Eastern Bankshares (EBC) 10-K 26 Feb 24 2023 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2023	Feb. 22, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39610
Entity Registrant Name	Eastern Bankshares, Inc.
Entity Incorporation, State or Country Code	MA
Entity Tax Identification Number	84-4199750
Entity Address, Address Line One	265 Franklin Street
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02110
City Area Code	800
Local Phone Number	327-8376
Title of 12(b) Security	Common Stock
Trading Symbol	EBC
Security Exchange Name	NASDAQ
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
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction	false
Entity Shell Company	false
Entity Public Float			$ 1,882,518,640
Entity Common Stock, Shares Outstanding		176,426,993
Documents Incorporated by Reference	Portions of the Registrant's definitive proxy statement relating to its 2024 annual meeting of shareholders (the “2024 Proxy Statement”) are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. The 2024 Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Central Index Key	0001810546

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2023
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Location	Boston, Massachusetts
Auditor Firm ID	42

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
ASSETS
Cash and due from banks	$ 87,233	$ 106,040
Short-term investments	605,843	63,465
Cash and cash equivalents	693,076	169,505
Available for sale (amortized cost $5,161,904 and $7,825,435, respectively)	4,407,521	6,690,778
Held to maturity (fair value $404,822 and $423,226, respectively)	449,721	476,647
Total securities	4,857,242	7,167,425
Loans held for sale	1,124	4,543
Loans:
Total loans	13,973,428	13,575,531
Allowance for loan losses	(148,993)	(142,211)
Unamortized premiums, net of unearned discounts and deferred fees, net of costs	(25,068)	(13,003)
Net loans	13,799,367	13,420,317
Federal Home Loan Bank stock, at cost	5,904	41,363
Premises and equipment	60,133	62,493
Bank-owned life insurance	164,702	160,790
Goodwill and other intangibles, net	566,205	568,009
Deferred income taxes, net	266,185	331,963
Prepaid expenses	183,073	165,368
Other assets	536,267	426,863
Assets of discontinued operations	0	128,219
Total assets	21,133,278	22,646,858
Deposits:
Demand	5,162,218	6,240,637
Interest checking accounts	3,737,361	4,568,122
Savings accounts	1,323,126	1,831,123
Money market investment	4,664,475	4,710,095
Certificates of deposit	2,709,037	1,624,382
Total deposits	17,596,217	18,974,359
Borrowed funds:
Short-term Federal Home Loan Bank advances	95	691,297
Escrow deposits of borrowers	21,978	22,314
Interest rate swap collateral funds	8,500	14,430
Long-term Federal Home Loan Bank advances	17,643	12,787
Total borrowed funds	48,216	740,828
Other liabilities	513,990	424,951
Liabilities of discontinued operations	0	34,930
Total liabilities	18,158,423	20,175,068
Commitments and contingencies (see Note 17)	0	0
Common shares, $0.01 par value, 1,000,000,000 shares authorized; 176,426,993 and 176,172,073 shares issued and outstanding at December 31, 2023 and 2022, respectively	1,767	1,762
Additional paid in capital	1,666,441	1,649,141
Unallocated common shares held by the Employee Stock Ownership Plan	(132,755)	(137,696)
Retained earnings	2,047,754	1,881,775
Accumulated other comprehensive income, net of tax	(608,352)	(923,192)
Total shareholders’ equity	2,974,855	2,471,790
Total liabilities and shareholders’ equity	21,133,278	22,646,858
Commercial and industrial | Commercial Portfolio Segment
Loans:
Total loans	3,034,068	3,150,946
Allowance for loan losses	(26,959)	(26,859)
Commercial real estate | Commercial Portfolio Segment
Loans:
Total loans	5,457,349	5,155,323
Allowance for loan losses	(65,475)	(54,730)
Commercial construction | Commercial Portfolio Segment
Loans:
Total loans	386,999	336,276
Allowance for loan losses	(6,666)	(7,085)
Business banking | Commercial Portfolio Segment
Loans:
Total loans	1,085,763	1,090,492
Allowance for loan losses	(14,913)	(16,189)
Residential real estate | Residential Portfolio Segment
Loans:
Total loans	2,565,485	2,460,849
Allowance for loan losses	(25,954)	(28,129)
Consumer home equity | Consumer Portfolio Segment
Loans:
Total loans	1,208,231	1,187,547
Allowance for loan losses	(5,595)	(6,454)
Other consumer | Consumer Portfolio Segment
Loans:
Total loans	$ 235,533	$ 194,098

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Available-for-sale debt securities, amortized cost	$ 5,161,904	$ 7,825,435
Held-to-maturity debt securities, fair value	$ 404,822	$ 423,226
Common stock, par value (in shares)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	1,000,000,000	1,000,000,000
Common stock issued (in shares)	176,426,993	176,172,073
Common stock outstanding (in shares)	176,426,993	176,172,073

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest and dividend income:
Interest and fees on loans	$ 652,095	$ 476,041	$ 367,585
Taxable interest and dividends on available for sale securities	101,233	118,690	58,312
Non-taxable interest and dividends on available for sale securities	5,736	7,179	7,376
Interest on federal funds sold and other short-term investments	37,395	3,271	1,886
Total interest and dividend income	796,459	605,181	435,159
Interest expense:
Interest on deposits	226,075	28,621	5,167
Interest on borrowings	19,975	8,506	165
Total interest expense	246,050	37,127	5,332
Net interest income	550,409	568,054	429,827
Provision for (release of) allowance for loan losses	20,052	17,925	(9,686)
Net interest income after provision for (release of) allowance for loan losses	530,357	550,129	439,513
Noninterest (loss) income:
Service charges on deposit accounts	28,631	30,392	24,271
Trust and investment advisory fees	24,264	23,593	24,588
Debit card processing fees	13,469	12,644	12,118
Interest rate swap income	1,536	6,009	5,634
Income (losses) from investments held in rabbi trusts	9,305	(10,762)	10,217
Losses on sale of commercial and industrial loans	(2,738)	0	0
(Losses) gains on sales of mortgage loans held for sale, net	(507)	248	3,605
(Losses) gains on sales of securities available for sale, net	(333,170)	(3,157)	1,166
Other	21,457	17,783	15,838
Total noninterest (loss) income	(237,753)	76,750	97,437
Noninterest expense:
Salaries and employee benefits	253,037	233,097	227,624
Office occupancy and equipment	35,992	37,445	37,261
Data processing	55,308	52,938	46,415
Professional services	17,385	15,805	21,283
Marketing	7,592	9,294	8,500
Loan expenses	4,466	6,384	9,114
FDIC insurance	21,874	6,250	4,226
Amortization of core deposit intangible asset	1,804	1,198	219
Other	21,144	26,238	6,313
Total noninterest expense	418,602	388,649	360,955
(Loss) income from continuing operations before income tax expense	(125,998)	238,230	175,995
Income tax (benefit) expense	(63,309)	51,719	30,464
Net (loss) income from continuing operations	(62,689)	186,511	145,531
Net income from discontinued operations	294,866	13,248	9,134
Net income	$ 232,177	$ 199,759	$ 154,665
Basic earnings per share
Basic (loss) earnings per share from continuing operations (in dollars per share)	$ (0.39)	$ 1.13	$ 0.85
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	1.82	0.08	0.05
Basic earnings per share (in dollars per share)	1.43	1.21	0.90
Diluted earnings per share:
Diluted (loss) earnings per share from continuing operations (in dollars per share)	(0.39)	1.13	0.85
Diluted earnings per share from discontinued operations (in dollars per share)	1.82	0.08	0.05
Diluted earnings per share (in dollars per share)	$ 1.43	$ 1.21	$ 0.90

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 232,177	$ 199,759	$ 154,665
Other comprehensive income (loss), net of tax:
Net change in fair value of securities available for sale	295,913	(821,570)	(104,258)
Net change in fair value of cash flow hedges	18,588	(57,520)	(22,454)
Net change in other comprehensive income for defined benefit postretirement plans	339	12,594	15,782
Total other comprehensive income (loss)	314,840	(866,496)	(110,930)
Total comprehensive income (loss)	$ 547,017	$ (666,737)	$ 43,735

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands		Total	Cumulative effect accounting adjustment		Common Stock	Additional Paid in Capital	Retained Earnings	Retained Earnings Cumulative effect accounting adjustment		Accumulated Other Comprehensive Income (Loss)	Unallocated Common Stock Held by ESOP
Beginning balance (in shares) at Dec. 31, 2020					186,758,154
Beginning balance at Dec. 31, 2020		$ 3,428,052			$ 1,868	$ 1,854,068	$ 1,665,607			$ 54,234	$ (147,725)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends to common shareholders		(51,619)					(51,619)
Repurchased common stock (in shares)					(1,135,878)
Repurchased common stock		(23,224)			$ (12)	(23,212)
Issuance of restricted stock awards (in shares)					683,056
Issuance of restricted stock awards		0			$ 7	(7)
Net income		154,665					154,665
Other comprehensive loss, net of tax		(110,930)								(110,930)
ESOP shares committed to be released		9,408				4,392					5,016
Ending balance (in shares) at Dec. 31, 2021					186,305,332
Ending balance at Dec. 31, 2021		$ 3,406,352	$ (20,098)	[1]	$ 1,863	1,835,241	1,768,653	$ (20,098)	[1]	(56,696)	(142,709)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	[1]	Accounting Standards Update 2016-13
Dividends to common shareholders		$ (66,539)					(66,539)
Repurchased common stock (in shares)					(10,112,272)
Repurchased common stock		(201,618)			$ (101)	(201,517)
Issuance of restricted stock awards (in shares)					31,559
Issuance of restricted stock awards		0			$ 1	(1)
Unvested restricted stock awards forfeited and subsequently cancelled (in shares)					(52,546)
Unvested restricted stock awards forfeited and subsequently cancelled		0			$ (1)	1
Share-based compensation		10,507				10,507
Net income		199,759					199,759
Other comprehensive loss, net of tax		(866,496)								(866,496)
ESOP shares committed to be released		$ 9,923				4,910					5,013
Ending balance (in shares) at Dec. 31, 2022		176,172,073			176,172,073
Ending balance at Dec. 31, 2022		$ 2,471,790	$ 822	[2]	$ 1,762	1,649,141	1,881,775	$ 822	[2]	(923,192)	(137,696)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	[2]	Accounting Standards Update 2022-02
Dividends to common shareholders		$ (67,020)					(67,020)
Issuance of restricted stock awards (in shares)					47,820
Issuance of restricted stock awards		0			$ 1	(1)
Issuance of common stock under share-based compensation arrangements (in shares)	[3]				207,100
Issuance of common stock under share-based compensation arrangements	[3]	(1,396)			$ 4	(1,400)
Share-based compensation		16,513				16,513
Net income		232,177					232,177
Other comprehensive loss, net of tax		314,840								314,840
ESOP shares committed to be released		$ 7,129				2,188					4,941
Ending balance (in shares) at Dec. 31, 2023		176,426,993			176,426,993
Ending balance at Dec. 31, 2023		$ 2,974,855			$ 1,767	$ 1,666,441	$ 2,047,754			$ (608,352)	$ (132,755)
[1] Represents gross transition adjustment amount of $28.0 million, net of taxes of $7.9 million, to reflect the cumulative impact on retained earnings pursuant to the Company’s adoption of Accounting Standards Update 2016-13. Refer to Note 4, “Loans and Allowance for Credit Losses” for additional discussion. Represents gross transition adjustment amount of $1.1 million, net of taxes of $0.3 million, to reflect the cumulative impact on retained earnings pursuant to the Company’s adoption of Accounting Standards Update 2022-02. Refer to Note 4, “Loans and Allowance for Credit Losses” for additional discussion. Represents shares issued, net of employee tax withheld, during the year ended December 31, 2023 upon the vesting of restricted stock units. Refer to Note 16, “Share-Based Compensation” for additional discussion.

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	Jan. 01, 2023	Jan. 01, 2022
Cumulative effect accounting adjustment
Retained earnings	$ 1,100	$ 28,000
Deferred income tax (benefit) expense	$ 300	$ 7,900

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net (loss) income from continuing operations		$ (62,689)	$ 186,511	$ 145,531
Net income from discontinued operations		294,866	13,248	9,134
Net income		232,177	199,759	154,665
Adjustments to reconcile net income to net cash provided by operating activities
Provision for (release of) allowance for loan losses		20,052	17,925	(9,686)
Depreciation and amortization		12,295	11,985	11,900
Amortization (accretion) of of deferred loan fees and premiums, net		6,445	(1,441)	(27,991)
Deferred income tax (benefit) expense		(18,267)	5,262	(5,663)
Amortization of investment security premiums and discounts, net		6,281	18,274	16,713
Right-of-use asset amortization		11,348	11,432	10,982
Share-based compensation		16,047	10,507	0
Increase in cash surrender value of bank-owned life insurance		(3,912)	(3,699)	(2,348)
Loss (gain) on life insurance benefits		0	663	(1,813)
Loss (gain) on sales of securities available for sale, net		333,170	3,157	(1,166)
(Gain) loss on sales of bank premises and equipment, net		0	(1,412)	4,715
Loss on lease termination/modification, net		395	593	2,582
Accretion of gains from terminated interest rate swaps		(46)	(10,193)	(31,234)
Employee Stock Ownership Plan expense		7,129	9,923	9,408
Loss on sales of commercial loans		2,738	0	0
Proceeds from sale of commercial loan transferred to held for sale		22,126	0	0
Other		25	17	(106)
Change in:
Loans held for sale		3,403	(3,354)	(47)
Prepaid pension expense		4,260	4,338	1,130
Other assets		(14,394)	5,431	62,380
Other liabilities		39,035	(52,800)	(16,132)
Net cash provided by operating activities - continuing operations		385,441	213,119	169,155
Net cash (used in) provided by operating activities - discontinued operations		(123,749)	16,823	5,335
Net cash provided by operating activities		261,692	229,942	174,490
Investing activities
Proceeds from sales of securities available for sale		1,899,724	431,193	23,798
Proceeds from maturities and principal paydowns of securities available for sale		423,885	1,049,522	939,575
Purchases of securities available for sale		0	(740,770)	(3,323,893)
Proceeds from maturities and principal paydowns of securities held to maturity		27,397	17,399	0
Purchases of securities held to maturity		0	(493,678)	0
Proceeds from sale of Federal Home Loan Bank stock		286,309	63,715	6,692
Purchases of Federal Home Loan Bank stock		(250,850)	(94,174)	(2,101)
Contributions to low income housing tax credit investments		(36,939)	(19,487)	(11,379)
Contributions to other equity investments		(720)	(788)	(2,519)
Distributions from other equity investments		362	1,170	337
Proceeds from life insurance policies		0	20,446	0
Net (increase) decrease in outstanding loans, excluding loan purchases and sales		(586,584)	(926,255)	380,807
Proceeds from sales of commercial loans held for investment		189,296	0	0
Purchases of loans		(31,980)	(380,234)	0
Acquisitions, net of cash and cash equivalents acquired		0	0	(9,085)
Purchased banking premises and equipment		(8,140)	(8,627)	(5,728)
Proceeds from sale of bank premises and equipment		0	17,313	21,981
Proceeds from sale of other real estate owned		0	0	125
Net cash provided by (used in) investing activities - continuing operations		1,911,760	(1,063,255)	(1,981,390)
Net cash provided by (used in) investing activities - discontinued operations		488,505	(13,400)	(4,354)
Net cash provided by (used in) investing activities		2,400,265	(1,076,655)	(1,985,744)
Financing activities
Net (decrease) increase in demand, savings, interest checking, and money market investment deposit accounts		(2,462,797)	(1,751,953)	1,155,868
Net increase (decrease) in time deposits		1,084,655	1,098,001	(58,144)
Net (decrease) increase in borrowed funds		(692,612)	706,550	2,580
Repayment of acquired subordinated debentures	[1]	0	0	(36,277)
Payments for repurchases of common stock		0	(201,618)	(23,224)
Dividends declared and paid to common shareholders		(66,671)	(65,886)	(51,564)
Net cash (used in) provided by financing activities - continuing operations		(2,137,425)	(214,906)	989,239
Net cash used in financing activities - discontinued operations		(961)	(668)	(263)
Net cash (used in) provided by financing activities		(2,138,386)	(215,574)	988,976
Net increase (decrease) in cash, cash equivalents, and restricted cash		523,571	(1,062,287)	(822,278)
Cash, cash equivalents, and restricted cash at beginning of period		169,505	1,231,792	2,054,070
Cash, cash equivalents, and restricted cash at end of period		693,076	169,505	1,231,792
Cash paid during the period for:
Interest paid on deposits and borrowings		231,765	35,241	5,354
Income taxes		65,921	41,751	43,299
Non-cash activities
Net increase in capital commitments relating to low income housing tax credit projects		102,001	55,233	28,291
Maturity of acquired securities sold under agreements to repurchase	[2]	0	0	274,982
Net decrease in operating lease right of use assets and operating lease liabilities relating to lease remeasurements		$ 3,881	$ 14,836	$ 0
[1] (1) The Company deposited funds into escrow prior to the Century acquisition date to pay the balance of subordinated debentures assumed in the Century acquisition which was considered to be a defeasance of the debt. Accordingly, Century recorded a payable to the Company in the amount of the escrow deposit and the Company recorded a receivable from Century in the same amount. The payable was reclassified to other assets upon acquisition and is reflected as such balance in the summary of net assets acquired. Subsequent to the closing of the acquisition and prior to December 31, 2021, the amounts placed in escrow were disbursed to the holders of the subordinated debentures resulting in a full pay-off of the outstanding balance of the debt. (2) Includes non-cash item representing maturity of acquired securities sold under agreements to repurchase which were converted to deposits upon maturity.

Corporate Structure and Nature

Corporate Structure and Nature of Operations; Basis of Presentation	12 Months Ended
	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Corporate Structure and Nature of Operations; Basis of Presentation	Corporate Structure and Nature of Operations; Basis of Presentation Corporate Structure and Nature of Operations Eastern Bankshares, Inc., a Massachusetts corporation (the “Company”), is a bank holding company. Through its wholly-owned subsidiary, Eastern Bank (the “Bank”), the Company provides a variety of banking services and trust and investment services, through its full-service bank branches, located primarily in eastern Massachusetts, and southern and coastal New Hampshire. Eastern Insurance Group was a wholly-owned subsidiary of the Bank. On September 19, 2023, the Company and the Bank entered into an asset purchase agreement in which Arthur J. Gallagher & Co. (“Gallagher”) agreed to purchase substantially all of Eastern Insurance Group’s assets for cash consideration and to assume certain liabilities. On October 31, 2023, the Company completed its sale of its insurance agency business to Gallagher. Substantially all of the historical results of our previously reported insurance agency business segment have been reflected as discontinued operations in our Consolidated Financial Statements for all periods presented herein, including, as of December 31, 2022 and 2021, the assets and liabilities associated with the discontinued operations being classified as assets and liabilities of discontinued operations in our Consolided Balance Sheets. Refer to Note 23, “Discontinued Operations” for further discussion regarding discontinued operations. The activities of the Company are subject to the regulatory supervision of the Board of Governors of the Federal Reserve System (“Federal Reserve”). The activities of the Bank are subject to the regulatory supervision of the Massachusetts Commissioner of Banks, the Federal Deposit Insurance Corporation (“FDIC”) and the Consumer Financial Protection Bureau (“CFPB”). The Company and the activities of the Bank and its subsidiaries are also subject to various Massachusetts, New Hampshire and Rhode Island business and banking regulations and, with regard to Eastern Insurance Group and through October 31, 2023, applicable insurance regulations. Basis of Presentation The Company’s Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States (“GAAP”) as set forth by the Financial Accounting Standards Board (“FASB”) and its Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) as well as the rules and interpretive releases of the SEC under the authority of federal securities laws. The Consolidated Financial Statements include the accounts of the Company, its wholly-owned subsidiaries, and entities in which it holds a controlling financial interest through being the primary beneficiary or through holding a majority of the voting interest. All intercompany accounts and transactions have been eliminated in consolidation. Certain previously reported amounts have been reclassified to conform to the current year’s presentation which includes: • certain loan servicing-related costs have been reclassified from professional services to loan expense; and • operational losses have been reclassified to other non-interest expense. As a result of the decision to sell substantially all of the assets and transfer certain liabilities of Eastern Insurance Group, the Company reclassified certain amounts previously reported including: • certain assets and liabilities previously reported in the insurance agency business were reclassified to assets and liabilities of discontinued operations, respectively, on the Consolidated Balance Sheets; • certain components of noninterest income and noninterest expense, including the associated income tax effects, previously reported in the insurance agency business were reclassified to net income from discontinued operations on the Consolidated Statements of Income; and •

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates In preparing the Consolidated Financial Statements in conformity with GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheets and income and expenses for the periods reported. Actual results could differ from those estimates based on changing conditions, including economic conditions and future events. Material estimates that are particularly susceptible to change relate to the determination of the allowance for loan losses, valuation and fair value measurements, allowance for credit losses on investment securities, the liabilities for benefit obligations (particularly pensions), the provision for income taxes and impairment of goodwill and the core deposit intangible. Cash and Cash Equivalents Cash and cash equivalents include cash on hand and amounts due from banks, federal funds sold, and other short-term investments including restricted cash pledged, all of which have an original maturity of 90 days or less. Cash and cash equivalents includes $11.5 million and $1.0 million of restricted cash pledged as collateral at December 31, 2023 and 2022, respectively, which for purposes of the Company’s Consolidated Statements of Cash Flows, is included in cash, cash equivalents and restricted cash. Securities Debt securities are classified at the time of purchase as either “trading,” “available for sale” (“AFS”) or “held to maturity” (“HTM”). Equity securities are measured at fair value with changes in the fair value recognized through net income. Debt securities that are bought and held principally for the purpose of resale in the near term are classified as trading securities and recorded at fair value, with subsequent changes in fair value included in net income. Debt securities that the Company has the positive intent and the ability to hold to maturity are classified as HTM securities and recorded at amortized cost. Debt securities not classified as either trading or HTM are classified as AFS and recorded at fair value, with changes in fair value excluded from net income and reported in other comprehensive income, net of related tax. Amortization of premiums and accretion of discounts are computed using the effective interest rate method. ASU 2016-13 made targeted changes to ASC 320 to eliminate the concept of “other than temporary” from the impairment loss estimation model for AFS securities. A summary of the changes made by the Company to the existing impairment model (previously referred to as the “OTTI” model) as a result of adoption of ASU 2016-13 is as follows: • The use of an allowance approach, rather than a permanent write-down of a security’s cost basis upon determination of an impairment loss. • The amount of the allowance is limited to the amount at which the security’s fair value is less than its amortized cost basis. • The Company may not consider the length of time a security’s fair value has been less than amortized cost. • The Company may not consider recoveries in fair value after the balance sheet date when assessing whether a credit loss exists. The Company’s AFS securities are carried at fair value. For AFS securities in an unrealized loss position, management will first evaluate whether there is intent to sell a security, or if it is more likely than not that the Company will be required to sell a security prior to anticipated recovery of its amortized cost basis. If either of these criteria are met, the Company will record a write-down of the security’s amortized cost basis to fair value through income. For those AFS securities which do not meet the intent or requirement to sell criteria, management will evaluate whether the decline in fair value is a result of credit related matters or other factors. In performing this assessment, management considers the creditworthiness of the issuer including whether the security is guaranteed by the U.S. federal government or other government agency, the extent to which fair value is less than amortized cost, and changes in credit rating during the period, among other factors. If this assessment indicates the existence of credit losses, an allowance for credit losses will be established, as determined by a discounted cash flow analysis. To the extent the estimated cash flows do not support the amortized cost, the deficiency is considered to be due to credit loss and is recognized in earnings. Changes in the allowance for credit losses are recorded as a provision for (or reversal of) credit loss expense. Losses are charged against the allowance when the security is determined to be uncollectible, or when either of the aforementioned criteria surrounding intent or requirement to sell have been met. On January 1, 2022, the date on which the Company adopted ASU 2016-13, no allowance for credit losses was recorded for AFS securities. Gains and losses on sales of securities are recognized at the time of sale on the specific-identification basis. Prior to the adoption of ASU 2016-13, management evaluated impaired securities for other-than-temporary impairment (“OTTI”) at least on a quarterly basis, and more frequently when economic or market concerns warranted such evaluation. Consideration was given to the length of time and the extent to which the fair value was less than cost, current market conditions, the financial condition and near-term prospects of the issuer, performance of collateral underlying the securities, the ratings of the individual securities, the interest rate environment, the Company’s intent to sell the security or whether it was more likely than not that the Company would be required to sell the debt security before its anticipated recovery, as well as other qualitative factors. If a decline in fair value below the amortized cost basis of an investment was judged to be other than temporary, the investment was written down to fair value. The portion of the impairment related to credit losses was included in net income, and the portion of the impairment related to other factors was included in other comprehensive income. Refer to Note 3, “Securities” for additional information regarding the measurement of impairment losses on AFS securities. Allowance for Credit Losses - Held to Maturity Securities The Company measures expected credit losses on HTM securities on a collective basis by major security type which, as of December 31, 2023, included government-sponsored residential and commercial mortgage-backed securities. Securities in the Company’s HTM portfolio are guaranteed by either the U.S. federal government or other government sponsored agencies with a long history of no credit losses. As a result, management has determined that these securities have a zero loss expectation and therefore does not record an allowance for credit losses on these securities. Refer to Note 3, “Securities” for additional information regarding the measurement of credit losses on HTM securities. Loans Loans are reported at their principal amount outstanding, net of deferred loan fees and costs and any unearned discount or unamortized premium for acquired loans. Unearned discount and unamortized premium are accreted and amortized, respectively, to interest and dividend income on a basis that results in level rates of return over the terms of the loans. For originated loans, origination fees and related direct incremental origination costs are offset, and the resulting net amount is deferred and amortized over the life of the related loans using the effective interest method, assuming a certain level of prepayments. When loans are sold or repaid, the unamortized fees and costs are recorded to interest and dividend income. Interest income on loans is accrued based upon the daily principal amount outstanding except for loans on non-accrual status. For acquired loans, interest income is also accrued based upon the daily principal amount outstanding and is adjusted further by the accretion of any discount or amortization of any premium associated with the loan. Non-performing Loans (“NPLs”) Non-accrual Loans Interest accruals are generally discontinued when management has determined that the borrower may be unable to meet contractual obligations and/or when loans are 90 days or more past due. Exceptions may be made if management believes that collateral held by the Company is clearly sufficient and in full satisfaction of both principal and interest. When a loan is placed on non-accrual, all interest previously accrued but not collected is reversed against current period income and amortization of deferred loan fees and costs is discontinued. Interest received on non-accrual loans is either applied against principal or reported as income according to management’s judgment as to the collectability of principal. Non-accrual loans may be returned to an accrual status when principal and interest payments are no longer delinquent, and the risk characteristics of the loan have improved to the extent that there no longer exists a concern as to the collectability of principal and interest. Loans are considered past due based upon the number of days delinquent according to their contractual terms. Non-accrual loans and loans that are more than 90 days past due but still accruing interest are considered NPLs. Loans Individually Assessed for Impairment ASU 2016-13 indicates that a loan should be measured for impairment individually if that loan shares no similar risk characteristics with other loans. For the Company, loans which have been identified as those to be individually assessed for impairment under CECL include loans that do not share similar risk characteristics with other loans in the corresponding reserve segment. Characteristics of loans meeting this definition may include, but are not limited to: • Loans determined to be collateral dependent as defined below; • Loans on non-accrual status; • Loans with a risk rating of 12 under the Company’s risk rating scale, substandard (well-defined weakness) or worse; • Loans to borrowers actively involved in bankruptcy proceeds; and • Loans that have been partially charged-off. Collateral-Dependent Loans Management considers a loan to be collateral-dependent when foreclosure of the underlying collateral is probable. In addition, in accordance with ASU 2016-13, the Company elected to apply the collateral-dependent practical expedient whereby the Company measures expected credit losses using the fair value of the collateral, less any estimated costs to sell, when foreclosure is not probable but repayment of the loan is expected to be provided substantially through the operation or sale of the collateral, and the borrower is experiencing financial difficulty. Modifications of Loans to Borrowers Experiencing Financial Difficulty The amendments in ASU 2022-02 eliminated the accounting guidance for TDRs by creditors in Subtopic 310-40, Receivables—Troubled Debt Restructurings by Creditors , while enhancing disclosure requirements for certain loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. Thus, as a result of adoption of this standard on January 1, 2023, rather than applying the recognition and measurement guidance for TDRs, the Company now applies the loan refinancing and restructuring guidance codified in paragraphs 310-20-35-9 through 35-11 of the Accounting Standards Codification to determine whether a modification results in a new loan or a continuation of an existing loan. Modifications to borrowers experiencing financial difficulty include principal forgiveness, interest rate reductions, term extensions, other-than-insignificant payment delays and combinations thereof. Expected losses or recoveries related to loans where modifications have been granted to borrowers experiencing financial difficulty have been included in the Company’s determination of the allowance for loan losses. Upon adoption of ASU 2022-02, the Company is no longer required to use a discounted cash flow method to measure the allowance for loan losses resulting from a modification to a borrower experiencing financial difficulty. Accordingly, the Company now applies the same credit methodology it uses for similar loans that were not modified. The Company adopted ASU 2022-02 using the modified retrospective transition method. Accordingly, upon adoption, commercial loan TDRs existing at that time which were measured using a discounted cash flow methodology and all residential real estate and consumer home equity loan TDRs were transitioned to the applicable segment of loans collectively evaluated for impairment based upon their risk characteristics. Commercial loan TDRs determined to be collateral dependent continue to be assessed for impairment on an individual basis. Prior to the Company’s adoption of ASU 2022-02, in cases where a borrower was experiencing financial difficulties and the Company made certain concessionary modifications to contractual terms, the loan was classified as a TDR. Modifications included adjustments to interest rates, extensions of maturity, consumer loans where the borrower’s obligations had been effectively discharged through Chapter 7 bankruptcy and the borrower had not reaffirmed the debt to the Company, and other actions intended to minimize economic loss and avoid foreclosure or repossession of collateral. Management identified loans as TDR loans when it had a reasonable expectation that it would execute a TDR modification with a borrower. In addition, management estimated expected credit losses on a collective basis if a group of TDR loans shared similar risk characteristics. If a TDR loan’s risk characteristics were not similar to those of any of the Company’s other TDR loans, expected credit losses on the TDR loan were measured individually. The impairment analysis discounted the present value of the anticipated cash flows by the loan’s contractual rate of interest in effect prior to the loan’s modification or the fair value of collateral if the loan was collateral dependent. The amount of credit loss, if any, was recorded as a specific loss allocation to each individual loan or as a loss allocation to the pool of loans, for those loans for which credit loss was measured on a collective basis, in the allowance for credit losses. Any commercial (commercial and industrial, commercial real estate, commercial construction, and business banking loans) or residential loan that had been classified as a TDR and which subsequently defaulted was reviewed to determine if the loan should be deemed collateral-dependent. In such an instance, any shortfall between the value of the collateral and the book value of the loan was determined by measuring the recorded investment in the loan against the fair value of the collateral less costs to sell. Refer to Note 4, “Loans and Allowance for Credit Losses” for additional information regarding the Company’s measurement of the allowance for loan losses as of December 31, 2023 and information regarding the Company’s TDR loans as of December 31, 2022 and for the year then ended. Purchased Credit-Deteriorated Loans The Company applied the prospective transition approach with respect to PCD assets upon adoption of ASU 2016-13. Under this approach, loans previously determined to be PCI loans are considered to be PCD loans as of January 1, 2022. PCD loans are acquired individual loans (or acquired groups of loans with similar risk characteristics) that, as of the date of acquisition, have experienced a more-than-insignificant deterioration in credit quality since origination, as determined by the Company’s assessment. A PCD loan is recorded at its purchase price plus the allowance for loan losses expected at the time of acquisition, or “gross up” of the amortized cost basis, if any. Changes in the current estimate of the allowance for loan losses subsequent to acquisition from the estimated allowance previously recorded are recognized in the income statement as provision for credit losses or reversal of provision for credit losses in subsequent periods as they arise. A purchased loan that does not qualify as a PCD asset is accounted for similar to the Company’s method of accounting for originated assets, whereby an allowance for loan losses is recognized with a corresponding increase to the income statement provision for loan losses. Evidence that purchased loans, measured at amortized cost, have more-than-insignificant deterioration in credit quality since origination and, therefore meet the PCD definition, may include past-due status, non-accrual status, risk rating and other standard indicators (i.e., TDRs, charge-offs, bankruptcy). Allowance for Credit Losses Through December 31, 2021, the allowance for loan losses represented management’s best estimate of incurred probable losses in the Company’s loan portfolios based upon management’s assessment of various factors, including the risk characteristics of its loan portfolio, current economic conditions, and trends in loan delinquencies and charge-offs. The Company’s methodology for determining the qualitative component through December 31, 2021 included an assessment of factors affecting the determination of incurred losses in the loan portfolio. Such factors included trends in economic conditions, loan growth, credit underwriting policy exceptions, regulatory and audit findings, and peer comparisons, among others. Upon adoption of ASU 2016-13, effective January 1, 2022, the Company changed its reserve methodology to estimate expected credit losses over the contractual life of loans and leases. The allowance for credit losses, or “ACL,” is established to provide for the Company’s current estimate of expected lifetime credit losses on loans measured at amortized cost and unfunded lending commitments at the balance sheet date and is established through a provision for credit losses charged to net income. Credit losses are charged directly to the ACL. Subsequent recoveries, if any, are credited to the ACL. Commercial and residential loans are charged-off in the period in which they are deemed uncollectible. Delinquent loans in these product types are subject to ongoing review and analysis to determine if a charge-off in the current period is appropriate. For consumer finance loans, policies and procedures exist that require charge-off consideration upon a certain triggering event depending on the product type. Charge-off triggers include: 120 days delinquent for automobile, home equity, and other consumer loans with the exception of cash reserve loans for which the trigger is 150 days delinquent; death of the borrower; or Chapter 7 bankruptcy. In addition to those events, the charge-off determination includes other loan quality indicators, such as collateral position and adequacy or the presence of other repayment sources. The ACL is evaluated on a regular basis by management. Management uses a methodology to systematically estimate the amount of expected lifetime losses in the portfolio. Expected lifetime losses are estimated on a collective basis for loans sharing similar risk characteristics and are determined using a quantitative model combined with an assessment of certain qualitative factors designed to address forecast risk and model risk inherent in the quantitative model output. For commercial and industrial, commercial real estate, commercial construction and business banking portfolios, the quantitative model uses a loan rating system which is comprised of management’s determination of a financial asset’s probability of default (“PD”), loss given default (“LGD”) and exposure at default (“EAD”), which are derived from both the Company’s and industry historical loss experience and other factors. For residential real estate, consumer home equity and other consumer portfolios, the Company’s quantitative model uses historical loss experience. The quantitative model estimates expected credit losses using loan level data over the estimated life of the exposure, considering the effect of prepayments. Economic forecasts are incorporated into the estimate over a reasonable and supportable forecast period, beyond which is a reversion to the Company’s and/or industry historical loss average. Management has determined that a reasonable and supportable forecast period of eight quarters, and a straight-line reversion period of four quarters, are appropriate forecast periods for purposes of estimating expected credit losses. As described above, quantitative model results are adjusted for risk factors not considered within the model but which are relevant in estimating the expected credit losses within the loan portfolio. The qualitative risk factors impacting the expected risk of loss within the loan portfolio include the following: • Lending policies and procedures, including underwriting standards and collection, charge-off and recovery practices; • Nature and volume of the portfolio; • Volume and severity of past-due, non-accrual and classified loans; • The value of the underlying collateral for loans that are not collateral dependent; • Concentrations of credit risk; • Model and data limitations; and • Other external factors, such as changes in legal, regulatory or competitive environments. Loans that do not share similar risk characteristics with any pools of assets are subject to individual evaluation and are removed from the collectively assessed pools. For loans that are individually evaluated, the Company uses either a discounted cash flow (“DCF”) approach or, for loans deemed to be collateral dependent or when foreclosure is probable, a fair value of collateral approach. Accrued interest receivable amounts are excluded from balances of loans held at amortized cost and are included within other assets on the Consolidated Balance Sheet. Management has elected not to measure an allowance for credit losses on these amounts as the Company employs a timely write-off policy. Consistent with the Company's policy for non-accrual loans, accrued interest receivable is typically written off when loans reach 90 days past due and are placed on non-accrual status. In the ordinary course of business, the Company enters into commitments to extend credit and standby letters of credit. Such financial instruments are recorded in the financial statements when they become payable. The credit risk associated with these commitments is evaluated in a manner similar to the reserving method for loans receivable previously described. The reserve for unfunded lending commitments is included in other liabilities in the Consolidated Balance Sheets. Additionally, various regulatory agencies, as an integral part of the Company’s examination process, periodically assess the appropriateness of the allowance for credit losses and may require the Company to increase its allowance for loan losses or recognize further loan charge-offs, in accordance with GAAP. Refer to Note 4, “Loans and Allowance for Credit Losses” for additional information regarding the Company’s measurement of credit losses on loans receivable and off-balance sheet commitments to lend as of December 31, 2023 and comparative allowance for loan loss information for which ASC 450, “Contingencies” and ASC 310, “Receivables” were applied (i.e., prior to the Company’s adoption of the CECL methodology previously described). Mortgage Banking Activities Mortgage loans held for sale to the secondary market are carried at the lower of cost or estimated market value on an individual loan basis. The Company enters into commitments to fund residential mortgage loans with an offsetting forward commitment to sell them in the secondary markets in order to mitigate interest rate risk. Gains or losses on sales of mortgage loans are recognized in the Consolidated Statements of Income at the time of sale. Interest income is recognized on loans held for sale between the time the loan is funded and the loan is sold. Direct loan origination costs and fees are deferred upon origination and are recognized in the Consolidated Statements of Income on the date of sale. Other Real Estate Owned OREO consists of properties and other assets acquired through foreclosure proceedings or acceptance of a deed in lieu of foreclosure. OREO is recorded in other assets in the Consolidated Balance Sheets, on an individual asset basis at the fair value less estimated costs to sell on the date control is obtained. Any write-downs to the cost of the related asset upon transfer to OREO to reflect the asset at fair value less estimated costs to sell is recorded through the allowance for loan losses. The Company relies primarily on third-party valuation information from certified appraisers and values are generally based upon recent appraisals of the underlying collateral, brokers’ opinions based upon recent sales of comparable properties, estimated equipment auction or liquidation values, income capitalization, or a combination of income capitalization and comparable sales. As of December 31, 2023 and 2022, the Company held no OREO. Federal Home Loan Bank Stock The Company, as a member of the Federal Home Loan Bank (“FHLB”) of Boston (“FHLBB”), is required to maintain an investment in capital stock of the FHLB. Based on redemption provisions, the stock has no quoted market value and is carried at cost. Premises and Equipment Land is carried at cost. Buildings, leasehold improvements and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the related assets. Leasehold improvements are amortized over the shorter of the lease terms or the estimated lives of the improvements. Expected lease terms include lease options to the extent that the exercise of such options is reasonably assured. Banking premises and equipment held for sale are carried at the lower of cost or estimated fair value, less estimated costs to sell. Goodwill and Core Deposit Intangible Acquisitions of businesses are accounted for using the acquisition method of accounting. Accordingly, the net assets of the companies acquired are recorded at their fair values at the date of acquisition. Goodwill represents the excess of purchase price over the fair value of net assets acquired. Other intangible assets represent acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights, or because the asset is capable of being sold or exchanged either on its own, or in combination with a related contract, asset, or liability. The Company evaluates goodwill for impairment at least annually, as of September 30, or more often if warranted, using a quantitative impairment approach. The quantitative impairment test compares the book value to the fair value of each reporting unit. If the book value exceeds the fair value, an impairment is charged to net income. Management has identified one reporting unit for purposes of testing goodwill for impairment which is referred to as “the banking business.” The Company’s other intangible asset, which is a core deposit intangible, a definite-lived intangible asset, is stated at cost less accumulated amortization. The Company evaluates its core deposit intangible asset for impairment whenever events or changes in circumstances indicate that the carrying value of the asset may not be fully recovered. The Company considers factors including, but not limited to, changes in legal factors and business climate that could affect the value of the intangible asset. Any impairment losses are charged to net income. The Company amortizes its core deposit intangible over its estimated useful life. The original estimated useful life of the core deposit identifiable intangible asset was ten years. The Company reassesses the useful life of its core deposit intangible asset at least annually, or more frequently based on specific events or changes in circumstances. Retirement Plans The Company provides benefits to its employees and executive officers through various retirement plans, including a defined benefit plan, a defined benefit supplemental executive retirement plan, a defined contribution plan, a benefit equalization plan, and an outside directors’ retainer continuance plan. The Company provides pension benefits for its employees using a noncontributory, qualified defined benefit plan, through membership in the Savings Banks Employees Retirement Association (“SBERA”). The Qualified Defined Benefit Pension Plan (“Defined Benefit Plan”) is a noncontributory, defined benefit plan. The Company’s employees become eligible after attaining age 21 and completing one year of service. Effective November 1, 2020, the Defined Benefit Plan, sponsored by the Company, was amended to convert the plan from a traditional final average earnings plan design to a cash balance plan design. Under the final average earnings plan design, benefits became fully vested after three years of eligible service for individuals employed on or before October 31, 1989. For individuals employed subsequent to October 31, 1989 and who were already in the Defined Benefit Plan as of November 1, 2020, benefits became fully vested after five years of eligible service. Under the cash balance plan design, hypothetical account balances are established for each participant and pension benefits are generally stated as the lump sum amount in that hypothetical account. Contribution credits equal to a percentage of a participant’s annual compensation (if the participant works at least 1,000 hours during the year) and interest credits equal to the greater of the 30-Year Treasury rate for September preceding the current plan year or 3.5% are added to a participant’s account each year. For employees hired prior to November 1, 2020, annual contribution credits generally increase as the participant remains employed with the Company. Employees hired on and after November 1, 2020 receive annual contribution credits equal to 5% of annual compensation, with no future increases. Notwithstanding the preceding sentence, since a cash balance plan is a defined benefit plan, the annual retirement benefit payable at normal retirement (age 65) is an annuity, which is the actuarial equivalent of the participant’s account balance under the cash balance plan design, plus their frozen benefit under the final average earnings plan design. However, under the Defined Benefit Plan, participants may elect, with the consent of their spouses if they are married, to have the benefits distributed as a lump sum rather than an annuity. The lump sum is equal to the sum of the actuarial equivalent of their frozen benefit under the final average earnings plan design, plus their cash balance account. Under the Company’s non-Qualified Benefit Equalization Plan (“BEP”), which is described further below, benefits are generally only payable as a lump sum, which is equal to the sum of the actuarial equivalent of their frozen benefit under the final average earnings plan design, plus their cash balance account. The Company’s annual contribution to the plan is based upon standards established by the Pension Protection Act. The contribution is based on an actuarial method intended to provide not only for benefits attributable to service to date, but also for those expected to be earned in the future. The Company also has an unfunded Defined Benefit Supplemental Executive Retirement Plan (“DB SERP”) that provides certain retired officers with defined pension benefits in excess of qualified plan limits imposed by U.S. federal tax law. The DB SERP has a plan year end of December 31. The Company’s BEP, which is an unfunded plan, provides retirement benefits to certain employees whose retirement benefits under the Defined Benefit Plan are limited per the Internal Revenue Code. The BEP has a plan year end of October 31. Effective November 1, 2020, the BEP, sponsored by the Company, was amended to convert the plan from a traditional final average earnings plan design to a cash balance plan design. The Company also has an unfunded Outside Directors’ Retainer Continuance Plan (“ODRCP”) that provides pension benefits to outside directors who retire from service. The Outside Directors’ Retainer Continuance Plan has a plan year end of December 31. Effective December 31, 2020, the Company closed the ODRCP to new participants and froze benefit accruals for active participants. Plan assets are invested in various investment funds and held at fair value which generally represents observable market prices. Pension liabi

Securities

Securities	12 Months Ended
	Dec. 31, 2023
Debt Securities [Abstract]
Securities	Securities Available for Sale Securities The amortized cost, gross unrealized gains and losses, ACL and fair value of available for sale securities as of the dates indicated were as follows: As of December 31, 2023 Amortized Unrealized Unrealized Allowance for Credit Losses Fair (In thousands) Debt securities: Government-sponsored residential mortgage-backed securities $ 3,302,165 $ — $ (521,527) $ — $ 2,780,638 Government-sponsored commercial mortgage-backed securities 1,326,029 — (201,653) — 1,124,376 U.S. Agency bonds 236,454 — (20,443) — 216,011 U.S. Treasury securities 99,552 — (4,400) — 95,152 State and municipal bonds and obligations 197,704 172 (6,532) — 191,344 $ 5,161,904 $ 172 $ (754,555) $ — $ 4,407,521 As of December 31, 2022 Amortized Unrealized Unrealized Allowance for Credit Losses Fair (In thousands) Debt securities: Government-sponsored residential mortgage-backed securities $ 4,855,763 $ — $ (743,855) $ — $ 4,111,908 Government-sponsored commercial mortgage-backed securities 1,570,119 — (221,165) — 1,348,954 U.S. Agency bonds 1,100,891 — (148,409) — 952,482 U.S. Treasury securities 99,324 — (6,267) — 93,057 State and municipal bonds and obligations 198,039 9 (14,956) — 183,092 Other debt securities 1,299 — (14) — 1,285 $ 7,825,435 $ 9 $ (1,134,666) $ — $ 6,690,778 The Company did not record a provision for credit losses on any AFS securities during either the year ended December 31, 2023 or 2022. Accrued interest receivable on AFS securities totaled $9.2 million and $12.9 million as of December 31, 2023 and December 31, 2022, respectively, and is included within other assets As of December 31, 2023 and 2022, the Company had no investments in obligations of individual states, counties, or municipalities which exceeded 10% of consolidated shareholders’ equity. The following table summarizes gross realized gains and losses from sales of AFS securities for the periods indicated: For the Years Ended December 31, 2023 2022 2021 (In thousands) Gross realized gains from sales of AFS securities $ — $ 1,775 $ 1,166 Gross realized losses from sales of AFS securities (333,170) (4,932) — Net (losses) gains from sales of AFS securities $ (333,170) $ (3,157) $ 1,166 Information pertaining to AFS securities with gross unrealized losses as of December 31, 2023 and 2022, for which the Company did not recognize a provision for credit losses under CECL, aggregated by investment category and length of time that individual securities have been in a continuous loss position, is as follows: As of December 31, 2023 Less than 12 Months 12 Months or Longer Total # of Gross Fair Gross Fair Gross Fair (Dollars in thousands) Government-sponsored residential mortgage-backed securities 324 $ — $ — $ 521,527 $ 2,780,638 $ 521,527 $ 2,780,638 Government-sponsored commercial mortgage-backed securities 187 — — 201,653 1,124,376 201,653 1,124,376 U.S. Agency bonds 23 — — 20,443 216,011 20,443 216,011 U.S. Treasury securities 6 36 4,927 4,364 90,225 4,400 95,152 State and municipal bonds and obligations 196 233 22,894 6,299 135,279 6,532 158,173 736 $ 269 $ 27,821 $ 754,286 $ 4,346,529 $ 754,555 $ 4,374,350 As of December 31, 2022 Less than 12 Months 12 Months or Longer Total # of Gross Fair Gross Fair Gross Fair (Dollars in thousands) Government-sponsored residential mortgage-backed securities 322 $ 42,196 $ 435,690 $ 701,659 $ 3,676,218 $ 743,855 $ 4,111,908 Government-sponsored commercial mortgage-backed securities 199 38,944 300,476 182,221 1,048,478 221,165 1,348,954 U.S. Agency bonds 37 645 4,145 147,764 948,337 148,409 952,482 U.S. Treasury securities 5 1,311 48,451 4,956 44,606 6,267 93,057 State and municipal bonds and obligations 237 14,942 179,614 14 225 14,956 179,839 Other debt securities 2 — — 14 1,285 14 1,285 802 $ 98,038 $ 968,376 $ 1,036,628 $ 5,719,149 $ 1,134,666 $ 6,687,525 The Company does not intend to sell these investments and has determined based upon available evidence that it is more-likely-than-not that the Company will not be required to sell each security before the expected recovery of its amortized cost basis. As a result, the Company did not recognize an ACL on these investments as of either December 31, 2023 or 2022. The causes of the impairments listed in the tables above by category are as follows as of December 31, 2023 and 2022: • Government-sponsored mortgage-backed securities, U.S. Agency bonds and U.S. Treasury securities – The securities with unrealized losses in these portfolios have contractual terms that generally do not permit the issuer to settle the security at a price less than the current par value of the investment. The decline in market value of these securities is attributable to changes in interest rates and not credit quality. Additionally, these securities are implicitly guaranteed by the U.S. government or one of its agencies. • State and municipal bonds and obligations – The securities with unrealized losses in this portfolio have contractual terms that generally do not permit the issuer to settle the security at a price less than the current par value of the investment. The decline in market value of these securities is attributable to changes in interest rates and not credit quality. • Other debt securities – As of December 31, 2022, there were two securities included in this portfolio in an unrealized loss position which consisted of two foreign debt securities. Both securities were performing in accordance with the terms of their respective contractual agreements. The decline in market value of these securities was attributable to changes in interest rates and not credit quality. Held to Maturity Securities The amortized cost, gross unrealized gains and losses, ACL and fair value of HTM securities as of the dates indicated were as follows: As of December 31, 2023 Amortized Unrealized Unrealized Allowance for Credit Losses Fair (In thousands) Debt securities: Government-sponsored residential mortgage-backed securities $ 254,752 $ — $ (24,433) $ — $ 230,319 Government-sponsored commercial mortgage-backed securities 194,969 — (20,466) — 174,503 $ 449,721 $ — $ (44,899) $ — $ 404,822 As of December 31, 2022 Amortized Unrealized Unrealized Allowance for Credit Losses Fair (In thousands) Debt securities: Government-sponsored residential mortgage-backed securities $ 276,493 $ — $ (30,150) $ — $ 246,343 Government-sponsored commercial mortgage-backed securities 200,154 — (23,271) — 176,883 $ 476,647 $ — $ (53,421) $ — $ 423,226 The Company did not record a provision for estimated credit losses on any HTM securities during either the year ended December 31, 2023 or 2022. The accrued interest receivable on HTM securities totaled $0.9 million and $1.0 million as of December 31, 2023 and 2022, respectively, and is included within other assets Available for Sale and Held to Maturity Securities Contractual Maturity The amortized cost and estimated fair value of AFS and HTM securities by scheduled contractual maturities as of dates indicated were as follows: As of December 31, 2023 Due in one year or less Due after one year to five years Due after five to ten years Due after ten years Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value (In thousands) AFS securities Government-sponsored residential mortgage-backed securities $ — $ — $ 29,288 $ 28,188 $ 22,735 $ 21,235 $ 3,250,142 $ 2,731,215 $ 3,302,165 $ 2,780,638 Government-sponsored commercial mortgage-backed securities — — 256,229 234,725 379,749 327,198 690,051 562,453 1,326,029 1,124,376 U.S. Agency bonds — — 236,454 216,011 — — — — 236,454 216,011 U.S. Treasury securities — — 99,552 95,152 — — — — 99,552 95,152 State and municipal bonds and obligations 213 209 30,131 29,393 44,047 43,260 123,313 118,482 197,704 191,344 Total available for sale securities 213 209 651,654 603,469 446,531 391,693 4,063,506 3,412,150 5,161,904 4,407,521 HTM securities Government-sponsored residential mortgage-backed securities — — — — — — 254,752 230,319 254,752 230,319 Government-sponsored commercial mortgage-backed securities — — 80,014 72,952 114,955 101,551 — — 194,969 174,503 Total held to maturity securities — — 80,014 72,952 114,955 101,551 254,752 230,319 449,721 404,822 Total $ 213 $ 209 $ 731,668 $ 676,421 $ 561,486 $ 493,244 $ 4,318,258 $ 3,642,469 $ 5,611,625 $ 4,812,343 As of December 31, 2022 Due in one year or less Due after one year to five years Due after five to ten years Due after ten years Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value (In Thousands) AFS securities Government-sponsored residential mortgage-backed securities $ — $ — $ 21,221 $ 20,284 $ 727,908 $ 648,132 $ 4,106,634 $ 3,443,492 $ 4,855,763 $ 4,111,908 Government-sponsored commercial mortgage-backed securities — — 191,762 171,992 649,659 556,641 728,698 620,321 1,570,119 1,348,954 U.S. Agency bonds — — 877,371 767,464 223,520 185,018 — — 1,100,891 952,482 U.S. Treasury securities — — 99,324 93,057 — — — — 99,324 93,057 State and municipal bonds and obligations 213 209 22,100 21,283 42,554 40,970 133,172 120,630 198,039 183,092 Other debt securities 1,299 1,285 — — — — — — 1,299 1,285 Total available for sale securities 1,512 1,494 1,211,778 1,074,080 1,643,641 1,430,761 4,968,504 4,184,443 7,825,435 6,690,778 HTM securities Government-sponsored residential mortgage-backed securities — — — — — — 276,493 246,343 276,493 246,343 Government-sponsored commercial mortgage-backed securities — — — — 200,154 176,883 — — 200,154 176,883 Total held to maturity securities — — — — 200,154 176,883 276,493 246,343 476,647 423,226 Total $ 1,512 $ 1,494 $ 1,211,778 $ 1,074,080 $ 1,843,795 $ 1,607,644 $ 5,244,997 $ 4,430,786 $ 8,302,082 $ 7,114,004 Mortgage-backed securities include investments in securities that are insured or guaranteed by Freddie Mac, Ginnie Mae or Fannie Mae. Mortgage-backed securities are purchased to achieve positive interest rate spread with minimal administrative expense, and to lower the Company’s credit risk. Mortgage-backed securities and callable securities are shown at their contractual maturity dates. However, both are expected to have shorter average lives due to expected prepayments and callable features, respectively. Included in the above maturity tables as of December 31, 2023 and 2022 were $394.4 million, and $852.9 million, respectively, of callable securities at fair value. Securities Pledged as Collateral As of December 31, 2023 and 2022, securities with a carrying value of $615.7 million and $437.9 million, respectively, were pledged to secure public deposits and for other purposes required by law. As of December 31, 2023 and 2022, deposits with associated pledged collateral included cash accounts from the Company’s wealth management division (“Eastern Wealth Management”) and municipal deposit accounts. In March 2023 the Federal Reserve created the Bank Term Funding Program (the “Program”) in order to support American businesses and households. The Program helps make available additional funding to eligible depository institutions in order to help assure banks have the ability to meet the needs of their depositors. The Program offers loans up to one year in length to banks in return for any collateral eligible for purchase by the Federal Reserve Banks in open market operations, such as U.S. Treasuries, U.S. agency securities, and U.S. agency mortgage-backed securities. As of December 31, 2023, securities with a carrying value of $2.4 billion were pledged as collateral through the Program. In addition, the Company pledged securities with a carrying value of $168.8 million to the Federal Reserve Discount Window (the “Discount Window”) as of December 31, 2023. No securities were pledged to the Program or the Discount Window as of December 31, 2022.

Loans and Allowance for Credit

Loans and Allowance for Credit Losses	12 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Loans and Allowance for Credit Losses	Loans and Allowance for Credit Losses Loans The following table provides a summary of the Company’s loan portfolio as of the dates indicated: As of December 31, 2023 2022 (In thousands) Commercial and industrial $ 3,034,068 $ 3,150,946 Commercial real estate 5,457,349 5,155,323 Commercial construction 386,999 336,276 Business banking 1,085,763 1,090,492 Residential real estate 2,565,485 2,460,849 Consumer home equity 1,208,231 1,187,547 Other consumer (1)(2) 235,533 194,098 Gross loans before unamortized premiums, unearned discounts and deferred fees and costs 13,973,428 13,575,531 Allowance for loan losses (3) (148,993) (142,211) Unamortized premiums, net of unearned discounts and deferred fees, net of costs (25,068) (13,003) Loans after the allowance for loan losses, unamortized premiums, unearned discounts and deferred fees and costs $ 13,799,367 $ 13,420,317 (1) Automobile loans are included in the other consumer portfolio above and amounted to $7.2 million and $18.1 million at December 31, 2023 and 2022, respectively. (2) Home improvement loans are included in the other consumer portfolio and amounted to $178.9 million and $121.1 million at December 31, 2023 and 2022, respectively. (3) The balance of accrued interest receivable excluded from amortized cost and the calculation of the allowance for loan losses amounted to $53.9 million and $45.2 million as of December 31, 2023 and 2022 , respectively, and is included within other assets on the Consolidated Balance Sheets. There are no other loan categories that exceed 10% of total loans not already reflected in the preceding table. The Company’s lending activities are conducted principally in the New England area with the exception of its Shared National Credit Program (“SNC Program”) portfolio and certain purchased loans. The Company participates in the SNC Program in an effort to improve its industry and geographical diversification. The SNC Program portfolio is included in the Company’s commercial and industrial, commercial real estate and commercial construction portfolios. The SNC Program portfolio is defined as loan syndications with exposure over $100 million and with three or more lenders participating. Most loans originated by the Company are either collateralized by real estate or other assets or guaranteed by federal and local governmental authorities. The ability and willingness of the single-family residential and consumer borrowers to honor their repayment commitments is generally dependent on the level of overall economic activity within the borrowers’ geographic areas and real estate values. The ability and willingness of commercial real estate, commercial and industrial, and construction loan borrowers to honor their repayment commitments is generally dependent on the health of the real estate economy in the borrowers’ geographic areas and the general economy. Loans Pledged as Collateral The carrying value of loans pledged to secure advances from the FHLBB were $4.6 billion and $3.9 billion at December 31, 2023 and 2022, respectively. The balance of funds borrowed from the FHLBB were $17.7 million and $704.1 million at December 31, 2023 and 2022, respectively. The carrying value of loans pledged to secure advances from the Federal Reserve Bank (“FRB”) was $1.1 billion at both December 31, 2023 and 2022, respectively. There were no funds borrowed from the FRB outstanding at December 31, 2023 and 2022. Serviced Loans At December 31, 2023 and 2022, mortgage loans partially or wholly-owned by others and serviced by the Company amounted to $77.2 million and $84.0 million, respectively. Purchased Loans The Company began purchasing residential real estate mortgage loans during the third quarter of 2022 and ceased such purchases in the first quarter of 2023. Loans purchased were subject to the same underwriting criteria as those loans originated directly by the Company. During the year ended December 31, 2023, the Company purchased $32.0 million of residential real estate mortgage loans. The Company purchased $380.2 million of residential real estate mortgage loans during the year ended December 31, 2022. As of December 31, 2023 and 2022, the amortized cost balance of loans purchased was $385.5 million and $376.1 million, respectively. Commercial Loan Sales During the year ended December 31, 2023, the Company sold $214.2 million of commercial and industrial loans previously included in the SNC program portfolio and recognized a loss on sale of $2.7 million. Allowance for Loan Losses The allowance for loan losses is established to provide for management’s estimate of expected lifetime credit losses on loans measured at amortized cost at the balance sheet date through a provision for loan losses charged to net income. Charge-offs, net of recoveries, are charged directly to the allowance for loan losses. Commercial and residential loans are charged-off in the period in which they are deemed uncollectible. Delinquent loans in these product types are subject to ongoing review and analysis to determine if a charge-off in the current period is appropriate. For consumer loans, policies and procedures exist that require charge-off consideration upon a certain triggering event depending on the product type. The following tables summarize the change in the allowance for loan losses by loan category for the periods indicated: For the Year Ended December 31, 2023 Commercial Commercial Commercial Business Residential Consumer Other Total (In thousands) Allowance for loan losses: Beginning balance $ 26,859 $ 54,730 $ 7,085 $ 16,189 $ 28,129 $ 6,454 $ 2,765 $ 142,211 Cumulative effect of change in accounting principle (1) 47 — — (140) (849) (201) — (1,143) Charge-offs (13) (8,008) — (4,645) — (7) (2,419) (15,092) Recoveries 296 198 — 1,867 97 41 466 2,965 Provision (release) (230) 18,555 (419) 1,642 (1,423) (692) 2,619 20,052 Ending balance $ 26,959 $ 65,475 $ 6,666 $ 14,913 $ 25,954 $ 5,595 $ 3,431 $ 148,993 (1) Represents the adjustment needed to reflect the cumulative day one impact pursuant to the Company’s adoption of ASU 2022-02 (i.e., cumulative effect adjustment related to the adoption of ASU 2022-02 as of January 1, 2023). The adjustment represents a $1.1 million decrease to the allowance attributable to the change in accounting methodology for estimating the allowance for loan losses resulting from the Company’s adoption of the standard. For the Year Ended December 31, 2022 Commercial Commercial Commercial Business Residential Consumer Other Other Total (In thousands) Allowance for loan losses: Beginning balance $ 18,018 $ 52,373 $ 2,585 $ 10,983 $ 6,556 $ 3,722 $ 3,308 $ 242 $ 97,787 Cumulative effect of change in accounting principle (1) 11,533 (6,655) 1,485 6,160 13,489 1,857 (541) (242) 27,086 Charge-offs (269) — — (2,292) — (1) (2,269) — (4,831) Recoveries 1,322 91 — 2,069 94 24 644 — 4,244 Provision (release) (3,745) 8,921 3,015 (731) 7,990 852 1,623 — 17,925 Ending balance $ 26,859 $ 54,730 $ 7,085 $ 16,189 $ 28,129 $ 6,454 $ 2,765 $ — $ 142,211 (1) R epresents the adjustment needed to reflect the cumulative day one impact pursuant to the Company’s adoption of ASU 2016-13 (i.e., cumulative effect adjustment related to the adoption of ASU 2016-13 as of January 1, 2022). The adjustment represents a $27.1 million increase to the allowance attributable to the change in accounting methodology for estimating the allowance for loan losses resulting from the Company’s adoption of the standard. The adjustment also includes the adjustment needed to reflect the day one reclassification of the Company’s PCI loan balances to PCD and the associated gross-up of $0.1 million, pursuant to the Company’s adoption of ASU 2016-13. The allowance for loan losses increased by $6.8 million to $149.0 million at December 31, 2023 from $142.2 million at December 31, 2022 and the allowance for loans losses as a percentage of total loans increased by 2 basis points to 1.07% at December 31, 2023 from 1.05% at December 31, 2022. The increase in allowance for loan losses was primarily due to increased loan balances. Total charge-offs increased by $10.3 million to $15.1 million during the year ended December 31, 2023 from $4.8 million during the year ended December 31, 2022. The increase was primarily due to charge-offs on non-performing commercial real estate loans collateralized by properties in the office risk category taken in the fourth quarter of 2023. Such loans had been previously reserved for on a specific reserve basis in the third quarter of 2023. Reserve for Unfunded Commitments Management evaluates the need for a reserve on unfunded lending commitments in a manner consistent with loans held for investment. The Company’s adoption of ASU 2022-02 on January 1, 2023 did not impact the reserve for unfunded lending commitments. Upon adoption of ASU 2016-13 on January 1, 2022, the Company recorded a transition adjustment related to the reserve for unfunded lending commitments of $1.0 million, resulting in a total reserve for unfunded lending commitments of $11.1 million as of January 1, 2022. As of December 31, 2023 and December 31, 2022, the Company’s reserve for unfunded lending commitments was $14.1 million and $13.2 million, respectively, which is recorded within other liabilities in the Company’s Consolidated Balance Sheets. Portfolio Segmentation Management uses a methodology to systematically estimate the amount of expected losses in each segment of loans in the Company’s portfolio. Commercial and industrial business banking, investment commercial real estate, and commercial and industrial loans are evaluated based upon loan-level risk characteristics, historical losses and other factors which form the basis for estimating expected losses. Other portfolios, including owner occupied commercial real estate (which includes business banking owner occupied commercial real estate), commercial construction, residential mortgages, home equity and consumer loans, are analyzed as groups taking into account delinquency ratios, and the Company’s and peer banks’ historical loss experience. For the purposes of estimating the allowance for loan losses, management segregates the loan portfolio into loan categories that share similar risk characteristics such as the purpose of the loan, repayment source, and collateral. These characteristics are considered when determining the appropriate level of the allowance for each category. Some examples of these risk characteristics unique to each loan category include: Commercial Lending Commercial and industrial : The primary risk associated with commercial and industrial loans is the ability of borrowers to achieve business results consistent with those projected at origination. Collateral frequently consists of a first lien position on business assets including, but not limited to, accounts receivable, inventory, aircraft and equipment. The primary repayment source is operating cash flow and, secondarily, the liquidation of assets. Under its lending guidelines, the Company generally requires a corporate or personal guarantee from individuals that hold material ownership in the borrowing entity when the loan-to-value of a commercial and industrial loan is in excess of a specified threshold. Commercial real estate : Collateral values are established by independent third-party appraisals and evaluations. Primary repayment sources include operating income generated by the real estate, permanent debt refinancing, sale of the real estate and, secondarily, liquidation of the collateral. Under its lending guidelines, the Company generally requires a corporate or personal guarantee from individuals that hold material ownership in the borrowing entity when the loan-to-value of a commercial real estate loan is in excess of a specified threshold. Commercial construction : These loans are generally considered to present a higher degree of risk than other real estate loans and may be affected by a variety of factors, such as adverse changes in interest rates and the borrower’s ability to control costs and adhere to time schedules. Construction loans are underwritten utilizing feasibility studies, independent appraisal reviews, sensitivity analysis of absorption and lease rates and financial analysis of the developers and property owners. Construction loans are generally based upon estimates of costs and value associated with the completed project. Construction loan repayment is substantially dependent on the ability of the borrower to complete the project and obtain permanent financing. Business banking : These loans are typically secured by all business assets or commercial real estate. Business banking originations include traditionally underwritten loans as well as partially automated scored loans. Business banking scored loans are determined by utilizing the Company’s proprietary decision matrix that has a number of quantitative factors including, but not limited to, a guarantor’s credit score, industry risk, and time in business. The Company also engages in Small Business Association (“SBA”) lending. The SBA guarantees reduce the Company’s loss due to default and are considered a credit enhancement to the loan structure. Residential Lending These loans are made to borrowers who demonstrate the ability to repay principal and interest on a monthly basis. Underwriting considerations include, among others, income sources and their reliability, willingness to repay as evidenced by credit repayment history, financial resources (including cash reserves) and the value of the collateral. The Company maintains policy standards for minimum credit score and cash reserves and maximum loan-to-value consistent with a “prime” portfolio. Collateral consists of mortgage liens on 1-4 family residential dwellings. The policy standards applied to loans originated by the Company are the same as those applied to purchased loans. The Company does not originate or purchase sub-prime or other high-risk loans. Residential loans are originated either for sale to investors or retained in the Company’s loan portfolio. Decisions about whether to sell or retain residential loans are made based on the interest rate characteristics, pricing for loans in the secondary mortgage market, competitive factors and the Company’s liquidity and capital needs. Consumer Lending Consumer home equity : Home equity lines of credit are granted for ten years with monthly interest-only repayment requirements. Full principal repayment is required at the end of the ten-year draw period. Home equity loans are term loans that require the monthly payment of principal and interest such that the loan will be fully amortized at maturity. Underwriting considerations are materially consistent with those utilized in residential real estate. Collateral consists of a senior or subordinate lien on owner-occupied residential property. Other consumer : The Company’s policy and underwriting in this category, which is comprised primarily of home improvement, automobile and aircraft loans, include the following factors, among others: income sources and reliability, credit histories, term of repayment, and collateral value, as applicable. These are typically granted on an unsecured basis, with the exception of aircraft and automobile loans. Credit Quality Commercial Lending Credit Quality The credit quality of the Company’s commercial loan portfolio is actively monitored and supported by a comprehensive credit approval process and all large dollar transactions are sent for approval to a committee of seasoned business line and credit professionals. The Company maintains an independent credit risk review function that reports directly to the Risk Management Committee of the Board of Directors. Credits that demonstrate significant deterioration in credit quality are transferred to a specialized group of experienced officers for individual attention. The Company monitors credit quality indicators and utilizes portfolio scorecards to assess the risk of its commercial portfolio. Specifically, the Company utilizes a 15-point credit risk-rating system to manage risk and identify potential problem loans. Under this point system, risk-rating assignments are based upon a number of quantitative and qualitative factors that are under continual review. Factors include cash flow, collateral coverage, liquidity, leverage, position within the industry, internal controls and management, financial reporting, and other considerations. Commercial loan risk ratings are (re)evaluated for each loan at least once-per-year. The risk-rating categories under the credit risk-rating system are defined as follows: 0 Risk Rating- Unrated Certain segments of the portfolios are not rated. These segments include aircraft loans, business banking scored loan products, and other commercial loans managed by exception. Loans within this unrated loan segment are monitored by delinquency status; and for lines of credit greater than $100,000 in exposure, an annual review is conducted which includes the review of the business score and loan and deposit account performance. The Company supplements performance data with current business credit scores for the business banking portfolio on a quarterly basis. Unrated commercial and business banking loans are generally restricted to commercial exposure of less than $1.5 million. Loans included in this category generally are not required to provide regular financial reporting or regular covenant monitoring. For purposes of estimating the allowance for loan losses, unrated loans are considered in the same manner as “Pass” rated loans. Unrated loans are included with “Pass” rated loans for disclosure purposes. 1-10 Risk Rating – Pass Loans with a risk rating of 1-10 are classified as “Pass” and are comprised of loans that range from “substantially risk free” which indicates borrowers of unquestioned credit standing, well-established national companies with a very strong financial condition, and loans fully secured by policy conforming cash levels, through “low pass” which indicates acceptable rated loans that may be experiencing weak cash flow, impending lease rollover or minor liquidity concerns. 11 Risk Rating – Special Mention (Potential Weakness) Loans to borrowers in this category exhibit potential weaknesses or downward trends deserving management’s close attention. While potentially weak, no loss of principal or interest is envisioned. Included in this category are borrowers who are performing as agreed, are weak when compared to industry standards, may be experiencing an interim loss and may be in declining industries. An element of asset quality, financial flexibility or management is below average. The Company does not consider borrowers within this category as new business prospects. Borrowers rated special mention may find it difficult to obtain alternative financing from traditional bank sources. 12 Risk Rating – Substandard (Well-Defined Weakness) Loans with a risk-rating of 12 exhibit well-defined weaknesses that, if not corrected, may jeopardize the orderly liquidation of the debt. A loan is classified as substandard if it is inadequately protected by the repayment capacity of the obligor or by the collateral pledged. Specifically, repayment under market rates and terms, or by the requirements under the existing loan documents, is in jeopardy, but no loss of principal or interest is envisioned. There is a possibility that a partial loss of principal and/or interest will occur in the future if the deficiencies are not corrected. Loss potential, while existing in the aggregate portfolio of substandard assets, does not have to exist in individual assets classified as substandard. Non-accrual is possible, but not mandatory, in this class. 13 Risk Rating – Doubtful (Loss Probable) Loans classified as doubtful have comparable weaknesses as found in the loans classified as substandard, with the added provision that such weaknesses make collection of the debt in full (based on currently existing facts, conditions and values) highly questionable and improbable. Serious problems exist such that a partial loss of principal is likely. The probability of loss exists, but because of reasonably specific pending factors that may work to strengthen the credit, estimated losses are deferred until a more exact status can be determined. Specific reserves will be the amount identified after specific review. Non-accrual is mandatory in this class. 14 Risk Rating – Loss Loans to borrowers in this category are deemed incapable of repayment. Loans to such borrowers are considered uncollectible and of such little value that continuance as active assets of the Company is not warranted. This classification does not mean that the loans have no recovery or salvage value, but rather, it is not practical or desirable to defer writing off these assets even though partial recovery may occur in the future. Loans in this category have a recorded investment of $0 at the time of the downgrade. Residential and Consumer Lending Credit Quality For the Company’s residential and consumer portfolios, the quality of the loan is best indicated by the repayment performance of an individual borrower. Updated appraisals, broker opinions of value and other collateral valuation methods are employed in the residential and consumer portfolios, typically for credits that are deteriorating. Delinquency status is determined using payment performance, while accrual status may be determined using a combination of payment performance, expected borrower viability and collateral value. Delinquent consumer loans are handled by a team of seasoned collection specialists. The following table details the amortized cost balances of the Company’s loan portfolios, presented by credit quality indicator and origination year as of December 31, 2023, and gross charge-offs for the year ended December 31, 2023: 2023 2022 2021 2020 2019 Prior Revolving Loans Revolving Loans Converted to Term Loans (1) Total (In thousands) Commercial and industrial Pass $ 477,138 $ 442,896 $ 350,782 $ 341,243 $ 140,641 $ 641,342 $ 485,448 $ 3,255 $ 2,882,745 Special Mention 4,229 25,796 14,994 13,563 89 553 51,106 455 110,785 Substandard 1,534 11,995 1,775 405 — 2,581 7,803 — 26,093 Doubtful — — — — — 8 — — 8 Loss — — — — — — — — — Total commercial and industrial 482,901 480,687 367,551 355,211 140,730 644,484 544,357 3,710 3,019,631 Current period gross charge-offs — 2 — — — 11 — — 13 Commercial real estate Pass 498,590 1,435,893 855,014 573,370 516,689 1,291,189 47,581 2,556 5,220,882 Special Mention 15,200 7,990 — 736 2,281 34,803 — — 61,010 Substandard 19,738 12,589 15,237 3,938 33,413 48,978 8,006 — 141,899 Doubtful 10,615 — — — — 19,441 — — 30,056 Loss — — — — — — — — — Total commercial real estate 544,143 1,456,472 870,251 578,044 552,383 1,394,411 55,587 2,556 5,453,847 Current period gross charge-offs 2,008 — — — — 6,000 — — 8,008 Commercial construction Pass 133,463 151,957 96,147 — — — 2,614 — 384,181 Special Mention 456 — — — — — — — 456 Substandard — — — — — — — — — Doubtful — — — — — — — — — Loss — — — — — — — — — Total commercial construction 133,919 151,957 96,147 — — — 2,614 — 384,637 Current period gross charge-offs — — — — — — — — — Business banking Pass 139,237 165,247 182,606 146,180 110,638 229,636 73,054 3,996 1,050,594 Special Mention 1,474 2,553 1,009 4,294 4,692 11,479 23 27 25,551 Substandard 1,310 596 2,684 2,071 1,464 3,423 594 579 12,721 Doubtful — — — — 507 220 — — 727 Loss — — — — — — — — — Total business banking 142,021 168,396 186,299 152,545 117,301 244,758 73,671 4,602 1,089,593 Current period gross charge-offs 188 161 1,596 86 654 590 — 1,370 4,645 Residential real estate Current and accruing 257,671 728,997 665,811 354,003 93,817 451,812 — — 2,552,111 30-89 days past due and accruing 750 6,615 2,437 2,112 1,496 8,219 — — 21,629 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual — 1,755 1,433 291 288 4,958 — — 8,725 Total residential real estate 258,421 737,367 669,681 356,406 95,601 464,989 — — 2,582,465 Current period gross charge-offs — — — — — — — — — Consumer home equity Current and accruing 30,393 84,065 9,151 4,899 4,166 80,687 970,882 9,472 1,193,715 30-89 days past due and accruing 148 483 — — — 558 7,509 223 8,921 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual — 66 — — — 1,466 6,770 230 8,532 Total consumer home equity 30,541 84,614 9,151 4,899 4,166 82,711 985,161 9,925 1,211,168 Current period gross charge-offs — — — — — — 7 — 7 Other consumer Current and accruing 93,659 36,601 23,962 12,427 11,367 14,609 13,353 85 206,063 30-89 days past due and accruing 170 271 153 25 12 92 40 — 763 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual 50 61 25 2 14 34 7 — 193 Total other consumer 93,879 36,933 24,140 12,454 11,393 14,735 13,400 85 207,019 Current period gross charge-offs 1,047 411 329 92 111 260 169 — 2,419 Total $ 1,685,825 $ 3,116,426 $ 2,223,220 $ 1,459,559 $ 921,574 $ 2,846,088 $ 1,674,790 $ 20,878 $ 13,948,360 (1) The amounts presented represent the amortized cost as of December 31, 2023 of revolving loans that were converted to term loans during the year ended December 31, 2023. The following table details the amortized cost balances of the Company’s loan portfolios, presented by credit quality indicator and origination year as of December 31, 2022: 2022 2021 2020 2019 2018 Prior Revolving Loans Revolving Loans Converted to Term Loans (1) Total (In thousands) Commercial and industrial Pass $ 778,144 $ 479,317 $ 415,990 $ 199,865 $ 100,716 $ 639,825 $ 473,148 $ 50 $ 3,087,055 Special Mention 2,298 1,307 7,267 4,841 147 — 1,196 670 17,726 Substandard 294 4,954 2,644 46 2,598 7,854 485 346 19,221 Doubtful — 5,249 — — — 23 3,254 — 8,526 Loss — — — — — — — — — Total commercial and industrial 780,736 490,827 425,901 204,752 103,461 647,702 478,083 1,066 3,132,528 Commercial real estate Pass 1,510,675 825,620 586,567 581,840 461,296 1,006,160 52,590 4,187 5,028,935 Special Mention — — 771 4,204 15,366 12,255 — — 32,596 Substandard — — 2,621 19,796 24,532 34,883 8,000 — 89,832 Doubtful — — — — — — — — — Loss — — — — — — — — — Total commercial real estate 1,510,675 825,620 589,959 605,840 501,194 1,053,298 60,590 4,187 5,151,363 Commercial construction Pass 91,397 178,648 28,956 20,767 — — 12,130 — 331,898 Special Mention — — 2,361 — — — — — 2,361 Substandard — — — — — — — — — Doubtful — — — — — — — — — Loss — — — — — — — — — Total commercial construction 91,397 178,648 31,317 20,767 — — 12,130 — 334,259 Business banking Pass 178,806 202,230 170,088 128,282 59,452 233,484 78,080 4,770 1,055,192 Special Mention — 991 4,635 4,605 3,740 7,584 145 — 21,700 Substandard — 3,482 1,424 2,663 570 7,505 2,230 221 18,095 Doubtful — — — 181 — 70 — — 251 Loss — — — — — — — — — Total business banking 178,806 206,703 176,147 135,731 63,762 248,643 80,455 4,991 1,095,238 Residential real estate Current and accruing 761,442 696,959 382,262 99,494 66,702 434,720 — — 2,441,579 30-89 days past due and accruing 4,652 5,470 1,245 2,762 2,951 11,646 — — 28,726 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual — — 144 1,491 1,015 7,100 — — 9,750 Total residential real estate 766,094 702,429 383,651 103,747 70,668 453,466 — — 2,480,055 Consumer home equity Current and accruing 97,395 10,774 5,840 5,015 21,092 73,927 953,829 7,320 1,175,192 30-89 days past due and accruing 559 — — — 72 944 7,239 247 9,061 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual — — — 61 274 1,303 5,120 296 7,054 Total consumer home equity 97,954 10,774 5,840 5,076 21,438 76,174 966,188 7,863 1,191,307 Other consumer Current and accruing 55,414 32,390 17,641 18,298 18,832 16,603 17,476 — 176,654 30-89 days past due and accruing 143 68 43 61 240 178 58 7 798 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual 31 93 39 2 92 44 15 10 326 Total other consumer 55,588 32,551 17,723 18,361 19,164 16,825 17,549 17 177,778 Total $ 3,481,250 $ 2,447,552 $ 1,630,538 $ 1,094,274 $ 779,687 $ 2,496,108 $ 1,614,995 $ 18,124 $ 13,562,528 (1) The amounts presented represent the amortized cost as of December 31, 2022 of revolving loans that were converted to term loans during the year ended December 31, 2022. Asset Quality The Company manages its loan portfolio with careful monitoring. As a general rule, loans more than 90 days past due with respect to principal and interest are classified as non-accrual loans. Exceptions may be made if management believes that collateral held by the Company is clearly sufficient and in full satisfaction of both principal and interest. The Company may also use discretion regarding other loans over 90 days delinquent if the loan is well secured and in the process of collection. Non-accrual loans and loans that are more than 90 days past due but still accruing interest are considered non-performing loans. Non-accrual loans may be returned to an accrual status when principal and interest payments are no longer delinquent, and the risk characteristics of the loan have improved to the extent that there no longer exists a concern as to the collectability of principal and interest. Loans are considered past due based upon the number of days delinquent according to their contractual terms. A loan is expected to remain on non-accrual status until it becomes current with respect to principal and interest, the loan is liquidated, or the loan is determined to be uncollectible and is charged-off against the allowance for loan losses. The following tables show the age analysis of past due loans as of the dates indicated: As of December 31, 2023 30-59 60-89 90 or More Total Past Current Total (In thousands) Commercial and industrial $ 3,316 $ — $ 465 $ 3,781 $ 3,015,850 $ 3,019,631 Commercial real estate — — — — 5,453,847 5,453,847 Commercial construction — — — — 384,637 384,637 Business banking 3,455 1,647 1,202 6,304 1,083,289 1,089,593 Residential real estate 17,116 4,888 6,764 28,768 2,553,697 2,582,465 Consumer home equity 6,517 2,600 8,204 17,321 1,193,847 1,211,168 Other consumer 532 235 189 956 206,063 207,019 Total $ 30,936 $ 9,370 $ 16,824 $ 57,130 $ 13,891,230 $ 13,948,360 As of December 31, 2022 30-59 60-89 90 or More Total Past Current Total (In thousands) Commercial and industrial $ 1,300 $ 385 $ 2,074 $ 3,759 $ 3,128,769 $ 3,132,528 Commercial real estate — — — — 5,151,363 5,151,363 Commercial construction — — — — 334,259 334,259 Business banking 6,642 845 3,517 11,004 1,084,234 1,095,238 Residential real estate 25,877 3,852 6,456 36,185 2,443,870 2,480,055 Consumer home equity 8,262 1,108 6,525 15,895 1,175,412 1,191,307 Other consumer 634 170 320 1,124 176,654 177,778 Total $ 42,715 $ 6,360 $ 18,892 $ 67,967 $ 13,494,561 $ 13,562,528 The following table presents information regarding non-accrual loans as of the dates indicated: As of December 31, 2023 As of December 31, 2022 Non-Accrual Loans With ACL Non-Accrual Loans Without ACL (1) Total Non-Accrual Loans Non-Accrual Loans With ACL Non-Accrual Loans Without ACL (1) Total Nonaccrual Loans (In thousands) Commercial and industrial $ 4 $ 464 $ 468 $ 3,270 $ 10,707 $ 13,977 Commercial real estate 13,969 16,087 30,056 — — — Commercial construction — — — — — — Business banking 4,572 11 4,583 5,844 1,653 7,497 Residential real estate 8,725 — 8,725 9,750 — 9,750 Consumer home equity 8,532 — 8,532 7,054 — 7,054 Other consumer 193 — 193 326 — 326 Total non-accrual loans $ 35,995 $ 16,562 $ 52,557 $ 26,244 $ 12,360 $ 38,604 (1) The loans on non-accrual status and without an ACL as of both December 31, 2023 and December 31, 2022, were primarily comprised of collateral dependent loans for which the fair value of the underlying loan collateral exceeded the loan carrying value. The amount of interest income recognized on non-accrual loans during the year ended December 31, 2023 and 2022 was not significant. As of both December 31, 2023 and December 31, 2022, there were no loans greater than 90 days past due and still accruing. It is the Company’s policy to reverse any accrued interest when a loan is put on non-accrual status and, generally, to record any payments received from a borrower related to a loan on non-accrual status as a reduction of the amortized cost basis of the loan. Accrued interest reversed against interest income for the years ended December 31, 2023 and 2022 was not significant. For collateral values for residential mortgage and home equity loans, the Company relies primarily upon third-party valuation information from certified appraisers and values are generally based upo

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment The information presented within this Note excludes discontinued operations. Refer to Note 23, “Discontinued Operations” for further discussion regarding discontinued operations. The following table summarizes the Company’s premises and equipment as of the dates indicated: As of December 31, Estimated 2023 2022 Useful Life (In thousands) (In years) Premises and equipment used in operations: Land $ 12,585 $ 12,585 N/A Buildings 70,597 70,771 5-30 Equipment 37,756 35,085 3-5 Leasehold improvements 34,790 36,424 5-25 Total cost 155,728 154,865 Accumulated depreciation (95,595) (92,372) Premises and equipment used in operations, net 60,133 62,493 Premises and equipment held for sale — — Net premises and equipment $ 60,133 $ 62,493 The Company recorded depreciation expense related to premises and equipment of $10.5 million, $10.7 million, and $11.6 million during the years ended December 31, 2023, 2022, and 2021, respectively. During the year ended December 31, 2023, no properties were transferred to held for sale, nor were any properties sold. During the year ended December 31, 2022, no properties were transferred to held for sale. During the year ended December 31, 2022, the Company sold five properties, four of which were acquired in connection with the Company’s acquisition of Century Bancorp, Inc. (“Century”). The properties sold during year ended December 31, 2022 were included in premises and equipment held for sale as of December 31, 2021. The aggregate proceeds from such sales of premises and equipment were $17.3 million. In connection with these sales, the Company recognized a gain on sale of $1.4 million, which is included in other noninterest income in the Consolidated Statements of Income. Properties transferred to held for sale during the year ended December 31, 2021 amounted to $37.6 million, which included five branch locations, four of which were acquired in connection with the Company’s acquisition of Century. The Company recorded a $1.2 million loss, representing estimated costs to sell, on properties transferred to held for sale during the year ended December 31, 2021. During the year ended December 31, 2021, the Company sold three properties, two of which were acquired in connection with the Company’s acquisition of Century and one of which was included in premises held for sale as of December 31, 2020. The aggregate proceeds from sales of premises and equipment were $22.0 million during the year ended December 31, 2021. In connection with these sales, the Company recognized no significant gain or loss.

Leases

Leases	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Leases	Leases The Company leases certain office space and equipment under various non-cancelable operating leases. These leases have original terms ranging from 1 year to 25 years. Operating lease liabilities and ROU assets are recognized at the lease commencement date based upon the present value of the future minimum lease payments over the lease term. Operating lease liabilities are recorded within other liabilities and ROU assets are recorded within other assets in the Company’s Consolidated Balance Sheets. The information presented within this Note excludes discontinued operations. Refer to Note 23, “Discontinued Operations” for further discussion regarding discontinued operations. As of the dates indicated, the Company had the following related to operating leases: As of December 31, 2023 As of December 31, 2022 (In thousands) Right-of-use assets $ 50,641 $ 48,817 Lease liabilities 55,617 52,105 Finance leases are not material. Finance lease liabilities are recorded within other liabilities and finance ROU assets are recorded within other assets in the Company’s Consolidated Balance Sheets. The following table is a summary of the Company’s components of net lease cost for the periods indicated: For the Year Ended December 31, 2023 2022 2021 (In thousands) Operating lease cost $ 12,439 $ 12,716 $ 12,559 Finance lease cost 338 309 160 Variable lease cost 2,766 2,547 2,012 Total lease cost $ 15,543 $ 15,572 $ 14,731 During the years ended December 31, 2023, 2022, and 2021 the Company made $13.3 million, $15.2 million, and $13.6 million in cash payments for operating and finance leases, respectively. Supplemental balance sheet information related to operating leases as of the dates indicated is as follows: As of December 31, 2023 As of December 31, 2022 Weighted-average remaining lease term (in years) 8.26 7.25 Weighted-average discount rate 3.76 % 2.62 % The following table sets forth the undiscounted cash flows of base rent related to operating leases outstanding as of December 31, 2023 with payments scheduled over the next five years and thereafter, including a reconciliation to the operating lease liability recognized in other liabilities in the Company’s Consolidated Balance Sheets: As of December 31, 2023 Year (In thousands) 2024 $ 11,506 2025 8,504 2026 7,143 2027 5,609 2028 5,886 Thereafter 27,770 Total minimum lease payments 66,418 Less: amount representing interest 10,801 Present value of future minimum lease payments $ 55,617 Lease Modifications and Terminations: During the year ended December 31, 2023, management determined not to exercise future lease term extension options related to four leases, which had previously been included in its determination of future lease payments, to exercise future lease term extension options related to ten leases, which had not previously been included in its determination of future lease payments, and to terminate one lease. Accordingly, the Company remeasured the present value of the future lease payments related to such leases which resulted in a net increase of the lease liabilities and a corresponding net increase of the lease ROU assets of $2.4 million. In connection with the lease termination, the Company recorded an impairment charge of $0.4 million.
Leases	Leases The Company leases certain office space and equipment under various non-cancelable operating leases. These leases have original terms ranging from 1 year to 25 years. Operating lease liabilities and ROU assets are recognized at the lease commencement date based upon the present value of the future minimum lease payments over the lease term. Operating lease liabilities are recorded within other liabilities and ROU assets are recorded within other assets in the Company’s Consolidated Balance Sheets. The information presented within this Note excludes discontinued operations. Refer to Note 23, “Discontinued Operations” for further discussion regarding discontinued operations. As of the dates indicated, the Company had the following related to operating leases: As of December 31, 2023 As of December 31, 2022 (In thousands) Right-of-use assets $ 50,641 $ 48,817 Lease liabilities 55,617 52,105 Finance leases are not material. Finance lease liabilities are recorded within other liabilities and finance ROU assets are recorded within other assets in the Company’s Consolidated Balance Sheets. The following table is a summary of the Company’s components of net lease cost for the periods indicated: For the Year Ended December 31, 2023 2022 2021 (In thousands) Operating lease cost $ 12,439 $ 12,716 $ 12,559 Finance lease cost 338 309 160 Variable lease cost 2,766 2,547 2,012 Total lease cost $ 15,543 $ 15,572 $ 14,731 During the years ended December 31, 2023, 2022, and 2021 the Company made $13.3 million, $15.2 million, and $13.6 million in cash payments for operating and finance leases, respectively. Supplemental balance sheet information related to operating leases as of the dates indicated is as follows: As of December 31, 2023 As of December 31, 2022 Weighted-average remaining lease term (in years) 8.26 7.25 Weighted-average discount rate 3.76 % 2.62 % The following table sets forth the undiscounted cash flows of base rent related to operating leases outstanding as of December 31, 2023 with payments scheduled over the next five years and thereafter, including a reconciliation to the operating lease liability recognized in other liabilities in the Company’s Consolidated Balance Sheets: As of December 31, 2023 Year (In thousands) 2024 $ 11,506 2025 8,504 2026 7,143 2027 5,609 2028 5,886 Thereafter 27,770 Total minimum lease payments 66,418 Less: amount representing interest 10,801 Present value of future minimum lease payments $ 55,617 Lease Modifications and Terminations: During the year ended December 31, 2023, management determined not to exercise future lease term extension options related to four leases, which had previously been included in its determination of future lease payments, to exercise future lease term extension options related to ten leases, which had not previously been included in its determination of future lease payments, and to terminate one lease. Accordingly, the Company remeasured the present value of the future lease payments related to such leases which resulted in a net increase of the lease liabilities and a corresponding net increase of the lease ROU assets of $2.4 million. In connection with the lease termination, the Company recorded an impairment charge of $0.4 million.

Goodwill and Core Deposit Intan

Goodwill and Core Deposit Intangible Asset	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Core Deposit Intangible Asset	Goodwill and Core Deposit Intangible Asset The table below sets forth the carrying amount of goodwill and other intangible assets, net of accumulated amortization, for the banking business as of the dates indicated below. The information presented within this Note excludes discontinued operations. Refer to Note 23, “Discontinued Operations” for further discussion regarding discontinued operations. As of December 31, 2023 2022 (In thousands) Balances not subject to amortization Goodwill $ 557,635 $ 557,635 Balances subject to amortization Core deposit intangible 8,570 10,374 Total goodwill and other intangible assets $ 566,205 $ 568,009 The changes in the carrying value of goodwill for the periods indicated were as follows: For the Years Ended December 31, 2023 2022 (In thousands) Balance at beginning of year $ 557,635 $ 557,635 Goodwill recorded during the year — — Balance at end of year $ 557,635 $ 557,635 The following table sets forth the carrying amount of the Company’s core deposit intangible asset, net of accumulated amortization, as of the dates indicated below: As of December 31, 2023 2022 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net (In thousands) Core deposit intangible $ 11,633 $ (3,063) $ 8,570 $ 15,969 $ (5,595) $ 10,374 Total $ 11,633 $ (3,063) $ 8,570 $ 15,969 $ (5,595) $ 10,374 The Company quantitatively assesses goodwill for impairment at the reporting unit level on an annual basis or sooner if an event occurs or circumstances change which might indicate that the fair value of a reporting unit is below its carrying amount. The Company has identified and assigned goodwill to one reporting unit - the banking business unit. In accordance with the accounting guidance codified in ASC 350-20, the Company performs a test of goodwill for impairment at least on an annual basis. An assessment is also required to be performed to the extent relevant events and/or circumstances occur which may indicate it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount. The failure of several banks in early 2023 led to economic uncertainty and an increase in volatility in the capital markets, particularly in the banking industry. Accordingly, the Company performed a qualitative assessment as of March 31, 2023 which included an assessment of current industry conditions and the impacts of those conditions on the Company’s financial position and results of operations. As a result of that assessment, the Company determined it was not more-likely-than-not that the carrying value of goodwill was greater than the fair value as of March 31, 2023. Therefore, a quantitative goodwill impairment test was not considered necessary at that time. During the second quarter of 2023, as the economic uncertainty impacting the banking industry persisted, the Company exercised the option afforded by ASC 350-20 and bypassed the qualitative assessment, opting to perform the quantitative impairment assessment irrespective of qualitative factors. The assessment included a comparison of the banking business’ book value to the implied fair value using a pricing multiple of the Company’s tangible book value as well as a comparison of the banking business’ book value to its estimated fair value based upon its discounted cash flows. The assessment also included a market capitalization analysis. Based upon the assessment, it was determined there was no impairment of the Company’s goodwill as of June 30, 2023. The Company performed its annual assessment for the banking business as of September 30, 2023. Similar to the assessment performed as of June 30, 2023, the assessment included a comparison of the banking business’ book value to the implied fair value using a pricing multiple of the Company’s tangible book value as well as a comparison of the banking business’ book value to its estimated fair value based upon its discounted cash flows. The assessment also included a market capitalization analysis. Based upon the assessment, it was determined there was no impairment of the Company’s goodwill as of September 30, 2023. Management performed an additional qualitative assessment as of December 31, 2023, to analyze changes in factors impacting assumptions used in its September 30, 2023 assessment. Based upon that assessment, management concluded that it was not more-likely-than-not that the carrying value of the goodwill of the banking business unit was greater than the fair value as of December 31, 2023 and a quantitative goodwill impairment test was not necessary as of December 31, 2023. The amortization expense of the Company’s core deposit intangible asset was $1.8 million, $1.2 million, and $0.2 million during the years ended December 31, 2023, 2022, and 2021, respectively. The original amortization period and remaining useful life of the Company’s core deposit intangible asset is 10.0 years and 4.3 years, respectively. Management performs an assessment of the remaining useful lives of the Company’s intangible assets on a quarterly basis to determine if such lives remain appropriate. As a result of the assessment performed during the second quarter of 2023, management reduced the remaining useful life of its core deposit intangible asset to five years which resulted in an increase in quarterly amortization expense. The effect of the increase on annual amortization expense was not material. The estimated amortization expense for the remaining useful life of the Company’s core deposit intangible asset is as follows: Year (In thousands) 2024 $ 2,017 2025 2,017 2026 2,017 2027 2,017 2028 502 Total amortization expense $ 8,570

Deposits

Deposits	12 Months Ended
	Dec. 31, 2023
Banking and Thrift, Interest [Abstract]
Deposits	Deposits The following table provides a summary of the Company’s deposits as of the dates indicated: As of December 31, 2023 2022 (In thousands) Demand $ 5,162,218 $ 6,240,637 Interest checking accounts 3,737,361 4,568,122 Savings accounts 1,323,126 1,831,123 Money market investment 4,664,475 4,710,095 Certificates of deposit 2,709,037 1,624,382 Total deposits $ 17,596,217 $ 18,974,359 At December 31, 2023 and 2022, the Company had a balance of $2.4 million and $2.3 million, respectively, in overdrafts. Overdrafts are included in loans in the Consolidated Balance Sheets. The following table summarizes certificate of deposits by maturity at December 31, 2023: Balance Percentage of Total Year (Dollars in thousands) 2024 $ 2,683,364 99.1 % 2025 15,484 0.6 % 2026 5,630 0.2 % 2027 2,940 0.1 % 2028 1,586 0.1 % Thereafter 33 0.0 % Total certificates of deposit $ 2,709,037 100.0 % The FDIC offers insurance coverage on deposits up to the federally insured limit of $250,000. The amount of certificates of deposit equal to or greater than $250,000, as of December 31, 2023 and 2022, was $867.6 million and $239.1 million, respectively. Included in the certificates of deposit balances above were $50.0 million and $928.6 million of brokered certificates of deposit at December 31, 2023 and 2022, respectively.

Borrowed Funds

Borrowed Funds	12 Months Ended
	Dec. 31, 2023
Federal Home Loan Banks [Abstract]
Borrowed Funds	Borrowed Funds Borrowed funds were comprised of the following: As of December 31, 2023 2022 (In thousands) Short-term FHLB advances $ 95 $ 691,297 Escrow deposits of borrowers 21,978 22,314 Interest rate swap collateral funds 8,500 14,430 Long-term FHLB advances 17,643 12,787 Total borrowed funds $ 48,216 $ 740,828 At December 31, 2023 and 2022, the Company had available and unused borrowing capacity of approximately $775.9 million and $538.9 million, respectively, at the Federal Reserve Discount Window. At December 31, 2023 and 2022, loans with collateral value of $636.8 million and $538.9 million, respectively, and securities with a collateral value of $139.1 million at December 31, 2023 were pledged to the Discount Window. No securities were pledged as collateral to the Federal Reserve Discount Window at December 31, 2022. At December 31, 2023, the Company had a $2.4 billion collateralized line of credit from the Federal Reserve Bank of Boston through the Bank Term Funding Program. Securities with a collateral value of $2.4 billion at December 31, 2023 were pledged to the Federal Reserve Bank of Boston under the Bank Term Funding Program . The Bank Term Funding Program was created by the Federal Reserve in March 2023. Interest expense on borrowed funds was as follows: For the Year Ended December 31, 2023 2022 2021 (In thousands) Federal funds purchased $ — $ 24 $ — Federal Home Loan Bank advances 19,247 8,263 163 Escrow deposits of borrowers 6 3 2 Interest rate swap collateral funds 722 216 — Total interest expense on borrowed funds $ 19,975 $ 8,506 $ 165 A summary of FHLBB advances by maturities were as follows: As of December 31, 2023 2022 Amount Weighted Average Amount Weighted Average (Dollars in thousands) Within one year $ 95 1.50 % $ 691,297 4.36 % Over one year to three years 3,409 0.73 % 2,835 0.86 % Over three years to five years 2,685 1.59 % 2,534 1.89 % Over five years 11,549 1.31 % 7,418 0.94 % Total Federal Home Loan Bank advances (1) $ 17,738 1.25 % $ 704,084 4.30 % (1) The weighted average interest rate of long-term FHLB advances as of December 31, 2023 and December 31, 2022 was 1.24% and 1.11%, respectively. At December 31, 2023 and 2022, advances from the FHLBB were secured by stock in the FHLBB, residential real estate loans and commercial real estate loans. The collateral value of residential real estate and commercial real estate loans securing these advances was $1.4 billion and $1.5 billion, respectively, at December 31, 2023, and $1.5 billion and $1.2 billion, respectively, at December 31, 2022. At December 31, 2023 and 2022, the Bank had available and unused borrowing capacity with the FHLBB of approximately $2.9 billion and $2.0 billion, respectively. As a member of the FHLBB, the Company is required to hold FHLBB stock. At December 31, 2023 and 2022, the Company had investments in the FHLBB of $5.9 million and $41.4 million, respectively. At its discretion, the FHLBB may declare dividends on the stock. Included in other noninterest income in the Consolidated Statements of Income are dividends received of $2.0 million, $0.3 million, and $0.2 million during the years ended December 31, 2023, 2022, and 2021, respectively.

Earnings Per Share ("EPS")

Earnings Per Share ("EPS")	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Earnings Per Share ("EPS")	Earnings Per Share ( “ EPS ” ) Basic EPS represents income available to common shareholders divided by the weighted-average number of common shares outstanding during the year. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common shares (such as stock options) were exercised or converted into additional common shares that would then share in the earnings of the Company. Diluted EPS is computed by dividing net income attributable to common shareholders by the weighted-average number of common shares outstanding for the year, plus the effect of potential dilutive common share equivalents computed using the treasury stock method. Shares held by the ESOP that have not been allocated or committed to be allocated to employees in accordance with the terms of the ESOP, referred to as “unallocated ESOP shares,” are not deemed outstanding for earnings per share calculations. For the Year Ended December 31, 2023 2022 2021 (Dollars in thousands, except per share data) Net income applicable to common shares: Net (loss) income from continuing operations $ (62,689) $ 186,511 $ 145,531 Net income from discontinued operations 294,866 13,248 9,134 Total net income $ 232,177 $ 199,759 $ 154,665 Average number of common shares outstanding 175,814,954 179,529,613 186,713,020 Less: Average unallocated ESOP shares (13,521,934) (14,019,256) (14,520,684) Average number of common shares outstanding used to calculate basic earnings per common share 162,293,020 165,510,357 172,192,336 Common stock equivalents - restricted stock awards and units 110,077 138,214 59,721 Average number of common shares outstanding used to calculate diluted earnings per common share 162,403,097 165,648,571 172,252,057 Basic earnings per share Basic (loss) earnings per share from continuing operations $ (0.39) $ 1.13 $ 0.85 Basic earnings per share from discontinued operations 1.82 0.08 0.05 Basic earnings per share $ 1.43 $ 1.21 $ 0.90 Diluted earnings per share Diluted (loss) earnings per share from continuing operations $ (0.39) $ 1.13 $ 0.85 Diluted earnings per share from discontinued operations 1.82 0.08 0.05 Diluted earnings per share $ 1.43 $ 1.21 $ 0.90

Low Income Housing Tax Credits

Low Income Housing Tax Credits and Other Tax Credit Investments	12 Months Ended
	Dec. 31, 2023
Investments in Affordable Housing Projects [Abstract]
Low Income Housing Tax Credits and Other Tax Credit Investments	Low Income Housing Tax Credits and Other Tax Credit Investments The Community Reinvestment Act (“CRA”) encourages banks to meet the credit needs of their communities for housing and other purposes, particularly in neighborhoods with low or moderate income. The Company has primarily invested in separate LIHTC projects, also referred to as qualified affordable housing projects, which provide the Company with tax credits and operating loss tax benefits over a period of 15 years. The return on these investments is generally generated through tax credits and tax losses. In addition to LIHTC projects, the Company invests in new market tax credit projects that qualify for CRA credits and eligible projects that qualify for renewable energy and historic tax credits. As of December 31, 2023 and 2022, the Company had $223.4 million and $131.3 million, respectively, in tax credit investments that were included in other assets in the Consolidated Balance Sheets. When permissible, the Company accounts for its investments in LIHTC projects using the proportional amortization method, under which it amortizes the initial cost of the investment in proportion to the amount of the tax credits and other tax benefits received and recognizes that amortization as a component of income tax expense. The net investment in the housing projects is included in other assets on the Consolidated Balance Sheets. The Company will continue to use the proportional amortization method on any new qualifying LIHTC investments. The following table presents the Company’s investments in LIHTC projects using the proportional amortization method as of the dates indicated: As of December 31, 2023 2022 (In thousands) Current recorded investment included in other assets $ 221,190 $ 128,765 Commitments to fund qualified affordable housing projects included in recorded investment noted above 149,207 84,145 The following table presents additional information related to the Company’s investments in LIHTC projects for the periods indicated: For the Year Ended December 31, 2023 2022 2021 (In thousands) Tax credits and other tax benefits recognized $ 11,624 $ 9,146 $ 6,484 Amortization expense included in income tax expense 9,577 7,503 5,753 The Company accounts for certain other investments in renewable energy projects using the equity method of accounting. These investments in renewable energy projects are included in other assets on the Consolidated Balance Sheets and totaled $2.2 million and $2.6 million at December 31, 2023 and 2022, respectively. There were no outstanding commitments related to these investments as of either December 31, 2023 or December 31, 2022.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The information presented within this Note excludes discontinued operations. Refer to Note 23, “Discontinued Operations” for further discussion regarding discontinued operations. The following table sets forth information regarding the Company’s tax provision and applicable tax rates for the periods indicated: For the Year Ended December 31, 2023 2022 2021 (Dollars in thousands) Combined federal and state income tax provisions $ (63,309) $ 51,719 $ 30,464 Effective income tax rates 50.25 % 21.71 % 17.32 % The Company recorded a net income tax benefit of $63.3 million for the year ended December 31, 2023 compared to net income tax expense of $51.7 million and $30.5 million for the years ended December 31, 2022 and 2021, respectively. The income tax benefit for the year ended December 31, 2023 was primarily due to pretax losses which largely resulted from losses on sales of available for sale securities in the first quarter of 2023. In addition, during the first quarter of 2023, the Company liquidated Market Street Securities Corporation (“MSSC”), a wholly owned subsidiary, and transferred all of MSSC’s assets to Eastern Bank. In connection with the liquidation and subsequent transfer of securities previously held by MSSC to Eastern Bank, the Company recognized an additional deferred income tax benefit of $23.7 million during the first quarter of 2023. This deferred income tax benefit resulted from a state tax rate change applied to the deferred tax asset related to the securities transferred to Eastern Bank. The provision for income taxes is comprised of the following components: For the Year Ended December 31, 2023 2022 2021 (In thousands) Current tax (benefit) expense: Federal $ (39,710) $ 36,436 $ 23,923 State (5,332) 10,021 12,204 Total current tax (benefit) expense (45,042) 46,457 36,127 Deferred tax (benefit) expense: Federal 1,219 (1,028) (7,984) State (19,486) 6,290 2,321 Total deferred tax (benefit) expense (18,267) 5,262 (5,663) Total income tax (benefit) expense $ (63,309) $ 51,719 $ 30,464 A reconciliation of the U.S. federal statutory rate to the Company’s effective income tax rate is detailed below: For the Year Ended December 31, 2023 2022 2021 (Dollars in thousands) Income tax (benefit) expense at statutory rate $ (26,458) 21.00 % $ 50,029 21.00 % $ 36,959 21.00 % (Decrease) increase resulting from: State income tax, net of federal tax benefit (1) (19,606) 15.56 % 12,885 5.41 % 11,475 6.53 % Valuation allowance — — % (700) (0.29) % (11,300) (6.42) % Amortization of qualified low-income housing investments 9,577 (7.60) % 7,503 3.15 % 5,753 3.27 % Tax credits (9,183) 7.29 % (7,300) (3.06) % (6,539) (3.72) % Tax-exempt income (14,161) 11.24 % (10,298) (4.32) % (5,665) (3.22) % Other, net (3,478) 2.76 % (400) (0.17) % (219) (0.12) % Actual income tax (benefit) expense $ (63,309) 50.25 % $ 51,719 21.71 % $ 30,464 17.32 % (1) Includes state tax benefit associated with MSSC liquidation of $23.7 million for the year ended December 31, 2023 described above. Significant components of the Company’s deferred tax assets and deferred tax liabilities are presented below: As of December 31, 2023 2022 (In thousands) Deferred tax assets: Unrealized loss on available for sale securities $ 193,134 $ 254,502 Allowance for loan losses 45,189 43,686 Cash flow hedges 12,302 18,192 Leases 15,664 14,858 Charitable contribution limitation carryover 4,844 12,273 Investment losses 7,339 7,918 Accrued expenses 10,042 5,426 Fixed assets 4,142 4,287 Loan basis difference fair value adjustments 3,455 4,009 Employee benefits — 354 PPP loans fee income — 58 Other 2,061 2,083 Total deferred tax assets 298,172 367,646 Deferred tax liabilities: Amortization of intangibles 9,660 16,439 Lease obligation 14,284 13,933 Partnerships 1,971 2,340 Trading securities 3,405 938 Employee benefits 824 — Other 1,843 2,033 Total deferred tax liabilities 31,987 35,683 Net deferred income tax assets $ 266,185 $ 331,963 The Company assesses the realizability of deferred tax assets and whether it is more likely than not that all or a portion of the deferred tax assets will be realized. The Company considers projections of future taxable income during the periods in which deferred tax assets and liabilities are scheduled to reverse. Additionally, in determining the availability of operating loss carrybacks and other tax attributes, both projected future taxable income and tax planning strategies are considered in making this assessment. As of December 31, 2020, the Company had established a valuation allowance of $12.0 million related to the $91.3 million stock donation and the $3.7 million cash contribution to the Eastern Bank Foundation. Based upon the level of available historical taxable income and projections for future taxable income over the periods for which the deferred tax assets are realizable, a release of $11.3 million was recorded during the year ended December 31, 2021. As of December 31, 2022, management made a similar determination and, accordingly, recorded a release of the remaining $0.7 million. As of December 31, 2023, management believes it is more likely than not that the Company will realize the entirety of its net deferred tax assets. Management performed an evaluation of the Company’s uncertain tax positions as of December 31, 2023 and 2022 and determined that liabilities for unrecognized tax benefits of $3.8 million and $6.0 million, respectively, was needed related to state tax positions. The decrease was primarily due to a reversal of $2.2 million recognized during the year ended December 31, 2023. The following table presents a reconciliation of the beginning and ending amount of unrecognized tax benefits for the periods indicated: For the Years Ended December 31, 2023 2022 2021 (In thousands) Beginning $ 5,782 $ 7,923 $ — Additions based on tax positions related to the current year — — — Additions for tax positions of prior years — — 7,923 Reductions related to settlements with taxing authorities — — — Reductions as a result of a lapse of the applicable statute of limitations (2,279) (2,141) — Ending $ 3,503 $ 5,782 $ 7,923 As of December 31, 2023, the amount that would reduce the effective tax rate, if recognized, is $3.8 million. The reduction in the effective tax rate is inclusive of the federal benefit for unrecognized state tax benefits, and accrued interest and penalties. The entire balance of unrecognized tax benefits, if recognized, would favorably affect the Company’s effective income tax rate. The Company recognizes penalties and accrued interest related to unrecognized tax benefits in tax expense. Accrued penalties and interest amounted to $1.0 million and $1.5 million at December 31, 2023 and 2022, respectively. The change in accrued penalties and interest for the current year impacted the Consolidated Statements of Income as a component of income tax expense by $0.5 million. During the year ended December 31, 2023, $2.3 million of unrecognized state tax benefits and $0.7 million of interest and penalties reversed upon expiration of the statute of limitations for the tax year to which the reserve was related. Management anticipates that approximately $1.9 million of unrecognized state tax benefits and $0.8 million of interest and penalties will reverse in 2024 upon expiration of the statute of limitations for the tax year to which the reserve is related. The Company had no net operating loss carryforwards for federal or state income tax purposes at December 31, 2023 and 2022, respectively. At December 31, 2023, the Bank’s federal pre-1988 reserve, for which no federal income tax provision has been made, was approximately $20.8 million. Under current federal law, these reserves are subject to recapture into taxable income, should the Company make non-dividend distributions, make distributions in excess of earnings and profits retained, as defined, or cease to maintain a banking type charter. A deferred tax liability is not recognized for the base year amount unless it becomes apparent that those temporary differences will reverse into taxable income in the foreseeable future. No deferred tax liability has been established as these two events are not expected to occur in the foreseeable future. The Company’s primary banking activities are in the states of Massachusetts, New Hampshire and Rhode Island; however, the Company also files additional state corporate income and/or franchise tax returns in states in which the Company has a filing requirement. The methods of filing, and the methods for calculating taxable and apportionable income, vary depending upon the laws of the taxing jurisdiction. The Company is subject to routine audits of its tax returns by the Internal Revenue Service and various state taxing authorities. The Company is no longer subject to federal and state income tax examinations by tax authorities for years before 2020. The Company invests in low-income affordable housing and renewable energy projects which provide the Company with tax benefits, including tax credits, generally over a period of approximately 5-15 years. When permissible, the Company accounts for its investments in Low Income Housing Tax Credit (“LIHTC”) projects using the proportional amortization method, under which it amortizes the initial cost of the investment in proportion to the amount of the tax credits and other tax benefits received and recognizes that amortization as a component of income tax expense. The net investment performance in the housing projects is included in other assets in the Consolidated Balance Sheets. The Company will continue to use the proportional amortization method on any new qualifying LIHTC investments. During the years ended December 31, 2023 and 2022, the Company generated federal tax credits primarily from LIHTC investments of $9.2 million and $7.3 million, respectively. During the years ended December 31, 2023 and 2022, the Company generated state tax credits from LIHTC investments of $0.4 million and less than $0.1 million, respectively. The Company treats the investment tax credits received as a reduction of federal income taxes for the year in which the credit arises using the flow-through method (i.e., the credit flows directly through the statement of income in the year of purchase). For additional information on these investments, refer to Note 11, “Low Income Housing Tax Credits and Other Tax Credit Investments.”

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity Dividends Information regarding dividends declared and paid is presented in the following table for the periods indicated: Dividends Declared per Share Dividends Declared Dividends Paid (In millions, except per share data) Three Months Ended March 31, 2023 $ 0.10 $ 16.3 $ 16.2 Three Months Ended June 30, 2023 $ 0.10 $ 16.4 $ 16.3 Three Months Ended September 30, 2023 $ 0.10 $ 16.4 $ 16.2 Three Months Ended December 31, 2023 $ 0.11 $ 18.0 $ 18.0 Three Months Ended March 31, 2022 $ 0.10 $ 17.1 $ 16.9 Three Months Ended June 30, 2022 $ 0.10 $ 16.7 $ 16.5 Three Months Ended September 30, 2022 $ 0.10 $ 16.5 $ 16.3 Three Months Ended December 31, 2022 $ 0.10 $ 16.3 $ 16.1

Minimum Regulatory Capital Requ

Minimum Regulatory Capital Requirements	12 Months Ended
	Dec. 31, 2023
Banking and Thrift, Interest [Abstract]
Minimum Regulatory Capital Requirements	Minimum Regulatory Capital Requirements The Company is subject to various regulatory capital requirements administered by federal banking agencies, including U.S. Basel III. Failure to meet minimum capital requirements can initiate certain mandatory, and possibly additional discretionary, actions by regulators that, if undertaken, could have a direct material effect on the Company’s Consolidated Financial Statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company must meet specific capital guidelines that involve quantitative measures of the Company’s assets, liabilities, and certain off-balance sheet items as calculated under regulatory accounting practices. The Company’s capital amounts and classification are also subject to qualitative judgements by the regulators about components, risk weightings, and other factors. Quantitative measures established by the regulators to ensure capital adequacy require the Company to maintain minimum capital amounts and ratios. All banking companies are required to have total regulatory capital of at least 8% of risk-weighted assets, common equity Tier 1 capital of at least 4.5% of risk-weighted assets, core capital (“Tier 1”) of at least 6% of risk-weighted assets, and a minimum Tier 1 leverage ratio of 4% of adjusted average assets. As of December 31, 2023 and 2022, the Company was categorized as “well-capitalized” based on the regulatory framework for prompt corrective action. To be categorized as well-capitalized, the Company must maintain (1) a minimum total regulatory capital ratio of 10%; (2) a minimum common equity Tier 1 capital ratio of 6.5%; (3) a minimum Tier 1 capital ratio of 8% and (4) a minimum Tier 1 leverage ratio of 5%. Management believes that the Company met all capital adequacy requirements to which it is subject as of December 31, 2023 and 2022. There have been no conditions or events that management believes would cause a change in the Company’s categorization. The Company’s actual capital amounts and ratios are presented in the following table as of the dates indicated: Actual For Capital Adequacy To Be Well- Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) As of December 31, 2023 Total regulatory capital (to risk-weighted assets) $ 3,187,130 19.55 % $ 1,304,508 ≥8 % $ 1,630,634 ≥10 % Common equity Tier 1 capital (to risk-weighted assets) 3,024,288 18.55 733,785 ≥4.5 1,059,912 ≥6.5 Tier 1 capital (to risk-weighted assets) 3,024,288 18.55 978,381 ≥6 1,304,508 ≥8 Tier 1 capital (to average assets) leverage 3,024,288 14.00 864,206 ≥4 1,080,258 ≥5 As of December 31, 2022 Total regulatory capital (to risk-weighted assets) $ 2,906,742 17.89 % $ 1,299,657 ≥8 % $ 1,624,571 ≥10 % Common equity Tier 1 capital (to risk-weighted assets) 2,751,694 16.94 731,057 ≥4.5 1,055,971 ≥6.5 Tier 1 capital (to risk-weighted assets) 2,751,694 16.94 974,743 ≥6 1,299,657 ≥8 Tier 1 capital (to average assets) leverage 2,751,694 12.03 915,233 ≥4 1,144,041 ≥5 The Company is subject to various capital requirements in connection with seller/servicer agreements that have been entered into with secondary market investors. Failure to maintain minimum capital requirements could result in an inability to originate and service loans for the respective investor and, therefore, could have a direct material effect on the Company’s financial statements. Management believes that the Company met all capital requirements in connection with seller/servicer agreements as of December 31, 2023 and 2022.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2023
Retirement Benefits [Abstract]
Employee Benefits	Employee Benefits Pension Plans The Company provides pension benefits for its employees using a noncontributory, qualified defined benefit plan, through membership in SBERA. SBERA offers a common and collective trust as the underlying investment structure for pension plans participating in the association. The target allocation mix for the common and collective trust portfolio calls for an equity-based investment deployment range of 49% to 63% of total common and collective trust portfolio assets. The remainder of the common and collective trust’s portfolio is allocated to fixed income securities with a target range of 28% to 42% and other investments, including global asset allocation and hedge funds, from 3% to 15%. The Trustees of SBERA, through SBERA's Investment Committee, select investment managers for the common and collective trust portfolio. A professional investment advisory firm is retained by the Investment Committee to provide allocation analysis and performance measurement, and to assist with manager searches. The overall investment objective is to diversify investments across a spectrum of investment types to limit risks from large market swings. In connection with the Company’s acquisition of Century during the year ended December 31, 2021, the Company acquired Century’s Qualified Defined Benefit Pension Plan. At the time of the acquisition, the plan had been frozen to new participants since 2006, and all participants in the plan were fully vested. Additionally, all Century employees retained following the acquisition were eligible to join the Company’s Defined Benefit Plan to the extent that eligibility requirements were satisfied based upon such employees’ prior service with Century. In connection with the sale of its insurance agency business, the Company amended its Defined Benefit Plan to allow for accelerated vesting for any employees of the insurance agency business and several employees of the Bank transitioning to Gallagher who were otherwise not vested in the Defined Benefit Plan at the time of sale. The Company has a BEP to provide retirement benefits to certain employees whose retirement benefits under the Defined Benefit Plan are limited per the Internal Revenue Code. In connection with the Company’s acquisition of Century, any Century employee retained following the acquisition and whose retirement benefits under the Defined Benefit Plan are limited per the Internal Revenue Code were added to the BEP. Additionally, such Century employees were credited for prior service with Century for purposes of determining vesting and eligibility pursuant to the BEP. In connection with the sale of its insurance agency business, the Company amended the BEP to allow for accelerated vesting for all employees of the insurance agency business and several employees of the Bank transitioning to Gallagher who were participating in the BEP and were otherwise not vested in the BEP at the time of sale. In addition, the Company amended the vesting criteria for the BEP to align with that of the Defined Benefit Plan, so that all BEP participants have been credited with service vesting in the same manner and vest according to the same three year cliff vesting schedule as provided under the Defined Benefit Plan. The Company has a DB SERP which provides certain retired officers with defined pension benefits in excess of qualified plan limits imposed by U.S. federal tax law. In connection with the Company’s acquisition of Century, the Company acquired Century’s Supplemental Executive Insurance/Retirement Plan (the “Supplemental Plan”). Upon completion of the acquisition, the Supplemental Plan was merged for accounting purposes only into the Company’s DB SERP, but it continues to be administered according to its terms. Further, the plan document of the Century Supplemental Plan contained change in control provisions which became effective upon the Company’s acquisition of Century. Accordingly, all participants of the Century Supplemental Plan were deemed to be fully vested upon the closing of the acquisition. The Company has a ODRCP which provides pension benefits to outside directors who retire from service. Effective December 31, 2020, the Company closed the ODRCP to new participants and froze benefit accruals for active participants. Refer to Note 2, Summary of Significant Accounting Policies , for additional discussion of the Company’s pension plans. Obligations and Funded Status The funded status and amounts recognized in the Company’s Consolidated Financial Statements for the Defined Benefit Plan, the BEP, the DB SERP, and the ODRCP are set forth in the following table: As of and for the Year Ended December 31, 2023 2022 2021 (In thousands) Change in benefit obligation: Benefit obligation at beginning of the year $ 362,530 $ 501,507 $ 361,147 Service cost (1) 24,474 31,382 31,660 Interest cost 17,559 10,582 5,694 Amendments 1,351 — (1,106) Actuarial loss (gain) 13,943 (133,282) (1,697) Acquisitions — — 125,854 Benefits paid (20,493) (47,659) (20,045) Benefit obligation at end of the year $ 399,364 $ 362,530 $ 501,507 Change in plan assets: Fair value of plan assets at beginning of year $ 419,366 $ 546,056 $ 449,643 Actual return on plan assets 63,811 (91,474) 50,879 Acquisitions — — 63,468 Employer contribution 5,680 12,443 2,111 Benefits paid (20,493) (47,659) (20,045) Fair value of plan assets at end of year 468,364 419,366 546,056 Overfunded status $ 69,000 $ 56,836 $ 44,549 Reconciliation of funding status: Past service credit $ 80,090 $ 108,909 $ 120,792 Unrecognized net loss (69,697) (99,002) (128,402) Prepaid benefit cost 58,607 46,929 52,159 Overfunded status $ 69,000 $ 56,836 $ 44,549 Accumulated benefit obligation $ 399,364 $ 362,530 $ 501,507 Amounts recognized in accumulated other comprehensive income (“AOCI”), net of tax: Unrecognized past service credit $ 57,501 $ 78,295 $ 86,837 Unrecognized net loss (50,039) (71,172) (92,308) Net amount $ 7,462 $ 7,123 $ (5,471) (1) Includes service costs related to employees of our insurance agency business. Refer to the later discussion within the “Components of Net Periodic Benefit Cost” section within this Note for further discussion. In accordance with the Pension Protection Act, the Company was not required to make any contributions to the Defined Benefit Plan for the plan year beginning November 1, 2022. Accordingly, during the year ended December 31, 2023, there were no contributions to the Defined Benefit Plan. Similarly, in accordance with the Pension Protection Act, the Company was not required to make any contributions to the Defined Benefit Plan for the plan year beginning November 1, 2021. However, the Company made a discretionary contribution to the Defined Benefit Plan of $7.2 million during the year ended December 31, 2022. The Company expects to make no contribution during the plan year beginning November 1, 2023. The net actuarial loss of $13.9 million during the year ended December 31, 2023 was primarily attributable to a decrease in the discount rate assumptions used for determining the benefit obligation which was partially offset by higher returns on plan assets than initially expected. The net actuarial gain of $133.3 million during the year ended December 31, 2022 was primarily attributable to higher returns on plan assets than initially expected and an increase in the discount rate assumptions which were partially offset by changes in demographic assumptions and in the participant mortality rate assumption. The net actuarial loss of $(1.7) million during the year ended December 31, 2021 was primarily attributable to a decrease in the discount rate assumptions used for determining the benefit obligation in that year from the corresponding prior year. Actuarial Assumptions The assumptions used in determining the benefit obligations at December 31, 2023 and 2022 were as follows: DB Plan BEP DB SERP ODRCP As of December 31, As of December 31, As of December 31, As of December 31, 2023 2022 2023 2022 2023 2022 2023 2022 Discount rate 4.99 % 5.18 % 4.89 % 5.07 % 4.96 % 5.18 % 4.91 % 5.13 % Rate of increase in compensation levels 4.50 % 4.50 % 4.50 % 4.50 % — % — % — % — % Interest rate credit for determining projected cash balance 4.47 % 3.55 % 4.47 % 3.55 % — % — % — % — % The assumptions used in determining the net periodic benefit cost for the years ended December 31, 2023, 2022, and 2021 were as follows: DB Plan For the Year Ended December 31, 2023 2022 2021 Discount rate - benefit cost 5.18 % 2.65 % 2.26 % Rate of compensation increase 4.50 % 4.50 % 5.25 % Expected rate of return on plan assets 7.50 % 7.00 % 7.50 % Interest rate credit for determining projected cash balance 3.55 % 3.50 % 3.50 % BEP For the Year Ended December 31, 2023 2022 2021 Discount rate - benefit cost 5.07 % 2.32 % 1.77 % Rate of compensation increase 4.50 % 4.50 % 5.25 % Interest rate credit for determining projected cash balance 3.55 % 3.50 % 3.50 % DB SERP For the Year Ended December 31, 2023 2022 2021 Discount rate - benefit cost 5.18 % 2.68 % 1.63 % ODRCP For the Year Ended December 31, 2023 2022 2021 Discount rate - benefit cost 5.13 % 2.32 % 1.81 % In general, the Company has selected its assumptions with respect to the expected long-term rate of return based on prevailing yields on high quality fixed income investments increased by a premium for equity return expectations. To determine the discount rate used in calculating the benefit obligation and the benefit cost for all of its defined benefit plans, the Company uses the spot rate approach whereby the individual spot rates on the FTSE above-median yield curve are applied to each corresponding year’s projected cash flow used to measure the respective plan’s service cost and interest cost. Plan Assets The Company owns a percentage of the SBERA defined benefit common collective trust. Based upon this ownership percentage, plan assets managed by SBERA on behalf of the Company amounted to $468.4 million and $419.4 million at December 31, 2023 and 2022, respectively. Investments held by the common collective trust include Level 1, 2 and 3 assets such as: collective funds, equity securities, mutual funds, hedge funds and short-term investments. The Fair Value Measurements and Disclosures Topic of the FASB ASC stipulates that an asset’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. As such, the Company classifies its interest in the common collective trust as a Level 3 asset. The table below presents a reconciliation of the Company’s interest in the SBERA common collective trust during the years indicated: For the Year Ended December 31, 2023 2022 (In thousands) Balance at beginning of year $ 419,366 $ 546,056 Net realized and unrealized gains and (losses) 63,811 (91,474) Contributions — 7,222 Benefits paid (14,813) (42,438) Balance at end of year $ 468,364 $ 419,366 Components of Net Periodic Benefit Cost The components of net pension expense for the plans for the periods indicated are as follows: For the Year Ended December 31, 2023 2022 2021 (In thousands) Components of net periodic benefit cost: Service cost (1) $ 24,474 $ 31,382 $ 31,660 Interest cost 17,559 10,582 5,694 Expected return on plan assets (30,127) (35,486) (33,333) Past service credit (11,560) (11,882) (11,796) Recognized net actuarial loss 9,563 11,032 13,400 Curtailment (2) (15,908) — — Settlement — 12,045 — Net periodic benefit cost $ (5,999) $ 17,673 $ 5,625 (1) Includes service costs related to employees of our insurance agency business. Such service costs were included in net income from discontinued operations as such costs are no longer incurred by the Company following the sale of the insurance agency business in October 2023. All other costs included in the determination of the benefit obligation for the Defined Benefit Plan and the BEP were included in net income from continuing operations as the Bank will assume the related liability upon dissolution of its Eastern Insurance Group subsidiary. Service costs included in net income from discontinued operations and included in the above table were $5.1 million, $7.5 million, and $7.7 million for the years ended December 31, 2023, 2022, and 2021, respectively. (2) The pension curtailment gain recognized during the year ended December 31, 2023 is included in discounted operations. Refer to the below discussion under “Pension Curtailment and Settlement” for further discussion. Except as indicated above as it relates to service costs included in discontinued operations, service costs for the Defined Benefit Plan, the BEP, and the DB SERP are recognized within salaries and employee benefits in the Consolidated Statement of Income. In addition, as indicated above, the pension curtailment gain is also included in discontinued operations within the gain on sale of discontinued operations. The remaining components of net periodic benefit cost are recognized in other noninterest expense Pension Curtailment and Settlement As discussed in the earlier “Pension Plans” section, during the year ended December 31, 2023 and in connection with the sale of its insurance agency business, the Company remeasured the plan assets and obligations of the Defined Benefit Plan and the obligations of the BEP to determine the resulting curtailment gain or loss. As a result and in accordance with ASC 715-30, “Compensation-Retirement Benefits - Defined Benefit Plans,” the Company recognized a curtailment gain upon completion of the sale of the insurance agency business associated with the prior service credits attributable to the employees of the insurance agency business, all of which transferred to Gallagher. The Company determined, with assistance from its actuaries, the amount of the resulting non-cash curtailment amount to be a gain of $15.9 million which was included in the gain on sale of the insurance agency business . As a practical expedient, ASC 715, “Compensation–Retirement Benefits,” permits employers to not apply pension plan settlement accounting and to treat settlement transactions as normal benefit payments if the cost of all settlements in the year is less than or equal to the sum of the service cost and interest cost components of net periodic benefit cost. The Company has elected this practical expedient. During the year ended December 31, 2022, lump sum payments from the Defined Benefit Plan exceeded the sum of the service cost and interest cost components (the “threshold”) of the Defined Benefit Plan’s net periodic pension cost. ASC 715-20, “Compensation-Retirement Benefits - Defined Benefit Plans,” requires that upon determining it is probable that such threshold will be met, an entity shall immediately recognize in earnings a pro rata portion of the aggregate unamortized gain or loss (e.g., “non-cash settlement charge”). In accordance with the applicable accounting guidance, the Company elected to apply a practical expedient to remeasure the plan assets and obligations as of the nearest month-end date upon the triggering of the previously mentioned threshold. Accordingly, the Company performed a remeasurement as of October 31, 2022 and, subsequently, as of December 31, 2022. The Company determined, with assistance from its actuaries, the amount of the resulting non-cash settlement charge to be a loss of $12.0 million which was recorded in other noninterest expense in the Consolidated Statement of Income . Benefits expected to be paid The following table summarizes estimated benefits to be paid from the Defined Benefit Plan and BEP for the plan years beginning on November 1, and the DB SERP and ODRCP for the plan years beginning January 1: Year (In thousands) 2024 $ 46,490 2025 32,612 2026 33,261 2027 35,240 2028 37,175 In aggregate for 2029-2033 186,883 Employee Tax Deferred Incentive Plan The Company has an employee tax deferred incentive plan, otherwise known as a 401(k) plan, under which the Company makes voluntary contributions within certain limitations. All employees who meet specified age and length of service requirements are eligible to participate in the 401(k) plan. The amount contributed by the Company is included in salaries and employee benefits expense. The amounts contributed to the plan for the years ended December 31, 2023, 2022, and 2021, were $5.2 million, $5.0 million and $4.6 million, respectively. Defined Contribution Supplemental Executive Retirement Plan The Company’s DC SERP, a defined contribution supplemental executive retirement plan, allows certain senior officers to earn benefits calculated as a percentage of their compensation. The participant benefits are adjusted based upon a deemed investment performance of measurement funds selected by the participant. These measurement funds are for tracking purposes and are used only to track the performance of a mutual fund, market index, savings instrument, or other designated investment or portfolio of investments. The Company recorded expense related to the DC SERP of $0.1 million, $0.4 million and $0.9 million in the years ended December 31, 2023, 2022, and 2021, respectively. The total amount due to participants under this plan was included in other liabilities on the Company’s Consolidated Balance Sheets and amounted to $20.3 million and $17.3 million at December 31, 2023 and 2022, respectively. Effective December 31, 2021, the Company closed the DC SERP to new participants and froze benefit accruals for active participants. Deferred Compensation Plans The Company sponsors three plans which allow for elective compensation deferrals by directors, former trustees, and certain senior-level employees. Each plan allows its participants to designate deemed investments for deferred amounts from certain options which include diversified choices, such as exchange traded funds and mutual funds. Portfolios with various risk profiles are available to participants with the approval of the Compensation Committee of the Board of Directors. The Company purchases and sells investments which track the deemed investment choices, so that it has available funds to meet its payment liabilities. Deferred amounts, adjusted for deemed investment performance, are paid at the time of a participant designated date or event, such as separation from service, death, or disability. The total amounts due to participants under the three plans were included in other liabilities on the Company’s Consolidated Balance Sheets and amounted to $28.2 million and $25.4 million at December 31, 2023 and 2022, respectively. Rabbi Trust Variable Interest Entity The Company established rabbi trusts to meet its obligations under certain executive non-qualified retirement benefits and deferred compensation plans and to mitigate the expense volatility of the aforementioned retirement plans. The rabbi trusts are considered VIEs as the equity investment at risk is insufficient to permit the trusts to finance their activities without additional subordinated financial support from the Company. The Company is considered the primary beneficiary of the rabbi trusts as it has the power to direct the activities of the rabbi trusts that significantly affect the rabbi trusts’ economic performance and it has the obligation to absorb losses of the rabbi trusts that could potentially be significant to the rabbi trusts by virtue of its contingent call options on the rabbi trusts’ assets in the event of the Company’s bankruptcy. As the primary beneficiary of these VIEs, the Company consolidates the rabbi trust investments. In general, the rabbi trust investments and any earnings received thereon are accumulated, reinvested and used exclusively for trust purposes. These rabbi trust investments consist primarily of cash and cash equivalents, U.S. government agency obligations, equity securities, mutual funds and other exchange-traded funds, and are recorded at fair value in other assets in the Company’s Consolidated Balance Sheets. Changes in fair value are recorded in noninterest income. Assets held in rabbi trust accounts by plan type, at fair value, were as follows: As of December 31, 2023 2022 (In thousands) DB SERP $ 16,349 $ 17,209 BEP 18,656 11,734 ODRCP 2,819 3,670 DC SERP 20,785 17,764 Deferred compensation plans 28,826 25,909 Total rabbi trust assets $ 87,435 $ 76,286 The following tables present the book value, net unrealized gain or loss, and market value of assets held in rabbi trust accounts by asset type: As of December 31, 2023 As of December 31, 2022 Book Value Unrealized Fair Value Book Value Unrealized Fair Value Asset Type (In thousands) Cash and cash equivalents $ 12,269 $ — $ 12,269 $ 5,575 $ — $ 5,575 Equities (1) 56,140 12,869 69,009 60,056 3,626 63,682 Fixed income 6,676 (519) 6,157 7,799 (770) 7,029 Total assets $ 75,085 $ 12,350 $ 87,435 $ 73,430 $ 2,856 $ 76,286 (1) Equities include mutual funds and other exchange-traded funds. The Company had equity securities held in rabbi trust accounts of $69.0 million and $63.7 million as of December 31, 2023 and 2022, respectively. Included in the equity securities presented in the tables above are exchange-traded mutual funds which had a net asset value of $48.9 million and $38.9 million as of December 31, 2023 and 2022, respectively.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	Share-Based Compensation Employee Stock Ownership Plan As part of the IPO completed on October 14, 2020, the Company established a tax-qualified Employee Stock Ownership Plan to provide eligible employees the opportunity to own Company shares. The ESOP borrowed $149.4 million from the Company to purchase 14,940,652 common shares during the IPO and in the open market. The loan is payable in annual installments over 30 years at an interest rate equal to the Prime rate as published in the The Wall Street Journal . As the loan is repaid to the Company, shares are released and allocated proportionally to eligible participants on the basis of each participant’s proportional share of compensation relative to the compensation of all participants. The unallocated ESOP shares are pledged as collateral on the loan. The Company accounts for its ESOP in accordance with FASB ASC 718-40, " Compensation – Stock Compensation" . Under this guidance, unreleased shares are deducted from shareholders’ equity as unearned ESOP shares in the accompanying Consolidated Balance Sheets. The Company recognizes compensation expense equal to the fair value of the ESOP shares during the periods in which they are committed to be released. To the extent that the fair value of the Company’s ESOP shares differs from the cost of such shares, the difference is credited or debited to equity. As the loan is internally leveraged, the loan receivable from the ESOP to the Company is not reported as an asset nor is the debt of the ESOP shown as a liability in the Company’s Consolidated Balance Sheets. Dividends on unallocated shares are used to pay the ESOP debt. The following table presents the amount of compensation expense associated with the ESOP and the amount of the loan payments made by the ESOP, including the portions related to principal and interest, for the periods indicated: Year Ended December 31, 2023 2022 2021 (In thousands) Compensation expense $ 7,129 $ 9,923 $ 9,408 Annual loan payment: Interest 9,374 4,724 4,826 Principal 2,914 3,147 3,045 Total loan payment $ 12,288 $ 7,871 $ 7,871 The number of shares committed to be released per year is estimated to be 495,339 through 2049 and 392,141 in the year 2050. The following table presents share information held by the ESOP: As of December 31, 2023 2022 (Dollars in thousands) Allocated shares 1,541,971 1,046,850 Shares committed to be released 103,230 104,464 Unallocated shares (suspense shares) 13,270,932 13,769,628 Total shares 14,916,133 14,920,942 Fair value of unallocated shares $ 188,447 $ 237,526 Share-Based Compensation Plan On November 29, 2021, the shareholders of the Company approved the Eastern Bankshares, Inc. 2021 Equity Incentive Plan (the “2021 Plan”). The 2021 Plan provides for the issuance of up to 26,146,141 shares of common stock pursuant to grants of restricted stock, restricted stock units (“RSUs”), non-qualified stock options and incentive stock options, any or all of which can be granted with performance-based vesting conditions. Under the 2021 Plan, 7,470,326 shares may be issued as restricted stock or RSUs, including those issued as performance shares and performance share units (“PSUs”), and 18,675,815 shares may be issued upon the exercise of stock options. These shares may be awarded from the Company’s authorized but unissued shares. However, the 2021 Plan permits the grant of additional awards of restricted stock or RSUs above the aforementioned limit, provided that, for each additional share of restricted stock or RSU awarded in excess of such limit, the pool of shares available to be issued upon the exercise of stock options will be reduced by three shares. Pursuant to the terms of the 2021 Plan, each of the Company’s non-employee directors were automatically granted awards of restricted stock on November 30, 2021. Such restricted stock awards vest pro-rata on an annual basis over a five-year period. The maximum term for stock options is ten years. In May 2023, the Company granted a total of 47,820 shares of restricted stock to the Company’s non-employee directors which vest after approximately one year from the date of grant. In May 2022, the Company granted a total of 31,559 shares of restricted stock to the Company’s non-employee directors which vest after approximately one year from the date of grant. In March 2023, the Company granted to all of the Company’s executive officers and certain other employees a total of 318,577 RSUs, which vest pro-rata on an annual basis over a period of three years from the date of the grant, and a total of 108,984 PSUs for which vesting is contingent upon the Compensation and Human Capital Management Committee of the Board of Director’s certification, after the conclusion of a three-year period from the date of the grant, that the Company has attained a threshold level of certain performance criteria over such period. In March 2022, the Company granted to all of the Company’s executive officers and certain other employees a total of 978,364 RSUs, which vest pro-rata on an annual basis over a period of three As of December 31, 2023 and 2022, there were 4,872,494 shares and 5,302,256 shares that remained available for issuance as restricted stock or RSU awards (including those that may be issued as performance shares and PSUs), respectively, and 18,675,815 shares that remained available for issuance upon the exercise of stock options at both dates. As of both December 31, 2023 and 2022, no stock options had been awarded under the 2021 Plan. The following table summarizes the Company’s restricted stock award activity for the periods indicated: For the Years Ended December 31, 2023 2022 Restricted Stock Awards Number of Shares Weighted-Average Grant Price Per Share Number of Shares Weighted-Average Grant Price Per Share Non-vested restricted stock at beginning of year 525,460 $ 20.08 683,056 $ 20.13 Granted 47,820 11.50 31,559 19.17 Vested (152,880) 19.95 (136,609) 20.13 Forfeited — — (52,546) 20.08 Non-vested restricted stock at end of year 420,400 $ 19.15 525,460 $ 20.08 During the year ended December 31, 2021, 683,056 RSA shares were granted which had a total grant date fair value of $13.7 million. During the year ended December 31, 2023, 152,880 RSA awards vested. Such awards had a grant date fair value of $3.0 million. During the year ended December 31, 2022, 136,609 RSA awards had vested. Such awards had a grant date fair value of $2.7 million. The following table summarizes the Company’s restricted stock unit activity for the periods indicated: For the Years Ended December 31, 2023 2022 Restricted Stock Units Number of Shares Weighted-Average Grant Price Per Share Number of Shares Weighted-Average Grant Price Per Share Non-vested restricted stock at beginning of year 972,325 $ 21.08 — $ — Granted 318,577 15.63 978,364 21.08 Vested (1) (302,908) 21.08 — — Forfeited (35,993) 15.73 (6,039) 21.08 Non-vested restricted stock at end of year 952,001 $ 19.46 972,325 $ 21.08 (1) Includes 95,808 shares withheld upon settlement for employee taxes. During the year ended December 31, 2023, 302,908 RSU awards vested. Such awards had a grant date fair value of $6.4 million. As of December 31, 2022, no RSU awards had vested. During the year ended year ended December 31, 2021, no RSU awards were granted. The following table summarizes the Company’s performance stock unit activity for the periods indicated: For the Years Ended December 31, 2023 2022 Performance Stock Units Number of Shares Weighted-Average Grant Price Per Share Number of Shares Weighted-Average Grant Price Per Share Non-vested restricted stock at beginning of year 533,676 $ 21.12 — $ — Granted 108,984 10.16 533,676 21.12 Forfeited (9,626) 10.16 — — Non-vested restricted stock at end of year 633,034 $ 19.40 533,676 $ 21.12 As of December 31, 2023, no PSU awards had vested. As of December 31, 2022, no PSU awards had vested. During the year ended year ended December 31, 2021, no PSU awards were granted. The following table shows share-based compensation expense under the 2021 Plan and the related tax benefit for the periods indicated: For the Years Ended December 31, 2023 2022 2021 (In millions) Share-based compensation expense $ 16.5 $ 10.5 $ 0.2 Related tax benefit (1) 4.7 3.0 0.1 (1) Estimated based upon the Company’s statutory rate for the respective period. As of December 31, 2023 and 2022, there was $26.8 million and $34.6 million, respectively, of total unrecognized compensation expense related to unvested restricted stock awards, restricted stock units and performance stock units granted and issued under the 2021 Plan, as applicable. As of December 31, 2023, this cost is expected to be recognized over a weighted average remaining period of approximately 2.2 years. As of December 31, 2022, this cost was expected to be recognized over a weighted average remaining period of approximately 3.3 years.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Financial Instruments with Off-Balance Sheet Risk In order to meet the financing needs of its customers and to reduce its own exposure to fluctuations in interest rates, the Company is party to financial instruments with off-balance sheet risk in the normal course of business. These financial instruments include commitments to extend credit, standby letters of credit, and forward commitments to sell loans, all of which involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the Consolidated Balance Sheets. The contract or notional amounts of those instruments reflect the extent of involvement the Company has in each particular class of financial instruments. Substantially all of the Company’s commitments to extend credit, which normally have fixed expiration dates or termination clauses, are contingent upon customers maintaining specific credit standards at the time of loan funding. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. In the event the customer does not perform in accordance with the terms of agreement with the third party, the Company would be required to fund the commitment. The maximum potential amount of future payments the Company could be required to make is represented by the contractual amount of the commitment. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. For forward loan sale commitments, the contract or notional amount does not represent exposure to credit loss. The Company does not sell loans with recourse. The following table summarizes the above financial instruments as of the dates indicated: As of December 31, 2023 2022 (In Thousands) Commitments to extend credit $ 6,027,356 $ 5,680,438 Standby letters of credit 58,632 65,154 Forward commitments to sell loans 9,198 10,008 Other Contingencies The Company has been named a defendant in various legal proceedings arising in the normal course of business. In the opinion of management, based on the advice of legal counsel, the ultimate resolution of these proceedings will not have a material effect on the Company’s Consolidated Financial Statements. On March 12 and 13, 2023, following the closures of Silicon Valley Bank (“SVB”) and Signature Bank and the appointment of the FDIC as the receiver for those banks, the FDIC announced that, under the systemic risk exception set forth in the Federal Deposit Insurance Act (“FDIA”), all insured and uninsured deposits of those banks were transferred to the respective bridge banks for SVB and Signature Bank. The FDIC also announced that, as required by the FDIA, any losses to the Deposit Insurance Fund (“DIF”) to support uninsured depositors would be recovered by a special assessment. On November 16, 2023, the FDIC published in the Federal Register its final rule that imposes special assessments to recover the loss to the DIF arising from the protection of uninsured depositors in connection with the systemic risk determination announced on March 12, 2023, following the closures of SVB and Signature Bank, as required by the FDIA. The assessment base for the special assessments is equal to an insured depository institution’s (“IDI”) estimated uninsured deposits, reported as of December 31, 2022, adjusted to exclude the first $5 billion in estimated uninsured deposits from the IDI, or for IDIs that are part of a holding company with one or more subsidiary IDIs, at the banking organization level. The final rule calls for the FDIC to collect special assessments at an annual rate of approximately 13.4 basis points, over eight quarterly assessment periods. Because the estimated loss pursuant to the systemic risk determination will be periodically adjusted, the FDIC retains the ability to cease collection early, extend the special assessment collection period one or more quarters beyond the initial eight-quarter collection period to collect the difference between actual or estimated losses and the amounts collected, and impose a final shortfall special assessment on a one-time basis after the receiverships for SVB and Signature Bank terminate. The final rule set an effective date of April 1, 2024, with special assessments collected beginning with the first quarterly assessment period of 2024 (i.e., January 1 through March 31, 2024, with an invoice payment date of June 28, 2024). The Company, based on the FDIC’s November 2023 final rule regarding a special assessment, determined that the total pre-tax amount of the Bank’s special assessment will be approximately $10.8 million, although the timing, amount and allocation of that special assessment remain subject to any actions by the FDIC, as described above, to cease collection early, extend the collection period, and impose a final shortfall special assessment. In accordance with ASC 450, Contingencies , the Company recognized the special assessment estimate of $10.8 million in full upon finalization of the rule in the fourth quarter of 2023.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2023
Summary of Derivative Instruments [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The Company uses derivative financial instruments to manage its interest rate risk resulting from the differences in the amount, timing, and duration of known or expected cash receipts and known or expected cash payments. Additionally, the Company enters into interest rate derivatives and foreign exchange contracts to accommodate the business requirements of its customers (“customer-related positions”) and risk participation agreements entered into as financial guarantees of performance on customer-related interest rate swap derivatives. The Company also enters into residential mortgage loan commitments to fund mortgage loans at specified rates and times in the future and enters into forward sale commitments to sell such residential mortgage loans at specified prices and times in the future, both of which are considered derivative instruments. Derivative instruments are carried at fair value in the Company’s Consolidated Financial Statements. The accounting for changes in the fair value of a derivative instrument is dependent upon whether or not the instrument qualifies as a hedge for accounting purposes, and further, by the type of hedging relationship. By using derivatives, the Company is exposed to credit risk to the extent that counterparties to the derivative contracts do not perform as required. Should a counterparty fail to perform under the terms of a derivative contract, the Company’s credit exposure on interest rate swaps is limited to the net positive fair value and accrued interest of all swaps with each counterparty plus any initial margin collateral posted. The Company seeks to minimize counterparty credit risk through credit approvals, limits, monitoring procedures, and obtaining collateral, where appropriate. As such, management believes the risk of incurring credit losses on derivative contracts with those counterparties is remote. The Company’s discounting methodology and interest calculation of cash margin uses the Secured Overnight Financing Rate, or SOFR, for U.S. dollar cleared interest rate swaps. Interest Rate Positions An interest rate swap is an agreement whereby one party agrees to pay a floating rate of interest on a notional principal amount in exchange for receiving a fixed rate of interest on the same notional amount, for a predetermined period of time, from a second party. The amounts relating to the notional principal amount are not actually exchanged. The Company has entered into interest rate swaps in which it pays floating and receives fixed interest in order to manage its interest rate risk exposure to the variability in interest cash flows on certain floating-rate loans. Such interest rate swaps include those which effectively convert the floating rate one-month SOFR or overnight indexed swap rate, or prime rate interest payments received on the loans to a fixed rate and consequently reduce the Company’s exposure to variability in short-term interest rates. For interest rate swaps that are accounted for as cash flow hedges, changes in fair value are included in other comprehensive income and reclassified into net income in the same period or periods during which the hedged forecasted transaction affects net income. The following tables reflect the Company’s derivative positions for interest rate swaps which qualify as cash flow hedges for accounting purposes as of the dates indicated: As of December 31, 2023 Weighted Average Rate Notional Weighted Average Current Receive Fixed Fair Value (1) (In thousands) (In Years) (In thousands) Interest rate swaps on loans $ 2,400,000 3.57 5.35 % 3.02 % $ (883) Total $ 2,400,000 $ (883) (1) The fair value included a net accrued interest payable balance of $2.6 million as of December 31, 2023. In addition, the fair value includes netting adjustments which represent the amounts recorded to convert derivative assets and liabilities cleared through the CME from a gross basis to a net basis in accordance with applicable accounting guidance. As of December 31, 2022 Weighted Average Rate Notional Weighted Average Current Receive Fixed Fair Value (1) (In thousands) (In Years) (In thousands) Interest rate swaps on loans $ 2,400,000 4.57 4.07 % 3.02 % $ (2,401) Total $ 2,400,000 $ (2,401) (1) The fair value included a net accrued interest payable balance of $1.5 million as of December 31, 2022. In addition, the fair value includes netting adjustments which represent the amounts recorded to convert derivative assets and liabilities cleared through the CME from a gross basis to a net basis in accordance with applicable accounting guidance. The maximum amount of time over which the Company is currently hedging its exposure to the variability in future cash flows of forecasted transactions related to the receipt of variable interest on existing financial instruments is four years. The Company expects approximately $38.5 million will be reclassified into interest income, as a reduction of such income, from other comprehensive income related to the Company’s active cash flow hedges in the next 12 months as of December 31, 2023. The reclassification is due to anticipated net payments on the swaps based upon the forward curve as of December 31, 2023. The Company discontinues cash flow hedge accounting if it is probable that the forecasted hedged transactions will not occur in the initially identified time period. At such time, the associated gains and losses deferred in accumulated other comprehensive income (“AOCI”) are reclassified immediately into earnings and any subsequent changes in the fair value of such derivatives are recognized directly in earnings. The following table presents the pre-tax impact of terminated cash flow hedges on AOCI for the periods indicated: Year Ended December 31, 2023 2022 2021 (In thousands) Unrealized gains on terminated hedges included in AOCI — January 1 $ 46 $ 10,239 $ 41,473 Unrealized gains on terminated hedges arising during the period — — — Reclassification adjustments for amortization of unrealized (gains) into net interest income (46) (10,193) (31,234) Unrealized gains on terminated hedges included in AOCI — December 31 $ — $ 46 $ 10,239 Customer-Related Positions Interest rate swaps offered to commercial customers do not qualify as hedges for accounting purposes. These swaps allow the Company to retain variable rate commercial loans while allowing the commercial customer to synthetically fix the loan rate by entering into a variable-to-fixed rate interest rate swap. The Company believes that its exposure to commercial customer derivatives is limited to non-performance by either the customer or the dealer because these contracts are simultaneously matched at inception with an offsetting transaction. Risk participation agreements are entered into as financial guarantees of performance on interest rate swap derivatives. The purchased (asset) or sold (liability) guarantee allow the Company to participate-out (fee paid) or participate-in (fee received) the risk associated with certain derivative positions executed with the borrower by the lead bank in a customer-related interest rate swap derivative. Foreign exchange contracts consist of those offered to commercial customers and those entered into to hedge the Company’s foreign currency risk associated with a foreign-currency loan. Neither qualifies as a hedge for accounting purposes. These commercial customer derivatives are offset with matching derivatives with correspondent-bank counterparties in order to minimize foreign exchange rate risk to the Company. Exposure with respect to these derivatives is largely limited to non-performance by either the customer or the other counterparty. Neither the Company nor the correspondent-bank counterparty are required to post collateral but each has established foreign-currency transaction limits to manage the exposure risk. The Company requires its customers to post collateral to minimize risk exposure. The following tables present the Company’s customer-related derivative positions as of the dates indicated below for those derivatives not designated as hedging: As of December 31, 2023 Number of Positions Total Notional (Dollars in thousands) Interest rate swaps 356 $ 2,405,835 Risk participation agreements 78 323,957 Foreign exchange contracts: Matched commercial customer book 98 87,601 Foreign currency loan 10 10,242 As of December 31, 2022 Number of Positions Total Notional (Dollars in thousands) Interest rate swaps 382 $ 2,404,003 Risk participation agreements 63 241,029 Foreign exchange contracts: Matched commercial customer book 32 7,877 Foreign currency loan 5 13,948 The level of interest rate swaps, risk participation agreements and foreign currency exchange contracts at the end of each period noted above was commensurate with the activity throughout those periods. The table below presents the fair value of the Company’s derivative financial instruments, as well as their classification on the Consolidated Balance Sheets for the periods indicated: Asset Derivatives Liability Derivatives Balance Sheet Fair Value at December 31, Fair Value at December 31, Balance Sheet Fair Value at December 31, Fair Value at December 31, (In thousands) Derivatives designated as hedging instruments Interest rate swaps Other assets $ 10 $ 16 Other liabilities $ 893 $ 2,417 Derivatives not designated as hedging instruments Customer-related positions: Interest rate swaps Other assets $ 19,535 $ 23,567 Other liabilities $ 61,217 $ 78,577 Risk participation agreements Other assets 151 78 Other liabilities 106 130 Foreign currency exchange contracts — matched customer book Other assets 760 198 Other liabilities 672 205 Foreign currency exchange contracts — foreign currency loan Other assets — 2 Other liabilities 187 93 $ 20,446 $ 23,845 $ 62,182 $ 79,005 Total $ 20,456 $ 23,861 $ 63,075 $ 81,422 The table below presents the net effect of the Company’s derivative financial instruments on the Consolidated Statements of Income as well as the effect of the Company’s derivative financial instruments included in other comprehensive income (“OCI”) as follows: For the Year Ended December 31, 2023 2022 2021 (In thousands) Derivatives designated as hedges: Loss in OCI on derivatives $ (24,855) $ (69,010) $ — (Loss) gain reclassified from OCI into interest income (effective portion) $ (48,795) $ 9,580 $ 31,234 Gain recognized in income on derivatives (ineffective portion and amount excluded from effectiveness test) Interest income $ — $ — $ — Other income — — — Total $ — $ — $ — Derivatives not designated as hedges: Customer-related positions: (Loss) gain recognized in interest rate swap income $ (274) $ 4,324 $ 4,962 Gain recognized in interest rate swap income for risk participation agreements 97 213 243 Gain (loss) recognized in other income for foreign currency exchange contracts: Matched commercial customer book 95 (22) 1 Foreign currency loan (96) (4) (27) Total (loss) gain for derivatives not designated as hedges $ (178) $ 4,511 $ 5,179 The Company has agreements with its customer-related interest rate swap derivative counterparties that contain a provision whereby if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. The Company also has agreements with certain of its customer-related interest rate swap derivative correspondent-bank counterparties that contain a provision whereby if the Company fails to maintain its status as a well-capitalized institution, then the counterparty could terminate the derivative positions and the Company would be required to settle its obligations under the agreements. The Company’s exposure related to its customer-related interest rate swap derivatives consists of exposure on cleared derivative transactions and exposure on non-cleared derivative transactions. Cleared derivative transactions are with CME and exposure is settled to market daily, with additional credit exposure related to initial-margin collateral pledged to CME at trade execution. At December 31, 2023, the Company had exposure to CME for settled variation margin in excess of the customer-related and non-customer-related interest rate swap termination values of $0.4 million. At December 31, 2022, the Company had no exposure to CME for settled variation margin in excess of the customer-related and non-customer-related interest rate swap termination values. In addition, at December 31, 2023 and 2022, the Company had posted initial-margin collateral in the form of U.S. Treasury notes amounting to $85.9 million and $84.1 million, respectively, to CME for these derivatives. The U.S. Treasury notes were considered restricted assets and were included in available for sale securities within the Company’s Consolidated Balance Sheets. At December 31, 2023, there were $1.9 million of customer-related interest rate swap derivatives with credit-risk contingent features in a net liability position. At December 31, 2022 there were no customer-related interest rate swap derivatives with credit-risk contingent features in a net liability position. The Company has minimum collateral posting thresholds with its customer-related interest rate swap derivative correspondent-bank counterparties to the extent that the Company has a liability position with the correspondent-bank counterparties. At December 31, 2023 and 2022, the Company had posted collateral in the form of cash amounting to $3.0 million and $1.0 million, respectively, which was considered to be a restricted asset and was included in other short-term investments within the Company’s Consolidated Balance Sheets. If the Company had breached any of these provisions at December 31, 2023 or 2022, it would have been required to settle its obligations under the agreements at the termination value. In addition, the Company had cross-default provisions with its commercial customer loan agreements which provide cross-collateralization with the customer loan collateral. Mortgage Banking Derivatives The Company enters into residential mortgage loan commitments in connection with its consumer mortgage banking activities to fund mortgage loans at specified rates and times in the future. In addition, the Company enters into forward sale commitments to sell such residential mortgage loans at specified prices and times in the future. These commitments are short-term in nature and generally expire in 30 to 60 days. The residential mortgage loan commitments that relate to the origination of mortgage loans that will be held for sale and the related forward sale commitments are considered derivative instruments under ASC Topic 815, “Derivatives and Hedging” and are reported at fair value. Changes in fair value are reported in earnings and included in other non-interest income

Balance Sheet Offsetting

Balance Sheet Offsetting	12 Months Ended
	Dec. 31, 2023
Offsetting [Abstract]
Balance Sheet Offsetting	Balance Sheet Offsetting Certain financial instruments, including derivatives, may be eligible for offset in the Consolidated Balance Sheets and/or subject to master netting arrangements or similar agreements. The Company’s derivative transactions with upstream financial institution counterparties are generally executed under International Swaps and Derivative Association master agreements which include “right of set-off” provisions. In such cases there is generally a legally enforceable right to offset recognized amounts. However, the Company does not offset fair value amounts recognized for derivative instruments. The Company nets the amount recognized for the right to reclaim cash collateral against the obligation to return cash collateral arising from derivative instruments executed with the same counterparty under a master netting arrangement. Collateral legally required to be maintained at dealer banks by the Company is monitored and adjusted as necessary. As of December 31, 2023 and 2022, it was determined that no additional collateral would have to be posted to immediately settle these instruments. The following tables present the Company’s asset and liability positions that were eligible for offset and the potential effect of netting arrangements on its financial position, as of the dates indicated: As of December 31, 2023 Gross Gross Net Gross Amounts Not Offset Net Financial Collateral (In thousands) Derivative Assets Interest rate swaps designated as cash flow hedges $ 10 $ — $ 10 $ — $ — $ 10 Customer-related positions: Interest rate swaps 19,535 — 19,535 4,871 (8,500) 6,164 Risk participation agreements 151 — 151 — — 151 Foreign currency exchange contracts – matched customer book 760 — 760 — — 760 $ 20,456 $ — $ 20,456 $ 4,871 $ (8,500) $ 7,085 Derivative Liabilities Interest rate swaps designated as cash flow hedges $ 893 $ — $ 893 $ — $ 893 $ — Customer-related positions: Interest rate swaps 61,217 — 61,217 4,871 1,860 54,486 Risk participation agreements 106 — 106 — — 106 Foreign currency exchange contracts – matched customer book 672 — 672 — — 672 Foreign currency exchange contracts – foreign currency loan 187 — 187 — — 187 $ 63,075 $ — $ 63,075 $ 4,871 $ 2,753 $ 55,451 As of December 31, 2022 Gross Gross Net Gross Amounts Not Offset Net Financial Collateral (In thousands) Derivative Assets Interest rate swaps designated as cash flow hedges $ 16 $ — $ 16 $ — $ — $ 16 Customer-related positions: Interest rate swaps 23,567 — 23,567 381 (14,430) 8,756 Risk participation agreements 78 — 78 — — 78 Foreign currency exchange contracts – matched customer book 198 — 198 — — 198 Foreign currency exchange contracts – foreign currency loan 2 — 2 — — 2 $ 23,861 $ — $ 23,861 $ 381 $ (14,430) $ 9,050 Derivative Liabilities Interest rate swaps designated as cash flow hedges $ 2,417 $ — $ 2,417 $ — $ 2,417 $ — Customer-related positions: Interest rate swaps 78,577 — 78,577 381 — 78,196 Risk participation agreements 130 — 130 — — 130 Foreign currency exchange contracts – matched customer book 205 — 205 — — 205 Foreign currency exchange contracts – foreign currency loan 93 — 93 — — 93 $ 81,422 $ — $ 81,422 $ 381 $ 2,417 $ 78,624

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities The Company uses fair value measurements to record adjustments to certain assets and liabilities and to determine fair value disclosures. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. Fair value is a market-based measure considered from the perspective of a market participant rather than an entity-specific measure. Therefore, even when market assumptions are not readily available, the Company’s own assumptions are set to reflect those that the Company believes market participants would use in pricing the asset or liability at the measurement date. The Company uses prices and inputs that are current as of the measurement date, including during periods of market dislocation. In periods of market dislocation, the observability of prices and inputs may be reduced for many instruments. This condition could cause an instrument to be reclassified from Level 1 to Level 2 or from Level 2 to Level 3. 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 Company’s entire holdings of a particular financial instrument. Because no active market exists for a portion of the Company’s financial instruments, fair value estimates are based on judgements regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments, and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgement, and therefore cannot be determined with precision. Changes in assumptions could significantly affect these estimates. The following methods and assumptions were used by the Company in estimating fair value disclosures: Cash and Cash Equivalents For these financial instruments, which have original maturities of 90 days or less, their carrying amounts reported in the Consolidated Balance Sheets approximate fair value. Securities Securities consisted of U.S. Treasury securities, U.S. Agency bonds, U.S. government-sponsored residential and commercial mortgage-backed securities, state and municipal bonds, and other debt securities. AFS securities are recorded at fair value. The Company’s U.S. Treasury securities are traded on active markets and therefore these securities were classified as Level 1. The fair value of U.S. Agency bonds were evaluated using relevant trade data, benchmark quotes and spreads obtained from publicly available trade data, and generated on a price, yield or spread basis as determined by the observed market data. Therefore, these securities were categorized as Level 2 given the use of observable inputs. The fair value of U.S. government-sponsored residential and commercial mortgage-backed securities were estimated using either a matrix or benchmarks. The inputs used include benchmark yields, reported trades, broker/dealer quotes, and issuer spreads. Therefore, these securities were categorized as Level 2 given the use of observable inputs. The fair value of state and municipal bonds were estimated using a valuation matrix with inputs including observable bond interest rate tables, recent transactions, and yield relationships. Therefore, these securities were categorized as Level 2 given the use of observable inputs. The fair value of other debt securities, which were held at December 31, 2022 and had matured as of December 31, 2023, were estimated using a valuation matrix with inputs including observable bond interest rate tables, recent transactions, and yield relationships. Therefore, these securities were categorized as Level 2 given the use of observable inputs. Fair value was based on the value of one unit without regard to any premium or discount that may result from concentrations of ownership of a financial instrument, possible tax ramifications, or estimated transaction costs. Loans Held for Sale The fair value of loans held for sale, whose carrying amounts approximate fair value, was estimated using the anticipated market price based upon pricing indications provided by investor banks. These assets were classified as Level 2 given the use of observable inputs. Loans The fair value of commercial construction, commercial and industrial lines of credit, and certain other consumer loans was estimated by discounting the contractual cash flows using interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. For commercial, commercial real estate, residential real estate, automobile, and consumer home equity loans, fair value was estimated by discounting contractual cash flows adjusted for prepayment estimates using interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. Loans are classified as Level 3 since the valuation methodology utilizes significant unobservable inputs. Loans that are deemed to be collateral-dependent, as described in Note 2, “Summary of Significant Accounting Policies” were recorded at the fair value of the underlying collateral. FHLB Stock The fair value of FHLB stock approximates the carrying amount based on the redemption provisions of the FHLB. These assets were classified as Level 2. Rabbi Trust Investments Rabbi trust investments consisted primarily of cash and cash equivalents, U.S. government agency obligations, equity securities, mutual funds and other exchange-traded funds, and were recorded at fair value and included in other assets. The purpose of these rabbi trust investments is to fund certain executive non-qualified retirement benefits and deferred compensation. The fair value of other U.S. government agency obligations were estimated using either a matrix or benchmarks. The inputs used include benchmark yields, reported trades, broker/dealer quotes, and issuer spreads. These securities were categorized as Level 2 given the use of observable inputs. The equity securities, mutual funds and other exchange-traded funds were valued based on quoted prices from the market. The equities, mutual funds and exchange-traded funds traded in an active market were categorized as Level 1 as they were valued based upon quoted prices from the market. Mutual funds at net asset value amounted to $48.9 million and $38.9 million at December 31, 2023 and 2022, respectively. There were no redemption restrictions on these mutual funds at the end of any period presented. Bank-Owned Life Insurance The fair value of bank-owned life insurance was based upon quotations received from bank-owned life insurance dealers. These assets were classified as Level 2 given the use of observable inputs. Deposits The fair value of deposits with no stated maturity, such as noninterest-bearing demand deposits, savings, interest checking accounts, and money market accounts, was equal to their carrying amount. The fair value of time deposits was based on the discounted value of contractual cash flows using current market interest rates. Deposits were classified as Level 2 given the use of observable market inputs. The fair value estimates of deposits do not include the benefit that results from the low-cost funding provided by the deposit liabilities compared to the cost of borrowing funds in the wholesale market (core deposit intangibles). FHLB Advances The fair value of FHLB advances was based on the discounted value of contractual cash flows. The discount rates used are representative of approximate rates currently offered on instruments with similar remaining maturities. FHLB advances were classified as Level 2. Escrow Deposits of Borrowers The fair value of escrow deposits of borrowers, which have no stated maturity, approximates the carrying amount. Escrow deposits of borrowers were classified as Level 2. Interest Rate Swap Collateral Funds The fair value of interest rate swap collateral funds approximates the carrying amount. Interest rate swap collateral funds were classified as Level 2. Interest Rate Swaps The fair value of interest rate swaps was determined using discounted cash flow analysis on the expected cash flows of the interest rate swaps. This analysis reflects the contractual terms of the interest rate swaps, including the period of maturity, and uses observable market-based inputs, including interest rate curves and implied volatility. In addition, for customer-related interest rate swaps, the analysis reflects a credit valuation adjustment to reflect the Company’s own non-performance risk and the respective counterparty’s non-performance risk in the fair value measurements. The majority of inputs used to value the Company’s interest rate swaps fall within Level 2 of the fair value hierarchy, but the credit valuation adjustments associated with the interest rate swaps utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by the Company and its counterparties. However, at December 31, 2023 and 2022, the impact of the Level 3 inputs on the overall valuation of the interest rate swaps was deemed insignificant to the overall valuation. As a result, the interest rate swaps were categorized as Level 2 within the fair value hierarchy. Risk Participations The fair value of risk participations was determined based upon the total expected exposure of the derivative which considers the present value of cash flows discounted using market-based inputs and were therefore categorized as Level 2 within the fair value hierarchy. The fair value also included a credit valuation adjustment which evaluates the credit risk of its counterparties by considering factors such as the likelihood of default by the counterparties, its net exposures, the remaining contractual life, as well as the amount of collateral securing the position. The change in value of derivative assets and liabilities attributable to credit risk was not significant during the reported periods. Foreign Currency Forward Contracts The fair values of foreign currency forward contracts were based upon the remaining expiration period of the contracts and bid quotations received from foreign exchange contract dealers and were categorized as Level 2 within the fair value hierarchy. Mortgage Derivatives The fair value of mortgage derivatives was determined based upon current market prices for similar assets in the secondary market and therefore are classified as Level 2 within the fair value hierarchy. Fair Value of Assets and Liabilities Measured on a Recurring Basis The following tables present the balances of assets and liabilities measured at fair value on a recurring basis as of December 31, 2023 and 2022: Fair Value Measurements at Reporting Date Using Balance as of December 31, 2023 Quoted Prices in Significant Significant Description (In thousands) Assets Securities available for sale Government-sponsored residential mortgage-backed securities $ 2,780,638 $ — $ 2,780,638 $ — Government-sponsored commercial mortgage-backed securities 1,124,376 — 1,124,376 — U.S. Agency bonds 216,011 — 216,011 — U.S. Treasury securities 95,152 95,152 — — State and municipal bonds and obligations 191,344 — 191,344 — Rabbi trust investments 87,435 81,278 6,157 — Loans held for sale 1,124 — 1,124 — Interest rate swap contracts Cash flow hedges - interest rate positions 10 — 10 — Customer-related positions 19,535 — 19,535 — Risk participation agreements 151 — 151 — Foreign currency forward contracts Matched customer book 760 — 760 — Mortgage derivatives 69 — 69 — Total $ 4,516,605 $ 176,430 $ 4,340,175 $ — Liabilities Interest rate swap contracts Cash flow hedges - interest rate positions $ 893 $ — $ 893 $ — Customer-related positions 61,217 — 61,217 — Risk participation agreements 106 — 106 — Foreign currency forward contracts Matched customer book 672 — 672 — Foreign currency loan 187 — 187 — Mortgage derivatives 36 — 36 — Total $ 63,111 $ — $ 63,111 $ — Fair Value Measurements at Reporting Date Using Description Balance as of December 31, 2022 Quoted Prices in Significant Significant (In thousands) Assets Securities available for sale Government-sponsored residential mortgage-backed securities $ 4,111,908 $ — $ 4,111,908 $ — Government-sponsored commercial mortgage-backed securities 1,348,954 — 1,348,954 — U.S. Agency bonds 952,482 — 952,482 — U.S. Treasury securities 93,057 93,057 — — State and municipal bonds and obligations 183,092 — 183,092 — Other debt securities 1,285 — 1,285 Rabbi trust investments 76,286 69,257 7,029 — Loans held for sale 4,543 — 4,543 — Interest rate swap contracts Cash flow hedges - interest rate positions 16 — 16 — Customer-related positions 23,567 — 23,567 — Risk participation agreements 78 — 78 — Foreign currency forward contracts Matched customer book 198 — 198 — Foreign currency loan 2 — 2 — Mortgage derivatives 62 — 62 — Total $ 6,795,530 $ 162,314 $ 6,633,216 $ — Liabilities Interest rate swap contracts Cash flow hedges - interest rate positions $ 2,417 $ — $ 2,417 $ — Customer-related positions 78,577 — 78,577 — Risk participation agreements 130 — 130 — Foreign currency forward contracts Matched customer book 205 — 205 — Foreign currency loan 93 — 93 — Mortgage derivatives 58 — 58 — Total $ 81,480 $ — $ 81,480 $ — There were no transfers to or from Level 1, 2 and 3 during the years ended December 31, 2023 and 2022. The Company held no assets or liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of December 31, 2023 nor December 31, 2022. Fair Value of Assets and Liabilities Measured on a Nonrecurring Basis The Company may also be required, from time to time, to measure certain other assets on a nonrecurring basis in accordance with generally accepted accounting principles. The following tables summarize the fair value of assets and liabilities measured at fair value on a nonrecurring basis, as of December 31, 2023 and 2022. Fair Value Measurements at Reporting Date Using Description Balance as of December 31, 2023 Quoted Prices Significant Significant (In thousands) Assets Individually assessed collateral-dependent loans whose fair value is based upon appraisals $ 27,874 $ — $ — $ 27,874 Fair Value Measurements at Reporting Date Using Description Balance as of December 31, 2022 Quoted Prices Significant Significant (In thousands) Assets Individually assessed collateral-dependent loans whose fair value is based upon appraisals $ 16,432 $ — $ — $ 16,432 For the valuation of the collateral-dependent loans, the Company relies primarily on third-party valuation information from certified appraisers, and values are generally based upon recent appraisals of the underlying collateral, brokers’ opinions based upon recent sales of comparable properties, estimated equipment auction or liquidation values, income capitalization, or a combination of income capitalization and comparable sales. Depending on the type of underlying collateral, valuations may be adjusted by management for qualitative factors such as economic factors and estimated liquidation expenses. The range of these possible adjustments may vary. Disclosures about Fair Value of Financial Instruments The estimated fair values and related carrying amounts for assets and liabilities for which fair value is only disclosed are shown below as of the dates indicated: Fair Value Measurements at Reporting Date Using Carrying Value as of December 31, 2023 Fair Value as of December 31, 2023 Quoted Prices Significant Significant (In thousands) Assets Held to maturity securities: Government-sponsored residential mortgage-backed securities $ 254,752 $ 230,319 $ — $ 230,319 $ — Government-sponsored commercial mortgage-backed securities 194,969 174,503 — 174,503 — Loans, net of allowance for loan losses 13,799,367 13,145,455 — — 13,145,455 FHLB stock 5,904 5,904 — 5,904 — Bank-owned life insurance 164,702 164,702 — 164,702 — Liabilities Deposits $ 17,596,217 $ 17,593,214 $ — $ 17,593,214 $ — FHLB advances 17,738 15,366 — 15,366 — Escrow deposits of borrowers 21,978 21,978 — 21,978 — Interest rate swap collateral funds 8,500 8,500 — 8,500 — Fair Value Measurements at Reporting Date Using Carrying Value as of December 31, 2022 Fair Value as of December 31, 2022 Quoted Prices Significant Significant (In thousands) Assets Held to maturity securities: Government-sponsored residential mortgage-backed securities $ 276,493 $ 246,343 $ — $ 246,343 $ — Government-sponsored commercial mortgage-backed securities 200,154 176,883 — 176,883 — Loans, net of allowance for loan losses 13,420,317 13,149,096 — — 13,149,096 FHLB stock 41,363 41,363 — 41,363 — Bank-owned life insurance 160,790 160,790 — 160,790 — Liabilities Deposits $ 18,974,359 $ 18,960,407 $ — $ 18,960,407 $ — FHLB advances 704,084 702,954 — 702,954 — Escrow deposits of borrowers 22,314 22,314 — 22,314 — Interest rate swap collateral funds 14,430 14,430 — 14,430 — This summary excludes certain financial assets and liabilities for which the carrying value approximates fair value. For financial assets, these may include cash and due from banks, federal funds sold and short-term investments. For financial liabilities, these may include federal funds purchased. These instruments would all be considered to be classified as Level 1 within the fair value hierarchy. Also excluded from the summary are financial instruments measured at fair value on a recurring and nonrecurring basis, as previously described.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers Revenue from contracts with customers within the scope of ASC 606, Revenue from Contracts with Customers (Topic 606) (“ASC 606”) is recognized when control of goods or services is transferred to the customer, in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. The Company considers the terms of the contract and all relevant facts and circumstances when applying this guidance. The Company measures revenue and timing of recognition by applying the following five steps: 1. Identify the contract(s) with the customers. 2. Identify the performance obligations. 3. Determine the transaction price. 4. Allocate the transaction price to the performance obligations. 5. Recognize revenue when (or as) the entity satisfies a performance obligation. The Company accounts for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. The information presented within this Note excludes discontinued operations. Refer to Note 23, “Discontinued Operations” for further discussion regarding discontinued operations. Performance obligations The Company’s performance obligations are generally satisfied either at a point in time or over time, as services are rendered. Unsatisfied performance obligations at the report date are not material to the Company’s Consolidated Financial Statements. A portion of the Company's noninterest (loss)/income is derived from contracts with customers within the scope of ASC 606. The Company has disaggregated such revenues by type of service, as presented in the table below. These categories reflect how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. For the Year Ended December 31, 2023 2022 2021 (In thousands) Service charges on deposit accounts $ 28,631 $ 30,392 $ 24,271 Trust and investment advisory fees 24,264 23,593 24,588 Debit card processing fees 13,469 12,644 12,118 Other non-interest income 10,502 10,670 8,446 Total noninterest income in-scope of ASC 606 76,866 77,299 69,423 Total noninterest (loss) income out-of-scope of ASC 606 (314,619) (549) 28,014 Total noninterest (loss) income $ (237,753) $ 76,750 $ 97,437 Additional information related to each of the revenue streams is further noted below. Deposit Service Charges The Company offers various deposit account products to its customers governed by specific deposit agreements applicable to either personal customers or business customers. These agreements identify the general conditions and obligations of both parties and include standard information regarding deposit account-related fees. Deposit account services include providing access to deposit accounts as well as access to the various deposit transactional services of the Company. These transactional services are primarily those that are identified in the standard fee schedule, and include, but are not limited to, services such as overdraft protection, wire transfer, and check collection. The Company may charge monthly fixed service fees associated with the customer having access to the deposit account as well as separate fixed fees associated with and at the time specific transactions are entered into by the customer. As such, the Company considers that its performance obligations are fulfilled when customers are provided deposit account access or when the requested deposit transaction is completed. Cash management services are a subset of the deposit service charges revenue stream. These services include automated clearing house, or ACH, transaction processing, positive pay, lockbox, and remote deposit services. These services are also governed by separate agreements entered into by the customer. The fee arrangement for these services is structured as a fixed fee per transaction which may be offset by earnings credits. An earnings credit is a discount that a customer receives based upon the investable balance in the applicable covered deposit account(s) for a given month. Earnings credits are only good for the given month. That is, if cash management fees for a given month are less than the month’s earnings credit, the remainder of the credit does not carry over to the following month. Cash management fees are recognized as revenue in the month that the services are provided. Cash management fees earned but not yet received amounted to $1.6 million and $2.1 million as of December 31, 2023 and 2022 respectively, and were included in other assets on the Consolidated Balance Sheets. Trust and Investment Advisory Fees The Company offers investment management and trust services to individuals, institutions, small businesses and charitable institutions. Each investment management product is governed by its own contract along with a separate identifiable fee schedule unique to that product. The Company also offers additional services, such as estate settlement, financial planning, tax services, and other special services quoted at the customer’s request. The asset management and/or custody fees are primarily based upon a percentage of the monthly valuation of the principal assets in the customer’s account. Customers are also charged a base fee which is prorated over a twelve-month period. Fees for additional or special services are generally fixed in nature and are charged as services are rendered. All revenue is recognized in correlation to the monthly management fee determinations or as transactional services are provided. Debit Card Processing Fees The Company provides debit cards to its customers which are authorized and settled through various card payment networks, and in exchange, the Company earns revenue as determined by each payment network’s interchange program. Regardless of the network that is utilized to authorize and settle the payment, the merchant that provides the product or service to the debit card holder is ultimately responsible for the interchange payment to the Company. Debit card processing fees are recognized as card transactions are settled within each network. Debit card processing fees earned but not yet received amounted to $0.4 million and 0.3 million as of December 31, 2023 and 2022, respectively, and were included in other assets on the Consolidated Balance Sheets. Other Noninterest Income The Company earns various types of other noninterest income that have been aggregated into one general revenue stream in the table noted above. Noninterest income in-scope of ASC 606 includes, but is not limited to, the following types of revenue with customers: safe deposit rent, ATM surcharge fees and customer checkbook fees. Individually, these sources of noninterest income are not material.

Other Comprehensive Income

Other Comprehensive Income	12 Months Ended
	Dec. 31, 2023
Statement of Other Comprehensive Income [Abstract]
Other Comprehensive Income	Other Comprehensive Income The following tables present a reconciliation of the changes in the components of other comprehensive income (loss) for the dates indicated including the amount of income tax benefit (expense) allocated to each component of other comprehensive income (loss): For the Year Ended December 31, 2023 Pre Tax Tax (Expense) Benefit After Tax (In thousands) Unrealized losses on securities available for sale: Change in fair value of securities available for sale $ 47,104 $ (9,731) $ 37,373 Less: reclassification adjustment for losses included in net income (333,170) 74,630 (258,540) Net change in fair value of securities available for sale 380,274 (84,361) 295,913 Unrealized losses on cash flow hedges: Change in fair value of cash flow hedges (1) (24,855) 8,165 (16,690) Less: net cash flow hedge losses reclassified into interest income (1) (48,795) 13,517 (35,278) Net change in fair value of cash flow hedges 23,940 (5,352) 18,588 Defined benefit pension plans: Change in actuarial net loss 19,742 (5,547) 14,195 BEP and Defined Benefit Plan amendments - accelerated vesting (1,351) 381 (970) Less: amortization of actuarial net loss (9,563) 2,693 (6,870) Less: BEP and Defined Benefit Plan curtailment gain 15,908 (4,490) 11,418 Less: net accretion of prior service credit 11,560 (3,222) 8,338 Net change in other comprehensive income for defined benefit pension plans 486 (147) 339 Total other comprehensive income $ 404,700 $ (89,860) $ 314,840 For the Year Ended December 31, 2022 Pre Tax Tax Benefit (Expense) After Tax (In thousands) Unrealized losses on securities available for sale: Change in fair value of securities available for sale $ (1,061,859) $ 238,005 $ (823,854) Less: reclassification adjustment for losses included in net income (3,157) 873 (2,284) Net change in fair value of securities available for sale (1,058,702) 237,132 (821,570) Unrealized losses on cash flow hedges: Change in fair value of cash flow hedges (1) (69,010) 18,377 (50,633) Less: net cash flow hedge gains reclassified into interest income (1) 9,580 (2,693) 6,887 Net change in fair value of cash flow hedges (78,590) 21,070 (57,520) Defined benefit pension plans: Change in actuarial net gain 6,323 (1,777) 4,546 Less: amortization of actuarial net loss (11,032) 3,101 (7,931) Less: Defined Benefit Plan settlement loss (12,045) 3,386 (8,659) Less: net accretion of prior service credit 11,882 (3,340) 8,542 Net change in other comprehensive income for defined benefit pension plans 17,518 (4,924) 12,594 Total other comprehensive loss $ (1,119,774) $ 253,278 $ (866,496) For the Year Ended December 31, 2021 Pre Tax Tax Benefit (Expense) After Tax (Dollars in thousands) Unrealized losses on securities available for sale: Change in fair value of securities available for sale $ (133,466) $ 30,117 $ (103,349) Less: reclassification adjustment for gains included in net income 1,166 (257) 909 Net change in fair value of securities available for sale (134,632) 30,374 (104,258) Unrealized gains on cash flow hedges: Change in fair value of cash flow hedges — — — Less: net cash flow hedge gains reclassified into interest income (1) 31,234 (8,780) 22,454 Net change in fair value of cash flow hedges (31,234) 8,780 (22,454) Defined benefit pension plans: Change in actuarial net gain 19,243 (5,409) 13,834 Less: amortization of actuarial net loss (13,400) 3,767 (9,633) Plan amendment - Century acquisition lump sum distribution option 1,106 (311) 795 Less: net accretion of prior service credit 11,796 (3,316) 8,480 Net change in other comprehensive income for defined benefit pension plans 21,953 (6,171) 15,782 Total other comprehensive loss $ (143,913) $ 32,983 $ (110,930) (1) Includes amortization of less than $0.1 million, $7.3 million, and $22.5 million for the years ended December 31, 2023, 2022, and 2021, respectively, of realized but unrecognized gains, net of tax, from the termination of interest rate swaps. The total original gain of $41.2 million, net of tax, became fully accreted into income during the year ended December 31, 2023. The balance of this gain had amortized to less than $0.1 million, and $7.4 million, net of tax, at December 31, 2022 and December 31, 2021, respectively. The following table illustrates the changes in the balances of each component of accumulated other comprehensive income (loss), net of tax: Unrealized Unrealized Defined Benefit Total (In thousands) Beginning balance: January 1, 2021 $ 45,672 $ 29,815 $ (21,253) $ 54,234 Other comprehensive (loss) income before reclassifications (103,349) — 14,629 (88,720) Less: Amounts reclassified from accumulated other comprehensive income 909 22,454 (1,153) 22,210 Net current-period other comprehensive (loss) income (104,258) (22,454) 15,782 (110,930) Ending balance: December 31, 2021 $ (58,586) $ 7,361 $ (5,471) $ (56,696) Other comprehensive (loss) income before reclassifications (823,854) (50,633) 4,546 (869,941) Less: Amounts reclassified from accumulated other comprehensive income (2,284) 6,887 (8,048) (3,445) Net current-period other comprehensive (loss) income (821,570) (57,520) 12,594 (866,496) Ending balance: December 31, 2022 $ (880,156) $ (50,159) $ 7,123 $ (923,192) Other comprehensive income (loss) before reclassifications 37,373 (16,690) 13,225 33,908 Less: Amounts reclassified from accumulated other comprehensive (loss) income (258,540) (35,278) 12,886 (280,932) Net current-period other comprehensive income 295,913 18,588 339 314,840 Ending balance: December 31, 2023 $ (584,243) $ (31,571) $ 7,462 $ (608,352) The following table illustrates the significant amounts reclassified out of each component of accumulated other comprehensive (loss)/income, net of tax: Year Ended December 31, Details about Accumulated Other Comprehensive (Loss)/Income Components 2023 2022 2021 Affected Line Item in the Statement Where Net Income is Presented (In thousands) Unrealized (losses) and gains on available-for-sale securities $ (333,170) $ (3,157) $ 1,166 (Losses) gains on sales of securities available for sale, net (333,170) (3,157) 1,166 Total before tax 74,630 873 (257) Tax benefit (expense) $ (258,540) $ (2,284) $ 909 Net of tax Unrealized (losses) gains on cash flow hedges $ (48,795) $ 9,580 $ 31,234 Interest income (48,795) 9,580 31,234 Total before tax 13,517 (2,693) (8,780) Tax benefit (expense) $ (35,278) $ 6,887 $ 22,454 Net of tax Accretion (amortization) of defined benefit pension items $ (9,563) $ (23,077) $ (13,400) Net periodic pension cost - see Note 15 BEP and Defined Benefit Plan curtailment gain 15,908 — — Net income from discontinued operations Accretion of prior service credit 11,560 11,882 11,796 Net periodic pension cost - see Note 15 17,905 (11,195) (1,604) Total before tax (5,019) 3,147 451 Tax (expense) benefit $ 12,886 $ (8,048) $ (1,153) Net of tax Total reclassifications for the period $ (280,932) $ (3,445) $ 22,210

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2023
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations On September 19, 2023, the Company announced that it had entered into an asset purchase agreement (“the agreement”) with Arthur J. Gallagher & Co. (“Gallagher”) to sell substantially all of the assets of its insurance agency business for a gross purchase price of $515.0 million. The agreement also provided for the assumption of certain liabilities of the insurance agency business by Gallagher. Management made the decision to sell certain assets of its insurance agency business to recognize the valuation premium of the business, while allowing the Company to focus on growth and strategic initiatives of its core banking business. In September 2023, following the approval of the sale by the Company’s board of directors, the Company reclassified substantially all of the assets and certain liabilities of its insurance agency business as held for sale in connection with a planned disposition of the business. A business is classified as held for sale when management, having the authority to approve the action, commits to a plan to sell the business, the sale is probable to occur during the next 12 months at a price that is reasonable in relation to its current fair value, and certain other criteria are met. In accordance with ASC 205, Presentation of Financial Statements , the Company classifies operations as discontinued when they meet all the criteria to be classified as held for sale and when the sale represents a strategic shift that will have a major impact on the Company’s financial condition and results of operations. Accordingly, the Consolidated Balance Sheets, Consolidated Statements of Income, and Consolidated Statements of Cash flows present discontinued operations for the current period and were adjusted on a retrospective basis for prior periods. On October 31, 2023, the Company completed the sale of its insurance agency business for net cash consideration at closing of $498.1 million, subject to customary post-closing working capital adjustments. The net cash proceeds at closing included the gross purchase price pursuant to the agreement of $515.0 million and an estimated working capital adjustment of $4.2 million, which were reduced by transaction expenses of $17.0 million and the settlement of certain obligations of the Company primarily related to employee post-retirement liabilities that originated prior to closing of $4.1 million. In addition, the Company transferred $7.4 million in fiduciary cash to Gallagher upon closing which is included in the determination of the gain on sale as of December 31, 2023 but was not included in the amount of net cash consideration of $498.1 million. In connection with the sale, the Company recognized a gain on sale of $408.6 million, which is subject to certain post-closing adjustments during the 120 day post-closing settlement period which ends on February 28, 2024. In addition, the Company recognized indirect noninterest expenses associated with the sale of approximately $22.3 million. The following is a summary of the assets and liabilities of the discontinued insurance agency business as of December 31, 2022: December 31, 2022 (In thousands) Assets Premises and equipment $ 163 Goodwill and intangibles, net 93,117 Deferred income taxes, net (315) Prepaid expenses 532 Other assets 34,722 Total assets $ 128,219 Liabilities Other liabilities $ 34,930 Total liabilities $ 34,930 Certain assets and liabilities previously reported as assets and liabilities of the insurance agency business will not be disposed of and will be transferred into the Bank upon dissolution of Eastern Insurance Group following the asset sale. The following is a summary of such assets and liabilities as of December 31, 2022: December 31, 2022 (In thousands) Assets Cash $ 66,507 Premises and equipment (1) 1,792 Bank-owned life insurance 2,066 Deferred income taxes 3,662 Other assets (2) 12,944 Total assets $ 86,971 Liabilities Other liabilities (3) $ 14,013 Total liabilities $ 14,013 (1) Includes buildings and related improvements. (2) Primarily includes assets held in rabbi trusts and the ROU asset associated with one lease which will be assumed by the Bank upon dissolution of Eastern Insurance Group. (3) Primarily includes employee post-retirement liabilities and the lease liability associated with one lease which will be assumed by the Bank upon dissolution of Eastern Insurance Group. The following presents operating results of the discontinued insurance agency business for the periods indicated: For the Years Ended December 31, 2023 2022 2021 (In thousands) Noninterest income: Insurance commissions $ 93,997 $ 99,887 $ 95,164 Other noninterest income 67 179 1,014 Total noninterest income 94,064 100,066 96,178 Noninterest expense: Salaries and employee benefits 76,109 65,089 68,292 Office occupancy and equipment 4,420 3,319 3,204 Data processing 3,577 4,335 4,424 Professional services 1,176 1,009 596 Marketing expenses 179 246 241 Amortization of intangible assets 2,002 2,666 2,293 Other 5,304 4,944 4,411 Total noninterest expense 92,767 81,608 83,461 Income from discontinued operations before income tax expense 1,297 18,458 12,717 Gain on sale of discontinued operations before income tax expense 408,629 — — Total gain on discontinued operations before income tax expense 409,926 18,458 12,717 Income tax expense 115,060 5,210 3,583 Income from discontinued operations, net of taxes (1) $ 294,866 $ 13,248 $ 9,134 (1) Represents net income from discontinued operations that is presented in the Consolidated Statements of Income. Certain income and expense amounts were excluded from discontinued operations as they relate to assets and liabilities which were not assumed by Gallagher. The following is a summary of such items and the corresponding income tax effect for the periods indicated: Years Ended December 31, 2023 2022 2021 (In thousands) Noninterest income: Income (losses) from investments held in rabbi trusts $ 697 $ (1,305) $ 937 Other noninterest income (1) 60 54 52 Total noninterest income (loss) 757 (1,251) 989 Noninterest expense: Salaries and employee benefits (2) 721 (1,292) 967 Office occupancy and equipment (3) 433 499 501 Other (4) 1,608 2,396 (2,151) Total noninterest expense 2,762 1,603 (683) (Loss) income before income tax expense (2,005) (2,854) 1,672 Income tax (benefit) expense (564) (802) 470 Net (loss) income (1,441) (2,052) 1,202 (1) Includes income on Company-owned life insurance policies which were not disposed of and will be transferred into the Bank upon dissolution of Eastern Insurance Group. (2) Includes expenses, which were a net credit for the year ended December 31, 2022, associated with certain employee post-retirement benefit plan expenses. (3) Includes depreciation expense associated with buildings and related improvements and ROU asset amortization related to one lease which were not disposed of and will be transferred into the Bank upon dissolution of Eastern Insurance Group. (4) Includes intercompany expenses and other credits associated with the Defined Benefit Plan and the BEP. Components of net periodic benefit cost associated with the Defined Benefit Plan and the BEP and included in other noninterest expense above were a net credit for the periods presented. Continuing Involvement Pursuant to a transition services agreement, the Company will perform certain transitional services to Gallagher for up to six months following the closing of the sale. Such services include the provision of certain information technology support and human resources support. The Company will be compensated for such services on a monthly basis and estimates the total compensation to be approximately $1.0 million over the six-month period plus reimbursement of any amounts paid by the Company in connection with its performance of the transitional services. Leases During the year ended December 31, 2023, upon reclassification of the above assets and liabilities to assets and liabilities of discontinued operations, the Company re-assessed the ROU assets of certain leases, which were assumed by Gallagher upon closing, and made the decision to abandon certain leases which were not assumed by Gallagher and for which Eastern Insurance Group is the lessee. The amounts of ROU asset and lease liability of leases included in assets and liabilities of discontinued operations and which were either assumed by Gallagher or terminated by the Company were $8.7 million and $9.2 million, respectively, at December 31, 2022. The Company retained one lease for which Eastern Insurance Group was lessee at the time of closing. Following the sale, the lease was partially sublet to Gallagher and Eastern Insurance Group’s obligation will be transferred to the Bank upon dissolution of Eastern Insurance Group which is expected to occur in 2024. As of December 31, 2023, the ROU asset and lease liability for such lease was $0.5 million and $0.3 million, respectively. As of December 31, 2022, the ROU asset and lease liability for such lease was $1.9 million and $2.2 million, respectively. During the year ended December 31, 2023, the Company remeasured the present value of the future lease payments related to each lease for which Eastern Insurance Group was the lessee which resulted in a net reduction of the lease liabilities and a corresponding net reduction of the lease ROU assets of $6.4 million. The Company recorded an impairment charge of $2.0 million related to leases which were terminated early following the closing of the asset sale. The impairment charge was included in net income from discontinued operations for the year ended December 31, 2023. Revenue Recognition - Insurance Commissions The Company acted as an agent in offering property, casualty, and life and health insurance to both commercial and consumer customers though Eastern Insurance Group. The Company also earned additional commissions from the insurers based upon meeting certain criteria, such as premium levels, growth rates, new business volume and loss experience. The Company recognized commission revenues when earned based upon the effective date of the policy or when services were rendered. Certain revenues were deferred to reflect delivery of services over the contract period. Upon the transfer of Eastern Insurance Group’s assets to Arthur J. Gallagher & Co., which occurred on October 31, 2023, the Company ceased to offer insurance products and services and thus no longer receives insurance-related commissions and revenues. The Company earned a fixed commission rate on the sales of these products and services. Commissions were earned on the contract effective date and generally were based upon a percentage of premiums for insurance coverage. Commission rates depended upon a large number of factors, including the type of risk being placed, the particular underwriting enterprise’s demand, the expected loss experience of the particular risk coverage, and historical benchmarks surrounding the level of effort necessary for the Company to place and service the insurance contract. The vast majority of the Company’s services and revenues were associated with the placement of an insurance contract. The Company also earned profit-sharing revenues, also referred to as contingency revenue, from the insurers with whom the Company placed business. These profit-sharing revenues were performance bonuses from the insurers based upon certain performance metrics such as floors on written premiums, loss rates, and growth rates. These amounts were in excess of the commission revenues discussed above, and not all business placed with underwriting enterprises was eligible for contingent revenues. Contingent revenues were variable and generally based upon the Company’s expectation of the ultimate profit-sharing revenue amounts to be earned and varied from period to period. The Company’s contracts were generally calendar year contracts whereby revenues from underwriting enterprises were received in the calendar year following placement, generally the first and second quarters, after verification of the performance indicators outlined in the contracts. Accordingly, during each reporting period, management made its best estimate of the amounts that had been earned using historical averages and other factors to project revenues. The Company based its estimates each period on a contract-by-contract basis. As estimates could have changed significantly from period to period, the Company did not recognize this revenue until it had concluded that, based upon all the facts and information available, it was probable that a significant revenue reversal would not occur in a future period.

Parents Company Financial State

Parents Company Financial Statements	12 Months Ended
	Dec. 31, 2023
Condensed Financial Information Disclosure [Abstract]
Parent Company Financial Statements	Parent Company Financial Statements Condensed financial information relative to Eastern Bankshares Inc.'s (“the parent company”) balance sheets at December 31, 2023 and 2022 and the related statements of income and cash flows for the years ended December 31, 2023, 2022 and 2021 are presented below. The statement of shareholders’ equity is not presented below as the parent company’s shareholders’ equity is that of the consolidated Company. BALANCE SHEETS As of December 31, 2023 2022 (In thousands) Assets Cash and cash equivalents (1) $ 118,256 $ 126,441 Goodwill and other intangibles, net 744 744 Deferred income taxes, net 6,763 13,182 Investment in subsidiaries 2,842,099 2,327,521 Other assets 8,202 4,557 Total assets $ 2,976,064 $ 2,472,445 Liabilities and shareholders’ equity Other liabilities $ 1,209 $ 655 Total liabilities 1,209 655 Shareholders’ equity 2,974,855 2,471,790 Total liabilities and shareholders’ equity $ 2,976,064 $ 2,472,445 (1) Includes $116.7 million and $125.0 that is eliminated in consolidation as of December 31, 2023 and 2022, respectively. STATEMENTS OF INCOME For the Year Ended December 31, 2023 2022 2021 (In thousands) Income Interest income $ 130 $ 15 $ — Total income 130 15 — Expenses Professional services 4,937 899 7,393 Other 3,706 3,070 222 Total expenses 8,643 3,969 7,615 Loss before income taxes and equity in undistributed income of subsidiaries (8,513) (3,954) (7,615) Income tax (benefit) expense (1,773) 269 (11,344) (Loss) income before equity in undistributed income of subsidiaries (6,740) (4,223) 3,729 Equity in undistributed income of subsidiaries 238,917 203,982 150,936 Net income $ 232,177 $ 199,759 $ 154,665 STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2023 2022 2021 (In thousands) Cash flows provided by operating activities Net income $ 232,177 $ 199,759 $ 154,665 Adjustments to reconcile net income to cash provided by operating activities Equity in undistributed income of subsidiaries (238,917) (203,982) (150,936) Share-based compensation 16,513 10,507 — ESOP expense 7,129 9,923 9,408 Change in: Deferred income taxes, net 6,419 4,792 (7,157) Other, net (4,115) (937) (388) Net cash provided by operating activities 19,206 20,062 5,592 Cash flows provided by (used in) investing activities Cash paid for acquisition, net of cash acquired — — (640,890) Return of investments in subsidiary 40,000 240,000 140,000 Contributions to other equity investments (720) (788) — Net cash provided by (used in) investing activities 39,280 239,212 (500,890) Cash flows used in financing activities Payment of subordinated debentures assumed in business combination (1) — — (36,277) Payments for shares repurchased under share repurchase plans — (201,618) (23,224) Dividends declared and paid to common shareholders (66,671) (65,886) (51,564) Net cash used in financing activities (66,671) (267,504) (111,065) Net decrease in cash and cash equivalents (8,185) (8,230) (606,363) Cash and cash equivalents at beginning of year 126,441 134,671 741,034 Cash and cash equivalents at end of year $ 118,256 $ 126,441 $ 134,671 (1) The Company deposited funds into escrow prior to the Century acquisition date to pay the balance of subordinated debentures assumed in the Century acquisition which was considered to be defeasance of the debt. Accordingly, Century recorded a payable to the Company in the amount of the escrow deposit and the Company recorded a receivable from Century in the same amount. The payable was reclassified to other assets upon acquisition. Subsequent to the closing of the acquisition and prior to December 31, 2021, the amounts placed in escrow were disbursed to the holders of the subordinated debentures resulting in a full pay-off of the outstanding balance of the debt.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2023
Related Party Transactions [Abstract]
Related Parties	Related Parties The Company has, and expects to have in the future, related party transactions in the ordinary course of business. The transactions include, but are not limited to, lending activities and deposit services with directors and executive officers of the Company and their affiliates. Based on the Company’s assessment, such transactions are consistent with prudent banking practices and are within applicable banking regulations. During the years ended December 31, 2023, 2022 and 2021, no such transactions involved amounts in excess of 5% of the Company’s total shareholders’ equity.

Quarterly Results of Operations

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 31, 2023
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations (Unaudited)	Quarterly Results of Operations (Unaudited) In connection with the sale of the insurance agency business, the Company reclassified certain assets and liabilities and the related results of operations to discontinued operations in the third quarter of 2023. Refer to Note 23, “Discontinued Operations” for further discussion regarding discontinued operations. The following unaudited supplementary information summarizes the retrospective changes to the Consolidated Statements of Income as a result of the decision to sell the insurance agency business for the periods indicated: First Quarter Second Quarter Third Quarter Fourth Quarter 2023 2022 2023 2022 2023 2022 2023 2022 (Dollars in thousands, except per share data) Interest and dividend income $ 188,880 $ 131,485 $ 201,765 $ 140,871 $ 202,168 $ 157,827 $ 203,646 $ 174,998 Interest expense 50,571 3,361 60,177 3,114 64,963 5,648 70,339 25,004 Net interest income 138,309 128,124 141,588 137,757 137,205 152,179 133,307 149,994 Provision for (release of) allowance for loan losses 25 (485) 7,501 1,050 7,328 6,480 5,198 10,880 Net interest income after provision for loan losses 138,284 128,609 134,087 136,707 129,877 145,699 128,109 139,114 Noninterest (loss) income (309,853) 17,655 26,204 17,146 19,157 19,524 26,739 22,425 Noninterest expense 95,891 89,246 99,934 91,055 101,748 95,765 121,029 112,583 (Loss) income from continuing operations before income tax expense (267,460) 57,018 60,357 62,798 47,286 69,458 33,819 48,956 Income tax (benefit) expense (65,379) 12,064 15,938 14,967 (16,178) 16,650 2,310 8,038 Net (loss) income from continuing operations (202,081) 44,954 44,419 47,831 63,464 52,808 31,509 40,918 Net income (loss) from discontinued operations 7,985 6,562 4,238 3,341 (4,351) 1,969 286,994 1,376 Net (loss) income $ (194,096) $ 51,516 $ 48,657 $ 51,172 $ 59,113 $ 54,777 $ 318,503 $ 42,294 Basic (loss) earnings per share: Continuing operations $ (1.25) $ 0.26 $ 0.27 $ 0.29 $ 0.39 $ 0.32 $ 0.19 $ 0.25 Discontinued operations 0.05 0.04 0.03 0.02 (0.03) 0.01 1.77 0.01 Basic (loss) earnings per share $ (1.20) $ 0.30 $ 0.30 $ 0.31 $ 0.36 $ 0.33 $ 1.96 $ 0.26 Diluted (loss) earnings per share: Continuing operations $ (1.25) $ 0.26 $ 0.27 $ 0.29 $ 0.39 $ 0.32 $ 0.19 $ 0.25 Discontinued operations 0.05 0.04 0.03 0.02 (0.03) 0.01 1.76 0.01 Diluted (loss) earnings per share $ (1.20) $ 0.30 $ 0.30 $ 0.31 $ 0.36 $ 0.33 $ 1.95 $ 0.26 Average common shares outstanding: Basic 161,991,373 169,857,950 162,232,236 166,533,920 162,370,469 163,718,962 162,571,066 162,032,522 Diluted 162,059,431 169,968,156 162,246,675 166,573,627 162,469,887 164,029,649 162,724,398 162,263,547

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net income	$ 232,177	$ 199,759	$ 154,665

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	12 Months Ended
	Dec. 31, 2023 shares	Dec. 31, 2023 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Deborah C. Jackson [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		Lead Director Deborah C. Jackson and Directors Luis A. Borgen and Bari A. Harlam each adopted a trading arrangement intended to satisfy the affirmative defense conditions of the SEC’s Rule 10b5-1(c) on November 17, 2023. In Ms. Jackson’s case, her plan provides for the sale of up to 13,626 shares of Company common stock and continues through December 6, 2024. Mr. Borgen’s plan provides for the sale of up to 57,489 shares of Company common stock and continues through December 31, 2024. Ms. Harlam’s plan provides for the sale of up to 6,881 shares of Company common stock and continues through May 22, 2024.
Name	Deborah C. Jackson
Title	Lead Director
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	November 17, 2023
Aggregate Available	13,626	13,626
Luis A. Borgen [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		Lead Director Deborah C. Jackson and Directors Luis A. Borgen and Bari A. Harlam each adopted a trading arrangement intended to satisfy the affirmative defense conditions of the SEC’s Rule 10b5-1(c) on November 17, 2023. In Ms. Jackson’s case, her plan provides for the sale of up to 13,626 shares of Company common stock and continues through December 6, 2024. Mr. Borgen’s plan provides for the sale of up to 57,489 shares of Company common stock and continues through December 31, 2024. Ms. Harlam’s plan provides for the sale of up to 6,881 shares of Company common stock and continues through May 22, 2024.
Name	Luis A. Borgen
Title	Directors
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	November 17, 2023
Aggregate Available	57,489	57,489
Bari A. Harlam [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		Lead Director Deborah C. Jackson and Directors Luis A. Borgen and Bari A. Harlam each adopted a trading arrangement intended to satisfy the affirmative defense conditions of the SEC’s Rule 10b5-1(c) on November 17, 2023. In Ms. Jackson’s case, her plan provides for the sale of up to 13,626 shares of Company common stock and continues through December 6, 2024. Mr. Borgen’s plan provides for the sale of up to 57,489 shares of Company common stock and continues through December 31, 2024. Ms. Harlam’s plan provides for the sale of up to 6,881 shares of Company common stock and continues through May 22, 2024.
Name	Bari A. Harlam
Title	Directors
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	November 17, 2023
Aggregate Available	6,881	6,881

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States (“GAAP”) as set forth by the Financial Accounting Standards Board (“FASB”) and its Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) as well as the rules and interpretive releases of the SEC under the authority of federal securities laws. The Consolidated Financial Statements include the accounts of the Company, its wholly-owned subsidiaries, and entities in which it holds a controlling financial interest through being the primary beneficiary or through holding a majority of the voting interest. All intercompany accounts and transactions have been eliminated in consolidation. Certain previously reported amounts have been reclassified to conform to the current year’s presentation which includes: • certain loan servicing-related costs have been reclassified from professional services to loan expense; and • operational losses have been reclassified to other non-interest expense. As a result of the decision to sell substantially all of the assets and transfer certain liabilities of Eastern Insurance Group, the Company reclassified certain amounts previously reported including: • certain assets and liabilities previously reported in the insurance agency business were reclassified to assets and liabilities of discontinued operations, respectively, on the Consolidated Balance Sheets; • certain components of noninterest income and noninterest expense, including the associated income tax effects, previously reported in the insurance agency business were reclassified to net income from discontinued operations on the Consolidated Statements of Income; and •
Use of Estimates	Use of Estimates In preparing the Consolidated Financial Statements in conformity with GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheets and income and expenses for the periods reported. Actual results could differ from those estimates based on changing conditions, including economic conditions and future events. Material estimates that are particularly susceptible to change relate to the determination of the allowance for loan losses, valuation and fair value measurements, allowance for credit losses on investment securities, the liabilities for benefit obligations (particularly pensions), the provision for income taxes and impairment of goodwill and the core deposit intangible.
Cash and Cash Equivalents	Cash and Cash Equivalents
Securities	Securities Debt securities are classified at the time of purchase as either “trading,” “available for sale” (“AFS”) or “held to maturity” (“HTM”). Equity securities are measured at fair value with changes in the fair value recognized through net income. Debt securities that are bought and held principally for the purpose of resale in the near term are classified as trading securities and recorded at fair value, with subsequent changes in fair value included in net income. Debt securities that the Company has the positive intent and the ability to hold to maturity are classified as HTM securities and recorded at amortized cost. Debt securities not classified as either trading or HTM are classified as AFS and recorded at fair value, with changes in fair value excluded from net income and reported in other comprehensive income, net of related tax. Amortization of premiums and accretion of discounts are computed using the effective interest rate method. ASU 2016-13 made targeted changes to ASC 320 to eliminate the concept of “other than temporary” from the impairment loss estimation model for AFS securities. A summary of the changes made by the Company to the existing impairment model (previously referred to as the “OTTI” model) as a result of adoption of ASU 2016-13 is as follows: • The use of an allowance approach, rather than a permanent write-down of a security’s cost basis upon determination of an impairment loss. • The amount of the allowance is limited to the amount at which the security’s fair value is less than its amortized cost basis. • The Company may not consider the length of time a security’s fair value has been less than amortized cost. • The Company may not consider recoveries in fair value after the balance sheet date when assessing whether a credit loss exists. The Company’s AFS securities are carried at fair value. For AFS securities in an unrealized loss position, management will first evaluate whether there is intent to sell a security, or if it is more likely than not that the Company will be required to sell a security prior to anticipated recovery of its amortized cost basis. If either of these criteria are met, the Company will record a write-down of the security’s amortized cost basis to fair value through income. For those AFS securities which do not meet the intent or requirement to sell criteria, management will evaluate whether the decline in fair value is a result of credit related matters or other factors. In performing this assessment, management considers the creditworthiness of the issuer including whether the security is guaranteed by the U.S. federal government or other government agency, the extent to which fair value is less than amortized cost, and changes in credit rating during the period, among other factors. If this assessment indicates the existence of credit losses, an allowance for credit losses will be established, as determined by a discounted cash flow analysis. To the extent the estimated cash flows do not support the amortized cost, the deficiency is considered to be due to credit loss and is recognized in earnings. Changes in the allowance for credit losses are recorded as a provision for (or reversal of) credit loss expense. Losses are charged against the allowance when the security is determined to be uncollectible, or when either of the aforementioned criteria surrounding intent or requirement to sell have been met. On January 1, 2022, the date on which the Company adopted ASU 2016-13, no allowance for credit losses was recorded for AFS securities. Gains and losses on sales of securities are recognized at the time of sale on the specific-identification basis. Prior to the adoption of ASU 2016-13, management evaluated impaired securities for other-than-temporary impairment (“OTTI”) at least on a quarterly basis, and more frequently when economic or market concerns warranted such evaluation. Consideration was given to the length of time and the extent to which the fair value was less than cost, current market conditions, the financial condition and near-term prospects of the issuer, performance of collateral underlying the securities, the ratings of the individual securities, the interest rate environment, the Company’s intent to sell the security or whether it was more likely than not that the Company would be required to sell the debt security before its anticipated recovery, as well as other qualitative factors.
Allowance for Credit Losses - Held to Maturity Securities	Allowance for Credit Losses - Held to Maturity Securities The Company measures expected credit losses on HTM securities on a collective basis by major security type which, as of December 31, 2023, included government-sponsored residential and commercial mortgage-backed securities. Securities in the Company’s HTM portfolio are guaranteed by either the U.S. federal government or other government sponsored agencies with a long history of no credit losses. As a result, management has determined that these securities have a zero loss expectation and therefore does not record an allowance for credit losses on these securities. Refer to Note 3, “Securities” for additional information regarding the measurement of credit losses on HTM securities. Loans Individually Assessed for Impairment ASU 2016-13 indicates that a loan should be measured for impairment individually if that loan shares no similar risk characteristics with other loans. For the Company, loans which have been identified as those to be individually assessed for impairment under CECL include loans that do not share similar risk characteristics with other loans in the corresponding reserve segment. Characteristics of loans meeting this definition may include, but are not limited to: • Loans determined to be collateral dependent as defined below; • Loans on non-accrual status; • Loans with a risk rating of 12 under the Company’s risk rating scale, substandard (well-defined weakness) or worse; • Loans to borrowers actively involved in bankruptcy proceeds; and • Loans that have been partially charged-off. Collateral-Dependent Loans Management considers a loan to be collateral-dependent when foreclosure of the underlying collateral is probable. In addition, in accordance with ASU 2016-13, the Company elected to apply the collateral-dependent practical expedient whereby the Company measures expected credit losses using the fair value of the collateral, less any estimated costs to sell, when foreclosure is not probable but repayment of the loan is expected to be provided substantially through the operation or sale of the collateral, and the borrower is experiencing financial difficulty. Modifications of Loans to Borrowers Experiencing Financial Difficulty The amendments in ASU 2022-02 eliminated the accounting guidance for TDRs by creditors in Subtopic 310-40, Receivables—Troubled Debt Restructurings by Creditors , while enhancing disclosure requirements for certain loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. Thus, as a result of adoption of this standard on January 1, 2023, rather than applying the recognition and measurement guidance for TDRs, the Company now applies the loan refinancing and restructuring guidance codified in paragraphs 310-20-35-9 through 35-11 of the Accounting Standards Codification to determine whether a modification results in a new loan or a continuation of an existing loan. Modifications to borrowers experiencing financial difficulty include principal forgiveness, interest rate reductions, term extensions, other-than-insignificant payment delays and combinations thereof. Expected losses or recoveries related to loans where modifications have been granted to borrowers experiencing financial difficulty have been included in the Company’s determination of the allowance for loan losses. Upon adoption of ASU 2022-02, the Company is no longer required to use a discounted cash flow method to measure the allowance for loan losses resulting from a modification to a borrower experiencing financial difficulty. Accordingly, the Company now applies the same credit methodology it uses for similar loans that were not modified. The Company adopted ASU 2022-02 using the modified retrospective transition method. Accordingly, upon adoption, commercial loan TDRs existing at that time which were measured using a discounted cash flow methodology and all residential real estate and consumer home equity loan TDRs were transitioned to the applicable segment of loans collectively evaluated for impairment based upon their risk characteristics. Commercial loan TDRs determined to be collateral dependent continue to be assessed for impairment on an individual basis. Prior to the Company’s adoption of ASU 2022-02, in cases where a borrower was experiencing financial difficulties and the Company made certain concessionary modifications to contractual terms, the loan was classified as a TDR. Modifications included adjustments to interest rates, extensions of maturity, consumer loans where the borrower’s obligations had been effectively discharged through Chapter 7 bankruptcy and the borrower had not reaffirmed the debt to the Company, and other actions intended to minimize economic loss and avoid foreclosure or repossession of collateral. Management identified loans as TDR loans when it had a reasonable expectation that it would execute a TDR modification with a borrower. In addition, management estimated expected credit losses on a collective basis if a group of TDR loans shared similar risk characteristics. If a TDR loan’s risk characteristics were not similar to those of any of the Company’s other TDR loans, expected credit losses on the TDR loan were measured individually. The impairment analysis discounted the present value of the anticipated cash flows by the loan’s contractual rate of interest in effect prior to the loan’s modification or the fair value of collateral if the loan was collateral dependent. The amount of credit loss, if any, was recorded as a specific loss allocation to each individual loan or as a loss allocation to the pool of loans, for those loans for which credit loss was measured on a collective basis, in the allowance for credit losses. Any commercial (commercial and industrial, commercial real estate, commercial construction, and business banking loans) or residential loan that had been classified as a TDR and which subsequently defaulted was reviewed to determine if the loan should be deemed collateral-dependent. In such an instance, any shortfall between the value of the collateral and the book value of the loan was determined by measuring the recorded investment in the loan against the fair value of the collateral less costs to sell. Refer to Note 4, “Loans and Allowance for Credit Losses” for additional information regarding the Company’s measurement of the allowance for loan losses as of December 31, 2023 and information regarding the Company’s TDR loans as of December 31, 2022 and for the year then ended. Purchased Credit-Deteriorated Loans The Company applied the prospective transition approach with respect to PCD assets upon adoption of ASU 2016-13. Under this approach, loans previously determined to be PCI loans are considered to be PCD loans as of January 1, 2022. PCD loans are acquired individual loans (or acquired groups of loans with similar risk characteristics) that, as of the date of acquisition, have experienced a more-than-insignificant deterioration in credit quality since origination, as determined by the Company’s assessment. A PCD loan is recorded at its purchase price plus the allowance for loan losses expected at the time of acquisition, or “gross up” of the amortized cost basis, if any. Changes in the current estimate of the allowance for loan losses subsequent to acquisition from the estimated allowance previously recorded are recognized in the income statement as provision for credit losses or reversal of provision for credit losses in subsequent periods as they arise. A purchased loan that does not qualify as a PCD asset is accounted for similar to the Company’s method of accounting for originated assets, whereby an allowance for loan losses is recognized with a corresponding increase to the income statement provision for loan losses. Evidence that purchased loans, measured at amortized cost, have more-than-insignificant deterioration in credit quality since origination and, therefore meet the PCD definition, may include past-due status, non-accrual status, risk rating and other standard indicators (i.e., TDRs, charge-offs, bankruptcy). Allowance for Credit Losses Through December 31, 2021, the allowance for loan losses represented management’s best estimate of incurred probable losses in the Company’s loan portfolios based upon management’s assessment of various factors, including the risk characteristics of its loan portfolio, current economic conditions, and trends in loan delinquencies and charge-offs. The Company’s methodology for determining the qualitative component through December 31, 2021 included an assessment of factors affecting the determination of incurred losses in the loan portfolio. Such factors included trends in economic conditions, loan growth, credit underwriting policy exceptions, regulatory and audit findings, and peer comparisons, among others. Upon adoption of ASU 2016-13, effective January 1, 2022, the Company changed its reserve methodology to estimate expected credit losses over the contractual life of loans and leases. The allowance for credit losses, or “ACL,” is established to provide for the Company’s current estimate of expected lifetime credit losses on loans measured at amortized cost and unfunded lending commitments at the balance sheet date and is established through a provision for credit losses charged to net income. Credit losses are charged directly to the ACL. Subsequent recoveries, if any, are credited to the ACL. Commercial and residential loans are charged-off in the period in which they are deemed uncollectible. Delinquent loans in these product types are subject to ongoing review and analysis to determine if a charge-off in the current period is appropriate. For consumer finance loans, policies and procedures exist that require charge-off consideration upon a certain triggering event depending on the product type. Charge-off triggers include: 120 days delinquent for automobile, home equity, and other consumer loans with the exception of cash reserve loans for which the trigger is 150 days delinquent; death of the borrower; or Chapter 7 bankruptcy. In addition to those events, the charge-off determination includes other loan quality indicators, such as collateral position and adequacy or the presence of other repayment sources. The ACL is evaluated on a regular basis by management. Management uses a methodology to systematically estimate the amount of expected lifetime losses in the portfolio. Expected lifetime losses are estimated on a collective basis for loans sharing similar risk characteristics and are determined using a quantitative model combined with an assessment of certain qualitative factors designed to address forecast risk and model risk inherent in the quantitative model output. For commercial and industrial, commercial real estate, commercial construction and business banking portfolios, the quantitative model uses a loan rating system which is comprised of management’s determination of a financial asset’s probability of default (“PD”), loss given default (“LGD”) and exposure at default (“EAD”), which are derived from both the Company’s and industry historical loss experience and other factors. For residential real estate, consumer home equity and other consumer portfolios, the Company’s quantitative model uses historical loss experience. The quantitative model estimates expected credit losses using loan level data over the estimated life of the exposure, considering the effect of prepayments. Economic forecasts are incorporated into the estimate over a reasonable and supportable forecast period, beyond which is a reversion to the Company’s and/or industry historical loss average. Management has determined that a reasonable and supportable forecast period of eight quarters, and a straight-line reversion period of four quarters, are appropriate forecast periods for purposes of estimating expected credit losses. As described above, quantitative model results are adjusted for risk factors not considered within the model but which are relevant in estimating the expected credit losses within the loan portfolio. The qualitative risk factors impacting the expected risk of loss within the loan portfolio include the following: • Lending policies and procedures, including underwriting standards and collection, charge-off and recovery practices; • Nature and volume of the portfolio; • Volume and severity of past-due, non-accrual and classified loans; • The value of the underlying collateral for loans that are not collateral dependent; • Concentrations of credit risk; • Model and data limitations; and • Other external factors, such as changes in legal, regulatory or competitive environments. Loans that do not share similar risk characteristics with any pools of assets are subject to individual evaluation and are removed from the collectively assessed pools. For loans that are individually evaluated, the Company uses either a discounted cash flow (“DCF”) approach or, for loans deemed to be collateral dependent or when foreclosure is probable, a fair value of collateral approach. Accrued interest receivable amounts are excluded from balances of loans held at amortized cost and are included within other assets on the Consolidated Balance Sheet. Management has elected not to measure an allowance for credit losses on these amounts as the Company employs a timely write-off policy. Consistent with the Company's policy for non-accrual loans, accrued interest receivable is typically written off when loans reach 90 days past due and are placed on non-accrual status. In the ordinary course of business, the Company enters into commitments to extend credit and standby letters of credit. Such financial instruments are recorded in the financial statements when they become payable. The credit risk associated with these commitments is evaluated in a manner similar to the reserving method for loans receivable previously described. The reserve for unfunded lending commitments is included in other liabilities in the Consolidated Balance Sheets. Additionally, various regulatory agencies, as an integral part of the Company’s examination process, periodically assess the appropriateness of the allowance for credit losses and may require the Company to increase its allowance for loan losses or recognize further loan charge-offs, in accordance with GAAP. Refer to Note 4, “Loans and Allowance for Credit Losses” for additional information regarding the Company’s measurement of credit losses on loans receivable and off-balance sheet commitments to lend as of December 31, 2023 and comparative allowance for loan loss information for which ASC 450, “Contingencies” and ASC 310, “Receivables” were applied (i.e., prior to the Company’s adoption of the CECL methodology previously described).
Loans	Loans
Non-accrual Loans	Non-accrual Loans
Mortgage Banking Activities	Mortgage Banking Activities
Other Real Estate Owned	Other Real Estate Owned
Federal Home Loan Bank Stock	Federal Home Loan Bank Stock
Premises and Equipment	Premises and Equipment Land is carried at cost. Buildings, leasehold improvements and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the related assets. Leasehold improvements are amortized over the shorter of the lease terms or the estimated lives of the improvements. Expected lease terms include lease options to the extent that the exercise of such options is reasonably assured.
Goodwill and Core Deposit Intangible	Goodwill and Core Deposit Intangible Acquisitions of businesses are accounted for using the acquisition method of accounting. Accordingly, the net assets of the companies acquired are recorded at their fair values at the date of acquisition. Goodwill represents the excess of purchase price over the fair value of net assets acquired. Other intangible assets represent acquired assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights, or because the asset is capable of being sold or exchanged either on its own, or in combination with a related contract, asset, or liability. The Company evaluates goodwill for impairment at least annually, as of September 30, or more often if warranted, using a quantitative impairment approach. The quantitative impairment test compares the book value to the fair value of each reporting unit. If the book value exceeds the fair value, an impairment is charged to net income. Management has identified one reporting unit for purposes of testing goodwill for impairment which is referred to as “the banking business.”
Retirement Plans, Employee Tax Deferred Incentive Plan, Defined Contribution Supplemental Executive Retirement Plan, and Deferred Compensation	Retirement Plans The Company provides benefits to its employees and executive officers through various retirement plans, including a defined benefit plan, a defined benefit supplemental executive retirement plan, a defined contribution plan, a benefit equalization plan, and an outside directors’ retainer continuance plan. The Company provides pension benefits for its employees using a noncontributory, qualified defined benefit plan, through membership in the Savings Banks Employees Retirement Association (“SBERA”). The Qualified Defined Benefit Pension Plan (“Defined Benefit Plan”) is a noncontributory, defined benefit plan. The Company’s employees become eligible after attaining age 21 and completing one year of service. Effective November 1, 2020, the Defined Benefit Plan, sponsored by the Company, was amended to convert the plan from a traditional final average earnings plan design to a cash balance plan design. Under the final average earnings plan design, benefits became fully vested after three years of eligible service for individuals employed on or before October 31, 1989. For individuals employed subsequent to October 31, 1989 and who were already in the Defined Benefit Plan as of November 1, 2020, benefits became fully vested after five years of eligible service. Under the cash balance plan design, hypothetical account balances are established for each participant and pension benefits are generally stated as the lump sum amount in that hypothetical account. Contribution credits equal to a percentage of a participant’s annual compensation (if the participant works at least 1,000 hours during the year) and interest credits equal to the greater of the 30-Year Treasury rate for September preceding the current plan year or 3.5% are added to a participant’s account each year. For employees hired prior to November 1, 2020, annual contribution credits generally increase as the participant remains employed with the Company. Employees hired on and after November 1, 2020 receive annual contribution credits equal to 5% of annual compensation, with no future increases. Notwithstanding the preceding sentence, since a cash balance plan is a defined benefit plan, the annual retirement benefit payable at normal retirement (age 65) is an annuity, which is the actuarial equivalent of the participant’s account balance under the cash balance plan design, plus their frozen benefit under the final average earnings plan design. However, under the Defined Benefit Plan, participants may elect, with the consent of their spouses if they are married, to have the benefits distributed as a lump sum rather than an annuity. The lump sum is equal to the sum of the actuarial equivalent of their frozen benefit under the final average earnings plan design, plus their cash balance account. Under the Company’s non-Qualified Benefit Equalization Plan (“BEP”), which is described further below, benefits are generally only payable as a lump sum, which is equal to the sum of the actuarial equivalent of their frozen benefit under the final average earnings plan design, plus their cash balance account. The Company’s annual contribution to the plan is based upon standards established by the Pension Protection Act. The contribution is based on an actuarial method intended to provide not only for benefits attributable to service to date, but also for those expected to be earned in the future. The Company also has an unfunded Defined Benefit Supplemental Executive Retirement Plan (“DB SERP”) that provides certain retired officers with defined pension benefits in excess of qualified plan limits imposed by U.S. federal tax law. The DB SERP has a plan year end of December 31. The Company’s BEP, which is an unfunded plan, provides retirement benefits to certain employees whose retirement benefits under the Defined Benefit Plan are limited per the Internal Revenue Code. The BEP has a plan year end of October 31. Effective November 1, 2020, the BEP, sponsored by the Company, was amended to convert the plan from a traditional final average earnings plan design to a cash balance plan design. The Company also has an unfunded Outside Directors’ Retainer Continuance Plan (“ODRCP”) that provides pension benefits to outside directors who retire from service. The Outside Directors’ Retainer Continuance Plan has a plan year end of December 31. Effective December 31, 2020, the Company closed the ODRCP to new participants and froze benefit accruals for active participants. Plan assets are invested in various investment funds and held at fair value which generally represents observable market prices. Pension liability is determined based on the actuarial cost method factoring in assumptions such as salary increases, expected retirement date, mortality rate, and employee turnover. The actuarial cost method used to compute the pension liabilities and related expense is the projected unit credit method. The projected benefit obligation is principally determined based on the present value of the projected benefit distributions at an assumed discount rate (which is the rate at which the projected benefit obligation could be effectively settled as of the measurement date). The discount rate which is utilized is determined using the spot rate approach whereby the individual spot rates on the Financial Times and Stock Exchange (“FTSE”) above-median yield curve are applied to each corresponding year’s projected cash flow used to measure the respective plan’s service cost and interest cost. Periodic pension expense (or income) includes service costs, interest costs based on the assumed discount rate, the expected return on plan assets, if applicable, based on the market value of assets and amortization of actuarial gains and losses. Net periodic benefit cost excluding service cost is included within other noninterest expense in the Consolidated Statements of Income. Service cost for all plans is included in salaries and employee benefits in the Consolidated Statements of Income. The amortization of actuarial gains and losses for the DB SERP and ODRCP is determined using the 10% corridor minimum amortization approach and is taken over the average remaining future service of the plan participants for the ODRCP, and over the average remaining future life expectancy of plan participants for the DB SERP. The amortization of actuarial gains and losses for the Defined Benefit Plan and BEP is determined without using the 10% corridor minimum amortization approach and is taken over the average remaining future service of the plan participants. The overfunded or underfunded status of the plans is recorded as an asset or liability on the Consolidated Balance Sheets, with changes in that status recognized through other comprehensive income, net of related taxes. Funded status represents the difference between the projected benefit obligation of the plan and the market value of the plan’s assets. Employee Tax Deferred Incentive Plan The Company has an employee tax deferred incentive plan (“401(k) plan”) under which the Company makes voluntary contributions within certain limitations. All employees who meet specified age and length of service requirements are eligible to participate in the 401(k) plan. The amount contributed by the Company is included in salaries and employee benefits expense. Defined Contribution Supplemental Executive Retirement Plan The Company has a defined contribution supplemental executive retirement plan (“DC SERP”), which allows certain senior officers to earn benefits calculated as a percentage of their compensation. The participant benefits are adjusted based upon a deemed investment performance of measurement funds selected by the participant. These measurement funds are for tracking purposes and are used only to track the performance of a mutual fund, market index, savings instrument, or other designated investment or portfolio of investments. Effective December 31, 2021, the Company closed the DC SERP to new participants and froze benefit accruals for active participants. Deferred Compensation The Company sponsors three plans which allow for elective compensation deferrals by directors, former trustees, and certain senior-level employees. Each plan allows its participants to designate deemed investments for deferred amounts from certain options which include diversified choices, such as exchange traded funds and mutual funds. Portfolios with various risk profiles are available to participants with the approval of the Compensation Committee. The Company purchases and sells investments which track the deemed investment choices, so that it has available funds to meet its payment liabilities. Deferred
Employee Stock Ownership Plan ("ESOP")	Employee Stock Ownership Plan (“ESOP”) Unallocated ESOP shares are shown as a reduction of equity and are presented in the Consolidated Statements of Shareholders’ Equity as unallocated common stock held by ESOP. Compensation expense for the Company’s ESOP is recorded at an amount equal to the shares committed to be allocated by the ESOP multiplied by the average fair market value of the shares during the year. The Company recognizes compensation expense ratably over the year based upon the Company’s estimate of the number of shares committed to be allocated by the ESOP. When the shares are committed to be released, unallocated common stock held by ESOP is reduced by the cost of the ESOP shares released and the difference between the average fair market value and the cost of the shares committed to be allocated by the ESOP is recorded as an adjustment to additional paid-in capital. The Company’s ESOP is classified as an internally leveraged plan as defined by ASC 718, “Compensation-Stock Compensation.” Accordingly, the loan receivable from the ESOP is not reported as an asset nor is the Company’s guarantee to fund the ESOP reported as a liability on the Company’s Consolidated Balance Sheet.
Share-Based Compensation	Share-Based Compensation The Company measures share-based compensation on the grant date fair value on a straight-line basis over the vesting period during which an employee is required to provide services in exchange for the award; the requisite service period. The Company uses various pricing models to estimate the fair value of stock awards granted. The Company measures the fair value of the restricted stock using the closing market price of the Company’s common stock on the date of grant. The Company records compensation expense equal to the grant date fair value of the Company’s restricted stock with a corresponding increase in equity. Reductions in compensation expense associated with forfeited awards are accounted for as incurred. Upon vesting, the tax effect of the difference between the fair value of the award and the recorded expense is recognized as a component of income tax expense. Refer to Note 16, “Share-Based Compensation” for additional information regarding the Company’s share-based compensation plan.
Variable Interest Entities ("VIE") and Voting Interest Entities ("VOE"), Rabbi Trust	Variable Interest Entities (“VIE”) and Voting Interest Entities (“VOE”) The Company is involved in the normal course of business with various types of special purpose entities, some of which meet the definition for VIEs and VOEs. VIEs are entities that possess any of the following characteristics: 1) the total equity investment at risk is insufficient to permit the legal entity to finance its activities without additional subordinated financial support from other parties; 2) as a group, the holders of the equity investment at risk lack any of the characteristics of a controlling financial interest; or 3) the equity investors’ voting rights are not proportional to the economics, and substantially all of the activities of the entity either involve or are conducted on behalf of an investor that has disproportionately few voting rights. The Company consolidates entities deemed to be VIEs when it, or a wholly-owned subsidiary, is determined to be the primary beneficiary. The primary beneficiary analysis is a qualitative analysis based on power and economics. An enterprise has a controlling financial interest in a VIE if it has both 1) the power to direct the activities of a VIE that most significantly impact the VIE’s economic performance and 2) the obligation to absorb losses of the VIE that potentially could be significant to the VIE or the right to receive benefits from the VIE that potentially could be significant to the VIE. VOEs are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holders with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. The Company generally consolidates VOEs when it, or a wholly-owned subsidiary, holds the majority of the voting interest in the VOE. Rabbi Trusts The Company established rabbi trusts to meet its obligations under certain executive non-qualified retirement benefits and deferred compensation plans and to mitigate the expense volatility of the aforementioned retirement plans. The rabbi trusts are considered VIEs as the equity investment at risk is insufficient to permit the trust to finance its activities without additional subordinated financial support from the Company. The Company is considered the primary beneficiary of the rabbi trusts as it has the power to direct the activities of the rabbi trusts that significantly affect the rabbi trust’s economic performance and it has the obligation to absorb losses of the rabbi trusts that could potentially be significant to the rabbi trusts by virtue of its contingent call options on the rabbi trust’s assets in the event of the Company’s bankruptcy. As the primary beneficiary of these VIEs, the Company consolidates the rabbi trust investments. In general, the rabbi trust investments and any earnings received thereon are accumulated, reinvested and used exclusively for trust purposes. These rabbi trust investments consist primarily of cash and cash equivalents, U.S. government agency obligations, equity securities, mutual funds and other exchange-traded funds, and are recorded at fair value in the Company’s Consolidated Balance Sheets. Changes in fair value are recorded in noninterest income in the Consolidated Statements of Income. These rabbi trust assets are included within other assets in the Company’s Consolidated Balance Sheets.
Bank Owned Life Insurance	Bank Owned Life Insurance
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are established for the temporary differences between the accounting basis and the tax basis of the Company’s assets and liabilities at enacted tax rates expected to be in effect when the amounts related to such temporary differences are realized or settled. A valuation allowance is established if it is considered more-likely-than-not that all or a portion of the deferred tax assets will not be realized. Interest and penalties paid on the underpayment of income taxes are classified as income tax expense.
Low Income Housing Tax Credits and Other Tax Credit Investments	Low Income Housing Tax Credits and Other Tax Credit Investments As part of its community reinvestment initiatives, the Company primarily invests in qualified affordable housing projects in addition to other tax credit investment projects. The Company receives low-income housing tax credits, investment tax credits, rehabilitation tax credits, solar tax credits and other tax credits as a result of its investments in these limited partnership investments. The Company accounts for its investments in qualified affordable housing projects using the proportional amortization method and amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits allocated to the Company. The amortization of the excess of the carrying amount of the investment over its estimated residual value is included as a component of income tax expense. At investment inception, the Company records a liability for the committed amount of the investment; this liability is reduced as contributions are made.
Advertising Cost	Advertising Costs All advertising costs are expensed in the period in which they are incurred. Advertising costs were not significant for any period presented.
Trust Operations	Trust Operations The Bank is a full-service trust company that provides a wide range of trust services to customers that includes managing customer investments, safekeeping customer assets, supplying disbursement services, and providing other fiduciary services. Trust assets held in a fiduciary or agency capacity for customers are not included in the accompanying Consolidated Balance Sheets as they are not assets of the Company. The fees charged are variable based on various factors such as the Company’s responsibility, the type of account, and account size. Customers are also charged a base fee which is prorated over a twelve-month period. Fees for additional or special services are generally fixed in nature and are charged as services are rendered. Revenue from administrative and management activities associated with these assets is recognized as performance obligations of underlying agreements are satisfied.
Derivative Financial Instruments	Derivative Financial Instruments Derivative instruments are carried at fair value in the Company’s Consolidated Financial Statements. The accounting for changes in the fair value of a derivative instrument is determined by whether it has been designated and qualifies as part of a hedging relationship, and further, by the type of hedging relationship. At the inception of a hedge, the Company documents certain items, including, but not limited to, the following: the relationship between hedging instruments and hedged items, the Company’s risk management objectives, hedging strategies, and the evaluation of hedge transaction effectiveness. Documentation includes linking all derivatives that are designated as hedges to specific assets or liabilities on the balance sheet or to specific forecasted transactions. The Company’s derivative instruments that are designated and qualify for hedge accounting are classified as cash flow hedges (i.e., hedging the exposure to variability in expected future cash flows associated with a recognized asset or liability, or a forecasted transaction). As such, changes in the fair value of the designated hedging instrument that is included in the assessment of hedge effectiveness are recorded in other comprehensive income and reclassified into net income in the same period or periods during which the hedged forecasted transaction affects net income. Such reclassifications are presented in the same income statement line item as the net income effect of the hedged item. If the hedging instrument is not highly effective at achieving offsetting cash flows attributable to the revised contractually specified interest rate(s), hedge accounting will be discontinued. At that time, accumulated other comprehensive income would be frozen and amortized, as long as the forecasted transactions are still probable of occurring. If a cash flow hedge is terminated, hedge accounting treatment would be retained, and accumulated other comprehensive income would be frozen and amortized, as long as the forecasted transactions are still probable of occurring. The Company’s derivative instruments not designated as hedging instruments are recorded at fair value and changes in fair value are recognized in other noninterest income. Derivative instruments not designated as hedging instruments include interest rate swaps, foreign exchange contracts offered to commercial customers to assist them in meeting their financing and investing objectives for their risk management purposes, and risk participation agreements entered into as financial guarantees of performance on customer-related interest rate swap derivatives. The interest rate and foreign exchange risks associated with customer interest rate swaps and foreign exchange contracts are mitigated by entering into similar derivatives having offsetting terms with correspondent bank counterparties.
Fair Value Measurements	Fair Value Measurements ASC 820 “ Fair Value Measurements and Disclosures ” (“ASC 820”) defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. A fair value measurement assumes that the transaction to sell the asset or transfer the liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market. An orderly transaction is a transaction that assumes exposure to the market for a period prior to the measurement date. Market participants are buyers and sellers in the principal market that are independent, knowledgeable, able and willing to transact. ASC 820 also establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements), and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below: Level 1 – Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 2 – Valuations based on quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3 – Prices or valuations that require unobservable inputs that reflect the Company’s own assumptions that are significant to the fair value measurement.
Leases	Leases The Company leases certain office space and equipment under various non-cancelable operating leases, some of which have renewal options to extend lease terms. At lease inception, the Company evaluates the lease terms to determine if the lease should be classified as an operating lease or a finance lease and recognizes a right of use (“ROU”) asset and corresponding lease liability. The Company makes the decision on whether to renew an option to extend a lease by considering various factors. The Company will recognize an adjustment to its ROU asset and lease liability when lease agreements are amended and executed. The discount rate used in determining the present value of lease payments is based on the Company’s incremental borrowing rate for borrowings with terms similar to each lease at commencement date. The Company has lease agreements with lease and non-lease components, which are generally accounted for as a single lease component. The Company has elected the short-term lease recognition exemption for all leases that qualify.
Common Share Repurchases	Common Share Repurchases Shares repurchased by the Company under the Company’s share repurchase programs have been classified as authorized but unissued shares. The cost of shares repurchased by the Company has been accounted for as a reduction to common stock and additional paid in capital balances. Massachusetts state law calls for repurchased shares to be classified as authorized but unissued shares. U.S. GAAP states that the accounting for share repurchases shall conform to state law where applicable. The Company’s most recent authorized program expired during the third quarter of 2023.
Earnings Per Share	Earnings Per Share Basic earnings per share represents income available to common shareholders divided by the weighted-average number of common shares outstanding during the period. Unallocated ESOP shares are not deemed outstanding for earnings per share calculations. ESOP shares committed to be released are considered to be outstanding for purposes of the earnings per share computation. ESOP shares that have not been legally released, but that relate to employee services rendered during an accounting period (interim or annual) ending before the related debt service payment is made, are considered committed to be released. Diluted earnings per share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued, as well as any adjustment to income that would result from the assumed issuance. Potential common shares that may be issued by the Company relate to outstanding stock awards and are determined using the treasury stock method.
Segment Reporting	Segment Reporting
Recent Accounting Pronouncements	Recent Accounting Pronouncements Relevant standards that were recently issued but not yet adopted as of December 31, 2023: In March 2023, the FASB issued ASU 2023-02, Investments–Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Tax Credit Structures Using the Proportional Amortization Method (“ASU 2023-02”). This update permits reporting entities to elect to account for their tax equity investments, regardless of the tax credit program from which the income tax credits are received, using the proportional amortization method if the following conditions are met: 1. It is probable that the income tax credits allocable to the tax equity investor will be available. 2. The tax equity investor does not have the ability to exercise significant influence over the operating and financial policies of the underlying project. 3. Substantially all of the projected benefits are from income tax credits and other income tax benefits. Projected benefits include income tax credits, other income tax benefits, and other non-income-tax-related benefits. The projected benefits are determined on a discounted basis, using a discount rate that is consistent with the cash flow assumptions used by the tax equity investor in making its decision to invest in the project. 4. The tax equity investor’s projected yield based solely on the cash flows from the income tax credits and other income tax benefits is positive. 5. The tax equity investor is a limited liability investor in the limited liability entity for both legal and tax purposes, and the tax equity investor’s liability is limited to its capital investment. Under existing accounting standards, the proportional amortization method is allowable only for equity investments in low-income-housing tax credit structures. Under the proportional amortization method, an entity amortizes the initial cost of the investment in proportion to the income tax credits and other income tax benefits received and recognizes the net amortization and income tax credits and other income tax benefits in the income statement as a component of income tax expense (benefit). Updates made by ASU 2023-02 allow a reporting entity to make an accounting policy election to apply the proportional amortization method on a tax-credit-program-by-tax-credit-program basis. The Company had previously made an accounting policy election to account for its investments in low-income-housing tax credit investments using the proportional amortization method. This election was made upon the Company’s adoption of ASU 2014-01, Investments–Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Qualified Affordable Housing Projects , which introduced the option to apply proportional amortization to low-income-housing tax credit investments . For public business entities, the amendments in ASU 2023-02 are effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted for all entities in an interim period. The Company adopted this standard on January 1, 2024 using the modified retrospective method. The adoption of this standard did not have a material impact on the Company’s Consolidated Financial Statements. In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements–Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative (“ASU 2023-06”) . The amendments in this update modify the disclosure or presentation requirements for a variety of topics in the codification. Certain amendments represent clarifications to or technical corrections of the current requirements. The following is a summary of the topics included in the update and which pertain to the Company: 1. Statement of cash flows (Topic 230): Requires an accounting policy disclosure in annual periods of where cash flows associated with derivative instruments and their related gains and loses are presented in the statement of cash flows; 2. Accounting changes and error corrections (Topic 250): Requires that when there has been a change in the reporting entity, the entity disclose any material prior-period adjustment and the effect of the adjustment on retained earnings in interim financial statements; 3. Earnings per share (Topic 260): Requires disclosure of the methods used in the diluted earnings-per-share computation for each dilutive security and clarifies that certain disclosures should be made during interim periods, and amends illustrative guidance to illustrate disclosure of the methods used in the diluted earnings per share computation; 4. Commitments (Topic 440): Requires disclosure of assets mortgaged, pledged, or otherwise subject to lien and the obligations collateralized; and 5. Debt (Topic 470): Requires disclosure of amounts and terms of unused lines of credit and unfunded commitments and the weighted-average interest rate on outstanding short-term borrowings. For public business entities, the amendments in ASU 2023-06 are effective on the date which the SEC’s removal of that related disclosure from Regulation S-X or Regulation S-K becomes effective. If by June 30, 2027, the SEC has not removed the applicable requirement from Regulation and S-X or Regulation S-K, the pending content of the related amendment will be removed from the codification and will not become effective for any entity. Early adoption is not permitted and the amendments are required to be applied on a prospective basis. The Company expects the adoption of this standard will not have a material impact on its Consolidated Financial Statements. In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures . The amendments in this update are intended to improve reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The amendments in this update: 1. Require that a public entity disclose, on an annual and interim basis, significant segment expenses that are regularly provided to the CODM and included within each reported measure of segment profit or loss (collectively referred to as the “significant expense principle”). 2. Require that a public entity disclose, on an annual and interim basis, an amount for other segment items by reportable segment and a description of its composition. The other segment items category is the difference between segment revenue less the segment expenses disclosed under the significant expense principle and each reported measure of segment profit or loss. 3. Require that a public entity provide all annual disclosures about a reportable segment’s profit or loss and assets currently required by ASC 280, Segment Reporting in interim periods. 4. Clarify that if the CODM uses more than one measure of a segment’s profit or loss in assessing segment performance and deciding how to allocate resources, a public entity may report one or more of those additional measures of segment profit. However, at least one of the reported segment profit or loss measures (or the single reported measure, if only one is disclosed) should be the measure that is most consistent with the measurement principles used in measuring the corresponding amounts in the public entity’s consolidated financial statements. In other words, in addition to the measure that is most consistent with the measurement principles under U.S. GAAP, a public entity is not precluded from reporting additional measures of a segment’s profit or loss that are used by the CODM in assessing segment performance and deciding how to allocate resources. 5. Require that a public entity disclose the title and position of the CODM and an explanation of how the CODM uses the reported measure(s) of segment profit or loss in assessing segment performance and deciding how to allocate resources. 6. Require that a public entity that has a single reportable segment provide all the disclosures required by the amendments in this update and all existing segment disclosures in Topic 280. For public business entities, the amendments in ASU 2023-07 are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted and adoption is required to be done on a retrospective basis. The Company expects the adoption of this standard will not have a material impact on its Consolidated Financial Statements. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures . The amendments in this update are intended to improve income tax disclosure requirements, primarily through enhanced disclosures related to the existing requirements to disclose a rate reconciliation, income taxes paid and certain other required disclosures. Specifically, the amendments in this update: 1. Require that a public entity disclose, on an annual basis: (1) specific categories in the rate reconciliation and (2) additional information for reconciling items that meet a quantitative threshold. The update requires disclosure of such reconciling items according to requirements indicated in the update. 2. Require that all entities disclose certain disaggregated information regarding income taxes paid. 3. Require that all entities disclose certain disaggregated information regarding income tax expense. 4. Eliminate the requirement to: (1) disclose the nature and estimate of the range of reasonably possible changes in the unrecognized tax benefits balance in the next 12 months or (2) make a statement that an estimate of the range cannot be made. 5. Remove the requirement to disclose the cumulative amount of each type of temporary difference when a deferred tax liability is not recognized because of exceptions to comprehensive recognition of deferred taxes related to subsidiaries and corporate joint ventures. For public business entities, the amendments in ASU 2023-09 are effective for annual periods beginning after December 15, 2024. Adoption should be done on a prospective basis and retrospective application is permitted. Relevant standards that were adopted during the year ended December 31, 2023: In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers (“ASU 2021-08”). This update modifies how an acquiring entity measures contract assets and contract liabilities of an acquiree in a business combination in accordance with Topic 606. The amendments in this update require the acquiring entity in a business combination to account for revenue contracts as if they had originated the contract and assess how the acquiree accounted for the contract under Topic 606. ASU 2021-08 improves comparability of recognition and measurement of revenue contracts with customers both before and after a business combination. For public business entities, the amendments in this update were effective for fiscal years beginning after December 15, 2022. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2023. The amendments in this update should be applied prospectively to business combinations occurring on or after the effective date of the amendments with early adoption permitted. The adoption of this standard on January 1, 2023 did not have a material impact on the Company’s Consolidated Financial Statements. In March 2022, the FASB issued ASU 2022-02, Financial Instruments–Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures (“ASU 2022-02”). The amendments in this update eliminate the accounting guidance on troubled debt restructurings (“TDRs”) for creditors in ASC 310-40 and amends the guidance on vintage disclosures, referenced in ASC 326-20-50, to require disclosure of current-period gross write-offs by year of origination. This update supersedes the existing accounting guidance for TDRs in ASC 310-40 in its entirety and requires entities to evaluate all receivable modifications under existing accounting guidance in ASC 310-20 to determine whether a modification made to a borrower results in a new loan or a continuation of an existing loan. In addition to the elimination of TDR accounting guidance, entities that adopt this update will no longer consider renewals, modifications and extensions that result from reasonably expected TDRs in their calculation of the allowance for credit losses. Further, if an entity employs a discounted cash flow method to calculate the allowance for credit losses, it will be required to use a post-modification-derived effective interest rate as part of its calculation. This update also requires new disclosures for receivables for which there has been a modification in their contractual cash flows resulting from borrowers experiencing financial difficulties. For public business entities, the amendments in this update were effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Entities may elect to apply the updated guidance on TDR recognition and measurement by using a modified retrospective transition method. The amendments on TDR disclosures and vintage disclosures should be adopted prospectively. On January 1, 2023, the Company adopted this standard by using the modified retrospective transition method, except with regard to amendments on TDR and vintage disclosures which were adopted prospectively. Accordingly, the Company recorded a cumulative-effect adjustment to retained earnings as of January 1, 2023. The adoption of this standard did not have a material impact on the Company’s Consolidated Financial Statements.

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2023
Debt Securities [Abstract]
Debt Securities, Available-for-Sale	The amortized cost, gross unrealized gains and losses, ACL and fair value of available for sale securities as of the dates indicated were as follows: As of December 31, 2023 Amortized Unrealized Unrealized Allowance for Credit Losses Fair (In thousands) Debt securities: Government-sponsored residential mortgage-backed securities $ 3,302,165 $ — $ (521,527) $ — $ 2,780,638 Government-sponsored commercial mortgage-backed securities 1,326,029 — (201,653) — 1,124,376 U.S. Agency bonds 236,454 — (20,443) — 216,011 U.S. Treasury securities 99,552 — (4,400) — 95,152 State and municipal bonds and obligations 197,704 172 (6,532) — 191,344 $ 5,161,904 $ 172 $ (754,555) $ — $ 4,407,521 As of December 31, 2022 Amortized Unrealized Unrealized Allowance for Credit Losses Fair (In thousands) Debt securities: Government-sponsored residential mortgage-backed securities $ 4,855,763 $ — $ (743,855) $ — $ 4,111,908 Government-sponsored commercial mortgage-backed securities 1,570,119 — (221,165) — 1,348,954 U.S. Agency bonds 1,100,891 — (148,409) — 952,482 U.S. Treasury securities 99,324 — (6,267) — 93,057 State and municipal bonds and obligations 198,039 9 (14,956) — 183,092 Other debt securities 1,299 — (14) — 1,285 $ 7,825,435 $ 9 $ (1,134,666) $ — $ 6,690,778
Schedule of Realized Gain (Loss)	The following table summarizes gross realized gains and losses from sales of AFS securities for the periods indicated: For the Years Ended December 31, 2023 2022 2021 (In thousands) Gross realized gains from sales of AFS securities $ — $ 1,775 $ 1,166 Gross realized losses from sales of AFS securities (333,170) (4,932) — Net (losses) gains from sales of AFS securities $ (333,170) $ (3,157) $ 1,166
Summary Of Government-Sponsored Residential Mortgage-Backed Securities With Gross Unrealized Losses	Information pertaining to AFS securities with gross unrealized losses as of December 31, 2023 and 2022, for which the Company did not recognize a provision for credit losses under CECL, aggregated by investment category and length of time that individual securities have been in a continuous loss position, is as follows: As of December 31, 2023 Less than 12 Months 12 Months or Longer Total # of Gross Fair Gross Fair Gross Fair (Dollars in thousands) Government-sponsored residential mortgage-backed securities 324 $ — $ — $ 521,527 $ 2,780,638 $ 521,527 $ 2,780,638 Government-sponsored commercial mortgage-backed securities 187 — — 201,653 1,124,376 201,653 1,124,376 U.S. Agency bonds 23 — — 20,443 216,011 20,443 216,011 U.S. Treasury securities 6 36 4,927 4,364 90,225 4,400 95,152 State and municipal bonds and obligations 196 233 22,894 6,299 135,279 6,532 158,173 736 $ 269 $ 27,821 $ 754,286 $ 4,346,529 $ 754,555 $ 4,374,350 As of December 31, 2022 Less than 12 Months 12 Months or Longer Total # of Gross Fair Gross Fair Gross Fair (Dollars in thousands) Government-sponsored residential mortgage-backed securities 322 $ 42,196 $ 435,690 $ 701,659 $ 3,676,218 $ 743,855 $ 4,111,908 Government-sponsored commercial mortgage-backed securities 199 38,944 300,476 182,221 1,048,478 221,165 1,348,954 U.S. Agency bonds 37 645 4,145 147,764 948,337 148,409 952,482 U.S. Treasury securities 5 1,311 48,451 4,956 44,606 6,267 93,057 State and municipal bonds and obligations 237 14,942 179,614 14 225 14,956 179,839 Other debt securities 2 — — 14 1,285 14 1,285 802 $ 98,038 $ 968,376 $ 1,036,628 $ 5,719,149 $ 1,134,666 $ 6,687,525
Debt Securities, Held-to-Maturity	The amortized cost, gross unrealized gains and losses, ACL and fair value of HTM securities as of the dates indicated were as follows: As of December 31, 2023 Amortized Unrealized Unrealized Allowance for Credit Losses Fair (In thousands) Debt securities: Government-sponsored residential mortgage-backed securities $ 254,752 $ — $ (24,433) $ — $ 230,319 Government-sponsored commercial mortgage-backed securities 194,969 — (20,466) — 174,503 $ 449,721 $ — $ (44,899) $ — $ 404,822 As of December 31, 2022 Amortized Unrealized Unrealized Allowance for Credit Losses Fair (In thousands) Debt securities: Government-sponsored residential mortgage-backed securities $ 276,493 $ — $ (30,150) $ — $ 246,343 Government-sponsored commercial mortgage-backed securities 200,154 — (23,271) — 176,883 $ 476,647 $ — $ (53,421) $ — $ 423,226
Summary Of Fair Value Of Available For Sale Securities By Contractual Maturities	The amortized cost and estimated fair value of AFS and HTM securities by scheduled contractual maturities as of dates indicated were as follows: As of December 31, 2023 Due in one year or less Due after one year to five years Due after five to ten years Due after ten years Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value (In thousands) AFS securities Government-sponsored residential mortgage-backed securities $ — $ — $ 29,288 $ 28,188 $ 22,735 $ 21,235 $ 3,250,142 $ 2,731,215 $ 3,302,165 $ 2,780,638 Government-sponsored commercial mortgage-backed securities — — 256,229 234,725 379,749 327,198 690,051 562,453 1,326,029 1,124,376 U.S. Agency bonds — — 236,454 216,011 — — — — 236,454 216,011 U.S. Treasury securities — — 99,552 95,152 — — — — 99,552 95,152 State and municipal bonds and obligations 213 209 30,131 29,393 44,047 43,260 123,313 118,482 197,704 191,344 Total available for sale securities 213 209 651,654 603,469 446,531 391,693 4,063,506 3,412,150 5,161,904 4,407,521 HTM securities Government-sponsored residential mortgage-backed securities — — — — — — 254,752 230,319 254,752 230,319 Government-sponsored commercial mortgage-backed securities — — 80,014 72,952 114,955 101,551 — — 194,969 174,503 Total held to maturity securities — — 80,014 72,952 114,955 101,551 254,752 230,319 449,721 404,822 Total $ 213 $ 209 $ 731,668 $ 676,421 $ 561,486 $ 493,244 $ 4,318,258 $ 3,642,469 $ 5,611,625 $ 4,812,343 As of December 31, 2022 Due in one year or less Due after one year to five years Due after five to ten years Due after ten years Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value (In Thousands) AFS securities Government-sponsored residential mortgage-backed securities $ — $ — $ 21,221 $ 20,284 $ 727,908 $ 648,132 $ 4,106,634 $ 3,443,492 $ 4,855,763 $ 4,111,908 Government-sponsored commercial mortgage-backed securities — — 191,762 171,992 649,659 556,641 728,698 620,321 1,570,119 1,348,954 U.S. Agency bonds — — 877,371 767,464 223,520 185,018 — — 1,100,891 952,482 U.S. Treasury securities — — 99,324 93,057 — — — — 99,324 93,057 State and municipal bonds and obligations 213 209 22,100 21,283 42,554 40,970 133,172 120,630 198,039 183,092 Other debt securities 1,299 1,285 — — — — — — 1,299 1,285 Total available for sale securities 1,512 1,494 1,211,778 1,074,080 1,643,641 1,430,761 4,968,504 4,184,443 7,825,435 6,690,778 HTM securities Government-sponsored residential mortgage-backed securities — — — — — — 276,493 246,343 276,493 246,343 Government-sponsored commercial mortgage-backed securities — — — — 200,154 176,883 — — 200,154 176,883 Total held to maturity securities — — — — 200,154 176,883 276,493 246,343 476,647 423,226 Total $ 1,512 $ 1,494 $ 1,211,778 $ 1,074,080 $ 1,843,795 $ 1,607,644 $ 5,244,997 $ 4,430,786 $ 8,302,082 $ 7,114,004

Loans and Allowance for Credi_2

Loans and Allowance for Credit Losses (Tables)	12 Months Ended
	Dec. 31, 2023
Receivables [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The following table provides a summary of the Company’s loan portfolio as of the dates indicated: As of December 31, 2023 2022 (In thousands) Commercial and industrial $ 3,034,068 $ 3,150,946 Commercial real estate 5,457,349 5,155,323 Commercial construction 386,999 336,276 Business banking 1,085,763 1,090,492 Residential real estate 2,565,485 2,460,849 Consumer home equity 1,208,231 1,187,547 Other consumer (1)(2) 235,533 194,098 Gross loans before unamortized premiums, unearned discounts and deferred fees and costs 13,973,428 13,575,531 Allowance for loan losses (3) (148,993) (142,211) Unamortized premiums, net of unearned discounts and deferred fees, net of costs (25,068) (13,003) Loans after the allowance for loan losses, unamortized premiums, unearned discounts and deferred fees and costs $ 13,799,367 $ 13,420,317 (1) Automobile loans are included in the other consumer portfolio above and amounted to $7.2 million and $18.1 million at December 31, 2023 and 2022, respectively. (2) Home improvement loans are included in the other consumer portfolio and amounted to $178.9 million and $121.1 million at December 31, 2023 and 2022, respectively. (3) The balance of accrued interest receivable excluded from amortized cost and the calculation of the allowance for loan losses amounted to $53.9 million and $45.2 million as of December 31, 2023 and 2022 , respectively, and is included within other assets on the Consolidated Balance Sheets.
Financing Receivable, Allowance for Credit Loss	The following tables summarize the change in the allowance for loan losses by loan category for the periods indicated: For the Year Ended December 31, 2023 Commercial Commercial Commercial Business Residential Consumer Other Total (In thousands) Allowance for loan losses: Beginning balance $ 26,859 $ 54,730 $ 7,085 $ 16,189 $ 28,129 $ 6,454 $ 2,765 $ 142,211 Cumulative effect of change in accounting principle (1) 47 — — (140) (849) (201) — (1,143) Charge-offs (13) (8,008) — (4,645) — (7) (2,419) (15,092) Recoveries 296 198 — 1,867 97 41 466 2,965 Provision (release) (230) 18,555 (419) 1,642 (1,423) (692) 2,619 20,052 Ending balance $ 26,959 $ 65,475 $ 6,666 $ 14,913 $ 25,954 $ 5,595 $ 3,431 $ 148,993 (1) Represents the adjustment needed to reflect the cumulative day one impact pursuant to the Company’s adoption of ASU 2022-02 (i.e., cumulative effect adjustment related to the adoption of ASU 2022-02 as of January 1, 2023). The adjustment represents a $1.1 million decrease to the allowance attributable to the change in accounting methodology for estimating the allowance for loan losses resulting from the Company’s adoption of the standard. For the Year Ended December 31, 2022 Commercial Commercial Commercial Business Residential Consumer Other Other Total (In thousands) Allowance for loan losses: Beginning balance $ 18,018 $ 52,373 $ 2,585 $ 10,983 $ 6,556 $ 3,722 $ 3,308 $ 242 $ 97,787 Cumulative effect of change in accounting principle (1) 11,533 (6,655) 1,485 6,160 13,489 1,857 (541) (242) 27,086 Charge-offs (269) — — (2,292) — (1) (2,269) — (4,831) Recoveries 1,322 91 — 2,069 94 24 644 — 4,244 Provision (release) (3,745) 8,921 3,015 (731) 7,990 852 1,623 — 17,925 Ending balance $ 26,859 $ 54,730 $ 7,085 $ 16,189 $ 28,129 $ 6,454 $ 2,765 $ — $ 142,211 (1) R epresents the adjustment needed to reflect the cumulative day one impact pursuant to the Company’s adoption of ASU 2016-13 (i.e., cumulative effect adjustment related to the adoption of ASU 2016-13 as of January 1, 2022). The adjustment represents a $27.1 million increase to the allowance attributable to the change in accounting methodology for estimating the allowance for loan losses resulting from the Company’s adoption of the standard. The adjustment also includes the adjustment needed to reflect the day one reclassification of the Company’s PCI loan balances to PCD and the associated gross-up of $0.1 million, pursuant to the Company’s adoption of ASU 2016-13. The following table summarizes the change in allowance for loan losses by loan category for the year ended December 31, 2021: For the Year Ended December 31, 2021 Commercial Commercial Commercial Business Residential Consumer Other Other Total (In thousands) Allowance for loan losses: Beginning balance $ 26,617 $ 54,569 $ 4,553 $ 13,152 $ 6,435 $ 3,744 $ 3,467 $ 494 $ 113,031 Charge-offs (1,558) (247) — (5,091) (35) (24) (2,047) — (9,002) Recoveries 935 4 — 1,524 122 185 674 — 3,444 (Release of) Provision (7,976) (1,953) (1,968) 1,398 34 (183) 1,214 (252) (9,686) Ending balance $ 18,018 $ 52,373 $ 2,585 $ 10,983 $ 6,556 $ 3,722 $ 3,308 $ 242 $ 97,787
Financing Receivable Credit Quality Indicators	The following table details the amortized cost balances of the Company’s loan portfolios, presented by credit quality indicator and origination year as of December 31, 2023, and gross charge-offs for the year ended December 31, 2023: 2023 2022 2021 2020 2019 Prior Revolving Loans Revolving Loans Converted to Term Loans (1) Total (In thousands) Commercial and industrial Pass $ 477,138 $ 442,896 $ 350,782 $ 341,243 $ 140,641 $ 641,342 $ 485,448 $ 3,255 $ 2,882,745 Special Mention 4,229 25,796 14,994 13,563 89 553 51,106 455 110,785 Substandard 1,534 11,995 1,775 405 — 2,581 7,803 — 26,093 Doubtful — — — — — 8 — — 8 Loss — — — — — — — — — Total commercial and industrial 482,901 480,687 367,551 355,211 140,730 644,484 544,357 3,710 3,019,631 Current period gross charge-offs — 2 — — — 11 — — 13 Commercial real estate Pass 498,590 1,435,893 855,014 573,370 516,689 1,291,189 47,581 2,556 5,220,882 Special Mention 15,200 7,990 — 736 2,281 34,803 — — 61,010 Substandard 19,738 12,589 15,237 3,938 33,413 48,978 8,006 — 141,899 Doubtful 10,615 — — — — 19,441 — — 30,056 Loss — — — — — — — — — Total commercial real estate 544,143 1,456,472 870,251 578,044 552,383 1,394,411 55,587 2,556 5,453,847 Current period gross charge-offs 2,008 — — — — 6,000 — — 8,008 Commercial construction Pass 133,463 151,957 96,147 — — — 2,614 — 384,181 Special Mention 456 — — — — — — — 456 Substandard — — — — — — — — — Doubtful — — — — — — — — — Loss — — — — — — — — — Total commercial construction 133,919 151,957 96,147 — — — 2,614 — 384,637 Current period gross charge-offs — — — — — — — — — Business banking Pass 139,237 165,247 182,606 146,180 110,638 229,636 73,054 3,996 1,050,594 Special Mention 1,474 2,553 1,009 4,294 4,692 11,479 23 27 25,551 Substandard 1,310 596 2,684 2,071 1,464 3,423 594 579 12,721 Doubtful — — — — 507 220 — — 727 Loss — — — — — — — — — Total business banking 142,021 168,396 186,299 152,545 117,301 244,758 73,671 4,602 1,089,593 Current period gross charge-offs 188 161 1,596 86 654 590 — 1,370 4,645 Residential real estate Current and accruing 257,671 728,997 665,811 354,003 93,817 451,812 — — 2,552,111 30-89 days past due and accruing 750 6,615 2,437 2,112 1,496 8,219 — — 21,629 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual — 1,755 1,433 291 288 4,958 — — 8,725 Total residential real estate 258,421 737,367 669,681 356,406 95,601 464,989 — — 2,582,465 Current period gross charge-offs — — — — — — — — — Consumer home equity Current and accruing 30,393 84,065 9,151 4,899 4,166 80,687 970,882 9,472 1,193,715 30-89 days past due and accruing 148 483 — — — 558 7,509 223 8,921 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual — 66 — — — 1,466 6,770 230 8,532 Total consumer home equity 30,541 84,614 9,151 4,899 4,166 82,711 985,161 9,925 1,211,168 Current period gross charge-offs — — — — — — 7 — 7 Other consumer Current and accruing 93,659 36,601 23,962 12,427 11,367 14,609 13,353 85 206,063 30-89 days past due and accruing 170 271 153 25 12 92 40 — 763 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual 50 61 25 2 14 34 7 — 193 Total other consumer 93,879 36,933 24,140 12,454 11,393 14,735 13,400 85 207,019 Current period gross charge-offs 1,047 411 329 92 111 260 169 — 2,419 Total $ 1,685,825 $ 3,116,426 $ 2,223,220 $ 1,459,559 $ 921,574 $ 2,846,088 $ 1,674,790 $ 20,878 $ 13,948,360 (1) The amounts presented represent the amortized cost as of December 31, 2023 of revolving loans that were converted to term loans during the year ended December 31, 2023. The following table details the amortized cost balances of the Company’s loan portfolios, presented by credit quality indicator and origination year as of December 31, 2022: 2022 2021 2020 2019 2018 Prior Revolving Loans Revolving Loans Converted to Term Loans (1) Total (In thousands) Commercial and industrial Pass $ 778,144 $ 479,317 $ 415,990 $ 199,865 $ 100,716 $ 639,825 $ 473,148 $ 50 $ 3,087,055 Special Mention 2,298 1,307 7,267 4,841 147 — 1,196 670 17,726 Substandard 294 4,954 2,644 46 2,598 7,854 485 346 19,221 Doubtful — 5,249 — — — 23 3,254 — 8,526 Loss — — — — — — — — — Total commercial and industrial 780,736 490,827 425,901 204,752 103,461 647,702 478,083 1,066 3,132,528 Commercial real estate Pass 1,510,675 825,620 586,567 581,840 461,296 1,006,160 52,590 4,187 5,028,935 Special Mention — — 771 4,204 15,366 12,255 — — 32,596 Substandard — — 2,621 19,796 24,532 34,883 8,000 — 89,832 Doubtful — — — — — — — — — Loss — — — — — — — — — Total commercial real estate 1,510,675 825,620 589,959 605,840 501,194 1,053,298 60,590 4,187 5,151,363 Commercial construction Pass 91,397 178,648 28,956 20,767 — — 12,130 — 331,898 Special Mention — — 2,361 — — — — — 2,361 Substandard — — — — — — — — — Doubtful — — — — — — — — — Loss — — — — — — — — — Total commercial construction 91,397 178,648 31,317 20,767 — — 12,130 — 334,259 Business banking Pass 178,806 202,230 170,088 128,282 59,452 233,484 78,080 4,770 1,055,192 Special Mention — 991 4,635 4,605 3,740 7,584 145 — 21,700 Substandard — 3,482 1,424 2,663 570 7,505 2,230 221 18,095 Doubtful — — — 181 — 70 — — 251 Loss — — — — — — — — — Total business banking 178,806 206,703 176,147 135,731 63,762 248,643 80,455 4,991 1,095,238 Residential real estate Current and accruing 761,442 696,959 382,262 99,494 66,702 434,720 — — 2,441,579 30-89 days past due and accruing 4,652 5,470 1,245 2,762 2,951 11,646 — — 28,726 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual — — 144 1,491 1,015 7,100 — — 9,750 Total residential real estate 766,094 702,429 383,651 103,747 70,668 453,466 — — 2,480,055 Consumer home equity Current and accruing 97,395 10,774 5,840 5,015 21,092 73,927 953,829 7,320 1,175,192 30-89 days past due and accruing 559 — — — 72 944 7,239 247 9,061 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual — — — 61 274 1,303 5,120 296 7,054 Total consumer home equity 97,954 10,774 5,840 5,076 21,438 76,174 966,188 7,863 1,191,307 Other consumer Current and accruing 55,414 32,390 17,641 18,298 18,832 16,603 17,476 — 176,654 30-89 days past due and accruing 143 68 43 61 240 178 58 7 798 Loans 90 days or more past due and still accruing — — — — — — — — — Non-accrual 31 93 39 2 92 44 15 10 326 Total other consumer 55,588 32,551 17,723 18,361 19,164 16,825 17,549 17 177,778 Total $ 3,481,250 $ 2,447,552 $ 1,630,538 $ 1,094,274 $ 779,687 $ 2,496,108 $ 1,614,995 $ 18,124 $ 13,562,528 (1) The amounts presented represent the amortized cost as of December 31, 2022 of revolving loans that were converted to term loans during the year ended December 31, 2022.
Financing Receivable, Past Due	The following tables show the age analysis of past due loans as of the dates indicated: As of December 31, 2023 30-59 60-89 90 or More Total Past Current Total (In thousands) Commercial and industrial $ 3,316 $ — $ 465 $ 3,781 $ 3,015,850 $ 3,019,631 Commercial real estate — — — — 5,453,847 5,453,847 Commercial construction — — — — 384,637 384,637 Business banking 3,455 1,647 1,202 6,304 1,083,289 1,089,593 Residential real estate 17,116 4,888 6,764 28,768 2,553,697 2,582,465 Consumer home equity 6,517 2,600 8,204 17,321 1,193,847 1,211,168 Other consumer 532 235 189 956 206,063 207,019 Total $ 30,936 $ 9,370 $ 16,824 $ 57,130 $ 13,891,230 $ 13,948,360 As of December 31, 2022 30-59 60-89 90 or More Total Past Current Total (In thousands) Commercial and industrial $ 1,300 $ 385 $ 2,074 $ 3,759 $ 3,128,769 $ 3,132,528 Commercial real estate — — — — 5,151,363 5,151,363 Commercial construction — — — — 334,259 334,259 Business banking 6,642 845 3,517 11,004 1,084,234 1,095,238 Residential real estate 25,877 3,852 6,456 36,185 2,443,870 2,480,055 Consumer home equity 8,262 1,108 6,525 15,895 1,175,412 1,191,307 Other consumer 634 170 320 1,124 176,654 177,778 Total $ 42,715 $ 6,360 $ 18,892 $ 67,967 $ 13,494,561 $ 13,562,528
Financing Receivable, Nonaccrual	The following table presents information regarding non-accrual loans as of the dates indicated: As of December 31, 2023 As of December 31, 2022 Non-Accrual Loans With ACL Non-Accrual Loans Without ACL (1) Total Non-Accrual Loans Non-Accrual Loans With ACL Non-Accrual Loans Without ACL (1) Total Nonaccrual Loans (In thousands) Commercial and industrial $ 4 $ 464 $ 468 $ 3,270 $ 10,707 $ 13,977 Commercial real estate 13,969 16,087 30,056 — — — Commercial construction — — — — — — Business banking 4,572 11 4,583 5,844 1,653 7,497 Residential real estate 8,725 — 8,725 9,750 — 9,750 Consumer home equity 8,532 — 8,532 7,054 — 7,054 Other consumer 193 — 193 326 — 326 Total non-accrual loans $ 35,995 $ 16,562 $ 52,557 $ 26,244 $ 12,360 $ 38,604 (1) The loans on non-accrual status and without an ACL as of both December 31, 2023 and December 31, 2022, were primarily comprised of collateral dependent loans for which the fair value of the underlying loan collateral exceeded the loan carrying value.
Summary of Loan Modifications to Borrowers Experiencing Financial Difficulty	The following table shows the amortized cost balance as of December 31, 2023 of loans modified during the year ended December 31, 2023 to borrowers experiencing financial difficulty by the type of concession granted: As of December 31, 2023 Amortized Cost Balance % of Total Portfolio (Dollars in thousands) Interest Rate Reduction: Business banking $ 43 0.00 % Residential real estate 301 0.01 % Consumer home equity 1,883 0.16 % Total interest rate reduction $ 2,227 0.02 % Other-than-Insignificant Delay in Repayment: Business banking $ 20 0.00 % Residential real estate 3,284 0.13 % Consumer home equity 1,004 0.08 % Total other-than-insignificant delay in repayment $ 4,308 0.03 % Term Extension: Business banking $ 274 0.03 % Total term extension $ 274 0.00 % Combination—Interest Rate Reduction & Other-than-Insignificant Delay in Repayment: Commercial real estate $ 10,615 0.19 % Business banking 86 0.01 % Consumer home equity 603 0.05 % Total combination—interest rate reduction & other-than-insignificant delay in repayment $ 11,304 0.08 % Combination—Interest Rate Reduction & Term Extension: Business banking $ 561 0.05 % Consumer home equity 213 0.02 % Total combination—interest rate reduction & term extension $ 774 0.01 % Combination—Term Extension & Other-than-Insignificant Delay in Repayment: Business banking $ 24 0.00 % Residential real estate 140 0.01 % Total combination—term extension & other-than-insignificant delay in repayment $ 164 0.00 % Combination—Interest Rate Reduction, Term Extension & Other-than-Insignificant Delay in Repayment Business banking $ 180 0.02 % Residential real estate 81 0.00 % Consumer home equity 51 0.00 % Total combination—interest rate reduction, term extension & other-than-insignificant delay in repayment $ 312 0.00 % Total by portfolio segment Commercial real estate $ 10,615 0.19 % Business banking 1,188 0.11 % Residential real estate 3,806 0.15 % Consumer home equity 3,754 0.31 % Total $ 19,363 0.14 % The following table describes the financial effect of the modifications made during the year ended December 31, 2023 to borrowers experiencing financial difficulty: Loan Type Financial Effect (1) Interest Rate Reduction Commercial real estate Reduced weighted-average contractual interest rate from 7.4% to 3.4%. Business banking Reduced weighted-average contractual interest rate from 9.8% to 7.6%. Residential real estate Reduced weighted-average contractual interest rate from 5.4% to 3.6%. Consumer home equity Reduced weighted-average contractual interest rate from 7.5% to 4.5%. Other-than-Insignificant Delay in Repayment Commercial real estate Interest-only period of 9 months for one borrower. Principal deferred to the end of the loan life. Business banking Deferred a weighted average of 4 payments. For principal and interest deferrals, the loans were re-amortized over an extended payment period resulting in reduced monthly payment amounts for the borrowers. For interest-only deferrals, interest accrued at the time of the modification was added to the end of the loan life. Residential real estate Deferred a weighted average of 7 principal and interest payments which were added to the end of the loan life. Consumer home equity Deferred a weighted average of 8 principal and interest payments which were added to the end of the loan life. Term Extension Business banking Added a weighted-average 4.3 years to the life of loans, which reduced monthly payment amounts for the borrowers. Residential real estate Added a weighted-average 23.7 years to the life of loans, which reduced monthly payment amounts for the borrowers. Consumer home equity Added a weighted-average 16.8 years to the life of loans, which reduced monthly payment amounts for the borrowers. (1) Loans that were modified in more than one manner are included in each modification type corresponding to the type of modifications performed. The following table shows the TDR loans on accrual and non-accrual status as of December 31, 2022 : TDRs on Accrual Status TDRs on Non-accrual Status Total TDRs Number of Loans Balance of Number of Loans Balance of Number of Loans Balance of (Dollars in thousands) Commercial and industrial 2 $ 4,449 9 $ 11,317 11 $ 15,766 Business banking 11 4,124 22 2,101 33 6,225 Residential real estate 114 17,618 28 4,016 142 21,634 Consumer home equity 51 2,632 19 1,917 70 4,549 Other consumer 1 11 — — 1 11 Total 179 $ 28,834 78 $ 19,351 257 $ 48,185 The following tables show the modifications which occurred during the periods indicated and the change in the recorded investment subsequent to the modifications occurring: For the Years Ended December 31, 2022 2021 Number Pre- Post- Number Pre- Post- Commercial and industrial 4 $ 5,415 $ 5,415 — $ — $ — Business banking 30 2,779 2,798 — — — Residential real estate 10 2,842 2,842 2 498 498 Consumer home equity 7 1,535 1,535 3 300 300 Total 51 $ 12,571 $ 12,590 5 $ 798 $ 798 (1) The post-modification balances represent the balance of the loan on the date of modification. These amounts may show an increase when modification includes capitalization of interest. The following table shows the Company’s post-modification balance of TDRs listed by type of modification during the periods indicated: For the Years Ended December 31, 2022 2021 (In thousands) Extended maturity $ 1,011 $ 200 Adjusted interest rate and extended maturity 1,088 — Interest only/principal deferred 1,499 — Covenant modification 2,418 — Court-ordered concession — 396 Principal and interest deferred 3,353 — Extended maturity and interest only/principal deferred 2,997 — Other 224 202 Total $ 12,590 $ 798
Financing Receivable, Modified, Past Due	The following table shows the age analysis of past due loans to borrowers experiencing financial difficulty as of December 31, 2023 that were modified during the 12-month period ended December 31, 2023: As of December 31, 2023 30-59 60-89 90 or More Total Past Current Total (In thousands) Commercial real estate $ — $ — $ — $ — $ 10,615 $ 10,615 Business banking — — — — 1,188 1,188 Residential real estate 366 227 — 593 3,213 3,806 Consumer home equity 51 — 400 451 3,303 3,754 Total $ 417 $ 227 $ 400 $ 1,044 $ 18,319 $ 19,363
Schedule of Participating Mortgage Loans	The following table summarizes the Company’s loan participations: As of and for the Year Ended December 31, 2023 2022 Balance Non-performing Gross Balance Non-performing Gross (Dollars in thousands) Commercial and industrial $ 985,394 0.00 % $ — $ 1,024,131 0.83 % $ — Commercial real estate 447,550 0.00 % — 422,042 0.00 % — Commercial construction 146,043 0.00 % — 96,134 0.00 % — Business banking 72 0.00 % 22 51 0.00 % 3 Total loan participations $ 1,579,059 0.00 % $ 22 $ 1,542,358 0.55 % $ 3
Schedule of Impaired Financing Receivables	The following table displays information regarding interest income recognized on impaired loans, by portfolio, for the year ended December 31, 2021: For the Year Ended December 31, 2021 Average Total (In thousands) With no allowance recorded: Commercial and industrial $ 11,813 $ 161 Commercial real estate 3,916 178 Business banking 4,352 99 Residential real estate 12,506 456 Consumer home equity 2,027 62 Other consumer 23 — Sub-total 34,637 956 With an allowance recorded: Commercial and industrial 7,229 — Commercial real estate 926 — Business banking 13,027 57 Residential real estate 12,322 474 Consumer home equity 2,106 65 Other consumer 63 — Sub-total 35,673 596 Total $ 70,310 $ 1,552
Summary of Activity in the Accretable Yield for the PCI Loan Portfolio	The following table summarizes activity in the accretable yield for the PCI loan portfolio: For the Year Ended December 31, 2021 (In thousands) Balance at beginning of period $ 2,495 Acquisition 8,896 Accretion (1,194) Other change in expected cash flows (1,475) Reclassification from non-accretable difference for loans with improved cash flows 1,649 Balance at end of period $ 10,371

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2023
Property, Plant and Equipment [Abstract]
Schedule of Premises and Equipment	The following table summarizes the Company’s premises and equipment as of the dates indicated: As of December 31, Estimated 2023 2022 Useful Life (In thousands) (In years) Premises and equipment used in operations: Land $ 12,585 $ 12,585 N/A Buildings 70,597 70,771 5-30 Equipment 37,756 35,085 3-5 Leasehold improvements 34,790 36,424 5-25 Total cost 155,728 154,865 Accumulated depreciation (95,595) (92,372) Premises and equipment used in operations, net 60,133 62,493 Premises and equipment held for sale — — Net premises and equipment $ 60,133 $ 62,493

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2023
Leases [Abstract]
Schedule of Operating Lease Balance Sheet Information	As of the dates indicated, the Company had the following related to operating leases: As of December 31, 2023 As of December 31, 2022 (In thousands) Right-of-use assets $ 50,641 $ 48,817 Lease liabilities 55,617 52,105
Summary of Lease Cost	The following table is a summary of the Company’s components of net lease cost for the periods indicated: For the Year Ended December 31, 2023 2022 2021 (In thousands) Operating lease cost $ 12,439 $ 12,716 $ 12,559 Finance lease cost 338 309 160 Variable lease cost 2,766 2,547 2,012 Total lease cost $ 15,543 $ 15,572 $ 14,731 Supplemental balance sheet information related to operating leases as of the dates indicated is as follows: As of December 31, 2023 As of December 31, 2022 Weighted-average remaining lease term (in years) 8.26 7.25 Weighted-average discount rate 3.76 % 2.62 %
Schedule of Future Minimum Lease Payments	The following table sets forth the undiscounted cash flows of base rent related to operating leases outstanding as of December 31, 2023 with payments scheduled over the next five years and thereafter, including a reconciliation to the operating lease liability recognized in other liabilities in the Company’s Consolidated Balance Sheets: As of December 31, 2023 Year (In thousands) 2024 $ 11,506 2025 8,504 2026 7,143 2027 5,609 2028 5,886 Thereafter 27,770 Total minimum lease payments 66,418 Less: amount representing interest 10,801 Present value of future minimum lease payments $ 55,617

Goodwill and Core Deposit Int_2

Goodwill and Core Deposit Intangible Asset (Tables)	12 Months Ended
	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill and Other Intangible Assets	As of December 31, 2023 2022 (In thousands) Balances not subject to amortization Goodwill $ 557,635 $ 557,635 Balances subject to amortization Core deposit intangible 8,570 10,374 Total goodwill and other intangible assets $ 566,205 $ 568,009
Schedule of Goodwill Carrying Value	The changes in the carrying value of goodwill for the periods indicated were as follows: For the Years Ended December 31, 2023 2022 (In thousands) Balance at beginning of year $ 557,635 $ 557,635 Goodwill recorded during the year — — Balance at end of year $ 557,635 $ 557,635
Summary of Carrying Amount and Accumulated Amortization of Other Intangible Assets	The following table sets forth the carrying amount of the Company’s core deposit intangible asset, net of accumulated amortization, as of the dates indicated below: As of December 31, 2023 2022 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net (In thousands) Core deposit intangible $ 11,633 $ (3,063) $ 8,570 $ 15,969 $ (5,595) $ 10,374 Total $ 11,633 $ (3,063) $ 8,570 $ 15,969 $ (5,595) $ 10,374
Schedule of Amortization Expense	The estimated amortization expense for the remaining useful life of the Company’s core deposit intangible asset is as follows: Year (In thousands) 2024 $ 2,017 2025 2,017 2026 2,017 2027 2,017 2028 502 Total amortization expense $ 8,570

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2023
Banking and Thrift, Interest [Abstract]
Summary of the Company’s Deposits	The following table provides a summary of the Company’s deposits as of the dates indicated: As of December 31, 2023 2022 (In thousands) Demand $ 5,162,218 $ 6,240,637 Interest checking accounts 3,737,361 4,568,122 Savings accounts 1,323,126 1,831,123 Money market investment 4,664,475 4,710,095 Certificates of deposit 2,709,037 1,624,382 Total deposits $ 17,596,217 $ 18,974,359
Summary of Certificate of Deposits Maturities	The following table summarizes certificate of deposits by maturity at December 31, 2023: Balance Percentage of Total Year (Dollars in thousands) 2024 $ 2,683,364 99.1 % 2025 15,484 0.6 % 2026 5,630 0.2 % 2027 2,940 0.1 % 2028 1,586 0.1 % Thereafter 33 0.0 % Total certificates of deposit $ 2,709,037 100.0 %

Borrowed Funds (Tables)

Borrowed Funds (Tables)	12 Months Ended
	Dec. 31, 2023
Federal Home Loan Banks [Abstract]
Federal Home Loan Bank, Advances	Borrowed funds were comprised of the following: As of December 31, 2023 2022 (In thousands) Short-term FHLB advances $ 95 $ 691,297 Escrow deposits of borrowers 21,978 22,314 Interest rate swap collateral funds 8,500 14,430 Long-term FHLB advances 17,643 12,787 Total borrowed funds $ 48,216 $ 740,828 Interest expense on borrowed funds was as follows: For the Year Ended December 31, 2023 2022 2021 (In thousands) Federal funds purchased $ — $ 24 $ — Federal Home Loan Bank advances 19,247 8,263 163 Escrow deposits of borrowers 6 3 2 Interest rate swap collateral funds 722 216 — Total interest expense on borrowed funds $ 19,975 $ 8,506 $ 165 A summary of FHLBB advances by maturities were as follows: As of December 31, 2023 2022 Amount Weighted Average Amount Weighted Average (Dollars in thousands) Within one year $ 95 1.50 % $ 691,297 4.36 % Over one year to three years 3,409 0.73 % 2,835 0.86 % Over three years to five years 2,685 1.59 % 2,534 1.89 % Over five years 11,549 1.31 % 7,418 0.94 % Total Federal Home Loan Bank advances (1) $ 17,738 1.25 % $ 704,084 4.30 % (1) The weighted average interest rate of long-term FHLB advances as of December 31, 2023 and December 31, 2022 was 1.24% and 1.11%, respectively.

Earnings Per Share ("EPS") (Tab

Earnings Per Share ("EPS") (Tables)	12 Months Ended
	Dec. 31, 2023
Earnings Per Share [Abstract]
Earnings Per Share, Basic and Diluted	For the Year Ended December 31, 2023 2022 2021 (Dollars in thousands, except per share data) Net income applicable to common shares: Net (loss) income from continuing operations $ (62,689) $ 186,511 $ 145,531 Net income from discontinued operations 294,866 13,248 9,134 Total net income $ 232,177 $ 199,759 $ 154,665 Average number of common shares outstanding 175,814,954 179,529,613 186,713,020 Less: Average unallocated ESOP shares (13,521,934) (14,019,256) (14,520,684) Average number of common shares outstanding used to calculate basic earnings per common share 162,293,020 165,510,357 172,192,336 Common stock equivalents - restricted stock awards and units 110,077 138,214 59,721 Average number of common shares outstanding used to calculate diluted earnings per common share 162,403,097 165,648,571 172,252,057 Basic earnings per share Basic (loss) earnings per share from continuing operations $ (0.39) $ 1.13 $ 0.85 Basic earnings per share from discontinued operations 1.82 0.08 0.05 Basic earnings per share $ 1.43 $ 1.21 $ 0.90 Diluted earnings per share Diluted (loss) earnings per share from continuing operations $ (0.39) $ 1.13 $ 0.85 Diluted earnings per share from discontinued operations 1.82 0.08 0.05 Diluted earnings per share $ 1.43 $ 1.21 $ 0.90

Low Income Housing Tax Credit_2

Low Income Housing Tax Credits and Other Tax Credit Investments (Tables)	12 Months Ended
	Dec. 31, 2023
Investments in Affordable Housing Projects [Abstract]
Summary of the Company's Investments in Low Income Housing Projects Accounted for Using the Proportional Amortization Method	The following table presents the Company’s investments in LIHTC projects using the proportional amortization method as of the dates indicated: As of December 31, 2023 2022 (In thousands) Current recorded investment included in other assets $ 221,190 $ 128,765 Commitments to fund qualified affordable housing projects included in recorded investment noted above 149,207 84,145 The following table presents additional information related to the Company’s investments in LIHTC projects for the periods indicated: For the Year Ended December 31, 2023 2022 2021 (In thousands) Tax credits and other tax benefits recognized $ 11,624 $ 9,146 $ 6,484 Amortization expense included in income tax expense 9,577 7,503 5,753

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Summary of Company's Tax Provision and Applicable Tax Rates	The following table sets forth information regarding the Company’s tax provision and applicable tax rates for the periods indicated: For the Year Ended December 31, 2023 2022 2021 (Dollars in thousands) Combined federal and state income tax provisions $ (63,309) $ 51,719 $ 30,464 Effective income tax rates 50.25 % 21.71 % 17.32 % The provision for income taxes is comprised of the following components: For the Year Ended December 31, 2023 2022 2021 (In thousands) Current tax (benefit) expense: Federal $ (39,710) $ 36,436 $ 23,923 State (5,332) 10,021 12,204 Total current tax (benefit) expense (45,042) 46,457 36,127 Deferred tax (benefit) expense: Federal 1,219 (1,028) (7,984) State (19,486) 6,290 2,321 Total deferred tax (benefit) expense (18,267) 5,262 (5,663) Total income tax (benefit) expense $ (63,309) $ 51,719 $ 30,464
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of the U.S. federal statutory rate to the Company’s effective income tax rate is detailed below: For the Year Ended December 31, 2023 2022 2021 (Dollars in thousands) Income tax (benefit) expense at statutory rate $ (26,458) 21.00 % $ 50,029 21.00 % $ 36,959 21.00 % (Decrease) increase resulting from: State income tax, net of federal tax benefit (1) (19,606) 15.56 % 12,885 5.41 % 11,475 6.53 % Valuation allowance — — % (700) (0.29) % (11,300) (6.42) % Amortization of qualified low-income housing investments 9,577 (7.60) % 7,503 3.15 % 5,753 3.27 % Tax credits (9,183) 7.29 % (7,300) (3.06) % (6,539) (3.72) % Tax-exempt income (14,161) 11.24 % (10,298) (4.32) % (5,665) (3.22) % Other, net (3,478) 2.76 % (400) (0.17) % (219) (0.12) % Actual income tax (benefit) expense $ (63,309) 50.25 % $ 51,719 21.71 % $ 30,464 17.32 % (1) Includes state tax benefit associated with MSSC liquidation of $23.7 million for the year ended December 31, 2023 described above.
Schedule of Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets and deferred tax liabilities are presented below: As of December 31, 2023 2022 (In thousands) Deferred tax assets: Unrealized loss on available for sale securities $ 193,134 $ 254,502 Allowance for loan losses 45,189 43,686 Cash flow hedges 12,302 18,192 Leases 15,664 14,858 Charitable contribution limitation carryover 4,844 12,273 Investment losses 7,339 7,918 Accrued expenses 10,042 5,426 Fixed assets 4,142 4,287 Loan basis difference fair value adjustments 3,455 4,009 Employee benefits — 354 PPP loans fee income — 58 Other 2,061 2,083 Total deferred tax assets 298,172 367,646 Deferred tax liabilities: Amortization of intangibles 9,660 16,439 Lease obligation 14,284 13,933 Partnerships 1,971 2,340 Trading securities 3,405 938 Employee benefits 824 — Other 1,843 2,033 Total deferred tax liabilities 31,987 35,683 Net deferred income tax assets $ 266,185 $ 331,963
Schedule of Unrecognized Tax Benefits Roll Forward	The following table presents a reconciliation of the beginning and ending amount of unrecognized tax benefits for the periods indicated: For the Years Ended December 31, 2023 2022 2021 (In thousands) Beginning $ 5,782 $ 7,923 $ — Additions based on tax positions related to the current year — — — Additions for tax positions of prior years — — 7,923 Reductions related to settlements with taxing authorities — — — Reductions as a result of a lapse of the applicable statute of limitations (2,279) (2,141) — Ending $ 3,503 $ 5,782 $ 7,923

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2023
Equity [Abstract]
Dividends Declared	Information regarding dividends declared and paid is presented in the following table for the periods indicated: Dividends Declared per Share Dividends Declared Dividends Paid (In millions, except per share data) Three Months Ended March 31, 2023 $ 0.10 $ 16.3 $ 16.2 Three Months Ended June 30, 2023 $ 0.10 $ 16.4 $ 16.3 Three Months Ended September 30, 2023 $ 0.10 $ 16.4 $ 16.2 Three Months Ended December 31, 2023 $ 0.11 $ 18.0 $ 18.0 Three Months Ended March 31, 2022 $ 0.10 $ 17.1 $ 16.9 Three Months Ended June 30, 2022 $ 0.10 $ 16.7 $ 16.5 Three Months Ended September 30, 2022 $ 0.10 $ 16.5 $ 16.3 Three Months Ended December 31, 2022 $ 0.10 $ 16.3 $ 16.1

Minimum Regulatory Capital Re_2

Minimum Regulatory Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2023
Banking and Thrift, Interest [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	The Company’s actual capital amounts and ratios are presented in the following table as of the dates indicated: Actual For Capital Adequacy To Be Well- Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) As of December 31, 2023 Total regulatory capital (to risk-weighted assets) $ 3,187,130 19.55 % $ 1,304,508 ≥8 % $ 1,630,634 ≥10 % Common equity Tier 1 capital (to risk-weighted assets) 3,024,288 18.55 733,785 ≥4.5 1,059,912 ≥6.5 Tier 1 capital (to risk-weighted assets) 3,024,288 18.55 978,381 ≥6 1,304,508 ≥8 Tier 1 capital (to average assets) leverage 3,024,288 14.00 864,206 ≥4 1,080,258 ≥5 As of December 31, 2022 Total regulatory capital (to risk-weighted assets) $ 2,906,742 17.89 % $ 1,299,657 ≥8 % $ 1,624,571 ≥10 % Common equity Tier 1 capital (to risk-weighted assets) 2,751,694 16.94 731,057 ≥4.5 1,055,971 ≥6.5 Tier 1 capital (to risk-weighted assets) 2,751,694 16.94 974,743 ≥6 1,299,657 ≥8 Tier 1 capital (to average assets) leverage 2,751,694 12.03 915,233 ≥4 1,144,041 ≥5

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2023
Retirement Benefits [Abstract]
Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets	The funded status and amounts recognized in the Company’s Consolidated Financial Statements for the Defined Benefit Plan, the BEP, the DB SERP, and the ODRCP are set forth in the following table: As of and for the Year Ended December 31, 2023 2022 2021 (In thousands) Change in benefit obligation: Benefit obligation at beginning of the year $ 362,530 $ 501,507 $ 361,147 Service cost (1) 24,474 31,382 31,660 Interest cost 17,559 10,582 5,694 Amendments 1,351 — (1,106) Actuarial loss (gain) 13,943 (133,282) (1,697) Acquisitions — — 125,854 Benefits paid (20,493) (47,659) (20,045) Benefit obligation at end of the year $ 399,364 $ 362,530 $ 501,507 Change in plan assets: Fair value of plan assets at beginning of year $ 419,366 $ 546,056 $ 449,643 Actual return on plan assets 63,811 (91,474) 50,879 Acquisitions — — 63,468 Employer contribution 5,680 12,443 2,111 Benefits paid (20,493) (47,659) (20,045) Fair value of plan assets at end of year 468,364 419,366 546,056 Overfunded status $ 69,000 $ 56,836 $ 44,549 Reconciliation of funding status: Past service credit $ 80,090 $ 108,909 $ 120,792 Unrecognized net loss (69,697) (99,002) (128,402) Prepaid benefit cost 58,607 46,929 52,159 Overfunded status $ 69,000 $ 56,836 $ 44,549 Accumulated benefit obligation $ 399,364 $ 362,530 $ 501,507 Amounts recognized in accumulated other comprehensive income (“AOCI”), net of tax: Unrecognized past service credit $ 57,501 $ 78,295 $ 86,837 Unrecognized net loss (50,039) (71,172) (92,308) Net amount $ 7,462 $ 7,123 $ (5,471) (1) Includes service costs related to employees of our insurance agency business. Refer to the later discussion within the “Components of Net Periodic Benefit Cost” section within this Note for further discussion.
Defined Benefit Plan, Assumptions	The assumptions used in determining the benefit obligations at December 31, 2023 and 2022 were as follows: DB Plan BEP DB SERP ODRCP As of December 31, As of December 31, As of December 31, As of December 31, 2023 2022 2023 2022 2023 2022 2023 2022 Discount rate 4.99 % 5.18 % 4.89 % 5.07 % 4.96 % 5.18 % 4.91 % 5.13 % Rate of increase in compensation levels 4.50 % 4.50 % 4.50 % 4.50 % — % — % — % — % Interest rate credit for determining projected cash balance 4.47 % 3.55 % 4.47 % 3.55 % — % — % — % — %
Schedule of Net Benefit Costs	The assumptions used in determining the net periodic benefit cost for the years ended December 31, 2023, 2022, and 2021 were as follows: DB Plan For the Year Ended December 31, 2023 2022 2021 Discount rate - benefit cost 5.18 % 2.65 % 2.26 % Rate of compensation increase 4.50 % 4.50 % 5.25 % Expected rate of return on plan assets 7.50 % 7.00 % 7.50 % Interest rate credit for determining projected cash balance 3.55 % 3.50 % 3.50 % BEP For the Year Ended December 31, 2023 2022 2021 Discount rate - benefit cost 5.07 % 2.32 % 1.77 % Rate of compensation increase 4.50 % 4.50 % 5.25 % Interest rate credit for determining projected cash balance 3.55 % 3.50 % 3.50 % DB SERP For the Year Ended December 31, 2023 2022 2021 Discount rate - benefit cost 5.18 % 2.68 % 1.63 % ODRCP For the Year Ended December 31, 2023 2022 2021 Discount rate - benefit cost 5.13 % 2.32 % 1.81 %
Reconciliation of Interest in SBERA Common Collective	The table below presents a reconciliation of the Company’s interest in the SBERA common collective trust during the years indicated: For the Year Ended December 31, 2023 2022 (In thousands) Balance at beginning of year $ 419,366 $ 546,056 Net realized and unrealized gains and (losses) 63,811 (91,474) Contributions — 7,222 Benefits paid (14,813) (42,438) Balance at end of year $ 468,364 $ 419,366
Summary of Components of Net Pension Expense	The components of net pension expense for the plans for the periods indicated are as follows: For the Year Ended December 31, 2023 2022 2021 (In thousands) Components of net periodic benefit cost: Service cost (1) $ 24,474 $ 31,382 $ 31,660 Interest cost 17,559 10,582 5,694 Expected return on plan assets (30,127) (35,486) (33,333) Past service credit (11,560) (11,882) (11,796) Recognized net actuarial loss 9,563 11,032 13,400 Curtailment (2) (15,908) — — Settlement — 12,045 — Net periodic benefit cost $ (5,999) $ 17,673 $ 5,625 (1) Includes service costs related to employees of our insurance agency business. Such service costs were included in net income from discontinued operations as such costs are no longer incurred by the Company following the sale of the insurance agency business in October 2023. All other costs included in the determination of the benefit obligation for the Defined Benefit Plan and the BEP were included in net income from continuing operations as the Bank will assume the related liability upon dissolution of its Eastern Insurance Group subsidiary. Service costs included in net income from discontinued operations and included in the above table were $5.1 million, $7.5 million, and $7.7 million for the years ended December 31, 2023, 2022, and 2021, respectively. (2) The pension curtailment gain recognized during the year ended December 31, 2023 is included in discounted operations. Refer to the below discussion under “Pension Curtailment and Settlement” for further discussion.
Schedule of Expected Benefit Payments	The following table summarizes estimated benefits to be paid from the Defined Benefit Plan and BEP for the plan years beginning on November 1, and the DB SERP and ODRCP for the plan years beginning January 1: Year (In thousands) 2024 $ 46,490 2025 32,612 2026 33,261 2027 35,240 2028 37,175 In aggregate for 2029-2033 186,883
Schedule of Assets Held in Rabbi Trust	Assets held in rabbi trust accounts by plan type, at fair value, were as follows: As of December 31, 2023 2022 (In thousands) DB SERP $ 16,349 $ 17,209 BEP 18,656 11,734 ODRCP 2,819 3,670 DC SERP 20,785 17,764 Deferred compensation plans 28,826 25,909 Total rabbi trust assets $ 87,435 $ 76,286 The following tables present the book value, net unrealized gain or loss, and market value of assets held in rabbi trust accounts by asset type: As of December 31, 2023 As of December 31, 2022 Book Value Unrealized Fair Value Book Value Unrealized Fair Value Asset Type (In thousands) Cash and cash equivalents $ 12,269 $ — $ 12,269 $ 5,575 $ — $ 5,575 Equities (1) 56,140 12,869 69,009 60,056 3,626 63,682 Fixed income 6,676 (519) 6,157 7,799 (770) 7,029 Total assets $ 75,085 $ 12,350 $ 87,435 $ 73,430 $ 2,856 $ 76,286 (1) Equities include mutual funds and other exchange-traded funds.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]
Employee Stock Ownership Plan (ESOP) Disclosures	The following table presents the amount of compensation expense associated with the ESOP and the amount of the loan payments made by the ESOP, including the portions related to principal and interest, for the periods indicated: Year Ended December 31, 2023 2022 2021 (In thousands) Compensation expense $ 7,129 $ 9,923 $ 9,408 Annual loan payment: Interest 9,374 4,724 4,826 Principal 2,914 3,147 3,045 Total loan payment $ 12,288 $ 7,871 $ 7,871 The following table presents share information held by the ESOP: As of December 31, 2023 2022 (Dollars in thousands) Allocated shares 1,541,971 1,046,850 Shares committed to be released 103,230 104,464 Unallocated shares (suspense shares) 13,270,932 13,769,628 Total shares 14,916,133 14,920,942 Fair value of unallocated shares $ 188,447 $ 237,526
Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity	The following table summarizes the Company’s restricted stock award activity for the periods indicated: For the Years Ended December 31, 2023 2022 Restricted Stock Awards Number of Shares Weighted-Average Grant Price Per Share Number of Shares Weighted-Average Grant Price Per Share Non-vested restricted stock at beginning of year 525,460 $ 20.08 683,056 $ 20.13 Granted 47,820 11.50 31,559 19.17 Vested (152,880) 19.95 (136,609) 20.13 Forfeited — — (52,546) 20.08 Non-vested restricted stock at end of year 420,400 $ 19.15 525,460 $ 20.08 During the year ended December 31, 2021, 683,056 RSA shares were granted which had a total grant date fair value of $13.7 million. During the year ended December 31, 2023, 152,880 RSA awards vested. Such awards had a grant date fair value of $3.0 million. During the year ended December 31, 2022, 136,609 RSA awards had vested. Such awards had a grant date fair value of $2.7 million. The following table summarizes the Company’s restricted stock unit activity for the periods indicated: For the Years Ended December 31, 2023 2022 Restricted Stock Units Number of Shares Weighted-Average Grant Price Per Share Number of Shares Weighted-Average Grant Price Per Share Non-vested restricted stock at beginning of year 972,325 $ 21.08 — $ — Granted 318,577 15.63 978,364 21.08 Vested (1) (302,908) 21.08 — — Forfeited (35,993) 15.73 (6,039) 21.08 Non-vested restricted stock at end of year 952,001 $ 19.46 972,325 $ 21.08 (1) Includes 95,808 shares withheld upon settlement for employee taxes. During the year ended December 31, 2023, 302,908 RSU awards vested. Such awards had a grant date fair value of $6.4 million. As of December 31, 2022, no RSU awards had vested. During the year ended year ended December 31, 2021, no RSU awards were granted. The following table summarizes the Company’s performance stock unit activity for the periods indicated: For the Years Ended December 31, 2023 2022 Performance Stock Units Number of Shares Weighted-Average Grant Price Per Share Number of Shares Weighted-Average Grant Price Per Share Non-vested restricted stock at beginning of year 533,676 $ 21.12 — $ — Granted 108,984 10.16 533,676 21.12 Forfeited (9,626) 10.16 — — Non-vested restricted stock at end of year 633,034 $ 19.40 533,676 $ 21.12
Share-based Compensation Expense Under the 2021 Plan and the Related Tax Benefit	The following table shows share-based compensation expense under the 2021 Plan and the related tax benefit for the periods indicated: For the Years Ended December 31, 2023 2022 2021 (In millions) Share-based compensation expense $ 16.5 $ 10.5 $ 0.2 Related tax benefit (1) 4.7 3.0 0.1 (1) Estimated based upon the Company’s statutory rate for the respective period.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Summary of Financial Instruments as of the Dates Indicated	As of December 31, 2023 2022 (In Thousands) Commitments to extend credit $ 6,027,356 $ 5,680,438 Standby letters of credit 58,632 65,154 Forward commitments to sell loans 9,198 10,008

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2023
Summary of Derivative Instruments [Abstract]
Schedule of Interest Rate Derivatives	The following tables reflect the Company’s derivative positions for interest rate swaps which qualify as cash flow hedges for accounting purposes as of the dates indicated: As of December 31, 2023 Weighted Average Rate Notional Weighted Average Current Receive Fixed Fair Value (1) (In thousands) (In Years) (In thousands) Interest rate swaps on loans $ 2,400,000 3.57 5.35 % 3.02 % $ (883) Total $ 2,400,000 $ (883) (1) The fair value included a net accrued interest payable balance of $2.6 million as of December 31, 2023. In addition, the fair value includes netting adjustments which represent the amounts recorded to convert derivative assets and liabilities cleared through the CME from a gross basis to a net basis in accordance with applicable accounting guidance. As of December 31, 2022 Weighted Average Rate Notional Weighted Average Current Receive Fixed Fair Value (1) (In thousands) (In Years) (In thousands) Interest rate swaps on loans $ 2,400,000 4.57 4.07 % 3.02 % $ (2,401) Total $ 2,400,000 $ (2,401) (1) The fair value included a net accrued interest payable balance of $1.5 million as of December 31, 2022. In addition, the fair value includes netting adjustments which represent the amounts recorded to convert derivative assets and liabilities cleared through the CME from a gross basis to a net basis in accordance with applicable accounting guidance.
Summary of Pre-tax Impact of Terminated Cash Flow Hedged on AOCI	The following table presents the pre-tax impact of terminated cash flow hedges on AOCI for the periods indicated: Year Ended December 31, 2023 2022 2021 (In thousands) Unrealized gains on terminated hedges included in AOCI — January 1 $ 46 $ 10,239 $ 41,473 Unrealized gains on terminated hedges arising during the period — — — Reclassification adjustments for amortization of unrealized (gains) into net interest income (46) (10,193) (31,234) Unrealized gains on terminated hedges included in AOCI — December 31 $ — $ 46 $ 10,239
Derivatives Not Designated as Hedging Instruments	The following tables present the Company’s customer-related derivative positions as of the dates indicated below for those derivatives not designated as hedging: As of December 31, 2023 Number of Positions Total Notional (Dollars in thousands) Interest rate swaps 356 $ 2,405,835 Risk participation agreements 78 323,957 Foreign exchange contracts: Matched commercial customer book 98 87,601 Foreign currency loan 10 10,242 As of December 31, 2022 Number of Positions Total Notional (Dollars in thousands) Interest rate swaps 382 $ 2,404,003 Risk participation agreements 63 241,029 Foreign exchange contracts: Matched commercial customer book 32 7,877 Foreign currency loan 5 13,948
Schedule of Derivative Financial Instruments	The table below presents the fair value of the Company’s derivative financial instruments, as well as their classification on the Consolidated Balance Sheets for the periods indicated: Asset Derivatives Liability Derivatives Balance Sheet Fair Value at December 31, Fair Value at December 31, Balance Sheet Fair Value at December 31, Fair Value at December 31, (In thousands) Derivatives designated as hedging instruments Interest rate swaps Other assets $ 10 $ 16 Other liabilities $ 893 $ 2,417 Derivatives not designated as hedging instruments Customer-related positions: Interest rate swaps Other assets $ 19,535 $ 23,567 Other liabilities $ 61,217 $ 78,577 Risk participation agreements Other assets 151 78 Other liabilities 106 130 Foreign currency exchange contracts — matched customer book Other assets 760 198 Other liabilities 672 205 Foreign currency exchange contracts — foreign currency loan Other assets — 2 Other liabilities 187 93 $ 20,446 $ 23,845 $ 62,182 $ 79,005 Total $ 20,456 $ 23,861 $ 63,075 $ 81,422
Schedule of Derivative Financial Instruments On The Consolidated Income Statements	The table below presents the net effect of the Company’s derivative financial instruments on the Consolidated Statements of Income as well as the effect of the Company’s derivative financial instruments included in other comprehensive income (“OCI”) as follows: For the Year Ended December 31, 2023 2022 2021 (In thousands) Derivatives designated as hedges: Loss in OCI on derivatives $ (24,855) $ (69,010) $ — (Loss) gain reclassified from OCI into interest income (effective portion) $ (48,795) $ 9,580 $ 31,234 Gain recognized in income on derivatives (ineffective portion and amount excluded from effectiveness test) Interest income $ — $ — $ — Other income — — — Total $ — $ — $ — Derivatives not designated as hedges: Customer-related positions: (Loss) gain recognized in interest rate swap income $ (274) $ 4,324 $ 4,962 Gain recognized in interest rate swap income for risk participation agreements 97 213 243 Gain (loss) recognized in other income for foreign currency exchange contracts: Matched commercial customer book 95 (22) 1 Foreign currency loan (96) (4) (27) Total (loss) gain for derivatives not designated as hedges $ (178) $ 4,511 $ 5,179

Balance Sheet Offsetting (Table

Balance Sheet Offsetting (Tables)	12 Months Ended
	Dec. 31, 2023
Offsetting [Abstract]
Disclosure Detail Of Balance Sheet Offsetting Of Financial Assets And Liabilities	The following tables present the Company’s asset and liability positions that were eligible for offset and the potential effect of netting arrangements on its financial position, as of the dates indicated: As of December 31, 2023 Gross Gross Net Gross Amounts Not Offset Net Financial Collateral (In thousands) Derivative Assets Interest rate swaps designated as cash flow hedges $ 10 $ — $ 10 $ — $ — $ 10 Customer-related positions: Interest rate swaps 19,535 — 19,535 4,871 (8,500) 6,164 Risk participation agreements 151 — 151 — — 151 Foreign currency exchange contracts – matched customer book 760 — 760 — — 760 $ 20,456 $ — $ 20,456 $ 4,871 $ (8,500) $ 7,085 Derivative Liabilities Interest rate swaps designated as cash flow hedges $ 893 $ — $ 893 $ — $ 893 $ — Customer-related positions: Interest rate swaps 61,217 — 61,217 4,871 1,860 54,486 Risk participation agreements 106 — 106 — — 106 Foreign currency exchange contracts – matched customer book 672 — 672 — — 672 Foreign currency exchange contracts – foreign currency loan 187 — 187 — — 187 $ 63,075 $ — $ 63,075 $ 4,871 $ 2,753 $ 55,451 As of December 31, 2022 Gross Gross Net Gross Amounts Not Offset Net Financial Collateral (In thousands) Derivative Assets Interest rate swaps designated as cash flow hedges $ 16 $ — $ 16 $ — $ — $ 16 Customer-related positions: Interest rate swaps 23,567 — 23,567 381 (14,430) 8,756 Risk participation agreements 78 — 78 — — 78 Foreign currency exchange contracts – matched customer book 198 — 198 — — 198 Foreign currency exchange contracts – foreign currency loan 2 — 2 — — 2 $ 23,861 $ — $ 23,861 $ 381 $ (14,430) $ 9,050 Derivative Liabilities Interest rate swaps designated as cash flow hedges $ 2,417 $ — $ 2,417 $ — $ 2,417 $ — Customer-related positions: Interest rate swaps 78,577 — 78,577 381 — 78,196 Risk participation agreements 130 — 130 — — 130 Foreign currency exchange contracts – matched customer book 205 — 205 — — 205 Foreign currency exchange contracts – foreign currency loan 93 — 93 — — 93 $ 81,422 $ — $ 81,422 $ 381 $ 2,417 $ 78,624

Fair Value of Assets and Liab_2

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Summary Of The Balances Of Assets And Liabilities Measured At Fair Value On A Recurring Basis	The following tables present the balances of assets and liabilities measured at fair value on a recurring basis as of December 31, 2023 and 2022: Fair Value Measurements at Reporting Date Using Balance as of December 31, 2023 Quoted Prices in Significant Significant Description (In thousands) Assets Securities available for sale Government-sponsored residential mortgage-backed securities $ 2,780,638 $ — $ 2,780,638 $ — Government-sponsored commercial mortgage-backed securities 1,124,376 — 1,124,376 — U.S. Agency bonds 216,011 — 216,011 — U.S. Treasury securities 95,152 95,152 — — State and municipal bonds and obligations 191,344 — 191,344 — Rabbi trust investments 87,435 81,278 6,157 — Loans held for sale 1,124 — 1,124 — Interest rate swap contracts Cash flow hedges - interest rate positions 10 — 10 — Customer-related positions 19,535 — 19,535 — Risk participation agreements 151 — 151 — Foreign currency forward contracts Matched customer book 760 — 760 — Mortgage derivatives 69 — 69 — Total $ 4,516,605 $ 176,430 $ 4,340,175 $ — Liabilities Interest rate swap contracts Cash flow hedges - interest rate positions $ 893 $ — $ 893 $ — Customer-related positions 61,217 — 61,217 — Risk participation agreements 106 — 106 — Foreign currency forward contracts Matched customer book 672 — 672 — Foreign currency loan 187 — 187 — Mortgage derivatives 36 — 36 — Total $ 63,111 $ — $ 63,111 $ — Fair Value Measurements at Reporting Date Using Description Balance as of December 31, 2022 Quoted Prices in Significant Significant (In thousands) Assets Securities available for sale Government-sponsored residential mortgage-backed securities $ 4,111,908 $ — $ 4,111,908 $ — Government-sponsored commercial mortgage-backed securities 1,348,954 — 1,348,954 — U.S. Agency bonds 952,482 — 952,482 — U.S. Treasury securities 93,057 93,057 — — State and municipal bonds and obligations 183,092 — 183,092 — Other debt securities 1,285 — 1,285 Rabbi trust investments 76,286 69,257 7,029 — Loans held for sale 4,543 — 4,543 — Interest rate swap contracts Cash flow hedges - interest rate positions 16 — 16 — Customer-related positions 23,567 — 23,567 — Risk participation agreements 78 — 78 — Foreign currency forward contracts Matched customer book 198 — 198 — Foreign currency loan 2 — 2 — Mortgage derivatives 62 — 62 — Total $ 6,795,530 $ 162,314 $ 6,633,216 $ — Liabilities Interest rate swap contracts Cash flow hedges - interest rate positions $ 2,417 $ — $ 2,417 $ — Customer-related positions 78,577 — 78,577 — Risk participation agreements 130 — 130 — Foreign currency forward contracts Matched customer book 205 — 205 — Foreign currency loan 93 — 93 — Mortgage derivatives 58 — 58 — Total $ 81,480 $ — $ 81,480 $ —
Summary Of The Fair Value Of Assets And Liabilities Measured At Fair Value On A Nonrecurring Basis	The following tables summarize the fair value of assets and liabilities measured at fair value on a nonrecurring basis, as of December 31, 2023 and 2022. Fair Value Measurements at Reporting Date Using Description Balance as of December 31, 2023 Quoted Prices Significant Significant (In thousands) Assets Individually assessed collateral-dependent loans whose fair value is based upon appraisals $ 27,874 $ — $ — $ 27,874 Fair Value Measurements at Reporting Date Using Description Balance as of December 31, 2022 Quoted Prices Significant Significant (In thousands) Assets Individually assessed collateral-dependent loans whose fair value is based upon appraisals $ 16,432 $ — $ — $ 16,432
Schedule of Fair Value of Financial Instruments	The estimated fair values and related carrying amounts for assets and liabilities for which fair value is only disclosed are shown below as of the dates indicated: Fair Value Measurements at Reporting Date Using Carrying Value as of December 31, 2023 Fair Value as of December 31, 2023 Quoted Prices Significant Significant (In thousands) Assets Held to maturity securities: Government-sponsored residential mortgage-backed securities $ 254,752 $ 230,319 $ — $ 230,319 $ — Government-sponsored commercial mortgage-backed securities 194,969 174,503 — 174,503 — Loans, net of allowance for loan losses 13,799,367 13,145,455 — — 13,145,455 FHLB stock 5,904 5,904 — 5,904 — Bank-owned life insurance 164,702 164,702 — 164,702 — Liabilities Deposits $ 17,596,217 $ 17,593,214 $ — $ 17,593,214 $ — FHLB advances 17,738 15,366 — 15,366 — Escrow deposits of borrowers 21,978 21,978 — 21,978 — Interest rate swap collateral funds 8,500 8,500 — 8,500 — Fair Value Measurements at Reporting Date Using Carrying Value as of December 31, 2022 Fair Value as of December 31, 2022 Quoted Prices Significant Significant (In thousands) Assets Held to maturity securities: Government-sponsored residential mortgage-backed securities $ 276,493 $ 246,343 $ — $ 246,343 $ — Government-sponsored commercial mortgage-backed securities 200,154 176,883 — 176,883 — Loans, net of allowance for loan losses 13,420,317 13,149,096 — — 13,149,096 FHLB stock 41,363 41,363 — 41,363 — Bank-owned life insurance 160,790 160,790 — 160,790 — Liabilities Deposits $ 18,974,359 $ 18,960,407 $ — $ 18,960,407 $ — FHLB advances 704,084 702,954 — 702,954 — Escrow deposits of borrowers 22,314 22,314 — 22,314 — Interest rate swap collateral funds 14,430 14,430 — 14,430 —

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2023
Revenue from Contract with Customer [Abstract]
Revenue from External Customers by Products and Services	A portion of the Company's noninterest (loss)/income is derived from contracts with customers within the scope of ASC 606. The Company has disaggregated such revenues by type of service, as presented in the table below. These categories reflect how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. For the Year Ended December 31, 2023 2022 2021 (In thousands) Service charges on deposit accounts $ 28,631 $ 30,392 $ 24,271 Trust and investment advisory fees 24,264 23,593 24,588 Debit card processing fees 13,469 12,644 12,118 Other non-interest income 10,502 10,670 8,446 Total noninterest income in-scope of ASC 606 76,866 77,299 69,423 Total noninterest (loss) income out-of-scope of ASC 606 (314,619) (549) 28,014 Total noninterest (loss) income $ (237,753) $ 76,750 $ 97,437

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2023
Statement of Other Comprehensive Income [Abstract]
Comprehensive Income (Loss)	The following tables present a reconciliation of the changes in the components of other comprehensive income (loss) for the dates indicated including the amount of income tax benefit (expense) allocated to each component of other comprehensive income (loss): For the Year Ended December 31, 2023 Pre Tax Tax (Expense) Benefit After Tax (In thousands) Unrealized losses on securities available for sale: Change in fair value of securities available for sale $ 47,104 $ (9,731) $ 37,373 Less: reclassification adjustment for losses included in net income (333,170) 74,630 (258,540) Net change in fair value of securities available for sale 380,274 (84,361) 295,913 Unrealized losses on cash flow hedges: Change in fair value of cash flow hedges (1) (24,855) 8,165 (16,690) Less: net cash flow hedge losses reclassified into interest income (1) (48,795) 13,517 (35,278) Net change in fair value of cash flow hedges 23,940 (5,352) 18,588 Defined benefit pension plans: Change in actuarial net loss 19,742 (5,547) 14,195 BEP and Defined Benefit Plan amendments - accelerated vesting (1,351) 381 (970) Less: amortization of actuarial net loss (9,563) 2,693 (6,870) Less: BEP and Defined Benefit Plan curtailment gain 15,908 (4,490) 11,418 Less: net accretion of prior service credit 11,560 (3,222) 8,338 Net change in other comprehensive income for defined benefit pension plans 486 (147) 339 Total other comprehensive income $ 404,700 $ (89,860) $ 314,840 For the Year Ended December 31, 2022 Pre Tax Tax Benefit (Expense) After Tax (In thousands) Unrealized losses on securities available for sale: Change in fair value of securities available for sale $ (1,061,859) $ 238,005 $ (823,854) Less: reclassification adjustment for losses included in net income (3,157) 873 (2,284) Net change in fair value of securities available for sale (1,058,702) 237,132 (821,570) Unrealized losses on cash flow hedges: Change in fair value of cash flow hedges (1) (69,010) 18,377 (50,633) Less: net cash flow hedge gains reclassified into interest income (1) 9,580 (2,693) 6,887 Net change in fair value of cash flow hedges (78,590) 21,070 (57,520) Defined benefit pension plans: Change in actuarial net gain 6,323 (1,777) 4,546 Less: amortization of actuarial net loss (11,032) 3,101 (7,931) Less: Defined Benefit Plan settlement loss (12,045) 3,386 (8,659) Less: net accretion of prior service credit 11,882 (3,340) 8,542 Net change in other comprehensive income for defined benefit pension plans 17,518 (4,924) 12,594 Total other comprehensive loss $ (1,119,774) $ 253,278 $ (866,496) For the Year Ended December 31, 2021 Pre Tax Tax Benefit (Expense) After Tax (Dollars in thousands) Unrealized losses on securities available for sale: Change in fair value of securities available for sale $ (133,466) $ 30,117 $ (103,349) Less: reclassification adjustment for gains included in net income 1,166 (257) 909 Net change in fair value of securities available for sale (134,632) 30,374 (104,258) Unrealized gains on cash flow hedges: Change in fair value of cash flow hedges — — — Less: net cash flow hedge gains reclassified into interest income (1) 31,234 (8,780) 22,454 Net change in fair value of cash flow hedges (31,234) 8,780 (22,454) Defined benefit pension plans: Change in actuarial net gain 19,243 (5,409) 13,834 Less: amortization of actuarial net loss (13,400) 3,767 (9,633) Plan amendment - Century acquisition lump sum distribution option 1,106 (311) 795 Less: net accretion of prior service credit 11,796 (3,316) 8,480 Net change in other comprehensive income for defined benefit pension plans 21,953 (6,171) 15,782 Total other comprehensive loss $ (143,913) $ 32,983 $ (110,930) (1) Includes amortization of less than $0.1 million, $7.3 million, and $22.5 million for the years ended December 31, 2023, 2022, and 2021, respectively, of realized but unrecognized gains, net of tax, from the termination of interest rate swaps. The total original gain of $41.2 million, net of tax, became fully accreted into income during the year ended December 31, 2023. The balance of this gain had amortized to less than $0.1 million, and $7.4 million, net of tax, at December 31, 2022 and December 31, 2021, respectively.
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table illustrates the changes in the balances of each component of accumulated other comprehensive income (loss), net of tax: Unrealized Unrealized Defined Benefit Total (In thousands) Beginning balance: January 1, 2021 $ 45,672 $ 29,815 $ (21,253) $ 54,234 Other comprehensive (loss) income before reclassifications (103,349) — 14,629 (88,720) Less: Amounts reclassified from accumulated other comprehensive income 909 22,454 (1,153) 22,210 Net current-period other comprehensive (loss) income (104,258) (22,454) 15,782 (110,930) Ending balance: December 31, 2021 $ (58,586) $ 7,361 $ (5,471) $ (56,696) Other comprehensive (loss) income before reclassifications (823,854) (50,633) 4,546 (869,941) Less: Amounts reclassified from accumulated other comprehensive income (2,284) 6,887 (8,048) (3,445) Net current-period other comprehensive (loss) income (821,570) (57,520) 12,594 (866,496) Ending balance: December 31, 2022 $ (880,156) $ (50,159) $ 7,123 $ (923,192) Other comprehensive income (loss) before reclassifications 37,373 (16,690) 13,225 33,908 Less: Amounts reclassified from accumulated other comprehensive (loss) income (258,540) (35,278) 12,886 (280,932) Net current-period other comprehensive income 295,913 18,588 339 314,840 Ending balance: December 31, 2023 $ (584,243) $ (31,571) $ 7,462 $ (608,352) The following table illustrates the significant amounts reclassified out of each component of accumulated other comprehensive (loss)/income, net of tax: Year Ended December 31, Details about Accumulated Other Comprehensive (Loss)/Income Components 2023 2022 2021 Affected Line Item in the Statement Where Net Income is Presented (In thousands) Unrealized (losses) and gains on available-for-sale securities $ (333,170) $ (3,157) $ 1,166 (Losses) gains on sales of securities available for sale, net (333,170) (3,157) 1,166 Total before tax 74,630 873 (257) Tax benefit (expense) $ (258,540) $ (2,284) $ 909 Net of tax Unrealized (losses) gains on cash flow hedges $ (48,795) $ 9,580 $ 31,234 Interest income (48,795) 9,580 31,234 Total before tax 13,517 (2,693) (8,780) Tax benefit (expense) $ (35,278) $ 6,887 $ 22,454 Net of tax Accretion (amortization) of defined benefit pension items $ (9,563) $ (23,077) $ (13,400) Net periodic pension cost - see Note 15 BEP and Defined Benefit Plan curtailment gain 15,908 — — Net income from discontinued operations Accretion of prior service credit 11,560 11,882 11,796 Net periodic pension cost - see Note 15 17,905 (11,195) (1,604) Total before tax (5,019) 3,147 451 Tax (expense) benefit $ 12,886 $ (8,048) $ (1,153) Net of tax Total reclassifications for the period $ (280,932) $ (3,445) $ 22,210

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2023
Discontinued Operations and Disposal Groups [Abstract]
Summary of the Asset and Liabilities of the Discontinued Insurance Agency Business	The following is a summary of the assets and liabilities of the discontinued insurance agency business as of December 31, 2022: December 31, 2022 (In thousands) Assets Premises and equipment $ 163 Goodwill and intangibles, net 93,117 Deferred income taxes, net (315) Prepaid expenses 532 Other assets 34,722 Total assets $ 128,219 Liabilities Other liabilities $ 34,930 Total liabilities $ 34,930 December 31, 2022 (In thousands) Assets Cash $ 66,507 Premises and equipment (1) 1,792 Bank-owned life insurance 2,066 Deferred income taxes 3,662 Other assets (2) 12,944 Total assets $ 86,971 Liabilities Other liabilities (3) $ 14,013 Total liabilities $ 14,013 (1) Includes buildings and related improvements. (2) Primarily includes assets held in rabbi trusts and the ROU asset associated with one lease which will be assumed by the Bank upon dissolution of Eastern Insurance Group. (3) Primarily includes employee post-retirement liabilities and the lease liability associated with one lease which will be assumed by the Bank upon dissolution of Eastern Insurance Group. The following presents operating results of the discontinued insurance agency business for the periods indicated: For the Years Ended December 31, 2023 2022 2021 (In thousands) Noninterest income: Insurance commissions $ 93,997 $ 99,887 $ 95,164 Other noninterest income 67 179 1,014 Total noninterest income 94,064 100,066 96,178 Noninterest expense: Salaries and employee benefits 76,109 65,089 68,292 Office occupancy and equipment 4,420 3,319 3,204 Data processing 3,577 4,335 4,424 Professional services 1,176 1,009 596 Marketing expenses 179 246 241 Amortization of intangible assets 2,002 2,666 2,293 Other 5,304 4,944 4,411 Total noninterest expense 92,767 81,608 83,461 Income from discontinued operations before income tax expense 1,297 18,458 12,717 Gain on sale of discontinued operations before income tax expense 408,629 — — Total gain on discontinued operations before income tax expense 409,926 18,458 12,717 Income tax expense 115,060 5,210 3,583 Income from discontinued operations, net of taxes (1) $ 294,866 $ 13,248 $ 9,134 (1) Represents net income from discontinued operations that is presented in the Consolidated Statements of Income. Years Ended December 31, 2023 2022 2021 (In thousands) Noninterest income: Income (losses) from investments held in rabbi trusts $ 697 $ (1,305) $ 937 Other noninterest income (1) 60 54 52 Total noninterest income (loss) 757 (1,251) 989 Noninterest expense: Salaries and employee benefits (2) 721 (1,292) 967 Office occupancy and equipment (3) 433 499 501 Other (4) 1,608 2,396 (2,151) Total noninterest expense 2,762 1,603 (683) (Loss) income before income tax expense (2,005) (2,854) 1,672 Income tax (benefit) expense (564) (802) 470 Net (loss) income (1,441) (2,052) 1,202 (1) Includes income on Company-owned life insurance policies which were not disposed of and will be transferred into the Bank upon dissolution of Eastern Insurance Group. (2) Includes expenses, which were a net credit for the year ended December 31, 2022, associated with certain employee post-retirement benefit plan expenses. (3) Includes depreciation expense associated with buildings and related improvements and ROU asset amortization related to one lease which were not disposed of and will be transferred into the Bank upon dissolution of Eastern Insurance Group. (4) Includes intercompany expenses and other credits associated with the Defined Benefit Plan and the BEP. Components of net periodic benefit cost associated with the Defined Benefit Plan and the BEP and included in other noninterest expense above were a net credit for the periods presented.
Summary of the Operating Results of the Discontinued Insurance Agency Business	The following is a summary of the assets and liabilities of the discontinued insurance agency business as of December 31, 2022: December 31, 2022 (In thousands) Assets Premises and equipment $ 163 Goodwill and intangibles, net 93,117 Deferred income taxes, net (315) Prepaid expenses 532 Other assets 34,722 Total assets $ 128,219 Liabilities Other liabilities $ 34,930 Total liabilities $ 34,930 December 31, 2022 (In thousands) Assets Cash $ 66,507 Premises and equipment (1) 1,792 Bank-owned life insurance 2,066 Deferred income taxes 3,662 Other assets (2) 12,944 Total assets $ 86,971 Liabilities Other liabilities (3) $ 14,013 Total liabilities $ 14,013 (1) Includes buildings and related improvements. (2) Primarily includes assets held in rabbi trusts and the ROU asset associated with one lease which will be assumed by the Bank upon dissolution of Eastern Insurance Group. (3) Primarily includes employee post-retirement liabilities and the lease liability associated with one lease which will be assumed by the Bank upon dissolution of Eastern Insurance Group. The following presents operating results of the discontinued insurance agency business for the periods indicated: For the Years Ended December 31, 2023 2022 2021 (In thousands) Noninterest income: Insurance commissions $ 93,997 $ 99,887 $ 95,164 Other noninterest income 67 179 1,014 Total noninterest income 94,064 100,066 96,178 Noninterest expense: Salaries and employee benefits 76,109 65,089 68,292 Office occupancy and equipment 4,420 3,319 3,204 Data processing 3,577 4,335 4,424 Professional services 1,176 1,009 596 Marketing expenses 179 246 241 Amortization of intangible assets 2,002 2,666 2,293 Other 5,304 4,944 4,411 Total noninterest expense 92,767 81,608 83,461 Income from discontinued operations before income tax expense 1,297 18,458 12,717 Gain on sale of discontinued operations before income tax expense 408,629 — — Total gain on discontinued operations before income tax expense 409,926 18,458 12,717 Income tax expense 115,060 5,210 3,583 Income from discontinued operations, net of taxes (1) $ 294,866 $ 13,248 $ 9,134 (1) Represents net income from discontinued operations that is presented in the Consolidated Statements of Income. Years Ended December 31, 2023 2022 2021 (In thousands) Noninterest income: Income (losses) from investments held in rabbi trusts $ 697 $ (1,305) $ 937 Other noninterest income (1) 60 54 52 Total noninterest income (loss) 757 (1,251) 989 Noninterest expense: Salaries and employee benefits (2) 721 (1,292) 967 Office occupancy and equipment (3) 433 499 501 Other (4) 1,608 2,396 (2,151) Total noninterest expense 2,762 1,603 (683) (Loss) income before income tax expense (2,005) (2,854) 1,672 Income tax (benefit) expense (564) (802) 470 Net (loss) income (1,441) (2,052) 1,202 (1) Includes income on Company-owned life insurance policies which were not disposed of and will be transferred into the Bank upon dissolution of Eastern Insurance Group. (2) Includes expenses, which were a net credit for the year ended December 31, 2022, associated with certain employee post-retirement benefit plan expenses. (3) Includes depreciation expense associated with buildings and related improvements and ROU asset amortization related to one lease which were not disposed of and will be transferred into the Bank upon dissolution of Eastern Insurance Group. (4) Includes intercompany expenses and other credits associated with the Defined Benefit Plan and the BEP. Components of net periodic benefit cost associated with the Defined Benefit Plan and the BEP and included in other noninterest expense above were a net credit for the periods presented.

Parent Company Financial Statem

Parent Company Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2023
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheet	BALANCE SHEETS As of December 31, 2023 2022 (In thousands) Assets Cash and cash equivalents (1) $ 118,256 $ 126,441 Goodwill and other intangibles, net 744 744 Deferred income taxes, net 6,763 13,182 Investment in subsidiaries 2,842,099 2,327,521 Other assets 8,202 4,557 Total assets $ 2,976,064 $ 2,472,445 Liabilities and shareholders’ equity Other liabilities $ 1,209 $ 655 Total liabilities 1,209 655 Shareholders’ equity 2,974,855 2,471,790 Total liabilities and shareholders’ equity $ 2,976,064 $ 2,472,445 (1) Includes $116.7 million and $125.0 that is eliminated in consolidation as of December 31, 2023 and 2022, respectively.
Condensed Income Statement	STATEMENTS OF INCOME For the Year Ended December 31, 2023 2022 2021 (In thousands) Income Interest income $ 130 $ 15 $ — Total income 130 15 — Expenses Professional services 4,937 899 7,393 Other 3,706 3,070 222 Total expenses 8,643 3,969 7,615 Loss before income taxes and equity in undistributed income of subsidiaries (8,513) (3,954) (7,615) Income tax (benefit) expense (1,773) 269 (11,344) (Loss) income before equity in undistributed income of subsidiaries (6,740) (4,223) 3,729 Equity in undistributed income of subsidiaries 238,917 203,982 150,936 Net income $ 232,177 $ 199,759 $ 154,665
Condensed Cash Flow Statement	STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2023 2022 2021 (In thousands) Cash flows provided by operating activities Net income $ 232,177 $ 199,759 $ 154,665 Adjustments to reconcile net income to cash provided by operating activities Equity in undistributed income of subsidiaries (238,917) (203,982) (150,936) Share-based compensation 16,513 10,507 — ESOP expense 7,129 9,923 9,408 Change in: Deferred income taxes, net 6,419 4,792 (7,157) Other, net (4,115) (937) (388) Net cash provided by operating activities 19,206 20,062 5,592 Cash flows provided by (used in) investing activities Cash paid for acquisition, net of cash acquired — — (640,890) Return of investments in subsidiary 40,000 240,000 140,000 Contributions to other equity investments (720) (788) — Net cash provided by (used in) investing activities 39,280 239,212 (500,890) Cash flows used in financing activities Payment of subordinated debentures assumed in business combination (1) — — (36,277) Payments for shares repurchased under share repurchase plans — (201,618) (23,224) Dividends declared and paid to common shareholders (66,671) (65,886) (51,564) Net cash used in financing activities (66,671) (267,504) (111,065) Net decrease in cash and cash equivalents (8,185) (8,230) (606,363) Cash and cash equivalents at beginning of year 126,441 134,671 741,034 Cash and cash equivalents at end of year $ 118,256 $ 126,441 $ 134,671 (1) The Company deposited funds into escrow prior to the Century acquisition date to pay the balance of subordinated debentures assumed in the Century acquisition which was considered to be defeasance of the debt. Accordingly, Century recorded a payable to the Company in the amount of the escrow deposit and the Company recorded a receivable from Century in the same amount. The payable was reclassified to other assets upon acquisition. Subsequent to the closing of the acquisition and prior to December 31, 2021, the amounts placed in escrow were disbursed to the holders of the subordinated debentures resulting in a full pay-off of the outstanding balance of the debt.

Quarterly Results of Operatio_2

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2023
Quarterly Financial Information Disclosure [Abstract]
Summary of Unaudited Supplementary Information	The following unaudited supplementary information summarizes the retrospective changes to the Consolidated Statements of Income as a result of the decision to sell the insurance agency business for the periods indicated: First Quarter Second Quarter Third Quarter Fourth Quarter 2023 2022 2023 2022 2023 2022 2023 2022 (Dollars in thousands, except per share data) Interest and dividend income $ 188,880 $ 131,485 $ 201,765 $ 140,871 $ 202,168 $ 157,827 $ 203,646 $ 174,998 Interest expense 50,571 3,361 60,177 3,114 64,963 5,648 70,339 25,004 Net interest income 138,309 128,124 141,588 137,757 137,205 152,179 133,307 149,994 Provision for (release of) allowance for loan losses 25 (485) 7,501 1,050 7,328 6,480 5,198 10,880 Net interest income after provision for loan losses 138,284 128,609 134,087 136,707 129,877 145,699 128,109 139,114 Noninterest (loss) income (309,853) 17,655 26,204 17,146 19,157 19,524 26,739 22,425 Noninterest expense 95,891 89,246 99,934 91,055 101,748 95,765 121,029 112,583 (Loss) income from continuing operations before income tax expense (267,460) 57,018 60,357 62,798 47,286 69,458 33,819 48,956 Income tax (benefit) expense (65,379) 12,064 15,938 14,967 (16,178) 16,650 2,310 8,038 Net (loss) income from continuing operations (202,081) 44,954 44,419 47,831 63,464 52,808 31,509 40,918 Net income (loss) from discontinued operations 7,985 6,562 4,238 3,341 (4,351) 1,969 286,994 1,376 Net (loss) income $ (194,096) $ 51,516 $ 48,657 $ 51,172 $ 59,113 $ 54,777 $ 318,503 $ 42,294 Basic (loss) earnings per share: Continuing operations $ (1.25) $ 0.26 $ 0.27 $ 0.29 $ 0.39 $ 0.32 $ 0.19 $ 0.25 Discontinued operations 0.05 0.04 0.03 0.02 (0.03) 0.01 1.77 0.01 Basic (loss) earnings per share $ (1.20) $ 0.30 $ 0.30 $ 0.31 $ 0.36 $ 0.33 $ 1.96 $ 0.26 Diluted (loss) earnings per share: Continuing operations $ (1.25) $ 0.26 $ 0.27 $ 0.29 $ 0.39 $ 0.32 $ 0.19 $ 0.25 Discontinued operations 0.05 0.04 0.03 0.02 (0.03) 0.01 1.76 0.01 Diluted (loss) earnings per share $ (1.20) $ 0.30 $ 0.30 $ 0.31 $ 0.36 $ 0.33 $ 1.95 $ 0.26 Average common shares outstanding: Basic 161,991,373 169,857,950 162,232,236 166,533,920 162,370,469 163,718,962 162,571,066 162,032,522 Diluted 162,059,431 169,968,156 162,246,675 166,573,627 162,469,887 164,029,649 162,724,398 162,263,547

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) plan reporting_unit segment h	Dec. 31, 2022 USD ($)	Jan. 01, 2022 USD ($)	Nov. 01, 2020	Oct. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Restricted cash	$ 11,500,000	$ 1,000,000
Debt securities, available-for-sale, allowance for credit loss, excluding accrued interest	0	0	$ 0
Other real estate	$ 0	$ 0
Number of reporting units | reporting_unit	1
Defined benefit plan, age requirement	21 years
Defined benefit plan, service requirement	1 year
Defined benefit plan, service requirement for full vesting for individuals employed on or before October 21, 1989	3 years
Defined benefit plan, service requirement for full vesting for individuals employed subsequent to October 31, 1989	5 years
Number of deferred compensation plans | plan	3
Number of reportable segments | segment	1
Pension Plan
Finite-Lived Intangible Assets [Line Items]
Contribution credits rate	4.47%	3.55%
Qualified Plan | Pension Plan
Finite-Lived Intangible Assets [Line Items]
Defined benefit plan, minimum working hours for eligibility | h	1,000
Defined benefit plan, treasury rate, term	30 years
Contribution credits rate					3.50%
Defined benefit plan, normal retirement age	65 years
Nonqualified Plan | Pension Plan
Finite-Lived Intangible Assets [Line Items]
Contribution credits rate				5%
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	10 years
Core Deposits | Maximum
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	10 years

Securities - Summary Of Debt Se

Securities - Summary Of Debt Securities (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022	Jan. 01, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 5,161,904,000	$ 7,825,435,000
Unrealized Gains	172,000	9,000
Unrealized Losses	(754,555,000)	(1,134,666,000)
Allowance for Credit Losses	0	0	$ 0
Fair Value	4,407,521,000	6,690,778,000
Government-sponsored residential mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,302,165,000	4,855,763,000
Unrealized Gains	0	0
Unrealized Losses	(521,527,000)	(743,855,000)
Allowance for Credit Losses	0	0
Fair Value	2,780,638,000	4,111,908,000
Government-sponsored commercial mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,326,029,000	1,570,119,000
Unrealized Gains	0	0
Unrealized Losses	(201,653,000)	(221,165,000)
Allowance for Credit Losses	0	0
Fair Value	1,124,376,000	1,348,954,000
U.S. Agency bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	236,454,000	1,100,891,000
Unrealized Gains	0	0
Unrealized Losses	(20,443,000)	(148,409,000)
Allowance for Credit Losses	0	0
Fair Value	216,011,000	952,482,000
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	99,552,000	99,324,000
Unrealized Gains	0	0
Unrealized Losses	(4,400,000)	(6,267,000)
Allowance for Credit Losses	0	0
Fair Value	95,152,000	93,057,000
State and municipal bonds and obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	197,704,000	198,039,000
Unrealized Gains	172,000	9,000
Unrealized Losses	(6,532,000)	(14,956,000)
Allowance for Credit Losses	0	0
Fair Value	$ 191,344,000	183,092,000
Other debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		1,299,000
Unrealized Gains		0
Unrealized Losses		(14,000)
Allowance for Credit Losses		0
Fair Value		$ 1,285,000

Securities - Narrative (Details

Securities - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2022	Dec. 31, 2022 holding	Jan. 01, 2022 USD ($)
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, allowance for credit loss, excluding accrued interest	$ 0		$ 0			$ 0
Debt securities, available-for-sale, accrued interest, after allowance for credit loss	$ 9,200,000		12,900,000
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Debt securities, available-for-sale, accrued interest writeoff	$ 0	$ 0
Number of holdings	736			802
Debt securities, held-to-maturity, allowance for credit loss, excluding accrued interest	$ 0		0
Debt securities, held-to-maturity, accrued interest, after allowance for credit loss	$ 900,000		1,000,000
Debt Securities, Held-to-Maturity, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Debt securities, held-to-maturity, accrued interest, writeoff	$ 0	$ 0
Debt securities, available-for-sale and held-to-maturity, fair value	4,812,343,000		7,114,004,000
Carrying value of securities pledged as collateral	615,700,000		437,900,000
Bank Term Funding Program
Debt Securities, Available-for-sale [Line Items]
Carrying value of securities pledged as collateral	2,400,000,000		0
Federal Reserve Discount Window
Debt Securities, Available-for-sale [Line Items]
Carrying value of securities pledged as collateral	168,800,000		0
Callable Securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale and held-to-maturity, fair value	$ 394,400,000		852,900,000
Other debt securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, available-for-sale, allowance for credit loss, excluding accrued interest			$ 0
Number of holdings				2	2
Foreign Debt Securities
Debt Securities, Available-for-sale [Line Items]
Number of holdings | holding					2

Securities - Schedule of Realiz

Securities - Schedule of Realized Gain (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt Securities [Abstract]
Gross realized gains from sales of AFS securities	$ 0	$ 1,775	$ 1,166
Gross realized losses from sales of AFS securities	(333,170)	(4,932)	0
Net (losses) gains from sales of AFS securities	$ (333,170)	$ (3,157)	$ 1,166

Securities - Summary Of Governm

Securities - Summary Of Government-Sponsored Residential Mortgage-Backed Securities With Gross Unrealized Losses (Details $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2022	Dec. 31, 2022 USD ($)	Dec. 31, 2022 holding
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Number of holdings	736	802
Gross Unrealized Losses
Less than 12 Months	$ 269		$ 98,038
12 Months or Longer	754,286		1,036,628
Total	754,555		1,134,666
Fair Value
Less than 12 Months	27,821		968,376
12 Months or Longer	4,346,529		5,719,149
Total	$ 4,374,350		6,687,525
Government-sponsored residential mortgage-backed securities
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Number of holdings	324	322
Gross Unrealized Losses
Less than 12 Months	$ 0		42,196
12 Months or Longer	521,527		701,659
Total	521,527		743,855
Fair Value
Less than 12 Months	0		435,690
12 Months or Longer	2,780,638		3,676,218
Total	$ 2,780,638		4,111,908
Government-sponsored commercial mortgage-backed securities
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Number of holdings	187	199
Gross Unrealized Losses
Less than 12 Months	$ 0		38,944
12 Months or Longer	201,653		182,221
Total	201,653		221,165
Fair Value
Less than 12 Months	0		300,476
12 Months or Longer	1,124,376		1,048,478
Total	$ 1,124,376		1,348,954
U.S. Agency bonds
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Number of holdings	23	37
Gross Unrealized Losses
Less than 12 Months	$ 0		645
12 Months or Longer	20,443		147,764
Total	20,443		148,409
Fair Value
Less than 12 Months	0		4,145
12 Months or Longer	216,011		948,337
Total	$ 216,011		952,482
U.S. Treasury securities
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Number of holdings	6	5
Gross Unrealized Losses
Less than 12 Months	$ 36		1,311
12 Months or Longer	4,364		4,956
Total	4,400		6,267
Fair Value
Less than 12 Months	4,927		48,451
12 Months or Longer	90,225		44,606
Total	$ 95,152		93,057
State and municipal bonds and obligations
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Number of holdings	196	237
Gross Unrealized Losses
Less than 12 Months	$ 233		14,942
12 Months or Longer	6,299		14
Total	6,532		14,956
Fair Value
Less than 12 Months	22,894		179,614
12 Months or Longer	135,279		225
Total	$ 158,173		179,839
Other debt securities
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Number of holdings		2		2
Gross Unrealized Losses
Less than 12 Months			0
12 Months or Longer			14
Total			14
Fair Value
Less than 12 Months			0
12 Months or Longer			1,285
Total			$ 1,285

Securities - Debt Securities, H

Securities - Debt Securities, Held-to-Maturity (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	$ 449,721,000	$ 476,647,000
Unrealized Gains	0	0
Unrealized Losses	(44,899,000)	(53,421,000)
Allowance for Credit Losses	0	0
Fair Value	404,822,000	423,226,000
Government-sponsored residential mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	254,752,000	276,493,000
Unrealized Gains	0	0
Unrealized Losses	(24,433,000)	(30,150,000)
Allowance for Credit Losses	0	0
Fair Value	230,319,000	246,343,000
Government-sponsored commercial mortgage-backed securities
Schedule of Held-to-Maturity Securities [Line Items]
Amortized Cost	194,969,000	200,154,000
Unrealized Gains	0	0
Unrealized Losses	(20,466,000)	(23,271,000)
Allowance for Credit Losses	0	0
Fair Value	$ 174,503,000	$ 176,883,000

Securities - Summary Of Fair Va

Securities - Summary Of Fair Value Of Securities By Contractual Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
AFS securities
Due in one year or less, Amortized Cost	$ 213	$ 1,512
Due in one year or less, Fair value	209	1,494
Due after one year to five years, Amortized Cost	651,654	1,211,778
Due after one year to five years, Fair value	603,469	1,074,080
Due after five to ten years, Amortized Cost	446,531	1,643,641
Due after five to ten years, Fair value	391,693	1,430,761
Due after ten years, Amortized Cost	4,063,506	4,968,504
Due after ten years, Fair value	3,412,150	4,184,443
Amortized Cost	5,161,904	7,825,435
Fair Value	4,407,521	6,690,778
HTM securities
Due in one year or less, Amortized Cost	0	0
Due in one year or less, Fair value	0	0
Due after one year to five years, Amortized Cost	80,014	0
Due after one year to five years, Fair value	72,952	0
Due after five to ten years, Amortized Cost	114,955	200,154
Due after five to ten years, Fair value	101,551	176,883
Due after ten years, Amortized Cost	254,752	276,493
Due after ten years, Fair value	230,319	246,343
Amortized Cost	449,721	476,647
Fair Value	404,822	423,226
Total
Due in one year or less, Amortized Cost	213	1,512
Due in one year or less, Fair value	209	1,494
Due after one year to five years, Amortized Cost	731,668	1,211,778
Due after one year to five years, Fair value	676,421	1,074,080
Due after five to ten years, Amortized Cost	561,486	1,843,795
Due after five to ten years, Fair value	493,244	1,607,644
Due after ten years, Amortized Cost	4,318,258	5,244,997
Due after ten years, Fair value	3,642,469	4,430,786
Amortized Cost	5,611,625	8,302,082
Fair Value	4,812,343	7,114,004
Government-sponsored residential mortgage-backed securities
AFS securities
Due in one year or less, Amortized Cost	0	0
Due in one year or less, Fair value	0	0
Due after one year to five years, Amortized Cost	29,288	21,221
Due after one year to five years, Fair value	28,188	20,284
Due after five to ten years, Amortized Cost	22,735	727,908
Due after five to ten years, Fair value	21,235	648,132
Due after ten years, Amortized Cost	3,250,142	4,106,634
Due after ten years, Fair value	2,731,215	3,443,492
Amortized Cost	3,302,165	4,855,763
Fair Value	2,780,638	4,111,908
HTM securities
Due in one year or less, Amortized Cost	0	0
Due in one year or less, Fair value	0	0
Due after one year to five years, Amortized Cost	0	0
Due after one year to five years, Fair value	0	0
Due after five to ten years, Amortized Cost	0	0
Due after five to ten years, Fair value	0	0
Due after ten years, Amortized Cost	254,752	276,493
Due after ten years, Fair value	230,319	246,343
Amortized Cost	254,752	276,493
Fair Value	230,319	246,343
Government-sponsored commercial mortgage-backed securities
AFS securities
Due in one year or less, Amortized Cost	0	0
Due in one year or less, Fair value	0	0
Due after one year to five years, Amortized Cost	256,229	191,762
Due after one year to five years, Fair value	234,725	171,992
Due after five to ten years, Amortized Cost	379,749	649,659
Due after five to ten years, Fair value	327,198	556,641
Due after ten years, Amortized Cost	690,051	728,698
Due after ten years, Fair value	562,453	620,321
Amortized Cost	1,326,029	1,570,119
Fair Value	1,124,376	1,348,954
HTM securities
Due in one year or less, Amortized Cost	0	0
Due in one year or less, Fair value	0	0
Due after one year to five years, Amortized Cost	80,014	0
Due after one year to five years, Fair value	72,952	0
Due after five to ten years, Amortized Cost	114,955	200,154
Due after five to ten years, Fair value	101,551	176,883
Due after ten years, Amortized Cost	0	0
Due after ten years, Fair value	0	0
Amortized Cost	194,969	200,154
Fair Value	174,503	176,883
U.S. Agency bonds
AFS securities
Due in one year or less, Amortized Cost	0	0
Due in one year or less, Fair value	0	0
Due after one year to five years, Amortized Cost	236,454	877,371
Due after one year to five years, Fair value	216,011	767,464
Due after five to ten years, Amortized Cost	0	223,520
Due after five to ten years, Fair value	0	185,018
Due after ten years, Amortized Cost	0	0
Due after ten years, Fair value	0	0
Amortized Cost	236,454	1,100,891
Fair Value	216,011	952,482
U.S. Treasury securities
AFS securities
Due in one year or less, Amortized Cost	0	0
Due in one year or less, Fair value	0	0
Due after one year to five years, Amortized Cost	99,552	99,324
Due after one year to five years, Fair value	95,152	93,057
Due after five to ten years, Amortized Cost	0	0
Due after five to ten years, Fair value	0	0
Due after ten years, Amortized Cost	0	0
Due after ten years, Fair value	0	0
Amortized Cost	99,552	99,324
Fair Value	95,152	93,057
State and municipal bonds and obligations
AFS securities
Due in one year or less, Amortized Cost	213	213
Due in one year or less, Fair value	209	209
Due after one year to five years, Amortized Cost	30,131	22,100
Due after one year to five years, Fair value	29,393	21,283
Due after five to ten years, Amortized Cost	44,047	42,554
Due after five to ten years, Fair value	43,260	40,970
Due after ten years, Amortized Cost	123,313	133,172
Due after ten years, Fair value	118,482	120,630
Amortized Cost	197,704	198,039
Fair Value	$ 191,344	183,092
Other debt securities
AFS securities
Due in one year or less, Amortized Cost		1,299
Due in one year or less, Fair value		1,285
Due after one year to five years, Amortized Cost		0
Due after one year to five years, Fair value		0
Due after five to ten years, Amortized Cost		0
Due after five to ten years, Fair value		0
Due after ten years, Amortized Cost		0
Due after ten years, Fair value		0
Amortized Cost		1,299
Fair Value		$ 1,285

Loans and Allowance for Credi_3

Loans and Allowance for Credit Losses - Summary of Company's Loan Portfolio as of the Dates Indicated (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	$ 13,973,428	$ 13,575,531
Allowance for loan losses	(148,993)	(142,211)	$ (97,787)	$ (113,031)
Unamortized premiums, net of unearned discounts and deferred fees, net of costs	(25,068)	(13,003)
Loans after the allowance for loan losses, unamortized premiums, unearned discounts and deferred fees and costs	13,799,367	13,420,317
Financing receivable, accrued interest, before allowance for credit loss	53,900	45,200
Commercial Portfolio Segment | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	3,034,068	3,150,946
Allowance for loan losses	(26,959)	(26,859)	(18,018)	(26,617)
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	5,457,349	5,155,323
Allowance for loan losses	(65,475)	(54,730)	(52,373)	(54,569)
Commercial Portfolio Segment | Commercial construction
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	386,999	336,276
Allowance for loan losses	(6,666)	(7,085)	(2,585)	(4,553)
Commercial Portfolio Segment | Business banking
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	1,085,763	1,090,492
Allowance for loan losses	(14,913)	(16,189)	(10,983)	(13,152)
Residential Portfolio Segment | Residential real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	2,565,485	2,460,849
Allowance for loan losses	(25,954)	(28,129)	(6,556)	(6,435)
Consumer Portfolio Segment | Consumer home equity
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	1,208,231	1,187,547
Allowance for loan losses	(5,595)	(6,454)	(3,722)	(3,744)
Consumer Portfolio Segment | Other Consumer
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	235,533	194,098
Allowance for loan losses	(3,431)	(2,765)	$ (3,308)	$ (3,467)
Consumer Portfolio Segment | Automobile loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	7,200	18,100
Consumer Portfolio Segment | Home Improvement Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Gross loans before unamortized premiums, unearned discounts and deferred fees and costs	$ 178,900	$ 121,100

Loans and Allowance for Credi_4

Loans and Allowance for Credit Losses - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) loan	Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan	Jan. 01, 2022 USD ($)	Dec. 31, 2020 USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items]
Loan syndications, amount	$ 100,000,000
Financing receivable, excluding accrued interest, after allowance for credit loss	13,799,367,000	$ 13,420,317,000
Debt, long-term and short-term, combined amount	48,216,000	740,828,000
Mortgage loans partially or wholly-owned by others and serviced by the Company	77,200,000	84,000,000
Proceeds from sales of commercial loans held for investment	189,296,000	0	$ 0
Loss on sales of commercial loans	2,738,000	0	0
Financing receivable, excluding accrued interest, allowance for credit loss, period increase (decrease)	6,800,000
Financing receivable, allowance for credit loss, excluding accrued interest	$ 148,993,000	$ 142,211,000	97,787,000		$ 113,031,000
Financing receivable, allowance for credit loss to outstanding, percent, period increase (decrease)	2
Financing receivable, allowance for credit loss to outstanding, percent	1.07%	1.05%
Financing receivable, excluding accrued interest, allowance for credit loss, writeoff, period increase	$ 10,300,000
Financing receivable, excluding accrued interest, allowance for credit loss, writeoff	15,092,000	$ 4,831,000	$ 9,002,000
Total loans	$ 13,973,428,000	13,575,531,000
Maximum number of days required for special mention	90 days
Outstanding recorded investment of loans that were new to troubled debt restructuring		11,000,000
Amount of specific reserve associated with the TDR		$ 1,800,000
Number of loans modified during the preceding 12 months that subsequently defaulted | loan		1	0
Amount of loans modified during the preceding 12 months that subsequently defaulted		$ 1,000,000
Amounts charged-off on TDRs		0	$ 0
Residential Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, collateral dependent loans	$ 800,000	600,000
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, collateral dependent loans	30,700,000	16,200,000
Unrated | Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
Lines of credit, exposure	100,000
Commercial and industrial | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Proceeds from sales of commercial loans held for investment	214,200,000
Loss on sales of commercial loans	2,700,000
Financing receivable, allowance for credit loss, excluding accrued interest	26,959,000	26,859,000	18,018,000		26,617,000
Financing receivable, excluding accrued interest, allowance for credit loss, writeoff	13,000	269,000	1,558,000
Total loans	3,034,068,000	3,150,946,000
Business banking | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	14,913,000	16,189,000	10,983,000		13,152,000
Financing receivable, excluding accrued interest, allowance for credit loss, writeoff	4,645,000	2,292,000	5,091,000
Total loans	1,085,763,000	1,090,492,000
Business banking | Line of Credit | Unrated | Commercial Portfolio Segment | Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Lines of credit, exposure	1,500,000
Unfunded Loan Commitment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	14,100,000	13,200,000		$ 11,100,000
Residential real estate | Residential Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued interest purchase	32,000,000	380,200,000
Amortized cost balance of loans purchased	385,500,000	376,100,000
Financing receivable, allowance for credit loss, excluding accrued interest	25,954,000	28,129,000	6,556,000		6,435,000
Financing receivable, excluding accrued interest, allowance for credit loss, writeoff	0	0	35,000
Total loans	$ 2,565,485,000	$ 2,460,849,000
Number of loans in process of foreclosure | loan	2	0
Mortgage loans in process of foreclosure, amount	$ 200,000
Consumer home equity | Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	5,595,000	$ 6,454,000	3,722,000		$ 3,744,000
Financing receivable, excluding accrued interest, allowance for credit loss, writeoff	7,000	1,000	24,000
Total loans	$ 1,208,231,000	$ 1,187,547,000
Number of loans in process of foreclosure | loan	3	0
Mortgage loans in process of foreclosure, amount	$ 200,000
Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest		$ (1,143,000)	27,086,000
Cumulative effect accounting adjustment | Commercial and industrial | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest		47,000	11,533,000
Cumulative effect accounting adjustment | Business banking | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest		(140,000)	6,160,000
Cumulative effect accounting adjustment | Unfunded Loan Commitment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest				$ 1,000,000
Cumulative effect accounting adjustment | Residential real estate | Residential Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest		(849,000)	13,489,000
Cumulative effect accounting adjustment | Consumer home equity | Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest		(201,000)	$ 1,857,000
Short-term FHLB advances
Financing Receivable, Allowance for Credit Loss [Line Items]
FHLB advances	17,700,000	704,100,000
Federal Reserve Bank Advances
Financing Receivable, Allowance for Credit Loss [Line Items]
Debt, long-term and short-term, combined amount	0	0
Asset Pledged as Collateral | Short-term FHLB advances
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, excluding accrued interest, after allowance for credit loss	4,600,000,000	3,900,000,000
Asset Pledged as Collateral | Federal Reserve Bank Advances
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, excluding accrued interest, after allowance for credit loss	$ 1,100,000,000	$ 1,100,000,000

Loans and Allowance for Credi_5

Loans and Allowance for Credit Losses - Summary of Changes in Allowance for Loan Losses by Loan Category (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 01, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 97,787	$ 142,211	$ 97,787	$ 113,031
Charge-offs		(15,092)	(4,831)	(9,002)
Recoveries		2,965	4,244	3,444
Provision (release)		20,052	17,925	(9,686)
Ending balance		148,993	142,211	97,787
Allowance for loan losses		148,993	142,211	97,787
Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	27,086	(1,143)	27,086
Ending balance			(1,143)	27,086
Allowance for loan losses			(1,143)	27,086
Cumulative effect accounting adjustment | Accounting Standards Update 2022-02
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance		(1,100)
Ending balance			(1,100)
Allowance for loan losses			(1,100)
Cumulative effect accounting adjustment | Accounting Standards Update 2016-13
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	27,100		27,100
Ending balance				27,100
Allowance for loan losses				27,100
PCI loan balances to PCD and the associated gross-up	100
Other Class Of Financing Receivable [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	242	0	242	494
Charge-offs			0	0
Recoveries			0	0
Provision (release)			0	(252)
Ending balance			0	242
Allowance for loan losses			0	242
Other Class Of Financing Receivable [Member] | Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(242)		(242)
Ending balance				(242)
Allowance for loan losses				(242)
Commercial Portfolio Segment | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	18,018	26,859	18,018	26,617
Charge-offs		(13)	(269)	(1,558)
Recoveries		296	1,322	935
Provision (release)		(230)	(3,745)	(7,976)
Ending balance		26,959	26,859	18,018
Allowance for loan losses		26,959	26,859	18,018
Commercial Portfolio Segment | Commercial and industrial | Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	11,533	47	11,533
Ending balance			47	11,533
Allowance for loan losses			47	11,533
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	52,373	54,730	52,373	54,569
Charge-offs		(8,008)	0	(247)
Recoveries		198	91	4
Provision (release)		18,555	8,921	(1,953)
Ending balance		65,475	54,730	52,373
Allowance for loan losses		65,475	54,730	52,373
Commercial Portfolio Segment | Commercial real estate | Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	(6,655)	0	(6,655)
Ending balance			0	(6,655)
Allowance for loan losses			0	(6,655)
Commercial Portfolio Segment | Commercial construction
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	2,585	7,085	2,585	4,553
Charge-offs		0	0	0
Recoveries		0	0	0
Provision (release)		(419)	3,015	(1,968)
Ending balance		6,666	7,085	2,585
Allowance for loan losses		6,666	7,085	2,585
Commercial Portfolio Segment | Commercial construction | Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,485	0	1,485
Ending balance			0	1,485
Allowance for loan losses			0	1,485
Commercial Portfolio Segment | Business banking
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	10,983	16,189	10,983	13,152
Charge-offs		(4,645)	(2,292)	(5,091)
Recoveries		1,867	2,069	1,524
Provision (release)		1,642	(731)	1,398
Ending balance		14,913	16,189	10,983
Allowance for loan losses		14,913	16,189	10,983
Commercial Portfolio Segment | Business banking | Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	6,160	(140)	6,160
Ending balance			(140)	6,160
Allowance for loan losses			(140)	6,160
Residential Portfolio Segment | Residential real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	6,556	28,129	6,556	6,435
Charge-offs		0	0	(35)
Recoveries		97	94	122
Provision (release)		(1,423)	7,990	34
Ending balance		25,954	28,129	6,556
Allowance for loan losses		25,954	28,129	6,556
Residential Portfolio Segment | Residential real estate | Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	13,489	(849)	13,489
Ending balance			(849)	13,489
Allowance for loan losses			(849)	13,489
Consumer Portfolio Segment | Consumer home equity
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,722	6,454	3,722	3,744
Charge-offs		(7)	(1)	(24)
Recoveries		41	24	185
Provision (release)		(692)	852	(183)
Ending balance		5,595	6,454	3,722
Allowance for loan losses		5,595	6,454	3,722
Consumer Portfolio Segment | Consumer home equity | Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,857	(201)	1,857
Ending balance			(201)	1,857
Allowance for loan losses			(201)	1,857
Consumer Portfolio Segment | Other Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3,308	2,765	3,308	3,467
Charge-offs		(2,419)	(2,269)	(2,047)
Recoveries		466	644	674
Provision (release)		2,619	1,623	1,214
Ending balance		3,431	2,765	3,308
Allowance for loan losses		3,431	2,765	3,308
Consumer Portfolio Segment | Other Consumer | Cumulative effect accounting adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ (541)	$ 0	(541)
Ending balance			0	(541)
Allowance for loan losses			$ 0	$ (541)

Loans and Allowance for Credi_6

Loans and Allowance for Credit Losses - Financing Receivable Credit Quality Indicators (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	$ 1,685,825	$ 3,481,250
2022	3,116,426	2,447,552
2021	2,223,220	1,630,538
2020	1,459,559	1,094,274
2019	921,574	779,687
Prior	2,846,088	2,496,108
Revolving Loans	1,674,790	1,614,995
Revolving Loans Converted to Term Loans	20,878	18,124
Total	13,948,360	13,562,528
Current period gross charge-offs
Total	15,092	4,831	$ 9,002
Commercial Portfolio Segment | Commercial and industrial
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	482,901	780,736
2022	480,687	490,827
2021	367,551	425,901
2020	355,211	204,752
2019	140,730	103,461
Prior	644,484	647,702
Revolving Loans	544,357	478,083
Revolving Loans Converted to Term Loans	3,710	1,066
Total	3,019,631	3,132,528
Current period gross charge-offs
2023	0
2022	2
2021	0
2020	0
2019	0
Prior	11
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total	13	269	1,558
Commercial Portfolio Segment | Commercial and industrial | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	477,138	778,144
2022	442,896	479,317
2021	350,782	415,990
2020	341,243	199,865
2019	140,641	100,716
Prior	641,342	639,825
Revolving Loans	485,448	473,148
Revolving Loans Converted to Term Loans	3,255	50
Total	2,882,745	3,087,055
Commercial Portfolio Segment | Commercial and industrial | Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	4,229	2,298
2022	25,796	1,307
2021	14,994	7,267
2020	13,563	4,841
2019	89	147
Prior	553	0
Revolving Loans	51,106	1,196
Revolving Loans Converted to Term Loans	455	670
Total	110,785	17,726
Commercial Portfolio Segment | Commercial and industrial | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	1,534	294
2022	11,995	4,954
2021	1,775	2,644
2020	405	46
2019	0	2,598
Prior	2,581	7,854
Revolving Loans	7,803	485
Revolving Loans Converted to Term Loans	0	346
Total	26,093	19,221
Commercial Portfolio Segment | Commercial and industrial | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	5,249
2021	0	0
2020	0	0
2019	0	0
Prior	8	23
Revolving Loans	0	3,254
Revolving Loans Converted to Term Loans	0	0
Total	8	8,526
Commercial Portfolio Segment | Commercial and industrial | Loss
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	544,143	1,510,675
2022	1,456,472	825,620
2021	870,251	589,959
2020	578,044	605,840
2019	552,383	501,194
Prior	1,394,411	1,053,298
Revolving Loans	55,587	60,590
Revolving Loans Converted to Term Loans	2,556	4,187
Total	5,453,847	5,151,363
Current period gross charge-offs
2023	2,008
2022	0
2021	0
2020	0
2019	0
Prior	6,000
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total	8,008	0	247
Commercial Portfolio Segment | Commercial real estate | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	498,590	1,510,675
2022	1,435,893	825,620
2021	855,014	586,567
2020	573,370	581,840
2019	516,689	461,296
Prior	1,291,189	1,006,160
Revolving Loans	47,581	52,590
Revolving Loans Converted to Term Loans	2,556	4,187
Total	5,220,882	5,028,935
Commercial Portfolio Segment | Commercial real estate | Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	15,200	0
2022	7,990	0
2021	0	771
2020	736	4,204
2019	2,281	15,366
Prior	34,803	12,255
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	61,010	32,596
Commercial Portfolio Segment | Commercial real estate | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	19,738	0
2022	12,589	0
2021	15,237	2,621
2020	3,938	19,796
2019	33,413	24,532
Prior	48,978	34,883
Revolving Loans	8,006	8,000
Revolving Loans Converted to Term Loans	0	0
Total	141,899	89,832
Commercial Portfolio Segment | Commercial real estate | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	10,615	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	19,441	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	30,056	0
Commercial Portfolio Segment | Commercial real estate | Loss
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Commercial Portfolio Segment | Commercial construction
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	133,919	91,397
2022	151,957	178,648
2021	96,147	31,317
2020	0	20,767
2019	0	0
Prior	0	0
Revolving Loans	2,614	12,130
Revolving Loans Converted to Term Loans	0	0
Total	384,637	334,259
Current period gross charge-offs
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total	0	0	0
Commercial Portfolio Segment | Commercial construction | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	133,463	91,397
2022	151,957	178,648
2021	96,147	28,956
2020	0	20,767
2019	0	0
Prior	0	0
Revolving Loans	2,614	12,130
Revolving Loans Converted to Term Loans	0	0
Total	384,181	331,898
Commercial Portfolio Segment | Commercial construction | Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	456	0
2022	0	0
2021	0	2,361
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	456	2,361
Commercial Portfolio Segment | Commercial construction | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Commercial Portfolio Segment | Commercial construction | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Commercial Portfolio Segment | Commercial construction | Loss
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Commercial Portfolio Segment | Business banking
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	142,021	178,806
2022	168,396	206,703
2021	186,299	176,147
2020	152,545	135,731
2019	117,301	63,762
Prior	244,758	248,643
Revolving Loans	73,671	80,455
Revolving Loans Converted to Term Loans	4,602	4,991
Total	1,089,593	1,095,238
Current period gross charge-offs
2023	188
2022	161
2021	1,596
2020	86
2019	654
Prior	590
Revolving Loans	0
Revolving Loans Converted to Term Loans	1,370
Total	4,645	2,292	5,091
Commercial Portfolio Segment | Business banking | Pass
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	139,237	178,806
2022	165,247	202,230
2021	182,606	170,088
2020	146,180	128,282
2019	110,638	59,452
Prior	229,636	233,484
Revolving Loans	73,054	78,080
Revolving Loans Converted to Term Loans	3,996	4,770
Total	1,050,594	1,055,192
Commercial Portfolio Segment | Business banking | Special Mention
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	1,474	0
2022	2,553	991
2021	1,009	4,635
2020	4,294	4,605
2019	4,692	3,740
Prior	11,479	7,584
Revolving Loans	23	145
Revolving Loans Converted to Term Loans	27	0
Total	25,551	21,700
Commercial Portfolio Segment | Business banking | Substandard
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	1,310	0
2022	596	3,482
2021	2,684	1,424
2020	2,071	2,663
2019	1,464	570
Prior	3,423	7,505
Revolving Loans	594	2,230
Revolving Loans Converted to Term Loans	579	221
Total	12,721	18,095
Commercial Portfolio Segment | Business banking | Doubtful
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	181
2019	507	0
Prior	220	70
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	727	251
Commercial Portfolio Segment | Business banking | Loss
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Residential Portfolio Segment | Residential real estate
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	258,421	766,094
2022	737,367	702,429
2021	669,681	383,651
2020	356,406	103,747
2019	95,601	70,668
Prior	464,989	453,466
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	2,582,465	2,480,055
Current period gross charge-offs
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	0
Revolving Loans	0
Revolving Loans Converted to Term Loans	0
Total	0	0	35
Residential Portfolio Segment | Residential real estate | Current and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	257,671	761,442
2022	728,997	696,959
2021	665,811	382,262
2020	354,003	99,494
2019	93,817	66,702
Prior	451,812	434,720
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	2,552,111	2,441,579
Residential Portfolio Segment | Residential real estate | 30-89 days past due and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	750	4,652
2022	6,615	5,470
2021	2,437	1,245
2020	2,112	2,762
2019	1,496	2,951
Prior	8,219	11,646
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	21,629	28,726
Residential Portfolio Segment | Residential real estate | Loans 90 days or more past due and still accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Residential Portfolio Segment | Residential real estate | Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	1,755	0
2021	1,433	144
2020	291	1,491
2019	288	1,015
Prior	4,958	7,100
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	8,725	9,750
Consumer Portfolio Segment | Consumer home equity
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	30,541	97,954
2022	84,614	10,774
2021	9,151	5,840
2020	4,899	5,076
2019	4,166	21,438
Prior	82,711	76,174
Revolving Loans	985,161	966,188
Revolving Loans Converted to Term Loans	9,925	7,863
Total	1,211,168	1,191,307
Current period gross charge-offs
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	0
Revolving Loans	7
Revolving Loans Converted to Term Loans	0
Total	7	1	24
Consumer Portfolio Segment | Consumer home equity | Current and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	30,393	97,395
2022	84,065	10,774
2021	9,151	5,840
2020	4,899	5,015
2019	4,166	21,092
Prior	80,687	73,927
Revolving Loans	970,882	953,829
Revolving Loans Converted to Term Loans	9,472	7,320
Total	1,193,715	1,175,192
Consumer Portfolio Segment | Consumer home equity | 30-89 days past due and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	148	559
2022	483	0
2021	0	0
2020	0	0
2019	0	72
Prior	558	944
Revolving Loans	7,509	7,239
Revolving Loans Converted to Term Loans	223	247
Total	8,921	9,061
Consumer Portfolio Segment | Consumer home equity | Loans 90 days or more past due and still accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Consumer Portfolio Segment | Consumer home equity | Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	66	0
2021	0	0
2020	0	61
2019	0	274
Prior	1,466	1,303
Revolving Loans	6,770	5,120
Revolving Loans Converted to Term Loans	230	296
Total	8,532	7,054
Consumer Portfolio Segment | Other Consumer
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	93,879	55,588
2022	36,933	32,551
2021	24,140	17,723
2020	12,454	18,361
2019	11,393	19,164
Prior	14,735	16,825
Revolving Loans	13,400	17,549
Revolving Loans Converted to Term Loans	85	17
Total	207,019	177,778
Current period gross charge-offs
2023	1,047
2022	411
2021	329
2020	92
2019	111
Prior	260
Revolving Loans	169
Revolving Loans Converted to Term Loans	0
Total	2,419	2,269	$ 2,047
Consumer Portfolio Segment | Other Consumer | Current and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	93,659	55,414
2022	36,601	32,390
2021	23,962	17,641
2020	12,427	18,298
2019	11,367	18,832
Prior	14,609	16,603
Revolving Loans	13,353	17,476
Revolving Loans Converted to Term Loans	85	0
Total	206,063	176,654
Consumer Portfolio Segment | Other Consumer | 30-89 days past due and accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	170	143
2022	271	68
2021	153	43
2020	25	61
2019	12	240
Prior	92	178
Revolving Loans	40	58
Revolving Loans Converted to Term Loans	0	7
Total	763	798
Consumer Portfolio Segment | Other Consumer | Loans 90 days or more past due and still accruing
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	0	0
2022	0	0
2021	0	0
2020	0	0
2019	0	0
Prior	0	0
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Total	0	0
Consumer Portfolio Segment | Other Consumer | Non-accrual
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
2023	50	31
2022	61	93
2021	25	39
2020	2	2
2019	14	92
Prior	34	44
Revolving Loans	7	15
Revolving Loans Converted to Term Loans	0	10
Total	$ 193	$ 326

Loans and Allowance for Credi_7

Loans and Allowance for Credit Losses - Financing Receivable, Past Due (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Total	$ 13,948,360	$ 13,562,528
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	30,936	42,715
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	9,370	6,360
90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total	16,824	18,892
Total Past Due
Financing Receivable, Past Due [Line Items]
Total	57,130	67,967
Current
Financing Receivable, Past Due [Line Items]
Total	13,891,230	13,494,561
Commercial Portfolio Segment | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total	3,019,631	3,132,528
Commercial Portfolio Segment | Commercial and industrial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	3,316	1,300
Commercial Portfolio Segment | Commercial and industrial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	385
Commercial Portfolio Segment | Commercial and industrial | 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total	465	2,074
Commercial Portfolio Segment | Commercial and industrial | Total Past Due
Financing Receivable, Past Due [Line Items]
Total	3,781	3,759
Commercial Portfolio Segment | Commercial and industrial | Current
Financing Receivable, Past Due [Line Items]
Total	3,015,850	3,128,769
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total	5,453,847	5,151,363
Commercial Portfolio Segment | Commercial real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial real estate | 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial real estate | Current
Financing Receivable, Past Due [Line Items]
Total	5,453,847	5,151,363
Commercial Portfolio Segment | Commercial construction
Financing Receivable, Past Due [Line Items]
Total	384,637	334,259
Commercial Portfolio Segment | Commercial construction | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial construction | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial construction | 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial construction | Total Past Due
Financing Receivable, Past Due [Line Items]
Total	0	0
Commercial Portfolio Segment | Commercial construction | Current
Financing Receivable, Past Due [Line Items]
Total	384,637	334,259
Commercial Portfolio Segment | Business banking
Financing Receivable, Past Due [Line Items]
Total	1,089,593	1,095,238
Commercial Portfolio Segment | Business banking | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	3,455	6,642
Commercial Portfolio Segment | Business banking | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,647	845
Commercial Portfolio Segment | Business banking | 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total	1,202	3,517
Commercial Portfolio Segment | Business banking | Total Past Due
Financing Receivable, Past Due [Line Items]
Total	6,304	11,004
Commercial Portfolio Segment | Business banking | Current
Financing Receivable, Past Due [Line Items]
Total	1,083,289	1,084,234
Residential Portfolio Segment | Residential real estate
Financing Receivable, Past Due [Line Items]
Total	2,582,465	2,480,055
Residential Portfolio Segment | Residential real estate | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	17,116	25,877
Residential Portfolio Segment | Residential real estate | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	4,888	3,852
Residential Portfolio Segment | Residential real estate | 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total	6,764	6,456
Residential Portfolio Segment | Residential real estate | Total Past Due
Financing Receivable, Past Due [Line Items]
Total	28,768	36,185
Residential Portfolio Segment | Residential real estate | Current
Financing Receivable, Past Due [Line Items]
Total	2,553,697	2,443,870
Consumer Portfolio Segment | Consumer home equity
Financing Receivable, Past Due [Line Items]
Total	1,211,168	1,191,307
Consumer Portfolio Segment | Consumer home equity | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	6,517	8,262
Consumer Portfolio Segment | Consumer home equity | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	2,600	1,108
Consumer Portfolio Segment | Consumer home equity | 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total	8,204	6,525
Consumer Portfolio Segment | Consumer home equity | Total Past Due
Financing Receivable, Past Due [Line Items]
Total	17,321	15,895
Consumer Portfolio Segment | Consumer home equity | Current
Financing Receivable, Past Due [Line Items]
Total	1,193,847	1,175,412
Consumer Portfolio Segment | Other Consumer
Financing Receivable, Past Due [Line Items]
Total	207,019	177,778
Consumer Portfolio Segment | Other Consumer | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	532	634
Consumer Portfolio Segment | Other Consumer | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	235	170
Consumer Portfolio Segment | Other Consumer | 90 or More Days Past Due
Financing Receivable, Past Due [Line Items]
Total	189	320
Consumer Portfolio Segment | Other Consumer | Total Past Due
Financing Receivable, Past Due [Line Items]
Total	956	1,124
Consumer Portfolio Segment | Other Consumer | Current
Financing Receivable, Past Due [Line Items]
Total	$ 206,063	$ 176,654

Loans and Allowance for Credi_8

Loans and Allowance for Credit Losses - Financing Receivable, Nonaccrual (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans With ACL	$ 35,995	$ 26,244
Non-Accrual Loans Without ACL	16,562	12,360
Total Non-Accrual Loans	52,557	38,604
Commercial Portfolio Segment | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans With ACL	4	3,270
Non-Accrual Loans Without ACL	464	10,707
Total Non-Accrual Loans	468	13,977
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans With ACL	13,969	0
Non-Accrual Loans Without ACL	16,087	0
Total Non-Accrual Loans	30,056	0
Commercial Portfolio Segment | Commercial construction
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans With ACL	0	0
Non-Accrual Loans Without ACL	0	0
Total Non-Accrual Loans	0	0
Commercial Portfolio Segment | Business banking
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans With ACL	4,572	5,844
Non-Accrual Loans Without ACL	11	1,653
Total Non-Accrual Loans	4,583	7,497
Residential Portfolio Segment | Residential real estate
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans With ACL	8,725	9,750
Non-Accrual Loans Without ACL	0	0
Total Non-Accrual Loans	8,725	9,750
Consumer Portfolio Segment | Consumer home equity
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans With ACL	8,532	7,054
Non-Accrual Loans Without ACL	0	0
Total Non-Accrual Loans	8,532	7,054
Consumer Portfolio Segment | Other Consumer
Financing Receivable, Past Due [Line Items]
Non-Accrual Loans With ACL	193	326
Non-Accrual Loans Without ACL	0	0
Total Non-Accrual Loans	$ 193	$ 326

Loans and Allowance for Credi_9

Loans and Allowance for Credit Losses - Loan Modifications to Borrowers Experiencing Financial Difficulty (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) payment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 19,363
% of Total Portfolio	0.14%
Total Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 1,044
30-59 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	417
60-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	227
90 or More Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	400
Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	18,319
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 2,227
% of Total Portfolio	0.02%
Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 4,308
% of Total Portfolio	0.03%
Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 274
% of Total Portfolio	0%
Combination - Interest Rate Reduction & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 11,304
% of Total Portfolio	0.08%
Combination - Interest Rate Reduction & Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 774
% of Total Portfolio	0.01%
Combination - Term Extension & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 164
% of Total Portfolio	0%
Combination - Interest Rate Reduction, Term Extension & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 312
% of Total Portfolio	0%
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 10,615
% of Total Portfolio	0.19%
Interest-only period | payment	9
Commercial Portfolio Segment | Commercial real estate | Total Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 0
Commercial Portfolio Segment | Commercial real estate | 30-59 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	0
Commercial Portfolio Segment | Commercial real estate | 60-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	0
Commercial Portfolio Segment | Commercial real estate | 90 or More Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	0
Commercial Portfolio Segment | Commercial real estate | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 10,615
Commercial Portfolio Segment | Commercial real estate | Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest Rate Reduction	7.40%
Commercial Portfolio Segment | Commercial real estate | Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest Rate Reduction	3.40%
Commercial Portfolio Segment | Commercial real estate | Combination - Interest Rate Reduction & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 10,615
% of Total Portfolio	0.19%
Commercial Portfolio Segment | Business banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 1,188
% of Total Portfolio	0.11%
Other-than-Insignificant Delay in Repayment | payment	4
Term Extension	4 years 3 months 18 days
Commercial Portfolio Segment | Business banking | Total Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 0
Commercial Portfolio Segment | Business banking | 30-59 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	0
Commercial Portfolio Segment | Business banking | 60-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	0
Commercial Portfolio Segment | Business banking | 90 or More Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	0
Commercial Portfolio Segment | Business banking | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 1,188
Commercial Portfolio Segment | Business banking | Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest Rate Reduction	9.80%
Commercial Portfolio Segment | Business banking | Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest Rate Reduction	7.60%
Commercial Portfolio Segment | Business banking | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 43
% of Total Portfolio	0%
Commercial Portfolio Segment | Business banking | Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 20
% of Total Portfolio	0%
Commercial Portfolio Segment | Business banking | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 274
% of Total Portfolio	0.03%
Commercial Portfolio Segment | Business banking | Combination - Interest Rate Reduction & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 86
% of Total Portfolio	0.01%
Commercial Portfolio Segment | Business banking | Combination - Interest Rate Reduction & Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 561
% of Total Portfolio	0.05%
Commercial Portfolio Segment | Business banking | Combination - Term Extension & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 24
% of Total Portfolio	0%
Commercial Portfolio Segment | Business banking | Combination - Interest Rate Reduction, Term Extension & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 180
% of Total Portfolio	0.02%
Residential Portfolio Segment | Residential real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 3,806
% of Total Portfolio	0.15%
Other-than-Insignificant Delay in Repayment | payment	7
Term Extension	23 years 8 months 12 days
Residential Portfolio Segment | Residential real estate | Total Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 593
Residential Portfolio Segment | Residential real estate | 30-59 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	366
Residential Portfolio Segment | Residential real estate | 60-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	227
Residential Portfolio Segment | Residential real estate | 90 or More Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	0
Residential Portfolio Segment | Residential real estate | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 3,213
Residential Portfolio Segment | Residential real estate | Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest Rate Reduction	5.40%
Residential Portfolio Segment | Residential real estate | Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest Rate Reduction	3.60%
Residential Portfolio Segment | Residential real estate | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 301
% of Total Portfolio	0.01%
Residential Portfolio Segment | Residential real estate | Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 3,284
% of Total Portfolio	0.13%
Residential Portfolio Segment | Residential real estate | Combination - Term Extension & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 140
% of Total Portfolio	0.01%
Residential Portfolio Segment | Residential real estate | Combination - Interest Rate Reduction, Term Extension & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 81
% of Total Portfolio	0%
Consumer Portfolio Segment | Consumer home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 3,754
% of Total Portfolio	0.31%
Other-than-Insignificant Delay in Repayment | payment	8
Term Extension	16 years 9 months 18 days
Consumer Portfolio Segment | Consumer home equity | Total Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 451
Consumer Portfolio Segment | Consumer home equity | 30-59 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	51
Consumer Portfolio Segment | Consumer home equity | 60-89 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	0
Consumer Portfolio Segment | Consumer home equity | 90 or More Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	400
Consumer Portfolio Segment | Consumer home equity | Current
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 3,303
Consumer Portfolio Segment | Consumer home equity | Maximum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest Rate Reduction	7.50%
Consumer Portfolio Segment | Consumer home equity | Minimum
Financing Receivable, Troubled Debt Restructuring [Line Items]
Interest Rate Reduction	4.50%
Consumer Portfolio Segment | Consumer home equity | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 1,883
% of Total Portfolio	0.16%
Consumer Portfolio Segment | Consumer home equity | Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 1,004
% of Total Portfolio	0.08%
Consumer Portfolio Segment | Consumer home equity | Combination - Interest Rate Reduction & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 603
% of Total Portfolio	0.05%
Consumer Portfolio Segment | Consumer home equity | Combination - Interest Rate Reduction & Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 213
% of Total Portfolio	0.02%
Consumer Portfolio Segment | Consumer home equity | Combination - Interest Rate Reduction, Term Extension & Other-than-Insignificant Delay in Repayment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Amortized Cost Balance	$ 51
% of Total Portfolio	0%

Loans and Allowance for Cred_10

Loans and Allowance for Credit Losses - Schedule of Participating Mortgage Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 1,579,059	$ 1,542,358
Non-performing Loan Rate (%)	0%	0.55%
Gross Charge-offs	$ 22	$ 3
Commercial Portfolio Segment | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 985,394	$ 1,024,131
Non-performing Loan Rate (%)	0%	0.83%
Gross Charge-offs	$ 0	$ 0
Commercial Portfolio Segment | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 447,550	$ 422,042
Non-performing Loan Rate (%)	0%	0%
Gross Charge-offs	$ 0	$ 0
Commercial Portfolio Segment | Commercial construction
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 146,043	$ 96,134
Non-performing Loan Rate (%)	0%	0%
Gross Charge-offs	$ 0	$ 0
Commercial Portfolio Segment | Business banking
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 72	$ 51
Non-performing Loan Rate (%)	0%	0%
Gross Charge-offs	$ 22	$ 3

Loans and Allowance for Cred_11

Loans and Allowance for Credit Losses - Summary of TDR Loans on Accrual and Nonaccrual (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) loan	Dec. 31, 2022 USD ($) contract	Dec. 31, 2021 contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans	257	51	5
Balance of Loans	$ 48,185	$ 48,185
Special Mention | Contractual Obligation Modification | TDRs on Accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	179
Balance of Loans	$ 28,834	28,834
Special Mention | Contractual Obligation Modification | TDRs on Non-accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	78
Balance of Loans	$ 19,351	$ 19,351
Commercial Portfolio Segment | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans	11	4	0
Balance of Loans	$ 15,766	$ 15,766
Commercial Portfolio Segment | Commercial and industrial | Special Mention | Contractual Obligation Modification | TDRs on Accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	2
Balance of Loans	$ 4,449	4,449
Commercial Portfolio Segment | Commercial and industrial | Special Mention | Contractual Obligation Modification | TDRs on Non-accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	9
Balance of Loans	$ 11,317	$ 11,317
Commercial Portfolio Segment | Business banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans	33	30	0
Balance of Loans	$ 6,225	$ 6,225
Commercial Portfolio Segment | Business banking | Special Mention | Contractual Obligation Modification | TDRs on Accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	11
Balance of Loans	$ 4,124	4,124
Commercial Portfolio Segment | Business banking | Special Mention | Contractual Obligation Modification | TDRs on Non-accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	22
Balance of Loans	$ 2,101	$ 2,101
Residential Portfolio Segment | Residential real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans	142	10	2
Balance of Loans	$ 21,634	$ 21,634
Residential Portfolio Segment | Residential real estate | Special Mention | Contractual Obligation Modification | TDRs on Accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	114
Balance of Loans	$ 17,618	17,618
Residential Portfolio Segment | Residential real estate | Special Mention | Contractual Obligation Modification | TDRs on Non-accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	28
Balance of Loans	$ 4,016	$ 4,016
Consumer Portfolio Segment | Consumer home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans	70	7	3
Balance of Loans	$ 4,549	$ 4,549
Consumer Portfolio Segment | Consumer home equity | Special Mention | Contractual Obligation Modification | TDRs on Accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	51
Balance of Loans	$ 2,632	2,632
Consumer Portfolio Segment | Consumer home equity | Special Mention | Contractual Obligation Modification | TDRs on Non-accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	19
Balance of Loans	$ 1,917	1,917
Consumer Portfolio Segment | Other Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	1
Balance of Loans	$ 11	11
Consumer Portfolio Segment | Other Consumer | Special Mention | Contractual Obligation Modification | TDRs on Accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	1
Balance of Loans	$ 11	11
Consumer Portfolio Segment | Other Consumer | Special Mention | Contractual Obligation Modification | TDRs on Non-accrual Status
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	0
Balance of Loans	$ 0	$ 0

Loans and Allowance for Cred_12

Loans and Allowance for Credit Losses - Summary of the Modifications Which Occurred During the Periods and the Change in the Recorded Investment Subsequent to the Modifications Occurring (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 loan	Dec. 31, 2022 contract	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	257	51		5
Pre- Modification Outstanding Recorded Investment			$ 12,571	$ 798
Post-Modification Outstanding Recorded Investment			12,590	$ 798
Commercial Portfolio Segment | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	11	4		0
Pre- Modification Outstanding Recorded Investment			5,415	$ 0
Post-Modification Outstanding Recorded Investment			5,415	$ 0
Commercial Portfolio Segment | Business banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	33	30		0
Pre- Modification Outstanding Recorded Investment			2,779	$ 0
Post-Modification Outstanding Recorded Investment			2,798	$ 0
Residential Portfolio Segment | Residential real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	142	10		2
Pre- Modification Outstanding Recorded Investment			2,842	$ 498
Post-Modification Outstanding Recorded Investment			2,842	$ 498
Consumer Portfolio Segment | Consumer home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	70	7		3
Pre- Modification Outstanding Recorded Investment			1,535	$ 300
Post-Modification Outstanding Recorded Investment			$ 1,535	$ 300
Consumer Portfolio Segment | Other Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | loan	1

Loans and Allowance for Cred_13

Loans and Allowance for Credit Losses - Summary of Post-modification Balance of TDRs listed by Type of Modification (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	$ 12,590	$ 798
Extended maturity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	1,011	200
Adjusted interest rate and extended maturity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	1,088	0
Interest only/principal deferred
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	1,499	0
Covenant modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	2,418	0
Court-ordered concession
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	0	396
Principal and interest deferred
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	3,353	0
Extended maturity and interest only/principal deferred
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	2,997	0
Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	$ 224	$ 202

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses - Summary of Information Regarding Interest Income Recognized on Impaired Loans,by Portfolio (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Average Recorded Investment
With no allowance recorded:	$ 34,637
With an allowance recorded:	35,673
Total	70,310
Total Interest Recognized
With no allowance recorded:	956
With an allowance recorded:	596
Total	1,552
Commercial and industrial | Commercial Portfolio Segment
Average Recorded Investment
With no allowance recorded:	11,813
With an allowance recorded:	7,229
Total Interest Recognized
With no allowance recorded:	161
With an allowance recorded:	0
Commercial real estate | Commercial Portfolio Segment
Average Recorded Investment
With no allowance recorded:	3,916
With an allowance recorded:	926
Total Interest Recognized
With no allowance recorded:	178
With an allowance recorded:	0
Business banking | Commercial Portfolio Segment
Average Recorded Investment
With no allowance recorded:	4,352
With an allowance recorded:	13,027
Total Interest Recognized
With no allowance recorded:	99
With an allowance recorded:	57
Residential real estate | Residential Portfolio Segment
Average Recorded Investment
With no allowance recorded:	12,506
With an allowance recorded:	12,322
Total Interest Recognized
With no allowance recorded:	456
With an allowance recorded:	474
Consumer home equity | Consumer Portfolio Segment
Average Recorded Investment
With no allowance recorded:	2,027
With an allowance recorded:	2,106
Total Interest Recognized
With no allowance recorded:	62
With an allowance recorded:	65
Other Consumer | Consumer Portfolio Segment
Average Recorded Investment
With no allowance recorded:	23
With an allowance recorded:	63
Total Interest Recognized
With no allowance recorded:	0
With an allowance recorded:	$ 0

Loans and Allowance for Loan _2

Loans and Allowance for Loan Losses - Summary of Activity in the Accretable Yield for the PCI Loan Portfolio (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 2,495
Acquisition	8,896
Accretion	(1,194)
Other change in expected cash flows	(1,475)
Reclassification from non-accretable difference for loans with improved cash flows	1,649
Balance at end of period	$ 10,371

Premises and Equipment - Schedu

Premises and Equipment - Schedule of Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total cost	$ 155,728	$ 154,865
Accumulated depreciation	(95,595)	(92,372)
Premises and equipment used in operations, net	60,133	62,493
Premises and equipment held for sale	0	0
Premises and equipment held for sale	60,133	62,493
Land
Property, Plant and Equipment [Line Items]
Total cost	12,585	12,585
Buildings
Property, Plant and Equipment [Line Items]
Total cost	$ 70,597	70,771
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	30 years
Equipment
Property, Plant and Equipment [Line Items]
Total cost	$ 37,756	35,085
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total cost	$ 34,790	$ 36,424
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	25 years

Premises and Equipment - Narrat

Premises and Equipment - Narrative (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) property	Dec. 31, 2022 USD ($) property	Dec. 31, 2021 USD ($) property
Property, Plant and Equipment [Line Items]
Depreciation	$ 10,500,000	$ 10,700,000	$ 11,600,000
Number of properties transferred to held for sale | property	0	0	5
Number of properties sold | property	0	5	3
Proceeds from sale of bank premises and equipment	$ 0	$ 17,313,000	$ 21,981,000
Gain (loss) on disposition of property plant equipment	$ 0	$ 1,412,000	(4,715,000)
Properties transferred to held for sale, amount			37,600,000
Loss on properties transferred to held for sale			$ 1,200,000
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations
Property, Plant and Equipment [Line Items]
Number of properties sold | property			1
Gain (loss) on disposition of property plant equipment			$ 0
Century Bancorp, Inc.
Property, Plant and Equipment [Line Items]
Number of properties transferred to held for sale | property			4
Number of properties sold | property		4	2

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) lease extension	Dec. 31, 2022 USD ($) extension lease	Dec. 31, 2021 USD ($)
Disclosure of Leases [Line Items]
Payment of leases	$ 13.3	$ 15.2	$ 13.6
Number of lease extensions not exercised | extension	4	2
Number of lease extensions exercised | extension	10	2
Number of leases terminated | lease	1	4
Net increase (decrease) in operating lease right of use assets and operating lease liabilities relating to lease remeasurements	$ 2.4	$ (14.4)
Impairment charge	$ 0.4	$ 0.6
Minimum
Disclosure of Leases [Line Items]
Operating lease remaining lease term	1 year
Maximum
Disclosure of Leases [Line Items]
Operating lease remaining lease term	25 years

Leases - Summary of Information

Leases - Summary of Information Relating to Operating Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Right-of-use assets	$ 50,641	$ 48,817
Lease liabilities	$ 55,617	$ 52,105
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Other liabilities	Other liabilities

Leases - Summary of Net Lease C

Leases - Summary of Net Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease cost	$ 12,439	$ 12,716	$ 12,559
Finance lease cost	338	309	160
Variable lease cost	2,766	2,547	2,012
Total lease cost	$ 15,543	$ 15,572	$ 14,731

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information Related to Operating Leases (Details)	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Weighted-average remaining lease term (in years)	8 years 3 months 3 days	7 years 3 months
Weighted-average discount rate	3.76%	2.62%

Leases - Summary of Reconciliat

Leases - Summary of Reconciliation to the Operating Lease Liability Recognized in the Company's Consolidated Balance Sheet in Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
2024	$ 11,506
2025	8,504
2026	7,143
2027	5,609
2028	5,886
Thereafter	27,770
Total minimum lease payments	66,418
Less: amount representing interest	10,801
Present value of future minimum lease payments	$ 55,617	$ 52,105

Goodwill and Core Deposit Int_3

Goodwill and Core Deposit Intangible Asset - Summary of Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Balances not subject to amortization
Goodwill	$ 557,635	$ 557,635	$ 557,635
Balances subject to amortization
Core deposit intangible	8,570	10,374
Total goodwill and other intangible assets	566,205	568,009
Core Deposits
Balances subject to amortization
Core deposit intangible	$ 8,570	$ 10,374

Goodwill and Core Deposit Int_4

Goodwill and Core Deposit Intangible Asset - Schedule of Goodwill Carrying Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Roll Forward]
Balance at beginning of year	$ 557,635	$ 557,635
Goodwill recorded during the year	0	0
Balance at end of year	$ 557,635	$ 557,635

Goodwill and Core Deposit Int_5

Goodwill and Core Deposit Intangible Asset - Carrying Amount and Accumulated Amortization of Other Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 11,633	$ 15,969
Accumulated Amortization	(3,063)	(5,595)
Total amortization expense	8,570	10,374
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	11,633	15,969
Accumulated Amortization	(3,063)	(5,595)
Total amortization expense	$ 8,570	$ 10,374

Goodwill and Core Deposit Int_6

Goodwill and Core Deposit Intangible Asset - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) reporting_unit	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jun. 30, 2023
Finite-Lived Intangible Assets [Line Items]
Number of reporting units | reporting_unit	1
Amortization of core deposit intangible asset | $	$ 1,804	$ 1,198	$ 219
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life	10 years
Remaining useful life of intangible	4 years 3 months 18 days			5 years

Goodwill and Core Deposit Int_7

Goodwill and Core Deposit Intangible Asset - Estimated Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
2024	$ 2,017
2025	2,017
2026	2,017
2027	2,017
2028	502
Total amortization expense	$ 8,570	$ 10,374

Deposits - Narrative (Details)

Deposits - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Banking and Thrift, Interest [Abstract]
Bank overdrafts	$ 2.4	$ 2.3
Time deposits equal to or grater than $250,000	867.6	239.1
Brokered certificates of deposit	$ 50	$ 928.6

Deposits - Summary of the Compa

Deposits - Summary of the Company’s Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Banking and Thrift, Interest [Abstract]
Demand	$ 5,162,218	$ 6,240,637
Interest checking accounts	3,737,361	4,568,122
Savings accounts	1,323,126	1,831,123
Money market investment	4,664,475	4,710,095
Certificates of deposit	2,709,037	1,624,382
Total deposits	$ 17,596,217	$ 18,974,359

Deposits - Summary of the Certi

Deposits - Summary of the Certificates of Deposits by Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Balance
2024	$ 2,683,364
2025	15,484
2026	5,630
2027	2,940
2028	1,586
Thereafter	33
Total certificates of deposit	$ 2,709,037	$ 1,624,382
Percentage of Total
2024	99.10%
2025	0.60%
2026	0.20%
2027	0.10%
2028	0.10%
Thereafter	0%
Total certificates of deposit	100%

Borrowed Funds - Summary of Bor

Borrowed Funds - Summary of Borrowed Funds (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Federal Home Loan Banks [Abstract]
Short-term FHLB advances	$ 95	$ 691,297
Escrow deposits of borrowers	21,978	22,314
Interest rate swap collateral funds	8,500	14,430
Long-term FHLB advances	17,643	12,787
Total borrowed funds	$ 48,216	$ 740,828

Borrowed Funds - Narrative (Det

Borrowed Funds - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Federal Home Loan Bank, Advances [Line Items]
Carrying value of securities pledged as collateral	$ 615,700,000	$ 437,900,000
Federal Home Loan Bank stock, at cost	5,904,000	41,363,000
Dividends received from investment in FHLB of Boston	2,000,000	300,000	$ 200,000
Federal Reserve Discount Window
Federal Home Loan Bank, Advances [Line Items]
Carrying value of securities pledged as collateral	168,800,000	0
Federal Reserve Discount Window | Loans Receivable
Federal Home Loan Bank, Advances [Line Items]
Carrying value of securities pledged as collateral	636,800,000	538,900,000
Federal Reserve Discount Window | Debt Securities
Federal Home Loan Bank, Advances [Line Items]
Carrying value of securities pledged as collateral	139,100,000	0
Bank Term Funding Program
Federal Home Loan Bank, Advances [Line Items]
Carrying value of securities pledged as collateral	2,400,000,000	0
Federal Home Loan Bank of Boston
Federal Home Loan Bank, Advances [Line Items]
Collateralized line of credit	2,400,000,000
Federal Home Loan Bank stock, at cost	5,900,000	41,400,000
Federal Home Loan Bank of Boston | Bank Term Funding Program
Federal Home Loan Bank, Advances [Line Items]
Carrying value of securities pledged as collateral	2,400,000,000
Federal Home Loan Bank of Boston | Short-term FHLB advances
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, available and unused borrowing capacity	2,900,000,000	2,000,000,000
Federal Home Loan Bank of Boston | Short-term FHLB advances | Residential Mortgage Backed Securities
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, advances secured by mortgage-backed securities	1,400,000,000	1,500,000,000
Federal Home Loan Bank of Boston | Short-term FHLB advances | Commercial Mortgage Backed Securities
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, advances secured by mortgage-backed securities	1,500,000,000	1,200,000,000
Federal Reserve Bank Advances
Federal Home Loan Bank, Advances [Line Items]
Federal Reserve Discount Window, available and unused borrowing capacity	$ 775,900,000	$ 538,900,000

Borrowed Funds - Interest Expen

Borrowed Funds - Interest Expense on Borrowed Funds (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Federal Home Loan Bank, Advances [Line Items]
Total interest expense on borrowed funds	$ 19,975	$ 8,506	$ 165
Federal Home Loan Bank advances
Federal Home Loan Bank, Advances [Line Items]
Total interest expense on borrowed funds	19,247	8,263	163
Escrow deposits of borrowers
Federal Home Loan Bank, Advances [Line Items]
Total interest expense on borrowed funds	6	3	2
Interest rate swap collateral funds
Federal Home Loan Bank, Advances [Line Items]
Total interest expense on borrowed funds	722	216	0
Federal funds purchased
Federal Home Loan Bank, Advances [Line Items]
Total interest expense on borrowed funds	$ 0	$ 24	$ 0

Borrowed Funds - Summary of FHL

Borrowed Funds - Summary of FHLB of Boston Advances (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Amount
Within one year	$ 95	$ 691,297
Federal Home Loan Bank of Boston
Amount
Within one year	95	691,297
Over one year to three years	3,409	2,835
Over three years to five years	2,685	2,534
Over five years	11,549	7,418
Total Federal Home Loan Bank advances	$ 17,738	$ 704,084
Weighted Average Interest Rate
Within one year	1.50%	4.36%
Over one year to three years	0.73%	0.86%
Over three years to five years	1.59%	1.89%
Over five years	1.31%	0.94%
Total Federal Home Loan Bank advances	1.25%	4.30%
Federal Home Loan Bank of Boston | Long-term FHLB advances
Weighted Average Interest Rate
Total Federal Home Loan Bank advances	1.24%	1.11%

Earnings Per Share ("EPS") (Det

Earnings Per Share ("EPS") (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Net (loss) income from continuing operations	$ (62,689)	$ 186,511	$ 145,531
Net income from discontinued operations	294,866	13,248	9,134
Net income	$ 232,177	$ 199,759	$ 154,665
Average number of common shares outstanding (in shares)	175,814,954	179,529,613	186,713,020
Less: Average unallocated ESOP shares (in shares)	(13,521,934)	(14,019,256)	(14,520,684)
Average number of common shares outstanding used to calculate basic earnings per common share (in shares)	162,293,020	165,510,357	172,192,336
Common stock equivalents - restricted stock awards and units (in shares)	110,077	138,214	59,721
Average number of common shares outstanding used to calculate diluted earnings per common share (in shares)	162,403,097	165,648,571	172,252,057
Basic earnings per share
Basic (loss) earnings per share from continuing operations (in dollars per share)	$ (0.39)	$ 1.13	$ 0.85
Basic earnings per share from discontinued operations (in dollars per share)	1.82	0.08	0.05
Basic earnings per share (in dollars per share)	1.43	1.21	0.90
Diluted earnings per share
Diluted (loss) earnings per share from continuing operations (in dollars per share)	(0.39)	1.13	0.85
Diluted earnings per share from discontinued operations (in dollars per share)	1.82	0.08	0.05
Diluted earnings per share (in dollars per share)	$ 1.43	$ 1.21	$ 0.90

Low Income Housing Tax Credit_3

Low Income Housing Tax Credits and Other Tax Credit Investments - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Investments In Affordable Housing Projects [Line Items]
Tax credit investments	$ 223,400,000	$ 131,300,000
Renewable Energy Program
Investments In Affordable Housing Projects [Line Items]
Equity investments	2,200,000	2,600,000
Outstanding investment commitments	$ 0	$ 0
Low income housing tax credit and other tax credit investments
Investments In Affordable Housing Projects [Line Items]
Tax credit period of benefits	15 years
Operating loss tax benefits period	15 years

Low Income Housing Tax Credit_4

Low Income Housing Tax Credits and Other Tax Credit Investments - Summary of the Company's Investments in Low Income Housing Projects Accounted for Using the Proportional Amortization Method (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Investments in Affordable Housing Projects [Abstract]
Current recorded investment included in other assets	$ 221,190	$ 128,765
Commitments to fund qualified affordable housing projects included in recorded investment noted above	149,207	84,145
Tax credits and other tax benefits recognized	11,624	9,146	$ 6,484
Amortization expense included in income tax expense	$ 9,577	$ 7,503	$ 5,753

Income Taxes - Summary of Compa

Income Taxes - Summary of Company's Tax Provision and Applicable Tax Rates (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Combined federal and state income tax provisions	$ (63,309)	$ 51,719	$ 30,464
Effective income tax rates	50.25%	21.71%	17.32%

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)		3 Months Ended	12 Months Ended
	Dec. 31, 2022	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Examination [Line Items]
Income tax (benefit) expense			$ (63,309,000)	$ 51,719,000	$ 30,464,000
Deferred state and local income tax benefit		$ 23,700,000	19,486,000	(6,290,000)	(2,321,000)
Deferred tax asset valuation allowance						$ 12,000,000
Stock donation						91,300,000
Charitable cash contribution						3,700,000
Valuation allowance, deferred tax asset, decrease, amount	$ 700,000				11,300,000
Unrecognized tax benefits	5,782,000		3,503,000	5,782,000	7,923,000	$ 0
Unrecognized tax benefits that would impact effective tax rate			3,800,000
Unrecognized tax benefits, income tax penalties and interest accrued	1,500,000		1,000,000	1,500,000
Unrecognized tax benefits, income tax penalties and interest expense			500,000
Reductions as a result of a lapse of the applicable statute of limitations			2,279,000	2,141,000	0
Tax interest and penalties, reduction resulting from lapse of applicable statute of limitations			700,000
Decrease in unrecognized tax benefits is reasonably possible			1,900,000
Decrease in tax interest and penalties is reasonably possible			800,000
Net operating loss carryforwards	0		0	0
Federal pre-1988 reserve with no tax provision			20,800,000
Tax credits and other tax benefits recognized			11,624,000	9,146,000	$ 6,484,000
Federal
Income Tax Examination [Line Items]
Tax credits and other tax benefits recognized			9,200,000	7,300,000
State
Income Tax Examination [Line Items]
Unrecognized tax benefits	$ 6,000,000		3,800,000	6,000,000
Release of uncertain tax positions			2,200,000
Tax credits and other tax benefits recognized			$ 400,000	$ 100,000

Income Taxes - Components of In

Income Taxes - Components of Income Tax Provisions (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current tax (benefit) expense:
Federal		$ (39,710)	$ 36,436	$ 23,923
State		(5,332)	10,021	12,204
Total current tax (benefit) expense		(45,042)	46,457	36,127
Deferred tax (benefit) expense:
Federal		1,219	(1,028)	(7,984)
State	$ (23,700)	(19,486)	6,290	2,321
Total deferred tax (benefit) expense		(18,267)	5,262	(5,663)
Total income tax (benefit) expense		$ (63,309)	$ 51,719	$ 30,464

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax (benefit) expense at statutory rate	$ (26,458)	$ 50,029	$ 36,959
State income tax, net of federal tax benefit	(19,606)	12,885	11,475
Valuation allowance	0	(700)	(11,300)
Amortization of qualified low-income housing investments	9,577	7,503	5,753
Tax credits	(9,183)	(7,300)	(6,539)
Tax-exempt income	(14,161)	(10,298)	(5,665)
Other, net	(3,478)	(400)	(219)
Total income tax (benefit) expense	$ (63,309)	$ 51,719	$ 30,464
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax (benefit) expense at statutory rate	21%	21%	21%
State income tax, net of federal tax benefit (1)	15.56%	5.41%	6.53%
Valuation allowance	0%	(0.29%)	(6.42%)
Amortization of qualified low-income housing investments	(7.60%)	3.15%	3.27%
Tax credits	7.29%	(3.06%)	(3.72%)
Tax-exempt income	11.24%	(4.32%)	(3.22%)
Other, net	2.76%	(0.17%)	(0.12%)
Actual income tax (benefit) expense	50.25%	21.71%	17.32%

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Unrealized loss on available for sale securities	$ 193,134	$ 254,502
Allowance for loan losses	45,189	43,686
Cash flow hedges	12,302	18,192
Leases	15,664	14,858
Charitable contribution limitation carryover	4,844	12,273
Investment losses	7,339	7,918
Accrued expenses	10,042	5,426
Fixed assets	4,142	4,287
Loan basis difference fair value adjustments	3,455	4,009
Employee benefits	0	354
PPP loans fee income	0	58
Other	2,061	2,083
Total deferred tax assets	298,172	367,646
Deferred tax liabilities:
Amortization of intangibles	9,660	16,439
Lease obligation	14,284	13,933
Partnerships	1,971	2,340
Trading securities	3,405	938
Employee benefits	824	0
Other	1,843	2,033
Total deferred tax liabilities	31,987	35,683
Net deferred income tax assets	$ 266,185	$ 331,963

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning	$ 5,782	$ 7,923	$ 0
Additions based on tax positions related to the current year	0	0	0
Additions for tax positions of prior years	0	0	7,923
Reductions related to settlements with taxing authorities	0	0	0
Reductions as a result of a lapse of the applicable statute of limitations	(2,279)	(2,141)	0
Ending	$ 3,503	$ 5,782	$ 7,923

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Equity [Abstract]
Dividends Declared per Share (in dollars per share)	$ 0.11	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.10
Dividends Declared	$ 18,000	$ 16,400	$ 16,400	$ 16,300	$ 16,300	$ 16,500	$ 16,700	$ 17,100
Dividends Paid	$ 18,000	$ 16,200	$ 16,300	$ 16,200	$ 16,100	$ 16,300	$ 16,500	$ 16,900	$ 66,671	$ 65,886	$ 51,564

Minimum Regulatory Capital Re_3

Minimum Regulatory Capital Requirements (Details) $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Total regulatory capital (to risk-weighted assets)
Actual, Amount	$ 3,187,130	$ 2,906,742
Actual, Ratio	0.1955	0.1789
For Capital Adequacy, Amount	$ 1,304,508	$ 1,299,657
For Capital Adequacy, Ratio	0.08	0.08
To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,630,634	$ 1,624,571
To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	0.10	0.10
Common equity Tier 1 capital (to risk-weighted assets)
Actual, Amount	$ 3,024,288	$ 2,751,694
Actual, Ratio	0.1855	0.1694
For Capital Adequacy, Amount	$ 733,785	$ 731,057
For Capital Adequacy, Ratio	0.045	0.045
To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,059,912	$ 1,055,971
To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	0.065	0.065
Tier 1 capital (to risk-weighted assets)
Actual, Amount	$ 3,024,288	$ 2,751,694
Actual, Ratio	0.1855	0.1694
For Capital Adequacy, Amount	$ 978,381	$ 974,743
For Capital Adequacy, Ratio	0.06	0.06
To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,304,508	$ 1,299,657
To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	0.08	0.08
Tier 1 capital (to average assets) leverage
Actual, Amount	$ 3,024,288	$ 2,751,694
Actual, Ratio	0.1400	0.1203
For Capital Adequacy, Amount	$ 864,206	$ 915,233
For Capital Adequacy, Ratio	0.04	0.04
To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,080,258	$ 1,144,041
To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	0.05	0.05

Employee Benefits - Narrative (

Employee Benefits - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) plan	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Defined Benefit Plan, Plan Assets, Category [Line Items]
Discretionary employer contribution to the defined benefit plan	$ 0	$ 7,200
Defined benefit plan, expected future employer contributions, current fiscal year	$ 0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other	Other	Other
Curtailment	$ 15,908	$ 0	$ 0
Loss due to settlement	0	12,045	0
Discretionary contributions for the Defined Contribution Plan	5,200	5,000	4,600
Defined contribution liability	$ 20,300	17,300
Number of deferred compensation plans | plan	3
Deferred compensation plans, liabilities	$ 28,200	25,400
Asset Management Arrangement
Defined Benefit Plan, Plan Assets, Category [Line Items]
Actuarial loss (gain)	(63,811)	91,474
Benefit obligation	468,364	419,366	546,056
Equity Securities
Defined Benefit Plan, Plan Assets, Category [Line Items]
Rabbi trust investments	69,000	63,700
Fair value, net asset (liability)	$ 48,900	38,900
Fixed income | Minimum
Defined Benefit Plan, Plan Assets, Category [Line Items]
Plan asset, target allocation percentages	28%
Fixed income | Maximum
Defined Benefit Plan, Plan Assets, Category [Line Items]
Plan asset, target allocation percentages	42%
Hedge Funds | Minimum
Defined Benefit Plan, Plan Assets, Category [Line Items]
Plan asset, target allocation percentages	3%
Hedge Funds | Maximum
Defined Benefit Plan, Plan Assets, Category [Line Items]
Plan asset, target allocation percentages	15%
Defined Benefit Plan, Equity Securities | Minimum
Defined Benefit Plan, Plan Assets, Category [Line Items]
Plan asset, target allocation percentages	49%
Defined Benefit Plan, Equity Securities | Maximum
Defined Benefit Plan, Plan Assets, Category [Line Items]
Plan asset, target allocation percentages	63%
Pension Plan
Defined Benefit Plan, Plan Assets, Category [Line Items]
Actuarial loss (gain)	$ 13,943	(133,282)	(1,697)
Benefit obligation	$ 399,364	362,530	501,507	$ 361,147
Pension Plan | BEP
Defined Benefit Plan, Plan Assets, Category [Line Items]
Defined benefit plan, service requirement for full vesting	3 years
Supplemental Employee Retirement Plan | DC SERP
Defined Benefit Plan, Plan Assets, Category [Line Items]
Defined contribution expense	$ 100	$ 400	$ 900

Employee Benefits - Obligations

Employee Benefits - Obligations and Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Change in benefit obligation:
Service cost	$ 24,474	$ 31,382	$ 31,660
Interest cost	17,559	10,582	5,694
Pension Plan
Change in benefit obligation:
Benefit obligation at beginning of the year	362,530	501,507	361,147
Service cost	24,474	31,382	31,660
Interest cost	17,559	10,582	5,694
Amendments	1,351	0	(1,106)
Actuarial loss (gain)	13,943	(133,282)	(1,697)
Acquisitions	0	0	125,854
Benefits paid	(20,493)	(47,659)	(20,045)
Benefit obligation at end of the year	399,364	362,530	501,507
Change in plan assets:
Fair value of plan assets at beginning of year	419,366	546,056	449,643
Actual return on plan assets	63,811	(91,474)	50,879
Acquisitions	0	0	63,468
Employer contribution	5,680	12,443	2,111
Benefits paid	(20,493)	(47,659)	(20,045)
Fair value of plan assets at end of year	468,364	419,366	546,056
Overfunded status	69,000	56,836	44,549
Reconciliation of funding status:
Past service credit	80,090	108,909	120,792
Unrecognized net loss	(69,697)	(99,002)	(128,402)
Prepaid benefit cost	58,607	46,929	52,159
Accumulated benefit obligation	399,364	362,530	501,507
Amounts recognized in accumulated other comprehensive income (“AOCI”), net of tax:
Unrecognized past service credit	57,501	78,295	86,837
Unrecognized net loss	(50,039)	(71,172)	(92,308)
Net amount	$ 7,462	$ 7,123	$ (5,471)

Employee Benefits - Actuarial A

Employee Benefits - Actuarial Assumptions (Details)	Dec. 31, 2023	Dec. 31, 2022
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.99%	5.18%
Rate of increase in compensation levels	4.50%	4.50%
Interest rate credit for determining projected cash balance	4.47%	3.55%
Pension Plan | BEP
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.89%	5.07%
Rate of increase in compensation levels	4.50%	4.50%
Interest rate credit for determining projected cash balance	4.47%	3.55%
Pension Plan | ODRCP
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.91%	5.13%
Rate of increase in compensation levels	0%	0%
Interest rate credit for determining projected cash balance	0%	0%
Supplemental Employee Retirement Plan | DB SERP
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.96%	5.18%
Rate of increase in compensation levels	0%	0%
Interest rate credit for determining projected cash balance	0%	0%

Employee Benefits - Assumptions

Employee Benefits - Assumptions Used to Determine Net Periodic Benefit (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate - benefit cost	5.18%	2.65%	2.26%
Rate of compensation increase	4.50%	4.50%	5.25%
Expected rate of return on plan assets	7.50%	7%	7.50%
Interest rate credit for determining projected cash balance	3.55%	3.50%	3.50%
Pension Plan | BEP
Defined Benefit Plan Disclosure [Line Items]
Discount rate - benefit cost	5.07%	2.32%	1.77%
Rate of compensation increase	4.50%	4.50%	5.25%
Interest rate credit for determining projected cash balance	3.55%	3.50%	3.50%
Pension Plan | ODRCP
Defined Benefit Plan Disclosure [Line Items]
Discount rate - benefit cost	5.13%	2.32%	1.81%
Supplemental Employee Retirement Plan | DB SERP
Defined Benefit Plan Disclosure [Line Items]
Discount rate - benefit cost	5.18%	2.68%	1.63%

Employee Benefits - Reconciliat

Employee Benefits - Reconciliation of Interest SBERA Common Collective (Details) - Asset Management Arrangement - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Change in benefit obligation:
Benefit obligation at beginning of the year	$ 419,366	$ 546,056
Net realized and unrealized gains and (losses)	63,811	(91,474)
Contributions	0	7,222
Benefits paid	(14,813)	(42,438)
Benefit obligation at end of the year	$ 468,364	$ 419,366

Employee Benefits - Components

Employee Benefits - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Components of net periodic benefit cost:
Service cost	$ 24,474	$ 31,382	$ 31,660
Interest cost	17,559	10,582	5,694
Expected return on plan assets	(30,127)	(35,486)	(33,333)
Past service credit	(11,560)	(11,882)	(11,796)
Recognized net actuarial loss	9,563	11,032	13,400
Curtailment	(15,908)	0	0
Settlement	0	12,045	0
Net periodic benefit cost	(5,999)	17,673	5,625
Discontinued Operations, Held-for-Sale | Insurance Agency Business
Components of net periodic benefit cost:
Service cost	$ 5,100	$ 7,500	$ 7,700

Employee Benefits - Benefits Ex

Employee Benefits - Benefits Expected to be Paid (Details) - Pension Plan $ in Thousands	Dec. 31, 2023 USD ($)
Defined Benefit Plan Disclosure [Line Items]
2024	$ 46,490
2025	32,612
2026	33,261
2027	35,240
2028	37,175
In aggregate for 2029-2033	$ 186,883

Employee Benefits- Assets Held

Employee Benefits- Assets Held in Rabbi Trust (Details) - Primary Beneficiary - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Rabbi trust investments	$ 87,435	$ 76,286
Deferred compensation plans
Defined Benefit Plan Disclosure [Line Items]
Rabbi trust investments	28,826	25,909
Supplemental Employee Retirement Plan | DB SERP
Defined Benefit Plan Disclosure [Line Items]
Rabbi trust investments	16,349	17,209
Supplemental Employee Retirement Plan | DC SERP
Defined Benefit Plan Disclosure [Line Items]
Rabbi trust investments	20,785	17,764
Pension Plan | BEP
Defined Benefit Plan Disclosure [Line Items]
Rabbi trust investments	18,656	11,734
Pension Plan | ODRCP
Defined Benefit Plan Disclosure [Line Items]
Rabbi trust investments	$ 2,819	$ 3,670

Employee Benefits - Asset Held

Employee Benefits - Asset Held In Rabbi Trust By Plan Type (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Primary Beneficiary
Defined Benefit Plan Disclosure [Line Items]
Book Value	$ 75,085	$ 73,430
Unrealized Gain/(Loss)	12,350	2,856
Fair Value	87,435	76,286
Cash and cash equivalents | Primary Beneficiary
Defined Benefit Plan Disclosure [Line Items]
Book Value	12,269	5,575
Fair Value	12,269	5,575
Equities
Defined Benefit Plan Disclosure [Line Items]
Fair Value	69,000	63,700
Equities | Primary Beneficiary
Defined Benefit Plan Disclosure [Line Items]
Book Value	56,140	60,056
Unrealized Gain/(Loss)	12,869	3,626
Fair Value	69,009	63,682
Fixed income | Primary Beneficiary
Defined Benefit Plan Disclosure [Line Items]
Book Value	6,676	7,799
Unrealized Gain/(Loss)	(519)	(770)
Fair Value	$ 6,157	$ 7,029

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details) - USD ($) $ in Millions			1 Months Ended					12 Months Ended			13 Months Ended	25 Months Ended
	Nov. 29, 2021	Oct. 14, 2020	May 31, 2023	Mar. 31, 2023	May 31, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount borrowed under ESOP		$ 149.4
Total shares (in shares)		14,940,652						14,916,133	14,920,942		14,920,942	14,916,133
ESOP loan term		30 years
Shares committed to be released (in shares)								103,230	104,464		104,464	103,230
Annual amount from 2022 through 2049
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares committed to be released (in shares)								495,339				495,339
Annual amount for 2050
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares committed to be released (in shares)								392,141				392,141
Eastern Bankshares, Inc. 2021 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	26,146,141
Reduction of shares available to be issued upon exercise of stock options with each additional restricted stock grant	3
Options granted in period (in shares)											0	0
Unrecognized compensation expense related to unvested awards								$ 26.8	$ 34.6		$ 34.6	$ 26.8
Period for recognition for unrecognized compensation expense related to unvested awards								2 years 2 months 12 days	3 years 3 months 18 days
Eastern Bankshares, Inc. 2021 Equity Incentive Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	7,470,326
Award vesting period				3 years
Grants in period (in shares)				318,577		978,364		318,577	978,364	0
Number of shares available for grant (in shares)								4,872,494	5,302,256		5,302,256	4,872,494
Equity instruments other than options vested in period (in shares)								302,908	0
Shares withheld for tax withholding obligation (in shares)								$ 6.4
Eastern Bankshares, Inc. 2021 Equity Incentive Plan | Restricted Stock Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						3 years
Eastern Bankshares, Inc. 2021 Equity Incentive Plan | Restricted Stock Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						5 years
Eastern Bankshares, Inc. 2021 Equity Incentive Plan | Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	18,675,815
Award expiration period	10 years
Number of shares available for grant (in shares)								18,675,815	18,675,815		18,675,815	18,675,815
Eastern Bankshares, Inc. 2021 Equity Incentive Plan | Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	5 years		1 year		1 year
Grants in period (in shares)			47,820		31,559			47,820	31,559	683,056
Equity instruments other than options vested in period (in shares)								152,880	136,609
Shares withheld for tax withholding obligation (in shares)								$ 3	$ 2.7
Eastern Bankshares, Inc. 2021 Equity Incentive Plan | Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				3 years		3 years
Grants in period (in shares)				108,984		533,676	0	108,984	533,676
Equity instruments other than options vested in period (in shares)											0	0

Share-Based Compensation - Comp

Share-Based Compensation - Compensation Expense Associated With the ESOP (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement [Abstract]
Compensation expense	$ 7,129	$ 9,923	$ 9,408
Interest	9,374	4,724	4,826
Principal	2,914	3,147	3,045
Total loan payment	$ 12,288	$ 7,871	$ 7,871

Share-Based Compensation - Shar

Share-Based Compensation - Share Information Held by the ESOP (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Oct. 14, 2020
Share-Based Payment Arrangement [Abstract]
Allocated shares (in shares)	1,541,971	1,046,850
Shares committed to be released (in shares)	103,230	104,464
Unallocated shares (suspense shares) (in shares)	13,270,932	13,769,628
Total shares (in shares)	14,916,133	14,920,942	14,940,652
Fair value of unallocated shares	$ 188,447	$ 237,526

Share-Based Compensation - Sh_2

Share-Based Compensation - Share-based Payment Arrangement, Restricted Stock, Restricted Stock Unit, and Performance Stock Unit, Activity (Details) - Eastern Bankshares, Inc. 2021 Equity Incentive Plan - USD ($) $ / shares in Units, $ in Millions	1 Months Ended					12 Months Ended			13 Months Ended	25 Months Ended
	May 31, 2023	Mar. 31, 2023	May 31, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2023
Restricted Stock Awards
Number of Shares
Non-vested stock at beginning of year (in shares)						525,460	683,056
Granted (in shares)	47,820		31,559			47,820	31,559	683,056
Vested (in shares)						(152,880)	(136,609)
Forfeited (in shares)						0	(52,546)
Non-vested stock at end of year (in shares)					683,056	420,400	525,460	683,056	525,460	420,400
Weighted-Average Grant Price Per Share
Non-vested stock at beginning of year (in dollars per share)						$ 20.08	$ 20.13
Granted (in dollars per share)						11.50	19.17
Vested (in dollars per share)						19.95	20.13
Forfeited (in dollars per share)						0	20.08
Non-vested stock at end of year (in dollars per share)					$ 20.13	$ 19.15	$ 20.08	$ 20.13	$ 20.08	$ 19.15
Total grant date fair value								$ 13.7
Restricted Stock Units
Number of Shares
Non-vested stock at beginning of year (in shares)						972,325	0
Granted (in shares)		318,577		978,364		318,577	978,364	0
Vested (in shares)						(302,908)	0
Forfeited (in shares)						(35,993)	(6,039)
Non-vested stock at end of year (in shares)					0	952,001	972,325	0	972,325	952,001
Weighted-Average Grant Price Per Share
Non-vested stock at beginning of year (in dollars per share)						$ 21.08	$ 0
Granted (in dollars per share)						15.63	21.08
Vested (in dollars per share)						21.08	0
Forfeited (in dollars per share)						15.73	21.08
Non-vested stock at end of year (in dollars per share)					$ 0	$ 19.46	$ 21.08	$ 0	$ 21.08	$ 19.46
Share-based payment arrangement, shares withheld for tax withholding obligation (in shares)						95,808
Performance Stock Units
Number of Shares
Non-vested stock at beginning of year (in shares)						533,676	0
Granted (in shares)		108,984		533,676	0	108,984	533,676
Vested (in shares)									0	0
Forfeited (in shares)						(9,626)	0
Non-vested stock at end of year (in shares)					0	633,034	533,676	0	533,676	633,034
Weighted-Average Grant Price Per Share
Non-vested stock at beginning of year (in dollars per share)						$ 21.12	$ 0
Granted (in dollars per share)						10.16	21.12
Forfeited (in dollars per share)						10.16	0
Non-vested stock at end of year (in dollars per share)					$ 0	$ 19.40	$ 21.12	$ 0	$ 21.12	$ 19.40

Share-Based Compensation - Sh_3

Share-Based Compensation - Share-based Compensation Expense Under the 2021 Plan and the Related Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 16,047	$ 10,507	$ 0
Eastern Bankshares, Inc. 2021 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	16,500	10,500	200
Related tax benefit	$ 4,700	$ 3,000	$ 100

Commitments and Contingencies -

Commitments and Contingencies - Summary of Financial Instruments as of the Dates Indicated (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Commitments to extend credit
Disclosure Of Financial Instruments Indicated [Line Items]
Contractual obligation	$ 6,027,356	$ 5,680,438
Standby letters of credit
Disclosure Of Financial Instruments Indicated [Line Items]
Contractual obligation	58,632	65,154
Forward commitments to sell loans
Disclosure Of Financial Instruments Indicated [Line Items]
Contractual obligation	$ 9,198	$ 10,008

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) $ in Millions	Dec. 31, 2023 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Loss Contingency Accrual	$ 10.8

Derivative Financial Instrume_3

Derivative Financial Instruments - Schedule of Interest Rate Derivatives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Notional Amount	$ 2,400,000	$ 2,400,000
Fair Value	(883)	(2,401)
Interest rate swaps | Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Notional Amount	$ 2,400,000	$ 2,400,000
Weighted Average Maturity	3 years 6 months 25 days	4 years 6 months 25 days
Current Rate Paid	5.35%	4.07%
Receive Fixed Swap Rate	3.02%	3.02%
Fair Value	$ (883)	$ (2,401)
Accrued interest payable	$ 2,600	$ 1,500

Derivative Financial Instrume_4

Derivative Financial Instruments - Pre-tax Impact of Terminated Cash Flow Hedges on AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
AOCI Attributable to Parent, Before Tax [Roll Forward]
Beginning balance	$ 2,471,790	$ 3,406,352	$ 3,428,052
Unrealized gains on terminated hedges arising during the period	0	0	0
Reclassification adjustments for amortization of unrealized (gains) into net interest income	$ (46)	$ (10,193)	$ (31,234)
OCI, Cash Flow Hedge, Reclassification for Discontinuance, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest Income (Expense), Net	Interest Income (Expense), Net	Interest Income (Expense), Net
Ending balance	$ 2,974,855	$ 2,471,790	$ 3,406,352
Accumulated Gain (Loss), Net, Terminated Cash Flow Hedge, Parent
AOCI Attributable to Parent, Before Tax [Roll Forward]
Beginning balance	46	10,239	41,473
Ending balance	$ 0	$ 46	$ 10,239

Derivative Financial Instrume_5

Derivative Financial Instruments - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative [Line Items]
Maximum length of time hedged in cash flow hedge	4 years
Credit exposure to settled variation margin in excess of customer related interest rate swap	$ 400,000	$ 0
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other	Other	Other
Derivative, notional amount	$ 2,400,000,000	$ 2,400,000,000
Derivative, gain (loss) on derivative, net	100,000	(200,000)	$ (700,000)
Derivative asset	20,456,000	23,861,000
Derivative liability	63,075,000	81,422,000
Loan Origination Commitments
Derivative [Line Items]
Derivative, notional amount	10,500,000	8,300,000
Derivative asset	100,000	100,000
Derivative liability	100,000	100,000
Forward Contracts
Derivative [Line Items]
Derivative, notional amount	9,200,000	10,000,000
Cleared Derivative Transaction
Derivative [Line Items]
Additional collateral posted	85,900,000	84,100,000
Non Cleared Derivative Transactions | Customer Related Interest Rate Swap Derivatives
Derivative [Line Items]
Additional collateral posted	3,000,000	1,000,000
Fair value of interest rate swap liabilities that are net in a net liability position	1,900,000	$ 0
Interest Income | Active Cash Flow Hedges
Derivative [Line Items]
Interest rate swap cash flow hedges amount expected to reclassified from other comprehensive income to income statement in the next twelve months (less than for amounts related to terminated cash flow hedges)	$ 38,500,000

Derivative Financial Instrume_6

Derivative Financial Instruments - Customer-Related Derivative Positions (Details) $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Total Notional	$ 2,400,000	$ 2,400,000
Interest rate swaps | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions	356	382
Total Notional	$ 2,405,835	$ 2,404,003
Risk participation agreements | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions	78	63
Total Notional	$ 323,957	$ 241,029
Matched commercial customer book | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions	98	32
Total Notional	$ 87,601	$ 7,877
Foreign currency loan | Not Designated as Hedging Instrument
Disclosure Of Customer Related Derivatives Not Designated As Hedging [Line Items]
Number of Positions	10	5
Total Notional	$ 10,242	$ 13,948

Derivative Financial Instrume_7

Derivative Financial Instruments - Classification On The Balance Sheet For The Periods Indicated (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Asset Derivatives
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Total	$ 20,456	$ 23,861
Liability Derivatives
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Total	$ 63,075	$ 81,422
Asset Derivatives
Asset Derivatives
Derivatives designated as hedging instruments, assets, at fair value	10	16
Derivatives not designated as hedging instruments, Interest rate swaps, Other assets	19,535	23,567
Derivatives not designated as hedging instruments, Other assets	20,446	23,845
Asset Derivatives | Risk participation agreements
Asset Derivatives
Derivatives not designated as hedging instruments, Other assets	151	78
Asset Derivatives | Foreign currency exchange contracts — matched customer book
Asset Derivatives
Derivatives not designated as hedging instruments, Other assets	760	198
Asset Derivatives | Foreign currency exchange contracts — foreign currency loan
Asset Derivatives
Derivatives not designated as hedging instruments, Other assets	0	2
Liability Derivatives
Liability Derivatives
Derivatives designated as hedging instruments, liabilities, at fair value	893	2,417
Derivative not designated as hedging instruments, Interest rate swaps, Other liabilities	61,217	78,577
Derivatives not designated as hedging instruments, Other liabilities	62,182	79,005
Liability Derivatives | Risk participation agreements
Liability Derivatives
Derivatives not designated as hedging instruments, Other liabilities	106	130
Liability Derivatives | Foreign currency exchange contracts — matched customer book
Liability Derivatives
Derivatives not designated as hedging instruments, Other liabilities	672	205
Liability Derivatives | Foreign currency exchange contracts — foreign currency loan
Liability Derivatives
Derivatives not designated as hedging instruments, Other liabilities	$ 187	$ 93

Derivative Financial Instrume_8

Derivative Financial Instruments - Company's Derivative Financial Instruments Included in OCI (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Loss in OCI on derivatives	$ (24,855)	$ (69,010)	$ 0
Gain recognized in income on derivatives (ineffective portion and amount excluded from effectiveness test)	0	0	0
Gain (loss) recognized in other income for foreign currency exchange contracts:	(178)	4,511	5,179
Interest Income
Derivative Instruments, Gain (Loss) [Line Items]
(Loss) gain reclassified from OCI into interest income (effective portion)	(48,795)	9,580	31,234
Interest Income | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain recognized in income on derivatives (ineffective portion and amount excluded from effectiveness test)	0	0	0
Interest Income | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
(Loss) gain recognized in interest rate swap income	(274)	4,324	4,962
Interest Income | Risk participation agreements
Derivative Instruments, Gain (Loss) [Line Items]
(Loss) gain recognized in interest rate swap income	97	213	243
Other Income
Derivative Instruments, Gain (Loss) [Line Items]
Gain recognized in income on derivatives (ineffective portion and amount excluded from effectiveness test)	0	0	0
Other Income | Foreign currency exchange contracts — matched customer book
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in other income for foreign currency exchange contracts:	95	(22)	1
Other Income | Foreign currency exchange contracts — foreign currency loan
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in other income for foreign currency exchange contracts:	$ (96)	$ (4)	$ (27)

Balance Sheet Offsetting - Disc

Balance Sheet Offsetting - Disclosure Detail Of Balance Sheet Offsetting Of Financial Assets And Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Derivative Liabilities
Net Amount	$ 63,075	$ 81,422
Customer-related positions
Derivative Assets
Gross Amounts Recognized	20,456	23,861
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	20,456	23,861
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	4,871	381
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	(8,500)	(14,430)
Net Amount	7,085	9,050
Derivative Liabilities
Gross Amounts Recognized	63,075	81,422
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	63,075	81,422
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	4,871	381
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	2,753	2,417
Net Amount	55,451	78,624
Interest rate swaps
Derivative Assets
Gross Amounts Recognized	10	16
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	10	16
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	0	0
Net Amount	10	16
Derivative Liabilities
Gross Amounts Recognized	893	2,417
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	893	2,417
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	893	2,417
Net Amount	0	0
Interest rate swaps | Customer-related positions
Derivative Assets
Gross Amounts Recognized	19,535	23,567
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	19,535	23,567
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	4,871	381
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	(8,500)	(14,430)
Net Amount	6,164	8,756
Derivative Liabilities
Gross Amounts Recognized	61,217	78,577
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	61,217	78,577
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	4,871	381
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	1,860	0
Net Amount	54,486	78,196
Risk participation agreements | Customer-related positions
Derivative Assets
Gross Amounts Recognized	151	78
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	151	78
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	0	0
Net Amount	151	78
Derivative Liabilities
Gross Amounts Recognized	106	130
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	106	130
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	0	0
Net Amount	106	130
Foreign currency exchange contracts — matched customer book | Customer-related positions
Derivative Assets
Gross Amounts Recognized	760	198
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	760	198
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	0	0
Net Amount	760	198
Derivative Liabilities
Gross Amounts Recognized	672	205
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	672	205
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	0	0
Net Amount	672	205
Foreign currency exchange contracts — foreign currency loan
Derivative Assets
Gross Amounts Recognized		2
Gross Amounts Offset in the Statement of Financial Position		0
Net Amounts Presented in the Statement of Financial Position		2
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments		0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)		0
Net Amount		2
Foreign currency exchange contracts — foreign currency loan | Customer-related positions
Derivative Liabilities
Gross Amounts Recognized	187	93
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts Presented in the Statement of Financial Position	187	93
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Collateral Pledged (Received)	0	0
Net Amount	$ 187	$ 93

Fair Value of Assets and Liab_3

Fair Value of Assets and Liabilities - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment in mutual funds	$ 48.9	$ 38.9
Carrying Value | Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial instruments original maturity	90 days

Fair Value of Assets and Liab_4

Fair Value of Assets and Liabilities - Summary Of The Balances Of Assets And Liabilities Measured At Fair Value On A Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets
Securities available for sale	$ 4,407,521	$ 6,690,778
Government-sponsored residential mortgage-backed securities
Assets
Securities available for sale	2,780,638	4,111,908
Government-sponsored commercial mortgage-backed securities
Assets
Securities available for sale	1,124,376	1,348,954
U.S. Agency bonds
Assets
Securities available for sale	216,011	952,482
U.S. Treasury securities
Assets
Securities available for sale	95,152	93,057
Other debt securities
Assets
Securities available for sale		1,285
Fair Value, Recurring
Assets
Rabbi trust investments	87,435	76,286
Loans held for sale	1,124	4,543
Risk participation agreements	151	78
Matched customer book	760	198
Foreign currency loan		2
Mortgage derivatives	69	62
Total	4,516,605	6,795,530
Liabilities
Risk participation agreements	106	130
Matched customer book	672	205
Foreign currency loan	187	93
Mortgage derivatives	36	58
Total	63,111	81,480
Fair Value, Recurring | Designated as Hedging Instrument
Assets
Customer-related positions	10	16
Liabilities
Cash flow hedges - interest rate positions	893	2,417
Fair Value, Recurring | Not Designated as Hedging Instrument
Assets
Customer-related positions	19,535	23,567
Liabilities
Customer-related positions	61,217	78,577
Fair Value, Recurring | Government-sponsored residential mortgage-backed securities
Assets
Securities available for sale	2,780,638	4,111,908
Fair Value, Recurring | Government-sponsored commercial mortgage-backed securities
Assets
Securities available for sale	1,124,376	1,348,954
Fair Value, Recurring | U.S. Agency bonds
Assets
Securities available for sale	216,011	952,482
Fair Value, Recurring | U.S. Treasury securities
Assets
Securities available for sale	95,152	93,057
Fair Value, Recurring | State and municipal bonds and obligations
Assets
Securities available for sale	191,344	183,092
Fair Value, Recurring | Other debt securities
Assets
Securities available for sale		1,285
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Rabbi trust investments	81,278	69,257
Loans held for sale	0	0
Risk participation agreements	0	0
Matched customer book	0	0
Foreign currency loan		0
Mortgage derivatives	0	0
Total	176,430	162,314
Liabilities
Risk participation agreements	0	0
Matched customer book	0	0
Foreign currency loan	0	0
Mortgage derivatives	0	0
Total	0	0
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Designated as Hedging Instrument
Assets
Customer-related positions	0	0
Liabilities
Cash flow hedges - interest rate positions	0	0
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Not Designated as Hedging Instrument
Assets
Customer-related positions	0	0
Liabilities
Customer-related positions	0	0
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Government-sponsored residential mortgage-backed securities
Assets
Securities available for sale	0	0
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Government-sponsored commercial mortgage-backed securities
Assets
Securities available for sale	0	0
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Agency bonds
Assets
Securities available for sale	0	0
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury securities
Assets
Securities available for sale	95,152	93,057
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | State and municipal bonds and obligations
Assets
Securities available for sale	0	0
Fair Value, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other debt securities
Assets
Securities available for sale		0
Fair Value, Recurring | Significant Other Observable Inputs (Level 2)
Assets
Rabbi trust investments	6,157	7,029
Loans held for sale	1,124	4,543
Risk participation agreements	151	78
Matched customer book	760	198
Foreign currency loan		2
Mortgage derivatives	69	62
Total	4,340,175	6,633,216
Liabilities
Risk participation agreements	106	130
Matched customer book	672	205
Foreign currency loan	187	93
Mortgage derivatives	36	58
Total	63,111	81,480
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Designated as Hedging Instrument
Assets
Customer-related positions	10	16
Liabilities
Cash flow hedges - interest rate positions	893	2,417
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Not Designated as Hedging Instrument
Assets
Customer-related positions	19,535	23,567
Liabilities
Customer-related positions	61,217	78,577
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Government-sponsored residential mortgage-backed securities
Assets
Securities available for sale	2,780,638	4,111,908
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Government-sponsored commercial mortgage-backed securities
Assets
Securities available for sale	1,124,376	1,348,954
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Agency bonds
Assets
Securities available for sale	216,011	952,482
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Treasury securities
Assets
Securities available for sale	0	0
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | State and municipal bonds and obligations
Assets
Securities available for sale	191,344	183,092
Fair Value, Recurring | Significant Other Observable Inputs (Level 2) | Other debt securities
Assets
Securities available for sale		1,285
Fair Value, Recurring | Significant Unobservable Inputs (Level 3)
Assets
Rabbi trust investments	0	0
Loans held for sale	0	0
Risk participation agreements	0	0
Matched customer book	0	0
Foreign currency loan		0
Mortgage derivatives	0	0
Total	0	0
Liabilities
Risk participation agreements	0	0
Matched customer book	0	0
Foreign currency loan	0	0
Mortgage derivatives	0	0
Total	0	0
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Designated as Hedging Instrument
Assets
Customer-related positions	0	0
Liabilities
Cash flow hedges - interest rate positions	0	0
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Not Designated as Hedging Instrument
Assets
Customer-related positions	0	0
Liabilities
Customer-related positions	0	0
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Government-sponsored residential mortgage-backed securities
Assets
Securities available for sale	0	0
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Government-sponsored commercial mortgage-backed securities
Assets
Securities available for sale	0	0
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | U.S. Agency bonds
Assets
Securities available for sale	0	0
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | U.S. Treasury securities
Assets
Securities available for sale	0	0
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | State and municipal bonds and obligations
Assets
Securities available for sale	$ 0	0
Fair Value, Recurring | Significant Unobservable Inputs (Level 3) | Other debt securities
Assets
Securities available for sale

Fair Value of Assets and Liab_5

Fair Value of Assets and Liabilities - Summary Of The Fair Value Of Assets And Liabilities Measured At Fair Value On A Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Individually assessed collateral-dependent loans whose fair value is based upon appraisals		$ 0
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Individually assessed collateral-dependent loans whose fair value is based upon appraisals		0
Fair Value, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Individually assessed collateral-dependent loans whose fair value is based upon appraisals	$ 27,874	16,432
Fair Value, Nonrecurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Individually assessed collateral-dependent loans whose fair value is based upon appraisals	0
Fair Value, Nonrecurring | Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Individually assessed collateral-dependent loans whose fair value is based upon appraisals	0
Fair Value, Nonrecurring | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Individually assessed collateral-dependent loans whose fair value is based upon appraisals	$ 27,874	$ 16,432

Fair Value of Assets and Liab_6

Fair Value of Assets and Liabilities - Schedule of Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	$ 449,721	$ 476,647
Loans, net of allowance for loan losses	13,799,367	13,420,317
FHLB stock	5,904	41,363
Bank-owned life insurance	164,702	160,790
Deposits	17,596,217	18,974,359
Escrow deposits of borrowers	21,978	22,314
Interest rate swap collateral funds	8,500	14,430
Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	254,752	276,493
Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	194,969	200,154
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	0	0
FHLB stock	0	0
Bank-owned life insurance	0	0
Deposits	0	0
FHLB advances	0	0
Escrow deposits of borrowers	0	0
Interest rate swap collateral funds	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	0	0
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	0	0
FHLB stock	5,904	41,363
Bank-owned life insurance	164,702	160,790
Deposits	17,593,214	18,960,407
FHLB advances	15,366	702,954
Escrow deposits of borrowers	21,978	22,314
Interest rate swap collateral funds	8,500	14,430
Significant Other Observable Inputs (Level 2) | Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	230,319	246,343
Significant Other Observable Inputs (Level 2) | Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	174,503	176,883
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	13,145,455	13,149,096
FHLB stock	0	0
Bank-owned life insurance	0	0
Deposits	0	0
FHLB advances	0	0
Escrow deposits of borrowers	0	0
Interest rate swap collateral funds	0	0
Significant Unobservable Inputs (Level 3) | Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	0	0
Significant Unobservable Inputs (Level 3) | Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	0	0
Carrying Value
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	13,799,367	13,420,317
FHLB stock	5,904	41,363
Bank-owned life insurance	164,702	160,790
Deposits	17,596,217	18,974,359
FHLB advances	17,738	704,084
Escrow deposits of borrowers	21,978	22,314
Interest rate swap collateral funds	8,500	14,430
Carrying Value | Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	254,752	276,493
Carrying Value | Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	194,969	200,154
Fair Value
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Loans, net of allowance for loan losses	13,145,455	13,149,096
FHLB stock	5,904	41,363
Bank-owned life insurance	164,702	160,790
Deposits	17,593,214	18,960,407
FHLB advances	15,366	702,954
Escrow deposits of borrowers	21,978	22,314
Interest rate swap collateral funds	8,500	14,430
Fair Value | Government-sponsored residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	230,319	246,343
Fair Value | Government-sponsored commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Held to maturity securities:	$ 174,503	$ 176,883

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Revenue from External Customers by Products and Services (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	$ 76,866	$ 77,299	$ 69,423
Total noninterest (loss) income out-of-scope of ASC 606	(314,619)	(549)	28,014
Total noninterest (loss) income	(237,753)	76,750	97,437
Service charges on deposit accounts
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	28,631	30,392	24,271
Trust and investment advisory fees
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	24,264	23,593	24,588
Debit card processing fees
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	13,469	12,644	12,118
Other non-interest income
Revenue from External Customer [Line Items]
Total noninterest income in-scope of ASC 606	$ 10,502	$ 10,670	$ 8,446

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Cash Management Fees
Disaggregation of Revenue [Line Items]
Fess earned but not yet received	$ 1.6	$ 2.1
Debit Card
Disaggregation of Revenue [Line Items]
Fess earned but not yet received	$ 0.4	$ 0.3

Other Comprehensive Income - Co

Other Comprehensive Income - Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pre Tax Amount
Total other comprehensive income (loss)	$ 404,700	$ (1,119,774)	$ (143,913)
Tax (Expense) Benefit
Total other comprehensive income (loss)	(89,860)	253,278	32,983
After Tax Amount
Before reclassifications	33,908	(869,941)	(88,720)
Less: reclassification adjustments	(280,932)	(3,445)	22,210
Total other comprehensive income (loss)	314,840	(866,496)	(110,930)
Accretion of gains from terminated interest rate swaps	(46)	(10,193)	(31,234)
Total realized gain, net of tax	41,200
Balance of gain after amortization, net of tax		100	7,400
Change in fair value of securities available for sale
Pre Tax Amount
Before reclassifications	47,104	(1,061,859)	(133,466)
Less: reclassification adjustments	(333,170)	(3,157)	1,166
Total other comprehensive income (loss)	380,274	(1,058,702)	(134,632)
Tax (Expense) Benefit
Before reclassifications	(9,731)	238,005	30,117
Less: reclassification adjustments	74,630	873	(257)
Total other comprehensive income (loss)	(84,361)	237,132	30,374
After Tax Amount
Before reclassifications	37,373	(823,854)	(103,349)
Less: reclassification adjustments	(258,540)	(2,284)	909
Total other comprehensive income (loss)	295,913	(821,570)	(104,258)
Unrealized losses on cash flow hedges:
Pre Tax Amount
Before reclassifications	(24,855)	(69,010)	0
Less: reclassification adjustments	(48,795)	9,580	31,234
Total other comprehensive income (loss)	23,940	(78,590)	(31,234)
Tax (Expense) Benefit
Before reclassifications	8,165	18,377	0
Less: reclassification adjustments	13,517	(2,693)	(8,780)
Total other comprehensive income (loss)	(5,352)	21,070	8,780
After Tax Amount
Before reclassifications	(16,690)	(50,633)	0
Less: reclassification adjustments	(35,278)	6,887	22,454
Total other comprehensive income (loss)	18,588	(57,520)	(22,454)
Defined Benefit Pension Plans
Pre Tax Amount
Total other comprehensive income (loss)	486	17,518	21,953
Tax (Expense) Benefit
Total other comprehensive income (loss)	(147)	(4,924)	(6,171)
After Tax Amount
Before reclassifications	13,225	4,546	14,629
Less: reclassification adjustments	12,886	(8,048)	(1,153)
Total other comprehensive income (loss)	339	12,594	15,782
Change in actuarial net loss
Pre Tax Amount
Before reclassifications	19,742	6,323	19,243
Tax (Expense) Benefit
Before reclassifications	(5,547)	(1,777)	(5,409)
After Tax Amount
Before reclassifications	14,195	4,546	13,834
BEP and Defined Benefit Plan amendments - accelerated vesting
Pre Tax Amount
Before reclassifications	(1,351)
Tax (Expense) Benefit
Before reclassifications	381
After Tax Amount
Before reclassifications	(970)
Less: amortization of actuarial net loss
Pre Tax Amount
Less: reclassification adjustments	(9,563)	(11,032)	(13,400)
Tax (Expense) Benefit
Less: reclassification adjustments	2,693	3,101	3,767
After Tax Amount
Less: reclassification adjustments	(6,870)	(7,931)	(9,633)
Less: BEP and Defined Benefit Plan curtailment gain
Pre Tax Amount
Less: reclassification adjustments	15,908
Tax (Expense) Benefit
Less: reclassification adjustments	(4,490)
After Tax Amount
Less: reclassification adjustments	11,418
Less: Defined Benefit Plan settlement loss
Pre Tax Amount
Less: reclassification adjustments		(12,045)
Tax (Expense) Benefit
Less: reclassification adjustments		3,386
After Tax Amount
Less: reclassification adjustments		(8,659)
Plan amendment - Century acquisition lump sum distribution option
Pre Tax Amount
Less: reclassification adjustments			1,106
Tax (Expense) Benefit
Less: reclassification adjustments			(311)
After Tax Amount
Less: reclassification adjustments			795
Less: net accretion of prior service credit
Pre Tax Amount
Less: reclassification adjustments	11,560	11,882	11,796
Tax (Expense) Benefit
Less: reclassification adjustments	(3,222)	(3,340)	(3,316)
After Tax Amount
Less: reclassification adjustments	8,338	8,542	8,480
Interest rate swaps
After Tax Amount
Accretion of gains from terminated interest rate swaps	$ 100	$ 7,300	$ 22,500

Other Comprehensive Income - Sc

Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 2,471,790	$ 3,406,352	$ 3,428,052
Other comprehensive income (loss) before reclassifications	33,908	(869,941)	(88,720)
Less: Amounts reclassified from accumulated other comprehensive income (loss)	(280,932)	(3,445)	22,210
Net current-period other comprehensive (loss) income	314,840	(866,496)	(110,930)
Ending balance	2,974,855	2,471,790	3,406,352
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(923,192)	(56,696)	54,234
Ending balance	(608,352)	(923,192)	(56,696)
Unrealized (Losses) and Gains on Available for Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(880,156)	(58,586)	45,672
Other comprehensive income (loss) before reclassifications	37,373	(823,854)	(103,349)
Less: Amounts reclassified from accumulated other comprehensive income (loss)	(258,540)	(2,284)	909
Net current-period other comprehensive (loss) income	295,913	(821,570)	(104,258)
Ending balance	(584,243)	(880,156)	(58,586)
Unrealized (Losses) and Gains on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(50,159)	7,361	29,815
Other comprehensive income (loss) before reclassifications	(16,690)	(50,633)	0
Less: Amounts reclassified from accumulated other comprehensive income (loss)	(35,278)	6,887	22,454
Net current-period other comprehensive (loss) income	18,588	(57,520)	(22,454)
Ending balance	(31,571)	(50,159)	7,361
Defined Benefit Pension Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	7,123	(5,471)	(21,253)
Other comprehensive income (loss) before reclassifications	13,225	4,546	14,629
Less: Amounts reclassified from accumulated other comprehensive income (loss)	12,886	(8,048)	(1,153)
Net current-period other comprehensive (loss) income	339	12,594	15,782
Ending balance	$ 7,462	$ 7,123	$ (5,471)

Other Comprehensive Income - _2

Other Comprehensive Income - Schedule of Reclassified Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
(Losses) gains on sales of securities available for sale, net	$ (333,170)	$ (3,157)	$ 1,166
Tax benefit (expense)	63,309	(51,719)	(30,464)
Net income from discontinued operations	294,866	13,248	9,134
Net of tax	232,177	199,759	154,665
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net of tax	(280,932)	(3,445)	22,210
Unrealized (losses) and gains on available-for-sale securities | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
(Losses) gains on sales of securities available for sale, net	(333,170)	(3,157)	1,166
Total before tax	(333,170)	(3,157)	1,166
Tax benefit (expense)	74,630	873	(257)
Net of tax	(258,540)	(2,284)	909
Unrealized (losses) gains on cash flow hedges | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	(48,795)	9,580	31,234
Interest income	(48,795)	9,580	31,234
Tax benefit (expense)	13,517	(2,693)	(8,780)
Net of tax	(35,278)	6,887	22,454
Accretion (amortization) of defined benefit pension items | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net periodic pension cost - see Note 15	(9,563)	(23,077)	(13,400)
Accretion of prior service credit | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total before tax	17,905	(11,195)	(1,604)
Tax benefit (expense)	(5,019)	3,147	451
Net periodic pension cost - see Note 15	11,560	11,882	11,796
Net of tax	12,886	(8,048)	(1,153)
BEP and Defined Benefit Plan curtailment gain | Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income from discontinued operations	$ 15,908	$ 0	$ 0

Discontinued Operations - Narra

Discontinued Operations - Narrative (Details) - USD ($) $ in Thousands		12 Months Ended
	Oct. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Sep. 19, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noninterest expense		$ 418,602	$ 388,649	$ 360,955
Net reduction of the lease ROU assets		(2,400)	14,400
Impairment charge		400	600
Discontinued Operations, Held-for-Sale | Insurance Agency Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross cash consideration					$ 515,000
Net cash consideration	$ 498,100
Working capital adjustment	4,200
Transaction expenses	17,000
Post-retirement liabilities	4,100
Fiduciary cash transferred	7,400
Gain (loss) on disposition of assets	408,600
Noninterest expense	$ 22,300
Total compensation		1,000
ROU lease asset			8,700
Lease liability			9,200
Net reduction of the lease ROU assets		6,400
Impairment charge		2,000
Disposal Group, Not Discontinued Operations, Transferrable Upon Sale to Entity | Insurance Agency Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
ROU lease asset		500	1,900
Lease liability		$ 300	$ 2,200

Discontinued Operations - Summa

Discontinued Operations - Summary of the Asset and Liabilities of the Discontinued Insurance Agency Business (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets
Total assets	$ 0	$ 128,219
Liabilities
Total liabilities	$ 0	34,930
Discontinued Operations, Held-for-Sale | Insurance Agency Business
Assets
Premises and equipment		163
Goodwill and intangibles, net		93,117
Deferred income taxes, net		(315)
Prepaid expenses		532
Other assets		34,722
Total assets		128,219
Liabilities
Other liabilities		34,930
Total liabilities		34,930
Disposal Group, Not Discontinued Operations, Transferrable Upon Sale to Entity | Insurance Agency Business
Assets
Cash		66,507
Premises and equipment		1,792
Bank-owned life insurance		2,066
Deferred income taxes, net		3,662
Other assets		12,944
Total assets		86,971
Liabilities
Other liabilities		14,013
Total liabilities		$ 14,013

Discontinued Operations - Sum_2

Discontinued Operations - Summary of the Operating Results of the Discontinued Insurance Agency Business (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Noninterest expense:
Net income from discontinued operations	$ 294,866	$ 13,248	$ 9,134
Discontinued Operations, Held-for-Sale | Insurance Agency Business
Noninterest income:
Insurance commissions	93,997	99,887	95,164
Other noninterest income	67	179	1,014
Total noninterest income (loss)	94,064	100,066	96,178
Noninterest expense:
Salaries and employee benefits	76,109	65,089	68,292
Office occupancy and equipment	4,420	3,319	3,204
Data processing	3,577	4,335	4,424
Professional services	1,176	1,009	596
Marketing expenses	179	246	241
Amortization of intangible assets	2,002	2,666	2,293
Other	5,304	4,944	4,411
Total noninterest expense	92,767	81,608	83,461
Income from discontinued operations before income tax expense	1,297	18,458	12,717
Gain on sale of discontinued operations before income tax expense	408,629	0	0
Total gain on discontinued operations before income tax expense	409,926	18,458	12,717
Income tax expense	115,060	5,210	3,583
Net income from discontinued operations	294,866	13,248	9,134
Disposal Group, Not Discontinued Operations, Transferrable Upon Sale to Entity | Insurance Agency Business
Noninterest income:
Income (losses) from investments held in rabbi trusts	697	(1,305)	937
Other noninterest income	60	54	52
Total noninterest income (loss)	757	(1,251)	989
Noninterest expense:
Salaries and employee benefits	721	(1,292)	967
Office occupancy and equipment	433	499	501
Other	1,608	2,396	(2,151)
Total noninterest expense	2,762	1,603	(683)
Total gain on discontinued operations before income tax expense	(2,005)	(2,854)	1,672
Income tax expense	(564)	(802)	470
Net income from discontinued operations	$ (1,441)	$ (2,052)	$ 1,202

Parent Company Financial Stat_2

Parent Company Financial Statements - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets
Goodwill and other intangibles, net	$ 566,205	$ 568,009
Deferred income taxes, net	266,185	331,963
Other assets	536,267	426,863
Total assets	21,133,278	22,646,858
Liabilities [Abstract]
Other liabilities	513,990	424,951
Total liabilities	18,158,423	20,175,068
Equity, Attributable to Parent [Abstract]
Total shareholders’ equity	2,974,855	2,471,790	$ 3,406,352	$ 3,428,052
Total liabilities and shareholders’ equity	21,133,278	22,646,858
Parent Company
Assets
Cash and cash equivalents	118,256	126,441
Goodwill and other intangibles, net	744	744
Deferred income taxes, net	6,763	13,182
Investment in subsidiaries	2,842,099	2,327,521
Other assets	8,202	4,557
Total assets	2,976,064	2,472,445
Liabilities [Abstract]
Other liabilities	1,209	655
Total liabilities	1,209	655
Equity, Attributable to Parent [Abstract]
Total shareholders’ equity	2,974,855	2,471,790
Total liabilities and shareholders’ equity	2,976,064	2,472,445
Other/Eliminations
Assets
Cash and cash equivalents	$ 116,700	$ 125,000

Parent Company Financial Stat_3

Parent Company Financial Statements - Statements of Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Expenses
Professional services	$ 17,385	$ 15,805	$ 21,283
Other	21,144	26,238	6,313
Total noninterest expense	418,602	388,649	360,955
Income tax (benefit) expense	(63,309)	51,719	30,464
Net income	232,177	199,759	154,665
Parent
Income
Total income	130	15	0
Expenses
Professional services	4,937	899	7,393
Other	3,706	3,070	222
Total noninterest expense	8,643	3,969	7,615
Loss before income taxes and equity in undistributed income of subsidiaries	(8,513)	(3,954)	(7,615)
Income tax (benefit) expense	(1,773)	269	(11,344)
(Loss) income before equity in undistributed income of subsidiaries	(6,740)	(4,223)	3,729
Equity in undistributed income of subsidiaries	238,917	203,982	150,936
Net income	$ 232,177	$ 199,759	$ 154,665

Parents Company Financial Sta_2

Parents Company Financial Statements - Statements of Cash Flows (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net income		$ 232,177	$ 199,759	$ 154,665
Adjustments to reconcile net income to net cash provided by operating activities
Share-based compensation		16,047	10,507	0
ESOP expense		7,129	9,923	9,408
Net cash provided by operating activities		261,692	229,942	174,490
Investing activities
Acquisitions, net of cash and cash equivalents acquired		0	0	(9,085)
Contributions to other equity investments		(720)	(788)	(2,519)
Net cash provided by (used in) investing activities		2,400,265	(1,076,655)	(1,985,744)
Financing activities
Payment of subordinated debentures assumed in business combination	[1]	0	0	(36,277)
Payments for shares repurchased under share repurchase plans		0	(201,618)	(23,224)
Net cash (used in) provided by financing activities		(2,138,386)	(215,574)	988,976
Net increase (decrease) in cash, cash equivalents, and restricted cash		523,571	(1,062,287)	(822,278)
Cash, cash equivalents, and restricted cash at beginning of period		169,505	1,231,792	2,054,070
Cash, cash equivalents, and restricted cash at end of period		693,076	169,505	1,231,792
Parent
Operating activities
Net income		232,177	199,759	154,665
Adjustments to reconcile net income to net cash provided by operating activities
Equity in undistributed income of subsidiaries		(238,917)	(203,982)	(150,936)
Share-based compensation		16,513	10,507	0
ESOP expense		7,129	9,923	9,408
Deferred income taxes, net		6,419	4,792	(7,157)
Other, net		(4,115)	(937)	(388)
Net cash provided by operating activities		19,206	20,062	5,592
Investing activities
Acquisitions, net of cash and cash equivalents acquired		0	0	(640,890)
Return of investments in subsidiary		40,000	240,000	140,000
Contributions to other equity investments		(720)	(788)	0
Net cash provided by (used in) investing activities		39,280	239,212	(500,890)
Financing activities
Payment of subordinated debentures assumed in business combination		0	0	(36,277)
Payments for shares repurchased under share repurchase plans		0	(201,618)	(23,224)
Dividends declared and paid to common shareholders		(66,671)	(65,886)	(51,564)
Net cash (used in) provided by financing activities		(66,671)	(267,504)	(111,065)
Net increase (decrease) in cash, cash equivalents, and restricted cash		(8,185)	(8,230)	(606,363)
Cash, cash equivalents, and restricted cash at beginning of period		126,441	134,671	741,034
Cash, cash equivalents, and restricted cash at end of period		$ 118,256	$ 126,441	$ 134,671
[1] (1) The Company deposited funds into escrow prior to the Century acquisition date to pay the balance of subordinated debentures assumed in the Century acquisition which was considered to be a defeasance of the debt. Accordingly, Century recorded a payable to the Company in the amount of the escrow deposit and the Company recorded a receivable from Century in the same amount. The payable was reclassified to other assets upon acquisition and is reflected as such balance in the summary of net assets acquired. Subsequent to the closing of the acquisition and prior to December 31, 2021, the amounts placed in escrow were disbursed to the holders of the subordinated debentures resulting in a full pay-off of the outstanding balance of the debt.

Quarterly Results of Operatio_3

Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest and dividend income									$ 796,459	$ 605,181	$ 435,159
Interest expense									246,050	37,127	5,332
Net interest income									550,409	568,054	429,827
Provision (release)									20,052	17,925	(9,686)
Net interest income after provision for (release of) allowance for loan losses									530,357	550,129	439,513
Total noninterest (loss) income									(237,753)	76,750	97,437
Noninterest expense									418,602	388,649	360,955
(Loss) income from continuing operations before income tax expense									(125,998)	238,230	175,995
Income tax (benefit) expense									(63,309)	51,719	30,464
Net (loss) income from continuing operations									(62,689)	186,511	145,531
Net income from discontinued operations									294,866	13,248	9,134
Net income									$ 232,177	$ 199,759	$ 154,665
Basic earnings per share
Basic (loss) earnings per share from continuing operations (in dollars per share)									$ (0.39)	$ 1.13	$ 0.85
Discontinued operations (in dollars per share)									1.82	0.08	0.05
Basic earnings per share (in dollars per share)									1.43	1.21	0.90
Diluted earnings per share:
Diluted (loss) earnings per share from continuing operations (in dollars per share)									(0.39)	1.13	0.85
Diluted earnings per share from discontinued operations (in dollars per share)									1.82	0.08	0.05
Diluted earnings per share (in dollars per share)									$ 1.43	$ 1.21	$ 0.90
Average common shares outstanding:
Basic (in shares)									162,293,020	165,510,357	172,192,336
Diluted (in shares)									162,403,097	165,648,571	172,252,057
Revision of Prior Period, Reclassification, Adjustment | Insurance Agency Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Interest and dividend income	$ 203,646	$ 202,168	$ 201,765	$ 188,880	$ 174,998	$ 157,827	$ 140,871	$ 131,485
Interest expense	70,339	64,963	60,177	50,571	25,004	5,648	3,114	3,361
Net interest income	133,307	137,205	141,588	138,309	149,994	152,179	137,757	128,124
Provision (release)	5,198	7,328	7,501	25	10,880	6,480	1,050	(485)
Net interest income after provision for (release of) allowance for loan losses	128,109	129,877	134,087	138,284	139,114	145,699	136,707	128,609
Total noninterest (loss) income	26,739	19,157	26,204	(309,853)	22,425	19,524	17,146	17,655
Noninterest expense	121,029	101,748	99,934	95,891	112,583	95,765	91,055	89,246
(Loss) income from continuing operations before income tax expense	33,819	47,286	60,357	(267,460)	48,956	69,458	62,798	57,018
Income tax (benefit) expense	2,310	(16,178)	15,938	(65,379)	8,038	16,650	14,967	12,064
Net (loss) income from continuing operations	31,509	63,464	44,419	(202,081)	40,918	52,808	47,831	44,954
Net income from discontinued operations	286,994	(4,351)	4,238	7,985	1,376	1,969	3,341	6,562
Net income	$ 318,503	$ 59,113	$ 48,657	$ (194,096)	$ 42,294	$ 54,777	$ 51,172	$ 51,516
Basic earnings per share
Basic (loss) earnings per share from continuing operations (in dollars per share)	$ 0.19	$ 0.39	$ 0.27	$ (1.25)	$ 0.25	$ 0.32	$ 0.29	$ 0.26
Discontinued operations (in dollars per share)	1.77	(0.03)	0.03	0.05	0.01	0.01	0.02	0.04
Basic earnings per share (in dollars per share)	1.96	0.36	0.30	(1.20)	0.26	0.33	0.31	0.30
Diluted earnings per share:
Diluted (loss) earnings per share from continuing operations (in dollars per share)	0.19	0.39	0.27	(1.25)	0.25	0.32	0.29	0.26
Diluted earnings per share from discontinued operations (in dollars per share)	1.76	(0.03)	0.03	0.05	0.01	0.01	0.02	0.04
Diluted earnings per share (in dollars per share)	$ 1.95	$ 0.36	$ 0.30	$ (1.20)	$ 0.26	$ 0.33	$ 0.31	$ 0.30
Average common shares outstanding:
Basic (in shares)	162,571,066	162,370,469	162,232,236	161,991,373	162,032,522	163,718,962	166,533,920	169,857,950
Diluted (in shares)	162,724,398	162,469,887	162,246,675	162,059,431	162,263,547	164,029,649	166,573,627	169,968,156