Cambridge Bancorp (CATC) 10-Q 6 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 31, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2020
Document Fiscal Year Focus	2020
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		6,927,592
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

CONSOLIDATED BALANCE SHEETS (UN

CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents	$ 60,742	$ 61,335
Investment securities
Available for sale, at fair value (amortized cost $130,761 and $141,109, respectively)	134,227	140,330
Held to maturity, at amortized cost (fair value $257,121 and $264,114, respectively)	244,551	258,172
Total investment securities	378,778	398,502
Loans held for sale, at lower of cost or fair value	2,614	1,546
Loans
Total loans	3,332,884	2,226,728
Less: allowance for credit losses on loans	(34,014)	(18,180)
Net loans	3,298,870	2,208,548
Federal Home Loan Bank of Boston Stock, at cost	9,262	7,854
Bank owned life insurance	45,747	37,319
Banking premises and equipment, net	18,482	14,756
Right-of-use asset operating leases	38,912	33,587
Deferred income taxes, net	11,855	8,229
Accrued interest receivable	8,631	7,052
Goodwill	51,912	31,206
Merger related intangibles, net	3,158	3,338
Other assets	93,787	42,291
Total assets	4,022,750	2,855,563
Deposits
Demand	929,846	630,593
Interest bearing checking	606,999	450,098
Money market	419,537	181,406
Savings	960,847	914,499
Certificates of deposit	358,614	182,282
Total deposits	3,275,843	2,358,878
Borrowings	237,897	135,691
Subordinated debt	9,920
Operating lease liabilities	40,453	35,054
Other liabilities	75,577	39,379
Total liabilities	3,639,690	2,569,002
Shareholders’ Equity
Common stock, par value $1.00; Authorized: 10,000,000 shares; Outstanding: 6,927,699 shares and 5,400,868 shares, respectively	6,928	5,401
Additional paid-in capital	224,540	136,766
Retained earnings	146,305	146,875
Accumulated other comprehensive income (loss)	5,287	(2,481)
Total shareholders’ equity	383,060	286,561
Total liabilities and shareholders’ equity	4,022,750	2,855,563
Residential Mortgage
Loans
Total loans	1,351,308	917,566
Commercial Mortgage
Loans
Total loans	1,413,427	1,060,574
Home Equity
Loans
Total loans	116,067	80,675
Commercial & Industrial
Loans
Total loans	414,243	133,236
Consumer
Loans
Total loans	$ 37,839	$ 34,677

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (UNAUDITED) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Available for sale securities, amortized cost	$ 130,761	$ 141,109
Held-to-maturity securities, fair value	$ 257,121	$ 264,114
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	10,000,000	10,000,000
Common stock, shares, outstanding	6,927,699	5,400,868

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME (LOSS) (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest and dividend income
Interest on taxable loans	$ 28,130	$ 21,355	$ 51,468	$ 37,639
Interest on tax-exempt loans	211	124	409	213
Interest on taxable investment securities	1,521	2,116	3,244	4,096
Interest on tax-exempt investment securities	601	575	1,196	1,146
Dividends on FHLB of Boston stock	52	81	153	157
Interest on overnight investments	16	219	156	337
Total interest and dividend income	30,531	24,470	56,626	43,588
Interest expense
Interest on deposits	1,396	4,379	4,525	6,880
Interest on borrowed funds	282	315	848	671
Interest on subordinated debt	64		64
Total interest expense	1,742	4,694	5,437	7,551
Net interest and dividend income	28,789	19,776	51,189	36,037
Provision for credit losses	14,430	596	16,430	503
Net interest and dividend income after provision for credit losses	14,359	19,180	34,759	35,534
Noninterest income
Bank owned life insurance income	165	162	325	289
Gain (loss) on disposition of investment securities	69	6	69	(81)
Gain on loans sold	193	15	312	31
Loan related derivative income	334	5	844	441
Other income	191	316	495	643
Total noninterest income	8,972	8,145	17,790	16,102
Noninterest expense
Salaries and employee benefits	13,542	11,459	26,558	22,286
Occupancy and equipment	2,938	2,691	5,745	5,021
Data processing	1,832	1,534	3,517	2,880
Professional services	1,098	760	1,957	1,567
Marketing	486	508	742	912
FDIC insurance	318	278	497	278
Nonoperating expenses	4,366	3,450	4,619	3,541
Other expenses	1,007	833	1,877	1,401
Total noninterest expense	25,587	21,513	45,512	37,886
(Loss) income before income taxes	(2,256)	5,812	7,037	13,750
Income tax (benefit) expense	(540)	1,540	1,521	3,280
Net (loss) income	$ (1,716)	$ 4,272	$ 5,516	$ 10,470
Share data:
Weighted average number of shares outstanding, basic	5,912,889	4,682,109	5,652,908	4,379,141
Weighted average number of shares outstanding, diluted	5,912,889	4,715,724	5,670,438	4,412,239
Basic (loss) earnings per share	$ (0.29)	$ 0.91	$ 0.97	$ 2.37
Diluted (loss) earnings per share	$ (0.29)	$ 0.90	$ 0.97	$ 2.35
Wealth Management Revenue
Noninterest income
Noninterest income	$ 7,035	$ 6,419	$ 13,662	$ 12,543
Deposit Account Fees
Noninterest income
Noninterest income	695	843	1,486	1,581
ATM/Debit Card Income
Noninterest income
Noninterest income	$ 290	$ 379	$ 597	$ 655

UNAUDITED CONSOLIDATED STATEMEN

UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (1,716)	$ 4,272	$ 5,516	$ 10,470
Unrealized gains on available for sale securities
Unrealized holding gains	810	1,453	3,310	2,548
Less: reclassification adjustment for (gains) losses included in net (loss) income	(57)	(4)	(57)	62
Total unrealized gains on securities	753	1,449	3,253	2,610
Derivatives
Change in interest rate contracts	270	1,219	4,516	1,189
Defined benefit retirement plans
Change in retirement liabilities		26	(1)	52
Other comprehensive income	1,023	2,694	7,768	3,851
Comprehensive (loss) income	$ (693)	$ 6,966	$ 13,284	$ 14,321

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS EQUITY' (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income / (Loss)
Beginning balance at Dec. 31, 2018	$ 167,026	$ 4,107	$ 38,271	$ 131,135	$ (6,487)
Net (loss) income	10,470			10,470
Other comprehensive income	3,851				3,851
Share based compensation and other share based activity	899	20	879
Dividends declared	(4,569)			(4,569)
Common stock issued for merger	59,417	723	58,694
Ending balance at Jun. 30, 2019	237,094	4,850	97,844	137,036	(2,636)
Beginning balance at Mar. 31, 2019	172,268	4,124	38,239	135,235	(5,330)
Net (loss) income	4,272			4,272
Other comprehensive income	2,694				2,694
Share based compensation and other share based activity	914	3	911
Dividends declared	(2,471)			(2,471)
Common stock issued for merger	59,417	723	58,694
Ending balance at Jun. 30, 2019	237,094	4,850	97,844	137,036	(2,636)
Beginning balance at Dec. 31, 2019	286,561	5,401	136,766	146,875	(2,481)
Cumulative effect of accounting changes (Note 4)	(347)			(347)
Net (loss) income	5,516			5,516
Other comprehensive income	7,768				7,768
Share based compensation and other share based activity	2,138	24	2,114
Dividends declared	(5,739)			(5,739)
Common stock issued for merger	87,163	1,503	85,660
Ending balance at Jun. 30, 2020	383,060	6,928	224,540	146,305	5,287
Beginning balance at Mar. 31, 2020	297,759	5,418	137,186	150,891	4,264
Net (loss) income	(1,716)			(1,716)
Other comprehensive income	1,023				1,023
Share based compensation and other share based activity	1,701	7	1,694
Dividends declared	(2,870)			(2,870)
Common stock issued for merger	87,163	1,503	85,660
Ending balance at Jun. 30, 2020	$ 383,060	$ 6,928	$ 224,540	$ 146,305	$ 5,287

CONSOLIDATED STATEMENTS OF CH_2

CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Retained Earnings
Dividends declared, per share	$ 0.53	$ 0.51	$ 1.06	$ 1.02

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 5,516	$ 10,470
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	16,430	503
(Accretion), depreciation, and amortization, net	(2,037)	889
Bank owned life insurance income	(325)	(289)
(Gain)/loss on disposition of investment securities	(69)	81
Share based compensation and other share based activity	2,138	899
Change in accrued interest receivable	1,136	(595)
Deferred income tax (benefit)/expense	(2,059)	885
Change in other assets, net	(32,232)	(5,860)
Change in other liabilities, net	22,895	774
Change in loans held for sale	(1,068)	(384)
Net cash provided by operating activities	10,325	7,373
CASH FLOWS FROM INVESTING ACTIVITIES
Origination of loans	(547,027)	(273,385)
Proceeds from principal payments of loans	311,795	212,719
Proceeds from calls/maturities of securities available for sale	30,868	13,876
Purchase of securities available for sale	(20,524)
Proceeds from sales of securities available for sale	10,821	26,150
Proceeds from calls/maturities of securities held to maturity	27,740	32,216
Purchase of securities held to maturity	(2,000)	(35,958)
Redemption of FHLB of Boston stock	4,977	65
Purchase of banking premises and equipment	(808)	(880)
Net cash acquired in business combinations	43,063	2,063
Net cash used in investing activities	(141,095)	(23,134)
CASH FLOWS FROM FINANCING ACTIVITIES
Change in demand, interest bearing, money market and savings accounts	189,949	59,049
Change in certificates of deposit	(33,705)	(18,090)
Change in borrowings	(20,328)	(545)
Cash dividends paid on common stock	(5,739)	(4,569)
Net cash provided by financing activities	130,177	35,845
Net change in cash and cash equivalents	(593)	20,084
Cash and cash equivalents at beginning of period	61,335	18,473
Cash and cash equivalents at end of period	60,742	38,557
Cash paid during the period for:
Interest	5,109	7,719
Income taxes	6,705	4,060
Significant non-cash transactions
Right-of-use assets for lessee operating leases		37,550
Transfer of other real estate owned	2,293	185
Common Stock issued to shareholders due to merger	87,163	59,417
Fair value of assets acquired, net of cash acquired	961,668	548,801
Fair value of liabilities assumed	$ 917,569	$ 491,447

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2020
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, 2020 and December 31, 2019, respectively, and the results of operations and cash flows for the interim periods presented in accordance with U.S. generally accepted accounting principles (“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, 2019 (the “2019 Form 10-K”), filed with the Securities and Exchange Commission on March 17, 2020.

Use of Estimates

Use of Estimates	6 Months Ended
	Jun. 30, 2020
Use Of Estimates [Abstract]
Use of Estimates	2. Use of Estimates The preparation of 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 financial statements. Actual results could differ from those estimates. The allowance for credit losses, the fair values of financial instruments, and the valuation of deferred tax assets are particularly subject to change.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	3. Subsequent Events Management has reviewed events occurring through August 6, 2020, the date the unaudited consolidated financial statements were available to be issued and determined that no subsequent events occurred requiring adjustment to or disclosure in these financial statements.

Mergers

Mergers	6 Months Ended
	Jun. 30, 2020
Business Combinations [Abstract]
Mergers	4 . MERGERS On June 1, 2020, the Company completed its merger with Wellesley Bancorp Inc. (“Wellesley”), adding 6 banking offices in Massachusetts. Under the terms of the Agreement and Plan of Merger, each outstanding share of Wellesley common stock was converted into 0.580 shares of the Company’s common stock. As a result of the merger, former Wellesley shareholders received an aggregate of 1,502,814 shares of the Company's common stock. The total consideration paid amounted to $88.8 million, based on the closing price of $58.00 of the Company's common stock, the value of Wellesley's exercisable options, and cash paid for fractional shares on May 31, 2020. The Company accounted for the merger using the acquisition method pursuant to the Business Combinations Topic of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”). Accordingly, the Company recorded merger expenses during the three months and six months ended June 30, 2020 of approximately $4.4 million and $4.6 million, respectively. Additionally, the Company recorded $8.6 million in provision for credit losses to reflect the impact of CECL merger accounting on June 1, 2020. T he acquisition method requires the acquirer to recognize the assets acquired and the liabilities assumed at their fair values as of the acquisition date. The following table summarizes the estimated fair value of the assets acquired and liabilities assumed as of the date of the acquisition: At June 1, 2020 Wellesley Book Value Purchase Accounting Adjustments Net Assets Acquired at Fair Value (dollars in thousands) Total Purchase Price $ 88,766 Assets Cash and cash equivalents $ 44,667 $ — $ 44,667 Investments 23,331 — 23,331 Gross Loans 883,659 (13,626 ) 870,033 Allowance for loan loss (8,461 ) 8,461 — Premises and equipment 2,972 1,040 4,012 Other assets 41,082 2,505 43,587 Total assets acquired 987,250 (1,620 ) 985,630 Liabilities Deposits 758,976 1,902 760,878 Borrowings & Subordinated debt 132,005 477 132,482 Other liabilities 21,847 2,362 24,209 Total liabilities assumed 912,828 4,741 917,569 Net Assets Acquired $ 74,422 $ (6,361 ) $ 68,061 Goodwill $ 20,705 Fair value adjustments to assets acquired and liabilities assumed are generally amortized using either an effective yield or straight-line basis over periods consistent with the average life, useful life, and/or contractual term of the related assets and liabilities. Fair values of the major categories of assets acquired and liabilities assumed were determined as follows: Cash and Cash Equivalents The fair values of cash and cash equivalents approximate the respective carrying amounts because the instruments are payable on demand or have short-term maturities. Investments The fair values of securities were based on quoted market prices for identical securities received from an independent, nationally-recognized, third-party pricing service. Prices provided by the independent pricing service were based on recent trading activity and other observable information including, but not limited to, market interest rate curves, referenced credit spreads, and estimated prepayment rates where applicable. Loans Fair value was determined using market participant assumptions in estimating the amount and timing of both principal and interest cash flows expected to be collected, as adjusted for an estimate of default rate and prepayments, and then applying a market-based discount rate to those cash flows. Premises and Equipment The fair value of premises was determined based upon appraisals by licensed real estate appraisers. The appraisal was based upon the best and highest use of the property with the final value determined based upon an analysis of the cost, sales comparison, and income capitalization approaches for the property appraised. Deposits The fair value of acquired savings and transaction deposit accounts was assumed to approximate the carrying value as these accounts have no stated maturity and are payable on demand. The fair value of time deposits was determined based on the present value of the contractual cash flows over the remaining period to maturity using a market interest rate. Borrowings The fair value represents the adjustment necessary because the weighted average interest rate of the Federal Home Loan Bank borrowings differed from the cost of similar funding at the time of acquisition. Subordinated debt The fair value represents the adjustment necessary because the interest rate of the subordinated debt differed from the cost of similar funding at the time of acquisition. Selected Pro Forma Results The following summarizes the unaudited pro forma results of operations as if the Company merged with Wellesley on December 31, 2019 and 2018, respectively. Amounts represent combined results for the Company and Wellesley. The selected pro forma financial information is presented for illustrative purposes only and is not necessarily indicative of the financial results of the combined companies had the acquisition actually been completed at the beginning of the periods presented, nor does it indicate future results for any other interim or full-year Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (dollars in thousands) Net interest and dividend income after provision for loan losses $ 28,056 $ 25,727 $ 55,141 $ 48,272 Net Income 11,352 9,227 20,697 16,818 Excluded from the pro forma results of operations for the three months and six months ended June 30, 2020 are merger-related costs of approximately $4.4 million and $4.6 million, respectively, recognized by the Company. These costs primarily consisted of contract terminations arising due to the merger, the acceleration of certain compensation and benefit costs, and other merger expenses. The provision recorded on acquired loans of $8.6 million was also excluded as a material, non-recurring adjustment. Optima Bank & Trust Company The Company completed its merger with Optima Bank & Trust Company (“Optima”) on April 17, 2019. Under the terms of the Agreement and Plan of Merger, each outstanding share of Optima common stock was converted into $32.00 in cash or 0.3468 shares of the Company’s common stock, with the transaction structured as 95 percent common stock and 5 percent cash. As a result of the merger, former Optima shareholders received an aggregate of approximately 722,746 shares of the Company’s common stock and an aggregate of approximately $3.5 million in cash. The total consideration paid amounted to $64.3 million. The Company accounted for the merger using the acquisition method and recorded total assets of $555.7 million, including $30.8 million in goodwill, and assumed total liabilities of $491.4 million. Additionally, the Company recorded merger expenses of $3.5

Recently Issued and Adopted Acc

Recently Issued and Adopted Accounting Guidance	6 Months Ended
	Jun. 30, 2020
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Recently Issued and Adopted Accounting Guidance	5 . Recently Issued and Adopted Accounting Guidance Accounting Standards Update 2020-04 - Facilitation of the Effects of Reference Rate Reform on Financial Reporting • Simplify accounting analyses for contract modifications. • Allow hedging relationships to continue without dedesignation if there are qualifying changes in the critical terms of an existing hedging relationship due to reference rate reform. • Allow a change in the systematic and rational method used to recognize in earnings the components excluded from the assessment of hedge effectiveness. • Allow a change in the designated benchmark interest rate to a different eligible benchmark interest rate in a fair value hedging relationship. • Allow the shortcut method for a fair value hedging relationship to continue for the remainder of the hedging relationship. • Simplify the assessment of hedge effectiveness and provide temporary optional expedients for cash flow hedging relationships affected by reference rate reform. • Allow a one-time election to sell or transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform and are classified as held to maturity before January 1, 2020. The amendments are effective for all entities from the beginning of an interim period that includes the issuance date of the ASU. An entity may elect to apply the amendments prospectively through December 31, 2022. The Company is currently assessing the impact the adoption of this guidance will have on our consolidated balance sheets, statements of income (loss), and cash flows. Accounting Standards Update 2018-15 - Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . Accounting Standards Update 2018-14 - Changes to the Disclosure Requirements for Defined Benefit Plans . Accounting Standards Update 2018-13 - Changes to the Disclosure Requirements for Fair Value Measurement . Accounting Standards Update 2016-13 - Financial Instruments - Credit Losses Measurement of Credit Losses on Financial Instruments The Company’s CECL methodology consists of quantitative and qualitative components. The quantitative component of the allowance for credit losses (“ACL”) is model based and utilizes a forward-looking macroeconomic forecast, complemented by qualitative components in estimating expected credit losses. The qualitative components of the ACL ASU 2016-13 also applies to off-balance sheet credit exposure not accounted for as insurance (loan commitments, standby letters of credit, financial guarantees and other similar investment) and net investments in leases recognized by a lessor in accordance with ASU 2016-02-Leases (Topic 842) on leases. January 1, 2020 CECL Transition (Day 1) Impact The CECL methodology reflects the Company’s view of the state of the economy and forecasted macroeconomic conditions and their impact on the Company’s loan and investment portfolios as of the adoption date. The following table illustrates the impact of Topic 326: January 1, 2020 As reported under ASC 326 Pre-ASC 326 Adoption Impact of ASC 326 Adoption (dollars in thousands) ASSETS Loans Residential mortgage $ 7,202 $ 5,141 $ 2,061 Commercial mortgage 9,545 10,992 (1,447 ) Home equity 256 461 (205 ) Commercial & Industrial 896 1,388 (492 ) Consumer 486 198 288 Allowance for credit losses on loans $ 18,385 $ 18,180 $ 205 LIABILITIES Allowance for credit losses on OBS credit exposure $ 326 $ 50 $ 276 Summary of significant accounting policies impacted by Topic 326 Debt Securities Investment securities are classified as either ‘held to maturity’ or ‘available for sale’ in accordance with the FASB ASC 320, Investments – Debt and Equity Securities. Debt and equity securities not classified as held to maturity are classified as available for sale and carried at fair value with unrealized after-tax gains and losses reported net as a separate component of shareholders’ equity. The Company classifies its securities based on its intention at the time of purchase. Allowance for credit losses- held to maturity securities The Company measures expected credit losses on held to maturity debt securities on a collective basis by security type and risk rating where available. The reserve for each pool is calculated based on a Probability of Default/Loss Given Default (PD/LGD) basis taking into consideration the expected life of each security. Held to maturity securities which are issued by the United States or are guaranteed by U.S. federal agencies do not currently have an allowance for credit loss as the Company determined these securities are either backed by the full faith and credit of the U.S. government and/or there is an unconditional commitment to make interest payments and to return the principal investment in full to investors when a debt security reaches maturity. The Company will evaluate this position no less than annually, however, certain items which may cause the Company to change this methodology include legislative changes that remove a government-sponsored enterprise’s (“GSE”) ability to draw funds from the U.S. government, or legislative changes to housing policy that reduce or eliminate the U.S. government’s implicit guarantee on such securities. For securities which are not U.S. treasury or agency backed, risk ratings are generally sourced from Moody’s or Standard & Poor’s (“S&P”). The Company updates loss given default, probability of default, and recovery rates for each security as that information becomes available but no less than annually. The expected remaining life to maturity of each applicable security is updated quarterly. Any expected credit losses on held to maturity securities would be presented as an allowance rather than as a direct write-down through the income statement if the Company does not intend to sell or believes that it is more- likely- than- not that the Company will be required to sell the security. Allowance for credit losses-available for sale securities The Company measures expected credit losses on available for sale securities based upon the gain or loss position of the security. For available-for sale debt securities in an unrealized loss position, which the Company does not intend to sell, or it is not more likely than not that the Company will be required to sell the security before recovery of our amortized cost, the Company evaluates qualitative criteria to determine any expected loss. This includes among other items the financial health of, and specific prospects for the issuer, including whether the issuer is in compliance with the terms and covenants of the security. The Company also evaluates quantitative criteria including determining whether there has been an adverse change in expected future cash flows of the security. If the Company do es not expect to recover the entire amortized cost basis of the security, an allowance for credit losses would be recorded, with a related charge to earnings, limited by the amount of the fair value of the security less its amortized cost . If the Company intend s to sell the security or it is more likely than not that the Company will be required to sell the debt security before recovery of its amortized cost basis, the Company recognize s the entire difference between the security’s amortized cost basis and its fair value in earnings. Loans Loans are reported at the amount of their outstanding principal, including deferred loan origination fees and costs, reduced by unearned discounts, and the allowance for credit losses. Loans are considered delinquent when a payment of principal and/or interest becomes past due 30 days following its scheduled payment due date. Loans on which the accrual of interest has been discontinued are designated as non-accrual loans. Loans are removed from non-accrual when they become less than 90 days past due and when concern no longer exists as to the collectability of principal or interest. Allowance for Credit Losses - Loans Losses on loan receivables are estimated and recognized upon origination of the loan, based on expected credit losses for the life of the loan balance as of the period end date. The Company uses a discounted cash flow method incorporating probability of default and loss given default forecasted based on statistically derived economic variable loss drivers combined with qualitative factors to estimate expected credit losses. This process includes estimates which involve modeling loss projections attributable to existing loan balances, considering historical experience, current conditions and future expectations for homogeneous pools of loans over the reasonable and supportable forecast period. As stated above, the Company also performs a qualitative assessment beyond model estimates, and apply qualitative adjustments as management deems necessary. The reasonable and supportable forecast period is determined based upon the accuracy level of historical loss forecast estimates, the specific loan level models and methodology utilized, and considers material changes in growth and credit strategy, and business changes which may not be applicable within the current environment. For periods beyond a reasonable and supportable forecast interval, the Company reverts to historical information over a period for which comparable data is available. The historical information either experienced by the Company, or by a selection of peer banks when appropriate, is derived from a combination of recessionary and non-recessionary performance periods for which data is available. Similar to the reasonable and supportable forecast period, the Company reassesses the reversion period at the segment level, considering any required adjustments for differences in underwriting standards, portfolio mix, and other relevant data shifts over time. The Company generally segments its loan receivable population into homogeneous pools of loans. Consistent with the Company’s other assumptions, the Company regularly reviews segmentation to determine whether the segmentation pools remain relevant as risk characteristics change. When a loan no longer meets the criteria of its initial pooling as a result of credit deterioration or other changes, the Company may evaluate the credit for estimated losses on an individual basis if it determines that they no longer retain the same risk characteristics. To the extent that there are a multitude of these loans with new similar credit characteristics, the Company would anticipate a change to the pooling methodology. Loans that do not share risk characteristics are evaluated on an individual basis and are also not included in the collective evaluation. For loans with real estate collateral, when management determines that foreclosure is probable, expected credit losses are based on the fair value of the collateral at the reporting date, adjusted for selling costs as appropriate. The Company evaluates the loan allowance for credit losses The underlying assumptions, estimates and assessments the Company uses to estimate the allowance for credit losses reflects the Company’s best estimate of model assumptions and forecasted conditions at that time. Changes in such estimates can significantly affect the allowance and provision for credit losses. It is possible and likely that the Company will experience credit losses that are different from the current estimates. Charge-offs are deducted from the allowance for credit losses when the Company considers the principal to be uncollectible, and subsequent recoveries are added to the allowance, generally at the time cash is received on a charged-off account. Allowance for Unfunded C ommitments The expected credit losses for unfunded commitments are measured over the contractual period of the Company’s exposure to credit risk. The estimate of credit loss incorporates assumptions for both the likelihood and amount of funding over the estimated life of the commitments, for the risk of loss, and current conditions and expectations. Management periodically reviews and updates its assumptions for estimated funding rates based on historical rates, and factors such as portfolio growth, changes to organizational structure, economic conditions, borrowing habits, or any other factor which could impact the likelihood that funding will occur. The Company does not reserve for unfunded commitments which are unconditionally cancellable. Acquired Loans Acquired loans are recorded at fair value at the date of acquisition based on a discounted cash flow methodology that considers various factors including the type of loan and related collateral, classification status, fixed or variable interest rate, term of loan and whether or not the loan was amortizing, and a discount rate reflecting the Company’s assessment of risk inherent in the cash flow estimates. Certain larger purchased loans are individually evaluated while certain purchased loans are grouped together according to similar risk characteristics and are treated in the aggregate when applying various valuation techniques. These cash flow evaluations are inherently subjective as they require material estimates, all of which may be susceptible to significant change. Starting January 1, 2020, loans acquired in a business combination that have experienced more-than-insignificant deterioration in credit quality since origination are considered purchased credit deteriorated (“PCD”) loans. The Company evaluated acquired loans for deterioration in credit quality based on, but not limited to, the following: (1) non-accrual status; (2) troubled debt restructured designation; (3) risk ratings of special mention, substandard or doubtful; (4) watchlist credits; and (5) delinquency status, including loans that are current on acquisition date, but had been previously delinquent. At the acquisition date, an estimate of expected credit losses is made for groups of PCD loans with similar risk characteristics and individual PCD loans without similar risk characteristics. This initial allowance for credit losses is allocated to individual PCD loans and added to the purchase price or acquisition date fair values to establish the initial amortized cost basis of the PCD loans. As the initial allowance for credit losses is added to the purchase price, there is no credit loss expense recognized upon acquisition of a PCD loan. Any difference between the unpaid principal balance of PCD loans and the amortized cost basis is considered to relate to noncredit factors and results in a discount or premium. Discounts and premiums are recognized through interest income on a level-yield method over the life of the loans. For acquired loans not deemed PCD at acquisition, the differences between the initial fair value and the unpaid principal balance are recognized as interest income on a level-yield basis over the lives of the related loans. At the acquisition date, an initial allowance for expected credit losses is estimated and recorded as credit loss expense. The subsequent measurement of expected credit losses for all acquired loans is the same as the subsequent measurement of expected credit losses for originated loans. See Note 8 – Loans and the Allowance for Credit Losses for a detailed discussion of the Company’s allowance for credit losses. See Note 2 - Basis of Presentation and Summary of Significant Accounting Policies

Cash and Cash Equivalents

Cash and Cash Equivalents	6 Months Ended
	Jun. 30, 2020
Cash And Cash Equivalents [Abstract]
Cash and Cash Equivalents	6 . Cash and cash equivalents At June 30, 2020 and December 31, 2019, cash and cash equivalents totaled $60.7 million and $61.3 million, respectively. There were no amounts required to be maintained at the Federal Reserve Bank of Boston (“FRB”) at June 30, 2020. At December 31, 2019, the Company maintained $31.5 million of cash and equivalents at the FRB Boston to satisfy reserve requirements. Additionally, at June 30, 2020 and December 31, 2019, respectively, 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 also pledged cash collateral to derivative counterparties totaling $37.4 million and $10.4 million at June 30, 2020 and December 31, 2019, respectively. See Note 18 - Derivatives and Hedging Activities .

Investment Securities

Investment Securities	6 Months Ended
	Jun. 30, 2020
Investments Debt And Equity Securities [Abstract]
Investment Securities	7 . 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, 2020 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (dollars in thousands) Available for sale securities U.S. GSE obligations $ 13,000 $ 734 $ — $ 13,734 $ 38,000 $ — $ (152 ) $ 37,848 Mortgage-backed securities 115,020 2,728 (9 ) 117,739 103,109 231 (858 ) 102,482 Corporate debt securities 2,741 15 (2 ) 2,754 — — — — Total available for sale securities $ 130,761 $ 3,477 $ (11 ) $ 134,227 $ 141,109 $ 231 $ (1,010 ) $ 140,330 Held to maturity securities U.S. GSE obligations $ — $ — $ — $ — $ 5,000 $ — $ — $ 5,000 Mortgage-backed securities 146,398 7,520 — 153,918 161,759 2,751 (111 ) 164,399 Corporate debt securities 6,984 263 — 7,247 6,980 116 — 7,096 Municipal securities 91,169 4,815 (28 ) 95,956 84,433 3,252 (66 ) 87,619 Total held to maturity securities $ 244,551 $ 12,598 $ (28 ) $ 257,121 $ 258,172 $ 6,119 $ (177 ) $ 264,114 Total $ 375,312 $ 16,075 $ (39 ) $ 391,348 $ 399,281 $ 6,350 $ (1,187 ) $ 404,444 All of the Company’s mortgage-backed securities have been issued by, or are collateralized by securities issued by, Government National Mortgage Association (GNMA), Federal National Mortgage Association (FNMA), or Federal Home Loan Mortgage Corporation (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, 2020 and temporarily impaired at December 31, 2019, aggregated by investment category and length of time that individual securities have been in a continuous loss position: June 30, 2020 Less than 12 months 12 months or longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (dollars in thousands) Available for sale securities Mortgage-backed securities $ — $ — $ 5,318 $ (9 ) $ 5,318 $ (9 ) Corporate debt securities 781 (2 ) — — 781 (2 ) Total available for sale securities $ 781 $ (2 ) $ 5,318 $ (9 ) $ 6,099 $ (11 ) Held to maturity securities Mortgage-backed securities $ — $ — $ — $ — $ — $ — Municipal securities 8,365 (28 ) — — 8,365 (28 ) Total held to maturity securities $ 8,365 $ (28 ) $ — $ — $ 8,365 $ (28 ) Total $ 9,146 $ (30 ) $ 5,318 $ (9 ) $ 14,464 $ (39 ) December 31, 2019 Less than 12 months 12 months or longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (dollars in thousands) Temporarily Impaired Securities Available for sale securities U.S. GSE obligations $ 12,912 $ (88 ) $ 24,936 $ (64 ) $ 37,848 $ (152 ) Mortgage-backed securities 33,381 (265 ) 50,766 (593 ) 84,147 (858 ) Corporate debt securities — — — — — — Total available for sale securities $ 46,293 $ (353 ) $ 75,702 $ (657 ) $ 121,995 $ (1,010 ) Held to maturity securities U.S. GSE obligations $ — $ — $ 5,000 $ — $ 5,000 $ — Mortgage-backed securities 14,838 (27 ) 12,928 (84 ) 27,766 (111 ) Corporate debt securities — — — — — — Municipal securities 4,934 (66 ) — — 4,934 (66 ) Total held to maturity securities $ 19,772 $ (93 ) $ 17,928 $ (84 ) $ 37,700 $ (177 ) Total temporarily impaired securities $ 66,065 $ (446 ) $ 93,630 $ (741 ) $ 159,695 $ (1,187 ) The Company adopted Topic 326 on January 1, 2020 and did not record an allowance for credit losses on its investment securities as of June 30, 2020. The Company regularly reviews debt securities for expected credit loss using both qualitative and quantitative criteria, as necessary based on the composition of the portfolio at period end. As of June 30, 2020, 24 debt securities had gross unrealized losses, with an aggregate depreciation of 0.26% from the Company’s amortized cost basis. The largest unrealized loss percentage and largest unrealized loss dollar amount of any single security was 0.97%, or $19,380, of its amortized cost. As of December 31, 2019, 68 debt securities had gross unrealized losses, with an aggregate depreciation of 0.74% from the Company’s amortized cost basis. The largest unrealized loss percentage of any single security was 3.15%, or $63,000 of its amortized cost. The largest unrealized dollar loss of any single security was $96,000, or 1.93%, of its amortized cost. The Company believes that the nature and duration of impairment 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) that 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, 2020 and December 31, 2019. The amortized cost and fair value of debt securities, aggregated by the earlier of guaranteed 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. Within One Year After One, But Within Five Years After Five, But Within Ten Years After Ten Years Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value At June 30, 2020 (dollars in thousands) Available for sale securities U.S. GSE obligations $ — $ — $ — $ — $ 5,000 $ 5,133 $ 8,000 $ 8,601 $ 13,000 $ 13,734 Mortgage-backed securities — — 975 978 35,702 37,157 78,343 79,604 115,020 117,739 Corporate debt securities 1,001 1,003 1,740 1,751 — — — — 2,741 2,754 Total available for sale securities $ 1,001 $ 1,003 $ 2,715 $ 2,729 $ 40,702 $ 42,290 $ 86,343 $ 88,205 $ 130,761 $ 134,227 Held to maturity securities U.S. GSE obligations $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Mortgage-backed securities — — 2 2 49,686 53,581 96,710 100,335 146,398 153,918 Corporate debt securities — — 6,984 7,247 — — — — 6,984 7,247 Municipal securities 1,878 1,893 15,379 15,916 47,944 51,111 25,968 27,036 91,169 95,956 Total held to maturity securities $ 1,878 $ 1,893 $ 22,365 $ 23,165 $ 97,630 $ 104,692 $ 122,678 $ 127,371 $ 244,551 $ 257,121 Total $ 2,879 $ 2,896 $ 25,080 $ 25,894 $ 138,332 $ 146,982 $ 209,021 $ 215,576 $ 375,312 $ 391,348 The following table sets forth information regarding sales of investment securities and the resulting gains (losses) from such sales: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (dollars in thousands) Amortized cost of securities sold $ 10,752 $ 10,231 $ 10,752 $ 26,231 Gross gains realized on securities sold 69 63 69 63 Gross losses realized on securities sold — (57 ) — (144 ) Net proceeds from securities sold $ 10,821 $ 10,237 $ 10,821 $ 26,150 The Company monitors the credit quality of certain debt securities through the use of credit rating among other factors on a quarterly basis. The following table summarizes the credit rating of the Company’s debt securities portfolio at June 30, 2020. June 30, 2020 Mortgage-backed Securities Corporate Debt Securities Municipal Securities U.S. GSE obligations Total (dollars in thousands) Available for sale securities, at fair value AAA/AA/A (1) $ 117,739 $ 1,784 $ — $ 13,734 $ 133,257 BBB/BB/B — 970 — — 970 Total available for sale securities $ 117,739 $ 2,754 $ — $ 13,734 $ 134,227 Held to maturity securities, at amortized cost AAA/AA/A $ 146,398 $ 6,984 $ 90,894 $ — $ 244,276 BBB/BB/B — — 275 — 275 Total held to maturity securities $ 146,398 $ 6,984 $ 91,169 $ — $ 244,551 (1) Includes Agency mortgage-backed pass-through securities and collateralized mortgage obligations issued by GSEs and U.S. government agencies, such as FNMA, FHLMC, and GNMA that are not rated by Moody’s or S&P. Each security contains a guarantee by the issuing 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, 2020
Receivables [Abstract]
Loans and the Allowance for Credit Losses	8 . LOANS AND THE ALLOWANCE FOR CREDIT LOSSES The Company’s lending activities are conducted primarily in Eastern Massachusetts and Southern New Hampshire. The Company grants single- and multi-family residential loans, commercial & industrial (“C&I”), commercial real estate (“CRE”), construction loans, and a variety of consumer loans. Most of the loans granted by the Company are secured by real estate collateral. Repayment of the Company’s residential loans are generally dependent on the health of the employment market in the borrowers’ geographic areas and that of the general economy with liquidation of the underlying real estate collateral being typically viewed as the primary source of repayment in the event of borrower default. The repayment of C&I loans depends primarily on the cash flow and credit worthiness of the borrower and secondarily on the underlying collateral provided by the borrower. As borrower cash flow may be difficult to predict, liquidation of the underlying collateral securing these loans is typically viewed as the primary source of repayment in the event of borrower default. However, collateral typically consists of equipment, inventory, accounts receivable, or other business assets that may fluctuate in value, so the liquidation of collateral in the event of default is often an insufficient source of repayment. The Company’s CRE loans are primarily made based on the cash flow from the collateral property and secondarily on the underlying collateral provided by the borrower, with liquidation of the underlying real estate collateral typically being viewed as the primary source of repayment in the event of borrower default. The Company’s construction loans are primarily made based on the borrower’s expected ability to execute and the future completed value of the collateral property, with sale of the underlying real estate collateral typically being viewed as the primary source of repayment. Loans outstanding are detailed by category as follows: June 30, 2020 December 31, 2019 (dollars in thousands) Residential mortgage Mortgages - fixed rate $ 535,633 $ 430,877 Mortgages - adjustable rate 775,475 467,139 Construction 37,366 17,374 Deferred costs net of unearned fees 2,834 2,176 Total residential mortgages 1,351,308 917,566 Commercial mortgage Mortgages - non-owner occupied 1,073,856 870,047 Mortgages - owner occupied 150,040 114,095 Construction 188,433 76,288 Deferred costs net of unearned fees 1,098 144 Total commercial mortgages 1,413,427 1,060,574 Home equity Home equity - lines of credit 110,014 73,880 Home equity - term loans 5,806 6,555 Deferred costs net of unearned fees 247 240 Total home equity 116,067 80,675 Commercial & industrial Commercial & industrial 418,455 133,337 Unearned fees, net of deferred costs (4,212 ) (101 ) Total commercial & industrial 414,243 133,236 Consumer Secured 36,941 33,453 Unsecured 877 1,199 Deferred costs net of unearned fees 21 25 Total consumer 37,839 34,677 Total loans $ 3,332,884 $ 2,226,728 Directors and officers of the Company and their associates are customers 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 nonaccrual loans. The Company also may use discretion regarding other loans over 90 days delinquent 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, 2020 . Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Total (dollars in thousands) Non-performing loans: Non-accrual loans $ 3,284 $ 4,752 $ 12 $ 52 $ 8,100 Loans past due >90 days, but still accruing 1,536 353 — — 1,889 Troubled debt restructurings 137 — — 125 262 Total $ 4,957 $ 5,105 $ 12 $ 177 $ 10,251 December 31, 2019 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Total (dollars in thousands) Non-performing loans: Non-accrual loans $ 1,298 $ 2,800 $ 12 $ 50 $ 4,160 Loans past due >90 days, but still accruing 527 486 — 251 1,264 Troubled debt restructurings 99 — — 128 227 Total $ 1,924 $ 3,286 $ 12 $ 429 $ 5,651 It is the Company’s policy to reverse any accrued interest when a loan is put on nonaccrual status, as such the Company did not record any interest income on nonaccrual loans during the three and six months ended June 30, 2020. Troubled Debt Restructurings (“TDRs”) Loans are considered restructured in a troubled debt restructuring when the Company has granted concessions to a borrower due to the borrower’s financial condition that it otherwise would not have considered. These concessions may include modifications of the terms of the debt such as deferral of payments, extension of maturity, reduction of principal balance, reduction of the stated interest rate other than normal market rate adjustments, or a combination of these concessions. Debt may be bifurcated with separate terms for each tranche of the restructured debt. Restructuring a loan in lieu of aggressively enforcing the collection of the loan may benefit the Company by increasing the ultimate probability of collection. Restructured loans are classified as accruing or non-accruing based on management’s assessment of the collectability of the loan. Loans which are already on nonaccrual status at the time of the restructuring generally remain on nonaccrual status for approximately six months or longer before management considers such loans for return to accruing status. Accruing restructured loans are placed into nonaccrual status if and when the borrower fails to comply with the restructured terms and management deems it unlikely that the borrower will return to a status of compliance in the near term. TDRs are individually evaluated for credit losses. There were no new TDRs during the three and six months ended June 30, 2020. At June 30, 2020, three loans were determined to be TDRs with a total carrying value of $262,000. There were no TDR defaults during the three and six months ended June 30, 2020. The allowance for credit losses includes a reserve for these TDRs of approximately $91,000 as of June 30, 2020. During the year ended December 31, 2019, the Company modified one loan with a carrying value of $128,000. December 31, 2019, three loans were determined to be TDRs with a total carrying value of $227,000. There were no TDR defaults during the year ended December 31, 2019. The allowance for loan losses includes a specific reserve for these TDRs of approximately $87,000 as of December 31, 2019. As of June 30, 2020 and December 31, 2019, there were no significant commitments to lend additional funds to borrowers whose loans were restructured. In response to the national pandemic (“COVID-19”) and its economic impact to customers, a short-term modification program that complies with the Coronavirus Aid, Relief, and Economic Security (“CARES”) Act was implemented to provide temporary payment relief to those borrowers directly impacted by COVID-19. The deferred payments along with interest accrued during the deferral period are due and payable on the maturity date. Under recently issued guidance, provided these loans were current as of either year end or the date of the modification, these loans are not considered TDR loans at June 30, 2020 June 30, 2020, the Company had $174.6 million of loans in deferral. Purchased Credit Deteriorated Loans As part of the Wellesley merger, the Company has purchased loans, for which there was, at acquisition, evidence of more than insignificant deterioration of credit quality since origination. The carrying amount of those loans was $19.4 million at June 30, 2020 . Under Topic 326, when loans are purchased with evidence of more than insignificant deterioration of credit, they are accounted for as PCD loans. PCD loans acquired in a transaction are marked to fair value through goodwill and a mark on yield is recorded. These loans are assessed on a regular basis and subsequent adjustments to the ACL are recorded on the statement of income(loss). On June 1, 2020, the Company acquired PCD loans with a fair value of $18.6 million and total discount of $825,000. In connection with Topic 326, the fair value mark was reduced by $438,000, which represents the ACL amount recorded in connection with the merger with Wellesley. The outstanding balance at June 30, 2020 and related allowance on PCD loans is as follows: Loan Balance ACL Balance (dollars in thousands) Residential Mortgages $ 1,106 $ 35 Commercial Mortgages 16,850 380 Home Equity 112 — Commercial & Industrial 1,318 19 Total $ 19,386 $ 434 Loans 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, 2020 2020 2019 2018 2017 2016 Prior Revolving loans amortized cost basis Total (in thousands) Residential: Current $ 198,574 $ 273,846 $ 220,751 $ 191,361 $ 125,926 $ 335,893 $ — $ 1,346,351 Non-performing — — 1,326 1,595 107 1,929 — 4,957 Total 198,574 273,846 222,077 192,956 126,033 337,822 — 1,351,308 Home equity: Current $ 2,455 $ 7,323 $ 11,597 $ 7,443 $ 2,564 $ 8,780 $ 75,893 $ 116,055 Non-performing — — — — — — 12 12 Total $ 2,455 $ 7,323 $ 11,597 $ 7,443 $ 2,564 $ 8,780 $ 75,905 $ 116,067 Consumer: Current $ 8,210 $ 9,443 $ 3,012 $ 3,042 $ 4,998 $ 8,558 $ 576 $ 37,839 Non-performing — — — — — — — — Total $ 8,210 $ 9,443 $ 3,012 $ 3,042 $ 4,998 $ 8,558 $ 576 $ 37,839 Credit Quality Indicator - by Origination Year as of June 30, 2020 2020 2019 2018 2017 2016 Prior Revolving loans amortized cost basis Revolving loans converted to term Total (in thousands) Commercial: Credit risk profile by internally assigned grade: 1-6 (Pass) $ 151,422 $ 424,598 $ 252,673 $ 128,003 $ 153,142 $ 288,586 $ — $ — $ 1,398,424 7 (Special Mention) — 161 581 1,643 88 10,048 — — 12,521 8 (Substandard) — 741 — — 220 847 — — 1,808 9 (Doubtful) — — — — — 674 — — 674 10 (Loss) — — — — — — — — — Total $ 151,422 $ 425,500 $ 253,254 $ 129,646 $ 153,450 $ 300,155 $ — $ — $ 1,413,427 Commercial & Industrial: Credit risk profile by internally assigned grade: 1-6 (Pass) $ 213,211 $ 60,282 $ 65,278 $ 21,345 $ 17,442 $ 14,100 $ 14,776 $ — $ 406,434 7 (Special Mention) 439 421 468 490 72 243 20 — 2,153 8 (Substandard) — 1,393 336 — 3,256 183 488 — 5,656 9 (Doubtful) — — — — — — — — — 10 (Loss) — — — — — — — — — Total $ 213,650 $ 62,096 $ 66,082 $ 21,835 $ 20,770 $ 14,526 $ 15,284 $ — $ 414,243 December 31, 2019 Residential Mortgages Home Equity Consumer (dollars in thousands) Credit risk profile based on payment activity: Performing $ 915,642 $ 80,663 $ 34,677 Non-performing 1,924 12 — Total $ 917,566 $ 80,675 $ 34,677 Commercial Mortgages Commercial & Industrial Credit risk profile by internally assigned grade: 1-6 (Pass) $ 1,050,037 $ 123,900 7 (Special Mention) 7,360 4,289 8 (Substandard) 3,177 5,047 9 (Doubtful) — — 10 (Loss) — — Total $ 1,060,574 $ 133,236 With respect to residential real estate 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 have are on non-accrual, or are past due more than 90 days but are still accruing, or are restructured. These loans may contain greater than average risk. With respect to commercial real estate mortgages and commercial 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 customer. • 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. 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, 2020 30-59 Days 60-89 Days 90 Days or greater Total Past Due Current Loans Total Amortized Cost 90+ Days and Accruing (dollars in thousands) Residential Mortgages $ 4,061 $ 1,307 $ 3,337 $ 8,705 $ 1,342,603 $ 1,351,308 $ 1,536 Commercial Mortgages 718 — 3,976 4,694 1,408,733 1,413,427 353 Home Equity 12 269 — 281 115,786 116,067 — Commercial & Industrial 218 831 125 1,174 413,069 414,243 — Consumer loans 3 — — 3 37,836 37,839 — Total $ 5,012 $ 2,407 $ 7,438 $ 14,857 $ 3,318,027 $ 3,332,884 $ 1,889 December 31, 2019 30-59 Days Past Due 60-89 Days Past Due 90 Days or Greater Total Past Due Current Loans Total (dollars in thousands) Residential Mortgages $ 8,710 $ 1,089 $ 1,047 $ 10,846 $ 906,720 $ 917,566 Commercial Mortgages 811 — 3,161 3,972 1,056,602 1,060,574 Home Equity 57 12 — 69 80,606 80,675 Commercial & Industrial 272 226 251 749 132,487 133,236 Consumer loans 4 5 — 9 34,668 34,677 Total $ 9,854 $ 1,332 $ 4,459 $ 15,645 $ 2,211,083 $ 2,226,728 There were no significant commitments to lend additional funds to borrowers whose loans were on nonaccrual status at June 30, 2020 and December 31, 2019. Other Real Estate Owned (“OREO”) As of June 30, 2020 and December 31, 2019, the Company recorded other real estate owned assets of $2.0 million and $163,000, respectively. OREO consists of real estate properties, which have primarily served as collateral to secure loans that are controlled or owned by the Bank. These properties are recorded at fair value less estimated costs to sell at the date control is established, resulting in a new cost basis. The amount by which the recorded investment in the loan exceeds the fair value (net of estimated costs to sell) of the foreclosed asset is charged to the allowance for credit losses. Subsequent declines in the fair value of the foreclosed asset below the new cost basis are recorded through the use of a valuation allowance. Subsequent increases in the fair value are recorded as reductions in the valuation allowance, but not below zero. All costs incurred thereafter in maintaining the property are generally charged to noninterest expense. Foreclosure Proceedings As of June 30, 2020 and December 31, 2019, one loan secured by one- to four-family residential property amounting to $339,000 was in process of foreclosure. The foreclosure proceedings for the aforementioned loan are on hold due to the COVID-19 pandemic and bankruptcy proceedings. Allowance for Credit Losses The following table presents changes in the allowance for credit losses disaggregated by loan category: For the Three Months Ended June 30, 2020 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan portfolio: Balance at March 31, 2020 $ 7,477 $ 10,881 $ 310 $ 946 $ 549 $ — $ 20,163 Provision for acquired loans 2,880 3,625 188 1,577 12 — 8,282 Initial allowance for PCD 35 382 — 20 — — 437 Charge-offs — (77 ) — (65 ) (16 ) — (158 ) Recoveries — — — 22 1 — 23 Provision for (Release of)-loan portfolio 1,488 3,256 154 439 (70 ) — 5,267 Allowance for credit losses - loan portfolio $ 11,880 $ 18,067 $ 652 $ 2,939 $ 476 $ — $ 34,014 Allowance for credit losses - unfunded commitments: Balance at March 31, 2020 $ — $ — $ — $ — $ — $ 283 $ 283 Acquired loan commitments — — — — — 356 356 Provision for - unfunded commitments — — — — — 525 525 Allowance for credit losses- unfunded commitments — — — — — 1,164 1,164 Total allowance for credit loss $ 11,880 $ 18,067 $ 652 $ 2,939 $ 476 $ 1,164 $ 35,178 For the Six Months Ended June 30, 2020 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan portfolio: Balance at December 31, 2019 $ 5,141 $ 10,905 $ 461 $ 1,475 $ 198 $ — $ 18,180 Adoption of ASC 326 2,061 (1,447 ) (205 ) (492 ) 288 — 205 Provision of acquired loans 2,880 3,625 188 1,577 12 — 8,282 Initial allowance for PCD 35 382 — 20 — — 437 Charge-offs — (264 ) — (154 ) (30 ) — (448 ) Recoveries — — — 34 14 — 48 Provision for (Release of)-loan portfolio 1,763 4,866 208 479 (6 ) — 7,310 Allowance for credit losses - loan portfolio $ 11,880 $ 18,067 $ 652 $ 2,939 $ 476 $ — $ 34,014 Allowance for credit losses - unfunded commitments: Balance at December 31, 2019 $ — $ — $ — $ — $ — $ 50 $ 50 Adoption of ASC 326 — — — — — 276 276 Acquired loan commitments — — — — — 356 356 Provision for - unfunded commitments — — — — — 482 482 Allowance for credit losses-unfunded commitments — — — — — 1,164 1,164 Total allowance for credit loss $ 11,880 $ 18,067 $ 652 $ 2,939 $ 476 $ 1,164 $ 35,178 The following table presents change in the allowance for loan losses disaggregated by loan category: For the Three Months Ended June 30, 2019 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Total (dollars in thousands) Allowance for loan losses: Balance at March 31, 2019 $ 5,256 $ 9,369 $ 534 $ 1,245 $ 248 $ 16,652 Charge-offs — (55 ) — (100 ) (9 ) (164 ) Recoveries — — — 12 4 16 Provision for (Release of) 207 115 (3 ) 288 (12 ) 595 Balance at June 30, 2019 $ 5,463 $ 9,429 $ 531 $ 1,445 $ 231 $ 17,099 For the Six Months Ended June 30, 2019 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Total (dollars in thousands) Allowance for loan losses: Balance at December 31, 2018 $ 4,946 $ 9,626 $ 517 $ 1,415 $ 264 $ 16,768 Charge-offs — (55 ) — (130 ) (20 ) (205 ) Recoveries — — — 25 8 33 Provision for (Release of) 517 (142 ) 14 135 (21 ) 503 Balance at June 30, 2019 $ 5,463 $ 9,429 $ 531 $ 1,445 $ 231 $ 17,099 The following is information pertaining to impaired loans: December 31, 2019 Carrying Value Average Carrying Value Unpaid Principal Balance Related Allowance Interest Income Recognized (dollars in thousands) With no required reserve recorded: Commercial mortgage $ 3,161 $ 1,385 $ 4,376 $ — $ 35 Residential mortgage 765 691 940 — 5 Home equity 93 96 133 — 1 Total $ 4,019 $ 2,172 $ 5,449 $ — $ 41 With required reserve recorded: Commercial and industrial $ 128 $ 59 $ 167 $ 87 $ — Total $ 128 $ 59 $ 167 $ 87 $ — Total: Commercial and industrial $ 128 $ 59 $ 167 $ 87 $ — Commercial mortgage 3,161 1,385 4,376 — 35 Residential mortgage 765 691 940 — 5 Home equity 93 96 133 — 1 Total $ 4,147 $ 2,231 $ 5,616 $ 87 $ 41 The following tables contain period-end balances of the allowance for loan losses and related loans receivable disaggregated by impairment method: December 31, 2019 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Total (dollars in thousands) Allowance for loan losses Individually evaluated for impairment $ — $ — $ — $ 87 $ — $ 87 Collectively evaluated for impairment 5,141 10,905 461 1,388 198 18,093 Total $ 5,141 $ 10,905 $ 461 $ 1,475 $ 198 $ 18,180 Loans receivable Individually evaluated for impairment $ 764 $ 3,161 $ 92 $ 128 $ — $ 4,145 Collectively evaluated for impairment 916,802 1,057,413 80,583 133,108 34,677 2,222,583 Total $ 917,566 $ 1,060,574 $ 80,675 $ 133,236 $ 34,677 $ 2,226,728

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 30, 2020
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	9 . GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill. As of June 30, 2020 and December 31, 2019, the carrying value of goodwill totaled $51.9 million and $31.2 million, respectively. Goodwill is tested for impairment, based on its fair value, at least annually. As of June 30, 2020 and December 31, 2019, no goodwill impairment has been recognized. Core deposit intangibles. In connection with the Optima merger, the Company recorded an asset for core deposit intangibles (“CDI”) of $3.6 million. Amortization of CDI totaled $90,000 and $180,000 for the three and six months ended June 30, 2020, respectively. For both the three and six months ended June 30, 2019, amortization of CDI totaled $90,000. As of June 30, 2020 and December 31, 2019, the carrying value of CDI assets totaled $3.2 million and $3.3 million, respectively. The weighted-average remaining amortization period for CDI was approximately nine years at June 30, 2020. Mortgage servicing rights. Periodically, the Company sells certain residential mortgage loans to the secondary market. Generally, these loans are sold without recourse or other credit enhancements. As of June 30, 2020 and December 31, 2019, loans held for sale totaled $2.6 million and $1.6 million, respectively. The Company either releases or retains the servicing rights on sold loans. For loans sold with servicing rights retained, the Company provides the servicing for the loans on a per-loan fee basis. Mortgage loans sold with servicing rights retained during the six months ended June 30, 2020 and June 30, 2019 were $9.5 million and $867,000, respectively. Total gain on loans sold for the three months ending June 30, 2020 and June 30, 2019 was $193,000 and $15,000, respectively. Total gain on loans sold for the six months ended June 30, 2020 and June 30, 2019 was $312,000 and $31,000, respectively. An analysis of mortgage servicing rights, which are included in other assets, follows: Mortgage Servicing Rights Valuation Allowance Total (dollars in thousands) Balance at December 31, 2018 $ 666 $ — $ 666 Mortgage servicing rights acquired as a result of the merger 334 334 Mortgage servicing rights capitalized 7 — 7 Amortization charged against servicing income (106 ) — (106 ) Change in impairment reserve — (10 ) (10 ) Balance at June 30, 2019 $ 901 $ (10 ) $ 891 Balance at December 31, 2019 $ 1,347 $ (26 ) $ 1,321 Mortgage servicing rights acquired as a result of the merger 50 — 50 Mortgage servicing rights capitalized 90 — 90 Amortization charged against servicing income (244 ) — (244 ) Change in impairment reserve — (97 ) (97 ) Balance at June 30, 2020 $ 1,243 $ (123 ) $ 1,120 The fair value of our mortgage servicing rights (“MSR”) portfolio was $1.1 million as of June 30, 2020 and June 30, 2019. The fair value of mortgage servicing rights is estimated based on the present value of expected cash flows, incorporating assumptions for discount rate, prepayment speed, and servicing cost. The weighted average amortization period for the mortgage servicing rights portfolio was 3.5 years and 5.2 years at June 30, 2020 and December 31, 2019, respectively. The estimated aggregate future amortization expense for mortgage servicing rights for each of the next five years and thereafter is as follows: Future Amortization Expense (dollars in thousands) Remainder of 2020 $ 169 2021 282 2022 213 2023 158 2024 117 2025 23 Thereafter 281 Total $ 1,243

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	10 . Income Taxes The Company’s effective tax rate was 23.9% and 21.6% for the three and six months ended June 30, 2020, as compared to 26.5% and 23.9% for the three and six months ended June 30, 2019. Net deferred tax assets totaled $11.9 million at June 30, 2020 and $8.2 million at December 31, 2019. The Company did not record a valuation allowance for deferred tax assets at June 30, 2020 or December 31, 2019. The components of income tax expense were as follows: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (dollars in thousands) Current income tax expense Federal $ 2,598 $ 1,305 $ 2,120 $ 1,676 State 1,186 552 1,460 719 Total current income tax expense 3,784 1,857 3,580 2,395 Deferred income tax expense / (benefit) Federal (2,956 ) (217 ) (1,356 ) 601 State (1,368 ) (100 ) (703 ) 284 Total deferred income tax expense / (benefit) (4,324 ) (317 ) (2,059 ) 885 Total income tax expense / (benefit) $ (540 ) $ 1,540 $ 1,521 $ 3,280

Pension and Retirement Plans

Pension and Retirement Plans	6 Months Ended
	Jun. 30, 2020
Compensation And Retirement Disclosure [Abstract]
Pension and Retirement Plans	11 . Pension and Retirement Plans The components of net periodic benefit cost (credit) were as follows: Three Months Ended June 30, Pension Plan Supplemental Retirement Plan Retirement Healthcare Plan 2020 2019 2020 2019 2020 2019 (dollars in thousands) Net periodic benefit cost (credit) Service cost $ — $ — $ 106 $ 75 $ 10 $ 5 Interest cost 297 414 55 85 5 6 Expected return on assets (921 ) (651 ) — — — — Amortization of prior service credit (1 ) (1 ) — — — — Amortization of net actuarial (gain) loss (39 ) 77 4 — 1 (1 ) Net periodic benefit cost (credit) $ (664 ) $ (161 ) $ 165 $ 160 $ 16 $ 10 Six Months Ended June 30, Pension Plan Supplemental Retirement Plan Retirement Healthcare Plan 2020 2019 2020 2019 2020 2019 (dollars in thousands) Net periodic benefit cost (credit) Service cost $ — $ — $ 177 $ 143 $ 16 $ 10 Interest cost 717 840 142 175 11 12 Expected return on assets (1,600 ) (1,360 ) — — — — Amortization of prior service credit (2 ) (2 ) — — — — Amortization of net actuarial (gain) loss — 77 4 — — (2 ) Net periodic benefit cost (credit) $ (885 ) $ (445 ) $ 323 $ 318 $ 27 $ 20 The Company made no contributions to the qualified defined benefit pension plan during the three and six months ended June 30, 2020 and 2019. The Company does not expect to make any contributions to the qualified defined benefit plan during the remainder of 2020. 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. Effective in 2019, 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 in the ESOP on January 1 or July 1 following the completion of 12 months of service consisting of at least 1,000 hours and upon the attainment of age 21. Purchases of the Company’s 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, 2020 and June 30, 2019 amounted to $892,000 and $552,000, respectively. Total expenses related to the PSP and the ESOP for the six months ended June 30, 2020 and June 30, 2019 amounted to $1.9 million and $1.1 million, respectively. Defined Contribution Supplemental Executive Retirement Plan (“DC SERP”) For executives participating in the DC SERP, the Company made a discretionary contribution of 10% of each executive’s base salary and bonus to his or her account under the Company’s DC SERP, the Executive Deferred Compensation Plan. Total expenses related to the DC SERP for the three months ended June 30, 2020 and June 30, 2019 amounted to $52,000 and $43,000, respectively. Total expenses related to the DC SERP for the six months ended June 30, 2020 and June 30, 2019 amounted to $95,000 and $86,000, respectively.

Stock Based Compensation

Stock Based Compensation	6 Months Ended
	Jun. 30, 2020
Share Based Compensation [Abstract]
Stock Based Compensation	1 2 . STOCK BASED COMPENSATION The following table presents the pre-tax expense associated with all outstanding non-vested RSAs, RSUs, PRSUs, and the related tax benefits recognized: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (dollars in thousands) Stock based compensation expense $ 1,331 $ 699 $ 2,311 $ 1,318 Related tax benefits $ 372 $ 197 $ 645 $ 370

Financial Instruments with Off-

Financial Instruments with Off-Balance-Sheet Risk	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Financial Instruments with Off-balance-Sheet Risk	1 3 . Financial Instruments with Off-Balance-Sheet Risk To meet the financing needs of its customers, 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 mortgage loans, derivatives contracts, risk participation agreements, 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. See Note 18 – Derivatives and Hedging Activities 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 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, 2020 December 31, 2019 (dollars in thousands) Financial instruments whose contractual amount represents credit risk: Commitments to extend credit: Unused portion of existing lines of credit $ 571,113 $ 428,020 Origination of new loans 70,207 24,413 Standby letters of credit 9,060 9,150 Financial instruments whose notional amount exceeds the amount of credit risk: Commitments to sell residential mortgage loans 25,253 3,909

Leases

Leases	6 Months Ended
	Jun. 30, 2020
Leases [Abstract]
Leases	1 4 . 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 2020 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, Six Months Ended June 30, 2020 2020 (dollars in thousands) Operating lease cost $ 1,598 $ 2,995 Variable lease cost (Cost excluded from lease payments) 1 1 Sublease income (16 ) (33 ) Total Operating Lease Cost $ 1,582 $ 2,963 Other Information Cash paid for amounts included in the measurement of lease liabilities - operating cash flows for operating leases $ 1,560 $ 2,924 Operating Lease - Operating cash flows (Liability reduction) 1,278 2,360 Weighted average lease term - operating leases 7.26 Years 7.26 Years Weighted average discount rate - operating leases 2.95 % 2.95 % Three Months Ended June 30, Six Months Ended June 30, 2019 2019 (dollars in thousands) Operating lease cost $ 1,321 $ 2,501 Variable lease cost (Cost excluded from lease payments) — — Sublease income (16 ) (32 ) Total Operating Lease Cost $ 1,305 $ 2,469 Other Information Cash paid for amounts included in the measurement of lease liabilities - operating cash flows for operating leases $ 1,231 $ 2,308 Operating Lease - Operating cash flows (Liability reduction) 937 1,744 Right-of-use assets obtained in exchange for new operating lease liabilities 4,656 4,656 Weighted average lease term - operating leases 8.56 Years 8.56 Years Weighted average discount rate - operating leases 3.38 % 3.38 % The total minimum lease payments due in future periods for lease agreements in effect at June 30, 2020 were as follows: Future Minimum Lease Payments (dollars in thousands) Remainder of 2020 $ 7,257 2021 7,005 2022 6,590 2023 6,115 2024 4,790 Thereafter 13,547 Total minimum lease payments 45,304 Less: interest (4,851 ) Total lease liability $ 40,453 The Company recorded additional right-of-use assets of $5.3 million during the second quarter of 2020 associated with leases acquired from the merger with Wellesley. 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 $1.5 million and $1.4 million for the quarter ended June 30, 2020 and June 30, 2019, respectively. Total rental expense was $3.0 million and $2.7 million for the six months ended June 30, 2020 and June 30, 2019, respectively.

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Shareholders' Equity	1 5 . Shareholders’ Equity As of June 30, 2020 and December 31, 2019, the Company and the Bank met all applicable minimum capital requirements and were considered “well-capitalized” by both the Federal Reserve Board and the Federal Deposit Insurance Corporation. The Company adopted ASU 2016-13 on January 1, 2020. The joint federal bank regulatory agencies issued an interim final rule that allows banking organizations to mitigate the effects of the CECL accounting standard in their regulatory capital. Banking organizations that are required under U.S. accounting standards to adopt CECL this year can elect to mitigate the estimated cumulative regulatory capital effects of CECL for up to two years, after which, the effects will be phased-in over a three-year Actual Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At June 30, 2020 Cambridge Bancorp: Total capital (to risk-weighted assets) $ 367,800 13.0 % $ 297,382 10.5 % N/A N/A Tier I capital (to risk-weighted assets) 322,702 11.4 % 240,738 8.5 % N/A N/A Common equity tier I capital (to risk-weighted assets) 322,702 11.4 % 198,255 7.0 % N/A N/A Tier I capital (to average assets) 322,702 10.0 % 129,195 4.0 % N/A N/A Cambridge Trust Company: Total capital (to risk-weighted assets) $ 359,380 12.7 % $ 297,356 10.5 % $ 283,196 10.0 % Tier I capital (to risk-weighted assets) 324,202 11.4 % 240,717 8.5 % 226,557 8.0 % Common equity tier I capital (to risk-weighted assets) 324,202 11.4 % 198,237 7.0 % 184,077 6.5 % Tier I capital (to average assets) 324,202 10.0 % 129,192 4.0 % 161,490 5.0 % Actual Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At December 31, 2019 Cambridge Bancorp: Total capital (to risk-weighted assets) $ 272,727 13.6 % $ 210,342 10.5 % N/A N/A Tier I capital (to risk-weighted assets) 254,497 12.7 % 170,277 8.5 % N/A N/A Common equity tier I capital (to risk-weighted assets) 254,497 12.7 % 140,228 7.0 % N/A N/A Tier I capital (to average assets) 254,497 9.0 % 113,365 4.0 % N/A N/A Cambridge Trust Company: Total capital (to risk-weighted assets) $ 271,034 13.5 % $ 210,341 10.5 % $ 200,325 10.0 % Tier I capital (to risk-weighted assets) 252,804 12.6 % 170,276 8.5 % 160,260 8.0 % Common equity tier I capital (to risk-weighted assets) 252,804 12.6 % 140,227 7.0 % 130,211 6.5 % Tier I capital (to average assets) 252,804 8.9 % 113,364 4.0 % 141,705 5.0 %

Other Comprehensive Income

Other Comprehensive Income	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Other Comprehensive Income	1 6 . Other Comprehensive Income The following table presents the changes in accumulated other comprehensive income (loss) (“AOCI”) during the period, by component, net of tax: Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Before Tax Amount Tax (Expense) or Benefit Net-of-tax Amount Before Tax Amount Tax (Expense) or Benefit Net-of-tax Amount (dollars in thousands) Unrealized gains/(losses) on available for sale securities Unrealized holding gains/(losses) $ 1,077 $ (267 ) $ 810 $ 1,909 $ (456 ) $ 1,453 Reclassification adjustment for (gains)/losses recognized in net income (73 ) 16 (57 ) (6 ) 2 (4 ) Derivatives Change in interest rate contracts 374 (104 ) 270 1,696 (477 ) 1,219 Defined benefit retirement plans Change in retirement liability (1 ) 1 — 36 (10 ) 26 Total Other Comprehensive Income/(Loss) $ 1,377 $ (354 ) $ 1,023 $ 3,635 $ (941 ) $ 2,694 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Before Tax Amount Tax (Expense) or Benefit Net-of-tax Amount Before Tax Amount Tax Expense Net-of-tax Amount (dollars in thousands) Unrealized gains/(losses) on available for sale securities Unrealized holding gains/(losses) $ 4,318 $ (1,008 ) $ 3,310 $ 3,334 $ (786 ) $ 2,548 Reclassification adjustment for (gains)/losses recognized in net income (73 ) 16 (57 ) 81 (19 ) 62 Derivatives Change in interest rate contracts 6,260 (1,744 ) 4,516 1,654 (465 ) 1,189 Defined benefit retirement plans Change in retirement liability (2 ) 1 (1 ) 72 (20 ) 52 Total Other Comprehensive Income/(Loss) $ 10,503 $ (2,735 ) $ 7,768 $ 5,141 $ (1,290 ) $ 3,851 Reclassifications out of AOCI that have an impact on net income (loss) are presented below: Three Months Ended June 30, Details about Accumulated Other Comprehensive Income Components 2020 2019 Affected Line Item in the Statement where Net Income (Loss) is Presented (dollars in thousands) Unrealized gains on available for sale securities $ 73 $ 6 Gain on disposition of investment securities Tax expense (16 ) (2 ) Provision for income taxes Net of tax $ 57 $ 4 Net income (loss) Six Months Ended June 30, Details about Accumulated Other Comprehensive Income Components 2020 2019 Affected Line Item in the Statement where Net Income (Loss) is Presented (dollars in thousands) Unrealized gains (losses) on available for sale securities $ 73 $ (81 ) Gain (Loss) on disposition of investment securities Tax benefit (expense) (16 ) 19 Provision for income taxes Net of tax $ 57 $ (62 ) Net income

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share	1 7 . 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, 2020 2019 2020 2019 (dollars in thousands, except per share data) Earnings per common share - basic: Numerator: Net (loss) income $ (1,716 ) $ 4,272 $ 5,516 $ 10,470 Less dividends and undistributed earnings allocated to participating securities 1 (35 ) (10 ) (94 ) Net (loss) income applicable to common shareholders $ (1,715 ) $ 4,237 $ 5,506 $ 10,376 Denominator: Weighted average common shares outstanding 5,913 4,682 5,653 4,379 (Loss) Earnings per common share – basic $ (0.29 ) $ 0.91 $ 0.97 $ 2.37 Earnings per common share - diluted: Numerator: Net (loss) income $ (1,716 ) $ 4,272 $ 5,516 $ 10,470 Less dividends and undistributed earnings allocated to participating securities — (35 ) (9 ) (94 ) Net (loss) income applicable to common shareholders $ (1,716 ) $ 4,237 $ 5,507 $ 10,376 Denominator: Weighted average common shares outstanding 5,913 4,682 5,653 4,379 Dilutive effect of common stock equivalents — 34 17 33 Weighted average diluted common shares outstanding 5,913 4,716 5,670 4,412 (Loss) Earnings per common share – diluted $ (0.29 ) $ 0.90 $ 0.97 $ 2.35

Derivatives And Hedging Activit

Derivatives And Hedging Activities	6 Months Ended
	Jun. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivatives And Hedging Activities	1 8 . DerivativeS 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 customers. 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 accumulated other comprehensive income (loss) 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 accumulated other comprehensive income (loss) related to derivatives will be reclassified to interest income as interest payments are received on the Company’s variable-rate assets. Non-designated Hedges Derivatives not designated as hedges are not speculative and result from a service the Company provides to certain customers. For the Company’s customers, 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 client’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 other 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 with a corresponding offset within other assets or other liabilities. 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, 2020 Derivative Assets Derivative Liabilities Notional Amount Balance Sheet Location Fair Value Notional Amount Balance Sheet Location Fair Value (dollars in thousands) (dollars in thousands) Derivatives designated as hedging instruments Interest rate contracts 150,000 Other Assets $ 9,074 $ — Other Liabilities $ — Total derivatives designated as hedging instruments $ 9,074 $ — Derivatives not designated as hedging instruments Loan related derivative contracts Interest rate swaps with customers 399,354 Other Assets $ 46,576 — Other Liabilities $ — Mirror swaps with counterparties — Other Assets — 399,354 Other Liabilities 46,576 Risk participation agreements-out to counterparties 26,580 Other Assets 82 — Other Liabilities — Risk participation agreements-in with counterparties — Other Assets — 113,676 Other Liabilities 674 Total derivatives not designated as hedging instruments $ 46,658 $ 47,250 December 31, 2019 Derivative Assets Derivative Liabilities Notional Amount Balance Sheet Location Fair Value Notional Amount Balance Sheet Location Fair Value (dollars in thousands) (dollars in thousands) Derivatives designated as hedging instruments Interest rate contracts 150,000 Other Assets $ 2,911 $ — Other Liabilities $ — Total derivatives designated as hedging instruments $ 2,911 $ — Derivatives not designated as hedging instruments Loan related derivative contracts Interest rate swaps with customers 241,187 Other Assets $ 12,980 $ — Other Liabilities $ — Mirror swaps with counterparties — Other Assets — 241,187 Other Liabilities 12,980 Risk participation agreements-out to counterparties 19,000 Other Assets 21 — Other Liabilities — Risk participation agreements-in with counterparties — Other Assets — 88,489 Other Liabilities 250 Total derivatives not designated as hedging instruments $ 13,001 $ 13,230 The following tables present the effect of cash flow hedge accounting on AOCI for the periods presented: 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) Recognized in OCI - Included Component Amount of Gain or (Loss) Recognized in OCI - Excluded Component For the Three Months Ended June 30, 2020 For the Three Months Ended June 30, 2020 (dollars in thousands) (dollars in thousands) Interest rate contracts $ 374 $ 413 $ (39 ) Interest Income $ 503 $ 542 $ (39 ) 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 For the Six Months Ended June 30, 2020 For the Six Months Ended June 30, 2020 (dollars in thousands) (dollars in thousands) Interest rate contracts $ 6,260 $ 7,047 $ (787 ) Interest Income $ 615 $ 703 $ (88 ) 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) Recognized in OCI - Included Component Amount of Gain or (Loss) Recognized in OCI - Excluded Component For the Three Months Ended June 30, 2019 For the Three Months Ended June 30, 2019 (dollars in thousands) (dollars in thousands) Interest rate contracts $ 1,647 $ 2,080 $ (433 ) Interest Income $ (48 ) $ — $ (48 ) 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) Recognized in OCI - Included Component Amount of Gain or (Loss) Recognized in OCI - Excluded Component For the Six Months Ended June 30, 2019 For the Six Months Ended June 30, 2019 (dollars in thousands) (dollars in thousands) Interest rate contracts $ 1,558 $ 2,080 $ (522 ) Interest Income $ (96 ) $ — $ (96 ) The Company estimates that an additional $2.5 million will be reclassified out of AOCI into earnings, as a reduction to interest income over the next twelve months. The following table presents the effect of the Company’s derivative financial instruments on the Consolidated Statements of Income (Loss) for the periods presented: Three Months Ended June 30, 2020 Six Months Ended June 30, 2020 Interest Income Interest Income (dollars in thousands) (dollars in thousands) Total amount of income presented in the statements of income (loss) statement in which the effects of cash flow hedges are recorded $ 503 $ 615 Gain or (loss) on cash flow hedging relationships in Subtopic 815-20 Interest rate contracts: Amount of gain reclassed from AOCI into income $ 503 $ 615 Amount of gain reclassed from AOCI into income - Included Component 542 703 Amount of loss reclassed from AOCI into income - Excluded Component $ (39 ) $ (88 ) Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Interest Income Interest Income (dollars in thousands) (dollars in thousands) Total amount of income presented in the statements of income (loss) statement in which the effects of cash flow hedges are recorded $ (48 ) $ (96 ) Gain or (loss) on cash flow hedging relationships in Subtopic 815-20 Interest rate contracts: Amount of loss reclassed from AOCI into income $ (48 ) $ (96 ) Amount of loss reclassed from AOCI into income - Included Component — — Amount of loss reclassed from AOCI into income - Excluded Component $ (48 ) $ (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 (Loss) as of the periods presented: Amount of Gain or (Loss) on Derivatives Recognized in Income Three Months Ended June 30, Three Months Ended June 30, 2020 2019 Location of Gain or (Loss) (dollars in thousands) Other contracts Other income $ 152 $ (61 ) Total $ 152 $ (61 ) Amount of Gain or (Loss) on Derivatives Recognized in Income Six Months Ended June 30, Six Months Ended June 30, 2020 2019 Location of Gain or (Loss) (dollars in thousands) Other contracts Other income $ 330 $ 13 Total $ 330 $ 13 Credit-risk-related Contingent Features By using derivatives, the Company is exposed to credit risk to the extent that counterparties to the derivative contracts do not perform as required. Should a counterparty fail to perform under the terms of a derivative contract, the Company’s credit exposure on interest rate swaps is limited to the net positive fair value and accrued interest of all swaps with each counterparty. 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. As of June 30, 2020 and December 31, 2019, the fair value of derivatives in a net liability position, which includes accrued interest but excludes any adjustment for nonperformance risk, related to these agreements was $37.3 million and $9.6 million, respectively. As of June 30, 2020, and December 31, 2019, the Company has minimum collateral posting thresholds with certain of its derivative counterparties and has posted cash collateral of $37.3 million and $10.4 million, respectively. If the Company had breached any of these provisions at June 30, 2020 or December 31, 2019, it could have been required to settle its obligations under the agreements at their termination value of $37.3 million and $9.6 million, respectively. 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 as June 30, 2020 and December 31, 2019: Gross Amounts Not Offset Gross Amounts Recognized Gross Amounts Offset Net Amounts Recognized Financial Instruments Collateral Pledged (Received) Net Amount June 30, 2020 (dollars in thousands) Offsetting of Derivative Assets Derivative Assets $ 55,732 $ — $ 55,732 $ 9,242 $ — $ 46,490 Offsetting of Derivative Liabilities Derivative Liabilities $ 47,250 $ — $ 47,250 $ 9,242 $ 37,334 $ 674 Gross Amounts Not Offset Gross Amounts Recognized Gross Amounts Offset Net Amounts Recognized Financial Instruments Collateral Pledged (Received) Net Amount December 31, 2019 (dollars in thousands) Offsetting of Derivative Assets Derivative Assets $ 15,912 $ — $ 15,912 $ 3,128 $ - $ 12,784 Offsetting of Derivative Liabilities Derivative Liabilities $ 13,230 $ — $ 13,230 $ 3,128 $ 9,645 $ 457

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	1 9 . 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, 2020 December 31, 2019 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value (dollars in thousands) Financial assets Cash and cash equivalents $ 60,742 $ 60,742 $ 61,335 $ 61,335 Securities available for sale 134,227 134,227 140,330 140,330 Securities held to maturity 244,551 257,121 258,172 264,114 Loans, net 3,298,870 3,242,624 2,208,548 2,160,087 Loans held for sale 2,614 3,228 1,546 2,051 FHLB Boston stock 9,262 9,262 7,854 7,854 Accrued interest receivable 8,631 8,631 7,052 7,052 Mortgage servicing rights 1,120 1,120 1,321 1,526 Interest rate contracts 9,074 9,074 2,911 2,911 Loan level interest rate swaps 46,576 46,576 12,980 12,980 Risk participation agreements out to counterparties 82 82 21 21 Financial liabilities Deposits 3,275,843 3,279,768 2,358,878 2,358,089 Borrowings 237,897 239,658 135,691 135,744 Subordinated debt 9,920 9,920 — — Loan level interest rate swaps 46,576 46,576 12,980 12,980 Risk participation agreements in with counterparties 674 674 250 250 The Company follows ASC 820, “Fair Value Measurements and Disclosures,” • 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 collateral dependent individually evaluated loans. In accordance with the requirements of ASU 2016-01, 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, 2020 Level 1 Level 2 Level 3 Total (dollars in thousands) Measured on a recurring basis Securities available for sale U.S. GSE obligations $ — $ 13,734 $ — $ 13,734 Mortgage-backed securities — 117,739 — 117,739 Corporate debt securities — 2,754 — 2,754 Other assets Interest rate swaps with customers — 46,576 — 46,576 Risk participation agreements out to counterparties — 82 — 82 Interest rate contracts — 9,074 — 9,074 Other liabilities Mirror swaps with counterparties — 46,576 — 46,576 Risk participation agreements in with counterparties — 674 — 674 Fair Value as of December 31, 2019 Level 1 Level 2 Level 3 Total (dollars in thousands) Measured on a recurring basis Securities available for sale U.S. GSE obligations $ — $ 37,848 $ — $ 37,848 Mortgage-backed securities — 102,482 — 102,482 Other assets Interest rate swaps with customers — 12,980 — 12,980 Risk participation agreements out to counterparties — 21 — 21 Interest rate contracts — 2,911 — 2,911 Other liabilities Mirror swaps with counterparties — 12,980 — 12,980 Risk participation agreements in with counterparties — 250 — 250 The following table presents the carrying value of assets held at June 30, 2020, which were measured at fair value on a non-recurring basis: June 30, 2020 Level 1 Level 2 Level 3 Total (dollars in thousands) Items recorded at fair value on a non-recurring basis Assets Mortgage servicing rights $ — $ — $ 1,120 $ 1,120 Loans held for sale 2,614 — — 2,614 Individually assessed collateral dependent loans — — 6,872 6,872 Other real estate owned — — 1,970 1,970 Total $ 2,614 $ — $ 9,962 $ 12,576 The following table presents the carrying value of assets held at December 31, 2019, which were measured at fair value on a non-recurring basis: December 31, 2019 Level 1 Level 2 Level 3 Total (dollars in thousands) Items recorded at fair value on a non-recurring basis Assets Collateral dependent impaired loans $ — $ — $ 2,541 $ 2,541 Loans held for sale 1,546 — — 1,546 Other real estate owned — — 163 163 Total $ 1,546 $ — $ 2,704 $ 4,250 Gain / loss on REO assets measured at fair value on a non-recurring basis. The Company recorded a loss of $486,000 on REO assets for the three and six months ended June 30, 2020. The Company did not record any gains (losses) for assets measured at fair value on a non-recurring basis for the three and six months ended June 30, 2019. 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. Loans held for sale . Loans held for sale are carried at the lower of fair value or carrying value (unpaid principal and unamortized loans fees). Other real estate owned . These properties are carried at fair value less estimated costs to sell. There were no transfers between levels for the three and six months ended June 30, 2020 nor the three and six months ended June 30, 2019. 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 collateral dependent 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 Stock The fair value of FHLB of Boston stock equals its carrying value since such stock is only redeemable at its par value. Subordinated Debt The fair value of subordinated debt is estimated using future cash flows, discounted at rates based upon current costs for debt securities with similar terms and remaining maturities. 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 Cash and cash equivalents and accrued interest receivable have fair values which approximate their respective carrying values because these instruments 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, 2020
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of 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 financial statements. Actual results could differ from those estimates. The allowance for credit losses, the fair values of financial instruments, and the valuation of deferred tax assets are particularly subject to change.
Recently Issued and Adopted Accounting Guidance	Recently Issued and Adopted Accounting Guidance Accounting Standards Update 2020-04 - Facilitation of the Effects of Reference Rate Reform on Financial Reporting • Simplify accounting analyses for contract modifications. • Allow hedging relationships to continue without dedesignation if there are qualifying changes in the critical terms of an existing hedging relationship due to reference rate reform. • Allow a change in the systematic and rational method used to recognize in earnings the components excluded from the assessment of hedge effectiveness. • Allow a change in the designated benchmark interest rate to a different eligible benchmark interest rate in a fair value hedging relationship. • Allow the shortcut method for a fair value hedging relationship to continue for the remainder of the hedging relationship. • Simplify the assessment of hedge effectiveness and provide temporary optional expedients for cash flow hedging relationships affected by reference rate reform. • Allow a one-time election to sell or transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform and are classified as held to maturity before January 1, 2020. The amendments are effective for all entities from the beginning of an interim period that includes the issuance date of the ASU. An entity may elect to apply the amendments prospectively through December 31, 2022. The Company is currently assessing the impact the adoption of this guidance will have on our consolidated balance sheets, statements of income (loss), and cash flows. Accounting Standards Update 2018-15 - Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . Accounting Standards Update 2018-14 - Changes to the Disclosure Requirements for Defined Benefit Plans . Accounting Standards Update 2018-13 - Changes to the Disclosure Requirements for Fair Value Measurement . Accounting Standards Update 2016-13 - Financial Instruments - Credit Losses Measurement of Credit Losses on Financial Instruments The Company’s CECL methodology consists of quantitative and qualitative components. The quantitative component of the allowance for credit losses (“ACL”) is model based and utilizes a forward-looking macroeconomic forecast, complemented by qualitative components in estimating expected credit losses. The qualitative components of the ACL ASU 2016-13 also applies to off-balance sheet credit exposure not accounted for as insurance (loan commitments, standby letters of credit, financial guarantees and other similar investment) and net investments in leases recognized by a lessor in accordance with ASU 2016-02-Leases (Topic 842) on leases. January 1, 2020 CECL Transition (Day 1) Impact The CECL methodology reflects the Company’s view of the state of the economy and forecasted macroeconomic conditions and their impact on the Company’s loan and investment portfolios as of the adoption date. The following table illustrates the impact of Topic 326: January 1, 2020 As reported under ASC 326 Pre-ASC 326 Adoption Impact of ASC 326 Adoption (dollars in thousands) ASSETS Loans Residential mortgage $ 7,202 $ 5,141 $ 2,061 Commercial mortgage 9,545 10,992 (1,447 ) Home equity 256 461 (205 ) Commercial & Industrial 896 1,388 (492 ) Consumer 486 198 288 Allowance for credit losses on loans $ 18,385 $ 18,180 $ 205 LIABILITIES Allowance for credit losses on OBS credit exposure $ 326 $ 50 $ 276 Summary of significant accounting policies impacted by Topic 326 Debt Securities Investment securities are classified as either ‘held to maturity’ or ‘available for sale’ in accordance with the FASB ASC 320, Investments – Debt and Equity Securities. Debt and equity securities not classified as held to maturity are classified as available for sale and carried at fair value with unrealized after-tax gains and losses reported net as a separate component of shareholders’ equity. The Company classifies its securities based on its intention at the time of purchase. Allowance for credit losses- held to maturity securities The Company measures expected credit losses on held to maturity debt securities on a collective basis by security type and risk rating where available. The reserve for each pool is calculated based on a Probability of Default/Loss Given Default (PD/LGD) basis taking into consideration the expected life of each security. Held to maturity securities which are issued by the United States or are guaranteed by U.S. federal agencies do not currently have an allowance for credit loss as the Company determined these securities are either backed by the full faith and credit of the U.S. government and/or there is an unconditional commitment to make interest payments and to return the principal investment in full to investors when a debt security reaches maturity. The Company will evaluate this position no less than annually, however, certain items which may cause the Company to change this methodology include legislative changes that remove a government-sponsored enterprise’s (“GSE”) ability to draw funds from the U.S. government, or legislative changes to housing policy that reduce or eliminate the U.S. government’s implicit guarantee on such securities. For securities which are not U.S. treasury or agency backed, risk ratings are generally sourced from Moody’s or Standard & Poor’s (“S&P”). The Company updates loss given default, probability of default, and recovery rates for each security as that information becomes available but no less than annually. The expected remaining life to maturity of each applicable security is updated quarterly. Any expected credit losses on held to maturity securities would be presented as an allowance rather than as a direct write-down through the income statement if the Company does not intend to sell or believes that it is more- likely- than- not that the Company will be required to sell the security. Allowance for credit losses-available for sale securities The Company measures expected credit losses on available for sale securities based upon the gain or loss position of the security. For available-for sale debt securities in an unrealized loss position, which the Company does not intend to sell, or it is not more likely than not that the Company will be required to sell the security before recovery of our amortized cost, the Company evaluates qualitative criteria to determine any expected loss. This includes among other items the financial health of, and specific prospects for the issuer, including whether the issuer is in compliance with the terms and covenants of the security. The Company also evaluates quantitative criteria including determining whether there has been an adverse change in expected future cash flows of the security. If the Company do es not expect to recover the entire amortized cost basis of the security, an allowance for credit losses would be recorded, with a related charge to earnings, limited by the amount of the fair value of the security less its amortized cost . If the Company intend s to sell the security or it is more likely than not that the Company will be required to sell the debt security before recovery of its amortized cost basis, the Company recognize s the entire difference between the security’s amortized cost basis and its fair value in earnings. Loans Loans are reported at the amount of their outstanding principal, including deferred loan origination fees and costs, reduced by unearned discounts, and the allowance for credit losses. Loans are considered delinquent when a payment of principal and/or interest becomes past due 30 days following its scheduled payment due date. Loans on which the accrual of interest has been discontinued are designated as non-accrual loans. Loans are removed from non-accrual when they become less than 90 days past due and when concern no longer exists as to the collectability of principal or interest. Allowance for Credit Losses - Loans Losses on loan receivables are estimated and recognized upon origination of the loan, based on expected credit losses for the life of the loan balance as of the period end date. The Company uses a discounted cash flow method incorporating probability of default and loss given default forecasted based on statistically derived economic variable loss drivers combined with qualitative factors to estimate expected credit losses. This process includes estimates which involve modeling loss projections attributable to existing loan balances, considering historical experience, current conditions and future expectations for homogeneous pools of loans over the reasonable and supportable forecast period. As stated above, the Company also performs a qualitative assessment beyond model estimates, and apply qualitative adjustments as management deems necessary. The reasonable and supportable forecast period is determined based upon the accuracy level of historical loss forecast estimates, the specific loan level models and methodology utilized, and considers material changes in growth and credit strategy, and business changes which may not be applicable within the current environment. For periods beyond a reasonable and supportable forecast interval, the Company reverts to historical information over a period for which comparable data is available. The historical information either experienced by the Company, or by a selection of peer banks when appropriate, is derived from a combination of recessionary and non-recessionary performance periods for which data is available. Similar to the reasonable and supportable forecast period, the Company reassesses the reversion period at the segment level, considering any required adjustments for differences in underwriting standards, portfolio mix, and other relevant data shifts over time. The Company generally segments its loan receivable population into homogeneous pools of loans. Consistent with the Company’s other assumptions, the Company regularly reviews segmentation to determine whether the segmentation pools remain relevant as risk characteristics change. When a loan no longer meets the criteria of its initial pooling as a result of credit deterioration or other changes, the Company may evaluate the credit for estimated losses on an individual basis if it determines that they no longer retain the same risk characteristics. To the extent that there are a multitude of these loans with new similar credit characteristics, the Company would anticipate a change to the pooling methodology. Loans that do not share risk characteristics are evaluated on an individual basis and are also not included in the collective evaluation. For loans with real estate collateral, when management determines that foreclosure is probable, expected credit losses are based on the fair value of the collateral at the reporting date, adjusted for selling costs as appropriate. The Company evaluates the loan allowance for credit losses The underlying assumptions, estimates and assessments the Company uses to estimate the allowance for credit losses reflects the Company’s best estimate of model assumptions and forecasted conditions at that time. Changes in such estimates can significantly affect the allowance and provision for credit losses. It is possible and likely that the Company will experience credit losses that are different from the current estimates. Charge-offs are deducted from the allowance for credit losses when the Company considers the principal to be uncollectible, and subsequent recoveries are added to the allowance, generally at the time cash is received on a charged-off account. Allowance for Unfunded C ommitments The expected credit losses for unfunded commitments are measured over the contractual period of the Company’s exposure to credit risk. The estimate of credit loss incorporates assumptions for both the likelihood and amount of funding over the estimated life of the commitments, for the risk of loss, and current conditions and expectations. Management periodically reviews and updates its assumptions for estimated funding rates based on historical rates, and factors such as portfolio growth, changes to organizational structure, economic conditions, borrowing habits, or any other factor which could impact the likelihood that funding will occur. The Company does not reserve for unfunded commitments which are unconditionally cancellable. Acquired Loans Acquired loans are recorded at fair value at the date of acquisition based on a discounted cash flow methodology that considers various factors including the type of loan and related collateral, classification status, fixed or variable interest rate, term of loan and whether or not the loan was amortizing, and a discount rate reflecting the Company’s assessment of risk inherent in the cash flow estimates. Certain larger purchased loans are individually evaluated while certain purchased loans are grouped together according to similar risk characteristics and are treated in the aggregate when applying various valuation techniques. These cash flow evaluations are inherently subjective as they require material estimates, all of which may be susceptible to significant change. Starting January 1, 2020, loans acquired in a business combination that have experienced more-than-insignificant deterioration in credit quality since origination are considered purchased credit deteriorated (“PCD”) loans. The Company evaluated acquired loans for deterioration in credit quality based on, but not limited to, the following: (1) non-accrual status; (2) troubled debt restructured designation; (3) risk ratings of special mention, substandard or doubtful; (4) watchlist credits; and (5) delinquency status, including loans that are current on acquisition date, but had been previously delinquent. At the acquisition date, an estimate of expected credit losses is made for groups of PCD loans with similar risk characteristics and individual PCD loans without similar risk characteristics. This initial allowance for credit losses is allocated to individual PCD loans and added to the purchase price or acquisition date fair values to establish the initial amortized cost basis of the PCD loans. As the initial allowance for credit losses is added to the purchase price, there is no credit loss expense recognized upon acquisition of a PCD loan. Any difference between the unpaid principal balance of PCD loans and the amortized cost basis is considered to relate to noncredit factors and results in a discount or premium. Discounts and premiums are recognized through interest income on a level-yield method over the life of the loans. For acquired loans not deemed PCD at acquisition, the differences between the initial fair value and the unpaid principal balance are recognized as interest income on a level-yield basis over the lives of the related loans. At the acquisition date, an initial allowance for expected credit losses is estimated and recorded as credit loss expense. The subsequent measurement of expected credit losses for all acquired loans is the same as the subsequent measurement of expected credit losses for originated loans. See Note 8 – Loans and the Allowance for Credit Losses for a detailed discussion of the Company’s allowance for credit losses. See Note 2 - Basis of Presentation and Summary of Significant Accounting Policies

Mergers (Tables)

Mergers (Tables)	6 Months Ended
	Jun. 30, 2020
Business Combinations [Abstract]
Summary of Estimated Fair Value of Assets Acquired and Liabilities Assumed	The following table summarizes the estimated fair value of the assets acquired and liabilities assumed as of the date of the acquisition: At June 1, 2020 Wellesley Book Value Purchase Accounting Adjustments Net Assets Acquired at Fair Value (dollars in thousands) Total Purchase Price $ 88,766 Assets Cash and cash equivalents $ 44,667 $ — $ 44,667 Investments 23,331 — 23,331 Gross Loans 883,659 (13,626 ) 870,033 Allowance for loan loss (8,461 ) 8,461 — Premises and equipment 2,972 1,040 4,012 Other assets 41,082 2,505 43,587 Total assets acquired 987,250 (1,620 ) 985,630 Liabilities Deposits 758,976 1,902 760,878 Borrowings & Subordinated debt 132,005 477 132,482 Other liabilities 21,847 2,362 24,209 Total liabilities assumed 912,828 4,741 917,569 Net Assets Acquired $ 74,422 $ (6,361 ) $ 68,061 Goodwill $ 20,705
Summary of Proforma Financial Information	The following summarizes the unaudited pro forma results of operations as if the Company merged with Wellesley on December 31, 2019 and 2018, respectively. Amounts represent combined results for the Company and Wellesley. The selected pro forma financial information is presented for illustrative purposes only and is not necessarily indicative of the financial results of the combined companies had the acquisition actually been completed at the beginning of the periods presented, nor does it indicate future results for any other interim or full-year Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (dollars in thousands) Net interest and dividend income after provision for loan losses $ 28,056 $ 25,727 $ 55,141 $ 48,272 Net Income 11,352 9,227 20,697 16,818

Recently Issued and Adopted A_2

Recently Issued and Adopted Accounting Guidance (Tables)	6 Months Ended
	Jun. 30, 2020
ASC 326
Schedule of Impact of Topic 326	The following table illustrates the impact of Topic 326: January 1, 2020 As reported under ASC 326 Pre-ASC 326 Adoption Impact of ASC 326 Adoption (dollars in thousands) ASSETS Loans Residential mortgage $ 7,202 $ 5,141 $ 2,061 Commercial mortgage 9,545 10,992 (1,447 ) Home equity 256 461 (205 ) Commercial & Industrial 896 1,388 (492 ) Consumer 486 198 288 Allowance for credit losses on loans $ 18,385 $ 18,180 $ 205 LIABILITIES Allowance for credit losses on OBS credit exposure $ 326 $ 50 $ 276

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value (dollars in thousands) Available for sale securities U.S. GSE obligations $ 13,000 $ 734 $ — $ 13,734 $ 38,000 $ — $ (152 ) $ 37,848 Mortgage-backed securities 115,020 2,728 (9 ) 117,739 103,109 231 (858 ) 102,482 Corporate debt securities 2,741 15 (2 ) 2,754 — — — — Total available for sale securities $ 130,761 $ 3,477 $ (11 ) $ 134,227 $ 141,109 $ 231 $ (1,010 ) $ 140,330 Held to maturity securities U.S. GSE obligations $ — $ — $ — $ — $ 5,000 $ — $ — $ 5,000 Mortgage-backed securities 146,398 7,520 — 153,918 161,759 2,751 (111 ) 164,399 Corporate debt securities 6,984 263 — 7,247 6,980 116 — 7,096 Municipal securities 91,169 4,815 (28 ) 95,956 84,433 3,252 (66 ) 87,619 Total held to maturity securities $ 244,551 $ 12,598 $ (28 ) $ 257,121 $ 258,172 $ 6,119 $ (177 ) $ 264,114 Total $ 375,312 $ 16,075 $ (39 ) $ 391,348 $ 399,281 $ 6,350 $ (1,187 ) $ 404,444
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, 2020 and temporarily impaired at December 31, 2019, aggregated by investment category and length of time that individual securities have been in a continuous loss position: June 30, 2020 Less than 12 months 12 months or longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (dollars in thousands) Available for sale securities Mortgage-backed securities $ — $ — $ 5,318 $ (9 ) $ 5,318 $ (9 ) Corporate debt securities 781 (2 ) — — 781 (2 ) Total available for sale securities $ 781 $ (2 ) $ 5,318 $ (9 ) $ 6,099 $ (11 ) Held to maturity securities Mortgage-backed securities $ — $ — $ — $ — $ — $ — Municipal securities 8,365 (28 ) — — 8,365 (28 ) Total held to maturity securities $ 8,365 $ (28 ) $ — $ — $ 8,365 $ (28 ) Total $ 9,146 $ (30 ) $ 5,318 $ (9 ) $ 14,464 $ (39 ) December 31, 2019 Less than 12 months 12 months or longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses (dollars in thousands) Temporarily Impaired Securities Available for sale securities U.S. GSE obligations $ 12,912 $ (88 ) $ 24,936 $ (64 ) $ 37,848 $ (152 ) Mortgage-backed securities 33,381 (265 ) 50,766 (593 ) 84,147 (858 ) Corporate debt securities — — — — — — Total available for sale securities $ 46,293 $ (353 ) $ 75,702 $ (657 ) $ 121,995 $ (1,010 ) Held to maturity securities U.S. GSE obligations $ — $ — $ 5,000 $ — $ 5,000 $ — Mortgage-backed securities 14,838 (27 ) 12,928 (84 ) 27,766 (111 ) Corporate debt securities — — — — — — Municipal securities 4,934 (66 ) — — 4,934 (66 ) Total held to maturity securities $ 19,772 $ (93 ) $ 17,928 $ (84 ) $ 37,700 $ (177 ) Total temporarily impaired securities $ 66,065 $ (446 ) $ 93,630 $ (741 ) $ 159,695 $ (1,187 )
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 guaranteed 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. Within One Year After One, But Within Five Years After Five, But Within Ten Years After Ten Years Total Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value At June 30, 2020 (dollars in thousands) Available for sale securities U.S. GSE obligations $ — $ — $ — $ — $ 5,000 $ 5,133 $ 8,000 $ 8,601 $ 13,000 $ 13,734 Mortgage-backed securities — — 975 978 35,702 37,157 78,343 79,604 115,020 117,739 Corporate debt securities 1,001 1,003 1,740 1,751 — — — — 2,741 2,754 Total available for sale securities $ 1,001 $ 1,003 $ 2,715 $ 2,729 $ 40,702 $ 42,290 $ 86,343 $ 88,205 $ 130,761 $ 134,227 Held to maturity securities U.S. GSE obligations $ — $ — $ — $ — $ — $ — $ — $ — $ — $ — Mortgage-backed securities — — 2 2 49,686 53,581 96,710 100,335 146,398 153,918 Corporate debt securities — — 6,984 7,247 — — — — 6,984 7,247 Municipal securities 1,878 1,893 15,379 15,916 47,944 51,111 25,968 27,036 91,169 95,956 Total held to maturity securities $ 1,878 $ 1,893 $ 22,365 $ 23,165 $ 97,630 $ 104,692 $ 122,678 $ 127,371 $ 244,551 $ 257,121 Total $ 2,879 $ 2,896 $ 25,080 $ 25,894 $ 138,332 $ 146,982 $ 209,021 $ 215,576 $ 375,312 $ 391,348
Summary of Gains (Losses) from Sale of Investment Securities	The following table sets forth information regarding sales of investment securities and the resulting gains (losses) from such sales: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (dollars in thousands) Amortized cost of securities sold $ 10,752 $ 10,231 $ 10,752 $ 26,231 Gross gains realized on securities sold 69 63 69 63 Gross losses realized on securities sold — (57 ) — (144 ) Net proceeds from securities sold $ 10,821 $ 10,237 $ 10,821 $ 26,150
Summary of Credit Rating of Debt Securities Portfolio	The Company monitors the credit quality of certain debt securities through the use of credit rating among other factors on a quarterly basis. The following table summarizes the credit rating of the Company’s debt securities portfolio at June 30, 2020. June 30, 2020 Mortgage-backed Securities Corporate Debt Securities Municipal Securities U.S. GSE obligations Total (dollars in thousands) Available for sale securities, at fair value AAA/AA/A (1) $ 117,739 $ 1,784 $ — $ 13,734 $ 133,257 BBB/BB/B — 970 — — 970 Total available for sale securities $ 117,739 $ 2,754 $ — $ 13,734 $ 134,227 Held to maturity securities, at amortized cost AAA/AA/A $ 146,398 $ 6,984 $ 90,894 $ — $ 244,276 BBB/BB/B — — 275 — 275 Total held to maturity securities $ 146,398 $ 6,984 $ 91,169 $ — $ 244,551 (1) Includes Agency mortgage-backed pass-through securities and collateralized mortgage obligations issued by GSEs and U.S. government agencies, such as FNMA, FHLMC, and GNMA that are not rated by Moody’s or S&P. Each security contains a guarantee by the issuing 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, 2020
Receivables [Abstract]
Loans Outstanding by Category	Loans outstanding are detailed by category as follows: June 30, 2020 December 31, 2019 (dollars in thousands) Residential mortgage Mortgages - fixed rate $ 535,633 $ 430,877 Mortgages - adjustable rate 775,475 467,139 Construction 37,366 17,374 Deferred costs net of unearned fees 2,834 2,176 Total residential mortgages 1,351,308 917,566 Commercial mortgage Mortgages - non-owner occupied 1,073,856 870,047 Mortgages - owner occupied 150,040 114,095 Construction 188,433 76,288 Deferred costs net of unearned fees 1,098 144 Total commercial mortgages 1,413,427 1,060,574 Home equity Home equity - lines of credit 110,014 73,880 Home equity - term loans 5,806 6,555 Deferred costs net of unearned fees 247 240 Total home equity 116,067 80,675 Commercial & industrial Commercial & industrial 418,455 133,337 Unearned fees, net of deferred costs (4,212 ) (101 ) Total commercial & industrial 414,243 133,236 Consumer Secured 36,941 33,453 Unsecured 877 1,199 Deferred costs net of unearned fees 21 25 Total consumer 37,839 34,677 Total loans $ 3,332,884 $ 2,226,728
Non-performing Loans Disaggregated by Loan Category	The following tables set forth information regarding non-performing loans disaggregated by loan category: June 30, 2020 . Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Total (dollars in thousands) Non-performing loans: Non-accrual loans $ 3,284 $ 4,752 $ 12 $ 52 $ 8,100 Loans past due >90 days, but still accruing 1,536 353 — — 1,889 Troubled debt restructurings 137 — — 125 262 Total $ 4,957 $ 5,105 $ 12 $ 177 $ 10,251 December 31, 2019 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Total (dollars in thousands) Non-performing loans: Non-accrual loans $ 1,298 $ 2,800 $ 12 $ 50 $ 4,160 Loans past due >90 days, but still accruing 527 486 — 251 1,264 Troubled debt restructurings 99 — — 128 227 Total $ 1,924 $ 3,286 $ 12 $ 429 $ 5,651
Schedule of Outstanding Balance and Related Allowance on PCD Loans	The outstanding balance at June 30, 2020 and related allowance on PCD loans is as follows: Loan Balance ACL Balance (dollars in thousands) Residential Mortgages $ 1,106 $ 35 Commercial Mortgages 16,850 380 Home Equity 112 — Commercial & Industrial 1,318 19 Total $ 19,386 $ 434
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, 2020 2020 2019 2018 2017 2016 Prior Revolving loans amortized cost basis Total (in thousands) Residential: Current $ 198,574 $ 273,846 $ 220,751 $ 191,361 $ 125,926 $ 335,893 $ — $ 1,346,351 Non-performing — — 1,326 1,595 107 1,929 — 4,957 Total 198,574 273,846 222,077 192,956 126,033 337,822 — 1,351,308 Home equity: Current $ 2,455 $ 7,323 $ 11,597 $ 7,443 $ 2,564 $ 8,780 $ 75,893 $ 116,055 Non-performing — — — — — — 12 12 Total $ 2,455 $ 7,323 $ 11,597 $ 7,443 $ 2,564 $ 8,780 $ 75,905 $ 116,067 Consumer: Current $ 8,210 $ 9,443 $ 3,012 $ 3,042 $ 4,998 $ 8,558 $ 576 $ 37,839 Non-performing — — — — — — — — Total $ 8,210 $ 9,443 $ 3,012 $ 3,042 $ 4,998 $ 8,558 $ 576 $ 37,839 Credit Quality Indicator - by Origination Year as of June 30, 2020 2020 2019 2018 2017 2016 Prior Revolving loans amortized cost basis Revolving loans converted to term Total (in thousands) Commercial: Credit risk profile by internally assigned grade: 1-6 (Pass) $ 151,422 $ 424,598 $ 252,673 $ 128,003 $ 153,142 $ 288,586 $ — $ — $ 1,398,424 7 (Special Mention) — 161 581 1,643 88 10,048 — — 12,521 8 (Substandard) — 741 — — 220 847 — — 1,808 9 (Doubtful) — — — — — 674 — — 674 10 (Loss) — — — — — — — — — Total $ 151,422 $ 425,500 $ 253,254 $ 129,646 $ 153,450 $ 300,155 $ — $ — $ 1,413,427 Commercial & Industrial: Credit risk profile by internally assigned grade: 1-6 (Pass) $ 213,211 $ 60,282 $ 65,278 $ 21,345 $ 17,442 $ 14,100 $ 14,776 $ — $ 406,434 7 (Special Mention) 439 421 468 490 72 243 20 — 2,153 8 (Substandard) — 1,393 336 — 3,256 183 488 — 5,656 9 (Doubtful) — — — — — — — — — 10 (Loss) — — — — — — — — — Total $ 213,650 $ 62,096 $ 66,082 $ 21,835 $ 20,770 $ 14,526 $ 15,284 $ — $ 414,243 December 31, 2019 Residential Mortgages Home Equity Consumer (dollars in thousands) Credit risk profile based on payment activity: Performing $ 915,642 $ 80,663 $ 34,677 Non-performing 1,924 12 — Total $ 917,566 $ 80,675 $ 34,677 Commercial Mortgages Commercial & Industrial Credit risk profile by internally assigned grade: 1-6 (Pass) $ 1,050,037 $ 123,900 7 (Special Mention) 7,360 4,289 8 (Substandard) 3,177 5,047 9 (Doubtful) — — 10 (Loss) — — Total $ 1,060,574 $ 133,236
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, 2020 30-59 Days 60-89 Days 90 Days or greater Total Past Due Current Loans Total Amortized Cost 90+ Days and Accruing (dollars in thousands) Residential Mortgages $ 4,061 $ 1,307 $ 3,337 $ 8,705 $ 1,342,603 $ 1,351,308 $ 1,536 Commercial Mortgages 718 — 3,976 4,694 1,408,733 1,413,427 353 Home Equity 12 269 — 281 115,786 116,067 — Commercial & Industrial 218 831 125 1,174 413,069 414,243 — Consumer loans 3 — — 3 37,836 37,839 — Total $ 5,012 $ 2,407 $ 7,438 $ 14,857 $ 3,318,027 $ 3,332,884 $ 1,889 December 31, 2019 30-59 Days Past Due 60-89 Days Past Due 90 Days or Greater Total Past Due Current Loans Total (dollars in thousands) Residential Mortgages $ 8,710 $ 1,089 $ 1,047 $ 10,846 $ 906,720 $ 917,566 Commercial Mortgages 811 — 3,161 3,972 1,056,602 1,060,574 Home Equity 57 12 — 69 80,606 80,675 Commercial & Industrial 272 226 251 749 132,487 133,236 Consumer loans 4 5 — 9 34,668 34,677 Total $ 9,854 $ 1,332 $ 4,459 $ 15,645 $ 2,211,083 $ 2,226,728
Summary of Changes in Allowance for Credit Losses Disaggregated by Loan Category	The following table presents changes in the allowance for credit losses disaggregated by loan category: For the Three Months Ended June 30, 2020 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan portfolio: Balance at March 31, 2020 $ 7,477 $ 10,881 $ 310 $ 946 $ 549 $ — $ 20,163 Provision for acquired loans 2,880 3,625 188 1,577 12 — 8,282 Initial allowance for PCD 35 382 — 20 — — 437 Charge-offs — (77 ) — (65 ) (16 ) — (158 ) Recoveries — — — 22 1 — 23 Provision for (Release of)-loan portfolio 1,488 3,256 154 439 (70 ) — 5,267 Allowance for credit losses - loan portfolio $ 11,880 $ 18,067 $ 652 $ 2,939 $ 476 $ — $ 34,014 Allowance for credit losses - unfunded commitments: Balance at March 31, 2020 $ — $ — $ — $ — $ — $ 283 $ 283 Acquired loan commitments — — — — — 356 356 Provision for - unfunded commitments — — — — — 525 525 Allowance for credit losses- unfunded commitments — — — — — 1,164 1,164 Total allowance for credit loss $ 11,880 $ 18,067 $ 652 $ 2,939 $ 476 $ 1,164 $ 35,178 For the Six Months Ended June 30, 2020 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Unfunded Commitments Total (dollars in thousands) Allowance for credit loss: Allowance for credit losses - loan portfolio: Balance at December 31, 2019 $ 5,141 $ 10,905 $ 461 $ 1,475 $ 198 $ — $ 18,180 Adoption of ASC 326 2,061 (1,447 ) (205 ) (492 ) 288 — 205 Provision of acquired loans 2,880 3,625 188 1,577 12 — 8,282 Initial allowance for PCD 35 382 — 20 — — 437 Charge-offs — (264 ) — (154 ) (30 ) — (448 ) Recoveries — — — 34 14 — 48 Provision for (Release of)-loan portfolio 1,763 4,866 208 479 (6 ) — 7,310 Allowance for credit losses - loan portfolio $ 11,880 $ 18,067 $ 652 $ 2,939 $ 476 $ — $ 34,014 Allowance for credit losses - unfunded commitments: Balance at December 31, 2019 $ — $ — $ — $ — $ — $ 50 $ 50 Adoption of ASC 326 — — — — — 276 276 Acquired loan commitments — — — — — 356 356 Provision for - unfunded commitments — — — — — 482 482 Allowance for credit losses-unfunded commitments — — — — — 1,164 1,164 Total allowance for credit loss $ 11,880 $ 18,067 $ 652 $ 2,939 $ 476 $ 1,164 $ 35,178 The following tables contain period-end balances of the allowance for loan losses and related loans receivable disaggregated by impairment method: December 31, 2019 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Total (dollars in thousands) Allowance for loan losses Individually evaluated for impairment $ — $ — $ — $ 87 $ — $ 87 Collectively evaluated for impairment 5,141 10,905 461 1,388 198 18,093 Total $ 5,141 $ 10,905 $ 461 $ 1,475 $ 198 $ 18,180 Loans receivable Individually evaluated for impairment $ 764 $ 3,161 $ 92 $ 128 $ — $ 4,145 Collectively evaluated for impairment 916,802 1,057,413 80,583 133,108 34,677 2,222,583 Total $ 917,566 $ 1,060,574 $ 80,675 $ 133,236 $ 34,677 $ 2,226,728
Summary of Changes in Allowance for Loan Losses Disaggregated by Loan Category	For the Three Months Ended June 30, 2019 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Total (dollars in thousands) Allowance for loan losses: Balance at March 31, 2019 $ 5,256 $ 9,369 $ 534 $ 1,245 $ 248 $ 16,652 Charge-offs — (55 ) — (100 ) (9 ) (164 ) Recoveries — — — 12 4 16 Provision for (Release of) 207 115 (3 ) 288 (12 ) 595 Balance at June 30, 2019 $ 5,463 $ 9,429 $ 531 $ 1,445 $ 231 $ 17,099 For the Six Months Ended June 30, 2019 Residential Mortgages Commercial Mortgages Home Equity Commercial & Industrial Consumer Total (dollars in thousands) Allowance for loan losses: Balance at December 31, 2018 $ 4,946 $ 9,626 $ 517 $ 1,415 $ 264 $ 16,768 Charge-offs — (55 ) — (130 ) (20 ) (205 ) Recoveries — — — 25 8 33 Provision for (Release of) 517 (142 ) 14 135 (21 ) 503 Balance at June 30, 2019 $ 5,463 $ 9,429 $ 531 $ 1,445 $ 231 $ 17,099
Information Pertaining to Impaired Loans	The following is information pertaining to impaired loans: December 31, 2019 Carrying Value Average Carrying Value Unpaid Principal Balance Related Allowance Interest Income Recognized (dollars in thousands) With no required reserve recorded: Commercial mortgage $ 3,161 $ 1,385 $ 4,376 $ — $ 35 Residential mortgage 765 691 940 — 5 Home equity 93 96 133 — 1 Total $ 4,019 $ 2,172 $ 5,449 $ — $ 41 With required reserve recorded: Commercial and industrial $ 128 $ 59 $ 167 $ 87 $ — Total $ 128 $ 59 $ 167 $ 87 $ — Total: Commercial and industrial $ 128 $ 59 $ 167 $ 87 $ — Commercial mortgage 3,161 1,385 4,376 — 35 Residential mortgage 765 691 940 — 5 Home equity 93 96 133 — 1 Total $ 4,147 $ 2,231 $ 5,616 $ 87 $ 41

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2020
Schedule of Mortgage Servicing Rights	An analysis of mortgage servicing rights, which are included in other assets, follows: Mortgage Servicing Rights Valuation Allowance Total (dollars in thousands) Balance at December 31, 2018 $ 666 $ — $ 666 Mortgage servicing rights acquired as a result of the merger 334 334 Mortgage servicing rights capitalized 7 — 7 Amortization charged against servicing income (106 ) — (106 ) Change in impairment reserve — (10 ) (10 ) Balance at June 30, 2019 $ 901 $ (10 ) $ 891 Balance at December 31, 2019 $ 1,347 $ (26 ) $ 1,321 Mortgage servicing rights acquired as a result of the merger 50 — 50 Mortgage servicing rights capitalized 90 — 90 Amortization charged against servicing income (244 ) — (244 ) Change in impairment reserve — (97 ) (97 ) Balance at June 30, 2020 $ 1,243 $ (123 ) $ 1,120
Mortgage Servicing Rights
Schedule of Aggregate Estimated Future Amortization Expense	The estimated aggregate future amortization expense for mortgage servicing rights for each of the next five years and thereafter is as follows: Future Amortization Expense (dollars in thousands) Remainder of 2020 $ 169 2021 282 2022 213 2023 158 2024 117 2025 23 Thereafter 281 Total $ 1,243

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 2019 2020 2019 (dollars in thousands) Current income tax expense Federal $ 2,598 $ 1,305 $ 2,120 $ 1,676 State 1,186 552 1,460 719 Total current income tax expense 3,784 1,857 3,580 2,395 Deferred income tax expense / (benefit) Federal (2,956 ) (217 ) (1,356 ) 601 State (1,368 ) (100 ) (703 ) 284 Total deferred income tax expense / (benefit) (4,324 ) (317 ) (2,059 ) 885 Total income tax expense / (benefit) $ (540 ) $ 1,540 $ 1,521 $ 3,280

Pension and Retirement Plans (T

Pension and Retirement Plans (Tables)	6 Months Ended
	Jun. 30, 2020
Compensation And Retirement Disclosure [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 Plan Retirement Healthcare Plan 2020 2019 2020 2019 2020 2019 (dollars in thousands) Net periodic benefit cost (credit) Service cost $ — $ — $ 106 $ 75 $ 10 $ 5 Interest cost 297 414 55 85 5 6 Expected return on assets (921 ) (651 ) — — — — Amortization of prior service credit (1 ) (1 ) — — — — Amortization of net actuarial (gain) loss (39 ) 77 4 — 1 (1 ) Net periodic benefit cost (credit) $ (664 ) $ (161 ) $ 165 $ 160 $ 16 $ 10 Six Months Ended June 30, Pension Plan Supplemental Retirement Plan Retirement Healthcare Plan 2020 2019 2020 2019 2020 2019 (dollars in thousands) Net periodic benefit cost (credit) Service cost $ — $ — $ 177 $ 143 $ 16 $ 10 Interest cost 717 840 142 175 11 12 Expected return on assets (1,600 ) (1,360 ) — — — — Amortization of prior service credit (2 ) (2 ) — — — — Amortization of net actuarial (gain) loss — 77 4 — — (2 ) Net periodic benefit cost (credit) $ (885 ) $ (445 ) $ 323 $ 318 $ 27 $ 20

Stock Based Compensation (Table

Stock Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
Share Based Compensation [Abstract]
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, PRSUs, and the related tax benefits recognized: Three Months Ended June 30, Six Months Ended June 30, 2020 2019 2020 2019 (dollars in thousands) Stock based compensation expense $ 1,331 $ 699 $ 2,311 $ 1,318 Related tax benefits $ 372 $ 197 $ 645 $ 370

Financial Instruments with Of_2

Financial Instruments with Off-Balance-Sheet Risk (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 December 31, 2019 (dollars in thousands) Financial instruments whose contractual amount represents credit risk: Commitments to extend credit: Unused portion of existing lines of credit $ 571,113 $ 428,020 Origination of new loans 70,207 24,413 Standby letters of credit 9,060 9,150 Financial instruments whose notional amount exceeds the amount of credit risk: Commitments to sell residential mortgage loans 25,253 3,909

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2020
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, Six Months Ended June 30, 2020 2020 (dollars in thousands) Operating lease cost $ 1,598 $ 2,995 Variable lease cost (Cost excluded from lease payments) 1 1 Sublease income (16 ) (33 ) Total Operating Lease Cost $ 1,582 $ 2,963 Other Information Cash paid for amounts included in the measurement of lease liabilities - operating cash flows for operating leases $ 1,560 $ 2,924 Operating Lease - Operating cash flows (Liability reduction) 1,278 2,360 Weighted average lease term - operating leases 7.26 Years 7.26 Years Weighted average discount rate - operating leases 2.95 % 2.95 % Three Months Ended June 30, Six Months Ended June 30, 2019 2019 (dollars in thousands) Operating lease cost $ 1,321 $ 2,501 Variable lease cost (Cost excluded from lease payments) — — Sublease income (16 ) (32 ) Total Operating Lease Cost $ 1,305 $ 2,469 Other Information Cash paid for amounts included in the measurement of lease liabilities - operating cash flows for operating leases $ 1,231 $ 2,308 Operating Lease - Operating cash flows (Liability reduction) 937 1,744 Right-of-use assets obtained in exchange for new operating lease liabilities 4,656 4,656 Weighted average lease term - operating leases 8.56 Years 8.56 Years Weighted average discount rate - operating leases 3.38 % 3.38 %
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, 2020 were as follows: Future Minimum Lease Payments (dollars in thousands) Remainder of 2020 $ 7,257 2021 7,005 2022 6,590 2023 6,115 2024 4,790 Thereafter 13,547 Total minimum lease payments 45,304 Less: interest (4,851 ) Total lease liability $ 40,453

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Schedule of Minimum Capital Requirements Considered Well Capitalized by FRB and FDIC	As of June 30, 2020 and December 31, 2019, the Company and the Bank met all applicable minimum capital requirements and were considered “well-capitalized” by both the Federal Reserve Board and the Federal Deposit Insurance Corporation. Actual Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At June 30, 2020 Cambridge Bancorp: Total capital (to risk-weighted assets) $ 367,800 13.0 % $ 297,382 10.5 % N/A N/A Tier I capital (to risk-weighted assets) 322,702 11.4 % 240,738 8.5 % N/A N/A Common equity tier I capital (to risk-weighted assets) 322,702 11.4 % 198,255 7.0 % N/A N/A Tier I capital (to average assets) 322,702 10.0 % 129,195 4.0 % N/A N/A Cambridge Trust Company: Total capital (to risk-weighted assets) $ 359,380 12.7 % $ 297,356 10.5 % $ 283,196 10.0 % Tier I capital (to risk-weighted assets) 324,202 11.4 % 240,717 8.5 % 226,557 8.0 % Common equity tier I capital (to risk-weighted assets) 324,202 11.4 % 198,237 7.0 % 184,077 6.5 % Tier I capital (to average assets) 324,202 10.0 % 129,192 4.0 % 161,490 5.0 % Actual Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) At December 31, 2019 Cambridge Bancorp: Total capital (to risk-weighted assets) $ 272,727 13.6 % $ 210,342 10.5 % N/A N/A Tier I capital (to risk-weighted assets) 254,497 12.7 % 170,277 8.5 % N/A N/A Common equity tier I capital (to risk-weighted assets) 254,497 12.7 % 140,228 7.0 % N/A N/A Tier I capital (to average assets) 254,497 9.0 % 113,365 4.0 % N/A N/A Cambridge Trust Company: Total capital (to risk-weighted assets) $ 271,034 13.5 % $ 210,341 10.5 % $ 200,325 10.0 % Tier I capital (to risk-weighted assets) 252,804 12.6 % 170,276 8.5 % 160,260 8.0 % Common equity tier I capital (to risk-weighted assets) 252,804 12.6 % 140,227 7.0 % 130,211 6.5 % Tier I capital (to average assets) 252,804 8.9 % 113,364 4.0 % 141,705 5.0 %

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Summary of Other Comprehensive Income	The following table presents the changes in accumulated other comprehensive income (loss) (“AOCI”) during the period, by component, net of tax: Three Months Ended June 30, 2020 Three Months Ended June 30, 2019 Before Tax Amount Tax (Expense) or Benefit Net-of-tax Amount Before Tax Amount Tax (Expense) or Benefit Net-of-tax Amount (dollars in thousands) Unrealized gains/(losses) on available for sale securities Unrealized holding gains/(losses) $ 1,077 $ (267 ) $ 810 $ 1,909 $ (456 ) $ 1,453 Reclassification adjustment for (gains)/losses recognized in net income (73 ) 16 (57 ) (6 ) 2 (4 ) Derivatives Change in interest rate contracts 374 (104 ) 270 1,696 (477 ) 1,219 Defined benefit retirement plans Change in retirement liability (1 ) 1 — 36 (10 ) 26 Total Other Comprehensive Income/(Loss) $ 1,377 $ (354 ) $ 1,023 $ 3,635 $ (941 ) $ 2,694 Six Months Ended June 30, 2020 Six Months Ended June 30, 2019 Before Tax Amount Tax (Expense) or Benefit Net-of-tax Amount Before Tax Amount Tax Expense Net-of-tax Amount (dollars in thousands) Unrealized gains/(losses) on available for sale securities Unrealized holding gains/(losses) $ 4,318 $ (1,008 ) $ 3,310 $ 3,334 $ (786 ) $ 2,548 Reclassification adjustment for (gains)/losses recognized in net income (73 ) 16 (57 ) 81 (19 ) 62 Derivatives Change in interest rate contracts 6,260 (1,744 ) 4,516 1,654 (465 ) 1,189 Defined benefit retirement plans Change in retirement liability (2 ) 1 (1 ) 72 (20 ) 52 Total Other Comprehensive Income/(Loss) $ 10,503 $ (2,735 ) $ 7,768 $ 5,141 $ (1,290 ) $ 3,851
Summary of Reclassifications out of AOCI Impact on Net Income (Loss)	Reclassifications out of AOCI that have an impact on net income (loss) are presented below: Three Months Ended June 30, Details about Accumulated Other Comprehensive Income Components 2020 2019 Affected Line Item in the Statement where Net Income (Loss) is Presented (dollars in thousands) Unrealized gains on available for sale securities $ 73 $ 6 Gain on disposition of investment securities Tax expense (16 ) (2 ) Provision for income taxes Net of tax $ 57 $ 4 Net income (loss) Six Months Ended June 30, Details about Accumulated Other Comprehensive Income Components 2020 2019 Affected Line Item in the Statement where Net Income (Loss) is Presented (dollars in thousands) Unrealized gains (losses) on available for sale securities $ 73 $ (81 ) Gain (Loss) on disposition of investment securities Tax benefit (expense) (16 ) 19 Provision for income taxes Net of tax $ 57 $ (62 ) Net income

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 2019 2020 2019 (dollars in thousands, except per share data) Earnings per common share - basic: Numerator: Net (loss) income $ (1,716 ) $ 4,272 $ 5,516 $ 10,470 Less dividends and undistributed earnings allocated to participating securities 1 (35 ) (10 ) (94 ) Net (loss) income applicable to common shareholders $ (1,715 ) $ 4,237 $ 5,506 $ 10,376 Denominator: Weighted average common shares outstanding 5,913 4,682 5,653 4,379 (Loss) Earnings per common share – basic $ (0.29 ) $ 0.91 $ 0.97 $ 2.37 Earnings per common share - diluted: Numerator: Net (loss) income $ (1,716 ) $ 4,272 $ 5,516 $ 10,470 Less dividends and undistributed earnings allocated to participating securities — (35 ) (9 ) (94 ) Net (loss) income applicable to common shareholders $ (1,716 ) $ 4,237 $ 5,507 $ 10,376 Denominator: Weighted average common shares outstanding 5,913 4,682 5,653 4,379 Dilutive effect of common stock equivalents — 34 17 33 Weighted average diluted common shares outstanding 5,913 4,716 5,670 4,412 (Loss) Earnings per common share – diluted $ (0.29 ) $ 0.90 $ 0.97 $ 2.35

Derivatives And Hedging Activ_2

Derivatives And Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 2020
Derivative Instruments And Hedging Activities Disclosure [Abstract]
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, 2020 Derivative Assets Derivative Liabilities Notional Amount Balance Sheet Location Fair Value Notional Amount Balance Sheet Location Fair Value (dollars in thousands) (dollars in thousands) Derivatives designated as hedging instruments Interest rate contracts 150,000 Other Assets $ 9,074 $ — Other Liabilities $ — Total derivatives designated as hedging instruments $ 9,074 $ — Derivatives not designated as hedging instruments Loan related derivative contracts Interest rate swaps with customers 399,354 Other Assets $ 46,576 — Other Liabilities $ — Mirror swaps with counterparties — Other Assets — 399,354 Other Liabilities 46,576 Risk participation agreements-out to counterparties 26,580 Other Assets 82 — Other Liabilities — Risk participation agreements-in with counterparties — Other Assets — 113,676 Other Liabilities 674 Total derivatives not designated as hedging instruments $ 46,658 $ 47,250 December 31, 2019 Derivative Assets Derivative Liabilities Notional Amount Balance Sheet Location Fair Value Notional Amount Balance Sheet Location Fair Value (dollars in thousands) (dollars in thousands) Derivatives designated as hedging instruments Interest rate contracts 150,000 Other Assets $ 2,911 $ — Other Liabilities $ — Total derivatives designated as hedging instruments $ 2,911 $ — Derivatives not designated as hedging instruments Loan related derivative contracts Interest rate swaps with customers 241,187 Other Assets $ 12,980 $ — Other Liabilities $ — Mirror swaps with counterparties — Other Assets — 241,187 Other Liabilities 12,980 Risk participation agreements-out to counterparties 19,000 Other Assets 21 — Other Liabilities — Risk participation agreements-in with counterparties — Other Assets — 88,489 Other Liabilities 250 Total derivatives not designated as hedging instruments $ 13,001 $ 13,230
Summary of Cash Flow Hedge Accounting on AOCI	The following tables present the effect of cash flow hedge accounting on AOCI for the periods presented: 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) Recognized in OCI - Included Component Amount of Gain or (Loss) Recognized in OCI - Excluded Component For the Three Months Ended June 30, 2020 For the Three Months Ended June 30, 2020 (dollars in thousands) (dollars in thousands) Interest rate contracts $ 374 $ 413 $ (39 ) Interest Income $ 503 $ 542 $ (39 ) 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 For the Six Months Ended June 30, 2020 For the Six Months Ended June 30, 2020 (dollars in thousands) (dollars in thousands) Interest rate contracts $ 6,260 $ 7,047 $ (787 ) Interest Income $ 615 $ 703 $ (88 ) 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) Recognized in OCI - Included Component Amount of Gain or (Loss) Recognized in OCI - Excluded Component For the Three Months Ended June 30, 2019 For the Three Months Ended June 30, 2019 (dollars in thousands) (dollars in thousands) Interest rate contracts $ 1,647 $ 2,080 $ (433 ) Interest Income $ (48 ) $ — $ (48 ) 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) Recognized in OCI - Included Component Amount of Gain or (Loss) Recognized in OCI - Excluded Component For the Six Months Ended June 30, 2019 For the Six Months Ended June 30, 2019 (dollars in thousands) (dollars in thousands) Interest rate contracts $ 1,558 $ 2,080 $ (522 ) Interest Income $ (96 ) $ — $ (96 )
Summary of Derivative Financial Instruments on the Consolidated Statements of Income (Loss)	The following table presents the effect of the Company’s derivative financial instruments on the Consolidated Statements of Income (Loss) for the periods presented: Three Months Ended June 30, 2020 Six Months Ended June 30, 2020 Interest Income Interest Income (dollars in thousands) (dollars in thousands) Total amount of income presented in the statements of income (loss) statement in which the effects of cash flow hedges are recorded $ 503 $ 615 Gain or (loss) on cash flow hedging relationships in Subtopic 815-20 Interest rate contracts: Amount of gain reclassed from AOCI into income $ 503 $ 615 Amount of gain reclassed from AOCI into income - Included Component 542 703 Amount of loss reclassed from AOCI into income - Excluded Component $ (39 ) $ (88 ) Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Interest Income Interest Income (dollars in thousands) (dollars in thousands) Total amount of income presented in the statements of income (loss) statement in which the effects of cash flow hedges are recorded $ (48 ) $ (96 ) Gain or (loss) on cash flow hedging relationships in Subtopic 815-20 Interest rate contracts: Amount of loss reclassed from AOCI into income $ (48 ) $ (96 ) Amount of loss reclassed from AOCI into income - Included Component — — Amount of loss reclassed from AOCI into income - Excluded Component $ (48 ) $ (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 (Loss) as of the periods presented: Amount of Gain or (Loss) on Derivatives Recognized in Income Three Months Ended June 30, Three Months Ended June 30, 2020 2019 Location of Gain or (Loss) (dollars in thousands) Other contracts Other income $ 152 $ (61 ) Total $ 152 $ (61 ) Amount of Gain or (Loss) on Derivatives Recognized in Income Six Months Ended June 30, Six Months Ended June 30, 2020 2019 Location of Gain or (Loss) (dollars in thousands) Other contracts Other income $ 330 $ 13 Total $ 330 $ 13
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 as June 30, 2020 and December 31, 2019: Gross Amounts Not Offset Gross Amounts Recognized Gross Amounts Offset Net Amounts Recognized Financial Instruments Collateral Pledged (Received) Net Amount June 30, 2020 (dollars in thousands) Offsetting of Derivative Assets Derivative Assets $ 55,732 $ — $ 55,732 $ 9,242 $ — $ 46,490 Offsetting of Derivative Liabilities Derivative Liabilities $ 47,250 $ — $ 47,250 $ 9,242 $ 37,334 $ 674 Gross Amounts Not Offset Gross Amounts Recognized Gross Amounts Offset Net Amounts Recognized Financial Instruments Collateral Pledged (Received) Net Amount December 31, 2019 (dollars in thousands) Offsetting of Derivative Assets Derivative Assets $ 15,912 $ — $ 15,912 $ 3,128 $ - $ 12,784 Offsetting of Derivative Liabilities Derivative Liabilities $ 13,230 $ — $ 13,230 $ 3,128 $ 9,645 $ 457

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 December 31, 2019 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value (dollars in thousands) Financial assets Cash and cash equivalents $ 60,742 $ 60,742 $ 61,335 $ 61,335 Securities available for sale 134,227 134,227 140,330 140,330 Securities held to maturity 244,551 257,121 258,172 264,114 Loans, net 3,298,870 3,242,624 2,208,548 2,160,087 Loans held for sale 2,614 3,228 1,546 2,051 FHLB Boston stock 9,262 9,262 7,854 7,854 Accrued interest receivable 8,631 8,631 7,052 7,052 Mortgage servicing rights 1,120 1,120 1,321 1,526 Interest rate contracts 9,074 9,074 2,911 2,911 Loan level interest rate swaps 46,576 46,576 12,980 12,980 Risk participation agreements out to counterparties 82 82 21 21 Financial liabilities Deposits 3,275,843 3,279,768 2,358,878 2,358,089 Borrowings 237,897 239,658 135,691 135,744 Subordinated debt 9,920 9,920 — — Loan level interest rate swaps 46,576 46,576 12,980 12,980 Risk participation agreements in with counterparties 674 674 250 250
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, 2020 Level 1 Level 2 Level 3 Total (dollars in thousands) Measured on a recurring basis Securities available for sale U.S. GSE obligations $ — $ 13,734 $ — $ 13,734 Mortgage-backed securities — 117,739 — 117,739 Corporate debt securities — 2,754 — 2,754 Other assets Interest rate swaps with customers — 46,576 — 46,576 Risk participation agreements out to counterparties — 82 — 82 Interest rate contracts — 9,074 — 9,074 Other liabilities Mirror swaps with counterparties — 46,576 — 46,576 Risk participation agreements in with counterparties — 674 — 674 Fair Value as of December 31, 2019 Level 1 Level 2 Level 3 Total (dollars in thousands) Measured on a recurring basis Securities available for sale U.S. GSE obligations $ — $ 37,848 $ — $ 37,848 Mortgage-backed securities — 102,482 — 102,482 Other assets Interest rate swaps with customers — 12,980 — 12,980 Risk participation agreements out to counterparties — 21 — 21 Interest rate contracts — 2,911 — 2,911 Other liabilities Mirror swaps with counterparties — 12,980 — 12,980 Risk participation agreements in with counterparties — 250 — 250
Schedule of Carrying Value of Assets Measured at Fair Value on a Non-Recurring Basis	The following table presents the carrying value of assets held at June 30, 2020, which were measured at fair value on a non-recurring basis: June 30, 2020 Level 1 Level 2 Level 3 Total (dollars in thousands) Items recorded at fair value on a non-recurring basis Assets Mortgage servicing rights $ — $ — $ 1,120 $ 1,120 Loans held for sale 2,614 — — 2,614 Individually assessed collateral dependent loans — — 6,872 6,872 Other real estate owned — — 1,970 1,970 Total $ 2,614 $ — $ 9,962 $ 12,576 The following table presents the carrying value of assets held at December 31, 2019, which were measured at fair value on a non-recurring basis: December 31, 2019 Level 1 Level 2 Level 3 Total (dollars in thousands) Items recorded at fair value on a non-recurring basis Assets Collateral dependent impaired loans $ — $ — $ 2,541 $ 2,541 Loans held for sale 1,546 — — 1,546 Other real estate owned — — 163 163 Total $ 1,546 $ — $ 2,704 $ 4,250

Mergers - Additional Informatio

Mergers - Additional Information (Details)	Jun. 01, 2020USD ($)$ / sharesshares	Apr. 17, 2019USD ($)$ / sharesshares	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Business Acquisition [Line Items]
Goodwill			$ 51,912,000		$ 51,912,000		$ 31,206,000
Acquisition-related Costs
Business Acquisition [Line Items]
Merger expenses			4,400,000		4,600,000
Provision for acquired loans					8,600,000
Wellesley Bancorp Inc
Business Acquisition [Line Items]
Number of banking offices	6
Business combination, share conversion ratio	0.580
Total consideration paid	$ 88,800,000
Common stock issued related to merger | shares	1,502,814
Business combination, share price | $ / shares	$ 58
Merger expenses			$ 4,400,000		$ 4,600,000
Business combination, provision for credit losses	$ 8,600
Total assets acquired	985,630,000
Goodwill	20,705,000
Total liabilities assumed	$ 917,569,000
Optima Bank And Trust Company
Business Acquisition [Line Items]
Business combination, share conversion ratio		0.3468
Total consideration paid		$ 64,300,000
Common stock issued related to merger | shares		722,746
Business combination, share price | $ / shares		$ 32
Merger expenses				$ 3,500,000		$ 3,500,000
Business combination percentage of common stock transaction		95.00%
Business combination percentage of cash transaction		5.00%
Cash payment related to merger		$ 3,500,000
Total assets acquired		555,700,000
Goodwill		30,800,000
Total liabilities assumed		$ 491,400,000

Mergers - Summary of Estimated

Mergers - Summary of Estimated Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 01, 2020	Dec. 31, 2019
Liabilities
Goodwill	$ 51,912		$ 31,206
Wellesley Bancorp Inc
Business Acquisition [Line Items]
Total Purchase Price		$ 88,766
Assets
Cash and cash equivalents		44,667
Investments		23,331
Gross Loans		870,033
Premises and equipment		4,012
Other assets		43,587
Total assets acquired		985,630
Liabilities
Deposits		760,878
Borrowings & Subordinated debt		132,482
Other liabilities		24,209
Total liabilities assumed		917,569
Net Assets Acquired		68,061
Goodwill		20,705
Wellesley Bancorp Inc | Wellesley Book Value
Assets
Cash and cash equivalents		44,667
Investments		23,331
Gross Loans		883,659
Allowance for loan loss		(8,461)
Premises and equipment		2,972
Other assets		41,082
Total assets acquired		987,250
Liabilities
Deposits		758,976
Borrowings & Subordinated debt		132,005
Other liabilities		21,847
Total liabilities assumed		912,828
Net Assets Acquired		74,422
Wellesley Bancorp Inc | Purchase Accounting Adjustments
Assets
Gross Loans		(13,626)
Allowance for loan loss		8,461
Premises and equipment		1,040
Other assets		2,505
Total assets acquired		(1,620)
Liabilities
Deposits		1,902
Borrowings & Subordinated debt		477
Other liabilities		2,362
Total liabilities assumed		4,741
Net Assets Acquired		$ (6,361)

Mergers - Summary of Proforma F

Mergers - Summary of Proforma Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Business Acquisition Pro Forma Information [Abstract]
Net interest and dividend income after provision for loan losses	$ 28,056	$ 25,727	$ 55,141	$ 48,272
Net Income	$ 11,352	$ 9,227	$ 20,697	$ 16,818

Recently Issued and Adopted A_3

Recently Issued and Adopted Accounting Standards - Additional Information (Details) - USD ($)	Jan. 01, 2020	Jun. 30, 2020
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Retained earnings, net of taxes		$ (347,000)
ASC 326
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Additional allowance for credit losses recorded	$ 481,000
Retained earnings, net of taxes	$ (347,000)

Recently Issued and Adopted A_4

Recently Issued and Adopted Accounting Standards - Schedule of Impact of Topic 326 (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Loans
Allowance for credit losses on loans	$ 35,178		$ 18,180
ASC 326
Loans
Allowance for credit losses on loans		$ 18,385
LIABILITIES
Allowance for credit losses on OBS credit exposure		326
Pre-ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		18,180
LIABILITIES
Allowance for credit losses on OBS credit exposure		50
Impact of ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		205
LIABILITIES
Allowance for credit losses on OBS credit exposure		276
Residential Mortgage | ASC 326
Loans
Allowance for credit losses on loans		7,202
Residential Mortgage | Pre-ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		5,141
Residential Mortgage | Impact of ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		2,061
Commercial Mortgage | ASC 326
Loans
Allowance for credit losses on loans		9,545
Commercial Mortgage | Pre-ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		10,992
Commercial Mortgage | Impact of ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		(1,447)
Home Equity | ASC 326
Loans
Allowance for credit losses on loans		256
Home Equity | Pre-ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		461
Home Equity | Impact of ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		(205)
Commercial & Industrial | ASC 326
Loans
Allowance for credit losses on loans		896
Commercial & Industrial | Pre-ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		1,388
Commercial & Industrial | Impact of ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		(492)
Consumer | ASC 326
Loans
Allowance for credit losses on loans		486
Consumer | Pre-ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		198
Consumer | Impact of ASC 326 Adoption | ASC 326
Loans
Allowance for credit losses on loans		$ 288

Cash and Cash Equivalents - Add

Cash and Cash Equivalents - Additional Information (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	$ 60,742,000	$ 61,335,000
Pledged cash collateral to derivative counterparties	37,400,000	10,400,000
Federal Reserve Bank of Boston
Cash And Cash Equivalents [Line Items]
Reserve balance of cash and due from banks	0	31,500,000
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, 2020	Dec. 31, 2019
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Amortized Cost	$ 130,761	$ 141,109
Available for sale securities, Gross Unrealized Gains	3,477	231
Available for sale securities, Gross Unrealized Losses	(11)	(1,010)
Available for sale securities, Fair Value	134,227	140,330
Held to maturity securities, Amortized Cost	244,551	258,172
Held to maturity securities, Gross Unrealized Gains	12,598	6,119
Held to maturity securities, Gross Unrealized Losses	(28)	(177)
Held to maturity securities, Fair Value	257,121	264,114
Total, Amortized Cost	375,312	399,281
Total, Gross Unrealized Gains	16,075	6,350
Total, Gross Unrealized Losses	(39)	(1,187)
Total, Fair Value	391,348	404,444
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Amortized Cost	91,169	84,433
Held to maturity securities, Gross Unrealized Gains	4,815	3,252
Held to maturity securities, Gross Unrealized Losses	(28)	(66)
Held to maturity securities, Fair Value	95,956	87,619
Mortgage Backed Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Amortized Cost	115,020	103,109
Available for sale securities, Gross Unrealized Gains	2,728	231
Available for sale securities, Gross Unrealized Losses	(9)	(858)
Available for sale securities, Fair Value	117,739	102,482
Held to maturity securities, Amortized Cost	146,398	161,759
Held to maturity securities, Gross Unrealized Gains	7,520	2,751
Held to maturity securities, Gross Unrealized Losses		(111)
Held to maturity securities, Fair Value	153,918	164,399
U.S. GSE Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Amortized Cost	13,000	38,000
Available for sale securities, Gross Unrealized Gains	734
Available for sale securities, Gross Unrealized Losses		(152)
Available for sale securities, Fair Value	13,734	37,848
Held to maturity securities, Amortized Cost		5,000
Held to maturity securities, Fair Value		5,000
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Amortized Cost	2,741
Available for sale securities, Gross Unrealized Gains	15
Available for sale securities, Gross Unrealized Losses	(2)
Available for sale securities, Fair Value	2,754
Held to maturity securities, Amortized Cost	6,984	6,980
Held to maturity securities, Gross Unrealized Gains	263	116
Held to maturity securities, Fair Value	$ 7,247	$ 7,096

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, 2020	Dec. 31, 2019
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Available for sale securities, Fair Value, Less than 12 months	$ 781	$ 46,293
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, Less than 12 months	(2)	(353)
Temporarily Impaired Securities, Available for sale securities, Fair Value, 12 months or longer	5,318	75,702
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, 12 months or longer	(9)	(657)
Temporarily Impaired Securities, Available for sale securities, Fair Value	6,099	121,995
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses	(11)	(1,010)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, Less than 12 months	8,365	19,772
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, Less than 12 months	(28)	(93)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, 12 months or longer		17,928
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, 12 months or longer		(84)
Temporarily Impaired Securities, Held to maturity securities, Fair Value	8,365	37,700
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses	(28)	(177)
Temporarily Impaired Securities, Fair Value, Less than 12 months	9,146	66,065
Temporarily Impaired Securities, Unrealized Losses, Less than 12 months	(30)	(446)
Temporarily Impaired Securities, Fair Value, 12 months or longer	5,318	93,630
Temporarily Impaired Securities, Unrealized Losses, 12 months or longer	(9)	(741)
Temporarily Impaired Securities, Fair Value	14,464	159,695
Temporarily Impaired Securities, Unrealized Losses	(39)	(1,187)
U.S. GSE Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Available for sale securities, Fair Value, Less than 12 months		12,912
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, Less than 12 months		(88)
Temporarily Impaired Securities, Available for sale securities, Fair Value, 12 months or longer		24,936
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, 12 months or longer		(64)
Temporarily Impaired Securities, Available for sale securities, Fair Value		37,848
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses		(152)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, 12 months or longer		5,000
Temporarily Impaired Securities, Held to maturity securities, Fair Value		5,000
Mortgage Backed Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Available for sale securities, Fair Value, Less than 12 months		33,381
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, Less than 12 months		(265)
Temporarily Impaired Securities, Available for sale securities, Fair Value, 12 months or longer	5,318	50,766
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, 12 months or longer	(9)	(593)
Temporarily Impaired Securities, Available for sale securities, Fair Value	5,318	84,147
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses	(9)	(858)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, Less than 12 months		14,838
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, Less than 12 months		(27)
Temporarily Impaired Securities, Held to maturity securities, Fair Value, 12 months or longer		12,928
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, 12 months or longer		(84)
Temporarily Impaired Securities, Held to maturity securities, Fair Value		27,766
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses		(111)
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Available for sale securities, Fair Value, Less than 12 months	781
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses, Less than 12 months	(2)
Temporarily Impaired Securities, Available for sale securities, Fair Value	781
Temporarily Impaired Securities, Available for sale securities, Unrealized Losses	(2)
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Temporarily Impaired Securities, Held to maturity securities, Fair Value, Less than 12 months	8,365	4,934
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses, Less than 12 months	(28)	(66)
Temporarily Impaired Securities, Held to maturity securities, Fair Value	8,365	4,934
Temporarily Impaired Securities, Held to maturity securities, Unrealized Losses	$ (28)	$ (66)

Investment Securities - Additio

Investment Securities - Additional Information (Details)	Jun. 30, 2020USD ($)Security	Dec. 31, 2019USD ($)Security
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Number of debt securities with unrealized losses | Security	24	68
Aggregate depreciation percentage of gross unrealized losses from amortized cost	0.26%	0.74%
Percentage of unrealized loss on amortized cost	0.97%
Unrealized loss of amortized cost basis	$ 19,380
Maximum
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Percentage of unrealized loss on amortized cost		3.15%
Unrealized loss of amortized cost basis		$ 63,000
Unrealized dollar loss of amortized cost basis		$ 96,000
Percentage of unrealized dollar loss on amortized cost		1.93%

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, 2020	Dec. 31, 2019
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Within One Year, Amortized Cost	$ 1,001
Available for sale securities, Within One Year, Fair Value	1,003
Available for sale securities, After One, But Within Five Years, Amortized Cost	2,715
Available for sale securities, After One, But Within Five Years, Fair Value	2,729
Available for sale securities, After Five, But Within Ten Years, Amortized Cost	40,702
Available for sale securities, After Five, But Within Ten Years, Fair Value	42,290
Available for sale securities, After Ten Years, Amortized Cost	86,343
Available for sale securities, After Ten Years, Fair Value	88,205
Available for sale securities, Total, Amortized Cost	130,761
Available for sale securities, Total, Fair Value	134,227
Held to maturity securities, Within One Year, Amortized Cost	1,878
Held to maturity securities, Within One Year, Fair Value	1,893
Held to maturity securities, After One, But Within Five Years, Amortized Cost	22,365
Held to maturity securities, After One, But Within Five Years, Fair Value	23,165
Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	97,630
Held to maturity securities, After Five, But Within Ten Years, Fair Value	104,692
Held to maturity securities, After Ten Years, Amortized Cost	122,678
Held to maturity securities, After Ten Years, Fair Value	127,371
Held to maturity securities, Amortized Cost	244,551	$ 258,172
Held to maturity securities, Fair Value	257,121	264,114
Available for sale securities and Held to maturity securities, Within One Year, Amortized Cost	2,879
Available for sale securities and Held to maturity securities, Within One Year, Fair Value	2,896
Available for sale securities and Held to maturity securities, After One, But Within Five Years, Amortized Cost	25,080
Available for sale securities and Held to maturity securities, After One, But Within Five Years, Fair Value	25,894
Available for sale securities and Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	138,332
Available for sale securities and Held to maturity securities, After Five, But Within Ten Years, Fair Value	146,982
Available for sale securities and Held to maturity securities, After Ten Years, Amortized Cost	209,021
Available for sale securities and Held to maturity securities, After Ten Years, Fair Value	215,576
Available for sale securities and Held to maturity securities, Total, Amortized Cost	375,312
Available for sale securities and Held to maturity securities, Total, Fair Value	391,348
U.S. GSE Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
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	5,133
Available for sale securities, After Ten Years, Amortized Cost	8,000
Available for sale securities, After Ten Years, Fair Value	8,601
Available for sale securities, Total, Amortized Cost	13,000
Available for sale securities, Total, Fair Value	13,734
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	975
Available for sale securities, After One, But Within Five Years, Fair Value	978
Available for sale securities, After Five, But Within Ten Years, Amortized Cost	35,702
Available for sale securities, After Five, But Within Ten Years, Fair Value	37,157
Available for sale securities, After Ten Years, Amortized Cost	78,343
Available for sale securities, After Ten Years, Fair Value	79,604
Available for sale securities, Total, Amortized Cost	115,020
Available for sale securities, Total, Fair Value	117,739
Held to maturity securities, After One, But Within Five Years, Amortized Cost	2
Held to maturity securities, After One, But Within Five Years, Fair Value	2
Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	49,686
Held to maturity securities, After Five, But Within Ten Years, Fair Value	53,581
Held to maturity securities, After Ten Years, Amortized Cost	96,710
Held to maturity securities, After Ten Years, Fair Value	100,335
Held to maturity securities, Amortized Cost	146,398
Held to maturity securities, Fair Value	153,918
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Available for sale securities, Within One Year, Amortized Cost	1,001
Available for sale securities, Within One Year, Fair Value	1,003
Available for sale securities, After One, But Within Five Years, Amortized Cost	1,740
Available for sale securities, After One, But Within Five Years, Fair Value	1,751
Available for sale securities, Total, Amortized Cost	2,741
Available for sale securities, Total, Fair Value	2,754
Held to maturity securities, After One, But Within Five Years, Amortized Cost	6,984
Held to maturity securities, After One, But Within Five Years, Fair Value	7,247
Held to maturity securities, Amortized Cost	6,984
Held to maturity securities, Fair Value	7,247
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Held to maturity securities, Within One Year, Amortized Cost	1,878
Held to maturity securities, Within One Year, Fair Value	1,893
Held to maturity securities, After One, But Within Five Years, Amortized Cost	15,379
Held to maturity securities, After One, But Within Five Years, Fair Value	15,916
Held to maturity securities, After Five, But Within Ten Years, Amortized Cost	47,944
Held to maturity securities, After Five, But Within Ten Years, Fair Value	51,111
Held to maturity securities, After Ten Years, Amortized Cost	25,968
Held to maturity securities, After Ten Years, Fair Value	27,036
Held to maturity securities, Amortized Cost	91,169	84,433
Held to maturity securities, Fair Value	$ 95,956	$ 87,619

Investment Securities - Summa_2

Investment Securities - Summary of Gains (Losses) from Sale of Investment Securities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Investments Debt And Equity Securities [Abstract]
Amortized cost of securities sold	$ 10,752	$ 10,231	$ 10,752	$ 26,231
Gross gains realized on securities sold	69	63	69	63
Gross losses realized on securities sold		(57)		(144)
Net proceeds from securities sold	$ 10,821	$ 10,237	$ 10,821	$ 26,150

Investment Securities - Summa_3

Investment Securities - Summary of Credit Rating of Debt Securities Portfolio (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	$ 134,227	$ 140,330
Total held to maturity securities	244,551	258,172
Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total held to maturity securities	91,169	84,433
Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	2,754
Total held to maturity securities	6,984	6,980
U.S. GSE Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	13,734	37,848
Total held to maturity securities		5,000
AAA/AA/A
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	133,257
Total held to maturity securities	244,276
AAA/AA/A | Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total held to maturity securities	90,894
AAA/AA/A | Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	1,784
Total held to maturity securities	6,984
AAA/AA/A | U.S. GSE Obligations
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	13,734
BBB/BB/B
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	970
Total held to maturity securities	275
BBB/BB/B | Municipal Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total held to maturity securities	275
BBB/BB/B | Corporate Debt Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	970
Mortgage Backed Securities
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	117,739	102,482
Total held to maturity securities	146,398	$ 161,759
Mortgage Backed Securities | AAA/AA/A
Schedule of Available for Sale Securities and Held to Maturity Securities [Line Items]
Total available for sale securities	117,739
Total held to maturity securities	$ 146,398

Loans and the Allowance for C_3

Loans and the Allowance for Credit Losses - Loans Outstanding by Category (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Loans And Leases Receivable Disclosure [Line Items]
Total loans	$ 3,332,884	$ 2,226,728
Residential Mortgage
Loans And Leases Receivable Disclosure [Line Items]
Deferred costs (fees) net of unearned fees	2,834	2,176
Total loans	1,351,308	917,566
Residential Mortgage | Construction
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	37,366	17,374
Residential Mortgage | Mortgages - Fixed Rate
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	535,633	430,877
Residential Mortgage | Mortgages - Adjustable Rate
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	775,475	467,139
Commercial Mortgage
Loans And Leases Receivable Disclosure [Line Items]
Deferred costs (fees) net of unearned fees	1,098	144
Total loans	1,413,427	1,060,574
Commercial Mortgage | Construction
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	188,433	76,288
Commercial Mortgage | Mortgages - Nonowner Occupied
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	1,073,856	870,047
Commercial Mortgage | Mortgages - Owner Occupied
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	150,040	114,095
Home Equity
Loans And Leases Receivable Disclosure [Line Items]
Deferred costs (fees) net of unearned fees	247	240
Total loans	116,067	80,675
Home Equity | Home Equity - Lines of Credit
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	110,014	73,880
Home Equity | Home Equity - Term Loans
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	5,806	6,555
Commercial & Industrial
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	418,455	133,337
Unearned fees, net of deferred costs	(4,212)	(101)
Total loans	414,243	133,236
Consumer
Loans And Leases Receivable Disclosure [Line Items]
Deferred costs (fees) net of unearned fees	21	25
Total loans	37,839	34,677
Consumer | Secured
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	36,941	33,453
Consumer | Unsecured
Loans And Leases Receivable Disclosure [Line Items]
Loans outstanding by category gross	$ 877	$ 1,199

Loans and the Allowance for C_4

Loans and the Allowance for Credit Losses - Non-performing Loans Disaggregated by Loan Category (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due >90 days, but still accruing	$ 1,889,000
Troubled debt restructurings	262,000	$ 227,000
Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due >90 days, but still accruing	1,536,000
Commercial Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Loans past due >90 days, but still accruing	353,000
Non-Performing Loans
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	8,100,000	4,160,000
Loans past due >90 days, but still accruing	1,889,000	1,264,000
Troubled debt restructurings	262,000	227,000
Total	10,251,000	5,651,000
Non-Performing Loans | Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	3,284,000	1,298,000
Loans past due >90 days, but still accruing	1,536,000	527,000
Troubled debt restructurings	137,000	99,000
Total	4,957,000	1,924,000
Non-Performing Loans | Commercial Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	4,752,000	2,800,000
Loans past due >90 days, but still accruing	353,000	486,000
Total	5,105,000	3,286,000
Non-Performing Loans | Home Equity
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	12,000	12,000
Total	12,000	12,000
Non-Performing Loans | Commercial & Industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Non-accrual loans	52,000	50,000
Loans past due >90 days, but still accruing		251,000
Troubled debt restructurings	125,000	128,000
Total	$ 177,000	$ 429,000

Loans and the Allowance for C_5

Loans and the Allowance for Credit Losses - Additional Information (Details)	Jun. 01, 2020USD ($)	Jun. 30, 2020USD ($)Loan	Jun. 30, 2020USD ($)Loan	Dec. 31, 2019USD ($)Loan
Financing Receivable Modifications [Line Items]
Interest income on nonaccrual loans		$ 0	$ 0
Number of TDRs defaulted during the period | Loan		0	0	1
Number of loans determined to be troubled debt restructurings | Loan			3	3
Troubled debt restructuring carrying value		$ 262,000	$ 262,000	$ 227,000
Number of loans modified as troubled debt restructuring | Loan		0	0	0
Allowance for credit losses on loans		$ 35,178,000	$ 35,178,000	$ 18,180,000
Specific allowances for troubled debt restructurings				87,000
Loans in deferral		174,600,000	174,600,000
Total loans		3,332,884,000	3,332,884,000	2,226,728,000
Commitments to lend additional funds to borrowers whose loans were on non-accrual status		0	0	0
Other real estate owned		2,000,000	2,000,000	163,000
Loans secured by one- to-four family residential properties in process of foreclosure		339,000	339,000	339,000
Wellesley Bancorp Inc
Financing Receivable Modifications [Line Items]
Allowance for credit losses on loans		434,000	434,000
Total loans		19,386,000	19,386,000
Wellesley Bancorp Inc | Credit Deteriorated Loans
Financing Receivable Modifications [Line Items]
Total loans		19,400,000	19,400,000
Fair value of acquired PCD loans	$ 18,600,000
Financing receivable discount	825,000
Reduction in fair value of acquired PCD loans	$ 438,000
Troubled Debt Restructurings
Financing Receivable Modifications [Line Items]
Troubled debt restructuring carrying value				$ 128,000
Allowance for credit losses on loans		$ 91,000	$ 91,000

Loans and the Allowance for C_6

Loans and the Allowance for Credit Losses - Schedule of Outstanding Balance and Related Allowance on PCD Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	$ 3,332,884	$ 2,226,728
ACL Balance	35,178	18,180
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	1,351,308	917,566
ACL Balance	11,880	5,141
Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	1,413,427	1,060,574
ACL Balance		10,905
Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	116,067	80,675
ACL Balance		461
Commercial & Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	414,243	133,236
ACL Balance	2,939	$ 1,475
Wellesley Bancorp Inc
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	19,386
ACL Balance	434
Wellesley Bancorp Inc | Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	1,106
ACL Balance	35
Wellesley Bancorp Inc | Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	16,850
ACL Balance	380
Wellesley Bancorp Inc | Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	112
Wellesley Bancorp Inc | Commercial & Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Loan Balance	1,318
ACL Balance	$ 19

Loans and the Allowance for C_7

Loans and the Allowance for Credit Losses - Loans Receivable Disaggregated by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment [Line Items]
Loans receivable	$ 3,332,884	$ 2,226,728
Residential Mortgage
Financing Receivable Recorded Investment [Line Items]
2020	198,574
2019	273,846
2018	222,077
2017	192,956
2016	126,033
Prior	337,822
Total	1,351,308
Loans receivable	1,351,308	917,566
Residential Mortgage | Performing
Financing Receivable Recorded Investment [Line Items]
2020	198,574
2019	273,846
2018	220,751
2017	191,361
2016	125,926
Prior	335,893
Total	1,346,351
Loans receivable		915,642
Residential Mortgage | Non-Performing Loans
Financing Receivable Recorded Investment [Line Items]
2018	1,326
2017	1,595
2016	107
Prior	1,929
Total	4,957
Loans receivable		1,924
Home Equity
Financing Receivable Recorded Investment [Line Items]
2020	2,455
2019	7,323
2018	11,597
2017	7,443
2016	2,564
Prior	8,780
Revolving loans amortized cost basis	75,905
Total	116,067
Loans receivable	116,067	80,675
Home Equity | Performing
Financing Receivable Recorded Investment [Line Items]
2020	2,455
2019	7,323
2018	11,597
2017	7,443
2016	2,564
Prior	8,780
Revolving loans amortized cost basis	75,893
Total	116,055
Loans receivable		80,663
Home Equity | Non-Performing Loans
Financing Receivable Recorded Investment [Line Items]
Revolving loans amortized cost basis	12
Total	12
Loans receivable		12
Consumer
Financing Receivable Recorded Investment [Line Items]
2020	8,210
2019	9,443
2018	3,012
2017	3,042
2016	4,998
Prior	8,558
Revolving loans amortized cost basis	576
Total	37,839
Loans receivable	37,839	34,677
Consumer | Performing
Financing Receivable Recorded Investment [Line Items]
2020	8,210
2019	9,443
2018	3,012
2017	3,042
2016	4,998
Prior	8,558
Revolving loans amortized cost basis	576
Total	37,839
Loans receivable		34,677
Commercial Mortgage
Financing Receivable Recorded Investment [Line Items]
2020	151,422
2019	425,500
2018	253,254
2017	129,646
2016	153,450
Prior	300,155
Total	1,413,427
Loans receivable	1,413,427	1,060,574
Commercial Mortgage | 1-6 (Pass)
Financing Receivable Recorded Investment [Line Items]
2020	151,422
2019	424,598
2018	252,673
2017	128,003
2016	153,142
Prior	288,586
Total	1,398,424
Commercial Mortgage | 7 (Special Mention)
Financing Receivable Recorded Investment [Line Items]
2019	161
2018	581
2017	1,643
2016	88
Prior	10,048
Total	12,521
Commercial Mortgage | 8 (Substandard)
Financing Receivable Recorded Investment [Line Items]
2019	741
2016	220
Prior	847
Total	1,808
Commercial Mortgage | 9 (Doubtful)
Financing Receivable Recorded Investment [Line Items]
Prior	674
Total	674
Commercial & Industrial
Financing Receivable Recorded Investment [Line Items]
2020	213,650
2019	62,096
2018	66,082
2017	21,835
2016	20,770
Prior	14,526
Revolving loans amortized cost basis	15,284
Total	414,243
Loans receivable	414,243	133,236
Commercial & Industrial | 1-6 (Pass)
Financing Receivable Recorded Investment [Line Items]
2020	213,211
2019	60,282
2018	65,278
2017	21,345
2016	17,442
Prior	14,100
Revolving loans amortized cost basis	14,776
Total	406,434
Loans receivable		123,900
Commercial & Industrial | 7 (Special Mention)
Financing Receivable Recorded Investment [Line Items]
2020	439
2019	421
2018	468
2017	490
2016	72
Prior	243
Revolving loans amortized cost basis	20
Total	2,153
Loans receivable		4,289
Commercial & Industrial | 8 (Substandard)
Financing Receivable Recorded Investment [Line Items]
2019	1,393
2018	336
2016	3,256
Prior	183
Revolving loans amortized cost basis	488
Total	5,656
Loans receivable		5,047
Commercial Mortgage
Financing Receivable Recorded Investment [Line Items]
Loans receivable	$ 1,413,427	1,060,574
Commercial Mortgage | 1-6 (Pass)
Financing Receivable Recorded Investment [Line Items]
Loans receivable		1,050,037
Commercial Mortgage | 7 (Special Mention)
Financing Receivable Recorded Investment [Line Items]
Loans receivable		7,360
Commercial Mortgage | 8 (Substandard)
Financing Receivable Recorded Investment [Line Items]
Loans receivable		$ 3,177

Loans and the Allowance for C_8

Loans and the Allowance for Credit Losses - Schedule of Loans Receivable Disaggregated by Past Due Status (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	$ 14,857	$ 15,645
Current Loans	3,318,027	2,211,083
Total loans	3,332,884	2,226,728
Amortized Cost 90+ Days and Accruing	1,889
30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	5,012	9,854
60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	2,407	1,332
90 Days or Greater
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	7,438	4,459
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	8,705	10,846
Current Loans	1,342,603	906,720
Total loans	1,351,308	917,566
Amortized Cost 90+ Days and Accruing	1,536
Residential Mortgage | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	4,061	8,710
Residential Mortgage | 60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	1,307	1,089
Residential Mortgage | 90 Days or Greater
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	3,337	1,047
Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	4,694	3,972
Current Loans	1,408,733	1,056,602
Total loans	1,413,427	1,060,574
Amortized Cost 90+ Days and Accruing	353
Commercial Mortgage | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	718	811
Commercial Mortgage | 90 Days or Greater
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	3,976	3,161
Commercial & Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	1,174	749
Current Loans	413,069	132,487
Total loans	414,243	133,236
Commercial & Industrial | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	218	272
Commercial & Industrial | 60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	831	226
Commercial & Industrial | 90 Days or Greater
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	125	251
Consumer loans
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	3	9
Current Loans	37,836	34,668
Total loans	37,839	34,677
Consumer loans | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	3	4
Consumer loans | 60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due		5
Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	281	69
Current Loans	115,786	80,606
Total loans	116,067	80,675
Home Equity | 30-59 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	12	57
Home Equity | 60-89 Days Past Due
Financing Receivable Allowance For Credit Losses [Line Items]
Total Principal Balance/Past Due	$ 269	$ 12

Loans and the Allowance for C_9

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, 2020	Jun. 30, 2020
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance		$ 18,180
Allowance for credit losses-loan portfolio, Ending Balance	$ 35,178	35,178
Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	20,163	18,180
Provision for acquired loans	8,282	8,282
Initial allowance for PCD	437	437
Charge-offs	(158)	(448)
Recoveries	23	48
Provision for (Release of)-loan portfolio	5,267	7,310
Allowance for credit losses-loan portfolio, Ending Balance	34,014	34,014
Funded Commitments | ASC 326
Financing Receivable Allowance For Credit Losses [Line Items]
Adoption of ASC 326		205
Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	283	50
Provision for (Release of)-loan portfolio	525	482
Acquired loan commitments	356	356
Allowance for credit losses- unfunded commitments	1,164	1,164
Unfunded Commitments | ASC 326
Financing Receivable Allowance For Credit Losses [Line Items]
Adoption of ASC 326		276
Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Ending Balance	652	652
Home Equity | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	310	461
Provision for acquired loans	188	188
Provision for (Release of)-loan portfolio	154	208
Allowance for credit losses-loan portfolio, Ending Balance	652	652
Home Equity | Funded Commitments | ASC 326
Financing Receivable Allowance For Credit Losses [Line Items]
Adoption of ASC 326		(205)
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance		5,141
Allowance for credit losses-loan portfolio, Ending Balance	11,880	11,880
Residential Mortgage | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	7,477	5,141
Provision for acquired loans	2,880	2,880
Initial allowance for PCD	35	35
Provision for (Release of)-loan portfolio	1,488	1,763
Allowance for credit losses-loan portfolio, Ending Balance	11,880	11,880
Residential Mortgage | Funded Commitments | ASC 326
Financing Receivable Allowance For Credit Losses [Line Items]
Adoption of ASC 326		2,061
Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Ending Balance	18,067	18,067
Commercial Mortgage | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	10,881	10,905
Provision for acquired loans	3,625	3,625
Initial allowance for PCD	382	382
Charge-offs	(77)	(264)
Provision for (Release of)-loan portfolio	3,256	4,866
Allowance for credit losses-loan portfolio, Ending Balance	18,067	18,067
Commercial Mortgage | Funded Commitments | ASC 326
Financing Receivable Allowance For Credit Losses [Line Items]
Adoption of ASC 326		(1,447)
Commercial & Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance		1,475
Allowance for credit losses-loan portfolio, Ending Balance	2,939	2,939
Commercial & Industrial | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	946	1,475
Provision for acquired loans	1,577	1,577
Initial allowance for PCD	20	20
Charge-offs	(65)	(154)
Recoveries	22	34
Provision for (Release of)-loan portfolio	439	479
Allowance for credit losses-loan portfolio, Ending Balance	2,939	2,939
Commercial & Industrial | Funded Commitments | ASC 326
Financing Receivable Allowance For Credit Losses [Line Items]
Adoption of ASC 326		(492)
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance		198
Allowance for credit losses-loan portfolio, Ending Balance	476	476
Consumer | Funded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	549	198
Provision for acquired loans	12	12
Charge-offs	(16)	(30)
Recoveries	1	14
Provision for (Release of)-loan portfolio	(70)	(6)
Allowance for credit losses-loan portfolio, Ending Balance	476	476
Consumer | Funded Commitments | ASC 326
Financing Receivable Allowance For Credit Losses [Line Items]
Adoption of ASC 326		288
Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Ending Balance	1,164	1,164
Unfunded Commitments | Unfunded Commitments
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses-loan portfolio, Beginning Balance	283	50
Provision for (Release of)-loan portfolio	525	482
Acquired loan commitments	356	356
Allowance for credit losses- unfunded commitments	$ 1,164	1,164
Unfunded Commitments | Unfunded Commitments | ASC 326
Financing Receivable Allowance For Credit Losses [Line Items]
Adoption of ASC 326		$ 276

Loans and the Allowance for _10

Loans and the Allowance for Credit Losses - Summary of Changes in Allowance for Loan Losses Disaggregated by Loan Category (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	$ 16,652	$ 16,768
Charge-offs	(164)	(205)
Recoveries	16	33
Provision for (Release of)	595	503
Allowance for loan losses, Ending balance	17,099	17,099
Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	534	517
Provision for (Release of)	(3)	14
Allowance for loan losses, Ending balance	531	531
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	5,256	4,946
Provision for (Release of)	207	517
Allowance for loan losses, Ending balance	5,463	5,463
Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	9,369	9,626
Charge-offs	(55)	(55)
Provision for (Release of)	115	(142)
Allowance for loan losses, Ending balance	9,429	9,429
Commercial & Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	1,245	1,415
Charge-offs	(100)	(130)
Recoveries	12	25
Provision for (Release of)	288	135
Allowance for loan losses, Ending balance	1,445	1,445
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	248	264
Charge-offs	(9)	(20)
Recoveries	4	8
Provision for (Release of)	(12)	(21)
Allowance for loan losses, Ending balance	$ 231	$ 231

Loans and the Allowance for _11

Loans and the Allowance for Credit Losses - Summary of Impaired Financing Receivables (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Financing Receivable Allowance For Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	$ 4,019
With no required reserve recorded, Average Carrying Value	2,172
With no required reserve recorded, Unpaid Principal Balance	5,449
With no required reserve recorded, Interest Income Recognized	41
With required reserve recorded, Carrying Value	128
With required reserve recorded, Average Carrying Value	59
With required reserve recorded, Unpaid Principal Balance	167
With required reserve recorded, Related Allowance	87
With required reserve recorded, Interest Income Recognized	41
Carrying Value	4,147
Average Carrying Value	2,231
Unpaid Principal Balance	5,616
Related Allowance	87
Commercial & Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
With required reserve recorded, Carrying Value	128
With required reserve recorded, Average Carrying Value	59
With required reserve recorded, Unpaid Principal Balance	167
With required reserve recorded, Related Allowance	87
Carrying Value	128
Average Carrying Value	59
Unpaid Principal Balance	167
Related Allowance	87
Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	3,161
With no required reserve recorded, Average Carrying Value	1,385
With no required reserve recorded, Unpaid Principal Balance	4,376
With no required reserve recorded, Interest Income Recognized	35
With required reserve recorded, Interest Income Recognized	35
Carrying Value	3,161
Average Carrying Value	1,385
Unpaid Principal Balance	4,376
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	765
With no required reserve recorded, Average Carrying Value	691
With no required reserve recorded, Unpaid Principal Balance	940
With no required reserve recorded, Interest Income Recognized	5
With required reserve recorded, Interest Income Recognized	5
Carrying Value	765
Average Carrying Value	691
Unpaid Principal Balance	940
Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
With no required reserve recorded, Carrying Value	93
With no required reserve recorded, Average Carrying Value	96
With no required reserve recorded, Unpaid Principal Balance	133
With no required reserve recorded, Interest Income Recognized	1
With required reserve recorded, Interest Income Recognized	1
Carrying Value	93
Average Carrying Value	96
Unpaid Principal Balance	$ 133

Loans and the Allowance for _12

Loans and the Allowance for Credit Losses - Summary of Allowance for Credit Losses and Related Loans Receivable Disaggregated by Impairment Method (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable Allowance For Credit Losses [Line Items]
Individually evaluated for impairment		$ 87
Collectively evaluated for impairment		18,093
Allowance for loan losses	$ 35,178	18,180
Individually evaluated for impairment		4,145
Collectively evaluated for impairment		2,222,583
Total loans	3,332,884	2,226,728
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Collectively evaluated for impairment		5,141
Allowance for loan losses	11,880	5,141
Individually evaluated for impairment		764
Collectively evaluated for impairment		916,802
Total loans	1,351,308	917,566
Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Collectively evaluated for impairment		10,905
Allowance for loan losses		10,905
Individually evaluated for impairment		3,161
Collectively evaluated for impairment		1,057,413
Total loans	1,413,427	1,060,574
Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Collectively evaluated for impairment		461
Allowance for loan losses		461
Individually evaluated for impairment		92
Collectively evaluated for impairment		80,583
Total loans	116,067	80,675
Commercial & Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Individually evaluated for impairment		87
Collectively evaluated for impairment		1,388
Allowance for loan losses	2,939	1,475
Individually evaluated for impairment		128
Collectively evaluated for impairment		133,108
Total loans	414,243	133,236
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Collectively evaluated for impairment		198
Allowance for loan losses	476	198
Collectively evaluated for impairment		34,677
Total loans	$ 37,839	$ 34,677

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Apr. 17, 2019
Finite Lived Intangible Assets [Line Items]
Carrying value of goodwill	$ 51,912,000		$ 51,912,000		$ 31,206,000
Impairment of goodwill recognized			0		0
Carrying value of intangible asset	3,158,000		$ 3,158,000		$ 3,338,000
Mortgage Servicing Rights
Finite Lived Intangible Assets [Line Items]
Weighted average amortization period			3 years 6 months		5 years 2 months 12 days
Loans held for sale	2,600,000		$ 2,600,000		$ 1,600,000
Amount of mortgage loans sold and servicing rights retained			9,500,000	$ 867,000
Net gains recognized in gain on loans held for sale	193,000	$ 15,000	312,000	31,000
Fair value of mortgage servicing rights portfolio	1,100,000	1,100,000	1,100,000	1,100,000
Optima Bank And Trust Company
Finite Lived Intangible Assets [Line Items]
Carrying value of goodwill						$ 30,800,000
Optima Bank And Trust Company | Core Deposit Intangibles
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired			3,600
Amortization of intangible asset	90,000	$ 90,000	180,000	$ 90,000
Carrying value of intangible asset	$ 3,200,000		$ 3,200,000		$ 3,300,000
Weighted average amortization period			9 years

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Schedule of Mortgage Servicing Rights (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning Balance, Mortgage servicing rights	$ 1,347	$ 666
Mortgage servicing rights acquired as a result of the merger, Mortgage servicing rights	50	334
Mortgage servicing rights capitalized, Mortgage servicing rights	90	7
Amortization charged against servicing income, Mortgage servicing rights	(244)	(106)
Ending Balance, Mortgage servicing rights	1,243	901
Beginning Balance, Valuation allowance	(26)
Change in impairment reserve, Valuation allowance	(97)	(10)
Ending Balance, Valudation allowance	(123)	(10)
Beginning Balance, Total	1,321	666
Mortgage servicing rights acquired as a result of the merger, Total	50	334
Mortgage servicing rights capitalized, Total	90	7
Amortization charged against servicing income, Total	(244)	(106)
Change in impairment reserve, Total	(97)	(10)
Ending Balance, Total	$ 1,120	$ 891

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Schedule of Aggregate Estimated Future Amortization Expense (Details) - Mortgage Servicing Rights $ in Thousands	Jun. 30, 2020USD ($)
Future Amortization Expense
Remainder of 2020	$ 169
2021	282
2022	213
2023	158
2024	117
2025	23
Thereafter	281
Total	$ 1,243

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Effective tax rate	23.90%	26.50%	21.60%	23.90%
Net deferred tax assets	$ 11,855,000		$ 11,855,000		$ 8,229,000
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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Current income tax expense
Federal	$ 2,598	$ 1,305	$ 2,120	$ 1,676
State	1,186	552	1,460	719
Total current income tax expense	3,784	1,857	3,580	2,395
Deferred income tax expense / (benefit)
Federal	(2,956)	(217)	(1,356)	601
State	(1,368)	(100)	(703)	284
Total deferred income tax expense / (benefit)	(4,324)	(317)	(2,059)	885
Total income tax expense / (benefit)	$ (540)	$ 1,540	$ 1,521	$ 3,280

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Plan
Net periodic benefit cost (credit)
Interest cost	$ 297	$ 414	$ 717	$ 840
Expected return on assets	(921)	(651)	(1,600)	(1,360)
Amortization of prior service credit	(1)	(1)	(2)	(2)
Amortization of net actuarial (gain) loss	(39)	77		77
Net periodic benefit cost (credit)	(664)	(161)	(885)	(445)
Supplemental Retirement Plan
Net periodic benefit cost (credit)
Service cost	106	75	177	143
Interest cost	55	85	142	175
Amortization of net actuarial (gain) loss	4		4
Net periodic benefit cost (credit)	165	160	323	318
Postretirement Healthcare Plan
Net periodic benefit cost (credit)
Service cost	10	5	16	10
Interest cost	5	6	11	12
Amortization of net actuarial (gain) loss	1	(1)		(2)
Net periodic benefit cost (credit)	$ 16	$ 10	$ 27	$ 20

Pension and Retirement Plans _2

Pension and Retirement Plans - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2020
Profit Sharing Plan | 401(k)
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, maximum employee contribution, percent			100.00%
Profit Sharing Plan | Discretionary Contribution
Defined Benefit Plan Disclosure [Line Items]
Normal retirement age of employees			65 years
Profit Sharing Plan | Maximum | 401(k)
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plan, employer matching contribution, percent			4.00%
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	$ 892,000	$ 552,000	$ 1,900,000	$ 1,100,000
Defined Contribution Supplemental Executive Retirement Plan (“DC SERP”)
Defined Benefit Plan Disclosure [Line Items]
Contribution expense related to plans	52,000	43,000	$ 95,000	86,000
Defined contribution plan, employer matching contribution, percent			10.00%
Qualified Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined benefit pension plan	$ 0	$ 0	$ 0	$ 0
Scenario Forecast | Qualified Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined benefit pension plan					$ 0

Stock Based Compensation - Sche

Stock 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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share Based Compensation [Abstract]
Stock based compensation expense	$ 1,331	$ 699	$ 2,311	$ 1,318
Related tax benefits	$ 372	$ 197	$ 645	$ 370

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, 2020	Dec. 31, 2019
Standby Letters of Credit
Financial instruments whose contractual amount represents credit risk:
Financial instruments with off-balance-sheet risk	$ 9,060	$ 9,150
Unused Portion of Existing Lines of Credit
Financial instruments whose contractual amount represents credit risk:
Financial instruments with off-balance-sheet risk	571,113	428,020
Origination of New Loans
Financial instruments whose contractual amount represents credit risk:
Financial instruments with off-balance-sheet risk	70,207	24,413
Commitments to Sell Residential Mortgage Loans
Financial instruments whose notional amount exceeds the amount of credit risk:
Financial instrument notional amount exceeds credit risk	$ 25,253	$ 3,909

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Commitments and Contingencies [Line Items]
Description of operating lease expiration terms			operating leases and their terms expire between 2020 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
Right-of-use asset operating leases	$ 38,912		$ 38,912		$ 33,587
Total rental expense	1,500	$ 1,400	3,000	$ 2,700
Wellesley Bancorp Inc
Commitments and Contingencies [Line Items]
Right-of-use asset operating leases	$ 5,300		$ 5,300

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Operating lease cost	$ 1,598	$ 1,321	$ 2,995	$ 2,501
Variable lease cost (Cost excluded from lease payments)	1		1
Sublease income	(16)	(16)	(33)	(32)
Total Operating Lease Cost	1,582	1,305	2,963	2,469
Other Information
Cash paid for amounts included in the measurement of lease liabilities - operating cash flows for operating leases	1,560	1,231	2,924	2,308
Operating Lease - Operating cash flows (Liability reduction)	$ 1,278	937	$ 2,360	1,744
Right-of-use assets obtained in exchange for new operating lease liabilities		$ 4,656		$ 4,656
Weighted average lease term - operating leases	7 years 3 months 3 days	8 years 6 months 21 days	7 years 3 months 3 days	8 years 6 months 21 days
Weighted average discount rate - operating leases	2.95%	3.38%	2.95%	3.38%

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, 2020	Dec. 31, 2019
Operating Leases Future Minimum Payments Due [Abstract]
Remainder of 2020	$ 7,257
2021	7,005
2022	6,590
2023	6,115
2024	4,790
Thereafter	13,547
Total minimum lease payments	45,304
Less: interest	(4,851)
Total lease liability	$ 40,453	$ 35,054

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Details)	6 Months Ended
	Jun. 30, 2020
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Current expected capital loss period	3 years
Percentage of changes in allowance for credit losses	25.00%
Maximum
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Current expected capital loss period	2 years

Shareholders' Equity - Minimum

Shareholders' Equity - Minimum Capital Requirements were Considered Well Capitalized by FRB and FDIC (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual, Amount	$ 367,800,000	$ 272,727,000
Tier I capital (to risk-weighted assets), Actual, Amount	322,702,000	254,497,000
Common equity tier I capital (to risk-weighted assets), Actual, Amount	322,702,000	254,497,000
Tier I capital (to average assets), Actual, Amount	$ 322,702,000	$ 254,497,000
Total capital (to risk-weighted assets), Actual, Ratio	13.00%	13.60%
Tier I capital (to risk-weighted assets), Actual, Ratio	11.40%	12.70%
Common equity tier I capital (to risk-weighted assets), Actual, Ratio	11.40%	12.70%
Tier I capital (to average assets), Actual, Ratio	10.00%	9.00%
Total capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	$ 297,382,000	$ 210,342,000
Tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	240,738,000	170,277,000
Common equity tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	198,255,000	140,228,000
Tier I capital (to average assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	$ 129,195,000	$ 113,365,000
Total capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	10.50%	10.50%
Tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	8.50%	8.50%
Common equity tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	7.00%	7.00%
Tier I capital (to average assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	4.00%	4.00%
Cambridge Trust Company
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk-weighted assets), Actual, Amount	$ 359,380,000	$ 271,034,000
Tier I capital (to risk-weighted assets), Actual, Amount	324,202,000	252,804,000
Common equity tier I capital (to risk-weighted assets), Actual, Amount	324,202,000	252,804,000
Tier I capital (to average assets), Actual, Amount	$ 324,202,000	$ 252,804,000
Total capital (to risk-weighted assets), Actual, Ratio	12.70%	13.50%
Tier I capital (to risk-weighted assets), Actual, Ratio	11.40%	12.60%
Common equity tier I capital (to risk-weighted assets), Actual, Ratio	11.40%	12.60%
Tier I capital (to average assets), Actual, Ratio	10.00%	8.90%
Total capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	$ 297,356,000	$ 210,341,000
Tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	240,717,000	170,276,000
Common equity tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	198,237,000	140,227,000
Tier I capital (to average assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Amount	$ 129,192,000	$ 113,364,000
Total capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	10.50%	10.50%
Tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	8.50%	8.50%
Common equity tier I capital (to risk-weighted assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	7.00%	7.00%
Tier I capital (to average assets), Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer, Ratio	4.00%	4.00%
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	$ 283,196,000	$ 200,325,000
Tier I capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	226,557,000	160,260,000
Common equity tier I capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	184,077,000	130,211,000
Tier I capital (to average assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Amount	$ 161,490,000	$ 141,705,000
Total capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier I capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	8.00%	8.00%
Common equity tier I capital (to risk-weighted assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	6.50%	6.50%
Tier I capital (to average assets), Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%	5.00%

Other Comprehensive Income - Su

Other Comprehensive Income - Summary of Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Unrealized gains/(losses) on available for sale securities, before tax amount
Unrealized holding gains/(losses), before tax amount	$ 1,077	$ 1,909	$ 4,318	$ 3,334
Reclassification adjustment for (gains)/losses recognized in net income, before tax amount	(73)	(6)	(73)	81
Derivatives, before tax amount
Change in interest rate contracts, before tax amount	374	1,696	6,260	1,654
Defined benefit retirement plans, before tax amount
Change in retirement liability, before tax amount	(1)	36	(2)	72
Total Other Comprehensive Income/(Loss), before tax amount	1,377	3,635	10,503	5,141
Unrealized gains/(losses) on available for sale securities, tax (expense) or benefit
Unrealized holding gains/(losses), tax (expense) or benefit	(267)	(456)	(1,008)	(786)
Reclassification adjustment for (gains)/losses recognized in net income, tax (expense) or benefit	16	2	16	(19)
Derivatives, tax (expense) or benefit
Change in interest rate contracts, tax (expense) or benefit	(104)	(477)	(1,744)	(465)
Defined benefit retirement plans, tax (expense) or benefit
Change in retirement liability, tax (expense) or benefit	1	(10)	1	(20)
Total Other Comprehensive Income/(Loss), tax (expense) or benefit	(354)	(941)	(2,735)	(1,290)
Unrealized gains/(losses) on available for sale securities, net-of-tax amount
Unrealized holding gains/(losses), net-of-tax amount	810	1,453	3,310	2,548
Reclassification adjustment for (gains)/losses recognized in net income, net-of-tax amount	(57)	(4)	(57)	62
Derivatives, net-of-tax amount
Change in interest rate contracts, net-of-tax amount	270	1,219	4,516	1,189
Defined benefit retirement plans, net-of-tax amount
Change in retirement liability, net-of-tax amount		26	(1)	52
Other comprehensive income	$ 1,023	$ 2,694	$ 7,768	$ 3,851

Other Comprehensive Income - _2

Other Comprehensive Income - Summary of Reclassifications out of AOCI Impact on Net Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains (losses) on available for sale securities	$ 69	$ 6	$ 69	$ (81)
Tax benefit (expense)	540	(1,540)	(1,521)	(3,280)
Net (loss) income	(1,716)	4,272	5,516	10,470
Reclassifications out of Accumulated Other Comprehensive Income
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains (losses) on available for sale securities	73	6	73	(81)
Tax benefit (expense)	(16)	(2)	(16)	19
Net (loss) income	$ 57	$ 4	$ 57	$ (62)

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net (loss) income	$ (1,716)	$ 4,272	$ 5,516	$ 10,470
Less dividends and undistributed earnings allocated to participating securities	1	(35)	(10)	(94)
Net (loss) income applicable to common shareholders	$ (1,715)	$ 4,237	$ 5,506	$ 10,376
Denominator:
Weighted average number of shares outstanding, basic	5,912,889	4,682,109	5,652,908	4,379,141
(Loss) Earnings per common share – basic	$ (0.29)	$ 0.91	$ 0.97	$ 2.37
Numerator:
Net (loss) income	$ (1,716)	$ 4,272	$ 5,516	$ 10,470
Less dividends and undistributed earnings allocated to participating securities		(35)	(9)	(94)
Net (loss) income applicable to common shareholders	$ (1,716)	$ 4,237	$ 5,507	$ 10,376
Denominator:
Weighted average number of shares outstanding, basic	5,912,889	4,682,109	5,652,908	4,379,141
Dilutive effect of common stock equivalents		34,000	17,000	33,000
Weighted average diluted common shares outstanding	5,912,889	4,715,724	5,670,438	4,412,239
(Loss) Earnings per common share – diluted	$ (0.29)	$ 0.90	$ 0.97	$ 2.35

Derivatives And Hedging Activ_3

Derivatives And Hedging Activities - Summary of Fair Values of Derivative Instruments in the Company's Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	$ 55,732	$ 15,912
Derivative Liabilities, Fair value	47,250	13,230
Derivatives Designated as Hedging Instruments
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	9,074	2,911
Derivatives Designated as Hedging Instruments | Interest Rate Contracts
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Notional amount	150,000	150,000
Derivatives Designated as Hedging Instruments | Interest Rate Contracts | Other Assets
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	9,074	2,911
Derivatives Not Designated as Hedging Instruments
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	46,658	13,001
Derivative Liabilities, Fair value	47,250	13,230
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Interest Rate Swaps with Customers
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Notional amount	399,354	241,187
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Interest Rate Swaps with Customers | Other Assets
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Assets, Fair value	46,576	12,980
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Mirror Swaps with Counterparties
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Liabilities, Notional Amount	399,354	241,187
Derivatives Not Designated as Hedging Instruments | Loan Related Derivative Contracts | Mirror Swaps with Counterparties | Other Liabilities
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative Liabilities, Fair value	46,576	12,980
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	26,580	19,000
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	82	21
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	113,676	88,489
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	$ 674	$ 250

Derivatives And Hedging Activ_4

Derivatives And Hedging Activities - Summary of Cash Flow Hedge Accounting on AOCI (Details) - Cash Flow Hedging - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest Income
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) Reclassified from AOCI into Income	$ 503	$ (48)	$ 615	$ (96)
Amount of Gain or (Loss) Recognized in OCI - Included Component	542		703
Amount of Gain or (Loss) Recognized in OCI - Excluded Component	(39)	(48)	(88)	(96)
Interest Rate Contracts
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) Recognized in OCI	374	1,647	6,260	1,558
Amount of Gain or (Loss) Recognized in OCI - Included Component	413	2,080	7,047	2,080
Amount of Gain or (Loss) Recognized in OCI - Excluded Component	$ (39)	$ (433)	$ (787)	$ (522)

Derivatives And Hedging Activ_5

Derivatives And Hedging Activities - Additional Information (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Estimated amount will be reclassified out of AOCI in to earnings	$ 2,500
Fair value of derivative liability	47,250	$ 13,230
Minimum collateral posting threshold of derivative counterparties	37,400	10,400
Notional amount	37,300	9,600
Minimum
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Minimum collateral posting threshold of derivative counterparties	37,300	10,400
Accrued Interest
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Fair value of derivative liability	$ 37,300	$ 9,600

Derivatives And Hedging Activ_6

Derivatives And Hedging Activities - Summary of Derivative Financial Instruments on the Consolidated Statements of Income (Loss) (Details) - Interest Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Total amount of income presented in the statements of income (loss) statement in which the effects of cash flow hedges are recorded	$ 503	$ (48)	$ 615	$ (96)
Interest Rate Contracts
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of gain reclassed from AOCI into income	503	(48)	615	(96)
Amount of gain reclassed from AOCI into income - Included Component	542		703
Amount of loss reclassed from AOCI into income - Excluded Component	$ (39)	$ (48)	$ (88)	$ (96)

Derivatives And Hedging Activ_7

Derivatives And Hedging Activities - Summary of Derivative Financial Instruments Not Designated as Hedging Instruments on the Consolidated Statements of Income (Loss) (Details) - Derivatives Not Designated as Hedging Instruments - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) on Derivatives Recognized in Income	$ 152	$ (61)	$ 330	$ 13
Other contracts | Other Income
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Amount of Gain or (Loss) on Derivatives Recognized in Income	$ 152	$ (61)	$ 330	$ 13

Derivatives And Hedging Activ_8

Derivatives And Hedging Activities - Schedule of Financial Instruments Eligible for Offset in Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Offsetting [Abstract]
Gross Amounts Recognized, Derivative assets	$ 55,732	$ 15,912
Net Amounts Recognized, Derivative Assets	55,732	15,912
Gross Amounts Not Offset, Financial Instruments, Derivative Assets	9,242	3,128
Gross Amounts Not Offset, Net amount, Derivative Assets	46,490	12,784
Gross Amounts Recognized, Derivative Liabilities	47,250	13,230
Net Amounts Recognized, Derivative Liabilities	47,250	13,230
Gross Amounts Not Offset, Financial Instruments, Derivative Liabilities	9,242	3,128
Gross Amounts Not Offset, Collateral Pledged (Received), Derivative Liabilities	37,334	9,645
Gross Amounts Not Offset, Net amount, Derivative Liabilities	$ 674	$ 457

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Carrying Values and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financial assets
Securities available for sale	$ 134,227	$ 140,330
Securities held to maturity	257,121	264,114
FHLB Boston stock	9,262	7,854
Recurring Basis | Carrying Value
Financial assets
Cash and cash equivalents	60,742	61,335
Securities available for sale	134,227	140,330
Securities held to maturity	244,551	258,172
Loans, net	3,298,870	2,208,548
Loans held for sale	2,614	1,546
FHLB Boston stock	9,262	7,854
Accrued interest receivable	8,631	7,052
Mortgage servicing rights	1,120	1,321
Interest rate contracts	9,074	2,911
Loan level interest rate swaps	46,576	12,980
Risk participation agreements out to counterparties	82	21
Financial liabilities
Deposits	3,275,843	2,358,878
Borrowings	237,897	135,691
Subordinated debt	9,920
Loan level interest rate swaps	46,576	12,980
Risk participation agreements in with counterparties	674	250
Recurring Basis | Estimated Fair Value
Financial assets
Cash and cash equivalents	60,742	61,335
Securities available for sale	134,227	140,330
Securities held to maturity	257,121	264,114
Loans, net	3,242,624	2,160,087
Loans held for sale	3,228	2,051
FHLB Boston stock	9,262	7,854
Accrued interest receivable	8,631	7,052
Mortgage servicing rights	1,120	1,526
Interest rate contracts	9,074	2,911
Loan level interest rate swaps	46,576	12,980
Risk participation agreements out to counterparties	82	21
Financial liabilities
Deposits	3,279,768	2,358,089
Borrowings	239,658	135,744
Subordinated debt	9,920
Loan level interest rate swaps	46,576	12,980
Risk participation agreements in with counterparties	$ 674	$ 250

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, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	$ 134,227	$ 140,330
U.S. GSE Obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	13,734	37,848
Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	2,754
Recurring Basis | U.S. GSE Obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	13,734	37,848
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	13,734	37,848
Recurring Basis | Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	117,739	102,482
Recurring Basis | Mortgage Backed Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	117,739	102,482
Recurring Basis | Corporate Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	2,754
Recurring Basis | Corporate Debt Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities available for sale	2,754
Recurring Basis | Interest Rate Swaps with Customers
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	46,576	12,980
Recurring Basis | Interest Rate Swaps with Customers | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	46,576	12,980
Recurring Basis | Risk Participation Agreements Out to Counterparties
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	82	21
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	82	21
Recurring Basis | Interest Rate Contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	9,074	2,911
Recurring Basis | Interest Rate Contracts | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets	9,074	2,911
Recurring Basis | Mirror Swaps with Counterparties
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other liabilities	46,576	12,980
Recurring Basis | Mirror Swaps with Counterparties | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other liabilities	46,576	12,980
Recurring Basis | Risk Participation Agreements in With Counterparties
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other liabilities	674	250
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	$ 674	$ 250

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, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	$ 12,576	$ 4,250
Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	2,614	1,546
Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	9,962	2,704
Collateral Dependent Impaired Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis		2,541
Collateral Dependent Impaired Loans | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis		2,541
Mortgage Servicing Rights
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	1,120
Mortgage Servicing Rights | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	1,120
Loans Held for Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	2,614	1,546
Loans Held for Sale | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	2,614	1,546
Individually Assessed Collateral Dependent Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	6,872
Individually Assessed Collateral Dependent Loans | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	6,872
Other Real Estate Owned
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	1,970	163
Other Real Estate Owned | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value, non-recurring basis	$ 1,970	$ 163

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Gain (loss) on REO assets	$ 486,000	$ 0	$ 486,000	$ 0
Transfers between levels	$ 0	$ 0	$ 0	$ 0