Webster Financial (WBS) 10-K 26 Feb 21 2020 FY Annual report Financial data

Cover

Cover - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Feb. 19, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2020
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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 Public Float			$ 2,500,000
Entity Common Stock, Shares Outstanding		90,289,817
Amendment Flag	false
Entity Central Index Key	0000801337
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2020
Documents Incorporated by Reference	Part III: Definitive Proxy Statement (the “Proxy Statement”) for the Annual Meeting of Shareholders to be held on April 22, 2021
ICFR Auditor Attestation Flag	true
Common Class A [Member] | NEW YORK STOCK EXCHANGE, INC. [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	WBS
Security Exchange Name	NYSE
Series F Preferred Stock [Member] | NEW YORK STOCK EXCHANGE, INC. [Member]
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

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
Cash and due from banks	$ 193,501	$ 185,341
Interest-bearing deposits	69,603	72,554
Investment securities available-for-sale, at fair value	3,326,776	2,925,833
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	5,568,188	5,293,918
Allowance for credit losses on investment securities held-to-maturity	(299)	0
Investment securities held-to-maturity, net	5,567,889	5,293,918
Federal Home Loan Bank and Federal Reserve Bank stock	77,594	149,046
Loans held for sale (valued under fair value option $14,000 and $35,750)	14,012	36,053
Loans and leases	21,641,215	20,036,986
Allowance for credit losses on loan and leases	(359,431)	(209,096)
Loans and leases, net	21,281,784	19,827,890
Deferred tax assets, net	81,286	61,975
Premises and equipment, net	226,743	270,413
Goodwill	538,373	538,373
Other intangible assets, net	22,383	21,917
Cash surrender value of life insurance policies	564,195	550,651
Accrued interest receivable and other assets	626,551	455,380
Total assets	32,590,690	30,389,344
Liabilities and shareholders' equity:
Non-interest-bearing	6,155,592	4,446,463
Interest-bearing	21,179,844	18,878,283
Total deposits	27,335,436	23,324,746
Securities sold under agreements to repurchase and other borrowings	995,355	1,040,431
Federal Home Loan Bank advances	133,164	1,948,476
Long-term debt	567,663	540,364
Lease liabilities	158,280	174,396
Accrued expenses and other liabilities	166,167	153,161
Total liabilities	29,356,065	27,181,574
Shareholders’ equity:
Common stock	937	937
Paid-in capital	1,109,532	1,113,250
Retained earnings	2,077,522	2,061,352
Treasury stock, at cost (3,487,389 and 1,659,749 shares)	(140,659)	(76,734)
Accumulated other comprehensive income (loss,) net of tax	42,256	(36,072)
Total shareholders' equity	3,234,625	3,207,770
Total liabilities and shareholders' equity	32,590,690	30,389,344
Series F Preferred Stock [Member]
Shareholders’ equity:
Preferred stock	$ 145,037	$ 145,037

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Debt Securities, Held-to-maturity, Fair Value	$ 5,835,364	$ 5,380,653
Loans Held-for-sale, Fair Value Disclosure	$ 14,000	$ 35,750
Preferred Stock, Par or Stated Value Per Share	$ 0.01
Preferred stock, shares authorized	3,000,000
Preferred Stock, Shares Outstanding	6,000	6,000
Preferred Stock, Shares Issued	6,000	6,000
Common stock par value (in usd per share)	$ 0.01	$ 0.01
Common Stock, Shares Authorized	200,000,000	200,000,000
Common stock, shares issued	93,686,311	93,686,311
Treasury Stock, Common, Shares	3,487,389	1,659,749

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest Income:
Interest and fees on loans and leases	$ 789,719	$ 924,693	$ 842,449
Taxable interest and dividends on securities	189,683	207,294	191,493
Non-taxable interest on securities	21,878	21,869	20,597
Loans held for sale	769	727	628
Interest income	1,002,049	1,154,583	1,055,167
Interest Expense:
Deposits	67,897	129,577	90,407
Securities sold under agreements to repurchase and other borrowings	5,941	17,953	13,491
Federal Home Loan Bank advances	18,767	31,399	33,461
Long-term debt	18,051	20,527	11,127
Interest expense	110,656	199,456	148,486
Net interest income	891,393	955,127	906,681
Provision for credit losses	137,750	37,800	42,000
Net interest income (loss) after provision for loan and lease losses	753,643	917,327	864,681
Non-interest Income:
Deposit service fees	156,032	168,022	162,183
Loan and lease related fees	29,127	31,327	32,025
Wealth and investment services	32,916	32,932	32,843
Mortgage banking activities	18,295	6,115	4,424
Increase in cash surrender value of life insurance policies	14,561	14,612	14,614
Gain on the sale of investment securities, net	8	29	0
Other income	34,338	32,278	36,479
Total non-interest income	285,277	285,315	282,568
Non-interest Expense:
Compensation and benefits	428,391	395,402	381,496
Occupancy	71,029	57,181	59,463
Technology and equipment	112,273	105,283	97,877
Intangible assets amortization	4,160	3,847	3,847
Marketing	14,125	16,286	16,838
Professional and outside services	32,424	21,380	20,300
Deposit insurance	18,316	17,954	34,749
Other expense	78,228	98,617	91,046
Total non-interest expense	758,946	715,950	705,616
Income before income tax expense	279,974	486,692	441,633
Income tax expense	59,353	103,969	81,215
Net income	220,621	382,723	360,418
Preferred stock dividends and other	(9,147)	(9,738)	(8,715)
Earnings applicable to common shareholders	$ 211,474	$ 372,985	$ 351,703
Earnings per common share:
Earnings per common share, Basic (in dollars per share)	$ 2.35	$ 4.07	$ 3.83
Earnings per common share, Diluted (in dollars per share)	$ 2.35	$ 4.06	$ 3.81

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other comprehensive (loss) income, net of tax:
Net income	$ 220,621	$ 382,723	$ 360,418
Investment securities available-for-sale	50,173	88,625	(43,427)
Derivative instruments	29,102	129	5,703
Total defined benefit pension and postretirement benefit plans	(947)	5,826	(1,397)
Other comprehensive (loss) income, net of tax	78,328	94,580	(39,121)
Comprehensive income	$ 298,949	$ 477,303	$ 321,297

Consolidated Statement of Share

Consolidated Statement of Shareholder Equity Statement - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Series E Preferred Stock [Member]	Series F Preferred Stock [Member]	Common Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Cumulative Effect, Period of Adoption, Adjustment [Member]	Retained Earnings [Member]Series E Preferred Stock [Member]	Retained Earnings [Member]Series F Preferred Stock [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]
Beginning Balance at Dec. 31, 2017	$ 2,701,958					$ 145,056	$ 937	$ 1,122,164	$ 1,595,762				$ (70,430)	$ (91,531)
Beginning Balance (Accountign Standards Update 2017-08 and 2016-01) at Dec. 31, 2017		$ (1,373)								$ (1,373)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax														94,580
Ending Balance at Sep. 30, 2018														(36,072)
Beginning Balance at Dec. 31, 2017	2,701,958					145,056	937	1,122,164	1,595,762				(70,430)	(91,531)
Beginning Balance (Accountign Standards Update 2017-08 and 2016-01) at Dec. 31, 2017		(1,373)								(1,373)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	360,418								360,418
Other Comprehensive Income (Loss), Net of Tax	(39,121)													(39,121)
Dividends, Common Stock	(115,343)							99	(115,442)
Dividends, Preferred Stock			$ (7,875)								$ (7,875)
Stockholders' Equity, Other				$ (22)								$ 22
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	11,612							(1,541)	3,275				9,878
Stock Issued During Period, Value, Stock Options Exercised	2,173							(5,762)					7,935
Stock Issued During Period, Value, Conversion of Units	0							(566)	(6,484)				7,050
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(13,779)												(13,779)
Stock Repurchased During Period, Value	(12,158)												(12,158)
Stock Issued During Period, Value, Other	(19)					(19)
Ending Balance at Dec. 31, 2018	2,886,515	(513)				145,037	937	1,114,394	1,828,303	(513)			(71,504)	(130,652)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared					$ 1.25
Preferred Stock, Dividends Per Share, Declared			$ 1,323.44
Other Comprehensive Income (Loss), Net of Tax														78,328
Ending Balance at Sep. 30, 2019														42,256
Beginning Balance at Dec. 31, 2018	$ 2,886,515	(513)				145,037	937	1,114,394	1,828,303	(513)			(71,504)	(130,652)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Net income	$ 382,723								382,723
Other Comprehensive Income (Loss), Net of Tax	94,580													94,580
Dividends, Common Stock	(141,286)								(141,286)
Dividends, Preferred Stock				$ (7,875)								(7,875)
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	12,626							885					11,741
Stock Issued During Period, Value, Stock Options Exercised	619							(2,029)					2,648
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(6,616)												(6,616)
Stock Repurchased During Period, Value	(13,003)												(13,003)
Ending Balance at Dec. 31, 2019	3,207,770	(51,213)				145,037	937	1,113,250	2,061,352	(51,213)			(76,734)	(36,072)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared					1.53
Preferred Stock, Dividends Per Share, Declared				$ 1,312.50
Beginning Balance at Sep. 30, 2019														42,256
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	90,473
Ending Balance at Dec. 31, 2019	$ 3,207,770	$ (51,213)				145,037	937	1,113,250	2,061,352	$ (51,213)			(76,734)	(36,072)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Net income	$ 220,621								220,621
Other Comprehensive Income (Loss), Net of Tax	78,328													78,328
Dividends, Common Stock	(145,363)								(145,363)
Dividends, Preferred Stock				$ (7,875)								$ (7,875)
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	12,179							(3,524)					15,703
Stock Issued During Period, Value, Stock Options Exercised	240							(194)					434
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(3,506)												(3,506)
Stock Repurchased During Period, Value	(76,556)												(76,556)
Ending 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]
Common Stock, Dividends, Per Share, Declared					$ 1.60
Preferred Stock, Dividends Per Share, Declared				$ 1,312.50

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities:
Net income	$ 220,621	$ 382,723	$ 360,418
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	137,750	37,800	42,000
Deferred tax expense (benefit)	(31,236)	927	9,472
Depreciation and amortization	36,616	37,507	38,750
Amortization of earning assets and funding premium/discount, net	75,929	49,731	50,984
Stock-based compensation	12,179	12,626	11,612
Gain on sale, net of write-down, on foreclosed and repossessed assets	(1,938)	(729)	(709)
Loss (gain) on sale, net of write-down, on premises and equipment	1,105	1,340	346
Gain on the sale of investment securities, net	(8)	(29)	0
Increase in cash surrender value of life insurance policies	(14,561)	(14,612)	(14,614)
Gain from life insurance policies	(1,219)	(4,933)	(2,553)
Mortgage banking activities	(18,295)	(6,115)	(4,424)
Proceeds from sale of loans held for sale	486,341	216,239	188,025
Originations of loans held for sale	(449,803)	(240,305)	(171,883)
Net change in right-of-use lease assets	27,868	2,479	0
Net decrease (increase) in derivative contract assets net of liabilities	(118,336)	(123,752)	(4,615)
Gain on sale of banking center deposits	0	0	(4,596)
Net (increase) decrease in accrued interest receivable and other assets	25,657	(23,790)	(739)
Net (decrease) increase in accrued expenses and other liabilities	(8,121)	(23,257)	(28,066)
Net cash provided by operating activities	380,549	303,850	469,408
Investing Activities:
Purchases of available-for-sale securities	(990,904)	(549,541)	(873,108)
Proceeds from maturities and principal payments of available-for-sale securities	627,577	556,283	538,747
Proceeds from sales of available-for-sale securities	8,963	70,087	0
Purchases of held-to-maturity securities	(1,297,535)	(1,571,604)	(393,693)
Proceeds from maturities and principal payments of held-to-maturity securities	983,864	573,703	524,862
Net proceeds from (purchase of) Federal Home Loan Bank stock	71,452	240	2,280
Purchases of intercompany debt securities	(12,244)	(6,065)	(1,215)
Net increase in loans	(1,681,947)	(1,642,501)	(990,014)
Proceeds from loans not originated for sale	9,197	20,931	1,687
Proceeds from life insurance policies	1,885	12,866	4,271
Proceeds from the sale of foreclosed properties and repossessed assets	11,497	11,562	8,011
Proceeds from the sale of premises and equipment	866	0	567
Additions to premises and equipment	(21,280)	(25,717)	(32,958)
Net (increase) decrease in interest-bearing deposits	0	0	(107,361)
Net cash provided by (used for) investing activities	(2,288,609)	(2,549,756)	(1,317,924)
Financing Activities:
Net increase in deposits	4,006,319	1,465,377	979,519
Proceeds from Federal Home Loan Bank advances	3,850,000	9,200,000	8,960,000
Repayments of Federal Home Loan Bank advances	(5,665,312)	(9,078,332)	(8,810,297)
Net (decrease) increase in securities sold under agreements to repurchase and other borrowings	(45,076)	458,557	(61,395)
Issuance of long-term debt	0	300,000	0
Debt issuance costs	0	(3,642)	0
Dividends paid to common shareholders	(144,965)	(140,783)	(114,959)
Dividends paid to preferred shareholders	(7,875)	(7,875)	(7,875)
Exercise of stock options	240	619	2,173
Common stock repurchased	(76,556)	(13,003)	(12,158)
Common shares acquired related to stock compensation plan activity	(3,506)	(6,616)	(13,779)
Net cash (used for) provided by financing activities	1,913,269	2,174,302	921,229
Net (decrease) increase in cash and cash equivalents	5,209	(71,604)	72,713
Cash and cash equivalents at beginning of year	257,895	329,499	256,786
Cash and cash equivalents at end of year	263,104	257,895	329,499
Supplemental disclosure of cash flow information:
Interest paid	118,123	197,200	144,726
Income taxes paid	94,072	110,057	60,925
Noncash investing and financing activities:
Transfer of loans and leases to foreclosed properties and repossessed assets	5,394	10,440	8,105
Transfer of loans from portfolio to loans held for sale	8,578	16,609	5,443
Deposits assumed	$ 4,657	$ 0	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
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 health savings accounts, 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 accounting and reporting policies of the Company that materially affect its financial statements conform with GAAP. The Consolidated Financial Statements and the accompanying Notes thereto include the accounts of Webster Financial Corporation and all other entities in which it has a controlling financial interest. Intercompany accounts and transactions have been eliminated in consolidation. Assets that the Company holds or manages in a fiduciary or agency capacity for customers, typically referred to as assets under administration or assets under management, are not included in the accompanying Consolidated Balance Sheets as those assets are not the Company's, and the Company is not the primary beneficiary. Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications had an immaterial effect on the Company's consolidated financial statements. Principles of Consolidation The purpose of consolidated financial statements is to present the results of operations and the financial position of the Company and its subsidiaries as if the consolidated group were a single economic entity. In accordance with the applicable accounting guidance for consolidations, the consolidated financial statements include any voting interest entity (VOE) in which the Company has a controlling financial interest and any variable interest entity (VIE) for which the Company is deemed to be the primary beneficiary. The Company generally consolidates its VOEs if the Company, directly or indirectly, owns more than 50% of the outstanding voting shares of the entity and the non-controlling shareholders do not hold any substantive participating or controlling rights. The Company evaluates VIEs to understand the purpose and design of the entity, and its involvement in the ongoing activities of the VIE and will consolidate the VIE if it has (i) the power to direct the activities of the VIE that most significantly affect the VIE's economic performance and (ii) an obligation to absorb losses of the VIE, or the right to receive benefits from the VIE, that could potentially be significant to the VIE. The Company accounts for unconsolidated partnerships and certain other investments using the equity method of accounting if it has the ability to significantly influence the operating and financial policies of the investee. This is generally presumed to exist when the Company owns between 20% and 50% of a corporation, or when it has greater than 3%-5% interest in a limited partnership or similarly structured entity. Refer to Note 2: Variable Interest Entities for further information. 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. Cash and Cash Equivalents Cash and cash equivalents, as referenced in the accompanying Consolidated Statements of Cash Flows, is comprised of cash and due from banks and interest-bearing deposits. Cash equivalents have a maturity of three months or less. Cash and due from banks, as referenced in the accompanying Consolidated Balance Sheets, includes cash on hand, certain deposits at the FRB of Boston, and cash due from banks. Restricted cash related to Federal Reserve System requirements and cash collateral received on derivative positions are included in cash and due from banks. Interest-bearing deposits, as referenced in the accompanying Consolidated Balance Sheets, includes deposits at the FRB of Boston in excess of reserve requirements and federal funds sold to other financial institutions. Federal funds sold essentially represents an uncollateralized loan and therefore the Company regularly evaluates the credit risk associated with the other financial institutions to assure that Webster does not become exposed to any significant credit risk on those cash equivalents. Investment in Debt Securities Debt security transactions are recognized on the trade date, which is the date the order to buy or sell the security is executed. Investment in debt securities are classified as available-for-sale or held-to-maturity at the time of purchase. Any classification change subsequent to trade date is reviewed for compliance with corporate objectives and accounting policies. Debt securities classified as held-to-maturity are those which Webster has the ability and intent to hold to maturity. Debt securities classified as held-to-maturity are recorded at amortized cost net of unamortized premiums and discounts. Discount accretion income and premium amortization expense are recognized as interest income using the effective interest method, with consideration given to prepayment assumptions on mortgage backed securities. Premiums are amortized to the earliest call date for debt securities purchased at a premium, with explicit, non-contingent call features and are callable at a fixed price and preset date. Debt securities classified as held-to-maturity are reviewed for credit losses under the CECL model with an allowance recorded on the balance sheet for expected lifetime credit losses. The allowance for credit losses is calculated on a pooled basis using statistical models which include forecasted scenarios of future economic conditions. Forecasts revert to long-run loss rates implicitly through the economic scenario, generally over three years. If the risk for a particular security no longer matches the collective assessment pool, it is removed and individually assessed for credit deterioration. A security will be placed on non-accrual status if collection of principal and interest in accordance with contractual terms is doubtful. Debt securities classified as available-for-sale are recorded at fair value with unrealized gains and losses recorded as a component of other comprehensive income (OCI) or other comprehensive loss (OCL). If a debt security is transferred from available-for-sale to held-to-maturity it is recorded at fair value at the time of transfer and the respective gain or loss would be recorded as a separate component of OCI or OCL and amortized as an adjustment to interest income over the remaining life of such security. Debt securities classified as available-for-sale are reviewed for credit losses when the fair value of a security falls below the amortized cost basis and the decline is evaluated to determine if any portion is attributable to credit loss. The decline in fair value attributable to credit loss is recorded directly to earnings, with a corresponding allowance for credit loss, limited to the amount that fair value is less than the amortized cost. If the credit quality subsequently improves, previously recorded allowance amounts may be reversed. The non-accrual policy for available-for-sale debt securities is the same as for held-to-maturity debt securities. When the Company intends to sell an impaired available-for-sale debt security, or if it is more likely than not that the Company will be required to sell the security, prior to recovery of the amortized cost basis, the entire fair value adjustment will immediately be recognized in earnings through non-interest income. The gain or loss on sale is calculated using the carrying value plus any related accumulated OCI or OCL balance associated with the securities sold. A zero credit loss assumption is maintained for U.S. Treasuries and agency-backed securities in both the held-to-maturity and available-for-sale portfolios. This assumption is subject to quarterly review to ensure it remains appropriate. Refer to Note 4: Investment Securities for further information related to investment in debt securities. Investment in Equity Securities The Company’s accounting treatment for unconsolidated equity investments differs for those with and without readily determinable fair values. Equity investments with readily determinable fair values are recorded at fair value with changes in fair value recorded in non-interest income. For equity investments without readily determinable fair values, the Company elected the measurement alternative, and therefore carries these investments at cost, less impairment, if any, plus or minus changes in observable prices. Certain equity investments that do not have a readily available fair value may qualify for net asset value (NAV) measurement based on specific requirements. The Company's alternative investments accounted for at NAV consist of investments in non-public entities that generally cannot be redeemed since the Company’s investments are distributed as the underlying equity is liquidated. On a quarterly basis, the Company reviews its equity investments without readily determinable fair values for impairment. If the equity investment is considered impaired, an impairment loss equal to the amount by which the carrying value exceeds its fair value is recorded through a charge to earnings. The impairment loss may be reversed in a subsequent period if there are observable transactions for the identical or similar investment of the same issuer at a higher amount than the carrying amount that was established when the impairment was recognized. Impairment as well as upward or downward adjustments resulting from observable price changes in orderly transactions for identical or similar investments are included in non-interest income. Equity investments in entities that finance affordable housing and other community development projects provide a return primarily through the realization of tax benefits. The Company applies the proportional amortization method to account for its investments in qualified affordable housing projects. Investment in Federal Home Loan Bank and Federal Reserve Bank Stock Webster Bank is a member of the FHLB and the Federal Reserve System, and is required to maintain an investment in capital stock of the FHLB of Boston and FRB of Boston. Based on redemption provisions, the stock of both the FHLB and the FRB has no quoted market value and is carried at cost. Membership stock is reviewed for impairment if economic circumstances would warrant review. Loans Held for Sale Loans that are classified as held for sale at the time of origination are accounted for under the fair value option. Loans not originated for sale but subsequently transferred to held for sale are valued at the lower of cost or fair value and are valued on an individual asset basis. Any cost amount in excess of fair value is recorded as a valuation allowance and recognized as a reduction of other non-interest income. Gains or losses on the sale of loans held for sale are recorded as part of mortgage banking activities, or other income. Cash flows from the sale of loans that were originated specifically for resale are presented as operating cash flows. Cash flows from the sale of loans originated for investment then subsequently transferred to held for sale are presented as investing cash flows. Refer to Note 6: Transfers of Financial Assets for further information. Transfers and Servicing of Financial Assets Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is generally considered to have been surrendered when: (i) the transferred assets are legally isolated from the Company or its consolidated affiliates, even in bankruptcy or other receivership; (ii) the transferee has the right to pledge or exchange the assets with no conditions that constrain the transferee and provide more than a trivial benefit to the Company; and (iii) the Company does not maintain the obligation or unilateral ability to reclaim or repurchase the assets. The Company sells financial assets in the normal course of business, the majority of which are residential mortgage loan sales, primarily to government-sponsored enterprises through established programs, commercial loan sales through participation agreements, and other individual or portfolio loan and securities sales. In accordance with accounting guidance for asset transfers, the Company considers any ongoing involvement with transferred assets in determining whether the assets can be derecognized from the balance sheet. With the exception of servicing the Company’s continuing involvement with financial assets sold is minimal and generally limited to market customary representation and warranty clauses covering certain characteristics of the mortgage loans sold and the Company's origination process. The gain or loss on sale depends on the previous carrying amount of the transferred financial assets, the consideration received, and any other assets obtained or liabilities incurred in exchange for the transferred assets. When the Company sells financial assets, it may retain servicing rights and/or other interests in the financial assets. Servicing assets and any other interests held by the Company are recorded at fair value upon transfer, and thereafter are carried at the lower of cost or fair value. Refer to Note 6: Transfers of Financial Assets for further information. Loans and Leases Loans and leases are stated at the principal amount outstanding, net of amounts charged off, unearned income, unamortized premiums and discounts, and deferred loan and lease fees or costs which are recognized as yield adjustments using the interest method. These yield adjustments are amortized over the contractual life of the related loans and leases adjusted for prepayments when applicable. Interest on loans and leases is credited to interest income as earned based on the interest rate applied to principal amounts outstanding. Prepayment fees are recognized in non-interest income. Cash flows from loans and leases are presented as investing cash flows. Non-accrual Loans Loans and leases are placed on non-accrual status when collection of principal and interest in accordance with contractual terms is doubtful, generally when principal or interest payments become 90 days delinquent, unless the loan or lease is well secured and in process of collection, or sooner if management concludes circumstances indicate that the borrower may be unable to meet contractual principal or interest payments. Residential real estate loans, excluding loans fully insured against loss and in the process of collection, and consumer loans are placed on non-accrual status at 90 days past due, or at the date when the Company is notified that the borrower is discharged in bankruptcy. Residential loans that are more than 90 days past due, fully insured against loss, and in the process of collection, remain accruing and are reported as 90 days or more past due and accruing. Commercial, commercial real estate loans, and equipment finance loans or leases are subject to a detailed review when 90 days past due to determine accrual status, or when payment is uncertain and a specific consideration is made to put a loan or lease on non-accrual status. When loans and leases are placed on non-accrual status, the accrual of interest is discontinued, and any unpaid accrued interest is reversed and charged against interest income. If ultimate repayment of a non-accrual loan or lease is expected, any payments received are applied in accordance with contractual terms. If ultimate repayment is not expected on commercial, commercial real estate, and equipment finance loans and leases, any payment received on a non-accrual loan or lease is applied to principal until the unpaid balance has been fully recovered. Any excess is then credited to interest income when received. If the Company determines, through a current valuation analysis, that principal can be recovered on residential real estate and consumer loans, interest payments are taken into income as received on a cash basis. Loans are generally removed from non-accrual status when they become current as to principal and interest or demonstrate a period of performance under contractual terms and, in the opinion of management, are fully collectible as to principal and interest. Pursuant to regulatory guidance, a loan discharged under Chapter 7 of the U.S. bankruptcy code is removed from non-accrual status when the bank expects full repayment of the remaining pre-discharged contractual principal and interest, and had at least six consecutive months of current payments. Refer to Note 5: Loans and Leases for further information. Allowance for Credit Losses on Loans and Leases The ACL on loans and leases is a contra-asset account that offsets the amortized cost basis of loans and leases for the credit losses expected to occur over the life of the asset. The ACL is established through a provision charged to expense. Executive management reviews and advises on the adequacy of the reserve which is maintained at a level management deems sufficient to cover expected losses within the loan and lease portfolios. The Company has elected to present accrued interest receivable separately from the amortized cost basis on the balance sheet and does not estimate an ACL on accrued interest as policies are in place to ensure timely write-offs and non-accruals. The ACL on loans and leases is determined using the CECL model which requires recognition of expected lifetime credit losses at the origination or purchase of an asset. Expected losses are determined through pooled, collective assessment of loans and leases with similar risk characteristics. If the risk characteristics of a loan or lease change and no longer match the collective assessment pool, it is removed and individually assessed for credit impairment. Management applies significant judgments and assumptions that influence the loss estimate and ACL on loan and lease balances. Collectively Assessed Loans and Leases. Collectively assessed loans and leases are segmented based on two portfolio segments, the commercial loans and leases and consumer loans. Expected losses are determined using a Probability of Default/Loss Given Default/Exposure at Default (PD/LGD/EAD) framework. Expected credit losses are calculated as the product of the probability of a loan defaulting, expected loss given the occurrence of a default, and the projected exposure of a loan at default. Summing the product across loans over their lives yields the lifetime expected credit losses for a given portfolio. The Company’s PD and LGD calculations are predictive models that measure the current risk profile of the loan pools using forecasts of future macroeconomic conditions, historical loss information, and credit risk ratings. The Company employs a dual grade credit risk grading system for estimating the PD and the LGD for commercial, commercial real estate, and equipment financing borrowers. 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) - (6) are considered pass ratings, and (7) - (10) are considered criticized as defined by the regulatory agencies. Risk ratings, assigned to differentiate risk within the portfolio, are reviewed on an ongoing basis and revised to reflect changes in a borrowers’ current financial position and outlook, risk profile, and the related collateral and structural position. Loan officers review updated financial information or other loan factors on at least an annual basis for all pass rated loans to assess the accuracy of the risk grade. Criticized loans undergo more frequent reviews and enhanced monitoring. A (7) "Special Mention" asset has the potential weakness that, if left uncorrected, may result in deterioration of the repayment prospects for the asset. A (8) "Substandard" asset has a well-defined weakness that jeopardizes the full repayment of the debt. An asset rated (9) "Doubtful" has all of the same weaknesses as a substandard credit with the added characteristic that the weakness makes collection or liquidation in full, given current facts, conditions, and values, improbable. Assets classified as (10) "Loss" in accordance with regulatory guidelines are considered uncollectible and charged off. For residential and consumer loans, the Company considers factors such as past due status, updated FICO scores, employment status, collateral, geography, loans discharged in bankruptcy, and the status of first lien position loans on second lien position loans as credit quality indicators. On an ongoing basis for portfolio monitoring purposes, the Company estimates the current value of property secured as collateral for home equity and residential first mortgage lending products. The estimate is based on home price indices compiled by the S&P/Case-Shiller Home Price Indices. The real estate price data is applied to the loan portfolios taking into account the age of the most recent valuation and geographic area. The Company’s models incorporate a single economic forecast scenario and macroeconomic assumptions over a reasonable and supportable forecast period. After the reasonable and supportable forecast period, the Company reverts on a straight-line basis to its historical loss rates, evaluated over the historical observation period, for the remaining life of the loans and leases. The calculation of exposure at default follows an iterative process to determine the expected remaining principal balance of a loan based on historical paydown rates for loans of similar segment within the same portfolio. The calculation of portfolio exposure in future quarters incorporates expected losses and principal paydown (PPD). PPD is the combination of contractual repayment and prepayment. A portion of the collective ACL is comprised of qualitative adjustments for risk characteristics which are not reflected or captured in the quantitative models but are likely to impact the measurement of estimated credit losses. Macroeconomic variables are used as inputs to the loss models and are selected based on the correlation of the variables to credit losses for each class of financing receivable as follows: the commercial model uses unemployment, GDP, and retail sales (for commercial unfunded); the residential model uses the Case-Shiller Home Price Index; home equity loan and line of credit models use interest rate spreads between U.S. Treasuries and corporate bonds and the home equity loan model also uses the Federal Housing Finance Agency (FHFA) home price index; personal loan and credit line models use the Case-Shiller and FHFA home price indices. There were no changes to the macroeconomic variables used in the loss models in the current year. Forecasted economic scenarios are sourced from a third party. Data from the baseline forecast scenario is used as the input to the modeled loss calculation. Changes in forecasts of macroeconomic variables will impact expectations of lifetime credit losses calculated by the loss models. However, the impact of changes in macroeconomic forecasts may be different for each portfolio and will reflect the credit quality and nature of the underlying assets at that time. To further refine the expected loss estimate qualitative factors are used reflecting consideration of: credit concentration, credit quality trends, the quality of internal loan reviews, the nature and volume of portfolio growth, staffing levels, underwriting exceptions, and economic considerations not reflected in the base loss model. Management may apply additional qualitative adjustments to reflect other relevant facts and circumstances that impact expected credit losses. These economic and qualitative inputs are used to forecast expected losses over a reasonable and supportable forecast period. The Company uses a 2-year reasonable and supportable forecast period, after which, loss rates revert to historical loss rates on a straight-line basis over a 1-year period. Historical loss rates are based on approximately 10 years of recently available data and are updated annually. In addition to the above considerations, the ACL calculation includes expectations of prepayments and recoveries. Extensions, renewals, and modifications are not included in the collective assessment; however, if there is a reasonable expectation of a TDR, the loan is removed from the collective assessment pool and is individually assessed. Individually Assessed Loans and Leases. When loans and leases no longer match the risk characteristics of the collective assessment pool, they are removed from the collectively assessed population and individually assessed for credit losses. Generally, all non-accrual loans, TDRs, potential TDRs, loans with a charge-off, and collateral dependent loans when the borrower is experiencing financial difficulty, are individually assessed. Individual assessment for collateral dependent commercial loans facing financial difficulty is based on the fair value of the collateral less estimated cost to sell, or the present value of the expected cash flows from the operation of the collateral, or a scenario weighted approach of both of these methods. If a loan is not collateral dependent, the individual assessment is based on a discounted cash flow approach. For collateral dependent commercial loans and leases, Webster's impairment process requires the Company to determine the fair value of the collateral by obtaining a third-party appraisal or asset valuation, an interim valuation analysis, blue book reference, or other internal methods. Fair value of the collateral for commercial loans is reevaluated quarterly. Whenever the Company has a third-party real estate appraisal performed by independent licensed appraisers, a licensed in-house appraisal officer or qualified individual reviews these appraisals for compliance with the Financial Institutions Reform Recovery and Enforcement Act and the Uniform Standards of Professional Appraisal Practice. Individual assessments for residential and home equity loans are based on a discounted cash flow approach or the fair value of collateral less the estimated costs to sell. Other consumer loans are individually assessed using a loss factor approach based on historical loss rates. For residential and consumer collateral dependent loans, a third-party appraisal is obtained upon loan default. Fair value of the collateral for residential and consumer collateral dependent loans is reevaluated every six months, by either obtaining a new appraisal or other internal valuation method. Fair value is also reassessed, with any excess amount charged off, for residential and home equity loans that reach 180 days past due per Federal Financial Institutions Examination Council guidelines. A fair value shortfall relative to the amortized cost balance is reflected as an impairment reserve within the ACL on loans and leases. Subsequent to an appraisal or other fair value estimate, should reliable information come to management's attention that the value has declined further, additional impairment may be recorded to reflect the particular situation, thereby increasing the ACL on loans and leases. If the credit quality subsequently improves the allowance is reversed up to a maximum of the previously recorded credit losses. Any individually assessed loan for which no specific valuation allowance is necessary is the result of either sufficient cash flow or sufficient collateral coverage relative to the amortized cost. Before the adoption of CECL on January 1, 2020, the allowance for loan and lease losses (ALLL) was determined under the ALLL incurred loss model which reflected management’s best estimate of probable losses that may be incurred within the existing loan and lease portfolio as of the related balance sheet date. The ALLL consists of three elements: (i) specific valuation allowances established for probable losses on impaired loans and leases; (ii) quantitative valuation allowances calculated using loss experience for like loans and leases with similar characteristics and trends, adjusted, as necessary, to reflect the impact of current conditions; and (iii) qualitative factors determined based on general economic conditions and other factors that may be internal or external to the Company. The reserve level reflects management’s view of trends in losses, portfolio quality, and economic, political, and regulatory conditions. While management utilized its best judgment based on the information available at the time, the ultimate adequacy of the allowance is dependent upon a variety of factors that are beyond the Company’s control, which include the performance its portfolio, economic conditions, interest rate sensitivity, and other external factors. The process for estimating probable losses under the ALLL approach is based on predictive models that measure the current risk profile of the loan and lease portfolio and combines the measurement with other quantitative and qualitative factors. To measure credit risk for the commercial, commercial real estate, and equipment financing portfolios, the Company employs a dual grade credit risk grading system for estimating the PD and the LGD. The credit risk grade system under the ALLL model is the same as described under the CECL approach. For residential and consumer loans, the Company's credit risk factors are also consistent with the factors used in the CECL approach. Back-testing was performed to compare original estimated losses and actual observed losses, resulting in ongoing refinements. The balance resulting from this process together with specific valuation allowances determines the overall reserve level. Refer to Note 5: Loans and Leases for further information. Charge-off of Uncollectible Loans Any loan may be charged-off if a loss confirming event has occurred or if there is a period of extended delinquency. Loss confirming events usually involve the receipt of specific adverse information about the borrower and may include bankruptcy when unsecured, foreclosure, or receipt of an asset valuation indicating a shortfall between the value of the collateral and the book value of the loan when that collateral asset is the sole source of repayment. The Company generally will charge-off commercial loans when it is determined that the specific loan or a portion thereof is uncollectible. This determination is based on facts and circumstances of the individual loan and normally includes considering the viability of the related business, the value of any collateral, the ability and willingness of any guarantors to perform and the overall financial condition of the borrower. The Company generally will charge-off residential real estate loans to the estimated fair value of its collateral, net of selling costs, when becoming 180 days past due. Allowance for Credit Losses on Unfunded Loan Commitments The allowance for credit losses on unfunded loan commitments provides for potential exposure inherent with funding the unused portion of legal commitments to lend that are not unconditionally cancellable by the Company. Accounting for unfunded l

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2020
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 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 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, in the accompanying Consolidated Balance Sheets. Earnings in the Rabbi Trust, including appreciation or depreciation, are reflected as other non-interest income, and changes in the corresponding liability are reflected as compensation and benefits, in the accompanying Consolidated Statements of Income. Refer to Note 18: 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 December 31, 2020 and December 31, 2019, the aggregate carrying value of the Company's tax credit finance investments was $37.2 million and $42.5 million, respectively, which represents the Company's maximum exposure to loss. At December 31, 2020 and December 31, 2019, unfunded commitments have been recognized, totaling $10.2 million and $15.1 million, respectively, and are included in accrued expenses and other liabilities in the accompanying Consolidated Balance Sheets. 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 in the accompanying Consolidated Balance Sheets, and the related interest expense is reported as interest expense on long-term debt in the accompanying Consolidated Statements of Income. 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 December 31, 2020 and December 31, 2019, the aggregate carrying value of the Company's other non-marketable investments in VIEs was $34.3 million and $21.8 million, respectively, and the maximum exposure to loss of the Company's other non-marketable investments in VIEs, including unfunded commitments, was $72.7 million and $64.2 million, respectively. Refer to Note 18: 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 in the accompanying 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 under the section “Principles of Consolidation.”

Business Developments

Business Developments	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Business Developments	Business Developments In the fourth quarter of 2020, the Company began implementing certain cost saving measures as part of its previously announced strategic initiatives. These actions include a plan to consolidate 26 banking centers into other nearby banking centers within its network and is expected to be completed by the end of the second quarter of 2021; as well as plans to simplify the organization which will result in reductions across various corporate, support, and other functions. The following table presents the changes in accrued expenses associated with strategic initiatives for the year ended December 31, 2020: (In thousands) Severance ROU Asset Other Total Beginning balance $ — $ — $ — $ — Charged to earnings 17,860 13,000 11,797 42,657 Charges against assets — (13,000) (1,009) (14,009) Cash payments (185) — (8,668) (8,853) Ending balance $ 17,675 $ — $ 2,120 $ 19,795 Reserves for strategic initiatives are included in accrued expenses and other liabilities in the accompanying Consolidated Balance Sheets. Severance cost are recorded as compensation and benefits, ROU asset charges are recorded as occupancy expense, and other is recorded as either occupancy, technology and equipment, professional and outside services, or other expense, in the accompanying Consolidated Statements of Income. These expenses are recorded in the corporate and reconciling category in the segment reporting presentation.

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities Held-to-Maturity Securities A summary of the amortized cost, fair value, and allowance for credit losses on investment securities held-to-maturity is presented below: At December 31, 2020 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value Allowance (2) 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 At December 31, 2019 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value Allowance (2) Net Carrying Value Agency CMO $ 167,443 $ 1,123 $ (1,200) $ 167,366 $ — $ 167,443 Agency MBS 2,957,900 60,602 (8,733) 3,009,769 — 2,957,900 Agency CMBS 1,172,491 6,444 (5,615) 1,173,320 — 1,172,491 Municipal bonds and notes 740,431 32,709 (21) 773,119 — 740,431 CMBS 255,653 2,278 (852) 257,079 — 255,653 Held-to-maturity securities $ 5,293,918 $ 103,156 $ (16,421) $ 5,380,653 $ — $ 5,293,918 (1) Amortized cost excludes accrued interest receivable of $22.1 million and $21.8 million at December 31, 2020 and December 31, 2019, respectively, which is included in accrued interest and other assets in the accompanying Consolidated Balance Sheets. (2) The Company adopted the new accounting standard for credit losses on January 1, 2020. For periods subsequent to adoption, the allowance is calculated under the CECL methodology and the resulting provision includes expected credit losses on held-to-maturity securities. The prior period did not have an allowance under applicable GAAP for that period. 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, no credit loss as of December 31, 2020. The current unrealized loss position of certain agency securities with no credit loss allowance can be attributed to the changing interest rate environment. An allowance for credit losses on investment securities held-to-maturity of $397 thousand was recorded for certain Municipal bonds and notes to account for expected lifetime credit loss upon adoption of the new accounting standard for credit losses. Expected lifetime credit loss on investment securities held-to-maturity is primarily attributed to securities not rated. The following table summarizes the activity in the allowance for credit losses on investment securities held-to-maturity: Year ended December 31, 2020 (In thousands) Municipal bonds and notes Beginning balance $ — Adoption of ASU No. 2016-13 (CECL) 397 Recovery of credit losses (98) Ending balance $ 299 Credit Quality Information The Company monitors the credit quality of held-to-maturity debt securities through credit ratings 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 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. Securities shown below that are not rated are collateralized with U.S. Treasury obligations, and credit quality indicators are updated at each quarter end. The following table summarizes credit ratings for amortized cost of held-to-maturity debt securities according to their lowest public credit rating as of December 31, 2020: Investment Grade (In thousands) Aaa Aa1 Aa2 Aa3 A1 A2 A3 Baa2 Not Rated Agency CMOs $ — $ 91,622 $ — $ — $ — $ — $ — $ — $ — Agency MBS — 2,419,751 — — — — — — — Agency CMBS — 2,101,227 — — — — — — — Municipal bonds and notes 209,376 165,056 201,081 115,619 33,264 8,475 2,066 190 4,380 CMBS 216,081 — — — — — — — — Total held-to-maturity $ 425,457 $ 4,777,656 $ 201,081 $ 115,619 $ 33,264 $ 8,475 $ 2,066 $ 190 $ 4,380 As of December 31, 2020, none of the held-to-maturity investment securities were in non-accrual status. Contractual Maturities The amortized cost and fair value of held-to-maturity debt securities by contractual maturity are set forth below: At December 31, 2020 (In thousands) Amortized Fair Due in one year or less $ 680 $ 685 Due after one year through five years 4,458 4,711 Due after five through ten years 278,974 294,528 Due after ten years 5,284,076 5,535,440 Total held-to-maturity debt securities $ 5,568,188 $ 5,835,364 For the maturity schedule above, investment securities which are not due at a single maturity date have been categorized based on the maturity date of the underlying collateral. Actual principal cash flows may differ from this maturity date presentation as borrowers have the right to 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 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 At December 31, 2019 Amortized Cost (1) Unrealized Unrealized Fair Value (2) Agency CMO $ 184,500 $ 2,218 $ (917) $ 185,801 Agency MBS 1,580,743 35,456 (4,035) 1,612,164 Agency CMBS 587,974 513 (6,935) 581,552 CMBS 432,085 38 (252) 431,871 CLO 92,628 45 (468) 92,205 Corporate debt 23,485 — (1,245) 22,240 Available-for-sale securities $ 2,901,415 $ 38,270 $ (13,852) $ 2,925,833 (1) Amortized cost excludes accrued interest receivable of $7.5 million and $8.1 million at December 31, 2020 and December 31, 2019, respectively, which is included in accrued interest and other assets in the accompanying Consolidated Balance Sheets. (2) Fair value represents net carrying value as there is no allowance for credit losses recorded on investment securities available-for-sale, as the securities are high credit quality, investment grade. Fair Value and Unrealized Losses The following tables provide information on fair value and unrealized losses for the individual available-for-sale securities with an unrealized loss, for which an allowance for credit losses 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 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) At December 31, 2019 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Unrealized Fair Unrealized # of Fair Unrealized Agency CMO $ 36,447 $ (352) $ 32,288 $ (565) 9 $ 68,735 $ (917) Agency MBS 41,408 (193) 299,674 (3,842) 79 341,082 (4,035) Agency CMBS 174,406 (1,137) 357,717 (5,798) 34 532,123 (6,935) CMBS 355,260 (232) 7,480 (20) 29 362,740 (252) CLO — — 43,232 (468) 2 43,232 (468) Corporate debt — — 22,240 (1,245) 4 22,240 (1,245) Available-for-sale in unrealized loss position $ 607,521 $ (1,914) $ 762,631 $ (11,938) 157 $ 1,370,152 $ (13,852) Unrealized losses on available-for-sale debt securities presented in the previous table have not been recognized in the accompanying Consolidated Statements of Income because the securities are high credit quality, investment grade securities that the Company does not intend to sell and will not be required to sell prior to their anticipated recovery, and the decline in fair value is primarily attributable to wider spreads in selected asset classes. Fair value is expected to recover as the securities approach maturity. As of December 31, 2020, none of the available-for-sale investment securities were in non-accrual status. Contractual Maturities The amortized cost and fair value of available-for-sale debt securities by contractual maturity are set forth below: At December 31, 2020 (In thousands) Amortized Fair Due in one year or less $ — $ — Due after one year through five years 1,448 1,489 Due after five through ten years 252,601 248,958 Due after ten years 2,980,201 3,076,329 Total available-for-sale debt securities $ 3,234,250 $ 3,326,776 For the maturity schedule above, investment securities which are not due at a single maturity date, have been categorized based on the maturity date of the underlying collateral. Actual principal cash flows may differ from this maturity date presentation as borrowers have the right to prepay obligations with or without prepayment penalties. Sales of Available-for Sale Investment Securities The following table provides information on sales of available-for-sale investment securities: Years ended December 31, (In thousands) 2020 2019 2018 Proceeds from sales $ 8,963 $ 70,087 $ — Gross realized gains on sales $ 8 $ 773 $ — Gross realized losses on sales — 744 — Gain on sale of investment securities, net $ 8 $ 29 $ — Other Information At December 31, 2020, the Company had a carrying value of $1.3 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. Investment securities with a carrying value totaling $3.9 billion at December 31, 2020 and $2.7 billion at December 31, 2019 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	12 Months Ended
	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Abstract]
Loans and Leases	Loans and Leases The following table summarizes loans and leases: At December 31, (In thousands) 2020 2019 Commercial non-mortgage $ 7,085,076 $ 5,296,611 Asset-based 890,598 1,046,886 Commercial real estate 6,322,637 5,949,339 Equipment financing 602,224 537,341 Commercial portfolio 14,900,535 12,830,177 Residential 4,782,016 4,972,685 Home equity 1,802,865 2,014,544 Other consumer 155,799 219,580 Consumer portfolio 6,740,680 7,206,809 Loans and leases (1) (2) (3) $ 21,641,215 $ 20,036,986 (1) Loan balances include net deferred (fees)/costs and net (premiums)/discounts of $(10.5) million and $17.6 million at December 31, 2020 and 2019, respectively. The change in net balance is driven by deferred fees on PPP loans. (2) At December 31, 2020, the Company had pledged $7.7 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 $57.8 million and $59.0 million at December 31, 2020 and 2019, respectively, which is included in accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets. Equipment financing includes net investment in leases of $236.1 million and $169.3 million at December 31, 2020 and 2019, respectively. Total undiscounted cash flows, primarily due within the next five years, amounted to $256.3 million at December 31, 2020. This lessor activity resulted in interest income of $7.1 million and $5.5 million for year ended December 31, 2020 and 2019, respectively. Loans and Leases Aging The following tables summarize the aging of loans and leases: 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 At December 31, 2019 (In thousands) 30-59 Days 60-89 Days 90 or More Days Past Due Non-accrual Total Past Due and Current Total Loans Commercial non-mortgage $ 2,094 $ 617 $ — $ 59,369 $ 62,080 $ 5,234,531 $ 5,296,611 Asset-based — — — 139 139 1,046,747 1,046,886 Commercial real estate 1,256 454 — 11,563 13,273 5,936,066 5,949,339 Equipment financing 5,493 292 — 5,433 11,218 526,123 537,341 Commercial portfolio 8,843 1,363 — 76,504 86,710 12,743,467 12,830,177 Residential 7,166 6,441 — 43,193 56,800 4,915,885 4,972,685 Home equity 8,267 5,551 — 30,170 43,988 1,970,556 2,014,544 Other consumer 4,269 807 — 1,192 6,268 213,312 219,580 Consumer portfolio 19,702 12,799 — 74,555 107,056 7,099,753 7,206,809 Total $ 28,545 $ 14,162 $ — $ 151,059 $ 193,766 $ 19,843,220 $ 20,036,986 The following table provides additional detail related to loans and leases on non-accrual status: At December 31, 2020 2019 (In thousands) Nonaccrual Nonaccrual With No Allowance Nonaccrual Nonaccrual With No Allowance Commercial non-mortgage $ 64,073 $ 16,985 $ 59,369 $ 13,584 Asset-based 2,594 — 139 — Commercial real estate 21,231 15,529 11,563 4,717 Equipment financing 7,299 2,983 5,433 2,159 Commercial portfolio 95,197 35,497 76,504 20,460 Residential 41,081 29,843 43,193 19,271 Home equity 31,030 24,091 30,170 15,195 Other consumer 652 2 1,192 — Consumer portfolio 72,763 53,936 74,555 34,466 Total $ 167,960 $ 89,433 $ 151,059 $ 54,926 Interest on non-accrual residential and home equity loans that would have been recorded as additional interest income had the loans been current in accordance with the original terms totaled $9.7 million, $11.3 million, and $9.7 million for the years ended December 31, 2020, 2019, and 2018, respectively. Allowance for Credit Losses on Loans and Leases The following tables summarize the activity in, as well as the loan and lease balances that were evaluated for, ACL on loans and leases: At or for the Years ended December 31, 2020 2019 2018 (In thousands) Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total ACL on loans and leases: Beginning balance $ 161,669 $ 47,427 $ 209,096 $ 164,073 $ 48,280 $ 212,353 $ 144,746 $ 55,248 $ 199,994 Adoption of ASU No. 2016-13 (CECL) 34,024 23,544 57,568 — — — — — — Provision charged to expense 156,336 (18,488) 137,848 29,174 8,626 37,800 35,356 6,644 42,000 Charge-offs (42,925) (12,408) (55,333) (33,327) (19,153) (52,480) (20,704) (22,683) (43,387) Recoveries 3,140 7,112 10,252 1,749 9,674 11,423 4,675 9,071 13,746 Ending balance $ 312,244 $ 47,187 $ 359,431 $ 161,669 $ 47,427 $ 209,096 $ 164,073 $ 48,280 $ 212,353 Individually evaluated for impairment 11,687 4,450 16,137 9,428 4,821 14,249 9,681 5,669 15,350 Collectively evaluated for impairment $ 300,557 $ 42,737 $ 343,294 $ 152,241 $ 42,606 $ 194,847 $ 154,392 $ 42,611 $ 197,003 Loan and lease balances: Individually evaluated for impairment $ 163,655 $ 145,767 $ 309,422 $ 131,123 $ 125,287 $ 256,410 $ 116,655 $ 142,675 $ 259,330 Collectively evaluated for impairment 14,736,880 6,594,913 21,331,793 12,699,054 7,081,522 19,780,576 11,535,493 6,670,666 18,206,159 Loans and leases $ 14,900,535 $ 6,740,680 $ 21,641,215 $ 12,830,177 $ 7,206,809 $ 20,036,986 $ 11,652,148 $ 6,813,341 $ 18,465,489 The increase in ACL at December 31, 2020 as compared to December 31, 2019, is primarily attributable to the initial adoption of the CECL lifetime loss accounting model and the impact of current and forecasted macroeconomic conditions on credit models, which were negatively affected by the emergence of the COVID-19 pandemic in 2020. 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. This credit risk grading system has not changed with the adoption of CECL. 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 (7) to (10) are considered criticized, as defined by the regulatory agencies. Risk ratings, assigned to differentiate risk within the portfolio, are reviewed on an ongoing basis and revised to reflect changes in a 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 a potential weakness that, if left uncorrected, may result in deterioration of the repayment prospects for the credit. A (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, given current facts, conditions, and values, improbable. Credits when classified as (10)-"Loss," in accordance with regulatory guidelines, are considered uncollectible and charged off. 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 table summarizes 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 as of 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 The following table summarizes residential and consumer loans segregated by origination year and risk rating exposure under FICO score groupings as of 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 The following table presents the required credit quality disclosures prior to the adoption of CECL: At December 31, 2019 (In thousands) Commercial Commercial Real Estate Equipment Financing (1) - (6) Pass $ 5,985,338 $ 5,860,981 $ 528,561 (7) Special Mention 94,809 26,978 808 (8) Substandard 259,490 61,380 7,972 (9) Doubtful 3,860 — — Total $ 6,343,497 $ 5,949,339 $ 537,341 Individually Assessed Loans and Leases The following tables summarize individually assessed loans and leases: 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 At December 31, 2019 (In thousands) Unpaid Amortized Cost Amortized Cost Amortized Cost Related Commercial non-mortgage $ 140,096 $ 102,254 $ 29,739 $ 72,515 $ 7,862 Asset based 465 139 — 139 5 Commercial real estate 29,292 23,297 14,818 8,479 1,143 Equipment financing 5,591 5,433 2,159 3,274 418 Residential 98,790 90,096 56,231 33,865 3,618 Home equity 38,503 35,191 27,672 7,519 1,203 Other consumer — — — — — Total $ 312,737 $ 256,410 $ 130,619 $ 125,791 $ 14,249 (1) Partially charged-off other consumer loans were included in collectively evaluated for impairment at December 31, 2019. The following table summarizes average amortized cost and interest income recognized for individually assessed loans and leases: Years ended December 31, 2020 2019 2018 (In thousands) Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Commercial non-mortgage $ 111,069 $ 3,836 $ — $ 100,771 $ 3,241 $ — $ 85,585 $ 3,064 $ — Asset based 1,367 — — 182 — — 407 — — Commercial real estate 28,588 699 — 17,062 385 — 11,027 198 — Equipment financing 6,366 — — 5,874 — — 4,820 112 — Residential 94,130 3,484 1,442 96,814 3,502 1,078 108,913 3,781 1,106 Home equity 41,070 1,315 1,826 37,167 1,045 981 42,290 1,158 980 Other consumer 327 32 — — — — — — — Total $ 282,917 $ 9,366 $ 3,268 $ 257,870 $ 8,173 $ 2,059 $ 253,042 $ 8,313 $ 2,086 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 are collateralized by equipment, inventory, receivables, or other non-real estate assets. Commercial real estate, residential, and home equity are collateralized by real estate. Collateral value on collateral dependent loans and leases was $150.3 million at December 31, 2020 and $109.8 million at December 31, 2019. The following table summarizes whether, or not, individually assessed loans and leases are collateral dependent: At December 31, 2020 At December 31, 2019 (In thousands) Collateral Dependent Not Considered Collateral Dependent Total Collateral Dependent Not Considered Collateral Dependent Total Commercial non-mortgage $ 11,074 $ 108,810 $ 119,884 $ 10,682 $ 91,572 $ 102,254 Asset-based 2,504 90 2,594 — 139 139 Commercial real estate 28,482 5,397 33,879 14,097 9,200 23,297 Equipment financing — 7,298 7,298 — 5,433 5,433 Residential 33,980 64,184 98,164 17,635 72,461 90,096 Home equity 26,796 20,154 46,950 17,136 18,055 35,191 Other consumer — 653 653 — — — Total amortized cost of CDA $ 102,836 $ 206,586 $ 309,422 $ 59,550 $ 196,860 $ 256,410 Troubled Debt Restructurings The following table summarizes information for TDRs: At December 31, (Dollars in thousands) 2020 2019 Accrual status $ 140,089 $ 136,449 Non-accrual status 95,338 100,989 Total TDRs $ 235,427 $ 237,438 Specific reserves for TDRs included in the balance of ACL on loans and leases $ 12,728 $ 12,956 Additional funds committed to borrowers in TDR status 12,895 4,856 The portion of TDRs deemed to be uncollectible, $18.4 million, $21.8 million, and $14.3 million, for the years ended December 31, 2020, 2019 and 2018, respectively, were charged-off. The following table provides information on the type of concession for loans and leases modified as TDRs: Years ended December 31, 2020 2019 2018 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 12 $ 1,142 18 $ 10,769 18 $ 1,656 Adjusted Interest Rate 1 96 2 112 — — Maturity/Rate Combined 9 984 11 673 18 10,327 Other (2) 27 40,434 31 70,002 21 46,359 Consumer portfolio Extended Maturity 6 673 13 1,926 5 489 Maturity/Rate Combined 15 1,467 19 2,381 15 1,565 Other (2) 122 10,895 42 2,908 66 6,385 Total TDRs 192 $ 55,691 136 $ 88,771 143 $ 66,781 (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. With respect to loans and leases modified as TDRs within the previous 12 months and for which there was a payment default, there were 4 loans and leases in the commercial portfolio with an amortized cost of $12.4 million for the year ended December 31, 2020. There were 7 loans and leases in the commercial portfolio with an amortized cost of $2.6 million for the year ended December 31, 2019. There were no significant amounts for the year ended December 31, 2018. TDRs in commercial non-mortgage, commercial real estate, and equipment financing segregated by risk rating exposure is as follows: At December 31, (In thousands) 2020 2019 Pass $ 12,462 $ 3,952 Special Mention — 63 Substandard 105,070 104,277 Doubtful 163 3,860 Total $ 117,695 $ 112,152

Transfers of Financial Assets

Transfers of Financial Assets	12 Months Ended
	Dec. 31, 2020
Transfers and Servicing [Abstract]
Transfers of Financial Assets	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 securitization. Residential mortgage origination fees, adjustments for changes in fair value, and gain or loss on loans sold are included as mortgage banking activities in the accompanying 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 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 Consolidated Statements of Income. The following table provides a summary of activity in the reserve for loan repurchases: Years ended December 31, (In thousands) 2020 2019 2018 Beginning balance $ 508 $ 674 $ 872 Provision (benefit) charged to expense 141 1,865 (160) Recoveries, net (settlements charged-off/repurchased loans, net) 98 (2,031) (38) Ending balance $ 747 $ 508 $ 674 The increase to the provision and corresponding charge-off during 2019 was related to a discrete legal settlement in connection with previously sold loans. The following table provides information for mortgage banking activities: Years ended December 31, (In thousands) 2020 2019 2018 Proceeds from sale $ 486,341 $ 216,239 $ 188,025 Loans sold with servicing rights retained 464,736 199,114 166,909 Net gain on sale $ 15,305 $ 4,031 $ 3,146 Ancillary fees 3,230 1,614 1,544 Fair value option adjustment (240) 470 (266) Additionally, loans not originated for sale were sold approximately at carrying value, except as noted, for cash proceeds of: $9.2 million, resulting in a gain of $0.3 million, for certain commercial loans for the year ended December 31, 2020; $17.0 million, resulting in a gain of $0.7 million, for certain commercial loans and $4.0 million for certain residential loans for the year ended December 31, 2019; and $1.3 million for certain commercial loans and $0.4 million for certain residential loans for the year ended December 31, 2018. The Company has retained servicing rights on residential mortgage loans totaling $2.3 billion and $2.4 billion at December 31, 2020 and 2019, respectively. The following table presents the changes in carrying value for mortgage servicing assets: Years ended December 31, (In thousands) 2020 2019 2018 Beginning balance $ 17,484 $ 21,215 $ 25,139 Additions 4,373 3,587 4,459 Amortization (6,562) (7,318) (8,383) Valuation allowance (1,873) — — Ending balance $ 13,422 $ 17,484 $ 21,215 Loan servicing fees, net of mortgage servicing rights amortization, were $1.5 million, $1.9 million, and $1.2 million, for the years ended December 31, 2020, 2019, and 2018, respectively, and are included as a component of loan and lease related fees in the accompanying Consolidated Statements of Income. Refer to Note 18: Fair Value Measurements for additional information on loans held for sale and mortgage servicing assets.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment A summary of premises and equipment follows: At December 31, (In thousands) 2020 2019 Land $ 9,436 $ 10,997 Buildings and improvements 70,195 77,892 Leasehold improvements 71,332 77,346 Fixtures and equipment 73,730 73,946 Data processing and software 270,780 263,445 Property and equipment 495,473 503,626 Less: Accumulated depreciation and amortization (396,211) (388,562) Property and equipment, net 99,262 115,064 Leased assets, net 127,481 155,349 Premises and equipment, net $ 226,743 $ 270,413 Depreciation and amortization of property and equipment was $32.5 million, $33.7 million, and $34.9 million for the years ended December 31, 2020, 2019, and 2018, respectively. During 2020, leased assets were impaired by $12.0 million due to the Company's decision to close 21 leased banking centers, which is recorded in occupancy in the accompanying Consolidated Statements of Income. Additional information about leased assets is provided in Note 8: Leasing . Assets held for disposition are included as a component of accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets. The following table provides a summary of activity for assets held for disposition: Years ended December 31, (In thousands) 2020 2019 Beginning balance $ — $ 91 Additions 2,654 — Write-downs — (91) Sales — — Ending balance $ 2,654 $ —

Leases Leases

Leases Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leasing The Company enters into leases, as lessee, primarily for office space, banking centers, and certain other operational assets. These leases are generally classified as operating leases, however, an insignificant amount are classified as finance leases. The Company's operating leases generally have lease terms for periods of 5 to 20 years with various renewal options. The Company does not have any material sub-lease agreements. The following table summarizes lessee information related to the Company’s operating ROU assets and lease liability: At December 31, 2020 (In thousands) Operating Leases Consolidated Balance Sheet Line Item Location ROU lease assets $ 127,481 Premises and equipment, net Lease liabilities 158,280 Operating lease liabilities The components of operating lease cost and other related information are as follows: (In thousands) At or for the Years ended December 31, 2020 2019 Lease Cost: Operating lease costs $ 30,339 $ 29,908 Variable lease costs 5,577 4,889 Sublease income (557) (577) Total operating lease cost $ 35,359 $ 34,220 Other Information: Cash paid for amounts included in the measurement of lease liabilities $ 31,212 $ 31,223 ROU lease assets obtained in exchange for new operating lease liabilities 9,211 22,948 The undiscounted scheduled maturities reconciled to total operating lease liabilities are as follows: (In thousands) At December 31, 2020 2021 $ 28,142 2022 27,069 2023 24,335 2024 21,321 2025 19,332 Thereafter 62,253 Total operating lease liability payments 182,452 Less: Present value adjustment 24,172 Lease liabilities $ 158,280 Weighted-average remaining lease term - operating leases, in years 8.04 Weighted-average discount rate - operating leases 3.19 %

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets The net carrying amount for goodwill at December 31, 2020 was $538.4 million, comprised of $516.6 million in Community Banking and $21.8 million in HSA Bank. There was no change to these carrying amounts during 2020 or 2019. Other intangible assets by reportable segment consisted of the following: At December 31, 2020 2019 (In thousands) Gross Carrying Accumulated Net Carrying Gross Carrying Accumulated Net Carrying Other intangible assets: HSA Bank - Core deposits $ 26,625 $ 15,618 $ 11,007 $ 22,000 $ 13,073 $ 8,927 HSA Bank - Customer relationships 21,000 9,624 11,376 21,000 8,010 12,990 Total other intangible assets $ 47,625 $ 25,242 $ 22,383 $ 43,000 $ 21,083 $ 21,917 The change in gross carrying amount for core deposits resulted from the HSA division of Webster Bank completing a purchase of low cost, long duration, health savings account deposits on July 30, 2020. The transaction gave rise to the recognition of a core deposit intangible asset, recorded at fair value, with an estimated useful life of 9 years. At December 31, 2020, the remaining estimated aggregate future amortization expense for other intangible assets is as follows: (In thousands) 2021 $ 4,513 2022 4,411 2023 4,315 2024 2,084 2025 2,084 Thereafter 4,976

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense reflects the following expense (benefit) components: Years ended December 31, (In thousands) 2020 2019 2018 Current: Federal $ 73,172 $ 84,447 $ 58,334 State and local 17,417 18,595 13,409 Total current 90,589 103,042 71,743 Deferred: Federal (23,799) 811 8,508 State and local (7,437) 116 964 Total deferred (31,236) 927 9,472 Total federal 49,373 85,258 66,842 Total state and local 9,980 18,711 14,373 Income tax expense $ 59,353 $ 103,969 $ 81,215 Included in the Company's income tax expense for the years ended December 31, 2020, 2019, and 2018, are net tax credits of approximately $1.1 million, $4.8 million, and $1.2 million, respectively. The $1.1 million of net tax credits in 2020 includes $0.8 million of expense for reductions in federal and state research tax credits previously estimated and recognized for 2018 and 2019. The $4.8 million of net tax credits in 2019 includes $3.0 million related to federal and state research tax credits, $2.4 million of which relates to the Company’s qualifying technology expenditures incurred between 2015 and 2017, and those estimated for 2018. The following table reflects a reconciliation of reported income tax expense to the amount that would result from applying the federal statutory rate of 21.0%: Years ended December 31, 2020 2019 2018 (Dollars in thousands) Amount Percent Amount Percent Amount Percent Income tax expense at federal statutory rate $ 58,795 21.0 % $ 102,205 21.0 % $ 92,743 21.0 % Reconciliation to reported income tax expense: SALT expense, net of federal 7,884 2.8 14,782 3.0 11,354 2.6 Tax-exempt interest income, net (7,181) (2.6) (6,752) (1.4) (6,475) (1.5) Increase in cash surrender value of life insurance (3,058) (1.1) (3,069) (0.6) (3,069) (0.7) Tax deficiencies (excess tax benefits), net 484 0.2 (2,251) (0.4) (4,483) (1.0) Non-deductible FDIC Deposit insurance premiums 2,172 0.8 1,904 0.4 2,215 0.5 Tax Act impacts, net (1) — — — — (10,982) (2.5) Other, net 257 0.1 (2,850) (0.6) (88) — Income tax expense and effective tax rate $ 59,353 21.2 % $ 103,969 21.4 % $ 81,215 18.4 % (1) Included in the Tax Act impacts, net for 2018 are $10.4 million of tax planning benefits related to the Tax Cuts and Jobs Act of 2017 (Tax Act). The following table reflects the significant components of the DTAs, net: At December 31, (In thousands) 2020 2019 Deferred tax assets: Allowance for loan and lease losses $ 93,791 $ 53,851 Net operating loss and credit carry forwards 66,840 69,827 Compensation and employee benefit plans 27,643 24,518 Lease liabilities under operating leases 41,679 45,923 Deferred loan fees, net 2,397 — Net unrealized loss on derivatives — 1,650 Other 6,353 7,871 Gross deferred tax assets 238,703 203,640 Valuation allowance 37,374 38,181 Total deferred tax assets, net of valuation allowance $ 201,329 $ 165,459 Deferred tax liabilities: Net unrealized gain on securities available for sale $ 24,364 $ 6,430 Net unrealized gain on derivatives 7,616 — ROU assets under operating leases 33,569 40,908 Equipment financing leases 38,511 31,332 Premises and equipment 6,735 7,838 Loan origination costs, net — 6,816 Goodwill and other intangible assets 5,954 6,172 Other 3,294 3,988 Gross deferred tax liabilities 120,043 103,484 Deferred tax assets, net $ 81,286 $ 61,975 The Company's DTAs, net increased by $19.3 million during 2020, reflecting the $31.2 million deferred tax benefit, a $15.9 million benefit recorded directly to shareholders' equity upon the January 1, 2020 adoption of CECL, and a $27.8 million expense allocated directly to shareholders' equity. The valuation allowance of $37.4 million and $38.2 million at December 31, 2020 and December 31, 2019, respectively, is attributable to SALT net operating loss carryforwards, and the $0.8 million decrease during 2020 is associated with a related decrease in the Company's gross DTAs for those carryforwards, resulting in no net change to its overall DTAs, net. SALT net operating loss carryforwards approximated $1.1 billion at December 31, 2020 and are scheduled to expire in varying amounts during tax years 2024 through 2032. The valuation allowance has been established for approximately $630.8 million of those net operating loss carryforwards estimated to expire unused. Credit carryovers of $0.3 million, net at December 31, 2020 have a five-year carryover period and are scheduled to expire in varying amounts during tax years 2023 through 2025. Management believes it is more likely than not that the results of future operations will generate sufficient taxable income to realize its total DTAs, net of the valuation allowance. Although taxable income in prior years is no longer able to be included as a source of taxable income, due to the general repeal of the carryback of net operating losses under the Tax Act, significant positive evidence remains in support of management's conclusion regarding the realizability of the Company's DTAs, including projected future reversals of existing taxable temporary differences and book-taxable income levels in recent and projected in future years. There can, however, be no assurance that any specific level of future income will be generated or that the Company’s DTAs will ultimately be realized. A deferred tax liability of $15.3 million has not been recognized for certain thrift bad-debt reserves, established before 1988, that would become taxable upon the occurrence of certain events: distributions by Webster Bank in excess of certain earnings and profits; the redemption of Webster Bank’s stock; or liquidation. Webster does not expect any of those events to occur. At December 31, 2020 the cumulative taxable temporary differences applicable to those reserves approximated $58.0 million.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2020
Deposit Liabilities [Abstract]
Deposits	Deposits A summary of deposits by type follows: At December 31, (In thousands) 2020 2019 Non-interest-bearing: Demand $ 6,155,592 $ 4,446,463 Interest-bearing: Health savings accounts 7,120,017 6,416,135 Checking 3,652,763 2,689,734 Money market 2,940,215 2,312,840 Savings 4,979,031 4,354,809 Time deposits 2,487,818 3,104,765 Total interest-bearing 21,179,844 18,878,283 Total deposits $ 27,335,436 $ 23,324,746 Time deposits and interest-bearing checking, included in above balances, obtained through brokers $ 720,440 $ 652,151 Time deposits, included in above balance, that exceed the FDIC limit 504,543 661,334 Demand deposit overdrafts reclassified as loan balances 2,007 1,721 The scheduled maturities of time deposits are as follows: (In thousands) At December 31, 2020 2021 $ 2,173,670 2022 186,612 2023 54,287 2024 22,302 2025 50,947 Time deposits $ 2,487,818

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Borrowings	Borrowings Total borrowings of $1.7 billion at December 31, 2020 and $3.5 billion at December 31, 2019, are described in detail below. The following table summarizes securities sold under agreements to repurchase and other borrowings: At December 31, (In thousands) 2020 2019 Total Outstanding Rate Total Outstanding Rate Securities sold under agreements to repurchase (1) : Original maturity of one year or less $ 269,330 0.13 % $ 240,431 0.19 % Original maturity of greater than one year, non-callable 200,000 0.84 200,000 1.78 Total securities sold under agreements to repurchase 469,330 0.43 440,431 0.91 Fed funds purchased 526,025 0.08 600,000 1.59 Securities sold under agreements to repurchase and other borrowings $ 995,355 0.25 $ 1,040,431 1.30 (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 U.S. Government agency mortgage-backed securities. 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 December 31, 2020 2019 (Dollars in thousands) Total Weighted-Average Contractual Coupon Rate Total Weighted-Average Contractual Coupon Rate Maturing within 1 year $ 25,000 0.38 % $ 1,690,000 1.79 % After 1 but within 2 years 110 — 200,000 2.53 After 2 but within 3 years 215 2.95 130 — After 3 but within 4 years 50,000 1.59 229 2.95 After 4 but within 5 years 50,000 1.42 50,000 1.59 After 5 years 7,839 2.66 8,117 2.66 FHLB advances $ 133,164 1.36 $ 1,948,476 1.87 Aggregate carrying value of assets pledged as collateral $ 7,387,054 $ 7,318,748 Remaining borrowing capacity 4,689,642 2,937,644 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: At December 31, (Dollars in thousands) 2020 2019 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) 344,164 317,486 Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (2) 77,320 77,320 Total notes and subordinated debt 571,484 544,806 Discount on senior fixed-rate notes (1,193) (1,412) Debt issuance cost on senior fixed-rate notes (2,628) (3,030) Long-term debt $ 567,663 $ 540,364 (1) The Company has de-designated its fair value hedging relationship on these notes. The $44.2 million basis adjustment included in the carrying value at December 31, 2020 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 3.18% at December 31, 2020 and 4.85% at December 31, 2019.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity Share activity during the year ended December 31, 2020 is as follows: Preferred Stock Series F Common Stock Issued Treasury Stock Held Common Stock Outstanding Balance at January 1, 2020 6,000 93,686,311 1,659,749 92,026,562 Restricted share activity — — (266,325) 266,325 Stock options exercised — — (10,230) 10,230 Common stock repurchased — — 2,104,195 (2,104,195) Balance at December 31, 2020 6,000 93,686,311 3,487,389 90,198,922 Common Stock Webster maintains a common stock repurchase program which authorizes management to purchase shares of its common stock, in open market or privately negotiated transactions, subject to market conditions and other factors. On October 29, 2019, the Company's Board of Directors approved a modification to this program, originally approved on October 24, 2017, increasing the maximum dollar amount available for repurchase to $200 million. Common stock repurchased during 2020 was acquired at an average cost of $36.38 per common share. The remaining repurchase authority under the common stock repurchase program was $123.4 million at December 31, 2020. Preferred Stock Webster has 6,000,000 depositary shares outstanding, each representing 1/1000th ownership interest in a share of Webster's 5.25% Series F Non-Cumulative Perpetual Preferred Stock, par value $0.01 per share, with a liquidation preference of $25,000 per share (equivalent to $25 per depositary share) (the Series F Preferred Stock). Webster will pay dividends as declared by the Board of Directors or a duly authorized committee of the Board. Dividends are payable at a rate of 5.25% per annum, quarterly in arrears, on the fifteenth day of each March, June, September, and December. Dividends on the Series F Preferred Stock are not cumulative and are not mandatory. If for any reason the Board of Directors or a duly authorized committee of the Board does not declare a dividend on the Series F Preferred Stock for any dividend period, such dividend will not accrue or be payable, and Webster will have no obligation to pay dividends for such dividend period, whether or not dividends are declared for any future dividend periods. The terms of the Series F Preferred Stock prohibit the Company from declaring or paying any cash dividends on its common stock, unless Webster has declared and paid full dividends on the Series F Preferred Stock for the most recently completed dividend period. The Company may redeem the Series F Preferred Stock, at its option in whole or in part, on December 15, 2022, or any dividend payment date thereafter, or in whole but not in part upon a "regulatory capital treatment event" as defined in the certificate of designation, at a redemption price equal to the liquidation preference plus any declared and unpaid dividends, without accumulation of any undeclared dividends. The Series F Preferred Stock does not have any voting rights except with respect to authorizing or increasing the authorized amount of senior stock, certain changes to the terms of the Series F Preferred Stock, or in the case of certain dividend non-payments.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss, Net of Tax	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Accumulated Other Comprehensive Loss, Net of Tax	Accumulated Other Comprehensive Income, Net of Tax The following table summarizes the changes in accumulated other comprehensive income (loss), net of tax (AOCI/AOCL), by component: (In thousands) Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Balance at December 31, 2017 $ (27,947) $ (15,016) $ (48,568) $ (91,531) Other comprehensive (loss) income before reclassifications (43,427) 208 (7,122) (50,341) Amounts reclassified from accumulated other comprehensive loss — 5,495 5,725 11,220 Net current-period other comprehensive (loss) income, net of tax (43,427) 5,703 (1,397) (39,121) Balance at December 31, 2018 (71,374) (9,313) (49,965) (130,652) Other comprehensive income (loss) before reclassifications 88,647 (4,945) 1,622 85,324 Amounts reclassified from accumulated other comprehensive loss (22) 5,074 4,204 9,256 Net current-period other comprehensive income (loss), net of tax 88,625 129 5,826 94,580 Balance at December 31, 2019 17,251 (9,184) (44,139) (36,072) Other comprehensive income (loss) before reclassifications 50,179 20,667 (3,887) 66,959 Amounts reclassified from accumulated other comprehensive loss (6) 8,435 2,940 11,369 Net current-period other comprehensive income (loss), net of tax 50,173 29,102 (947) 78,328 Balance at December 31, 2020 $ 67,424 $ 19,918 $ (45,086) $ 42,256 The following table provides information for the items reclassified from AOCI/AOCL: Years ended December 31, Accumulated Other Comprehensive Income (Loss) Components 2020 2019 2018 Associated Line Item in the Consolidated Statement Of Income (In thousands) Securities available-for-sale: Unrealized gains on investments $ 8 $ 29 $ — Gain on sale of investment securities, net Tax expense (2) (7) — Income tax expense Net of tax $ 6 $ 22 $ — Derivative instruments: Hedge terminations $ (7,884) $ (5,509) $ (7,425) Interest expense Premium amortization (3,536) (1,323) — Interest income Tax benefit 2,985 1,758 1,930 Income tax expense Net of tax $ (8,435) $ (5,074) $ (5,495) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (3,976) $ (5,706) $ (7,708) Other non-interest expense Tax benefit 1,036 1,502 1,983 Income tax expense Net of tax $ (2,940) $ (4,204) $ (5,725) The following tables summarize the items and related tax effects for each component of OCI/OCL, net of tax: Year ended December 31, 2020 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Securities available-for-sale: Net unrealized gain during the period $ 68,116 $ (17,937) $ 50,179 Reclassification for net gain included in net income (8) 2 (6) Total securities available-for-sale 68,108 (17,935) 50,173 Derivative instruments: Net unrealized gain during the period 27,683 (7,016) 20,667 Reclassification adjustment for net loss included in net income 11,420 (2,985) 8,435 Total derivative instruments 39,103 (10,001) 29,102 Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (5,262) 1,375 (3,887) Reclassification adjustment for amortization of net loss included in net income 3,976 (1,036) 2,940 Total defined benefit pension and postretirement benefit plans (1,286) 339 (947) Other comprehensive income, net of tax $ 105,925 $ (27,597) $ 78,328 Year ended December 31, 2019 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Securities available-for-sale: Net unrealized gain during the period $ 120,333 $ (31,686) $ 88,647 Reclassification for net gain included in net income (29) 7 (22) Total securities available-for-sale 120,304 (31,679) 88,625 Derivative instruments: Net unrealized loss during the period (6,672) 1,727 (4,945) Reclassification adjustment for net loss included in net income 6,832 (1,758) 5,074 Total derivative instruments 160 (31) 129 Defined benefit pension and other postretirement benefit plans: Current year actuarial gain 2,202 (580) 1,622 Reclassification adjustment for amortization of net loss included in net income 5,706 (1,502) 4,204 Total defined benefit pension and postretirement benefit plans 7,908 (2,082) 5,826 Other comprehensive income, net of tax $ 128,372 $ (33,792) $ 94,580 Year ended December 31, 2018 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Securities available-for-sale: Net unrealized loss during the period $ (58,792) $ 15,365 $ (43,427) Reclassification for net gain included in net income — — — Total securities available-for-sale (58,792) 15,365 (43,427) Derivative instruments: Net unrealized gain during the period 280 (72) 208 Reclassification adjustment for net loss included in net income 7,425 (1,930) 5,495 Total derivative instruments 7,705 (2,002) 5,703 Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (9,600) 2,478 (7,122) Reclassification adjustment for amortization of net loss included in net income 7,708 (1,983) 5,725 Total defined benefit pension and postretirement benefit plans (1,892) 495 (1,397) Other comprehensive loss, net of tax $ (52,979) $ 13,858 $ (39,121)

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2020
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 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 allowance for credit losses, that together equal total capital. The following table provides information on the capital ratios for Webster Financial Corporation and Webster Bank: At December 31, 2020 Actual (1) 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 At December 31, 2019 Actual Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,516,361 11.56 % $ 979,739 4.5 % $ 1,415,179 6.5 % Total risk-based capital 2,950,181 13.55 1,741,758 8.0 2,177,198 10.0 Tier 1 risk-based capital 2,661,398 12.22 1,306,319 6.0 1,741,758 8.0 Tier 1 leverage capital 2,661,398 8.96 1,188,507 4.0 1,485,634 5.0 Webster Bank CET1 risk-based capital $ 2,527,645 11.61 % $ 979,497 4.5 % $ 1,414,829 6.5 % Total risk-based capital 2,739,108 12.58 1,741,328 8.0 2,176,660 10.0 Tier 1 risk-based capital 2,527,645 11.61 1,305,996 6.0 1,741,328 8.0 Tier 1 leverage capital 2,527,645 8.51 1,187,953 4.0 1,484,941 5.0 (1) In accordance with regulatory capital rules, the Company elected an option to delay the estimated impact of CECL on its regulatory capital over a two-year deferral and subsequent three-year transition period ending December 31, 2024. As a result, capital ratios and amounts as of December 31, 2020 exclude the impact of the increased allowance for credit losses 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 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 $20 million dividends to Webster Financial Corporation during the year ended December 31, 2020 compared to $360 million during the year ended December 31, 2019. Cash Restrictions. Webster Bank is required by Federal Reserve System regulations to hold cash reserve balances on hand or with a Federal Reserve Bank. To address liquidity concerns due to COVID-19 the Federal Reserve reset the requirement to zero, effective March 26, 2020. The reserve requirement ratio is subject to adjustment as conditions warrant. Pursuant to this requirement, the Bank held $93.8 million at December 31, 2019.

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share Reconciliation of the calculation of basic and diluted earnings per common share follows: Years ended December 31, (In thousands, except per share data) 2020 2019 2018 Earnings for basic and diluted earnings per common share: Net income $ 220,621 $ 382,723 $ 360,418 Less: Preferred stock dividends 7,875 7,875 7,853 Net income available to common shareholders 212,746 374,848 352,565 Less: Earnings applicable to participating securities (1) 1,272 1,863 862 Earnings applicable to common shareholders $ 211,474 $ 372,985 $ 351,703 Shares: Weighted-average common shares outstanding - basic 89,967 91,559 91,930 Effect of dilutive securities 184 323 297 Weighted-average common shares outstanding - diluted 90,151 91,882 92,227 Earnings per common share (1) : Basic $ 2.35 $ 4.07 $ 3.83 Diluted 2.35 4.06 3.81 (1) Earnings per common share amounts under the two-class method, for nonvested time-based restricted shares with nonforfeitable dividends and dividend rights, are determined the same as the presentation above. Dilutive Securities The Company maintains stock compensation plans under which restricted stock, restricted stock units, non-qualified stock options, incentive stock options, or stock appreciation rights may be granted to employees and directors. The effect of dilutive securities for the periods presented is primarily the result of outstanding stock options, as well as non-participating restricted stock. Potential common shares from non-participating restricted stock of 44 thousand, 73 thousand, and 47 thousand for the years ended December 31, 2020, 2019, and 2018, respectively, are excluded from the effect of dilutive securities because they would have been anti-dilutive under the treasury stock method. Refer to Note 20: Share-Based Plans for further information relating to potential common shares excluded from the effect of dilutive securities.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
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, by correlation, or other means. • Level 3: Inputs for determining the fair value of the respective assets or liabilities are not observable. Level 3 valuations are reliant upon pricing models and techniques that require significant management judgment or estimation. Assets and Liabilities Measured at Fair Value on a Recurring Basis Available-for-Sale Investment Securities . When quoted prices are available in an active market, the Company classifies available-for-sale investment securities within Level 1 of the valuation hierarchy. U.S. Treasury Bills are classified within Level 1 of the fair value hierarchy. When quoted market prices are not available, the Company employs an independent pricing service that utilizes matrix pricing to calculate fair value. Such fair value measurements consider observable data such as dealer quotes, market spreads, cash flows, yield curves, live trading levels, trade execution data, market consensus prepayments speeds, credit information, and respective terms and conditions for debt instruments. Management maintains procedures to monitor the pricing service's results and has an established process to challenge their valuations, or methodologies, that appear unusual or unexpected. Available-for-Sale investment securities which include Agency CMO, Agency MBS, Agency CMBS, CMBS, CLO, and corporate debt, are classified within Level 2 of the fair value hierarchy. Derivative Instruments . Foreign exchange contracts are valued based on unadjusted quoted prices in active markets and classified within Level 1 of the fair value hierarchy. All other derivative instruments are valued using third-party valuation software, which considers the present value of cash flows discounted using observable forward rate assumptions. The resulting fair value is validated against valuations performed by independent third parties and are classified within Level 2 of the fair value hierarchy. 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 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 December 31, 2020 2019 (In thousands) Fair Value Unpaid Principal Balance Difference Fair Value Unpaid Principal Balance Difference Originated loans held for sale $ 14,000 $ 13,511 $ 489 $ 35,750 $ 35,186 $ 564 Investments Held in Rabbi Trust. Investments held in the Rabbi Trust primarily include mutual funds that invest in equity and fixed income securities. Shares of mutual funds are valued based on net asset value, which represents quoted market prices for the underlying shares held in the mutual funds. Therefore, investments held in the Rabbi Trust are classified within Level 1 of the fair value hierarchy. 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 as of December 31, 2020. Alternative Investments. Equity investments have a readily determinable fair value when quoted prices are available in an active market. Accordingly, such alternative investments are classified within Level 1 of the fair value hierarchy. Equity investments that do not have a readily available fair value may qualify for 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 December 31, 2020, these alternative investments had a remaining unfunded commitment of $22.0 million. Summaries of the fair values of assets and liabilities measured at fair value on a recurring basis are as follows: 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) 205 332,651 — 332,856 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 $ 3,673,427 $ — $ 3,689,555 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 218 $ 12,136 $ — $ 12,354 At December 31, 2019 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: Agency CMO $ — $ 185,801 $ — $ 185,801 Agency MBS — 1,612,164 — 1,612,164 Agency CMBS — 581,552 — 581,552 CMBS — 431,871 — 431,871 CLO — 92,205 — 92,205 Corporate debt — 22,240 — 22,240 Total available-for-sale investment securities — 2,925,833 — 2,925,833 Gross derivative instruments, before netting (1) 328 145,709 — 146,037 Originated loans held for sale — 35,750 — 35,750 Investments held in Rabbi Trust 4,780 — — 4,780 Alternative investments (2) — — — 4,331 Total financial assets held at fair value $ 5,108 $ 3,107,292 $ — $ 3,116,731 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 611 $ 13,202 $ — $ 13,813 (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 17: Derivative Financial Instruments. (2) 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 December 31, 2020, 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 $17.4 million at December 31, 2020, which includes $1.6 million measured at fair value where there was net write-up identified due to observable price changes. No other adjustments or reductions for impairments were identified. 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. On the occasion that these loans should include adjustments for changes in loan characteristics using unobservable inputs, the loans would be classified within Level 3. Collateral Dependent 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. Right of Use Lease Assets. The carrying value of right of use lease assets at December 31, 2020 was $127.5 million, of which includes $1.5 million of right of use lease assets measured at fair value as the result of an impairment as part of the Company's decision to consolidate certain banking center locations. As such, ROU assets are classified within Level 3 of the fair value hierarchy. Other Real Estate Owned and Repossessed Assets. The total book value of OREO and repossessed assets was $2.3 million at December 31, 2020. 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 $14.9 million at December 31, 2020. Fair Value of Financial Instruments and Servicing Assets The Company is required to disclose the estimated fair value of financial instruments for which it is practicable to estimate fair value, as well as servicing assets. The following is a description of valuation methodologies used for those assets and liabilities. Cash, Due from Banks, and Interest-bearing Deposits . The carrying amount of cash, due from banks, and interest-bearing deposits is used to approximate fair value, given the short time frame to maturity and, as such, these assets do not present unanticipated credit concerns. Cash, due from banks, and interest-bearing deposits are classified within Level 1 of the fair value hierarchy. Held-to-Maturity Investment Securities . When quoted market prices are not available, the Company employs an independent pricing service that utilizes matrix pricing to calculate fair value. Such fair value measurements consider observable data such as dealer quotes, market spreads, cash flows, yield curves, live trading levels, trade execution data, market consensus prepayments speeds, credit information, and respective terms and conditions for debt instruments. Management maintains procedures to monitor the pricing service's results and has an established process to challenge their valuations, or methodologies, that appear unusual or unexpected. Held-to-Maturity investment securities, which include Agency CMO, Agency MBS, Agency CMBS, CMBS, and municipal bonds and notes, are classified within Level 2 of the fair value hierarchy. Loans and Leases, net . The estimated fair value of loans and leases held for investment is calculated using a discounted cash flow method, using future prepayments and market interest rates inclusive of an illiquidity premium for comparable loans and leases. The associated cash flows are adjusted for credit and other potential losses. Fair value for 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 the carrying value. Fair value for all other balances are estimated using discounted cash flow analysis based on current market rates adjusted for associated credit risks, as appropriate. Securities sold under agreements to repurchase and other borrowings are classified within Level 2 of the fair value hierarchy. Federal Home Loan Bank Advances and Long-Term Debt . The fair value of FHLB advances and long-term debt is estimated using a discounted cash flow technique. Discount rates are matched with the time period of the expected cash flow and are adjusted, as appropriate, to reflect credit risk. FHLB advances and long-term debt are classified within Level 2 of the fair value hierarchy. Mortgage Servicing Assets . Mortgage servicing assets are 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 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 Consolidated Statements of Income. During the year ended December 31, 2020, the Company recorded a $1.9 million valuation allowance. Mortgage servicing assets are classified within Level 3 of the fair value hierarchy. Fair value of selected financial instruments and servicing assets amounts are as follows: At December 31, 2020 2019 (In thousands) Carrying Fair Carrying Fair Assets: Level 2 Held-to-maturity investment securities $ 5,567,889 $ 5,835,364 $ 5,293,918 $ 5,380,653 Level 3 Loans and leases, net 21,281,784 21,413,397 19,827,890 19,961,632 Mortgage servicing assets 13,422 14,362 17,484 33,250 Liabilities: Level 2 Deposit liabilities $ 24,847,618 $ 24,847,618 $ 20,219,981 $ 20,219,981 Time deposits 2,487,818 2,494,601 3,104,765 3,102,316 Securities sold under agreements to repurchase and other borrowings 995,355 1,000,189 1,040,431 1,041,042 FHLB advances 133,164 139,035 1,948,476 1,950,035 Long-term debt (1) 567,663 538,407 540,364 555,775 (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 for determination of fair value. Refer to Note 12: Borrowings for additional information.

Retirement Benefit Plans

Retirement Benefit Plans	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Retirement Benefit Plans	Retirement Benefit Plans Defined Benefit Pension and Other Postretirement Benefits Webster Bank offered a defined benefit noncontributory pension plan through December 31, 2007 for eligible employees who met certain minimum service and age requirements. Pension plan benefits are based upon employee earnings during the period of credited service. A supplemental defined benefit retirement plan (SERP) was also offered to certain employees who were at the Executive Vice President level or above through December 31, 2007. The SERP provides eligible participants with additional pension benefits. Webster Bank also provides postretirement healthcare benefits to certain retired employees. The Webster Bank Pension Plan and the SERP were frozen as of December 31, 2007. No additional benefits have been accrued since that time. Employees hired on or after January 1, 2007 receive no qualified or supplemental retirement income under the plans. All other employees accrue no additional qualified or supplemental retirement benefits after January 1, 2008, and the amount of their qualified and supplemental retirement benefits will not exceed the amount of benefits determined as of December 31, 2007. The measurement date is December 31 for the Webster Bank Pension Plan, SERP, and postretirement healthcare benefits. The mortality assumptions used in the pension liability assessment for the year ended December 31, 2020 were the Pri-2012 mortality table projected to measurement date with scale MP-2020. The following table sets forth changes in benefit obligation, changes in plan assets, and the funded status of the defined benefit pension and other postretirement benefits at December 31: Pension Plan SERP Other (In thousands) 2020 2019 2020 2019 2020 2019 Change in benefit obligation: Beginning balance $ 241,404 $ 209,513 $ 1,935 $ 1,835 $ 2,399 $ 2,612 Interest cost 6,511 7,941 46 65 46 85 Actuarial loss (gain) 27,376 33,157 194 163 (307) (103) Benefits paid and administrative expenses (8,877) (9,207) (129) (128) (140) (195) Ending balance (1) 266,414 241,404 2,046 1,935 1,998 2,399 Change in plan assets: Beginning balance 239,621 191,972 — — — — Actual return on plan assets 35,524 46,856 — — — — Employer contributions — 10,000 129 128 140 195 Benefits paid and administrative expenses (8,877) (9,207) (129) (128) (140) (195) Ending balance 266,268 239,621 — — — — Funded status of the plan at year end (2) $ (146) $ (1,783) $ (2,046) $ (1,935) $ (1,998) $ (2,399) (1) The total accumulated benefit obligation for the defined benefit pension and other postretirement benefits was $270.5 million and $245.7 million at December 31, 2020 and 2019, respectively. (2) The underfunded status amounts are included in accrued expense and other liabilities in the accompanying Consolidated Balance Sheets. The following table summarizes the impact on AOCI related to the defined benefit pension and other postretirement benefits at December 31: Pension Plan SERP Other (In thousands) 2020 2019 2020 2019 2020 2019 Net actuarial loss (gain) included in AOCI $ 57,902 $ 56,555 $ 773 $ 602 $ (690) $ (458) Deferred tax benefit (expense) 12,881 12,528 172 133 (153) (101) Amounts included in accumulated AOCI, net of tax $ 45,021 $ 44,027 $ 601 $ 469 $ (537) $ (357) Expected future benefit payments for the defined benefit pension and other postretirement benefits are presented below: (In thousands) Pension Plan SERP Other 2021 $ 9,657 $ 131 $ 254 2022 10,294 132 237 2023 10,465 132 219 2024 10,887 138 201 2025 11,304 136 182 2026-2030 61,336 625 638 The components of the net periodic benefit cost (benefit) for the defined benefit pension and other postretirement benefits were as follows for the years ended December 31: Pension Plan SERP Other (In thousands) 2020 2019 2018 2020 2019 2018 2020 2019 2018 Service cost $ — $ — $ — $ — $ — $ — $ — $ — $ — Interest cost on benefit obligations 6,511 7,941 7,212 46 65 103 46 85 78 Expected return on plan assets (13,522) (11,436) (12,716) — — — — — — Recognized net loss (gain) 4,027 5,705 4,862 23 14 2,846 (74) (13) — Net periodic benefit cost (benefit) $ (2,984) $ 2,210 $ (642) $ 69 $ 79 $ 2,949 $ (28) $ 72 $ 78 Changes in funded status related to the defined benefit pension and other postretirement benefits and recognized as a component of OCI in the consolidated statement of comprehensive income as follows for the years ended December 31: Pension Plan SERP Other (In thousands) 2020 2019 2018 2020 2019 2018 2020 2019 2018 Net (gain) loss $ 5,375 $ (2,263) $ 9,952 $ 194 $ 164 $ — $ (307) $ (103) $ (352) Amounts reclassified from AOCI (4,027) (5,705) (4,862) (23) (14) (2,846) 74 13 — Total (gain) loss recognized in OCI $ 1,348 $ (7,968) $ 5,090 $ 171 $ 150 $ (2,846) $ (233) $ (90) $ (352) Fair Value Measurement The following is a description of the valuation methodologies used to measure the fair value of pension plan assets and includes the classification of those instruments within the valuation hierarchy: Exchange traded fund. The exchange traded fund has quoted market prices on an exchange, in an active market, which represents the net asset value of the shares held in the fund and is classified within Level 1 of the fair value hierarchy. The fair value for the exchange traded fund is benchmarked against the Standard & Poor's 500 Index. Money market fund. The money market fund is carried at cost, which approximates fair value given the short time frame to maturity for cash and cash equivalents and is classified within Level 1 of the fair value hierarchy. Common collective trusts. Common collective trusts hold investments in fixed income and equity funds. Transactions may occur daily within a trust. Should a full redemption of the trust be initiated, the investment advisor reserves the right to temporarily delay withdrawals in order to ensure that the liquidation of securities is carried out in an orderly business manner. Common collective trusts are benchmarked against the Standard and Poor’s 500 Stock Index, the S&P 400 Mid Cap Index, the Russell 2000 Index, the MSCI ACWI ex U.S. Index, and the Barclays Capital U.S. Long Credit Index. As such, common collective trusts are classified within Level 2 of the fair value hierarchy. A summary of the fair value and hierarchy classification of financial assets of the pension plan is as follows: At December 31, 2020 2019 (In thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Exchange traded fund $ 39,645 $ — $ — $ 39,645 $ 36,552 $ — $ — $ 36,552 Cash and cash equivalents 861 — — 861 1,225 — — 1,225 Common collective trusts — 225,762 — 225,762 — 201,844 — 201,844 Total pension plan assets $ 40,506 $ 225,762 $ — $ 266,268 $ 37,777 $ 201,844 $ — $ 239,621 (1) For 2019, the common collective trusts were reported in the NAV category in the fair value leveling table. Due to the readily available nature of the fair value (at NAV) for these investments, they have been classified as Level 2 within the fair value hierarchy in current and prior periods presented. Asset Management The following table presents the target allocation and the pension plan asset allocation for the periods indicated, by asset category: Target Allocation Percentage of Pension Plan Assets 2021 2020 2019 Fixed income investments 62 % 61 % 61 % Equity investments 38 38 38 Cash and cash equivalents — 1 1 Total 100 % 100 % 100 % The Retirement Plan Committee is a fiduciary under ERISA and is charged with the responsibility for directing and monitoring the investment management of the pension plan. To assist the Retirement Plan Committee in this function, it engages the services of investment managers and advisors who possess the necessary expertise to manage the pension plan assets within the established investment policy guidelines and objectives. The investment policy guidelines and objectives are reviewed at a minimum annually by the Retirement Plan Committee. The primary objective of the pension plan investment strategy is to provide long-term total return through capital appreciation and dividend and interest income. The Plan invests in registered investment companies and bank collective trusts. The volatility, as measured by standard deviation, of the pension plan assets should not exceed that of the Composite Index. The investment policy guidelines allow the pension plan assets to be invested in certain types of cash equivalents, fixed income securities, equity securities, mutual funds, and collective trusts. Investments in mutual funds and collective trust funds are substantially limited to funds with the securities characteristic of their assigned benchmarks. The investment strategy for the pension plan is designed to maintain a diversified portfolio with an expected weighted-average long-term rate of 5.50%, however, there is no certainty that the portfolio will perform to expectations. Asset allocations are monitored monthly and the portfolio is re-balanced when appropriate. Weighted-average assumptions used to determine benefit obligations at December 31 are as follows: Pension Plan SERP Other 2020 2019 2020 2019 2020 2019 Discount rate 2.29 % 3.07 % 1.91 % 2.82 % 1.40 % 2.50 % Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31 are as follows: Pension Plan SERP Other 2020 2019 2018 2020 2019 2018 2020 2019 2018 Discount rate 3.07 % 4.12 % 3.50 % 2.82 % 3.95 % 3.30 % 2.50 % 3.69 % 3.00 % Expected long-term return on assets 5.75 % 6.00 % 6.00 % n/a n/a n/a n/a n/a n/a Assumed healthcare cost trend n/a n/a n/a n/a n/a n/a 6.50 % 6.50 % 7.00 % The assumed healthcare cost-trend rate for 2020 is 6.50%, declining 0.25% each year thereafter until 2030 when the rate will be 4.40%. Multiple-Employer Plan For the benefit of former employees of a bank acquired by the Company, the Bank is a sponsor of a multiple-employer pension plan that does not segregate the assets or liabilities of its employers participating in the plan. The plan administrator confirmed Webster Bank’s portion of the plan is under-funded by $2.6 million as of July 1, 2020, the date of the latest actuarial valuation. The following table sets forth contributions and funding status of Webster Bank's portion of this plan: (Dollars in thousands) Contributions by Webster Bank for the year ended December 31, Funded Status of the Plan at December 31, Plan Name Employer Identification Number Plan Number 2020 2019 2018 2020 2019 Pentegra Defined Benefit Plan for Financial Institutions 13-5645888 333 $998 $863 $679 At least 80 percent At least 80 percent Multi-employer accounting is applied to the Fund. As a multiple-employer pension plan, there are no collective bargained contracts affecting its contribution or benefit provisions. Any shortfall amortization basis is being amortized over seven years, as required by the Pension Protection Act. All benefit accruals were frozen as of September 1, 2004. The Company's contributions to this plan did not exceed more than 5% of total contributions in the plan for the years ended December 31, 2020, 2019, and 2018. Webster Bank Retirement Savings Plan Webster Bank provides an employee retirement savings plan governed by section 401(k) of the Internal Revenue Code. Webster Bank matches 100% of the first 2% and 50% of the next 6% of employees’ pre-tax contributions based on annual compensation. If a participant fails to make a pre-tax contribution election within 90 days of his or her date of hire, automatic pre-tax contributions will commence 90 days after his or her date of hire at a rate equal to 3% of compensation. Compensation and benefit expense included $13.8 million, $13.2 million, and $12.4 million for the years ended December 31, 2020, 2019, and 2018, respectively, of employer contributions.

Share-Based Plans

Share-Based Plans	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Share-Based Plans	Note 20: Share-Based Plans Stock Compensation Plans Webster maintains stock compensation plans to better align the interests of its employees and directors with those of its shareholders. The Plans have shareholder approval for up to 13.4 million shares of common stock. At December 31, 2020, there were 0.9 million common shares remaining available for grant, while no stock appreciation rights have been granted. Stock compensation cost is recognized over the required service vesting period for the awards, based on the grant-date fair value, net of estimated forfeitures, and is included as a component of compensation and benefits reflected in non-interest expense. Stock compensation expense for restricted stock of $12.2 million, $12.6 million, and $11.6 million, and an income tax benefit of $2.6 million, $6.1 million, and $8.5 million, was recognized for the years ended December 31, 2020, 2019, and 2018, respectively. At December 31, 2020 there was $15.5 million of unrecognized stock compensation expense for restricted stock, expected to be recognized over a weighted-average period of 1.9 years. The following table summarizes the activity under the stock compensation plans for the year ended December 31, 2020: Unvested Restricted Stock Awards Outstanding Stock Options Outstanding Time-Based Performance-Based Number of Weighted-Average Number of Weighted-Average Number of Weighted-Average Balance at January 1, 2020 450,224 $ 54.53 233,304 $ 54.94 420,931 $ 23.35 Granted 296,435 37.79 106,739 40.56 — — Vested 171,852 52.22 79,836 56.18 — — Forfeited 27,622 45.98 9,541 50.42 — — Exercised — — — — 10,230 23.51 Balance at December 31, 2020 547,185 46.59 250,666 48.77 410,701 23.35 Time-based restricted stock . Time-based restricted stock awards vest over the applicable service period ranging from 1 to 3 years. The number of time-based awards that may be granted to an eligible individual in a calendar year is limited to 100,000 shares. Compensation expense is recorded over the vesting period based on fair value, which is measured using the Company's common stock closing price at the date of grant. Performance-based restricted stock . Performance-based restricted stock awards vest after a 3 year performance period. The awards vest with a share quantity dependent on that performance, in a range from zero to 150%. The performance criteria for 50% of the shares granted in 2020 is based upon Webster's ranking for total shareholder return versus Webster's compensation peer group companies and the remaining 50% is based upon Webster's average of return on equity during the 3 year vesting period. The compensation peer group companies are utilized because they represent the financial institutions that best compare with Webster. The Company records compensation expense over the vesting period, based on a fair value calculated using the Monte-Carlo simulation model, which allows for the incorporation of the performance condition for the 50% of the performance-based shares tied to total shareholder return versus the compensation peer group, and based on a fair value of the market price on the date of grant for the remaining 50% of the performance-based shares tied to Webster's return on equity. Compensation expense is subject to adjustment based on management's assessment of Webster's return on equity performance relative to the target number of shares condition. The total fair value of restricted stock awards vested during the years ended December 31, 2020, 2019, and 2018 was $13.5 million, $12.5 million, and $11.1 million, respectively. Stock options . Stock option awards have an exercise price equal to the market price of Webster Financial Corporation's stock on the date of grant. Each option grants the holder the right to acquire a share of Webster Financial Corporation common stock over a contractual life of up to 10 years. There have been no stock options granted since 2013. At December 31, 2020, there was stock options outstanding for 410,701 shares of common stock, all of which are exercisable, with a weighted-average exercise price of $23.35 and a weighted-average remaining contractual life of 1.7 years, comprised of 376,813 non-qualified stock options and 33,888 incentive stock options. Total pretax intrinsic value, which is the difference between Webster's closing stock price on the last trading day of the year and the weighted-average exercise price multiplied by the number of shares, represents aggregate intrinsic value that would have been received by the option holders had they all exercised their options at that time. At December 31, 2020, as all awarded options have vested, all of the outstanding options are exercisable, and the aggregate intrinsic value of these options was $7.7 million. The total intrinsic value of options exercised during the years ended December 31, 2020, 2019, and 2018 was $0.1 million, $2.4 million, and $9.7 million, respectively.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting Webster’s operations are organized into three reportable segments that represent its primary businesses - Commercial Banking, HSA Bank, and Community Banking. These segments reflect how executive management responsibilities are assigned, the type of customer served, how products and services are provided, and how discrete financial information is currently evaluated. Certain Corporate Treasury activities, along with the amounts required to reconcile profitability metrics to amounts reported in accordance with GAAP, are included in the Corporate and Reconciling category. Description of Segment Reporting Methodology Webster uses an internal profitability reporting system to generate information by operating segment, which is based on a series of management estimates for funds transfer pricing, and allocations for 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 reported results of any operating segment do not affect the consolidated financial position or results of operations of Webster as a whole. The full profitability measurement reports, which are prepared for each operating segment, reflect non-GAAP reporting methodologies. The differences between full profitability and GAAP results are reconciled in the Corporate and Reconciling category. Webster allocates interest income and interest expense to each business, while any mismatch associated with the matched maturity funding concept called Funds Transfer Pricing (FTP) is absorbed in corporate treasury activities. The allocation process considers the specific interest rate risk and liquidity risk of financial instruments and other assets and liabilities in each line of business. The matched maturity funding concept considers the origination date and the earlier of the maturity date or the repricing date of a financial instrument to assign a FTP rate for loans and deposits originated each day. Loans are assigned an FTP rate for funds used and deposits are assigned an FTP rate for funds provided. Beginning in 2020, Webster refined the FTP calculation to reflect the allocation of capital credit to net interest income to better align segment results with key measurements used to review segment performance. Prior period net interest income and income tax expense were revised to reflect this change. Webster allocates a majority of non-interest expense to each reportable segment using a full-absorption costing process. Costs, including corporate overhead, are analyzed, pooled by process, and assigned to the appropriate reportable segment. The results of funds transfer pricing and allocations for non-interest expense, as well as non-interest income produces pre-tax, pre-provision net revenue, under which basis the segments are reviewed by executive management. Webster also allocates the provision for credit losses to each segment based on management’s estimate of the inherent loss content in each of the specific loan and lease portfolios. Allowance for credit losses is included in total assets within the Corporate and Reconciling category. The following table presents total assets for Webster's reportable segments and the Corporate and Reconciling category: At December 31, 2020 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Total assets $ 12,689,255 $ 80,352 $ 9,769,824 $ 10,051,259 $ 32,590,690 At December 31, 2019 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Total assets $ 11,541,803 $ 80,176 $ 9,348,727 $ 9,418,638 $ 30,389,344 The following tables present the operating results, including all appropriate allocations, for Webster’s reportable segments and the Corporate and Reconciling category: Year ended December 31, 2020 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Net interest income $ 423,869 $ 162,363 $ 422,979 $ (117,818) $ 891,393 Non-interest income 58,366 100,826 106,279 19,806 285,277 Non-interest expense 187,572 140,637 390,596 40,141 758,946 Pre-tax, pre-provision net revenue 294,663 122,552 138,662 (138,153) 417,724 Provision for credit losses 137,993 — (144) (99) 137,750 Income before income tax expense 156,670 122,552 138,806 (138,054) 279,974 Income tax expense 38,368 32,721 27,484 (39,220) 59,353 Net income $ 118,302 $ 89,831 $ 111,322 $ (98,834) $ 220,621 Year ended December 31, 2019 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Net interest income $ 403,258 $ 172,685 $ 420,898 $ (41,714) $ 955,127 Non-interest income 59,063 97,041 109,270 19,941 285,315 Non-interest expense 181,580 135,586 388,399 10,385 715,950 Pre-tax, pre-provision net revenue 280,741 134,140 141,769 (32,158) 524,492 Provision for credit losses 25,407 — 12,393 — 37,800 Income before income tax expense 255,334 134,140 129,376 (32,158) 486,692 Income tax expense 63,323 35,547 27,428 (22,329) 103,969 Net income $ 192,011 $ 98,593 $ 101,948 $ (9,829) $ 382,723 Year ended December 31, 2018 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Net interest income $ 381,098 $ 147,920 $ 422,063 $ (44,400) $ 906,681 Non-interest income 64,765 89,323 109,669 18,811 282,568 Non-interest expense 174,054 124,594 384,603 22,365 705,616 Pre-tax, pre-provision net revenue 271,809 112,649 147,129 (47,954) 483,633 Provision for credit losses 32,388 — 9,612 — 42,000 Income before income tax expense 239,421 112,649 137,517 (47,954) 441,633 Income tax expense 58,898 29,289 27,366 (34,338) 81,215 Net income $ 180,523 $ 83,360 $ 110,151 $ (13,616) $ 360,418

Revenue from contracts with Cus

Revenue from contracts with Customers Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	Revenue from Contracts with Customers The following tables present revenues within the scope of ASC 606, Revenue from Contracts with Customers and the net amount of other sources of non-interest income that is within the scope of other GAAP topics: Year ended December 31, 2020 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income: Deposit service fees $ 11,634 $ 92,693 $ 51,599 $ 106 $ 156,032 Wealth and investment services 10,644 — 22,307 (35) 32,916 Other — 8,133 1,656 — 9,789 Revenue from contracts with customers 22,278 100,826 75,562 71 198,737 Other sources of non-interest income 36,088 — 30,717 19,735 86,540 Total non-interest income $ 58,366 $ 100,826 $ 106,279 $ 19,806 $ 285,277 Year ended December 31, 2019 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income: Deposit service fees $ 12,136 $ 92,096 $ 63,572 $ 218 $ 168,022 Wealth and investment services 10,330 — 22,637 (35) 32,932 Other — 4,945 2,394 — 7,339 Revenue from contracts with customers 22,466 97,041 88,603 183 208,293 Other sources of non-interest income 36,597 — 20,667 19,758 77,022 Total non-interest income $ 59,063 $ 97,041 $ 109,270 $ 19,941 $ 285,315 Year ended December 31, 2018 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income: Deposit service fees $ 12,775 $ 85,809 $ 63,522 $ 77 $ 162,183 Wealth and investment services 10,145 — 22,732 (34) 32,843 Other — 3,514 2,133 — 5,647 Revenue from contracts with customers 22,920 89,323 88,387 43 200,673 Other sources of non-interest income 41,845 — 21,282 18,768 81,895 Total non-interest income $ 64,765 $ 89,323 $ 109,669 $ 18,811 $ 282,568 The major types of revenue streams that are within the scope of ASC 606 are described below: Deposit service fees predominately consist of fees earned from deposit accounts and interchange fees. Fees earned from deposit accounts relate to event-driven services and periodic account maintenance activities. Webster's obligations for event-driven services are satisfied at the time the service is delivered, while the obligations for maintenance services is satisfied monthly. Interchange fees are assessed as the performance obligation is satisfied, which is at the point in time the card transaction is authorized. Wealth and investment services consists of fees earned from investment and securities-related services, trust and other related services. Obligations for wealth and investment services are generally satisfied over time through a time-based measurement of progress, 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 in Note 21: Segment Reporting. Contracts with customers have not generated significant contract assets and liabilities.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Credit-Related Financial Instruments The Company offers credit-related financial instruments, in the normal course of business to meet certain financing needs of its customers, that involve off-balance sheet risk. These transactions may include an unused commitment to extend credit, standby letter of credit, or commercial letter of credit. Such transactions involve, to varying degrees, elements of credit risk. Commitments to Extend Credit . The Company makes commitments under various terms to lend funds to customers at a future point in time. These commitments include revolving credit arrangements, term loan commitments, and short-term borrowing agreements. Most of these loans have fixed expiration dates or other termination clauses where a fee may be required. Since commitments routinely expire without being funded, or after required availability of collateral occurs, the total commitment amount does not necessarily represent future liquidity requirements. Standby Letter of Credit . A standby letter of credit commits the Company to make payments on behalf of customers if certain specified future events occur. The Company has recourse against the customer for any amount required to be paid to a third party under a standby letter of credit, which is often part of a larger credit agreement under which security is provided. Historically, a large percentage of standby letters of credit expire without being funded. The contractual amount of a standby letter of credit represents the maximum amount of potential future payments the Company could be required to make, and is the Company's maximum credit risk. Commercial Letter of Credit . A commercial letter of credit is issued to facilitate either domestic or foreign trade arrangements for customers. As a general rule, drafts are committed to be drawn when the goods underlying the transaction are in transit. Similar to a standby letter of credit, a commercial letter of credit is often secured by an underlying security agreement including the assets or inventory they relate to. The following table summarizes the outstanding amounts of credit-related financial instruments with off-balance sheet risk: At December 31, (In thousands) 2020 2019 Commitments to extend credit $ 6,517,840 $ 6,162,658 Standby letter of credit 207,201 188,103 Commercial letter of credit 30,522 29,180 Total credit-related financial instruments with off-balance sheet risk $ 6,755,563 $ 6,379,941 These commitments subject the Company to potential exposure in excess of amounts recorded in the financial statements, and therefore, management maintains an allowance for credit losses 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. The allowance is reported as a component of accrued expenses and other liabilities in the accompanying Consolidated Balance Sheets. The following table provides a summary of activity in the allowance for credit losses on unfunded loan commitments: Years ended December 31, (In thousands) 2020 2019 2018 Beginning balance $ 2,367 $ 2,506 $ 2,362 Adoption of ASU No. 2016-13 (CECL) 9,139 — — Provision (benefit) 1,249 (139) 144 Ending balance $ 12,755 $ 2,367 $ 2,506

Parent Company Information

Parent Company Information	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Parent Company Information	Parent Company Information Financial information for the Parent Company only is presented in the following tables: Condensed Balance Sheets December 31, (In thousands) 2020 2019 Assets: Cash and due from banks $ 302,315 $ 510,940 Intercompany debt securities 150,000 150,000 Investment in subsidiaries 3,340,556 3,079,549 Alternative investments 8,970 5,356 Other assets 8,122 13,537 Total assets $ 3,809,963 $ 3,759,382 Liabilities and shareholders’ equity: Senior notes $ 490,343 $ 463,044 Junior subordinated debt 77,320 77,320 Accrued interest payable 5,862 6,057 Due to subsidiaries 324 52 Other liabilities 1,489 5,139 Total liabilities 575,338 551,612 Shareholders’ equity 3,234,625 3,207,770 Total liabilities and shareholders’ equity $ 3,809,963 $ 3,759,382 Condensed Statements of Income Years ended December 31, (In thousands) 2020 2019 2018 Operating Income: Dividend income from bank subsidiary $ 20,000 $ 360,000 $ 290,000 Interest on securities and deposits 5,530 10,728 7,342 Alternative investments (loss) income 2,467 (256) 290 Other non-interest income 634 382 805 Total operating income 28,631 370,854 298,437 Operating Expense: Interest expense on borrowings 18,684 21,062 11,127 Non-interest expense 16,426 15,527 19,105 Total operating expense 35,110 36,589 30,232 Income before income tax benefit and equity in undistributed earnings of subsidiaries (6,479) 334,265 268,205 Income tax benefit 4,572 4,671 2,207 Equity in undistributed earnings of subsidiaries 222,528 43,787 90,006 Net income $ 220,621 $ 382,723 $ 360,418 Condensed Statements of Comprehensive Income Years ended December 31, (In thousands) 2020 2019 2018 Net income $ 220,621 $ 382,723 $ 360,418 Other comprehensive income (loss), net of tax: Derivative instruments 2,622 1,479 1,447 Other comprehensive income (loss) of subsidiaries 75,706 93,101 (40,568) Other comprehensive income (loss), net of tax 78,328 94,580 (39,121) Comprehensive income $ 298,949 $ 477,303 $ 321,297 Condensed Statements of Cash Flows Years ended December 31, (In thousands) 2020 2019 2018 Net cash provided by operating activities $ 27,790 $ 362,617 $ 282,986 Investing activities: Alternative investments capital call (3,751) (1,850) — Investment in subsidiaries — (296,000) — Net cash used for investing activities (3,751) (297,850) — Financing activities: Issuance of long-term debt — 296,358 — Cash dividends paid to common shareholders (144,967) (140,783) (114,959) Cash dividends paid to preferred shareholders (7,875) (7,875) (7,875) Exercise of stock options 240 619 2,173 Common stock repurchased and acquired from stock compensation plan activity (80,062) (19,619) (25,937) Net cash (used for) provided by financing activities (232,664) 128,700 (146,598) Increase in cash and cash equivalents (208,625) 193,467 136,388 Cash and cash equivalents at beginning of year 510,940 317,473 181,085 Cash and cash equivalents at end of year $ 302,315 $ 510,940 $ 317,473

Selected Quarterly Consolidated

Selected Quarterly Consolidated Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2020
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Consolidated Financial Information (Unaudited)	Selected Quarterly Consolidated Financial Information (Unaudited) 2020 (In thousands, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 274,470 $ 252,275 $ 239,239 $ 236,065 Interest expense 43,669 27,868 19,983 19,136 Net interest income 230,801 224,407 219,256 216,929 Provision for credit losses 76,000 40,000 22,750 (1,000) Non-interest income 73,378 60,076 75,060 76,763 Non-interest expense 178,836 176,584 183,996 219,530 Income before income tax expense 49,343 67,899 87,570 75,162 Income tax expense 11,144 14,802 18,289 15,118 Net income $ 38,199 $ 53,097 $ 69,281 $ 60,044 Earnings applicable to common shareholders $ 36,021 $ 50,729 $ 66,890 $ 57,715 Earnings per common share: Basic $ 0.40 $ 0.57 $ 0.75 $ 0.64 Diluted 0.39 0.57 0.75 0.64 2019 (In thousands, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 286,190 $ 292,257 $ 294,136 $ 282,000 Interest expense 44,639 50,470 53,597 50,750 Net interest income 241,551 241,787 240,539 231,250 Provision for credit losses 8,600 11,900 11,300 6,000 Non-interest income 68,612 75,853 69,931 70,919 Non-interest expense 175,686 180,640 179,894 179,730 Income before income tax expense 125,877 125,100 119,276 116,439 Income tax expense 26,141 26,451 25,411 25,966 Net income $ 99,736 $ 98,649 $ 93,865 $ 90,473 Earnings applicable to common shareholders $ 97,549 $ 96,193 $ 91,442 $ 88,066 Earnings per common share: Basic $ 1.06 $ 1.05 $ 1.00 $ 0.96 Diluted 1.06 1.05 1.00 0.96

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accounting and reporting policies of the Company that materially affect its financial statements conform with GAAP. The Consolidated Financial Statements and the accompanying Notes thereto include the accounts of Webster Financial Corporation and all other entities in which it has a controlling financial interest. Intercompany accounts and transactions have been eliminated in consolidation. Assets that the Company holds or manages in a fiduciary or agency capacity for customers, typically referred to as assets under administration or assets under management, are not included in the accompanying Consolidated Balance Sheets as those assets are not the Company's, and the Company is not the primary beneficiary. Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications had an immaterial effect on the Company's consolidated financial statements.
Variable Interest Entities	Principles of Consolidation The purpose of consolidated financial statements is to present the results of operations and the financial position of the Company and its subsidiaries as if the consolidated group were a single economic entity. In accordance with the applicable accounting guidance for consolidations, the consolidated financial statements include any voting interest entity (VOE) in which the Company has a controlling financial interest and any variable interest entity (VIE) for which the Company is deemed to be the primary beneficiary. The Company generally consolidates its VOEs if the Company, directly or indirectly, owns more than 50% of the outstanding voting shares of the entity and the non-controlling shareholders do not hold any substantive participating or controlling rights. The Company evaluates VIEs to understand the purpose and design of the entity, and its involvement in the ongoing activities of the VIE and will consolidate the VIE if it has (i) the power to direct the activities of the VIE that most significantly affect the VIE's economic performance and (ii) an obligation to absorb losses of the VIE, or the right to receive benefits from the VIE, that could potentially be significant to the VIE. The Company accounts for unconsolidated partnerships and certain other investments using the equity method of accounting if it has the ability to significantly influence the operating and financial policies of the investee. This is generally presumed to exist when the Company owns between 20% and 50% of a corporation, or when it has greater than 3%-5% interest in a limited partnership or similarly structured entity. Refer to Note 2: Variable Interest Entities for further information.
Use of Estimates	Use of EstimatesThe 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.
Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents, as referenced in the accompanying Consolidated Statements of Cash Flows, is comprised of cash and due from banks and interest-bearing deposits. Cash equivalents have a maturity of three months or less. Cash and due from banks, as referenced in the accompanying Consolidated Balance Sheets, includes cash on hand, certain deposits at the FRB of Boston, and cash due from banks. Restricted cash related to Federal Reserve System requirements and cash collateral received on derivative positions are included in cash and due from banks. Interest-bearing deposits, as referenced in the accompanying Consolidated Balance Sheets, includes deposits at the FRB of Boston in excess of reserve requirements and federal funds sold to other financial institutions. Federal funds sold essentially represents an uncollateralized loan and therefore the Company regularly evaluates the credit risk associated with the other financial institutions to assure that Webster does not become exposed to any significant credit risk on those cash equivalents.
Investment Securities	Investment in Debt Securities Debt security transactions are recognized on the trade date, which is the date the order to buy or sell the security is executed. Investment in debt securities are classified as available-for-sale or held-to-maturity at the time of purchase. Any classification change subsequent to trade date is reviewed for compliance with corporate objectives and accounting policies. Debt securities classified as held-to-maturity are those which Webster has the ability and intent to hold to maturity. Debt securities classified as held-to-maturity are recorded at amortized cost net of unamortized premiums and discounts. Discount accretion income and premium amortization expense are recognized as interest income using the effective interest method, with consideration given to prepayment assumptions on mortgage backed securities. Premiums are amortized to the earliest call date for debt securities purchased at a premium, with explicit, non-contingent call features and are callable at a fixed price and preset date. Debt securities classified as held-to-maturity are reviewed for credit losses under the CECL model with an allowance recorded on the balance sheet for expected lifetime credit losses. The allowance for credit losses is calculated on a pooled basis using statistical models which include forecasted scenarios of future economic conditions. Forecasts revert to long-run loss rates implicitly through the economic scenario, generally over three years. If the risk for a particular security no longer matches the collective assessment pool, it is removed and individually assessed for credit deterioration. A security will be placed on non-accrual status if collection of principal and interest in accordance with contractual terms is doubtful. Debt securities classified as available-for-sale are recorded at fair value with unrealized gains and losses recorded as a component of other comprehensive income (OCI) or other comprehensive loss (OCL). If a debt security is transferred from available-for-sale to held-to-maturity it is recorded at fair value at the time of transfer and the respective gain or loss would be recorded as a separate component of OCI or OCL and amortized as an adjustment to interest income over the remaining life of such security. Debt securities classified as available-for-sale are reviewed for credit losses when the fair value of a security falls below the amortized cost basis and the decline is evaluated to determine if any portion is attributable to credit loss. The decline in fair value attributable to credit loss is recorded directly to earnings, with a corresponding allowance for credit loss, limited to the amount that fair value is less than the amortized cost. If the credit quality subsequently improves, previously recorded allowance amounts may be reversed. The non-accrual policy for available-for-sale debt securities is the same as for held-to-maturity debt securities. When the Company intends to sell an impaired available-for-sale debt security, or if it is more likely than not that the Company will be required to sell the security, prior to recovery of the amortized cost basis, the entire fair value adjustment will immediately be recognized in earnings through non-interest income. The gain or loss on sale is calculated using the carrying value plus any related accumulated OCI or OCL balance associated with the securities sold. A zero credit loss assumption is maintained for U.S. Treasuries and agency-backed securities in both the held-to-maturity and available-for-sale portfolios. This assumption is subject to quarterly review to ensure it remains appropriate. Refer to Note 4: Investment Securities for further information related to investment in debt securities. Investment in Equity Securities The Company’s accounting treatment for unconsolidated equity investments differs for those with and without readily determinable fair values. Equity investments with readily determinable fair values are recorded at fair value with changes in fair value recorded in non-interest income. For equity investments without readily determinable fair values, the Company elected the measurement alternative, and therefore carries these investments at cost, less impairment, if any, plus or minus changes in observable prices. Certain equity investments that do not have a readily available fair value may qualify for net asset value (NAV) measurement based on specific requirements. The Company's alternative investments accounted for at NAV consist of investments in non-public entities that generally cannot be redeemed since the Company’s investments are distributed as the underlying equity is liquidated. On a quarterly basis, the Company reviews its equity investments without readily determinable fair values for impairment. If the equity investment is considered impaired, an impairment loss equal to the amount by which the carrying value exceeds its fair value is recorded through a charge to earnings. The impairment loss may be reversed in a subsequent period if there are observable transactions for the identical or similar investment of the same issuer at a higher amount than the carrying amount that was established when the impairment was recognized. Impairment as well as upward or downward adjustments resulting from observable price changes in orderly transactions for identical or similar investments are included in non-interest income. Equity investments in entities that finance affordable housing and other community development projects provide a return primarily through the realization of tax benefits. The Company applies the proportional amortization method to account for its investments in qualified affordable housing projects.
Loans Held for Sale	Loans Held for Sale Loans that are classified as held for sale at the time of origination are accounted for under the fair value option. Loans not originated for sale but subsequently transferred to held for sale are valued at the lower of cost or fair value and are valued on an individual asset basis. Any cost amount in excess of fair value is recorded as a valuation allowance and recognized as a reduction of other non-interest income. Gains or losses on the sale of loans held for sale are recorded as part of mortgage banking activities, or other income. Cash flows from the sale of loans that were originated specifically for resale are presented as operating cash flows. Cash flows from the sale of loans originated for investment then subsequently transferred to held for sale are presented as investing cash flows. Refer to Note 6: Transfers of Financial Assets for further information.
Transfers and Servicing of Financial Assets	Transfers and Servicing of Financial Assets Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is generally considered to have been surrendered when: (i) the transferred assets are legally isolated from the Company or its consolidated affiliates, even in bankruptcy or other receivership; (ii) the transferee has the right to pledge or exchange the assets with no conditions that constrain the transferee and provide more than a trivial benefit to the Company; and (iii) the Company does not maintain the obligation or unilateral ability to reclaim or repurchase the assets. The Company sells financial assets in the normal course of business, the majority of which are residential mortgage loan sales, primarily to government-sponsored enterprises through established programs, commercial loan sales through participation agreements, and other individual or portfolio loan and securities sales. In accordance with accounting guidance for asset transfers, the Company considers any ongoing involvement with transferred assets in determining whether the assets can be derecognized from the balance sheet. With the exception of servicing the Company’s continuing involvement with financial assets sold is minimal and generally limited to market customary representation and warranty clauses covering certain characteristics of the mortgage loans sold and the Company's origination process. The gain or loss on sale depends on the previous carrying amount of the transferred financial assets, the consideration received, and any other assets obtained or liabilities incurred in exchange for the transferred assets. When the Company sells financial assets, it may retain servicing rights and/or other interests in the financial assets. Servicing assets and any other interests held by the Company are recorded at fair value upon transfer, and thereafter are carried at the lower of cost or fair value. Refer to Note 6: Transfers of Financial Assets for further information.
Loans and Leases	Loans and Leases Loans and leases are stated at the principal amount outstanding, net of amounts charged off, unearned income, unamortized premiums and discounts, and deferred loan and lease fees or costs which are recognized as yield adjustments using the interest method. These yield adjustments are amortized over the contractual life of the related loans and leases adjusted for prepayments when applicable. Interest on loans and leases is credited to interest income as earned based on the interest rate applied to principal amounts outstanding. Prepayment fees are recognized in non-interest income. Cash flows from loans and leases are presented as investing cash flows. Non-accrual Loans Loans and leases are placed on non-accrual status when collection of principal and interest in accordance with contractual terms is doubtful, generally when principal or interest payments become 90 days delinquent, unless the loan or lease is well secured and in process of collection, or sooner if management concludes circumstances indicate that the borrower may be unable to meet contractual principal or interest payments. Residential real estate loans, excluding loans fully insured against loss and in the process of collection, and consumer loans are placed on non-accrual status at 90 days past due, or at the date when the Company is notified that the borrower is discharged in bankruptcy. Residential loans that are more than 90 days past due, fully insured against loss, and in the process of collection, remain accruing and are reported as 90 days or more past due and accruing. Commercial, commercial real estate loans, and equipment finance loans or leases are subject to a detailed review when 90 days past due to determine accrual status, or when payment is uncertain and a specific consideration is made to put a loan or lease on non-accrual status. When loans and leases are placed on non-accrual status, the accrual of interest is discontinued, and any unpaid accrued interest is reversed and charged against interest income. If ultimate repayment of a non-accrual loan or lease is expected, any payments received are applied in accordance with contractual terms. If ultimate repayment is not expected on commercial, commercial real estate, and equipment finance loans and leases, any payment received on a non-accrual loan or lease is applied to principal until the unpaid balance has been fully recovered. Any excess is then credited to interest income when received. If the Company determines, through a current valuation analysis, that principal can be recovered on residential real estate and consumer loans, interest payments are taken into income as received on a cash basis.
Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments	Allowance for Credit Losses on Loans and Leases The ACL on loans and leases is a contra-asset account that offsets the amortized cost basis of loans and leases for the credit losses expected to occur over the life of the asset. The ACL is established through a provision charged to expense. Executive management reviews and advises on the adequacy of the reserve which is maintained at a level management deems sufficient to cover expected losses within the loan and lease portfolios. The Company has elected to present accrued interest receivable separately from the amortized cost basis on the balance sheet and does not estimate an ACL on accrued interest as policies are in place to ensure timely write-offs and non-accruals. The ACL on loans and leases is determined using the CECL model which requires recognition of expected lifetime credit losses at the origination or purchase of an asset. Expected losses are determined through pooled, collective assessment of loans and leases with similar risk characteristics. If the risk characteristics of a loan or lease change and no longer match the collective assessment pool, it is removed and individually assessed for credit impairment. Management applies significant judgments and assumptions that influence the loss estimate and ACL on loan and lease balances. Collectively Assessed Loans and Leases. Collectively assessed loans and leases are segmented based on two portfolio segments, the commercial loans and leases and consumer loans. Expected losses are determined using a Probability of Default/Loss Given Default/Exposure at Default (PD/LGD/EAD) framework. Expected credit losses are calculated as the product of the probability of a loan defaulting, expected loss given the occurrence of a default, and the projected exposure of a loan at default. Summing the product across loans over their lives yields the lifetime expected credit losses for a given portfolio. The Company’s PD and LGD calculations are predictive models that measure the current risk profile of the loan pools using forecasts of future macroeconomic conditions, historical loss information, and credit risk ratings. The Company employs a dual grade credit risk grading system for estimating the PD and the LGD for commercial, commercial real estate, and equipment financing borrowers. 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) - (6) are considered pass ratings, and (7) - (10) are considered criticized as defined by the regulatory agencies. Risk ratings, assigned to differentiate risk within the portfolio, are reviewed on an ongoing basis and revised to reflect changes in a borrowers’ current financial position and outlook, risk profile, and the related collateral and structural position. Loan officers review updated financial information or other loan factors on at least an annual basis for all pass rated loans to assess the accuracy of the risk grade. Criticized loans undergo more frequent reviews and enhanced monitoring. A (7) "Special Mention" asset has the potential weakness that, if left uncorrected, may result in deterioration of the repayment prospects for the asset. A (8) "Substandard" asset has a well-defined weakness that jeopardizes the full repayment of the debt. An asset rated (9) "Doubtful" has all of the same weaknesses as a substandard credit with the added characteristic that the weakness makes collection or liquidation in full, given current facts, conditions, and values, improbable. Assets classified as (10) "Loss" in accordance with regulatory guidelines are considered uncollectible and charged off. For residential and consumer loans, the Company considers factors such as past due status, updated FICO scores, employment status, collateral, geography, loans discharged in bankruptcy, and the status of first lien position loans on second lien position loans as credit quality indicators. On an ongoing basis for portfolio monitoring purposes, the Company estimates the current value of property secured as collateral for home equity and residential first mortgage lending products. The estimate is based on home price indices compiled by the S&P/Case-Shiller Home Price Indices. The real estate price data is applied to the loan portfolios taking into account the age of the most recent valuation and geographic area. The Company’s models incorporate a single economic forecast scenario and macroeconomic assumptions over a reasonable and supportable forecast period. After the reasonable and supportable forecast period, the Company reverts on a straight-line basis to its historical loss rates, evaluated over the historical observation period, for the remaining life of the loans and leases. The calculation of exposure at default follows an iterative process to determine the expected remaining principal balance of a loan based on historical paydown rates for loans of similar segment within the same portfolio. The calculation of portfolio exposure in future quarters incorporates expected losses and principal paydown (PPD). PPD is the combination of contractual repayment and prepayment. A portion of the collective ACL is comprised of qualitative adjustments for risk characteristics which are not reflected or captured in the quantitative models but are likely to impact the measurement of estimated credit losses. Macroeconomic variables are used as inputs to the loss models and are selected based on the correlation of the variables to credit losses for each class of financing receivable as follows: the commercial model uses unemployment, GDP, and retail sales (for commercial unfunded); the residential model uses the Case-Shiller Home Price Index; home equity loan and line of credit models use interest rate spreads between U.S. Treasuries and corporate bonds and the home equity loan model also uses the Federal Housing Finance Agency (FHFA) home price index; personal loan and credit line models use the Case-Shiller and FHFA home price indices. There were no changes to the macroeconomic variables used in the loss models in the current year. Forecasted economic scenarios are sourced from a third party. Data from the baseline forecast scenario is used as the input to the modeled loss calculation. Changes in forecasts of macroeconomic variables will impact expectations of lifetime credit losses calculated by the loss models. However, the impact of changes in macroeconomic forecasts may be different for each portfolio and will reflect the credit quality and nature of the underlying assets at that time. To further refine the expected loss estimate qualitative factors are used reflecting consideration of: credit concentration, credit quality trends, the quality of internal loan reviews, the nature and volume of portfolio growth, staffing levels, underwriting exceptions, and economic considerations not reflected in the base loss model. Management may apply additional qualitative adjustments to reflect other relevant facts and circumstances that impact expected credit losses. These economic and qualitative inputs are used to forecast expected losses over a reasonable and supportable forecast period. The Company uses a 2-year reasonable and supportable forecast period, after which, loss rates revert to historical loss rates on a straight-line basis over a 1-year period. Historical loss rates are based on approximately 10 years of recently available data and are updated annually. In addition to the above considerations, the ACL calculation includes expectations of prepayments and recoveries. Extensions, renewals, and modifications are not included in the collective assessment; however, if there is a reasonable expectation of a TDR, the loan is removed from the collective assessment pool and is individually assessed. Individually Assessed Loans and Leases. When loans and leases no longer match the risk characteristics of the collective assessment pool, they are removed from the collectively assessed population and individually assessed for credit losses. Generally, all non-accrual loans, TDRs, potential TDRs, loans with a charge-off, and collateral dependent loans when the borrower is experiencing financial difficulty, are individually assessed. Individual assessment for collateral dependent commercial loans facing financial difficulty is based on the fair value of the collateral less estimated cost to sell, or the present value of the expected cash flows from the operation of the collateral, or a scenario weighted approach of both of these methods. If a loan is not collateral dependent, the individual assessment is based on a discounted cash flow approach. For collateral dependent commercial loans and leases, Webster's impairment process requires the Company to determine the fair value of the collateral by obtaining a third-party appraisal or asset valuation, an interim valuation analysis, blue book reference, or other internal methods. Fair value of the collateral for commercial loans is reevaluated quarterly. Whenever the Company has a third-party real estate appraisal performed by independent licensed appraisers, a licensed in-house appraisal officer or qualified individual reviews these appraisals for compliance with the Financial Institutions Reform Recovery and Enforcement Act and the Uniform Standards of Professional Appraisal Practice. Individual assessments for residential and home equity loans are based on a discounted cash flow approach or the fair value of collateral less the estimated costs to sell. Other consumer loans are individually assessed using a loss factor approach based on historical loss rates. For residential and consumer collateral dependent loans, a third-party appraisal is obtained upon loan default. Fair value of the collateral for residential and consumer collateral dependent loans is reevaluated every six months, by either obtaining a new appraisal or other internal valuation method. Fair value is also reassessed, with any excess amount charged off, for residential and home equity loans that reach 180 days past due per Federal Financial Institutions Examination Council guidelines. A fair value shortfall relative to the amortized cost balance is reflected as an impairment reserve within the ACL on loans and leases. Subsequent to an appraisal or other fair value estimate, should reliable information come to management's attention that the value has declined further, additional impairment may be recorded to reflect the particular situation, thereby increasing the ACL on loans and leases. If the credit quality subsequently improves the allowance is reversed up to a maximum of the previously recorded credit losses. Any individually assessed loan for which no specific valuation allowance is necessary is the result of either sufficient cash flow or sufficient collateral coverage relative to the amortized cost. Before the adoption of CECL on January 1, 2020, the allowance for loan and lease losses (ALLL) was determined under the ALLL incurred loss model which reflected management’s best estimate of probable losses that may be incurred within the existing loan and lease portfolio as of the related balance sheet date. The ALLL consists of three elements: (i) specific valuation allowances established for probable losses on impaired loans and leases; (ii) quantitative valuation allowances calculated using loss experience for like loans and leases with similar characteristics and trends, adjusted, as necessary, to reflect the impact of current conditions; and (iii) qualitative factors determined based on general economic conditions and other factors that may be internal or external to the Company. The reserve level reflects management’s view of trends in losses, portfolio quality, and economic, political, and regulatory conditions. While management utilized its best judgment based on the information available at the time, the ultimate adequacy of the allowance is dependent upon a variety of factors that are beyond the Company’s control, which include the performance its portfolio, economic conditions, interest rate sensitivity, and other external factors. The process for estimating probable losses under the ALLL approach is based on predictive models that measure the current risk profile of the loan and lease portfolio and combines the measurement with other quantitative and qualitative factors. To measure credit risk for the commercial, commercial real estate, and equipment financing portfolios, the Company employs a dual grade credit risk grading system for estimating the PD and the LGD. The credit risk grade system under the ALLL model is the same as described under the CECL approach. For residential and consumer loans, the Company's credit risk factors are also consistent with the factors used in the CECL approach. Back-testing was performed to compare original estimated losses and actual observed losses, resulting in ongoing refinements. The balance resulting from this process together with specific valuation allowances determines the overall reserve level. Refer to Note 5: Loans and Leases for further information. Charge-off of Uncollectible Loans Any loan may be charged-off if a loss confirming event has occurred or if there is a period of extended delinquency. Loss confirming events usually involve the receipt of specific adverse information about the borrower and may include bankruptcy when unsecured, foreclosure, or receipt of an asset valuation indicating a shortfall between the value of the collateral and the book value of the loan when that collateral asset is the sole source of repayment. The Company generally will charge-off commercial loans when it is determined that the specific loan or a portion thereof is uncollectible. This determination is based on facts and circumstances of the individual loan and normally includes considering the viability of the related business, the value of any collateral, the ability and willingness of any guarantors to perform and the overall financial condition of the borrower. The Company generally will charge-off residential real estate loans to the estimated fair value of its collateral, net of selling costs, when becoming 180 days past due. Allowance for Credit Losses on Unfunded Loan Commitments The allowance for credit losses on unfunded loan commitments provides for potential exposure inherent with funding the unused portion of legal commitments to lend that are not unconditionally cancellable by the Company. Accounting for unfunded loan commitments follows the CECL model. The calculation of the allowance includes the probability of funding to occur and a corresponding estimate of expected lifetime credit losses on amounts assumed to be funded. 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, relevant forecast information, and management's qualitative factors. The allowance for credit losses on unfunded credit commitments is included within other liabilities in the accompanying Consolidated Balance Sheets and the related credit expense is reported as a component of other non-interest expense in the accompanying Consolidated Statements of Income. Refer to Note 23: Commitments and Contingencies for further information.
Troubled Debt Restructurings	Troubled Debt Restructurings A modified loan is considered a TDR when the following two conditions are met: (i) the borrower is experiencing financial difficulty; and (ii) the modification constitutes a concession. The Company considers all aspects of the restructuring in determining whether a concession has been granted, including the borrower's ability to access funds at a market rate. In general, a concession exists when the modified terms of the loan are more attractive to the borrower than standard market terms. Modified terms are dependent upon the financial position and needs of the individual borrower. The most common types of modifications include covenant modifications and forbearance. Loans for which the borrower has been discharged under Chapter 7 bankruptcy are considered collateral dependent TDR, impaired at the date of discharge, and charged down to the fair value of collateral less cost to sell, if management considers that loss potential likely exists. The Company’s policy is to place consumer loan TDRs, except those that were performing prior to TDR status, on non-accrual status for a minimum period of six months. Commercial TDR are evaluated on a case-by-case basis for determination of whether or not to place them on non-accrual status. Loans qualify for return to accrual status once they have demonstrated performance with the restructured terms of the loan agreement for a minimum of six months. Initially, all TDRs are reported as impaired. Generally, TDRs are classified as impaired loans and reported as TDR for the remaining life of the loan. Impaired and TDR classification may be removed if the borrower demonstrates compliance with the modified terms for a minimum of six months and through a fiscal year-end and the restructuring agreement specifies a market rate of interest equal to that which would be provided to a borrower with similar credit at the time of restructuring. In the limited circumstance that a loan is removed from TDR classification, it is the Company’s policy to continue to base its measure of loan impairment on the contractual terms specified by the loan agreement. Refer to Note 5: Loans and Leases for further information.
Foreclosed and Repossessed Assets	Foreclosed and Repossessed Assets Real estate acquired through foreclosure or completion of a deed in lieu of foreclosure and other assets acquired through repossession are recorded at fair value less estimated cost to sell at the date of transfer. Subsequent to the acquisition date, the foreclosed and repossessed assets are carried at the lower of cost or fair value less estimated selling costs and are included within other assets in the accompanying Consolidated Balance Sheets. Independent appraisals generally are obtained to substantiate fair value and may be subject to adjustment based upon historical experience or specific geographic trends impacting the property. Upon transfer to other real estate owned (OREO) the excess of loan balance over fair value less cost to sell is charged off against the ACL. Subsequent write-downs in value, maintenance costs as incurred, and gains or losses upon sale are charged to non-interest expense in the accompanying Consolidated Statements of Income.
Premises and Equipment	Property and Equipment Property and equipment is carried at cost, less accumulated depreciation and amortization, which is computed on a straight-line basis over the estimated useful lives of the assets, as follows: Minimum Maximum Building and Improvements 5 - 40 years Leasehold improvements 5 - 20 years (or lease term, if shorter) Fixtures and equipment 5 - 10 years Data processing and software 3 - 7 years Repairs and maintenance costs are charged to non-interest expense as incurred. Property and equipment that is actively marketed for sale is reclassified to assets held for disposition. The cost and accumulated depreciation and amortization relating to property and equipment retired or otherwise disposed of are eliminated, and any resulting losses are charged to non-interest expense. Refer to Note 7: Premises and Equipment for further information. Leasing A ROU asset and corresponding lease liability is recognized at the lease commencement date when the Company is a lessee. ROU lease assets are included in premises and equipment in the accompanying Consolidated Balance Sheets. A ROU asset reflects the present value of the future minimum lease payments adjusted for any initial direct costs, incentives, or other payments prior to the lease commencement date. A lease liability represents a legal obligation to make lease payments and is determined by the present value of the future minimum lease payments discounted using the rate implicit in the lease, or the Company’s incremental borrowing rate. Variable lease payments that are dependent on an index, or rate, are initially measured using the index or rate at the commencement date and are included in the measurement of the lease liability. Renewal options are not included as part of the ROU asset or lease liability unless the option is deemed reasonably certain to exercise. For real estate leases, lease components and non-lease components are accounted for as a single lease component. For equipment leases, lease and non-lease components are accounted for separately. Operating lease expense is comprised of operating lease costs and variable lease costs, net of sublease income, and is reflected as part of occupancy within non-interest expense in the accompanying Consolidated Statements of Income. Operating lease expense is recorded on a straight-line basis. Refer to Note 8: Leasing for further information.
Goodwill	Goodwill Goodwill represents the excess purchase price of businesses acquired over the fair value of the identifiable net assets acquired and is assigned to specific reporting units. Goodwill is not subject to amortization but rather is evaluated for impairment annually, or more frequently if events occur or circumstances change indicating it would more likely than not result in a reduction of the fair value of the reporting units below their carrying value, including goodwill. Goodwill may be evaluated for impairment by performing a qualitative assessment to determine whether it is more likely than not that the fair value of the reporting units is less than their carrying amount, including goodwill. If the qualitative assessment indicates it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill, or if for any other reason the Company determines to be appropriate, then a quantitative assessment will be performed. The quantitative assessment process utilizes an equally weighted combined income and market approach to arrive at an indicated fair value range for the reporting units. The fair value calculated for each reporting unit is compared to its carrying amount, including goodwill, to ascertain if goodwill impairment exists. If the fair value exceeds the carrying amount, including goodwill for a reporting unit it is not considered impaired. If the fair value is below the carrying amount, including goodwill for a reporting unit then an impairment charge is recognized for the amount by which the carrying amount exceeds the calculated fair value, up to but not exceeding the amount of goodwill allocated to the reporting unit. The resulting amount is charged to non-interest expense. The Company completed a quantitative assessment for its reporting units during its most recent annual impairment review. Based on this quantitative assessment, the Company determined that there was no evidence of impairment to the balance of its goodwill. Refer to Note 9: Goodwill and Other Intangible Assets for further information.
Other Intangible Assets	Other Intangible Assets Other intangible assets represent purchased assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights, or because it is capable of being sold or exchanged either separately or in combination with a related contract, asset, or liability. Other intangible assets with finite useful lives, such as core deposits and customer relationships, are amortized to non-interest expense over their estimated useful lives and are evaluated for impairment whenever events occur or circumstances change indicating the carrying amount of the asset may not be recoverable. Refer to Note 9: Goodwill and Other Intangible Assets for further information.
Cash Surrender Value of Life Insurance	Cash Surrender Value of Life Insurance Investment in life insurance represents the cash surrender value of life insurance policies on certain current and former employees of Webster. Cash surrender value increases are recorded in non-interest income, decreases are the result of collection on the policies, with death benefit proceeds in excess of cash surrender value recorded in other non-interest income upon the death of an insured.
Securities Sold Under Agreements to Repurchase	Securities Sold Under Agreements to Repurchase These agreements are accounted for as secured financing transactions since Webster maintains effective control over the transferred investment securities and the transfer meets the other criteria for such accounting. Obligations to repurchase the sold investment securities are reflected as a liability in the accompanying Consolidated Balance Sheets. The investment securities sold, with agreement to repurchase, to wholesale dealers are transferred to a custodial account for the benefit of the dealer or bank with whom each transaction is executed. The dealers or banks may sell, loan, or otherwise hypothecate such securities to other parties in the normal course of their operations and agree to resell to Webster the same securities at the maturity date of the agreements. Webster also enters into repurchase agreements with Bank customers. The investment securities sold with agreement to repurchase to Bank customers are not transferred but internally pledged to the repurchase agreement transaction. Refer to Note 12: Borrowings for further information.
Revenue Recognition for Alternative Revenue Programs, Policy [Policy Text Block]	Revenue From Contracts With Customers Revenue from contracts with customers generally comprises non-interest income earned by the Company in exchange for services provided to customers and is recognized when services are complete or as they are rendered. These revenue streams include deposit service fees, wealth and investment services, and an insignificant component of other non-interest income in the accompanying Consolidated Statements of Income. The Company identifies the performance obligations included in the contracts with customers, determines the transaction price, allocates the transaction price to the performance obligations, as applicable, and recognizes revenue when performance obligations are satisfied. Services provided over a period of time are typically transferred to customers evenly over the term of the contracts and revenue is recognized evenly over the period services are provided. Contract receivables are included in accrued interest receivable and other assets. Payment terms vary by services offered, and the time between completion of performance obligations and payment is typically not significant. Refer to Note 22: Revenue from Contracts with Customers for further information.
Share-based Compensation	Share-Based Compensation 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. Share awards are issued from available treasury shares. Share-based compensation cost is recognized over the vesting period, is based on the grant-date fair value, net of a reduction for estimated forfeitures which is adjusted for actual forfeitures as they occur, and is reported as a component of compensation and benefits within non-interest expense. Awards are generally subject to a 3-year vesting period, while certain conditions provide for a 1-year vesting period. For restricted stock and restricted stock unit awards, fair value is measured using the Company's common stock closing price at the date of grant. For certain performance-based restricted stock awards, fair value is measured using the Monte Carlo valuation methodology, which provides for the 3-year performance period. Awards ultimately vest in a range from zero to 150% of the target number of shares under the grant. Compensation expense is subject to adjustment based on management's assessment of Webster's return on equity performance relative to the target number of shares condition. Stock option awards use the Black-Scholes Option-Pricing Model to measure fair value at the date of grant. Excess tax benefit or tax deficiency results when tax return deductions differ from recognized compensation cost determined using the grant-date fair value approach for financial statement purposes.
Income Taxes	Income Taxes Income tax expense, or benefit, is comprised of two components, current and deferred. The current component reflects taxes payable or refundable for a current period based on applicable tax laws, and the deferred component represents the tax effects of temporary differences between amounts recognized for financial accounting and tax purposes. Deferred tax assets and liabilities reflect the tax effects of such differences that are anticipated to result in taxable or deductible amounts in the future, when the temporary differences reverse. DTAs are recognized if it is more likely than not they will be realized, and may be reduced by a valuation allowance if it is more likely than not that all or some portion will not be realized. Tax positions that are uncertain but meet a more likely than not recognition threshold are initially and subsequently measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The determination of whether or not a tax position meets the more likely than not recognition threshold considers the facts, circumstances, and information available at the reporting date and is subject to management's judgment. Webster recognizes interest expense and penalties on uncertain tax positions as a component of income tax expense and recognizes interest income on refundable income taxes as a component of other non-interest income. Refer to Note 10: Income Taxes for further information.
Earnings Per Common Share	Earnings Per Common Share Earnings per common share is calculated under the two-class method. Basic earnings per common share is computed by dividing earnings applicable to common shareholders by the weighted-average number of common shares outstanding, excluding outstanding participating securities, during the pertinent period. Certain unvested restricted stock awards are participating securities as they have non-forfeitable rights to dividends. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of shares resulting from stock compensation and warrants for common stock, using the treasury stock method. A reconciliation of the weighted-average shares used in calculating basic earnings per common share and the weighted-average common shares used in calculating diluted earnings per common share is provided in Note 16: Earnings Per Common Share.
Comprehensive Income	Comprehensive Income Comprehensive income includes all changes in shareholders’ equity during a period, except those resulting from transactions with shareholders. Comprehensive income consists of net income, and the after-tax effect of the following items: changes in net unrealized gain/loss on securities available for sale, changes in net unrealized gain/loss on derivative instruments, and changes in net actuarial gain/loss for defined benefit pension and other postretirement benefit plans. Comprehensive income is reported in the consolidated statement of shareholders' equity, consolidated statement of comprehensive income, and detailed in Note 14: Accumulated Other Comprehensive Income, Net of Tax.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities Derivatives are recognized at fair value and included in accrued interest receivable and other assets and accrued expenses and other liabilities in the accompanying Consolidated Balance Sheets. The value of exchange-traded contracts is based on quoted market prices while non-exchange traded contracts are valued based on dealer quotes, pricing models, discounted cash flow methodologies, or similar techniques for which the determination of fair value may require management judgment or estimation, relating to future rates and credit activities. Cash flows from derivative financial instruments are included in net cash provided by operating activities in the accompanying Consolidated Statements of Cash Flows. Derivatives Designated in Hedge Relationships. The Company uses derivatives to hedge exposures, or to modify interest rate characteristics, for certain balance sheet accounts under its interest rate risk management strategy. The Company designates derivatives in qualifying hedge relationships as fair value or cash flow hedges for accounting purposes. Derivative financial instruments receive hedge accounting treatment if they are qualified and properly designated as a hedge and remain highly effective in offsetting changes in the fair value or cash flows attributable to the risk being hedged both at hedge inception and on an ongoing basis throughout the life of the hedge. Quarterly prospective and retrospective assessments are performed to ensure hedging relationships continue to be highly effective. If a hedge relationship were no longer highly effective, hedge accounting would be discontinued. The change in fair value on a derivative designated and qualifying as a fair value hedge, as well as the offsetting change in fair value on the hedged item attributable to the risk being hedged, is recognized in earnings in the same accounting period. The gain or loss on a derivative designated and qualifying as a cash flow hedge is initially recorded as a component of accumulated other comprehensive loss, net of tax (AOCL) and subsequently reclassified to interest income as hedged interest payments are received or to interest expense as hedged interest payments are made in the same period during which the hedged transaction affects earnings. Derivatives Not Designated in Hedge Relationships . The Company also enters into derivative transactions which are not designated in hedge relationships. Derivative financial instruments not designated in hedge relationships are recorded at fair value with changes in fair value recognized in other non-interest income in the accompanying Consolidated Statements of Income. Offsetting Assets and Liabilities . The Company presents derivative assets and derivative liabilities with the same counterparty and the related variation margin of cash collateral on a net basis in the accompanying Consolidated Balance Sheets. Cash collateral relating to initial margin is included in accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets. Securities collateral is not offset. The Company clears all dealer eligible contracts through the Chicago Mercantile Exchange (CME), and has elected to record non-cleared derivative positions subject to a legally enforceable master netting agreement on a net basis. Refer to Note 17: Derivative Financial Instruments for further information.
Fair Value Measurements	Fair Value Measurements The Company measures many of its assets and liabilities on a fair value basis, in accordance with Accounting Standards Codification (ASC) Topic 820, " Fair Value Measurement. " Fair value is used on a recurring basis for certain assets and liabilities in which fair value is the primary basis of accounting. Examples of these include derivative instruments, available-for-sale securities, and loans held for sale where the Company has elected the fair value option. Additionally, fair value is used on a non-recurring basis to evaluate assets or liabilities for impairment. Examples of these include impaired loans and leases, mortgage servicing assets, long-lived assets, goodwill, and loans not originated for sale but subsequently transferred to held for sale, which are accounted for at the lower of cost or fair value. Further information regarding the Company's policies and methodology used to measure fair value is presented in Note 18: Fair Value Measurements.
Employee Retirement Benefit Plan	Employee Retirement Benefit Plans Webster Bank maintains a defined-contribution plan offering traditional 401(k) and Roth 401(k) options that are available to employees aged 21 and above, beginning 90 days after hire. All expenses of maintaining this qualified plan, as well as matching contributions, are charged to other expense within non-interest expense. Webster Bank maintains a noncontributory defined-benefit pension plan covering all employees that were participants on or before December 31, 2007. Costs related to this qualified plan, based upon actuarial computations of current and future benefits for eligible employees, are charged to other expense within non-interest expense and are funded in accordance with the requirements of the Employee Retirement Income Security Act. The plan is recorded as an asset when over-funded or a liability when under-funded. There is a supplemental retirement plan for select executive level employees that were participants on or before December 31, 2007. There is also a postretirement healthcare benefits plan for certain retired employees. Refer to Note 19: Retirement Benefit Plans for further information about these plans. Loan Modifications Under the CARES Act and Interagency Statement The Coronavirus Aid, Relief, and Economic Security Act (CARES Act) Section 4013, and the Revised Interagency Statement on Loan Modifications and Reporting for Financial Institutions Working with Customers Affected by the Coronavirus. On March 27, 2020, the CARES Act, which provides relief from certain requirements under GAAP, was signed into law. Section 4013 of the CARES Act gives entities temporary relief from the accounting and disclosure requirements for troubled debt restructurings (TDRs) under ASC 310-40 in certain situations. In addition, on April 7, 2020, the federal banking agencies issued an interagency statement that offers practical expedients for evaluating whether loan modifications in response to the COVID-19 pandemic are TDRs. The interagency statement was originally issued on March 22, 2020, but was revised to address the relationship between their original TDR guidance and the guidance in Section 4013 of the CARES Act. On December 27, 2020, the Consolidated Appropriations Act, 2021 extended the relief offered by the CARES Act related to TDRs. To qualify for TDR accounting and disclosure relief under the CARES Act, the applicable loan must not have been more than 30 days past due as of December 31, 2019, and the modification must be executed between March 1, 2020, and December 31, 2020, subsequently extended through January 1, 2022, or the date that is 60 days after the termination date of the national emergency declared by the President on March 13, 2020, under the National Emergencies Act related to the outbreak of COVID-19. The CARES Act applies to modifications made as a result of COVID-19 including: forbearance agreements, interest rate modifications, repayment plans, and other arrangements to defer or delay payment of principal or interest. The interagency statement does not require the modification to be completed within a certain time period if it is related to COVID-19 and the loan was not more than 30 days past due as of the date of the Company’s implementation of its modification programs. Moreover, the interagency statement applies to short-term modifications including payment deferrals, fee waivers, extensions of repayment terms, or other insignificant payment delays as a result of COVID-19. The Company continues to apply section 4013 of the CARES Act and the interagency statement in connection with applicable modifications. For modifications that qualify under either the CARES Act or the interagency statement, TDR accounting and reporting is suspended through the period of the modification; however, the Company will continue to apply its existing non-accrual policies including consideration of the loan's past due status which is determined on the basis of the contractual terms of the loan. Once a loan has been contractually modified, the past due status is generally based on the updated terms including payment deferrals.
Recently Adopted and Issued Accounting Standards Updates	Recently Adopted Accounting Standards Updates Effective January 1, 2020, the following new accounting guidance was adopted by the Company: ASU No. 2020-04, Reference Rate Reform (Topic 848) - Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The Accounting Standards Update (the Update) provides optional expedients and exceptions available to contracts, hedging relationships, and other transactions affected by reference rate reform. In addition to expedients for contract modifications, the Update allows for a one-time transfer or sale of held-to-maturity securities that reference an eligible rate. The Company will consider this one-time securities transfer along with other expedients available under the Update as the Company proceeds with reference rate reform activities. The Update became effective during the first quarter 2020, and applies to contract modifications and amendments made as of the beginning of the reporting period including the Update issuance date, March 12, 2020, and applies through December 31, 2022. The adoption of this guidance did not have a material effect on the Company's consolidated financial statements. ASU No. 2019-04, Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments. The Update amends guidance on credit losses, hedge accounting, and recognition and measurement of financial instruments. The changes provide clarifications and codification improvements in relation to recently issued accounting updates. The amendments to the guidance on credit losses are considered in the paragraphs below related to our adoption of ASU 2016-13, and has been adopted concurrently with those Updates. The Company adopted the Update during the first quarter 2020 on a prospective basis. The adoption of this guidance did not have a material effect on the Company's consolidated financial statements. ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40) - Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. The Update aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The updated guidance also requires an entity to amortize the capitalized implementation costs as an expense over the term of the hosting arrangement presented in the same income statement line item as the fees associated with the hosting arrangement. The Company adopted the Update during the first quarter 2020 on a prospective basis to implementation costs incurred after the date of adoption. The adoption of this guidance did not have a material effect on the Company's consolidated financial statements. ASU No. 2018-13, Fair Value Measurement (Topic 820) - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement. The Update modifies the disclosure requirements for fair value measurements. The updated guidance no longer requires entities to disclose the amount and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy. However, it requires public companies to disclose changes in unrealized gains and losses for the period included in other comprehensive income (OCI) for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop Level 3 measurements. The Company adopted the Update during the first quarter 2020 on a prospective basis. The adoption of this guidance did not have a material effect on the Company's consolidated financial statements. ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment. The Update simplifies quantitative goodwill impairment testing by requiring entities to compare the fair value of a reporting unit with its carrying amount and recognize an impairment charge for any amount by which the carrying amount exceeds the fair value of a reporting unit, up to but not exceeding the amount of goodwill allocated to the reporting unit. The Update changes current guidance by eliminating the second step of the goodwill impairment analysis which involves calculating the implied fair value of goodwill determined in the same manner as the amount of goodwill recognized in a business combination upon acquisition. Entities still have the option to first perform a qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. The Company adopted the Update during the first quarter 2020 on a prospective basis. The adoption of this guidance did not have a material effect on the Company's consolidated financial statements. ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) - Measurement of Credit Losses on Financial Instruments and subsequent ASUs issued to clarify this Topic. The Updates replace the existing incurred loss approach for recognizing credit losses with a new credit loss methodology known as the current expected credit loss (CECL) model. The CECL methodology requires earlier recognition of credit losses using a lifetime credit loss measurement approach for financial assets carried at amortized cost. The Updates also revised the accounting for credit losses on available-for-sale debt securities, by eliminating the other-than-temporary impairment model and requiring credit losses be presented as an allowance rather than a direct write-down, although determined outside the scope of the CECL methodology. The CECL accounting model applies to assets measured at amortized cost including loans, held-to-maturity debt securities, net investments in leases, and off-balance sheet credit exposures. CECL requires recognition of credit losses at purchase or origination using a lifetime credit loss measurement approach. The allowance for credit losses is based on the composition, characteristics, and credit quality of the loan and securities portfolios as of the reporting date and includes consideration of current economic conditions and reasonable and supportable forecasts at that date. The CECL methodology also requires consideration of a broader range of reasonable and supportable information to determine the allowance for credit losses including economic forecasts. The "Investment in Debt Securities," "Allowance for Credit Losses on Loans and Leases," and "Allowance for Credit Losses on Unfunded Loan Commitments" sections of this note provide detailed information relating to accounting policy reflective of adoption of the Updates. Impact of Adoption . The Company adopted the Updates during the first quarter 2020, using the modified retrospective method. Upon adoption, the Company recorded an increase in its allowance for credit losses as a cumulative effect adjustment. This adjustment, net of tax, reduced the Company's beginning total shareholders' equity at January 1, 2020. Upon adoption, the Company's allowance for credit losses reflected all credit losses expected over the lifetime of the Company's financial assets held at amortized cost. Periods prior to January 1, 2020, are reported in accordance with previously applicable GAAP. The impact of the January 1, 2020, adoption entry is summarized in the table below: December 31, 2019 January 1, 2020 (In thousands) Pre-ASC 326 Adoption Impact of Adoption Reported Under ASC 326 Assets: Allowance for credit losses on investment securities held-to-maturity $ — $ (397) $ (397) Allowance for credit losses on loans and leases (1) (209,096) (57,568) (266,664) Deferred tax assets, net 61,975 15,891 77,866 Liabilities and shareholders' equity: Accrued expenses and other liabilities 153,161 9,139 162,300 Retained earnings 2,061,352 (51,213) 2,010,139 (1) The total allowance for credit losses on loans and leases as of January 1, 2020 consists of $252.5 million assessed on a collective basis and $14.2 million assessed on an individual basis. The Company has elected to defer the CECL impact on regulatory capital for two years, followed by a three-year transition period. For additional information on accounting for credit losses refer to Note 4: Investment Securities, Note 5: Loans and Leases, and Note 23: Commitments and Contingencies. ASU No. 2018-14, Compensation-Retirement Benefits - Defined Benefit Plan - General (Subtopic 715-20) - Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans. The Update modifies disclosure requirements for employers that sponsor defined benefit pension and other postretirement plans, including eliminating certain disclosure requirements determined to be not useful to users of the financial statements. The Company adopted the Update for December 31, 2020 disclosures. The adoption did not have a material effect on the Company's consolidated financial statements. Accounting Standards Issued but not yet Adopted The following new accounting guidance, applicable to the Company, has been issued by the FASB but is pending adoption: ASU No. 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes. The Update provides simplifications 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 Update will be effective for the Company on January 1, 2021. The Company does not expect this Update to have a material impact on its consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Property, Plant and Equipment	A summary of premises and equipment follows: At December 31, (In thousands) 2020 2019 Land $ 9,436 $ 10,997 Buildings and improvements 70,195 77,892 Leasehold improvements 71,332 77,346 Fixtures and equipment 73,730 73,946 Data processing and software 270,780 263,445 Property and equipment 495,473 503,626 Less: Accumulated depreciation and amortization (396,211) (388,562) Property and equipment, net 99,262 115,064 Leased assets, net 127,481 155,349 Premises and equipment, net $ 226,743 $ 270,413

Business Developments (Tables)

Business Developments (Tables)	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Reserve by Type of Cost	The following table presents the changes in accrued expenses associated with strategic initiatives for the year ended December 31, 2020: (In thousands) Severance ROU Asset Other Total Beginning balance $ — $ — $ — $ — Charged to earnings 17,860 13,000 11,797 42,657 Charges against assets — (13,000) (1,009) (14,009) Cash payments (185) — (8,668) (8,853) Ending balance $ 17,675 $ — $ 2,120 $ 19,795

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Summary of Investment Securities	Held-to-Maturity Securities A summary of the amortized cost, fair value, and allowance for credit losses on investment securities held-to-maturity is presented below: At December 31, 2020 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value Allowance (2) 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 At December 31, 2019 (In thousands) Amortized Cost (1) Unrealized Unrealized Fair Value Allowance (2) Net Carrying Value Agency CMO $ 167,443 $ 1,123 $ (1,200) $ 167,366 $ — $ 167,443 Agency MBS 2,957,900 60,602 (8,733) 3,009,769 — 2,957,900 Agency CMBS 1,172,491 6,444 (5,615) 1,173,320 — 1,172,491 Municipal bonds and notes 740,431 32,709 (21) 773,119 — 740,431 CMBS 255,653 2,278 (852) 257,079 — 255,653 Held-to-maturity securities $ 5,293,918 $ 103,156 $ (16,421) $ 5,380,653 $ — $ 5,293,918
Other than Temporary Impairment, Credit Losses Recognized in Earnings	At December 31, 2020 (In thousands) Amortized Fair Due in one year or less $ 680 $ 685 Due after one year through five years 4,458 4,711 Due after five through ten years 278,974 294,528 Due after ten years 5,284,076 5,535,440 Total held-to-maturity debt securities $ 5,568,188 $ 5,835,364 For the maturity schedule above, investment securities which are not due at a single maturity date have been categorized based on the maturity date of the underlying collateral. Actual principal cash flows may differ from this maturity date presentation as borrowers have the right to repay obligations with or without prepayment penalties.
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value	Fair Value and Unrealized Losses The following tables provide information on fair value and unrealized losses for the individual available-for-sale securities with an unrealized loss, for which an allowance for credit losses 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 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) At December 31, 2019 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Unrealized Fair Unrealized # of Fair Unrealized Agency CMO $ 36,447 $ (352) $ 32,288 $ (565) 9 $ 68,735 $ (917) Agency MBS 41,408 (193) 299,674 (3,842) 79 341,082 (4,035) Agency CMBS 174,406 (1,137) 357,717 (5,798) 34 532,123 (6,935) CMBS 355,260 (232) 7,480 (20) 29 362,740 (252) CLO — — 43,232 (468) 2 43,232 (468) Corporate debt — — 22,240 (1,245) 4 22,240 (1,245) Available-for-sale in unrealized loss position $ 607,521 $ (1,914) $ 762,631 $ (11,938) 157 $ 1,370,152 $ (13,852)
Summary of Debt Securities by Contractual Maturity	Contractual Maturities The amortized cost and fair value of available-for-sale debt securities by contractual maturity are set forth below: At December 31, 2020 (In thousands) Amortized Fair Due in one year or less $ — $ — Due after one year through five years 1,448 1,489 Due after five through ten years 252,601 248,958 Due after ten years 2,980,201 3,076,329 Total available-for-sale debt securities $ 3,234,250 $ 3,326,776 For the maturity schedule above, investment securities which are not due at a single maturity date, have been categorized based on the maturity date of the underlying collateral. Actual principal cash flows may differ from this maturity date presentation as borrowers have the right to prepay obligations with or without prepayment penalties.

Loans and Leases (Tables)

Loans and Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Loans and Leases Receivable Disclosure [Abstract]
Past Due Financing Receivables	Loans and Leases Aging The following tables summarize the aging of loans and leases: 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 At December 31, 2019 (In thousands) 30-59 Days 60-89 Days 90 or More Days Past Due Non-accrual Total Past Due and Current Total Loans Commercial non-mortgage $ 2,094 $ 617 $ — $ 59,369 $ 62,080 $ 5,234,531 $ 5,296,611 Asset-based — — — 139 139 1,046,747 1,046,886 Commercial real estate 1,256 454 — 11,563 13,273 5,936,066 5,949,339 Equipment financing 5,493 292 — 5,433 11,218 526,123 537,341 Commercial portfolio 8,843 1,363 — 76,504 86,710 12,743,467 12,830,177 Residential 7,166 6,441 — 43,193 56,800 4,915,885 4,972,685 Home equity 8,267 5,551 — 30,170 43,988 1,970,556 2,014,544 Other consumer 4,269 807 — 1,192 6,268 213,312 219,580 Consumer portfolio 19,702 12,799 — 74,555 107,056 7,099,753 7,206,809 Total $ 28,545 $ 14,162 $ — $ 151,059 $ 193,766 $ 19,843,220 $ 20,036,986
Activity In Allowance For Losses	Allowance for Credit Losses on Loans and Leases The following tables summarize the activity in, as well as the loan and lease balances that were evaluated for, ACL on loans and leases: At or for the Years ended December 31, 2020 2019 2018 (In thousands) Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total Commercial Portfolio Consumer Portfolio Total ACL on loans and leases: Beginning balance $ 161,669 $ 47,427 $ 209,096 $ 164,073 $ 48,280 $ 212,353 $ 144,746 $ 55,248 $ 199,994 Adoption of ASU No. 2016-13 (CECL) 34,024 23,544 57,568 — — — — — — Provision charged to expense 156,336 (18,488) 137,848 29,174 8,626 37,800 35,356 6,644 42,000 Charge-offs (42,925) (12,408) (55,333) (33,327) (19,153) (52,480) (20,704) (22,683) (43,387) Recoveries 3,140 7,112 10,252 1,749 9,674 11,423 4,675 9,071 13,746 Ending balance $ 312,244 $ 47,187 $ 359,431 $ 161,669 $ 47,427 $ 209,096 $ 164,073 $ 48,280 $ 212,353 Individually evaluated for impairment 11,687 4,450 16,137 9,428 4,821 14,249 9,681 5,669 15,350 Collectively evaluated for impairment $ 300,557 $ 42,737 $ 343,294 $ 152,241 $ 42,606 $ 194,847 $ 154,392 $ 42,611 $ 197,003 Loan and lease balances: Individually evaluated for impairment $ 163,655 $ 145,767 $ 309,422 $ 131,123 $ 125,287 $ 256,410 $ 116,655 $ 142,675 $ 259,330 Collectively evaluated for impairment 14,736,880 6,594,913 21,331,793 12,699,054 7,081,522 19,780,576 11,535,493 6,670,666 18,206,159 Loans and leases $ 14,900,535 $ 6,740,680 $ 21,641,215 $ 12,830,177 $ 7,206,809 $ 20,036,986 $ 11,652,148 $ 6,813,341 $ 18,465,489 The increase in ACL at December 31, 2020 as compared to December 31, 2019, is primarily attributable to the initial adoption of the CECL lifetime loss accounting model and the impact of current and forecasted macroeconomic conditions on credit models, which were negatively affected by the emergence of the COVID-19 pandemic in 2020. 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. This credit risk grading system has not changed with the adoption of CECL. 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 (7) to (10) are considered criticized, as defined by the regulatory agencies. Risk ratings, assigned to differentiate risk within the portfolio, are reviewed on an ongoing basis and revised to reflect changes in a 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 a potential weakness that, if left uncorrected, may result in deterioration of the repayment prospects for the credit. A (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, given current facts, conditions, and values, improbable. Credits when classified as (10)-"Loss," in accordance with regulatory guidelines, are considered uncollectible and charged off. 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 table summarizes 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 as of 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 The following table summarizes residential and consumer loans segregated by origination year and risk rating exposure under FICO score groupings as of 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 The following table presents the required credit quality disclosures prior to the adoption of CECL: At December 31, 2019 (In thousands) Commercial Commercial Real Estate Equipment Financing (1) - (6) Pass $ 5,985,338 $ 5,860,981 $ 528,561 (7) Special Mention 94,809 26,978 808 (8) Substandard 259,490 61,380 7,972 (9) Doubtful 3,860 — — Total $ 6,343,497 $ 5,949,339 $ 537,341
Impaired Loans	Individually Assessed Loans and Leases The following tables summarize individually assessed loans and leases: 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 At December 31, 2019 (In thousands) Unpaid Amortized Cost Amortized Cost Amortized Cost Related Commercial non-mortgage $ 140,096 $ 102,254 $ 29,739 $ 72,515 $ 7,862 Asset based 465 139 — 139 5 Commercial real estate 29,292 23,297 14,818 8,479 1,143 Equipment financing 5,591 5,433 2,159 3,274 418 Residential 98,790 90,096 56,231 33,865 3,618 Home equity 38,503 35,191 27,672 7,519 1,203 Other consumer — — — — — Total $ 312,737 $ 256,410 $ 130,619 $ 125,791 $ 14,249 (1) Partially charged-off other consumer loans were included in collectively evaluated for impairment at December 31, 2019. The following table summarizes average amortized cost and interest income recognized for individually assessed loans and leases: Years ended December 31, 2020 2019 2018 (In thousands) Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Average Accrued Cash Basis Interest Income Commercial non-mortgage $ 111,069 $ 3,836 $ — $ 100,771 $ 3,241 $ — $ 85,585 $ 3,064 $ — Asset based 1,367 — — 182 — — 407 — — Commercial real estate 28,588 699 — 17,062 385 — 11,027 198 — Equipment financing 6,366 — — 5,874 — — 4,820 112 — Residential 94,130 3,484 1,442 96,814 3,502 1,078 108,913 3,781 1,106 Home equity 41,070 1,315 1,826 37,167 1,045 981 42,290 1,158 980 Other consumer 327 32 — — — — — — — Total $ 282,917 $ 9,366 $ 3,268 $ 257,870 $ 8,173 $ 2,059 $ 253,042 $ 8,313 $ 2,086
Financing Receivable Credit Quality Indicators
Troubled Debt Restructurings on Financing Receivables	Troubled Debt Restructurings The following table summarizes information for TDRs: At December 31, (Dollars in thousands) 2020 2019 Accrual status $ 140,089 $ 136,449 Non-accrual status 95,338 100,989 Total TDRs $ 235,427 $ 237,438 Specific reserves for TDRs included in the balance of ACL on loans and leases $ 12,728 $ 12,956 Additional funds committed to borrowers in TDR status 12,895 4,856 The portion of TDRs deemed to be uncollectible, $18.4 million, $21.8 million, and $14.3 million, for the years ended December 31, 2020, 2019 and 2018, respectively, were charged-off. The following table provides information on the type of concession for loans and leases modified as TDRs: Years ended December 31, 2020 2019 2018 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 12 $ 1,142 18 $ 10,769 18 $ 1,656 Adjusted Interest Rate 1 96 2 112 — — Maturity/Rate Combined 9 984 11 673 18 10,327 Other (2) 27 40,434 31 70,002 21 46,359 Consumer portfolio Extended Maturity 6 673 13 1,926 5 489 Maturity/Rate Combined 15 1,467 19 2,381 15 1,565 Other (2) 122 10,895 42 2,908 66 6,385 Total TDRs 192 $ 55,691 136 $ 88,771 143 $ 66,781 (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. With respect to loans and leases modified as TDRs within the previous 12 months and for which there was a payment default, there were 4 loans and leases in the commercial portfolio with an amortized cost of $12.4 million for the year ended December 31, 2020. There were 7 loans and leases in the commercial portfolio with an amortized cost of $2.6 million for the year ended December 31, 2019. There were no significant amounts for the year ended December 31, 2018. TDRs in commercial non-mortgage, commercial real estate, and equipment financing segregated by risk rating exposure is as follows: At December 31, (In thousands) 2020 2019 Pass $ 12,462 $ 3,952 Special Mention — 63 Substandard 105,070 104,277 Doubtful 163 3,860 Total $ 117,695 $ 112,152

Transfers of Financial Assets (

Transfers of Financial Assets (Tables)	12 Months Ended
	Dec. 31, 2020
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: Years ended December 31, (In thousands) 2020 2019 2018 Beginning balance $ 508 $ 674 $ 872 Provision (benefit) charged to expense 141 1,865 (160) Recoveries, net (settlements charged-off/repurchased loans, net) 98 (2,031) (38) Ending balance $ 747 $ 508 $ 674
Schedule of Loan Sale Activity [Table Text Block]	The following table provides information for mortgage banking activities: Years ended December 31, (In thousands) 2020 2019 2018 Proceeds from sale $ 486,341 $ 216,239 $ 188,025 Loans sold with servicing rights retained 464,736 199,114 166,909 Net gain on sale $ 15,305 $ 4,031 $ 3,146 Ancillary fees 3,230 1,614 1,544 Fair value option adjustment (240) 470 (266)
Servicing Asset at Amortized Cost	The Company has retained servicing rights on residential mortgage loans totaling $2.3 billion and $2.4 billion at December 31, 2020 and 2019, respectively. The following table presents the changes in carrying value for mortgage servicing assets: Years ended December 31, (In thousands) 2020 2019 2018 Beginning balance $ 17,484 $ 21,215 $ 25,139 Additions 4,373 3,587 4,459 Amortization (6,562) (7,318) (8,383) Valuation allowance (1,873) — — Ending balance $ 13,422 $ 17,484 $ 21,215 Loan servicing fees, net of mortgage servicing rights amortization, were $1.5 million, $1.9 million, and $1.2 million, for the years ended December 31, 2020, 2019, and 2018, respectively, and are included as a component of loan and lease related fees in the accompanying Consolidated Statements of Income.

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	A summary of premises and equipment follows: At December 31, (In thousands) 2020 2019 Land $ 9,436 $ 10,997 Buildings and improvements 70,195 77,892 Leasehold improvements 71,332 77,346 Fixtures and equipment 73,730 73,946 Data processing and software 270,780 263,445 Property and equipment 495,473 503,626 Less: Accumulated depreciation and amortization (396,211) (388,562) Property and equipment, net 99,262 115,064 Leased assets, net 127,481 155,349 Premises and equipment, net $ 226,743 $ 270,413
Disclosure of Long Lived Assets Held-for-sale	The following table provides a summary of activity for assets held for disposition: Years ended December 31, (In thousands) 2020 2019 Beginning balance $ — $ 91 Additions 2,654 — Write-downs — (91) Sales — — Ending balance $ 2,654 $ —

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Operating lease costs	The following table summarizes lessee information related to the Company’s operating ROU assets and lease liability: At December 31, 2020 (In thousands) Operating Leases Consolidated Balance Sheet Line Item Location ROU lease assets $ 127,481 Premises and equipment, net Lease liabilities 158,280 Operating lease liabilities
Lease, Cost	The components of operating lease cost and other related information are as follows: (In thousands) At or for the Years ended December 31, 2020 2019 Lease Cost: Operating lease costs $ 30,339 $ 29,908 Variable lease costs 5,577 4,889 Sublease income (557) (577) Total operating lease cost $ 35,359 $ 34,220 Other Information: Cash paid for amounts included in the measurement of lease liabilities $ 31,212 $ 31,223 ROU lease assets obtained in exchange for new operating lease liabilities 9,211 22,948
Lessee, Operating Lease, Liability, Maturity	The undiscounted scheduled maturities reconciled to total operating lease liabilities are as follows: (In thousands) At December 31, 2020 2021 $ 28,142 2022 27,069 2023 24,335 2024 21,321 2025 19,332 Thereafter 62,253 Total operating lease liability payments 182,452 Less: Present value adjustment 24,172 Lease liabilities $ 158,280 Weighted-average remaining lease term - operating leases, in years 8.04 Weighted-average discount rate - operating leases 3.19 %

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	oodwill at December 31, 2020 was $538.4 million, comprised of $516.6 million in Community Banking and $21.8 million in HSA Bank. There was no change to these carrying amounts during 2020 or 2019. Other intangible assets by reportable segment consisted of the following: At December 31, 2020 2019 (In thousands) Gross Carrying Accumulated Net Carrying Gross Carrying Accumulated Net Carrying Other intangible assets: HSA Bank - Core deposits $ 26,625 $ 15,618 $ 11,007 $ 22,000 $ 13,073 $ 8,927 HSA Bank - Customer relationships 21,000 9,624 11,376 21,000 8,010 12,990 Total other intangible assets $ 47,625 $ 25,242 $ 22,383 $ 43,000 $ 21,083 $ 21,917
Schedule Of Expected Amortization Expense, Next Four Years	At December 31, 2020, the remaining estimated aggregate future amortization expense for other intangible assets is as follows: (In thousands) 2021 $ 4,513 2022 4,411 2023 4,315 2024 2,084 2025 2,084 Thereafter 4,976

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Income tax expense reflects the following expense (benefit) components: Years ended December 31, (In thousands) 2020 2019 2018 Current: Federal $ 73,172 $ 84,447 $ 58,334 State and local 17,417 18,595 13,409 Total current 90,589 103,042 71,743 Deferred: Federal (23,799) 811 8,508 State and local (7,437) 116 964 Total deferred (31,236) 927 9,472 Total federal 49,373 85,258 66,842 Total state and local 9,980 18,711 14,373 Income tax expense $ 59,353 $ 103,969 $ 81,215
Schedule of Effective Income Tax Rate Reconciliation	he following table reflects a reconciliation of reported income tax expense to the amount that would result from applying the federal statutory rate of 21.0%: Years ended December 31, 2020 2019 2018 (Dollars in thousands) Amount Percent Amount Percent Amount Percent Income tax expense at federal statutory rate $ 58,795 21.0 % $ 102,205 21.0 % $ 92,743 21.0 % Reconciliation to reported income tax expense: SALT expense, net of federal 7,884 2.8 14,782 3.0 11,354 2.6 Tax-exempt interest income, net (7,181) (2.6) (6,752) (1.4) (6,475) (1.5) Increase in cash surrender value of life insurance (3,058) (1.1) (3,069) (0.6) (3,069) (0.7) Tax deficiencies (excess tax benefits), net 484 0.2 (2,251) (0.4) (4,483) (1.0) Non-deductible FDIC Deposit insurance premiums 2,172 0.8 1,904 0.4 2,215 0.5 Tax Act impacts, net (1) — — — — (10,982) (2.5) Other, net 257 0.1 (2,850) (0.6) (88) — Income tax expense and effective tax rate $ 59,353 21.2 % $ 103,969 21.4 % $ 81,215 18.4 %
Schedule of Deferred Tax Assets and Liabilities	The following table reflects the significant components of the DTAs, net: At December 31, (In thousands) 2020 2019 Deferred tax assets: Allowance for loan and lease losses $ 93,791 $ 53,851 Net operating loss and credit carry forwards 66,840 69,827 Compensation and employee benefit plans 27,643 24,518 Lease liabilities under operating leases 41,679 45,923 Deferred loan fees, net 2,397 — Net unrealized loss on derivatives — 1,650 Other 6,353 7,871 Gross deferred tax assets 238,703 203,640 Valuation allowance 37,374 38,181 Total deferred tax assets, net of valuation allowance $ 201,329 $ 165,459 Deferred tax liabilities: Net unrealized gain on securities available for sale $ 24,364 $ 6,430 Net unrealized gain on derivatives 7,616 — ROU assets under operating leases 33,569 40,908 Equipment financing leases 38,511 31,332 Premises and equipment 6,735 7,838 Loan origination costs, net — 6,816 Goodwill and other intangible assets 5,954 6,172 Other 3,294 3,988 Gross deferred tax liabilities 120,043 103,484 Deferred tax assets, net $ 81,286 $ 61,975
Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible	The following table reflects a reconciliation of the beginning and ending balances of unrecognized tax benefits (UTBs): Years ended December 31, (In thousands) 2020 2019 2018 Beginning balance $ 4,813 $ 2,856 $ 3,595 Additions as a result of tax positions taken during the current year 87 1,106 249 Additions as a result of tax positions taken during prior years 572 1,744 71 Reductions as a result of tax positions taken during prior years (694) (238) (474) Reductions relating to settlements with taxing authorities (130) (18) (97) Reductions as a result of lapse of statute of limitation periods (396) (637) (488) Ending balance $ 4,252 $ 4,813 $ 2,856

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2020
Deposit Liabilities [Abstract]
Deposit Liabilities, Type [Table Text Block]	A summary of deposits by type follows: At December 31, (In thousands) 2020 2019 Non-interest-bearing: Demand $ 6,155,592 $ 4,446,463 Interest-bearing: Health savings accounts 7,120,017 6,416,135 Checking 3,652,763 2,689,734 Money market 2,940,215 2,312,840 Savings 4,979,031 4,354,809 Time deposits 2,487,818 3,104,765 Total interest-bearing 21,179,844 18,878,283 Total deposits $ 27,335,436 $ 23,324,746 Time deposits and interest-bearing checking, included in above balances, obtained through brokers $ 720,440 $ 652,151 Time deposits, included in above balance, that exceed the FDIC limit 504,543 661,334 Demand deposit overdrafts reclassified as loan balances 2,007 1,721
Time Deposit Maturities [Table Text Block]	The scheduled maturities of time deposits are as follows: (In thousands) At December 31, 2020 2021 $ 2,173,670 2022 186,612 2023 54,287 2024 22,302 2025 50,947 Time deposits $ 2,487,818

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Repurchase Agreements	The following table summarizes securities sold under agreements to repurchase and other borrowings: At December 31, (In thousands) 2020 2019 Total Outstanding Rate Total Outstanding Rate Securities sold under agreements to repurchase (1) : Original maturity of one year or less $ 269,330 0.13 % $ 240,431 0.19 % Original maturity of greater than one year, non-callable 200,000 0.84 200,000 1.78 Total securities sold under agreements to repurchase 469,330 0.43 440,431 0.91 Fed funds purchased 526,025 0.08 600,000 1.59 Securities sold under agreements to repurchase and other borrowings $ 995,355 0.25 $ 1,040,431 1.30 (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 U.S. Government agency mortgage-backed securities. Repurchase agreement counterparties are limited to primary dealers in government securities and commercial/municipal customers through the Corporate Treasury function.
Federal Home Loan Bank, Advances	The following table provides information for FHLB advances: At December 31, 2020 2019 (Dollars in thousands) Total Weighted-Average Contractual Coupon Rate Total Weighted-Average Contractual Coupon Rate Maturing within 1 year $ 25,000 0.38 % $ 1,690,000 1.79 % After 1 but within 2 years 110 — 200,000 2.53 After 2 but within 3 years 215 2.95 130 — After 3 but within 4 years 50,000 1.59 229 2.95 After 4 but within 5 years 50,000 1.42 50,000 1.59 After 5 years 7,839 2.66 8,117 2.66 FHLB advances $ 133,164 1.36 $ 1,948,476 1.87 Aggregate carrying value of assets pledged as collateral $ 7,387,054 $ 7,318,748 Remaining borrowing capacity 4,689,642 2,937,644 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.
Schedule of Long-Term Debt	The following table summarizes long-term debt: At December 31, (Dollars in thousands) 2020 2019 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) 344,164 317,486 Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (2) 77,320 77,320 Total notes and subordinated debt 571,484 544,806 Discount on senior fixed-rate notes (1,193) (1,412) Debt issuance cost on senior fixed-rate notes (2,628) (3,030) Long-term debt $ 567,663 $ 540,364 (1) The Company has de-designated its fair value hedging relationship on these notes. The $44.2 million basis adjustment included in the carrying value at December 31, 2020 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 3.18% at December 31, 2020 and 4.85% at December 31, 2019.

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Stock by Class	Share activity during the year ended December 31, 2020 is as follows: Preferred Stock Series F Common Stock Issued Treasury Stock Held Common Stock Outstanding Balance at January 1, 2020 6,000 93,686,311 1,659,749 92,026,562 Restricted share activity — — (266,325) 266,325 Stock options exercised — — (10,230) 10,230 Common stock repurchased — — 2,104,195 (2,104,195) Balance at December 31, 2020 6,000 93,686,311 3,487,389 90,198,922

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss, Net of Tax (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Schedule of Other Comprehensive Income (Loss)	The following table summarizes the changes in accumulated other comprehensive income (loss), net of tax (AOCI/AOCL), by component: (In thousands) Securities Available For Sale Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Balance at December 31, 2017 $ (27,947) $ (15,016) $ (48,568) $ (91,531) Other comprehensive (loss) income before reclassifications (43,427) 208 (7,122) (50,341) Amounts reclassified from accumulated other comprehensive loss — 5,495 5,725 11,220 Net current-period other comprehensive (loss) income, net of tax (43,427) 5,703 (1,397) (39,121) Balance at December 31, 2018 (71,374) (9,313) (49,965) (130,652) Other comprehensive income (loss) before reclassifications 88,647 (4,945) 1,622 85,324 Amounts reclassified from accumulated other comprehensive loss (22) 5,074 4,204 9,256 Net current-period other comprehensive income (loss), net of tax 88,625 129 5,826 94,580 Balance at December 31, 2019 17,251 (9,184) (44,139) (36,072) Other comprehensive income (loss) before reclassifications 50,179 20,667 (3,887) 66,959 Amounts reclassified from accumulated other comprehensive loss (6) 8,435 2,940 11,369 Net current-period other comprehensive income (loss), net of tax 50,173 29,102 (947) 78,328 Balance at December 31, 2020 $ 67,424 $ 19,918 $ (45,086) $ 42,256
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table provides information for the items reclassified from AOCI/AOCL: Years ended December 31, Accumulated Other Comprehensive Income (Loss) Components 2020 2019 2018 Associated Line Item in the Consolidated Statement Of Income (In thousands) Securities available-for-sale: Unrealized gains on investments $ 8 $ 29 $ — Gain on sale of investment securities, net Tax expense (2) (7) — Income tax expense Net of tax $ 6 $ 22 $ — Derivative instruments: Hedge terminations $ (7,884) $ (5,509) $ (7,425) Interest expense Premium amortization (3,536) (1,323) — Interest income Tax benefit 2,985 1,758 1,930 Income tax expense Net of tax $ (8,435) $ (5,074) $ (5,495) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (3,976) $ (5,706) $ (7,708) Other non-interest expense Tax benefit 1,036 1,502 1,983 Income tax expense Net of tax $ (2,940) $ (4,204) $ (5,725) The following tables summarize the items and related tax effects for each component of OCI/OCL, net of tax: Year ended December 31, 2020 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Securities available-for-sale: Net unrealized gain during the period $ 68,116 $ (17,937) $ 50,179 Reclassification for net gain included in net income (8) 2 (6) Total securities available-for-sale 68,108 (17,935) 50,173 Derivative instruments: Net unrealized gain during the period 27,683 (7,016) 20,667 Reclassification adjustment for net loss included in net income 11,420 (2,985) 8,435 Total derivative instruments 39,103 (10,001) 29,102 Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (5,262) 1,375 (3,887) Reclassification adjustment for amortization of net loss included in net income 3,976 (1,036) 2,940 Total defined benefit pension and postretirement benefit plans (1,286) 339 (947) Other comprehensive income, net of tax $ 105,925 $ (27,597) $ 78,328 Year ended December 31, 2019 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Securities available-for-sale: Net unrealized gain during the period $ 120,333 $ (31,686) $ 88,647 Reclassification for net gain included in net income (29) 7 (22) Total securities available-for-sale 120,304 (31,679) 88,625 Derivative instruments: Net unrealized loss during the period (6,672) 1,727 (4,945) Reclassification adjustment for net loss included in net income 6,832 (1,758) 5,074 Total derivative instruments 160 (31) 129 Defined benefit pension and other postretirement benefit plans: Current year actuarial gain 2,202 (580) 1,622 Reclassification adjustment for amortization of net loss included in net income 5,706 (1,502) 4,204 Total defined benefit pension and postretirement benefit plans 7,908 (2,082) 5,826 Other comprehensive income, net of tax $ 128,372 $ (33,792) $ 94,580 Year ended December 31, 2018 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Securities available-for-sale: Net unrealized loss during the period $ (58,792) $ 15,365 $ (43,427) Reclassification for net gain included in net income — — — Total securities available-for-sale (58,792) 15,365 (43,427) Derivative instruments: Net unrealized gain during the period 280 (72) 208 Reclassification adjustment for net loss included in net income 7,425 (1,930) 5,495 Total derivative instruments 7,705 (2,002) 5,703 Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (9,600) 2,478 (7,122) Reclassification adjustment for amortization of net loss included in net income 7,708 (1,983) 5,725 Total defined benefit pension and postretirement benefit plans (1,892) 495 (1,397) Other comprehensive loss, net of tax $ (52,979) $ 13,858 $ (39,121)

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2020
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 December 31, 2020 Actual (1) 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 At December 31, 2019 Actual Minimum Requirement Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Webster Financial Corporation CET1 risk-based capital $ 2,516,361 11.56 % $ 979,739 4.5 % $ 1,415,179 6.5 % Total risk-based capital 2,950,181 13.55 1,741,758 8.0 2,177,198 10.0 Tier 1 risk-based capital 2,661,398 12.22 1,306,319 6.0 1,741,758 8.0 Tier 1 leverage capital 2,661,398 8.96 1,188,507 4.0 1,485,634 5.0 Webster Bank CET1 risk-based capital $ 2,527,645 11.61 % $ 979,497 4.5 % $ 1,414,829 6.5 % Total risk-based capital 2,739,108 12.58 1,741,328 8.0 2,176,660 10.0 Tier 1 risk-based capital 2,527,645 11.61 1,305,996 6.0 1,741,328 8.0 Tier 1 leverage capital 2,527,645 8.51 1,187,953 4.0 1,484,941 5.0

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share Basic And Diluted	Reconciliation of the calculation of basic and diluted earnings per common share follows: Years ended December 31, (In thousands, except per share data) 2020 2019 2018 Earnings for basic and diluted earnings per common share: Net income $ 220,621 $ 382,723 $ 360,418 Less: Preferred stock dividends 7,875 7,875 7,853 Net income available to common shareholders 212,746 374,848 352,565 Less: Earnings applicable to participating securities (1) 1,272 1,863 862 Earnings applicable to common shareholders $ 211,474 $ 372,985 $ 351,703 Shares: Weighted-average common shares outstanding - basic 89,967 91,559 91,930 Effect of dilutive securities 184 323 297 Weighted-average common shares outstanding - diluted 90,151 91,882 92,227 Earnings per common share (1) : Basic $ 2.35 $ 4.07 $ 3.83 Diluted 2.35 4.06 3.81
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Potential common shares from non-participating restricted stock of 44 thousand, 73 thousand, and 47 thousand for the years ended December 31, 2020, 2019, and 2018, respectively, are excluded from the effect of dilutive securities because they would have been anti-dilutive under the treasury stock method.

Derivative Financial Instrument

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	The following table presents the notional amounts and fair values of derivative positions: At December 31, 2020 At December 31, 2019 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 $ 39,641 $ 25,000 $ 103 $ 1,225,000 $ 11,855 $ 300,000 $ 3,153 Not designated as hedging instruments: Interest rate derivatives (1) 4,533,441 292,096 4,356,339 11,874 4,869,139 133,455 4,090,522 9,732 Mortgage banking derivatives (2) 40,771 855 — — 27,873 329 57,000 110 Other (3) 108,987 264 360,497 377 76,544 398 275,279 818 Total not designated as hedging instruments 4,683,199 293,215 4,716,836 12,251 4,973,556 134,182 4,422,801 10,660 Gross derivative instruments, before netting $ 5,683,199 332,856 $ 4,741,836 12,354 $ 6,198,556 146,037 $ 4,722,801 13,813 Less: Master netting agreements 7,522 7,522 4,779 4,779 Cash collateral 33,043 4,485 8,100 1,871 Total derivative instruments, after netting $ 292,291 $ 347 $ 133,158 $ 7,163
Schedule of Net Investment Hedges, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table presents fair value positions transitioned from gross to net upon applying counterparty netting agreements: At December 31, 2020 (In thousands) Gross Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 40,565 $ 40,565 $ — $ 785 $ 785 Liability derivatives 12,007 12,007 — 1,247 1,247 At December 31, 2019 (In thousands) Gross Offset Amount Net Amount on Balance Sheet Amounts Not Offset Net Amounts Asset derivatives $ 13,012 $ 12,879 $ 133 $ 299 $ 432 Liability derivatives 6,710 6,650 60 329 389
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following tables present the income statement effect of derivatives designated as hedges and additional information related to a fair value hedging adjustment: Recognized In Years ended December 31, (In thousands) Net Interest Income 2020 2019 2018 Fair value hedges: (1) Recognized on derivatives Long-term debt $ 30,693 $ 17,486 $ — Recognized on hedged items Long-term debt (30,693) (17,486) — Net recognized on fair value hedges $ — $ — $ — Cash flow hedges: Interest rate derivatives Long-term debt $ 8,206 $ 4,241 $ 6,557 Interest rate derivatives Interest and fees on loans and leases (6,373) 1,314 — Net recognized on cash flow hedges $ 1,833 $ 5,555 $ 6,557 Consolidated Balance Sheet Line Item in Which Hedged Item is Located Carrying Amount of Hedged Item Cumulative Amount of Fair Value Hedging Adjustment Included in Carrying Amount (1) At December 31, At December 31, (In thousands) 2020 2019 2020 2019 Long-term debt $ 344,164 $ 317,486 $ 44,164 $ 17,486
Other Derivatives Not Designated For Hedge Accounting	The following table presents the income statement effect of derivatives not designated as hedging instruments: Recognized In Years ended December 31, (In thousands) Non-interest Income 2020 2019 2018 Interest rate derivatives Other income $ 11,068 $ 8,477 $ 10,376 Mortgage banking derivatives Mortgage banking activities 636 (6) (378) Other Other income (1,696) 1,100 2,391 Total not designated as hedging instruments $ 10,008 $ 9,571 $ 12,389

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Option, Disclosures [Table Text Block]	Assets and Liabilities Measured at Fair Value on a Recurring Basis Available-for-Sale Investment Securities . When quoted prices are available in an active market, the Company classifies available-for-sale investment securities within Level 1 of the valuation hierarchy. U.S. Treasury Bills are classified within Level 1 of the fair value hierarchy. When quoted market prices are not available, the Company employs an independent pricing service that utilizes matrix pricing to calculate fair value. Such fair value measurements consider observable data such as dealer quotes, market spreads, cash flows, yield curves, live trading levels, trade execution data, market consensus prepayments speeds, credit information, and respective terms and conditions for debt instruments. Management maintains procedures to monitor the pricing service's results and has an established process to challenge their valuations, or methodologies, that appear unusual or unexpected. Available-for-Sale investment securities which include Agency CMO, Agency MBS, Agency CMBS, CMBS, CLO, and corporate debt, are classified within Level 2 of the fair value hierarchy. Derivative Instruments . Foreign exchange contracts are valued based on unadjusted quoted prices in active markets and classified within Level 1 of the fair value hierarchy. All other derivative instruments are valued using third-party valuation software, which considers the present value of cash flows discounted using observable forward rate assumptions. The resulting fair value is validated against valuations performed by independent third parties and are classified within Level 2 of the fair value hierarchy. 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 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 December 31, 2020 2019 (In thousands) Fair Value Unpaid Principal Balance Difference Fair Value Unpaid Principal Balance Difference Originated loans held for sale $ 14,000 $ 13,511 $ 489 $ 35,750 $ 35,186 $ 564
Fair Value Of Assets And Liabilities Measured On Recurring Basis	Summaries of the fair values of assets and liabilities measured at fair value on a recurring basis are as follows: At 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) 205 332,651 — 332,856 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 $ 3,673,427 $ — $ 3,689,555 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 218 $ 12,136 $ — $ 12,354 At December 31, 2019 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: Agency CMO $ — $ 185,801 $ — $ 185,801 Agency MBS — 1,612,164 — 1,612,164 Agency CMBS — 581,552 — 581,552 CMBS — 431,871 — 431,871 CLO — 92,205 — 92,205 Corporate debt — 22,240 — 22,240 Total available-for-sale investment securities — 2,925,833 — 2,925,833 Gross derivative instruments, before netting (1) 328 145,709 — 146,037 Originated loans held for sale — 35,750 — 35,750 Investments held in Rabbi Trust 4,780 — — 4,780 Alternative investments (2) — — — 4,331 Total financial assets held at fair value $ 5,108 $ 3,107,292 $ — $ 3,116,731 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 611 $ 13,202 $ — $ 13,813 (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 17: Derivative Financial Instruments. (2) 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	Fair value of selected financial instruments and servicing assets amounts are as follows: At December 31, 2020 2019 (In thousands) Carrying Fair Carrying Fair Assets: Level 2 Held-to-maturity investment securities $ 5,567,889 $ 5,835,364 $ 5,293,918 $ 5,380,653 Level 3 Loans and leases, net 21,281,784 21,413,397 19,827,890 19,961,632 Mortgage servicing assets 13,422 14,362 17,484 33,250 Liabilities: Level 2 Deposit liabilities $ 24,847,618 $ 24,847,618 $ 20,219,981 $ 20,219,981 Time deposits 2,487,818 2,494,601 3,104,765 3,102,316 Securities sold under agreements to repurchase and other borrowings 995,355 1,000,189 1,040,431 1,041,042 FHLB advances 133,164 139,035 1,948,476 1,950,035 Long-term debt (1) 567,663 538,407 540,364 555,775 (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 for determination of fair value. Refer to Note 12: Borrowings for additional information.

Retirement Benefit Plans (Table

Retirement Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Schedule of Defined Benefit Plans Disclosures	The following table sets forth changes in benefit obligation, changes in plan assets, and the funded status of the defined benefit pension and other postretirement benefits at December 31: Pension Plan SERP Other (In thousands) 2020 2019 2020 2019 2020 2019 Change in benefit obligation: Beginning balance $ 241,404 $ 209,513 $ 1,935 $ 1,835 $ 2,399 $ 2,612 Interest cost 6,511 7,941 46 65 46 85 Actuarial loss (gain) 27,376 33,157 194 163 (307) (103) Benefits paid and administrative expenses (8,877) (9,207) (129) (128) (140) (195) Ending balance (1) 266,414 241,404 2,046 1,935 1,998 2,399 Change in plan assets: Beginning balance 239,621 191,972 — — — — Actual return on plan assets 35,524 46,856 — — — — Employer contributions — 10,000 129 128 140 195 Benefits paid and administrative expenses (8,877) (9,207) (129) (128) (140) (195) Ending balance 266,268 239,621 — — — — Funded status of the plan at year end (2) $ (146) $ (1,783) $ (2,046) $ (1,935) $ (1,998) $ (2,399) (1) The total accumulated benefit obligation for the defined benefit pension and other postretirement benefits was $270.5 million and $245.7 million at December 31, 2020 and 2019, respectively. (2) The underfunded status amounts are included in accrued expense and other liabilities in the accompanying Consolidated Balance Sheets.
Schedule of Net Periodic Benefit Cost Not yet Recognized	The following table summarizes the impact on AOCI related to the defined benefit pension and other postretirement benefits at December 31: Pension Plan SERP Other (In thousands) 2020 2019 2020 2019 2020 2019 Net actuarial loss (gain) included in AOCI $ 57,902 $ 56,555 $ 773 $ 602 $ (690) $ (458) Deferred tax benefit (expense) 12,881 12,528 172 133 (153) (101) Amounts included in accumulated AOCI, net of tax $ 45,021 $ 44,027 $ 601 $ 469 $ (537) $ (357)
Schedule of Expected Benefit Payments	Expected future benefit payments for the defined benefit pension and other postretirement benefits are presented below: (In thousands) Pension Plan SERP Other 2021 $ 9,657 $ 131 $ 254 2022 10,294 132 237 2023 10,465 132 219 2024 10,887 138 201 2025 11,304 136 182 2026-2030 61,336 625 638
Summary of Net Periodic Benefit Cost	The components of the net periodic benefit cost (benefit) for the defined benefit pension and other postretirement benefits were as follows for the years ended December 31: Pension Plan SERP Other (In thousands) 2020 2019 2018 2020 2019 2018 2020 2019 2018 Service cost $ — $ — $ — $ — $ — $ — $ — $ — $ — Interest cost on benefit obligations 6,511 7,941 7,212 46 65 103 46 85 78 Expected return on plan assets (13,522) (11,436) (12,716) — — — — — — Recognized net loss (gain) 4,027 5,705 4,862 23 14 2,846 (74) (13) — Net periodic benefit cost (benefit) $ (2,984) $ 2,210 $ (642) $ 69 $ 79 $ 2,949 $ (28) $ 72 $ 78
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)	Changes in funded status related to the defined benefit pension and other postretirement benefits and recognized as a component of OCI in the consolidated statement of comprehensive income as follows for the years ended December 31: Pension Plan SERP Other (In thousands) 2020 2019 2018 2020 2019 2018 2020 2019 2018 Net (gain) loss $ 5,375 $ (2,263) $ 9,952 $ 194 $ 164 $ — $ (307) $ (103) $ (352) Amounts reclassified from AOCI (4,027) (5,705) (4,862) (23) (14) (2,846) 74 13 — Total (gain) loss recognized in OCI $ 1,348 $ (7,968) $ 5,090 $ 171 $ 150 $ (2,846) $ (233) $ (90) $ (352)
Schedule of Changes in Fair Value of Plan Assets	A summary of the fair value and hierarchy classification of financial assets of the pension plan is as follows: At December 31, 2020 2019 (In thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Exchange traded fund $ 39,645 $ — $ — $ 39,645 $ 36,552 $ — $ — $ 36,552 Cash and cash equivalents 861 — — 861 1,225 — — 1,225 Common collective trusts — 225,762 — 225,762 — 201,844 — 201,844 Total pension plan assets $ 40,506 $ 225,762 $ — $ 266,268 $ 37,777 $ 201,844 $ — $ 239,621
Schedule of Assumptions Used	Weighted-average assumptions used to determine benefit obligations at December 31 are as follows: Pension Plan SERP Other 2020 2019 2020 2019 2020 2019 Discount rate 2.29 % 3.07 % 1.91 % 2.82 % 1.40 % 2.50 % Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31 are as follows: Pension Plan SERP Other 2020 2019 2018 2020 2019 2018 2020 2019 2018 Discount rate 3.07 % 4.12 % 3.50 % 2.82 % 3.95 % 3.30 % 2.50 % 3.69 % 3.00 % Expected long-term return on assets 5.75 % 6.00 % 6.00 % n/a n/a n/a n/a n/a n/a Assumed healthcare cost trend n/a n/a n/a n/a n/a n/a 6.50 % 6.50 % 7.00 %
Schedule of Multiemployer Plans	The following table sets forth contributions and funding status of Webster Bank's portion of this plan: (Dollars in thousands) Contributions by Webster Bank for the year ended December 31, Funded Status of the Plan at December 31, Plan Name Employer Identification Number Plan Number 2020 2019 2018 2020 2019 Pentegra Defined Benefit Plan for Financial Institutions 13-5645888 333 $998 $863 $679 At least 80 percent At least 80 percent
Schedule of Allocation of Plan Assets	The following table presents the target allocation and the pension plan asset allocation for the periods indicated, by asset category: Target Allocation Percentage of Pension Plan Assets 2021 2020 2019 Fixed income investments 62 % 61 % 61 % Equity investments 38 38 38 Cash and cash equivalents — 1 1 Total 100 % 100 % 100 %

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Operating Results And Total Assets Reportable Segments	The following table presents total assets for Webster's reportable segments and the Corporate and Reconciling category: At December 31, 2020 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Total assets $ 12,689,255 $ 80,352 $ 9,769,824 $ 10,051,259 $ 32,590,690 At December 31, 2019 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Total assets $ 11,541,803 $ 80,176 $ 9,348,727 $ 9,418,638 $ 30,389,344 The following tables present the operating results, including all appropriate allocations, for Webster’s reportable segments and the Corporate and Reconciling category: Year ended December 31, 2020 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Net interest income $ 423,869 $ 162,363 $ 422,979 $ (117,818) $ 891,393 Non-interest income 58,366 100,826 106,279 19,806 285,277 Non-interest expense 187,572 140,637 390,596 40,141 758,946 Pre-tax, pre-provision net revenue 294,663 122,552 138,662 (138,153) 417,724 Provision for credit losses 137,993 — (144) (99) 137,750 Income before income tax expense 156,670 122,552 138,806 (138,054) 279,974 Income tax expense 38,368 32,721 27,484 (39,220) 59,353 Net income $ 118,302 $ 89,831 $ 111,322 $ (98,834) $ 220,621 Year ended December 31, 2019 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Net interest income $ 403,258 $ 172,685 $ 420,898 $ (41,714) $ 955,127 Non-interest income 59,063 97,041 109,270 19,941 285,315 Non-interest expense 181,580 135,586 388,399 10,385 715,950 Pre-tax, pre-provision net revenue 280,741 134,140 141,769 (32,158) 524,492 Provision for credit losses 25,407 — 12,393 — 37,800 Income before income tax expense 255,334 134,140 129,376 (32,158) 486,692 Income tax expense 63,323 35,547 27,428 (22,329) 103,969 Net income $ 192,011 $ 98,593 $ 101,948 $ (9,829) $ 382,723 Year ended December 31, 2018 (In thousands) Commercial HSA Community Banking Corporate and Consolidated Net interest income $ 381,098 $ 147,920 $ 422,063 $ (44,400) $ 906,681 Non-interest income 64,765 89,323 109,669 18,811 282,568 Non-interest expense 174,054 124,594 384,603 22,365 705,616 Pre-tax, pre-provision net revenue 271,809 112,649 147,129 (47,954) 483,633 Provision for credit losses 32,388 — 9,612 — 42,000 Income before income tax expense 239,421 112,649 137,517 (47,954) 441,633 Income tax expense 58,898 29,289 27,366 (34,338) 81,215 Net income $ 180,523 $ 83,360 $ 110,151 $ (13,616) $ 360,418

Revenue from contracts with C_2

Revenue from contracts with Customers Revenue from Contracts with Customers Revenue from contracts with customers (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue from External Customers by Products and Services [Table Text Block]	Revenue from Contracts with Customers The following tables present revenues within the scope of ASC 606, Revenue from Contracts with Customers and the net amount of other sources of non-interest income that is within the scope of other GAAP topics: Year ended December 31, 2020 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income: Deposit service fees $ 11,634 $ 92,693 $ 51,599 $ 106 $ 156,032 Wealth and investment services 10,644 — 22,307 (35) 32,916 Other — 8,133 1,656 — 9,789 Revenue from contracts with customers 22,278 100,826 75,562 71 198,737 Other sources of non-interest income 36,088 — 30,717 19,735 86,540 Total non-interest income $ 58,366 $ 100,826 $ 106,279 $ 19,806 $ 285,277 Year ended December 31, 2019 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income: Deposit service fees $ 12,136 $ 92,096 $ 63,572 $ 218 $ 168,022 Wealth and investment services 10,330 — 22,637 (35) 32,932 Other — 4,945 2,394 — 7,339 Revenue from contracts with customers 22,466 97,041 88,603 183 208,293 Other sources of non-interest income 36,597 — 20,667 19,758 77,022 Total non-interest income $ 59,063 $ 97,041 $ 109,270 $ 19,941 $ 285,315 Year ended December 31, 2018 (In thousands) Commercial HSA Community Corporate and Consolidated Non-interest Income: Deposit service fees $ 12,775 $ 85,809 $ 63,522 $ 77 $ 162,183 Wealth and investment services 10,145 — 22,732 (34) 32,843 Other — 3,514 2,133 — 5,647 Revenue from contracts with customers 22,920 89,323 88,387 43 200,673 Other sources of non-interest income 41,845 — 21,282 18,768 81,895 Total non-interest income $ 64,765 $ 89,323 $ 109,669 $ 18,811 $ 282,568

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Reserve For Unfunded Credit Commitments	The following table provides a summary of activity in the reserve for loan repurchases: Years ended December 31, (In thousands) 2020 2019 2018 Beginning balance $ 508 $ 674 $ 872 Provision (benefit) charged to expense 141 1,865 (160) Recoveries, net (settlements charged-off/repurchased loans, net) 98 (2,031) (38) Ending balance $ 747 $ 508 $ 674

Parent Company Information (Tab

Parent Company Information (Tables)	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Schedule of Parent Company Information Balance Sheet	Financial information for the Parent Company only is presented in the following tables: Condensed Balance Sheets December 31, (In thousands) 2020 2019 Assets: Cash and due from banks $ 302,315 $ 510,940 Intercompany debt securities 150,000 150,000 Investment in subsidiaries 3,340,556 3,079,549 Alternative investments 8,970 5,356 Other assets 8,122 13,537 Total assets $ 3,809,963 $ 3,759,382 Liabilities and shareholders’ equity: Senior notes $ 490,343 $ 463,044 Junior subordinated debt 77,320 77,320 Accrued interest payable 5,862 6,057 Due to subsidiaries 324 52 Other liabilities 1,489 5,139 Total liabilities 575,338 551,612 Shareholders’ equity 3,234,625 3,207,770 Total liabilities and shareholders’ equity $ 3,809,963 $ 3,759,382
Schedule of Parent Company Information Income Statement	Condensed Statements of Income Years ended December 31, (In thousands) 2020 2019 2018 Operating Income: Dividend income from bank subsidiary $ 20,000 $ 360,000 $ 290,000 Interest on securities and deposits 5,530 10,728 7,342 Alternative investments (loss) income 2,467 (256) 290 Other non-interest income 634 382 805 Total operating income 28,631 370,854 298,437 Operating Expense: Interest expense on borrowings 18,684 21,062 11,127 Non-interest expense 16,426 15,527 19,105 Total operating expense 35,110 36,589 30,232 Income before income tax benefit and equity in undistributed earnings of subsidiaries (6,479) 334,265 268,205 Income tax benefit 4,572 4,671 2,207 Equity in undistributed earnings of subsidiaries 222,528 43,787 90,006 Net income $ 220,621 $ 382,723 $ 360,418
Schedule of Parent Company Information Comprehensive Income Statement	Condensed Statements of Comprehensive Income Years ended December 31, (In thousands) 2020 2019 2018 Net income $ 220,621 $ 382,723 $ 360,418 Other comprehensive income (loss), net of tax: Derivative instruments 2,622 1,479 1,447 Other comprehensive income (loss) of subsidiaries 75,706 93,101 (40,568) Other comprehensive income (loss), net of tax 78,328 94,580 (39,121) Comprehensive income $ 298,949 $ 477,303 $ 321,297
Schedule of Parent Company Information Cash Flow Statement	Condensed Statements of Cash Flows Years ended December 31, (In thousands) 2020 2019 2018 Net cash provided by operating activities $ 27,790 $ 362,617 $ 282,986 Investing activities: Alternative investments capital call (3,751) (1,850) — Investment in subsidiaries — (296,000) — Net cash used for investing activities (3,751) (297,850) — Financing activities: Issuance of long-term debt — 296,358 — Cash dividends paid to common shareholders (144,967) (140,783) (114,959) Cash dividends paid to preferred shareholders (7,875) (7,875) (7,875) Exercise of stock options 240 619 2,173 Common stock repurchased and acquired from stock compensation plan activity (80,062) (19,619) (25,937) Net cash (used for) provided by financing activities (232,664) 128,700 (146,598) Increase in cash and cash equivalents (208,625) 193,467 136,388 Cash and cash equivalents at beginning of year 510,940 317,473 181,085 Cash and cash equivalents at end of year $ 302,315 $ 510,940 $ 317,473

Selected Quarterly Consolidat_2

Selected Quarterly Consolidated Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Selected Quarterly Financial Information [Abstract]
Schedule of Quarterly Financial Information	2020 (In thousands, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 274,470 $ 252,275 $ 239,239 $ 236,065 Interest expense 43,669 27,868 19,983 19,136 Net interest income 230,801 224,407 219,256 216,929 Provision for credit losses 76,000 40,000 22,750 (1,000) Non-interest income 73,378 60,076 75,060 76,763 Non-interest expense 178,836 176,584 183,996 219,530 Income before income tax expense 49,343 67,899 87,570 75,162 Income tax expense 11,144 14,802 18,289 15,118 Net income $ 38,199 $ 53,097 $ 69,281 $ 60,044 Earnings applicable to common shareholders $ 36,021 $ 50,729 $ 66,890 $ 57,715 Earnings per common share: Basic $ 0.40 $ 0.57 $ 0.75 $ 0.64 Diluted 0.39 0.57 0.75 0.64 2019 (In thousands, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 286,190 $ 292,257 $ 294,136 $ 282,000 Interest expense 44,639 50,470 53,597 50,750 Net interest income 241,551 241,787 240,539 231,250 Provision for credit losses 8,600 11,900 11,300 6,000 Non-interest income 68,612 75,853 69,931 70,919 Non-interest expense 175,686 180,640 179,894 179,730 Income before income tax expense 125,877 125,100 119,276 116,439 Income tax expense 26,141 26,451 25,411 25,966 Net income $ 99,736 $ 98,649 $ 93,865 $ 90,473 Earnings applicable to common shareholders $ 97,549 $ 96,193 $ 91,442 $ 88,066 Earnings per common share: Basic $ 1.06 $ 1.05 $ 1.00 $ 0.96 Diluted 1.06 1.05 1.00 0.96

Summary of Significant Accoun_4

Summary of Significant Accounting Policies New Accounting Pronouncements - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)Segment	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of portfolio segments | Segment	2
ROU lease assets				$ 127,481	$ 157,234
Lease liabilities	$ 158,280		$ 174,396	$ 158,280	$ 178,802
Allowance for credit losses on investment securities held-to-maturity	(299)		0
Financing Receivable, Allowance for Credit Loss			(209,096)
Deferred Tax Assets, Tax Deferred Expense			61,975
Accrued expenses and other liabilities	166,167		153,161
Retained earnings	2,077,522		2,061,352
Individually evaluated for impairment	16,137		14,249			$ 15,350
Collectively evaluated for impairment	$ 343,294		$ 194,847			$ 197,003
Building and Building Improvements | Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Building and Building Improvements | Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, Plant and Equipment, Useful Life	40 years
Leasehold Improvements | Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Leasehold Improvements | Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Furniture and Fixtures | Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Furniture and Fixtures | Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Information Technology and Data Processing | Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Information Technology and Data Processing | Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, Plant and Equipment, Useful Life	7 years
Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses on investment securities held-to-maturity	$ (397)	$ (397)
Financing Receivable, Allowance for Credit Loss	(57,568)	(266,664)
Deferred Tax Assets, Tax Deferred Expense	15,891	77,866
Accrued expenses and other liabilities	9,139	162,300
Retained earnings	$ (51,213)	2,010,139
Individually evaluated for impairment		(14,200)
Collectively evaluated for impairment		$ (252,500)

Variable Interest Entities (Det

Variable Interest Entities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Assets	$ 32,590,690	$ 30,389,344
Liabilities	29,356,065	27,181,574
Other Assets [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	37,200	42,500
Accounts Payable and Accrued Liabilities [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Liabilities	10,200	15,100
Other Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	34,300	21,800
Unfunded Loan Commitment [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Variable interest entities, total exposure of other investments including unfunded commitments	$ 72,700	$ 64,200

Business Developments - Changes

Business Developments - Changes in Accrued Expense (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Restructuring Reserve [Roll Forward]
Beginning balance	$ 0
Charged to earnings	42,657
Charges against assets	(14,009)
Cash payments	(8,853)
Ending balance	19,795
Severance
Restructuring Reserve [Roll Forward]
Beginning balance	0
Charged to earnings	17,860
Charges against assets	0
Cash payments	(185)
Ending balance	17,675
ROU Asset
Restructuring Reserve [Roll Forward]
Beginning balance	0
Charged to earnings	13,000
Charges against assets	(13,000)
Cash payments	0
Ending balance	0
Other
Restructuring Reserve [Roll Forward]
Beginning balance	0
Charged to earnings	11,797
Charges against assets	(1,009)
Cash payments	(8,668)
Ending balance	$ 2,120

Business Developments - Narrati

Business Developments - Narrative (Details)	12 Months Ended
	Dec. 31, 2020banking_center
Restructuring and Related Activities [Abstract]
Banking centers consolidated	26

Investment Securities (Summary

Investment Securities (Summary Of Investment Securities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	$ 5,568,188	$ 5,293,918
Unrealized Gains	269,717	103,156
Unrealized Losses	(2,541)	(16,421)
Fair Value	5,835,364	5,380,653
Debt Securities, Held-to-maturity, Allowance for Credit Loss	299	0
Debt Securities, Held-to-maturity, Current	5,567,889	5,293,918
Interest Receivable	57,800	59,000
Debt Securities, Available-for-sale [Abstract]
Debt Securities, Available-for-sale, Amortized Cost	3,234,250	2,901,415
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	101,997	38,270
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	9,471	13,852
Investment securities available-for-sale, at fair value	3,326,776	2,925,833
Held-to-maturity Securities [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Interest Receivable	22,100	21,800
Available-for-sale Securities
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Interest Receivable	7,500	8,100
Collateralized Mortgage Obligations [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	91,622	167,443
Unrealized Gains	1,785	1,123
Unrealized Losses	(241)	(1,200)
Fair Value	93,166	167,366
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0	0
Debt Securities, Held-to-maturity, Current	91,622	167,443
Debt Securities, Available-for-sale [Abstract]
Debt Securities, Available-for-sale, Amortized Cost	148,711	184,500
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	6,000	2,218
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	98	917
Investment securities available-for-sale, at fair value	154,613	185,801
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	2,419,751	2,957,900
Unrealized Gains	137,863	60,602
Unrealized Losses	(84)	(8,733)
Fair Value	2,557,530	3,009,769
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0	0
Debt Securities, Held-to-maturity, Current	2,419,751	2,957,900
Debt Securities, Available-for-sale [Abstract]
Debt Securities, Available-for-sale, Amortized Cost	1,389,100	1,580,743
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	68,598	35,456
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	289	4,035
Investment securities available-for-sale, at fair value	1,457,409	1,612,164
Agency commercial mortgage-backed securities (agency CMBS) [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	2,101,227	1,172,491
Unrealized Gains	60,484	6,444
Unrealized Losses	(2,213)	(5,615)
Fair Value	2,159,498	1,173,320
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0	0
Debt Securities, Held-to-maturity, Current	2,101,227	1,172,491
Debt Securities, Available-for-sale [Abstract]
Debt Securities, Available-for-sale, Amortized Cost	1,092,430	587,974
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	26,317	513
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1,514	6,935
Investment securities available-for-sale, at fair value	1,117,233	581,552
Commercial Mortgage Backed Securities [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	216,081	255,653
Unrealized Gains	9,214	2,278
Unrealized Losses	0	(852)
Fair Value	225,295	257,079
Debt Securities, Held-to-maturity, Allowance for Credit Loss	0	0
Debt Securities, Held-to-maturity, Current	216,081	255,653
Debt Securities, Available-for-sale [Abstract]
Debt Securities, Available-for-sale, Amortized Cost	512,759	432,085
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1,082	38
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	5,823	252
Investment securities available-for-sale, at fair value	508,018	431,871
Collateralized loan obligations (CLO) [Member]
Debt Securities, Available-for-sale [Abstract]
Debt Securities, Available-for-sale, Amortized Cost	76,693	92,628
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	45
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	310	468
Investment securities available-for-sale, at fair value	76,383	92,205
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Abstract]
Debt Securities, Available-for-sale, Amortized Cost	14,557	23,485
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1,437	1,245
Investment securities available-for-sale, at fair value	13,120	22,240
Municipal Bonds [Member]
Debt Securities, Held-to-maturity, Fair Value to Amortized Cost [Abstract]
Amortized Cost	739,507	740,431
Unrealized Gains	60,371	32,709
Unrealized Losses	(3)	(21)
Fair Value	799,875	773,119
Debt Securities, Held-to-maturity, Allowance for Credit Loss	299	0
Debt Securities, Held-to-maturity, Current	739,208	$ 740,431
Callable [Member]
Debt Securities, Available-for-sale [Abstract]
Investment securities available-for-sale, at fair value	$ 1,300,000

Investment Securities (Summar_2

Investment Securities (Summary Of Gross Unrealized Losses Not Considered OTTI) (Detail) $ in Thousands	Dec. 31, 2020USD ($)numberOfHoldings	Dec. 31, 2019USD ($)numberOfHoldings
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 894,628	$ 607,521
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(7,699)	(1,914)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	61,347	762,631
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (1,772)	$ (11,938)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | numberOfHoldings	88	157
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 955,975	$ 1,370,152
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(9,471)	(13,852)
Collateralized Mortgage Obligations [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	13,137	36,447
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(49)	(352)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	5,944	32,288
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (49)	$ (565)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | numberOfHoldings	5	9
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 19,081	$ 68,735
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(98)	(917)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	33,742	41,408
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(219)	(193)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	4,561	299,674
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (70)	$ (3,842)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | numberOfHoldings	30	79
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 38,303	$ 341,082
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(289)	(4,035)
Agency commercial mortgage-backed securities (agency CMBS) [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	376,330	174,406
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1,514)	(1,137)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	357,717
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 0	$ (5,798)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | numberOfHoldings	8	34
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 376,330	$ 532,123
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(1,514)	(6,935)
Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	409,591	355,260
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(5,486)	(232)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	23,167	7,480
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (337)	$ (20)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | numberOfHoldings	38	29
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 432,758	$ 362,740
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(5,823)	(252)
Collateralized loan obligations (CLO) [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	57,728	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(265)	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	18,655	43,232
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (45)	$ (468)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | numberOfHoldings	4	2
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 76,383	$ 43,232
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	(310)	(468)
Corporate Debt Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	4,100	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(166)	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	9,020	22,240
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ (1,271)	$ (1,245)
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | numberOfHoldings	3	4
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 13,120	$ 22,240
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ (1,437)	$ (1,245)

Investment Securities (Narrativ

Investment Securities (Narrative) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Investment securities available-for-sale, at fair value	$ 3,326,776	$ 2,925,833
Securities pledged to secure public funds, carrying value	3,900,000	$ 2,700,000
Callable [Member]
Debt Securities, Available-for-sale [Line Items]
Investment securities available-for-sale, at fair value	$ 1,300,000

Investment Securities (Summar_3

Investment Securities (Summary Of Sale Proceeds Of Available For Sale Securities) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales of available-for-sale securities	$ 8,963	$ 70,087	$ 0
Gains	8	773	0
Losses	0	744	0
Debt Securities, Available-for-sale, Realized Gain (Loss)	$ (8)	$ (29)	$ 0

Investment Securities (Summar_4

Investment Securities (Summary Of Debt Securities By Contractual Maturity) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
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
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	1,448
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	252,601
Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost	2,980,201
Debt Securities, Available-for-sale, Amortized Cost	3,234,250	$ 2,901,415
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value	0
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	1,489
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	248,958
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	3,076,329
Available for Sale, Fair Value - Total debt securities	3,326,776	2,925,833
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost [Abstract]
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost	680
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	4,458
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	278,974
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Amortized Cost	5,284,076
Amortized Cost	5,568,188	5,293,918
Debt Securities, Held-to-maturity, Maturity, Fair Value [Abstract]
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value	685
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	4,711
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	294,528
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	5,535,440
Debt Securities, Held-to-maturity, Fair Value	$ 5,835,364	$ 5,380,653

Investment Securities (Summar_5

Investment Securities (Summary of Debt Securities Held-to-Maturity) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	$ 5,568,188	$ 5,293,918
Interest Receivable	57,800	59,000
Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	91,622	167,443
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	2,419,751	2,957,900
Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	2,101,227	1,172,491
Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	739,507	740,431
Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	216,081	$ 255,653
Moody's, Aaa Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	425,457
Moody's, Aaa Rating [Member] | Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aaa Rating [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aaa Rating [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aaa Rating [Member] | Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	209,376
Moody's, Aaa Rating [Member] | Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	216,081
Moody's, Aa1 Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	4,777,656
Moody's, Aa1 Rating [Member] | Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	91,622
Moody's, Aa1 Rating [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	2,419,751
Moody's, Aa1 Rating [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	2,101,227
Moody's, Aa1 Rating [Member] | Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	165,056
Moody's, Aa1 Rating [Member] | Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aa2 Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	201,081
Moody's, Aa2 Rating [Member] | Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aa2 Rating [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aa2 Rating [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aa2 Rating [Member] | Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	201,081
Moody's, Aa2 Rating [Member] | Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aa3 Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	115,619
Moody's, Aa3 Rating [Member] | Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aa3 Rating [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aa3 Rating [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Aa3 Rating [Member] | Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	115,619
Moody's, Aa3 Rating [Member] | Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A1 Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	33,264
Moody's, A1 Rating [Member] | Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A1 Rating [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A1 Rating [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A1 Rating [Member] | Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	33,264
Moody's, A1 Rating [Member] | Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A2 Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	8,475
Moody's, A2 Rating [Member] | Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A2 Rating [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A2 Rating [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A2 Rating [Member] | Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	8,475
Moody's, A2 Rating [Member] | Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A3 Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	2,066
Moody's, A3 Rating [Member] | Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A3 Rating [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A3 Rating [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, A3 Rating [Member] | Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	2,066
Moody's, A3 Rating [Member] | Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Baa2 Rating [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	190
Moody's, Baa2 Rating [Member] | Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Baa2 Rating [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Baa2 Rating [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Baa2 Rating [Member] | Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	190
Moody's, Baa2 Rating [Member] | Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Not Rated [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	4,380
Moody's, Not Rated [Member] | Collateralized Mortgage Obligations [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Not Rated [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Not Rated [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	0
Moody's, Not Rated [Member] | Municipal Bonds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	4,380
Moody's, Not Rated [Member] | Commercial Mortgage Backed Securities [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	$ 0

Investment Securities (Debt and

Investment Securities (Debt and Equity Securities Allowance for Credit Losses) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Debt Securities, Held-to-maturity, Allowance for Credit Loss	$ 299	$ 0
Debt Securities, Held-to-maturity, Allowance for Credit Loss, Recovery	$ (98)
Cumulative Effect, Period of Adoption, Adjustment [Member]
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Debt Securities, Held-to-maturity, Allowance for Credit Loss		$ 397

Loans and Leases (Detail)

Loans and Leases (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 21,641,215,000	$ 20,036,986,000	$ 18,465,489,000
Unamortized premiums	(10,500,000)	17,600,000
Pledged loans as collateral	7,700,000,000
Lessee, Operating Lease, Liability, Payments, Due	182,452,000
Interest Receivable	57,800,000	59,000,000
Leasing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	236,100,000	169,300,000
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	14,900,535,000	12,830,177,000	11,652,148,000
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	6,322,637,000	5,949,339,000
Commercial Portfolio Segment [Member] | Equipment Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	602,224,000	537,341,000
Sales-type and Direct Financing Leases, Interest Income	7,100,000	5,500,000
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	7,085,076,000	5,296,611,000
Commercial Portfolio Segment [Member] | Asset Based Lending [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	890,598,000	1,046,886,000
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases		5,949,339,000
Finance Leases Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases		537,341,000
Lessee, Operating Lease, Liability, Payments, Due	256,300,000
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	6,740,680,000	7,206,809,000	$ 6,813,341,000
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,802,865,000	2,014,544,000
Consumer Portfolio Segment [Member] | 522291 Consumer Lending [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	155,799,000	219,580,000
Consumer Portfolio Segment [Member] | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 4,782,016,000	$ 4,972,685,000

Loans and Leases (Summary Of Lo

Loans and Leases (Summary Of Loan And Lease Portfolio Aging By Class Of Loan) (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	$ 200,942,000	$ 193,766,000
90 or More Days Past Due and Accruing	445,000	0
Non-accrual	167,960,000	151,059,000
Current	21,440,273,000	19,843,220,000
Total Loans and Leases	21,641,215,000	20,036,986,000	$ 18,465,489,000
Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	92,177,000	107,056,000
Non-accrual	72,763,000	74,555,000
Current	6,648,503,000	7,099,753,000
Total Loans and Leases	6,740,680,000	7,206,809,000	6,813,341,000
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	38,301,000	43,988,000
Non-accrual	31,030,000	30,170,000
Current	1,764,564,000	1,970,556,000
Total Loans and Leases	1,802,865,000	2,014,544,000
Consumer Portfolio Segment [Member] | Consumer Borrower [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	2,131,000	6,268,000
Non-accrual	652,000	1,192,000
Current	153,668,000	213,312,000
Total Loans and Leases	155,799,000	219,580,000
Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	51,745,000	56,800,000
Non-accrual	41,081,000	43,193,000
Current	4,730,271,000	4,915,885,000
Total Loans and Leases	4,782,016,000	4,972,685,000
Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	108,765,000	86,710,000
Non-accrual	95,197,000	76,504,000
Current	14,791,770,000	12,743,467,000
Total Loans and Leases	14,900,535,000	12,830,177,000	$ 11,652,148,000
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	24,250,000	13,273,000
Non-accrual	21,231,000	11,563,000
Current	6,298,387,000	5,936,066,000
Total Loans and Leases	6,322,637,000	5,949,339,000
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	66,033,000	62,080,000
Non-accrual	64,073,000	59,369,000
Current	7,019,043,000	5,234,531,000
Total Loans and Leases	7,085,076,000	5,296,611,000
Commercial Portfolio Segment [Member] | Asset Based Lending [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	3,768,000	139,000
Non-accrual	2,594,000	139,000
Current	886,830,000	1,046,747,000
Total Loans and Leases	890,598,000	1,046,886,000
Commercial Portfolio Segment [Member] | 6172 Finance Lessors [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	14,714,000	11,218,000
Non-accrual	7,299,000	5,433,000
Current	587,510,000	526,123,000
Total Loans and Leases	602,224,000	537,341,000
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases		5,949,339,000
Finance Leases Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases		537,341,000
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	20,005,000	28,545,000
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	10,712,000	19,702,000
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	5,500,000	8,267,000
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Consumer Borrower [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	878,000	4,269,000
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	4,334,000	7,166,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	9,293,000	8,843,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	2,400,000	1,256,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	612,000	2,094,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Asset Based Lending [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	1,174,000	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | 6172 Finance Lessors [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	5,107,000	5,493,000
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	12,532,000	14,162,000
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	8,702,000	12,799,000
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	1,771,000	5,551,000
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Consumer Borrower [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	601,000	807,000
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	6,330,000	6,441,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	3,830,000	1,363,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	619,000	454,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	903,000	617,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Asset Based Lending [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | 6172 Finance Lessors [Member]
Financing Receivable, Past Due [Line Items]
Total Past Due and Non-accrual	2,308,000	292,000
Financial Asset, Equal to or Greater than 90 Days Past Due | Consumer Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
90 or More Days Past Due and Accruing	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Past Due [Line Items]
90 or More Days Past Due and Accruing	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Consumer Portfolio Segment [Member] | Consumer Borrower [Member]
Financing Receivable, Past Due [Line Items]
90 or More Days Past Due and Accruing	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Past Due [Line Items]
90 or More Days Past Due and Accruing	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Commercial Portfolio Segment [Member]
Financing Receivable, Past Due [Line Items]
90 or More Days Past Due and Accruing	445,000	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
90 or More Days Past Due and Accruing	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Past Due [Line Items]
90 or More Days Past Due and Accruing	445,000	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Commercial Portfolio Segment [Member] | Asset Based Lending [Member]
Financing Receivable, Past Due [Line Items]
90 or More Days Past Due and Accruing	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Commercial Portfolio Segment [Member] | 6172 Finance Lessors [Member]
Financing Receivable, Past Due [Line Items]
90 or More Days Past Due and Accruing	$ 0	$ 0

Loans and Leases (Narrative) (D

Loans and Leases (Narrative) (Detail)	12 Months Ended
	Dec. 31, 2020USD ($)loan	Dec. 31, 2019USD ($)loan	Dec. 31, 2018USD ($)loan
Loans and Leases Receivable Disclosure [Abstract]
Interest on non-accrual loans that would have been recorded as additional interest income	$ 9,700,000	$ 11,300,000	$ 9,700,000
Write-down of TDR's	$ (18,400,000)	$ (21,800,000)	$ (14,300,000)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans and Leases | loan	192	136	143
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans and Leases | loan	4	7
Financing Receivable, Troubled Debt Restructuring, Subsequent Default	$ 12,400,000	$ 2,600,000	$ 0

Loans and Leases (Allowance For

Loans and Leases (Allowance For Loan And Lease Losses By Portfolio Segment) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 209,096	$ 212,353	$ 199,994
Provision (benefit) charged to expense	137,848	37,800	42,000
Losses charged off	(55,333)	(52,480)	(43,387)
Recoveries	10,252	11,423	13,746
Balance, end of period	209,096	212,353	199,994	$ 359,431	$ 209,096	$ 212,353	$ 199,994
Individually evaluated for impairment				16,137	14,249	15,350
Collectively evaluated for impairment				343,294	194,847	197,003
Individually evaluated for impairment				309,422	256,410	259,330
Collectively evaluated for impairment				21,331,793	19,780,576	18,206,159
Total Loans and Leases				21,641,215	20,036,986	18,465,489
Financing Receivable, Allowance for Credit Loss					209,096
Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss					57,568	0	0
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	47,427	48,280	55,248
Provision (benefit) charged to expense	(18,488)	8,626	6,644
Losses charged off	(12,408)	(19,153)	(22,683)
Recoveries	7,112	9,674	9,071
Balance, end of period	47,427	48,280	55,248	47,187	47,427	48,280	55,248
Individually evaluated for impairment				4,450	4,821	5,669
Collectively evaluated for impairment				42,737	42,606	42,611
Individually evaluated for impairment				145,767	125,287	142,675
Collectively evaluated for impairment				6,594,913	7,081,522	6,670,666
Total Loans and Leases				6,740,680	7,206,809	6,813,341
Consumer Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss					23,544	0	0
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	161,669	164,073	144,746
Provision (benefit) charged to expense	156,336	29,174	35,356
Losses charged off	(42,925)	(33,327)	(20,704)
Recoveries	3,140	1,749	4,675
Balance, end of period	$ 161,669	$ 164,073	$ 144,746	312,244	161,669	164,073	144,746
Individually evaluated for impairment				11,687	9,428	9,681
Collectively evaluated for impairment				300,557	152,241	154,392
Individually evaluated for impairment				163,655	131,123	116,655
Collectively evaluated for impairment				14,736,880	12,699,054	11,535,493
Total Loans and Leases				$ 14,900,535	12,830,177	11,652,148
Commercial Portfolio Segment [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Financing Receivable, Allowance for Credit Loss					34,024	$ 0	$ 0
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Total Loans and Leases					5,949,339
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Total Loans and Leases					$ 537,341

Loans and Leases (Impaired Loan

Loans and Leases (Impaired Loans And Leases By Class) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	$ 439,619
Total Recorded Investment	309,422	$ 256,410
Recorded Investment No Allowance	177,908
Recorded Investment With Allowance	131,514
Related Valuation Allowance	16,137
Average Recorded Investment	282,917	257,870	$ 253,042
Accrued Interest Income	9,366	8,173	8,313
Cash Basis Interest Income	3,268	2,059	2,086
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance		312,737
Total Recorded Investment		256,410
Recorded Investment No Allowance		130,619
Recorded Investment With Allowance		125,791
Related Valuation Allowance		14,249
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	109,156	38,503
Total Recorded Investment	46,950	35,191
Recorded Investment No Allowance	34,335	27,672
Recorded Investment With Allowance	12,615	7,519
Related Valuation Allowance	988	1,203
Average Recorded Investment	41,070	37,167	42,290
Accrued Interest Income	1,315	1,045	1,158
Cash Basis Interest Income	1,826	981	980
Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	108,077
Total Recorded Investment	98,164	90,096
Recorded Investment No Allowance	58,915
Recorded Investment With Allowance	39,249
Related Valuation Allowance	3,357
Average Recorded Investment	94,130	96,814	108,913
Accrued Interest Income	3,484	3,502	3,781
Cash Basis Interest Income	1,442	1,078	1,106
Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	2,381	0
Total Recorded Investment	653	0
Recorded Investment No Allowance	2	0
Recorded Investment With Allowance	651	0
Related Valuation Allowance	105	0
Average Recorded Investment	327	0	0
Accrued Interest Income	32	0	0
Cash Basis Interest Income	0	0	0
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	172,069	140,096
Total Recorded Investment	119,884	102,254
Recorded Investment No Allowance	55,742	29,739
Recorded Investment With Allowance	64,142	72,515
Related Valuation Allowance	9,665	7,862
Average Recorded Investment	111,069	100,771	85,585
Accrued Interest Income	3,836	3,241	3,064
Cash Basis Interest Income	0	0	0
Commercial Portfolio Segment [Member] | Asset Based Lending [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	2,989	465
Total Recorded Investment	2,594	139
Recorded Investment No Allowance	0	0
Recorded Investment With Allowance	2,594	139
Related Valuation Allowance	50	5
Average Recorded Investment	1,367	182	407
Accrued Interest Income	0	0	0
Cash Basis Interest Income	0	0	0
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	37,177	29,292
Total Recorded Investment	33,879	23,297
Recorded Investment No Allowance	25,931	14,818
Recorded Investment With Allowance	7,948	8,479
Related Valuation Allowance	1,610	1,143
Average Recorded Investment	28,588	17,062	11,027
Accrued Interest Income	699	385	198
Cash Basis Interest Income	0	0	0
Commercial Portfolio Segment [Member] | Equipment Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	7,770	5,591
Total Recorded Investment	7,298	5,433
Recorded Investment No Allowance	2,983	2,159
Recorded Investment With Allowance	4,315	3,274
Related Valuation Allowance	362	418
Average Recorded Investment	6,366	5,874	4,820
Accrued Interest Income	0	0	112
Cash Basis Interest Income	$ 0	0	$ 0
Commercial Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance		98,790
Total Recorded Investment		90,096
Recorded Investment No Allowance		56,231
Recorded Investment With Allowance		33,865
Related Valuation Allowance		$ 3,618

Loans and Leases (Interest Inco

Loans and Leases (Interest Income From Impaired Loans And Leases, By Class) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 282,917	$ 257,870	$ 253,042
Accrued Interest Income	9,366	8,173	8,313
Cash Basis Interest Income	3,268	2,059	2,086
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	41,070	37,167	42,290
Accrued Interest Income	1,315	1,045	1,158
Cash Basis Interest Income	$ 1,826	$ 981	$ 980

Loans and Leases (Commercial, C

Loans and Leases (Commercial, Commercial Real Estate Loans And Equipment Financing Loans Segregated By Risk Rating Exposure) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	$ 21,641,215	$ 20,036,986	$ 18,465,489
Commercial Non-Real Estate Portfolio Segment
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		6,343,497
Commercial Non-Real Estate Portfolio Segment | (1) - (6) Pass [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		5,985,338
Commercial Non-Real Estate Portfolio Segment | (7) Special Mention [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		94,809
Commercial Non-Real Estate Portfolio Segment | (8) Substandard [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		259,490
Commercial Non-Real Estate Portfolio Segment | (9) Doubtful [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		3,860
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		5,949,339
Commercial Real Estate Portfolio Segment [Member] | (1) - (6) Pass [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		5,860,981
Commercial Real Estate Portfolio Segment [Member] | (7) Special Mention [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		26,978
Commercial Real Estate Portfolio Segment [Member] | (8) Substandard [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		61,380
Commercial Real Estate Portfolio Segment [Member] | (9) Doubtful [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		537,341
Finance Leases Portfolio Segment [Member] | (1) - (6) Pass [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		528,561
Finance Leases Portfolio Segment [Member] | (7) Special Mention [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		808
Finance Leases Portfolio Segment [Member] | (8) Substandard [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		7,972
Finance Leases Portfolio Segment [Member] | (9) Doubtful [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases		$ 0

Loans and Leases (Summary Of Th

Loans and Leases (Summary Of The Recorded Investment Of Company's TDRs) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDR	$ 235,427	$ 237,438
Specific reserves for TDR included in the balance of ALLL	359,431	209,096	$ 212,353	$ 199,994
Additional funds committed to borrowers in TDR status	12,895	4,856
Performing Financial Instruments [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDR	140,089	136,449
Nonperforming Financial Instruments [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDR	95,338	100,989
Troubled Debt Restructures [Member] | Nonperforming Financial Instruments [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Specific reserves for TDR included in the balance of ALLL	$ 12,728	$ 12,956

Loans and Leases (Information o

Loans and Leases (Information on How Loans and Leases were Modified as a TDR) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)loan	Dec. 31, 2019USD ($)loan	Dec. 31, 2018USD ($)loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases	192	136	143
Post-Modification Recorded Investment | $	$ 55,691	$ 88,771	$ 66,781
Commercial Portfolio Segment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases	4	7
Commercial Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases	12	18	18
Post-Modification Recorded Investment | $	$ 1,142	$ 10,769	$ 1,656
Commercial Portfolio Segment [Member] | Adjusted Interest Rates [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases	1	2	0
Post-Modification Recorded Investment | $	$ 96	$ 112	$ 0
Commercial Portfolio Segment [Member] | Combination Rate and Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases	9	11	18
Post-Modification Recorded Investment | $	$ 984	$ 673	$ 10,327
Commercial Portfolio Segment [Member] | Other Concessions
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases	27	31	21
Post-Modification Recorded Investment | $	$ 40,434	$ 70,002	$ 46,359
Consumer Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases	6	13	5
Post-Modification Recorded Investment | $	$ 673	$ 1,926	$ 489
Consumer Portfolio Segment [Member] | Combination Rate and Maturity [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases	15	19	15
Post-Modification Recorded Investment | $	$ 1,467	$ 2,381	$ 1,565
Consumer Portfolio Segment [Member] | Other Concessions
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans and Leases	122	42	66
Post-Modification Recorded Investment | $	$ 10,895	$ 2,908	$ 6,385

Loans and Leases (Investments i

Loans and Leases (Investments in TDRs, Segregated by Risk Rating Exposure) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	$ 235,427	$ 237,438
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	117,695	112,152
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (1) - (6) Pass [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	12,462	3,952
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (7) Special Mention [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	0	63
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (8) Substandard [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	105,070	104,277
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (9) Doubtful [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total recorded investment of TDRs	$ 163	$ 3,860

Loans and Leases (Credit Qualit

Loans and Leases (Credit Quality Indicators) (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	$ 3,228,277,000
Financing Receivable, Year One, Originated, Current Fiscal Year	5,461,818,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,635,131,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,728,575,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,645,809,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,487,739,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	3,453,866,000
Loans and leases	21,641,215,000	$ 20,036,986,000	$ 18,465,489,000
Consumer Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	1,392,880,000
Financing Receivable, Year One, Originated, Current Fiscal Year	1,345,637,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	853,627,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	253,438,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	447,194,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	578,606,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,869,298,000
Loans and leases	6,740,680,000	7,206,809,000	6,813,341,000
Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	23,691,000
Financing Receivable, Year One, Originated, Current Fiscal Year	32,857,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	65,114,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	26,238,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	5,411,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,468,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,020,000
Loans and leases	155,799,000
Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	1,231,789,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	746,435,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	167,979,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	402,761,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	536,400,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,696,652,000
Loans and leases	4,782,016,000	4,972,685,000
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	1,369,189,000
Financing Receivable, Year One, Originated, Current Fiscal Year	80,991,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	42,078,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	59,221,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	39,022,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	40,738,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	171,626,000
Loans and leases	1,802,865,000	2,014,544,000
Commercial Portfolio Segment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	1,835,397,000
Financing Receivable, Year One, Originated, Current Fiscal Year	4,116,181,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,781,504,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,475,137,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,198,615,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	909,133,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,584,568,000
Loans and leases	14,900,535,000	12,830,177,000	$ 11,652,148,000
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	28,113,000
Financing Receivable, Year One, Originated, Current Fiscal Year	966,426,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,472,718,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,334,949,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	639,091,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	593,209,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,288,131,000
Loans and leases	6,322,637,000	5,949,339,000
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member] | (7) Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	27,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	10,385,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	70,704,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	37,539,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	35,617,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	69,832,000
Loans and leases	224,104,000
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member] | (1) - (6) Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	28,113,000
Financing Receivable, Year One, Originated, Current Fiscal Year	965,582,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,461,201,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,242,322,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	527,931,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	554,630,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,165,331,000
Loans and leases	5,945,110,000
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member] | (8) Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	817,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,132,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	21,923,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	73,621,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,962,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	52,968,000
Loans and leases	153,423,000
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	1,024,172,000
Financing Receivable, Year One, Originated, Current Fiscal Year	2,858,624,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,137,847,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,035,468,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	518,078,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	255,172,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	255,715,000
Loans and leases	7,085,076,000	5,296,611,000
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member] | (7) Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	38,496,000
Financing Receivable, Year One, Originated, Current Fiscal Year	32,535,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	33,969,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	62,034,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	435,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	8,357,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	13,757,000
Loans and leases	189,583,000
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member] | (1) - (6) Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	936,592,000
Financing Receivable, Year One, Originated, Current Fiscal Year	2,771,373,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,052,080,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	907,110,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	481,321,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	231,280,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	218,001,000
Loans and leases	6,597,757,000
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member] | (8) Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	49,084,000
Financing Receivable, Year One, Originated, Current Fiscal Year	54,716,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	51,798,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	66,324,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	36,159,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	15,535,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	23,957,000
Loans and leases	297,573,000
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member] | (9) Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	163,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Loans and leases	163,000
Commercial Portfolio Segment [Member] | Asset Based Lending [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	783,112,000
Financing Receivable, Year One, Originated, Current Fiscal Year	26,344,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	18,464,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	23,898,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	11,333,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	10,963,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	16,484,000
Loans and leases	890,598,000	1,046,886,000
Commercial Portfolio Segment [Member] | Asset Based Lending [Member] | (7) Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	41,687,000
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	775,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Loans and leases	42,462,000
Commercial Portfolio Segment [Member] | Asset Based Lending [Member] | (1) - (6) Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	741,336,000
Financing Receivable, Year One, Originated, Current Fiscal Year	26,344,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	15,960,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	23,123,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	11,333,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	10,963,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	16,484,000
Loans and leases	845,543,000
Commercial Portfolio Segment [Member] | Asset Based Lending [Member] | (8) Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	89,000
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,504,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Loans and leases	2,593,000
Commercial Portfolio Segment [Member] | Equipment Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	264,787,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	152,475,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	80,822,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	30,113,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	49,789,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	24,238,000
Loans and leases	602,224,000	$ 537,341,000
Commercial Portfolio Segment [Member] | Equipment Loan [Member] | (7) Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	7,934,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	11,043,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	6,981,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,220,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,577,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	788,000
Loans and leases	29,543,000
Commercial Portfolio Segment [Member] | Equipment Loan [Member] | (1) - (6) Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	249,370,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	135,263,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	68,092,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	26,433,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	43,469,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	22,879,000
Loans and leases	545,506,000
Commercial Portfolio Segment [Member] | Equipment Loan [Member] | (8) Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	7,483,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	6,169,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	5,749,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,460,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,743,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	571,000
Loans and leases	27,175,000
579 and below [Member] | Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	1,428,000
Financing Receivable, Year One, Originated, Current Fiscal Year	608,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	982,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	500,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	183,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	37,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	215,000
Loans and leases	3,953,000
579 and below [Member] | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	36,498,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	673,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	3,278,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,179,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	53,794,000
Loans and leases	97,422,000
579 and below [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	30,501,000
Financing Receivable, Year One, Originated, Current Fiscal Year	129,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	919,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	880,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,070,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,073,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	7,163,000
Loans and leases	41,735,000
800+ [Member] | Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	7,171,000
Financing Receivable, Year One, Originated, Current Fiscal Year	2,827,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5,725,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,610,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	658,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	115,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	190,000
Loans and leases	19,296,000
800+ [Member] | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	360,336,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	283,755,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	61,048,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	178,849,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	268,044,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	805,537,000
Loans and leases	1,957,569,000
800+ [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	542,600,000
Financing Receivable, Year One, Originated, Current Fiscal Year	30,604,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	16,567,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	25,205,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	14,439,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	17,192,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	59,956,000
Loans and leases	706,563,000
740-799 [Member] | Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	5,119,000
Financing Receivable, Year One, Originated, Current Fiscal Year	12,317,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	21,036,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	8,925,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,493,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	457,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	263,000
Loans and leases	49,610,000
740-799 [Member] | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	654,973,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	288,173,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	58,249,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	133,416,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	176,286,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	492,720,000
Loans and leases	1,803,817,000
740-799 [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	434,271,000
Financing Receivable, Year One, Originated, Current Fiscal Year	34,797,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	13,565,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	19,715,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	11,073,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	12,839,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	43,802,000
Loans and leases	570,062,000
670 to 739 [Member] | Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	8,403,000
Financing Receivable, Year One, Originated, Current Fiscal Year	14,761,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	31,952,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	11,843,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,284,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	665,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	228,000
Loans and leases	70,136,000
670 to 739 [Member] | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	199,329,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	118,620,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	39,125,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	75,375,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	76,666,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	248,268,000
Loans and leases	757,383,000
670 to 739 [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	275,691,000
Financing Receivable, Year One, Originated, Current Fiscal Year	13,753,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	8,855,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	10,761,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	10,206,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	7,318,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	44,025,000
Loans and leases	370,609,000
580-669 [Member] | Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	1,570,000
Financing Receivable, Year One, Originated, Current Fiscal Year	2,344,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	5,419,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,360,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	793,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	194,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	124,000
Loans and leases	12,804,000
580-669 [Member] | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	0
Financing Receivable, Year One, Originated, Current Fiscal Year	17,151,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	19,389,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	8,884,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	11,843,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	12,225,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	96,333,000
Loans and leases	165,825,000
580-669 [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Revolving	86,126,000
Financing Receivable, Year One, Originated, Current Fiscal Year	1,708,000
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,172,000
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	2,660,000
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,234,000
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	2,316,000
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	16,680,000
Loans and leases	$ 113,896,000

Loans and Leases (Impaired Coll

Loans and Leases (Impaired Collateral) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 309,422	$ 256,410
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	119,884	102,254
Commercial Portfolio Segment [Member] | Asset Based Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	2,594	139
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	33,879	23,297
Commercial Portfolio Segment [Member] | Equipment Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	7,298	5,433
Commercial Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment		90,096
Consumer Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment		256,410
Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	98,164	90,096
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	46,950	35,191
Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	653	0
Collateral Pledged [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	102,836	59,550
Collateral Pledged [Member] | Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	11,074	10,682
Collateral Pledged [Member] | Commercial Portfolio Segment [Member] | Asset Based Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	2,504	0
Collateral Pledged [Member] | Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	28,482	14,097
Collateral Pledged [Member] | Commercial Portfolio Segment [Member] | Equipment Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Collateral Pledged [Member] | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	33,980	17,635
Collateral Pledged [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	26,796	17,136
Collateral Pledged [Member] | Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	0	0
Uncollateralized [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	206,586	196,860
Uncollateralized [Member] | Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	108,810	91,572
Uncollateralized [Member] | Commercial Portfolio Segment [Member] | Asset Based Loans [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	90	139
Uncollateralized [Member] | Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	5,397	9,200
Uncollateralized [Member] | Commercial Portfolio Segment [Member] | Equipment Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	7,298	5,433
Uncollateralized [Member] | Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	64,184	72,461
Uncollateralized [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	20,154	18,055
Uncollateralized [Member] | Consumer Portfolio Segment [Member] | Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	653	0
Collateral Value [Member]
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, Recorded Investment	$ 150,300	$ 109,800

Loans and Leases (Nonaccrual) (

Loans and Leases (Nonaccrual) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	$ 167,960	$ 151,059
Financing Receivable, Nonaccrual, No Allowance	89,433	54,926
Interest on non-accrual loans that would have been recorded as additional interest income	9,700	11,300	$ 9,700
Commercial Portfolio Segment [Member]
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	95,197	76,504
Financing Receivable, Nonaccrual, No Allowance	35,497	20,460
Commercial Portfolio Segment [Member] | Non-Real Estate Receivables [Member]
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	64,073	59,369
Financing Receivable, Nonaccrual, No Allowance	16,985	13,584
Commercial Portfolio Segment [Member] | Asset Based Lending [Member]
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	2,594	139
Financing Receivable, Nonaccrual, No Allowance	0	0
Commercial Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	21,231	11,563
Financing Receivable, Nonaccrual, No Allowance	15,529	4,717
Commercial Portfolio Segment [Member] | 6172 Finance Lessors [Member]
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	7,299	5,433
Financing Receivable, Nonaccrual, No Allowance	2,983	2,159
Consumer Portfolio Segment [Member]
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	72,763	74,555
Financing Receivable, Nonaccrual, No Allowance	53,936	34,466
Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	41,081	43,193
Financing Receivable, Nonaccrual, No Allowance	29,843	19,271
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	31,030	30,170
Financing Receivable, Nonaccrual, No Allowance	24,091	15,195
Consumer Portfolio Segment [Member] | 522291 Consumer Lending [Member]
Financing Receivable, Nonaccrual [Line Items]
Non-accrual	652	1,192
Financing Receivable, Nonaccrual, No Allowance	$ 2	$ 0

Transfers of Financial Assets_2

Transfers of Financial Assets (Reserve for loan repurchases) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance		$ 2,506	$ 2,362
(Benefit) provision charged to expense			144
Ending balance			2,506
SEC Schedule, 12-09, Reserve, Off-balance Sheet Activity [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 508	674	872
(Benefit) provision charged to expense	141	1,865	(160)
Repurchased loans and settlements charged off	98	(2,031)	(38)
Ending balance	$ 747	$ 508	$ 674

Transfers of Financial Assets_3

Transfers of Financial Assets (Loans sold) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Servicing Assets at Fair Value [Line Items]
Net gain on sale	$ 18,295	$ 6,115	$ 4,424
Residential Mortgage [Member]
Servicing Assets at Fair Value [Line Items]
Proceeds from sale	486,341	216,239	188,025
Net gain on sale	15,305	4,031	3,146
Ancillary Fee Income Generated by Servicing Financial Assets, Amount	3,230	1,614	1,544
Fair value option adjustment	(240)	470	(266)
Commercial Loan [Member]
Servicing Assets at Fair Value [Line Items]
Net gain on sale	300	700
Residential Mortgage Loans Servicing Retained [Member] | Residential Mortgage [Member]
Servicing Assets at Fair Value [Line Items]
Proceeds from sale	$ 464,736	$ 199,114	$ 166,909

Transfers of Financial Assets_4

Transfers of Financial Assets (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Retained servicing rights			$ 2,400,000
Proceeds from loans not originated for sale		$ 9,197	20,931	$ 1,687
Net gain on sale		18,295	6,115	4,424
Residential Mortgage [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Retained servicing rights		2,300,000
Bank servicing fees	$ 1,900	1,500		1,200
Proceeds from loans not originated for sale			4,000	400
Net gain on sale		15,305	4,031	3,146
Commercial Loan [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds from loans not originated for sale		9,200	17,000	$ 1,300
Net gain on sale		$ 300	$ 700

Transfers of Financial Assets S

Transfers of Financial Assets Servicing Assets at Amortized Cost Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Beginning balance	$ 17,484	$ 21,215	$ 25,139
Additions	4,373	3,587	4,459
Amortization	(6,562)	(7,318)	(8,383)
Valuation allowance	(1,873)	0	0
Ending balance	$ 13,422	$ 17,484	$ 21,215

Premises and Equipment (Summary

Premises and Equipment (Summary of Premises and Equipment) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)banking_center	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Property, Plant and Equipment [Abstract]
Land	$ 9,436	$ 10,997
Buildings and improvements	70,195	77,892
Leasehold improvements	71,332	77,346
Fixtures and equipment	73,730	73,946
Data processing and software	270,780	263,445
Total premises and equipment	495,473	503,626
Less: Accumulated depreciation and amortization	(396,211)	(388,562)
Property and equipment, net	99,262	115,064
Net Investment in Lease	127,481	155,349
Premises and equipment, net	226,743	270,413
Depreciation and amortization	32,500	$ 33,700	$ 34,900
Leased assets impairment loss	$ 12,000
Leased banking centers closed | banking_center	21

Premises and Equipment (Disclos

Premises and Equipment (Disclosure of Long Lived Assets Held-for-sale) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Movement in Property, Plant and Equipment [Roll Forward]
Beginning balance	$ 0	$ 91
Additions	2,654	0
Write-downs	0	(91)
Sales	0	0
Ending balance	$ 2,654	$ 0

Leases - Operating ROU Assets a

Leases - Operating ROU Assets and Lease Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jan. 01, 2019
Operating Leased Assets [Line Items]
ROU lease assets			$ 127,481	$ 157,234
Lease liabilities	$ 158,280	$ 174,396	$ 158,280	$ 178,802
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet
Minimum [Member]
Operating Leased Assets [Line Items]
Lease term	5 years
Maximum [Member]
Operating Leased Assets [Line Items]
Lease term	20 years

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease, Cost [Abstract]
Operating lease costs	$ 30,339	$ 29,908
Variable lease costs	5,577	4,889
Sublease income	(557)	(577)
Total operating lease cost	35,359	34,220
Cash paid for amounts included in the measurement of lease liabilities	31,212	31,223
ROU lease assets obtained in exchange for new operating lease liabilities	$ 9,211	$ 22,948

Leases - Maturity of Operating

Leases - Maturity of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jan. 01, 2019
Lessee, Operating Lease, Liability, Payment, Due, Rolling Maturity [Abstract]
2021	$ 28,142
2022	27,069
2023	24,335
2024	21,321
2025	19,332
Thereafter	62,253
Total operating lease liability payments	182,452
Less: Present value adjustment	24,172
Lease liabilities	$ 158,280	$ 174,396	$ 158,280	$ 178,802
Weighted-average remaining lease term - operating leases, in years	8 years 14 days
Weighted-average discount rate - operating leases	3.19%

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Gross Carrying Value And Accumulated Amortization Of Other Intangible Assets) (Detail) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 538,373,000	$ 538,373,000
Gross Carrying Amount	47,625,000	43,000,000
Accumulated Amortization	(25,242,000)	(21,083,000)
Net Carrying Amount	22,383,000	21,917,000
Community Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	516,600,000
HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	21,800,000
Core Deposits [Member] | HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	26,625,000	22,000,000
Accumulated Amortization	(15,618,000)	(13,073,000)
Net Carrying Amount	11,007,000	8,927,000
Customer Relationships [Member] | HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	21,000,000	21,000,000
Accumulated Amortization	(9,624,000)	(8,010,000)
Net Carrying Amount	$ 11,376,000	$ 12,990,000

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Schedule Of Expected Future Amortization Expense) (Detail) $ in Thousands	Dec. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 4,513
2021	4,411
2022	4,315
2023	2,084
2024	2,084
Thereafter	$ 4,976

Income Taxes (Income Tax Expens

Income Taxes (Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal									$ 73,172	$ 84,447	$ 58,334
State and local									17,417	18,595	13,409
Total current									90,589	103,042	71,743
Deferred:
Federal									(23,799)	811	8,508
State and local									(7,437)	116	964
Total deferred									(31,236)	927	9,472
Total:
Total federal									49,373	85,258	66,842
Total state and local									9,980	18,711	14,373
Income tax expense	$ 15,118	$ 18,289	$ 14,802	$ 11,144	$ 25,966	$ 25,411	$ 26,451	$ 26,141	$ 59,353	$ 103,969	$ 81,215

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Net tax credits	$ 1,100	$ 4,800	$ 1,200
Tax Cuts and Jobs Act, Measurement Period Adjustment, Income Tax Expense (Benefit)			10,400
Increase (decrease) in deferred income taxes	19,300
Deferred tax expense (benefit)	(31,236)	927	9,472
Tax benefit directly allocated to shareholder's equity	27,800
Deferred tax assets	238,703	203,640
Valuation allowance	37,374	38,181
Valuation allowance increase (decrease)	(800)
Unrecognized deferred tax liability for thrift bad-debt reserves	15,300
Unrecognized tax benefits that would impact effective tax rate	3,500	3,900	2,300
Cumulative taxable temporary differences	58,000
Interest and penalties	100	100	$ 0
Accrued interest and penalties related to UTBs	1,700	1,800
Cumulative Effect, Period of Adoption, Adjustment [Member]
Operating Loss Carryforwards [Line Items]
Deferred tax assets		15,900
Research Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Net tax credits		3,000
Investment Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Net tax credits	800	2,400
General Business Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Net tax credits	300
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance	37,400	$ 38,200
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	630,800
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Domestic	1,100,000
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	1,600
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Decrease in Unrecognized Tax Benefits is Reasonably Possible	$ 2,700

Income Taxes (Schedule of Effec

Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense at federal statutory rate									$ 58,795	$ 102,205	$ 92,743
SALT expense, net of federal									7,884	14,782	11,354
Tax-exempt interest income, net									(7,181)	(6,752)	(6,475)
Increase in cash surrender value of life insurance									(3,058)	(3,069)	(3,069)
Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Amount									(484)	2,251	4,483
Non-deductible FDIC deposit insurance premiums									2,172	1,904	2,215
Tax Act impacts, net									0	0	10,982
Other, net									(257)	2,850	88
Income tax expense	$ 15,118	$ 18,289	$ 14,802	$ 11,144	$ 25,966	$ 25,411	$ 26,451	$ 26,141	$ 59,353	$ 103,969	$ 81,215
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax expense at federal statutory rate									21.00%	21.00%	21.00%
SALT expense, net of federal									2.80%	3.00%	2.60%
Tax-exempt interest income, net									(2.60%)	(1.40%)	(1.50%)
Increase in cash surrender value of life insurance									(1.10%)	(0.60%)	(0.70%)
Tax deficiencies (excess tax benefits), net									(0.20%)	0.40%	1.00%
Non-deductible FDIC deposit insurance premiums									0.80%	0.40%	0.50%
Tax Act impacts, net									0.00%	0.00%	2.50%
Other, net									(0.10%)	0.60%	0.00%
Income tax expense and effective tax rate									21.20%	21.40%	18.40%

Income Taxes (Schedule of Defer

Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Allowance for loan and lease losses	$ 93,791	$ 53,851
Net operating loss and credit carry forwards	66,840	69,827
Compensation and employee benefit plans	27,643	24,518
Lease liabilities under operating leases	41,679	45,923
Deferred loan fees, net	2,397	0
Net unrealized loss on derivatives	0	1,650
Other	6,353	7,871
Gross deferred tax assets	238,703	203,640
Valuation allowance	(37,374)	(38,181)
Total deferred tax assets, net of valuation allowance	201,329	165,459
Deferred tax liabilities:
Net unrealized gain on securities available for sale	24,364	6,430
Net unrealized gain on derivatives	7,616	0
ROU assets under operating leases	33,569	40,908
Equipment financing leases	38,511	31,332
Premises and equipment	6,735	7,838
Loan origination costs, net	0	6,816
Goodwill and other intangible assets	5,954	6,172
Other	3,294	3,988
Gross deferred tax liabilities	120,043	103,484
Deferred tax assets, net	$ 81,286	$ 61,975

Income Taxes (Summary of Positi

Income Taxes (Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 4,813	$ 2,856	$ 3,595
Additions as a result of tax positions taken during the current year	87	1,106	249
Additions as a result of tax positions taken during prior years	572	1,744	71
Reductions as a result of tax positions taken during prior years	(694)	(238)	(474)
Reductions relating to settlements with taxing authorities	(130)	(18)	(97)
Reductions as a result of lapse of statute of limitation periods	(396)	(637)	(488)
Ending balance	$ 4,252	$ 4,813	$ 2,856

Deposits (Summary Of Deposits)

Deposits (Summary Of Deposits) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deposit Liabilities [Abstract]
Demand	$ 6,155,592	$ 4,446,463
Health Savings Accounts	7,120,017	6,416,135
Checking	3,652,763	2,689,734
Money market	2,940,215	2,312,840
Savings	4,979,031	4,354,809
Time deposits	2,487,818	3,104,765
Total interest-bearing	21,179,844	18,878,283
Total deposits	27,335,436	23,324,746
Time deposits and interest-bearing checking, included in above balances, obtained through brokers	720,440	652,151
Time deposits, included in above balance, that exceed the FDIC limit	504,543	661,334
Demand deposit overdrafts reclassified as loan balances	$ 2,007	$ 1,721

Deposits (Scheduled Maturities

Deposits (Scheduled Maturities Of Time Deposits) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deposit Liabilities [Abstract]
2020	$ 2,173,670
2021	186,612
2022	54,287
2023	22,302
2024	50,947
Total time deposits	$ 2,487,818	$ 3,104,765

Borrowings Borrowings - (Narrat

Borrowings Borrowings - (Narrative) (Details) - USD ($) $ in Billions	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Total borrowings	$ 1.7	$ 3.5

Borrowings (Summary Of Securiti

Borrowings (Summary Of Securities Sold Under Agreements To Repurchase And Other Borrowings) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets Sold under Agreements to Repurchase [Line Items]
Total securities sold under agreements to repurchase	$ 469,330	$ 440,431
Fed funds purchased	526,025	600,000
Securities sold under agreements to repurchase and other borrowings	995,355	1,040,431
Original maturity of one year or less [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total securities sold under agreements to repurchase	269,330	240,431
Original maturity of greater than one year, non-callable [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total securities sold under agreements to repurchase	$ 200,000	$ 200,000
Securities Sold under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	0.43%	0.91%
Securities Sold under Agreements to Repurchase [Member] | Original maturity of one year or less [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	0.13%	0.19%
Securities Sold under Agreements to Repurchase [Member] | Original maturity of greater than one year, non-callable [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	0.84%	1.78%
Federal Funds Purchased [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	0.08%	1.59%
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	0.25%	1.30%

Borrowings (Summary Of Advances

Borrowings (Summary Of Advances Payable To The Federal Home Loan Bank) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Maturity, Rolling Year [Abstract]
FHLB advances maturing within 1 year, Weighted-Average Contractual Coupon Rate (as a percent)	0.38%	1.79%
FHLB advances maturing after 1 but within 2 years, Weighted-Average Contractual Coupon Rate (as a percent)	0.00%	2.53%
FHLB advances maturing after 2 but within 3 years, Weighted-Average Contractual Coupon Rate (as a percent)	2.95%	0.00%
FHLB advances maturing after 3 but within 4 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.59%	2.95%
FHLB advances maturing after 4 but within 5 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.42%	1.59%
FHLB advances maturing after 5 years, Weighted-Average Contractual Coupon Rate (as a percent)	2.66%	2.66%
Federal Home Loan Bank, Advances, Weighted Average Interest Rate (as a percent)	1.36%	1.87%
Aggregate carrying value of assets pledged as collateral	$ 7,387,054	$ 7,318,748
Remaining borrowing capacity	4,689,642	2,937,644
FHLB advances maturing within 1 year, Total Outstanding	25,000	1,690,000
FHLB advances maturing after 1 but within 2 years, Total Outstanding	110	200,000
FHLB advances maturing after 2 but within 3 years, Total Outstanding	215	130
FHLB advances maturing after 3 but within 4 years, Total Outstanding	50,000	229
FHLB advances maturing after 4 but within 5 years, Total Outstanding	50,000	50,000
FHLB advances maturing after 5 years, Total Outstanding	7,839	8,117
FHLB advances	$ 133,164	$ 1,948,476

Borrowings (Long-Term Debt) (De

Borrowings (Long-Term Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Debt Instrument [Line Items]
Notes and subordinated debt	$ 571,484	$ 544,806
Debt issuance cost on senior fixed-rate notes	(2,628)	(3,030)
Long-term debt	$ 567,663	$ 540,364
Long term debt, variable interest rate, percentage	3.18%	4.85%
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)			$ 17,486
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest rate spread of LIBOR plus (as a percent)	2.95%
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	$ 77,320	$ 77,320
Long-term Debt [Member]
Debt Instrument [Line Items]
Discount on senior fixed-rate notes	(1,193)	(1,412)
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	44,200
Debt Instrument, Redemption, Period One [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	$ 150,000	150,000
Debt instrument, stated interest rate, percentage	4.375%
Debt Instrument, Redemption, Period Two | Senior Notes [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	$ 344,164	$ 317,486
Debt instrument, stated interest rate, percentage	4.10%

Shareholders' Equity (Class of

Shareholders' Equity (Class of Stock Disclosure) (Details)	12 Months Ended
	Dec. 31, 2020shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock Held, beginning balance	1,659,749
Common Stock Outstanding, beginning balance	92,026,562
Restricted share activity	266,325
Stock options exercised	(10,230)
Common stock repurchased	(2,104,195)
Treasury Stock Held, ending balance	3,487,389
Common Stock Outstanding, ending balance	90,198,922
Series F Preferred Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, beginning balance	6,000
Restricted share activity	0
Stock options exercised	0
Common stock repurchased	0
Shares, ending balance	6,000
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, beginning balance	93,686,311
Restricted share activity	0
Stock options exercised	0
Common stock repurchased	0
Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted share activity	(266,325)
Stock options exercised	(10,230)
Common stock repurchased	(2,104,195)

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019$ / sharesshares
Class of Stock [Line Items]
Stock repurchase program, authorized amount | $	$ 200,000
Common stock, shares issued | shares	93,686,311	93,686,311
Stock repurchase program, remaining authorized repurchase amount | $	$ 6,000
Common stock par value (in usd per share)	$ 0.01	$ 0.01
Depositary shares, ownership of preferred shares	0.001
Preferred Stock, Par or Stated Value Per Share	$ 0.01
Preferred stock, liquidation preference per share (in usd per share)	$ 25,000
Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares issued | shares	93,686,311
Treasury stock acquired, average cost per share (in usd per share)	$ 36.38
Stock repurchase program, remaining authorized repurchase amount | $	$ 123,400
Series F Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percent)	5.25%
Preferred Stock, Par or Stated Value Per Share	$ 0.01
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Par or Stated Value Per Share	$ 25

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss, Net of Tax (Schedule of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 2,886,515	$ 2,701,958	$ 3,207,770	$ 2,886,515	$ 2,701,958
Other comprehensive (loss) income, net of tax			78,328	94,580	(39,121)
Ending Balance			3,234,625	3,207,770	2,886,515
Available For Sale and Transferred Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(71,374)	(27,947)		(71,374)	(27,947)
Other comprehensive income (loss) before reclassifications	50,179	88,647			(43,427)
Amounts reclassified from accumulated other comprehensive loss	(6)	(22)			0
Other comprehensive (loss) income, net of tax	50,173	88,625			(43,427)
Ending Balance	67,424	17,251			(71,374)
Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(9,313)	(15,016)		(9,313)	(15,016)
Other comprehensive income (loss) before reclassifications	20,667	(4,945)			208
Amounts reclassified from accumulated other comprehensive loss	8,435	5,074			5,495
Other comprehensive (loss) income, net of tax	29,102	129			5,703
Ending Balance	19,918	(9,184)			(9,313)
Defined Benefit Pension and Postretirement Benefit Plans [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(49,965)	(48,568)		(49,965)	(48,568)
Other comprehensive income (loss) before reclassifications	(3,887)	1,622			(7,122)
Amounts reclassified from accumulated other comprehensive loss	2,940	4,204	2,940	4,204	5,725
Other comprehensive (loss) income, net of tax	(947)	5,826			(1,397)
Ending Balance	(45,086)	(44,139)			(49,965)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(130,652)	(91,531)	(36,072)	(130,652)	(91,531)
Other comprehensive income (loss) before reclassifications	66,959	85,324			(50,341)
Amounts reclassified from accumulated other comprehensive loss	11,369	9,256			11,220
Other comprehensive (loss) income, net of tax	78,328	94,580	78,328	94,580	(39,121)
Ending Balance	$ 42,256	$ (36,072)	$ 42,256	$ (36,072)	$ (130,652)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Loss, Net of Tax (Schedule of Reclassifications from AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended								9 Months Ended		12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Gain on the sale of investment securities, net											$ 8	$ 29	$ 0
Interest expense	$ (19,136)	$ (19,983)	$ (27,868)	$ (43,669)	$ (50,750)	$ (53,597)	$ (50,470)	$ (44,639)			(110,656)	(199,456)	(148,486)
Interest income	236,065	239,239	252,275	274,470	282,000	294,136	292,257	286,190			1,002,049	1,154,583	1,055,167
Income tax expense	$ (15,118)	$ (18,289)	$ (14,802)	$ (11,144)	$ (25,966)	$ (25,411)	$ (26,451)	$ (26,141)			(59,353)	(103,969)	(81,215)
Earnings applicable to common shareholders											211,474	372,985	351,703
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Including Noncontrolling Interest [Member] | Reclassification out of accumualted comprehensive income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Gain on the sale of investment securities, net											8	29	0
Available For Sale and Transferred Securities [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax									$ 6	$ 22			0
Available For Sale and Transferred Securities [Member] | Reclassification out of accumualted comprehensive income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense											(2)	(7)	0
Earnings applicable to common shareholders											6	22	0
Derivative Instruments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax									(8,435)	(5,074)			(5,495)
Derivative Instruments | Reclassification out of accumualted comprehensive income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest expense											(7,884)	(5,509)	(7,425)
Interest income											(3,536)	(1,323)	0
Income tax expense											2,985	1,758	1,930
Earnings applicable to common shareholders											(8,435)	(5,074)	(5,495)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax											(3,976)	(5,706)	(7,708)
Defined benefit pension and postretirement benefit plans [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Tax benefit											1,036	1,502	1,983
Net of tax									$ (2,940)	$ (4,204)	$ (2,940)	$ (4,204)	$ (5,725)

Accumulated Other Comprehensi_5

Accumulated Other Comprehensive Loss, Net of Tax (Schedule of Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Available-for-sale securities:
Net unrealized loss during the period	$ 68,116	$ 120,333	$ (58,792)
Reclassification for net gain included in net income	(8)	(29)	0
Total available-for-sale securities	68,108	120,304	(58,792)
Derivative instruments:
Net unrealized gain during the period	27,683	(6,672)	280
Reclassification adjustment for net loss included in net income	11,420	6,832	7,425
Total derivative instruments	39,103	160	7,705
Defined benefit pension and other postretirement benefit plans:
Current year actuarial loss	(5,262)	2,202	(9,600)
Reclassification adjustment for amortization of net loss included in net income	3,976	5,706	7,708
Total (gain) loss recognized in OCI	1,286	(7,908)	1,892
Available-for-sale securities:
Net unrealized loss during the period	(17,937)	(31,686)	15,365
Reclassification for net gain included in net income	(2)	(7)	0
Total securities available-for-sale	17,935	31,679	(15,365)
Derivative instruments:
Net unrealized gain during the period	(7,016)	1,727	(72)
Reclassification adjustment for net loss included in net income	(2,985)	(1,758)	(1,930)
Total derivative instruments	(10,001)	(31)	(2,002)
Defined benefit pension and other postretirement benefit plans:
Current year actuarial loss	1,375	(580)	2,478
Reclassification adjustment for amortization of net loss included in net income	(1,036)	(1,502)	(1,983)
Total defined benefit pension and postretirement benefit plans	339	(2,082)	495
Available-for-sale securities:
Net unrealized loss during the period	50,179	88,647	(43,427)
Reclassification for net gain included in net income	(6)	(22)	0
Total available-for-sale securities	50,173	88,625	(43,427)
Derivative instruments:
Net unrealized gain during the period	20,667	(4,945)	208
Reclassification adjustment for net loss included in net income	8,435	5,074	5,495
Total derivative instruments	29,102	129	5,703
Defined benefit pension and other postretirement benefit plans:
Current year actuarial loss	(3,887)	1,622	(7,122)
Reclassification adjustment for amortization of net loss included in net income	2,940	4,204	5,725
Total defined benefit pension and postretirement benefit plans	(947)	5,826	(1,397)
Other Comprehensive Income (Loss), Pre-Tax Amount	105,925	128,372	(52,979)
Other Comprehensive Income (Loss), Tax Benefit (Expense)	(27,597)	(33,792)	13,858
Other comprehensive (loss) income, net of tax	$ 78,328	$ 94,580	$ (39,121)

Regulatory Matters (Information

Regulatory Matters (Information On The Capital Ratios) (Detail) $ in Thousands	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital	$ 2,543,131	$ 2,516,361
Common Equity Tier One Capital Required for Capital Adequacy	$ 1,008,512	$ 979,739
Common Equity Tier One Capital Ratio	0.1135	0.1156
Common Equity Tier One Capital Required to be Well-Capitalized	$ 1,456,739	$ 1,415,179
Total risk-based capital, Actual Amount	$ 3,045,652	$ 2,950,181
Total risk-based capital, Actual Ratio	0.1359	0.1355
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,792,910	$ 1,741,758
Total risk-based capital, Capital Requirements, Minimum Ratio	0.080	0.080
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 2,241,137	$ 2,177,198
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	0.100	0.100
Tier 1 risk-based capital, Actual Amount	$ 2,688,168	$ 2,661,398
Tier 1 risk-based capital, Actual Ratio	0.1199	0.1222
Tier 1 risk-based capital, Capital Requirements, Minimum Amount	$ 1,344,682	$ 1,306,319
Tier 1 risk-based capital, Capital Requirements, Minimum Ratio	0.060	0.060
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Amount	$ 1,792,910	$ 1,741,758
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Ratio	0.080	0.080
Tier 1 leverage capital, Actual Amount	$ 2,688,168	$ 2,661,398
Tier 1 leverage capital, Actual Ratio	0.0832	0.0896
Tier 1 leverage capital, Capital Requirements, Minimum Amount	$ 1,291,980	$ 1,188,507
Tier 1 leverage capital, Capital Requirements, Minimum Ratio	0.040	0.040
Tier 1 leverage capital, Capital Requirements, Well Capitalized Amount	$ 1,614,975	$ 1,485,634
Tier 1 leverage capital, Capital Requirements, Well Capitalized Ratio	0.050	0.050
Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital	$ 2,791,474	$ 2,527,645
Common Equity Tier One Capital Required for Capital Adequacy	$ 1,008,027	$ 979,497
Common Equity Tier One Capital Ratio	0.1246	0.1161
Common Equity Tier One Capital Required to be Well-Capitalized	$ 1,456,039	$ 1,414,829
Total risk-based capital, Actual Amount	$ 3,071,505	$ 2,739,108
Total risk-based capital, Actual Ratio	0.1371	0.1258
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,792,048	$ 1,741,328
Total risk-based capital, Capital Requirements, Minimum Ratio	0.080	0.080
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 2,240,060	$ 2,176,660
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	0.100	0.100
Tier 1 risk-based capital, Actual Amount	$ 2,791,474	$ 2,527,645
Tier 1 risk-based capital, Actual Ratio	0.1246	0.1161
Tier 1 risk-based capital, Capital Requirements, Minimum Amount	$ 1,344,036	$ 1,305,996
Tier 1 risk-based capital, Capital Requirements, Minimum Ratio	0.060	0.060
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Amount	$ 1,792,048	$ 1,741,328
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Ratio	0.080	0.080
Tier 1 leverage capital, Actual Amount	$ 2,791,474	$ 2,527,645
Tier 1 leverage capital, Actual Ratio	0.0865	0.0851
Tier 1 leverage capital, Capital Requirements, Minimum Amount	$ 1,291,415	$ 1,187,953
Tier 1 leverage capital, Capital Requirements, Minimum Ratio	0.040	0.040
Tier 1 leverage capital, Capital Requirements, Well Capitalized Amount	$ 1,614,268	$ 1,484,941
Tier 1 leverage capital, Capital Requirements, Well Capitalized Ratio	0.050	0.050
Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.045	0.045
Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets [Member] | Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.045	0.045
Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.065	0.065
Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets [Member] | Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier One Capital Ratio	0.065	0.065

Regulatory Matters Regulatory M

Regulatory Matters Regulatory Matters - Narrative (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash dividends paid to parent company	$ 360	$ 20
Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash held by Bank			$ 93.8

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								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share Reconciliation [Abstract]
Net income	$ 60,044	$ 69,281	$ 53,097	$ 38,199	$ 90,473	$ 93,865	$ 98,649	$ 99,736	$ 220,621	$ 382,723	$ 360,418
Less: Preferred stock dividends									7,875	7,875	7,853
Net income available to common shareholders, basic										374,848	352,565
Net income available to common shareholders, diluted									212,746	374,848	352,565
Less: Earnings applicable to participating securities, basic									1,272	1,863	862
Less: Earnings applicable to participating securities, diluted									1,272	1,863	862
Earnings applicable to common shareholders									211,474	372,985	351,703
Earnings applicable to common shareholders, diluted									$ 211,474	$ 372,985	$ 351,703
Earnings per common share:
Earnings per common share, Basic (in dollars per share)	$ 0.64	$ 0.75	$ 0.57	$ 0.40	$ 0.96	$ 1	$ 1.05	$ 1.06	$ 2.35	$ 4.07	$ 3.83
Earnings per common share, Diluted (in dollars per share)	$ 0.64	$ 0.75	$ 0.57	$ 0.39	$ 0.96	$ 1	$ 1.05	$ 1.06	$ 2.35	$ 4.06	$ 3.81
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted-average common shares outstanding - basic									89,967	91,559	91,930
Stock options and restricted stock (in shares)									184	323	297
Weighted Average Number of Shares Outstanding, Diluted									90,151	91,882	92,227

Earnings Per Common Share (Sche

Earnings Per Common Share (Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares	44	73	47

Derivative Financial Instrume_2

Derivative Financial Instruments (Schedule fair value of derivative instruments) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts		$ 6,198,556	$ 5,683,199
Derivative Asset, Fair Value, Gross Asset Including Not Subject to Master Netting Arrangement		146,037	332,856
Derivative Asset, Fair Value, Amount Offset Against Collateral		4,779	7,522
Asset Derivatives, Fair Value, Less: Cash collateral posted		8,100	33,043
Derivative asset		133,158	292,291
Liability Derivatives, Notional Amount		4,722,801	4,741,836
Derivative Liability, Fair Value, Gross Liability Including Not Subject to Master Netting Arrangement		13,813	12,354
Derivative Liability, Fair Value, Amount Offset Against Collateral		4,779	7,522
Liability Derivatives, Fair Value, Less: Cash collateral posted		1,871	4,485
Derivative liability		7,163	347
CME SWAPS MARKETS (CME) [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value, Less: Cash collateral posted	$ 79,000
Cross Currency Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	80,500	65,700
Liability Derivatives, Notional Amount	338,900	223,400
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	40,565	13,012
Derivative Asset, Fair Value, Amount Offset Against Collateral	40,565	12,879
Derivative asset	0	133
Derivative Liability, Fair Value, Gross Liability	12,007	6,710
Derivative Liability, Fair Value, Amount Offset Against Collateral	12,007	6,650
Derivative liability	0	60
Designated as Hedging Instrument [Member] | Interest rate derivatives [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts		1,225,000	1,000,000
Derivative Asset, Fair Value, Gross Asset		11,855	39,641
Liability Derivatives, Notional Amount		300,000	25,000
Derivative Liability, Fair Value, Gross Liability		3,153	103
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts		4,973,556	4,683,199
Asset Derivatives, Fair Value, Positions not subject to master netting agreement		134,182	293,215
Liability Derivatives, Notional Amount		4,422,801	4,716,836
Liability Derivatives, Fair Value, Positions not subject to master netting agreement		10,660	12,251
Not Designated as Hedging Instrument [Member] | Interest rate derivatives [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts		4,869,139	4,533,441
Derivative Asset, Fair Value, Gross Asset		133,455	292,096
Liability Derivatives, Notional Amount		4,090,522	4,356,339
Derivative Liability, Fair Value, Gross Liability		9,732	11,874
Not Designated as Hedging Instrument [Member] | Mortgage Banking Derivatives [Member] | RPA-Out [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts		27,873	40,771
Derivative Asset, Fair Value, Gross Asset		329	855
Not Designated as Hedging Instrument [Member] | Mortgage Banking Derivatives [Member] | RPA-In [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Notional Amount		57,000	0
Derivative Liability, Fair Value, Gross Liability		110	0
Not Designated as Hedging Instrument [Member] | Other Contract [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts		76,544	108,987
Derivative Asset, Fair Value, Gross Asset		398	264
Liability Derivatives, Notional Amount		275,279	360,497
Derivative Liability, Fair Value, Gross Liability		818	$ 377
Not Designated as Hedging Instrument [Member] | CME SWAPS MARKETS (CME) [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional Amounts	100,000	1,100,000
Liability Derivatives, Notional Amount	3,200,000	$ 2,600,000
Interest Rate Lock Commitments [Member]
Derivatives, Fair Value [Line Items]
Other Commitment	$ 2,000

Derivative Financial Instrume_3

Derivative Financial Instruments (Offsetting Derivatives) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Derivative [Line Items]
Derivative instrument asset, Amount Offset, Total		$ (4,779)	$ (7,522)
Derivative instrument asset, Amount Offset		8,100	33,043
Derivative asset		133,158	292,291
Derivative Liability, Fair Value, Amount Offset Against Collateral		4,779	7,522
Derivative Liability, Collateral, Right to Reclaim Cash, Offset		(1,871)	(4,485)
Derivative liability		7,163	347
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	$ (785)	(299)
Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	(785)	(432)
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	(1,247)	(329)
Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	(1,247)	(389)
Hedge Accounting Positions [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset	40,565	13,012
Derivative instrument asset, Amount Offset, Total	(40,565)	(12,879)
Derivative asset	0	133
Derivative Liability, Fair Value, Gross Liability	12,007	6,710
Derivative Liability, Fair Value, Amount Offset Against Collateral	12,007	6,650
Derivative liability	$ 0	60
Interest Rate Derivatives [Member] | Hedge Accounting Positions [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Gross Asset		11,855	39,641
Derivative Liability, Fair Value, Gross Liability		$ 3,153	$ 103

Derivative Financial Instrume_4

Derivative Financial Instruments Impact of Fair Value on Qualifying Hedges (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Mar. 31, 2020	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings		$ 9,571	$ 12,389
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	$ 17,486
Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	0	0	0
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	1,833	5,555	6,557
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	10,008
Operating Expense [Member] | Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(30,693)	(17,486)	0
Interest rate derivatives [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	11,068	8,477	10,376
Interest rate derivatives [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	8,206	4,241	6,557
Interest rate derivatives [Member] | Other Income [Member] | Not Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(6,373)	1,314	0
Mortgage Banking Derivatives [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	636	(6)	(378)
Other Contract [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(1,696)	1,100	2,391
Long-term Debt [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Liability, Fair Value Hedge	344,164				$ 317,486
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	44,164			$ 48,200
Long-term Debt [Member] | Operating Expense [Member] | Designated as Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 30,693	$ 17,486	$ 0

Derivative Financial Instrume_5

Derivative Financial Instruments (Schedule of the changes in the fair value of non-hedge accounting derivatives) (Detail) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings		$ 9,571	$ 12,389
Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 10,008
Interest Rate Derivatives [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	11,068	8,477	10,376
Mortgage Banking Derivatives [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	636	(6)	(378)
Other Contract [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(1,696)	1,100	2,391
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	0	0	0
Fair Value Hedging [Member] | Operating Expense [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(30,693)	(17,486)	0
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	1,833	5,555	6,557
Cash Flow Hedging [Member] | Interest Rate Derivatives [Member] | Operating Expense [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	8,206	4,241	6,557
Cash Flow Hedging [Member] | Interest Rate Derivatives [Member] | Other Income [Member] | Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	(6,373)	1,314	0
Long-term Debt [Member] | Fair Value Hedging [Member] | Operating Expense [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Fair Value Hedges Recognized in Earnings	$ 30,693	$ 17,486	$ 0

Derivative Financial Instrume_6

Derivative Financial Instruments (AOCI Related to Cash Flow Hedges) (Narrative) (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Remaining unamortized gain (loss) on termination of cash flow hedges	$ 300
Price Risk Derivative [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Remaining unamortized gain (loss)	9,000
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Estimate of amount to be reclassified from AOCL	$ (10,300)
Maximum Length of Time Hedged in Cash Flow Hedge	3 years 7 months 6 days
Remaining unamortized gain (loss)	$ 1,000

Derivative Financial Instrume_7

Derivative Financial Instruments (Counterparty Credit Risk Narrative) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Derivative [Line Items]
Derivative instrument asset, Amount Offset		$ 8,100	$ 33,043
Derivative, Collateral, Right to Reclaim Cash	$ 302,000
Credit Derivative, Maximum Exposure, Undiscounted	296,300
Valuation, Cost Approach [Member]
Derivative [Line Items]
Derivative, Collateral, Right to Reclaim Cash	34,300
Valuation, Market Approach [Member]
Derivative [Line Items]
Credit Derivative, Maximum Exposure, Undiscounted	39,500
CME SWAPS MARKETS (CME) [Member]
Derivative [Line Items]
Derivative instrument asset, Amount Offset	79,000
Derivative, Collateral, Right to Reclaim Cash	$ 252,000

Derivative Financial Instrume_8

Derivative Financial Instruments Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Derivative [Line Items]
Derivative Asset, Fair Value, Amount Offset Against Collateral		$ 4,779	$ 7,522
Derivative Asset		133,158	292,291
Derivative Liability, Fair Value, Amount Offset Against Collateral		4,779	7,522
Derivative Liability		7,163	$ 347
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	$ 785	299
Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	785	432
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	1,247	329
Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	1,247	389
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	12,007	6,710
Derivative Asset, Fair Value, Gross Asset	40,565	13,012
Derivative Asset, Fair Value, Amount Offset Against Collateral	40,565	12,879
Derivative Asset	0	133
Derivative Liability, Fair Value, Amount Offset Against Collateral	12,007	6,650
Derivative Liability	$ 0	$ 60

Fair Value Measurements Fair va

Fair Value Measurements Fair value Option, Disclosures (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans Held-for-sale, Fair Value Disclosure	$ 14,000	$ 35,750
Loans held for sale (valued under fair value option $14,000 and $35,750)	14,012	36,053
Fair Value, Option, Loans Held as Assets, Aggregate Difference	489	564
loans held for sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Loans held for sale (valued under fair value option $14,000 and $35,750)	$ 13,511	$ 35,186

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jan. 01, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unused Commitments to Extend Credit	$ 6,755,563	$ 6,379,941
ROU lease assets			$ 127,481	$ 157,234
Mortgage Loans in Process of Foreclosure, Amount	14,900
Valuation Allowance for Impairment of Recognized Servicing Assets, Sales and Disposals	1,900
Rabbi Trust [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	1,600
Alternative investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure			$ 22,000
Fair Value, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
ROU lease assets	127,500
ROU assets impaired	1,500
Other Assets, Fair Value Disclosure	2,300
Fair Value, Nonrecurring [Member] | Alternative investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unused Commitments to Extend Credit	17,400
Alternative investments, written up	$ 1,600

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Assets And Liabilities Measured On Recurring Basis) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	$ 3,326,776	$ 2,925,833
Derivative asset		133,158	$ 292,291
Loans Held-for-sale, Fair Value Disclosure	14,000	35,750
Derivative liability		7,163	347
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	3,326,776	2,925,833
Alternative Investment	11,112	4,331
Assets, Fair Value Disclosure	3,689,555	3,116,731
Derivative liability	12,354	13,813
Fair Value, Recurring [Member] | Derivative instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	332,856	146,037
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Alternative Investment	0	0
Assets, Fair Value Disclosure	5,016	5,108
Derivative liability	218	611
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Derivative instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	205	328
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	3,326,776	2,925,833
Alternative Investment	0
Assets, Fair Value Disclosure	3,673,427	3,107,292
Derivative liability	12,136	13,202
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	332,651	145,709
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Alternative Investment	0	0
Assets, Fair Value Disclosure	0	0
Derivative liability	0	0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Derivative instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Investments held In Rabbi Trust [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets, Fair Value Disclosure	4,811	4,780
Investments held In Rabbi Trust [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets, Fair Value Disclosure	4,811	4,780
Investments held In Rabbi Trust [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets, Fair Value Disclosure	0	0
Investments held In Rabbi Trust [Member] | Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets, Fair Value Disclosure	0	0
Alternative investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets, Fair Value Disclosure			$ 22,000
Loan Origination Commitments [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	14,000	35,750
Loan Origination Commitments [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	0	0
Loan Origination Commitments [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	14,000	35,750
Loan Origination Commitments [Member] | Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	0	0
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	13,120	22,240
Corporate Debt Securities [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	13,120	22,240
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	13,120	22,240
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Collateralized loan obligations (CLO) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	76,383	92,205
Collateralized loan obligations (CLO) [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	76,383	92,205
Collateralized loan obligations (CLO) [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Collateralized loan obligations (CLO) [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	76,383	92,205
Collateralized loan obligations (CLO) [Member] | Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	508,018	431,871
Commercial Mortgage Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	508,018	431,871
Commercial Mortgage Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Commercial Mortgage Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	508,018	431,871
Commercial Mortgage Backed Securities [Member] | Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Agency commercial mortgage-backed securities (agency CMBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	1,117,233	581,552
Agency commercial mortgage-backed securities (agency CMBS) [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	1,117,233	581,552
Agency commercial mortgage-backed securities (agency CMBS) [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Agency commercial mortgage-backed securities (agency CMBS) [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	1,117,233	581,552
Agency commercial mortgage-backed securities (agency CMBS) [Member] | Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	1,457,409	1,612,164
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	1,457,409	1,612,164
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	1,457,409	1,612,164
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	154,613	185,801
Collateralized Mortgage Obligations [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	154,613	185,801
Collateralized Mortgage Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	0	0
Collateralized Mortgage Obligations [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	154,613	185,801
Collateralized Mortgage Obligations [Member] | Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	$ 0	$ 0

Fair Value Measurements (Summar

Fair Value Measurements (Summary Of Estimated Fair Values Of Significant Financial Instruments) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reported Value Measurement [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	$ 5,567,889	$ 5,293,918
Loans and leases, net	21,281,784	19,827,890
Securities sold under agreements to repurchase and other borrowings	995,355	1,040,431
FHLB advances	133,164	1,948,476
Long-term debt	567,663	540,364
Reported Value Measurement [Member] | Fair Value, Nonrecurring [Member] | Deposits other than time deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deposits	24,847,618	20,219,981
Reported Value Measurement [Member] | Fair Value, Nonrecurring [Member] | Time Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deposits	2,487,818	3,104,765
Reported Value Measurement [Member] | Fair Value, Nonrecurring [Member] | Residential Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing assets, Carrying Amount	13,422	17,484
Investment securities held-to-maturity (fair value of $5,835,364 and $5,380,653)	5,568,188	5,293,918
Debt Securities, Held-to-maturity, Fair Value	5,835,364	5,380,653
Loans Held-for-sale, Fair Value Disclosure	14,000	35,750
Mortgage servicing assets, Carrying Amount	13,422	17,484	$ 21,215	$ 25,139
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	5,835,364	5,380,653
Securities sold under agreements to repurchase and other borrowings	1,000,189	1,041,042
FHLB advances	139,035	1,950,035
Long-term debt	538,407	555,775
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Nonrecurring [Member] | Deposits other than time deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deposits	24,847,618	20,219,981
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Nonrecurring [Member] | Time Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deposits	2,494,601	3,102,316
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and leases, net	21,413,397	19,961,632
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Nonrecurring [Member] | Residential Mortgage [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing assets	$ 14,362	$ 33,250

Retirement Benefit Plans (Narra

Retirement Benefit Plans (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2020
Defined Benefit Plan Disclosure [Line Items]
Healthcare-cost trend rate in 2024 (as a percent)	4.40%			6.50%
Funded status of plan	$ 2,600
Shortfall amortization period	7 years
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees' gross pay	2.00%
Employer matching contribution, additional percent of match	50.00%
Employer additional matching contribution, percent of employees' gross pay	6.00%
Employer additional matching contribution, percent of employees' gross pay, default	3.00%
Compensation expense	$ 13,800	$ 13,200	$ 12,400
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan	(146)	(1,783)
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan	(2,046)	(1,935)
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan	$ (1,998)	$ (2,399)

Retirement Benefit Plans (Chang

Retirement Benefit Plans (Changes in Plan Assets and Funded Status of Pension Plans and Other Postretirement Benefit Plans) (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in plan assets:
Beginning balance			$ 239,621
Ending balance			266,268	$ 239,621
Funded status of the plan at year end (2)			2,600
Accumulated benefit obligation			270,500	245,700
Pension Plan [Member]
Change in benefit obligation:
Beginning balance	$ 209,513		241,404	209,513
Interest cost			6,511	7,941	$ 7,212
Actuarial loss (gain)			(27,376)	(33,157)
Benefits paid and administrative expenses			(8,877)	(9,207)
Ending balance (1)			266,414	241,404	209,513
Change in plan assets:
Beginning balance	191,972		239,621	191,972
Actual return on plan assets			35,524	46,856
Employer contributions			0	10,000
Benefits paid and administrative expenses			(8,877)	(9,207)
Ending balance			266,268	239,621	191,972
Funded status of the plan at year end (2)			(146)	(1,783)
SERP [Member]
Change in benefit obligation:
Beginning balance	1,835		1,935	1,835
Interest cost	46	$ 65	46	65	103
Actuarial loss (gain)			(194)	(163)
Benefits paid and administrative expenses			(129)	(128)
Ending balance (1)			2,046	1,935	1,835
Change in plan assets:
Beginning balance	0		0	0
Actual return on plan assets			0	0
Employer contributions			129	128
Benefits paid and administrative expenses			(129)	(128)
Ending balance			0	0	0
Funded status of the plan at year end (2)			(2,046)	(1,935)
Other Benefits [Member]
Change in benefit obligation:
Beginning balance	2,612		2,399	2,612
Interest cost	46	$ 85	46	85	78
Actuarial loss (gain)			307	103
Benefits paid and administrative expenses			(140)	(195)
Ending balance (1)			1,998	2,399	2,612
Change in plan assets:
Beginning balance	$ 0		0	0
Actual return on plan assets			0	0
Employer contributions			140	195
Benefits paid and administrative expenses			(140)	(195)
Ending balance			0	0	$ 0
Funded status of the plan at year end (2)			$ (1,998)	$ (2,399)

Retirement Benefit Plans (Summa

Retirement Benefit Plans (Summary of Components of Accumulated Other Comprehensive Loss Related to Pensions and Postretirement Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain) included in AOCI	$ 57,902	$ 56,555
Deferred tax benefit	12,881	12,528
Amounts included in accumulated AOCL, net of tax	45,021	44,027
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain) included in AOCI	773	602
Deferred tax benefit	172	133
Amounts included in accumulated AOCL, net of tax	601	469
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Amounts included in accumulated AOCL, net of tax	(537)	(357)
Other Postretirement Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss (gain) included in AOCI	(690)	(458)
Deferred tax benefit	$ (153)	$ (101)

Retirement Benefit Plans (Expec

Retirement Benefit Plans (Expected Future Benefit Payments) (Details) $ in Thousands	Dec. 31, 2020USD ($)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
2020	$ 9,657
2021	10,294
2022	10,465
2023	10,887
2024	11,304
2025-2029	61,336
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
2020	131
2021	132
2022	132
2023	138
2024	136
2025-2029	625
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2020	254
2021	237
2022	219
2023	201
2024	182
2025-2029	$ 638

Retirement Benefit Plans (Sum_2

Retirement Benefit Plans (Summary of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost			$ 0	$ 0	$ 0
Interest cost on benefit obligations			6,511	7,941	7,212
Expected return on plan assets			(13,522)	(11,436)	(12,716)
Recognized net loss			4,027	5,705	4,862
Net periodic benefit cost (benefit)			(2,984)	2,210	(642)
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0			0
Interest cost on benefit obligations	46	65	46	65	103
Expected return on plan assets	0	0			0
Recognized net loss	23	14			2,846
Net periodic benefit cost (benefit)	69	79			2,949
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0			0
Interest cost on benefit obligations	46	85	$ 46	$ 85	78
Expected return on plan assets	0	0			0
Recognized net loss	(74)	(13)			0
Net periodic benefit cost (benefit)	$ (28)	$ 72			$ 78

Retirement Benefit Plans (Cha_2

Retirement Benefit Plans (Changes in Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net (gain) loss	$ 5,262	$ (2,202)	$ 9,600
Amounts reclassified from AOCL	(3,976)	(5,706)	(7,708)
Total (gain) loss recognized in OCI	1,286	(7,908)	1,892
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net (gain) loss	5,375	(2,263)	9,952
Amounts reclassified from AOCL	(4,027)	(5,705)	(4,862)
Total (gain) loss recognized in OCI	1,348	(7,968)	5,090
SERP [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net (gain) loss	194	164	0
Amounts reclassified from AOCL	(23)	(14)	(2,846)
Total (gain) loss recognized in OCI	171	150	(2,846)
Other Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net (gain) loss	(307)	(103)	(352)
Amounts reclassified from AOCL	74	13	0
Total (gain) loss recognized in OCI	$ (233)	$ (90)	$ (352)

Retirement Benefit Plans (Sum_3

Retirement Benefit Plans (Summary of Fair Value of Plan Assets by Level) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 266,268	$ 239,621
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	40,506	37,777
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	225,762	201,844
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Exchange traded funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39,645	36,552
Exchange traded funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39,645	36,552
Exchange traded funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Exchange traded funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	861	1,225
Defined Benefit Plan, Cash and Cash Equivalents [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	861	1,225
Defined Benefit Plan, Cash and Cash Equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Cash and Cash Equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Common Collective Trust
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	225,762	201,844
Defined Benefit Plan, Common Collective Trust | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Defined Benefit Plan, Common Collective Trust | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	225,762	201,844
Defined Benefit Plan, Common Collective Trust | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0

Retirement Benefit Plans (Weigh

Retirement Benefit Plans (Weighted Average Assumptions used to Determine Benefit Obligations) (Details)	Dec. 31, 2020	Dec. 31, 2019
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	2.29%	3.07%
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	1.91%	2.82%
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	1.40%	2.50%

Retirement Benefit Plans (Wei_2

Retirement Benefit Plans (Weighted Average Assumptions used to Determine Net Periodic Benefit Cost) (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on assets (as a percent)		5.50%
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	3.07%		4.12%	3.50%
Expected long-term return on assets (as a percent)		5.75%	6.00%	6.00%
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	2.82%		3.95%	3.30%
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)		2.50%	3.69%	3.00%
Assumed healthcare cost trend (as a percent)	6.50%	6.50%	6.50%	7.00%

Retirement Benefit Plans (Contr

Retirement Benefit Plans (Contributions and Funding Status of the Fund) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Contributions by Webster Bank	$ 998	$ 863	$ 679

Retirement Benefit Plans (Detai

Retirement Benefit Plans (Details)	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%	100.00%
Fixed Income Funds [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	62.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	61.00%	61.00%
Equity Funds [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	38.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	38.00%	38.00%
Defined Benefit Plan, Cash and Cash Equivalents [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	1.00%	1.00%

Share-Based Plans (Narrative) (

Share-Based Plans (Narrative) (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized	13,400,000
Number of common shares available for grant	900,000
Stock appreciation rights granted	0
Unrecognized stock compensation expense	$ 15,500
Unrecognized stock compensation expense, recognition period (in years)	1 year 10 months 24 days
Award vesting percentage	50.00%
Fair value of restricted stock awards	$ 13,500	$ 12,500	$ 11,100
Stock options granted	266,325
Number of options outstanding (in shares)	410,701
Aggregate intrinsic value	$ 7,700
Total intrinsic value of options exercised	$ 100	$ 2,400	$ 9,700
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 23.35
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock appreciation rights granted	296,435
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares available for grant	100,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock appreciation rights granted	106,739
Performance Shares [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	0.00%
Performance Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	150.00%
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	0
Number of options outstanding (in shares)	410,701	420,931
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 23.35	$ 23.35
Non-Qualified Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding (in shares)	376,813
Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (in years)	10
Number of options outstanding (in shares)	33,888

Share-Based Plans (Summary of S

Share-Based Plans (Summary of Stock-based Compensation Expense Recognized) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit	$ 2,600	$ 6,100	$ 8,500
Restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 12,200	$ 12,600	$ 11,600

Share-Based Plans (Summary of R

Share-Based Plans (Summary of Restricted Stock and Stock Option Activity) (Detail)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted Stock, Granted (in shares)	0
Restricted stock, Outstanding at end of period (in shares)	250,666
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options granted, Number of Shares	266,325
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares	0
Options exercised, Number of Shares	10,230
Options outstanding, at end of period, Number of Shares	410,701
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Options vested, Weighted-Average Exercise Price (in dollars per share) | $ / shares	$ 0
Options, at end of period, Weighted-average Exercise Price (in dollars per share) | $ / shares	$ 23.35
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock, Outstanding at beginning of period (in shares)	450,224
Restricted Stock, Granted (in shares)	296,435
Restricted stock, Vested restricted stock awards (in shares)	171,852
Restricted stock, Forfeited (in shares)	27,622
Restricted stock, Outstanding at end of period (in shares)	547,185
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted stock, at beginning of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 54.53
Restricted stock, Granted (in dollars per share) | $ / shares	37.79
Restricted stock, Vested restricted stock awards (in dollars per share) | $ / shares	52.22
Restricted stock, Forfeited (in dollars per share) | $ / shares	45.98
Restricted stock, at end of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 46.59
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock, Outstanding at beginning of period (in shares)	233,304
Restricted Stock, Granted (in shares)	106,739
Restricted stock, Vested restricted stock awards (in shares)	79,836
Restricted stock, Forfeited (in shares)	9,541
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted stock, at beginning of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 54.94
Restricted stock, Granted (in dollars per share) | $ / shares	40.56
Restricted stock, Vested restricted stock awards (in dollars per share) | $ / shares	56.18
Restricted stock, Forfeited (in dollars per share) | $ / shares	50.42
Restricted stock, at end of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 48.77
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, at beginning of period, Number of Shares	420,931
Options granted, Number of Shares	0
Options forfeited, Number of Shares	0
Options exercised, Number of Shares	10,230
Options outstanding, at end of period, Number of Shares	410,701
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Options, at beginning of period, Weighted-average Exercise Price (in dollars per share) | $ / shares	$ 23.35
Options granted, Weighted-Average Exercise Price (in dollars per share) | $ / shares	0
Options forfeited, Weighted-Average Exercise Price (in dollars per share) | $ / shares	0
Options exercised, Weighted-Average Exercise Price (in dollars per share) | $ / shares	23.51
Options, at end of period, Weighted-average Exercise Price (in dollars per share) | $ / shares	$ 23.35

Share-Based Plans (Options Outs

Share-Based Plans (Options Outstanding and Options Exercisable) (Details)	12 Months Ended
	Dec. 31, 2020shares
Share-based Payment Arrangement [Abstract]
Options Outstanding, Weighted-Average Remaining Contractual Life (years)	1 year 8 months 12 days
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	1 year 8 months 12 days
Number of options outstanding (in shares)	410,701
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	410,701

Segment Reporting (Operating Re

Segment Reporting (Operating Results and Total Assets Reportable Segments) (Detail) - USD ($) $ in Thousands	3 Months Ended								9 Months Ended		12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total Assets	$ 32,590,690				$ 30,389,344						$ 32,590,690	$ 30,389,344
Net interest income (expense)	216,929	$ 219,256	$ 224,407	$ 230,801	231,250	$ 240,539	$ 241,787	$ 241,551			891,393	955,127	$ 906,681
Noninterest Income									$ 285,277	$ 285,315	285,277	285,315	282,568
Non-interest expense	219,530	183,996	176,584	178,836	179,730	179,894	180,640	175,686			758,946	715,950	705,616
Pre-tax, pre-provision net revenue											417,724	524,492	483,633
Provision for credit losses	(1,000)	22,750	40,000	76,000	6,000	11,300	11,900	8,600			137,750	37,800	42,000
Provision for Loan and Lease Losses											137,848	37,800	42,000
Income (loss) before income tax expense	75,162	87,570	67,899	49,343	116,439	119,276	125,100	125,877			279,974	486,692	441,633
Income tax expense	15,118	18,289	14,802	11,144	25,966	25,411	26,451	26,141			59,353	103,969	81,215
Net income	60,044	$ 69,281	$ 53,097	$ 38,199	90,473	$ 93,865	$ 98,649	$ 99,736			220,621	382,723	360,418
Operating Segments [Member] | Commercial Banking [Member]
Segment Reporting Information [Line Items]
Total Assets	12,689,255				11,541,803						12,689,255	11,541,803
Net interest income (expense)											423,869	403,258	381,098
Noninterest Income									58,366	59,063	58,366	59,063	64,765
Non-interest expense											187,572	181,580	174,054
Pre-tax, pre-provision net revenue											294,663	280,741	271,809
Provision for Loan and Lease Losses											137,993	25,407	32,388
Income (loss) before income tax expense											156,670	255,334	239,421
Income tax expense											38,368	63,323	58,898
Net income											118,302	192,011	180,523
Operating Segments [Member] | HSA Bank [Member]
Segment Reporting Information [Line Items]
Total Assets	80,352				80,176						80,352	80,176
Net interest income (expense)											162,363	172,685	147,920
Noninterest Income									100,826	97,041	100,826	97,041	89,323
Non-interest expense											140,637	135,586	124,594
Pre-tax, pre-provision net revenue											122,552	134,140	112,649
Provision for Loan and Lease Losses											0	0	0
Income (loss) before income tax expense											122,552	134,140	112,649
Income tax expense											32,721	35,547	29,289
Net income											89,831	98,593	83,360
Operating Segments [Member] | Community Banking [Member]
Segment Reporting Information [Line Items]
Total Assets	9,769,824				9,348,727						9,769,824	9,348,727
Net interest income (expense)											422,979	420,898	422,063
Noninterest Income									106,279	109,270	106,279	109,270	109,669
Non-interest expense											390,596	388,399	384,603
Pre-tax, pre-provision net revenue											138,662	141,769	147,129
Provision for Loan and Lease Losses											(144)	12,393	9,612
Income (loss) before income tax expense											138,806	129,376	137,517
Income tax expense											27,484	27,428	27,366
Net income											111,322	101,948	110,151
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total Assets	$ 10,051,259				$ 9,418,638						10,051,259	9,418,638
Net interest income (expense)											(117,818)	(41,714)	(44,400)
Noninterest Income									$ 19,806	$ 19,941	19,806	19,941	18,811
Non-interest expense											40,141	10,385	22,365
Pre-tax, pre-provision net revenue											(138,153)	(32,158)	(47,954)
Provision for Loan and Lease Losses											(99)	0	0
Income (loss) before income tax expense											(138,054)	(32,158)	(47,954)
Income tax expense											(39,220)	(22,329)	(34,338)
Net income											$ (98,834)	$ (9,829)	$ (13,616)

Segment Reporting Segment Repor

Segment Reporting Segment Reporting Narrative (Details)	12 Months Ended
	Dec. 31, 2020Segment
Segment Reporting Information [Line Items]
Number of Reportable Segments	3

Revenue from contracts with C_3

Revenue from contracts with Customers Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer, Excluding Assessed Tax	$ 198,737	$ 208,293			$ 200,673
Noninterest Income	285,277	285,315	$ 285,277	$ 285,315	282,568
Deposit Service Fees [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	156,032	168,022			162,183
Investment Advisory, Management and Administrative Service [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	32,916	32,932			32,843
Other Non Interest Income [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	9,789	7,339			5,647
Non-Interest Income Within the Scope of Other GAAP Topics [Member]
Noninterest Income	86,540	77,022			81,895
Operating Segments [Member] | Commercial Banking [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	22,278	22,466			22,920
Noninterest Income	58,366	59,063	58,366	59,063	64,765
Operating Segments [Member] | Commercial Banking [Member] | Deposit Service Fees [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	11,634	12,136			12,775
Operating Segments [Member] | Commercial Banking [Member] | Investment Advisory, Management and Administrative Service [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	10,644	10,330			10,145
Operating Segments [Member] | Commercial Banking [Member] | Other Non Interest Income [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0			0
Operating Segments [Member] | Commercial Banking [Member] | Non-Interest Income Within the Scope of Other GAAP Topics [Member]
Noninterest Income	36,088	36,597			41,845
Operating Segments [Member] | Community Banking [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	75,562	88,603			88,387
Noninterest Income	106,279	109,270	106,279	109,270	109,669
Operating Segments [Member] | Community Banking [Member] | Deposit Service Fees [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	51,599	63,572			63,522
Operating Segments [Member] | Community Banking [Member] | Investment Advisory, Management and Administrative Service [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	22,307	22,637			22,732
Operating Segments [Member] | Community Banking [Member] | Other Non Interest Income [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	1,656	2,394			2,133
Operating Segments [Member] | Community Banking [Member] | Non-Interest Income Within the Scope of Other GAAP Topics [Member]
Noninterest Income	30,717	20,667			21,282
Operating Segments [Member] | HSA Bank [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	100,826	97,041			89,323
Noninterest Income	100,826	97,041	100,826	97,041	89,323
Operating Segments [Member] | HSA Bank [Member] | Deposit Service Fees [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	92,693	92,096			85,809
Operating Segments [Member] | HSA Bank [Member] | Investment Advisory, Management and Administrative Service [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0			0
Operating Segments [Member] | HSA Bank [Member] | Other Non Interest Income [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	8,133	4,945			3,514
Operating Segments [Member] | HSA Bank [Member] | Non-Interest Income Within the Scope of Other GAAP Topics [Member]
Noninterest Income	0	0			0
Corporate, Non-Segment [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	71	183			43
Noninterest Income	19,806	19,941	$ 19,806	$ 19,941	18,811
Corporate, Non-Segment [Member] | Deposit Service Fees [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	106	218			77
Corporate, Non-Segment [Member] | Investment Advisory, Management and Administrative Service [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	(35)	(35)			(34)
Corporate, Non-Segment [Member] | Other Non Interest Income [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	0	0			0
Corporate, Non-Segment [Member] | Non-Interest Income Within the Scope of Other GAAP Topics [Member]
Noninterest Income	$ 19,735	$ 19,758			$ 18,768

Commitments and Contingencies_2

Commitments and Contingencies (Outstanding Financial Instruments Contract Amounts Represent Credit Risk) (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Unused Commitments to Extend Credit	$ 6,755,563	$ 6,379,941
Standby letters of credit [Member]
Loss Contingencies [Line Items]
Unused Commitments to Extend Credit	207,201	188,103
Letter of Credit [Member]
Loss Contingencies [Line Items]
Unused Commitments to Extend Credit	30,522	29,180
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Unused Commitments to Extend Credit	$ 6,517,840	$ 6,162,658

Commitments and Contingencies_3

Commitments and Contingencies (Schedule for Unfunded Commitments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Unused Commitments to Extend Credit	$ 6,755,563	$ 6,379,941
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance		2,506	$ 2,362
Provision			144
Ending balance			2,506
Accounting Standards Update 2016-13 [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	0	0
Ending balance	9,139	0	0
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	2,367	2,506
Provision	1,249	(139)
Ending balance	$ 12,755	$ 2,367	$ 2,506

Parent Company Information (Com

Parent Company Information (Components of Condensed Balance Sheets The Parent Company) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets:
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 263,104	$ 257,895	$ 329,499	$ 256,786
Intercompany debt securities		150,000
Other assets	626,551	455,380
Total Assets	32,590,690	30,389,344
Liabilities and shareholders’ equity:
Liabilities	29,356,065	27,181,574
Total liabilities and shareholders' equity	32,590,690	30,389,344
Parent Company [Member]
Assets:
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	302,315	510,940	$ 317,473	$ 181,085
Intercompany debt securities	150,000
Investment in subsidiaries	3,340,556	3,079,549
Alternative investments	8,970	5,356
Other assets	8,122	13,537
Total Assets	3,809,963	3,759,382
Liabilities and shareholders’ equity:
Senior notes	490,343	463,044
Junior subordinated debt	77,320	77,320
Accrued interest payable	5,862	6,057
Due to subsidiaries	324	52
Other liabilities	1,489	5,139
Liabilities	575,338	551,612
Shareholders’ equity	3,234,625	3,207,770
Total liabilities and shareholders' equity	$ 3,809,963	$ 3,759,382

Parent Company Information (C_2

Parent Company Information (Components of Condensed Income Statement The Parent Company) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Income:
Other non-interest income	$ 76,763	$ 75,060	$ 60,076	$ 73,378	$ 70,919	$ 69,931	$ 75,853	$ 68,612
Total operating income									$ 417,724	$ 524,492	$ 483,633
Operating Expense:
Compensation and benefits									428,391	395,402	381,496
Non-interest expense									78,228	98,617	91,046
Income tax benefit	(15,118)	(18,289)	(14,802)	(11,144)	(25,966)	(25,411)	(26,451)	(26,141)	(59,353)	(103,969)	(81,215)
Net income	$ 60,044	$ 69,281	$ 53,097	$ 38,199	$ 90,473	$ 93,865	$ 98,649	$ 99,736	220,621	382,723	360,418
Parent Company [Member]
Operating Income:
Dividend income from bank subsidiary									20,000	360,000	290,000
Interest on securities and deposits									5,530	10,728	7,342
Alternative investments income									2,467	(256)	290
Other non-interest income									634	382	805
Total operating income									28,631	370,854	298,437
Operating Expense:
Interest expense on borrowings									18,684	21,062	11,127
Non-interest expense									16,426	15,527	19,105
Total operating expense									35,110	36,589	30,232
Income before income tax benefit and equity in undistributed earnings of subsidiaries									(6,479)	334,265	268,205
Income tax benefit									4,572	4,671	2,207
Equity in undistributed earnings of subsidiaries									222,528	43,787	90,006
Net income									$ 220,621	$ 382,723	$ 360,418

Parent Company Information (C_3

Parent Company Information (Components of Condensed Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other comprehensive income (loss), net of tax:
Derivative instruments	$ 29,102	$ 129	$ 5,703
Other comprehensive (loss) income, net of tax	78,328	94,580	(39,121)
Parent Company [Member]
Condensed Statement of Income Captions [Line Items]
Net income	220,621	382,723	360,418
Other comprehensive income (loss), net of tax:
Derivative instruments	2,622	1,479	1,447
Other comprehensive income (loss) of subsidiaries	75,706	93,101	(40,568)
Other comprehensive (loss) income, net of tax	78,328	94,580	(39,121)
Comprehensive income	$ 298,949	$ 477,303	$ 321,297

Parent Company Information (C_4

Parent Company Information (Components of Condensed Cash Flow The Parent Company) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net cash provided by operating activities	$ 380,549	$ 303,850	$ 469,408
Investing activities:
Alternative investments capital call	(12,244)	(6,065)	(1,215)
Net cash provided by (used for) investing activities	(2,288,609)	(2,549,756)	(1,317,924)
Financing activities:
Cash dividends paid to common shareholders	(144,965)	(140,783)	(114,959)
Cash dividends paid to preferred shareholders	(7,875)	(7,875)	(7,875)
Exercise of stock options	240	619	2,173
Common stock repurchased and acquired from stock compensation plan activity	(76,556)	(13,003)	(12,158)
Net cash (used for) provided by financing activities	1,913,269	2,174,302	921,229
Net (decrease) increase in cash and cash equivalents	5,209	(71,604)	72,713
Cash and cash equivalents at beginning of year	257,895	329,499	256,786
Cash and cash equivalents at end of year	263,104	257,895	329,499
Parent Company [Member]
Operating activities:
Net cash provided by operating activities	27,790	362,617	282,986
Investing activities:
Alternative investments capital call	(3,751)	(1,850)	0
Investment in subsidiaries	0	(296,000)	0
Net cash provided by (used for) investing activities	(3,751)	(297,850)	0
Financing activities:
Issuance of long-term debt	0	296,358	0
Cash dividends paid to common shareholders	144,967	140,783	114,959
Cash dividends paid to preferred shareholders	7,875	7,875	7,875
Exercise of stock options	240	619	2,173
Common stock repurchased and acquired from stock compensation plan activity	80,062	19,619	25,937
Net cash (used for) provided by financing activities	(232,664)	128,700	(146,598)
Net (decrease) increase in cash and cash equivalents	(208,625)	193,467	136,388
Cash and cash equivalents at beginning of year	510,940	317,473	181,085
Cash and cash equivalents at end of year	$ 302,315	$ 510,940	$ 317,473

Selected Quarterly Consolidat_3

Selected Quarterly Consolidated Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Selected Quarterly Financial Information [Abstract]
Interest income	$ 236,065	$ 239,239	$ 252,275	$ 274,470	$ 282,000	$ 294,136	$ 292,257	$ 286,190	$ 1,002,049	$ 1,154,583	$ 1,055,167
Interest expense	19,136	19,983	27,868	43,669	50,750	53,597	50,470	44,639	110,656	199,456	148,486
Net interest income	216,929	219,256	224,407	230,801	231,250	240,539	241,787	241,551	891,393	955,127	906,681
Provision for credit losses	(1,000)	22,750	40,000	76,000	6,000	11,300	11,900	8,600	137,750	37,800	42,000
Non-interest income	76,763	75,060	60,076	73,378	70,919	69,931	75,853	68,612
Non-interest expense	219,530	183,996	176,584	178,836	179,730	179,894	180,640	175,686	758,946	715,950	705,616
Income before income tax expense	75,162	87,570	67,899	49,343	116,439	119,276	125,100	125,877	279,974	486,692	441,633
Income tax expense	15,118	18,289	14,802	11,144	25,966	25,411	26,451	26,141	59,353	103,969	81,215
Net income	60,044	69,281	53,097	38,199	90,473	93,865	98,649	99,736	$ 220,621	$ 382,723	$ 360,418
Earnings applicable to common shareholders	$ 57,715	$ 66,890	$ 50,729	$ 36,021	$ 88,066	$ 91,442	$ 96,193	$ 97,549
Earnings per common share:
Earnings per common share, Basic (in dollars per share)	$ 0.64	$ 0.75	$ 0.57	$ 0.40	$ 0.96	$ 1	$ 1.05	$ 1.06	$ 2.35	$ 4.07	$ 3.83
Earnings per common share, Diluted (in dollars per share)	$ 0.64	$ 0.75	$ 0.57	$ 0.39	$ 0.96	$ 1	$ 1.05	$ 1.06	$ 2.35	$ 4.06	$ 3.81