Cambridge Bancorp (CATC) 10-Q 3 Aug 23 2023 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2023	Jul. 28, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Trading Symbol	CATC
Entity Registrant Name	CAMBRIDGE BANCORP
Entity Central Index Key	0000711772
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		7,845,868
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity Tax Identification Number	04-2777442
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Incorporation, State or Country Code	MA
Entity Address, Address Line One	1336 Massachusetts Avenue
Entity Address, State or Province	MA
Entity Address, City or Town	Cambridge
Entity Address, Postal Zip Code	02138
City Area Code	617
Local Phone Number	876-5500
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity File Number	001-38184

UNAUDITED CONSOLIDATED BALANCE

UNAUDITED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Assets
Cash and cash equivalents	$ 33,398	$ 30,719
Investment securities
Available for sale, at fair value (amortized cost $172,568 and $182,027, respectively)	144,306	153,416
Held to maturity, at amortized cost (fair value $839,025 and $885,586, respectively)	1,007,471	1,051,997
Total investment securities	1,151,777	1,205,413
Loans
Total loans	4,025,226	4,062,856
Less: allowance for credit losses on loans	(38,073)	(37,774)
Net loans	3,987,153	4,025,082
Federal Home Loan Bank of Boston Stock, at cost	20,247	6,264
Bank owned life insurance	34,866	34,484
Banking premises and equipment, net	22,654	23,297
Right-of-use asset operating leases	23,111	25,098
Deferred income taxes, net	15,841	17,990
Accrued interest receivable	14,573	14,118
Goodwill	64,539	64,539
Merger-related intangibles, net	6,996	7,443
Other assets	114,467	105,290
Total assets	5,489,622	5,559,737
Deposits
Demand	1,059,563	1,366,395
Interest-bearing checking	1,171,164	908,961
Money market	981,304	1,162,773
Savings	593,210	790,628
Certificates of deposit	637,349	586,619
Total deposits	4,442,590	4,815,376
Borrowings	408,926	105,212
Operating lease liabilities	25,376	27,413
Other liabilities	85,726	94,184
Total liabilities	4,962,618	5,042,185
Shareholders’ Equity
Common stock, par value $1.00; Authorized: 10,000,000 shares; Outstanding: 7,845,868 shares and 7,796,440 shares, respectively	7,846	7,796
Additional paid-in capital	293,500	293,186
Retained earnings	246,428	237,369
Accumulated other comprehensive loss	(20,770)	(20,799)
Total shareholders’ equity	527,004	517,552
Total liabilities and shareholders’ equity	5,489,622	5,559,737
Residential Mortgage
Loans
Total loans	1,617,194	1,648,838
Commercial Mortgage
Loans
Total loans	1,916,159	1,914,423
Home Equity
Loans
Total loans	95,975	111,351
Commercial and Industrial
Loans
Total loans	367,403	350,650
Consumer
Loans
Total loans	$ 28,495	$ 37,594

UNAUDITED CONSOLIDATED BALANC_2

UNAUDITED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Available for sale securities, amortized cost	$ 172,568	$ 182,027
Held-to-maturity securities, fair value	$ 839,025	$ 885,586
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares, outstanding	7,845,868	7,796,440

UNAUDITED CONSOLIDATED STATEMEN

UNAUDITED CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Interest and dividend income
Interest on taxable loans	$ 47,731	$ 30,235	$ 93,064	$ 58,639
Interest on tax-exempt loans	382	354	758	704
Interest on taxable investment securities	4,957	4,989	10,007	9,400
Interest on tax-exempt investment securities	570	627	1,155	1,281
Dividends on FHLB of Boston stock	340	32	412	57
Interest on overnight investments	164	42	490	96
Total interest and dividend income	54,144	36,279	105,886	70,177
Interest expense
Interest on deposits	20,040	1,844	35,984	3,740
Interest on borrowed funds	4,343	254	5,893	387
Total interest expense	24,383	2,098	41,877	4,127
Net interest and dividend income	29,761	34,181	64,009	66,050
Provision for (Release of) credit losses	80		140	(412)
Net interest and dividend income after provision for (release of) credit losses	29,681	34,181	63,869	66,462
Noninterest income
Bank owned life insurance income	192	1,343	379	1,530
Gain on loans sold, net		4	13	98
Loan related derivative income (loss)	(7)	45	227	341
Other income	476	476	1,440	1,794
Total noninterest income	10,029	11,149	20,744	22,503
Noninterest expense
Salaries and employee benefits	16,984	17,048	35,472	34,439
Occupancy and equipment	3,571	3,613	7,318	7,155
Data processing	2,602	2,601	5,243	5,246
Professional services	863	1,070	1,986	2,134
Marketing	658	218	1,084	442
FDIC insurance	768	472	1,147	927
Non-operating expenses	3,491	246	3,915	246
Other expenses	1,408	1,029	2,508	1,583
Total noninterest expense	30,345	26,297	58,673	52,172
Income before income taxes	9,365	19,033	25,940	36,793
Income tax expense	2,250	5,375	6,409	9,819
Net income	$ 7,115	$ 13,658	$ 19,531	$ 26,974
Share data:
Weighted average shares outstanding, basic	7,837,708	6,981,907	7,816,611	6,959,856
Weighted average shares outstanding, diluted	7,854,955	7,026,807	7,842,106	7,013,538
Basic earnings per share	$ 0.91	$ 1.95	$ 2.50	$ 3.86
Diluted earnings per share	$ 0.91	$ 1.94	$ 2.49	$ 3.83
Wealth Management Revenue
Noninterest income
Noninterest income	$ 8,076	$ 8,122	$ 16,013	$ 16,696
Deposit Account Fees
Noninterest income
Noninterest income	878	732	1,747	1,238
ATM/Debit Card Income
Noninterest income
Noninterest income	$ 414	$ 427	$ 925	$ 806

UNAUDITED CONSOLIDATED STATEM_2

UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 7,115	$ 13,658	$ 19,531	$ 26,974
Available for sale securities
Unrealized holding gains (losses)	(1,666)	(4,137)	276	(12,364)
Total unrealized gains (losses) on available for sale securities	(1,666)	(4,137)	276	(12,364)
Interest rate swaps designated as cash flow hedges
Unrealized holding gains (losses)	(512)	(257)	(455)	(1,483)
Less: reclassification adjustment for gains (losses) realized in net income	104	(283)	208	(724)
Total unrealized losses on interest rate swaps	(408)	(540)	(247)	(2,207)
Other comprehensive income (loss)	(2,074)	(4,677)	29	(14,571)
Comprehensive income	$ 5,041	$ 8,981	$ 19,560	$ 12,403

UNAUDITED CONSOLIDATED STATEM_3

UNAUDITED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2021	$ 437,837	$ 6,968	$ 229,205	$ 202,874	$ (1,210)
Net income	26,974			26,974
Other comprehensive income (loss)	(14,571)				(14,571)
Share based compensation and other share-based activity	752	39	713
Dividends declared	(8,941)			(8,941)
Ending balance at Jun. 30, 2022	442,051	7,007	229,918	220,907	(15,781)
Beginning balance at Mar. 31, 2022	436,165	7,001	228,538	211,730	(11,104)
Net income	13,658			13,658
Other comprehensive income (loss)	(4,677)				(4,677)
Share based compensation and other share-based activity	1,386	6	1,380
Dividends declared	(4,481)			(4,481)
Ending balance at Jun. 30, 2022	442,051	7,007	229,918	220,907	(15,781)
Beginning balance at Dec. 31, 2022	517,552	7,796	293,186	237,369	(20,799)
Net income	19,531			19,531
Other comprehensive income (loss)	29				29
Share based compensation and other share-based activity	364	50	314
Dividends declared	(10,472)			(10,472)
Ending balance at Jun. 30, 2023	527,004	7,846	293,500	246,428	(20,770)
Beginning balance at Mar. 31, 2023	525,949	7,834	292,250	244,561	(18,696)
Net income	7,115			7,115
Other comprehensive income (loss)	(2,074)				(2,074)
Share based compensation and other share-based activity	1,262	12	1,250
Dividends declared	(5,248)			(5,248)
Ending balance at Jun. 30, 2023	$ 527,004	$ 7,846	$ 293,500	$ 246,428	$ (20,770)

UNAUDITED CONSOLIDATED STATEM_4

UNAUDITED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Retained Earnings
Dividends declared, per share	$ 0.67	$ 0.64	$ 1.34	$ 1.28

UNAUDITED CONSOLIDATED STATEM_5

UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 19,531	$ 26,974
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for (Release of) credit losses	140	(412)
Amortization (accretion) of deferred charges and fees, net	1,226	1,170
Depreciation (accretion)and amortization, net	639	268
Bank owned life insurance income	(379)	(1,530)
Share-based compensation and other share-based activity	365	752
Change in accrued interest receivable	(455)	(899)
Deferred income tax expense	2,166	2,872
Change in loans held for sale		1,490
Change in other assets, net	(9,191)	(26,817)
Change in other liabilities, net	(3,405)	(2,008)
Net cash provided by operating activities	10,637	1,860
CASH FLOWS FROM INVESTING ACTIVITIES
Origination of loans	(313,132)	(624,799)
Proceeds from principal payments of loans	346,435	445,460
Purchase of loans		(23,655)
Proceeds from calls/maturities of securities available for sale	9,335	17,201
Purchase of securities available for sale		(10,170)
Proceeds from calls/maturities of securities held to maturity	43,970	75,089
Purchase of securities held to maturity		(205,063)
Death benefit on bank-owned life insurance		4,068
Redemption on bank-owned life insurance		10,811
(Purchase) redemption of FHLB of Boston stock	(13,983)	(5,702)
Purchase of banking premises and equipment	(911)	(647)
Net cash (provided by) used in investing activities	71,714	(317,407)
CASH FLOWS FROM FINANCING ACTIVITIES
Change in demand, interest bearing, money market and savings accounts	(423,516)	(30,766)
Change in certificates of deposit	50,602	(36,268)
Change in borrowings	303,714	236,392
Cash dividends paid on common stock	(10,472)	(8,941)
Net cash (used in) provided by financing activities	(79,672)	160,417
Net change in cash and cash equivalents	2,679	(155,130)
Cash and cash equivalents at beginning of period	30,719	180,153
Cash and cash equivalents at end of period	33,398	25,023
Cash paid during the period for:
Interest	41,587	4,136
Income taxes	$ 9,895	$ 15,337

Insider Trading Arrangements

Insider Trading Arrangements	6 Months Ended
	Jun. 30, 2023
Insider Trading Arr [Line Items]
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	1. BASIS OF PRESENTATION The unaudited consolidated financial statements include the accounts of Cambridge Bancorp (the “Company”) and its wholly owned subsidiary, Cambridge Trust Company (the “Bank”), and the Bank’s wholly owned subsidiaries, Cambridge Trust Company of New Hampshire Inc., CTC Security Corporation, and CTC Security Corporation III. References to the Company herein relate to the consolidated group of companies. All significant intercompany accounts and transactions have been eliminated in preparation of the consolidated financial statements. The Company is a state-chartered, federally registered bank holding company headquartered in Cambridge, Massachusetts and was incorporated in 1983. The Company is the sole shareholder of the Bank, a Massachusetts trust company chartered in 1890, which is a commercial bank. The Company operates as a private bank offering a full range of private banking and wealth management services to its clients. The private banking business, the Company’s only reportable operating segment, is managed as a single strategic unit. The unaudited consolidated financial statements reflect all adjustments (consisting of normal recurring adjustments) and disclosures necessary to present fairly the Company’s financial position, as of June 30, 2023 and December 31, 2022, and the results of operations and cash flows for the interim periods presented in accordance with generally accepted accounting principles in the United States (“GAAP”). Interim results are not necessarily reflective of the results of the entire year. For further information, refer to the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022 , filed with the Securities and Exchange Commission (the “SEC”) on March 16, 2023.

Use of Estimates

Use of Estimates	6 Months Ended
	Jun. 30, 2023
Use Of Estimates [Abstract]
Use of Estimates	2. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements. Actual results could differ from those estimates. The allowance for credit losses is particularly subject to change.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	3. Subsequent Events Management has reviewed events occurring through August 3, 2023, the date the unaudited consolidated financial statements were available to be issued and determined that no other subsequent events occurred requiring adjustment to or disclosure in these unaudited consolidated financial statements.

Recently Issued Accounting Guid

Recently Issued Accounting Guidance	6 Months Ended
	Jun. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Recently Issued Accounting Guidance	4. Recently Issued Accounting Guidance Accounting Pronouncements Recently Adopted In March 2022, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2022-02, Financial Instruments – Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures. The amendments in this ASU eliminate the accounting guidance for troubled debt restructurings (“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. For public business entities, the amendments in this ASU require an entity to disclose current-period gross write-offs by year of origination for financing receivables and net investments in leases. This ASU was effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption was permitted. The Company adopted the new standard on January 1, 2023 and the adoption did not have a material impact on the consolidated financial statements. In March 2022, the FASB issued ASU 2022-01, Derivatives and Hedging (Topic 815): Fair Value Hedging - Portfolio Layer Method . The amendments in this ASU allow multiple hedged layers to be designated for a single closed portfolio of financial assets or one or more beneficial interests secured by a portfolio of financial instruments. The amendments in this ASU also clarify the accounting for and promote consistency in the reporting of hedge basis adjustments applicable to both a single hedged layer and multiple hedged layers. These amendments are effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. The Company adopted the new standard on January 1, 2023 and provided the additional disclosures required for the Company's fair value hedging relationships.

Cash and Cash Equivalents

Cash and Cash Equivalents	6 Months Ended
	Jun. 30, 2023
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	5. Cash and cash equivalents At June 30, 2023 and December 31, 2022, cash and cash equivalents totaled $ 33.4 million and $ 30.7 million , respectively. There were no amounts required to be maintained at the Federal Reserve Bank of Boston at June 30, 2023 and December 31, 2022. At June 30, 2023 and December 31, 2022 , the Company pledged $ 500,000 to the New Hampshire Banking Department relating to Cambridge Trust Company of New Hampshire, Inc.’s operations in that state. The Company did no t have any cash pledged as collateral to derivative counterparties at June 30, 2023, or at December 31, 2022, respectively. See Note 16 - Derivative and Hedging Activities for a discussion of the Company’s derivative and hedging activities .

Investment Securities

Investment Securities	6 Months Ended
	Jun. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Investment Securities	6. Investment Securities Investment securities have been classified in the unaudited consolidated balance sheets according to management’s intent. The carrying amounts of securities and their approximate fair values were as follows: June 30, 2023 December 31, 2022 Amortized Gross Gross Fair Amortized Gross Gross Fair (dollars in thousands) Available for sale securities U.S. Government Sponsored $ 22,997 $ — $ ( 3,041 ) $ 19,956 $ 22,997 $ — $ ( 3,264 ) $ 19,733 Mortgage-backed securities 149,571 1 ( 25,222 ) 124,350 158,034 3 ( 25,354 ) 132,683 Corporate debt securities — — — — 996 4 — 1,000 Total available for sale securities $ 172,568 $ 1 $ ( 28,263 ) $ 144,306 $ 182,027 $ 7 $ ( 28,618 ) $ 153,416 Held to maturity securities U.S. Treasury Notes $ 4,005 $ — $ ( 42 ) $ 3,963 $ 3,970 $ — $ ( 18 ) $ 3,952 Mortgage-backed securities 913,304 1 ( 160,034 ) 753,271 951,372 4 ( 157,208 ) 794,168 Corporate debt securities 250 — ( 6 ) 244 250 — ( 6 ) 244 Municipal securities 89,912 17 ( 8,382 ) 81,547 96,405 88 ( 9,271 ) 87,222 Total held to maturity securities $ 1,007,471 $ 18 $ ( 168,464 ) $ 839,025 $ 1,051,997 $ 92 $ ( 166,503 ) $ 885,586 Total $ 1,180,039 $ 19 $ ( 196,727 ) $ 983,331 $ 1,234,024 $ 99 $ ( 195,121 ) $ 1,039,002 All of the Company’s mortgage-backed securities have been issued by, or are collateralized by securities issued by, either the Government National Mortgage Association (“Ginnie Mae” or “GNMA”), the Federal National Mortgage Association (“Fannie Mae” or “FNMA”), or the Federal Home Loan Mortgage Corporation (“Freddie Mac” or “FHLMC”). The following tables show the Company’s securities with gross unrealized losses for which an allowance for credit losses has not been recorded at June 30, 2023 or at December 31, 2022, aggregated by investment category and length of time that individual securities have been in a continuous loss position: June 30, 2023 Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized (dollars in thousands) Available for sale securities U.S. Government Sponsored Enterprise $ — $ — $ 19,957 $ ( 3,041 ) $ 19,957 $ ( 3,041 ) Mortgage-backed securities 164 ( 2 ) 124,038 ( 25,220 ) 124,202 ( 25,222 ) Total available for sale securities $ 164 $ ( 2 ) $ 143,995 $ ( 28,261 ) $ 144,159 $ ( 28,263 ) Held to maturity securities U.S. Treasury Notes $ 3,963 $ ( 42 ) $ — $ — $ 3,963 $ ( 42 ) Mortgage-backed securities 19,527 ( 1,183 ) 733,229 ( 158,851 ) 752,756 ( 160,034 ) Corporate debt securities — — 244 ( 6 ) 244 ( 6 ) Municipal securities 30,290 ( 302 ) 40,768 ( 8,080 ) 71,058 ( 8,382 ) Total held to maturity securities $ 53,780 $ ( 1,527 ) $ 774,241 $ ( 166,937 ) $ 828,021 $ ( 168,464 ) Total $ 53,944 $ ( 1,529 ) $ 918,236 $ ( 195,198 ) $ 972,180 $ ( 196,727 ) December 31, 2022 Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized (dollars in thousands) Available for sale securities U.S. Government Sponsored Enterprise $ 10,722 $ ( 2,278 ) $ 9,012 $ ( 986 ) $ 19,734 $ ( 3,264 ) Mortgage-backed securities 41,832 ( 3,097 ) 90,545 ( 22,257 ) 132,377 ( 25,354 ) Total available for sale securities $ 52,554 $ ( 5,375 ) $ 99,557 $ ( 23,243 ) $ 152,111 $ ( 28,618 ) Held to maturity securities U.S. Treasury Notes $ 3,952 $ ( 18 ) $ — $ — $ 3,952 $ ( 18 ) Mortgage-backed securities 230,708 ( 22,362 ) 562,835 ( 134,846 ) 793,543 ( 157,208 ) Corporate debt securities 243 ( 6 ) — — 243 ( 6 ) Municipal securities 51,969 ( 4,388 ) 13,714 ( 4,883 ) 65,683 ( 9,271 ) Total held to maturity securities $ 286,872 $ ( 26,774 ) $ 576,549 $ ( 139,729 ) $ 863,421 $ ( 166,503 ) Total $ 339,426 $ ( 32,149 ) $ 676,106 $ ( 162,972 ) $ 1,015,532 $ ( 195,121 ) As of June 30, 2023 , 449 debt securities had gross unrealized losses, with an aggregate depreciation of 16.8 % from the Company’s amortized cost basis. The largest unrealized dollar loss of any single security was $ 2.0 million, or 22.2 % of its amortized cost. The largest unrealized loss percentage of any single security was 36.6 % of its amortized cost, or $ 860,000 . The Company believes that the nature and duration of unrealized losses on its debt security positions are primarily a function of interest rate movements and changes in investment spreads and does not consider full repayment of principal on the reported debt obligations to be at risk. Since nearly all of these securities are rated “investment grade” and (a) the Company does not intend to sell these securities before recovery and (b) it is more likely than not that the Company will not be required to sell these securities before recovery, the Company does not expect to suffer a credit loss as of June 30, 2023. The Company had no pledged securities as collateral for repurchase agreements at June 30, 2023. The Company pledged U.S. Government obligations with an amortized cost of $ 9.1 million and a fair value of $ 8.0 million as collateral for repurchase agreements at December 31, 2022. The amortized cost and fair value of debt securities, aggregated by the earlier of call date or contractual maturity, are shown below. Maturities of mortgage-backed securities do not take into consideration scheduled amortization or prepayments. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. June 30, 2023 Within One Year After One, But After Five, But After Ten Years Total Amortized Fair Amortized Fair Amortized Fair Amortized Fair Amortized Fair (dollars in thousands) Available for sale securities U.S. Government Sponsored Enterprise obligations $ — $ — $ 9,997 $ 9,096 $ 5,000 $ 4,416 $ 8,000 $ 6,444 $ 22,997 $ 19,956 Mortgage-backed securities — — 12,855 11,992 38,005 31,522 98,711 80,836 149,571 124,350 Corporate debt securities — — — — — — — — — — Total available for sale securities $ — $ — $ 22,852 $ 21,088 $ 43,005 $ 35,938 $ 106,711 $ 87,280 $ 172,568 $ 144,306 Held to maturity securities U.S. Treasury Notes $ 994 $ 991 $ 3,011 $ 2,972 $ — $ — $ — $ — $ 4,005 $ 3,963 Mortgage-backed securities — — 25,022 23,414 50,536 42,774 837,746 687,083 913,304 753,271 Corporate debt securities 250 244 — — — — — — 250 244 Municipal securities 5,941 5,926 19,636 19,460 25,697 25,119 38,638 31,042 89,912 81,547 Total held to maturity securities $ 7,185 $ 7,161 $ 47,669 $ 45,846 $ 76,233 $ 67,893 $ 876,384 $ 718,125 $ 1,007,471 $ 839,025 Total $ 7,185 $ 7,161 $ 70,521 $ 66,934 $ 119,238 $ 103,831 $ 983,095 $ 805,405 $ 1,180,039 $ 983,331 There were no sales of investment securities during the three and six months ended June 30, 2023 or June 30, 2022. The Company monitors the credit quality of certain debt securities through the use of credit ratings among other factors on a quarterly basis. Credit ratings are opinions about the credit quality of a security and are utilized by the Company to make informed decisions. Investment grade securities are rated BBB-/Baa3 or higher and are generally considered to be of low risk. At June 30, 2023 and December 31, 2022 respectively, the Company’s debt securities portfolio did not contain any securities below investment grade, as reported by major credit rating agencies. At June 30, 2023 and December 31, 2022, respectively, none of the Company's investment securities were delinquent or in non-accrual status. The following tables summarize the credit rating of the Company’s debt securities portfolio at June 30, 2023 and December 31, 2022. June 30, 2023 Mortgage-backed Securities (1) Corporate Debt Securities Municipal Securities U.S. GSE Obligations U.S. Treasury Notes Total (dollars in thousands) Available for sale securities, at fair value AAA/AA/A $ 124,350 $ — $ — $ 19,956 $ — $ 144,306 BBB/BB/B — — — — — — Total available for sale securities $ 124,350 $ — $ — $ 19,956 $ — $ 144,306 Held to maturity securities, at amortized cost AAA/AA/A $ 913,304 $ 250 $ 89,912 $ — $ 4,005 $ 1,007,471 Total held to maturity securities $ 913,304 $ 250 $ 89,912 $ — $ 4,005 $ 1,007,471 December 31, 2022 Mortgage-backed Securities (1) Corporate Debt Securities Municipal Securities U.S. GSE Obligations U.S. Treasury Notes Total (dollars in thousands) Available for sale securities, at fair value AAA/AA/A $ 132,683 $ — $ — $ 19,733 $ — $ 152,416 BBB/BB/B — 1,000 — — — 1,000 Total available for sale securities $ 132,683 $ 1,000 $ — $ 19,733 $ — $ 153,416 Held to maturity securities, at amortized cost AAA/AA/A $ 951,372 $ 250 $ 96,405 $ — $ 3,970 $ 1,051,997 Total held to maturity securities $ 951,372 $ 250 $ 96,405 $ — $ 3,970 $ 1,051,997 (1) Includes agency mortgage-backed pass-through securities and collateralized mortgage obligations issued by U.S. Government Sponsored Enterprises (“GSEs”) and U.S. government agencies, such as FNMA, FHLMC, and GNMA that are not rated by Moody’s or Standard & Poor's. Each security contains a guarantee by the issuing U.S. GSE or agency and therefore carries an implicit guarantee of the U.S. government. These have been categorized as AAA/AA/A.

Loans and the Allowance for Cre

Loans and the Allowance for Credit Losses	6 Months Ended
	Jun. 30, 2023
Receivables [Abstract]
Loans and the Allowance for Credit Losses	7. LOANS AND THE ALLOWANCE FOR CREDIT LOSSES Loans outstanding are detailed by category as follows: June 30, 2023 December 31, 2022 (dollars in thousands) Residential mortgage Mortgages - fixed rate $ 805,220 $ 902,968 Mortgages - adjustable rate 765,618 703,958 Construction 41,445 35,299 Deferred costs, net of unearned fees 4,911 6,613 Total residential mortgages 1,617,194 1,648,838 Commercial mortgage Mortgages - non-owner occupied 1,634,435 1,592,732 Mortgages - owner occupied 168,478 183,591 Construction 110,971 135,782 Deferred costs, net of unearned fees 2,275 2,318 Total commercial mortgages 1,916,159 1,914,423 Home equity Home equity - lines of credit 92,561 108,961 Home equity - term loans 3,156 2,098 Deferred costs, net of unearned fees 258 292 Total home equity 95,975 111,351 Commercial and industrial Commercial and industrial 366,116 349,026 Paycheck Protection Program loans 841 1,384 Unearned fees, net of deferred costs 446 240 Total commercial and industrial 367,403 350,650 Consumer Secured 26,734 35,679 Unsecured 1,745 1,897 Deferred costs, net of unearned fees 16 18 Total consumer 28,495 37,594 Total loans $ 4,025,226 $ 4,062,856 Directors and officers of the Company and their associates are clients of, and have other transactions with the Company in the normal course of business. All loans and commitments included in such transactions were made on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with other persons and do not involve more than normal risk of collection or present other unfavorable features. Asset Quality The Company’s philosophy toward managing its loan portfolios is predicated upon careful monitoring, which stresses early detection and response to delinquent and default situations. The Company seeks to make arrangements to resolve any delinquent or default situation over the shortest possible time frame. As a general rule, loans more than 90 days past due with respect to principal or interest are classified as non-accrual loans. The Company may use discretion regarding other loans over 90 days past due if the loan is well secured and/or in process of collection. The following tables set forth information regarding non-performing loans disaggregated by loan category: June 30, 2023 Residential Commercial Home Commercial and Total (dollars in thousands) Non-performing loans: Non-accrual loans $ 6,083 $ 606 $ 398 $ 112 $ 7,199 Total $ 6,083 $ 606 $ 398 $ 112 $ 7,199 December 31, 2022 Residential Commercial Home Commercial and Total (dollars in thousands) Non-performing loans: Non-accrual loans $ 4,733 $ 311 $ 722 $ 73 $ 5,839 Troubled debt restructurings 622 — — 81 $ 703 Total $ 5,355 $ 311 $ 722 $ 154 $ 6,542 Loan Modifications and Restructurings The Company adopted ASU 2022-02, which eliminates the recognition and measurement of TDRs. Due to the removal of the TDR designation, the Company evaluates all loan restructurings according to the accounting guidance for loan modifications to determine if the restructuring results in a new loan or a continuation of the existing loan. Loan modifications to borrowers experiencing financial difficulty that result in a change in the timing or amount of contractual cash flows include situations where there is principal forgiveness, interest rate reductions, other-than-insignificant payment delays, term extensions, and combinations of the listed modifications. Therefore, the disclosures related to loan restructurings are only for modifications that directly affect cash flows. The allowance for credit losses incorporates an estimate of lifetime expected credit losses and is recorded on each asset upon origination. The starting point for the estimate of the allowance for credit losses is historical loss information, which includes losses from modifications of receivables to borrowers experiencing financial difficulty. The Company uses a discounted cash flow model to determine the allowance for credit losses. An assessment of whether a borrower is experiencing financial difficulty is made at the time of a modification. Because the effect of most modifications made to borrowers experiencing financial difficulty is already included in the allowance for credit losses, a change to the allowance for credit losses is generally not recorded upon modification. At June 30, 2023, the Company had no loan modifications or restructurings due to borrower financial difficulty. Foreclosure proceedings As of June 30, 2023 , there were two loans in process of foreclosure with a carrying value of approximately $ 628,000 . Both of these loans are secured by one to four family residential property. As of December 31, 2022, there were no loans in process of foreclosure. Loans by Credit Quality Indicator With respect to residential mortgages, home equity, and consumer loans, the Company utilizes the following categories as indicators of credit quality: • Performing – These loans are accruing and are considered having low to moderate risk. • Non-performing – These loans are on non-accrual, are more than 90 days past due but are still accruing, or are restructured. These loans may contain greater than average risk. With respect to commercial real estate mortgages and commercial and industrial loans, the Company utilizes a 10-grade internal loan rating system as an indicator of credit quality. The grades are as follows: • Loans rated 1-6 (Pass) – These loans are considered “pass” rated with low to moderate risk. • Loans rated 7 (Special Mention) – These loans have potential weaknesses warranting close attention, which, if left uncorrected, may result in deterioration of the credit at some future date. • Loans rated 8 (Substandard) – These loans have well-defined weaknesses that jeopardize the orderly liquidation of the debt under the original loan terms. Loss potential exists but is not identifiable in any one client. • Loans rated 9 (Doubtful) – These loans have pronounced weaknesses that make full collection highly questionable and improbable. • Loans rated 10 (Loss) – These loans are considered uncollectible and continuance as a bankable asset is not warranted. The following tables contain period-end balances of loans receivable disaggregated by credit quality indicator: Credit Quality Indicator - by Origination Year as of June 30, 2023 2023 2022 2021 2020 2019 Prior Revolving loans amortized cost basis Total (dollars in thousands) Residential Mortgage: Current $ 35,475 $ 336,012 $ 516,545 $ 284,119 $ 114,442 $ 324,518 $ — $ 1,611,111 Non-performing — — — 200 1,276 4,607 — 6,083 Total $ 35,475 $ 336,012 $ 516,545 $ 284,319 $ 115,718 $ 329,125 $ — $ 1,617,194 Current-period gross write-offs $ — $ — $ — $ — $ — $ — $ — $ — Home equity: Current $ 3,040 $ 4,289 $ 2,650 $ 1,503 $ 2,996 $ 16,075 $ 65,024 $ 95,577 Non-performing — 61 — — — 337 — 398 Total $ 3,040 $ 4,350 $ 2,650 $ 1,503 $ 2,996 $ 16,412 $ 65,024 $ 95,975 Current-period gross write-offs $ — $ — $ — $ — $ — $ — $ — $ — Consumer: Current $ 3,852 $ 10,154 $ 4,841 $ 3,244 $ 698 $ 5,121 $ 585 $ 28,495 Non-performing — — — — — — — — Total $ 3,852 $ 10,154 $ 4,841 $ 3,244 $ 698 $ 5,121 $ 585 $ 28,495 Current-period gross write-offs $ — $ — $ — $ — $ — $ 25 $ — $ 25 Credit Quality Indicator - by Origination Year as of June 30, 2023 2023 2022 2021 2020 2019 Prior Revolving loans amortized cost basis Total (dollars in thousands) Commercial Mortgage: Credit risk profile by internally 1-6 (Pass) $ 31,974 $ 461,974 $ 369,955 $ 230,573 $ 261,839 $ 468,282 $ — $ 1,824,597 7 (Special Mention) 1,847 — — 2,067 44,867 42,175 — 90,956 8 (Substandard) — — — — — 606 — 606 9 (Doubtful) — — — — — — — — 10 (Loss) — — — — — — — — Total $ 33,821 $ 461,974 $ 369,955 $ 232,640 $ 306,706 $ 511,063 $ — $ 1,916,159 Current-period gross write-offs $ — $ — $ — $ — $ — $ — $ — $ — Commercial and Industrial: Credit risk profile by internally 1-6 (Pass) $ 31,393 $ 137,643 $ 56,468 $ 69,581 $ 23,972 $ 43,827 $ 459 $ 363,343 7 (Special Mention) 60 858 151 110 195 123 10 1,507 8 (Substandard) — — — 585 1,823 145 — 2,553 9 (Doubtful) — — — — — — — — 10 (Loss) — — — — — — — — Total $ 31,453 $ 138,501 $ 56,619 $ 70,276 $ 25,990 $ 44,095 $ 469 $ 367,403 Current-period gross write-offs $ — $ — $ — $ — $ — $ 11 $ — $ 11 Credit Quality Indicator - by Origination Year as of December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving loans amortized cost basis Total (dollars in thousands) Residential Mortgage: Current $ 314,599 $ 511,217 $ 276,698 $ 113,251 $ 77,620 $ 350,098 $ — $ 1,643,483 Non-performing — — 206 315 684 4,150 — 5,355 Total $ 314,599 $ 511,217 $ 276,904 $ 113,566 $ 78,304 $ 354,248 $ — $ 1,648,838 Home equity: Current $ 3,611 $ — $ — $ 58 $ 360 $ 481 $ 106,119 $ 110,629 Non-performing — — — — — — 722 722 Total $ 3,611 $ — $ — $ 58 $ 360 $ 481 $ 106,841 $ 111,351 Consumer: Current $ 13,214 $ 8,482 $ 5,353 $ 444 $ 2,078 $ 7,424 $ 599 $ 37,594 Non-performing — — — — — — — — Total $ 13,214 $ 8,482 $ 5,353 $ 444 $ 2,078 $ 7,424 $ 599 $ 37,594 Credit Quality Indicator - by Origination Year as of December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving loans amortized cost basis Total (dollars in thousands) Commercial Mortgage: Credit risk profile by internally 1-6 (Pass) $ 411,927 $ 330,593 $ 222,073 $ 260,588 $ 125,398 $ 489,564 $ — $ 1,840,143 7 (Special Mention) — — 4,562 41,578 21,697 6,132 — 73,969 8 (Substandard) — — — — — 311 — 311 9 (Doubtful) — — — — — — — — 10 (Loss) — — — — — — — — Total $ 411,927 $ 330,593 $ 226,635 $ 302,166 $ 147,095 $ 496,007 $ — $ 1,914,423 Commercial and Industrial: Credit risk profile by internally 1-6 (Pass) $ 128,301 $ 67,727 $ 62,025 $ 28,557 $ 18,794 $ 36,836 $ 475 $ 342,715 7 (Special Mention) — 4,211 130 161 407 121 10 5,040 8 (Substandard) — — 628 2,102 81 84 — 2,895 9 (Doubtful) — — — — — — — — 10 (Loss) — — — — — — — — Total $ 128,301 $ 71,938 $ 62,783 $ 30,820 $ 19,282 $ 37,041 $ 485 $ 350,650 Delinquencies The past due status of a loan is determined in accordance with its contractual repayment terms. All loan types are reported past due when one scheduled payment is due and unpaid for 30 days or more. Loan delinquencies can be attributed to many factors, such as but not limited to, a continuing weakness in, or deteriorating, economic conditions in the region in which the collateral is located, the loss of a tenant or lower lease rates for commercial borrowers, or the loss of income for consumers and the resulting liquidity impacts on the borrowers. The following tables contain period-end balances of loans receivable disaggregated by past due status: June 30, 2023 30-59 Days 60-89 Days 90 Days or greater Total Past Due Current Loans Total (dollars in thousands) Residential mortgage $ 8,865 $ 370 $ 1,857 $ 11,092 $ 1,606,102 $ 1,617,194 Commercial mortgage 9,919 — — 9,919 1,906,240 1,916,159 Home equity 536 297 148 981 94,994 95,975 Commercial and industrial 82 472 — 554 366,849 367,403 Consumer 26 3 10 39 28,456 28,495 Total $ 19,428 $ 1,142 $ 2,015 $ 22,585 $ 4,002,641 $ 4,025,226 December 31, 2022 30-59 Days 60-89 Days 90 Days Total Current Total (dollars in thousands) Residential mortgage $ 11,359 $ 1,454 $ 1,809 $ 14,622 $ 1,634,216 $ 1,648,838 Commercial mortgage — — — — 1,914,423 1,914,423 Home equity 962 393 214 1,569 109,782 111,351 Commercial and industrial 65 269 — 334 350,316 350,650 Consumer 81 — — 81 37,513 37,594 Total $ 12,467 $ 2,116 $ 2,023 $ 16,606 $ 4,046,250 $ 4,062,856 There were no significant commitments to lend additional funds to borrowers whose loans were on non-accrual status at June 30, 2023 and December 31, 2022. Allowance for Credit Losses The following tables present changes in the allowance for credit losses disaggregated by loan category: Three Months Ended June 30, 2023 Residential Commercial Home Commercial & Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan Balance at March 31, 2023 $ 13,164 $ 19,596 $ 528 $ 4,152 $ 565 $ — $ 38,005 Charge-offs — — — — ( 22 ) — ( 22 ) Recoveries — — — 9 1 — 10 Provision for (release of) credit 433 ( 297 ) ( 60 ) 91 ( 87 ) — 80 Allowance for credit losses - $ 13,597 $ 19,299 $ 468 $ 4,252 $ 457 $ — $ 38,073 Allowance for credit losses - Balance at March 31, 2023 $ — $ — $ — $ — $ — $ 1,931 $ 1,931 Provision for (release of) credit — — — — — — — Allowance for credit losses- $ — $ — $ — $ — $ — $ 1,931 $ 1,931 Total allowance for credit loss $ 13,597 $ 19,299 $ 468 $ 4,252 $ 457 $ 1,931 $ 40,004 Six Months Ended June 30, 2023 Residential Commercial Home Commercial & Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan Balance at December 31, 2022 $ 13,321 $ 19,086 $ 573 $ 4,153 $ 641 $ — $ 37,774 Charge-offs — — — ( 11 ) ( 25 ) — ( 36 ) Recoveries — — — 19 11 — 30 Provision for (release of) credit 276 213 ( 105 ) 91 ( 170 ) — 305 Allowance for credit losses - $ 13,597 $ 19,299 $ 468 $ 4,252 $ 457 $ — $ 38,073 Allowance for credit losses - Balance at December 31, 2022 $ — $ — $ — $ — $ — $ 2,096 $ 2,096 Provision for (release of) credit — — — — — ( 165 ) ( 165 ) Allowance for credit losses- $ — $ — $ — $ — $ — $ 1,931 $ 1,931 Total allowance for credit loss $ 13,597 $ 19,299 $ 468 $ 4,252 $ 457 $ 1,931 $ 40,004 Three Months Ended June 30, 2022 Residential Commercial Home Commercial & Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan Balance at March 31, 2022 $ 13,193 $ 17,138 $ 377 $ 2,897 $ 505 $ — $ 34,110 Charge-offs — — — ( 3 ) ( 3 ) — ( 6 ) Recoveries — — — 10 10 — 20 Provision for (release of) credit ( 554 ) 629 23 ( 52 ) ( 46 ) — — Allowance for credit losses - loan portfolio at June 30, 2022 $ 12,639 $ 17,767 $ 400 $ 2,852 $ 466 $ — $ 34,124 Allowance for credit losses - Balance at March 31, 2022 $ — $ — $ — $ — $ — $ 1,371 $ 1,371 Release of credit losses - unfunded commitments — — — — — — — Allowance for credit losses- — — — — — 1,371 1,371 Total allowance for credit loss $ 12,639 $ 17,767 $ 400 $ 2,852 $ 466 $ 1,371 $ 35,495 Six Months Ended June 30, 2022 Residential Commercial Home Commercial & Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan Balance at December 31, 2021 $ 13,383 $ 17,133 $ 406 $ 2,989 $ 585 $ — $ 34,496 Charge-offs — — — ( 3 ) ( 28 ) — ( 31 ) Recoveries — — — 46 12 — 58 Provision for (release of) credit ( 744 ) 634 ( 6 ) ( 180 ) ( 103 ) — ( 399 ) Allowance for credit losses - loan portfolio at June 30, 2022 $ 12,639 $ 17,767 $ 400 $ 2,852 $ 466 $ — $ 34,124 Allowance for credit losses - Balance at December 31, 2021 $ — $ — $ — $ — $ — $ 1,384 $ 1,384 Release of credit — — — — — ( 13 ) ( 13 ) Allowance for credit losses- — — — — — 1,371 1,371 Total allowance for credit loss $ 12,639 $ 17,767 $ 400 $ 2,852 $ 466 $ 1,371 $ 35,495

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes The Company’s effective tax rate was 24.0 % and 24.7 % for the three and six months ended June 30, 2023 , respectively. The Company’s effective tax rate was 28.2 % and 26.7 % for the three and six months ended June 30, 2022, respectively. Net deferred tax assets totaled $ 15.8 million and $ 18.0 million at June 30, 2023 and December 31, 2022 , respectively. The Company did no t record a valuation allowance for deferred tax assets at June 30, 2023 or December 31, 2022. The components of income tax expense were as follows: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 (dollars in thousands) Current income tax expense Federal $ 1,998 $ 3,868 $ 3,032 $ 4,963 State 745 1,595 1,211 1,984 Total current income tax expense $ 2,743 $ 5,463 $ 4,243 $ 6,947 Deferred income tax expense (benefit) Federal $ ( 338 ) $ ( 61 ) $ 1,537 $ 1,964 State ( 155 ) ( 27 ) 629 908 Total deferred income tax expense (benefit) ( 493 ) ( 88 ) 2,166 2,872 Total income tax expense $ 2,250 $ 5,375 $ 6,409 $ 9,819

Pension and Retirement Plans

Pension and Retirement Plans	6 Months Ended
	Jun. 30, 2023
Retirement Benefits [Abstract]
Pension and Retirement Plans	9 . Pension and Retirement Plans The components of net periodic benefit cost (credit) were as follows: Three Months Ended June 30, Pension Plan Supplemental Retirement Healthcare Plan 2023 2022 2023 2022 2023 2022 (dollars in thousands) Net periodic benefit cost (credit) Service cost $ — $ — $ 68 $ 98 $ 4 $ 6 Interest cost 450 345 100 71 5 5 Expected return on assets ( 799 ) ( 1,002 ) — — — — Amortization of net actuarial (gain) loss — — — — ( 5 ) — Net periodic benefit cost (credit) $ ( 349 ) $ ( 657 ) $ 168 $ 169 $ 4 $ 11 Six Months Ended June 30, Pension Plan Supplemental Retirement Healthcare Plan 2023 2022 2023 2022 2023 2022 (dollars in thousands) Net periodic benefit cost (credit) Service cost $ — $ — $ 136 $ 199 $ 8 $ 14 Interest cost 903 655 200 130 11 10 Expected return on assets ( 1,602 ) ( 1,938 ) — — — — Amortization of net actuarial (gain) loss — — — — ( 11 ) — Net periodic benefit cost (credit) $ ( 699 ) $ ( 1,283 ) $ 336 $ 329 $ 8 $ 24 The Company froze the accrual of benefits on the qualified defined benefit pension plan in 2017. The Company did no t make any contributions to the qualified defined benefit pension plan during the three and six months ended June 30, 2023 , no r does it expect to make any contributions to the qualified defined benefit plan during the remainder of 2023. Employee Profit-Sharing and 401(k) Plan The Company maintains a Profit-Sharing Plan (“PSP”) that provides for deferral of federal and state income taxes on employee contributions allowed under Section 401(k) of federal law. The Company matches employee contributions up to 100 % of the first 4 % of each participant’s salary, eligible bonus, and eligible incentive. Employees are eligible to participate in the PSP on the first day of their initial date of service. Each year, the Company may also make a discretionary contribution to the PSP and employees are eligible to participate in the discretionary contribution portion of the PSP on the first day of their initial date of service. Additionally, employees must be employed on the last day of the calendar year or retire at the normal retirement age of 65 during the calendar year to receive the discretionary contribution. Employee Stock Ownership Plan The Company has an Employee Stock Ownership Plan (“ESOP”) for its eligible employees. Employees are eligible to participate upon the attainment of age 21 and the completion of 12 months of service consisting of at least 1,000 hours. Purchases of the Company’s common stock by the ESOP will be funded by employer contributions or reinvestment of cash dividends. Total expenses related to the PSP and ESOP for the three months ended June 30, 2023 and June 30, 2022 were $ 646,000 and $ 1.1 million , respectively. Total expenses related to the PSP and ESOP for the six months ended June 30, 2023 and June 30, 2022 were $ 1.5 million and $ 2.5 million , respectively. Defined Contribution Supplemental Executive Retirement Plan For executives participating in the Defined Contribution Supplemental Executive Retirement Plan (“DC SERP”), the Company will make a discretionary contribution of up to 10 % of each executive’s base salary and bonus to his or her account under the Company’s DC SERP. Total expenses related to the DC SERP for the three months ended June 30, 2023 was a credit of $ 16,000 and $ 68,000 for the three months ended June 30, 2022. Total expenses related to the DC SERP for the six months ended June 30, 2023, and June 30, 2022, were $ 25,000 and $ 135,000 , respectively.

Share Based Compensation

Share Based Compensation	6 Months Ended
	Jun. 30, 2023
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Share Based Compensation	10. share based compensation Time Vested Restricted Stock Awards (“RSAs”) and Time Vested Restricted Stock Units (“RSUs”) During the three and six months ended June 30, 2023 , the Company issued the following RSAs and RSUs pursuant to the Cambridge Bancorp 2017 Equity and Cash Incentive Plan (the “2017 Plan”). RSAs vest either over a three-year or five-year period. RSUs vest over a three-year period. T he fair value of RSAs and RSUs are based upon the closing price of the Company’s common stock on the date of the applicable grant. The holders of RSAs participate fully in the rewards of stock ownership of the Company, including voting and dividend rights. The holders of RSUs do not participate in the rewards of stock ownership of the Company until they are vested. Three Months Ended June 30, 2023 Six Months ended June 30, 2023 Type of Award Shares Granted Weighted Average Fair Value Per Share at Grant Date Shares Granted Weighted Average Fair Value Per Share at Grant Date RSAs 510 $ 49.15 13,675 $ 82.73 RSUs 18,731 $ 51.65 19,253 $ 52.53 Performance-Based Restricted Stock Units (“PRSUs”) During the three and six months ended June 30, 2023, the Company granted PRSUs from the 2017 Plan, as shown in the table below. PRSUs are subject to a three-year performance period and are earned based on performance factors, as determined, at the time of grant. Three Months Ended June 30, 2023 Six Months ended June 30, 2023 Type of Award Shares Granted Weighted Average Fair Value Per Share at Grant Date Shares Granted Weighted Average Fair Value Per Share at Grant Date PRSUs 22,895 $ 51.65 27,554 $ 55.13 The following table presents the pre-tax expense associated with all outstanding non-vested RSAs, RSUs, and PRSUs, and the related tax benefits recognized: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 (dollars in thousands) Share based compensation expense $ 603 $ 943 $ 1,170 $ 1,591 Related tax benefits $ 168 $ 263 $ 327 $ 444 Share-based activity in the statement of changes in shareholders’ equity includes RSA, RSU, and PRSU expense, as well as expense related to the Company’s share-based compensation for directors and shares repurchased by the Company for shares tendered by employees to cover income tax liability as grants vest. The 2017 Plan allows Directors of the Company to receive their annual retainer fee in the form of stock in the Company. The total shares issued under the 2017 Plan for the three and six months ended June 30, 2023 was 12,195 , respectively. The total shares issued under the 2017 Plan for the three and six months ended June 30, 2022 was 6,617 and 6,776 , respectively.

Financial Instruments with Off-

Financial Instruments with Off-Balance-Sheet Risk	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Financial Instruments with Off-Balance-Sheet Risk	11. Financial Instruments with Off-Balance-Sheet Risk To meet the financing needs of its clients, the Company is a party to financial instruments with off-balance-sheet risk in the normal course of business. These financial instruments are primarily comprised of commitments to extend credit, commitments to sell residential real estate mortgage loans, and standby letters of credit. Those instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for loan commitments and standby letters of credit is represented by the contractual amount of those instruments assuming that the amounts are fully advanced, and that collateral or other security is of no value. The Company generally uses the same credit policies in making commitments and conditional obligations as it does for on-balance-sheet instruments. Off-balance-sheet financial instruments with contractual amounts that present credit risk include the following: June 30, 2023 December 31, 2022 (dollars in thousands) Financial instruments whose contractual amount represents credit risk: Commitments to extend credit: Unused portion of existing lines of credit $ 1,038,589 $ 1,073,567 Origination of new loans 39,349 25,411 Standby letters of credit 32,645 24,234 Financial instruments whose notional amount exceeds the amount of credit risk: Commitments to sell residential mortgage loans — 250

Leases

Leases	6 Months Ended
	Jun. 30, 2023
Leases [Abstract]
Leases	12. LEASES Lease Commitments . The Company is obligated under various lease agreements covering its main office, branch offices, and other locations. These agreements are accounted for as operating leases and their terms expire between 2023 and 2032 and, in some instances, contain options to renew for periods up to 30 years. The components of operating lease cost and other related information are as follows: Three Months Ended June 30, 2023 2022 (dollars in thousands) Operating lease cost $ 1,673 $ 1,743 Variable lease cost (cost excluded from lease payments) 7 1 Sublease income ( 128 ) ( 17 ) Total operating lease cost $ 1,552 $ 1,727 Other Information Cash paid for amounts included in the measurement of lease liabilities - $ 1,821 $ 1,805 Operating Lease - operating cash flows (liability reduction) 1,637 1,586 Weighted average lease term - operating leases 5.18 Years 5.80 Years Weighted average discount rate - operating leases 3.06 % 2.97 % For the Six Months Ended June 30, 2023 2022 (dollars in thousands) Operating lease cost $ 3,411 $ 3,486 Variable lease cost (cost excluded from lease payments) 14 2 Sublease income ( 256 ) ( 33 ) Total operating lease cost $ 3,169 $ 3,455 Other Information Cash paid for amounts included in the measurement of lease liabilities - operating cash flows for operating leases $ 3,664 $ 3,638 Operating Lease - operating cash flows (liability reduction) 3,291 3,191 Weighted average lease term - operating leases 5.18 Years 5.80 Years Weighted average discount rate - operating leases 3.06 % 2.97 % The total minimum lease payments due in future periods for lease agreements in effect at June 30, 2023 were as follows: Future Minimum June 30, 2023 Lease Payments (dollars in thousands) Remainder of 2023 $ 3,552 2024 6,301 2025 5,314 2026 4,065 2027 2,267 Thereafter 5,962 Total minimum lease payments $ 27,461 Less: interest ( 2,085 ) Total lease liability $ 25,376 Several of the Company’s lease agreements contain clauses calling for escalation of minimum lease payments contingent on increases in real estate taxes, gross income adjustments, percentage increases in the consumer price index, and certain ancillary maintenance costs. Total rental expense was $ 1.8 million and $ 1.9 million for the three months ended June 30, 2023 and June 30, 2022 , respectively. Total rental expense was $ 3.7 million for both the six months ended June 30, 2023 and June 30, 2022 , respectively.

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Shareholders' Equity	13. Shareholders’ Equity As of June 30, 2023 and December 31, 2022, the Company and the Bank met all applicable minimum capital requirements and were considered “well-capitalized” by both the Federal Reserve Bank (“FRB”) and the Federal Deposit Insurance Corporation (“FDIC”). Actual Minimum Capital Minimum To Be Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At June 30, 2023 Cambridge Bancorp: Total capital (to risk-weighted assets) $ 516,242 14.1 % $ 384,543 10.5 % N/A N/A Tier 1 capital (to risk-weighted assets) 476,239 13.0 % 311,297 8.5 % N/A N/A Common equity tier I capital (to risk-weighted assets) 476,239 13.0 % 256,362 7.0 % N/A N/A Tier 1 capital (to average assets) 476,239 8.7 % 218,011 4.0 % N/A N/A Cambridge Trust Company: Total capital (to risk-weighted assets) $ 494,631 13.5 % $ 384,507 10.5 % $ 366,198 10.0 % Tier 1 capital (to risk-weighted assets) 454,627 12.4 % 311,268 8.5 % 292,958 8.0 % Common equity tier I capital (to risk-weighted assets) 454,627 12.4 % 256,338 7.0 % 238,028 6.5 % Tier 1 capital (to average assets) 454,627 8.3 % 217,998 4.0 % 272,498 5.0 % Actual Minimum Capital Minimum To Be Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At December 31, 2022 Cambridge Bancorp: Total capital (to risk-weighted assets) $ 506,239 13.5 % $ 393,285 10.5 % N/A N/A Tier 1 capital (to risk-weighted assets) 466,369 12.5 % 318,373 8.5 % N/A N/A Common equity tier I capital (to risk-weighted assets) 466,369 12.5 % 262,190 7.0 % N/A N/A Tier 1 capital (to average assets) 466,369 8.5 % 219,309 4.0 % N/A N/A Cambridge Trust Company: Total capital (to risk-weighted assets) $ 490,175 13.1 % $ 393,246 10.5 % $ 374,520 10.0 % Tier 1 capital (to risk-weighted assets) 450,305 12.0 % 318,342 8.5 % 299,616 8.0 % Common equity tier I capital (to risk-weighted assets) 450,305 12.0 % 262,164 7.0 % 243,438 6.5 % Tier 1 capital (to average assets) 450,305 8.2 % 219,296 4.0 % 274,120 5.0 %

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Other Comprehensive Income (Loss)	14. Other Comprehensive INcome (LOSS) The following tables present the changes in accumulated other comprehensive income (loss) (“AOCI”) (“AOCL”) during the periods, by component, net of tax: Three Months Ended June 30, 2023 Three Months Ended June 30, 2022 Before Tax Tax (Expense) Net-of-tax Before Tax Tax (Expense) Net-of-tax (dollars in thousands) Available for sale securities Unrealized holding gains (losses) $ ( 2,259 ) $ 593 $ ( 1,666 ) $ ( 5,579 ) $ 1,442 $ ( 4,137 ) Interest rate swaps designated as cash flow Unrealized holding (losses) gains ( 711 ) 199 ( 512 ) ( 358 ) 101 ( 257 ) Reclassification adjustment for (losses) income recognized in net income 145 ( 41 ) 104 ( 391 ) 108 ( 283 ) Total other comprehensive income (loss) $ ( 2,825 ) $ 751 $ ( 2,074 ) $ ( 6,328 ) $ 1,651 $ ( 4,677 ) Six Months Ended June 30, 2023 Six Months Ended June 30, 2022 Before Tax Tax (Expense) Net-of-tax Before Tax Tax (Expense) or Benefit Net-of-tax (dollars in thousands) Available for sale securities Unrealized holding gains (losses) $ 349 $ ( 73 ) $ 276 $ ( 16,595 ) $ 4,231 $ ( 12,364 ) Interest rate swaps designated as cash flow . Unrealized holding (losses) gains ( 633 ) 178 ( 455 ) ( 2,058 ) 575 ( 1,483 ) Reclassification adjustment for (losses) income recognized in net income 289 ( 81 ) 208 ( 1,005 ) 281 ( 724 ) Total other comprehensive income (loss) $ 5 $ 24 $ 29 $ ( 19,658 ) $ 5,087 $ ( 14,571 ) Reclassifications out of AOCI and AOCL that have an impact on net income are presented below. Three Months Ended Details about Accumulated Other Comprehensive Income (Loss) Components June 30, 2023 June 30, 2022 Affected Line Item in the (dollars in thousands) Unrealized (losses) gains on derivatives $ ( 145 ) $ 391 Interest on taxable loans Tax benefit (expense) 41 ( 108 ) Income tax expense Net of tax $ ( 104 ) $ 283 Net income Six Months Ended Details about Accumulated Other Comprehensive Loss Components June 30, 2023 June 30, 2022 Affected Line Item in the (dollars in thousands) Unrealized (losses) gains on derivatives $ ( 289 ) $ 1,005 Interest on taxable loans Tax benefit (expense) 81 ( 281 ) Income tax expense Net of tax $ ( 208 ) $ 724 Net income

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Earnings Per Share	15. Earnings per Share The following represents a reconciliation between basic and diluted earnings per share: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 (dollars in thousands, except per share data) Earnings per common share - basic: Numerator: Net income $ 7,115 $ 13,658 $ 19,531 $ 26,974 Less dividends and undistributed earnings allocated ( 2 ) ( 43 ) ( 20 ) ( 122 ) Net income applicable to common shareholders $ 7,113 $ 13,615 $ 19,511 $ 26,852 Denominator: Weighted average common shares outstanding 7,838 6,982 7,817 6,960 Earnings per common share - basic $ 0.91 $ 1.95 $ 2.50 $ 3.86 Earnings per common share - diluted: Numerator: Net income $ 7,115 $ 13,658 $ 19,531 $ 26,974 Less dividends and undistributed earnings allocated ( 2 ) ( 43 ) ( 20 ) ( 122 ) Net income applicable to common shareholders $ 7,113 $ 13,615 $ 19,511 $ 26,852 Denominator: Weighted average common shares outstanding 7,838 6,982 7,817 6,960 Dilutive effect of common stock equivalents 17 45 25 54 Weighted average diluted common shares outstanding 7,855 7,027 7,842 7,014 Earnings per common share - diluted $ 0.91 $ 1.94 $ 2.49 $ 3.83

Derivative And Hedging Activiti

Derivative And Hedging Activities	6 Months Ended
	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative And Hedging Activities	16. Derivative AND HEDGING ACTIVITIES The Company utilizes interest rate swaps and floors to mitigate exposure to interest rate risk and to facilitate the needs of its clients. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts principally related to the Company’s assets. Cash Flow Hedges of Interest Rate Risk The Company uses interest rate floors to manage its exposure to interest rate movements. Interest rate floors designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty if interest rates fall below the strike rate on the contract in exchange for an up-front premium. For derivatives designated and that qualify as cash flow hedges of interest rate risk, the gain or loss on the derivative is recorded in AOCI and AOCL and subsequently reclassified into interest income in the same period(s) during which the hedged transaction affects earnings. Gains and losses on the derivative representing hedge components excluded from the assessment of effectiveness are recognized over the life of the hedge on a systematic and rational basis. The earnings recognition of excluded components is presented in interest income. Amounts reported in AOCI and AOCL related to derivatives will be reclassified to interest income as interest payments are received on the Company’s variable-rate assets. During the next twelve months, the Company estimates that $ 444,000 will be reclassified out of AOCI and AOCL into earning s, as a decrease to interest income. Fair Value Hedges of Interest Rate Risk The Company is exposed to changes in the fair value of certain pools of fixed-rate assets due to changes in benchmark interest rates. The Company uses interest rate swaps to manage its exposure to changes in fair value on these instruments attributable to changes in the designated benchmark interest rate. The Company's interest rate swaps designated as fair value hedges involve the payment of fixed-rate amounts to a counterparty in exchange for the Company receiving variable-rate payments over the life of the agreements without the exchange of the underlying notional amount. For derivatives designated and that qualify as fair value hedges, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedged risk are recognized in interest income. T he Company recorded the following amounts on the balance sheet related to cumulative basis adjustment for fair value hedges: Line Item in the Statement of Financial Position in Which the Hedged Item is Included Carrying Amount of the Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities) June 30, 2023 December 31, 2022 June 30, 2023 December 31, 2022 (dollars in thousands) Fixed Rate Assets $ 494,744 $ — $ 5,256 $ — Total $ 494,744 $ — $ 5,256 $ — These amounts include the amortized cost basis of closed portfolios of fixed rate residential loans used to designate hedging relationships in which the hedged item is the stated amount of assets in the closed portfolio anticipated to be outstanding for the designated hedged period. At June 30, 2023, the amortized cost basis of the closed portfolios used in these hedging relationships wa s $ 696.1 million; the cumulative basis adjustments associated with these hedging relationships was $ 5.3 million; and the notional amount of the designated hedged items were $ 500.0 million. The Company had no fair value hedges at December 31, 2022. The notional amounts of these agreements do not represent amounts exchanged by the parties and, thus, are not a measure of the potential loss exposure. At June 30, 2023 , the Company’s fair value hedges had a weighted average remaining maturity of 1.78 years, and a weighted average fixed rate of 4.16 %. Derivatives not designated as hedging instruments Derivatives not designated as hedges result from a service the Company provides to certain clients. For the Company’s clients, these are interest rate swaps and risk participation agreements. Interest Rate Swaps. The Company enters into interest rate swap contracts to help commercial loan borrowers manage their interest rate risk. The interest rate swap contracts with commercial loan borrowers allow them to convert floating-rate loan payments to fixed rate loan payments. When the Company enters into an interest rate swap contract with a commercial loan borrower, it simultaneously enters into a “mirror” swap contract with a third party. The third party exchanges the borrower’s fixed-rate loan payments for floating-rate loan payments. These derivatives are not designated as hedges and therefore, changes in fair value are recognized in earnings. Because these derivatives have mirror-image contractual terms, the changes in fair value substantially offset each other through earnings. Fees earned in connection with the execution of derivatives related to this program are recognized in earnings through loan-related derivative income. The credit risk associated with swap transactions is the risk of default by the counterparty. To minimize this risk, the Company enters into interest rate agreements only with highly rated counterparties that management believes to be creditworthy. The notional amounts of these agreements do not represent amounts exchanged by the parties and, thus, are not a measure of the potential loss exposure. Risk Participation Agreements. The Company enters into risk participation agreements (“RPAs”) with other banks participating in commercial loan arrangements. Participating banks guarantee the performance on borrower-related interest rate swap contracts. RPAs are derivative financial instruments and are recorded at fair value. These derivatives are not designated as hedges and, therefore, changes in fair value are recognized in earnings. Under a risk participation-out agreement, a derivative asset, the Company participates out a portion of the credit risk associated with the interest rate swap position executed with the commercial borrower for a fee paid to the participating bank. Under a risk participation-in agreement, a derivative liability, the Company assumes, or participates in, a portion of the credit risk associated with the interest rate swap position with the commercial borrower for a fee received from the other bank. The following tables present the notional amount, the location, and fair values of derivative instruments in the Company’s consolidated balance sheets: June 30, 2023 Derivative Assets Derivative Liabilities Notional Amount Balance Sheet Fair Value Notional Amount Balance Sheet Fair Value (dollars in thousands) (dollars in thousands) Derivatives designated as hedging instruments Interest rate contracts-cash flow hedging relationships $ 250,000 Other Assets $ 1,333 $ — Other Liabilities $ — Interest rate contracts-fair value hedging relationships 500,000 Other Assets 5,219 — Other Liabilities — Total derivatives designated as hedging instruments $ 6,552 $ — Derivatives not designated as hedging instruments Loan related derivative contracts Interest rate contracts $ 499,917 Other Assets $ 49,083 $ 499,917 Other Liabilities $ 49,083 Risk participation agreements-out to counterparties 52,070 Other Assets 24 — Other Liabilities — Risk participation agreements-in with counterparties — Other Assets — 81,644 Other Liabilities 44 Total derivatives not designated as hedging instruments $ 49,107 $ 49,127 December 31, 2022 Derivative Assets Derivative Liabilities Notional Amount Balance Sheet Fair Value Notional Amount Balance Sheet Fair Value (dollars in thousands) (dollars in thousands) Derivatives designated as hedging instruments Interest rate contracts-cash flow hedging relationships $ 250,000 Other Assets $ 1,966 $ — Other Liabilities $ — Total derivatives designated as hedging instruments $ 1,966 $ — Derivatives not designated as hedging instruments Loan related derivative contracts Interest rate contracts $ 499,619 Other Assets $ 50,784 $ 499,619 Other Liabilities $ 50,784 Risk participation agreements-out to counterparties 46,604 Other Assets 23 — Other Liabilities — Risk participation agreements-in with counterparties — Other Assets — 71,046 Other Liabilities 43 Total derivatives not designated as hedging instruments $ 50,807 $ 50,827 The following tables present the changes to AOCI and AOCL as a result of cash flow hedge accounting as of the periods presented: Three Months Ended June 30, 2023 Amount of Gain Amount of Gain Amount of Gain Location of Gain Amount of Gain Amount of Gain or (Loss) Reclassified from AOCL into Income Included Component Amount of Gain or (Loss) Reclassified from AOCL into Income Excluded Component (dollars in thousands) (dollars in thousands) Interest rate contracts $ ( 711 ) $ — $ ( 711 ) Interest Income $ ( 145 ) $ — $ ( 145 ) Six Months Ended June 30, 2023 Amount of Gain or (Loss) Recognized in OCI Amount of Gain or (Loss) Recognized in OCI Included Component Amount of Gain or (Loss) Recognized in OCI Excluded Component Location of Gain or (Loss) Amount of Gain or (Loss) Reclassified from AOCL into Income Amount of Gain or (Loss) Reclassified from AOCL into Income Included Component Amount of Gain or (Loss) Reclassified from AOCL into Income Excluded Component (dollars in thousands) (dollars in thousands) Interest rate contracts $ ( 633 ) $ — $ ( 633 ) Interest Income $ ( 289 ) $ ( 96 ) $ ( 193 ) Three Months Ended June 30, 2022 Amount of Gain Amount of Gain Amount of Gain Location of Gain Amount of Gain Amount of Gain Amount of Gain (dollars in thousands) (dollars in thousands) Interest rate contracts $ ( 358 ) $ ( 101 ) $ ( 257 ) Interest Income $ 391 $ 439 $ ( 48 ) Six Months Ended June 30, 2022 Amount of Gain or (Loss) Recognized in OCI Amount of Gain or (Loss) Recognized in OCI - Included Component Amount of Gain or (Loss) Recognized in OCI - Excluded Component Location of Gain or (Loss) Amount of Gain or (Loss) Reclassified from AOCI into Income Amount of Gain or (Loss) Reclassified from AOCI into Income Included Component Amount of Gain or (Loss) Reclassified from AOCI into Income Excluded Component (dollars in thousands) (dollars in thousands) Interest rate contracts $ ( 2,058 ) $ ( 2,012 ) $ ( 46 ) Interest Income $ 1,005 $ 1,101 $ ( 96 ) The following table presents the effect of the Company’s derivative financial instruments that are not designated as hedging instruments on the consolidated statements of income as of the periods presented: Amount of Gain or (Loss) Recognized in Income Three Months Ended June 30, 2023 June 30, 2022 Location of Gain or (Loss) (dollars in thousands) Other contracts Loan-related derivative income $ ( 14 ) $ ( 33 ) Amount of Gain or (Loss) Recognized in Income Six Months Ended June 30, 2023 June 30, 2022 Location of Gain or (Loss) (dollars in thousands) Other contracts Loan-related derivative income $ ( 31 ) $ ( 110 ) Credit-risk-related Contingent Features By entering into derivative transactions, 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. The Company seeks to minimize counterparty credit risk through credit approvals, limits, monitoring procedures, and obtaining collateral, where appropriate. Institutional counterparties must have an investment grade credit rating and be approved by the Company’s board of directors. As such, management believes the risk of incurring credit losses on derivative contracts with institutional counterparties is remote. The Company has agreements with its derivative counterparties that contain a provision where 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. In addition, the Company also has agreements with certain of its derivative counterparties that contain a provision where if the Company fails to maintain its status as a well-capitalized institution, then the counterparty could terminate the derivative position(s) and the Company would be required to settle its obligations under the agreements. Balance Sheet Offsetting Certain financial instruments may be eligible for offset in the consolidated balance sheet and/or subject to master netting arrangements or similar agreements. The Company’s derivative transactions with institutional counterparties are generally executed under International Swaps and Derivative Association (“ISDA”) master agreements which include “right of set-off” provisions. In such cases there is generally a legally enforceable right to offset recognized amounts and there may be an intention to settle such amounts on a net basis. Generally, the Company does not offset such financial instruments for financial reporting purposes. The following tables present the information about financial instruments that are eligible for offset in the consolidated balance sheets at June 30, 2023 and December 31, 2022: Gross Amounts Not Offset Gross Amounts Recognized Gross Amounts Offset Net Amounts Recognized Financial Instruments Collateral Pledged (Received) Net Amount June 30, 2023 (dollars in thousands) Offsetting of Derivative Assets Derivative Assets $ 55,660 $ — $ 55,660 $ 109 $ ( 55,352 ) $ 199 Offsetting of Derivative Liabilities Derivative Liabilities $ 49,083 $ — $ 49,083 $ 109 $ — $ 48,974 Gross Amounts Not Offset Gross Amounts Recognized Gross Amounts Offset Net Amounts Recognized Financial Instruments Collateral Pledged (Received) Net Amount December 31, 2022 (dollars in thousands) Offsetting of Derivative Assets Derivative Assets $ 52,773 $ — $ 52,773 $ 48 $ ( 52,130 ) $ 595 Offsetting of Derivative Liabilities Derivative Liabilities $ 50,827 $ — $ 50,827 $ 48 $ — $ 50,875 At June 30, 2023 and December 31, 2022, respectively, there were no derivatives in a net liability position related to these agreements .

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	17. Fair Value Measurements The following is a summary of the carrying values and estimated fair values of the Company’s significant financial instruments as of the dates indicated: June 30, 2023 December 31, 2022 Carrying Estimated Carrying Estimated (dollars in thousands) Financial assets Cash and cash equivalents $ 33,398 $ 33,398 $ 30,719 $ 30,719 Securities available for sale 144,306 144,306 153,416 153,416 Securities held to maturity 1,007,471 839,025 1,051,997 885,586 Loans, net 3,987,153 3,643,268 4,025,082 3,783,051 FHLB of Boston stock 20,247 20,247 6,264 6,264 Accrued interest receivable 14,573 14,573 14,118 14,118 Mortgage servicing rights 1,529 2,208 1,665 2,336 Interest rate contracts - cash flow hedge 1,333 1,333 1,966 1,966 Loan level interest rate swaps 49,083 49,083 50,784 50,784 Risk participation agreements out to counterparties 24 24 23 23 Interest rate contracts - fair value hedge 5,219 5,219 — — Financial liabilities Deposits, excluding wholesale deposits 4,086,260 4,081,744 4,433,817 4,429,190 Wholesale deposits 356,330 356,084 381,559 381,505 Borrowings 408,926 407,551 105,212 105,202 Loan level interest rate swaps 49,083 49,083 50,784 50,784 Risk participation agreements in with counterparties 44 44 43 43 The Company follows ASC 820, Fair Value Measurements and Disclosures (“ASC 820”) for financial assets and liabilities. ASC 820 defines fair value, establishes a framework for measuring fair value, and expands disclosure requirements about fair value measurements. ASC 820, among other things, emphasizes that fair value is a market-based measurement, not an entity-specific measurement, and states that a fair value measurement should be determined based on the assumptions the market participants would use in pricing the asset or liability. In addition, ASC 820 specifies a hierarchy of valuation techniques based on whether the types of valuation information (“inputs”) are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s market assumptions. These two types of inputs have created the following fair value hierarchy: • Level 1 – Quoted prices for identical assets or liabilities in active markets. • Level 2 – Quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in inactive markets, and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets. • Level 3 – Valuations derived from techniques in which one or more significant inputs or significant value drivers are unobservable in the markets and which reflect the Company’s market assumptions. Under ASC 820, fair values are based on the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When available, the Company uses quoted market prices to determine fair value. If quoted prices are not available, fair value is based upon valuation techniques, such as matrix pricing or other models that use, where possible, current market-based or independently sourced market parameters, such as interest rates. If observable market-based inputs are not available, the Company uses unobservable inputs to determine appropriate valuation adjustments using methodologies applied consistently over time. Valuation techniques based on unobservable inputs are highly subjective and require judgments regarding significant matters, such as the amount and timing of future cash flows and the selection of discount rates that may appropriately reflect market and credit risks. Changes in these judgments often have a material impact on the fair value estimates. In addition, since these estimates are as of a specific point in time, they are susceptible to material near-term changes. The fair values disclosed do not reflect any premium or discount that could result from offering significant holdings of financial instruments at bulk sale, nor do they reflect the possible tax ramifications or estimated transaction costs. Changes in economic conditions may also dramatically affect the estimated fair values. The Company uses fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. Securities available for sale, derivative instruments, and hedges are recorded at fair value on a recurring basis. Additionally, from time to time, the Company may be required to record at fair value other assets on a nonrecurring basis, such as individually evaluated collateral dependent loans. The Company uses an exit price notion for its fair value disclosures. The following tables summarize certain assets and liabilities reported at fair value on a recurring basis: Fair Value as of June 30, 2023 Level 1 Level 2 Level 3 Total (dollars in thousands) Measured on a recurring basis Securities available for sale U.S. GSE obligations $ — $ 19,956 $ — $ 19,956 Mortgage-backed securities — 124,350 — 124,350 Corporate debt securities — — — — Other assets Interest rate swaps with clients — 49,083 — 49,083 Risk participation agreements -out to counterparties — 24 — 24 Interest rate contracts - cash flow hedge — 1,333 — 1,333 Interest rate contracts - fair value hedge — 5,219 — 5,219 Other liabilities Interest rate swaps with counterparties — 49,083 — 49,083 Risk participation agreements-in with counterparties — 44 — 44 Fair Value as of December 31, 2022 Level 1 Level 2 Level 3 Total (dollars in thousands) Measured on a recurring basis Securities available for sale U.S. GSE obligations $ — $ 19,733 $ — $ 19,733 Mortgage-backed securities — 132,683 — 132,683 Corporate debt securities — 1,000 — 1,000 Other assets Interest rate swaps with clients — 50,784 — 50,784 Risk participation agreements-out to counterparties — 23 — 23 Interest rate contracts — 1,966 — 1,966 Other liabilities Interest rate swaps with counterparties — 50,784 — 50,784 Risk participation agreements-in with counterparties — 43 — 43 The following tables present the carrying value of assets held at June 30, 2023 and December 31, 2022, which were measured at fair value on a non-recurring basis: June 30, 2023 Level 1 Level 2 Level 3 Total (dollars in thousands) Items recorded at fair value on a non-recurring basis Assets Individually evaluated collateral dependent loans $ — $ — $ 89 $ 89 Total $ — $ — $ 89 $ 89 December 31, 2022 Level 1 Level 2 Level 3 Total (dollars in thousands) Items recorded at fair value on a non-recurring basis Assets Individually evaluated collateral dependent loans — — 103 103 Total $ — $ — $ 103 $ 103 Individually evaluated collateral dependent loans . Collateral dependent loans are carried at the lower of cost or fair value of the collateral less estimated costs to sell which approximates fair value. The Company uses the appraisal value of the collateral and applies certain adjustments depending on the nature, quality, and type of collateral securing the loan. There were no transfers between levels for the three and six months ended June 30, 2023 or June 30, 2022. The following is a description of the principal valuation methodologies used by the Company to estimate the fair values of its financial instruments: Investment Securities For investment securities, fair values are primarily based upon valuations obtained from a national pricing service which uses matrix pricing with inputs that are observable in the market or can be derived from, or corroborated by, observable market data. When available, quoted prices in active markets for identical securities are utilized. Loans Held for Sale For loans held for sale, fair values are estimated using projected future cash flows, discounted at rates based upon either trades of similar loans or mortgage-backed securities, or at current rates at which similar loans would be made to borrowers with similar credit ratings and for similar remaining maturities. Loans For most categories of loans, fair values are estimated using projected future cash flows, discounted at rates based upon current rates at which similar loans would be made to borrowers with similar credit ratings, and for similar remaining maturities. Projected estimated cash flows are adjusted for prepayment assumptions, liquidity premium assumptions, and credit loss assumptions. Loans that are deemed to be impaired in accordance with ASC 310, Receivables, are valued based upon the lower of cost or fair value of the underlying collateral. Federal Home Loan Bank of Boston (“FHLB of Boston”) Stock The fair value of FHLB of Boston stock equals its carrying value since such stock is only redeemable at its par value. Deposits The fair value of non-maturity deposit accounts is the amount payable on demand at the reporting date. This amount does not take into account the value of the Bank’s long-term relationships with core depositors. The fair value of fixed-maturity certificates of deposit is estimated using a replacement cost of funds approach and is based upon rates currently offered for deposits of similar remaining maturities. Borrowings For long-term borrowings, fair values are estimated using future cash flows, discounted at rates based upon current costs for debt securities with similar terms and remaining maturities. Other Financial Assets and Liabilities Cash and cash equivalents, accrued interest receivable, and short-term borrowings have fair values which approximate their respective carrying values because these instruments are payable on demand or have short-term maturities and present relatively low credit risk and interest rate risk. Derivative Instruments and Hedges The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves and implied volatilities. The Company incorporates credit valuation adjustments to appropriately reflect nonperformance risk in the fair value measurements. In adjusting the fair value of its derivative contracts for the effect of nonperformance risk, the Company has considered the impact of netting and any applicable credit enhancements, such as collateral postings. Off-Balance-Sheet Financial Instruments In the course of originating loans and extending credit, the Company will charge fees in exchange for its commitment. While these commitment fees have value, the Company has not estimated their value due to the short-term nature of the underlying commitments and their immateriality. Values Not Determined In accordance with ASC 820, the Company has not estimated fair values for non-financial assets, such as banking premises and equipment, goodwill, the intangible value of the Company’s portfolio of loans serviced for itself, and the intangible value inherent in the Company’s deposit relationships (i.e., core deposits), among others. Accordingly, the aggregate fair value amounts presented do not represent the underlying value of the Company.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Recently Issued Accounting Guidance	Accounting Pronouncements Recently Adopted In March 2022, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2022-02, Financial Instruments – Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures. The amendments in this ASU eliminate the accounting guidance for troubled debt restructurings (“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. For public business entities, the amendments in this ASU require an entity to disclose current-period gross write-offs by year of origination for financing receivables and net investments in leases. This ASU was effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption was permitted. The Company adopted the new standard on January 1, 2023 and the adoption did not have a material impact on the consolidated financial statements. In March 2022, the FASB issued ASU 2022-01, Derivatives and Hedging (Topic 815): Fair Value Hedging - Portfolio Layer Method . The amendments in this ASU allow multiple hedged layers to be designated for a single closed portfolio of financial assets or one or more beneficial interests secured by a portfolio of financial instruments. The amendments in this ASU also clarify the accounting for and promote consistency in the reporting of hedge basis adjustments applicable to both a single hedged layer and multiple hedged layers. These amendments are effective for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years. The Company adopted the new standard on January 1, 2023 and provided the additional disclosures required for the Company's fair value hedging relationships.

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Jun. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Carrying Amounts of Securities and Their Approximate Fair Values	Investment securities have been classified in the unaudited consolidated balance sheets according to management’s intent. The carrying amounts of securities and their approximate fair values were as follows: June 30, 2023 December 31, 2022 Amortized Gross Gross Fair Amortized Gross Gross Fair (dollars in thousands) Available for sale securities U.S. Government Sponsored $ 22,997 $ — $ ( 3,041 ) $ 19,956 $ 22,997 $ — $ ( 3,264 ) $ 19,733 Mortgage-backed securities 149,571 1 ( 25,222 ) 124,350 158,034 3 ( 25,354 ) 132,683 Corporate debt securities — — — — 996 4 — 1,000 Total available for sale securities $ 172,568 $ 1 $ ( 28,263 ) $ 144,306 $ 182,027 $ 7 $ ( 28,618 ) $ 153,416 Held to maturity securities U.S. Treasury Notes $ 4,005 $ — $ ( 42 ) $ 3,963 $ 3,970 $ — $ ( 18 ) $ 3,952 Mortgage-backed securities 913,304 1 ( 160,034 ) 753,271 951,372 4 ( 157,208 ) 794,168 Corporate debt securities 250 — ( 6 ) 244 250 — ( 6 ) 244 Municipal securities 89,912 17 ( 8,382 ) 81,547 96,405 88 ( 9,271 ) 87,222 Total held to maturity securities $ 1,007,471 $ 18 $ ( 168,464 ) $ 839,025 $ 1,051,997 $ 92 $ ( 166,503 ) $ 885,586 Total $ 1,180,039 $ 19 $ ( 196,727 ) $ 983,331 $ 1,234,024 $ 99 $ ( 195,121 ) $ 1,039,002
Gross Unrealized Losses of Aggregated by Investment Category and Length of Time that Individual Securities have been in Continuous Loss Position	The following tables show the Company’s securities with gross unrealized losses for which an allowance for credit losses has not been recorded at June 30, 2023 or at December 31, 2022, aggregated by investment category and length of time that individual securities have been in a continuous loss position: June 30, 2023 Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized (dollars in thousands) Available for sale securities U.S. Government Sponsored Enterprise $ — $ — $ 19,957 $ ( 3,041 ) $ 19,957 $ ( 3,041 ) Mortgage-backed securities 164 ( 2 ) 124,038 ( 25,220 ) 124,202 ( 25,222 ) Total available for sale securities $ 164 $ ( 2 ) $ 143,995 $ ( 28,261 ) $ 144,159 $ ( 28,263 ) Held to maturity securities U.S. Treasury Notes $ 3,963 $ ( 42 ) $ — $ — $ 3,963 $ ( 42 ) Mortgage-backed securities 19,527 ( 1,183 ) 733,229 ( 158,851 ) 752,756 ( 160,034 ) Corporate debt securities — — 244 ( 6 ) 244 ( 6 ) Municipal securities 30,290 ( 302 ) 40,768 ( 8,080 ) 71,058 ( 8,382 ) Total held to maturity securities $ 53,780 $ ( 1,527 ) $ 774,241 $ ( 166,937 ) $ 828,021 $ ( 168,464 ) Total $ 53,944 $ ( 1,529 ) $ 918,236 $ ( 195,198 ) $ 972,180 $ ( 196,727 ) December 31, 2022 Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized (dollars in thousands) Available for sale securities U.S. Government Sponsored Enterprise $ 10,722 $ ( 2,278 ) $ 9,012 $ ( 986 ) $ 19,734 $ ( 3,264 ) Mortgage-backed securities 41,832 ( 3,097 ) 90,545 ( 22,257 ) 132,377 ( 25,354 ) Total available for sale securities $ 52,554 $ ( 5,375 ) $ 99,557 $ ( 23,243 ) $ 152,111 $ ( 28,618 ) Held to maturity securities U.S. Treasury Notes $ 3,952 $ ( 18 ) $ — $ — $ 3,952 $ ( 18 ) Mortgage-backed securities 230,708 ( 22,362 ) 562,835 ( 134,846 ) 793,543 ( 157,208 ) Corporate debt securities 243 ( 6 ) — — 243 ( 6 ) Municipal securities 51,969 ( 4,388 ) 13,714 ( 4,883 ) 65,683 ( 9,271 ) Total held to maturity securities $ 286,872 $ ( 26,774 ) $ 576,549 $ ( 139,729 ) $ 863,421 $ ( 166,503 ) Total $ 339,426 $ ( 32,149 ) $ 676,106 $ ( 162,972 ) $ 1,015,532 $ ( 195,121 )
Schedule of Amortized Cost and Fair Value of Debt Securities, Aggregated By Earlier of Guaranteed Call Date or Contractual Maturity	The amortized cost and fair value of debt securities, aggregated by the earlier of call date or contractual maturity, are shown below. Maturities of mortgage-backed securities do not take into consideration scheduled amortization or prepayments. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. June 30, 2023 Within One Year After One, But After Five, But After Ten Years Total Amortized Fair Amortized Fair Amortized Fair Amortized Fair Amortized Fair (dollars in thousands) Available for sale securities U.S. Government Sponsored Enterprise obligations $ — $ — $ 9,997 $ 9,096 $ 5,000 $ 4,416 $ 8,000 $ 6,444 $ 22,997 $ 19,956 Mortgage-backed securities — — 12,855 11,992 38,005 31,522 98,711 80,836 149,571 124,350 Corporate debt securities — — — — — — — — — — Total available for sale securities $ — $ — $ 22,852 $ 21,088 $ 43,005 $ 35,938 $ 106,711 $ 87,280 $ 172,568 $ 144,306 Held to maturity securities U.S. Treasury Notes $ 994 $ 991 $ 3,011 $ 2,972 $ — $ — $ — $ — $ 4,005 $ 3,963 Mortgage-backed securities — — 25,022 23,414 50,536 42,774 837,746 687,083 913,304 753,271 Corporate debt securities 250 244 — — — — — — 250 244 Municipal securities 5,941 5,926 19,636 19,460 25,697 25,119 38,638 31,042 89,912 81,547 Total held to maturity securities $ 7,185 $ 7,161 $ 47,669 $ 45,846 $ 76,233 $ 67,893 $ 876,384 $ 718,125 $ 1,007,471 $ 839,025 Total $ 7,185 $ 7,161 $ 70,521 $ 66,934 $ 119,238 $ 103,831 $ 983,095 $ 805,405 $ 1,180,039 $ 983,331
Summary of Credit Rating of Debt Securities Portfolio	The following tables summarize the credit rating of the Company’s debt securities portfolio at June 30, 2023 and December 31, 2022. June 30, 2023 Mortgage-backed Securities (1) Corporate Debt Securities Municipal Securities U.S. GSE Obligations U.S. Treasury Notes Total (dollars in thousands) Available for sale securities, at fair value AAA/AA/A $ 124,350 $ — $ — $ 19,956 $ — $ 144,306 BBB/BB/B — — — — — — Total available for sale securities $ 124,350 $ — $ — $ 19,956 $ — $ 144,306 Held to maturity securities, at amortized cost AAA/AA/A $ 913,304 $ 250 $ 89,912 $ — $ 4,005 $ 1,007,471 Total held to maturity securities $ 913,304 $ 250 $ 89,912 $ — $ 4,005 $ 1,007,471 December 31, 2022 Mortgage-backed Securities (1) Corporate Debt Securities Municipal Securities U.S. GSE Obligations U.S. Treasury Notes Total (dollars in thousands) Available for sale securities, at fair value AAA/AA/A $ 132,683 $ — $ — $ 19,733 $ — $ 152,416 BBB/BB/B — 1,000 — — — 1,000 Total available for sale securities $ 132,683 $ 1,000 $ — $ 19,733 $ — $ 153,416 Held to maturity securities, at amortized cost AAA/AA/A $ 951,372 $ 250 $ 96,405 $ — $ 3,970 $ 1,051,997 Total held to maturity securities $ 951,372 $ 250 $ 96,405 $ — $ 3,970 $ 1,051,997 (1) Includes agency mortgage-backed pass-through securities and collateralized mortgage obligations issued by U.S. Government Sponsored Enterprises (“GSEs”) and U.S. government agencies, such as FNMA, FHLMC, and GNMA that are not rated by Moody’s or Standard & Poor's. Each security contains a guarantee by the issuing U.S. GSE or agency and therefore carries an implicit guarantee of the U.S. government. These have been categorized as AAA/AA/A.

Loans and the Allowance for C_2

Loans and the Allowance for Credit Losses (Tables)	6 Months Ended
	Jun. 30, 2023
Receivables [Abstract]
Loans Outstanding by Category	Loans outstanding are detailed by category as follows: June 30, 2023 December 31, 2022 (dollars in thousands) Residential mortgage Mortgages - fixed rate $ 805,220 $ 902,968 Mortgages - adjustable rate 765,618 703,958 Construction 41,445 35,299 Deferred costs, net of unearned fees 4,911 6,613 Total residential mortgages 1,617,194 1,648,838 Commercial mortgage Mortgages - non-owner occupied 1,634,435 1,592,732 Mortgages - owner occupied 168,478 183,591 Construction 110,971 135,782 Deferred costs, net of unearned fees 2,275 2,318 Total commercial mortgages 1,916,159 1,914,423 Home equity Home equity - lines of credit 92,561 108,961 Home equity - term loans 3,156 2,098 Deferred costs, net of unearned fees 258 292 Total home equity 95,975 111,351 Commercial and industrial Commercial and industrial 366,116 349,026 Paycheck Protection Program loans 841 1,384 Unearned fees, net of deferred costs 446 240 Total commercial and industrial 367,403 350,650 Consumer Secured 26,734 35,679 Unsecured 1,745 1,897 Deferred costs, net of unearned fees 16 18 Total consumer 28,495 37,594 Total loans $ 4,025,226 $ 4,062,856
Non-performing Loans Disaggregated by Loan Category	The following tables set forth information regarding non-performing loans disaggregated by loan category: June 30, 2023 Residential Commercial Home Commercial and Total (dollars in thousands) Non-performing loans: Non-accrual loans $ 6,083 $ 606 $ 398 $ 112 $ 7,199 Total $ 6,083 $ 606 $ 398 $ 112 $ 7,199 December 31, 2022 Residential Commercial Home Commercial and Total (dollars in thousands) Non-performing loans: Non-accrual loans $ 4,733 $ 311 $ 722 $ 73 $ 5,839 Troubled debt restructurings 622 — — 81 $ 703 Total $ 5,355 $ 311 $ 722 $ 154 $ 6,542
Loans Receivable Disaggregated by Credit Quality Indicator	The following tables contain period-end balances of loans receivable disaggregated by credit quality indicator: Credit Quality Indicator - by Origination Year as of June 30, 2023 2023 2022 2021 2020 2019 Prior Revolving loans amortized cost basis Total (dollars in thousands) Residential Mortgage: Current $ 35,475 $ 336,012 $ 516,545 $ 284,119 $ 114,442 $ 324,518 $ — $ 1,611,111 Non-performing — — — 200 1,276 4,607 — 6,083 Total $ 35,475 $ 336,012 $ 516,545 $ 284,319 $ 115,718 $ 329,125 $ — $ 1,617,194 Current-period gross write-offs $ — $ — $ — $ — $ — $ — $ — $ — Home equity: Current $ 3,040 $ 4,289 $ 2,650 $ 1,503 $ 2,996 $ 16,075 $ 65,024 $ 95,577 Non-performing — 61 — — — 337 — 398 Total $ 3,040 $ 4,350 $ 2,650 $ 1,503 $ 2,996 $ 16,412 $ 65,024 $ 95,975 Current-period gross write-offs $ — $ — $ — $ — $ — $ — $ — $ — Consumer: Current $ 3,852 $ 10,154 $ 4,841 $ 3,244 $ 698 $ 5,121 $ 585 $ 28,495 Non-performing — — — — — — — — Total $ 3,852 $ 10,154 $ 4,841 $ 3,244 $ 698 $ 5,121 $ 585 $ 28,495 Current-period gross write-offs $ — $ — $ — $ — $ — $ 25 $ — $ 25 Credit Quality Indicator - by Origination Year as of June 30, 2023 2023 2022 2021 2020 2019 Prior Revolving loans amortized cost basis Total (dollars in thousands) Commercial Mortgage: Credit risk profile by internally 1-6 (Pass) $ 31,974 $ 461,974 $ 369,955 $ 230,573 $ 261,839 $ 468,282 $ — $ 1,824,597 7 (Special Mention) 1,847 — — 2,067 44,867 42,175 — 90,956 8 (Substandard) — — — — — 606 — 606 9 (Doubtful) — — — — — — — — 10 (Loss) — — — — — — — — Total $ 33,821 $ 461,974 $ 369,955 $ 232,640 $ 306,706 $ 511,063 $ — $ 1,916,159 Current-period gross write-offs $ — $ — $ — $ — $ — $ — $ — $ — Commercial and Industrial: Credit risk profile by internally 1-6 (Pass) $ 31,393 $ 137,643 $ 56,468 $ 69,581 $ 23,972 $ 43,827 $ 459 $ 363,343 7 (Special Mention) 60 858 151 110 195 123 10 1,507 8 (Substandard) — — — 585 1,823 145 — 2,553 9 (Doubtful) — — — — — — — — 10 (Loss) — — — — — — — — Total $ 31,453 $ 138,501 $ 56,619 $ 70,276 $ 25,990 $ 44,095 $ 469 $ 367,403 Current-period gross write-offs $ — $ — $ — $ — $ — $ 11 $ — $ 11 Credit Quality Indicator - by Origination Year as of December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving loans amortized cost basis Total (dollars in thousands) Residential Mortgage: Current $ 314,599 $ 511,217 $ 276,698 $ 113,251 $ 77,620 $ 350,098 $ — $ 1,643,483 Non-performing — — 206 315 684 4,150 — 5,355 Total $ 314,599 $ 511,217 $ 276,904 $ 113,566 $ 78,304 $ 354,248 $ — $ 1,648,838 Home equity: Current $ 3,611 $ — $ — $ 58 $ 360 $ 481 $ 106,119 $ 110,629 Non-performing — — — — — — 722 722 Total $ 3,611 $ — $ — $ 58 $ 360 $ 481 $ 106,841 $ 111,351 Consumer: Current $ 13,214 $ 8,482 $ 5,353 $ 444 $ 2,078 $ 7,424 $ 599 $ 37,594 Non-performing — — — — — — — — Total $ 13,214 $ 8,482 $ 5,353 $ 444 $ 2,078 $ 7,424 $ 599 $ 37,594 Credit Quality Indicator - by Origination Year as of December 31, 2022 2022 2021 2020 2019 2018 Prior Revolving loans amortized cost basis Total (dollars in thousands) Commercial Mortgage: Credit risk profile by internally 1-6 (Pass) $ 411,927 $ 330,593 $ 222,073 $ 260,588 $ 125,398 $ 489,564 $ — $ 1,840,143 7 (Special Mention) — — 4,562 41,578 21,697 6,132 — 73,969 8 (Substandard) — — — — — 311 — 311 9 (Doubtful) — — — — — — — — 10 (Loss) — — — — — — — — Total $ 411,927 $ 330,593 $ 226,635 $ 302,166 $ 147,095 $ 496,007 $ — $ 1,914,423 Commercial and Industrial: Credit risk profile by internally 1-6 (Pass) $ 128,301 $ 67,727 $ 62,025 $ 28,557 $ 18,794 $ 36,836 $ 475 $ 342,715 7 (Special Mention) — 4,211 130 161 407 121 10 5,040 8 (Substandard) — — 628 2,102 81 84 — 2,895 9 (Doubtful) — — — — — — — — 10 (Loss) — — — — — — — — Total $ 128,301 $ 71,938 $ 62,783 $ 30,820 $ 19,282 $ 37,041 $ 485 $ 350,650
Schedule of Loans Receivable Disaggregated by Past Due Status	The following tables contain period-end balances of loans receivable disaggregated by past due status: June 30, 2023 30-59 Days 60-89 Days 90 Days or greater Total Past Due Current Loans Total (dollars in thousands) Residential mortgage $ 8,865 $ 370 $ 1,857 $ 11,092 $ 1,606,102 $ 1,617,194 Commercial mortgage 9,919 — — 9,919 1,906,240 1,916,159 Home equity 536 297 148 981 94,994 95,975 Commercial and industrial 82 472 — 554 366,849 367,403 Consumer 26 3 10 39 28,456 28,495 Total $ 19,428 $ 1,142 $ 2,015 $ 22,585 $ 4,002,641 $ 4,025,226 December 31, 2022 30-59 Days 60-89 Days 90 Days Total Current Total (dollars in thousands) Residential mortgage $ 11,359 $ 1,454 $ 1,809 $ 14,622 $ 1,634,216 $ 1,648,838 Commercial mortgage — — — — 1,914,423 1,914,423 Home equity 962 393 214 1,569 109,782 111,351 Commercial and industrial 65 269 — 334 350,316 350,650 Consumer 81 — — 81 37,513 37,594 Total $ 12,467 $ 2,116 $ 2,023 $ 16,606 $ 4,046,250 $ 4,062,856
Summary of Changes in Allowance for Credit Losses Disaggregated by Loan Category	The following tables present changes in the allowance for credit losses disaggregated by loan category: Three Months Ended June 30, 2023 Residential Commercial Home Commercial & Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan Balance at March 31, 2023 $ 13,164 $ 19,596 $ 528 $ 4,152 $ 565 $ — $ 38,005 Charge-offs — — — — ( 22 ) — ( 22 ) Recoveries — — — 9 1 — 10 Provision for (release of) credit 433 ( 297 ) ( 60 ) 91 ( 87 ) — 80 Allowance for credit losses - $ 13,597 $ 19,299 $ 468 $ 4,252 $ 457 $ — $ 38,073 Allowance for credit losses - Balance at March 31, 2023 $ — $ — $ — $ — $ — $ 1,931 $ 1,931 Provision for (release of) credit — — — — — — — Allowance for credit losses- $ — $ — $ — $ — $ — $ 1,931 $ 1,931 Total allowance for credit loss $ 13,597 $ 19,299 $ 468 $ 4,252 $ 457 $ 1,931 $ 40,004 Six Months Ended June 30, 2023 Residential Commercial Home Commercial & Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan Balance at December 31, 2022 $ 13,321 $ 19,086 $ 573 $ 4,153 $ 641 $ — $ 37,774 Charge-offs — — — ( 11 ) ( 25 ) — ( 36 ) Recoveries — — — 19 11 — 30 Provision for (release of) credit 276 213 ( 105 ) 91 ( 170 ) — 305 Allowance for credit losses - $ 13,597 $ 19,299 $ 468 $ 4,252 $ 457 $ — $ 38,073 Allowance for credit losses - Balance at December 31, 2022 $ — $ — $ — $ — $ — $ 2,096 $ 2,096 Provision for (release of) credit — — — — — ( 165 ) ( 165 ) Allowance for credit losses- $ — $ — $ — $ — $ — $ 1,931 $ 1,931 Total allowance for credit loss $ 13,597 $ 19,299 $ 468 $ 4,252 $ 457 $ 1,931 $ 40,004 Three Months Ended June 30, 2022 Residential Commercial Home Commercial & Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan Balance at March 31, 2022 $ 13,193 $ 17,138 $ 377 $ 2,897 $ 505 $ — $ 34,110 Charge-offs — — — ( 3 ) ( 3 ) — ( 6 ) Recoveries — — — 10 10 — 20 Provision for (release of) credit ( 554 ) 629 23 ( 52 ) ( 46 ) — — Allowance for credit losses - loan portfolio at June 30, 2022 $ 12,639 $ 17,767 $ 400 $ 2,852 $ 466 $ — $ 34,124 Allowance for credit losses - Balance at March 31, 2022 $ — $ — $ — $ — $ — $ 1,371 $ 1,371 Release of credit losses - unfunded commitments — — — — — — — Allowance for credit losses- — — — — — 1,371 1,371 Total allowance for credit loss $ 12,639 $ 17,767 $ 400 $ 2,852 $ 466 $ 1,371 $ 35,495 Six Months Ended June 30, 2022 Residential Commercial Home Commercial & Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan Balance at December 31, 2021 $ 13,383 $ 17,133 $ 406 $ 2,989 $ 585 $ — $ 34,496 Charge-offs — — — ( 3 ) ( 28 ) — ( 31 ) Recoveries — — — 46 12 — 58 Provision for (release of) credit ( 744 ) 634 ( 6 ) ( 180 ) ( 103 ) — ( 399 ) Allowance for credit losses - loan portfolio at June 30, 2022 $ 12,639 $ 17,767 $ 400 $ 2,852 $ 466 $ — $ 34,124 Allowance for credit losses - Balance at December 31, 2021 $ — $ — $ — $ — $ — $ 1,384 $ 1,384 Release of credit — — — — — ( 13 ) ( 13 ) Allowance for credit losses- — — — — — 1,371 1,371 Total allowance for credit loss $ 12,639 $ 17,767 $ 400 $ 2,852 $ 466 $ 1,371 $ 35,495

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Components of Income Tax Expense	The components of income tax expense were as follows: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 (dollars in thousands) Current income tax expense Federal $ 1,998 $ 3,868 $ 3,032 $ 4,963 State 745 1,595 1,211 1,984 Total current income tax expense $ 2,743 $ 5,463 $ 4,243 $ 6,947 Deferred income tax expense (benefit) Federal $ ( 338 ) $ ( 61 ) $ 1,537 $ 1,964 State ( 155 ) ( 27 ) 629 908 Total deferred income tax expense (benefit) ( 493 ) ( 88 ) 2,166 2,872 Total income tax expense $ 2,250 $ 5,375 $ 6,409 $ 9,819

Pension and Retirement Plans (T

Pension and Retirement Plans (Tables)	6 Months Ended
	Jun. 30, 2023
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost (Credit)	The components of net periodic benefit cost (credit) were as follows: Three Months Ended June 30, Pension Plan Supplemental Retirement Healthcare Plan 2023 2022 2023 2022 2023 2022 (dollars in thousands) Net periodic benefit cost (credit) Service cost $ — $ — $ 68 $ 98 $ 4 $ 6 Interest cost 450 345 100 71 5 5 Expected return on assets ( 799 ) ( 1,002 ) — — — — Amortization of net actuarial (gain) loss — — — — ( 5 ) — Net periodic benefit cost (credit) $ ( 349 ) $ ( 657 ) $ 168 $ 169 $ 4 $ 11

Share Based Compensation (Table

Share Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2023
Schedule of Shares Issued and Fair Value of RSAs, RSUs	During the three and six months ended June 30, 2023 , the Company issued the following RSAs and RSUs pursuant to the Cambridge Bancorp 2017 Equity and Cash Incentive Plan (the “2017 Plan”). RSAs vest either over a three-year or five-year period. RSUs vest over a three-year period. T he fair value of RSAs and RSUs are based upon the closing price of the Company’s common stock on the date of the applicable grant. The holders of RSAs participate fully in the rewards of stock ownership of the Company, including voting and dividend rights. The holders of RSUs do not participate in the rewards of stock ownership of the Company until they are vested. Three Months Ended June 30, 2023 Six Months ended June 30, 2023 Type of Award Shares Granted Weighted Average Fair Value Per Share at Grant Date Shares Granted Weighted Average Fair Value Per Share at Grant Date RSAs 510 $ 49.15 13,675 $ 82.73 RSUs 18,731 $ 51.65 19,253 $ 52.53
Schedule of Pre-tax Expense Associated with All Outstanding Non-vested RSAs, RSUs, Performance Based Restricted Stock Units and Related Tax Benefits	The following table presents the pre-tax expense associated with all outstanding non-vested RSAs, RSUs, and PRSUs, and the related tax benefits recognized: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 (dollars in thousands) Share based compensation expense $ 603 $ 943 $ 1,170 $ 1,591 Related tax benefits $ 168 $ 263 $ 327 $ 444
Performance-Based Restricted Stock Units
Schedule of Shares Issued and Fair Value of RSAs, RSUs	During the three and six months ended June 30, 2023, the Company granted PRSUs from the 2017 Plan, as shown in the table below. PRSUs are subject to a three-year performance period and are earned based on performance factors, as determined, at the time of grant. Three Months Ended June 30, 2023 Six Months ended June 30, 2023 Type of Award Shares Granted Weighted Average Fair Value Per Share at Grant Date Shares Granted Weighted Average Fair Value Per Share at Grant Date PRSUs 22,895 $ 51.65 27,554 $ 55.13

Financial Instruments with Of_2

Financial Instruments with Off-Balance-Sheet Risk (Tables)	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Summary of Off-Balance-Sheet Financial Instruments with Contractual Amounts Include Present Credit Risk	Off-balance-sheet financial instruments with contractual amounts that present credit risk include the following: June 30, 2023 December 31, 2022 (dollars in thousands) Financial instruments whose contractual amount represents credit risk: Commitments to extend credit: Unused portion of existing lines of credit $ 1,038,589 $ 1,073,567 Origination of new loans 39,349 25,411 Standby letters of credit 32,645 24,234 Financial instruments whose notional amount exceeds the amount of credit risk: Commitments to sell residential mortgage loans — 250

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2023
Leases [Abstract]
Summary of Components of Operating Lease Cost and Other Related Information	The components of operating lease cost and other related information are as follows: Three Months Ended June 30, 2023 2022 (dollars in thousands) Operating lease cost $ 1,673 $ 1,743 Variable lease cost (cost excluded from lease payments) 7 1 Sublease income ( 128 ) ( 17 ) Total operating lease cost $ 1,552 $ 1,727 Other Information Cash paid for amounts included in the measurement of lease liabilities - $ 1,821 $ 1,805 Operating Lease - operating cash flows (liability reduction) 1,637 1,586 Weighted average lease term - operating leases 5.18 Years 5.80 Years Weighted average discount rate - operating leases 3.06 % 2.97 % For the Six Months Ended June 30, 2023 2022 (dollars in thousands) Operating lease cost $ 3,411 $ 3,486 Variable lease cost (cost excluded from lease payments) 14 2 Sublease income ( 256 ) ( 33 ) Total operating lease cost $ 3,169 $ 3,455 Other Information Cash paid for amounts included in the measurement of lease liabilities - operating cash flows for operating leases $ 3,664 $ 3,638 Operating Lease - operating cash flows (liability reduction) 3,291 3,191 Weighted average lease term - operating leases 5.18 Years 5.80 Years Weighted average discount rate - operating leases 3.06 % 2.97 %
Schedule of Total Minimum Lease Payments Due in Future Periods for Lease Agreements	The total minimum lease payments due in future periods for lease agreements in effect at June 30, 2023 were as follows: Future Minimum June 30, 2023 Lease Payments (dollars in thousands) Remainder of 2023 $ 3,552 2024 6,301 2025 5,314 2026 4,065 2027 2,267 Thereafter 5,962 Total minimum lease payments $ 27,461 Less: interest ( 2,085 ) Total lease liability $ 25,376

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Schedule of Minimum Capital Requirements Considered Well Capitalized by FRB and FDIC	As of June 30, 2023 and December 31, 2022, the Company and the Bank met all applicable minimum capital requirements and were considered “well-capitalized” by both the Federal Reserve Bank (“FRB”) and the Federal Deposit Insurance Corporation (“FDIC”). Actual Minimum Capital Minimum To Be Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At June 30, 2023 Cambridge Bancorp: Total capital (to risk-weighted assets) $ 516,242 14.1 % $ 384,543 10.5 % N/A N/A Tier 1 capital (to risk-weighted assets) 476,239 13.0 % 311,297 8.5 % N/A N/A Common equity tier I capital (to risk-weighted assets) 476,239 13.0 % 256,362 7.0 % N/A N/A Tier 1 capital (to average assets) 476,239 8.7 % 218,011 4.0 % N/A N/A Cambridge Trust Company: Total capital (to risk-weighted assets) $ 494,631 13.5 % $ 384,507 10.5 % $ 366,198 10.0 % Tier 1 capital (to risk-weighted assets) 454,627 12.4 % 311,268 8.5 % 292,958 8.0 % Common equity tier I capital (to risk-weighted assets) 454,627 12.4 % 256,338 7.0 % 238,028 6.5 % Tier 1 capital (to average assets) 454,627 8.3 % 217,998 4.0 % 272,498 5.0 % Actual Minimum Capital Minimum To Be Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At December 31, 2022 Cambridge Bancorp: Total capital (to risk-weighted assets) $ 506,239 13.5 % $ 393,285 10.5 % N/A N/A Tier 1 capital (to risk-weighted assets) 466,369 12.5 % 318,373 8.5 % N/A N/A Common equity tier I capital (to risk-weighted assets) 466,369 12.5 % 262,190 7.0 % N/A N/A Tier 1 capital (to average assets) 466,369 8.5 % 219,309 4.0 % N/A N/A Cambridge Trust Company: Total capital (to risk-weighted assets) $ 490,175 13.1 % $ 393,246 10.5 % $ 374,520 10.0 % Tier 1 capital (to risk-weighted assets) 450,305 12.0 % 318,342 8.5 % 299,616 8.0 % Common equity tier I capital (to risk-weighted assets) 450,305 12.0 % 262,164 7.0 % 243,438 6.5 % Tier 1 capital (to average assets) 450,305 8.2 % 219,296 4.0 % 274,120 5.0 %

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Summary of Accumulated Other Comprehensive Income (Loss) ("AOCI") ("AOCL")	The following tables present the changes in accumulated other comprehensive income (loss) (“AOCI”) (“AOCL”) during the periods, by component, net of tax: Three Months Ended June 30, 2023 Three Months Ended June 30, 2022 Before Tax Tax (Expense) Net-of-tax Before Tax Tax (Expense) Net-of-tax (dollars in thousands) Available for sale securities Unrealized holding gains (losses) $ ( 2,259 ) $ 593 $ ( 1,666 ) $ ( 5,579 ) $ 1,442 $ ( 4,137 ) Interest rate swaps designated as cash flow Unrealized holding (losses) gains ( 711 ) 199 ( 512 ) ( 358 ) 101 ( 257 ) Reclassification adjustment for (losses) income recognized in net income 145 ( 41 ) 104 ( 391 ) 108 ( 283 ) Total other comprehensive income (loss) $ ( 2,825 ) $ 751 $ ( 2,074 ) $ ( 6,328 ) $ 1,651 $ ( 4,677 ) Six Months Ended June 30, 2023 Six Months Ended June 30, 2022 Before Tax Tax (Expense) Net-of-tax Before Tax Tax (Expense) or Benefit Net-of-tax (dollars in thousands) Available for sale securities Unrealized holding gains (losses) $ 349 $ ( 73 ) $ 276 $ ( 16,595 ) $ 4,231 $ ( 12,364 ) Interest rate swaps designated as cash flow . Unrealized holding (losses) gains ( 633 ) 178 ( 455 ) ( 2,058 ) 575 ( 1,483 ) Reclassification adjustment for (losses) income recognized in net income 289 ( 81 ) 208 ( 1,005 ) 281 ( 724 ) Total other comprehensive income (loss) $ 5 $ 24 $ 29 $ ( 19,658 ) $ 5,087 $ ( 14,571 )
Summary of Reclassifications out of Accumulated Other Comprehensive Income (Loss) ("AOCI") ("AOCL")	Reclassifications out of AOCI and AOCL that have an impact on net income are presented below. Three Months Ended Details about Accumulated Other Comprehensive Income (Loss) Components June 30, 2023 June 30, 2022 Affected Line Item in the (dollars in thousands) Unrealized (losses) gains on derivatives $ ( 145 ) $ 391 Interest on taxable loans Tax benefit (expense) 41 ( 108 ) Income tax expense Net of tax $ ( 104 ) $ 283 Net income Six Months Ended Details about Accumulated Other Comprehensive Loss Components June 30, 2023 June 30, 2022 Affected Line Item in the (dollars in thousands) Unrealized (losses) gains on derivatives $ ( 289 ) $ 1,005 Interest on taxable loans Tax benefit (expense) 81 ( 281 ) Income tax expense Net of tax $ ( 208 ) $ 724 Net income

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Summary of Reconciliation Between Basic and Diluted Earnings Per Share	The following represents a reconciliation between basic and diluted earnings per share: Three Months Ended June 30, Six Months Ended June 30, 2023 2022 2023 2022 (dollars in thousands, except per share data) Earnings per common share - basic: Numerator: Net income $ 7,115 $ 13,658 $ 19,531 $ 26,974 Less dividends and undistributed earnings allocated ( 2 ) ( 43 ) ( 20 ) ( 122 ) Net income applicable to common shareholders $ 7,113 $ 13,615 $ 19,511 $ 26,852 Denominator: Weighted average common shares outstanding 7,838 6,982 7,817 6,960 Earnings per common share - basic $ 0.91 $ 1.95 $ 2.50 $ 3.86 Earnings per common share - diluted: Numerator: Net income $ 7,115 $ 13,658 $ 19,531 $ 26,974 Less dividends and undistributed earnings allocated ( 2 ) ( 43 ) ( 20 ) ( 122 ) Net income applicable to common shareholders $ 7,113 $ 13,615 $ 19,511 $ 26,852 Denominator: Weighted average common shares outstanding 7,838 6,982 7,817 6,960 Dilutive effect of common stock equivalents 17 45 25 54 Weighted average diluted common shares outstanding 7,855 7,027 7,842 7,014 Earnings per common share - diluted $ 0.91 $ 1.94 $ 2.49 $ 3.83

Derivative And Hedging Activi_2

Derivative And Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Cumulative Basis Adjustment for Fair Value Hedges	he Company recorded the following amounts on the balance sheet related to cumulative basis adjustment for fair value hedges: Line Item in the Statement of Financial Position in Which the Hedged Item is Included Carrying Amount of the Hedged Assets/(Liabilities) Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities) June 30, 2023 December 31, 2022 June 30, 2023 December 31, 2022 (dollars in thousands) Fixed Rate Assets $ 494,744 $ — $ 5,256 $ — Total $ 494,744 $ — $ 5,256 $ —
Summary of Fair Values of Derivative Instruments in the Company's Consolidated Balance Sheets	The following tables present the notional amount, the location, and fair values of derivative instruments in the Company’s consolidated balance sheets: June 30, 2023 Derivative Assets Derivative Liabilities Notional Amount Balance Sheet Fair Value Notional Amount Balance Sheet Fair Value (dollars in thousands) (dollars in thousands) Derivatives designated as hedging instruments Interest rate contracts-cash flow hedging relationships $ 250,000 Other Assets $ 1,333 $ — Other Liabilities $ — Interest rate contracts-fair value hedging relationships 500,000 Other Assets 5,219 — Other Liabilities — Total derivatives designated as hedging instruments $ 6,552 $ — Derivatives not designated as hedging instruments Loan related derivative contracts Interest rate contracts $ 499,917 Other Assets $ 49,083 $ 499,917 Other Liabilities $ 49,083 Risk participation agreements-out to counterparties 52,070 Other Assets 24 — Other Liabilities — Risk participation agreements-in with counterparties — Other Assets — 81,644 Other Liabilities 44 Total derivatives not designated as hedging instruments $ 49,107 $ 49,127 December 31, 2022 Derivative Assets Derivative Liabilities Notional Amount Balance Sheet Fair Value Notional Amount Balance Sheet Fair Value (dollars in thousands) (dollars in thousands) Derivatives designated as hedging instruments Interest rate contracts-cash flow hedging relationships $ 250,000 Other Assets $ 1,966 $ — Other Liabilities $ — Total derivatives designated as hedging instruments $ 1,966 $ — Derivatives not designated as hedging instruments Loan related derivative contracts Interest rate contracts $ 499,619 Other Assets $ 50,784 $ 499,619 Other Liabilities $ 50,784 Risk participation agreements-out to counterparties 46,604 Other Assets 23 — Other Liabilities — Risk participation agreements-in with counterparties — Other Assets — 71,046 Other Liabilities 43 Total derivatives not designated as hedging instruments $ 50,807 $ 50,827
Summary of Changes to AOCI and AOCL as a Result of Cash Flow Hedge Accounting	The following tables present the changes to AOCI and AOCL as a result of cash flow hedge accounting as of the periods presented: Three Months Ended June 30, 2023 Amount of Gain Amount of Gain Amount of Gain Location of Gain Amount of Gain Amount of Gain or (Loss) Reclassified from AOCL into Income Included Component Amount of Gain or (Loss) Reclassified from AOCL into Income Excluded Component (dollars in thousands) (dollars in thousands) Interest rate contracts $ ( 711 ) $ — $ ( 711 ) Interest Income $ ( 145 ) $ — $ ( 145 ) Six Months Ended June 30, 2023 Amount of Gain or (Loss) Recognized in OCI Amount of Gain or (Loss) Recognized in OCI Included Component Amount of Gain or (Loss) Recognized in OCI Excluded Component Location of Gain or (Loss) Amount of Gain or (Loss) Reclassified from AOCL into Income Amount of Gain or (Loss) Reclassified from AOCL into Income Included Component Amount of Gain or (Loss) Reclassified from AOCL into Income Excluded Component (dollars in thousands) (dollars in thousands) Interest rate contracts $ ( 633 ) $ — $ ( 633 ) Interest Income $ ( 289 ) $ ( 96 ) $ ( 193 ) Three Months Ended June 30, 2022 Amount of Gain Amount of Gain Amount of Gain Location of Gain Amount of Gain Amount of Gain Amount of Gain (dollars in thousands) (dollars in thousands) Interest rate contracts $ ( 358 ) $ ( 101 ) $ ( 257 ) Interest Income $ 391 $ 439 $ ( 48 ) Six Months Ended June 30, 2022 Amount of Gain or (Loss) Recognized in OCI Amount of Gain or (Loss) Recognized in OCI - Included Component Amount of Gain or (Loss) Recognized in OCI - Excluded Component Location of Gain or (Loss) Amount of Gain or (Loss) Reclassified from AOCI into Income Amount of Gain or (Loss) Reclassified from AOCI into Income Included Component Amount of Gain or (Loss) Reclassified from AOCI into Income Excluded Component (dollars in thousands) (dollars in thousands) Interest rate contracts $ ( 2,058 ) $ ( 2,012 ) $ ( 46 ) Interest Income $ 1,005 $ 1,101 $ ( 96 )
Summary of Derivative Financial Instruments Not Designated as Hedging Instruments on the Consolidated Statements of Income	The following table presents the effect of the Company’s derivative financial instruments that are not designated as hedging instruments on the consolidated statements of income as of the periods presented: Amount of Gain or (Loss) Recognized in Income Three Months Ended June 30, 2023 June 30, 2022 Location of Gain or (Loss) (dollars in thousands) Other contracts Loan-related derivative income $ ( 14 ) $ ( 33 ) Amount of Gain or (Loss) Recognized in Income Six Months Ended June 30, 2023 June 30, 2022 Location of Gain or (Loss) (dollars in thousands) Other contracts Loan-related derivative income $ ( 31 ) $ ( 110 )
Schedule of Financial Instruments Eligible for Offset in Consolidated Balance Sheet	The following tables present the information about financial instruments that are eligible for offset in the consolidated balance sheets at June 30, 2023 and December 31, 2022: Gross Amounts Not Offset Gross Amounts Recognized Gross Amounts Offset Net Amounts Recognized Financial Instruments Collateral Pledged (Received) Net Amount June 30, 2023 (dollars in thousands) Offsetting of Derivative Assets Derivative Assets $ 55,660 $ — $ 55,660 $ 109 $ ( 55,352 ) $ 199 Offsetting of Derivative Liabilities Derivative Liabilities $ 49,083 $ — $ 49,083 $ 109 $ — $ 48,974 Gross Amounts Not Offset Gross Amounts Recognized Gross Amounts Offset Net Amounts Recognized Financial Instruments Collateral Pledged (Received) Net Amount December 31, 2022 (dollars in thousands) Offsetting of Derivative Assets Derivative Assets $ 52,773 $ — $ 52,773 $ 48 $ ( 52,130 ) $ 595 Offsetting of Derivative Liabilities Derivative Liabilities $ 50,827 $ — $ 50,827 $ 48 $ — $ 50,875

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Summary of Carrying Values and Estimated Fair Values of Financial Instruments	The following is a summary of the carrying values and estimated fair values of the Company’s significant financial instruments as of the dates indicated: June 30, 2023 December 31, 2022 Carrying Estimated Carrying Estimated (dollars in thousands) Financial assets Cash and cash equivalents $ 33,398 $ 33,398 $ 30,719 $ 30,719 Securities available for sale 144,306 144,306 153,416 153,416 Securities held to maturity 1,007,471 839,025 1,051,997 885,586 Loans, net 3,987,153 3,643,268 4,025,082 3,783,051 FHLB of Boston stock 20,247 20,247 6,264 6,264 Accrued interest receivable 14,573 14,573 14,118 14,118 Mortgage servicing rights 1,529 2,208 1,665 2,336 Interest rate contracts - cash flow hedge 1,333 1,333 1,966 1,966 Loan level interest rate swaps 49,083 49,083 50,784 50,784 Risk participation agreements out to counterparties 24 24 23 23 Interest rate contracts - fair value hedge 5,219 5,219 — — Financial liabilities Deposits, excluding wholesale deposits 4,086,260 4,081,744 4,433,817 4,429,190 Wholesale deposits 356,330 356,084 381,559 381,505 Borrowings 408,926 407,551 105,212 105,202 Loan level interest rate swaps 49,083 49,083 50,784 50,784 Risk participation agreements in with counterparties 44 44 43 43
Summary of Certain Assets and Liabilities Reported at Fair Value on a Recurring Basis	The following tables summarize certain assets and liabilities reported at fair value on a recurring basis: Fair Value as of June 30, 2023 Level 1 Level 2 Level 3 Total (dollars in thousands) Measured on a recurring basis Securities available for sale U.S. GSE obligations $ — $ 19,956 $ — $ 19,956 Mortgage-backed securities — 124,350 — 124,350 Corporate debt securities — — — — Other assets Interest rate swaps with clients — 49,083 — 49,083 Risk participation agreements -out to counterparties — 24 — 24 Interest rate contracts - cash flow hedge — 1,333 — 1,333 Interest rate contracts - fair value hedge — 5,219 — 5,219 Other liabilities Interest rate swaps with counterparties — 49,083 — 49,083 Risk participation agreements-in with counterparties — 44 — 44 Fair Value as of December 31, 2022 Level 1 Level 2 Level 3 Total (dollars in thousands) Measured on a recurring basis Securities available for sale U.S. GSE obligations $ — $ 19,733 $ — $ 19,733 Mortgage-backed securities — 132,683 — 132,683 Corporate debt securities — 1,000 — 1,000 Other assets Interest rate swaps with clients — 50,784 — 50,784 Risk participation agreements-out to counterparties — 23 — 23 Interest rate contracts — 1,966 — 1,966 Other liabilities Interest rate swaps with counterparties — 50,784 — 50,784 Risk participation agreements-in with counterparties — 43 — 43
Schedule of Carrying Value of Assets Measured at Fair Value on a Non-Recurring Basis	The following tables present the carrying value of assets held at June 30, 2023 and December 31, 2022, which were measured at fair value on a non-recurring basis: June 30, 2023 Level 1 Level 2 Level 3 Total (dollars in thousands) Items recorded at fair value on a non-recurring basis Assets Individually evaluated collateral dependent loans $ — $ — $ 89 $ 89 Total $ — $ — $ 89 $ 89 December 31, 2022 Level 1 Level 2 Level 3 Total (dollars in thousands) Items recorded at fair value on a non-recurring basis Assets Individually evaluated collateral dependent loans — — 103 103 Total $ — $ — $ 103 $ 103

Cash and Cash Equivalents - Add

Cash and Cash Equivalents - Additional Information (Details) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	$ 33,398,000	$ 30,719,000
Cash pledged as collateral to derivative counterparties	0	0
Federal Reserve Bank of Boston
Cash And Cash Equivalents [Line Items]
Reserve balance of cash and due from banks	0	0
New Hampshire
Cash And Cash Equivalents [Line Items]
Pledged amount to federal banking department	$ 500,000	$ 500,000

Investment Securities - Summary

Investment Securities - Summary of Carrying Amounts of Securities and Their Approximate Fair Values (Details) - USD ($) $ in Thousands		Jun. 30, 2023	Dec. 31, 2022
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Amortized Cost		$ 172,568	$ 182,027
Available for sale securities, Gross Unrealized Gains		1	7
Available for sale securities, Gross Unrealized Losses		(28,263)	(28,618)
Total available for sale securities		144,306	153,416
Held to maturity securities, Amortized Cost		1,007,471	1,051,997
Held to maturity securities, Gross Unrealized Gains		18	92
Held to maturity securities, Gross Unrealized Losses		(168,464)	(166,503)
Held-to-maturity securities, fair value		839,025	885,586
Total, Amortized Cost		1,180,039	1,234,024
Total, Gross Unrealized Gains		19	99
Total, Gross Unrealized Losses		(196,727)	(195,121)
Total, Fair Value		983,331	1,039,002
U.S. Government Sponsored Enterprise Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Amortized Cost		22,997	22,997
Available for sale securities, Gross Unrealized Losses		(3,041)	(3,264)
Total available for sale securities		19,956	19,733
U.S. Treasury Notes
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Amortized Cost		4,005	3,970
Held to maturity securities, Gross Unrealized Gains
Held to maturity securities, Gross Unrealized Losses		(42)	(18)
Held-to-maturity securities, fair value		3,963	3,952
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Amortized Cost			996
Available for sale securities, Gross Unrealized Gains			4
Total available for sale securities			1,000
Held to maturity securities, Amortized Cost		250	250
Held to maturity securities, Gross Unrealized Losses		(6)	(6)
Held-to-maturity securities, fair value		244	244
Mortgage Backed Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Amortized Cost		149,571	158,034
Available for sale securities, Gross Unrealized Gains		1	3
Available for sale securities, Gross Unrealized Losses		(25,222)	(25,354)
Total available for sale securities	[1]	124,350	132,683
Held to maturity securities, Amortized Cost	[1]	913,304	951,372
Held to maturity securities, Gross Unrealized Gains		1	4
Held to maturity securities, Gross Unrealized Losses		(160,034)	(157,208)
Held-to-maturity securities, fair value		753,271	794,168
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Amortized Cost		89,912	96,405
Held to maturity securities, Gross Unrealized Gains		17	88
Held to maturity securities, Gross Unrealized Losses		(8,382)	(9,271)
Held-to-maturity securities, fair value		$ 81,547	$ 87,222
[1] Includes agency mortgage-backed pass-through securities and collateralized mortgage obligations issued by U.S. Government Sponsored Enterprises (“GSEs”) and U.S. government agencies, such as FNMA, FHLMC, and GNMA that are not rated by Moody’s or Standard & Poor's. Each security contains a guarantee by the issuing U.S. GSE or agency and therefore carries an implicit guarantee of the U.S. government. These have been categorized as AAA/AA/A.

Investment Securities - Gross U

Investment Securities - Gross Unrealized Losses of Aggregated by Investment Category and Length of Time that Individual Securities have been in Continuous Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Fair Value, Less than 12 months	$ 164	$ 52,554
Available for sale securities, Unrealized Losses, Less than 12 months	(2)	(5,375)
Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer, Total	143,995	99,557
Available for sale securities, Unrealized Losses, 12 months or longer	(28,261)	(23,243)
Available for sale securities, Fair Value	144,159	152,111
Available for sale securities, Unrealized Losses	(28,263)	(28,618)
Held to maturity securities, Fair Value, Less than 12 months	53,780	286,872
Held to maturity securities, Unrealized Losses, Less than 12 months	(1,527)	(26,774)
Held to maturity securities, Fair Value, 12 months or longer	774,241	576,549
Held to maturity securities, Unrealized Losses, 12 months or longer	(166,937)	(139,729)
Held to maturity securities, Fair Value	828,021	863,421
Held to maturity securities, Unrealized Losses	(168,464)	(166,503)
Fair Value, Less than 12 months	53,944	339,426
Unrealized Losses, Less than 12 months	(1,529)	(32,149)
Fair Value, 12 months or longer	918,236	676,106
Unrealized Losses, 12 months or longer	(195,198)	(162,972)
Fair Value	972,180	1,015,532
Unrealized Losses	(196,727)	(195,121)
U.S. Government Sponsored Enterprise Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Fair Value, Less than 12 months		10,722
Available for sale securities, Unrealized Losses, Less than 12 months		(2,278)
Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer, Total	19,957	9,012
Available for sale securities, Unrealized Losses, 12 months or longer	(3,041)	(986)
Available for sale securities, Fair Value	19,957	19,734
Available for sale securities, Unrealized Losses	(3,041)	(3,264)
U.S. Treasury Notes
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Fair Value, Less than 12 months	3,963	3,952
Held to maturity securities, Unrealized Losses, Less than 12 months	(42)	(18)
Held to maturity securities, Fair Value	3,963	3,952
Held to maturity securities, Unrealized Losses	(42)	(18)
Mortgage Backed Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Fair Value, Less than 12 months	164	41,832
Available for sale securities, Unrealized Losses, Less than 12 months	(2)	(3,097)
Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer, Total	124,038	90,545
Available for sale securities, Unrealized Losses, 12 months or longer	(25,220)	(22,257)
Available for sale securities, Fair Value	124,202	132,377
Available for sale securities, Unrealized Losses	(25,222)	(25,354)
Held to maturity securities, Fair Value, Less than 12 months	19,527	230,708
Held to maturity securities, Unrealized Losses, Less than 12 months	(1,183)	(22,362)
Held to maturity securities, Fair Value, 12 months or longer	733,229	562,835
Held to maturity securities, Unrealized Losses, 12 months or longer	(158,851)	(134,846)
Held to maturity securities, Fair Value	752,756	793,543
Held to maturity securities, Unrealized Losses	(160,034)	(157,208)
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Fair Value, Less than 12 months		243
Held to maturity securities, Unrealized Losses, Less than 12 months		(6)
Held to maturity securities, Fair Value, 12 months or longer	244
Held to maturity securities, Unrealized Losses, 12 months or longer	(6)
Held to maturity securities, Fair Value	244	243
Held to maturity securities, Unrealized Losses	(6)	(6)
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Fair Value, Less than 12 months	30,290	51,969
Held to maturity securities, Unrealized Losses, Less than 12 months	(302)	(4,388)
Held to maturity securities, Fair Value, 12 months or longer	40,768	13,714
Held to maturity securities, Unrealized Losses, 12 months or longer	(8,080)	(4,883)
Held to maturity securities, Fair Value	71,058	65,683
Held to maturity securities, Unrealized Losses	$ (8,382)	$ (9,271)

Investment Securities - Additio

Investment Securities - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($) Security	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) Security	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Number of debt securities with unrealized losses | Security	449		449
Available for sale securities, amortized cost	$ 172,568,000		$ 172,568,000		$ 182,027,000
Aggregate depreciation percentage of gross unrealized losses from amortized cost	16.80%		16.80%
Percentage of unrealized dollar loss on amortized cost	22.20%		22.20%
Percentage of unrealized loss on amortized cost	36.60%		36.60%
Unrealized dollar loss of amortized cost basis	$ 2,000,000		$ 2,000,000
Unrealized loss of amortized cost basis	860,000		860,000
Net proceeds from securities sold	0	$ 0	0	$ 0
Asset Pledged As Collateral
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, amortized cost					9,100,000
Security held as collateral, fair value	$ 0		$ 0		$ 8,000,000

Investment Securities - Schedul

Investment Securities - Schedule of Amortized Cost and Fair Value of Debt Securities, Aggregated By Earlier of Guaranteed Call Date or Contractual Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, After One, But Within Five Years, Amortized Cost	$ 22,852
Available for sale securities, After One, But Within Five Years, Fair Value	21,088
Available for sale securities, After Five, But Within Ten Years, Amortized Cost	43,005
Available for sale securities, After Five, But Within Ten Years, Fair Value	35,938
Available for sale securities, After Ten Years, Amortized Cost	106,711
Available for sale securities, After Ten Years, Fair Value	87,280
Available for sale securities, Total, Amortized Cost	172,568
Available for sale securities, Total, Fair Value	144,306
Held to maturity securities, Within One Year, Amortized Cost	7,185
Held to maturity securities, Within One Year, Fair Value	7,161
Held to maturity securities, After One, But Within Five Years, Amortized Cost	47,669
Held to maturity securities, After One, But Within Five Years, Fair Value	45,846
Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	76,233
Held to maturity securities, After Five, But Within Ten Years, Fair Value	67,893
Held to maturity securities, After Ten Years, Amortized Cost	876,384
Held to maturity securities, After Ten Years, Fair Value	718,125
Held to maturity securities, Amortized Cost	1,007,471	$ 1,051,997
Held to maturity securities, Fair Value	839,025	885,586
Available for sale securities and Held to maturity securities, Within One Year, Amortized Cost	7,185
Available for sale securities and Held to maturity securities, Within One Year, Fair Value	7,161
Available for sale securities and Held to maturity securities, After One, But Within Five Years, Amortized Cost	70,521
Available for sale securities and Held to maturity securities, After One, But Within Five Years, Fair Value	66,934
Available for sale securities and Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	119,238
Available for sale securities and Held to maturity securities, After Five, But Within Ten Years, Fair Value	103,831
Available for sale securities and Held to maturity securities, After Ten Years, Amortized Cost	983,095
Available for sale securities and Held to maturity securities, After Ten Years, Fair Value	805,405
Available for sale securities and Held to maturity securities, Total, Amortized Cost	1,180,039
Available for sale securities and Held to maturity securities, Total, Fair Value	983,331
U.S. Government Sponsored Enterprise Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, After One, But Within Five Years, Amortized Cost	9,997
Available for sale securities, After One, But Within Five Years, Fair Value	9,096
Available for sale securities, After Five, But Within Ten Years, Amortized Cost	5,000
Available for sale securities, After Five, But Within Ten Years, Fair Value	4,416
Available for sale securities, After Ten Years, Amortized Cost	8,000
Available for sale securities, After Ten Years, Fair Value	6,444
Available for sale securities, Total, Amortized Cost	22,997
Available for sale securities, Total, Fair Value	19,956
U.S. Treasury Notes
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Within One Year, Amortized Cost	994
Held to maturity securities, Within One Year, Fair Value	991
Held to maturity securities, After One, But Within Five Years, Amortized Cost	3,011
Held to maturity securities, After One, But Within Five Years, Fair Value	2,972
Held to maturity securities, Amortized Cost	4,005
Held to maturity securities, Fair Value	3,963
Mortgage Backed Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, After One, But Within Five Years, Amortized Cost	12,855
Available for sale securities, After One, But Within Five Years, Fair Value	11,992
Available for sale securities, After Five, But Within Ten Years, Amortized Cost	38,005
Available for sale securities, After Five, But Within Ten Years, Fair Value	31,522
Available for sale securities, After Ten Years, Amortized Cost	98,711
Available for sale securities, After Ten Years, Fair Value	80,836
Available for sale securities, Total, Amortized Cost	149,571
Available for sale securities, Total, Fair Value	124,350
Held to maturity securities, After One, But Within Five Years, Amortized Cost	25,022
Held to maturity securities, After One, But Within Five Years, Fair Value	23,414
Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	50,536
Held to maturity securities, After Five, But Within Ten Years, Fair Value	42,774
Held to maturity securities, After Ten Years, Amortized Cost	837,746
Held to maturity securities, After Ten Years, Fair Value	687,083
Held to maturity securities, Amortized Cost	913,304
Held to maturity securities, Fair Value	753,271
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Within One Year, Amortized Cost	250
Held to maturity securities, Within One Year, Fair Value	244
Held to maturity securities, Amortized Cost	250
Held to maturity securities, Fair Value	244
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Within One Year, Amortized Cost	5,941
Held to maturity securities, Within One Year, Fair Value	5,926
Held to maturity securities, After One, But Within Five Years, Amortized Cost	19,636
Held to maturity securities, After One, But Within Five Years, Fair Value	19,460
Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	25,697
Held to maturity securities, After Five, But Within Ten Years, Fair Value	25,119
Held to maturity securities, After Ten Years, Amortized Cost	38,638
Held to maturity securities, After Ten Years, Fair Value	31,042
Held to maturity securities, Amortized Cost	89,912	96,405
Held to maturity securities, Fair Value	$ 81,547	$ 87,222

Investment Securities - Summa_2

Investment Securities - Summary of Credit Rating of Debt Securities Portfolio (Details) - USD ($) $ in Thousands		Jun. 30, 2023	Dec. 31, 2022
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities		$ 144,306	$ 153,416
Total held to maturity securities		1,007,471	1,051,997
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total held to maturity securities		89,912	96,405
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities			1,000
Total held to maturity securities		250	250
U.S. Government Sponsored Enterprise Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities		19,956	19,733
U.S. Treasury Notes
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total held to maturity securities		4,005	3,970
AAA/AA/A
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities		144,306	152,416
Total held to maturity securities		1,007,471	1,051,997
AAA/AA/A | Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total held to maturity securities		89,912	96,405
AAA/AA/A | Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total held to maturity securities		250	250
AAA/AA/A | U.S. Government Sponsored Enterprise Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities		19,956	19,733
AAA/AA/A | U.S. Treasury Notes
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total held to maturity securities		4,005	3,970
BBB/BB/B
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities			1,000
BBB/BB/B | Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities			1,000
Mortgage Backed Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	[1]	124,350	132,683
Total held to maturity securities	[1]	913,304	951,372
Mortgage Backed Securities | AAA/AA/A
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	[1]	124,350	132,683
Total held to maturity securities	[1]	$ 913,304	$ 951,372
[1] Includes agency mortgage-backed pass-through securities and collateralized mortgage obligations issued by U.S. Government Sponsored Enterprises (“GSEs”) and U.S. government agencies, such as FNMA, FHLMC, and GNMA that are not rated by Moody’s or Standard & Poor's. Each security contains a guarantee by the issuing U.S. GSE or agency and therefore carries an implicit guarantee of the U.S. government. These have been categorized as AAA/AA/A.

Loans and the Allowance for C_3

Loans and the Allowance for Credit Losses - Loans Outstanding by Category (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Loans And Leases Receivable Disclosure [Line Items]
Total loans	$ 4,025,226	$ 4,062,856
Residential Mortgage
Loans And Leases Receivable Disclosure [Line Items]
Deferred costs (fees) net of unearned fees	4,911	6,613
Total loans	1,617,194	1,648,838
Residential Mortgage | Construction
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	41,445	35,299
Residential Mortgage | Mortgages - Fixed Rate
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	805,220	902,968
Residential Mortgage | Mortgages - Adjustable Rate
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	765,618	703,958
Commercial Mortgage
Loans And Leases Receivable Disclosure [Line Items]
Deferred costs (fees) net of unearned fees	2,275	2,318
Total loans	1,916,159	1,914,423
Commercial Mortgage | Construction
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	110,971	135,782
Commercial Mortgage | Mortgages - Non-owner Occupied
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	1,634,435	1,592,732
Commercial Mortgage | Mortgages - Owner Occupied
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	168,478	183,591
Home Equity
Loans And Leases Receivable Disclosure [Line Items]
Deferred costs (fees) net of unearned fees	258	292
Total loans	95,975	111,351
Home Equity | Home Equity - Lines of Credit
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	92,561	108,961
Home Equity | Home Equity - Term Loans
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	3,156	2,098
Commercial and Industrial
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	366,116	349,026
Unearned fees, net of deferred costs	446	240
Total loans	367,403	350,650
Commercial and Industrial | Paycheck Protection Program Loans
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	841	1,384
Consumer
Loans And Leases Receivable Disclosure [Line Items]
Deferred costs (fees) net of unearned fees	16	18
Total loans	28,495	37,594
Consumer | Secured
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	26,734	35,679
Consumer | Unsecured
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	$ 1,745	$ 1,897

Loans and the Allowance for C_4

Loans and the Allowance for Credit Losses - Additional Information (Details)	Jun. 30, 2023 USD ($) Loan	Dec. 31, 2022 USD ($) Loan
Financing Receivable Modifications [Line Items]
Number Of Loans In Process Of Foreclosure | Loan		0
Commitments to lend additional funds to borrowers whose loans were on non-accrual status | $	$ 0	$ 0
One to Four Family Residential Property
Financing Receivable Modifications [Line Items]
Number Of Loans In Process Of Foreclosure | Loan	2
Loans in process of foreclosure, carrying value | $	$ 628,000

Loans and the Allowance for C_5

Loans and the Allowance for Credit Losses - Non-performing Loans Disaggregated by Loan Category (Details) - Non-Performing Loans - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	$ 7,199	$ 5,839
Troubled debt restructurings		703
Total	7,199	6,542
Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	6,083	4,733
Troubled debt restructurings		622
Total	6,083	5,355
Commercial Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	606	311
Total	606	311
Home Equity
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	398	722
Total	398	722
Commercial and Industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	112	73
Troubled debt restructurings		81
Total	$ 112	$ 154

Loans and the Allowance for C_6

Loans and the Allowance for Credit Losses - Loans Receivable Disaggregated by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Residential Mortgage
Financing Receivable Recorded Investment [Line Items]
2023	$ 35,475	$ 314,599
2022	336,012	511,217
2021	516,545	276,904
2020	284,319	113,566
2019	115,718	78,304
Prior	329,125	354,248
Total	1,617,194	1,648,838
Residential Mortgage | Current
Financing Receivable Recorded Investment [Line Items]
2023	35,475	314,599
2022	336,012	511,217
2021	516,545	276,698
2020	284,119	113,251
2019	114,442	77,620
Prior	324,518	350,098
Total	1,611,111	1,643,483
Residential Mortgage | Non-Performing Loans
Financing Receivable Recorded Investment [Line Items]
2021		206
2020	200	315
2019	1,276	684
Prior	4,607	4,150
Total	6,083	5,355
Home Equity
Financing Receivable Recorded Investment [Line Items]
2023	3,040	3,611
2022	4,350
2021	2,650
2020	1,503	58
2019	2,996	360
Prior	16,412	481
Revolving loans amortized cost basis	65,024	106,841
Total	95,975	111,351
Home Equity | Current
Financing Receivable Recorded Investment [Line Items]
2023	3,040	3,611
2022	4,289
2021	2,650
2020	1,503	58
2019	2,996	360
Prior	16,075	481
Revolving loans amortized cost basis	65,024	106,119
Total	95,577	110,629
Home Equity | Non-Performing Loans
Financing Receivable Recorded Investment [Line Items]
2022	61
Prior	337
Revolving loans amortized cost basis		722
Total	398	722
Consumer
Financing Receivable Recorded Investment [Line Items]
2023	3,852	13,214
2022	10,154	8,482
2021	4,841	5,353
2020	3,244	444
2019	698	2,078
Prior	5,121	7,424
Revolving loans amortized cost basis	585	599
Total	28,495	37,594
Current period gross writeoffs	25
Consumer | Current
Financing Receivable Recorded Investment [Line Items]
2023	3,852	13,214
2022	10,154	8,482
2021	4,841	5,353
2020	3,244	444
2019	698	2,078
Prior	5,121	7,424
Revolving loans amortized cost basis	585	599
Total	28,495	37,594
Commercial Mortgage
Financing Receivable Recorded Investment [Line Items]
2023	33,821	411,927
2022	461,974	330,593
2021	369,955	226,635
2020	232,640	302,166
2019	306,706	147,095
Prior	511,063	496,007
Total	1,916,159	1,914,423
Commercial Mortgage | 1-6 (Pass)
Financing Receivable Recorded Investment [Line Items]
2023	31,974	411,927
2022	461,974	330,593
2021	369,955	222,073
2020	230,573	260,588
2019	261,839	125,398
Prior	468,282	489,564
Total	1,824,597	1,840,143
Commercial Mortgage | 7 (Special Mention)
Financing Receivable Recorded Investment [Line Items]
2023	1,847
2021		4,562
2020	2,067	41,578
2019	44,867	21,697
Prior	42,175	6,132
Total	90,956	73,969
Commercial Mortgage | 8 (Substandard)
Financing Receivable Recorded Investment [Line Items]
Prior	606	311
Total	606	311
Commercial and Industrial
Financing Receivable Recorded Investment [Line Items]
2023	31,453	128,301
2022	138,501	71,938
2021	56,619	62,783
2020	70,276	30,820
2019	25,990	19,282
Prior	44,095	37,041
Revolving loans amortized cost basis	469	485
Total	367,403	350,650
Current period gross writeoffs	11
Commercial and Industrial | 1-6 (Pass)
Financing Receivable Recorded Investment [Line Items]
2023	31,393	128,301
2022	137,643	67,727
2021	56,468	62,025
2020	69,581	28,557
2019	23,972	18,794
Prior	43,827	36,836
Revolving loans amortized cost basis	459	475
Total	363,343	342,715
Commercial and Industrial | 7 (Special Mention)
Financing Receivable Recorded Investment [Line Items]
2023	60
2022	858	4,211
2021	151	130
2020	110	161
2019	195	407
Prior	123	121
Revolving loans amortized cost basis	10	10
Total	1,507	5,040
Commercial and Industrial | 8 (Substandard)
Financing Receivable Recorded Investment [Line Items]
2021		628
2020	585	2,102
2019	1,823	81
Prior	145	84
Total	$ 2,553	$ 2,895

Loans and the Allowance for C_7

Loans and the Allowance for Credit Losses - Schedule of Loans Receivable Disaggregated by Past Due Status (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	$ 4,002,641	$ 4,046,250
Total loans	4,025,226	4,062,856
30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	19,428	12,467
60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	1,142	2,116
90 Days or Greater
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	2,015	2,023
Total Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	22,585	16,606
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	1,606,102	1,634,216
Total loans	1,617,194	1,648,838
Residential Mortgage | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	8,865	11,359
Residential Mortgage | 60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	370	1,454
Residential Mortgage | 90 Days or Greater
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	1,857	1,809
Residential Mortgage | Total Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	11,092	14,622
Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	1,906,240	1,914,423
Total loans	1,916,159	1,914,423
Commercial Mortgage | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	9,919
Commercial Mortgage | Total Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	9,919
Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	94,994	109,782
Total loans	95,975	111,351
Home Equity | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	536	962
Home Equity | 60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	297	393
Home Equity | 90 Days or Greater
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	148	214
Home Equity | Total Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	981	1,569
Commercial and Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	366,849	350,316
Total loans	367,403	350,650
Commercial and Industrial | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	82	65
Commercial and Industrial | 60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	472	269
Commercial and Industrial | Total Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	554	334
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	28,456	37,513
Total loans	28,495	37,594
Consumer | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	26	81
Consumer | 60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	3
Consumer | 90 Days or Greater
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	10
Consumer | Total Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	$ 39	$ 81

Loans and the Allowance for C_8

Loans and the Allowance for Credit Losses - Summary of Changes in Allowance for Credit Losses Disaggregated by Loan Category (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Financing Receivable Allowance For Credit Losses [Line Items]
Provision for (release of) credit losses - unfunded commitments			$ 140	$ (412)
Allowance for credit losses-loan portfolio, Ending Balance	$ 40,004	$ 35,495	40,004	35,495
Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	38,005	34,110	37,774	34,496
Charge-offs	(22)	(6)	(36)	(31)
Recoveries	10	20	30	58
Provision for (release of) credit losses - loan portfolio	80		305	(399)
Allowance for credit losses-loan portfolio, Ending Balance	38,073	34,124	38,073	34,124
Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	1,931	1,371	2,096	1,384
Provision for (release of) credit losses - unfunded commitments			(165)	(13)
Allowance for credit losses-unfunded commitments	1,931	1,371	1,931	1,371
Allowance for credit losses-loan portfolio, Ending Balance	40,004	35,495	40,004	35,495
Residential Mortgage | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	13,164	13,193	13,321	13,383
Provision for (release of) credit losses - loan portfolio	433	(554)	276	(744)
Allowance for credit losses-loan portfolio, Ending Balance	13,597	12,639	13,597	12,639
Residential Mortgage | Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Ending Balance	13,597	12,639	13,597	12,639
Commercial Mortgage | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	19,596	17,138	19,086	17,133
Provision for (release of) credit losses - loan portfolio	(297)	629	213	634
Allowance for credit losses-loan portfolio, Ending Balance	19,299	17,767	19,299	17,767
Commercial Mortgage | Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Ending Balance	19,299	17,767	19,299	17,767
Home Equity | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	528	377	573	406
Provision for (release of) credit losses - loan portfolio	(60)	23	(105)	(6)
Allowance for credit losses-loan portfolio, Ending Balance	468	400	468	400
Home Equity | Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Ending Balance	468	400	468	400
Commercial & Industrial | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	4,152	2,897	4,153	2,989
Charge-offs		(3)	(11)	(3)
Recoveries	9	10	19	46
Provision for (release of) credit losses - loan portfolio	91	(52)	91	(180)
Allowance for credit losses-loan portfolio, Ending Balance	4,252	2,852	4,252	2,852
Commercial & Industrial | Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Ending Balance	4,252	2,852	4,252	2,852
Consumer | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	565	505	641	585
Charge-offs	(22)	(3)	(25)	(28)
Recoveries	1	10	11	12
Provision for (release of) credit losses - loan portfolio	(87)	(46)	(170)	(103)
Allowance for credit losses-loan portfolio, Ending Balance	457	466	457	466
Consumer | Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Ending Balance	457	466	457	466
Unfunded Commitments | Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	1,931	1,371	2,096	1,384
Provision for (release of) credit losses - unfunded commitments			(165)	(13)
Allowance for credit losses-unfunded commitments	1,931	1,371	1,931	1,371
Allowance for credit losses-loan portfolio, Ending Balance	$ 1,931	$ 1,371	$ 1,931	$ 1,371

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Effective tax rate	24%	28.20%	24.70%	26.70%
Net deferred tax assets	$ 15,841,000		$ 15,841,000		$ 17,990,000
Deferred tax assets, valuation allowance	$ 0		$ 0		$ 0

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Current income tax expense
Federal	$ 1,998	$ 3,868	$ 3,032	$ 4,963
State	745	1,595	1,211	1,984
Total current income tax expense	2,743	5,463	4,243	6,947
Deferred income tax expense (benefit)
Federal	(338)	(61)	1,537	1,964
State	(155)	(27)	629	908
Total deferred income tax expense (benefit)	(493)	(88)	2,166	2,872
Total income tax expense	$ 2,250	$ 5,375	$ 6,409	$ 9,819

Pension and Retirement Plans -

Pension and Retirement Plans - Components of Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pension Plan
Net periodic benefit cost (credit)
Interest cost	$ 450	$ 345	$ 903	$ 655
Expected return on assets	(799)	(1,002)	(1,602)	(1,938)
Net periodic benefit cost (credit)	(349)	(657)	(699)	(1,283)
Supplemental Retirement Plan
Net periodic benefit cost (credit)
Service cost	68	98	136	199
Interest cost	100	71	200	130
Net periodic benefit cost (credit)	168	169	336	329
Postretirement Healthcare Plan
Net periodic benefit cost (credit)
Service cost	4	6	8	14
Interest cost	5	5	11	10
Amortization of net actuarial (gain) loss	(5)		(11)
Net periodic benefit cost (credit)	$ 4	$ 11	$ 8	$ 24

Pension and Retirement Plans _2

Pension and Retirement Plans - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Profit Sharing Plan | 401(k)
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, maximum employee contribution, percent			100%
Profit Sharing Plan | 401(k) | Maximum
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent			4%
Profit Sharing Plan | Discretionary Contribution
Defined Benefit Plan Disclosure [Line Items]
Normal retirement age of employees			65 years
Employee Stock Ownership Plan (ESOP)
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, minimum service period required for eligibility			12 months
Defined contribution plan, minimum number of hours of service per year required for eligibility			1000 hours
Employee Stock Ownership Plan (ESOP) | Minimum
Defined Benefit Plan Disclosure [Line Items]
Employee eligibility age under the plan			21 years
Profit Sharing and ESOP Plans
Defined Benefit Plan Disclosure [Line Items]
Contribution expense related to plans	$ 646,000	$ 1,100,000	$ 1,500,000	$ 2,500,000
Defined Contribution Supplemental Executive Retirement Plan ("DC SERP")
Defined Benefit Plan Disclosure [Line Items]
Contribution expense related to plans	16,000	$ 68,000	$ 25,000	$ 135,000
Defined Contribution Supplemental Executive Retirement Plan ("DC SERP") | Maximum
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent			10%
Qualified Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined benefit pension plan	$ 0		$ 0

Share Based Compensation - Sche

Share Based Compensation - Schedule of Shares Issued and Fair Value of RSAs and RSUs (Details) - 2017 Equity and Cash Incentive Plan - $ / shares	3 Months Ended	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2023
RSAs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares Granted	18,731	19,253
Weighted Average Fair Value Per Share at Grant Date	$ 51.65	$ 52.53
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares Granted	510	13,675
Weighted Average Fair Value Per Share at Grant Date	$ 49.15	$ 82.73
PRSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares Granted	22,895	27,554
Weighted Average Fair Value Per Share at Grant Date	$ 51.65	$ 55.13

Share Based Compensation - Addi

Share Based Compensation - Additional Information (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
DSP Plan and 2017 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total shares issued under this plan	12,195	6,617	12,195	6,776
Restricted Stock | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options time-vest period	3 years		3 years
Restricted Stock | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options time-vest period	5 years		5 years
Restricted Stock | 2017 Equity and Cash Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted	18,731		19,253
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options time-vest period			3 years
Restricted Stock Units | 2017 Equity and Cash Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted	510		13,675
Performance-Based Restricted Stock Units | 2017 Cash Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance-based restricted stock units performance period	3 years		3 years
Performance-Based Restricted Stock Units | 2017 Equity and Cash Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock units granted	22,895		27,554

Share Based Compensation - Sc_2

Share Based Compensation - Schedule of Pre-tax Expense Associated with All Outstanding Non-vested RSAs, RSUs, Performance Based Restricted Stock Units and Related Tax Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share-Based Payment Arrangement, Noncash Expense [Abstract]
Share based compensation expense	$ 603	$ 943	$ 1,170	$ 1,591
Related tax benefits	$ 168	$ 263	$ 327	$ 444

Financial Instruments with Of_3

Financial Instruments with Off-Balance-Sheet Risk - Summary of Off-Balance-Sheet Financial Instruments with Contractual Amounts Include Present Credit Risk (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Standby Letters of Credit
Financial instruments whose contractual amount represents credit risk:
Financial instruments with off-balance-sheet risk	$ 32,645	$ 24,234
Unused Portion of Existing Lines of Credit
Financial instruments whose contractual amount represents credit risk:
Financial instruments with off-balance-sheet risk	1,038,589	1,073,567
Origination of New Loans
Financial instruments whose contractual amount represents credit risk:
Financial instruments with off-balance-sheet risk	39,349	25,411
Commitments to Sell Residential Mortgage Loans
Financial instruments whose notional amount exceeds the amount of credit risk:
Financial instrument notional amount exceeds credit risk	$ 0	$ 250

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Leases [Abstract]
Description of operating lease expiration terms			operating leases and their terms expire between 2023 and 2032 and, in some instances, contain options to renew for periods up to
Renewal option period for operating leases	30 years		30 years
Existence of option to expire			true
Total rental expense	$ 1.8	$ 1.9	$ 3.7	$ 3.7

Leases - Summary of Components

Leases - Summary of Components of Operating Lease Cost and Other Related Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Leases [Abstract]
Operating lease cost	$ 1,673	$ 1,743	$ 3,411	$ 3,486
Variable lease cost (cost excluded from lease payments)	7	1	14	2
Sublease income	(128)	(17)	(256)	(33)
Total operating lease cost	1,552	1,727	3,169	3,455
Other Information
Cash paid for amounts included in the measurement of lease liabilities - operating cash flows for operating leases	1,821	1,805	3,664	3,638
Operating Lease - operating cash flows (liability reduction)	$ 1,637	$ 1,586	$ 3,291	$ 3,191
Weighted average lease term - operating leases	5 years 2 months 4 days	5 years 9 months 18 days	5 years 2 months 4 days	5 years 9 months 18 days
Weighted average discount rate - operating leases	3.06%	2.97%	3.06%	2.97%

Leases - Schedule of Total Mini

Leases - Schedule of Total Minimum Lease Payments Due in Future Periods for Lease Agreements (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Remainder of 2023	$ 3,552
2024	6,301
2025	5,314
2026	4,065
2027	2,267
Thereafter	5,962
Total minimum lease payments	27,461
Less: interest	(2,085)
Total lease liability	$ 25,376	$ 27,413

Shareholders' Equity - Minimum

Shareholders' Equity - Minimum Capital Requirements were Considered Well Capitalized by FRB and FDIC (Details)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual, Amount	$ 516,242,000	$ 506,239,000
Tier I capital (to risk-weighted assets), Actual, Amount	476,239,000	466,369,000
Common equity tier I capital (to risk-weighted assets), Actual, Amount	476,239,000	466,369,000
Tier I capital (to average assets), Actual, Amount	$ 476,239,000	$ 466,369,000
Total capital (to risk-weighted assets), Actual, Ratio	0.141	0.135
Tier I capital (to risk-weighted assets), Actual, Ratio	0.130	0.125
Common equity tier I capital (to risk-weighted assets), Actual, Ratio	0.130	0.125
Tier I capital (to average assets), Actual, Ratio	0.087	0.085
Total capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	$ 384,543,000	$ 393,285,000
Tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	311,297,000	318,373,000
Common equity tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	256,362,000	262,190,000
Tier I capital (to average assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	$ 218,011,000	$ 219,309,000
Total capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	0.105	0.105
Tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	0.085	0.085
Common equity tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	0.070	0.070
Tier I capital (to average assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	0.040	0.040
Cambridge Trust Company
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual, Amount	$ 494,631,000	$ 490,175,000
Tier I capital (to risk-weighted assets), Actual, Amount	454,627,000	450,305,000
Common equity tier I capital (to risk-weighted assets), Actual, Amount	454,627,000	450,305,000
Tier I capital (to average assets), Actual, Amount	$ 454,627,000	$ 450,305,000
Total capital (to risk-weighted assets), Actual, Ratio	0.135	0.131
Tier I capital (to risk-weighted assets), Actual, Ratio	0.124	0.120
Common equity tier I capital (to risk-weighted assets), Actual, Ratio	0.124	0.120
Tier I capital (to average assets), Actual, Ratio	0.083	0.082
Total capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	$ 384,507,000	$ 393,246,000
Tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	311,268,000	318,342,000
Common equity tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	256,338,000	262,164,000
Tier I capital (to average assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	$ 217,998,000	$ 219,296,000
Total capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	0.105	0.105
Tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	0.085	0.085
Common equity tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	0.070	0.070
Tier I capital (to average assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	0.040	0.040
Cambridge Trust Company | Minimum
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	$ 366,198,000	$ 374,520,000
Tier I capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	292,958,000	299,616,000
Common equity tier I capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	238,028,000	243,438,000
Tier I capital (to average assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	$ 272,498,000	$ 274,120,000
Total capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	0.100	0.100
Tier I capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	0.080	0.080
Common equity tier I capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	0.065	0.065
Tier I capital (to average assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	0.050	0.050

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) - Summary of Accumulated Other Comprehensive Income (Loss) ("AOCI") ("AOCL") (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Available for sale securities, before tax amount
Unrealized holding gains (losses)	$ (2,259)	$ (5,579)	$ 349	$ (16,595)
Interest rate swaps designated as cash flow hedges, before tax amount
Unrealized holding (losses) gains, before tax amount	(711)	(358)	(633)	(2,058)
Reclassification adjustment for (losses) income recognized in net income, before tax amount	145	(391)	289	(1,005)
Defined benefit retirement plans, before tax amount
Total other comprehensive income (loss)	(2,825)	(6,328)	5	(19,658)
Available for sale securities, tax (expense) or benefit
Unrealized holding gains (losses)	593	1,442	(73)	4,231
Interest rate swaps designated as cash flow hedges, tax (expense) or benefit
Unrealized holding (losses) gains, tax (expense) or benefit	199	101	178	575
Reclassification adjustment for (losses) income recognized in net income, tax (expense) or benefit	(41)	108	(81)	281
Defined benefit retirement plans, tax (expense) or benefit
Total other comprehensive (loss) income, tax (expense) or benefit	751	1,651	24	5,087
Available for sale securities
Unrealized holding gains (losses)	(1,666)	(4,137)	276	(12,364)
Interest rate swaps designated as cash flow hedges
Unrealized holding (losses) gains, net-of-tax amount	(512)	(257)	(455)	(1,483)
Reclassification adjustment for (losses) income realized in net income	104	(283)	208	(724)
Defined benefit retirement plans
Other comprehensive income (loss)	$ (2,074)	$ (4,677)	$ 29	$ (14,571)

Other Comprehensive Income (L_4

Other Comprehensive Income (Loss) - Summary of Reclassifications out of Accumulated Other Comprehensive Income (Loss) ("AOCI") ("AOCL") (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Reclassification Adjustment Out Of Accumulated Other Comprehensive Loss [Line Items]
Tax benefit (expense)	$ (2,250)	$ (5,375)	$ (6,409)	$ (9,819)
Net income	7,115	13,658	19,531	26,974
Reclassifications out of Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment Out Of Accumulated Other Comprehensive Loss [Line Items]
Unrealized (losses) gains on derivatives	(145)	391	(289)	1,005
Tax benefit (expense)	41	(108)	81	(281)
Net income	$ (104)	$ 283	$ (208)	$ 724

Earnings Per Share - Summary of

Earnings Per Share - Summary of Reconciliation Between Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator:
Net income	$ 7,115	$ 13,658	$ 19,531	$ 26,974
Less dividends and undistributed earnings allocated to participating securities	(2)	(43)	(20)	(122)
Net income applicable to common shareholders	$ 7,113	$ 13,615	$ 19,511	$ 26,852
Denominator:
Weighted average common shares outstanding	7,837,708	6,981,907	7,816,611	6,959,856
Earnings per common share - basic	$ 0.91	$ 1.95	$ 2.50	$ 3.86
Numerator:
Net income	$ 7,115	$ 13,658	$ 19,531	$ 26,974
Less dividends and undistributed earnings allocated to participating securities	(2)	(43)	(20)	(122)
Net income applicable to common shareholders	$ 7,113	$ 13,615	$ 19,511	$ 26,852
Denominator:
Weighted average number of shares outstanding, basic	7,837,708	6,981,907	7,816,611	6,959,856
Dilutive effect of common stock equivalents	17,000	45,000	25,000	54,000
Weighted average diluted common shares outstanding	7,854,955	7,026,807	7,842,106	7,013,538
Earnings per common share - diluted	$ 0.91	$ 1.94	$ 2.49	$ 3.83

Derivative And Hedging Activi_3

Derivative And Hedging Activities - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Estimated amount will be reclassified out of AOCI and AOCL into earnings	$ 444,000
Fair value of derivative liability	49,083,000		$ 50,827,000
Available for sale securities, amortized cost	172,568,000		182,027,000
Fair Value Hedges
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets/(liabilities)	5,256,000
Carrying Amount of Hedged Assets/(Liabilities)	$ 494,744,000		0
Weighted average remaining maturity	1 year 9 months 10 days
Weighted average fixed interest rate	4.16%
Fair Value Hedges | Fixed Rate Assets [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets/(liabilities)	$ 5,256,000
Available for sale securities, amortized cost	696,100,000
Carrying Amount of Hedged Assets/(Liabilities)	494,744,000
Derivatives Designated as Hedging Instruments
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Notional amount	$ 500,000,000
Accrued Interest
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Fair value of derivative liability		$ 0	$ 0

Derivative And Hedging Activi_4

Derivative And Hedging Activities - Summary of Cumulative Basis Adjustment for Fair Value Hedges (Details) - Fair Value Hedges - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Carrying Amount of Hedged Assets/(Liabilities)	$ 494,744,000	$ 0
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets/(liabilities)	5,256,000
Fixed Rate Assets
Derivatives, Fair Value [Line Items]
Carrying Amount of Hedged Assets/(Liabilities)	494,744,000
Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets/(liabilities)	$ 5,256,000

Derivative And Hedging Activi_5

Derivative And Hedging Activities - Summary of Fair Values of Derivative Instruments in the Company's Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	$ 55,660	$ 52,773
Derivative Liabilities, Fair value	49,083	50,827
Derivatives Designated as Hedging Instruments
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	6,552	1,966
Derivatives Designated as Hedging Instruments | Interest Rate Contracts | Cash Flow Hedging
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Notional amount	250,000	250,000
Derivatives Designated as Hedging Instruments | Interest Rate Contracts | Fair Value Hedging
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Notional amount	500,000
Derivatives Designated as Hedging Instruments | Interest Rate Contracts | Other Assets | Cash Flow Hedging
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	1,333	1,966
Derivatives Designated as Hedging Instruments | Interest Rate Contracts | Other Assets | Fair Value Hedging
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	5,219
Derivatives Not Designated as Hedging Instruments
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	49,107	50,807
Derivative Liabilities, Fair value	49,127	50,827
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Interest Rate Contracts
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Notional amount	499,917
Derivative Liabilities, Notional Amount	499,917	499,619
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Interest Rate Contracts | Other Assets
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	49,083
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Interest Rate Contracts | Other Liabilities
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Liabilities, Fair value	49,083	50,784
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Interest Rate Swaps with Clients
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Notional amount		499,619
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Interest Rate Swaps with Clients | Other Assets
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value		50,784
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Risk Participation Agreements Out to Counterparties
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Notional amount	52,070	46,604
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Risk Participation Agreements Out to Counterparties | Other Assets
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	24	23
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Risk Participation Agreements with Counterparties
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Liabilities, Notional Amount	81,644	71,046
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Risk Participation Agreements with Counterparties | Other Liabilities
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Liabilities, Fair value	$ 44	$ 43

Derivative And Hedging Activi_6

Derivative And Hedging Activities - Summary of Changes to AOCI and AOCL as a Result of Cash Flow Hedge Accounting (Details) - Cash Flow Hedging - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Interest Income
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) Reclassified from AOCI and AOCL into Income	$ (145)	$ 391	$ (289)	$ 1,005
Amount of Gain or (Loss) Reclassified from AOCI and AOCL into Income Included Component		439	(96)	1,101
Amount of Gain or (Loss) Reclassified from AOCI and AOCL into Income Excluded Component	(145)	(48)	(193)	(96)
Interest Rate Contracts
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) Recognized in OCI	(711)	(358)	(633)	(2,058)
Amount of Gain or (Loss) Recognized in OCI - Included Component		(101)		(2,012)
Amount of Gain or (Loss) Recognized in OCI - Excluded Component	$ (711)	$ (257)	$ (633)	$ (46)

Derivative And Hedging Activi_7

Derivative And Hedging Activities - Summary of Derivative Financial Instruments Not Designated as Hedging Instruments on the Consolidated Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Other contracts | Loan related derivative income | Derivatives Not Designated as Hedging Instruments
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	$ (14)	$ (33)	$ (31)	$ (110)

Derivative And Hedging Activi_8

Derivative And Hedging Activities - Schedule of Financial Instruments Eligible for Offset in Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Offsetting [Abstract]
Gross Amounts Recognized, Derivative assets	$ 55,660	$ 52,773
Net Amounts Recognized, Derivative Assets	$ 55,660	$ 52,773
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
Gross Amounts Not Offset, Financial Instruments, Derivative Assets	$ 109	$ 48
Gross Amounts Not Offset, Collateral Pledged (Received), Derivative Assets	(55,352)	(52,130)
Gross Amounts Not Offset, Net amount, Derivative Assets	199	595
Gross Amounts Recognized, Derivative Liabilities	49,083	50,827
Net Amounts Recognized, Derivative Liabilities	$ 49,083	$ 50,827
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other Liabilities	Other Liabilities
Gross Amounts Not Offset, Financial Instruments, Derivative Liabilities	$ 109	$ 48
Gross Amounts Not Offset, Net amount, Derivative Liabilities	$ 48,974	$ 50,875

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Carrying Values and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Financial assets
Securities available for sale	$ 144,306	$ 153,416
Securities held to maturity	839,025	885,586
FHLB of Boston stock	20,247	6,264
Recurring Basis | Carrying Value
Financial assets
Cash and cash equivalents	33,398	30,719
Securities available for sale	144,306	153,416
Securities held to maturity	1,007,471	1,051,997
Loans, net	3,987,153	4,025,082
FHLB of Boston stock	20,247	6,264
Accrued interest receivable	14,573	14,118
Mortgage servicing rights	1,529	1,665
Loan level interest rate swaps	49,083	50,784
Risk participation agreements out to counterparties	24	23
Financial liabilities
Deposits, excluding wholesale deposits	4,086,260	4,433,817
Deposits, Wholesale	356,330	381,559
Borrowings	408,926	105,212
Loan level interest rate swaps	49,083	50,784
Risk participation agreements in with counterparties	44	43
Recurring Basis | Estimated Fair Value
Financial assets
Cash and cash equivalents	33,398	30,719
Securities available for sale	144,306	153,416
Securities held to maturity	839,025	885,586
Loans, net	3,643,268	3,783,051
FHLB of Boston stock	20,247	6,264
Accrued interest receivable	14,573	14,118
Mortgage servicing rights	2,208	2,336
Loan level interest rate swaps	49,083	50,784
Risk participation agreements out to counterparties	24	23
Financial liabilities
Deposits, excluding wholesale deposits	4,081,744	4,429,190
Deposits, Wholesale	356,084	381,505
Borrowings	407,551	105,202
Loan level interest rate swaps	49,083	50,784
Risk participation agreements in with counterparties	44	43
Cash Flow Hedging | Recurring Basis | Carrying Value
Financial assets
Interest rate contracts - cash flow hedge	1,333	1,966
Interest rate contracts - fair value hedge	1,333	1,966
Cash Flow Hedging | Recurring Basis | Estimated Fair Value
Financial assets
Interest rate contracts - cash flow hedge	1,333	1,966
Interest rate contracts - fair value hedge	1,333	$ 1,966
Fair Value Hedging | Recurring Basis
Financial assets
Interest rate contracts - cash flow hedge	5,219
Interest rate contracts - fair value hedge	5,219
Fair Value Hedging | Recurring Basis | Estimated Fair Value
Financial assets
Interest rate contracts - cash flow hedge	5,219
Interest rate contracts - fair value hedge	$ 5,219

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Certain Assets and Liabilities Reported at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	$ 144,306	$ 153,416
U.S. GSE Obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	19,956	19,733
Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale		1,000
Recurring Basis | U.S. GSE Obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	19,956	19,733
Recurring Basis | U.S. GSE Obligations | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	19,956	19,733
Recurring Basis | Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	124,350	132,683
Recurring Basis | Mortgage Backed Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	124,350	132,683
Recurring Basis | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale		1,000
Recurring Basis | Corporate Debt Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale		1,000
Recurring Basis | Interest Rate Swaps with Clients
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	49,083	50,784
Other liabilities	49,083	50,784
Recurring Basis | Interest Rate Swaps with Clients | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	49,083	50,784
Other liabilities	49,083	50,784
Recurring Basis | Risk Participation Agreements Out to Counterparties
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	24	23
Recurring Basis | Risk Participation Agreements Out to Counterparties | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	24	23
Recurring Basis | Interest Rate Contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets		1,966
Recurring Basis | Interest Rate Contracts | Cash Flow Hedging
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	1,333
Recurring Basis | Interest Rate Contracts | Fair Value Hedging
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	5,219
Recurring Basis | Interest Rate Contracts | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets		1,966
Recurring Basis | Interest Rate Contracts | Level 2 | Cash Flow Hedging
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	1,333
Recurring Basis | Interest Rate Contracts | Level 2 | Fair Value Hedging
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	5,219
Recurring Basis | Risk Participation Agreements in With Counterparties
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other liabilities	44	43
Recurring Basis | Risk Participation Agreements in With Counterparties | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other liabilities	$ 44	$ 43

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Carrying Value of Assets Measured at Fair Value on a Non-Recurring Basis (Details) - Non-recurring - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	$ 89	$ 103
Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	89	103
Individually Evaluated Collateral Dependent Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	89	103
Individually Evaluated Collateral Dependent Loans | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	$ 89	$ 103

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Transfers between levels	$ 0	$ 0	$ 0	$ 0