	18,989,006	17,696,399
Total deposits	23,280,665	21,858,845
Securities sold under agreements to repurchase and other borrowings	1,210,692	581,874
Federal Home Loan Bank advances	1,392,849	1,826,808
Long-term debt	549,158	226,021
Accrued expenses and other liabilities	309,342	230,252
Total liabilities	26,742,706	24,723,800
Shareholders’ equity:
Common stock, $.01 par value: Authorized - 200,000,000 shares: Issued (93,651,601 shares)	937	937
Paid-in capital	1,115,204	1,114,394
Retained earnings	2,010,930	1,828,303
Treasury stock, at cost (1,652,279 and 1,508,456 shares)	(82,480)	(71,504)
Accumulated other comprehensive loss, net of tax	(37,234)	(130,652)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	3,152,394	2,886,515
Total liabilities and shareholders' equity	29,895,100	27,610,315
Series F Preferred Stock [Member]
Shareholders’ equity:
Preferred stock, $.01 par value; Authorized - 3,000,000 shares: Series E issued and outstanding (5,060 shares)	$ 145,037	$ 145,037

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Securities held-to-maturity ,fair value	$ 5,285,705	$ 4,209,121
Loans Held-for-sale, Fair Value Disclosure	$ 27,061	$ 7,908
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	3,000,000	3,000,000
Preferred stock, shares issued (in shares)	6,000	5,060
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)	93,686,311	93,686,311
Treasury stock ,shares (in shares)	1,652,279	1,508,456

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest Income:
Interest and fees on loans and leases	$ 236,453	$ 215,448	$ 701,166	$ 616,488
Taxable interest and dividends on investments	52,046	47,646	154,556	142,361
Non-taxable interest on investment securities	5,471	5,061	16,402	15,428
Loans held for sale	166	208	459	498
Total interest income	294,136	268,363	872,583	774,775
Interest Expense:
Deposits	34,214	24,397	97,991	62,778
Securities sold under agreements to repurchase and other borrowings	6,571	3,084	13,227	10,722
Federal Home Loan Bank advances	6,910	7,685	22,467	23,437
Long-term debt	5,902	2,825	15,021	8,288
Total interest expense	53,597	37,991	148,706	105,225
Net interest income	240,539	230,372	723,877	669,550
Provision for loan and lease losses	11,300	10,500	31,800	32,000
Net interest income after provision for loan and lease losses	229,239	219,872	692,077	637,550
Non-interest Income:
Deposit service fees	41,410	40,601	127,552	121,911
Loan and lease related fees	8,246	10,782	22,623	24,111
Wealth and investment services	8,496	8,412	24,456	24,738
Mortgage banking activities	2,133	1,305	3,829	3,684
Increase in cash surrender value of life insurance policies	3,708	3,706	10,942	10,921
Other income			24,994	24,040
Noninterest Income, Other	5,938	7,478
Total non-interest income	69,931	72,284	214,396	209,405
Non-interest Expense:
Compensation and benefits	98,623	96,640	294,935	284,457
Occupancy	14,087	14,502	42,802	45,489
Technology and equipment	26,180	24,553	77,644	73,019
Intangible assets amortization	961	961	2,885	2,885
Marketing	4,758	4,052	12,329	12,493
Professional and outside services	5,024	4,930	16,706	14,099
Deposit insurance	4,409	9,694	13,292	30,098
Other expense	25,852	23,451	75,627	68,317
Total non-interest expense	179,894	178,783	536,220	530,857
Income (loss) before income tax expense	119,276	113,373	370,253	316,098
Income tax expense	25,411	13,700	78,003	54,518
Net income	93,865	99,673	292,250	261,580
Preferred stock dividends and other	(2,423)	(2,213)	(7,331)	(6,540)
Earnings applicable to common shareholders	$ 91,442	$ 97,460	$ 284,919	$ 255,040
Earnings per common share:
Basic (in dollars per share)	$ 1	$ 1.06	$ 3.11	$ 2.77
Diluted (in dollars per share)	$ 1	$ 1.06	$ 3.10	$ 2.77

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 93,865	$ 99,673	$ 292,250	$ 261,580
Other comprehensive income (loss), net of tax:
Investment securities available-for-sale	24,304	(13,811)	86,272	(50,481)
Derivative instruments	3,603	1,635	3,985	5,837
Defined benefit pension and other postretirement benefit plans	1,049	2,548	3,161	4,611
Other comprehensive income (loss), net of tax	28,956	(9,628)	93,418	(40,033)
Comprehensive income	$ 122,821	$ 90,045	$ 385,668	$ 221,547

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Series E Preferred Stock [Member]	Series F Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Paid-In Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Series E Preferred Stock [Member]	Retained Earnings [Member]Series F Preferred Stock [Member]	Treasury Stock, at cost [Member]	AOCI Attributable to Parent [Member]
Beginning Balance at Dec. 31, 2017	$ 2,701,958			$ 145,056	$ 937	$ 1,122,164	$ 1,595,762			$ (70,430)	$ (91,531)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	261,580						261,580
Other comprehensive income, net of tax	(40,033)										(40,033)
Dividends and dividend equivalents declared on common stock	(84,903)					99	(85,002)
Dividends on preferred stock		$ (5,906)						$ (5,906)
Stockholders' Equity, Other			$ 22						$ 22
Stock-based compensation	8,598					(1,541)	2,426			7,713
Exercise of stock options	2,110					(5,308)				7,418
Stock Issued During Period, Value, Conversion of Units	0					(566)	(6,484)			7,050
Common shares acquired from stock compensation plan activity	(13,689)									(13,689)
Common stock repurchase program	(12,158)									(12,158)
Stock Issued During Period, Value, Other	(19)		(19)
Ending Balance at Sep. 30, 2018	2,816,198			145,037	937	1,114,848	1,761,036			(74,096)	(131,564)
Beginning Balance at Jun. 30, 2018	2,761,723			145,037	937	1,115,414	1,699,767			(77,496)	(121,936)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	99,673						99,673
Other comprehensive income, net of tax	(9,628)										(9,628)
Dividends and dividend equivalents declared on common stock	(30,724)					0	(30,724)
Dividends on preferred stock		$ (1,968)						$ (1,968)
Stock-based compensation	2,719					0	772			1,947
Stock Issued During Period, Value, Conversion of Units	0					(566)	(6,484)			7,050
Common shares acquired from stock compensation plan activity	(5,597)									(5,597)
Ending Balance at Sep. 30, 2018	2,816,198			145,037	937	1,114,848	1,761,036			(74,096)	(131,564)
Cumulative Effect of New Accounting Principle in Period of Adoption	(1,362)						(1,362)
Beginning Balance at Dec. 31, 2018	2,886,515			145,037	937	1,114,394	1,828,303			(71,504)	(130,652)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	292,250						292,250
Other comprehensive income, net of tax	93,418										93,418
Dividends and dividend equivalents declared on common stock	(104,381)						(104,381)
Dividends on preferred stock			(5,906)						(5,906)
Stock-based compensation	9,684					2,839	1,179			5,666
Exercise of stock options	621					(2,029)				2,650
Common shares acquired from stock compensation plan activity	(6,289)									(6,289)
Common stock repurchase program	(13,003)									(13,003)
Ending Balance at Sep. 30, 2019	3,152,394			145,037	937	1,115,204	2,010,930			(82,480)	(37,234)
Beginning Balance at Jun. 30, 2019	3,065,217			145,037	937	1,113,893	1,955,933			(84,393)	(66,190)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	93,865						93,865
Other comprehensive income, net of tax	28,956										28,956
Dividends and dividend equivalents declared on common stock	(36,900)						(36,900)
Dividends on preferred stock			$ (1,968)						$ (1,968)
Stock-based compensation	3,268					1,311	0			1,957
Common shares acquired from stock compensation plan activity	(44)									(44)
Ending Balance at Sep. 30, 2019	3,152,394			$ 145,037	$ 937	$ 1,115,204	2,010,930			$ (82,480)	$ (37,234)
Cumulative Effect of New Accounting Principle in Period of Adoption	$ (515)						$ (515)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Dividends on common stock and dividend equivalents declared (in dollars per share)	$ 0.4	$ 0.33	$ 1.13	$ 0.92
Series E Preferred Stock [Member]
Dividends on preferred stock (in dollars per share)		$ 328.125		$ 995.3125
Series F Preferred Stock [Member]
Dividends on preferred stock (in dollars per share)	$ 328.125		$ 984.375

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating Activities:
Net income	$ 292,250	$ 261,580
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	31,800	32,000
Deferred tax expense	3,647	13,138
Depreciation and amortization	28,159	28,991
Amortization of premium/discount on earning assets and funding, net	36,667	38,905
Stock-based compensation	9,684	8,598
Gain on sale, net of write-down, on foreclosed and repossessed assets	(827)	(745)
Loss on sale, net of write-down, on premises and equipment	1,213	295
Increase in cash surrender value of life insurance policies	(10,942)	(10,921)
Gain from life insurance policies	(4,626)	(1,453)
Mortgage banking activities	(3,829)	(3,684)
Proceeds from sale of loans held for sale	129,700	147,105
Origination of loans held for sale	(146,746)	(141,699)
Net increase in right-of-use lease assets	(4,274)	0
Net (increase) decrease in derivative contract assets net of liabilities	(164,977)	130,250
Net increase in accrued interest receivable and other assets	(25,803)	(9,506)
Net (decrease) increase in accrued expenses and other liabilities	(39,033)	3,529
Net cash provided by operating activities	132,063	496,383
Investing Activities:
Purchases of available for sale investment securities	(351,091)	(760,575)
Proceeds from maturities and principal payments of available for sale investment securities	394,369	445,704
Purchases of held-to-maturity investment securities	(1,289,977)	(283,770)
Proceeds from maturities and principal payments of held-to-maturity investment securities	400,779	414,487
Net proceeds from Federal Home Loan Bank stock	32,302	17,826
Alternative investments (capital call) return of capital, net	(4,040)	231
Net increase in loans	(1,147,426)	(826,400)
Proceeds from loans not originated for sale	20,542	674
Proceeds from life insurance policies	9,193	4,271
Proceeds from the sale of foreclosed and repossessed assets	10,901	7,046
Additions to premises and equipment	(18,771)	(25,481)
Net cash used for investing activities (1)	(1,943,219)	(1,005,987)
Financing Activities:
Net increase in deposits	1,421,819	1,003,445
Proceeds from Federal Home Loan Bank advances	5,725,000	5,225,000
Repayments of Federal Home Loan Bank advances	(6,158,959)	(5,460,221)
Net decrease in securities sold under agreements to repurchase and other borrowings	628,818	(78,781)
Issuance of long-term debt	300,000	0
Debt issuance costs	(3,642)	0
Dividends paid to common shareholders	(103,971)	(85,002)
Dividends paid to preferred shareholders	(5,906)	(5,906)
Exercise of stock options	621	2,110
Common stock repurchase program	(13,003)	(12,158)
Common shares purchased related to stock compensation plan activity	(6,289)	(13,689)
Net cash (used for) provided by financing activities	1,784,488	574,798
Net decrease in cash and due from banks	(26,668)	65,194
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Beginning of Period	329,499	256,786
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents End of Period	302,831	321,980
Supplemental disclosure of cash flow information:
Interest paid	151,859	104,861
Income taxes paid	90,574	51,237
Noncash investing and financing activities:
Real Estate Owned, Transfer to Real Estate Owned	7,224	5,548
Transfer of loans from portfolio to loans-held-for-sale	15,968	482
Operating Lease, Right-of-Use Asset	161,730	0
Operating Lease, Liability	$ 180,832	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies Nature of Operations Webster Financial Corporation (the Holding Company) is a bank holding company and financial holding company under the Bank Holding Company Act, incorporated under the laws of Delaware in 1986 and headquartered in Waterbury, Connecticut. The Holding Company's principal asset is all of the outstanding capital stock of Webster Bank, National Association (Webster Bank). Webster delivers financial services to individuals, families, and businesses primarily within its regional footprint from New York to Massachusetts. Webster provides business and consumer banking, mortgage lending, financial planning, trust, and investment services through banking offices, ATMs, 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. On a nationwide basis, through its HSA Bank division, Webster Bank offers and administers health savings accounts, flexible spending accounts, health reimbursement accounts, and commuter benefits. 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 related Notes, for the year ended December 31, 2018 , included in our Form 10-K filed with the SEC. Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications had an immaterial effect on the Company's Condensed Consolidated Financial Statements. Use of Estimates The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities as well as income and expense during the reporting period. Actual results could differ significantly 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. Accounting Standards Adopted During 2019 Effective January 1, 2019 , the following ASUs were adopted by the Company: ASU No. 2018-16, Derivatives and Hedging (Topic 815) - Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes. The Update permits the use of the OIS rate based on SOFR as a U.S. benchmark interest rate for hedge accounting purposes under Topic 815 in addition to the interest rates on direct U.S. Treasury obligations, the London Interbank Offered Rate swap rate, the OIS rate based on the Fed Funds Effective Rate, and the Securities Industry and Financial Markets Association Municipal Swap Rate. The Company adopted the Update during the first quarter of 2019 on a prospective basis. The adoption of this guidance did not have a material effect on the Company's consolidated financial statements. ASU No. 2017-12, Derivatives and Hedging (Topic 815) - Targeted Improvements to Accounting for Hedging Activities. The purpose of the Update is to better align a company’s risk management and financial reporting for hedging activities with the economic objectives of those activities. The Update expands an entity's ability to hedge non-financial and financial risk components and reduce complexity in hedges of interest rate risk. The guidance eliminates the requirement to separately measure and report hedge ineffectiveness, and generally requires the entire change in fair value of a hedging instrument to be presented in the same income statement line in which the earnings effect of the hedged item is reported. The Company adopted the Update during the first quarter of 2019 on a modified retrospective basis. The adoption of this guidance did not have a material effect on the Company's consolidated financial statements. The Company has provided enhanced disclosures in Note 13: Derivative Financial Instruments as a result of adopting this Update. ASU No. 2016-02, Leases (Topic 842) and subsequent ASUs issued to amend this Topic. The Updates introduce a lessee model that requires substantially all leases to be recorded as assets and liabilities on the balance sheet and requires expanded quantitative and qualitative disclosures regarding key information about leasing arrangements. The lessor model remains substantially the same with targeted improvements that do not materially impact the Company. The Company adopted the Updates during the first quarter of 2019 using the new transition method option that allows the use of effective date, January 1, 2019, as the date of initial application of the new lease accounting standard and to recognize a cumulative-effect adjustment to the opening balance of retained earnings upon adoption. The Company elected the transition relief package of practical expedients which forgoes the requirement to reassess the existence of leases in existing contracts, their lease classification and the accounting treatment of their initial direct costs. As a practical expedient, the Company has also made a policy election to not separate non-lease components from lease components for its real estate leases and instead account for each separate lease components and non-lease components associated with that lease component as a single lease component. The Company will separately account for the lease and non-lease components in its equipment leases. The Company determines whether a contract contains a lease based on whether a contract, or a part of a contract, conveys the right to control the use of an identified asset for a period of time in exchange for consideration. The discount rate used is either the rate implicit in the lease, or when a rate cannot be readily determined an incremental borrowing rate. The incremental borrowing rate is the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and amount equal to the lease payments, in a similar economic environment. As a result of adopting this Update, the Company recognized $157.2 million of right-of-use asset (ROU) and $178.2 million of lease liability, as of January 1, 2019. The Company also recorded a $515 thousand cumulative-effect adjustment directly to retained earnings as of January 1, 2019 for abandoned leased properties and the remaining deferred gains on sale-leaseback transactions which occurred prior to the date of adoption. See Note 9: Leasing for further information. Accounting Standards Issued But Not Yet Adopted The following list identifies ASUs applicable to the Company that have been issued by the FASB but are not yet effective: ASU No. 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments. The Update amends guidance on credit losses, hedge accounting, and recognition and measurement of financial instruments. The changes provide clarifications and codification improvements in relation to recently issued accounting updates. The amendments to the guidance on credit losses are considered in the paragraphs below related to our adoption of ASU 2016-13, and will be adopted concurrently with those Updates. The clarifications and amendments to the guidance on hedge accounting and recognition and measurement of financial instruments will be effective for the Company on January 1, 2020. The Company does not expect these changes to have a material impact on its consolidated financial statements. ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40) - Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. The Update aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The updated guidance also requires an entity to amortize the capitalized implementation costs as an expense over the term of the hosting arrangement and to present in the same income statement line item as the fees associated with the hosting arrangement. The Update is effective for the Company on January 1, 2020. Early adoption is permitted. The Company will apply the amendments in this update prospectively to all implementation costs incurred after the date of adoption. The Company does not expect this Update to have a material impact on its consolidated financial statements. ASU No. 2018-14, Compensation-Retirement Benefits - Defined Benefit Plan - General (Subtopic 715-20) - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans. The Update modifies disclosure requirements for employers that sponsor defined benefit pension and other postretirement plans. The updated guidance will be effective for the Company on January 1, 2021. The Company does not expect this Update to have a material impact on its consolidated financial statements. ASU No. 2018-13, Fair Value Measurement (Topic 820) - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. The Update modifies the disclosure requirements on fair value measurements. The updated guidance will no longer require entities to disclose the amount and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy. However, it will require public companies to disclose changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop Level 3 measurements. The Update is effective for the Company on January 1, 2020, and earlier adoption is permitted. The Company does not expect this Update to have a material impact on its consolidated financial statements. ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment. The Update simplifies quantitative goodwill impairment testing by requiring entities to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for any amount by which the carrying amount exceeds the reporting unit's fair value, to the extent that the loss recognized does not exceed the amount of goodwill allocated to that reporting unit. This changes current guidance by eliminating the second step of the goodwill impairment analysis which involves calculating the implied fair value of goodwill determined in the same manner as the amount of goodwill recognized in a business combination upon acquisition. Entities will still have the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. The Update must be applied prospectively and is effective for the Company on January 1, 2020. Early adoption is permitted. The Company does not expect this new guidance to have a material impact on its consolidated financial statements. ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) - Measurement of Credit Losses on Financial Instruments and subsequent ASUs issued to clarify this Topic. The Update will replace today's incurred loss approach for recognizing credit losses with a new credit loss methodology known as the current expected credit loss (CECL) model. The CECL model requires earlier recognition of credit losses using a lifetime credit loss measurement approach for financial assets carried at amortized cost. The CECL model also requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. To implement the new standard, the Company has established a project lead and has empowered a steering committee comprised of members from different disciplines including Credit, Accounting, Finance, Financial Analytics, IT, and Treasury, as well as specific working groups to focus on key components of the development process. Through these working groups, the Company is evaluating the effect that this Update, including subsequent ASUs issued to clarify this Topic, will have on its financial statements and related disclosures. The implementation project plan is made up of targeted work streams focused on credit models, data management, and treasury and accounting matters. The new credit models will include additional assumptions used to calculate credit losses over the estimated life of the financial assets and will include the impact of forecasted macroeconomic conditions. During the third quarter of 2019, the Company began to run its new credit models in parallel with its existing models under the incurred loss approach and has completed the validations of these new credit models. For the remainder of 2019, the Company is focused on finalizing its methodology for qualitative adjustments and the full implementation of new processes, controls and third party solutions. The Company is also continuing to work on updating its policies and drafting the new required disclosures under this Update.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
Variable Interest Entities	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities The Company has an investment interest in the following entities that meet the definition of a variable interest entity (VIE). Consolidated Rabbi Trust. The Company established a Rabbi Trust to meet the obligations due under its Deferred Compensation Plan for Directors and Officers and to mitigate the expense volatility of the aforementioned plan. The funding of the Rabbi Trust and the discontinuation of the Deferred Compensation Plan for Directors and Officers occurred during 2012. Invested assets 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 activities of the Rabbi Trust that significantly affect the VIE's economic performance 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, on the consolidated balance sheet. 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 consolidated income statement. See Note 14: Fair Value Measurements for additional information. Non-Consolidated Tax Credit - Finance Investments. The Company makes non-marketable 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 VIEs. The Company applies the proportional amortization method to account for its investments in qualified affordable housing projects. At September 30, 2019 and December 31, 2018 , the aggregate carrying value of the Company's tax credit-finance investments was $43.5 million and $29.1 million , respectively, which represents the Company's maximum exposure to loss. At September 30, 2019 and December 31, 2018 , unfunded commitments have been recognized, totaling $15.5 million and $10.4 million , respectively, and are included in accrued expenses and other liabilities on the consolidated balance sheet. Webster Statutory Trust. The Company owns all the outstanding common stock of Webster Statutory Trust, a financial vehicle that has issued, and in the future may issue, trust preferred securities. The trust is a VIE in which the Company is not the primary beneficiary. 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 on the consolidated balance sheet, and the related interest expense is reported as interest expense on long-term debt in the consolidated income statement. Other Non-Marketable Investments. The Company invests in various alternative investments in which it holds a variable interest. These investments are non-public entities which cannot be redeemed since the Company’s investment is distributed as the underlying equity is 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 impact the economic performance of the VIEs. At September 30, 2019 and December 31, 2018 , the aggregate carrying value of the Company's other investments in VIEs was $20.3 million and $17.6 million , respectively, and the total exposure of the Company's other investments in VIEs, including unfunded commitments, was $54.5 million and $31.0 million , respectively. Refer to Note 14: Fair Value Measurements for additional information. The Company's equity interests in Other Non-Marketable Investments, as well as Tax Credit - Finance Investments and Webster Statutory Trust, are included in accrued interest receivable and other assets on the consolidated balance sheet. For a description of the Company's accounting policy regarding the consolidation of VIEs, refer to Note 1 to the Consolidated Financial Statements included in its Form 10-K, for the year ended December 31, 2018 .

Investment Securities

Investment Securities	9 Months Ended
Investment Securities	Sep. 30, 2019
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, 2019 At December 31, 2018 (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 $ 19,918 $ 6 $ — $ 19,924 $ 7,549 $ 1 $ — $ 7,550 Agency CMO 198,917 2,704 (665 ) 200,956 238,968 412 (4,457 ) 234,923 Agency MBS 1,573,984 29,930 (5,078 ) 1,598,836 1,521,534 1,631 (42,076 ) 1,481,089 Agency CMBS 611,925 1,239 (2,814 ) 610,350 608,167 — (41,930 ) 566,237 CMBS 403,782 182 (46 ) 403,918 447,897 645 (2,961 ) 445,581 CLO 95,099 73 (367 ) 94,805 114,641 94 (1,964 ) 112,771 Corporate debt 35,567 — (4,253 ) 31,314 55,860 — (5,281 ) 50,579 Available-for-sale $ 2,939,192 $ 34,134 $ (13,223 ) $ 2,960,103 $ 2,994,616 $ 2,783 $ (98,669 ) $ 2,898,730 Held-to-maturity: Agency CMO $ 179,773 $ 1,430 $ (680 ) $ 180,523 $ 208,113 $ 287 $ (5,255 ) $ 203,145 Agency MBS 3,085,000 54,083 (11,249 ) 3,127,834 2,517,823 8,250 (79,701 ) 2,446,372 Agency CMBS 950,217 13,430 (1,569 ) 962,078 667,500 53 (22,572 ) 644,981 Municipal bonds and notes 742,844 33,780 (17 ) 776,607 715,041 2,907 (18,285 ) 699,663 CMBS 235,687 3,012 (36 ) 238,663 216,943 405 (2,388 ) 214,960 Held-to-maturity $ 5,193,521 $ 105,735 $ (13,551 ) $ 5,285,705 $ 4,325,420 $ 11,902 $ (128,201 ) $ 4,209,121 Other-Than-Temporary Impairment The amount in the amortized cost columns in the table above includes other-than-temporary impairment (OTTI) related to certain CLO positions that were previously considered Covered Funds as defined by Section 619 of the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010. The Company has taken measures to bring its CLO positions into conformance with these requirements. The following table presents activity for OTTI: Three months ended September 30, Nine months ended September 30, (In thousands) 2019 2018 2019 2018 Beginning balance $ 822 $ 1,103 $ 822 $ 1,364 Reduction for investment securities called — (281 ) — (542 ) Ending balance $ 822 $ 822 $ 822 $ 822 Fair Value and Unrealized Losses The following tables provide information on fair value and unrealized losses for the individual investment securities with an unrealized loss, aggregated by classification and length of time that the individual investment securities have been in a continuous unrealized loss position: At September 30, 2019 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 $ 18,109 $ (146 ) $ 35,751 $ (519 ) 11 $ 53,860 $ (665 ) Agency MBS 47,966 (33 ) 419,082 (5,045 ) 85 467,048 (5,078 ) Agency CMBS — — 461,840 (2,814 ) 28 461,840 (2,814 ) CMBS 49,418 (35 ) 3,489 (11 ) 8 52,907 (46 ) CLO 18,405 (294 ) 24,927 (73 ) 2 43,332 (367 ) Corporate debt 7,787 (767 ) 23,527 (3,486 ) 7 31,314 (4,253 ) Available-for-sale in an unrealized loss position $ 141,685 $ (1,275 ) $ 968,616 $ (11,948 ) 141 $ 1,110,301 $ (13,223 ) Held-to-maturity: Agency CMO $ 15,744 $ (40 ) $ 58,852 $ (640 ) 8 $ 74,596 $ (680 ) Agency MBS 183,181 (1,219 ) 858,373 (10,030 ) 119 1,041,554 (11,249 ) Agency CMBS 127,662 (1,552 ) 4,187 (17 ) 6 131,849 (1,569 ) Municipal bonds and notes 2,517 (17 ) — — 1 2,517 (17 ) CMBS 46,610 (36 ) — — 3 46,610 (36 ) Held-to-maturity in an unrealized loss position $ 375,714 $ (2,864 ) $ 921,412 $ (10,687 ) 137 $ 1,297,126 $ (13,551 ) At December 31, 2018 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 $ 15,524 $ (72 ) $ 180,641 $ (4,385 ) 36 $ 196,165 $ (4,457 ) Agency MBS 321,678 (2,078 ) 975,084 (39,998 ) 184 1,296,762 (42,076 ) Agency CMBS — — 566,237 (41,930 ) 37 566,237 (41,930 ) CMBS 343,457 (2,937 ) 5,193 (24 ) 39 348,650 (2,961 ) CLO 83,305 (1,695 ) 14,873 (269 ) 5 98,178 (1,964 ) Corporate debt 35,990 (1,820 ) 14,589 (3,461 ) 8 50,579 (5,281 ) Available-for-sale in an unrealized loss position $ 799,954 $ (8,602 ) $ 1,756,617 $ (90,067 ) 309 $ 2,556,571 $ (98,669 ) Held-to-maturity: Agency CMO $ 691 $ (1 ) $ 182,396 $ (5,254 ) 25 $ 183,087 $ (5,255 ) Agency MBS 288,635 (1,916 ) 1,892,951 (77,785 ) 272 2,181,586 (79,701 ) Agency CMBS — — 635,284 (22,572 ) 56 635,284 (22,572 ) Municipal bonds and notes 68,351 (882 ) 414,776 (17,403 ) 223 483,127 (18,285 ) CMBS 24,881 (270 ) 132,464 (2,118 ) 20 157,345 (2,388 ) Held-to-maturity in an unrealized loss position $ 382,558 $ (3,069 ) $ 3,257,871 $ (125,132 ) 596 $ 3,640,429 $ (128,201 ) Impairment Analysis The following impairment analysis summarizes the basis for evaluating if investment securities within the Company’s available-for-sale and held-to-maturity portfolios are other-than-temporarily impaired as of September 30, 2019 . Unless otherwise noted for an investment security type, management does not intend to sell these investment securities and has determined, based upon available evidence, that it is more likely than not that the Company will not be required to sell these investment securities before the recovery of their amortized cost. As such, based on the following impairment analysis, the Company does not consider any of these investment securities, in unrealized loss positions, to be other-than-temporarily impaired at September 30, 2019 . Available-for-Sale Securities Agency CMO. There were unrealized losses of $0.7 million on the Company’s investment in Agency CMO securities issued by government agencies at September 30, 2019 , compared to $4.5 million at December 31, 2018 . Unrealized losses decreased due to lower market rates while principal balances decreased for this asset class since December 31, 2018 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or implicit. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Agency MBS. There were unrealized losses of $5.1 million on the Company’s investment in Agency MBS securities issued by government agencies at September 30, 2019 , compared to $42.1 million at December 31, 2018 . Unrealized losses decreased due to lower market rates while principal balances increased for this asset class since December 31, 2018 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or implicit. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Agency CMBS. There were unrealized losses of $2.8 million on the Company's investment in Agency Commercial Mortgage-Backed Securities (CMBS) issued by government agencies at September 30, 2019 , compared to $41.9 million at December 31, 2018 . Unrealized losses decreased due to lower market rates while principal balances increased for this asset class since December 31, 2018 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or implicit. There has been no change in the credit quality, and the contractual cash flows are performing as expected. CMBS. There were unrealized losses of $46 thousand on the Company’s investment in CMBS at September 30, 2019 , compared to $3.0 million at December 31, 2018 . Unrealized losses decreased due to reduced market spreads while balances decreased for the portfolio of mainly floating rate CMBS at September 30, 2019 compared to December 31, 2018 . Internal stress tests are performed on individual bonds to monitor potential losses under stress scenarios. Contractual cash flows for the bonds continue to perform as expected. CLO. There were unrealized losses of $0.4 million on the Company’s investments in CLO at September 30, 2019 compared to $2.0 million unrealized losses at December 31, 2018 . Unrealized losses decreased due to reduced market spreads while principal decreased from December 31, 2018 . Internal stress tests are performed on individual bonds to monitor potential losses under stress scenarios. Contractual cash flows for the bonds continue to perform as expected. Corporate debt. There were unrealized losses of $4.3 million on the Company's corporate debt portfolio at September 30, 2019 , compared to $5.3 million at December 31, 2018 . Unrealized losses decreased due to reduced market spreads while principal balances decreased since December 31, 2018 . The Company performs periodic credit reviews of the issuer to assess the likelihood for ultimate recovery of amortized cost. Contractual cash flows for the bonds continue to perform as expected. Held-to-Maturity Securities Agency CMO. There were unrealized losses of $0.7 million on the Company’s investment in Agency CMO securities issued by government agencies at September 30, 2019 , compared to $5.3 million at December 31, 2018 . Unrealized losses decreased due to lower market rates while principal balances decreased since December 31, 2018 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or implicit. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Agency MBS. There were unrealized losses of $11.2 million on the Company’s investment Agency MBS securities issued by government agencies at September 30, 2019 , compared to $79.7 million at December 31, 2018 . Unrealized losses decreased due to lower market rates while principal balances increased for this asset class since December 31, 2018 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or implicit. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Agency CMBS. There were unrealized losses of $1.6 million on the Company’s investment in Agency CMBS at September 30, 2019 , compared to $22.6 million at December 31, 2018 . Unrealized losses decreased due to lower market rates while principal balances increased since December 31, 2018 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or implicit. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Municipal bonds and notes. There were unrealized losses of $17 thousand on the Company’s investment in municipal bonds and notes at September 30, 2019 , compared to $18.3 million at December 31, 2018 . Unrealized losses decreased due to lower market rates while principal balances increased since December 31, 2018 . The Company performs periodic credit reviews of the issuers and the securities are currently performing as expected. CMBS. There were unrealized losses of $36 thousand on the Company’s investment in CMBS at September 30, 2019 , compared to $2.4 million unrealized losses at December 31, 2018 . Unrealized losses decreased due to lower market rates on mainly seasoned fixed rate conduit transactions while principal balances increased since December 31, 2018 . Internal stress tests are performed on individual bonds to monitor potential losses under stress scenarios. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Sales of Available-for Sale Investment Securities There were no sales during the three and nine months ended September 30, 2019 and 2018 . Contractual Maturities The amortized cost and fair value of debt securities by contractual maturity are set forth below: At September 30, 2019 Available-for-Sale Held-to-Maturity (In thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 19,918 $ 19,924 $ 1,045 $ 1,049 Due after one year through five years 17,000 17,000 6,260 6,392 Due after five through ten years 305,691 305,533 222,076 228,011 Due after ten years 2,596,583 2,617,646 4,964,140 5,050,253 Total debt securities $ 2,939,192 $ 2,960,103 $ 5,193,521 $ 5,285,705 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, 2019 , the Company had a carrying value of $1.3 billion in callable debt securities in its CMBS, CLO, and municipal bond portfolios. These maturities may change due to calls. The Company considers this prepayment risk in the evaluation of its interest rate risk profile. Investment securities with a carrying value totaling $3.0 billion at September 30, 2019 and $2.2 billion December 31, 2018 were pledged to secure public funds, trust deposits, repurchase agreements, and for other purposes, as required or permitted by law.

Loans and Leases

Loans and Leases	9 Months Ended
Loans and Leases	Sep. 30, 2019
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, 2018 Commercial $ 6,488,056 $ 6,216,606 Commercial Real Estate 5,398,084 4,927,145 Equipment Financing 521,828 508,397 Residential 4,873,726 4,416,637 Consumer 2,269,952 2,396,704 Loans and leases (1) (2) $ 19,551,646 $ 18,465,489 (1) Includes net deferred fees/costs and net premiums/discounts of $13.9 million at both September 30, 2019 and December 31, 2018 . (2) At September 30, 2019 the Company had pledged $7.6 billion of eligible loans as collateral to support borrowing capacity at the Federal Home Loan Bank (FHLB) of Boston and the Federal Reserve Bank (FRB) of Boston. The equipment financing portfolio includes net investment in leases of $164.2 million at September 30, 2019 . Total undiscounted cash flows to be received from the Company's net investment in leases are $178.5 million at September 30, 2019 and are primarily due within the next five years. The Company's lessor portfolio has recognized interest income of $1.2 million and $4.0 million for the three and nine months ended September 30, 2019 , respectively. Loans and Leases Aging The following tables summarize the aging of loans and leases: At September 30, 2019 (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 Commercial: Commercial non-mortgage $ 2,760 $ 450 $ 92 $ 58,750 $ 62,052 $ 5,303,238 $ 5,365,290 Asset-based — — — 9,162 9,162 1,113,604 1,122,766 Commercial real estate: Commercial real estate 1,296 141 — 9,852 11,289 5,087,967 5,099,256 Commercial construction — — — 2,968 2,968 295,860 298,828 Equipment financing 1,666 525 — 5,488 7,679 514,149 521,828 Residential 6,752 6,727 — 43,839 57,318 4,816,408 4,873,726 Consumer: Home equity 9,192 2,290 — 31,452 42,934 2,007,428 2,050,362 Other consumer 3,075 697 — 1,388 5,160 214,430 219,590 Total $ 24,741 $ 10,830 $ 92 $ 162,899 $ 198,562 $ 19,353,084 $ 19,551,646 At December 31, 2018 (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 Commercial: Commercial non-mortgage $ 1,011 $ 702 $ 104 $ 55,810 $ 57,627 $ 5,189,808 $ 5,247,435 Asset-based — — — 224 224 968,947 969,171 Commercial real estate: Commercial real estate 1,275 245 — 8,242 9,762 4,698,552 4,708,314 Commercial construction — — — — — 218,831 218,831 Equipment financing 510 405 — 6,314 7,229 501,168 508,397 Residential 8,513 4,301 — 49,188 62,002 4,354,635 4,416,637 Consumer: Home equity 9,250 5,385 — 33,495 48,130 2,121,049 2,169,179 Other consumer 1,774 957 — 1,494 4,225 223,300 227,525 Total $ 22,333 $ 11,995 $ 104 $ 154,767 $ 189,199 $ 18,276,290 $ 18,465,489 Interest on non-accrual loans and leases that would have been recorded as additional interest income had the loans and leases been current in accordance with the original terms totaled $3.1 million and $4.3 million for the three months ended September 30, 2019 and 2018 , respectively, and $8.9 million and $7.9 million for the nine months ended September 30, 2019 and 2018 , respectively. Allowance for Loan and Lease Losses The following tables summarize the activity in, as well as the loan and lease balances that were evaluated for, the ALLL: At or for three months ended September 30, 2019 (In thousands) Commercial Commercial Real Estate Equipment Financing Residential Consumer Total ALLL: Balance, beginning of period $ 98,800 $ 61,068 $ 4,476 $ 21,221 $ 26,106 $ 211,671 Provision (benefit) charged to expense 11,202 (423 ) (176 ) (689 ) 1,386 11,300 Charge-offs (11,255 ) (32 ) (36 ) (872 ) (3,765 ) (15,960 ) Recoveries 124 3 49 356 1,609 2,141 Balance, end of period $ 98,871 $ 60,616 $ 4,313 $ 20,016 $ 25,336 $ 209,152 At or for three months ended September 30, 2018 (In thousands) Commercial Commercial Real Estate Equipment Financing Residential Consumer Total ALLL: Balance, beginning of period $ 95,340 $ 55,833 $ 5,383 $ 19,007 $ 31,759 $ 207,322 Provision (benefit) charged to expense 5,686 4,146 (213 ) 407 474 10,500 Charge-offs (740 ) (1,922 ) (136 ) (874 ) (4,863 ) (8,535 ) Recoveries 431 143 11 133 1,827 2,545 Balance, end of period $ 100,717 $ 58,200 $ 5,045 $ 18,673 $ 29,197 $ 211,832 At or for the nine months ended September 30, 2019 (In thousands) Commercial Commercial Real Estate Equipment Financing Residential Consumer Total ALLL: Balance, beginning of period $ 98,793 $ 60,151 $ 5,129 $ 19,599 $ 28,681 $ 212,353 Provision (benefit) charged to expense 22,820 3,901 (208 ) 2,865 2,422 31,800 Charge-offs (24,106 ) (3,478 ) (679 ) (3,277 ) (11,836 ) (43,376 ) Recoveries 1,364 42 71 829 6,069 8,375 Balance, end of period $ 98,871 $ 60,616 $ 4,313 $ 20,016 $ 25,336 $ 209,152 Individually evaluated for impairment $ 14,555 $ 735 $ 177 $ 3,625 $ 1,274 $ 20,366 Collectively evaluated for impairment $ 84,316 $ 59,881 $ 4,136 $ 16,391 $ 24,062 $ 188,786 Loan and lease balances: Individually evaluated for impairment $ 117,418 $ 16,224 $ 5,487 $ 95,666 $ 35,836 $ 270,631 Collectively evaluated for impairment 6,370,638 5,381,860 516,341 4,778,060 2,234,116 19,281,015 Loans and leases $ 6,488,056 $ 5,398,084 $ 521,828 $ 4,873,726 $ 2,269,952 $ 19,551,646 At or for the nine months ended September 30, 2018 (In thousands) Commercial Commercial Real Estate Equipment Financing Residential Consumer Total ALLL: Balance, beginning of period $ 89,533 $ 49,407 $ 5,806 $ 19,058 $ 36,190 $ 199,994 Provision (benefit) charged to expense 17,596 10,678 (557 ) 1,316 2,967 32,000 Charge-offs (7,869 ) (2,039 ) (246 ) (2,545 ) (14,844 ) (27,543 ) Recoveries 1,457 154 42 844 4,884 7,381 Balance, end of period $ 100,717 $ 58,200 $ 5,045 $ 18,673 $ 29,197 $ 211,832 Individually evaluated for impairment $ 10,491 $ 1,544 $ 15 $ 4,319 $ 1,428 $ 17,797 Collectively evaluated for impairment $ 90,226 $ 56,656 $ 5,030 $ 14,354 $ 27,769 $ 194,035 Loan and lease balances: Individually evaluated for impairment $ 104,353 $ 9,767 $ 6,489 $ 105,600 $ 39,808 $ 266,017 Collectively evaluated for impairment 6,070,043 4,761,558 512,565 4,309,463 2,401,373 18,055,002 Loans and leases $ 6,174,396 $ 4,771,325 $ 519,054 $ 4,415,063 $ 2,441,181 $ 18,321,019 Impaired Loans and Leases The following tables summarize impaired loans and leases: At September 30, 2019 (In thousands) Unpaid Principal Balance Total Recorded Investment Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Commercial non-mortgage $ 148,932 $ 108,256 $ 36,250 $ 72,006 $ 14,550 Asset-based 9,490 9,162 9,013 149 5 Commercial real estate 19,270 13,256 7,202 6,054 735 Commercial construction 2,969 2,968 2,968 — — Equipment financing 5,540 5,487 2,403 3,084 177 Residential 105,576 95,666 61,236 34,430 3,625 Consumer - home equity 64,723 35,836 28,023 7,813 1,274 Total $ 356,500 $ 270,631 $ 147,095 $ 123,536 $ 20,366 At December 31, 2018 (In thousands) Unpaid Principal Balance Total Recorded Investment Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Commercial non-mortgage $ 120,165 $ 99,287 $ 65,724 $ 33,563 $ 7,818 Asset-based 550 225 — 225 6 Commercial real estate 13,355 10,828 2,125 8,703 1,661 Equipment financing 6,368 6,315 2,946 3,369 196 Residential 113,575 103,531 64,899 38,632 4,286 Consumer - home equity 44,654 39,144 30,576 8,568 1,383 Total $ 298,667 $ 259,330 $ 166,270 $ 93,060 $ 15,350 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, 2019 2018 2019 2018 (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 Commercial non-mortgage $ 102,996 $ 751 $ — $ 94,618 $ 847 $ — $ 103,772 $ 2,515 $ — $ 87,603 $ 2,257 $ — Asset based 4,673 — — 1,095 — — 4,694 — — 809 — — Commercial real estate: Commercial real estate 13,567 60 — 11,222 30 — 12,042 194 — 10,497 164 — Commercial construction 1,484 — — — — — 1,484 — — — — — Equipment financing 4,718 — — 6,337 41 — 5,901 — — 4,907 112 — Residential 97,917 862 271 107,618 923 301 99,599 2,682 817 109,948 2,852 819 Consumer - home equity 36,584 247 246 40,722 292 238 37,490 803 767 42,622 876 738 Total $ 261,939 $ 1,920 $ 517 $ 261,612 $ 2,133 $ 539 $ 264,982 $ 6,194 $ 1,584 $ 256,386 $ 6,261 $ 1,557 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 default (PD) and the loss given default (LGD). The credit risk grade system assigns a rating to each borrower and to the facility, which together form a Composite Credit Risk Profile. 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 Composite Credit Risk Profile has ten grades, with each grade corresponding to a progressively greater risk of default. Grades (1) - (6) are considered pass ratings, and (7) - (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 a borrower's current financial position and outlook, risk profile, and the related collateral and structural position. Loan officers review updated financial information or other loan factors 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 (7) Special Mention credit has the potential weakness that, if left uncorrected, may result in deterioration of the repayment prospects for the asset. An (8) Substandard asset has a well defined weakness that jeopardizes the full repayment of the debt. An asset rated (9) Doubtful 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 (10) Loss, 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 $ 6,122,391 $ 5,781,138 $ 5,253,649 $ 4,773,298 $ 512,219 $ 494,585 (7) Special Mention 97,969 206,351 81,256 75,338 915 1,303 (8) Substandard 263,833 222,405 63,179 78,509 8,694 12,509 (9) Doubtful 3,863 6,712 — — — — Total $ 6,488,056 $ 6,216,606 $ 5,398,084 $ 4,927,145 $ 521,828 $ 508,397 For residential and consumer loans, the primary credit quality indicator that the Company considers is past due status. Other factors, such as, updated Fair Isaac Corporation (FICO) scores, employment status, collateral, geography, loans discharged in bankruptcy, and the status of first lien position loans on second lien position loans, may also be evaluated as credit quality indicators. On an ongoing basis for portfolio monitoring purposes, the Company estimates the current value of property secured as collateral for 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 real estate price 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 troubled debt restructurings (TDRs): (Dollars in thousands) At September 30, At December 31, 2018 Accrual status $ 137,493 $ 138,479 Non-accrual status 111,643 91,935 Total recorded investment of TDRs $ 249,136 $ 230,414 Specific reserves for TDRs included in the balance of ALLL $ 20,015 $ 11,930 Additional funds committed to borrowers in TDR status 3,621 3,893 For the portion of TDRs deemed to be uncollectible, Webster charged off $11.0 million and $1.1 million for the three months ended September 30, 2019 and 2018 , respectively, and $16.7 million , and $6.3 million for the nine months ended September 30, 2019 and 2018 , respectively. 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, 2019 2018 2019 2018 Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) (Dollars in thousands) Commercial non - mortgage Extended Maturity 2 $ 29 4 $ 537 8 $ 222 7 $ 622 Adjusted Interest Rate 1 12 — — 2 112 — — Maturity/Rate Combined 3 225 8 8,185 6 296 10 8,236 Other (2) 6 30,586 8 10,585 25 64,642 17 39,328 Commercial real estate Extended Maturity — — — — — — 2 97 Maturity/Rate Combined — — — — — — 1 245 Other (2) 1 2,180 — — 3 4,816 1 5,111 Residential Extended Maturity 1 67 1 20 5 1,007 1 20 Maturity/Rate Combined 1 368 4 440 14 2,216 7 716 Other (2) 2 243 3 356 6 785 16 2,798 Consumer - home equity Extended Maturity 1 134 1 148 5 504 3 341 Maturity/Rate Combined 2 30 3 170 4 140 6 618 Other (2) 8 375 5 258 27 1,595 30 1,951 Total TDRs 28 $ 34,249 37 $ 20,699 105 $ 76,335 101 $ 60,083 (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 for the three and nine months ended September 30, 2019 and 2018 . Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 (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 Commercial non - mortgage 4 $ 3,940 — $ — 4 $ 3,940 — $ — Residential — — 1 241 — — 2 261 Consumer - home equity 1 78 — — 1 78 — — Total 5 $ 4,018 1 $ 241 5 $ 4,018 2 $ 261 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, 2019 At December 31, 2018 (1) - (6) Pass $ 11,877 $ 13,165 (7) Special Mention 68 84 (8) Substandard 101,825 67,880 (9) Doubtful 3,863 6,610 Total $ 117,633 $ 87,739

Transfers of Financial Assets

Transfers of Financial Assets	9 Months Ended
Transfers of Financial Assets	Sep. 30, 2019
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. Residential mortgage origination fees, adjustments for changes in fair value, any gain or loss from initial measurement on loans held for sale, and the gain or loss on loans sold are included as mortgage banking activities in the consolidated income statement. 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 loan repurchase requests received by the Company for which management evaluates 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 loan repurchase requests for which the Company has not yet been notified. 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 consolidated income statement. 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) 2019 2018 2019 2018 Beginning balance $ 684 $ 674 $ 674 $ 872 Provision (benefit) charged to expense 19 18 1,839 (172 ) Repurchased loans and settlements charged off (7 ) (10 ) (1,817 ) (18 ) Ending balance $ 696 $ 682 $ 696 $ 682 The increase to the provision and corresponding charge-off during the nine months ended September 30, 2019 was related to a discrete legal settlement in connection with previously sold loans. The following table provides information for mortgage banking activities: Three months ended September 30, Nine months ended September 30, (In thousands) 2019 2018 2019 2018 Residential mortgage loans held for sale: Proceeds from sale $ 66,236 $ 57,042 $ 129,700 $ 147,105 Loans sold with servicing rights retained 60,493 51,104 117,306 130,740 Net gain on sale 1,652 1,051 2,510 2,732 Ancillary fees 470 463 1,051 1,275 Fair value option adjustment 11 (209 ) 268 (323 ) Additionally, certain loans not originated for sale were sold at approximately carrying value, consisting of residential loans for cash proceeds of $4.0 million and commercial loans for cash proceeds of $16.6 million resulting in a gain of approximately $615 thousand for the nine months ended September 30, 2019 , and commercial loans for cash proceeds of $674 thousand for the nine months ended September 30, 2018 . The Company services residential mortgage loans totaling $2.4 billion at September 30, 2019 and $2.5 billion at December 31, 2018 . The following table presents the changes in carrying value for mortgage servicing assets: Three months ended September 30, Nine months ended September 30, (In thousands) 2019 2018 2019 2018 Beginning balance $ 18,712 $ 23,341 $ 21,215 $ 25,139 Additions 966 1,428 2,219 3,878 Amortization (1,801 ) (2,125 ) (5,557 ) (6,373 ) Ending balance $ 17,877 $ 22,644 $ 17,877 $ 22,644 Mortgage servicing assets are recorded at fair value upon transfer, and thereafter are carried at the lower of cost or fair value. Loan servicing fees, net of mortgage servicing rights amortization, were $0.5 million and $0.3 million for the three months ended September 30, 2019 and 2018 , respectively, and $1.4 million and $0.9 million for the nine months ended September 30, 2019 and 2018 , respectively, and are included as a component of loan related fees in the consolidated income statement. See Note 14: Fair Value Measurements for additional fair value information on mortgage servicing assets and loans held for sale.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
Goodwill and Other Intangible Assets	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets There has been no change during 2019 in the carrying amounts for goodwill. For additional information on goodwill refer to the Company's Annual Report on Form 10-K for the year ended December 31, 2018 . Other intangible assets by reportable segment consisted of the following: At September 30, 2019 At December 31, 2018 (In thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount HSA Bank - Core deposits $ 22,000 $ (12,515 ) $ 9,485 $ 22,000 $ (10,842 ) $ 11,158 HSA Bank - Customer relationships 21,000 (7,606 ) 13,394 21,000 (6,394 ) 14,606 Total other intangible assets $ 43,000 $ (20,121 ) $ 22,879 $ 43,000 $ (17,236 ) $ 25,764 At September 30, 2019 , the remaining estimated aggregate future amortization expense for other intangible assets is as follows: (In thousands) Remainder of 2019 $ 961 2020 3,847 2021 3,847 2022 3,847 2023 3,847 Thereafter 6,530

Deposits

Deposits	9 Months Ended
Deposits	Sep. 30, 2019
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 $ 4,291,659 $ 4,162,446 Interest-bearing: Health savings accounts 6,288,218 5,740,601 Checking 2,619,452 2,518,472 Money market 2,560,918 2,100,084 Savings 4,264,853 4,140,696 Time deposits 3,255,565 3,196,546 Total interest-bearing $ 18,989,006 $ 17,696,399 Total deposits $ 23,280,665 $ 21,858,845 Time deposits and interest-bearing checking, included in above balances, obtained through brokers $ 671,595 $ 869,003 Time deposits, included in above balance, that exceed the FDIC limit 531,103 555,949 Deposit overdrafts reclassified as loan balances 2,244 2,245 The scheduled maturities of time deposits are as follows: (In thousands) At September 30, Remainder of 2019 $ 1,003,978 2020 1,803,664 2021 330,610 2022 70,868 2023 28,889 Thereafter 17,556 Total time deposits $ 3,255,565

Borrowings

Borrowings	9 Months Ended
Borrowings	Sep. 30, 2019
Debt Disclosure [Abstract]
Borrowings	Borrowings Total borrowings of $3.2 billion at September 30, 2019 and $2.6 billion at December 31, 2018 are described in detail below. The following table summarizes securities sold under agreements to repurchase and other borrowings: At September 30, At December 31, (In thousands) Amount Rate Amount Rate Securities sold under agreements to repurchase (1) : Original maturity of one year or less $ 190,692 0.42 % $ 236,874 0.35 % Original maturity of greater than one year, non-callable 200,000 1.57 — — Total securities sold under agreements to repurchase 390,692 1.01 236,874 0.35 Fed funds purchased 820,000 1.91 345,000 2.52 Securities sold under agreements to repurchase and other borrowings $ 1,210,692 1.62 $ 581,874 1.64 (1) The Company has right of offset with respect to all repurchase agreement assets and liabilities. However, securities sold under agreements to repurchase represents the gross amount for these transactions, as only liabilities are outstanding for the periods presented. 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 or municipal customers through Webster’s Treasury Unit. The following table provides information for FHLB advances: At September 30, At December 31, (Dollars in thousands) Amount Weighted- Average Contractual Coupon Rate Amount Weighted- Average Contractual Coupon Rate Maturing within 1 year $ 1,109,295 2.07 % $ 1,403,026 2.55 % After 1 but within 2 years 75,000 1.51 215,000 1.73 After 2 but within 3 years 150,036 3.03 200,000 3.16 After 3 but within 4 years 181 1.71 150 — After 4 but within 5 years 50,150 1.59 242 2.95 After 5 years 8,187 2.65 8,390 2.65 FHLB advances and overall rate $ 1,392,849 2.13 $ 1,826,808 2.52 Aggregate carrying value of assets pledged as collateral $ 7,208,616 $ 6,689,761 Remaining borrowing capacity 3,393,626 2,568,664 Webster Bank is in compliance with FHLB collateral requirements for the periods presented. Eligible collateral, primarily certain residential and commercial real estate 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 4.100% Senior fixed-rate notes due March 25, 2029 (1) 326,436 — Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (2) 77,320 77,320 Total notes and subordinated debt 553,756 227,320 Discount on senior fixed-rate notes (1,467 ) (608 ) Debt issuance cost on senior fixed-rate notes (3,131 ) (691 ) Long-term debt $ 549,158 $ 226,021 (1) In March 2019, the Company completed a $300.0 million senior fixed-rate notes issuance. The fixed interest rate has been designated in a fair value hedging relationship and swapped to a weighted-average variable rate of 3.62% at September 30, 2019 . The $26.4 million basis adjustment included in the carrying value reflects the changes in the benchmark rate. (2) The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month London Interbank Offered Rate plus 2.95% , was 5.09% at September 30, 2019 and 5.74% at December 31, 2018 .

Leases Leases

Leases Leases	9 Months Ended
Leases Leases	Sep. 30, 2019
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	Leasing The Company, as lessee, primarily leases office space, banking centers, and certain other assets. These leases are generally classified as operating leases, however, an insignificant amount of the leases are classified as finance leases. The Company's operating leases generally have lease terms for periods of 5 to 20 years with various renewal options. The Company, by policy, does not include renewal options for leases as part of its ROU assets and lease liabilities unless they are deemed reasonably certain to exercise. The Company does not have any material sub-lease agreements. During 2019, the Company began recognizing operating leases on its consolidated balance sheet by recording a lease liability representing the Company’s legal obligation to make lease payments, and a ROU asset representing its legal right to use the leased office space, banking centers and certain other assets. The following table summarizes lessee information related to the Company’s operating ROU assets and lease liability: At September 30, 2019 (In thousands) Operating Leases Consolidated Balance Sheet Line Item Location ROU lease assets $ 161,730 Premises and equipment, net Lease liabilities 180,832 Accrued expenses and other liabilities Operating lease expense is comprised of operating lease costs and variable lease costs, net of sublease income. The pattern and measurement of expense recognition of these costs was not significantly impacted by the adoption of ASU 2016-02 and subsequent ASUs issued to amend Topic 842. Variable lease payments are defined as payments made for the right to use an asset that vary because of changes in facts or circumstances occurring after the commencement date, other than the passage of time. Variable lease payments that are dependent on an index or a rate are initially measured using the index or rate at the commencement date and are included in the measurement of a lease liability. Variable lease payments that are not dependent on an index or a rate, or changes in variable payments based on an index or rate after the commencement date, are excluded from the measurement of a lease liability and recognized in the period incurred. All variable lease payments are included within variable lease costs presented below. The components of operating lease cost and other related information are as follows: (In thousands) Three months ended September 30, 2019 Nine months ended September 30, 2019 Lease Cost: Operating lease costs $ 7,512 $ 22,384 Variable lease costs 1,292 3,613 Sublease income (142 ) (437 ) Total operating lease cost $ 8,662 $ 25,560 Other Information: Cash paid for amounts included in the measurement of lease liabilities $ 7,938 $ 23,349 Right-of-use assets obtained in exchange for new operating lease liabilities 9,983 22,917 Weighted-average remaining lease term, in years - operating leases at September 30, 2019 8.5 Weighted-average discount rate - operating leases at September 30, 2019 3.31 % The undiscounted scheduled maturities reconciled to total operating lease liabilities are as follows: (In thousands) At September 30, 2019 Remainder of 2019 $ 5,379 2020 31,041 2021 30,075 2022 26,560 2023 23,656 Thereafter 94,332 Total operating lease liability payments 211,043 Less: Present value adjustment 30,211 Lease liabilities $ 180,832 See Note 4: Loans and Leases

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss, Net of Tax	9 Months Ended
Accumulated Other Comprehensive Loss, Net of Tax	Sep. 30, 2019
Equity [Abstract]
Accumulated Other Comprehensive Loss, Net of Tax	Accumulated Other Comprehensive Loss, Net of Tax The following tables summarize the changes in accumulated other comprehensive loss (AOCL), net of tax by component: Three months ended September 30, 2019 Nine months ended September 30, 2019 (In thousands) Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Beginning balance $ (9,406 ) $ (8,931 ) $ (47,853 ) $ (66,190 ) $ (71,374 ) $ (9,313 ) $ (49,965 ) $ (130,652 ) OCI before reclassifications 24,304 2,216 — 26,520 86,272 507 — 86,779 Amounts reclassified from AOCL — 1,387 1,049 2,436 — 3,478 3,161 6,639 Net current-period OCI 24,304 3,603 1,049 28,956 86,272 3,985 3,161 93,418 Ending balance $ 14,898 $ (5,328 ) $ (46,804 ) $ (37,234 ) $ 14,898 $ (5,328 ) $ (46,804 ) $ (37,234 ) Three months ended September 30, 2018 Nine months ended September 30, 2018 (In thousands) Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Beginning balance $ (64,617 ) $ (10,814 ) $ (46,505 ) $ (121,936 ) $ (27,947 ) $ (15,016 ) $ (48,568 ) $ (91,531 ) (OCL)/OCI before reclassifications (13,811 ) 197 — (13,614 ) (50,481 ) 1,620 — (48,861 ) Amounts reclassified from AOCL — 1,438 2,548 3,986 — 4,217 4,611 8,828 Net current-period (OCL)/OCI (13,811 ) 1,635 2,548 (9,628 ) (50,481 ) 5,837 4,611 (40,033 ) Ending balance $ (78,428 ) $ (9,179 ) $ (43,957 ) $ (131,564 ) $ (78,428 ) $ (9,179 ) $ (43,957 ) $ (131,564 ) 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 2019 2018 2019 2018 Derivative instruments: Hedge terminations $ (1,375 ) $ (1,932 ) $ (4,174 ) $ (5,664 ) Interest expense Premium amortization (515 ) — (527 ) — Interest income Tax benefit 503 494 1,223 1,447 Income tax expense Net of tax $ (1,387 ) $ (1,438 ) $ (3,478 ) $ (4,217 ) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (1,421 ) $ (3,431 ) $ (4,280 ) $ (6,209 ) (1) Tax benefit 372 883 1,119 1,598 Income tax expense Net of tax $ (1,049 ) $ (2,548 ) $ (3,161 ) $ (4,611 ) (1) These AOCL components are included in the computation of net periodic benefit cost, see Note 15: Retirement Benefit Plans for further details.

Regulatory Matters

Regulatory Matters	9 Months Ended
Regulatory Matters	Sep. 30, 2019
Broker-Dealer, Net Capital Requirement, SEC Regulation [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 Office of the Comptroller of the Currency (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 adjustments. 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: At September 30, 2019 Actual Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,461,028 11.63 % $ 952,020 4.5 % $ 1,375,140 6.5 % Total risk-based capital 2,895,006 13.68 1,692,480 8.0 2,115,600 10.0 Tier 1 risk-based capital 2,606,065 12.32 1,269,360 6.0 1,692,480 8.0 Tier 1 leverage capital 2,606,065 8.99 1,158,906 4.0 1,448,632 5.0 Webster Bank CET1 risk-based capital $ 2,617,731 12.37 % $ 952,532 4.5 % $ 1,375,879 6.5 % Total risk-based capital 2,829,352 13.37 1,693,390 8.0 2,116,737 10.0 Tier 1 risk-based capital 2,617,731 12.37 1,270,042 6.0 1,693,390 8.0 Tier 1 leverage capital 2,617,731 9.04 1,158,512 4.0 1,448,140 5.0 At December 31, 2018 Actual Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,284,978 11.44 % $ 898,972 4.5 % $ 1,298,514 6.5 % Total risk-based capital 2,722,194 13.63 1,598,172 8.0 1,997,715 10.0 Tier 1 risk-based capital 2,430,015 12.16 1,198,629 6.0 1,598,172 8.0 Tier 1 leverage capital 2,430,015 9.02 1,077,303 4.0 1,346,628 5.0 Webster Bank CET1 risk-based capital $ 2,170,566 10.87 % $ 898,317 4.5 % $ 1,297,569 6.5 % Total risk-based capital 2,385,425 11.95 1,597,008 8.0 1,996,260 10.0 Tier 1 risk-based capital 2,170,566 10.87 1,197,756 6.0 1,597,008 8.0 Tier 1 leverage capital 2,170,566 8.06 1,076,712 4.0 1,345,889 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. Federal and state banking regulations limit the amount of dividends that may be paid by Webster Bank, without the express approval of the OCC, to its retained net profits, defined by the OCC as net income less dividends declared during the period, for the preceding two years plus retained net profits up to the date of any dividend declaration. In addition, the effect of any dividend declaration must not cause the regulatory capital of Webster Bank to fall below specified minimum levels and, 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 $170 million during the nine months ended September 30, 2019 compared to $220 million during the nine months ended September 30, 2018 . Cash Restrictions Webster Bank is required by Federal Reserve System regulations to hold cash reserve balances on hand or with a Federal Reserve Bank. Pursuant to this requirement, it held $93.2 million at September 30, 2019 and $81.2 million at December 31, 2018 . These restricted cash amounts are included in cash and due from banks, on the consolidated balance sheet.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
Earnings Per Common Share	Sep. 30, 2019
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) 2019 2018 2019 2018 Earnings for basic and diluted earnings per common share: Net income $ 93,865 $ 99,673 $ 292,250 $ 261,580 Less: Preferred stock dividends 1,968 1,968 5,906 5,884 Net income available to common shareholders 91,897 97,705 286,344 255,696 Less: Earnings applicable to participating restricted stock 455 245 1,425 656 Earnings applicable to common shareholders $ 91,442 $ 97,460 $ 284,919 $ 255,040 Shares: Weighted-average common shares outstanding - basic 91,559 91,959 91,554 91,912 Effect of dilutive securities 315 249 329 309 Weighted-average common shares outstanding - diluted 91,874 92,208 91,883 92,221 Earnings per common share: Basic $ 1.00 $ 1.06 $ 3.11 $ 2.77 Diluted 1.00 1.06 3.10 2.77 Dilutive Securities The Company maintains stock compensation plans under which restricted stock, restricted stock units, non-qualified stock options, incentive stock options, or stock appreciation rights may be granted to employees and directors. The effect of dilutive securities for the periods presented is primarily the result of outstanding stock options, as well as non-participating restricted stock. Potential common shares from non-participating restricted stock, of 44 thousand and 97 thousand for the three months ended September 30, 2019 and 2018 , respectively, and 69 thousand and 54 thousand for the nine months ended September 30, 2019 and 2018 , respectively, are excluded from the effect of dilutive securities because under application of the treasury stock method they would have been anti-dilutive.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
Derivative Financial Instruments	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments Webster uses derivative financial instruments, primarily interest rate swaps, caps, and floors, under its interest rate risk management strategy, to mitigate certain economic risks and to achieve greater stability in interest income and interest expense. For additional information on Webster's accounting policies for derivatives and risk management objectives or related exposure of using derivatives see Note 1 to the Consolidated Financial Statements and Note 15: Derivative Financial Instruments , respectively, in the Notes to Consolidated Financial Statements contained in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 . Derivative Positions and Offsetting Derivative positions are recorded at fair value with asset derivatives included in accrued interest receivable and other assets and liability derivatives included in accrued expenses and other liabilities on the consolidated balance sheet. The following table presents the notional amounts and fair value of derivative positions: At September 30, 2019 At December 31, 2018 Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives (In thousands) Notional Fair Notional Fair Notional Fair Notional Fair Designated as hedging instruments: Interest rate derivatives (1) (2) $ 1,525,000 $ 19,209 $ — $ — $ 325,000 $ 3,050 $ — $ — Not designated as hedging instruments: Interest rate derivatives (1) 4,401,353 180,852 4,026,716 9,114 4,435,530 42,205 3,643,985 38,029 Mortgage banking derivatives (3) 61,367 506 74,000 184 13,599 226 17,000 293 Other (4) 107,022 776 151,219 762 85,432 797 140,601 688 Total not designated as hedging instruments 4,569,742 182,134 4,251,935 10,060 4,534,561 43,228 3,801,586 39,010 Gross derivative instruments, before netting $ 6,094,742 201,343 $ 4,251,935 10,060 $ 4,859,561 46,278 $ 3,801,586 39,010 Less: Master netting agreements 6,240 6,240 2,495 2,495 Cash collateral 13,299 2,506 4,936 — Total derivative instruments, after netting $ 181,804 $ 1,314 $ 38,847 $ 36,515 (1) Balances related to Chicago Mercantile Exchange (CME) are presented as a single unit of account. Notional amounts of interest rate swaps cleared through CME include $0.7 billion and $1.9 billion for asset derivatives and $2.8 billion and $1.1 billion for liability derivatives at September 30, 2019 and December 31, 2018 , respectively. The related fair values approximate zero . (2) The increase in the notional amount is due to $1.0 billion interest rate floors purchased as part of the Company's balance sheet repositioning strategy. (3) Notional amounts related to residential loan commitments include mandatory forward commitments of $74.0 million , while notional amounts do not include approved floating rate commitments of $11.0 million , at September 30, 2019 . (4) Other derivatives include foreign currency forward contracts related to lending arrangements and customer hedging activity, a Visa equity swap transaction, and risk participation agreements. Notional amounts of risk participation agreements include $65.0 million and $65.0 million for asset derivatives and $139.5 million and $96.3 million for liability derivatives at September 30, 2019 and December 31, 2018 , respectively, that have insignificant related fair values. All eligible dealer contracts are cleared through CME. In accordance with its rulebook, CME legally characterizes variation margin payments as settlement of derivatives rather than collateral against derivative positions. The Company has elected to record non-cleared derivative positions subject to a legally enforceable master netting agreement on a net basis. In addition, cash collateral received or posted is offset; however, securities collateral is not offset. At September 30, 2019 , $13.3 million of cash collateral received is included in cash and due from banks on the consolidated balance sheet and is considered restricted in nature. The following table presents fair value positions transitioned from gross to net upon application of counterparty netting agreements: At September 30, 2019 (In thousands) Gross Amount Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 19,683 19,539 $ 144 $ (201 ) $ (57 ) Liability derivatives 8,816 8,746 70 (104 ) (34 ) At December 31, 2018 (In thousands) Gross Amount Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 9,928 $ 7,431 $ 2,497 $ (755 ) $ 1,742 Liability derivatives 2,566 2,495 71 — 71 Derivative Activity The following table presents the change in fair value for derivatives designated as fair value hedges as well as the offsetting change in fair value on the hedged item and the income statement effect of derivatives designated as cash flow hedges: Recognized In Three months ended September 30, Nine months ended September 30, (In thousands) Net Interest Income 2019 2018 2019 2018 Fair value hedges: Recognized on derivatives Long-term debt $ 10,624 $ — $ 26,436 $ — Recognized on hedged items Long-term debt (10,624 ) — (26,436 ) — Net recognized on fair value hedges $ — $ — $ — $ — Cash flow hedges: Interest rate derivatives Long-term debt $ 1,095 $ 1,667 $ 3,028 $ 5,158 Interest rate derivatives Interest and fees on loans and leases 515 — 527 — Net recognized on cash flow hedges $ 1,610 $ 1,667 $ 3,555 $ 5,158 Additional information related to fair value hedges: Consolidated Balance Sheet Line Item in Which Hedged Item is Located Carrying Amount of Hedged Item Cumulative Amount of Fair Value Hedging Adjustment Included in Carrying Amount At September 30, At September 30, (In thousands) 2019 2018 2019 2018 Long-term debt $ 326,436 $ — $ 26,436 $ — The following table presents the effect on the income statement for derivatives not designated as hedging instruments: Recognized In Three months ended September 30, Nine months ended September 30, (In thousands) Non-interest Income 2019 2018 2019 2018 Interest rate derivatives Other income $ 784 $ 1,623 $ 5,906 $ 7,372 Mortgage banking derivatives Mortgage banking activities 347 (26 ) 96 (95 ) Other Other income 1,679 (204 ) 1,603 1,230 Total not designated as hedging instruments $ 2,810 $ 1,393 $ 7,605 $ 8,507 For purchased options designated as cash flow hedges time value is excluded from the assessment of hedge effectiveness. Premiums related to time value are amortized to net interest income on a straight-line basis. During 2019, premiums of $13.5 million were excluded from the assessment of hedge effectiveness which had a remaining unamortized balance of $12.9 million at September 30, 2019 . Amounts for the change in fair value of derivatives qualifying for cash flow hedge accounting treatment are recorded to AOCL and reclassified to interest income as hedged interest payments are received or to interest expense as hedged interest payments are made. Over the next twelve months, an estimated $4.4 million reduction to interest expense will be reclassified from AOCL. Gains or losses on hedge termination are also recorded to AOCL and subsequently amortized into interest expense over the respective terms of the hedged debt instruments. Over the next twelve months, an estimated $2.7 million increase to interest expense will be reclassified from AOCL. At September 30, 2019 , the remaining unamortized loss on terminated cash flow hedges is $5.8 million . The maximum length of time over which forecasted transactions are hedged is 10 years years. Additional information about cash flow hedge activity impacting AOCL and the related amounts reclassified to interest expense is provided in Note 10: Accumulated Other Comprehensive Loss, Net of Tax . Information about the valuation methods used to measure the fair value of derivatives is provided in Note 14: Fair Value Measurements . Derivative Exposure The Company had approximately $160.4 million in net margin posted with financial counterparties or the derivative clearing organization at September 30, 2019 , which is primarily comprised of $57.8 million in initial margin collateral posted at CME and $113.5 million in CME variation margin posted . Webster regularly evaluates the credit risk of its derivative customers, taking into account the likelihood of default, net exposures, and remaining contractual life, among other related factors. Credit risk exposure is mitigated as transactions with customers are generally secured by the same collateral of the underlying transactions being hedged. Current net credit exposure relating to interest rate derivatives with Webster Bank customers was $180.5 million at September 30, 2019 . 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 $36.5 million at September 30, 2019 .

Fair Value Measurements

Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2019
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 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. 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,) 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 available-for-sale investment securities within Level 1 of the valuation hierarchy. 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 results and has an established process to challenge their valuations, or methodologies, that appear unusual or unexpected. Available-for-Sale investment securities which include Agency CMO, Agency MBS, Agency CMBS, CMBS, CLO, and corporate debt, 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. All other 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 value is validated against valuations performed by independent third parties and are classified within Level 2 of the fair value hierarchy. Webster evaluates the credit risk of its counterparties to determine if any fair value adjustment related to credit risk may be required, by considering factors such as the likelihood of default by the counterparty, its net exposure, remaining contractual life, as well as the collateral securing the position. The change in value of derivative assets and liabilities attributable to credit risk was not significant during the reported periods. Webster reviews its counterparty exposure on a regular basis. When necessary, appropriate business actions are taken to mitigate the exposure. In accordance with its rulebook, CME legally characterizes variation margin payments for over-the-counter derivatives as settlement rather than collateral against derivative positions. This impacts Webster's counterparty relationship with CME, resulting in the fair value of the instrument including cash collateral to be represented as a single unit of account. 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. 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 Accounting Standards Codification ( ASC) Topic 825 "Financial Instruments." Electing to measure originated loans held for sale at fair value reduces certain timing differences and better matches changes in the value of these assets with changes in the value of the derivatives used as an economic hedge on these assets. 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. The following table compares the fair value to unpaid principal balance of assets accounted for under the fair value option: At September 30, 2019 At December 31, 2018 (In thousands) Fair Value Unpaid Principal Balance Difference Fair Value Unpaid Principal Balance Difference Originated loans held for sale $ 27,061 $ 26,696 $ 365 $ 7,908 $ 8,227 $ (319 ) 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 cost basis of the investments held in the Rabbi Trust is $1.7 million at September 30, 2019 . Alternative Investments. Equity investments have a readily determinable fair value when quoted prices are available in an active market. Accordingly, such alternative investments are classified within Level 1 of the fair value hierarchy. Equity investments that do not have a readily available fair value may qualify for net asset value (NAV) measurement based on specific requirements. The Company's alternative investments accounted for at NAV consist of investments in non-public entities that generally cannot be redeemed since the Company’s investments are distributed as the underlying equity is liquidated. Alternative investments recorded at NAV are not classified within the fair value hierarchy. At September 30, 2019 , these alternative investments had a remaining unfunded commitment of $25.0 million , with the increase from prior periods due to one new investment. Summaries of the fair values of assets and liabilities measured at fair value on a recurring basis are as follows: At September 30, 2019 (In thousands) Level 1 Level 2 Level 3 NAV Total Financial assets held at fair value: U.S. Treasury Bills $ 19,924 $ — $ — $ — $ 19,924 Agency CMO — 200,956 — — 200,956 Agency MBS — 1,598,836 — — 1,598,836 Agency CMBS — 610,350 — — 610,350 CMBS — 403,918 — — 403,918 CLO — 94,805 — — 94,805 Corporate debt — 31,314 — — 31,314 Total available-for-sale investment securities 19,924 2,940,179 — — 2,960,103 Gross derivative instruments, before netting (1) 658 200,685 — — 201,343 Originated loans held for sale — 27,061 — — 27,061 Investments held in Rabbi Trust 4,673 — — — 4,673 Alternative investments — — — 3,217 3,217 Total financial assets held at fair value $ 25,255 $ 3,167,925 $ — $ 3,217 $ 3,196,397 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 491 $ 9,569 $ — $ — $ 10,060 At December 31, 2018 (In thousands) Level 1 Level 2 Level 3 NAV Total Financial assets held at fair value: U.S. Treasury Bills $ 7,550 $ — $ — $ — $ 7,550 Agency CMO — 234,923 — — 234,923 Agency MBS — 1,481,089 — — 1,481,089 Agency CMBS — 566,237 — — 566,237 CMBS — 445,581 — — 445,581 CLO — 112,771 — — 112,771 Corporate debt — 50,579 — — 50,579 Total available-for-sale investment securities 7,550 2,891,180 — — 2,898,730 Gross derivative instruments, before netting (1) 758 45,520 — — 46,278 Originated loans held for sale — 7,908 — — 7,908 Investments held in Rabbi Trust 4,307 — — — 4,307 Alternative investments — — — 2,563 2,563 Total financial assets held at fair value $ 12,615 $ 2,944,608 $ — $ 2,563 $ 2,959,786 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 588 $ 38,422 $ — $ — $ 39,010 (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 13: Derivative Financial Instruments . 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. At September 30, 2019 , no significant assets classified within Level 3 were identified and measured under this basis. The following is a description of valuation methodologies used for assets measured at fair value on a non-recurring basis. Alternative Investments. The measurement alternative has been elected for alternative investments without readily determinable fair values that do not qualify for the NAV practical expedient. The measurement alternative requires investments to be accounted for at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer. These alternative investments are investments in non-public entities that generally cannot be redeemed since the investment is distributed as the underlying equity is liquidated. Accordingly, these alternative investments are classified within Level 2 of the fair value hierarchy. The carrying amount of these alternative investments was $6.9 million at September 30, 2019 . No reduction for impairments, or adjustments due to observable price changes, was identified during the nine months ended September 30, 2019 . 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 primarily consists of commercial loans with observable inputs and is classified within Level 2. On the occasion that these loans should 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 within Level 3 of the fair value hierarchy. Other Real Estate Owned and Repossessed Assets. The total book value of other real estate owned (OREO) and repossessed assets was $4.0 million at September 30, 2019 . OREO and repossessed assets are accounted for at the lower of cost or fair value and are considered to be recognized at fair value when recorded 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. Fair Value of Financial Instruments and Servicing Assets The Company is required to disclose the estimated fair value of financial instruments for which it is practicable to estimate fair value, as well as servicing assets. 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 results and has an established process to challenge their valuations, or methodologies, that appear unusual or unexpected. Held-to-Maturity investment securities, which include Agency CMO, Agency MBS, Agency CMBS, CMBS, and municipal bonds and notes, 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. Deposit liabilities are classified within Level 2 of the fair value hierarchy. Time Deposits. The fair value of a fixed-maturity certificate of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. Time deposits are classified within Level 2 of the fair value hierarchy. Securities Sold Under Agreements to Repurchase and Other Borrowings. The fair value of securities sold under agreements to repurchase and other borrowings that mature within 90 days is the carrying value. Fair value for all other balances are estimated using discounted cash flow analysis based on current market rates adjusted for associated credit risks, as appropriate. 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. Mortgage Servicing Assets. Mortgage servicing assets are accounted for at cost and subsequently measured under the amortization method. Mortgage servicing assets are subject to impairment testing and considered to be recognized at fair value when they are recorded at below cost. Amortization and impairment charges, if any, are included as a component of other non-interest income in the consolidated income statement. 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 estimated fair values of selected financial instruments and servicing assets are as follows: At September 30, 2019 At December 31, 2018 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Value Assets: Level 2 Held-to-maturity investment securities $ 5,193,521 $ 5,285,705 $ 4,325,420 $ 4,209,121 Level 3 Loans and leases, net 19,342,494 19,602,007 18,253,136 18,155,798 Mortgage servicing assets 17,877 34,025 21,215 45,478 Liabilities: Level 2 Deposit liabilities $ 20,025,100 $ 20,025,100 $ 18,662,299 $ 18,662,299 Time deposits 3,255,565 3,255,994 3,196,546 3,175,948 Securities sold under agreements to repurchase and other borrowings 1,210,692 1,207,411 581,874 581,874 FHLB advances 1,392,849 1,395,735 1,826,808 1,826,381 Long-term debt (1) 549,158 557,956 226,021 229,306 (1) Adjustments to the carrying amount of long-term debt for unamortized discount and debt issuance cost on senior fixed-rate notes are not included for determination of fair value, see Note 8: Borrowings .

Retirement Benefit Plans

Retirement Benefit Plans	9 Months Ended
Retirement Benefit Plans	Sep. 30, 2019
Retirement Benefits [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, 2019 2018 (In thousands) Pension Plan SERP Other Benefits Pension Plan SERP Other Benefits Interest cost on benefit obligations $ 2,001 $ 16 $ 22 $ 1,857 $ 35 $ 20 Expected return on plan assets (2,815 ) — — (3,178 ) — — Recognized net loss 1,420 4 (2 ) 1,160 2,271 — Net periodic benefit cost $ 606 $ 20 $ 20 $ (161 ) $ 2,306 $ 20 Nine months ended September 30, 2019 2018 (In thousands) Pension Plan SERP Other Benefits Pension Plan SERP Other Benefits Interest cost on benefit obligations $ 5,956 $ 48 $ 64 $ 5,577 $ 201 $ 59 Expected return on plan assets (8,445 ) — — (9,538 ) — — Recognized net loss 4,280 11 (10 ) 3,480 2,729 — Net periodic benefit cost $ 1,791 $ 59 $ 54 $ (481 ) $ 2,930 $ 59 During 2019, the Company made a discretionary $10.0 million cash contribution to the Webster Bank Pension Plan. Additional contributions may be made, as deemed appropriate by management, in conjunction with information provided by the plan's actuaries.

Segment Reporting

Segment Reporting	9 Months Ended
Segment Reporting	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting Webster’s operations are organized into three reportable segments that represent its primary businesses - Commercial Banking, HSA Bank, and Community Banking. These three segments reflect how executive management responsibilities are assigned, the type of customer served, how products and services are provided, and how discrete financial information is currently evaluated. Certain corporate treasury activities of the Company, along with the amounts required to reconcile profitability metrics to amounts reported in accordance with GAAP, are included in the Corporate and Reconciling category. Description of Segment Reporting Methodology Webster uses an internal profitability reporting system to generate information by operating segment, which is based on a series of management estimates for funds transfer pricing, and allocations for 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 any mismatch associated with the matched maturity funding concept called Funds Transfer Pricing is absorbed in corporate treasury activities. 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. 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. During the three months ended June 30, 2019, Webster refined and improved the precision of this allocation approach. Prior period provision for loan and lease losses amounts were revised accordingly. Allowance for loan and lease losses are included within the Corporate and Reconciling category’s total assets. 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. The following table presents total assets for Webster's reportable segments and the Corporate and Reconciling category: (In thousands) Commercial Banking HSA Bank Community Banking Corporate and Reconciling Consolidated Total At September 30, 2019 $ 11,174,036 $ 75,636 $ 9,228,537 $ 9,416,891 $ 29,895,100 At December 31, 2018 10,477,050 70,826 8,727,335 8,335,104 27,610,315 The following tables present the operating results for Webster’s reportable segments and the Corporate and Reconciling category: Three months ended September 30, 2019 (In thousands) Commercial Banking HSA Bank Community Banking Corporate and Reconciling Consolidated Total Net interest income (expense) $ 96,817 $ 42,206 $ 99,459 $ 2,057 $ 240,539 Non-interest income 13,987 23,526 28,115 4,303 69,931 Non-interest expense 45,261 32,918 99,835 1,880 179,894 Pre-tax, pre-provision net revenue 65,543 32,814 27,739 4,480 130,576 Provision for loan and lease losses 9,312 — 1,988 — 11,300 Income (loss) before income tax expense 56,231 32,814 25,751 4,480 119,276 Income tax expense (benefit) 13,828 8,531 5,128 (2,076 ) 25,411 Net income $ 42,403 $ 24,283 $ 20,623 $ 6,556 $ 93,865 Three months ended September 30, 2018 (In thousands) Commercial Banking HSA Community Banking Corporate and Reconciling Consolidated Total Net interest income (expense) $ 91,243 $ 36,731 $ 101,952 $ 446 $ 230,372 Non-interest income 18,305 22,159 26,848 4,972 72,284 Non-interest expense 44,506 30,753 95,769 7,755 178,783 Pre-tax, pre-provision net revenue 65,042 28,137 33,031 (2,337 ) 123,873 Provision for loan and lease losses 9,991 — 509 — 10,500 Income (loss) before income tax expense 55,051 28,137 32,522 (2,337 ) 113,373 Income tax expense (benefit) 13,542 7,316 6,472 (13,630 ) 13,700 Net income $ 41,509 $ 20,821 $ 26,050 $ 11,293 $ 99,673 Nine months ended September 30, 2019 (In thousands) Commercial Banking HSA Bank Community Banking Corporate and Reconciling Consolidated Total Net interest income (expense) $ 279,498 $ 126,573 $ 303,518 $ 14,288 $ 723,877 Non-interest income 42,643 74,082 81,172 16,499 214,396 Non-interest expense 136,075 100,693 291,076 8,376 536,220 Pre-tax, pre-provision net revenue 186,066 99,962 93,614 22,411 402,053 Provision for loan and lease losses 23,294 — 8,506 — 31,800 Income (loss) before income tax expense 162,772 99,962 85,108 22,411 370,253 Income tax expense (benefit) 40,037 25,990 16,940 (4,964 ) 78,003 Net income $ 122,735 $ 73,972 $ 68,168 $ 27,375 $ 292,250 Nine months ended September 30, 2018 (In thousands) Commercial Banking HSA Bank Community Banking Corporate and Reconciling Consolidated Total Net interest income (expense) $ 264,353 $ 104,920 $ 302,782 $ (2,505 ) $ 669,550 Non-interest income 48,662 67,710 78,421 14,612 209,405 Non-interest expense 128,730 93,488 287,795 20,844 530,857 Pre-tax, pre-provision net revenue 184,285 79,142 93,408 (8,737 ) 348,098 Provision for loan and lease losses 25,468 — 6,532 — 32,000 Income (loss) before income tax expense 158,817 79,142 86,876 (8,737 ) 316,098 Income tax expense (benefit) 39,069 20,577 17,288 (22,416 ) 54,518 Net income $ 119,748 $ 58,565 $ 69,588 $ 13,679 $ 261,580

Revenue from Contracts with Cus

Revenue from Contracts with Customers Revenue from Contracts with customers	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	Revenue from Contracts with Customers The following tables present revenues within the scope of ASC 606, Revenue from Contracts with Customers and the net amount of other sources of non-interest income that is within the scope of other GAAP topics: Three months ended September 30, 2019 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income Deposit service fees $ 2,987 $ 22,264 $ 16,047 $ 112 $ 41,410 Wealth and investment services 2,650 — 5,855 (9 ) 8,496 Other — 1,262 650 — 1,912 Revenue from contracts with customers 5,637 23,526 22,552 103 51,818 Other sources of non-interest income 8,350 — 5,563 4,200 18,113 Total non-interest income $ 13,987 $ 23,526 $ 28,115 $ 4,303 $ 69,931 Three months ended September 30, 2018 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income Deposit service fees $ 3,211 $ 21,294 $ 16,107 $ (11 ) $ 40,601 Wealth and investment services 2,577 — 5,843 (8 ) 8,412 Other — 865 352 — 1,217 Revenue from contracts with customers 5,788 22,159 22,302 (19 ) 50,230 Other sources of non-interest income 12,517 — 4,546 4,991 22,054 Total non-interest income $ 18,305 $ 22,159 $ 26,848 $ 4,972 $ 72,284 Nine months ended September 30, 2019 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income Deposit service fees $ 9,108 $ 70,496 $ 47,701 $ 247 $ 127,552 Wealth and investment services 7,676 — 16,806 (26 ) 24,456 Other — 3,586 1,855 — 5,441 Revenue from contracts with customers 16,784 74,082 66,362 221 157,449 Other sources of non-interest income 25,859 — 14,810 16,278 56,947 Total non-interest income $ 42,643 $ 74,082 $ 81,172 $ 16,499 $ 214,396 Nine months ended September 30, 2018 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income Deposit service fees $ 9,613 $ 65,112 $ 47,079 $ 107 $ 121,911 Wealth and investment services 7,703 — 17,060 (25 ) 24,738 Other — 2,598 1,485 — 4,083 Revenue from contracts with customers 17,316 67,710 65,624 82 150,732 Other sources of non-interest income 31,346 — 12,797 14,530 58,673 Total non-interest income $ 48,662 $ 67,710 $ 78,421 $ 14,612 $ 209,405 The major types of revenue streams that are within the scope of ASC 606 are described below: Deposit service fees, predominately consist of fees earned from deposit accounts and interchange fees. Fees earned from deposit accounts relate to event-driven services and periodic account maintenance activities. Webster's obligations for event-driven services are satisfied at the time the service is delivered, while the obligations for maintenance services is satisfied monthly. Interchange fees are assessed as the performance obligation is satisfied, which is at the point in time the card transaction is authorized. Wealth and investment services, consists of fees earned from investment and securities-related services, trust and other related services. Obligations for wealth and investment services are generally satisfied over time through a time-based measurement of progress, while certain obligations may be satisfied at points in time for activities that are transactional in nature. These disaggregated amounts are reconciled to non-interest income as presented in Note 16: Segment Reporting . Contracts with customers did not generate significant contract assets and liabilities.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2019
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. 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. The following table summarizes the outstanding amounts of credit-related financial instruments with off-balance sheet risk: (In thousands) At September 30 At December 31, 2018 Commitments to extend credit $ 5,894,781 $ 5,840,585 Standby letter of credit 194,430 189,040 Commercial letter of credit 21,609 21,181 Total credit-related financial instruments with off-balance sheet risk $ 6,110,820 $ 6,050,806 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 on the consolidated balance sheet. 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) 2019 2018 2019 2018 Beginning balance $ 2,537 $ 2,596 $ 2,506 $ 2,362 (Benefit) provision charged to expense (68 ) 28 (37 ) 262 Ending balance $ 2,469 $ 2,624 $ 2,469 $ 2,624

Subsequent Events

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company has evaluated events from the date of the Condensed Consolidated Financial Statements and accompanying Notes thereto, September 30, 2019 , through the issuance of this Quarterly Report on Form 10-Q. On October 29, 2019, the Company's Board of Directors approved an increase of its repurchase authority from $78.7 million to $200.0 million under the Company's common stock repurchase program. Except for the common stock repurchase plan repurchase authority increase, the Company determined that no other significant events were identified requiring recognition or disclosure in this report.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2019
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 related Notes, for the year ended December 31, 2018 , included in our Form 10-K filed with the SEC. Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications had an immaterial effect on the Company's Condensed Consolidated Financial Statements. Use of Estimates
New Accounting Pronouncements, Policy [Policy Text Block]	Accounting Standards Adopted During 2019 Effective January 1, 2019 , the following ASUs were adopted by the Company: ASU No. 2018-16, Derivatives and Hedging (Topic 815) - Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes. The Update permits the use of the OIS rate based on SOFR as a U.S. benchmark interest rate for hedge accounting purposes under Topic 815 in addition to the interest rates on direct U.S. Treasury obligations, the London Interbank Offered Rate swap rate, the OIS rate based on the Fed Funds Effective Rate, and the Securities Industry and Financial Markets Association Municipal Swap Rate. The Company adopted the Update during the first quarter of 2019 on a prospective basis. The adoption of this guidance did not have a material effect on the Company's consolidated financial statements. ASU No. 2017-12, Derivatives and Hedging (Topic 815) - Targeted Improvements to Accounting for Hedging Activities. The purpose of the Update is to better align a company’s risk management and financial reporting for hedging activities with the economic objectives of those activities. The Update expands an entity's ability to hedge non-financial and financial risk components and reduce complexity in hedges of interest rate risk. The guidance eliminates the requirement to separately measure and report hedge ineffectiveness, and generally requires the entire change in fair value of a hedging instrument to be presented in the same income statement line in which the earnings effect of the hedged item is reported. The Company adopted the Update during the first quarter of 2019 on a modified retrospective basis. The adoption of this guidance did not have a material effect on the Company's consolidated financial statements. The Company has provided enhanced disclosures in Note 13: Derivative Financial Instruments as a result of adopting this Update. ASU No. 2016-02, Leases (Topic 842) and subsequent ASUs issued to amend this Topic. The Updates introduce a lessee model that requires substantially all leases to be recorded as assets and liabilities on the balance sheet and requires expanded quantitative and qualitative disclosures regarding key information about leasing arrangements. The lessor model remains substantially the same with targeted improvements that do not materially impact the Company. The Company adopted the Updates during the first quarter of 2019 using the new transition method option that allows the use of effective date, January 1, 2019, as the date of initial application of the new lease accounting standard and to recognize a cumulative-effect adjustment to the opening balance of retained earnings upon adoption. The Company elected the transition relief package of practical expedients which forgoes the requirement to reassess the existence of leases in existing contracts, their lease classification and the accounting treatment of their initial direct costs. As a practical expedient, the Company has also made a policy election to not separate non-lease components from lease components for its real estate leases and instead account for each separate lease components and non-lease components associated with that lease component as a single lease component. The Company will separately account for the lease and non-lease components in its equipment leases. The Company determines whether a contract contains a lease based on whether a contract, or a part of a contract, conveys the right to control the use of an identified asset for a period of time in exchange for consideration. The discount rate used is either the rate implicit in the lease, or when a rate cannot be readily determined an incremental borrowing rate. The incremental borrowing rate is the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and amount equal to the lease payments, in a similar economic environment. As a result of adopting this Update, the Company recognized $157.2 million of right-of-use asset (ROU) and $178.2 million of lease liability, as of January 1, 2019. The Company also recorded a $515 thousand cumulative-effect adjustment directly to retained earnings as of January 1, 2019 for abandoned leased properties and the remaining deferred gains on sale-leaseback transactions which occurred prior to the date of adoption. See Note 9: Leasing for further information. Accounting Standards Issued But Not Yet Adopted The following list identifies ASUs applicable to the Company that have been issued by the FASB but are not yet effective: ASU No. 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments. The Update amends guidance on credit losses, hedge accounting, and recognition and measurement of financial instruments. The changes provide clarifications and codification improvements in relation to recently issued accounting updates. The amendments to the guidance on credit losses are considered in the paragraphs below related to our adoption of ASU 2016-13, and will be adopted concurrently with those Updates. The clarifications and amendments to the guidance on hedge accounting and recognition and measurement of financial instruments will be effective for the Company on January 1, 2020. The Company does not expect these changes to have a material impact on its consolidated financial statements. ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40) - Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. The Update aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The updated guidance also requires an entity to amortize the capitalized implementation costs as an expense over the term of the hosting arrangement and to present in the same income statement line item as the fees associated with the hosting arrangement. The Update is effective for the Company on January 1, 2020. Early adoption is permitted. The Company will apply the amendments in this update prospectively to all implementation costs incurred after the date of adoption. The Company does not expect this Update to have a material impact on its consolidated financial statements. ASU No. 2018-14, Compensation-Retirement Benefits - Defined Benefit Plan - General (Subtopic 715-20) - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans. The Update modifies disclosure requirements for employers that sponsor defined benefit pension and other postretirement plans. The updated guidance will be effective for the Company on January 1, 2021. The Company does not expect this Update to have a material impact on its consolidated financial statements. ASU No. 2018-13, Fair Value Measurement (Topic 820) - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. The Update modifies the disclosure requirements on fair value measurements. The updated guidance will no longer require entities to disclose the amount and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy. However, it will require public companies to disclose changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop Level 3 measurements. The Update is effective for the Company on January 1, 2020, and earlier adoption is permitted. The Company does not expect this Update to have a material impact on its consolidated financial statements. ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment. The Update simplifies quantitative goodwill impairment testing by requiring entities to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for any amount by which the carrying amount exceeds the reporting unit's fair value, to the extent that the loss recognized does not exceed the amount of goodwill allocated to that reporting unit. This changes current guidance by eliminating the second step of the goodwill impairment analysis which involves calculating the implied fair value of goodwill determined in the same manner as the amount of goodwill recognized in a business combination upon acquisition. Entities will still have the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. The Update must be applied prospectively and is effective for the Company on January 1, 2020. Early adoption is permitted. The Company does not expect this new guidance to have a material impact on its consolidated financial statements. ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) - Measurement of Credit Losses on Financial Instruments and subsequent ASUs issued to clarify this Topic. The Update will replace today's incurred loss approach for recognizing credit losses with a new credit loss methodology known as the current expected credit loss (CECL) model. The CECL model requires earlier recognition of credit losses using a lifetime credit loss measurement approach for financial assets carried at amortized cost. The CECL model also requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. To implement the new standard, the Company has established a project lead and has empowered a steering committee comprised of members from different disciplines including Credit, Accounting, Finance, Financial Analytics, IT, and Treasury, as well as specific working groups to focus on key components of the development process. Through these working groups, the Company is evaluating the effect that this Update, including subsequent ASUs issued to clarify this Topic, will have on its financial statements and related disclosures. The implementation project plan is made up of targeted work streams focused on credit models, data management, and treasury and accounting matters. The new credit models will include additional assumptions used to calculate credit losses over the estimated life of the financial assets and will include the impact of forecasted macroeconomic conditions. During the third quarter of 2019, the Company began to run its new credit models in parallel with its existing models under the incurred loss approach and has completed the validations of these new credit models. For the remainder of 2019, the Company is focused on finalizing its methodology for qualitative adjustments and the full implementation of new processes, controls and third party solutions. The Company is also continuing to work on updating its policies and drafting the new required disclosures under this Update. These Updates are effective for the Company on January 1, 2020. The Company currently expects an increase in its allowance for loan and lease losses of approximately 25% to 35% upon the adoption of these Updates. This increase will be reflected as a reduction to the Company's beginning total shareholders' equity as of January 1, 2020. This estimated impact is still subject to further refinement based on continuing reviews of models, methodologies, assumptions and judgments. The magnitude of the increase will depend on the composition, characteristics, and credit quality of the loan and securities portfolios as well as the economic conditions in effect at the adoption date.

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
Investment Securities (Tables)	Sep. 30, 2019
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, 2019 At December 31, 2018 (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 $ 19,918 $ 6 $ — $ 19,924 $ 7,549 $ 1 $ — $ 7,550 Agency CMO 198,917 2,704 (665 ) 200,956 238,968 412 (4,457 ) 234,923 Agency MBS 1,573,984 29,930 (5,078 ) 1,598,836 1,521,534 1,631 (42,076 ) 1,481,089 Agency CMBS 611,925 1,239 (2,814 ) 610,350 608,167 — (41,930 ) 566,237 CMBS 403,782 182 (46 ) 403,918 447,897 645 (2,961 ) 445,581 CLO 95,099 73 (367 ) 94,805 114,641 94 (1,964 ) 112,771 Corporate debt 35,567 — (4,253 ) 31,314 55,860 — (5,281 ) 50,579 Available-for-sale $ 2,939,192 $ 34,134 $ (13,223 ) $ 2,960,103 $ 2,994,616 $ 2,783 $ (98,669 ) $ 2,898,730 Held-to-maturity: Agency CMO $ 179,773 $ 1,430 $ (680 ) $ 180,523 $ 208,113 $ 287 $ (5,255 ) $ 203,145 Agency MBS 3,085,000 54,083 (11,249 ) 3,127,834 2,517,823 8,250 (79,701 ) 2,446,372 Agency CMBS 950,217 13,430 (1,569 ) 962,078 667,500 53 (22,572 ) 644,981 Municipal bonds and notes 742,844 33,780 (17 ) 776,607 715,041 2,907 (18,285 ) 699,663 CMBS 235,687 3,012 (36 ) 238,663 216,943 405 (2,388 ) 214,960 Held-to-maturity $ 5,193,521 $ 105,735 $ (13,551 ) $ 5,285,705 $ 4,325,420 $ 11,902 $ (128,201 ) $ 4,209,121
Summary of Changes in OTTI	Three months ended September 30, Nine months ended September 30, (In thousands) 2019 2018 2019 2018 Beginning balance $ 822 $ 1,103 $ 822 $ 1,364 Reduction for investment securities called — (281 ) — (542 ) Ending balance $ 822 $ 822 $ 822 $ 822
Summary of Gross Unrealized Losses not Considered OTTI	The following tables provide information on fair value and unrealized losses for the individual investment securities with an unrealized loss, aggregated by classification and length of time that the individual investment securities have been in a continuous unrealized loss position: At September 30, 2019 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 $ 18,109 $ (146 ) $ 35,751 $ (519 ) 11 $ 53,860 $ (665 ) Agency MBS 47,966 (33 ) 419,082 (5,045 ) 85 467,048 (5,078 ) Agency CMBS — — 461,840 (2,814 ) 28 461,840 (2,814 ) CMBS 49,418 (35 ) 3,489 (11 ) 8 52,907 (46 ) CLO 18,405 (294 ) 24,927 (73 ) 2 43,332 (367 ) Corporate debt 7,787 (767 ) 23,527 (3,486 ) 7 31,314 (4,253 ) Available-for-sale in an unrealized loss position $ 141,685 $ (1,275 ) $ 968,616 $ (11,948 ) 141 $ 1,110,301 $ (13,223 ) Held-to-maturity: Agency CMO $ 15,744 $ (40 ) $ 58,852 $ (640 ) 8 $ 74,596 $ (680 ) Agency MBS 183,181 (1,219 ) 858,373 (10,030 ) 119 1,041,554 (11,249 ) Agency CMBS 127,662 (1,552 ) 4,187 (17 ) 6 131,849 (1,569 ) Municipal bonds and notes 2,517 (17 ) — — 1 2,517 (17 ) CMBS 46,610 (36 ) — — 3 46,610 (36 ) Held-to-maturity in an unrealized loss position $ 375,714 $ (2,864 ) $ 921,412 $ (10,687 ) 137 $ 1,297,126 $ (13,551 ) At December 31, 2018 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 $ 15,524 $ (72 ) $ 180,641 $ (4,385 ) 36 $ 196,165 $ (4,457 ) Agency MBS 321,678 (2,078 ) 975,084 (39,998 ) 184 1,296,762 (42,076 ) Agency CMBS — — 566,237 (41,930 ) 37 566,237 (41,930 ) CMBS 343,457 (2,937 ) 5,193 (24 ) 39 348,650 (2,961 ) CLO 83,305 (1,695 ) 14,873 (269 ) 5 98,178 (1,964 ) Corporate debt 35,990 (1,820 ) 14,589 (3,461 ) 8 50,579 (5,281 ) Available-for-sale in an unrealized loss position $ 799,954 $ (8,602 ) $ 1,756,617 $ (90,067 ) 309 $ 2,556,571 $ (98,669 ) Held-to-maturity: Agency CMO $ 691 $ (1 ) $ 182,396 $ (5,254 ) 25 $ 183,087 $ (5,255 ) Agency MBS 288,635 (1,916 ) 1,892,951 (77,785 ) 272 2,181,586 (79,701 ) Agency CMBS — — 635,284 (22,572 ) 56 635,284 (22,572 ) Municipal bonds and notes 68,351 (882 ) 414,776 (17,403 ) 223 483,127 (18,285 ) CMBS 24,881 (270 ) 132,464 (2,118 ) 20 157,345 (2,388 ) Held-to-maturity in an unrealized loss position $ 382,558 $ (3,069 ) $ 3,257,871 $ (125,132 ) 596 $ 3,640,429 $ (128,201 )
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, 2019 Available-for-Sale Held-to-Maturity (In thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 19,918 $ 19,924 $ 1,045 $ 1,049 Due after one year through five years 17,000 17,000 6,260 6,392 Due after five through ten years 305,691 305,533 222,076 228,011 Due after ten years 2,596,583 2,617,646 4,964,140 5,050,253 Total debt securities $ 2,939,192 $ 2,960,103 $ 5,193,521 $ 5,285,705

Loans and Leases (Tables)

Loans and Leases (Tables)	9 Months Ended
Loans and Leases (Tables)	Sep. 30, 2019
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, 2018 Commercial $ 6,488,056 $ 6,216,606 Commercial Real Estate 5,398,084 4,927,145 Equipment Financing 521,828 508,397 Residential 4,873,726 4,416,637 Consumer 2,269,952 2,396,704 Loans and leases (1) (2) $ 19,551,646 $ 18,465,489 (1) Includes net deferred fees/costs and net premiums/discounts of $13.9 million at both September 30, 2019 and December 31, 2018 . (2) At September 30, 2019 the Company had pledged $7.6 billion of eligible loans as collateral to support borrowing capacity at the Federal Home Loan Bank (FHLB) of Boston and the Federal Reserve Bank (FRB) of Boston.
Past Due Financing Receivables	The following tables summarize the aging of loans and leases: At September 30, 2019 (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 Commercial: Commercial non-mortgage $ 2,760 $ 450 $ 92 $ 58,750 $ 62,052 $ 5,303,238 $ 5,365,290 Asset-based — — — 9,162 9,162 1,113,604 1,122,766 Commercial real estate: Commercial real estate 1,296 141 — 9,852 11,289 5,087,967 5,099,256 Commercial construction — — — 2,968 2,968 295,860 298,828 Equipment financing 1,666 525 — 5,488 7,679 514,149 521,828 Residential 6,752 6,727 — 43,839 57,318 4,816,408 4,873,726 Consumer: Home equity 9,192 2,290 — 31,452 42,934 2,007,428 2,050,362 Other consumer 3,075 697 — 1,388 5,160 214,430 219,590 Total $ 24,741 $ 10,830 $ 92 $ 162,899 $ 198,562 $ 19,353,084 $ 19,551,646 At December 31, 2018 (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 Commercial: Commercial non-mortgage $ 1,011 $ 702 $ 104 $ 55,810 $ 57,627 $ 5,189,808 $ 5,247,435 Asset-based — — — 224 224 968,947 969,171 Commercial real estate: Commercial real estate 1,275 245 — 8,242 9,762 4,698,552 4,708,314 Commercial construction — — — — — 218,831 218,831 Equipment financing 510 405 — 6,314 7,229 501,168 508,397 Residential 8,513 4,301 — 49,188 62,002 4,354,635 4,416,637 Consumer: Home equity 9,250 5,385 — 33,495 48,130 2,121,049 2,169,179 Other consumer 1,774 957 — 1,494 4,225 223,300 227,525 Total $ 22,333 $ 11,995 $ 104 $ 154,767 $ 189,199 $ 18,276,290 $ 18,465,489
Activity In Allowance For Losses	The following tables summarize the activity in, as well as the loan and lease balances that were evaluated for, the ALLL: At or for three months ended September 30, 2019 (In thousands) Commercial Commercial Real Estate Equipment Financing Residential Consumer Total ALLL: Balance, beginning of period $ 98,800 $ 61,068 $ 4,476 $ 21,221 $ 26,106 $ 211,671 Provision (benefit) charged to expense 11,202 (423 ) (176 ) (689 ) 1,386 11,300 Charge-offs (11,255 ) (32 ) (36 ) (872 ) (3,765 ) (15,960 ) Recoveries 124 3 49 356 1,609 2,141 Balance, end of period $ 98,871 $ 60,616 $ 4,313 $ 20,016 $ 25,336 $ 209,152 At or for three months ended September 30, 2018 (In thousands) Commercial Commercial Real Estate Equipment Financing Residential Consumer Total ALLL: Balance, beginning of period $ 95,340 $ 55,833 $ 5,383 $ 19,007 $ 31,759 $ 207,322 Provision (benefit) charged to expense 5,686 4,146 (213 ) 407 474 10,500 Charge-offs (740 ) (1,922 ) (136 ) (874 ) (4,863 ) (8,535 ) Recoveries 431 143 11 133 1,827 2,545 Balance, end of period $ 100,717 $ 58,200 $ 5,045 $ 18,673 $ 29,197 $ 211,832 At or for the nine months ended September 30, 2019 (In thousands) Commercial Commercial Real Estate Equipment Financing Residential Consumer Total ALLL: Balance, beginning of period $ 98,793 $ 60,151 $ 5,129 $ 19,599 $ 28,681 $ 212,353 Provision (benefit) charged to expense 22,820 3,901 (208 ) 2,865 2,422 31,800 Charge-offs (24,106 ) (3,478 ) (679 ) (3,277 ) (11,836 ) (43,376 ) Recoveries 1,364 42 71 829 6,069 8,375 Balance, end of period $ 98,871 $ 60,616 $ 4,313 $ 20,016 $ 25,336 $ 209,152 Individually evaluated for impairment $ 14,555 $ 735 $ 177 $ 3,625 $ 1,274 $ 20,366 Collectively evaluated for impairment $ 84,316 $ 59,881 $ 4,136 $ 16,391 $ 24,062 $ 188,786 Loan and lease balances: Individually evaluated for impairment $ 117,418 $ 16,224 $ 5,487 $ 95,666 $ 35,836 $ 270,631 Collectively evaluated for impairment 6,370,638 5,381,860 516,341 4,778,060 2,234,116 19,281,015 Loans and leases $ 6,488,056 $ 5,398,084 $ 521,828 $ 4,873,726 $ 2,269,952 $ 19,551,646 At or for the nine months ended September 30, 2018 (In thousands) Commercial Commercial Real Estate Equipment Financing Residential Consumer Total ALLL: Balance, beginning of period $ 89,533 $ 49,407 $ 5,806 $ 19,058 $ 36,190 $ 199,994 Provision (benefit) charged to expense 17,596 10,678 (557 ) 1,316 2,967 32,000 Charge-offs (7,869 ) (2,039 ) (246 ) (2,545 ) (14,844 ) (27,543 ) Recoveries 1,457 154 42 844 4,884 7,381 Balance, end of period $ 100,717 $ 58,200 $ 5,045 $ 18,673 $ 29,197 $ 211,832 Individually evaluated for impairment $ 10,491 $ 1,544 $ 15 $ 4,319 $ 1,428 $ 17,797 Collectively evaluated for impairment $ 90,226 $ 56,656 $ 5,030 $ 14,354 $ 27,769 $ 194,035 Loan and lease balances: Individually evaluated for impairment $ 104,353 $ 9,767 $ 6,489 $ 105,600 $ 39,808 $ 266,017 Collectively evaluated for impairment 6,070,043 4,761,558 512,565 4,309,463 2,401,373 18,055,002 Loans and leases $ 6,174,396 $ 4,771,325 $ 519,054 $ 4,415,063 $ 2,441,181 $ 18,321,019
Impaired Loans	The following tables summarize impaired loans and leases: At September 30, 2019 (In thousands) Unpaid Principal Balance Total Recorded Investment Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Commercial non-mortgage $ 148,932 $ 108,256 $ 36,250 $ 72,006 $ 14,550 Asset-based 9,490 9,162 9,013 149 5 Commercial real estate 19,270 13,256 7,202 6,054 735 Commercial construction 2,969 2,968 2,968 — — Equipment financing 5,540 5,487 2,403 3,084 177 Residential 105,576 95,666 61,236 34,430 3,625 Consumer - home equity 64,723 35,836 28,023 7,813 1,274 Total $ 356,500 $ 270,631 $ 147,095 $ 123,536 $ 20,366 At December 31, 2018 (In thousands) Unpaid Principal Balance Total Recorded Investment Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Commercial non-mortgage $ 120,165 $ 99,287 $ 65,724 $ 33,563 $ 7,818 Asset-based 550 225 — 225 6 Commercial real estate 13,355 10,828 2,125 8,703 1,661 Equipment financing 6,368 6,315 2,946 3,369 196 Residential 113,575 103,531 64,899 38,632 4,286 Consumer - home equity 44,654 39,144 30,576 8,568 1,383 Total $ 298,667 $ 259,330 $ 166,270 $ 93,060 $ 15,350 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, 2019 2018 2019 2018 (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 Commercial non-mortgage $ 102,996 $ 751 $ — $ 94,618 $ 847 $ — $ 103,772 $ 2,515 $ — $ 87,603 $ 2,257 $ — Asset based 4,673 — — 1,095 — — 4,694 — — 809 — — Commercial real estate: Commercial real estate 13,567 60 — 11,222 30 — 12,042 194 — 10,497 164 — Commercial construction 1,484 — — — — — 1,484 — — — — — Equipment financing 4,718 — — 6,337 41 — 5,901 — — 4,907 112 — Residential 97,917 862 271 107,618 923 301 99,599 2,682 817 109,948 2,852 819 Consumer - home equity 36,584 247 246 40,722 292 238 37,490 803 767 42,622 876 738 Total $ 261,939 $ 1,920 $ 517 $ 261,612 $ 2,133 $ 539 $ 264,982 $ 6,194 $ 1,584 $ 256,386 $ 6,261 $ 1,557
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 $ 6,122,391 $ 5,781,138 $ 5,253,649 $ 4,773,298 $ 512,219 $ 494,585 (7) Special Mention 97,969 206,351 81,256 75,338 915 1,303 (8) Substandard 263,833 222,405 63,179 78,509 8,694 12,509 (9) Doubtful 3,863 6,712 — — — — Total $ 6,488,056 $ 6,216,606 $ 5,398,084 $ 4,927,145 $ 521,828 $ 508,397
Troubled Debt Restructurings on Financing Receivables	Troubled Debt Restructurings The following table summarizes information for troubled debt restructurings (TDRs): (Dollars in thousands) At September 30, At December 31, 2018 Accrual status $ 137,493 $ 138,479 Non-accrual status 111,643 91,935 Total recorded investment of TDRs $ 249,136 $ 230,414 Specific reserves for TDRs included in the balance of ALLL $ 20,015 $ 11,930 Additional funds committed to borrowers in TDR status 3,621 3,893 For the portion of TDRs deemed to be uncollectible, Webster charged off $11.0 million and $1.1 million for the three months ended September 30, 2019 and 2018 , respectively, and $16.7 million , and $6.3 million for the nine months ended September 30, 2019 and 2018 , respectively. 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, 2019 2018 2019 2018 Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) (Dollars in thousands) Commercial non - mortgage Extended Maturity 2 $ 29 4 $ 537 8 $ 222 7 $ 622 Adjusted Interest Rate 1 12 — — 2 112 — — Maturity/Rate Combined 3 225 8 8,185 6 296 10 8,236 Other (2) 6 30,586 8 10,585 25 64,642 17 39,328 Commercial real estate Extended Maturity — — — — — — 2 97 Maturity/Rate Combined — — — — — — 1 245 Other (2) 1 2,180 — — 3 4,816 1 5,111 Residential Extended Maturity 1 67 1 20 5 1,007 1 20 Maturity/Rate Combined 1 368 4 440 14 2,216 7 716 Other (2) 2 243 3 356 6 785 16 2,798 Consumer - home equity Extended Maturity 1 134 1 148 5 504 3 341 Maturity/Rate Combined 2 30 3 170 4 140 6 618 Other (2) 8 375 5 258 27 1,595 30 1,951 Total TDRs 28 $ 34,249 37 $ 20,699 105 $ 76,335 101 $ 60,083 (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 for the three and nine months ended September 30, 2019 and 2018 . Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 (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 Commercial non - mortgage 4 $ 3,940 — $ — 4 $ 3,940 — $ — Residential — — 1 241 — — 2 261 Consumer - home equity 1 78 — — 1 78 — — Total 5 $ 4,018 1 $ 241 5 $ 4,018 2 $ 261 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, 2019 At December 31, 2018 (1) - (6) Pass $ 11,877 $ 13,165 (7) Special Mention 68 84 (8) Substandard 101,825 67,880 (9) Doubtful 3,863 6,610 Total $ 117,633 $ 87,739

Transfers of Financial Assets (

Transfers of Financial Assets (Tables)	9 Months Ended
Transfers of Financial Assets (Tables)	Sep. 30, 2019
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) 2019 2018 2019 2018 Beginning balance $ 684 $ 674 $ 674 $ 872 Provision (benefit) charged to expense 19 18 1,839 (172 ) Repurchased loans and settlements charged off (7 ) (10 ) (1,817 ) (18 ) Ending balance $ 696 $ 682 $ 696 $ 682 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) 2019 2018 2019 2018 Beginning balance $ 2,537 $ 2,596 $ 2,506 $ 2,362 (Benefit) provision charged to expense (68 ) 28 (37 ) 262 Ending balance $ 2,469 $ 2,624 $ 2,469 $ 2,624
Transfer of Financial Assets Accounted for as Sales [Table Text Block]	The following table provides information for mortgage banking activities: Three months ended September 30, Nine months ended September 30, (In thousands) 2019 2018 2019 2018 Residential mortgage loans held for sale: Proceeds from sale $ 66,236 $ 57,042 $ 129,700 $ 147,105 Loans sold with servicing rights retained 60,493 51,104 117,306 130,740 Net gain on sale 1,652 1,051 2,510 2,732 Ancillary fees 470 463 1,051 1,275 Fair value option adjustment 11 (209 ) 268 (323 )
Servicing Asset at Amortized Cost [Table Text Block]	The following table presents the changes in carrying value for mortgage servicing assets: Three months ended September 30, Nine months ended September 30, (In thousands) 2019 2018 2019 2018 Beginning balance $ 18,712 $ 23,341 $ 21,215 $ 25,139 Additions 966 1,428 2,219 3,878 Amortization (1,801 ) (2,125 ) (5,557 ) (6,373 ) Ending balance $ 17,877 $ 22,644 $ 17,877 $ 22,644

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
Goodwill and Other Intangible Assets (Tables)	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	ther intangible assets by reportable segment consisted of the following: At September 30, 2019 At December 31, 2018 (In thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount HSA Bank - Core deposits $ 22,000 $ (12,515 ) $ 9,485 $ 22,000 $ (10,842 ) $ 11,158 HSA Bank - Customer relationships 21,000 (7,606 ) 13,394 21,000 (6,394 ) 14,606 Total other intangible assets $ 43,000 $ (20,121 ) $ 22,879 $ 43,000 $ (17,236 ) $ 25,764
Schedule Of Expected Amortization Expense, Next Four Years	At September 30, 2019 , the remaining estimated aggregate future amortization expense for other intangible assets is as follows: (In thousands) Remainder of 2019 $ 961 2020 3,847 2021 3,847 2022 3,847 2023 3,847 Thereafter 6,530

Deposits (Tables)

Deposits (Tables)	9 Months Ended
Deposits (Tables)	Sep. 30, 2019
Banking and Thrift [Abstract]
Deposit Liabilities, Type [Table Text Block]	A summary of deposits by type follows: (In thousands) At September 30, At December 31, Non-interest-bearing: Demand $ 4,291,659 $ 4,162,446 Interest-bearing: Health savings accounts 6,288,218 5,740,601 Checking 2,619,452 2,518,472 Money market 2,560,918 2,100,084 Savings 4,264,853 4,140,696 Time deposits 3,255,565 3,196,546 Total interest-bearing $ 18,989,006 $ 17,696,399 Total deposits $ 23,280,665 $ 21,858,845 Time deposits and interest-bearing checking, included in above balances, obtained through brokers $ 671,595 $ 869,003 Time deposits, included in above balance, that exceed the FDIC limit 531,103 555,949 Deposit overdrafts reclassified as loan balances 2,244 2,245
Time Deposit Maturities [Table Text Block]	The scheduled maturities of time deposits are as follows: (In thousands) At September 30, Remainder of 2019 $ 1,003,978 2020 1,803,664 2021 330,610 2022 70,868 2023 28,889 Thereafter 17,556 Total time deposits $ 3,255,565

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
Borrowings (Tables)	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Repurchase Agreements	The following table summarizes securities sold under agreements to repurchase and other borrowings: At September 30, At December 31, (In thousands) Amount Rate Amount Rate Securities sold under agreements to repurchase (1) : Original maturity of one year or less $ 190,692 0.42 % $ 236,874 0.35 % Original maturity of greater than one year, non-callable 200,000 1.57 — — Total securities sold under agreements to repurchase 390,692 1.01 236,874 0.35 Fed funds purchased 820,000 1.91 345,000 2.52 Securities sold under agreements to repurchase and other borrowings $ 1,210,692 1.62 $ 581,874 1.64
Federal Home Loan Bank, Advances	The following table provides information for FHLB advances: At September 30, At December 31, (Dollars in thousands) Amount Weighted- Average Contractual Coupon Rate Amount Weighted- Average Contractual Coupon Rate Maturing within 1 year $ 1,109,295 2.07 % $ 1,403,026 2.55 % After 1 but within 2 years 75,000 1.51 215,000 1.73 After 2 but within 3 years 150,036 3.03 200,000 3.16 After 3 but within 4 years 181 1.71 150 — After 4 but within 5 years 50,150 1.59 242 2.95 After 5 years 8,187 2.65 8,390 2.65 FHLB advances and overall rate $ 1,392,849 2.13 $ 1,826,808 2.52 Aggregate carrying value of assets pledged as collateral $ 7,208,616 $ 6,689,761 Remaining borrowing capacity 3,393,626 2,568,664
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 4.100% Senior fixed-rate notes due March 25, 2029 (1) 326,436 — Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (2) 77,320 77,320 Total notes and subordinated debt 553,756 227,320 Discount on senior fixed-rate notes (1,467 ) (608 ) Debt issuance cost on senior fixed-rate notes (3,131 ) (691 ) Long-term debt $ 549,158 $ 226,021 (1) In March 2019, the Company completed a $300.0 million senior fixed-rate notes issuance. The fixed interest rate has been designated in a fair value hedging relationship and swapped to a weighted-average variable rate of 3.62% at September 30, 2019 . The $26.4 million basis adjustment included in the carrying value reflects the changes in the benchmark rate. (2) The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month London Interbank Offered Rate plus 2.95% , was 5.09% at September 30, 2019 and 5.74% at December 31, 2018 .

Leases Leases (Tables)

Leases Leases (Tables)	9 Months Ended
Leases Leases (Tables)	Sep. 30, 2019
Leases [Abstract]
Schedule of Components of Leveraged Lease Investments [Table Text Block]	The following table summarizes lessee information related to the Company’s operating ROU assets and lease liability: At September 30, 2019 (In thousands) Operating Leases Consolidated Balance Sheet Line Item Location ROU lease assets $ 161,730 Premises and equipment, net Lease liabilities 180,832 Accrued expenses and other liabilities
Lease, Cost [Table Text Block]	The components of operating lease cost and other related information are as follows: (In thousands) Three months ended September 30, 2019 Nine months ended September 30, 2019 Lease Cost: Operating lease costs $ 7,512 $ 22,384 Variable lease costs 1,292 3,613 Sublease income (142 ) (437 ) Total operating lease cost $ 8,662 $ 25,560 Other Information: Cash paid for amounts included in the measurement of lease liabilities $ 7,938 $ 23,349 Right-of-use assets obtained in exchange for new operating lease liabilities 9,983 22,917 Weighted-average remaining lease term, in years - operating leases at September 30, 2019 8.5 Weighted-average discount rate - operating leases at September 30, 2019 3.31 %
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	The undiscounted scheduled maturities reconciled to total operating lease liabilities are as follows: (In thousands) At September 30, 2019 Remainder of 2019 $ 5,379 2020 31,041 2021 30,075 2022 26,560 2023 23,656 Thereafter 94,332 Total operating lease liability payments 211,043 Less: Present value adjustment 30,211 Lease liabilities $ 180,832

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss, Net of Tax (Tables)	9 Months Ended
Accumulated Other Comprehensive Loss, Net of Tax (Tables)	Sep. 30, 2019
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Loss by Component	The following tables summarize the changes in accumulated other comprehensive loss (AOCL), net of tax by component: Three months ended September 30, 2019 Nine months ended September 30, 2019 (In thousands) Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Beginning balance $ (9,406 ) $ (8,931 ) $ (47,853 ) $ (66,190 ) $ (71,374 ) $ (9,313 ) $ (49,965 ) $ (130,652 ) OCI before reclassifications 24,304 2,216 — 26,520 86,272 507 — 86,779 Amounts reclassified from AOCL — 1,387 1,049 2,436 — 3,478 3,161 6,639 Net current-period OCI 24,304 3,603 1,049 28,956 86,272 3,985 3,161 93,418 Ending balance $ 14,898 $ (5,328 ) $ (46,804 ) $ (37,234 ) $ 14,898 $ (5,328 ) $ (46,804 ) $ (37,234 ) Three months ended September 30, 2018 Nine months ended September 30, 2018 (In thousands) Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Beginning balance $ (64,617 ) $ (10,814 ) $ (46,505 ) $ (121,936 ) $ (27,947 ) $ (15,016 ) $ (48,568 ) $ (91,531 ) (OCL)/OCI before reclassifications (13,811 ) 197 — (13,614 ) (50,481 ) 1,620 — (48,861 ) Amounts reclassified from AOCL — 1,438 2,548 3,986 — 4,217 4,611 8,828 Net current-period (OCL)/OCI (13,811 ) 1,635 2,548 (9,628 ) (50,481 ) 5,837 4,611 (40,033 ) Ending balance $ (78,428 ) $ (9,179 ) $ (43,957 ) $ (131,564 ) $ (78,428 ) $ (9,179 ) $ (43,957 ) $ (131,564 )
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 2019 2018 2019 2018 Derivative instruments: Hedge terminations $ (1,375 ) $ (1,932 ) $ (4,174 ) $ (5,664 ) Interest expense Premium amortization (515 ) — (527 ) — Interest income Tax benefit 503 494 1,223 1,447 Income tax expense Net of tax $ (1,387 ) $ (1,438 ) $ (3,478 ) $ (4,217 ) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (1,421 ) $ (3,431 ) $ (4,280 ) $ (6,209 ) (1) Tax benefit 372 883 1,119 1,598 Income tax expense Net of tax $ (1,049 ) $ (2,548 ) $ (3,161 ) $ (4,611 ) (1) These AOCL components are included in the computation of net periodic benefit cost, see Note 15: Retirement Benefit Plans for further details.

Regulatory Matters (Tables)

Regulatory Matters (Tables)	9 Months Ended
Regulatory Matters (Tables)	Sep. 30, 2019
Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]
Information On The Capital Ratios	The following table provides information on the capital ratios for Webster Financial Corporation and Webster Bank: At September 30, 2019 Actual Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,461,028 11.63 % $ 952,020 4.5 % $ 1,375,140 6.5 % Total risk-based capital 2,895,006 13.68 1,692,480 8.0 2,115,600 10.0 Tier 1 risk-based capital 2,606,065 12.32 1,269,360 6.0 1,692,480 8.0 Tier 1 leverage capital 2,606,065 8.99 1,158,906 4.0 1,448,632 5.0 Webster Bank CET1 risk-based capital $ 2,617,731 12.37 % $ 952,532 4.5 % $ 1,375,879 6.5 % Total risk-based capital 2,829,352 13.37 1,693,390 8.0 2,116,737 10.0 Tier 1 risk-based capital 2,617,731 12.37 1,270,042 6.0 1,693,390 8.0 Tier 1 leverage capital 2,617,731 9.04 1,158,512 4.0 1,448,140 5.0 At December 31, 2018 Actual Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,284,978 11.44 % $ 898,972 4.5 % $ 1,298,514 6.5 % Total risk-based capital 2,722,194 13.63 1,598,172 8.0 1,997,715 10.0 Tier 1 risk-based capital 2,430,015 12.16 1,198,629 6.0 1,598,172 8.0 Tier 1 leverage capital 2,430,015 9.02 1,077,303 4.0 1,346,628 5.0 Webster Bank CET1 risk-based capital $ 2,170,566 10.87 % $ 898,317 4.5 % $ 1,297,569 6.5 % Total risk-based capital 2,385,425 11.95 1,597,008 8.0 1,996,260 10.0 Tier 1 risk-based capital 2,170,566 10.87 1,197,756 6.0 1,597,008 8.0 Tier 1 leverage capital 2,170,566 8.06 1,076,712 4.0 1,345,889 5.0

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
Earnings Per Common Share (Tables)	Sep. 30, 2019
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) 2019 2018 2019 2018 Earnings for basic and diluted earnings per common share: Net income $ 93,865 $ 99,673 $ 292,250 $ 261,580 Less: Preferred stock dividends 1,968 1,968 5,906 5,884 Net income available to common shareholders 91,897 97,705 286,344 255,696 Less: Earnings applicable to participating restricted stock 455 245 1,425 656 Earnings applicable to common shareholders $ 91,442 $ 97,460 $ 284,919 $ 255,040 Shares: Weighted-average common shares outstanding - basic 91,559 91,959 91,554 91,912 Effect of dilutive securities 315 249 329 309 Weighted-average common shares outstanding - diluted 91,874 92,208 91,883 92,221 Earnings per common share: Basic $ 1.00 $ 1.06 $ 3.11 $ 2.77 Diluted 1.00 1.06 3.10 2.77

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
Derivative Financial Instruments (Tables)	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The following table presents the notional amounts and fair value of derivative positions: At September 30, 2019 At December 31, 2018 Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives (In thousands) Notional Fair Notional Fair Notional Fair Notional Fair Designated as hedging instruments: Interest rate derivatives (1) (2) $ 1,525,000 $ 19,209 $ — $ — $ 325,000 $ 3,050 $ — $ — Not designated as hedging instruments: Interest rate derivatives (1) 4,401,353 180,852 4,026,716 9,114 4,435,530 42,205 3,643,985 38,029 Mortgage banking derivatives (3) 61,367 506 74,000 184 13,599 226 17,000 293 Other (4) 107,022 776 151,219 762 85,432 797 140,601 688 Total not designated as hedging instruments 4,569,742 182,134 4,251,935 10,060 4,534,561 43,228 3,801,586 39,010 Gross derivative instruments, before netting $ 6,094,742 201,343 $ 4,251,935 10,060 $ 4,859,561 46,278 $ 3,801,586 39,010 Less: Master netting agreements 6,240 6,240 2,495 2,495 Cash collateral 13,299 2,506 4,936 — Total derivative instruments, after netting $ 181,804 $ 1,314 $ 38,847 $ 36,515 (1) Balances related to Chicago Mercantile Exchange (CME) are presented as a single unit of account. Notional amounts of interest rate swaps cleared through CME include $0.7 billion and $1.9 billion for asset derivatives and $2.8 billion and $1.1 billion for liability derivatives at September 30, 2019 and December 31, 2018 , respectively. The related fair values approximate zero . (2) The increase in the notional amount is due to $1.0 billion interest rate floors purchased as part of the Company's balance sheet repositioning strategy. (3) Notional amounts related to residential loan commitments include mandatory forward commitments of $74.0 million , while notional amounts do not include approved floating rate commitments of $11.0 million , at September 30, 2019 . (4) Other derivatives include foreign currency forward contracts related to lending arrangements and customer hedging activity, a Visa equity swap transaction, and risk participation agreements. Notional amounts of risk participation agreements include $65.0 million and $65.0 million for asset derivatives and $139.5 million and $96.3 million for liability derivatives at September 30, 2019 and December 31, 2018 , respectively, that have insignificant related fair values.
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table presents fair value positions transitioned from gross to net upon application of counterparty netting agreements: At September 30, 2019 (In thousands) Gross Amount Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 19,683 19,539 $ 144 $ (201 ) $ (57 ) Liability derivatives 8,816 8,746 70 (104 ) (34 ) At December 31, 2018 (In thousands) Gross Amount Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 9,928 $ 7,431 $ 2,497 $ (755 ) $ 1,742 Liability derivatives 2,566 2,495 71 — 71
Schedule of Net Investment Hedges, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table presents the change in fair value for derivatives designated as fair value hedges as well as the offsetting change in fair value on the hedged item and the income statement effect of derivatives designated as cash flow hedges: Recognized In Three months ended September 30, Nine months ended September 30, (In thousands) Net Interest Income 2019 2018 2019 2018 Fair value hedges: Recognized on derivatives Long-term debt $ 10,624 $ — $ 26,436 $ — Recognized on hedged items Long-term debt (10,624 ) — (26,436 ) — Net recognized on fair value hedges $ — $ — $ — $ — Cash flow hedges: Interest rate derivatives Long-term debt $ 1,095 $ 1,667 $ 3,028 $ 5,158 Interest rate derivatives Interest and fees on loans and leases 515 — 527 — Net recognized on cash flow hedges $ 1,610 $ 1,667 $ 3,555 $ 5,158
Other Derivatives Not Designated For Hedge Accounting	Additional information related to fair value hedges: Consolidated Balance Sheet Line Item in Which Hedged Item is Located Carrying Amount of Hedged Item Cumulative Amount of Fair Value Hedging Adjustment Included in Carrying Amount At September 30, At September 30, (In thousands) 2019 2018 2019 2018 Long-term debt $ 326,436 $ — $ 26,436 $ — The following table presents the effect on the income statement for derivatives not designated as hedging instruments: Recognized In Three months ended September 30, Nine months ended September 30, (In thousands) Non-interest Income 2019 2018 2019 2018 Interest rate derivatives Other income $ 784 $ 1,623 $ 5,906 $ 7,372 Mortgage banking derivatives Mortgage banking activities 347 (26 ) 96 (95 ) Other Other income 1,679 (204 ) 1,603 1,230 Total not designated as hedging instruments $ 2,810 $ 1,393 $ 7,605 $ 8,507

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
Fair Value Measurements (Tables)	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Option, Disclosures	The following table compares the fair value to unpaid principal balance of assets accounted for under the fair value option: At September 30, 2019 At December 31, 2018 (In thousands) Fair Value Unpaid Principal Balance Difference Fair Value Unpaid Principal Balance Difference Originated loans held for sale $ 27,061 $ 26,696 $ 365 $ 7,908 $ 8,227 $ (319 )
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, 2019 (In thousands) Level 1 Level 2 Level 3 NAV Total Financial assets held at fair value: U.S. Treasury Bills $ 19,924 $ — $ — $ — $ 19,924 Agency CMO — 200,956 — — 200,956 Agency MBS — 1,598,836 — — 1,598,836 Agency CMBS — 610,350 — — 610,350 CMBS — 403,918 — — 403,918 CLO — 94,805 — — 94,805 Corporate debt — 31,314 — — 31,314 Total available-for-sale investment securities 19,924 2,940,179 — — 2,960,103 Gross derivative instruments, before netting (1) 658 200,685 — — 201,343 Originated loans held for sale — 27,061 — — 27,061 Investments held in Rabbi Trust 4,673 — — — 4,673 Alternative investments — — — 3,217 3,217 Total financial assets held at fair value $ 25,255 $ 3,167,925 $ — $ 3,217 $ 3,196,397 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 491 $ 9,569 $ — $ — $ 10,060 At December 31, 2018 (In thousands) Level 1 Level 2 Level 3 NAV Total Financial assets held at fair value: U.S. Treasury Bills $ 7,550 $ — $ — $ — $ 7,550 Agency CMO — 234,923 — — 234,923 Agency MBS — 1,481,089 — — 1,481,089 Agency CMBS — 566,237 — — 566,237 CMBS — 445,581 — — 445,581 CLO — 112,771 — — 112,771 Corporate debt — 50,579 — — 50,579 Total available-for-sale investment securities 7,550 2,891,180 — — 2,898,730 Gross derivative instruments, before netting (1) 758 45,520 — — 46,278 Originated loans held for sale — 7,908 — — 7,908 Investments held in Rabbi Trust 4,307 — — — 4,307 Alternative investments — — — 2,563 2,563 Total financial assets held at fair value $ 12,615 $ 2,944,608 $ — $ 2,563 $ 2,959,786 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 588 $ 38,422 $ — $ — $ 39,010 (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 13: Derivative Financial Instruments .
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, 2019 At December 31, 2018 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Value Assets: Level 2 Held-to-maturity investment securities $ 5,193,521 $ 5,285,705 $ 4,325,420 $ 4,209,121 Level 3 Loans and leases, net 19,342,494 19,602,007 18,253,136 18,155,798 Mortgage servicing assets 17,877 34,025 21,215 45,478 Liabilities: Level 2 Deposit liabilities $ 20,025,100 $ 20,025,100 $ 18,662,299 $ 18,662,299 Time deposits 3,255,565 3,255,994 3,196,546 3,175,948 Securities sold under agreements to repurchase and other borrowings 1,210,692 1,207,411 581,874 581,874 FHLB advances 1,392,849 1,395,735 1,826,808 1,826,381 Long-term debt (1) 549,158 557,956 226,021 229,306 (1) Adjustments to the carrying amount of long-term debt for unamortized discount and debt issuance cost on senior fixed-rate notes are not included for determination of fair value, see Note 8: Borrowings .

Retirement Benefit Plans (Table

Retirement Benefit Plans (Tables)	9 Months Ended
Retirement Benefit Plans (Tables)	Sep. 30, 2019
Retirement Benefits [Abstract]
Summary of Net Periodic Benefit Cost	The following table summarizes the components of net periodic benefit cost: Three months ended September 30, 2019 2018 (In thousands) Pension Plan SERP Other Benefits Pension Plan SERP Other Benefits Interest cost on benefit obligations $ 2,001 $ 16 $ 22 $ 1,857 $ 35 $ 20 Expected return on plan assets (2,815 ) — — (3,178 ) — — Recognized net loss 1,420 4 (2 ) 1,160 2,271 — Net periodic benefit cost $ 606 $ 20 $ 20 $ (161 ) $ 2,306 $ 20 Nine months ended September 30, 2019 2018 (In thousands) Pension Plan SERP Other Benefits Pension Plan SERP Other Benefits Interest cost on benefit obligations $ 5,956 $ 48 $ 64 $ 5,577 $ 201 $ 59 Expected return on plan assets (8,445 ) — — (9,538 ) — — Recognized net loss 4,280 11 (10 ) 3,480 2,729 — Net periodic benefit cost $ 1,791 $ 59 $ 54 $ (481 ) $ 2,930 $ 59

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
Segment Reporting (Tables)	Sep. 30, 2019
Segment Reporting [Abstract]
Operating Results And Total Assets Reportable Segments	The following table presents total assets for Webster's reportable segments and the Corporate and Reconciling category: (In thousands) Commercial Banking HSA Bank Community Banking Corporate and Reconciling Consolidated Total At September 30, 2019 $ 11,174,036 $ 75,636 $ 9,228,537 $ 9,416,891 $ 29,895,100 At December 31, 2018 10,477,050 70,826 8,727,335 8,335,104 27,610,315 The following tables present the operating results for Webster’s reportable segments and the Corporate and Reconciling category: Three months ended September 30, 2019 (In thousands) Commercial Banking HSA Bank Community Banking Corporate and Reconciling Consolidated Total Net interest income (expense) $ 96,817 $ 42,206 $ 99,459 $ 2,057 $ 240,539 Non-interest income 13,987 23,526 28,115 4,303 69,931 Non-interest expense 45,261 32,918 99,835 1,880 179,894 Pre-tax, pre-provision net revenue 65,543 32,814 27,739 4,480 130,576 Provision for loan and lease losses 9,312 — 1,988 — 11,300 Income (loss) before income tax expense 56,231 32,814 25,751 4,480 119,276 Income tax expense (benefit) 13,828 8,531 5,128 (2,076 ) 25,411 Net income $ 42,403 $ 24,283 $ 20,623 $ 6,556 $ 93,865 Three months ended September 30, 2018 (In thousands) Commercial Banking HSA Community Banking Corporate and Reconciling Consolidated Total Net interest income (expense) $ 91,243 $ 36,731 $ 101,952 $ 446 $ 230,372 Non-interest income 18,305 22,159 26,848 4,972 72,284 Non-interest expense 44,506 30,753 95,769 7,755 178,783 Pre-tax, pre-provision net revenue 65,042 28,137 33,031 (2,337 ) 123,873 Provision for loan and lease losses 9,991 — 509 — 10,500 Income (loss) before income tax expense 55,051 28,137 32,522 (2,337 ) 113,373 Income tax expense (benefit) 13,542 7,316 6,472 (13,630 ) 13,700 Net income $ 41,509 $ 20,821 $ 26,050 $ 11,293 $ 99,673 Nine months ended September 30, 2019 (In thousands) Commercial Banking HSA Bank Community Banking Corporate and Reconciling Consolidated Total Net interest income (expense) $ 279,498 $ 126,573 $ 303,518 $ 14,288 $ 723,877 Non-interest income 42,643 74,082 81,172 16,499 214,396 Non-interest expense 136,075 100,693 291,076 8,376 536,220 Pre-tax, pre-provision net revenue 186,066 99,962 93,614 22,411 402,053 Provision for loan and lease losses 23,294 — 8,506 — 31,800 Income (loss) before income tax expense 162,772 99,962 85,108 22,411 370,253 Income tax expense (benefit) 40,037 25,990 16,940 (4,964 ) 78,003 Net income $ 122,735 $ 73,972 $ 68,168 $ 27,375 $ 292,250 Nine months ended September 30, 2018 (In thousands) Commercial Banking HSA Bank Community Banking Corporate and Reconciling Consolidated Total Net interest income (expense) $ 264,353 $ 104,920 $ 302,782 $ (2,505 ) $ 669,550 Non-interest income 48,662 67,710 78,421 14,612 209,405 Non-interest expense 128,730 93,488 287,795 20,844 530,857 Pre-tax, pre-provision net revenue 184,285 79,142 93,408 (8,737 ) 348,098 Provision for loan and lease losses 25,468 — 6,532 — 32,000 Income (loss) before income tax expense 158,817 79,142 86,876 (8,737 ) 316,098 Income tax expense (benefit) 39,069 20,577 17,288 (22,416 ) 54,518 Net income $ 119,748 $ 58,565 $ 69,588 $ 13,679 $ 261,580

Revenue from Contracts with C_2

Revenue from Contracts with Customers Disaggregation of Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue [Table Text Block]	The following tables present revenues within the scope of ASC 606, Revenue from Contracts with Customers and the net amount of other sources of non-interest income that is within the scope of other GAAP topics: Three months ended September 30, 2019 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income Deposit service fees $ 2,987 $ 22,264 $ 16,047 $ 112 $ 41,410 Wealth and investment services 2,650 — 5,855 (9 ) 8,496 Other — 1,262 650 — 1,912 Revenue from contracts with customers 5,637 23,526 22,552 103 51,818 Other sources of non-interest income 8,350 — 5,563 4,200 18,113 Total non-interest income $ 13,987 $ 23,526 $ 28,115 $ 4,303 $ 69,931 Three months ended September 30, 2018 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income Deposit service fees $ 3,211 $ 21,294 $ 16,107 $ (11 ) $ 40,601 Wealth and investment services 2,577 — 5,843 (8 ) 8,412 Other — 865 352 — 1,217 Revenue from contracts with customers 5,788 22,159 22,302 (19 ) 50,230 Other sources of non-interest income 12,517 — 4,546 4,991 22,054 Total non-interest income $ 18,305 $ 22,159 $ 26,848 $ 4,972 $ 72,284 Nine months ended September 30, 2019 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income Deposit service fees $ 9,108 $ 70,496 $ 47,701 $ 247 $ 127,552 Wealth and investment services 7,676 — 16,806 (26 ) 24,456 Other — 3,586 1,855 — 5,441 Revenue from contracts with customers 16,784 74,082 66,362 221 157,449 Other sources of non-interest income 25,859 — 14,810 16,278 56,947 Total non-interest income $ 42,643 $ 74,082 $ 81,172 $ 16,499 $ 214,396 Nine months ended September 30, 2018 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income Deposit service fees $ 9,613 $ 65,112 $ 47,079 $ 107 $ 121,911 Wealth and investment services 7,703 — 17,060 (25 ) 24,738 Other — 2,598 1,485 — 4,083 Revenue from contracts with customers 17,316 67,710 65,624 82 150,732 Other sources of non-interest income 31,346 — 12,797 14,530 58,673 Total non-interest income $ 48,662 $ 67,710 $ 78,421 $ 14,612 $ 209,405

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
Commitments and Contingencies (Tables)	Sep. 30, 2019
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 At December 31, 2018 Commitments to extend credit $ 5,894,781 $ 5,840,585 Standby letter of credit 194,430 189,040 Commercial letter of credit 21,609 21,181 Total credit-related financial instruments with off-balance sheet risk $ 6,110,820 $ 6,050,806
Reserve For Unfunded Credit Commitments	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) 2019 2018 2019 2018 Beginning balance $ 684 $ 674 $ 674 $ 872 Provision (benefit) charged to expense 19 18 1,839 (172 ) Repurchased loans and settlements charged off (7 ) (10 ) (1,817 ) (18 ) Ending balance $ 696 $ 682 $ 696 $ 682 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) 2019 2018 2019 2018 Beginning balance $ 2,537 $ 2,596 $ 2,506 $ 2,362 (Benefit) provision charged to expense (68 ) 28 (37 ) 262 Ending balance $ 2,469 $ 2,624 $ 2,469 $ 2,624

Summary of Significant Accoun_3

Summary of Significant Accounting Policies New Accounting Pronouncements or Change in Accounting Principle (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset	$ 161,730	$ 157,234	$ 0
Operating Lease, Liability	180,832	178,208	$ 0
ASU No. 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	$ 515
Operating Lease, Right-of-Use Asset		157,200
Operating Lease, Liability		$ 178,200

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, 2019	Dec. 31, 2018
Other Assets [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 43.5	$ 29.1
Accounts Payable and Accrued Liabilities [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	15.5	10.4
Other Investments [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	20.3	17.6
Unfunded Loan Commitment [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	$ 54.5	$ 31

Investment Securities (Summary

Investment Securities (Summary Of Investment Securities) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	$ 2,939,192	$ 2,994,616
Unrealized Gains	34,134	2,783
Unrealized Losses	(13,223)	(98,669)
Fair Value	2,960,103	2,898,730
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	5,193,521	4,325,420
Unrealized Gains	105,735	11,902
Unrealized Losses	(13,551)	(128,201)
Fair Value	5,285,705	4,209,121
US Treasury Bill Securities [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	19,918	7,549
Unrealized Gains	6	1
Unrealized Losses	0	0
Fair Value	19,924	7,550
Agency CMO [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	198,917	238,968
Unrealized Gains	2,704	412
Unrealized Losses	(665)	(4,457)
Fair Value	200,956	234,923
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	179,773	208,113
Unrealized Gains	1,430	287
Unrealized Losses	(680)	(5,255)
Fair Value	180,523	203,145
Agency MBS [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	1,573,984	1,521,534
Unrealized Gains	29,930	1,631
Unrealized Losses	(5,078)	(42,076)
Fair Value	1,598,836	1,481,089
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	3,085,000	2,517,823
Unrealized Gains	54,083	8,250
Unrealized Losses	(11,249)	(79,701)
Fair Value	3,127,834	2,446,372
Agency CMBS [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	611,925	608,167
Unrealized Gains	1,239	0
Unrealized Losses	(2,814)	(41,930)
Fair Value	610,350	566,237
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	950,217	667,500
Unrealized Gains	13,430	53
Unrealized Losses	(1,569)	(22,572)
Fair Value	962,078	644,981
Non-agency CMBS [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	403,782	447,897
Unrealized Gains	182	645
Unrealized Losses	(46)	(2,961)
Fair Value	403,918	445,581
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	235,687	216,943
Unrealized Gains	3,012	405
Unrealized Losses	(36)	(2,388)
Fair Value	238,663	214,960
CLO [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	95,099	114,641
Unrealized Gains	73	94
Unrealized Losses	(367)	(1,964)
Fair Value	94,805	112,771
Corporate debt securities [Member]
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	35,567	55,860
Unrealized Gains	0	0
Unrealized Losses	(4,253)	(5,281)
Fair Value	31,314	50,579
Municipal bonds and notes [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	742,844	715,041
Unrealized Gains	33,780	2,907
Unrealized Losses	(17)	(18,285)
Fair Value	$ 776,607	$ 699,663

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning Balance OTTI	$ 822	$ 1,103	$ 822	$ 1,364
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	0	(281)	0	(542)
Ending Balance OTTI	$ 822	$ 822	$ 822	$ 822

Investment Securities (Summar_2

Investment Securities (Summary Of Gross Unrealized Losses Not Considered OTTI) (Detail) $ in Thousands	Sep. 30, 2019USD ($)holding	Dec. 31, 2018USD ($)holding
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 141,685	$ 799,954
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1,275)	(8,602)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	968,616	1,756,617
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (11,948)	$ (90,067)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions \| holding	141	309
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 1,110,301	$ 2,556,571
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(13,223)	(98,669)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	375,714	382,558
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(2,864)	(3,069)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	921,412	3,257,871
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (10,687)	$ (125,132)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions \| holding	137	596
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	$ 1,297,126	$ 3,640,429
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	(13,551)	(128,201)
Agency CMO [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	18,109	15,524
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(146)	(72)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	35,751	180,641
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (519)	$ (4,385)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions \| holding	11	36
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 53,860	$ 196,165
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(665)	(4,457)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	15,744	691
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(40)	(1)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	58,852	182,396
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (640)	$ (5,254)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions \| holding	8	25
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	$ 74,596	$ 183,087
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	(680)	(5,255)
Agency MBS [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	47,966	321,678
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(33)	(2,078)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	419,082	975,084
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (5,045)	$ (39,998)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions \| holding	85	184
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 467,048	$ 1,296,762
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(5,078)	(42,076)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	183,181	288,635
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1,219)	(1,916)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	858,373	1,892,951
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (10,030)	$ (77,785)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions \| holding	119	272
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	$ 1,041,554	$ 2,181,586
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	(11,249)	(79,701)
Agency CMBS [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	461,840	566,237
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (2,814)	$ (41,930)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions \| holding	28	37
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 461,840	$ 566,237
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(2,814)	(41,930)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	127,662
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1,552)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	4,187	635,284
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (17)	$ (22,572)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions \| holding	6	56
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	$ 131,849	$ 635,284
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	(1,569)	(22,572)
Non-agency CMBS [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	49,418	343,457
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(35)	(2,937)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	3,489	5,193
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (11)	$ (24)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions \| holding	8	39
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 52,907	$ 348,650
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(46)	(2,961)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	46,610	24,881
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (36)	(270)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value		132,464
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		$ (2,118)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions \| holding	3	20
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	$ 46,610	$ 157,345
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	(36)	(2,388)
CLO [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	18,405	83,305
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(294)	(1,695)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	24,927	14,873
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (73)	$ (269)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions \| holding	2	5
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 43,332	$ 98,178
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(367)	(1,964)
Corporate Debt Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	7,787	35,990
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(767)	(1,820)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	23,527	14,589
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (3,486)	$ (3,461)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions \| holding	7	8
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 31,314	$ 50,579
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(4,253)	(5,281)
Municipal bonds and notes [Member]
Schedule of Investments [Line Items]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	2,517	68,351
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (17)	(882)
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value		414,776
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		$ (17,403)
Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions \| holding	1	223
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	$ 2,517	$ 483,127
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	$ (17)	$ (18,285)

Investment Securities (Summar_3

Investment Securities (Summary Of Debt Securities By Contractual Maturity) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Available-for-sale, Amortized Cost - Due in one year or less	$ 19,918
Available-for-sale, Amortized Cost - Due after one year through five years	17,000
Available-for-sale, Amortized Cost - Due after five through ten years	305,691
Available-for-sale, Amortized Cost - Due after ten years	2,596,583
Available-for-sale, Amortized Cost - Total debt securities	2,939,192	$ 2,994,616
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Available-for-sale, Fair Value - Due in one year or less	19,924
Available-for-sale, Fair Value - Due after one year through five years	17,000
Available-for-sale, Fair Value - Due after five through ten years	305,533
Available-for-sale, Fair Value - Due after ten years	2,617,646
Debt Securities, Available-for-sale	2,960,103	2,898,730
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Held-to-maturity, Amortized Cost - Due in one year or less	1,045
Held-to-maturity, Amortized Cost - Due after one year through five years	6,260
Held-to-maturity, Amortized Cost - Due after five through ten years	222,076
Held-to-maturity, Amortized Cost - Due after ten years	4,964,140
Amortized Cost	5,193,521	4,325,420
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Held to maturity, Fair Value - Due in one year or less	1,049
Held-to-maturity, Fair Value - Due after one year through five years	6,392
Held to maturity, Fair Value - Due after five through ten years	228,011
Held to maturity, Fair Value - Due after ten years	5,050,253
Fair Value	$ 5,285,705	$ 4,209,121

Investment Securities Investmen

Investment Securities Investment Securities (Narrative) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Abstract]
Unrealized Losses	$ (13,223)	$ (98,669)
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Unrealized Losses	(13,551)	(128,201)
Debt Securities, Available-for-sale	2,960,103	2,898,730
Pledged Financial Instruments, Not Separately Reported, Securities	3,000,000	2,200,000
Agency CMO [Member]
Debt Securities, Available-for-sale [Abstract]
Unrealized Losses	(665)	(4,457)
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Unrealized Losses	(680)	(5,255)
Debt Securities, Available-for-sale	200,956	234,923
Agency MBS [Member]
Debt Securities, Available-for-sale [Abstract]
Unrealized Losses	(5,078)	(42,076)
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Unrealized Losses	(11,249)	(79,701)
Debt Securities, Available-for-sale	1,598,836	1,481,089
Agency CMBS [Member]
Debt Securities, Available-for-sale [Abstract]
Unrealized Losses	(2,814)	(41,930)
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Unrealized Losses	(1,569)	(22,572)
Debt Securities, Available-for-sale	610,350	566,237
Non-agency CMBS [Member]
Debt Securities, Available-for-sale [Abstract]
Unrealized Losses	(46)	(2,961)
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Unrealized Losses	(36)	(2,388)
Debt Securities, Available-for-sale	403,918	445,581
CLO [Member]
Debt Securities, Available-for-sale [Abstract]
Unrealized Losses	(367)	(1,964)
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Debt Securities, Available-for-sale	94,805	112,771
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Abstract]
Unrealized Losses	(4,253)	(5,281)
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Debt Securities, Available-for-sale	31,314	50,579
Municipal Bonds [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Unrealized Losses	(17)	$ (18,285)
Callable at the option of the counterparty [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Debt Securities, Available-for-sale	$ 1,300,000

Investment Securities (Narrativ

Investment Securities (Narrative) (Summary Of Realized Gain (Loss) on Investments (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Gain (Loss) on Investments [Line Items]
Proceeds from Sale of Debt Securities, Available-for-sale	$ 0	$ 0

Loans and Leases (Narrative) (D

Loans and Leases (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Liability, Payments, Due	$ 211,043		$ 211,043
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	3,100	$ 4,300	8,900	$ 7,900
Write-down of TDR's	(11,000)	$ (1,100)	(16,700)	$ (6,300)
Finance Leases Portfolio Segment [Member]
Operating Leased Assets [Line Items]
Net Investment in Direct Financing and Sales Type Leases	164,200		164,200
Lessee, Operating Lease, Liability, Payments, Due	178,500		178,500
Sales-type and Direct Financing Leases, Interest Income	$ 1,200		$ 4,000

Loans and Leases (Detail)

Loans and Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 19,551,646	$ 18,465,489	$ 18,321,019
Unamortized premiums	13,900	13,900
Pledged Financial Instruments, Not Separately Reported, Loans Receivable Pledged as Collateral	7,600,000
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	6,488,056	6,216,606	6,174,396
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	5,398,084	4,927,145	4,771,325
Finance Leases Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	521,828	508,397	519,054
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	4,873,726	4,416,637	4,415,063
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 2,269,952	$ 2,396,704	$ 2,441,181

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, 2019	Dec. 31, 2018	Sep. 30, 2018
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	$ 198,562	$ 189,199
Financing Receivable, 90 Days or More Past Due, Still Accruing	92	104
Financing Receivable, Nonaccrual	162,899	154,767
Financing Receivable, Not Past Due	19,353,084	18,276,290
Loans and leases	19,551,646	18,465,489	$ 18,321,019
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	24,741	22,333
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	10,830	11,995
Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and leases	6,488,056	6,216,606	6,174,396
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	62,052	57,627
Financing Receivable, 90 Days or More Past Due, Still Accruing	92	104
Financing Receivable, Nonaccrual	58,750	55,810
Financing Receivable, Not Past Due	5,303,238	5,189,808
Loans and leases	5,365,290	5,247,435
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	2,760	1,011
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	450	702
Commercial Portfolio Segment [Member] \| Asset Based Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	9,162	224
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	9,162	224
Financing Receivable, Not Past Due	1,113,604	968,947
Loans and leases	1,122,766	969,171
Commercial Portfolio Segment [Member] \| Asset Based Loans [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Commercial Portfolio Segment [Member] \| Asset Based Loans [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and leases	5,398,084	4,927,145	4,771,325
Commercial Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	2,968	0
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	2,968	0
Financing Receivable, Not Past Due	295,860	218,831
Loans and leases	298,828	218,831
Commercial Real Estate Portfolio Segment [Member] \| Construction Loans [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Commercial Real Estate Portfolio Segment [Member] \| Construction Loans [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Commercial Real Estate Portfolio Segment [Member] \| Real Estate Loan [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	11,289	9,762
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	9,852	8,242
Financing Receivable, Not Past Due	5,087,967	4,698,552
Loans and leases	5,099,256	4,708,314
Commercial Real Estate Portfolio Segment [Member] \| Real Estate Loan [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,296	1,275
Commercial Real Estate Portfolio Segment [Member] \| Real Estate Loan [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	141	245
Finance Leases Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	7,679	7,229
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	5,488	6,314
Financing Receivable, Not Past Due	514,149	501,168
Loans and leases	521,828	508,397	519,054
Finance Leases Portfolio Segment [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,666	510
Finance Leases Portfolio Segment [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	525	405
Residential Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	57,318	62,002
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	43,839	49,188
Financing Receivable, Not Past Due	4,816,408	4,354,635
Loans and leases	4,873,726	4,416,637	4,415,063
Residential Portfolio Segment [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	6,752	8,513
Residential Portfolio Segment [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	6,727	4,301
Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Loans and leases	2,269,952	2,396,704	$ 2,441,181
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	42,934	48,130
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	31,452	33,495
Financing Receivable, Not Past Due	2,007,428	2,121,049
Loans and leases	2,050,362	2,169,179
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	9,192	9,250
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	2,290	5,385
Consumer Portfolio Segment [Member] \| Consumer Borrower [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	5,160	4,225
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	1,388	1,494
Financing Receivable, Not Past Due	214,430	223,300
Loans and leases	219,590	227,525
Consumer Portfolio Segment [Member] \| Consumer Borrower [Member] \| Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	3,075	1,774
Consumer Portfolio Segment [Member] \| Consumer Borrower [Member] \| Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	$ 697	$ 957

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 211,671	$ 207,322	$ 212,353	$ 199,994
Provision (benefit) charged to expense	11,300	10,500	31,800	32,000
Charge-offs	(15,960)	(8,535)	(43,376)	(27,543)
Recoveries	2,141	2,545	8,375	7,381
Balance, end of period	211,671	207,322	212,353	199,994	$ 209,152	$ 212,353	$ 211,832
ALLL, Individually evaluated for impairment					20,366		17,797
ALLL, Collectively evaluated for impairment					188,786		194,035
Loan and lease balances, Individually evaluated for impairment					270,631		266,017
Loan and lease balances, Collectively evaluated for impairment					19,281,015		18,055,002
Loans and leases					19,551,646	18,465,489	18,321,019
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	98,800	95,340	98,793	89,533
Provision (benefit) charged to expense	11,202	5,686	22,820	17,596
Charge-offs	(11,255)	(740)	(24,106)	(7,869)
Recoveries	124	431	1,364	1,457
Balance, end of period	98,800	95,340	98,793	89,533	98,871	98,793	100,717
ALLL, Individually evaluated for impairment					14,555		10,491
ALLL, Collectively evaluated for impairment					84,316		90,226
Loan and lease balances, Individually evaluated for impairment					117,418		104,353
Loan and lease balances, Collectively evaluated for impairment					6,370,638		6,070,043
Loans and leases					6,488,056	6,216,606	6,174,396
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	61,068	55,833	60,151	49,407
Provision (benefit) charged to expense	(423)	4,146	3,901	10,678
Charge-offs	(32)	(1,922)	(3,478)	(2,039)
Recoveries	3	143	42	154
Balance, end of period	61,068	55,833	60,151	49,407	60,616	60,151	58,200
ALLL, Individually evaluated for impairment					735		1,544
ALLL, Collectively evaluated for impairment					59,881		56,656
Loan and lease balances, Individually evaluated for impairment					16,224		9,767
Loan and lease balances, Collectively evaluated for impairment					5,381,860		4,761,558
Loans and leases					5,398,084	4,927,145	4,771,325
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	4,476	5,383	5,129	5,806
Provision (benefit) charged to expense	(176)	(213)	(208)	(557)
Charge-offs	(36)	(136)	(679)	(246)
Recoveries	49	11	71	42
Balance, end of period	4,476	5,383	5,129	5,806	4,313	5,129	5,045
ALLL, Individually evaluated for impairment					177		15
ALLL, Collectively evaluated for impairment					4,136		5,030
Loan and lease balances, Individually evaluated for impairment					5,487		6,489
Loan and lease balances, Collectively evaluated for impairment					516,341		512,565
Loans and leases					521,828	508,397	519,054
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	21,221	19,007	19,599	19,058
Provision (benefit) charged to expense	(689)	407	2,865	1,316
Charge-offs	(872)	(874)	(3,277)	(2,545)
Recoveries	356	133	829	844
Balance, end of period	21,221	19,007	19,599	19,058	20,016	19,599	18,673
ALLL, Individually evaluated for impairment					3,625		4,319
ALLL, Collectively evaluated for impairment					16,391		14,354
Loan and lease balances, Individually evaluated for impairment					95,666		105,600
Loan and lease balances, Collectively evaluated for impairment					4,778,060		4,309,463
Loans and leases					4,873,726	4,416,637	4,415,063
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	26,106	31,759	28,681	36,190
Provision (benefit) charged to expense	1,386	474	2,422	2,967
Charge-offs	(3,765)	(4,863)	(11,836)	(14,844)
Recoveries	1,609	1,827	6,069	4,884
Balance, end of period	$ 26,106	$ 31,759	$ 28,681	$ 36,190	25,336	28,681	29,197
ALLL, Individually evaluated for impairment					1,274		1,428
ALLL, Collectively evaluated for impairment					24,062		27,769
Loan and lease balances, Individually evaluated for impairment					35,836		39,808
Loan and lease balances, Collectively evaluated for impairment					2,234,116		2,401,373
Loans and leases					$ 2,269,952	$ 2,396,704	$ 2,441,181

Loans and Leases (Impaired Loan

Loans and Leases (Impaired Loans And Leases By Class) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	$ 356,500	$ 298,667
Total Recorded Investment	270,631	259,330
Recorded Investment No Allowance	147,095	166,270
Recorded Investment With Allowance	123,536	93,060
Related Valuation Allowance	20,366	15,350
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	148,932	120,165
Total Recorded Investment	108,256	99,287
Recorded Investment No Allowance	36,250	65,724
Recorded Investment With Allowance	72,006	33,563
Related Valuation Allowance	14,550	7,818
Commercial Portfolio Segment [Member] \| Asset Based Loans [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	9,490	550
Total Recorded Investment	9,162	225
Recorded Investment No Allowance	9,013	0
Recorded Investment With Allowance	149	225
Related Valuation Allowance	5	6
Commercial Real Estate Portfolio Segment [Member] \| Real Estate Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	19,270	13,355
Total Recorded Investment	13,256	10,828
Recorded Investment No Allowance	7,202	2,125
Recorded Investment With Allowance	6,054	8,703
Related Valuation Allowance	735	1,661
Commercial Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	2,969
Total Recorded Investment	2,968
Recorded Investment No Allowance	2,968
Recorded Investment With Allowance	0
Related Valuation Allowance	0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	5,540	6,368
Total Recorded Investment	5,487	6,315
Recorded Investment No Allowance	2,403	2,946
Recorded Investment With Allowance	3,084	3,369
Related Valuation Allowance	177	196
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	105,576	113,575
Total Recorded Investment	95,666	103,531
Recorded Investment No Allowance	61,236	64,899
Recorded Investment With Allowance	34,430	38,632
Related Valuation Allowance	3,625	4,286
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance		44,654
Total Recorded Investment		39,144
Recorded Investment No Allowance		30,576
Recorded Investment With Allowance		8,568
Related Valuation Allowance		$ 1,383
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	64,723
Total Recorded Investment	35,836
Recorded Investment No Allowance	28,023
Recorded Investment With Allowance	7,813
Related Valuation Allowance	$ 1,274

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 261,939	$ 261,612	$ 264,982	$ 256,386
Accrued Interest Income	1,920	2,133	6,194	6,261
Cash Basis Interest Income	517	539	1,584	1,557
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	102,996	94,618	103,772	87,603
Accrued Interest Income	751	847	2,515	2,257
Commercial Portfolio Segment [Member] \| Asset Based Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,673	1,095	4,694	809
Accrued Interest Income	0	0	0	0
Commercial Real Estate Portfolio Segment [Member] \| Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	13,567	11,222	12,042	10,497
Accrued Interest Income	60	30	194	164
Commercial Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	1,484	0	1,484	0
Accrued Interest Income			0	0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,718	6,337	5,901	4,907
Accrued Interest Income	0	41	0	112
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	97,917	107,618	99,599	109,948
Accrued Interest Income	862	923	2,682	2,852
Cash Basis Interest Income	271	301	817	819
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	36,584	40,722	37,490	42,622
Accrued Interest Income	247	292	803	876
Cash Basis Interest Income	$ 246	$ 238	$ 767	$ 738

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, 2019	Dec. 31, 2018	Sep. 30, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	$ 19,551,646	$ 18,465,489	$ 18,321,019
Commercial Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	6,488,056	6,216,606	6,174,396
Commercial Portfolio Segment [Member] \| (1) - (6) Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	6,122,391	5,781,138
Commercial Portfolio Segment [Member] \| (7) Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	97,969	206,351
Commercial Portfolio Segment [Member] \| (8) Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	263,833	222,405
Commercial Portfolio Segment [Member] \| (9) Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	3,863	6,712
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	5,398,084	4,927,145	4,771,325
Commercial Real Estate Portfolio Segment [Member] \| (1) - (6) Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	5,253,649	4,773,298
Commercial Real Estate Portfolio Segment [Member] \| (7) Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	81,256	75,338
Commercial Real Estate Portfolio Segment [Member] \| (8) Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	63,179	78,509
Commercial Real Estate Portfolio Segment [Member] \| (9) Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	0	0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	521,828	508,397	$ 519,054
Finance Leases Portfolio Segment [Member] \| (1) - (6) Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	512,219	494,585
Finance Leases Portfolio Segment [Member] \| (7) Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	915	1,303
Finance Leases Portfolio Segment [Member] \| (8) Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	8,694	12,509
Finance Leases Portfolio Segment [Member] \| (9) Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and leases	$ 0	$ 0

Loans and Leases (Summary Of Th

Loans and Leases (Summary Of The Recorded Investment Of Company's TDRs) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	$ 249,136		$ 230,414
Specific reserves for TDRs included in the balance of ALLL	209,152	$ 211,671	212,353	$ 211,832	$ 207,322	$ 199,994
Additional funds committed to borrowers in TDR status	3,621		3,893
Performing Financial Instruments [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	137,493		138,479
Nonperforming Financial Instruments [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	111,643		91,935
Nonperforming Financial Instruments [Member] \| Troubled Debt Restructures [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Specific reserves for TDRs included in the balance of ALLL	$ 20,015		$ 11,930

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, 2019USD ($)loan	Sep. 30, 2018USD ($)loan	Sep. 30, 2019USD ($)loan	Sep. 30, 2018USD ($)loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	28	37	105	101
Post-Modification Recorded Investment \| $	$ 34,249	$ 20,699	$ 76,335	$ 60,083
Commercial Portfolio Segment [Member] \| Contractual Interest Rate Reduction [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	1	0	2	0
Post-Modification Recorded Investment \| $	$ 12	$ 0	$ 112	$ 0
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member] \| Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	2	4	8	7
Post-Modification Recorded Investment \| $	$ 29	$ 537	$ 222	$ 622
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member] \| Maturity/Rate Combined [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	3	8	6	10
Post-Modification Recorded Investment \| $	$ 225	$ 8,185	$ 296	$ 8,236
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member] \| Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	6	8	25	17
Post-Modification Recorded Investment \| $	$ 30,586	$ 10,585	$ 64,642	$ 39,328
Commercial Real Estate Portfolio Segment [Member] \| Real Estate Loan [Member] \| Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	0	0	0	2
Post-Modification Recorded Investment \| $	$ 0	$ 0	$ 0	$ 97
Commercial Real Estate Portfolio Segment [Member] \| Real Estate Loan [Member] \| Maturity/Rate Combined [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	0	0	0	1
Post-Modification Recorded Investment \| $	$ 0	$ 0	$ 0	$ 245
Commercial Real Estate Portfolio Segment [Member] \| Real Estate Loan [Member] \| Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	1	0	3	1
Post-Modification Recorded Investment \| $	$ 2,180	$ 0	$ 4,816	$ 5,111
Residential Portfolio Segment [Member] \| Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	1	1	5	1
Post-Modification Recorded Investment \| $	$ 67	$ 20	$ 1,007	$ 20
Residential Portfolio Segment [Member] \| Maturity/Rate Combined [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	1	4	14	7
Post-Modification Recorded Investment \| $	$ 368	$ 440	$ 2,216	$ 716
Residential Portfolio Segment [Member] \| Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	2	3	6	16
Post-Modification Recorded Investment \| $	$ 243	$ 356	$ 785	$ 2,798
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member] \| Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	1	1	5	3
Post-Modification Recorded Investment \| $	$ 134	$ 148	$ 504	$ 341
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member] \| Maturity/Rate Combined [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	2	3	4	6
Post-Modification Recorded Investment \| $	$ 30	$ 170	$ 140	$ 618
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member] \| Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases \| loan	8	5	27	30
Post-Modification Recorded Investment \| $	$ 375	$ 258	$ 1,595	$ 1,951

Loans and Leases Loans and Leas

Loans and Leases Loans and Leases (Information on TDRs with subsequent default) (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)loan	Sep. 30, 2018USD ($)loan	Sep. 30, 2019USD ($)loan	Sep. 30, 2018USD ($)loan	Dec. 31, 2018USD ($)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment With Allowance	$ 123,536		$ 123,536		$ 93,060
Related Valuation Allowance	20,366		20,366		15,350
Unpaid Principal Balance	$ 356,500		$ 356,500		298,667
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| loan	5	1	5	2
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 4,018	$ 241	$ 4,018	$ 261
Impaired Financing Receivable, Recorded Investment	270,631		270,631		259,330
Recorded Investment No Allowance	147,095		147,095		166,270
Residential Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment With Allowance	34,430		34,430		38,632
Related Valuation Allowance	3,625		3,625		4,286
Unpaid Principal Balance	105,576		105,576		113,575
Impaired Financing Receivable, Recorded Investment	95,666		95,666		103,531
Recorded Investment No Allowance	$ 61,236		$ 61,236		64,899
Residential Portfolio Segment [Member] \| Real Estate Loan [Member] \| Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| loan	0	1	0	2
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 0	$ 241	$ 0	$ 261
Consumer Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment With Allowance					8,568
Related Valuation Allowance					1,383
Unpaid Principal Balance					44,654
Impaired Financing Receivable, Recorded Investment					39,144
Recorded Investment No Allowance					30,576
Consumer Portfolio Segment [Member] \| Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| loan				0
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment With Allowance	7,813		7,813
Related Valuation Allowance	1,274		1,274
Unpaid Principal Balance	64,723		64,723
Impaired Financing Receivable, Recorded Investment	35,836		35,836
Recorded Investment No Allowance	$ 28,023		$ 28,023
Consumer Portfolio Segment [Member] \| Home Equity Loan [Member] \| Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| loan	1	0	1	0
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 78	$ 0	$ 78	$ 0
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment With Allowance	72,006		72,006		33,563
Related Valuation Allowance	14,550		14,550		7,818
Unpaid Principal Balance	148,932		148,932		120,165
Impaired Financing Receivable, Recorded Investment	108,256		108,256		99,287
Recorded Investment No Allowance	$ 36,250		$ 36,250		65,724
Commercial Portfolio Segment [Member] \| Commercial and Industrial Sector [Member] \| Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts \| loan	4	0	4
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 3,940	$ 0	$ 3,940	$ 0
Commercial Real Estate Portfolio Segment [Member] \| Real Estate Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment With Allowance	6,054		6,054		8,703
Related Valuation Allowance	735		735		1,661
Unpaid Principal Balance	19,270		19,270		13,355
Impaired Financing Receivable, Recorded Investment	13,256		13,256		10,828
Recorded Investment No Allowance	7,202		7,202		$ 2,125
Commercial Real Estate Portfolio Segment [Member] \| Construction Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Recorded Investment With Allowance	0		0
Related Valuation Allowance	0		0
Unpaid Principal Balance	2,969		2,969
Impaired Financing Receivable, Recorded Investment	2,968		2,968
Recorded Investment No Allowance	$ 2,968		$ 2,968

Loans and Leases (Investments i

Loans and Leases (Investments in TDRs, Segregated by Risk Rating Exposure) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	$ 249,136	$ 230,414
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	117,633	87,739
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] \| (1) - (6) Pass [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	11,877	13,165
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] \| (7) Special Mention [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	68	84
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] \| (8) Substandard [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	101,825	67,880
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] \| (9) Doubtful [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	$ 3,863	$ 6,610

Transfers of Financial Assets_2

Transfers of Financial Assets (Reserve for loan repurchases) (Detail) - SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 684	$ 674	$ 674	$ 872
Provision (benefit) charged to expense	19	18	1,839	(172)
Repurchased loans and settlements charged off	(7)	(10)	(1,817)	(18)
Ending balance	$ 696	$ 682	$ 696	$ 682

Transfers of Financial Assets_3

Transfers of Financial Assets (Loans sold) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net gain on sale	$ 2,133	$ 1,305	$ 3,829	$ 3,684
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale	66,236	57,042	129,700	147,105
Net gain on sale	1,652	1,051	2,510	2,732
Ancillary Fee Income Generated by Servicing Financial Assets, Amount	470	463	1,051	1,275
Fair value option adjustment	11	(209)	268	(323)
Residential Mortgage [Member] \| Residential Mortgage Loans Servicing Retained [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale	$ 60,493	$ 51,104	$ 117,306	$ 130,740

Transfers of Financial Assets_4

Transfers of Financial Assets (Mortgage Servicing Assets) (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Retained servicing rights					$ 2,500,000
Proceeds from loans not originated for sale			$ 20,542	$ 674
Mortgage banking activities	$ 2,133	$ 1,305	3,829	3,684
Residential Mortgage [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Retained servicing rights	2,400,000		2,400,000
Contractually Specified Servicing Fees, Amount	500	300	1,400	900
Proceeds from loans not originated for sale			4,000
Mortgage banking activities	$ 1,652	$ 1,051	2,510	2,732
Commercial Loan [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds from loans not originated for sale			16,600	$ 674
Mortgage banking activities			$ 615

Transfers of Financial Assets S

Transfers of Financial Assets Servicing Assets at Amortized Cost Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Beginning Balance	$ 18,712	$ 23,341	$ 21,215	$ 25,139
Additions	966	1,428	2,219	3,878
Amortization	(1,801)	(2,125)	(5,557)	(6,373)
Ending Balance	$ 17,877	$ 22,644	$ 17,877	$ 22,644

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Gross Carrying Value And Accumulated Amortization Of Other Intangible Assets) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 43,000	$ 43,000
Accumulated Amortization	(20,121)	(17,236)
Net Carrying Amount	22,879	25,764
Core Deposits [Member] \| HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	22,000	22,000
Accumulated Amortization	(12,515)	(10,842)
Net Carrying Amount	9,485	11,158
Customer Relationships [Member] \| HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	21,000	21,000
Accumulated Amortization	(7,606)	(6,394)
Net Carrying Amount	$ 13,394	$ 14,606

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Schedule Of Expected Future Amortization Expense) (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2019	$ 961
2020	3,847
2021	3,847
2022	3,847
2023	3,847
Thereafter	$ 6,530

Deposits (Summary Of Deposits)

Deposits (Summary Of Deposits) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Non-interest-bearing:
Demand	$ 4,291,659	$ 4,162,446
Interest-bearing:
HSA	6,288,218	5,740,601
Checking	2,619,452	2,518,472
Money market	2,560,918	2,100,084
Savings	4,264,853	4,140,696
Time deposits	3,255,565	3,196,546
Total interest-bearing	18,989,006	17,696,399
Total deposits	23,280,665	21,858,845
Time deposits and interest-bearing checking, included in above balances, obtained through brokers	671,595	869,003
Time deposits, included in above balance, that exceed the FDIC limit	531,103	555,949
Deposit overdrafts reclassified as loan balances	$ 2,244	$ 2,245

Deposits (Scheduled Maturities

Deposits (Scheduled Maturities Of Time Deposits) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Banking and Thrift [Abstract]
Remainder of 2019	$ 1,003,978
2020	1,803,664
2021	330,610
2022	70,868
2023	28,889
Thereafter	17,556
Total time deposits	$ 3,255,565	$ 3,196,546

Borrowings Borrowings - (Narrat

Borrowings Borrowings - (Narrative) (Details) - USD ($) $ in Billions	Sep. 30, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Total borrowings	$ 3.2	$ 2.6

Borrowings (Summary Of Securiti

Borrowings (Summary Of Securities Sold Under Agreements To Repurchase And Other Borrowings) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under agreements to repurchase	$ 390,692	$ 236,874
Fed funds purchased	820,000	345,000
Securities sold under agreements to repurchase and other borrowings	$ 1,210,692	$ 581,874
Securities Sold under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.01%	0.35%
Federal Funds Purchased [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.91%	2.52%
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.62%	1.64%
Original maturity of one year or less [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under agreements to repurchase	$ 190,692	$ 236,874
Original maturity of one year or less [Member] \| Securities Sold under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.42%	0.35%
Original maturity of greater than one year, non-callable [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities sold under agreements to repurchase	$ 200,000	$ 0
Original maturity of greater than one year, non-callable [Member] \| Securities Sold under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.57%	0.00%

Borrowings Borrowings (Summary

Borrowings Borrowings (Summary Of Advances Payable To the Federal Home Loan Bank) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Federal Home Loan Bank, Advances, Maturity, Rolling Year [Abstract]
FHLB advances maturing within 1 year, Total Outstanding	$ 1,109,295	$ 1,403,026
FHLB advances maturing after 1 but within 2 years, Total Outstanding	75,000	215,000
FHLB advances maturing after 2 but within 3 years, Total Outstanding	150,036	200,000
FHLB advances maturing after 3 but within 4 years, Total Outstanding	181	150
FHLB advances maturing after 4 but within 5 years, Total Outstanding	50,150	242
FHLB advances maturing after 5 years, Total Outstanding	8,187	8,390
Federal Home Loan Bank, Advances	$ 1,392,849	$ 1,826,808
Federal Home Loan Bank, Advances, Weighted Average Interest Rate [Abstract]
FHLB advances maturing within 1 year, Weighted Average Contractual Coupon Rate (as a percent)	2.07%	2.55%
FHLB advances maturing after 1 but within 2 years, Weighted Average Contractual Coupon Rate (as a percent)	1.51%	1.73%
FHLB advances maturing after 2 but within 3 years, Weighted Average Contractual Coupon Rate (as a percent)	3.03%	3.16%
FHLB advances maturing after 3 but within 4 years, Weighted Average Contractual Coupon Rate (as a percent)	1.71%	0.00%
FHLB advances maturing after 4 but within 5 years, Weighted Average Contractual Coupon Rate (as a percent)	1.59%	2.95%
FHLB advances maturing after 5 years, Weighted Average Contractual Coupon Rate (as a percent)	2.65%	2.65%
Federal Home Loan Bank, Advances, Weighted Average Contractual Coupon Rate (as a percent)	2.13%	2.52%
Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Home Loan Bank Debt	$ 7,208,616	$ 6,689,761
Remaining borrowing capacity	$ 3,393,626	$ 2,568,664

Borrowings (Long Term Debt) (De

Borrowings (Long Term Debt) (Details) - USD ($)		9 Months Ended
Borrowings (Long Term Debt) (Details) - USD ($)		Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Notes and subordinated debt		$ 553,756,000	$ 227,320,000
Long-term Debt, Weighted Average Interest Rate, over Time		3.62%
Debt issuance cost on senior fixed-rates		$ (3,131,000)	(691,000)
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)		0
Long-term debt		$ 549,158,000	$ 226,021,000
Variable interest rate		5.09%	5.74%
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		$ (1,467,000)	$ (608,000)
4.375% Senior fixed-rate notes due February 15, 2024 [Member]
Debt Instrument [Line Items]
Notes and subordinated debt		300,000,000
Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	[1]	$ 77,320,000	77,320,000
Debt Instrument, Redemption, Period One [Member] \| 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
Debt Instrument, Redemption, Period Two [Member] \| 4.375% Senior fixed-rate notes due February 15, 2024 [Member]
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)		4.10%
Notes and subordinated debt		$ 326,436,000	$ 0
Long-term Debt [Member]
Debt Instrument [Line Items]
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)		$ 26,436,000

[1]	The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month London Interbank Offered Rate plus 2.95% , was 5.09% at September 30, 2019 and 5.74% at December 31, 2018

Leases Lessee Accounting (Detai

Leases Lessee Accounting (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Sep. 30, 2018
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 161,730	$ 157,234	$ 0
Operating Lease, Liability	$ 180,832	$ 178,208	$ 0

Leases Lease Cost (Details)

Leases Lease Cost (Details) $ in Thousands	3 Months Ended	9 Months Ended
Leases Lease Cost (Details) $ in Thousands	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Lease, Cost [Abstract]
Operating Lease, Cost	$ 7,512	$ 22,384
Variable Lease, Cost	1,292	3,613
Sublease Income	(142)	(437)
Lease, Cost	8,662	25,560
Operating Lease, Payments	7,938	23,349
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 9,983	$ 22,917
Operating Lease, Weighted Average Remaining Lease Term	8 years 6 months	8 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	3.31%	3.31%

Leases Operating Lease Liabilit

Leases Operating Lease Liabilities, Payments, Due, Rolling Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Sep. 30, 2018
Lessee, Operating Lease, Liability, Payment, Due, Rolling Maturity [Abstract]
Lessee, Operating Lease, Liability, Payments, Due Next Rolling Twelve Months	$ 5,379
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Two	31,041
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Three	30,075
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Four	26,560
Lessee, Operating Lease, Liability, Payments, Due in Rolling Year Five	23,656
Lessee, Operating Lease, Liability, Payments, Due after Rolling Year Five	94,332
Lessee, Operating Lease, Liability, Payments, Due	211,043
Operating Lease, Liability	180,832	$ 178,208	$ 0
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	$ 30,211

Leases Leases (Details)

Leases Leases (Details)	Sep. 30, 2019
Minimum [Member]
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Term of Contract	5 years
Maximum [Member]
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Term of Contract	20 years

Accumulated Other Comprehensi_3

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 3,065,217	$ 2,761,723	$ 2,886,515	$ 2,701,958
Other comprehensive income (loss), net of tax	28,956	(9,628)	93,418	(40,033)
Ending Balance	3,152,394	2,816,198	3,152,394	2,816,198
Available For Sale and Transferred Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(9,406)	(64,617)	(71,374)	(27,947)
OCI before reclassifications	24,304	(13,811)	86,272	(50,481)
Amounts reclassified from AOCL	0	0	0	0
Other comprehensive income (loss), net of tax	24,304	(13,811)	86,272	(50,481)
Ending Balance	14,898	(78,428)	14,898	(78,428)
Derivative Instruments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(8,931)	(10,814)	(9,313)	(15,016)
OCI before reclassifications	2,216	197	507	1,620
Amounts reclassified from AOCL	1,387	1,438	3,478	4,217
Other comprehensive income (loss), net of tax	3,603	1,635	3,985	5,837
Ending Balance	(5,328)	(9,179)	(5,328)	(9,179)
Defined Benefit Pension and Other Postretirement Benefit Plans [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(47,853)	(46,505)	(49,965)	(48,568)
OCI before reclassifications	0	0	0	0
Amounts reclassified from AOCL	1,049	2,548	3,161	4,611
Other comprehensive income (loss), net of tax	1,049	2,548	3,161	4,611
Ending Balance	(46,804)	(43,957)	(46,804)	(43,957)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(66,190)	(121,936)	(130,652)	(91,531)
OCI before reclassifications	26,520	(13,614)	86,779	(48,861)
Amounts reclassified from AOCL	2,436	3,986	6,639	8,828
Other comprehensive income (loss), net of tax	28,956	(9,628)	93,418	(40,033)
Ending Balance	$ (37,234)	$ (131,564)	$ (37,234)	$ (131,564)

Accumulated Other Comprehensi_4

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	$ (25,411)	$ (13,700)	$ (78,003)	$ (54,518)
Earnings applicable to common shareholders	91,442	97,460	284,919	255,040
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	0	0	0	0
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	(1,387)	(1,438)	(3,478)	(4,217)
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]
Other Nonoperating Expense	(1,375)	(1,932)	(4,174)	(5,664)
Interest Income, Other	(515)	0	(527)	0
Income tax expense	503	494	1,223	1,447
Earnings applicable to common shareholders	(1,387)	(1,438)	(3,478)	(4,217)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(1,421)	(3,431)	(4,280)	(6,209)
Defined benefit pension and postretirement benefit plans [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	372	883	1,119	1,598
Net of tax	$ (1,049)	$ (2,548)	$ (3,161)	$ (4,611)

Regulatory Matters (Information

Regulatory Matters (Information On The Capital Ratios) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital	$ 2,461,028		$ 2,284,978
Common Equity Tier One Capital Ratio	11.63%		11.44%
Common Equity Tier One Capital Required for Capital Adequacy	$ 952,020		$ 898,972
Common Equity Tier One Capital Required to be Well-Capitalized	1,375,140		1,298,514
Total risk-based capital, Actual Amount	$ 2,895,006		$ 2,722,194
Total risk-based capital, Actual Ratio	13.68%		13.63%
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,692,480		$ 1,598,172
Total risk-based capital, Capital Requirements, Minimum Ratio	8.00%		8.00%
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 2,115,600		$ 1,997,715
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	10.00%		10.00%
Tier 1 capital, Actual Amount	$ 2,606,065		$ 2,430,015
Tier 1 capital, Actual Ratio	12.32%		12.16%
Tier 1 capital, Capital Requirements, Minimum Amount	$ 1,269,360		$ 1,198,629
Tier 1 capital, Capital Requirements, Minimum Ratio	6.00%		6.00%
Tier 1 capital, Capital Requirements, Well Capitalized Amount	$ 1,692,480		$ 1,598,172
Tier 1 capital, Capital Requirements, Well Capitalized Ratio	8.00%		8.00%
Tier 1 leverage capital ratio, Actual Amount	$ 2,606,065		$ 2,430,015
Tier 1 leverage capital ratio, Actual Ratio	8.99%		9.02%
Tier 1 leverage capital ratio, Capital Requirements, Minimum Amount	$ 1,158,906		$ 1,077,303
Tier 1 leverage capital ratio, Capital Requirements, Minimum Ratio	4.00%		4.00%
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Amount	$ 1,448,632		$ 1,346,628
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Ratio	5.00%		5.00%
Dividends paid	$ 170,000	$ 220,000
Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital	$ 2,617,731		$ 2,170,566
Common Equity Tier One Capital Ratio	12.37%		10.87%
Common Equity Tier One Capital Required for Capital Adequacy	$ 952,532		$ 898,317
Common Equity Tier One Capital Required to be Well-Capitalized	1,375,879		1,297,569
Total risk-based capital, Actual Amount	$ 2,829,352		$ 2,385,425
Total risk-based capital, Actual Ratio	13.37%		11.95%
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,693,390		$ 1,597,008
Total risk-based capital, Capital Requirements, Minimum Ratio	8.00%		8.00%
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 2,116,737		$ 1,996,260
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	10.00%		10.00%
Tier 1 capital, Actual Amount	$ 2,617,731		$ 2,170,566
Tier 1 capital, Actual Ratio	12.37%		10.87%
Tier 1 capital, Capital Requirements, Minimum Amount	$ 1,270,042		$ 1,197,756
Tier 1 capital, Capital Requirements, Minimum Ratio	6.00%		6.00%
Tier 1 capital, Capital Requirements, Well Capitalized Amount	$ 1,693,390		$ 1,597,008
Tier 1 capital, Capital Requirements, Well Capitalized Ratio	8.00%		8.00%
Tier 1 leverage capital ratio, Actual Amount	$ 2,617,731		$ 2,170,566
Tier 1 leverage capital ratio, Actual Ratio	9.04%		8.06%
Tier 1 leverage capital ratio, Capital Requirements, Minimum Amount	$ 1,158,512		$ 1,076,712
Tier 1 leverage capital ratio, Capital Requirements, Minimum Ratio	4.00%		4.00%
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Amount	$ 1,448,140		$ 1,345,889
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Ratio	5.00%		5.00%
Cash Pass-through Reserve, Federal Home Loan Bank	$ 93,200		$ 81,200
Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	4.50%		4.50%
Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets [Member] \| Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	4.50%		4.50%
Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	6.50%		6.50%
Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets [Member] \| Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	6.50%		6.50%

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings for basic and diluted earnings per common share:
Net income	$ 93,865	$ 99,673	$ 292,250	$ 261,580
Less: Preferred stock dividends	1,968	1,968	5,906	5,884
Undistributed Earnings, Basic	91,897	97,705	286,344	255,696
Net income available to common shareholders	91,897	97,705	286,344	255,696
Less: Earnings applicable to participating restricted stock	455	245	1,425	656
Less: Earnings applicable to participating securities	455	245	1,425	656
Earnings applicable to common shareholders	91,442	97,460	284,919	255,040
Earnings applicable to common shareholders	$ 91,442	$ 97,460	$ 284,919	$ 255,040
Shares:
Weighted average common shares outstanding - basic (in shares)	91,559	91,959	91,554	91,912
Stock options and restricted stock (in shares)	315	249	329	309
Weighted-average common shares outstanding - diluted (in shares)	91,874	92,208	91,883	92,221
Earnings per common share:
Basic (in dollars per share)	$ 1	$ 1.06	$ 3.11	$ 2.77
Diluted (in dollars per share)	$ 1	$ 1.06	$ 3.10	$ 2.77

Earnings Per Common Share Sched

Earnings Per Common Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share Narrative (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
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	44	97	69	54

Derivative Financial Instrume_3

Derivative Financial Instruments (Schedule fair value of derivative instruments) (Detail) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	$ 6,094,742,000	$ 4,859,561,000
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	201,343,000	46,278,000
Derivative Asset, Fair Value, Amount Offset Against Collateral	6,240,000	2,495,000
Asset Derivatives, Fair Value, Less: Cash collateral posted	13,299,000	4,936,000
Derivative Asset	181,804,000	38,847,000
Liability Derivatives, Notional Amount	4,251,935,000	3,801,586,000
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	10,060,000	39,010,000
Derivative Liability, Fair Value, Amount Offset Against Collateral	6,240,000	2,495,000
Liability Derivatives, Fair Value, Less: Cash collateral posted	2,506,000	0
Derivative liability	1,314,000	36,515,000
CME [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value, Less: Cash collateral posted	57,800,000
Derivative Asset	0
Interest Rate Floor [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	1,000,000,000
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	19,683,000	9,928,000
Derivative Asset, Fair Value, Amount Offset Against Collateral	19,539,000	7,431,000
Derivative Asset	144,000	2,497,000
Derivative Liability, Fair Value, Gross Liability	8,816,000	2,566,000
Derivative Liability, Fair Value, Amount Offset Against Collateral	8,746,000	2,495,000
Derivative liability	70,000	71,000
Designated as Hedging Instrument [Member] \| CME [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value, Less: Cash collateral posted	13,300,000
Designated as Hedging Instrument [Member] \| Interest rate derivatives [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	1,525,000,000	325,000,000
Derivative Asset, Fair Value, Gross Asset	19,209,000	3,050,000
Liability Derivatives, Notional Amount	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	4,569,742,000	4,534,561,000
Asset Derivatives, Fair Value, Positions not subject to master netting agreement	182,134,000	43,228,000
Liability Derivatives, Notional Amount	4,251,935,000	3,801,586,000
Liability Derivatives, Fair Value, Positions not subject to master netting agreement	10,060,000	39,010,000
Not Designated as Hedging Instrument [Member] \| Interest Rate Swap, CME [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	700,000,000	1,900,000,000
Liability Derivatives, Notional Amount	2,800,000,000	1,100,000,000
Not Designated as Hedging Instrument [Member] \| Interest rate derivatives [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	4,401,353,000	4,435,530,000
Derivative Asset, Fair Value, Gross Asset	180,852,000	42,205,000
Liability Derivatives, Notional Amount	4,026,716,000	3,643,985,000
Derivative Liability, Fair Value, Gross Liability	9,114,000	38,029,000
Not Designated as Hedging Instrument [Member] \| Credit Risk Contract [Member] \| RPA-Out [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	65,000,000	65,000,000
Not Designated as Hedging Instrument [Member] \| Credit Risk Contract [Member] \| RPA-In [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Notional Amount	139,500,000	96,300,000
Not Designated as Hedging Instrument [Member] \| Mortgage Banking Derivatives [Member] \| RPA-Out [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	61,367,000	13,599,000
Derivative Asset, Fair Value, Gross Asset	506,000	226,000
Not Designated as Hedging Instrument [Member] \| Mortgage Banking Derivatives [Member] \| RPA-In [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Notional Amount	74,000,000	17,000,000
Derivative Liability, Fair Value, Gross Liability	184,000	293,000
Not Designated as Hedging Instrument [Member] \| Other Contract [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	107,022,000	85,432,000
Derivative Asset, Fair Value, Gross Asset	776,000	797,000
Liability Derivatives, Notional Amount	151,219,000	140,601,000
Derivative Liability, Fair Value, Gross Liability	762,000	$ 688,000
Loan Origination Commitments [Member]
Derivatives, Fair Value [Line Items]
Other Commitment	74,000,000
Interest Rate Lock Commitments [Member]
Derivatives, Fair Value [Line Items]
Other Commitment	$ 11,000,000

Derivative Financial Instrume_4

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 2,810	$ 1,393		$ 8,507
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings			$ 7,605
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	784	1,623	5,906	7,372
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	347	(26)	96	(95)
Other Contract [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	1,679	(204)	1,603	1,230
Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	0	0	0	0
Fair Value Hedging [Member] \| Operating Expense [Member] \| Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(10,624)	0	(26,436)	0
Cash Flow Hedging [Member] \| Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	1,610	1,667	3,555	5,158
Cash Flow Hedging [Member] \| 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	1,095	1,667	3,028	5,158
Cash Flow Hedging [Member] \| Interest Rate Derivatives [Member] \| Other Income [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	515	0	527	0
Long-term Debt [Member] \| Fair Value Hedging [Member] \| Operating Expense [Member] \| Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 10,624	$ 0	$ 26,436	$ 0

Derivative Financial Instrume_5

Derivative Financial Instruments (AOCI Related to Cash Flow Hedges) (Narrative) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Loss from Components Excluded from Assessment of Fair Value Hedge Effectiveness	$ 13.5
Gain (Loss) on Components Excluded from Assessment of Interest Rate Cash Flow Hedge Effectiveness	12.9
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Estimate of amount to be reclassified from AOCL	(2.7)
Remaining unamortized gain (loss) on termination of cash flow hedges	(5.8)
Cash Flow Hedging [Member] \| Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Estimate of amount to be reclassified from AOCL	$ 4.4

Derivative Financial Instrume_6

Derivative Financial Instruments (Offsetting Derivatives) (Detail) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative instrument asset, Amount Offset, Total	$ (6,240,000)	$ (2,495,000)
Derivative instrument asset, Amount Offset	13,299,000	4,936,000
Derivative Asset	181,804,000	38,847,000
Derivative Liability, Fair Value, Amount Offset Against Collateral	6,240,000	2,495,000
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	(2,506,000)	0
Derivative liability	1,314,000	36,515,000
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	(201,000)	(755,000)
Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	(57,000)	(1,742,000)
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	(104,000)	0
Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	(34,000)	(71,000)
Hedge Accounting Positions [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	19,683,000	9,928,000
Derivative instrument asset, Amount Offset, Total	(19,539,000)	(7,431,000)
Derivative Asset	144,000	2,497,000
Derivative Liability, Fair Value, Gross Liability	8,816,000	2,566,000
Derivative Liability, Fair Value, Amount Offset Against Collateral	8,746,000	2,495,000
Derivative liability	70,000	71,000
CME [Member]
Derivative [Line Items]
Derivative instrument asset, Amount Offset	57,800,000
Derivative Asset	0
CME [Member] \| Hedge Accounting Positions [Member]
Derivative [Line Items]
Derivative instrument asset, Amount Offset	13,300,000
Interest Rate Derivatives [Member] \| Hedge Accounting Positions [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	19,209,000	3,050,000
Derivative Liability, Fair Value, Gross Liability	$ 0	$ 0

Derivative Financial Instrume_7

Derivative Financial Instruments Impact of Fair Value on Qualifying Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 2,810	$ 1,393		$ 8,507
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	0		$ 0
Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	0	0	0	0
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	1,610	1,667	3,555	5,158
Operating Expense [Member] \| Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(10,624)	0	(26,436)	0
Long-term Debt [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Liability, Fair Value Hedge	326,436		326,436		$ 0
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	26,436		26,436
Long-term Debt [Member] \| Operating Expense [Member] \| Designated as Hedging Instrument [Member] \| Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 10,624	$ 0	$ 26,436	$ 0

Derivative Financial Instrume_8

Derivative Financial Instruments (Counterparty Credit Risk Narrative) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Maximum Length of Time Hedged in Cash Flow Hedge	10 years
Derivative instrument asset, Amount Offset	$ 13,299	$ 4,936
Derivative, Collateral, Right to Reclaim Cash	160,400
Credit Derivative, Maximum Exposure, Undiscounted	180,500
Valuation, Market Approach [Member]
Derivative [Line Items]
Credit Derivative, Maximum Exposure, Undiscounted	36,500
CME [Member]
Derivative [Line Items]
Derivative instrument asset, Amount Offset	57,800
Derivative, Collateral, Right to Reclaim Cash	$ 113,500

Derivative Financial Instrume_9

Derivative Financial Instruments Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative Asset, Fair Value, Amount Offset Against Collateral	$ 6,240	$ 2,495
Derivative Asset	181,804	38,847
Derivative Liability, Fair Value, Amount Offset Against Collateral	6,240	2,495
Derivative Liability	1,314	36,515
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	201	755
Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	57	1,742
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	104	0
Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	34	71
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	8,816	2,566
Derivative Asset, Fair Value, Gross Asset	19,683	9,928
Derivative Asset, Fair Value, Amount Offset Against Collateral	19,539	7,431
Derivative Asset	144	2,497
Derivative Liability, Fair Value, Amount Offset Against Collateral	8,746	2,495
Derivative Liability	$ 70	$ 71

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 6,110,820	$ 6,050,806
Fair Value, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Book value of other real estate owned (OREO) and repossessed assets	4,000
Rabbi Trust [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	1,700
Alternative investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total credit-related financial instruments with off-balance sheet risk	25,000
Alternative investments [Member] \| Fair Value, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	$ 6,900

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Assets And Liabilities Measured On Recurring and Nonrecurring Basis) (Detail) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Financial assets held at fair value:
Debt Securities, Available-for-sale		$ 2,960,103	$ 2,898,730
Derivative Asset		181,804	38,847
Loans Held-for-sale, Fair Value Disclosure		27,061	7,908
Financial liabilities held at fair value:
Derivative liability		1,314	36,515
US Treasury Bill Securities [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		19,924	7,550
Agency CMO [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		200,956	234,923
Agency MBS [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		1,598,836	1,481,089
Agency CMBS [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		610,350	566,237
Non-agency CMBS [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		403,918	445,581
CLO [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		94,805	112,771
Corporate debt securities [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		31,314	50,579
Fair Value, Recurring [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		2,960,103	2,898,730
Alternative Investment		3,217	2,563
Total financial assets held at fair value		3,196,397	2,959,786
Financial liabilities held at fair value:
Derivative liability	[1]	10,060	39,010
Fair Value, Recurring [Member] \| Quoted Prices in Active Markets For Identical Assets (Level 1) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		19,924	7,550
Alternative Investment		0	0
Total financial assets held at fair value		25,255	12,615
Financial liabilities held at fair value:
Derivative liability	[1]	491	588
Fair Value, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		2,940,179	2,891,180
Alternative Investment		0	0
Total financial assets held at fair value		3,167,925	2,944,608
Financial liabilities held at fair value:
Derivative liability	[1]	9,569	38,422
Fair Value, Recurring [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Financial assets held at fair value:
Alternative Investment		3,217	2,563
Total financial assets held at fair value		3,217	2,563
Financial liabilities held at fair value:
Derivative liability			0
Fair Value, Recurring [Member] \| Derivative instruments [Member]
Financial assets held at fair value:
Derivative Asset	[1]	201,343	46,278
Fair Value, Recurring [Member] \| Derivative instruments [Member] \| Quoted Prices in Active Markets For Identical Assets (Level 1) [Member]
Financial assets held at fair value:
Derivative Asset	[1]	658	758
Fair Value, Recurring [Member] \| Derivative instruments [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Derivative Asset	[1]	200,685	45,520
Fair Value, Recurring [Member] \| Derivative instruments [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Financial assets held at fair value:
Derivative Asset			0
Fair Value, Recurring [Member] \| Investments Held In Rabbi Trust [Member]
Financial assets held at fair value:
Other assets		4,673	4,307
Fair Value, Recurring [Member] \| Investments Held In Rabbi Trust [Member] \| Quoted Prices in Active Markets For Identical Assets (Level 1) [Member]
Financial assets held at fair value:
Other assets		4,673	4,307
Fair Value, Recurring [Member] \| Investments Held In Rabbi Trust [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Financial assets held at fair value:
Other assets			0
Fair Value, Recurring [Member] \| Loan Origination Commitments [Member]
Financial assets held at fair value:
Loans Held-for-sale, Fair Value Disclosure		27,061	7,908
Fair Value, Recurring [Member] \| Loan Origination Commitments [Member] \| Quoted Prices in Active Markets For Identical Assets (Level 1) [Member]
Financial assets held at fair value:
Loans Held-for-sale, Fair Value Disclosure		0	0
Fair Value, Recurring [Member] \| Loan Origination Commitments [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Loans Held-for-sale, Fair Value Disclosure		27,061	7,908
Fair Value, Recurring [Member] \| Loan Origination Commitments [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Financial assets held at fair value:
Loans Held-for-sale, Fair Value Disclosure		0
Fair Value, Recurring [Member] \| US Treasury Bill Securities [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		19,924	7,550
Fair Value, Recurring [Member] \| US Treasury Bill Securities [Member] \| Quoted Prices in Active Markets For Identical Assets (Level 1) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		19,924	7,550
Fair Value, Recurring [Member] \| Agency CMO [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		200,956	234,923
Fair Value, Recurring [Member] \| Agency CMO [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		200,956	234,923
Fair Value, Recurring [Member] \| Agency MBS [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		1,598,836	1,481,089
Fair Value, Recurring [Member] \| Agency MBS [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		1,598,836	1,481,089
Fair Value, Recurring [Member] \| Agency CMBS [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		610,350	566,237
Fair Value, Recurring [Member] \| Agency CMBS [Member] \| Quoted Prices in Active Markets For Identical Assets (Level 1) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		0	0
Fair Value, Recurring [Member] \| Agency CMBS [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		610,350	566,237
Fair Value, Recurring [Member] \| Agency CMBS [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		0	0
Fair Value, Recurring [Member] \| Agency CMBS [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		0	0
Fair Value, Recurring [Member] \| Non-agency CMBS [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		403,918	445,581
Fair Value, Recurring [Member] \| Non-agency CMBS [Member] \| Quoted Prices in Active Markets For Identical Assets (Level 1) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		0	0
Fair Value, Recurring [Member] \| Non-agency CMBS [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		403,918	445,581
Fair Value, Recurring [Member] \| Non-agency CMBS [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		0	0
Fair Value, Recurring [Member] \| Non-agency CMBS [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		0	0
Fair Value, Recurring [Member] \| CLO [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		94,805	112,771
Fair Value, Recurring [Member] \| CLO [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		94,805	112,771
Fair Value, Recurring [Member] \| Corporate debt securities [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		31,314	50,579
Fair Value, Recurring [Member] \| Corporate debt securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Financial assets held at fair value:
Debt Securities, Available-for-sale		$ 31,314	$ 50,579

[1]	or 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 13: Derivative Financial Instruments .

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Option, Disclosures (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Held-for-sale, Fair Value Disclosure	$ 27,061	$ 7,908
Loans held for sale (valued under fair value option $27,061 and $7,908)	27,061	11,869
Fair Value, Option, Loans Held as Assets, Aggregate Difference	365	(319)
loans held for sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans held for sale (valued under fair value option $27,061 and $7,908)	$ 26,696	$ 8,227

Fair Value Measurements (Summar

Fair Value Measurements (Summary Of Estimated Fair Values Of Significant Financial Instruments) (Detail) - USD ($) $ in Thousands		Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity		$ 5,193,521		$ 4,325,420
Debt Securities, Held-to-maturity, Fair Value		5,285,705		4,209,121
Mortgage servicing assets, Carrying Amount		17,877	$ 18,712	21,215	$ 22,644	$ 23,341	$ 25,139
Fair Value, Nonrecurring [Member] \| Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity		5,193,521		4,325,420
Loans and leases, net		19,342,494		18,253,136
Securities sold under agreements to repurchase and other borrowings		1,210,692		581,874
FHLB advances	[1]	1,392,849		1,826,808
Long-term debt	[1]	549,158		226,021
Fair Value, Nonrecurring [Member] \| Reported Value Measurement [Member] \| Deposits Liabilities, other than time deposits [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		20,025,100		18,662,299
Fair Value, Nonrecurring [Member] \| Reported Value Measurement [Member] \| Time Deposits [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		3,255,565		3,196,546
Fair Value, Nonrecurring [Member] \| Reported Value Measurement [Member] \| Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage servicing assets, Carrying Amount		17,877		21,215
Fair Value, 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]
Debt Securities, Held-to-maturity, Fair Value		5,285,705		4,209,121
Securities sold under agreements to repurchase and other borrowings		1,207,411		581,874
FHLB advances	[1]	1,395,735		1,826,381
Long-term debt	[1]	557,956		229,306
Fair Value, 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		19,602,007		18,155,798
Fair Value, 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		20,025,100		18,662,299
Fair Value, 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		3,255,994		3,175,948
Fair Value, 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		$ 34,025		$ 45,478

[1]	djustments to the carrying amount of long-term debt for unamortized discount and debt issuance cost on senior fixed-rate notes are not included for determination of fair value, see Note 8: Borrowings .

Retirement Benefit Plans (Detai

Retirement Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Retirement Benefit Plans (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligations	$ 2,001	$ 1,857	$ 5,956	$ 5,577
Expected return on plan assets	(2,815)	(3,178)	(8,445)	(9,538)
Recognized net loss	1,420	1,160	4,280	3,480
Net periodic benefit cost	606	(161)	1,791	(481)
Defined Benefit Plan, Plan Assets, Contributions by Employer			10,000
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligations	16	35	48	201
Expected return on plan assets	0	0	0	0
Recognized net loss	4	2,271	11	2,729
Net periodic benefit cost	20	2,306	59	2,930
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligations	22	20	64	59
Expected return on plan assets	0	0	0	0
Recognized net loss	(2)	0	(10)	0
Net periodic benefit cost	$ 20	$ 20	$ 54	$ 59

Segment Reporting (Operating Re

Segment Reporting (Operating Results and Total Assets Reportable Segments) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total Assets	$ 29,895,100		$ 29,895,100		$ 27,610,315
Net interest income (expense)	240,539	$ 230,372	723,877	$ 669,550
Noninterest Income	69,931	72,284	214,396	209,405
Total non-interest expense	179,894	178,783	536,220	530,857
Pre-tax, pre-provision net revenue	130,576	123,873	402,053	348,098
Provision for Loan and Lease Losses	11,300	10,500	31,800	32,000
Income (loss) before income tax expense	119,276	113,373	370,253	316,098
Income tax expense	25,411	13,700	78,003	54,518
Net income	93,865	99,673	292,250	261,580
Operating Segments [Member] \| Commercial Banking [Member]
Segment Reporting Information [Line Items]
Total Assets	11,174,036		11,174,036		10,477,050
Net interest income (expense)	96,817	91,243	279,498	264,353
Noninterest Income	13,987	18,305	42,643	48,662
Total non-interest expense	45,261	44,506	136,075	128,730
Pre-tax, pre-provision net revenue	65,543	65,042	186,066	184,285
Provision for Loan and Lease Losses	9,312	9,991	23,294	25,468
Income (loss) before income tax expense	56,231	55,051	162,772	158,817
Income tax expense	13,828	13,542	40,037	39,069
Net income	42,403	41,509	122,735	119,748
Operating Segments [Member] \| HSA Bank [Member]
Segment Reporting Information [Line Items]
Total Assets	75,636		75,636		70,826
Net interest income (expense)	42,206	36,731	126,573	104,920
Noninterest Income	23,526	22,159	74,082	67,710
Total non-interest expense	32,918	30,753	100,693	93,488
Pre-tax, pre-provision net revenue	32,814	28,137	99,962	79,142
Provision for Loan and Lease Losses	0	0	0	0
Income (loss) before income tax expense	32,814	28,137	99,962	79,142
Income tax expense	8,531	7,316	25,990	20,577
Net income	24,283	20,821	73,972	58,565
Operating Segments [Member] \| Community Banking [Member]
Segment Reporting Information [Line Items]
Total Assets	9,228,537		9,228,537		8,727,335
Net interest income (expense)	99,459	101,952	303,518	302,782
Noninterest Income	28,115	26,848	81,172	78,421
Total non-interest expense	99,835	95,769	291,076	287,795
Pre-tax, pre-provision net revenue	27,739	33,031	93,614	93,408
Provision for Loan and Lease Losses	1,988	509	8,506	6,532
Income (loss) before income tax expense	25,751	32,522	85,108	86,876
Income tax expense	5,128	6,472	16,940	17,288
Net income	20,623	26,050	68,168	69,588
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total Assets	9,416,891		9,416,891		$ 8,335,104
Net interest income (expense)	2,057	446	14,288	(2,505)
Noninterest Income	4,303	4,972	16,499	14,612
Total non-interest expense	1,880	7,755	8,376	20,844
Pre-tax, pre-provision net revenue	4,480	(2,337)	22,411	(8,737)
Provision for Loan and Lease Losses	0	0	0	0
Income (loss) before income tax expense	4,480	(2,337)	22,411	(8,737)
Income tax expense	(2,076)	(13,630)	(4,964)	(22,416)
Net income	$ 6,556	$ 11,293	$ 27,375	$ 13,679

Segment Reporting Segment Repor

Segment Reporting Segment Reporting Narrative (Details)	9 Months Ended
Segment Reporting Segment Reporting Narrative (Details)	Sep. 30, 2019Segment
Segment Reporting Information [Line Items]
Number of Reportable Segments	3

Revenue from Contracts with C_3

Revenue from Contracts with Customers Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 51,818	$ 50,230	$ 157,449	$ 150,732
Noninterest Income	69,931	72,284	214,396	209,405
Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	41,410	40,601	127,552	121,911
Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	8,496	8,412	24,456	24,738
Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,912	1,217	5,441	4,083
Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Noninterest Income	18,113	22,054	56,947	58,673
Operating Segments [Member] \| Commercial Banking [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	5,637	5,788	16,784	17,316
Noninterest Income	13,987	18,305	42,643	48,662
Operating Segments [Member] \| Commercial Banking [Member] \| Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,987	3,211	9,108	9,613
Operating Segments [Member] \| Commercial Banking [Member] \| Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,650	2,577	7,676	7,703
Operating Segments [Member] \| Commercial Banking [Member] \| Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Operating Segments [Member] \| Commercial Banking [Member] \| Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Noninterest Income	8,350	12,517	25,859	31,346
Operating Segments [Member] \| Community Banking [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	22,552	22,302	66,362	65,624
Noninterest Income	28,115	26,848	81,172	78,421
Operating Segments [Member] \| Community Banking [Member] \| Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	16,047	16,107	47,701	47,079
Operating Segments [Member] \| Community Banking [Member] \| Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	5,855	5,843	16,806	17,060
Operating Segments [Member] \| Community Banking [Member] \| Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	650	352	1,855	1,485
Operating Segments [Member] \| Community Banking [Member] \| Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Noninterest Income	5,563	4,546	14,810	12,797
Operating Segments [Member] \| HSA Bank [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	23,526	22,159	74,082	67,710
Noninterest Income	23,526	22,159	74,082	67,710
Operating Segments [Member] \| HSA Bank [Member] \| Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	22,264	21,294	70,496	65,112
Operating Segments [Member] \| HSA Bank [Member] \| Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Operating Segments [Member] \| HSA Bank [Member] \| Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,262	865	3,586	2,598
Operating Segments [Member] \| HSA Bank [Member] \| Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Noninterest Income	0	0	0	0
Corporate, Non-Segment [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	103	(19)	221	82
Noninterest Income	4,303	4,972	16,499	14,612
Corporate, Non-Segment [Member] \| Deposit service fees [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	112	(11)	247	107
Corporate, Non-Segment [Member] \| Wealth and investment services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(9)	(8)	(26)	(25)
Corporate, Non-Segment [Member] \| Other non interest income [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Corporate, Non-Segment [Member] \| Non-interest income within the scope of other GAAP topics [Member]
Disaggregation of Revenue [Line Items]
Noninterest Income	$ 4,200	$ 4,991	$ 16,278	$ 14,530

Commitments and Contingencies_2

Commitments and Contingencies (Outstanding Financial Instruments Contract Amounts Represent Credit Risk) (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 6,110,820	$ 6,050,806
Standby letter of credit [Member]
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	194,430	189,040
Commercial letter of credit [Member]
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	21,609	21,181
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 5,894,781	$ 5,840,585

(Reserve for Unfunded Commitmen

(Reserve for Unfunded Commitments) (Detail) - SEC Schedule, 12-09, Allowance, Credit Loss [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 2,537	$ 2,596	$ 2,506	$ 2,362
(Benefit) provision charged to expense	(68)	28	(37)	262
Ending balance	$ 2,469	$ 2,624	$ 2,469	$ 2,624

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Millions	Oct. 29, 2019	Sep. 30, 2019
Subsequent Event [Line Items]
Share repurchase authority (in shares)		$ 78.7
Subsequent Event
Subsequent Event [Line Items]
Share repurchase authority (in shares)	$ 200