Webster Financial (WBS) 10-Q 3 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 29, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
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 Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		90,588,670
Entity Central Index Key	0000801337
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2021
Common Class A
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	WBS
Security Exchange Name	NYSE
Series F Preferred Stock
Entity Information [Line Items]
Title of 12(b) Security	Depositary Shares, each representing 1/1000th interest in a share
Trading Symbol	WBS PrF
Security Exchange Name	NYSE

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets [Abstract]
Cash and due from banks	$ 161,369	$ 193,501
Interest-bearing deposits	2,442,790	69,603
Investment securities available-for-sale, at fair value	3,410,443	3,326,776
Investment securities held-to-maturity, net of allowance for credit losses of $234 and $299	5,986,308	5,567,889
Federal Home Loan Bank and Federal Reserve Bank stock	75,936	77,594
Loans held for sale (valued under fair value option $10,032 and $14,000)	24,969	14,012
Loans and leases	21,580,335	21,641,215
Allowance for credit losses on loans and leases	(314,922)	(359,431)
Loans and leases, net	21,265,413	21,281,784
Deferred tax assets, net	96,489	81,286
Premises and equipment, net	209,573	226,743
Goodwill	538,373	538,373
Other intangible assets, net	18,987	22,383
Cash surrender value of life insurance policies	572,368	564,195
Accrued interest receivable and other assets	571,240	626,551
Total assets	35,374,258	32,590,690
Liabilities and Equity [Abstract]
Non-interest-bearing	7,154,835	6,155,592
Interest-bearing	22,871,492	21,179,844
Total deposits	30,026,327	27,335,436
Securities sold under agreements to repurchase and other borrowings	655,871	995,355
Federal Home Loan Bank advances	113,334	133,164
Long-term debt	564,114	567,663
Operating lease liabilities	150,708	158,280
Accrued expenses and other liabilities	477,715	166,167
Total liabilities	31,988,069	29,356,065
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock	145,037	145,037
Common stock	937	937
Paid-in capital	1,104,885	1,109,532
Retained earnings	2,260,560	2,077,522
Treasury stock, at cost (3,097,840 and 3,487,389 shares)	(126,738)	(140,659)
Accumulated other comprehensive income, net of tax	1,508	42,256
Total shareholders' equity	3,386,189	3,234,625
Total liabilities and shareholders' equity	$ 35,374,258	$ 32,590,690

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for credit losses	$ (234)	$ (299)
Value under fair value options	$ 10,032	$ 14,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	3,000,000	3,000,000
Series F outstanding (in shares)	6,000	6,000
Series F issued (in shares)	6,000	6,000
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Issued (93,686,311 shares)	93,686,311	93,686,311
Treasury stock, at cost (3,097,840 and 3,487,389 shares)	3,097,840	3,487,389

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest and Dividend Income, Operating [Abstract]
Interest and fees on loans and leases	$ 196,273	$ 188,001	$ 572,728	$ 600,709
Taxable interest and dividends on investments	38,208	45,549	118,125	148,240
Non-taxable interest on investment securities	5,154	5,460	15,770	16,447
Loans held for sale	57	229	201	588
Total interest income	239,692	239,239	706,824	765,984
Interest Expense [Abstract]
Deposits	4,571	12,598	16,104	59,246
Securities sold under agreements to repurchase and other borrowings	721	608	2,216	5,318
Federal Home Loan Bank advances	492	2,528	1,539	13,145
Long-term debt	4,217	4,249	12,658	13,811
Total interest expense	10,001	19,983	32,517	91,520
Net interest income	229,691	219,256	674,307	674,464
Provision for credit losses	7,750	22,750	(39,500)	138,750
Net interest income after provision for credit losses	221,941	196,506	713,807	535,714
Noninterest Income [Abstract]
Deposit service fees	40,258	39,278	122,166	117,687
Loan and lease related fees	10,881	6,568	27,056	20,032
Wealth and investment services	9,985	8,255	29,475	24,096
Mortgage banking activities	1,525	7,087	5,486	14,185
Increase in cash surrender value of life insurance policies	3,666	3,695	10,802	10,899
Gain on Sale of Investments	0	0	0	8
Other income	17,460	10,177	38,249	21,607
Total non-interest income	83,775	75,060	233,234	208,514
Noninterest Expense [Abstract]
Compensation and benefits	105,352	104,019	310,706	305,637
Occupancy	12,430	14,275	42,090	43,005
Technology and equipment	28,441	27,846	84,081	83,151
Intangible assets amortization	1,124	1,089	3,395	3,013
Marketing	3,721	3,852	9,452	10,640
Professional and outside services	7,074	9,223	37,875	21,044
Deposit insurance	3,855	4,204	11,560	13,944
Other expense	18,240	19,488	56,088	58,982
Total non-interest expense	180,237	183,996	555,247	539,416
Income before income tax expense	125,479	87,570	391,794	204,812
Income tax expense	29,766	18,289	93,968	44,235
Net income	95,713	69,281	297,826	160,577
Preferred stock dividends and other	(2,542)	(2,391)	(7,567)	(6,819)
Earnings applicable to common shareholders	$ 93,171	$ 66,890	$ 290,259	$ 153,758
Earnings Per Share, Basic and Diluted [Abstract]
Basic	$ 1.03	$ 0.75	$ 3.23	$ 1.71
Diluted	$ 1.03	$ 0.75	$ 3.22	$ 1.70

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 95,713	$ 69,281	$ 297,826	$ 160,577
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Investment securities available-for-sale	(3,394)	11,766	(35,220)	57,991
Derivative instruments	(1,731)	(1,912)	(7,755)	27,921
Defined benefit pension and other postretirement benefit plans	743	738	2,227	2,197
Other comprehensive (loss) income, net of tax	(4,382)	10,592	(40,748)	88,109
Comprehensive Income (Loss), Net of Tax, Attributable to Parent, Total	$ 91,331	$ 79,873	$ 257,078	$ 248,686

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Series F Preferred Stock	Preferred Stock	Preferred StockCumulative Effect, Period of Adoption, Adjustment	Common Stock	Common StockCumulative Effect, Period of Adoption, Adjustment	Paid-In Capital	Paid-In CapitalCumulative Effect, Period of Adoption, Adjustment	Retained Earnings	Retained EarningsCumulative Effect, Period of Adoption, Adjustment	Retained EarningsSeries F Preferred Stock	Treasury Stock, at cost	Treasury Stock, at costCumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income, Net of Tax	Accumulated Other Comprehensive Income, Net of TaxCumulative Effect, Period of Adoption, Adjustment
Beginning Balance at Dec. 31, 2019	$ 3,207,770	$ (51,213)		$ 145,037	$ 0	$ 937	$ 0	$ 1,113,250	$ 0	$ 2,061,352	$ (51,213)		$ (76,734)	$ 0	$ (36,072)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	160,577									160,577
Other Comprehensive Income (Loss), Net of Tax	88,109														88,109
Dividends and dividend equivalents declared on common stock	(109,190)									(109,190)
Dividends on preferred stock			$ (5,906)									$ (5,906)
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	9,356							(6,672)		0			16,028
Stock Issued During Period, Value, Stock Options Exercised	118							(105)					223
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(3,375)												(3,375)
Stock Repurchased During Period, Value	(76,556)												(76,556)
Ending Balance at Sep. 30, 2020	$ 3,219,690			145,037		937		1,106,473		2,055,620			(140,414)		52,037
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared	$ 1.20
Dividends on preferred stock (in dollars per share)			$ 984.375
Beginning Balance at Jun. 30, 2020	$ 3,174,779			145,037		937		1,103,756		2,024,487			(140,883)		41,445
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	69,281									69,281
Other Comprehensive Income (Loss), Net of Tax	10,592														10,592
Dividends and dividend equivalents declared on common stock	(36,180)									(36,180)
Dividends on preferred stock			$ (1,968)									(1,968)
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	3,342							2,717		0			625
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(156)												(156)
Ending Balance at Sep. 30, 2020	$ 3,219,690			145,037		937		1,106,473		2,055,620			(140,414)		52,037
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared	$ 0.40
Dividends on preferred stock (in dollars per share)			$ 328.125
Beginning Balance at Dec. 31, 2020	$ 3,234,625			145,037		937		1,109,532		2,077,522			(140,659)		42,256
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	297,826									297,826
Other Comprehensive Income (Loss), Net of Tax	(40,748)														(40,748)
Dividends and dividend equivalents declared on common stock	(108,882)									(108,882)
Dividends on preferred stock			$ (5,906)									(5,906)
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	10,076							508		0			9,568
Stock Issued During Period, Value, Stock Options Exercised	3,469							(5,155)					8,624
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(4,271)												(4,271)
Ending Balance at Sep. 30, 2021	$ 3,386,189			145,037		937		1,104,885		2,260,560			(126,738)		1,508
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared	$ 1.20
Dividends on preferred stock (in dollars per share)			$ 984.375
Beginning Balance at Jun. 30, 2021	$ 3,329,705			145,037		937		1,101,126		2,203,160			(126,445)		5,890
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	95,713									95,713
Other Comprehensive Income (Loss), Net of Tax	(4,382)														(4,382)
Dividends and dividend equivalents declared on common stock	(36,345)									(36,345)
Dividends on preferred stock			$ (1,968)									$ (1,968)
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	3,643							3,819		0			(176)
Stock Issued During Period, Value, Stock Options Exercised	83							(60)					143
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(260)												(260)
Ending Balance at Sep. 30, 2021	$ 3,386,189			$ 145,037		$ 937		$ 1,104,885		$ 2,260,560			$ (126,738)		$ 1,508
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared	$ 0.40
Dividends on preferred stock (in dollars per share)			$ 328.125

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income	$ 297,826	$ 160,577
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Provision for credit losses	(39,500)	138,750
Deferred Income Tax Expense (Benefit)	(692)	(29,976)
Depreciation, Amortization and Accretion, Net	27,071	27,448
Accretion (Amortization) of Discounts and Premiums, Investments	102,648	47,178
Share-based Payment Arrangement, Noncash Expense	10,076	9,356
Gains (Losses) on Sales of Other Real Estate	(367)	(1,073)
Gain (Loss) on Disposition of Property Plant Equipment	688	184
Gain on sale of investment securities, net	0	(8)
Life Insurance, Corporate or Bank Owned, Change in Value	(10,802)	(10,899)
Bank Owned Life Insurance Income	(1,350)	(352)
Gain (Loss) on Sales of Loans, Net	(5,486)	(14,185)
Proceeds from Sale of Loans Held-for-sale	199,991	342,747
Payments for Origination of Mortgage Loans Held-for-sale	(192,948)	(324,319)
Increase (Decrease) in Financial Instruments Used in Operating Activities	4,074	8,634
Increase (Decrease) in Derivative Assets and Liabilities	140,991	(172,647)
Gain on sale of banking centers	(786)	0
Increase (Decrease) in Other Operating Assets	(77,859)	23,353
Increase (Decrease) in Other Accounts Payable and Accrued Liabilities	10,594	(43,272)
Net Cash Provided by (Used in) Operating Activities, Total	464,169	161,496
Net Cash Provided by (Used in) Investing Activities [Abstract]
Payments to Acquire Debt Securities, Available-for-sale	(857,820)	(586,228)
Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale	729,877	422,572
Proceeds from Sale of Debt Securities, Available-for-sale	0	8,963
Payments to Acquire Held-to-maturity Securities	(1,203,951)	(1,005,535)
Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities	1,007,842	655,521
Payments for (Proceeds from) Federal Home Loan Bank Stock	1,658	59,435
Payments for (Proceeds from) Other Investing Activities	(8,897)	(7,423)
Payments for (Proceeds from) Other Loans and Leases	(66,526)	(1,869,715)
Proceeds of Other Loans and Leases Held-for-investment	61,274	6,414
Proceeds from Life Insurance Policy	5,074	1,625
Proceeds from Sale of Foreclosed Assets	1,285	8,047
Proceeds from Sale of Productive Assets	2,912	641
Payments to Acquire Property, Plant, and Equipment	(11,229)	(14,016)
Net Cash Provided by (Used in) Investing Activities, Total	(338,501)	(2,319,699)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Increase (Decrease) in Deposits	2,689,995	3,590,551
Proceeds from FHLBank Borrowings, Financing Activities	180,470	3,775,000
Payments of FHLBank Borrowings, Financing Activities	(200,300)	(5,290,233)
Increase (Decrease) in Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Net	(339,484)	261,391
Payments of Ordinary Dividends, Common Stock	(108,586)	(108,882)
Payments of Ordinary Dividends, Preferred Stock and Preference Stock	(5,906)	(5,906)
Proceeds from Stock Options Exercised	3,469	118
Payments for Repurchase of Common Stock	0	(76,556)
Payments for Repurchase of Equity, Share-based Compensation	(4,271)	(3,375)
Net Cash Provided by (Used in) Financing Activities, Total	2,215,387	2,142,108
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	2,341,055	(16,095)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Beginning Balance	263,104	257,895
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Ending Balance	2,604,159	241,800
Supplemental Cash Flow Information [Abstract]
Interest Paid, Excluding Capitalized Interest, Operating Activities	42,567	103,550
Income Taxes Paid	107,812	77,376
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Real Estate Owned, Transfer to Real Estate Owned	1,048	5,178
Transfer of Portfolio Loans and Leases to Held-for-sale	74,923	5,805
Unsettled purchases of investment securities	284,713	0
Payments for Deposits	$ 0	$ 4,657

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations Webster Financial Corporation is a bank holding company and financial holding company under the BHC Act, incorporated under the laws of Delaware in 1986, and headquartered in Waterbury, Connecticut. Webster Bank is the principal consolidated subsidiary of Webster Financial Corporation. Webster Bank, including its HSA Bank division, deliver a wide range of banking, investment, and financial services to individuals, families, and businesses. Webster Bank serves consumer and business customers with mortgage lending, financial planning, trust, and investment services through a distribution network consisting of banking centers, ATMs, a customer care center, and a full range of web and mobile-based banking services throughout southern New England and Westchester County, New York. It also offers equipment financing, commercial real estate lending, asset-based lending, and treasury and payment solutions primarily in the eastern U.S. HSA Bank is a leading provider of HSAs, while also delivering health reimbursement arrangements, and flexible spending and commuter benefit account administration services to employers and individuals in all 50 states. Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements of the Company have been prepared in accordance with GAAP for interim financial information and 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 thereto, for the year ended December 31, 2020, included in our Form 10-K filed with the SEC. In the opinion of management, all necessary adjustments are reflected to present fairly the financial position and results of operations as of the dates and for the periods shown. Operating results for the three and nine months ended September 30, 2021 are not necessarily indicative of results that may be attained during the full year ending December 31, 2021, or any future period. There have been no changes to the Company's significant accounting policies from those described within that Form 10-K, except as described within the Recently Adopted Accounting Standards Updates section of this note. Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications did not have a significant impact on the Company's 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 and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Recently Adopted Accounting Standards Updates ASU No. 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes. The Accounting Standards Update (the Update) provides simplification to the accounting for income taxes related to a variety of topics and makes minor codification improvements. Changes include a requirement that the effects of an enacted change in tax law be reflected in the computation of the annual effective tax rate in the first interim period that includes the enactment date of the new legislation and clarification on presentation of non-income based taxes. The Company adopted the Update on January 1, 2021 on a prospective basis. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. ASU No. 2021-01, Reference Rate Reform (Topic 848) - Scope. The Update clarifies that certain optional expedients and exceptions provided for in ASU No. 2020-04 for applying GAAP to contract modifications and hedging relationships apply to derivatives that are affected by the discounting transition. The amendments are elective and apply to all entities that have derivative instruments that use an interest rate for margining, discounting, or contract price alignment that is modified as a result of reference rate reform. The Update was effective upon issuance for application on either a retrospective basis as of any date from the beginning of an interim period that includes or is subsequent to March 22, 2020, or on a prospective basis beginning on January 7, 2021. The Company adopted the Update on a prospective basis. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. Relevant Accounting Standards Issued But Not Yet Adopted The Company has adopted all applicable Accounting Standards Updates issued by the Financial Accounting Standards Board (FASB) as of September 30, 2021.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2021
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. Investments held in the Rabbi Trust primarily consist of mutual funds that invest in equity and fixed income securities. The Company is considered the primary beneficiary of the Rabbi Trust as it has the power to direct the activities of the Rabbi Trust that most 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 accompanying Condensed Consolidated Balance Sheets. Earnings in the Rabbi Trust, including appreciation or depreciation, are reflected as other non-interest income, and changes in the corresponding liability are reflected as compensation and benefits, on the accompanying Condensed Consolidated Statement of Income. Refer to Note 15: 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 the Company is not the primary beneficiary. 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 and the Company does not have the obligation to absorb expected losses or the right to receive residual returns. The Company applies the proportional amortization method to account for its investments in qualified affordable housing projects. At September 30, 2021 and December 31, 2020, the aggregate carrying value of the Company's tax credit-finance investments was $44.6 million and $37.2 million, respectively, which represents the Company's maximum exposure to loss. At September 30, 2021 and December 31, 2020, unfunded commitments have been recognized, totaling $12.6 million and $10.2 million, respectively, and are included in accrued expenses and other liabilities on the accompanying Condensed Consolidated Balance Sheets. During the nine months ended September 30, 2021, the Company approved additional commitments of $10.6 million to fund tax credit-finance investments. There were no commitments approved during the nine months ended September 30, 2020. 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 accompanying Condensed Consolidated Balance Sheets, and the related interest expense is reported as interest expense on long-term debt on the accompanying Condensed Consolidated Statements of Income. Refer to Note 10: Borrowings for additional information. 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, 2021 and December 31, 2020, the aggregate carrying value of the Company's other non-marketable investments in VIEs was $53.0 million and $34.3 million, respectively, and the maximum exposure to loss of the Company's other non-marketable investments in VIEs, including unfunded commitments, was $83.3 million and $72.7 million, respectively. Refer to Note 15: 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 accompanying Condensed Consolidated Balance Sheets. For a description of the Company's accounting policy regarding the consolidation of VIEs, refer to Note 1: Summary of Significant Accounting Policies to the Consolidated Financial Statements included in its Form 10-K for the year ended December 31, 2020.

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities Held-to-Maturity Securities A summary of the amortized cost, fair value, and ACL on investment securities held-to-maturity is presented below: At September 30, 2021 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value Allowance Net Carrying Value Agency CMO $ 50,146 $ 1,075 $ (48) $ 51,173 $ — $ 50,146 Agency MBS 2,544,509 101,289 (5,403) 2,640,395 — 2,544,509 Agency CMBS 2,509,487 22,432 (22,094) 2,509,825 — 2,509,487 Municipal bonds and notes 707,552 49,961 — 757,513 234 707,318 CMBS 174,848 5,686 — 180,534 — 174,848 Held-to-maturity securities $ 5,986,542 $ 180,443 $ (27,545) $ 6,139,440 $ 234 $ 5,986,308 At December 31, 2020 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value Allowance Net Carrying Value Agency CMO $ 91,622 $ 1,785 $ (241) $ 93,166 $ — $ 91,622 Agency MBS 2,419,751 137,863 (84) 2,557,530 — 2,419,751 Agency CMBS 2,101,227 60,484 (2,213) 2,159,498 — 2,101,227 Municipal bonds and notes 739,507 60,371 (3) 799,875 299 739,208 CMBS 216,081 9,214 — 225,295 — 216,081 Held-to-maturity securities $ 5,568,188 $ 269,717 $ (2,541) $ 5,835,364 $ 299 $ 5,567,889 (1) Amortized cost excludes accrued interest receivable of $16.7 million and $22.1 million at September 30, 2021 and December 31, 2020, respectively, which is included in accrued interest receivable and other assets on the accompanying Condensed Consolidated Balance Sheets. Agency securities represent obligations issued by a U.S. government-sponsored enterprise or other federally-related entity and are either explicitly or implicitly guaranteed, and therefore, assumed to be zero loss. Securities with unrealized losses and no allowance are considered to be of high credit quality, and therefore, zero credit loss is recorded as of September 30, 2021. The current unrealized loss position of certain agency securities and non-agency CMBS with no credit loss allowance can be attributed to the changing interest rate environment. An ACL on investment securities held-to-maturity is recorded for certain Municipal bonds and notes to account for expected lifetime credit losses. The following table summarizes the activity in the ACL on investment securities held-to-maturity: Three months ended September 30, Nine months ended September 30, (In thousands) 2021 2020 2021 2020 Balance beginning of period $ 382 $ 309 $ 299 $ — Adoption of ASU No. 2016-13 (CECL) — — — 397 Provision (benefit) for credit losses (148) (3) (65) (91) Balance end of period $ 234 $ 306 $ 234 $ 306 Credit Quality Information The Company monitors the credit quality of held-to-maturity debt securities through credit ratings provided by Standard & Poor's Rating Services (S&P), Moody's Investor Services (Moody's), Fitch Ratings, Inc., Kroll Bond Rating Agency, or DBRS Inc. Credit ratings express opinions about the credit quality of a security. Investment grade securities are rated BBB- or higher by S&P, or Baa3 or higher by Moody's, and are generally considered by the rating agencies and market participants to be of low credit risk. Conversely, securities rated below investment grade, labeled as speculative grade by the rating agencies, are considered to have distinctively higher credit risk than investment grade securities. At September 30, 2021, there were no held-to-maturity investment securities rated below investment grade. The securities illustrated below that are not rated are collateralized with U.S. Government obligations, and credit quality indicators are updated at each quarter end. The following table summarizes credit ratings for the amortized cost of held-to-maturity debt securities according to their lowest public credit rating at September 30, 2021: Investment Grade (In thousands) Aaa Aa1 Aa2 Aa3 A1 A2 A3 Baa2 Not Rated Agency CMOs $ — $ 50,146 $ — $ — $ — $ — $ — $ — $ — Agency MBS — 2,544,509 — — — — — — — Agency CMBS — 2,509,487 — — — — — — — Municipal bonds and notes 207,813 119,988 227,479 104,454 36,045 8,464 — 190 3,119 CMBS 174,848 — — — — — — — — Total held-to-maturity $ 382,661 $ 5,224,130 $ 227,479 $ 104,454 $ 36,045 $ 8,464 $ — $ 190 $ 3,119 At September 30, 2021, there were no held-to-maturity investment securities in non-accrual status. Contractual Maturities The amortized cost and fair value of held-to-maturity debt securities presented by contractual maturity are set forth below: At September 30, 2021 (In thousands) Amortized Fair Due in one year or less $ 380 $ 382 Due after one year through five years 5,933 6,222 Due after five years through ten years 294,506 307,837 Due after ten years 5,685,723 5,824,999 Total held-to-maturity debt securities $ 5,986,542 $ 6,139,440 For the maturity schedule above, investment securities that 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 repay obligations with or without prepayment penalties. Available-for-Sale Securities A summary of the amortized cost and fair value of available-for-sale securities is presented below: At September 30, 2021 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value (2) Agency CMO $ 102,257 $ 3,549 $ (23) $ 105,783 Agency MBS 1,552,693 50,705 (6,614) 1,596,784 Agency CMBS 901,654 6,852 (9,920) 898,586 CMBS 769,546 869 (329) 770,086 CLO 25,000 — (33) 24,967 Corporate debt 14,576 174 (513) 14,237 Available-for-sale securities $ 3,365,726 $ 62,149 $ (17,432) $ 3,410,443 At December 31, 2020 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value (2) Agency CMO $ 148,711 $ 6,000 $ (98) $ 154,613 Agency MBS 1,389,100 68,598 (289) 1,457,409 Agency CMBS 1,092,430 26,317 (1,514) 1,117,233 CMBS 512,759 1,082 (5,823) 508,018 CLO 76,693 — (310) 76,383 Corporate debt 14,557 — (1,437) 13,120 Available-for-sale securities $ 3,234,250 $ 101,997 $ (9,471) $ 3,326,776 (1) Amortized cost excludes accrued interest receivable of $6.6 million and $7.5 million at September 30, 2021 and December 31, 2020, respectively, which is included in accrued interest receivable and other assets on the accompanying Condensed Consolidated Balance Sheets. (2) Fair value represents net carrying value as there is no ACL recorded on investment securities available-for-sale, as the securities are high credit quality and investment grade. Fair Value and Unrealized Losses The following table provides information on fair value and unrealized losses for the individual available-for-sale securities with an unrealized loss, for which an ACL on investment securities available-for-sale has not been recorded, aggregated by classification and length of time that the individual investment securities have been in a continuous unrealized loss position: At September 30, 2021 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Unrealized Fair Unrealized # of Fair Unrealized Agency CMO $ 6,734 $ (19) $ 1,066 $ (4) 4 $ 7,800 $ (23) Agency MBS 495,080 (6,397) 19,902 (217) 55 514,982 (6,614) Agency CMBS 180,305 (2,583) 285,865 (7,337) 14 466,170 (9,920) CMBS 220,036 (238) 92,807 (91) 27 312,843 (329) CLO — — 24,967 (33) 1 24,967 (33) Corporate debt — — 9,788 (513) 2 9,788 (513) Available-for-sale in unrealized loss position $ 902,155 $ (9,237) $ 434,395 $ (8,195) 103 $ 1,336,550 $ (17,432) At December 31, 2020 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Unrealized Fair Unrealized # of Fair Unrealized Agency CMO $ 13,137 $ (49) $ 5,944 $ (49) 5 $ 19,081 $ (98) Agency MBS 33,742 (219) 4,561 (70) 30 38,303 (289) Agency CMBS 376,330 (1,514) — — 8 376,330 (1,514) CMBS 409,591 (5,486) 23,167 (337) 38 432,758 (5,823) CLO 57,728 (265) 18,655 (45) 4 76,383 (310) Corporate debt 4,100 (166) 9,020 (1,271) 3 13,120 (1,437) Available-for-sale in unrealized loss position $ 894,628 $ (7,699) $ 61,347 $ (1,772) 88 $ 955,975 $ (9,471) Unrealized losses on available-for-sale debt securities presented in the previous table have not been recognized in the accompanying Condensed Consolidated Statements of Income based on impairment analysis. The Company does not intend and is not required to sell prior to their anticipated recovery because the securities are investment grade, and the decline in fair value is primarily attributable to higher market rates. Fair value is expected to recover as the securities approach maturity. At September 30, 2021, there were no available-for-sale investment securities in non-accrual status. Contractual Maturities The amortized cost and fair value of available-for-sale debt securities presented by contractual maturity are set forth below: At September 30, 2021 (In thousands) Amortized Fair Due in one year or less $ — $ — Due after one year through five years 2,266 2,338 Due after five through ten years 152,856 153,009 Due after ten years 3,210,604 3,255,096 Total available-for-sale debt securities $ 3,365,726 $ 3,410,443 For the maturity schedule above, investment securities that 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 repay obligations with or without prepayment penalties. Sales of Available-for Sale Investment Securities There were no sales of available-for-sale securities during the three and nine months ended September 30, 2021, nor during the three months ended September 30, 2020. For the nine months ended September 30, 2020, proceeds from sales of available-for-sale securities were $9.0 million, which resulted in realized gains of $8.0 thousand. Other Information At September 30, 2021, the Company had a carrying value of $1.5 billion in callable debt securities in its CMBS, CLO, and municipal bond portfolios. The Company considers this prepayment risk in the evaluation of its interest rate risk profile. Held-to-maturity and available-for-sale investment securities with carrying values of $3.0 billion and $1.9 billion at September 30, 2021, respectively, and $2.6 billion and $1.3 billion at December 31, 2020, respectively, 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
	Sep. 30, 2021
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, 2020 Commercial non-mortgage $ 6,552,241 $ 7,085,076 Asset-based 986,782 890,598 Commercial real estate 6,522,679 6,322,637 Equipment financing 620,104 602,224 Commercial portfolio 14,681,806 14,900,535 Residential 5,167,527 4,782,016 Home equity 1,633,873 1,802,865 Other consumer 97,129 155,799 Consumer portfolio 6,898,529 6,740,680 Loans and leases (1) (2) (3) $ 21,580,335 $ 21,641,215 (1) Loan balances include net deferred costs/(fees) and net discounts/(premiums) of $5.4 million and $(10.5) million at September 30, 2021 and December 31, 2020, respectively. (2) At September 30, 2021, the Company had pledged $7.5 billion of eligible loans as collateral to support borrowing capacity at the FHLB of Boston and the FRB of Boston. (3) Loan balances exclude accrued interest receivable of $55.2 million and $57.8 million at September 30, 2021 and December 31, 2020, respectively, which is included in accrued interest receivable and other assets on the accompanying Condensed Consolidated Balance Sheets. Equipment financing includes net investment in leases of $213.7 million and $236.1 million at September 30, 2021 and December 31, 2020, respectively. Total undiscounted cash flows, primarily due within the next five years, amounted to $231.5 million at September 30, 2021. This lessor activity resulted in interest income of $1.8 million and $1.8 million for the three months ended September 30, 2021 and 2020, respectively, and $5.6 million and $5.2 million for the nine months ended September 30, 2021 and 2020, respectively. Loans and Leases Aging The following table summarizes the aging of loans and leases: At September 30, 2021 (In thousands) 30-59 Days 60-89 Days 90 or More Days Past Due Non-accrual Total Past Due and Non-accrual Current Total Loans Commercial non-mortgage $ 2,051 $ 2,264 $ 105 $ 36,448 $ 40,868 $ 6,511,373 $ 6,552,241 Asset-based — — — 2,111 2,111 984,671 986,782 Commercial real estate 128 696 — 15,963 16,787 6,505,892 6,522,679 Equipment financing 1,215 9 — 4,222 5,446 614,658 620,104 Commercial portfolio 3,394 2,969 105 58,744 65,212 14,616,594 14,681,806 Residential 2,892 538 — 19,325 22,755 5,144,772 5,167,527 Home equity 4,905 1,437 — 23,322 29,664 1,604,209 1,633,873 Other consumer 564 266 — 263 1,093 96,036 97,129 Consumer portfolio 8,361 2,241 — 42,910 53,512 6,845,017 6,898,529 Total $ 11,755 $ 5,210 $ 105 $ 101,654 $ 118,724 $ 21,461,611 $ 21,580,335 At December 31, 2020 (In thousands) 30-59 Days 60-89 Days 90 or More Days Past Due Non-accrual Total Past Due and Non-accrual Current Total Loans Commercial non-mortgage $ 612 $ 903 $ 445 $ 64,073 $ 66,033 $ 7,019,043 $ 7,085,076 Asset-based 1,174 — — 2,594 3,768 886,830 890,598 Commercial real estate 2,400 619 — 21,231 24,250 6,298,387 6,322,637 Equipment financing 5,107 2,308 — 7,299 14,714 587,510 602,224 Commercial portfolio 9,293 3,830 445 95,197 108,765 14,791,770 14,900,535 Residential 4,334 6,330 — 41,081 51,745 4,730,271 4,782,016 Home equity 5,500 1,771 — 31,030 38,301 1,764,564 1,802,865 Other consumer 878 601 — 652 2,131 153,668 155,799 Consumer portfolio 10,712 8,702 — 72,763 92,177 6,648,503 6,740,680 Total $ 20,005 $ 12,532 $ 445 $ 167,960 $ 200,942 $ 21,440,273 $ 21,641,215 The following table provides additional detail related to loans and leases on non-accrual status: At September 30, 2021 At December 31, 2020 (In thousands) Non-accrual Non-accrual With No Allowance Non-accrual Non-accrual With No Allowance Commercial non-mortgage $ 36,448 $ 8,081 $ 64,073 $ 16,985 Asset-based 2,111 2,111 2,594 — Commercial real estate 15,963 4,951 21,231 15,529 Equipment financing 4,222 — 7,299 2,983 Commercial portfolio 58,744 15,143 95,197 35,497 Residential 19,325 11,420 41,081 29,843 Home equity 23,322 18,798 31,030 24,091 Other consumer 263 — 652 2 Consumer portfolio 42,910 30,218 72,763 53,936 Total $ 101,654 $ 45,361 $ 167,960 $ 89,433 Interest on non-accrual residential and home equity loans, which would have been recorded as additional interest income had the loans been current in accordance with the original terms, totaled $2.4 million and $3.4 million for the three months ended September 30, 2021 and 2020, respectively, and $7.2 million and $9.0 million for the nine months ended September 30, 2021 and 2020, respectively. Refer to Note 1: Summary of Significant Accounting Policies to the Consolidated Financial Statements included in the Company's Form 10-K for the year ended December 31, 2020, for details of non-accrual policies. Allowance for Credit Losses on Loans and Leases The following table summarizes the activity in, as well as the loan and lease balances that were evaluated for, ACL on loans and leases: At or for the three months ended September 30, 2021 2020 (In thousands) Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total ACL on loans and leases: Balance, beginning of period $ 263,071 $ 44,874 $ 307,945 $ 291,520 $ 67,002 $ 358,522 (Benefit) provision 7,681 217 7,898 31,618 (8,865) 22,753 Charge-offs (1,723) (2,053) (3,776) (13,494) (2,263) (15,757) Recoveries 142 2,713 2,855 2,025 2,268 4,293 Balance, end of period $ 269,171 $ 45,751 $ 314,922 $ 311,669 $ 58,142 $ 369,811 At or for the nine months ended September 30, 2021 2020 (In thousands) Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total ACL on loans and leases: Balance, beginning of period $ 312,244 $ 47,187 $ 359,431 $ 161,669 $ 47,427 $ 209,096 Adoption of ASU No. 2016-13 (CECL) — — — 34,024 23,544 57,568 (Benefit) provision (37,049) (2,386) (39,435) 147,466 (8,625) 138,841 Charge-offs (8,638) (7,835) (16,473) (34,362) (9,630) (43,992) Recoveries 2,614 8,785 11,399 2,872 5,426 8,298 Balance, end of period $ 269,171 $ 45,751 $ 314,922 $ 311,669 $ 58,142 $ 369,811 Individually evaluated for impairment 7,791 4,308 12,099 18,303 4,376 22,679 Collectively evaluated for impairment $ 261,380 $ 41,443 $ 302,823 $ 293,366 $ 53,766 $ 347,132 Loan and lease balances: Individually evaluated for impairment $ 116,280 $ 104,677 $ 220,957 $ 158,324 $ 149,583 $ 307,907 Collectively evaluated for impairment 14,565,526 6,793,852 21,359,378 14,761,792 6,782,324 21,544,116 Loans and leases $ 14,681,806 $ 6,898,529 $ 21,580,335 $ 14,920,116 $ 6,931,907 $ 21,852,023 Credit Quality Indicators. To measure credit risk for the commercial portfolio, the Company employs a dual grade credit risk grading system for estimating the PD and 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 loss. Grades (1) to (6) are considered pass ratings, and grades (7) to (10) are considered criticized, as defined by the regulatory agencies. Risk ratings assigned in order to differentiate risk within the portfolio are reviewed on an ongoing basis and revised to reflect changes in a borrowers’ current financial position and outlook, risk profile, and the related collateral and structural position. Loan officers review updated financial information on at least an annual basis for all pass rated loans to assess the accuracy of the risk grade. Criticized loans undergo more frequent reviews and enhanced monitoring. A (7) - "Special Mention" rating has the potential weakness that, if left uncorrected, may result in deterioration of the repayment prospects for the credit. An (8) - "Substandard" rating has a well-defined weakness that jeopardizes the full repayment of the debt. A (9) - "Doubtful" rating has all of the same weaknesses as a substandard credit with the added characteristic that the weakness makes collection or liquidation in full improbably, given current facts, conditions, and values. Credits when classified as (10) - "Loss", in accordance with regulatory guidelines, are considered uncollectible and charged off. The following tables summarize commercial, commercial real estate, and equipment financing loans and leases segregated by origination year and risk rating exposure under the Composite Credit Risk Profile grades at September 30, 2021 and December 31, 2020: At September 30, 2021 (In thousands) 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Commercial non-mortgage Pass $ 1,680,524 $ 1,261,582 $ 862,131 $ 673,196 $ 291,995 $ 317,590 $ 1,068,077 $ 6,155,095 Special mention 13,242 45,084 38,253 32,989 9,994 16,578 15,835 171,975 Substandard 3,791 47,048 31,030 85,798 8,646 19,647 29,210 225,170 Doubtful — 1 — — — — — 1 Commercial non-mortgage 1,697,557 1,353,715 931,414 791,983 310,635 353,815 1,113,122 6,552,241 Asset-based Pass 7,612 20,768 13,115 13,998 6,272 26,747 835,405 923,917 Special mention — — — 700 — — 60,054 60,754 Substandard — — 2,111 — — — — 2,111 Asset-based 7,612 20,768 15,226 14,698 6,272 26,747 895,459 986,782 Commercial real estate Pass 847,147 891,343 1,450,959 1,074,542 377,030 1,484,768 34,906 6,160,695 Special mention 350 2,232 — 79,138 54,177 105,173 — 241,070 Substandard — 887 792 21,565 43,194 54,475 — 120,913 Doubtful — — — — — 1 — 1 Commercial real estate 847,497 894,462 1,451,751 1,175,245 474,401 1,644,417 34,906 6,522,679 Equipment financing Pass 174,137 203,641 101,319 49,725 16,835 39,771 — 585,428 Special mention — 120 8,101 3,620 87 1,055 — 12,983 Substandard — 8,989 4,093 3,566 1,512 3,533 — 21,693 Equipment financing 174,137 212,750 113,513 56,911 18,434 44,359 — 620,104 Commercial portfolio $ 2,726,803 $ 2,481,695 $ 2,511,904 $ 2,038,837 $ 809,742 $ 2,069,338 $ 2,043,487 $ 14,681,806 At December 31, 2020 (In thousands) 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total Commercial non-mortgage Pass $ 2,771,373 $ 1,052,080 $ 907,110 $ 481,321 $ 231,280 $ 218,001 $ 936,592 $ 6,597,757 Special mention 32,535 33,969 62,034 435 8,357 13,757 38,496 189,583 Substandard 54,716 51,798 66,324 36,159 15,535 23,957 49,084 297,573 Doubtful — — — 163 — — — 163 Commercial non-mortgage 2,858,624 1,137,847 1,035,468 518,078 255,172 255,715 1,024,172 7,085,076 Asset-based Pass 26,344 15,960 23,123 11,333 10,963 16,484 741,336 845,543 Special mention — — 775 — — — 41,687 42,462 Substandard — 2,504 — — — — 89 2,593 Asset-based 26,344 18,464 23,898 11,333 10,963 16,484 783,112 890,598 Commercial real estate Pass 965,582 1,461,201 1,242,322 527,931 554,630 1,165,331 28,113 5,945,110 Special mention 27 10,385 70,704 37,539 35,617 69,832 — 224,104 Substandard 817 1,132 21,923 73,621 2,962 52,968 — 153,423 Commercial real estate 966,426 1,472,718 1,334,949 639,091 593,209 1,288,131 28,113 6,322,637 Equipment financing Pass 249,370 135,263 68,092 26,433 43,469 22,879 — 545,506 Special mention 7,934 11,043 6,981 1,220 1,577 788 — 29,543 Substandard 7,483 6,169 5,749 2,460 4,743 571 — 27,175 Equipment financing 264,787 152,475 80,822 30,113 49,789 24,238 — 602,224 Commercial portfolio $ 4,116,181 $ 2,781,504 $ 2,475,137 $ 1,198,615 $ 909,133 $ 1,584,568 $ 1,835,397 $ 14,900,535 To measure credit risk for the consumer portfolio, the most relevant credit characteristic is the FICO score, which is a widely used credit scoring system that ranges from 300 to 850. A lower FICO score is indicative of higher credit risk. FICO scores are updated at least quarterly. The following tables summarize residential and consumer loans segregated by origination year and risk rating exposure under FICO score groupings at September 30, 2021 and December 31, 2020: At September 30, 2021 (In thousands) 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Residential 800+ $ 360,987 $ 450,223 $ 178,412 $ 41,697 $ 128,474 $ 792,003 $ — $ 1,951,796 740-799 857,968 471,194 180,238 38,171 91,741 507,048 — 2,146,360 670-739 300,754 141,427 81,670 25,831 41,147 248,879 — 839,708 580-669 24,569 14,716 9,338 4,394 7,531 76,066 — 136,614 579 and below 10,308 1,451 43,787 868 1,892 34,743 — 93,049 Residential 1,554,586 1,079,011 493,445 110,961 270,785 1,658,739 — 5,167,527 Home equity 800+ 27,832 28,501 10,373 17,474 11,631 60,951 491,283 648,045 740-799 29,181 27,269 9,710 14,530 8,428 39,651 414,321 543,090 670-739 12,260 10,657 7,106 8,338 7,369 35,743 234,066 315,539 580-669 364 1,530 1,750 1,529 1,885 15,669 73,350 96,077 579 and below 255 454 874 1,026 304 6,001 22,208 31,122 Home equity 69,892 68,411 29,813 42,897 29,617 158,015 1,235,228 1,633,873 Other consumer 800+ 377 1,544 3,254 1,141 323 120 10,386 17,145 740-799 2,314 6,694 10,540 4,047 590 379 4,857 29,421 670-739 542 9,433 16,762 5,021 909 234 8,106 41,007 580-669 245 1,232 3,215 972 347 207 1,313 7,531 579 and below 106 176 283 195 63 54 1,148 2,025 Other consumer 3,584 19,079 34,054 11,376 2,232 994 25,810 97,129 Consumer portfolio 1,628,062 1,166,501 557,312 165,234 302,634 1,817,748 1,261,038 6,898,529 Commercial portfolio 2,726,803 2,481,695 2,511,904 2,038,837 809,742 2,069,338 2,043,487 14,681,806 Loans and leases $ 4,354,865 $ 3,648,196 $ 3,069,216 $ 2,204,071 $ 1,112,376 $ 3,887,086 $ 3,304,525 $ 21,580,335 At December 31, 2020 (In thousands) 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total Residential 800+ $ 360,336 $ 283,755 $ 61,048 $ 178,849 $ 268,044 $ 805,537 $ — $ 1,957,569 740-799 654,973 288,173 58,249 133,416 176,286 492,720 — 1,803,817 670-739 199,329 118,620 39,125 75,375 76,666 248,268 — 757,383 580-669 17,151 19,389 8,884 11,843 12,225 96,333 — 165,825 579 and below — 36,498 673 3,278 3,179 53,794 — 97,422 Residential 1,231,789 746,435 167,979 402,761 536,400 1,696,652 — 4,782,016 Home equity 800+ 30,604 16,567 25,205 14,439 17,192 59,956 542,600 706,563 740-799 34,797 13,565 19,715 11,073 12,839 43,802 434,271 570,062 670-739 13,753 8,855 10,761 10,206 7,318 44,025 275,691 370,609 580-669 1,708 2,172 2,660 2,234 2,316 16,680 86,126 113,896 579 and below 129 919 880 1,070 1,073 7,163 30,501 41,735 Home equity 80,991 42,078 59,221 39,022 40,738 171,626 1,369,189 1,802,865 Other consumer 800+ 2,827 5,725 2,610 658 115 190 7,171 19,296 740-799 12,317 21,036 8,925 1,493 457 263 5,119 49,610 670-739 14,761 31,952 11,843 2,284 665 228 8,403 70,136 580-669 2,344 5,419 2,360 793 194 124 1,570 12,804 579 and below 608 982 500 183 37 215 1,428 3,953 Other consumer 32,857 65,114 26,238 5,411 1,468 1,020 23,691 155,799 Consumer portfolio 1,345,637 853,627 253,438 447,194 578,606 1,869,298 1,392,880 6,740,680 Commercial portfolio 4,116,181 2,781,504 2,475,137 1,198,615 909,133 1,584,568 1,835,397 14,900,535 Loans and leases $ 5,461,818 $ 3,635,131 $ 2,728,575 $ 1,645,809 $ 1,487,739 $ 3,453,866 $ 3,228,277 $ 21,641,215 Individually Assessed Loans and Leases The following table summarizes individually assessed loans and leases: At September 30, 2021 (In thousands) Unpaid Amortized Cost Amortized Cost No Allowance Amortized Cost With Allowance Related Commercial non-mortgage $ 107,251 $ 84,054 $ 34,246 $ 49,808 $ 5,470 Asset-based 2,253 2,111 2,111 — — Commercial real estate 29,357 25,893 11,203 14,690 1,449 Equipment financing 4,732 4,222 — 4,222 872 Residential 68,514 65,018 35,337 29,681 2,503 Home equity 43,764 39,396 28,078 11,318 1,689 Other consumer 282 263 — 263 116 Total $ 256,153 $ 220,957 $ 110,975 $ 109,982 $ 12,099 At December 31, 2020 (In thousands) Unpaid Amortized Cost Amortized Cost No Allowance Amortized Cost With Allowance Related Commercial non-mortgage $ 172,069 $ 119,884 $ 55,742 $ 64,142 $ 9,665 Asset-based 2,989 2,594 — 2,594 50 Commercial real estate 37,177 33,879 25,931 7,948 1,610 Equipment financing 7,770 7,298 2,983 4,315 362 Residential 108,077 98,164 58,915 39,249 3,357 Home equity 109,156 46,950 34,335 12,615 988 Other consumer 2,381 653 2 651 105 Total $ 439,619 $ 309,422 $ 177,908 $ 131,514 $ 16,137 The following table summarizes average amortized cost and interest income recognized for individually assessed loans and leases: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 (In thousands) Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Commercial non-mortgage $ 90,662 $ 729 $ — $ 127,676 $ 954 $ — $ 101,969 $ 2,270 $ — $ 114,027 $ 2,882 $ — Asset-based 2,243 — — 1,949 — — 2,353 — — 1,950 — — Commercial real estate 23,512 132 — 24,555 192 — 29,886 440 — 22,440 507 — Equipment financing 6,192 — — 7,488 — — 5,760 — — 6,308 — — Residential 66,920 590 46 103,608 741 289 81,591 1,806 487 95,270 2,352 1,149 Home equity 40,341 218 63 49,309 302 297 43,173 727 579 41,826 1,002 1,540 Other consumer 338 — — 948 13 — 458 — — 340 30 — Total $ 230,208 $ 1,669 $ 109 $ 315,533 $ 2,202 $ 586 $ 265,190 $ 5,243 $ 1,066 $ 282,161 $ 6,773 $ 2,689 Collateral Dependent Loans and Leases. A loan is considered collateral dependent when the borrower is experiencing financial difficulty and repayment is substantially expected through the operation or sale of collateral. A collateral dependent loan is individually assessed based on the fair value of the collateral, less costs to sell, as of the reporting date. Commercial non-mortgage, asset based, and equipment financing loans are collateralized by equipment, inventory, receivables, or other non-real estate assets. Commercial real estate, residential, and home equity loans are collateralized by real estate. Collateral value on collateral dependent loans and leases was $104.4 million at September 30, 2021 and $150.3 million at December 31, 2020. The following table summarizes whether, or not, individually assessed loans and leases are collateral dependent: At September 30, 2021 At December 31, 2020 (In thousands) Collateral Dependent Not Considered Collateral Dependent Total Collateral Dependent Not Considered Collateral Dependent Total Commercial non-mortgage $ 8,062 $ 75,992 $ 84,054 $ 11,074 $ 108,810 $ 119,884 Asset-based 2,111 — 2,111 2,504 90 2,594 Commercial real estate 21,229 4,664 25,893 28,482 5,397 33,879 Equipment financing — 4,222 4,222 — 7,298 7,298 Residential 16,029 48,989 65,018 33,980 64,184 98,164 Home equity 21,014 18,382 39,396 26,796 20,154 46,950 Other consumer — 263 263 — 653 653 Total amortized cost $ 68,445 $ 152,512 $ 220,957 $ 102,836 $ 206,586 $ 309,422 Troubled Debt Restructurings The following table summarizes information for TDRs: (In thousands) At September 30, 2021 At December 31, 2020 Accrual status $ 116,777 $ 140,089 Non-accrual status 47,257 95,338 Total TDRs $ 164,034 $ 235,427 Specific reserves for TDRs included in the balance of ACL on loans and leases $ 8,980 $ 12,728 Additional funds committed to borrowers in TDR status 6,504 12,895 The portion of TDRs deemed to be uncollectible, $1.1 million and $7.8 million for the three months ended September 30, 2021 and 2020, respectively, and $3.3 million and $10.8 million for the nine months ended September 30, 2021 and 2020, respectively, were charged off. The following table provides information on the type of concession for loans modified as TDRs: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Number of Post- Modification Recorded Investment (1) Number of Post- Modification Recorded Investment (1) Number of Post- Modification Recorded Investment (1) Number of Post- Modification Recorded Investment (1) (Dollars in thousands) Commercial portfolio Extended Maturity 1 $ 48 — $ — 9 $ 788 7 $ 579 Maturity/Rate Combined 2 94 2 333 8 304 8 885 Other (2) — — 4 312 3 114 27 40,434 Consumer portfolio Extended Maturity — — 2 165 2 127 6 673 Maturity/Rate Combined — — 5 440 8 1,426 11 1,151 Other (2) 3 153 17 708 19 1,354 111 9,895 Total TDRs 6 $ 295 30 $ 1,958 49 $ 4,113 170 $ 53,617 (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. There were no significant amounts of loans 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, 2021 and 2020. TDRs in commercial non-mortgage, commercial real estate, and equipment financing segregated by risk rating exposure is as follows: (In thousands) At September 30, 2021 At December 31, 2020 Pass $ 7,327 $ 12,462 Special Mention 8,670 — Substandard 58,797 105,070 Doubtful — 163 Total $ 74,794 $ 117,695

Transfers of Financial Assets

Transfers of Financial Assets	9 Months Ended
	Sep. 30, 2021
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, and gains or losses on loans sold are included as mortgage banking activities on the accompanying Condensed Consolidated Statements of Income. The Company may be required to repurchase a loan in the event of certain breaches of the representations and warranties, or in the event of default of the borrower within 90 days of sale, as provided for in the sale agreements. A reserve for loan repurchases provides for estimated losses pertaining to the potential repurchase of loans associated with the Company’s mortgage banking activities. The reserve reflects 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 accompanying Condensed Consolidated Statements of Income. The following table provides a summary of activity in the reserve for loan repurchases: Three months ended September 30, Nine months ended September 30, (In thousands) 2021 2020 2021 2020 Beginning balance $ 782 $ 655 $ 747 $ 508 Provision charged to expense 16 50 59 99 (Charge-offs/settlements) recoveries, net — — (8) 98 Ending balance $ 798 $ 705 $ 798 $ 705 The following table provides information for mortgage banking activities: Three months ended September 30, Nine months ended September 30, (In thousands) 2021 2020 2021 2020 Residential mortgage loans held for sale: Proceeds from sale $ 52,256 $ 172,579 $ 199,991 $ 342,747 Loans sold with servicing rights retained 50,643 164,054 192,421 325,832 Net gain on sale 1,063 6,244 4,523 11,587 Ancillary fees 313 1,018 1,231 2,243 Fair value option adjustment 149 (175) (268) 355 Additionally, certain commercial and consumer loans not originated for sale were sold for cash proceeds of $61.3 million for the nine months ended September 30, 2021, resulting in a gain of $1.3 million, and $6.4 million for the nine months ended September 30, 2020, resulting in a gain of $295 thousand. The Company services residential mortgage loans for other entities totaling $2.1 billion at September 30, 2021 and $2.3 billion at December 31, 2020. 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) 2021 2020 2021 2020 Beginning balance $ 11,501 $ 14,926 $ 13,422 $ 17,484 Additions 483 1,301 1,685 3,269 Amortization (1,363) (1,616) (4,295) (4,992) Adjustment to valuation allowance (454) (203) (645) (1,353) Ending balance $ 10,167 $ 14,408 $ 10,167 $ 14,408 Loan servicing fees, net of mortgage servicing rights amortization, were $0.4 million and $0.3 million for the three months ended September 30, 2021 and 2020, respectively, and $1.2 million and $1.1 million for the nine months ended September 30, 2021 and 2020, respectively, and are included within loan and lease related fees on the accompanying Condensed Consolidated Statements of Income. Refer to Note 15: Fair Value Measurements for additional information on loans held for sale and mortgage servicing assets.

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leasing	Leasing The Company enters into operating leases, as lessee, primarily for office space, banking centers, and certain other operational assets. The Company's operating leases generally have lease terms for periods of 5 to 20 years with various renewal options. The Company does not have any material sub-lease agreements. The following table summarizes lessee information related to the Company’s operating ROU lease assets and lease liabilities: At September 30, 2021 (In thousands) Operating Leases Condensed Consolidated Balance Sheet Line Item Location ROU lease assets $ 123,407 Premises and equipment, net Lease liabilities 150,708 Operating lease liabilities The components of operating lease cost and other related information are as follows: At or for the three months ended September 30, At or for the nine months ended September 30, (In thousands) 2021 2020 2021 2020 Lease Cost: Operating lease costs $ 6,487 $ 7,381 $ 19,598 $ 22,212 Variable lease costs 1,063 1,297 3,714 4,217 Sublease income (141) (141) (412) (428) Total operating lease cost $ 7,409 $ 8,537 $ 22,900 $ 26,001 Other Information: Cash paid for amounts included in the measurement of lease liabilities $ 7,498 $ 7,823 $ 23,003 $ 23,359 ROU lease assets obtained in exchange for new operating lease liabilities 2,586 856 12,144 9,552 The undiscounted scheduled maturities reconciled to total operating lease liabilities are as follows: (In thousands) At September 30, 2021 Remainder of 2021 $ 5,141 2022 28,292 2023 26,443 2024 23,666 2025 21,687 Thereafter 66,806 Total operating lease liability payments 172,035 Less: Present value adjustment 21,327 Lease liabilities $ 150,708 Weighted-average remaining lease term, in years 7.67 Weighted-average discount rate 3.07%

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets There has been no change during the three and nine months ended September 30, 2021 in the carrying amount for goodwill. For goodwill by reportable segment, refer to Note 17: Segment Reporting. Other intangible assets by reportable segment consisted of the following: At September 30, 2021 At December 31, 2020 (In thousands) Gross Carrying Accumulated Net Carrying Gross Carrying Accumulated Net Carrying HSA Bank - Core deposits $ 26,625 $ 17,801 $ 8,824 $ 26,625 $ 15,618 $ 11,007 HSA Bank - Customer relationships 21,000 10,837 10,163 21,000 9,624 11,376 Total other intangible assets $ 47,625 $ 28,638 $ 18,987 $ 47,625 $ 25,242 $ 22,383 At September 30, 2021, the remaining estimated aggregate future amortization expense for other intangible assets is as follows: (In thousands) Remainder of 2021 $ 1,117 2022 4,411 2023 4,315 2024 2,084 2025 2,084 Thereafter 4,976

Deposits

Deposits	9 Months Ended
	Sep. 30, 2021
Deposit Liabilities [Abstract]
Deposits	Deposits A summary of deposits by type is as follows: (In thousands) At September 30, At December 31, Non-interest-bearing: Demand $ 7,154,835 $ 6,155,592 Interest-bearing: Health savings accounts 7,329,405 7,120,017 Checking 4,181,825 3,652,763 Money market 3,958,700 2,940,215 Savings 5,517,189 4,979,031 Time deposits 1,884,373 2,487,818 Total interest-bearing $ 22,871,492 $ 21,179,844 Total deposits $ 30,026,327 $ 27,335,436 Time deposits and interest-bearing checking obtained through brokers (included in above balances) $ 109,312 $ 720,440 Time deposits that exceed the FDIC limit (included in above balance) 308,498 504,543 Deposit overdrafts reclassified as loan balances 1,111 2,007 The scheduled maturities of time deposits are as follows: (In thousands) At September 30, Remainder of 2021 $ 646,277 2022 1,022,752 2023 103,532 2024 44,240 2025 50,664 Thereafter 16,908 Total time deposits $ 1,884,373

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Borrowings	Borrowings Total borrowings of $1.3 billion at September 30, 2021 and $1.7 billion at December 31, 2020 are described in detail below. The following table summarizes securities sold under agreements to repurchase and other borrowings: At September 30, At December 31, (Dollars in thousands) Total Outstanding Rate Total Outstanding Rate Securities sold under agreements to repurchase (1) : Original maturity of one year or less $ 455,871 0.11 % $ 269,330 0.13 % Original maturity of greater than one year, non-callable 200,000 1.22 200,000 0.84 Total securities sold under agreements to repurchase 655,871 0.45 469,330 0.43 Fed funds purchased — — 526,025 0.08 Securities sold under agreements to repurchase and other borrowings $ 655,871 0.45 $ 995,355 0.25 (1) The Company has right of offset with respect to all repurchase agreement assets and liabilities. Total securities sold under agreements to repurchase are presented as gross transactions, as only liabilities are outstanding for the periods presented. Repurchase agreements are used as a source of borrowed funds and are collateralized by Agency MBS. Repurchase agreement counterparties are limited to primary dealers in government securities and commercial/municipal customers through the Corporate Treasury function. The following table provides information for FHLB advances: At September 30, 2021 At December 31, 2020 (Dollars in thousands) Total Outstanding Weighted- Total Outstanding Weighted- Maturing within 1 year $ 11 — % $ 25,000 0.38 % After 1 but within 2 years 157 1.75 110 — After 2 but within 3 years 50,132 1.59 215 2.95 After 3 but within 4 years 50,000 1.42 50,000 1.59 After 4 but within 5 years — — 50,000 1.42 After 5 years 13,034 2.57 7,839 2.66 FHLB advances $ 113,334 1.63 $ 133,164 1.36 Aggregate carrying value of assets pledged as collateral $ 7,150,473 $ 7,387,054 Remaining borrowing capacity 4,704,060 4,689,642 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) 340,149 344,164 Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (2) 77,320 77,320 Total notes and subordinated debt 567,469 571,484 Discount on senior fixed-rate notes (1,029) (1,193) Debt issuance cost on senior fixed-rate notes (2,326) (2,628) Long-term debt $ 564,114 $ 567,663 (1) The Company de-designated its fair value hedging relationship on these notes. A basis adjustment of $40.1 million and $44.2 million at September 30, 2021 and December 31, 2020, respectively, is included in the carrying value and is being amortized over the remaining life of the notes. (2) The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95%, was 3.07% at September 30, 2021 and 3.18% at December 31, 2020.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income, Net of Tax	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Accumulated Other Comprehensive Income, Net of Tax	Accumulated Other Comprehensive Income, Net of Tax The following table summarizes the changes in each component of accumulated other comprehensive income (loss), net of tax (AOCI/AOCL): Three months ended September 30, 2021 Nine months ended September 30, 2021 (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 $ 35,598 $ 13,894 $ (43,602) $ 5,890 $ 67,424 $ 19,918 $ (45,086) $ 42,256 Other comprehensive (loss) before reclassifications (3,394) (2,560) — (5,954) (35,220) (10,205) — (45,425) Amounts reclassified from accumulated other comprehensive income (loss) — 829 743 1,572 — 2,450 2,227 4,677 Net current-period other comprehensive (loss) income, net of tax (3,394) (1,731) 743 (4,382) (35,220) (7,755) 2,227 (40,748) Ending balance $ 32,204 $ 12,163 $ (42,859) $ 1,508 $ 32,204 $ 12,163 $ (42,859) $ 1,508 Three months ended September 30, 2020 Nine months ended September 30, 2020 (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 $ 63,476 $ 20,649 $ (42,680) $ 41,445 $ 17,251 $ (9,184) $ (44,139) $ (36,072) Other comprehensive income (loss) before reclassifications 11,766 (3,310) — 8,456 57,997 23,655 — 81,652 Amounts reclassified from accumulated other comprehensive income (loss) — 1,398 738 2,136 (6) 4,266 2,197 6,457 Net current-period other comprehensive income (loss), net of tax 11,766 (1,912) 738 10,592 57,991 27,921 2,197 88,109 Ending balance $ 75,242 $ 18,737 $ (41,942) $ 52,037 $ 75,242 $ 18,737 $ (41,942) $ 52,037 The following table further details the amounts reclassified from AOCI (AOCL): (In thousands) Three months ended September 30, Nine months ended September 30, Associated Line Item on the Condensed Consolidated Statements of Income AOCI (AOCL) Component 2021 2020 2021 2020 Securities available-for-sale: Unrealized gains on investment securities $ — $ — $ — $ 8 Gain on sale of investment securities, net Tax expense — — — (2) Income tax expense Net of tax $ — $ — $ — $ 6 Derivative instruments: Hedge terminations $ (1,046) $ (967) $ (3,088) $ (3,228) Interest expense Premium amortization (76) (926) (229) (2,548) Interest income Tax benefit 293 495 867 1,510 Income tax expense Net of tax $ (829) $ (1,398) $ (2,450) $ (4,266) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (1,008) $ (1,002) $ (3,023) $ (2,982) Other non-interest expense Tax benefit 265 264 796 785 Income tax expense Net of tax $ (743) $ (738) $ (2,227) $ (2,197)

Regulatory Matters

Regulatory Matters	9 Months Ended
	Sep. 30, 2021
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 OCC. Regulatory authorities can initiate certain mandatory actions if either 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. Total risk-based capital is comprised of three categories as defined by Basel III capital rules: CET1 capital, Tier 1 capital, and Tier 2 capital. CET1 capital includes common shareholders' equity, less deductions for goodwill, other intangibles, and certain deferred tax adjustments. For purposes of CET1 capital, common shareholders' equity excludes AOCI (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 ACL, that together equal total capital. The following table provides information on the capital ratios for Webster Financial Corporation and Webster Bank: At September 30, 2021 Actual (1) Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,729,789 11.77 % $ 1,044,068 4.5 % $ 1,508,098 6.5 % Total risk-based capital 3,200,180 13.79 1,856,121 8.0 2,320,151 10.0 Tier 1 risk-based capital 2,874,826 12.39 1,392,091 6.0 1,856,121 8.0 Tier 1 leverage capital 2,874,826 8.37 1,373,218 4.0 1,716,523 5.0 Webster Bank CET1 risk-based capital $ 2,961,510 12.77 % $ 1,043,279 4.5 % $ 1,506,959 6.5 % Total risk-based capital 3,209,544 13.84 1,854,719 8.0 2,318,399 10.0 Tier 1 risk-based capital 2,961,510 12.77 1,391,039 6.0 1,854,719 8.0 Tier 1 leverage capital 2,961,510 8.63 1,372,558 4.0 1,715,698 5.0 At December 31, 2020 Actual Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,543,131 11.35 % $ 1,008,512 4.5 % $ 1,456,739 6.5 % Total risk-based capital 3,045,652 13.59 1,792,910 8.0 2,241,137 10.0 Tier 1 risk-based capital 2,688,168 11.99 1,344,682 6.0 1,792,910 8.0 Tier 1 leverage capital 2,688,168 8.32 1,291,980 4.0 1,614,975 5.0 Webster Bank CET1 risk-based capital $ 2,791,474 12.46 % $ 1,008,027 4.5 % $ 1,456,039 6.5 % Total risk-based capital 3,071,505 13.71 1,792,048 8.0 2,240,060 10.0 Tier 1 risk-based capital 2,791,474 12.46 1,344,036 6.0 1,792,048 8.0 Tier 1 leverage capital 2,791,474 8.65 1,291,415 4.0 1,614,268 5.0 (1) In accordance with regulatory capital rules, the Company elected an option to delay the estimated impact of the adoption of CECL on its regulatory capital over a two-year deferral period and subsequent three-year transition period ending December 31, 2024. As a result, capital ratios and amounts exclude the impact of the increased ACL on loans, held-to-maturity debt securities, and unfunded loan commitments attributed to the adoption of CECL, adjusted for an approximation of the after-tax provision for credit losses attributable to CECL relative to the incurred loss methodology during the deferral period. 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. Dividends paid by the Bank are subject to various federal and state regulatory limitations. Express approval by the OCC is required if the effect of dividends declared would cause the regulatory capital of the Bank to fall below specified minimum levels, or would exceed the net income for that year combined with the undistributed net income for the preceding two years. Webster Bank paid $160.0 million in dividends to Webster Financial Corporation during the nine months ended September 30, 2021, whereas no dividends were paid during the nine months ended September 30, 2020. Cash Restrictions. Webster Bank is required by Federal Reserve System regulations to hold cash reserve balances on hand or with an FRB. To address liquidity concerns due to COVID-19, the Federal Reserve reset the requirement to zero. The reserve requirement ratio remains subject to adjustment as conditions warrant.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share A reconciliation of the calculation of basic and diluted earnings per common share is as follows: Three months ended September 30, Nine months ended September 30, (In thousands, except per share data) 2021 2020 2021 2020 Earnings for basic and diluted earnings per common share: Net income $ 95,713 $ 69,281 $ 297,826 $ 160,577 Less: Preferred stock dividends 1,968 1,968 5,906 5,906 Net income available to common shareholders 93,745 67,313 291,920 154,671 Less: Earnings applicable to participating securities (1) 574 423 1,661 913 Earnings applicable to common shareholders $ 93,171 $ 66,890 $ 290,259 $ 153,758 Shares: Weighted-average common shares outstanding - basic 90,038 89,630 89,960 90,076 Effect of dilutive securities 194 108 226 159 Weighted-average common shares outstanding - diluted 90,232 89,738 90,186 90,235 Earnings per common share (1) : Basic $ 1.03 $ 0.75 $ 3.23 $ 1.71 Diluted 1.03 0.75 3.22 1.70 (1) Earnings per common share amounts under the two-class method for unvested time-based restricted stock with non-forfeitable dividends and dividend rights are computed the same as the presentation above. Dilutive Securities Webster 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 attributed to outstanding stock options and non-participating, performance-based restricted stock.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments Derivative Positions and Offsetting Derivatives Designated in Hedge Relationships . Interest rate swaps allow the Company to change the fixed or variable nature of an interest rate without the exchange of the underlying notional amount. Certain pay fixed/receive variable interest rate swaps are designated as cash flow hedges to effectively convert variable-rate debt into fixed-rate debt, while certain receive fixed/pay variable interest rate swaps are designated as fair value hedges to effectively convert fixed-rate long-term debt into variable-rate debt. Certain purchased options are designated as cash flow hedges. Purchased options allow the Company to limit the potential adverse impact of variable interest rates by establishing a cap or floor rate in exchange for an upfront premium. The purchased options designated as cash flow hedges represent interest rate caps where payment is received from the counterparty if interest rates rise above the cap rate, and interest rate floors where payment is received from the counterparty when interest rates fall below the floor rate. Derivatives Not Designated in Hedge Relationships. The Company also enters into other derivative transactions to manage economic risks, but does not designate the instruments in hedge relationships. Further, the Company enters into derivative contracts to accommodate customer needs. Derivative contracts with customers are offset with dealer counterparty transactions structured with matching terms to ensure minimal impact on earnings. The following table presents the notional amounts and fair values, including accrued interest, of derivative positions: At September 30, 2021 At December 31, 2020 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) $ 1,000,000 $ 26,923 $ — $ — $ 1,000,000 $ 40,854 $ 25,000 $ 110 Not designated as hedging instruments: Interest rate derivatives (1) 4,434,047 178,749 4,360,615 17,566 4,421,627 297,085 4,468,153 12,203 Mortgage banking derivatives (2) 30,663 300 — — 40,771 855 — — Other (3) 108,875 359 362,668 109 108,987 264 360,497 377 Total not designated as hedging instruments 4,573,585 179,408 4,723,283 17,675 4,571,385 298,204 4,828,650 12,580 Gross derivative instruments, before netting $ 5,573,585 206,331 $ 4,723,283 17,675 $ 5,571,385 339,058 $ 4,853,650 12,690 Less: Master netting agreements 4,772 4,772 7,748 7,748 Cash collateral 28,679 2,731 33,972 4,550 Total derivative instruments, after netting $ 172,880 $ 10,172 $ 297,338 $ 392 (1) Balances related to Chicago Mercantile Exchange (CME) are presented as a single unit of account. In accordance with its rule book, CME legally characterizes variation margin payments as settlement of derivatives rather than collateral against derivative positions. Notional amounts of interest rate swaps cleared through CME include $0.3 billion and $0.1 billion for asset derivatives and $3.0 billion and $3.2 billion for liability derivatives at September 30, 2021 and December 31, 2020, respectively. The related fair values approximate zero. (2) Notional amounts related to residential loans exclude approved floating rate commitments of $0.7 million at September 30, 2021. (3) 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 $82.8 million and $80.5 million for asset derivatives and $355.1 million and $338.9 million for liability derivatives at September 30, 2021 and December 31, 2020, respectively, that have insignificant related fair values. The following table presents fair value positions transitioned from gross to net upon applying contractual counterparty netting agreements: At September 30, 2021 (In thousands) Gross Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 33,451 $ 33,451 $ — $ 100 $ 100 Liability derivatives 7,503 7,503 — 701 701 At December 31, 2020 (In thousands) Gross Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 41,774 $ 41,720 $ 54 $ 666 $ 720 Liability derivatives 12,352 12,298 54 265 319 Derivative Activity The following table presents 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 2021 2020 2021 2020 Interest rate derivatives Long-term debt $ 90 $ 1,152 $ 334 $ 3,501 Interest rate derivatives Interest and fees on loans and leases (2,706) (2,657) (7,933) (3,754) Net recognized on cash flow hedges $ (2,616) $ (1,505) $ (7,599) $ (253) The following table presents information related to a fair value hedging adjustment: Condensed Consolidated Balance Sheet Line Item in Which Hedged Item is Located Carrying Amount of Previously Hedged Item Cumulative Amount of Fair Value Hedging Adjustment Included in Carrying Amount (In thousands) At September 30, At December 31, At September 30, At December 31, Long-term debt $ 340,149 $ 344,164 $ 40,149 $ 44,164 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 2021 2020 2021 2020 Interest rate derivatives Other income $ 2,727 $ 3,824 $ 7,132 $ 7,227 Mortgage banking derivatives Mortgage banking activities 38 872 (556) 2,498 Other Other income 611 (1,229) 780 (332) Total not designated as hedging instruments $ 3,376 $ 3,467 $ 7,356 $ 9,393 Purchased options designated as cash flow hedges exclude time-value premiums from the assessment of hedge effectiveness. Time-value premiums are amortized on a straight-line basis. At September 30, 2021, the remaining unamortized balance of time-value premiums was $7.8 million. Over the next twelve months, an estimated $10.5 million decrease to interest expense will be reclassified from AOCI (AOCL) relating to cash flow hedges, and an estimated $0.3 million increase to interest expense will be reclassified from AOCI (AOCL) relating to hedge terminations. At September 30, 2021, the remaining unamortized loss on terminated cash flow hedges is $0.7 million. The maximum length of time over which forecasted transactions are hedged is 2.8 years. Additional information about cash flow hedge activity impacting AOCI (AOCL) and the related amounts reclassified to interest expense is provided in Note 11: Accumulated Other Comprehensive Income, Net of Tax. Information about the valuation methods used to measure the fair value of derivatives is provided in Note 15: Fair Value Measurements. Derivative Exposure At September 30, 2021, the Company had $63.0 million in initial margin collateral posted at CME. In addition, $29.4 million of cash collateral received is included in cash and due from banks on the accompanying Condensed Consolidated Balance Sheets. 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. Current net credit exposure relating to interest rate derivatives with Webster Bank customers was $172.6 million at September 30, 2021. 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 $35.5 million at September 30, 2021. The Company incorporates a credit valuation adjustment (CVA) and debit valuation adjustment (DVA) to reflect nonperformance risk in the fair value measurement of its derivatives. Various factors impact changes in the CVA and DVA over time, including changes in the credit spreads of the parties to the contracts, as well as changes in market rates and volatilities, which affect the total expected exposure of the derivative instruments.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
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, rate volatility, prepayment speeds, credit ratings,) or inputs that are derived principally or corroborated by market data, 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 fair value 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 . The fair values presented for derivative instruments include any accrued interest. 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. 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, 2021 At December 31, 2020 (In thousands) Fair Value Unpaid Principal Balance Difference Fair Value Unpaid Principal Balance Difference Originated loans held for sale $ 10,032 $ 9,926 $ 106 $ 14,000 $ 13,511 $ 489 Investments Held in Rabbi Trust. Investments held in the Rabbi Trust primarily include open-ended mutual funds that invest in equity and fixed income securities. Shares of mutual funds are valued based on net asset value (NAV), 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. The Company 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 $1.6 million at September 30, 2021. 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. At September 30, 2021, these alternative investments had a carrying amount of $1.3 million and no remaining unfunded commitment. During the nine months ended September 30, 2021, there was a $49 thousand write-down due to an observable price change. Equity investments that do not have a readily available fair value may qualify for NAV practical expedient 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, 2021, these alternative investments had a remaining unfunded commitment of $15.4 million. A summary of the financial assets and liabilities measured at fair value on a recurring basis is as follows: At September 30, 2021 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: Agency CMO $ — $ 105,783 $ — $ 105,783 Agency MBS — 1,596,784 — 1,596,784 Agency CMBS — 898,586 — 898,586 CMBS — 770,086 — 770,086 CLO — 24,967 — 24,967 Corporate debt — 14,237 — 14,237 Total available-for-sale investment securities — 3,410,443 — 3,410,443 Gross derivative instruments, before netting (1) 330 206,001 — 206,331 Originated loans held for sale — 10,032 — 10,032 Investments held in Rabbi Trust 3,597 — — 3,597 Alternative investments (2) 1,323 — — 22,546 Total financial assets held at fair value $ 5,250 $ 3,626,476 $ — $ 3,652,949 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 38 $ 17,637 $ — $ 17,675 At December 31, 2020 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: Agency CMO $ — $ 154,613 $ — $ 154,613 Agency MBS — 1,457,409 — 1,457,409 Agency CMBS — 1,117,233 — 1,117,233 CMBS — 508,018 — 508,018 CLO — 76,383 — 76,383 Corporate debt — 13,120 — 13,120 Total available-for-sale investment securities — 3,326,776 — 3,326,776 Gross derivative instruments, before netting (1) 205 338,853 — 339,058 Originated loans held for sale — 14,000 — 14,000 Investments held in Rabbi Trust 4,811 — — 4,811 Alternative investments (2) — — — 11,112 Total financial assets held at fair value $ 5,016 $ 3,679,629 $ — $ 3,695,757 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 218 $ 12,472 $ — $ 12,690 (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, refer to Note 14: Derivative Financial Instruments. (2) Certain alternative investments are recorded at NAV. Assets measured at NAV are not classified within the fair value hierarchy. 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, 2021, 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 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 $23.2 million at September 30, 2021, which is inclusive of $3.9 million and $0.2 million measured at fair value where there were $3.3 million in write-ups due to observable price changes and a $0.3 million write-down due to impairment, respectively. No other adjustments were identified during the nine months ended September 30, 2021. 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 fair value 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. Collateral Dependent Loans and Leases. Loans and leases for which the payment 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, less estimated cost to sell, using customized discounting criteria. Accordingly, such collateral dependent loans and leases are classified within Level 3 of the fair value hierarchy. Other Real Estate Owned (OREO) and Repossessed Assets. The total book value of OREO and repossessed assets was $2.4 million at September 30, 2021. 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. In addition, the amortized cost of consumer loans secured by residential real estate property that are in process of foreclosure amounted to $11.2 million at September 30, 2021. 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 for servicing assets. The following is a description of the 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 based on 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 collateral dependent 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 equal to the carrying value. Fair value for all other balances are estimated using a 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 flows 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 initially recorded at fair value and subsequently measured under the amortization method. 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 related servicing revenue stream. Mortgage servicing assets are reviewed quarterly and held at the lower of the carrying amount or fair value. Fair value adjustments, if any, are included as a component of loan related fees in the accompanying Condensed Consolidated Statements of Income. Mortgage servicing assets are classified within Level 3 of the fair value hierarchy. The carrying amounts, estimated fair values, and classifications within the fair value hierarchy of selected financial instruments and servicing assets are summarized as follows: At September 30, 2021 At December 31, 2020 (In thousands) Carrying Fair Carrying Fair Assets: Level 2 Held-to-maturity investment securities, net $ 5,986,308 $ 6,139,440 $ 5,567,889 $ 5,835,364 Level 3 Loans and leases, net 21,265,413 21,393,481 21,281,784 21,413,397 Mortgage servicing assets 10,167 13,032 13,422 14,362 Liabilities: Level 2 Deposit liabilities $ 28,141,954 $ 28,141,954 $ 24,847,618 $ 24,847,618 Time deposits 1,884,373 1,885,341 2,487,818 2,494,601 Securities sold under agreements to repurchase and other borrowings 655,871 660,146 995,355 1,000,189 FHLB advances 113,334 117,237 133,164 139,035 Long-term debt (1) 564,114 522,251 567,663 538,407 (1) Adjustments to the carrying amount of long-term debt for basis adjustment and unamortized discount and debt issuance cost on senior fixed-rate notes are not included in the determination of fair value. Refer to Note 10: Borrowings for additional information.

Retirement Benefit Plans

Retirement Benefit Plans	9 Months Ended
	Sep. 30, 2021
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 (income) cost: Three months ended September 30, 2021 2020 (In thousands) Pension Plan SERP Other Pension Plan SERP Other Benefits Interest cost on benefit obligations $ 1,166 $ 7 $ 4 $ 1,531 $ 12 $ 9 Expected return on plan assets (3,595) — — (3,380) — — Recognized net loss (gain) 1,019 8 (20) 1,036 5 (38) Net periodic benefit (income) cost $ (1,410) $ 15 $ (16) $ (813) $ 17 $ (29) Nine months ended September 30, 2021 2020 (In thousands) Pension Plan SERP Other Benefits Pension Plan SERP Other Benefits Interest cost on benefit obligations $ 3,498 $ 20 $ 12 $ 4,881 $ 35 $ 34 Expected return on plan assets (10,786) — — (10,140) — — Recognized net loss (gain) 3,058 25 (60) 3,021 17 (55) Net periodic benefit (income) cost $ (4,230) $ 45 $ (48) $ (2,238) $ 52 $ (21) The components of net periodic benefit (income) cost are included within other non-interest expense on the accompanying Condensed Consolidated Statements of Income. The weighted-average expected long-term rate of return on plan assets for the three and nine months ended September 30, 2021 was 5.50%, as determined at the beginning of the fiscal year.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2021
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 Retail Banking. These segments reflect how executive management responsibilities are assigned, how discrete financial information is evaluated, the type of customer served, and how products and services are provided. Certain Treasury activities, along with the amounts required to reconcile profitability metrics to those reported in accordance with GAAP, are included in the Corporate and Reconciling category. Effective January 1, 2021, management realigned certain of the Company's business banking and investment services operations to better serve its customers and deliver operational efficiencies. The previously reported Community Banking segment was also renamed as Retail Banking. Under this realignment, $131.0 million of goodwill was reallocated, on a relative fair value basis, from Retail Banking to Commercial Banking. There was no goodwill impairment as a result of the reorganization. Prior period amounts have been recasted to reflect the realignment. Description of Segment Reporting Methodology Webster uses an internal profitability reporting system to generate information by reportable segment, which is based on a series of management estimates for funds transfer pricing, and allocations for non-interest expense, provision for credit losses, 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 results of any reportable 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 reportable 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, through an internal matched maturity Funds Transfer Pricing (FTP) process. The goal of the FTP allocation is to encourage loan and deposit growth consistent with the Company’s overall profitability objectives. The FTP process considers the specific interest rate risk and liquidity risk of financial instruments and other assets and liabilities in each line of business. Loans are assigned an FTP rate for funds used and deposits are assigned an FTP rate for funds provided. The allocation 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. The FTP process transfers the corporate interest rate risk exposure to the treasury function included within the Corporate and Reconciling category where such exposures are centrally managed. 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. Business development costs are generally included in the Corporate and Reconciling category. The results of funds transfer pricing and allocations for non-interest expense, as well as non-interest income produces PPNR, under which basis the segments are reviewed by executive management. Webster also allocates the provision for credit losses to each reportable segment based on management's estimate of the inherent loss content in each of the specific loan and lease portfolios. ACL on loans and leases is included in total assets within the Corporate and Reconciling category. The following table presents balance sheet information, including all appropriate allocations, for Webster's reportable segments and the Corporate and Reconciling category: At September 30, 2021 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Goodwill $ 131,000 $ 21,813 $ 385,560 $ — $ 538,373 Total assets 14,862,455 74,236 7,538,017 12,899,550 35,374,258 At December 31, 2020 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Goodwill $ 131,000 $ 21,813 $ 385,560 $ — $ 538,373 Total assets 14,732,792 80,352 7,726,287 10,051,259 32,590,690 The following tables present the operating results, including all appropriate allocations, for Webster’s reportable segments and the Corporate and Reconciling category: Three months ended September 30, 2021 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Net interest income $ 152,556 $ 42,074 $ 98,028 $ (62,967) $ 229,691 Non-interest income 30,076 24,756 16,998 11,945 83,775 Non-interest expense 64,917 32,800 73,480 9,040 180,237 Pre-tax, pre-provision net revenue 117,715 34,030 41,546 (60,062) 133,229 Provision for credit losses 5,099 — 2,799 (148) 7,750 Income before income tax expense 112,616 34,030 38,747 (59,914) 125,479 Income tax expense 28,492 9,086 8,524 (16,336) 29,766 Net income $ 84,124 $ 24,944 $ 30,223 $ (43,578) $ 95,713 Three months ended September 30, 2020 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Net interest income $ 132,026 $ 39,861 $ 83,609 $ (36,240) $ 219,256 Non-interest income 20,710 27,235 21,359 5,756 75,060 Non-interest expense 66,482 34,789 80,119 2,606 183,996 Pre-tax, pre-provision net revenue 86,254 32,307 24,849 (33,090) 110,320 Provision for credit losses 31,753 — (9,000) (3) 22,750 Income before income tax expense 54,501 32,307 33,849 (33,087) 87,570 Income tax expense 13,299 8,626 7,379 (11,015) 18,289 Net income $ 41,202 $ 23,681 $ 26,470 $ (22,072) $ 69,281 Nine months ended September 30, 2021 (In thousands) Commercial HSA Retail Banking Corporate and Consolidated Net interest income $ 435,718 $ 126,376 $ 279,381 $ (167,168) $ 674,307 Non-interest income 80,966 78,315 49,832 24,121 233,234 Non-interest expense 191,198 101,842 221,950 40,257 $ 555,247 Pre-tax, pre-provision net revenue 325,486 $ 102,849 107,263 (183,304) 352,294 Provision for credit losses (37,602) — (1,833) (65) (39,500) Income before income tax expense 363,088 102,849 109,096 (183,239) 391,794 Income tax expense 91,861 27,461 24,001 (49,355) 93,968 Net income $ 271,227 $ 75,388 $ 85,095 $ (133,884) $ 297,826 Nine months ended September 30, 2020 (In thousands) Commercial HSA Retail Banking Corporate and Consolidated Net interest income $ 377,736 $ 121,868 $ 246,417 $ (71,557) $ 674,464 Non-interest income 64,975 76,721 56,083 10,735 208,514 Non-interest expense 192,964 105,887 237,528 3,037 539,416 Pre-tax, pre-provision net revenue 249,747 92,702 64,972 (63,859) 343,562 Provision for credit losses 144,340 — (5,499) (91) 138,750 Income before income tax expense 105,407 92,702 70,471 (63,768) 204,812 Income tax expense 25,720 24,751 15,362 (21,598) 44,235 Net income $ 79,687 $ 67,951 $ 55,109 $ (42,170) $ 160,577

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers The following table presents revenues within the scope of ASC Topic 606, Revenue from Contracts with Customers, along with the net amount of other sources of non-interest income that are within the scope of other GAAP topics, by reportable segment: Three months ended September 30, 2021 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Non-interest Income: Deposit service fees $ 4,207 $ 22,886 $ 13,078 $ 87 $ 40,258 Wealth and investment services 9,993 — — (8) 9,985 Other 361 1,870 265 — 2,496 Revenue from contracts with customers 14,561 24,756 13,343 79 52,739 Other sources of non-interest income 15,515 — 3,655 11,866 31,036 Total non-interest income $ 30,076 $ 24,756 $ 16,998 $ 11,945 $ 83,775 Three months ended September 30, 2020 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Non-interest Income: Deposit service fees $ 3,615 $ 23,667 $ 11,972 $ 24 $ 39,278 Wealth and investment services 8,234 — — 21 8,255 Other 277 3,568 249 — 4,094 Revenue from contracts with customers 12,126 27,235 12,221 45 51,627 Other sources of non-interest income 8,584 — 9,138 5,711 23,433 Total non-interest income $ 20,710 $ 27,235 $ 21,359 $ 5,756 $ 75,060 Nine months ended September 30, 2021 (In thousands) Commercial HSA Retail Banking Corporate and Consolidated Non-interest Income: Deposit service fees $ 12,412 $ 72,382 $ 37,115 $ 257 $ 122,166 Wealth and investment services 29,501 — — (26) 29,475 Other 939 5,933 814 — 7,686 Revenue from contracts with customers 42,852 78,315 37,929 231 159,327 Other sources of non-interest income 38,114 — 11,903 23,890 73,907 Total non-interest income $ 80,966 $ 78,315 $ 49,832 $ 24,121 $ 233,234 Nine months ended September 30, 2020 (In thousands) Commercial HSA Retail Banking Corporate and Consolidated Non-interest Income: Deposit service fees $ 10,969 $ 70,250 $ 36,460 $ 8 $ 117,687 Wealth and investment services 24,120 — — (24) 24,096 Other 896 6,471 687 — 8,054 Revenue from contracts with customers 35,985 76,721 37,147 (16) 149,837 Other sources of non-interest income 28,990 — 18,936 10,751 58,677 Total non-interest income $ 64,975 $ 76,721 $ 56,083 $ 10,735 $ 208,514 The major sources of revenue from contracts with customers 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 are satisfied monthly. Interchange fees are assessed as the performance obligation is satisfied, which is the point in time that 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, but 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 within Note 17: Segment Reporting. Contracts with customers did not generate significant contract assets and liabilities.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
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 a 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 Letters 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 Letters 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, 2020 Commitments to extend credit $ 6,953,871 $ 6,517,840 Standby letters of credit 220,895 207,201 Commercial letters of credit 49,783 30,522 Total credit-related financial instruments with off-balance sheet risk $ 7,224,549 $ 6,755,563 These commitments subject the Company to potential exposure in excess of amounts recorded in the financial statements, and therefore, management maintains an ACL on unfunded loan commitments to provide for expected losses in connection with funding the unused portion of legal commitments to lend when those commitments are not unconditionally cancellable by Webster. Loss calculation factors are consistent with the ACL methodology for funded loans using: PD and LGD applied to the underlying borrower risk and facility grades, a draw down factor applied to utilization rates, and relevant forecast information. This allowance is reported as a component of accrued expenses and other liabilities on the accompanying Condensed Consolidated Balance Sheets. The following table provides a summary of activity in the ACL on unfunded loan commitments: Three months ended September 30, Nine months ended September 30, (In thousands) 2021 2020 2021 2020 Beginning balance $ 11,974 $ 10,739 $ 12,755 $ 2,367 Adoption of ASU No. 2016-13 (CECL) — — — 9,139 (Benefit) provision 196 1,146 (585) 379 Ending balance $ 12,170 $ 11,885 $ 12,170 $ 11,885 Litigation The Company is subject to certain legal proceedings and claims in the ordinary course of business. Legal contingencies are evaluated based on information currently available, including advice of counsel and assessment of available insurance coverage. The Company establishes an accrual for specific legal matters when it determines that the likelihood of an unfavorable outcome is probable and the loss is reasonably estimable. Once established, each accrual is adjusted to reflect any subsequent developments. Legal proceedings are subject to inherent uncertainties, and unfavorable rulings may occur that could cause Webster to either adjust its litigation accrual or incur actual losses that exceed the current estimate, which ultimately could have a material adverse effect, either individually or in the aggregate, on its business, financial condition, or operating results. Webster will consider settlement of cases when it is in the best interests of the Company and its shareholders. However, the Company intends

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsThe Company has evaluated subsequent events from the date of the Condensed Consolidated Financial Statements and accompanying Notes thereto, September 30, 2021, through the date of issuance, and determined that no significant events were identified requiring recognition or disclosure.

Business Developments

Business Developments	9 Months Ended
	Sep. 30, 2021
Business Combination and Restructuring and Related Activities [Abstract]
Business Developments	Business Developments Pending Merger On April 19, 2021, Webster and Sterling announced that their boards of directors approved by unanimous vote a definitive agreement under which the two companies will combine in an all-stock transaction. Under the terms of the agreement, Sterling will merge into Webster, and Sterling's shareholders will receive a fixed exchange ratio of 0.463 of a Webster common share for each share of Sterling common stock owned. In addition, at the effective time of the merger, each outstanding share of Sterling's 6.50% Series A Non-Cumulative Perpetual Preferred Stock will be converted into the right to receive a newly created series of Webster preferred stock having substantially the same terms. The proposed merger was approved by the respective shareholders of both Webster and Sterling on August 17, 2021. Webster Bank and Sterling National Bank, the respective subsidiary banks of Webster and Sterling, also received approval to merge from the OCC on August 2, 2021 as part of the proposed merger between Webster and Sterling. Completion of the merger remains subject to regulatory approval by the Board of Governors of the Federal Reserve System and the satisfaction of the other customary closing conditions set forth in the merger agreement. In connection with the proposed transaction, the Company incurred $9.8 million and $26.9 million of merger-related expenses during the three and nine months ended September 30, 2021, respectively, primarily consisting of professional fees for investment banking, legal, and consulting services, and employee severance and retention costs. Merger-related expenses are recorded as either professional and outside services, compensation and benefits, or other non-interest expense on the accompanying Condensed Consolidated Statements of Income, and are presented in the Corporate and Reconciling category for segment reporting purposes. Strategic Initiatives During the fourth quarter of 2020, the Company launched a strategic plan to drive incremental revenue and cost savings measures across the organization through the consolidation of banking centers and corporate facilities, process automation, ancillary spend reduction, and other organizational actions. The following table presents the changes in accrued expenses associated with the Company's strategic initiatives for the three and nine months ended September 30, 2021: Three months ended September 30, 2021 (In thousands) Severance ROU Asset Other Total Beginning balance $ 13,964 $ — $ 2,230 $ 16,194 Charged to earnings 1 91 53 145 Adjustments (1) (3,903) — (253) (4,156) Charged against assets — (91) (246) (337) Net cash (payments) receipts (3,923) — 193 (3,730) Ending balance $ 6,139 $ — $ 1,977 $ 8,116 Nine months ended September 30, 2021 (In thousands) Severance ROU Asset Other Total Beginning balance $ 17,675 $ — $ 2,120 $ 19,795 Charged to earnings 2,106 361 8,987 11,454 Adjustments (1) (3,903) — (984) (4,887) Charged against assets — (361) (3,776) (4,137) Net cash (payments) receipts (9,739) — (4,370) (14,109) Ending balance $ 6,139 $ — $ 1,977 $ 8,116 (1) Adjustments reflect changes in retention assumptions, gains on sale of banking centers, and other facilities-related adjustments. Severance costs are recorded as compensation and benefits, Right-of-Use (ROU) lease asset charges are recorded as occupancy expense, and Other is recorded as either occupancy, technology and equipment, professional and outside services, or other non-interest expense on the accompanying Condensed Consolidated Statements of Income. Strategic initiative costs are presented in the Corporate and Reconciling category for segment reporting purposes.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements of the Company have been prepared in accordance with GAAP for interim financial information and 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 thereto, for the year ended December 31, 2020, included in our Form 10-K filed with the SEC. In the opinion of management, all necessary adjustments are reflected to present fairly the financial position and results of operations as of the dates and for the periods shown. Operating results for the three and nine months ended September 30, 2021 are not necessarily indicative of results that may be attained during the full year ending December 31, 2021, or any future period. There have been no changes to the Company's significant accounting policies from those described within that Form 10-K, except as described within the Recently Adopted Accounting Standards Updates section of this note.
Use of Estimates	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 and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Recently Adopted Accounting Standards Updates	Recently Adopted Accounting Standards Updates ASU No. 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes. The Accounting Standards Update (the Update) provides simplification to the accounting for income taxes related to a variety of topics and makes minor codification improvements. Changes include a requirement that the effects of an enacted change in tax law be reflected in the computation of the annual effective tax rate in the first interim period that includes the enactment date of the new legislation and clarification on presentation of non-income based taxes. The Company adopted the Update on January 1, 2021 on a prospective basis. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. ASU No. 2021-01, Reference Rate Reform (Topic 848) - Scope. The Update clarifies that certain optional expedients and exceptions provided for in ASU No. 2020-04 for applying GAAP to contract modifications and hedging relationships apply to derivatives that are affected by the discounting transition. The amendments are elective and apply to all entities that have derivative instruments that use an interest rate for margining, discounting, or contract price alignment that is modified as a result of reference rate reform. The Update was effective upon issuance for application on either a retrospective basis as of any date from the beginning of an interim period that includes or is subsequent to March 22, 2020, or on a prospective basis beginning on January 7, 2021. The Company adopted the Update on a prospective basis. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. Relevant Accounting Standards Issued But Not Yet Adopted The Company has adopted all applicable Accounting Standards Updates issued by the Financial Accounting Standards Board (FASB) as of September 30, 2021.

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Held-to-maturity	A summary of the amortized cost, fair value, and ACL on investment securities held-to-maturity is presented below: At September 30, 2021 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value Allowance Net Carrying Value Agency CMO $ 50,146 $ 1,075 $ (48) $ 51,173 $ — $ 50,146 Agency MBS 2,544,509 101,289 (5,403) 2,640,395 — 2,544,509 Agency CMBS 2,509,487 22,432 (22,094) 2,509,825 — 2,509,487 Municipal bonds and notes 707,552 49,961 — 757,513 234 707,318 CMBS 174,848 5,686 — 180,534 — 174,848 Held-to-maturity securities $ 5,986,542 $ 180,443 $ (27,545) $ 6,139,440 $ 234 $ 5,986,308 At December 31, 2020 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value Allowance Net Carrying Value Agency CMO $ 91,622 $ 1,785 $ (241) $ 93,166 $ — $ 91,622 Agency MBS 2,419,751 137,863 (84) 2,557,530 — 2,419,751 Agency CMBS 2,101,227 60,484 (2,213) 2,159,498 — 2,101,227 Municipal bonds and notes 739,507 60,371 (3) 799,875 299 739,208 CMBS 216,081 9,214 — 225,295 — 216,081 Held-to-maturity securities $ 5,568,188 $ 269,717 $ (2,541) $ 5,835,364 $ 299 $ 5,567,889 (1) Amortized cost excludes accrued interest receivable of $16.7 million and $22.1 million at September 30, 2021 and December 31, 2020, respectively, which is included in accrued interest receivable and other assets on the accompanying Condensed Consolidated Balance Sheets. The following table summarizes the activity in the ACL on investment securities held-to-maturity: Three months ended September 30, Nine months ended September 30, (In thousands) 2021 2020 2021 2020 Balance beginning of period $ 382 $ 309 $ 299 $ — Adoption of ASU No. 2016-13 (CECL) — — — 397 Provision (benefit) for credit losses (148) (3) (65) (91) Balance end of period $ 234 $ 306 $ 234 $ 306 The following table summarizes credit ratings for the amortized cost of held-to-maturity debt securities according to their lowest public credit rating at September 30, 2021: Investment Grade (In thousands) Aaa Aa1 Aa2 Aa3 A1 A2 A3 Baa2 Not Rated Agency CMOs $ — $ 50,146 $ — $ — $ — $ — $ — $ — $ — Agency MBS — 2,544,509 — — — — — — — Agency CMBS — 2,509,487 — — — — — — — Municipal bonds and notes 207,813 119,988 227,479 104,454 36,045 8,464 — 190 3,119 CMBS 174,848 — — — — — — — — Total held-to-maturity $ 382,661 $ 5,224,130 $ 227,479 $ 104,454 $ 36,045 $ 8,464 $ — $ 190 $ 3,119 The amortized cost and fair value of held-to-maturity debt securities presented by contractual maturity are set forth below: At September 30, 2021 (In thousands) Amortized Fair Due in one year or less $ 380 $ 382 Due after one year through five years 5,933 6,222 Due after five years through ten years 294,506 307,837 Due after ten years 5,685,723 5,824,999 Total held-to-maturity debt securities $ 5,986,542 $ 6,139,440
Debt Securities, Available-for-sale	A summary of the amortized cost and fair value of available-for-sale securities is presented below: At September 30, 2021 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value (2) Agency CMO $ 102,257 $ 3,549 $ (23) $ 105,783 Agency MBS 1,552,693 50,705 (6,614) 1,596,784 Agency CMBS 901,654 6,852 (9,920) 898,586 CMBS 769,546 869 (329) 770,086 CLO 25,000 — (33) 24,967 Corporate debt 14,576 174 (513) 14,237 Available-for-sale securities $ 3,365,726 $ 62,149 $ (17,432) $ 3,410,443 At December 31, 2020 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value (2) Agency CMO $ 148,711 $ 6,000 $ (98) $ 154,613 Agency MBS 1,389,100 68,598 (289) 1,457,409 Agency CMBS 1,092,430 26,317 (1,514) 1,117,233 CMBS 512,759 1,082 (5,823) 508,018 CLO 76,693 — (310) 76,383 Corporate debt 14,557 — (1,437) 13,120 Available-for-sale securities $ 3,234,250 $ 101,997 $ (9,471) $ 3,326,776 (1) Amortized cost excludes accrued interest receivable of $6.6 million and $7.5 million at September 30, 2021 and December 31, 2020, respectively, which is included in accrued interest receivable and other assets on the accompanying Condensed Consolidated Balance Sheets. (2) Fair value represents net carrying value as there is no ACL recorded on investment securities available-for-sale, as the securities are high credit quality and investment grade. The following table provides information on fair value and unrealized losses for the individual available-for-sale securities with an unrealized loss, for which an ACL on investment securities available-for-sale has not been recorded, aggregated by classification and length of time that the individual investment securities have been in a continuous unrealized loss position: At September 30, 2021 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Unrealized Fair Unrealized # of Fair Unrealized Agency CMO $ 6,734 $ (19) $ 1,066 $ (4) 4 $ 7,800 $ (23) Agency MBS 495,080 (6,397) 19,902 (217) 55 514,982 (6,614) Agency CMBS 180,305 (2,583) 285,865 (7,337) 14 466,170 (9,920) CMBS 220,036 (238) 92,807 (91) 27 312,843 (329) CLO — — 24,967 (33) 1 24,967 (33) Corporate debt — — 9,788 (513) 2 9,788 (513) Available-for-sale in unrealized loss position $ 902,155 $ (9,237) $ 434,395 $ (8,195) 103 $ 1,336,550 $ (17,432) At December 31, 2020 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Unrealized Fair Unrealized # of Fair Unrealized Agency CMO $ 13,137 $ (49) $ 5,944 $ (49) 5 $ 19,081 $ (98) Agency MBS 33,742 (219) 4,561 (70) 30 38,303 (289) Agency CMBS 376,330 (1,514) — — 8 376,330 (1,514) CMBS 409,591 (5,486) 23,167 (337) 38 432,758 (5,823) CLO 57,728 (265) 18,655 (45) 4 76,383 (310) Corporate debt 4,100 (166) 9,020 (1,271) 3 13,120 (1,437) Available-for-sale in unrealized loss position $ 894,628 $ (7,699) $ 61,347 $ (1,772) 88 $ 955,975 $ (9,471) The amortized cost and fair value of available-for-sale debt securities presented by contractual maturity are set forth below: At September 30, 2021 (In thousands) Amortized Fair Due in one year or less $ — $ — Due after one year through five years 2,266 2,338 Due after five through ten years 152,856 153,009 Due after ten years 3,210,604 3,255,096 Total available-for-sale debt securities $ 3,365,726 $ 3,410,443

Loans and Leases (Tables)

Loans and Leases (Tables)	9 Months Ended
	Sep. 30, 2021
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, 2020 Commercial non-mortgage $ 6,552,241 $ 7,085,076 Asset-based 986,782 890,598 Commercial real estate 6,522,679 6,322,637 Equipment financing 620,104 602,224 Commercial portfolio 14,681,806 14,900,535 Residential 5,167,527 4,782,016 Home equity 1,633,873 1,802,865 Other consumer 97,129 155,799 Consumer portfolio 6,898,529 6,740,680 Loans and leases (1) (2) (3) $ 21,580,335 $ 21,641,215 (1) Loan balances include net deferred costs/(fees) and net discounts/(premiums) of $5.4 million and $(10.5) million at September 30, 2021 and December 31, 2020, respectively. (2) At September 30, 2021, the Company had pledged $7.5 billion of eligible loans as collateral to support borrowing capacity at the FHLB of Boston and the FRB of Boston. (3) Loan balances exclude accrued interest receivable of $55.2 million and $57.8 million at September 30, 2021 and December 31, 2020, respectively, which is included in accrued interest receivable and other assets on the accompanying Condensed Consolidated Balance Sheets.
Past Due Financing Receivables	The following table summarizes the aging of loans and leases: At September 30, 2021 (In thousands) 30-59 Days 60-89 Days 90 or More Days Past Due Non-accrual Total Past Due and Non-accrual Current Total Loans Commercial non-mortgage $ 2,051 $ 2,264 $ 105 $ 36,448 $ 40,868 $ 6,511,373 $ 6,552,241 Asset-based — — — 2,111 2,111 984,671 986,782 Commercial real estate 128 696 — 15,963 16,787 6,505,892 6,522,679 Equipment financing 1,215 9 — 4,222 5,446 614,658 620,104 Commercial portfolio 3,394 2,969 105 58,744 65,212 14,616,594 14,681,806 Residential 2,892 538 — 19,325 22,755 5,144,772 5,167,527 Home equity 4,905 1,437 — 23,322 29,664 1,604,209 1,633,873 Other consumer 564 266 — 263 1,093 96,036 97,129 Consumer portfolio 8,361 2,241 — 42,910 53,512 6,845,017 6,898,529 Total $ 11,755 $ 5,210 $ 105 $ 101,654 $ 118,724 $ 21,461,611 $ 21,580,335 At December 31, 2020 (In thousands) 30-59 Days 60-89 Days 90 or More Days Past Due Non-accrual Total Past Due and Non-accrual Current Total Loans Commercial non-mortgage $ 612 $ 903 $ 445 $ 64,073 $ 66,033 $ 7,019,043 $ 7,085,076 Asset-based 1,174 — — 2,594 3,768 886,830 890,598 Commercial real estate 2,400 619 — 21,231 24,250 6,298,387 6,322,637 Equipment financing 5,107 2,308 — 7,299 14,714 587,510 602,224 Commercial portfolio 9,293 3,830 445 95,197 108,765 14,791,770 14,900,535 Residential 4,334 6,330 — 41,081 51,745 4,730,271 4,782,016 Home equity 5,500 1,771 — 31,030 38,301 1,764,564 1,802,865 Other consumer 878 601 — 652 2,131 153,668 155,799 Consumer portfolio 10,712 8,702 — 72,763 92,177 6,648,503 6,740,680 Total $ 20,005 $ 12,532 $ 445 $ 167,960 $ 200,942 $ 21,440,273 $ 21,641,215
Financing Receivable, Nonaccrual	The following table provides additional detail related to loans and leases on non-accrual status: At September 30, 2021 At December 31, 2020 (In thousands) Non-accrual Non-accrual With No Allowance Non-accrual Non-accrual With No Allowance Commercial non-mortgage $ 36,448 $ 8,081 $ 64,073 $ 16,985 Asset-based 2,111 2,111 2,594 — Commercial real estate 15,963 4,951 21,231 15,529 Equipment financing 4,222 — 7,299 2,983 Commercial portfolio 58,744 15,143 95,197 35,497 Residential 19,325 11,420 41,081 29,843 Home equity 23,322 18,798 31,030 24,091 Other consumer 263 — 652 2 Consumer portfolio 42,910 30,218 72,763 53,936 Total $ 101,654 $ 45,361 $ 167,960 $ 89,433
Activity In Allowance For Losses	The following table summarizes the activity in, as well as the loan and lease balances that were evaluated for, ACL on loans and leases: At or for the three months ended September 30, 2021 2020 (In thousands) Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total ACL on loans and leases: Balance, beginning of period $ 263,071 $ 44,874 $ 307,945 $ 291,520 $ 67,002 $ 358,522 (Benefit) provision 7,681 217 7,898 31,618 (8,865) 22,753 Charge-offs (1,723) (2,053) (3,776) (13,494) (2,263) (15,757) Recoveries 142 2,713 2,855 2,025 2,268 4,293 Balance, end of period $ 269,171 $ 45,751 $ 314,922 $ 311,669 $ 58,142 $ 369,811 At or for the nine months ended September 30, 2021 2020 (In thousands) Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total ACL on loans and leases: Balance, beginning of period $ 312,244 $ 47,187 $ 359,431 $ 161,669 $ 47,427 $ 209,096 Adoption of ASU No. 2016-13 (CECL) — — — 34,024 23,544 57,568 (Benefit) provision (37,049) (2,386) (39,435) 147,466 (8,625) 138,841 Charge-offs (8,638) (7,835) (16,473) (34,362) (9,630) (43,992) Recoveries 2,614 8,785 11,399 2,872 5,426 8,298 Balance, end of period $ 269,171 $ 45,751 $ 314,922 $ 311,669 $ 58,142 $ 369,811 Individually evaluated for impairment 7,791 4,308 12,099 18,303 4,376 22,679 Collectively evaluated for impairment $ 261,380 $ 41,443 $ 302,823 $ 293,366 $ 53,766 $ 347,132 Loan and lease balances: Individually evaluated for impairment $ 116,280 $ 104,677 $ 220,957 $ 158,324 $ 149,583 $ 307,907 Collectively evaluated for impairment 14,565,526 6,793,852 21,359,378 14,761,792 6,782,324 21,544,116 Loans and leases $ 14,681,806 $ 6,898,529 $ 21,580,335 $ 14,920,116 $ 6,931,907 $ 21,852,023 The following table provides a summary of activity in the ACL on unfunded loan commitments: Three months ended September 30, Nine months ended September 30, (In thousands) 2021 2020 2021 2020 Beginning balance $ 11,974 $ 10,739 $ 12,755 $ 2,367 Adoption of ASU No. 2016-13 (CECL) — — — 9,139 (Benefit) provision 196 1,146 (585) 379 Ending balance $ 12,170 $ 11,885 $ 12,170 $ 11,885
Impaired Loans	The following table summarizes individually assessed loans and leases: At September 30, 2021 (In thousands) Unpaid Amortized Cost Amortized Cost No Allowance Amortized Cost With Allowance Related Commercial non-mortgage $ 107,251 $ 84,054 $ 34,246 $ 49,808 $ 5,470 Asset-based 2,253 2,111 2,111 — — Commercial real estate 29,357 25,893 11,203 14,690 1,449 Equipment financing 4,732 4,222 — 4,222 872 Residential 68,514 65,018 35,337 29,681 2,503 Home equity 43,764 39,396 28,078 11,318 1,689 Other consumer 282 263 — 263 116 Total $ 256,153 $ 220,957 $ 110,975 $ 109,982 $ 12,099 At December 31, 2020 (In thousands) Unpaid Amortized Cost Amortized Cost No Allowance Amortized Cost With Allowance Related Commercial non-mortgage $ 172,069 $ 119,884 $ 55,742 $ 64,142 $ 9,665 Asset-based 2,989 2,594 — 2,594 50 Commercial real estate 37,177 33,879 25,931 7,948 1,610 Equipment financing 7,770 7,298 2,983 4,315 362 Residential 108,077 98,164 58,915 39,249 3,357 Home equity 109,156 46,950 34,335 12,615 988 Other consumer 2,381 653 2 651 105 Total $ 439,619 $ 309,422 $ 177,908 $ 131,514 $ 16,137 The following table summarizes average amortized cost and interest income recognized for individually assessed loans and leases: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 (In thousands) Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Commercial non-mortgage $ 90,662 $ 729 $ — $ 127,676 $ 954 $ — $ 101,969 $ 2,270 $ — $ 114,027 $ 2,882 $ — Asset-based 2,243 — — 1,949 — — 2,353 — — 1,950 — — Commercial real estate 23,512 132 — 24,555 192 — 29,886 440 — 22,440 507 — Equipment financing 6,192 — — 7,488 — — 5,760 — — 6,308 — — Residential 66,920 590 46 103,608 741 289 81,591 1,806 487 95,270 2,352 1,149 Home equity 40,341 218 63 49,309 302 297 43,173 727 579 41,826 1,002 1,540 Other consumer 338 — — 948 13 — 458 — — 340 30 — Total $ 230,208 $ 1,669 $ 109 $ 315,533 $ 2,202 $ 586 $ 265,190 $ 5,243 $ 1,066 $ 282,161 $ 6,773 $ 2,689 The following table summarizes whether, or not, individually assessed loans and leases are collateral dependent: At September 30, 2021 At December 31, 2020 (In thousands) Collateral Dependent Not Considered Collateral Dependent Total Collateral Dependent Not Considered Collateral Dependent Total Commercial non-mortgage $ 8,062 $ 75,992 $ 84,054 $ 11,074 $ 108,810 $ 119,884 Asset-based 2,111 — 2,111 2,504 90 2,594 Commercial real estate 21,229 4,664 25,893 28,482 5,397 33,879 Equipment financing — 4,222 4,222 — 7,298 7,298 Residential 16,029 48,989 65,018 33,980 64,184 98,164 Home equity 21,014 18,382 39,396 26,796 20,154 46,950 Other consumer — 263 263 — 653 653 Total amortized cost $ 68,445 $ 152,512 $ 220,957 $ 102,836 $ 206,586 $ 309,422
Financing Receivable Credit Quality Indicators	The following tables summarize commercial, commercial real estate, and equipment financing loans and leases segregated by origination year and risk rating exposure under the Composite Credit Risk Profile grades at September 30, 2021 and December 31, 2020: At September 30, 2021 (In thousands) 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Commercial non-mortgage Pass $ 1,680,524 $ 1,261,582 $ 862,131 $ 673,196 $ 291,995 $ 317,590 $ 1,068,077 $ 6,155,095 Special mention 13,242 45,084 38,253 32,989 9,994 16,578 15,835 171,975 Substandard 3,791 47,048 31,030 85,798 8,646 19,647 29,210 225,170 Doubtful — 1 — — — — — 1 Commercial non-mortgage 1,697,557 1,353,715 931,414 791,983 310,635 353,815 1,113,122 6,552,241 Asset-based Pass 7,612 20,768 13,115 13,998 6,272 26,747 835,405 923,917 Special mention — — — 700 — — 60,054 60,754 Substandard — — 2,111 — — — — 2,111 Asset-based 7,612 20,768 15,226 14,698 6,272 26,747 895,459 986,782 Commercial real estate Pass 847,147 891,343 1,450,959 1,074,542 377,030 1,484,768 34,906 6,160,695 Special mention 350 2,232 — 79,138 54,177 105,173 — 241,070 Substandard — 887 792 21,565 43,194 54,475 — 120,913 Doubtful — — — — — 1 — 1 Commercial real estate 847,497 894,462 1,451,751 1,175,245 474,401 1,644,417 34,906 6,522,679 Equipment financing Pass 174,137 203,641 101,319 49,725 16,835 39,771 — 585,428 Special mention — 120 8,101 3,620 87 1,055 — 12,983 Substandard — 8,989 4,093 3,566 1,512 3,533 — 21,693 Equipment financing 174,137 212,750 113,513 56,911 18,434 44,359 — 620,104 Commercial portfolio $ 2,726,803 $ 2,481,695 $ 2,511,904 $ 2,038,837 $ 809,742 $ 2,069,338 $ 2,043,487 $ 14,681,806 At December 31, 2020 (In thousands) 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total Commercial non-mortgage Pass $ 2,771,373 $ 1,052,080 $ 907,110 $ 481,321 $ 231,280 $ 218,001 $ 936,592 $ 6,597,757 Special mention 32,535 33,969 62,034 435 8,357 13,757 38,496 189,583 Substandard 54,716 51,798 66,324 36,159 15,535 23,957 49,084 297,573 Doubtful — — — 163 — — — 163 Commercial non-mortgage 2,858,624 1,137,847 1,035,468 518,078 255,172 255,715 1,024,172 7,085,076 Asset-based Pass 26,344 15,960 23,123 11,333 10,963 16,484 741,336 845,543 Special mention — — 775 — — — 41,687 42,462 Substandard — 2,504 — — — — 89 2,593 Asset-based 26,344 18,464 23,898 11,333 10,963 16,484 783,112 890,598 Commercial real estate Pass 965,582 1,461,201 1,242,322 527,931 554,630 1,165,331 28,113 5,945,110 Special mention 27 10,385 70,704 37,539 35,617 69,832 — 224,104 Substandard 817 1,132 21,923 73,621 2,962 52,968 — 153,423 Commercial real estate 966,426 1,472,718 1,334,949 639,091 593,209 1,288,131 28,113 6,322,637 Equipment financing Pass 249,370 135,263 68,092 26,433 43,469 22,879 — 545,506 Special mention 7,934 11,043 6,981 1,220 1,577 788 — 29,543 Substandard 7,483 6,169 5,749 2,460 4,743 571 — 27,175 Equipment financing 264,787 152,475 80,822 30,113 49,789 24,238 — 602,224 Commercial portfolio $ 4,116,181 $ 2,781,504 $ 2,475,137 $ 1,198,615 $ 909,133 $ 1,584,568 $ 1,835,397 $ 14,900,535 To measure credit risk for the consumer portfolio, the most relevant credit characteristic is the FICO score, which is a widely used credit scoring system that ranges from 300 to 850. A lower FICO score is indicative of higher credit risk. FICO scores are updated at least quarterly. The following tables summarize residential and consumer loans segregated by origination year and risk rating exposure under FICO score groupings at September 30, 2021 and December 31, 2020: At September 30, 2021 (In thousands) 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total Residential 800+ $ 360,987 $ 450,223 $ 178,412 $ 41,697 $ 128,474 $ 792,003 $ — $ 1,951,796 740-799 857,968 471,194 180,238 38,171 91,741 507,048 — 2,146,360 670-739 300,754 141,427 81,670 25,831 41,147 248,879 — 839,708 580-669 24,569 14,716 9,338 4,394 7,531 76,066 — 136,614 579 and below 10,308 1,451 43,787 868 1,892 34,743 — 93,049 Residential 1,554,586 1,079,011 493,445 110,961 270,785 1,658,739 — 5,167,527 Home equity 800+ 27,832 28,501 10,373 17,474 11,631 60,951 491,283 648,045 740-799 29,181 27,269 9,710 14,530 8,428 39,651 414,321 543,090 670-739 12,260 10,657 7,106 8,338 7,369 35,743 234,066 315,539 580-669 364 1,530 1,750 1,529 1,885 15,669 73,350 96,077 579 and below 255 454 874 1,026 304 6,001 22,208 31,122 Home equity 69,892 68,411 29,813 42,897 29,617 158,015 1,235,228 1,633,873 Other consumer 800+ 377 1,544 3,254 1,141 323 120 10,386 17,145 740-799 2,314 6,694 10,540 4,047 590 379 4,857 29,421 670-739 542 9,433 16,762 5,021 909 234 8,106 41,007 580-669 245 1,232 3,215 972 347 207 1,313 7,531 579 and below 106 176 283 195 63 54 1,148 2,025 Other consumer 3,584 19,079 34,054 11,376 2,232 994 25,810 97,129 Consumer portfolio 1,628,062 1,166,501 557,312 165,234 302,634 1,817,748 1,261,038 6,898,529 Commercial portfolio 2,726,803 2,481,695 2,511,904 2,038,837 809,742 2,069,338 2,043,487 14,681,806 Loans and leases $ 4,354,865 $ 3,648,196 $ 3,069,216 $ 2,204,071 $ 1,112,376 $ 3,887,086 $ 3,304,525 $ 21,580,335 At December 31, 2020 (In thousands) 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total Residential 800+ $ 360,336 $ 283,755 $ 61,048 $ 178,849 $ 268,044 $ 805,537 $ — $ 1,957,569 740-799 654,973 288,173 58,249 133,416 176,286 492,720 — 1,803,817 670-739 199,329 118,620 39,125 75,375 76,666 248,268 — 757,383 580-669 17,151 19,389 8,884 11,843 12,225 96,333 — 165,825 579 and below — 36,498 673 3,278 3,179 53,794 — 97,422 Residential 1,231,789 746,435 167,979 402,761 536,400 1,696,652 — 4,782,016 Home equity 800+ 30,604 16,567 25,205 14,439 17,192 59,956 542,600 706,563 740-799 34,797 13,565 19,715 11,073 12,839 43,802 434,271 570,062 670-739 13,753 8,855 10,761 10,206 7,318 44,025 275,691 370,609 580-669 1,708 2,172 2,660 2,234 2,316 16,680 86,126 113,896 579 and below 129 919 880 1,070 1,073 7,163 30,501 41,735 Home equity 80,991 42,078 59,221 39,022 40,738 171,626 1,369,189 1,802,865 Other consumer 800+ 2,827 5,725 2,610 658 115 190 7,171 19,296 740-799 12,317 21,036 8,925 1,493 457 263 5,119 49,610 670-739 14,761 31,952 11,843 2,284 665 228 8,403 70,136 580-669 2,344 5,419 2,360 793 194 124 1,570 12,804 579 and below 608 982 500 183 37 215 1,428 3,953 Other consumer 32,857 65,114 26,238 5,411 1,468 1,020 23,691 155,799 Consumer portfolio 1,345,637 853,627 253,438 447,194 578,606 1,869,298 1,392,880 6,740,680 Commercial portfolio 4,116,181 2,781,504 2,475,137 1,198,615 909,133 1,584,568 1,835,397 14,900,535 Loans and leases $ 5,461,818 $ 3,635,131 $ 2,728,575 $ 1,645,809 $ 1,487,739 $ 3,453,866 $ 3,228,277 $ 21,641,215
Troubled Debt Restructurings on Financing Receivables	The following table summarizes information for TDRs: (In thousands) At September 30, 2021 At December 31, 2020 Accrual status $ 116,777 $ 140,089 Non-accrual status 47,257 95,338 Total TDRs $ 164,034 $ 235,427 Specific reserves for TDRs included in the balance of ACL on loans and leases $ 8,980 $ 12,728 Additional funds committed to borrowers in TDR status 6,504 12,895 The following table provides information on the type of concession for loans modified as TDRs: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Number of Post- Modification Recorded Investment (1) Number of Post- Modification Recorded Investment (1) Number of Post- Modification Recorded Investment (1) Number of Post- Modification Recorded Investment (1) (Dollars in thousands) Commercial portfolio Extended Maturity 1 $ 48 — $ — 9 $ 788 7 $ 579 Maturity/Rate Combined 2 94 2 333 8 304 8 885 Other (2) — — 4 312 3 114 27 40,434 Consumer portfolio Extended Maturity — — 2 165 2 127 6 673 Maturity/Rate Combined — — 5 440 8 1,426 11 1,151 Other (2) 3 153 17 708 19 1,354 111 9,895 Total TDRs 6 $ 295 30 $ 1,958 49 $ 4,113 170 $ 53,617 (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. TDRs in commercial non-mortgage, commercial real estate, and equipment financing segregated by risk rating exposure is as follows: (In thousands) At September 30, 2021 At December 31, 2020 Pass $ 7,327 $ 12,462 Special Mention 8,670 — Substandard 58,797 105,070 Doubtful — 163 Total $ 74,794 $ 117,695

Transfers of Financial Assets (

Transfers of Financial Assets (Tables)	9 Months Ended
	Sep. 30, 2021
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) 2021 2020 2021 2020 Beginning balance $ 782 $ 655 $ 747 $ 508 Provision charged to expense 16 50 59 99 (Charge-offs/settlements) recoveries, net — — (8) 98 Ending balance $ 798 $ 705 $ 798 $ 705
Transfer of Financial Assets Accounted for as Sales	The following table provides information for mortgage banking activities: Three months ended September 30, Nine months ended September 30, (In thousands) 2021 2020 2021 2020 Residential mortgage loans held for sale: Proceeds from sale $ 52,256 $ 172,579 $ 199,991 $ 342,747 Loans sold with servicing rights retained 50,643 164,054 192,421 325,832 Net gain on sale 1,063 6,244 4,523 11,587 Ancillary fees 313 1,018 1,231 2,243 Fair value option adjustment 149 (175) (268) 355
Servicing Asset at Amortized Cost	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) 2021 2020 2021 2020 Beginning balance $ 11,501 $ 14,926 $ 13,422 $ 17,484 Additions 483 1,301 1,685 3,269 Amortization (1,363) (1,616) (4,295) (4,992) Adjustment to valuation allowance (454) (203) (645) (1,353) Ending balance $ 10,167 $ 14,408 $ 10,167 $ 14,408

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Schedule of Components of Leveraged Lease Investments	The following table summarizes lessee information related to the Company’s operating ROU lease assets and lease liabilities: At September 30, 2021 (In thousands) Operating Leases Condensed Consolidated Balance Sheet Line Item Location ROU lease assets $ 123,407 Premises and equipment, net Lease liabilities 150,708 Operating lease liabilities
Lease, Cost	The components of operating lease cost and other related information are as follows: At or for the three months ended September 30, At or for the nine months ended September 30, (In thousands) 2021 2020 2021 2020 Lease Cost: Operating lease costs $ 6,487 $ 7,381 $ 19,598 $ 22,212 Variable lease costs 1,063 1,297 3,714 4,217 Sublease income (141) (141) (412) (428) Total operating lease cost $ 7,409 $ 8,537 $ 22,900 $ 26,001 Other Information: Cash paid for amounts included in the measurement of lease liabilities $ 7,498 $ 7,823 $ 23,003 $ 23,359 ROU lease assets obtained in exchange for new operating lease liabilities 2,586 856 12,144 9,552
Lessee, Operating Lease, Liability, Maturity	The undiscounted scheduled maturities reconciled to total operating lease liabilities are as follows: (In thousands) At September 30, 2021 Remainder of 2021 $ 5,141 2022 28,292 2023 26,443 2024 23,666 2025 21,687 Thereafter 66,806 Total operating lease liability payments 172,035 Less: Present value adjustment 21,327 Lease liabilities $ 150,708 Weighted-average remaining lease term, in years 7.67 Weighted-average discount rate 3.07%

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Other intangible assets by reportable segment consisted of the following: At September 30, 2021 At December 31, 2020 (In thousands) Gross Carrying Accumulated Net Carrying Gross Carrying Accumulated Net Carrying HSA Bank - Core deposits $ 26,625 $ 17,801 $ 8,824 $ 26,625 $ 15,618 $ 11,007 HSA Bank - Customer relationships 21,000 10,837 10,163 21,000 9,624 11,376 Total other intangible assets $ 47,625 $ 28,638 $ 18,987 $ 47,625 $ 25,242 $ 22,383
Schedule Of Expected Amortization Expense, Next Four Years	At September 30, 2021, the remaining estimated aggregate future amortization expense for other intangible assets is as follows: (In thousands) Remainder of 2021 $ 1,117 2022 4,411 2023 4,315 2024 2,084 2025 2,084 Thereafter 4,976

Deposits (Tables)

Deposits (Tables)	9 Months Ended
	Sep. 30, 2021
Deposit Liabilities [Abstract]
Deposit Liabilities, Type	A summary of deposits by type is as follows: (In thousands) At September 30, At December 31, Non-interest-bearing: Demand $ 7,154,835 $ 6,155,592 Interest-bearing: Health savings accounts 7,329,405 7,120,017 Checking 4,181,825 3,652,763 Money market 3,958,700 2,940,215 Savings 5,517,189 4,979,031 Time deposits 1,884,373 2,487,818 Total interest-bearing $ 22,871,492 $ 21,179,844 Total deposits $ 30,026,327 $ 27,335,436 Time deposits and interest-bearing checking obtained through brokers (included in above balances) $ 109,312 $ 720,440 Time deposits that exceed the FDIC limit (included in above balance) 308,498 504,543 Deposit overdrafts reclassified as loan balances 1,111 2,007
Time Deposit Maturities	The scheduled maturities of time deposits are as follows: (In thousands) At September 30, Remainder of 2021 $ 646,277 2022 1,022,752 2023 103,532 2024 44,240 2025 50,664 Thereafter 16,908 Total time deposits $ 1,884,373

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2021
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, (Dollars in thousands) Total Outstanding Rate Total Outstanding Rate Securities sold under agreements to repurchase (1) : Original maturity of one year or less $ 455,871 0.11 % $ 269,330 0.13 % Original maturity of greater than one year, non-callable 200,000 1.22 200,000 0.84 Total securities sold under agreements to repurchase 655,871 0.45 469,330 0.43 Fed funds purchased — — 526,025 0.08 Securities sold under agreements to repurchase and other borrowings $ 655,871 0.45 $ 995,355 0.25
Federal Home Loan Bank, Advances	The following table provides information for FHLB advances: At September 30, 2021 At December 31, 2020 (Dollars in thousands) Total Outstanding Weighted- Total Outstanding Weighted- Maturing within 1 year $ 11 — % $ 25,000 0.38 % After 1 but within 2 years 157 1.75 110 — After 2 but within 3 years 50,132 1.59 215 2.95 After 3 but within 4 years 50,000 1.42 50,000 1.59 After 4 but within 5 years — — 50,000 1.42 After 5 years 13,034 2.57 7,839 2.66 FHLB advances $ 113,334 1.63 $ 133,164 1.36 Aggregate carrying value of assets pledged as collateral $ 7,150,473 $ 7,387,054 Remaining borrowing capacity 4,704,060 4,689,642
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) 340,149 344,164 Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (2) 77,320 77,320 Total notes and subordinated debt 567,469 571,484 Discount on senior fixed-rate notes (1,029) (1,193) Debt issuance cost on senior fixed-rate notes (2,326) (2,628) Long-term debt $ 564,114 $ 567,663 (1) The Company de-designated its fair value hedging relationship on these notes. A basis adjustment of $40.1 million and $44.2 million at September 30, 2021 and December 31, 2020, respectively, is included in the carrying value and is being amortized over the remaining life of the notes. (2) The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95%, was 3.07% at September 30, 2021 and 3.18% at December 31, 2020.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income, Net of Tax (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Loss by Component	The following table summarizes the changes in each component of accumulated other comprehensive income (loss), net of tax (AOCI/AOCL): Three months ended September 30, 2021 Nine months ended September 30, 2021 (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 $ 35,598 $ 13,894 $ (43,602) $ 5,890 $ 67,424 $ 19,918 $ (45,086) $ 42,256 Other comprehensive (loss) before reclassifications (3,394) (2,560) — (5,954) (35,220) (10,205) — (45,425) Amounts reclassified from accumulated other comprehensive income (loss) — 829 743 1,572 — 2,450 2,227 4,677 Net current-period other comprehensive (loss) income, net of tax (3,394) (1,731) 743 (4,382) (35,220) (7,755) 2,227 (40,748) Ending balance $ 32,204 $ 12,163 $ (42,859) $ 1,508 $ 32,204 $ 12,163 $ (42,859) $ 1,508 Three months ended September 30, 2020 Nine months ended September 30, 2020 (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 $ 63,476 $ 20,649 $ (42,680) $ 41,445 $ 17,251 $ (9,184) $ (44,139) $ (36,072) Other comprehensive income (loss) before reclassifications 11,766 (3,310) — 8,456 57,997 23,655 — 81,652 Amounts reclassified from accumulated other comprehensive income (loss) — 1,398 738 2,136 (6) 4,266 2,197 6,457 Net current-period other comprehensive income (loss), net of tax 11,766 (1,912) 738 10,592 57,991 27,921 2,197 88,109 Ending balance $ 75,242 $ 18,737 $ (41,942) $ 52,037 $ 75,242 $ 18,737 $ (41,942) $ 52,037
Schedule of Accumulated Other Comprehensive Loss	The following table further details the amounts reclassified from AOCI (AOCL): (In thousands) Three months ended September 30, Nine months ended September 30, Associated Line Item on the Condensed Consolidated Statements of Income AOCI (AOCL) Component 2021 2020 2021 2020 Securities available-for-sale: Unrealized gains on investment securities $ — $ — $ — $ 8 Gain on sale of investment securities, net Tax expense — — — (2) Income tax expense Net of tax $ — $ — $ — $ 6 Derivative instruments: Hedge terminations $ (1,046) $ (967) $ (3,088) $ (3,228) Interest expense Premium amortization (76) (926) (229) (2,548) Interest income Tax benefit 293 495 867 1,510 Income tax expense Net of tax $ (829) $ (1,398) $ (2,450) $ (4,266) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (1,008) $ (1,002) $ (3,023) $ (2,982) Other non-interest expense Tax benefit 265 264 796 785 Income tax expense Net of tax $ (743) $ (738) $ (2,227) $ (2,197)

Regulatory Matters (Tables)

Regulatory Matters (Tables)	9 Months Ended
	Sep. 30, 2021
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, 2021 Actual (1) Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,729,789 11.77 % $ 1,044,068 4.5 % $ 1,508,098 6.5 % Total risk-based capital 3,200,180 13.79 1,856,121 8.0 2,320,151 10.0 Tier 1 risk-based capital 2,874,826 12.39 1,392,091 6.0 1,856,121 8.0 Tier 1 leverage capital 2,874,826 8.37 1,373,218 4.0 1,716,523 5.0 Webster Bank CET1 risk-based capital $ 2,961,510 12.77 % $ 1,043,279 4.5 % $ 1,506,959 6.5 % Total risk-based capital 3,209,544 13.84 1,854,719 8.0 2,318,399 10.0 Tier 1 risk-based capital 2,961,510 12.77 1,391,039 6.0 1,854,719 8.0 Tier 1 leverage capital 2,961,510 8.63 1,372,558 4.0 1,715,698 5.0 At December 31, 2020 Actual Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,543,131 11.35 % $ 1,008,512 4.5 % $ 1,456,739 6.5 % Total risk-based capital 3,045,652 13.59 1,792,910 8.0 2,241,137 10.0 Tier 1 risk-based capital 2,688,168 11.99 1,344,682 6.0 1,792,910 8.0 Tier 1 leverage capital 2,688,168 8.32 1,291,980 4.0 1,614,975 5.0 Webster Bank CET1 risk-based capital $ 2,791,474 12.46 % $ 1,008,027 4.5 % $ 1,456,039 6.5 % Total risk-based capital 3,071,505 13.71 1,792,048 8.0 2,240,060 10.0 Tier 1 risk-based capital 2,791,474 12.46 1,344,036 6.0 1,792,048 8.0 Tier 1 leverage capital 2,791,474 8.65 1,291,415 4.0 1,614,268 5.0

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Earnings Per Share Basic And Diluted	A reconciliation of the calculation of basic and diluted earnings per common share is as follows: Three months ended September 30, Nine months ended September 30, (In thousands, except per share data) 2021 2020 2021 2020 Earnings for basic and diluted earnings per common share: Net income $ 95,713 $ 69,281 $ 297,826 $ 160,577 Less: Preferred stock dividends 1,968 1,968 5,906 5,906 Net income available to common shareholders 93,745 67,313 291,920 154,671 Less: Earnings applicable to participating securities (1) 574 423 1,661 913 Earnings applicable to common shareholders $ 93,171 $ 66,890 $ 290,259 $ 153,758 Shares: Weighted-average common shares outstanding - basic 90,038 89,630 89,960 90,076 Effect of dilutive securities 194 108 226 159 Weighted-average common shares outstanding - diluted 90,232 89,738 90,186 90,235 Earnings per common share (1) : Basic $ 1.03 $ 0.75 $ 3.23 $ 1.71 Diluted 1.03 0.75 3.22 1.70 (1) Earnings per common share amounts under the two-class method for unvested time-based restricted stock with non-forfeitable dividends and dividend rights are computed the same as the presentation above.

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table presents the notional amounts and fair values, including accrued interest, of derivative positions: At September 30, 2021 At December 31, 2020 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) $ 1,000,000 $ 26,923 $ — $ — $ 1,000,000 $ 40,854 $ 25,000 $ 110 Not designated as hedging instruments: Interest rate derivatives (1) 4,434,047 178,749 4,360,615 17,566 4,421,627 297,085 4,468,153 12,203 Mortgage banking derivatives (2) 30,663 300 — — 40,771 855 — — Other (3) 108,875 359 362,668 109 108,987 264 360,497 377 Total not designated as hedging instruments 4,573,585 179,408 4,723,283 17,675 4,571,385 298,204 4,828,650 12,580 Gross derivative instruments, before netting $ 5,573,585 206,331 $ 4,723,283 17,675 $ 5,571,385 339,058 $ 4,853,650 12,690 Less: Master netting agreements 4,772 4,772 7,748 7,748 Cash collateral 28,679 2,731 33,972 4,550 Total derivative instruments, after netting $ 172,880 $ 10,172 $ 297,338 $ 392 (1) Balances related to Chicago Mercantile Exchange (CME) are presented as a single unit of account. In accordance with its rule book, CME legally characterizes variation margin payments as settlement of derivatives rather than collateral against derivative positions. Notional amounts of interest rate swaps cleared through CME include $0.3 billion and $0.1 billion for asset derivatives and $3.0 billion and $3.2 billion for liability derivatives at September 30, 2021 and December 31, 2020, respectively. The related fair values approximate zero. (2) Notional amounts related to residential loans exclude approved floating rate commitments of $0.7 million at September 30, 2021. (3) 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 $82.8 million and $80.5 million for asset derivatives and $355.1 million and $338.9 million for liability derivatives at September 30, 2021 and December 31, 2020, respectively, that have insignificant related fair values.
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location	The following table presents fair value positions transitioned from gross to net upon applying contractual counterparty netting agreements: At September 30, 2021 (In thousands) Gross Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 33,451 $ 33,451 $ — $ 100 $ 100 Liability derivatives 7,503 7,503 — 701 701 At December 31, 2020 (In thousands) Gross Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 41,774 $ 41,720 $ 54 $ 666 $ 720 Liability derivatives 12,352 12,298 54 265 319
Schedule of Net Investment Hedges, Statements of Financial Performance and Financial Position, Location	The following table presents 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 2021 2020 2021 2020 Interest rate derivatives Long-term debt $ 90 $ 1,152 $ 334 $ 3,501 Interest rate derivatives Interest and fees on loans and leases (2,706) (2,657) (7,933) (3,754) Net recognized on cash flow hedges $ (2,616) $ (1,505) $ (7,599) $ (253) Condensed Consolidated Balance Sheet Line Item in Which Hedged Item is Located Carrying Amount of Previously Hedged Item Cumulative Amount of Fair Value Hedging Adjustment Included in Carrying Amount (In thousands) At September 30, At December 31, At September 30, At December 31, Long-term debt $ 340,149 $ 344,164 $ 40,149 $ 44,164
Other Derivatives Not Designated For Hedge Accounting	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 2021 2020 2021 2020 Interest rate derivatives Other income $ 2,727 $ 3,824 $ 7,132 $ 7,227 Mortgage banking derivatives Mortgage banking activities 38 872 (556) 2,498 Other Other income 611 (1,229) 780 (332) Total not designated as hedging instruments $ 3,376 $ 3,467 $ 7,356 $ 9,393

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Option, Disclosures	At September 30, 2021 At December 31, 2020 (In thousands) Fair Value Unpaid Principal Balance Difference Fair Value Unpaid Principal Balance Difference Originated loans held for sale $ 10,032 $ 9,926 $ 106 $ 14,000 $ 13,511 $ 489
Fair Value Of Assets And Liabilities Measured On Recurring Basis	A summary of the financial assets and liabilities measured at fair value on a recurring basis is as follows: At September 30, 2021 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: Agency CMO $ — $ 105,783 $ — $ 105,783 Agency MBS — 1,596,784 — 1,596,784 Agency CMBS — 898,586 — 898,586 CMBS — 770,086 — 770,086 CLO — 24,967 — 24,967 Corporate debt — 14,237 — 14,237 Total available-for-sale investment securities — 3,410,443 — 3,410,443 Gross derivative instruments, before netting (1) 330 206,001 — 206,331 Originated loans held for sale — 10,032 — 10,032 Investments held in Rabbi Trust 3,597 — — 3,597 Alternative investments (2) 1,323 — — 22,546 Total financial assets held at fair value $ 5,250 $ 3,626,476 $ — $ 3,652,949 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 38 $ 17,637 $ — $ 17,675 At December 31, 2020 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: Agency CMO $ — $ 154,613 $ — $ 154,613 Agency MBS — 1,457,409 — 1,457,409 Agency CMBS — 1,117,233 — 1,117,233 CMBS — 508,018 — 508,018 CLO — 76,383 — 76,383 Corporate debt — 13,120 — 13,120 Total available-for-sale investment securities — 3,326,776 — 3,326,776 Gross derivative instruments, before netting (1) 205 338,853 — 339,058 Originated loans held for sale — 14,000 — 14,000 Investments held in Rabbi Trust 4,811 — — 4,811 Alternative investments (2) — — — 11,112 Total financial assets held at fair value $ 5,016 $ 3,679,629 $ — $ 3,695,757 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 218 $ 12,472 $ — $ 12,690 (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, refer to Note 14: Derivative Financial Instruments. (2) Certain alternative investments are recorded at NAV. Assets measured at NAV are not classified within the fair value hierarchy.
Summary Of Estimated Fair Values Of Significant Financial Instruments	The carrying amounts, estimated fair values, and classifications within the fair value hierarchy of selected financial instruments and servicing assets are summarized as follows: At September 30, 2021 At December 31, 2020 (In thousands) Carrying Fair Carrying Fair Assets: Level 2 Held-to-maturity investment securities, net $ 5,986,308 $ 6,139,440 $ 5,567,889 $ 5,835,364 Level 3 Loans and leases, net 21,265,413 21,393,481 21,281,784 21,413,397 Mortgage servicing assets 10,167 13,032 13,422 14,362 Liabilities: Level 2 Deposit liabilities $ 28,141,954 $ 28,141,954 $ 24,847,618 $ 24,847,618 Time deposits 1,884,373 1,885,341 2,487,818 2,494,601 Securities sold under agreements to repurchase and other borrowings 655,871 660,146 995,355 1,000,189 FHLB advances 113,334 117,237 133,164 139,035 Long-term debt (1) 564,114 522,251 567,663 538,407 (1) Adjustments to the carrying amount of long-term debt for basis adjustment and unamortized discount and debt issuance cost on senior fixed-rate notes are not included in the determination of fair value. Refer to Note 10: Borrowings for additional information.

Retirement Benefit Plans (Table

Retirement Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2021
Retirement Benefits [Abstract]
Summary of Net Periodic Benefit Cost	The following table summarizes the components of net periodic benefit (income) cost: Three months ended September 30, 2021 2020 (In thousands) Pension Plan SERP Other Pension Plan SERP Other Benefits Interest cost on benefit obligations $ 1,166 $ 7 $ 4 $ 1,531 $ 12 $ 9 Expected return on plan assets (3,595) — — (3,380) — — Recognized net loss (gain) 1,019 8 (20) 1,036 5 (38) Net periodic benefit (income) cost $ (1,410) $ 15 $ (16) $ (813) $ 17 $ (29) Nine months ended September 30, 2021 2020 (In thousands) Pension Plan SERP Other Benefits Pension Plan SERP Other Benefits Interest cost on benefit obligations $ 3,498 $ 20 $ 12 $ 4,881 $ 35 $ 34 Expected return on plan assets (10,786) — — (10,140) — — Recognized net loss (gain) 3,058 25 (60) 3,021 17 (55) Net periodic benefit (income) cost $ (4,230) $ 45 $ (48) $ (2,238) $ 52 $ (21)

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Operating Results And Total Assets Reportable Segments	The following table presents balance sheet information, including all appropriate allocations, for Webster's reportable segments and the Corporate and Reconciling category: At September 30, 2021 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Goodwill $ 131,000 $ 21,813 $ 385,560 $ — $ 538,373 Total assets 14,862,455 74,236 7,538,017 12,899,550 35,374,258 At December 31, 2020 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Goodwill $ 131,000 $ 21,813 $ 385,560 $ — $ 538,373 Total assets 14,732,792 80,352 7,726,287 10,051,259 32,590,690 The following tables present the operating results, including all appropriate allocations, for Webster’s reportable segments and the Corporate and Reconciling category: Three months ended September 30, 2021 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Net interest income $ 152,556 $ 42,074 $ 98,028 $ (62,967) $ 229,691 Non-interest income 30,076 24,756 16,998 11,945 83,775 Non-interest expense 64,917 32,800 73,480 9,040 180,237 Pre-tax, pre-provision net revenue 117,715 34,030 41,546 (60,062) 133,229 Provision for credit losses 5,099 — 2,799 (148) 7,750 Income before income tax expense 112,616 34,030 38,747 (59,914) 125,479 Income tax expense 28,492 9,086 8,524 (16,336) 29,766 Net income $ 84,124 $ 24,944 $ 30,223 $ (43,578) $ 95,713 Three months ended September 30, 2020 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Net interest income $ 132,026 $ 39,861 $ 83,609 $ (36,240) $ 219,256 Non-interest income 20,710 27,235 21,359 5,756 75,060 Non-interest expense 66,482 34,789 80,119 2,606 183,996 Pre-tax, pre-provision net revenue 86,254 32,307 24,849 (33,090) 110,320 Provision for credit losses 31,753 — (9,000) (3) 22,750 Income before income tax expense 54,501 32,307 33,849 (33,087) 87,570 Income tax expense 13,299 8,626 7,379 (11,015) 18,289 Net income $ 41,202 $ 23,681 $ 26,470 $ (22,072) $ 69,281 Nine months ended September 30, 2021 (In thousands) Commercial HSA Retail Banking Corporate and Consolidated Net interest income $ 435,718 $ 126,376 $ 279,381 $ (167,168) $ 674,307 Non-interest income 80,966 78,315 49,832 24,121 233,234 Non-interest expense 191,198 101,842 221,950 40,257 $ 555,247 Pre-tax, pre-provision net revenue 325,486 $ 102,849 107,263 (183,304) 352,294 Provision for credit losses (37,602) — (1,833) (65) (39,500) Income before income tax expense 363,088 102,849 109,096 (183,239) 391,794 Income tax expense 91,861 27,461 24,001 (49,355) 93,968 Net income $ 271,227 $ 75,388 $ 85,095 $ (133,884) $ 297,826 Nine months ended September 30, 2020 (In thousands) Commercial HSA Retail Banking Corporate and Consolidated Net interest income $ 377,736 $ 121,868 $ 246,417 $ (71,557) $ 674,464 Non-interest income 64,975 76,721 56,083 10,735 208,514 Non-interest expense 192,964 105,887 237,528 3,037 539,416 Pre-tax, pre-provision net revenue 249,747 92,702 64,972 (63,859) 343,562 Provision for credit losses 144,340 — (5,499) (91) 138,750 Income before income tax expense 105,407 92,702 70,471 (63,768) 204,812 Income tax expense 25,720 24,751 15,362 (21,598) 44,235 Net income $ 79,687 $ 67,951 $ 55,109 $ (42,170) $ 160,577

Revenue from Contracts with C_2

Revenue from Contracts with Customers Disaggregation of Revenue (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents revenues within the scope of ASC Topic 606, Revenue from Contracts with Customers, along with the net amount of other sources of non-interest income that are within the scope of other GAAP topics, by reportable segment: Three months ended September 30, 2021 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Non-interest Income: Deposit service fees $ 4,207 $ 22,886 $ 13,078 $ 87 $ 40,258 Wealth and investment services 9,993 — — (8) 9,985 Other 361 1,870 265 — 2,496 Revenue from contracts with customers 14,561 24,756 13,343 79 52,739 Other sources of non-interest income 15,515 — 3,655 11,866 31,036 Total non-interest income $ 30,076 $ 24,756 $ 16,998 $ 11,945 $ 83,775 Three months ended September 30, 2020 (In thousands) Commercial Banking HSA Bank Retail Banking Corporate and Reconciling Consolidated Total Non-interest Income: Deposit service fees $ 3,615 $ 23,667 $ 11,972 $ 24 $ 39,278 Wealth and investment services 8,234 — — 21 8,255 Other 277 3,568 249 — 4,094 Revenue from contracts with customers 12,126 27,235 12,221 45 51,627 Other sources of non-interest income 8,584 — 9,138 5,711 23,433 Total non-interest income $ 20,710 $ 27,235 $ 21,359 $ 5,756 $ 75,060 Nine months ended September 30, 2021 (In thousands) Commercial HSA Retail Banking Corporate and Consolidated Non-interest Income: Deposit service fees $ 12,412 $ 72,382 $ 37,115 $ 257 $ 122,166 Wealth and investment services 29,501 — — (26) 29,475 Other 939 5,933 814 — 7,686 Revenue from contracts with customers 42,852 78,315 37,929 231 159,327 Other sources of non-interest income 38,114 — 11,903 23,890 73,907 Total non-interest income $ 80,966 $ 78,315 $ 49,832 $ 24,121 $ 233,234 Nine months ended September 30, 2020 (In thousands) Commercial HSA Retail Banking Corporate and Consolidated Non-interest Income: Deposit service fees $ 10,969 $ 70,250 $ 36,460 $ 8 $ 117,687 Wealth and investment services 24,120 — — (24) 24,096 Other 896 6,471 687 — 8,054 Revenue from contracts with customers 35,985 76,721 37,147 (16) 149,837 Other sources of non-interest income 28,990 — 18,936 10,751 58,677 Total non-interest income $ 64,975 $ 76,721 $ 56,083 $ 10,735 $ 208,514

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2021
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, 2020 Commitments to extend credit $ 6,953,871 $ 6,517,840 Standby letters of credit 220,895 207,201 Commercial letters of credit 49,783 30,522 Total credit-related financial instruments with off-balance sheet risk $ 7,224,549 $ 6,755,563
Activity In Allowance For Losses	The following table summarizes the activity in, as well as the loan and lease balances that were evaluated for, ACL on loans and leases: At or for the three months ended September 30, 2021 2020 (In thousands) Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total ACL on loans and leases: Balance, beginning of period $ 263,071 $ 44,874 $ 307,945 $ 291,520 $ 67,002 $ 358,522 (Benefit) provision 7,681 217 7,898 31,618 (8,865) 22,753 Charge-offs (1,723) (2,053) (3,776) (13,494) (2,263) (15,757) Recoveries 142 2,713 2,855 2,025 2,268 4,293 Balance, end of period $ 269,171 $ 45,751 $ 314,922 $ 311,669 $ 58,142 $ 369,811 At or for the nine months ended September 30, 2021 2020 (In thousands) Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total ACL on loans and leases: Balance, beginning of period $ 312,244 $ 47,187 $ 359,431 $ 161,669 $ 47,427 $ 209,096 Adoption of ASU No. 2016-13 (CECL) — — — 34,024 23,544 57,568 (Benefit) provision (37,049) (2,386) (39,435) 147,466 (8,625) 138,841 Charge-offs (8,638) (7,835) (16,473) (34,362) (9,630) (43,992) Recoveries 2,614 8,785 11,399 2,872 5,426 8,298 Balance, end of period $ 269,171 $ 45,751 $ 314,922 $ 311,669 $ 58,142 $ 369,811 Individually evaluated for impairment 7,791 4,308 12,099 18,303 4,376 22,679 Collectively evaluated for impairment $ 261,380 $ 41,443 $ 302,823 $ 293,366 $ 53,766 $ 347,132 Loan and lease balances: Individually evaluated for impairment $ 116,280 $ 104,677 $ 220,957 $ 158,324 $ 149,583 $ 307,907 Collectively evaluated for impairment 14,565,526 6,793,852 21,359,378 14,761,792 6,782,324 21,544,116 Loans and leases $ 14,681,806 $ 6,898,529 $ 21,580,335 $ 14,920,116 $ 6,931,907 $ 21,852,023 The following table provides a summary of activity in the ACL on unfunded loan commitments: Three months ended September 30, Nine months ended September 30, (In thousands) 2021 2020 2021 2020 Beginning balance $ 11,974 $ 10,739 $ 12,755 $ 2,367 Adoption of ASU No. 2016-13 (CECL) — — — 9,139 (Benefit) provision 196 1,146 (585) 379 Ending balance $ 12,170 $ 11,885 $ 12,170 $ 11,885

Business Developments (Tables)

Business Developments (Tables)	9 Months Ended
	Sep. 30, 2021
Business Combination and Restructuring and Related Activities [Abstract]
Schedule of Changes in Reserves Associated with Strategic Initiatives	The following table presents the changes in accrued expenses associated with the Company's strategic initiatives for the three and nine months ended September 30, 2021: Three months ended September 30, 2021 (In thousands) Severance ROU Asset Other Total Beginning balance $ 13,964 $ — $ 2,230 $ 16,194 Charged to earnings 1 91 53 145 Adjustments (1) (3,903) — (253) (4,156) Charged against assets — (91) (246) (337) Net cash (payments) receipts (3,923) — 193 (3,730) Ending balance $ 6,139 $ — $ 1,977 $ 8,116 Nine months ended September 30, 2021 (In thousands) Severance ROU Asset Other Total Beginning balance $ 17,675 $ — $ 2,120 $ 19,795 Charged to earnings 2,106 361 8,987 11,454 Adjustments (1) (3,903) — (984) (4,887) Charged against assets — (361) (3,776) (4,137) Net cash (payments) receipts (9,739) — (4,370) (14,109) Ending balance $ 6,139 $ — $ 1,977 $ 8,116 (1) Adjustments reflect changes in retention assumptions, gains on sale of banking centers, and other facilities-related adjustments.

Variable Interest Entities (Var

Variable Interest Entities (Variable Interest Entity, Consolidated, Carrying Amount, Assets) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Variable Interest Entity [Line Items]
Assets	$ 35,374,258		$ 32,590,690
Liabilities	31,988,069		29,356,065
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Liabilities Assumed	10,600	$ 0
Other Assets | Tax Credit - Finance Investments | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	44,600		37,200
Accounts Payable and Accrued Liabilities | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Liabilities			10,200
Accounts Payable and Accrued Liabilities | Tax Credit - Finance Investments | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Liabilities	12,600
Other Investments | Other Non-Marketable Investments | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Assets	53,000		34,300
Unfunded Loan Commitment | Other Non-Marketable Investments | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	$ 83,300		$ 72,700

Investments, Debt and Equity Se

Investments, Debt and Equity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Amortized Cost(1)	$ 5,986,542		$ 5,568,188
Unrealized Gains	180,443		269,717
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	(27,545)		(2,541)
Debt Securities, Held-to-maturity, Fair Value	6,139,440		5,835,364
Allowance for credit losses on investment securities held-to-maturity	234	$ 382	299	$ 306	$ 309	$ 0
Net Carrying Value	5,986,308		5,567,889
Interest receivable	16,700		22,100
Agency CMO
Schedule of Investments [Line Items]
Amortized Cost(1)	50,146		91,622
Unrealized Gains	1,075		1,785
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	(48)		(241)
Debt Securities, Held-to-maturity, Fair Value	51,173		93,166
Allowance for credit losses on investment securities held-to-maturity	0		0
Net Carrying Value	50,146		91,622
Agency MBS
Schedule of Investments [Line Items]
Amortized Cost(1)	2,544,509		2,419,751
Unrealized Gains	101,289		137,863
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	(5,403)		(84)
Debt Securities, Held-to-maturity, Fair Value	2,640,395		2,557,530
Allowance for credit losses on investment securities held-to-maturity	0		0
Net Carrying Value	2,544,509		2,419,751
Agency Commercial Mortgage Backed Securities
Schedule of Investments [Line Items]
Amortized Cost(1)	2,509,487		2,101,227
Unrealized Gains	22,432		60,484
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	(22,094)		(2,213)
Debt Securities, Held-to-maturity, Fair Value	2,509,825		2,159,498
Allowance for credit losses on investment securities held-to-maturity	0		0
Net Carrying Value	2,509,487		2,101,227
Municipal Bonds
Schedule of Investments [Line Items]
Amortized Cost(1)	707,552		739,507
Unrealized Gains	49,961		60,371
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	0		(3)
Debt Securities, Held-to-maturity, Fair Value	757,513		799,875
Allowance for credit losses on investment securities held-to-maturity	234		299
Net Carrying Value	707,318		739,208
Non-agency CMBS
Schedule of Investments [Line Items]
Amortized Cost(1)	174,848		216,081
Unrealized Gains	5,686		9,214
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	0		0
Debt Securities, Held-to-maturity, Fair Value	180,534		225,295
Allowance for credit losses on investment securities held-to-maturity	0		0
Net Carrying Value	$ 174,848		$ 216,081

Investments, Debt and Equity _2

Investments, Debt and Equity Securities Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Beginning Balance	$ 382	$ 309	$ 299	$ 0
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Recovery	(148)	(3)	(65)	(91)
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Ending Balance	234	306	234	306
Cumulative Effect, Period of Adoption, Adjustment
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Roll Forward]
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Beginning Balance	$ 0	$ 0	$ 0	$ 397

Investment Securities (Summary

Investment Securities (Summary Of Debt Securities Held-to Maturity) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
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	$ 380
Held-to-maturity, Amortized Cost - Due after one year through five years	5,933
Held-to-maturity, Amortized Cost - Due after five through ten years	294,506
Held-to-maturity, Amortized Cost - Due after ten years	5,685,723
Amortized Cost(1)	5,986,542	$ 5,568,188
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Held to maturity, Fair Value - Due in one year or less	382
Held-to-maturity, Fair Value - Due after one year through five years	6,222
Held to maturity, Fair Value - Due after five through ten years	307,837
Held to maturity, Fair Value - Due after ten years	5,824,999
Fair Value(2)	6,139,440	5,835,364
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	17,432	9,471
Amortized Cost	3,365,726	3,234,250
Unrealized Gains	62,149	101,997
Investment securities available-for-sale, at fair value	3,410,443	3,326,776
Moody's, Aaa Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	382,661
Moody's, Aa1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	5,224,130
Moody's, Aa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	227,479
Moody's, Aa3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	104,454
Moody's, A1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	36,045
Moody's, A2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	8,464
Moody's, A3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Moody's, Baa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	190
Moody's, Not Rated
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	3,119
Agency CMO
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	50,146	91,622
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Fair Value(2)	51,173	93,166
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	23	98
Amortized Cost	102,257	148,711
Unrealized Gains	3,549	6,000
Investment securities available-for-sale, at fair value	105,783	154,613
Agency CMO | Moody's, Aaa Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMO | Moody's, Aa1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	50,146
Agency CMO | Moody's, Aa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMO | Moody's, Aa3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMO | Moody's, A1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMO | Moody's, A2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMO | Moody's, A3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMO | Moody's, Baa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMO | Moody's, Not Rated
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency MBS
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	2,544,509	2,419,751
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Fair Value(2)	2,640,395	2,557,530
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	6,614	289
Amortized Cost	1,552,693	1,389,100
Unrealized Gains	50,705	68,598
Investment securities available-for-sale, at fair value	1,596,784	1,457,409
Agency MBS | Moody's, Aaa Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency MBS | Moody's, Aa1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	2,544,509
Agency MBS | Moody's, Aa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency MBS | Moody's, Aa3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency MBS | Moody's, A1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency MBS | Moody's, A2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency MBS | Moody's, A3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency MBS | Moody's, Baa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency MBS | Moody's, Not Rated
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMBS
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	2,509,487	2,101,227
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Fair Value(2)	2,509,825	2,159,498
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	9,920	1,514
Amortized Cost	901,654	1,092,430
Unrealized Gains	6,852	26,317
Investment securities available-for-sale, at fair value	898,586	1,117,233
Agency CMBS | Moody's, Aaa Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMBS | Moody's, Aa1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	2,509,487
Agency CMBS | Moody's, Aa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMBS | Moody's, Aa3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMBS | Moody's, A1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMBS | Moody's, A2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMBS | Moody's, A3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMBS | Moody's, Baa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Agency CMBS | Moody's, Not Rated
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Municipal bonds and notes
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	707,552	739,507
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Fair Value(2)	757,513	799,875
Municipal bonds and notes | Moody's, Aaa Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	207,813
Municipal bonds and notes | Moody's, Aa1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	119,988
Municipal bonds and notes | Moody's, Aa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	227,479
Municipal bonds and notes | Moody's, Aa3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	104,454
Municipal bonds and notes | Moody's, A1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	36,045
Municipal bonds and notes | Moody's, A2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	8,464
Municipal bonds and notes | Moody's, A3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Municipal bonds and notes | Moody's, Baa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	190
Municipal bonds and notes | Moody's, Not Rated
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	3,119
Non-agency CMBS
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	174,848	216,081
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Fair Value(2)	180,534	225,295
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	329	5,823
Amortized Cost	769,546	512,759
Unrealized Gains	869	1,082
Investment securities available-for-sale, at fair value	770,086	508,018
Non-agency CMBS | Moody's, Aaa Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	174,848
Non-agency CMBS | Moody's, Aa1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Non-agency CMBS | Moody's, Aa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Non-agency CMBS | Moody's, Aa3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Non-agency CMBS | Moody's, A1 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Non-agency CMBS | Moody's, A2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Non-agency CMBS | Moody's, A3 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Non-agency CMBS | Moody's, Baa2 Rating
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
Non-agency CMBS | Moody's, Not Rated
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Amortized Cost(1)	0
CLO
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	33	310
Amortized Cost	25,000	76,693
Unrealized Gains	0	0
Investment securities available-for-sale, at fair value	24,967	76,383
Corporate Debt Securities
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	513	1,437
Amortized Cost	14,576	14,557
Unrealized Gains	174	0
Investment securities available-for-sale, at fair value	$ 14,237	$ 13,120

Investment Securities (Summar_2

Investment Securities (Summary Of Debt Securities Available-for-Sale) (Detail) $ in Thousands	Sep. 30, 2021USD ($)holding	Dec. 31, 2020USD ($)holding
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	$ 3,365,726	$ 3,234,250
Unrealized Gains	62,149	101,997
Unrealized Losses	(17,432)	(9,471)
Investment securities available-for-sale, at fair value	3,410,443	3,326,776
Interest receivable	6,600	7,500
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	902,155	894,628
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(9,237)	(7,699)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	434,395	61,347
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (8,195)	$ (1,772)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	103	88
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 1,336,550	$ 955,975
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(17,432)	(9,471)
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost	0
Available-for-sale, Amortized Cost - Due after one year through five years	2,266
Available-for-sale, Amortized Cost - Due after five through ten years	152,856
Available-for-sale, Amortized Cost - Due after ten years	3,210,604
Amortized Cost - Total available-for-sale debt securities	3,365,726	3,234,250
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Available-for-sale, Fair Value - Due in one year or less	0
Available-for-sale, Fair Value - Due after one year through five years	2,338
Available-for-sale, Fair Value - Due after five through ten years	153,009
Available-for-sale, Fair Value - Due after ten years	3,255,096
Fair Value, Total available-for-sale debt securities	3,410,443	3,326,776
Agency CMO
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	102,257	148,711
Unrealized Gains	3,549	6,000
Unrealized Losses	(23)	(98)
Investment securities available-for-sale, at fair value	105,783	154,613
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	6,734	13,137
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(19)	(49)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,066	5,944
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (4)	$ (49)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	4	5
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 7,800	$ 19,081
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(23)	(98)
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Amortized Cost - Total available-for-sale debt securities	102,257	148,711
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Fair Value, Total available-for-sale debt securities	105,783	154,613
Agency MBS
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	1,552,693	1,389,100
Unrealized Gains	50,705	68,598
Unrealized Losses	(6,614)	(289)
Investment securities available-for-sale, at fair value	1,596,784	1,457,409
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	495,080	33,742
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(6,397)	(219)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	19,902	4,561
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (217)	$ (70)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	55	30
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 514,982	$ 38,303
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(6,614)	(289)
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Amortized Cost - Total available-for-sale debt securities	1,552,693	1,389,100
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Fair Value, Total available-for-sale debt securities	1,596,784	1,457,409
Agency CMBS
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	901,654	1,092,430
Unrealized Gains	6,852	26,317
Unrealized Losses	(9,920)	(1,514)
Investment securities available-for-sale, at fair value	898,586	1,117,233
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	180,305	376,330
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(2,583)	(1,514)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	285,865	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (7,337)	$ 0
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	14	8
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 466,170	$ 376,330
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(9,920)	(1,514)
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Amortized Cost - Total available-for-sale debt securities	901,654	1,092,430
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Fair Value, Total available-for-sale debt securities	898,586	1,117,233
Non-agency CMBS
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	769,546	512,759
Unrealized Gains	869	1,082
Unrealized Losses	(329)	(5,823)
Investment securities available-for-sale, at fair value	770,086	508,018
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	220,036	409,591
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(238)	(5,486)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	92,807	23,167
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (91)	$ (337)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	27	38
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 312,843	$ 432,758
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(329)	(5,823)
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Amortized Cost - Total available-for-sale debt securities	769,546	512,759
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Fair Value, Total available-for-sale debt securities	770,086	508,018
CLO
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	25,000	76,693
Unrealized Gains	0	0
Unrealized Losses	(33)	(310)
Investment securities available-for-sale, at fair value	24,967	76,383
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months		57,728
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(265)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	24,967	18,655
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (33)	$ (45)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	1	4
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 24,967	$ 76,383
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(33)	(310)
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Amortized Cost - Total available-for-sale debt securities	25,000	76,693
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Fair Value, Total available-for-sale debt securities	24,967	76,383
Corporate Debt Securities
Debt Securities, Available-for-sale [Abstract]
Amortized Cost	14,576	14,557
Unrealized Gains	174	0
Unrealized Losses	(513)	(1,437)
Investment securities available-for-sale, at fair value	14,237	13,120
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0	4,100
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	(166)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	9,788	9,020
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (513)	$ (1,271)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | holding	2	3
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 9,788	$ 13,120
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(513)	(1,437)
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Amortized Cost - Total available-for-sale debt securities	14,576	14,557
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Fair Value, Total available-for-sale debt securities	$ 14,237	$ 13,120

Investment Securities (Narrativ

Investment Securities (Narrative) (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Held-to-maturity investment securities in non-accrual status		$ 0
Proceeds from Sale of Debt Securities, Available-for-sale		0	$ 8,963,000
Debt Securities, Available-for-sale, Realized Gain			8,000
Investment securities available-for-sale, at fair value		3,410,443,000		$ 3,326,776,000
Held-to-maturity securities pledged		3,000,000,000		2,600,000,000
Available-for-sale securities pledged		1,900,000,000		1,300,000,000
Corporate Debt Securities
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Proceeds from Sale of Debt Securities, Available-for-sale	$ 0		$ 9,000,000
Investment securities available-for-sale, at fair value		14,237,000		$ 13,120,000
Callable
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Investment securities available-for-sale, at fair value		$ 1,500,000,000

Loans and Leases (Detail)

Loans and Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 21,580,335	$ 21,641,215	$ 21,852,023
Unamortized premiums	5,400	(10,500)
Pledged Financial Instruments, Not Separately Reported, Loans Receivable Pledged as Collateral	7,500,000
Interest receivable	55,200	57,800
Commercial Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	14,681,806	14,900,535	14,920,116
Commercial Portfolio Segment | Commercial non-mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	6,552,241	7,085,076
Commercial Portfolio Segment | Asset-based
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	986,782	890,598
Commercial Portfolio Segment | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	6,522,679	6,322,637
Commercial Portfolio Segment | Equipment financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	620,104	602,224
Consumer Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	6,898,529	6,740,680	$ 6,931,907
Consumer Portfolio Segment | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	5,167,527	4,782,016
Consumer Portfolio Segment | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	1,633,873	1,802,865
Consumer Portfolio Segment | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 97,129	$ 155,799

Loans and Leases (Narrative) (D

Loans and Leases (Narrative) (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)loan	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)loan	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Operating Leased Assets [Line Items]
Total operating lease liability payments	$ 172,035		$ 172,035
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	2,400	$ 3,400	7,200	$ 9,000
Write-down	$ (1,100)	(7,800)	$ (3,300)	(10,800)
Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts | loan	0		0
Commercial Portfolio Segment | Equipment financing
Operating Leased Assets [Line Items]
Sales-Type Lease, Net Investment in Lease, before Allowance for Credit Loss	$ 213,700		$ 213,700		$ 236,100
Total operating lease liability payments	231,500		231,500
Sales-type and Direct Financing Leases, Interest Income	$ 1,800	$ 1,800	$ 5,600	$ 5,200

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 307,945	$ 358,522	$ 359,431	$ 209,096
(Benefit) provision	7,898	22,753	(39,435)	138,841
Charge-offs	(3,776)	(15,757)	(16,473)	(43,992)
Recoveries	2,855	4,293	11,399	8,298
Balance, end of period	314,922	369,811	314,922	369,811	$ 359,431
ALLL, Individually evaluated for impairment	12,099	22,679	12,099	22,679
ALLL, Collectively evaluated for impairment	302,823	347,132	302,823	347,132
Loan and lease balances, Individually evaluated for impairment	220,957	307,907	220,957	307,907
Loan and lease balances, Collectively evaluated for impairment	21,359,378	21,544,116	21,359,378	21,544,116
Loans and leases	21,580,335	21,852,023	21,580,335	21,852,023	21,641,215
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period			0	57,568
Balance, end of period					0
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	263,071	291,520	312,244	161,669
(Benefit) provision	7,681	31,618	(37,049)	147,466
Charge-offs	(1,723)	(13,494)	(8,638)	(34,362)
Recoveries	142	2,025	2,614	2,872
Balance, end of period	269,171	311,669	269,171	311,669	312,244
ALLL, Individually evaluated for impairment	7,791	18,303	7,791	18,303
ALLL, Collectively evaluated for impairment	261,380	293,366	261,380	293,366
Loan and lease balances, Individually evaluated for impairment	116,280	158,324	116,280	158,324
Loan and lease balances, Collectively evaluated for impairment	14,565,526	14,761,792	14,565,526	14,761,792
Loans and leases	14,681,806	14,920,116	14,681,806	14,920,116	14,900,535
Commercial Portfolio Segment | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period			0	34,024
Balance, end of period					0
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	44,874	67,002	47,187	47,427
(Benefit) provision	217	(8,865)	(2,386)	(8,625)
Charge-offs	(2,053)	(2,263)	(7,835)	(9,630)
Recoveries	2,713	2,268	8,785	5,426
Balance, end of period	45,751	58,142	45,751	58,142	47,187
ALLL, Individually evaluated for impairment	4,308	4,376	4,308	4,376
ALLL, Collectively evaluated for impairment	41,443	53,766	41,443	53,766
Loan and lease balances, Individually evaluated for impairment	104,677	149,583	104,677	149,583
Loan and lease balances, Collectively evaluated for impairment	6,793,852	6,782,324	6,793,852	6,782,324
Loans and leases	$ 6,898,529	$ 6,931,907	6,898,529	6,931,907	6,740,680
Consumer Portfolio Segment | Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period			$ 0	$ 23,544
Balance, end of period					$ 0

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, 2021	Dec. 31, 2020	Sep. 30, 2020
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 105	$ 445
Financing Receivable, Nonaccrual	101,654	167,960	$ 167,960
Loans and leases	21,580,335	21,641,215	21,852,023
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	118,724	200,942
Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	11,755	20,005
Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	5,210	12,532
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	21,461,611	21,440,273
Commercial Portfolio Segment
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	105	445
Financing Receivable, Nonaccrual	58,744	95,197	95,197
Loans and leases	14,681,806	14,900,535	14,920,116
Commercial Portfolio Segment | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	65,212	108,765
Commercial Portfolio Segment | Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	3,394	9,293
Commercial Portfolio Segment | Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	2,969	3,830
Commercial Portfolio Segment | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	14,616,594	14,791,770
Commercial Portfolio Segment | Commercial non-mortgage
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	105	445
Financing Receivable, Nonaccrual	36,448	64,073	64,073
Loans and leases	6,552,241	7,085,076
Commercial Portfolio Segment | Commercial non-mortgage | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	40,868	66,033
Commercial Portfolio Segment | Commercial non-mortgage | Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	2,051	612
Commercial Portfolio Segment | Commercial non-mortgage | Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	2,264	903
Commercial Portfolio Segment | Commercial non-mortgage | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	6,511,373	7,019,043
Commercial Portfolio Segment | Asset-based
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	2,111	2,594	2,594
Loans and leases	986,782	890,598
Commercial Portfolio Segment | Asset-based | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	2,111	3,768
Commercial Portfolio Segment | Asset-based | Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	0	1,174
Commercial Portfolio Segment | Asset-based | Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	0	0
Commercial Portfolio Segment | Asset-based | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	984,671	886,830
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	15,963	21,231	21,231
Loans and leases	6,522,679	6,322,637
Commercial Portfolio Segment | Commercial real estate | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	16,787	24,250
Commercial Portfolio Segment | Commercial real estate | Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	128	2,400
Commercial Portfolio Segment | Commercial real estate | Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	696	619
Commercial Portfolio Segment | Commercial real estate | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	6,505,892	6,298,387
Commercial Portfolio Segment | Equipment financing
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	4,222	7,299	7,299
Loans and leases	620,104	602,224
Commercial Portfolio Segment | Equipment financing | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	5,446	14,714
Commercial Portfolio Segment | Equipment financing | Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	1,215	5,107
Commercial Portfolio Segment | Equipment financing | Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	9	2,308
Commercial Portfolio Segment | Equipment financing | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	614,658	587,510
Consumer Portfolio Segment
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	42,910	72,763	72,763
Loans and leases	6,898,529	6,740,680	6,931,907
Consumer Portfolio Segment | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	53,512	92,177
Consumer Portfolio Segment | Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	8,361	10,712
Consumer Portfolio Segment | Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	2,241	8,702
Consumer Portfolio Segment | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	6,845,017	6,648,503
Consumer Portfolio Segment | Residential
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	19,325	41,081	41,081
Loans and leases	5,167,527	4,782,016
Consumer Portfolio Segment | Residential | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	22,755	51,745
Consumer Portfolio Segment | Residential | Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	2,892	4,334
Consumer Portfolio Segment | Residential | Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	538	6,330
Consumer Portfolio Segment | Residential | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	5,144,772	4,730,271
Consumer Portfolio Segment | Home equity
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	23,322	31,030	$ 31,030
Loans and leases	1,633,873	1,802,865
Consumer Portfolio Segment | Home equity | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	29,664	38,301
Consumer Portfolio Segment | Home equity | Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	4,905	5,500
Consumer Portfolio Segment | Home equity | Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	1,437	1,771
Consumer Portfolio Segment | Home equity | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	1,604,209	1,764,564
Consumer Portfolio Segment | Other consumer
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Financing Receivable, Nonaccrual	263	652
Loans and leases	97,129	155,799
Consumer Portfolio Segment | Other consumer | Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	1,093	2,131
Consumer Portfolio Segment | Other consumer | Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	564	878
Consumer Portfolio Segment | Other consumer | Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	266	601
Consumer Portfolio Segment | Other consumer | Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans and leases	$ 96,036	$ 153,668

Loans and Leases Nonaccrual (De

Loans and Leases Nonaccrual (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	$ 101,654	$ 167,960	$ 167,960
Financing Receivable, Nonaccrual, No Allowance	45,361		89,433
Commercial Portfolio Segment
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	58,744	95,197	95,197
Financing Receivable, Nonaccrual, No Allowance	15,143		35,497
Commercial Portfolio Segment | Commercial non-mortgage
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	36,448	64,073	64,073
Financing Receivable, Nonaccrual, No Allowance	8,081		16,985
Commercial Portfolio Segment | Asset-based
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	2,111	2,594	2,594
Financing Receivable, Nonaccrual, No Allowance	2,111		0
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	15,963	21,231	21,231
Financing Receivable, Nonaccrual, No Allowance	4,951		15,529
Commercial Portfolio Segment | Equipment financing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	4,222	7,299	7,299
Financing Receivable, Nonaccrual, No Allowance	0		2,983
Consumer Portfolio Segment
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	42,910	72,763	72,763
Financing Receivable, Nonaccrual, No Allowance	30,218		53,936
Consumer Portfolio Segment | Residential
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	19,325	41,081	41,081
Financing Receivable, Nonaccrual, No Allowance	11,420		29,843
Consumer Portfolio Segment | Home equity
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	23,322	$ 31,030	31,030
Financing Receivable, Nonaccrual, No Allowance	18,798		24,091
Consumer Portfolio Segment | Other consumer
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual	263		652
Financing Receivable, Nonaccrual, No Allowance	$ 0		$ 2

Loans and Leases (Credit Qualit

Loans and Leases (Credit Quality Indicators) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	$ 4,354,865	$ 5,461,818
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	3,648,196	3,635,131
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,069,216	2,728,575
Financing Receivable, Originated Three Years before Latest Fiscal Year	2,204,071	1,645,809
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,112,376	1,487,739
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	3,887,086	3,453,866
Financing Receivable, Revolving	3,304,525	3,228,277
Loans and leases	21,580,335	21,641,215	$ 21,852,023
Commercial Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	2,726,803	4,116,181
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	2,481,695	2,781,504
Financing Receivable, Originated Two Years before Latest Fiscal Year	2,511,904	2,475,137
Financing Receivable, Originated Three Years before Latest Fiscal Year	2,038,837	1,198,615
Financing Receivable, Originated Four Years before Latest Fiscal Year	809,742	909,133
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	2,069,338	1,584,568
Financing Receivable, Revolving	2,043,487	1,835,397
Loans and leases	14,681,806	14,900,535	14,920,116
Commercial Portfolio Segment | Commercial non-mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	1,697,557	2,858,624
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,353,715	1,137,847
Financing Receivable, Originated Two Years before Latest Fiscal Year	931,414	1,035,468
Financing Receivable, Originated Three Years before Latest Fiscal Year	791,983	518,078
Financing Receivable, Originated Four Years before Latest Fiscal Year	310,635	255,172
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	353,815	255,715
Financing Receivable, Revolving	1,113,122	1,024,172
Loans and leases	6,552,241	7,085,076
Commercial Portfolio Segment | Asset-based
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	7,612	26,344
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	20,768	18,464
Financing Receivable, Originated Two Years before Latest Fiscal Year	15,226	23,898
Financing Receivable, Originated Three Years before Latest Fiscal Year	14,698	11,333
Financing Receivable, Originated Four Years before Latest Fiscal Year	6,272	10,963
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	26,747	16,484
Financing Receivable, Revolving	895,459	783,112
Loans and leases	986,782	890,598
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	847,497	966,426
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	894,462	1,472,718
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,451,751	1,334,949
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,175,245	639,091
Financing Receivable, Originated Four Years before Latest Fiscal Year	474,401	593,209
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,644,417	1,288,131
Financing Receivable, Revolving	34,906	28,113
Loans and leases	6,522,679	6,322,637
Commercial Portfolio Segment | Equipment financing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	174,137	264,787
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	212,750	152,475
Financing Receivable, Originated Two Years before Latest Fiscal Year	113,513	80,822
Financing Receivable, Originated Three Years before Latest Fiscal Year	56,911	30,113
Financing Receivable, Originated Four Years before Latest Fiscal Year	18,434	49,789
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	44,359	24,238
Financing Receivable, Revolving	0	0
Loans and leases	620,104	602,224
Commercial Portfolio Segment | (1) - (6) Pass | Commercial non-mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	1,680,524	2,771,373
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,261,582	1,052,080
Financing Receivable, Originated Two Years before Latest Fiscal Year	862,131	907,110
Financing Receivable, Originated Three Years before Latest Fiscal Year	673,196	481,321
Financing Receivable, Originated Four Years before Latest Fiscal Year	291,995	231,280
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	317,590	218,001
Financing Receivable, Revolving	1,068,077	936,592
Loans and leases	6,155,095	6,597,757
Commercial Portfolio Segment | (1) - (6) Pass | Asset-based
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	7,612	26,344
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	20,768	15,960
Financing Receivable, Originated Two Years before Latest Fiscal Year	13,115	23,123
Financing Receivable, Originated Three Years before Latest Fiscal Year	13,998	11,333
Financing Receivable, Originated Four Years before Latest Fiscal Year	6,272	10,963
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	26,747	16,484
Financing Receivable, Revolving	835,405	741,336
Loans and leases	923,917	845,543
Commercial Portfolio Segment | (1) - (6) Pass | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	847,147	965,582
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	891,343	1,461,201
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,450,959	1,242,322
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,074,542	527,931
Financing Receivable, Originated Four Years before Latest Fiscal Year	377,030	554,630
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,484,768	1,165,331
Financing Receivable, Revolving	34,906	28,113
Loans and leases	6,160,695	5,945,110
Commercial Portfolio Segment | (1) - (6) Pass | Equipment financing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	174,137	249,370
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	203,641	135,263
Financing Receivable, Originated Two Years before Latest Fiscal Year	101,319	68,092
Financing Receivable, Originated Three Years before Latest Fiscal Year	49,725	26,433
Financing Receivable, Originated Four Years before Latest Fiscal Year	16,835	43,469
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	39,771	22,879
Financing Receivable, Revolving	0	0
Loans and leases	585,428	545,506
Commercial Portfolio Segment | (7) Special Mention | Commercial non-mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	13,242	32,535
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	45,084	33,969
Financing Receivable, Originated Two Years before Latest Fiscal Year	38,253	62,034
Financing Receivable, Originated Three Years before Latest Fiscal Year	32,989	435
Financing Receivable, Originated Four Years before Latest Fiscal Year	9,994	8,357
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	16,578	13,757
Financing Receivable, Revolving	15,835	38,496
Loans and leases	171,975	189,583
Commercial Portfolio Segment | (7) Special Mention | Asset-based
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0	0
Financing Receivable, Originated Two Years before Latest Fiscal Year	0	775
Financing Receivable, Originated Three Years before Latest Fiscal Year	700	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0	0
Financing Receivable, Revolving	60,054	41,687
Loans and leases	60,754	42,462
Commercial Portfolio Segment | (7) Special Mention | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	350	27
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	2,232	10,385
Financing Receivable, Originated Two Years before Latest Fiscal Year	0	70,704
Financing Receivable, Originated Three Years before Latest Fiscal Year	79,138	37,539
Financing Receivable, Originated Four Years before Latest Fiscal Year	54,177	35,617
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	105,173	69,832
Financing Receivable, Revolving	0	0
Loans and leases	241,070	224,104
Commercial Portfolio Segment | (7) Special Mention | Equipment financing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0	7,934
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	120	11,043
Financing Receivable, Originated Two Years before Latest Fiscal Year	8,101	6,981
Financing Receivable, Originated Three Years before Latest Fiscal Year	3,620	1,220
Financing Receivable, Originated Four Years before Latest Fiscal Year	87	1,577
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,055	788
Financing Receivable, Revolving	0	0
Loans and leases	12,983	29,543
Commercial Portfolio Segment | (8) Substandard | Commercial non-mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	3,791	54,716
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	47,048	51,798
Financing Receivable, Originated Two Years before Latest Fiscal Year	31,030	66,324
Financing Receivable, Originated Three Years before Latest Fiscal Year	85,798	36,159
Financing Receivable, Originated Four Years before Latest Fiscal Year	8,646	15,535
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	19,647	23,957
Financing Receivable, Revolving	29,210	49,084
Loans and leases	225,170	297,573
Commercial Portfolio Segment | (8) Substandard | Asset-based
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	0	2,504
Financing Receivable, Originated Two Years before Latest Fiscal Year	2,111	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0	0
Financing Receivable, Revolving	0	89
Loans and leases	2,111	2,593
Commercial Portfolio Segment | (8) Substandard | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0	817
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	887	1,132
Financing Receivable, Originated Two Years before Latest Fiscal Year	792	21,923
Financing Receivable, Originated Three Years before Latest Fiscal Year	21,565	73,621
Financing Receivable, Originated Four Years before Latest Fiscal Year	43,194	2,962
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	54,475	52,968
Financing Receivable, Revolving	0	0
Loans and leases	120,913	153,423
Commercial Portfolio Segment | (8) Substandard | Equipment financing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	0	7,483
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	8,989	6,169
Financing Receivable, Originated Two Years before Latest Fiscal Year	4,093	5,749
Financing Receivable, Originated Three Years before Latest Fiscal Year	3,566	2,460
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,512	4,743
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	3,533	571
Financing Receivable, Revolving	0	0
Loans and leases	21,693	27,175
Commercial Portfolio Segment | (9) Doubtful | Commercial non-mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year		0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year		0
Financing Receivable, Originated Two Years before Latest Fiscal Year		0
Financing Receivable, Originated Three Years before Latest Fiscal Year		163
Financing Receivable, Originated Four Years before Latest Fiscal Year		0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year		0
Financing Receivable, Revolving		0
Loans and leases		163
Loans and leases	1
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1
Financing Receivable, Originated Two Years before Latest Fiscal Year	0
Financing Receivable, Originated Three Years before Latest Fiscal Year	0
Financing Receivable, Originated Four Years before Latest Fiscal Year	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	0
Financing Receivable, Revolving	0
Financing Receivable, Originated in Current Fiscal Year	0
Consumer Portfolio Segment
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	1,628,062	1,345,637
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,166,501	853,627
Financing Receivable, Originated Two Years before Latest Fiscal Year	557,312	253,438
Financing Receivable, Originated Three Years before Latest Fiscal Year	165,234	447,194
Financing Receivable, Originated Four Years before Latest Fiscal Year	302,634	578,606
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,817,748	1,869,298
Financing Receivable, Revolving	1,261,038	1,392,880
Loans and leases	6,898,529	6,740,680	$ 6,931,907
Consumer Portfolio Segment | Residential
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	1,554,586	1,231,789
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,079,011	746,435
Financing Receivable, Originated Two Years before Latest Fiscal Year	493,445	167,979
Financing Receivable, Originated Three Years before Latest Fiscal Year	110,961	402,761
Financing Receivable, Originated Four Years before Latest Fiscal Year	270,785	536,400
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	1,658,739	1,696,652
Financing Receivable, Revolving	0	0
Loans and leases	5,167,527	4,782,016
Consumer Portfolio Segment | Residential | 800+
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	360,987	360,336
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	450,223	283,755
Financing Receivable, Originated Two Years before Latest Fiscal Year	178,412	61,048
Financing Receivable, Originated Three Years before Latest Fiscal Year	41,697	178,849
Financing Receivable, Originated Four Years before Latest Fiscal Year	128,474	268,044
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	792,003	805,537
Financing Receivable, Revolving	0	0
Loans and leases	1,951,796	1,957,569
Consumer Portfolio Segment | Residential | 740-799
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	857,968	654,973
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	471,194	288,173
Financing Receivable, Originated Two Years before Latest Fiscal Year	180,238	58,249
Financing Receivable, Originated Three Years before Latest Fiscal Year	38,171	133,416
Financing Receivable, Originated Four Years before Latest Fiscal Year	91,741	176,286
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	507,048	492,720
Financing Receivable, Revolving	0	0
Loans and leases	2,146,360	1,803,817
Consumer Portfolio Segment | Residential | 670 to 739
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	300,754	199,329
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	141,427	118,620
Financing Receivable, Originated Two Years before Latest Fiscal Year	81,670	39,125
Financing Receivable, Originated Three Years before Latest Fiscal Year	25,831	75,375
Financing Receivable, Originated Four Years before Latest Fiscal Year	41,147	76,666
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	248,879	248,268
Financing Receivable, Revolving	0	0
Loans and leases	839,708	757,383
Consumer Portfolio Segment | Residential | 580-669
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	24,569	17,151
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	14,716	19,389
Financing Receivable, Originated Two Years before Latest Fiscal Year	9,338	8,884
Financing Receivable, Originated Three Years before Latest Fiscal Year	4,394	11,843
Financing Receivable, Originated Four Years before Latest Fiscal Year	7,531	12,225
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	76,066	96,333
Financing Receivable, Revolving	0	0
Loans and leases	136,614	165,825
Consumer Portfolio Segment | Residential | 579 and below
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	10,308	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,451	36,498
Financing Receivable, Originated Two Years before Latest Fiscal Year	43,787	673
Financing Receivable, Originated Three Years before Latest Fiscal Year	868	3,278
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,892	3,179
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	34,743	53,794
Financing Receivable, Revolving	0	0
Loans and leases	93,049	97,422
Consumer Portfolio Segment | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	69,892	80,991
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	68,411	42,078
Financing Receivable, Originated Two Years before Latest Fiscal Year	29,813	59,221
Financing Receivable, Originated Three Years before Latest Fiscal Year	42,897	39,022
Financing Receivable, Originated Four Years before Latest Fiscal Year	29,617	40,738
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	158,015	171,626
Financing Receivable, Revolving	1,235,228	1,369,189
Loans and leases	1,633,873	1,802,865
Consumer Portfolio Segment | Home equity | 800+
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	27,832	30,604
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	28,501	16,567
Financing Receivable, Originated Two Years before Latest Fiscal Year	10,373	25,205
Financing Receivable, Originated Three Years before Latest Fiscal Year	17,474	14,439
Financing Receivable, Originated Four Years before Latest Fiscal Year	11,631	17,192
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	60,951	59,956
Financing Receivable, Revolving	491,283	542,600
Loans and leases	648,045	706,563
Consumer Portfolio Segment | Home equity | 740-799
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	29,181	34,797
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	27,269	13,565
Financing Receivable, Originated Two Years before Latest Fiscal Year	9,710	19,715
Financing Receivable, Originated Three Years before Latest Fiscal Year	14,530	11,073
Financing Receivable, Originated Four Years before Latest Fiscal Year	8,428	12,839
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	39,651	43,802
Financing Receivable, Revolving	414,321	434,271
Loans and leases	543,090	570,062
Consumer Portfolio Segment | Home equity | 670 to 739
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	12,260	13,753
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	10,657	8,855
Financing Receivable, Originated Two Years before Latest Fiscal Year	7,106	10,761
Financing Receivable, Originated Three Years before Latest Fiscal Year	8,338	10,206
Financing Receivable, Originated Four Years before Latest Fiscal Year	7,369	7,318
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	35,743	44,025
Financing Receivable, Revolving	234,066	275,691
Loans and leases	315,539	370,609
Consumer Portfolio Segment | Home equity | 580-669
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	364	1,708
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,530	2,172
Financing Receivable, Originated Two Years before Latest Fiscal Year	1,750	2,660
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,529	2,234
Financing Receivable, Originated Four Years before Latest Fiscal Year	1,885	2,316
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	15,669	16,680
Financing Receivable, Revolving	73,350	86,126
Loans and leases	96,077	113,896
Consumer Portfolio Segment | Home equity | 579 and below
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	255	129
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	454	919
Financing Receivable, Originated Two Years before Latest Fiscal Year	874	880
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,026	1,070
Financing Receivable, Originated Four Years before Latest Fiscal Year	304	1,073
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	6,001	7,163
Financing Receivable, Revolving	22,208	30,501
Loans and leases	31,122	41,735
Consumer Portfolio Segment | Consumer Loan
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	3,584	32,857
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	19,079	65,114
Financing Receivable, Originated Two Years before Latest Fiscal Year	34,054	26,238
Financing Receivable, Originated Three Years before Latest Fiscal Year	11,376	5,411
Financing Receivable, Originated Four Years before Latest Fiscal Year	2,232	1,468
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	994	1,020
Financing Receivable, Revolving	25,810	23,691
Loans and leases	97,129	155,799
Consumer Portfolio Segment | Consumer Loan | 800+
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	377	2,827
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,544	5,725
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,254	2,610
Financing Receivable, Originated Three Years before Latest Fiscal Year	1,141	658
Financing Receivable, Originated Four Years before Latest Fiscal Year	323	115
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	120	190
Financing Receivable, Revolving	10,386	7,171
Loans and leases	17,145	19,296
Consumer Portfolio Segment | Consumer Loan | 740-799
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	2,314	12,317
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	6,694	21,036
Financing Receivable, Originated Two Years before Latest Fiscal Year	10,540	8,925
Financing Receivable, Originated Three Years before Latest Fiscal Year	4,047	1,493
Financing Receivable, Originated Four Years before Latest Fiscal Year	590	457
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	379	263
Financing Receivable, Revolving	4,857	5,119
Loans and leases	29,421	49,610
Consumer Portfolio Segment | Consumer Loan | 670 to 739
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	542	14,761
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	9,433	31,952
Financing Receivable, Originated Two Years before Latest Fiscal Year	16,762	11,843
Financing Receivable, Originated Three Years before Latest Fiscal Year	5,021	2,284
Financing Receivable, Originated Four Years before Latest Fiscal Year	909	665
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	234	228
Financing Receivable, Revolving	8,106	8,403
Loans and leases	41,007	70,136
Consumer Portfolio Segment | Consumer Loan | 580-669
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	245	2,344
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	1,232	5,419
Financing Receivable, Originated Two Years before Latest Fiscal Year	3,215	2,360
Financing Receivable, Originated Three Years before Latest Fiscal Year	972	793
Financing Receivable, Originated Four Years before Latest Fiscal Year	347	194
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	207	124
Financing Receivable, Revolving	1,313	1,570
Loans and leases	7,531	12,804
Consumer Portfolio Segment | Consumer Loan | 579 and below
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Originated in Current Fiscal Year	106	608
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year	176	982
Financing Receivable, Originated Two Years before Latest Fiscal Year	283	500
Financing Receivable, Originated Three Years before Latest Fiscal Year	195	183
Financing Receivable, Originated Four Years before Latest Fiscal Year	63	37
Financing Receivable, Originated Five or More Years before Latest Fiscal Year	54	215
Financing Receivable, Revolving	1,148	1,428
Loans and leases	$ 2,025	$ 3,953

Loans and Leases (Impaired Loan

Loans and Leases (Impaired Loans And Leases By Class) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	$ 256,153
Amortized Cost	220,957	$ 309,422
Amortized Cost No Allowance	110,975
Amortized Cost With Allowance	109,982
Related Allowance	12,099
Commercial Portfolio Segment | Commercial non-mortgage
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	107,251	172,069
Amortized Cost	84,054	119,884
Amortized Cost No Allowance	34,246	55,742
Amortized Cost With Allowance	49,808	64,142
Related Allowance	5,470	9,665
Commercial Portfolio Segment | Asset-based
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	2,253	2,989
Amortized Cost	2,111	2,594
Amortized Cost No Allowance	2,111	0
Amortized Cost With Allowance	0	2,594
Related Allowance	0	50
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	29,357	37,177
Amortized Cost	25,893	33,879
Amortized Cost No Allowance	11,203	25,931
Amortized Cost With Allowance	14,690	7,948
Related Allowance	1,449	1,610
Commercial Portfolio Segment | Equipment financing
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	4,732	7,770
Amortized Cost	4,222	7,298
Amortized Cost No Allowance	0	2,983
Amortized Cost With Allowance	4,222	4,315
Related Allowance	872	362
Commercial Portfolio Segment | Residential
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance		108,077
Amortized Cost		98,164
Amortized Cost No Allowance		58,915
Amortized Cost With Allowance		39,249
Related Allowance		3,357
Consumer Portfolio Segment
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance		439,619
Amortized Cost		309,422
Amortized Cost No Allowance		177,908
Amortized Cost With Allowance		131,514
Related Allowance		16,137
Consumer Portfolio Segment | Residential
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	68,514
Amortized Cost	65,018	98,164
Amortized Cost No Allowance	35,337
Amortized Cost With Allowance	29,681
Related Allowance	2,503
Consumer Portfolio Segment | Home equity
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	43,764	109,156
Amortized Cost	39,396	46,950
Amortized Cost No Allowance	28,078	34,335
Amortized Cost With Allowance	11,318	12,615
Related Allowance	1,689	988
Consumer Portfolio Segment | Consumer Loan
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	282	2,381
Amortized Cost	263	653
Amortized Cost No Allowance	0	2
Amortized Cost With Allowance	263	651
Related Allowance	$ 116	$ 105

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 230,208	$ 315,533	$ 265,190	$ 282,161
Accrued Interest Income	1,669	2,202	5,243	6,773
Cash Basis Interest Income	109	586	1,066	2,689
Commercial Portfolio Segment | Commercial non-mortgage
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	90,662	127,676	101,969	114,027
Accrued Interest Income	729	954	2,270	2,882
Cash Basis Interest Income	0	0	0	0
Commercial Portfolio Segment | Asset-based
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	2,243	1,949	2,353	1,950
Accrued Interest Income	0	0	0	0
Cash Basis Interest Income	0	0	0	0
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	23,512	24,555	29,886	22,440
Accrued Interest Income	132	192	440	507
Cash Basis Interest Income	0	0	0	0
Commercial Portfolio Segment | Equipment financing
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	6,192	7,488	5,760	6,308
Accrued Interest Income	0	0	0	0
Cash Basis Interest Income	0	0	0	0
Consumer Portfolio Segment | Residential
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	66,920	103,608	81,591	95,270
Accrued Interest Income	590	741	1,806	2,352
Cash Basis Interest Income	46	289	487	1,149
Consumer Portfolio Segment | Home equity
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	40,341	49,309	43,173	41,826
Accrued Interest Income	218	302	727	1,002
Cash Basis Interest Income	63	297	579	1,540
Consumer Portfolio Segment | Consumer Loan
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Average Recorded Investment	338	948	458	340
Accrued Interest Income	0	13	0	30
Cash Basis Interest Income	$ 0	$ 0	$ 0	$ 0

Loans and Leases Impaired Colla

Loans and Leases Impaired Collateral (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 220,957	$ 309,422
Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	68,445	102,836
Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	152,512	206,586
Collateral Value
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	104,400	150,300
Commercial Portfolio Segment | Commercial non-mortgage
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	84,054	119,884
Commercial Portfolio Segment | Commercial non-mortgage | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	8,062	11,074
Commercial Portfolio Segment | Commercial non-mortgage | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	75,992	108,810
Commercial Portfolio Segment | Asset-based
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	2,111	2,594
Commercial Portfolio Segment | Asset-based | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	2,111	2,504
Commercial Portfolio Segment | Asset-based | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	90
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	25,893	33,879
Commercial Portfolio Segment | Commercial real estate | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	21,229	28,482
Commercial Portfolio Segment | Commercial real estate | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	4,664	5,397
Commercial Portfolio Segment | Equipment financing
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	4,222	7,298
Commercial Portfolio Segment | Equipment financing | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Commercial Portfolio Segment | Equipment financing | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	4,222	7,298
Commercial Portfolio Segment | Residential
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment		98,164
Consumer Portfolio Segment
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment		309,422
Consumer Portfolio Segment | Residential
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	65,018	98,164
Consumer Portfolio Segment | Residential | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	16,029	33,980
Consumer Portfolio Segment | Residential | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	48,989	64,184
Consumer Portfolio Segment | Home equity
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	39,396	46,950
Consumer Portfolio Segment | Home equity | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	21,014	26,796
Consumer Portfolio Segment | Home equity | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	18,382	20,154
Consumer Portfolio Segment | Consumer Loan
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	263	653
Consumer Portfolio Segment | Consumer Loan | Collateral Pledged
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Consumer Portfolio Segment | Consumer Loan | Uncollateralized
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 263	$ 653

Loans and Leases (Summary Of Th

Loans and Leases (Summary Of The Recorded Investment Of Company's TDRs) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	$ 164,034		$ 235,427
Specific reserves for TDRs included in the balance of ACL on loans and leases	314,922	$ 307,945	359,431	$ 369,811	$ 358,522	$ 209,096
Additional funds committed to borrowers in TDR status	6,504		12,895
Performing Financial Instruments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	116,777		140,089
Nonperforming Financial Instruments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	47,257		95,338
Nonperforming Financial Instruments | Troubled Debt Restructures
Financing Receivable, Troubled Debt Restructuring [Line Items]
Specific reserves for TDRs included in the balance of ACL on loans and leases	$ 8,980		$ 12,728

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, 2021USD ($)loan	Sep. 30, 2020USD ($)loan	Sep. 30, 2021USD ($)loan	Sep. 30, 2020USD ($)loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	6	30	49	170
Post-Modification Recorded Investment | $	$ 295	$ 1,958	$ 4,113	$ 53,617
Commercial Portfolio Segment | Extended Maturity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	1	0	9	7
Post-Modification Recorded Investment | $	$ 48	$ 0	$ 788	$ 579
Commercial Portfolio Segment | Maturity/Rate Combined
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	2	2	8	8
Post-Modification Recorded Investment | $	$ 94	$ 333	$ 304	$ 885
Commercial Portfolio Segment | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	0	4	3	27
Post-Modification Recorded Investment | $	$ 0	$ 312	$ 114	$ 40,434
Consumer Portfolio Segment | Extended Maturity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	0	2	2	6
Post-Modification Recorded Investment | $	$ 0	$ 165	$ 127	$ 673
Consumer Portfolio Segment | Maturity/Rate Combined
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	0	5	8	11
Post-Modification Recorded Investment | $	$ 0	$ 440	$ 1,426	$ 1,151
Consumer Portfolio Segment | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	3	17	19	111
Post-Modification Recorded Investment | $	$ 153	$ 708	$ 1,354	$ 9,895

Loans and Leases (Investments i

Loans and Leases (Investments in TDRs, Segregated by Risk Rating Exposure) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	$ 164,034	$ 235,427
Commercial Portfolio Segment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	74,794	117,695
Commercial Portfolio Segment | (1) - (6) Pass
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	7,327	12,462
Commercial Portfolio Segment | (7) Special Mention
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	8,670	0
Commercial Portfolio Segment | (8) Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	58,797	105,070
Commercial Portfolio Segment | (9) Doubtful
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	$ 0	$ 163

Transfers of Financial Assets_2

Transfers of Financial Assets (Reserve for loan repurchases) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward]
Beginning balance			$ 747	$ 508
Provision charged to expense			59	99
(Charge-offs/settlements) recoveries, net			(8)	98
Ending balance	$ 798	$ 705	$ 798	$ 705
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity
Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward]
Beginning balance	782	655
Provision charged to expense	16	50
(Charge-offs/settlements) recoveries, net	$ 0	$ 0

Transfers of Financial Assets_3

Transfers of Financial Assets (Loans sold) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net gain on sale	$ 1,525	$ 7,087	$ 5,486	$ 14,185
Consumer Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Ancillary fees	313	1,018	1,231	2,243
Consumer Portfolio Segment | Residential Mortgage Loans Servicing Retained
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale	50,643	164,054	192,421	325,832
Consumer Portfolio Segment | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds from sale	52,256	172,579	199,991	342,747
Net gain on sale	1,063	6,244	4,523	11,587
Fair value option adjustment	$ 149	$ (175)	$ (268)	$ 355

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds of Other Loans and Leases Held-for-investment			$ 61,274	$ 6,414
Mortgage banking activities	$ 1,525	$ 7,087	5,486	14,185
Retained servicing rights					$ 2,300,000
Residential
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds of Other Loans and Leases Held-for-investment			61,300
Commercial Loan [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds of Other Loans and Leases Held-for-investment				6,400
Mortgage banking activities			1,300	295
Consumer Portfolio Segment | Residential
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Mortgage banking activities	1,063	6,244	4,523	11,587
Retained servicing rights	2,100,000		2,100,000		$ 2,100,000
Contractually Specified Servicing Fees, Amount	$ 400	$ 300	$ 1,200	$ 1,100

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Beginning Balance	$ 11,501	$ 14,926	$ 13,422	$ 17,484
Additions	483	1,301	1,685	3,269
Amortization	(1,363)	(1,616)	(4,295)	(4,992)
Mortgage Servicing Rights (MSR) Impairment (Recovery)	(454)	(203)	(645)	(1,353)
Ending Balance	$ 10,167	$ 14,408	$ 10,167	$ 14,408

Leases Lessee Accounting (Detai

Leases Lessee Accounting (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Leases [Abstract]
Operating Lease, Right-of-Use Asset	$ 123,407
Less: Present value adjustment	$ 150,708	$ 158,280

Leases Lessee Cost (Details)

Leases Lessee Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lease, Cost [Abstract]
Operating lease costs	$ 6,487	$ 7,381	$ 19,598	$ 22,212
Variable lease costs	1,063	1,297	3,714	4,217
Sublease income	(141)	(141)	(412)	(428)
Total operating lease cost	7,409	8,537	22,900	26,001
Cash paid for amounts included in the measurement of lease liabilities	7,498	7,823	23,003	23,359
ROU lease assets obtained in exchange for new operating lease liabilities	$ 2,586	$ 856	$ 12,144	$ 9,552
Weighted-average remaining lease term, in years	7 years 8 months 1 day		7 years 8 months 1 day
Weighted-average discount rate	3.07%		3.07%

Leases Operating Lease Liabilit

Leases Operating Lease Liabilities, Payments, Due, Rolling Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Lessee, Operating Lease, Liability, Payment, Due, Rolling Maturity [Abstract]
Remainder of 2021	$ 5,141
2022	28,292
2023	26,443
2024	23,666
2025	21,687
Thereafter	66,806
Total operating lease liability payments	172,035
Less: Present value adjustment	150,708	$ 158,280
Lease liabilities	$ 21,327

Leases (Details)

Leases (Details)	Sep. 30, 2021
Minimum
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Term of Contract	5 years
Maximum
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Term of Contract	20 years

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, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 47,625	$ 47,625
Accumulated Amortization	28,638	25,242
Net Carrying Amount	18,987	22,383
Core Deposits | HSA Bank
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	26,625	26,625
Accumulated Amortization	17,801	15,618
Net Carrying Amount	8,824	11,007
Customer Relationships | HSA Bank
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	21,000	21,000
Accumulated Amortization	10,837	9,624
Net Carrying Amount	$ 10,163	$ 11,376

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Schedule Of Expected Future Amortization Expense) (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2021	$ 1,117
2022	4,411
2023	4,315
2024	2,084
2025	2,084
Thereafter	$ 4,976

Deposits (Summary Of Deposits)

Deposits (Summary Of Deposits) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Non-interest-bearing:
Demand	$ 7,154,835	$ 6,155,592
Interest-bearing:
HSA	7,329,405	7,120,017
Checking	4,181,825	3,652,763
Money market	3,958,700	2,940,215
Savings	5,517,189	4,979,031
Time deposits	1,884,373	2,487,818
Total interest-bearing	22,871,492	21,179,844
Total deposits	30,026,327	27,335,436
Time deposits and interest-bearing checking obtained through brokers (included in above balances)	109,312	720,440
Time deposits that exceed the FDIC limit (included in above balance)	308,498	504,543
Deposit overdrafts reclassified as loan balances	$ 1,111	$ 2,007

Deposits (Scheduled Maturities

Deposits (Scheduled Maturities Of Time Deposits) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Deposit Liabilities [Abstract]
Remainder of 2021	$ 646,277
2022	1,022,752
2023	103,532
2024	44,240
2025	50,664
Thereafter	16,908
Time deposits	$ 1,884,373	$ 2,487,818

Borrowings Borrowings - (Narrat

Borrowings Borrowings - (Narrative) (Details) - USD ($) $ in Billions	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Total Outstanding	$ 1.3	$ 1.7

Borrowings (Summary Of Securiti

Borrowings (Summary Of Securities Sold Under Agreements To Repurchase And Other Borrowings) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets Sold under Agreements to Repurchase [Line Items]
Total Outstanding	$ 1,300,000	$ 1,700,000
Securities sold under agreements to repurchase
Assets Sold under Agreements to Repurchase [Line Items]
Total Outstanding	$ 655,871	$ 469,330
Rate	0.45%	0.43%
Fed funds purchased
Assets Sold under Agreements to Repurchase [Line Items]
Total Outstanding	$ 0	$ 526,025
Rate	0.00%	0.08%
Securities sold under agreements to repurchase and other borrowings
Assets Sold under Agreements to Repurchase [Line Items]
Total Outstanding	$ 655,871	$ 995,355
Rate	0.45%	0.25%
Original maturity of one year or less | Securities sold under agreements to repurchase
Assets Sold under Agreements to Repurchase [Line Items]
Total Outstanding	$ 455,871	$ 269,330
Rate	0.11%	0.13%
Original maturity of greater than one year, non-callable | Securities sold under agreements to repurchase
Assets Sold under Agreements to Repurchase [Line Items]
Total Outstanding	$ 200,000	$ 200,000
Rate	1.22%	0.84%

Borrowings Borrowings (Summary

Borrowings Borrowings (Summary Of Advances Payable To the Federal Home Loan Bank) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Federal Home Loan Bank, Advances, Maturity, Rolling Year [Abstract]
FHLB advances maturing within 1 year, Total Outstanding	$ 11	$ 25,000
FHLB advances maturing after 1 but within 2 years, Total Outstanding	157	110
FHLB advances maturing after 2 but within 3 years, Total Outstanding	50,132	215
FHLB advances maturing after 3 but within 4 years, Total Outstanding	50,000	50,000
FHLB advances maturing after 4 but within 5 years, Total Outstanding	0	50,000
FHLB advances maturing after 5 years, Total Outstanding	13,034	7,839
Federal Home Loan Bank, Advances	$ 113,334	$ 133,164
Federal Home Loan Bank, Advances, Weighted Average Interest Rate [Abstract]
FHLB advances maturing within 1 year, Weighted Average Contractual Coupon Rate (as a percent)	0.00%	0.38%
FHLB advances maturing after 1 but within 2 years, Weighted Average Contractual Coupon Rate (as a percent)	1.75%	0.00%
FHLB advances maturing after 2 but within 3 years, Weighted Average Contractual Coupon Rate (as a percent)	1.59%	2.95%
FHLB advances maturing after 3 but within 4 years, Weighted Average Contractual Coupon Rate (as a percent)	1.42%	1.59%
FHLB advances maturing after 4 but within 5 years, Weighted Average Contractual Coupon Rate (as a percent)	0.00%	1.42%
FHLB advances maturing after 5 years, Weighted Average Contractual Coupon Rate (as a percent)	2.57%	2.66%
Federal Home Loan Bank, Advances, Weighted Average Contractual Coupon Rate (as a percent)	1.63%	1.36%
Aggregate carrying value of assets pledged as collateral	$ 7,150,473	$ 7,387,054
Remaining borrowing capacity	$ 4,704,060	$ 4,689,642

Borrowings (Long Term Debt) (De

Borrowings (Long Term Debt) (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Notes and subordinated debt	$ 567,469,000	$ 571,484,000
Debt issuance cost on senior fixed-rates	(2,326,000)	(2,628,000)
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	340,149,000	344,164,000
Long-term debt	$ 564,114,000	$ 567,663,000
Variable interest rate	3.07%	3.18%
London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate	2.95%
Long-term Debt
Debt Instrument [Line Items]
Discount on senior fixed-rate notes	$ (1,029,000)	$ (1,193,000)
Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033
Debt Instrument [Line Items]
Notes and subordinated debt	$ 77,320,000	77,320,000
Debt Instrument, Redemption, Period One | 4.375% Senior fixed-rate notes due February 15, 2024
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 | 4.375% Senior fixed-rate notes due February 15, 2024
Debt Instrument [Line Items]
Senior notes, interest rate (as a percent)	4.10%
Notes and subordinated debt	$ 340,149,000	344,164,000
Long-term Debt
Debt Instrument [Line Items]
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	$ 40,149,000	$ 44,164,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income, Net of Tax (Schedule of Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 3,329,705	$ 3,174,779	$ 3,234,625	$ 3,207,770
Net current-period other comprehensive (loss) income, net of tax	(4,382)	10,592	(40,748)	88,109
Ending Balance	3,386,189	3,219,690	3,386,189	3,219,690
Available For Sale and Transferred Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	35,598	63,476	67,424	17,251
Other comprehensive (loss) before reclassifications	(3,394)	11,766	(35,220)	57,997
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	(6)
Net current-period other comprehensive (loss) income, net of tax	(3,394)	11,766	(35,220)	57,991
Ending Balance	32,204	75,242	32,204	75,242
Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	13,894	20,649	19,918	(9,184)
Other comprehensive (loss) before reclassifications	(2,560)	(3,310)	(10,205)	23,655
Amounts reclassified from accumulated other comprehensive income (loss)	829	1,398	2,450	4,266
Net current-period other comprehensive (loss) income, net of tax	(1,731)	(1,912)	(7,755)	27,921
Ending Balance	12,163	18,737	12,163	18,737
Defined Benefit Pension and Other Postretirement Benefit Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(43,602)	(42,680)	(45,086)	(44,139)
Other comprehensive (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	743	738	2,227	2,197
Net current-period other comprehensive (loss) income, net of tax	743	738	2,227	2,197
Ending Balance	(42,859)	(41,942)	(42,859)	(41,942)
Accumulated Other Comprehensive Income, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	5,890	41,445	42,256	(36,072)
Other comprehensive (loss) before reclassifications	(5,954)	8,456	(45,425)	81,652
Amounts reclassified from accumulated other comprehensive income (loss)	1,572	2,136	4,677	6,457
Net current-period other comprehensive (loss) income, net of tax	(4,382)	10,592	(40,748)	88,109
Ending Balance	$ 1,508	$ 52,037	$ 1,508	$ 52,037

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income, Net of Tax (Schedule of Accumulated Other Comprehensive Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	$ (29,766)	$ (18,289)	$ (93,968)	$ (44,235)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	0		0	(2)
Net of tax	0	0	0	6
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Reclassification out of accumualted comprehensive income
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Debt Securities, Available-for-sale, Gain (Loss)	0	0	0	8
Income tax expense		0
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	(829)	(1,398)	(2,450)	(4,266)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges | Reclassification out of accumualted comprehensive income
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense	293	495	867	1,510
Net of tax	(829)	(1,398)	(2,450)	(4,266)
Other Nonoperating Expense	(1,046)	(967)	(3,088)	(3,228)
Interest Income, Other	(76)	(926)	(229)	(2,548)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss)
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	(1,008)	(1,002)	(3,023)	(2,982)
Defined benefit pension and postretirement benefit plans
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	(743)	(738)	(2,227)	(2,197)
Income tax expense	$ 265	$ 264	$ 796	$ 785

Regulatory Matters (Information

Regulatory Matters (Information On The Capital Ratios) (Detail)	9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital	$ 2,729,789,000		$ 2,543,131,000
Common Equity Tier One Capital Ratio	0.1177		0.1135
Common Equity Tier One Capital Required for Capital Adequacy	$ 1,044,068,000		$ 1,008,512,000
Common Equity Tier One Capital Required to be Well-Capitalized	1,508,098,000		1,456,739,000
Total risk-based capital, Actual Amount	$ 3,200,180,000		$ 3,045,652,000
Total risk-based capital, Actual Ratio	0.1379		0.1359
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,856,121,000		$ 1,792,910,000
Total risk-based capital, Capital Requirements, Minimum Ratio	0.080		0.080
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 2,320,151,000		$ 2,241,137,000
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	0.100		0.100
Tier 1 capital, Actual Amount	$ 2,874,826,000		$ 2,688,168,000
Tier 1 capital, Actual Ratio	0.1239		0.1199
Tier 1 capital, Capital Requirements, Minimum Amount	$ 1,392,091,000		$ 1,344,682,000
Tier 1 capital, Capital Requirements, Minimum Ratio	0.060		0.060
Tier 1 capital, Capital Requirements, Well Capitalized Amount	$ 1,856,121,000		$ 1,792,910,000
Tier 1 capital, Capital Requirements, Well Capitalized Ratio	0.080		0.080
Tier 1 leverage capital ratio, Actual Amount	$ 2,874,826,000		$ 2,688,168,000
Tier 1 leverage capital ratio, Actual Ratio	0.0837		0.0832
Tier 1 leverage capital ratio, Capital Requirements, Minimum Amount	$ 1,373,218,000		$ 1,291,980,000
Tier 1 leverage capital ratio, Capital Requirements, Minimum Ratio	0.040		0.040
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Amount	$ 1,716,523,000		$ 1,614,975,000
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Ratio	0.050		0.050
Dividends paid	$ 160,000,000	$ 0
Subsidiaries
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital	$ 2,961,510,000		$ 2,791,474,000
Common Equity Tier One Capital Ratio	0.1277		0.1246
Common Equity Tier One Capital Required for Capital Adequacy	$ 1,043,279,000		$ 1,008,027,000
Common Equity Tier One Capital Required to be Well-Capitalized	1,506,959,000		1,456,039,000
Total risk-based capital, Actual Amount	$ 3,209,544,000		$ 3,071,505,000
Total risk-based capital, Actual Ratio	0.1384		0.1371
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,854,719,000		$ 1,792,048,000
Total risk-based capital, Capital Requirements, Minimum Ratio	0.080		0.080
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 2,318,399,000		$ 2,240,060,000
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	0.100		0.100
Tier 1 capital, Actual Amount	$ 2,961,510,000		$ 2,791,474,000
Tier 1 capital, Actual Ratio	0.1277		0.1246
Tier 1 capital, Capital Requirements, Minimum Amount	$ 1,391,039,000		$ 1,344,036,000
Tier 1 capital, Capital Requirements, Minimum Ratio	0.060		0.060
Tier 1 capital, Capital Requirements, Well Capitalized Amount	$ 1,854,719,000		$ 1,792,048,000
Tier 1 capital, Capital Requirements, Well Capitalized Ratio	0.080		0.080
Tier 1 leverage capital ratio, Actual Amount	$ 2,961,510,000		$ 2,791,474,000
Tier 1 leverage capital ratio, Actual Ratio	0.0863		0.0865
Tier 1 leverage capital ratio, Capital Requirements, Minimum Amount	$ 1,372,558,000		$ 1,291,415,000
Tier 1 leverage capital ratio, Capital Requirements, Minimum Ratio	0.040		0.040
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Amount	$ 1,715,698,000		$ 1,614,268,000
Tier 1 leverage capital ratio, Capital Requirements, Well Capitalized Ratio	0.050		0.050
Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.045		0.045
Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets | Subsidiaries
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.045		0.045
Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.065		0.065
Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets | Subsidiaries
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.065		0.065

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings for basic and diluted earnings per common share:
Net income	$ 95,713	$ 69,281	$ 297,826	$ 160,577
Less: Preferred stock dividends	1,968	1,968	5,906	5,906
Undistributed Earnings, Basic	93,745	67,313	291,920	154,671
Undistributed Earnings, Diluted, Total	93,745	67,313	291,920	154,671
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	574	423	1,661	913
Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted	574	423	1,661	913
Earnings applicable to common shareholders	93,171	66,890	290,259	153,758
Earnings applicable to common shareholders	$ 93,171	$ 66,890	$ 290,259	$ 153,758
Shares:
Weighted-average common shares outstanding - basic	90,038	89,630	89,960	90,076
Effect of dilutive securities	194	108	226	159
Weighted-average common shares outstanding - diluted	90,232	89,738	90,186	90,235
Earnings per common share (1):
Basic	$ 1.03	$ 0.75	$ 3.23	$ 1.71
Diluted	$ 1.03	$ 0.75	$ 3.22	$ 1.70

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restricted stock (due to performance conditions on non-participating shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	96	47	125

Derivative Financial Instrume_3

Derivative Financial Instruments (Schedule fair value of derivative instruments) (Detail) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	$ 5,573,585,000	$ 5,571,385,000
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement	206,331,000	339,058,000
Derivative Asset, Fair Value, Amount Offset Against Collateral	4,772,000	7,748,000
Asset Derivatives, Fair Value, Less: Cash collateral posted	28,679,000	33,972,000
Gross derivative instruments, before netting (1)	172,880,000	297,338,000
Liability Derivatives, Notional Amount	4,723,283,000	4,853,650,000
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement	17,675,000	12,690,000
Derivative Liability, Fair Value, Amount Offset Against Collateral	4,772,000	7,748,000
Liability Derivatives, Fair Value, Less: Cash collateral posted	2,731,000	4,550,000
Derivative liability	10,172,000	392,000
CME
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value, Less: Cash collateral posted	63,000,000
Gross derivative instruments, before netting (1)	0
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	33,451,000	41,774,000
Derivative Asset, Fair Value, Amount Offset Against Collateral	33,451,000	41,720,000
Gross derivative instruments, before netting (1)	0	54,000
Derivative Liability, Fair Value, Gross Liability	7,503,000	12,352,000
Derivative Liability, Fair Value, Amount Offset Against Collateral	7,503,000	12,298,000
Derivative liability	0	54,000
Designated as Hedging Instrument | Interest rate derivatives
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	1,000,000,000	1,000,000,000
Derivative Asset, Fair Value, Gross Asset	26,923,000	40,854,000
Liability Derivatives, Notional Amount	0	25,000,000
Derivative Liability, Fair Value, Gross Liability	0	110,000
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	4,573,585,000	4,571,385,000
Asset Derivatives, Fair Value, Positions not subject to master netting agreement	179,408,000	298,204,000
Liability Derivatives, Notional Amount	4,723,283,000	4,828,650,000
Liability Derivatives, Fair Value, Positions not subject to master netting agreement	17,675,000	12,580,000
Not Designated as Hedging Instrument | Interest Rate Swap, CME
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	300,000,000	100,000,000
Liability Derivatives, Notional Amount	3,000,000,000	3,200,000,000
Not Designated as Hedging Instrument | Interest rate derivatives
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	4,434,047,000	4,421,627,000
Derivative Asset, Fair Value, Gross Asset	178,749,000	297,085,000
Liability Derivatives, Notional Amount	4,360,615,000	4,468,153,000
Derivative Liability, Fair Value, Gross Liability	17,566,000	12,203,000
Not Designated as Hedging Instrument | Credit Risk Contract | RPA-Out
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	82,800,000	80,500,000
Not Designated as Hedging Instrument | Credit Risk Contract | RPA-In
Derivatives, Fair Value [Line Items]
Liability Derivatives, Notional Amount	355,100,000	338,900,000
Not Designated as Hedging Instrument | Mortgage Banking Derivatives | RPA-Out
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	30,663,000	40,771,000
Derivative Asset, Fair Value, Gross Asset	300,000	855,000
Not Designated as Hedging Instrument | Mortgage Banking Derivatives | RPA-In
Derivatives, Fair Value [Line Items]
Liability Derivatives, Notional Amount	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument | Other Contract
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	108,875,000	108,987,000
Derivative Asset, Fair Value, Gross Asset	359,000	264,000
Liability Derivatives, Notional Amount	362,668,000	360,497,000
Derivative Liability, Fair Value, Gross Liability	109,000	$ 377,000
Interest Rate Lock Commitments
Derivatives, Fair Value [Line Items]
Other Commitment	$ 700,000

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 3,376	$ 3,467		$ 9,393
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings			$ 7,356
Interest Rate Derivatives | Operating Expense | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	2,727	3,824	7,132	7,227
Mortgage Banking Derivatives | Operating Expense | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	38	872	(556)	2,498
Other Contract | Operating Expense | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	611	(1,229)	780	(332)
Cash Flow Hedging | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(2,616)	(1,505)	(7,599)	(253)
Cash Flow Hedging | Interest Rate Derivatives | Operating Expense | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	90	1,152	334	3,501
Cash Flow Hedging | Interest Rate Derivatives | Other Income | Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ (2,706)	$ (2,657)	$ (7,933)	$ (3,754)

Derivative Financial Instrume_5

Derivative Financial Instruments (AOCI Related to Cash Flow Hedges) (Narrative) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Components Excluded from Assessment of Interest Rate Cash Flow Hedge Effectiveness	$ 7.8
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Estimate of amount to be reclassified from AOCL	0.3
Remaining unamortized gain (loss) on termination of cash flow hedges	(0.7)
Cash Flow Hedging | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Estimate of amount to be reclassified from AOCL	$ (10.5)

Derivative Financial Instrume_6

Derivative Financial Instruments (Offsetting Derivatives) (Detail) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Derivative Asset, Fair Value, Amount Offset Against Collateral	$ 4,772,000	$ 7,748,000
Derivative instrument asset, Amount Offset	28,679,000	33,972,000
Gross derivative instruments, before netting (1)	172,880,000	297,338,000
Derivative Liability, Fair Value, Amount Offset Against Collateral	4,772,000	7,748,000
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	2,731,000	4,550,000
Derivative liability	10,172,000	392,000
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	100,000	666,000
Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	100,000	720,000
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	701,000	265,000
Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	701,000	319,000
Hedge Accounting Positions
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	33,451,000	41,774,000
Derivative Asset, Fair Value, Amount Offset Against Collateral	33,451,000	41,720,000
Gross derivative instruments, before netting (1)	0	54,000
Derivative Liability, Fair Value, Gross Liability	7,503,000	12,352,000
Derivative Liability, Fair Value, Amount Offset Against Collateral	7,503,000	12,298,000
Derivative liability	0	54,000
CME
Derivative [Line Items]
Derivative instrument asset, Amount Offset	63,000,000
Gross derivative instruments, before netting (1)	0
Interest Rate Derivatives | Hedge Accounting Positions
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	26,923,000	40,854,000
Derivative Liability, Fair Value, Gross Liability	$ 0	$ 110,000

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 3,376	$ 3,467		$ 9,393
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	340,149		$ 340,149		$ 344,164
Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(2,616)	$ (1,505)	(7,599)	$ (253)
Long-term Debt
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	$ 40,149		$ 40,149		$ 44,164

Derivative Financial Instrume_8

Derivative Financial Instruments (Counterparty Credit Risk Narrative) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Maximum Length of Time Hedged in Cash Flow Hedge	2 years 9 months 18 days
Derivative instrument asset, Amount Offset	$ 28,679	$ 33,972
Credit Derivative, Maximum Exposure, Undiscounted	172,600
Cash and Due from Banks
Derivative [Line Items]
Derivative, Collateral, Right to Reclaim Cash	29,400
Valuation, Market Approach
Derivative [Line Items]
Credit Derivative, Maximum Exposure, Undiscounted	35,500
CME
Derivative [Line Items]
Derivative instrument asset, Amount Offset	$ 63,000

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, 2021	Dec. 31, 2020
Derivative [Line Items]
Derivative Asset, Fair Value, Amount Offset Against Collateral	$ 4,772	$ 7,748
Derivative Asset	172,880	297,338
Derivative Liability, Fair Value, Amount Offset Against Collateral	4,772	7,748
Derivative Liability	10,172	392
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	100	666
Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	100	720
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	701	265
Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	701	319
Designated as Hedging Instrument
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	7,503	12,352
Derivative Asset, Fair Value, Gross Asset	33,451	41,774
Derivative Asset, Fair Value, Amount Offset Against Collateral	33,451	41,720
Derivative Asset	0	54
Derivative Liability, Fair Value, Amount Offset Against Collateral	7,503	12,298
Derivative Liability	$ 0	$ 54

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Remaining unfunded commitment	$ 6,504		$ 6,504		$ 12,895
Write-down	(1,100)	$ (7,800)	(3,300)	$ (10,800)
Unused Commitments to Extend Credit	7,224,549		7,224,549		$ 6,755,563
Unused Commitments To Extend Credit, Carrying Amount Of Investment Written Up	3,900		3,900
Unused Commitments To Extend Credit, Carrying Amount Of Investment Written Down	200		200
Mortgage Loans in Process of Foreclosure, Amount	11,200		11,200
Fair Value, Nonrecurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	2,400		2,400
Rabbi Trust
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	1,600		1,600
Alternative investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	15,400		15,400
Carrying amount of alternative investments	1,300		1,300
Remaining unfunded commitment	0		0
Write-down			(49)
Alternative investments | Fair Value, Nonrecurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unused Commitments to Extend Credit	23,200		23,200
Unused Commitments to Extend Credit, Written Up	3,300		3,300
Unused Commitments to Extend Credit, Written Down	$ (300)		$ (300)

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, 2021	Dec. 31, 2020
Financial assets held at fair value:
Total available-for-sale investment securities	$ 3,410,443	$ 3,326,776
Gross derivative instruments, before netting (1)	172,880	297,338
Value under fair value options	10,032	14,000
Financial liabilities held at fair value:
Derivative liability	10,172	392
Agency CMO
Financial assets held at fair value:
Total available-for-sale investment securities	105,783	154,613
Agency MBS
Financial assets held at fair value:
Total available-for-sale investment securities	1,596,784	1,457,409
Agency CMBS
Financial assets held at fair value:
Total available-for-sale investment securities	898,586	1,117,233
Non-agency CMBS
Financial assets held at fair value:
Total available-for-sale investment securities	770,086	508,018
CLO
Financial assets held at fair value:
Total available-for-sale investment securities	24,967	76,383
Corporate debt securities
Financial assets held at fair value:
Total available-for-sale investment securities	14,237	13,120
Fair Value, Recurring
Financial assets held at fair value:
Total available-for-sale investment securities	3,410,443	3,326,776
Alternative investments (2)	22,546	11,112
Total financial assets held at fair value	3,652,949	3,695,757
Financial liabilities held at fair value:
Derivative liability	17,675	12,690
Fair Value, Recurring | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Alternative investments (2)	1,323	0
Total financial assets held at fair value	5,250	5,016
Financial liabilities held at fair value:
Derivative liability	38	218
Fair Value, Recurring | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Total available-for-sale investment securities	3,410,443	3,326,776
Alternative investments (2)	0	0
Total financial assets held at fair value	3,626,476	3,679,629
Financial liabilities held at fair value:
Derivative liability	17,637	12,472
Fair Value, Recurring | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Alternative investments (2)	0	0
Total financial assets held at fair value	0	0
Financial liabilities held at fair value:
Derivative liability	0	0
Fair Value, Recurring | Derivative instruments
Financial assets held at fair value:
Gross derivative instruments, before netting (1)	206,331	339,058
Fair Value, Recurring | Derivative instruments | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Gross derivative instruments, before netting (1)	330	205
Fair Value, Recurring | Derivative instruments | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Gross derivative instruments, before netting (1)	206,001	338,853
Fair Value, Recurring | Derivative instruments | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Gross derivative instruments, before netting (1)	0	0
Fair Value, Recurring | Investments Held In Rabbi Trust
Financial assets held at fair value:
Other assets	3,597	4,811
Fair Value, Recurring | Investments Held In Rabbi Trust | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Other assets	3,597	4,811
Fair Value, Recurring | Investments Held In Rabbi Trust | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Other assets	0	0
Fair Value, Recurring | Investments Held In Rabbi Trust | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Other assets	0	0
Fair Value, Recurring | Loan Origination Commitments
Financial assets held at fair value:
Value under fair value options	10,032	14,000
Fair Value, Recurring | Loan Origination Commitments | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Value under fair value options	0	0
Fair Value, Recurring | Loan Origination Commitments | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Value under fair value options	10,032	14,000
Fair Value, Recurring | Loan Origination Commitments | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Value under fair value options	0	0
Fair Value, Recurring | Agency CMO
Financial assets held at fair value:
Total available-for-sale investment securities	105,783	154,613
Fair Value, Recurring | Agency CMO | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | Agency CMO | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Total available-for-sale investment securities	105,783	154,613
Fair Value, Recurring | Agency CMO | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | Agency MBS
Financial assets held at fair value:
Total available-for-sale investment securities	1,596,784	1,457,409
Fair Value, Recurring | Agency MBS | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | Agency MBS | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Total available-for-sale investment securities	1,596,784	1,457,409
Fair Value, Recurring | Agency MBS | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | Agency CMBS
Financial assets held at fair value:
Total available-for-sale investment securities	898,586	1,117,233
Fair Value, Recurring | Agency CMBS | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | Agency CMBS | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Total available-for-sale investment securities	898,586	1,117,233
Fair Value, Recurring | Agency CMBS | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | Non-agency CMBS
Financial assets held at fair value:
Total available-for-sale investment securities	770,086	508,018
Fair Value, Recurring | Non-agency CMBS | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | Non-agency CMBS | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Total available-for-sale investment securities	770,086	508,018
Fair Value, Recurring | Non-agency CMBS | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | CLO
Financial assets held at fair value:
Total available-for-sale investment securities	24,967	76,383
Fair Value, Recurring | CLO | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | CLO | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Total available-for-sale investment securities	24,967	76,383
Fair Value, Recurring | CLO | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | Corporate debt securities
Financial assets held at fair value:
Total available-for-sale investment securities	14,237	13,120
Fair Value, Recurring | Corporate debt securities | Quoted Prices in Active Markets For Identical Assets (Level 1)
Financial assets held at fair value:
Total available-for-sale investment securities	0	0
Fair Value, Recurring | Corporate debt securities | Significant Other Observable Inputs (Level 2)
Financial assets held at fair value:
Total available-for-sale investment securities	14,237	13,120
Fair Value, Recurring | Corporate debt securities | Significant Unobservable Inputs (Level 3)
Financial assets held at fair value:
Total available-for-sale investment securities	$ 0	$ 0

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Option, Disclosures (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Option, Quantitative Disclosures [Line Items]
Value under fair value options	$ 10,032	$ 14,000
Loans held for sale (valued under fair value option $10,032 and $14,000)	24,969	14,012
Fair Value, Option, Loans Held as Assets, Aggregate Difference	106	489
loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans held for sale (valued under fair value option $10,032 and $14,000)	$ 9,926	$ 13,511

Fair Value Measurements (Summar

Fair Value Measurements (Summary Of Estimated Fair Values Of Significant Financial Instruments) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, Fair Value	$ 6,139,440		$ 5,835,364
Mortgage servicing assets, Carrying Amount	10,167	$ 11,501	13,422	$ 14,408	$ 14,926	$ 17,484
Fair Value, Nonrecurring | Reported Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-Maturity, Carrying Amount	5,986,308		5,567,889
Loans and leases, net	21,265,413		21,281,784
Securities sold under agreements to repurchase and other borrowings	655,871		995,355
FHLB advances	113,334		133,164
Long-term debt	564,114		567,663
Fair Value, Nonrecurring | Reported Value Measurement | Deposits Liabilities, other than time deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	28,141,954		24,847,618
Fair Value, Nonrecurring | Reported Value Measurement | Time Deposits
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	1,884,373		2,487,818
Fair Value, Nonrecurring | Reported Value Measurement | Residential
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage servicing assets, Carrying Amount	10,167		13,422
Fair Value, Nonrecurring | Estimate of Fair Value Measurement | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Held-to-maturity, Fair Value	6,139,440		5,835,364
Securities sold under agreements to repurchase and other borrowings	660,146		1,000,189
FHLB advances	117,237		139,035
Long-term debt	522,251		538,407
Fair Value, Nonrecurring | Estimate of Fair Value Measurement | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases, net	21,393,481		21,413,397
Fair Value, Nonrecurring | Estimate of Fair Value Measurement | Deposits Liabilities, other than time deposits | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	28,141,954		24,847,618
Fair Value, Nonrecurring | Estimate of Fair Value Measurement | Time Deposits | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Time deposits	1,885,341		2,494,601
Fair Value, Nonrecurring | Estimate of Fair Value Measurement | Residential | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage servicing assets, Fair value	$ 13,032		$ 14,362

Retirement Benefit Plans (Detai

Retirement Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Weighted-average expected long-term rate of return			5.50%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligations	$ 1,166	$ 1,531	$ 3,498	$ 4,881
Expected return on plan assets	(3,595)	(3,380)	(10,786)	(10,140)
Recognized net loss (gain)	1,019	1,036	3,058	3,021
Net periodic benefit (income) cost	(1,410)	(813)	(4,230)	(2,238)
Supplemental Employee Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligations	7	12	20	35
Expected return on plan assets	0	0	0	0
Recognized net loss (gain)	8	5	25	17
Net periodic benefit (income) cost	15	17	45	52
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost on benefit obligations	4	9	12	34
Expected return on plan assets	0	0	0	0
Recognized net loss (gain)	(20)	(38)	(60)	(55)
Net periodic benefit (income) cost	$ (16)	$ (29)	$ (48)	$ (21)

Segment Reporting Segment Repor

Segment Reporting Segment Reporting Narrative (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)Segment	Jan. 01, 2021USD ($)	Dec. 31, 2020USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | Segment	3
Goodwill	$ 538,373		$ 538,373
Commercial Banking | Scenario, Adjustment
Segment Reporting Information [Line Items]
Goodwill		$ 131,000
Retail Banking | Scenario, Adjustment
Segment Reporting Information [Line Items]
Goodwill		$ 131,000

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Goodwill	$ 538,373		$ 538,373		$ 538,373
Assets	35,374,258		35,374,258		32,590,690
Net interest income	229,691	$ 219,256	674,307	$ 674,464
Non-interest income	83,775	75,060	233,234	208,514
Non-interest expense	180,237	183,996	555,247	539,416
Pre-tax, pre-provision net revenue	133,229	110,320	352,294	343,562
Provision for credit losses	7,750	22,750	(39,500)	138,750
Income before income tax expense	125,479	87,570	391,794	204,812
Income tax expense	29,766	18,289	93,968	44,235
Net income	95,713	69,281	297,826	160,577
Operating Segments | Commercial Banking
Segment Reporting Information [Line Items]
Goodwill	131,000		131,000		131,000
Assets	14,862,455		14,862,455		14,732,792
Net interest income	152,556	132,026	435,718	377,736
Non-interest income	30,076	20,710	80,966	64,975
Non-interest expense	64,917	66,482	191,198	192,964
Pre-tax, pre-provision net revenue	117,715	86,254	325,486	249,747
Provision for credit losses	5,099	31,753	(37,602)	144,340
Income before income tax expense	112,616	54,501	363,088	105,407
Income tax expense	28,492	13,299	91,861	25,720
Net income	84,124	41,202	271,227	79,687
Operating Segments | HSA Bank
Segment Reporting Information [Line Items]
Goodwill	21,813		21,813		21,813
Assets	74,236		74,236		80,352
Net interest income	42,074	39,861	126,376	121,868
Non-interest income	24,756	27,235	78,315	76,721
Non-interest expense	32,800	34,789	101,842	105,887
Pre-tax, pre-provision net revenue	34,030	32,307	102,849	92,702
Provision for credit losses	0	0	0	0
Income before income tax expense	34,030	32,307	102,849	92,702
Income tax expense	9,086	8,626	27,461	24,751
Net income	24,944	23,681	75,388	67,951
Operating Segments | Retail Banking
Segment Reporting Information [Line Items]
Goodwill	385,560		385,560		385,560
Assets	7,538,017		7,538,017		7,726,287
Net interest income	98,028	83,609	279,381	246,417
Non-interest income	16,998	21,359	49,832	56,083
Non-interest expense	73,480	80,119	221,950	237,528
Pre-tax, pre-provision net revenue	41,546	24,849	107,263	64,972
Provision for credit losses	2,799	(9,000)	(1,833)	(5,499)
Income before income tax expense	38,747	33,849	109,096	70,471
Income tax expense	8,524	7,379	24,001	15,362
Net income	30,223	26,470	85,095	55,109
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Goodwill	0		0		0
Assets	12,899,550		12,899,550		$ 10,051,259
Net interest income	(62,967)	(36,240)	(167,168)	(71,557)
Non-interest income	11,945	5,756	24,121	10,735
Non-interest expense	9,040	2,606	40,257	3,037
Pre-tax, pre-provision net revenue	(60,062)	(33,090)	(183,304)	(63,859)
Provision for credit losses	(148)	(3)	(65)	(91)
Income before income tax expense	(59,914)	(33,087)	(183,239)	(63,768)
Income tax expense	(16,336)	(11,015)	(49,355)	(21,598)
Net income	$ (43,578)	$ (22,072)	$ (133,884)	$ (42,170)

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, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 52,739	$ 51,627	$ 159,327	$ 149,837
Non-interest income	83,775	75,060	233,234	208,514
Deposit service fees
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	40,258	39,278	122,166	117,687
Wealth and investment services
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	9,985	8,255	29,475	24,096
Other non interest income
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,496	4,094	7,686	8,054
Non-interest income within the scope of other GAAP topics
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	31,036
Non-interest income		23,433	73,907	58,677
Operating Segments | Commercial Banking
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	14,561	12,126	42,852	35,985
Non-interest income	30,076	20,710	80,966	64,975
Operating Segments | Commercial Banking | Deposit service fees
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,207	3,615	12,412	10,969
Operating Segments | Commercial Banking | Wealth and investment services
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	9,993	8,234	29,501	24,120
Operating Segments | Commercial Banking | Other non interest income
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	361	277	939	896
Operating Segments | Commercial Banking | Non-interest income within the scope of other GAAP topics
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	15,515
Non-interest income		8,584	38,114	28,990
Operating Segments | HSA Bank
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	24,756	27,235	78,315	76,721
Non-interest income	24,756	27,235	78,315	76,721
Operating Segments | HSA Bank | Deposit service fees
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	22,886	23,667	72,382	70,250
Operating Segments | HSA Bank | Wealth and investment services
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Operating Segments | HSA Bank | Other non interest income
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,870	3,568	5,933	6,471
Operating Segments | HSA Bank | Non-interest income within the scope of other GAAP topics
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0
Non-interest income		0	0	0
Operating Segments | Retail Banking
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	13,343	12,221	37,929	37,147
Non-interest income	16,998	21,359	49,832	56,083
Operating Segments | Retail Banking | Deposit service fees
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	13,078	11,972	37,115	36,460
Operating Segments | Retail Banking | Wealth and investment services
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Operating Segments | Retail Banking | Other non interest income
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	265	249	814	687
Operating Segments | Retail Banking | Non-interest income within the scope of other GAAP topics
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	3,655
Non-interest income		9,138	11,903	18,936
Corporate, Non-Segment
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	79	45	231	(16)
Non-interest income	11,945	5,756	24,121	10,735
Corporate, Non-Segment | Deposit service fees
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	87	24	257	8
Corporate, Non-Segment | Wealth and investment services
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(8)	21	(26)	(24)
Corporate, Non-Segment | Other non interest income
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Corporate, Non-Segment | Non-interest income within the scope of other GAAP topics
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 11,866
Non-interest income		$ 5,711	$ 23,890	$ 10,751

Commitments and Contingencies_2

Commitments and Contingencies (Outstanding Financial Instruments Contract Amounts Represent Credit Risk) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Unused Commitments to Extend Credit	$ 7,224,549	$ 6,755,563
Standby letter of credit
Loss Contingencies [Line Items]
Unused Commitments to Extend Credit	220,895	207,201
Commercial letter of credit
Loss Contingencies [Line Items]
Unused Commitments to Extend Credit	49,783	30,522
Commitments to extend credit
Loss Contingencies [Line Items]
Unused Commitments to Extend Credit	$ 6,953,871	$ 6,517,840

(Reserve for Unfunded Commitmen

(Reserve for Unfunded Commitments) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounting Standards Update 2016-13
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 0	$ 0	$ 0	$ 9,139
SEC Schedule, 12-09, Allowance, Credit Loss
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	11,974	10,739	12,755	2,367
(Benefit) provision	196	1,146	(585)	379
Ending balance	$ 12,170	$ 11,885	$ 12,170	$ 11,885

Business Developments - Narrati

Business Developments - Narrative (Details) $ in Millions	Apr. 19, 2021	Sep. 30, 2021USD ($)	Sep. 30, 2021USD ($)
Business Acquisition [Line Items]
Merger-related expenses		$ 9.8	$ 26.9
Sterling
Business Acquisition [Line Items]
Share exchange ratio	0.463

Business Developments - Changes

Business Developments - Changes in Reserves Associated with Strategic Initiatives (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Restructuring Reserve [Roll Forward]
Beginning balance	$ 16,194	$ 19,795
Charged to earnings	145	11,454
Adjustments	(4,156)	(4,887)
Charged against assets	(337)	(4,137)
Net cash (payments) receipts	(3,730)	(14,109)
Ending balance	8,116	8,116
Employee Severance
Restructuring Reserve [Roll Forward]
Beginning balance	13,964	17,675
Charged to earnings	1	2,106
Adjustments	(3,903)	(3,903)
Charged against assets	0	0
Net cash (payments) receipts	(3,923)	(9,739)
Ending balance	6,139	6,139
Other Restructuring
Restructuring Reserve [Roll Forward]
Beginning balance	2,230	2,120
Charged to earnings	53	8,987
Adjustments	(253)	(984)
Charged against assets	(246)	(3,776)
Net cash (payments) receipts	193	(4,370)
Ending balance	1,977	1,977
Right-of-Use Asset Charges
Restructuring Reserve [Roll Forward]
Beginning balance	0	0
Charged to earnings	91	361
Adjustments	0	0
Charged against assets	(91)	(361)
Net cash (payments) receipts	0	0
Ending balance	$ 0	$ 0