Randolph Bancorp (RNDB) 10-K 12 Mar 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 29, 2020	Jun. 30, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Trading Symbol	RNDB
Entity Registrant Name	Randolph Bancorp, Inc.
Entity Central Index Key	0001667161
Current Fiscal Year End Date	--12-31
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, par value $.01 per share
Entity Incorporation, State or Country Code	MA
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		5,567,917
Entity Shell Company	false
Entity File Number	001-37780
Entity Tax Identification Number	81-1844402
Entity Address, Address Line One	10 Cabot Place
Entity Address, City or Town	Stoughton
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02072
City Area Code	781
Local Phone Number	963-2100
Document Annual Report	true
Document Transition Report	false
Entity Public Float			$ 70,667,426
Documents Incorporated by Reference	Portions of the Registrant’s Proxy Statement for its 2020 Annual Meeting of Shareholders are incorporated by reference into Part III of this Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 4,371	$ 3,451
Interest-bearing deposits	3,881	3,667
Total cash and cash equivalents	8,252	7,118
Certificates of deposit	490	2,205
Securities available for sale, at fair value	57,503	50,556
Loans held for sale, at fair value	62,792	38,474
Loans, net of allowance for loan losses of $4,280 in 2019 and $4,437 in 2018	469,131	483,846
Federal Home Loan Bank of Boston stock, at cost	2,417	4,700
Accrued interest receivable	1,393	1,504
Mortgage servicing rights, net	8,556	7,786
Premises and equipment, net	5,748	6,368
Bank-owned life insurance	8,441	8,256
Foreclosed real estate, net		65
Other assets	6,281	3,462
Total assets	631,004	614,340
Deposits:
Noninterest-bearing	61,603	64,229
Interest bearing	344,581	312,321
Brokered	90,858	60,580
Total deposits	497,042	437,130
Federal Home Loan Bank of Boston advances	44,403	89,036
Mortgagors' escrow accounts	2,052	2,129
Post-employment benefit obligations	2,464	2,551
Other liabilities	6,581	5,533
Total liabilities	552,542	536,379
Commitments and contingencies (Note 16)
Stockholders' Equity:
Preferred stock, no par value; authorized: 1,000,000 shares; issued: none
Common stock, $.01 par value; authorized: 15,000,000 shares; issued and outstanding: 5,576,855 shares at December 31, 2019 and 5,903,793 shares at December 31, 2018	56	60
Additional paid-in capital	51,127	55,608
Retained earnings	31,757	28,329
ESOP-Unearned compensation	(3,944)	(4,132)
Accumulated other comprehensive loss, net of tax	(534)	(1,904)
Total stockholders' equity	78,462	77,961
Total liabilities and stockholders' equity	$ 631,004	$ 614,340

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Loans, allowance for loan losses	$ 4,280	$ 4,437
Preferred stock, par value	$ 0	$ 0
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	15,000,000	15,000,000
Common stock, shares issued	5,576,855	5,903,793
Common stock, shares outstanding	5,576,855	5,903,793

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Interest and dividend income:
Loans	$ 23,631	$ 19,541
Securities-taxable	1,467	1,318
Securities-tax exempt	43	120
Interest-bearing deposits and certificates of deposit	90	305
Total interest and dividend income	25,231	21,284
Interest expense:
Deposits	5,328	3,070
Federal Home Loan Bank of Boston advances	2,070	1,518
Total interest expense	7,398	4,588
Net interest income	17,833	16,696
Provision for loan losses		762
Net interest income after provision for loan losses	17,833	15,934
Non-interest income:
Customer service fees	1,407	1,464
Gain on loan origination and sale activities, net	18,900	7,539
Mortgage servicing fees, net	394	1,264
Gain (loss) on sales/calls of securities and impairment write-down, net	16	(11)
Increase in cash surrender value of life insurance	185	218
Gain on sales of buildings		2,476
Other	761	733
Total non-interest income	21,663	13,683
Non-interest expenses:
Salaries and employee benefits	24,896	19,765
Occupancy and equipment	2,783	2,873
Data processing	810	692
Professional fees	1,185	1,164
Marketing	967	1,141
Restructuring charges		968
Other	5,309	5,069
Total non-interest expenses	35,950	31,672
Income (loss) before income taxes	3,546	(2,055)
Income tax expense	118	31
Net income (loss)	$ 3,428	$ (2,086)
Weighted average common shares outstanding (basic and diluted)	5,383,617	5,570,720
Income (loss) per common share (basic and diluted)	$ 0.64	$ (0.37)

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Net income (loss)		$ 3,428	$ (2,086)
Securities available for sale:
Unrealized holding gains (losses)		1,517	(721)
Reclassification adjustment for net (gains) losses and impairment write-down realized in income	[1]	(16)	11
Net unrealized gain (loss)		1,501	(710)
Net-of-tax amount		1,501	(710)
Net-of-tax amount		(131)	(27)
Total other comprehensive income (loss)		1,370	(737)
Comprehensive income (loss)		4,798	(2,823)
Supplemental Retirement Plan [Member]
Securities available for sale:
Actuarial losses	[2]	36	41
Prior service credits recognized	[2]	(84)	(89)
Actuarial gains (losses) arising during the year		(83)	21
Net change in supplemental retirement plan		$ (131)	$ (27)
[1]	Amounts are included in gain (loss) on sales/calls of securities and impairment write-down, net in the consolidated statements of operations.
[2]	Amounts are included in other non-interest expenses in the consolidated statements of operations.

Consolidated Statements Changes

Consolidated Statements Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Unearned Compensation ESOP [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning balance at Dec. 31, 2017	$ 81,483	$ 61	$ 56,493	$ 30,415	$ (4,319)	$ (1,167)
Beginning balance, shares at Dec. 31, 2017		6,034,276
Net income (loss)	(2,086)			(2,086)
Other comprehensive income (loss)	(737)					(737)
Stock repurchased	(1,716)	$ (1)	(1,715)
Stock repurchased, shares		(109,910)
Restricted stock awards forfeited, shares		(15,710)
Share redemption for tax withholdings for restricted stock vesting	(81)		(81)
Share redemption for tax with holdings for restricted stock vesting, shares		(4,863)
Stock-based compensation	797		797
ESOP shares committed to be released	301		114		187
Ending balance at Dec. 31, 2018	77,961	$ 60	55,608	28,329	(4,132)	(1,904)
Ending balance, shares at Dec. 31, 2018		5,903,793
Net income (loss)	3,428			3,428
Other comprehensive income (loss)	1,370					1,370
Stock repurchased	(5,438)	$ (4)	(5,434)
Stock repurchased, shares		(353,572)
Restricted stock awards granted, shares		33,335
Restricted stock awards forfeited, shares		(2,500)
Share redemption for tax withholdings for restricted stock vesting	(61)		(61)
Share redemption for tax with holdings for restricted stock vesting, shares		(4,201)
Stock-based compensation	919		919
ESOP shares committed to be released	283		95		188
Ending balance at Dec. 31, 2019	$ 78,462	$ 56	$ 51,127	$ 31,757	$ (3,944)	$ (534)
Ending balance, shares at Dec. 31, 2019		5,576,855

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ 3,428,000	$ (2,086,000)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Provision for loan losses		762,000
Loans originated for sale	(913,656,000)	(393,251,000)
Net gain on sales of mortgage loans	(18,900,000)	(7,539,000)
Proceeds from sales of mortgage loans	913,548,000	391,149,000
Net amortization of securities	187,000	183,000
Net change in deferred loan costs and fees, and purchase premiums	102,000	(56,000)
(Gain) loss on sales/calls of securities and impairment write-down	(16,000)	11,000
Gain on sales of buildings		(2,476,000)
Depreciation and amortization	857,000	835,000
Impairment write-down on property and equipment		166,000
Impairment write-down on foreclosed real estate		36,000
Stock-based compensation	919,000	797,000
ESOP expense	283,000	301,000
Increase in cash surrender value of life insurance	(185,000)	(218,000)
Net increase in mortgage servicing rights	(770,000)	(1,389,000)
Other, net	(2,272,000)	1,484,000
Net cash used in operating activities	(16,475,000)	(11,291,000)
Cash flows from investing activities:
Redemptions of certificates of deposit	1,715,000	735,000
Securities available for sale:
Sales	534,000	8,958,000
Calls/maturities	500,000	5,562,000
Purchases	(12,395,000)	(9,993,000)
Principal payments on mortgage-backed securities	5,760,000	5,589,000
Loan originations, net of principal repayments	(8,583,000)	(96,088,000)
Proceeds from sale of portfolio loans	23,689,000	25,038,000
Loan purchases and participations	(5,412,000)	(16,180,000)
Redemptions (purchases) of Federal Home Loan Bank of Boston stock, net	2,283,000	(1,390,000)
Proceeds from sale of foreclosed real estate	61,000
Proceeds from sales of buildings		5,834,000
Purchases of premises and equipment	(237,000)	(1,430,000)
Net cash provided by (used in) investing activities	7,915,000	(73,365,000)
Cash flows from financing activities:
Net increase in non-brokered deposits	29,634,000	16,820,000
Net increase in brokered deposits	30,278,000	53,474,000
Net increase (decrease) in short-term Federal Home Loan Bank of Boston borrowings	(62,862,000)	17,945,000
Issuance of long-term Federal Home Loan Bank of Boston advances	20,000,000
Repayments of long-term Federal Home Loan Bank of Boston advances	(1,771,000)	(4,863,000)
Net increase (decrease) in mortgagors' escrow accounts	(77,000)	1,222,000
Repurchases of common stock	(5,438,000)	(1,716,000)
Stock repurchase payable	(70,000)	70,000
Net cash provided by financing activities	9,694,000	82,952,000
Net change in cash and cash equivalents	1,134,000	(1,704,000)
Cash and cash equivalents at beginning of year	7,118,000	8,822,000
Cash and cash equivalents at end of year	8,252,000	7,118,000
Supplemental cash flow information:
Interest paid on deposits and borrowed funds	7,057,000	4,390,000
Income taxes paid (refunded), net	(266,000)	33,000
Non-cash items:
Donation of land, net	73,000
Transfer of portfolio loans to held for sale	$ 28,608,000	28,057,000
Transfer of property and equipment to assets held for sale		$ 2,897,000

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	1. BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations Envision Bank (the “Bank”) provides a variety of financial services to individuals and small businesses through its five branch offices in Massachusetts and twelve loan production offices and lending centers located throughout Massachusetts and Southern New Hampshire. The Bank’s primary deposit products are checking, savings and term certificate accounts and its primary lending products are residential and commercial mortgage loans. The Bank is also actively involved in the sale and servicing of residential mortgage loans in the secondary market. The Federal Deposit Insurance Corporation (“FDIC”) provides insurance coverage on all deposits up to $250,000 per depositor. As an FDIC insured institution, the Bank is subject to supervision, examination and regulation by the FDIC. Additionally, as a Massachusetts chartered savings bank, the Bank’s depositors are also insured by the Depositors Insurance Fund (“DIF”), a private industry-sponsored insurance company. The DIF insures bank deposits in excess of the FDIC insurance limits. Basis of Presentation The consolidated financial statements include the accounts of Randolph Bancorp, Inc. (a Massachusetts corporation) and its wholly-owned subsidiary, Envision Bank (together, the “Company”). The Bank has subsidiaries involved in owning investment securities and foreclosed real estate and a subsidiary which provides loan closing services. All intercompany accounts and transactions have been eliminated in consolidation. The following significant accounting and reporting policies of the Company conform to U.S. generally accepted accounting principles (“GAAP”) and are used in preparing and presenting these consolidated financial statements. Use of estimates In preparing consolidated financial statements in conformity with GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the consolidated balance sheet and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near term relate to the allowance for loan losses, mortgage servicing rights, deferred tax assets and fair value measurements. Cash and cash equivalents Cash equivalents include amounts due from banks, federal funds sold on a daily basis and interest-bearing deposits with original maturities of ninety days or less. Certificates of deposit Certificates of deposit have original maturities ranging from one to five years and are carried at cost. Fair value hierarchy The Company groups its assets and liabilities that are measured at fair value in three levels based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. Level 1 – Valuation is based on quoted prices in active markets for identical assets and liabilities. Valuations are obtained from readily available pricing sources. Level 2 – Valuation is based on observable inputs other than Level 1 prices, such as quoted prices for similar assets and liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets and liabilities. Level 3 – Valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities. Level 3 assets and liabilities include those for which the value is determined using unobservable inputs to pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. Transfers between levels are recognized at the end of a reporting period, if applicable. Securities All securities are classified as available for sale and are recorded at fair value, with unrealized gains and losses excluded from earnings and reported in other comprehensive income/loss. Purchase premiums and discounts are recognized in interest income using the level yield method over the terms of the securities. Anticipated prepayments on mortgage-backed securities are used in applying this method. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. On a quarterly basis, the Company evaluates all securities with a decline in fair value below the amortized cost of the investment to determine whether or not the impairment is deemed to be other than temporary (“OTTI”). OTTI is required to be recognized: (1) if the Company intends to sell the security; (2) if it is “more likely than not” that the Company will be required to sell the security before recovery of its amortized cost basis; or (3) for debt securities, if the present value of expected cash flows is not sufficient to recover the entire amortized cost basis. For all impaired debt securities that the Company intends to sell, or more likely than not will be required to sell, the full amount of the decline in fair value is recognized as OTTI through earnings. For all other impaired debt securities, credit-related OTTI is recognized through earnings and non-credit related OTTI is recognized in other comprehensive income/loss, net of applicable taxes. Because the Company’s assessments are based on available factual information as well as subjective information, the determination as to whether an OTTI exists and, if so, the amount of impairment, is subjective and, therefore, the timing and amount of OTTI constitute material estimates that are subject to significant change. Federal Home Loan Bank of Boston stock The Bank, as a member of the Federal Home Loan Bank of Boston (“FHLBB”), is required to maintain an investment in capital stock of the FHLBB. Based on redemption provisions of the FHLBB, the stock has no quoted market value and is carried at cost. The Company periodically evaluates for impairment based on ultimate recovery of its cost basis in the FHLBB stock. Loans held for sale and related derivatives The origination of residential mortgage loans is an integral part of the Company’s business. The Company generally sells its originations of such loans in the secondary market to either government-sponsored enterprises (“GSEs”) or other financial institutions. The servicing of loans sold to GSEs is generally retained while loans sold to other financial institutions are generally done on a servicing released basis. The Bank utilizes the fair value option pursuant to Accounting Standards Codification (“ASC”) 825, “Financial Instruments” for its residential mortgage loans being held for sale. Fair value is determined based on either commitments in effect from investors or prevailing market price and include the value of mortgage servicing rights. Gains and losses on the sales of loans are determined using the specific identification method. In determining the amount of the gain or loss the Company takes into consideration the direct costs of originating the loan. Also included in the net gain on loan origination and sale activities presented in the accompanying statements of operations are fair value adjustments for mortgage banking derivatives (interest rate lock commitments with borrowers, and forward loan sale commitments with investors for the delivery of mortgage loans to third party investors including To Be Announced securities (“TBAs”)) and loans held for sale. Loans The Company grants residential real estate, commercial real estate, construction, commercial and consumer loans to customers. A substantial portion of the loan portfolio is represented by mortgage loans in Massachusetts and Rhode Island. The ability of the Company’s borrowers to honor their contracts is affected by real estate values and general economic conditions in these markets. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off are reported at their outstanding unpaid principal balances adjusted for charge-offs, the allowance for loan losses, and net deferred loan origination fees and costs and purchase premiums. Interest income is accrued on the unpaid principal balance. Certain direct loan origination costs and purchase premiums, net of origination fees, are deferred and recognized in interest income using the level yield method without anticipating prepayments. Interest is not accrued on loans which are ninety days or more past due, or when, in the judgment of management, the collectability of the principal or interest becomes doubtful. Past due status is based on contractual terms of the loan. Interest income previously accrued on such loans is reversed against current period earnings. Loans are returned to accrual status when all principal and interest amounts contractually due are brought current and future payments are reasonably assured. The Company periodically may agree to modify the contractual terms of loans. When a loan is modified and a concession is made to a borrower experiencing financial difficulty, the modification is considered a troubled debt restructuring (“TDR”). All TDRs are initially classified as impaired and placed on nonaccrual status. Generally, a nonaccrual loan that is restructured remains on nonaccrual for a period of six months to demonstrate that the borrower can meet the restructured terms. If the borrower’s ability to meet the revised terms is not reasonably assured, the loan remains on nonaccrual status. Allowance for loan losses The allowance for loan losses is a valuation allowance for probable incurred credit losses. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses is evaluated on a regular basis and is based upon management’s periodic review of the collectibility of the loans in light of historical experience, the nature and volume of the loan portfolio, adverse situations that may affect the borrower’s ability to repay, estimated value of any underlying collateral and prevailing economic conditions. This evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as either additional information becomes available or circumstances change. The allowance for loan losses is allocated to loan types using both a formula-based approach applied to groups of loans (general component) and an analysis of certain individual loans for impairment (allocated component). General component The general component of the allowance for loan losses covers loans that are collectively evaluated for impairment and is based on historical loss experience adjusted for qualitative factors stratified by loan segments. Management uses a rolling average of historical losses based on a trailing 48 month time frame appropriate to capture relevant loss data for each loan segment. This historical loss factor is supplemented by the following qualitative factors: levels/trends in delinquencies; trends in volume and terms of loans; effects of changes in risk selection and underwriting standards and other changes in lending policies, procedures and practices; experience/ability/depth of lending management and staff; national and local economic trends and conditions, regulatory and legal factors; and risk rating concentrations. The qualitative factors are determined based on the various risk characteristics of each loan segment. Risk characteristics relevant to each portfolio segment are as follows: Residential one-to four-family real estate – The Company generally does not originate loans with a loan-to-value ratio greater than 80 percent. All loans in this segment are collateralized by one-to four-family owner, and non-owner-occupied, residential real estate and repayment is dependent on the credit quality of the individual borrower. The overall health of the economy, including unemployment rates and housing prices, will have an effect on the credit quality in this segment. Second mortgages and home equity lines of credit (HELOC) – Loans in this segment are primarily secured by second-position liens, and the Company may or may not also have a first-position lien. Regardless of which creditor is in first position, the Company does not originate loans with a combined loan-to-value ratio greater than 80 percent. All loans in this segment are collateralized by owner-occupied residential real estate and repayment is dependent on the credit quality of the individual borrower. The overall health of the economy, including unemployment rates and housing prices, will have an effect on the credit quality in this segment. Commercial real estate – Loans in this segment consist of owner-occupied and non-owner-occupied property primarily located in Massachusetts and Rhode Island. The underlying cash flows generated by the operating entities of owner-occupied real estate support the associated debt. Rental cash flows, for which management obtains periodic rent rolls, support the debt associated with non-owner-occupied real estate and can be negatively impacted by increased vacancy rates. Construction – Loans in this segment primarily include residential real estate development loans for which payment is derived from sale of the property. Credit risk is affected by cost overruns, time to sell at an adequate price, and market conditions. Commercial and Industrial – Loans in this segment are made to businesses and are generally secured by assets of the business. Repayment is expected from the cash flows of the business. A weakened economy, and resultant decreased consumer spending, would have an effect on the credit quality in this segment. Consumer – Loans in this segment primarily include personal unsecured loans, refinanced student loans and auto loans purchased from third party lenders. Repayment is dependent on the credit quality of the individual borrower. Allocated component The allocated component of the allowance for loan losses relates to loans that are individually classified as impaired. Residential real estate, commercial and industrial, commercial real estate and construction loans are evaluated for impairment on a loan-by-loan basis. Impairment is measured by either the present value of expected future cash flows discounted at the loan’s effective interest rate, or the fair value of the collateral if the loan is collateral dependent. An allowance is established when the discounted cash flows (or collateral value) of the impaired loan are lower than the carrying value of that loan. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, the Company does not generally identify individual consumer loans or second mortgages and HELOCs for impairment disclosures unless such loans are 90 days past due or are classified as a troubled debt restructuring. A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Bank-owned life insurance Bank-owned life insurance policies are reflected on the consolidated balance sheets at their cash surrender value net of charges or other amounts that are probable at settlement. Changes in the net cash surrender value of the policies, as well as insurance proceeds received, are reflected in non-interest income in the consolidated statements of operations and are not subject to income taxes, unless such policies are surrendered prior to the death of the insured individuals. Mortgage servicing rights The Company services mortgage loans for others. Mortgage servicing rights are recognized as separate assets at fair value when rights are acquired through purchase or through sale of financial assets (“MSRs”). Capitalized servicing rights are amortized into mortgage servicing income in proportion to, and over the period of, the estimated future net servicing income of the underlying financial assets. MSRs are evaluated for impairment based upon the fair value of the rights as compared to amortized cost. Impairment is determined by stratifying rights by predominant risk characteristics, such as interest rates and terms. Fair value is based on a valuation model that calculates the present value of estimated future net servicing income, using market-based assumptions. Impairment is recognized through a valuation allowance for an individual stratum, to the extent that fair value is less than the capitalized amount for the stratum. Changes in the valuation allowance, if any, are reported in mortgage servicing income. Premises and equipment Land is carried at cost. Buildings, equipment and leasehold improvements are stated at cost, less accumulated depreciation and amortization computed predominantly on the straight-line method over the estimated useful lives of the assets or the expected terms of the leases, if shorter. Expected terms include lease option periods to the extent that the exercise of such options is reasonably assured. Premises and equipment held for sale are stated at the lower of amortized cost or fair value less costs to sell. Transfers of financial assets Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. During the normal course of business, the Company may transfer a portion of a financial asset, for example, a participation loan. In order to be eligible for sales treatment, all cash flows from the loan must be divided proportionately, the rights of each loan holder must have the same priority, the loan holders must have no recourse to the transferor other than standard representations and warranties, and no loan holder can have the right to pledge or exchange the entire loan. In certain cases, the Company may have an obligation to repurchase mortgage loans sold to third parties and to refund fees to the purchaser if a payment default or prepayment occurs, in each case within a prescribed time period not exceeding four months after the sale date, or in the case of a violation of its representations and warranties under the provisions of its loan sale agreements. The Company evaluates its obligations under these provisions and recognizes a liability for the fair value of its recourse obligations. At December 31, 2019 and 2018, the Company determined that its obligations in connection with the recourse provisions of its loan sale agreements were insignificant. Foreclosed real estate Real estate acquired through, or in lieu of, loan foreclosure are held for sale and are initially recorded at fair value, less costs to sell, at the date of foreclosure, establishing a new cost basis. Subsequent to foreclosure, valuations are periodically performed by management and the assets are carried at the lower of carrying amount or fair value less costs to sell. Revenue and expenses from operations, changes in the valuation allowance and any direct write-downs are included in foreclosed real estate expense. Supplemental retirement plan The Company accounts for its supplemental retirement plan using an actuarial model that allocates cost over the service period of participants in the plan. The Company accounts for the over-funded or under-funded status of the plan as an asset or liability in its consolidated balance sheets and recognizes changes in the funded status in the year in which the changes occur through other comprehensive income/loss. Employee Stock Ownership Plan Compensation expense for the Employee Stock Ownership Plan (“ESOP”) is computed based on the number of shares allocated to participants during the period multiplied by the average fair market value of the Company’s shares. This expense is recognized ratably throughout the year based on the expected allocation of shares for the year. Unearned compensation applicable to the ESOP is reflected as a reduction of stockholders’ equity. The difference between the average fair market value and cost of the shares allocated by the ESOP is recorded as an adjustment to additional paid-in capital. Stock-based compensation The fair value of restricted stock and stock options is determined on the date of grant and amortized to compensation expense with a corresponding increase to additional paid-in capital over the required service period, but in no event beyond the date of an employee’s or director’s date of termination. Forfeitures of unvested awards and grants are recorded as incurred. Advertising costs Advertising costs are expensed as incurred. Income taxes Deferred income tax assets and liabilities are determined using the liability (or balance sheet) method. Under this method, the net deferred tax asset or liability is determined based on the tax effects of the temporary differences between the book and tax basis of the various balance sheet assets and liabilities and gives current recognition to changes in tax rates and laws. A valuation allowance is established against deferred tax assets when, based upon available evidence including historical and projected taxable income, that some or all of the deferred tax assets will not be realized. A tax position is recognized as a benefit if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. The Company does not have any uncertain tax positions at December 31, 2019 and 2018 which require accrual or disclosure. The Company records interest and penalties as part of income tax expense. No interest or penalties were recorded for the years ended December 31, 2019 and 2018. Comprehensive income (loss) Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income (loss). Although certain changes in assets and liabilities are reported as a separate component of equity, such items, along with net income (loss), are components of comprehensive income (loss). The components of accumulated other comprehensive loss (“AOCI”), included in stockholders’ equity, are as follows: December 31, December 31, 2019 2018 (In thousands) Securities available for sale: Net unrealized gain (loss) $ 167 $ (1,334 ) Tax effect (313 ) (313 ) Net-of-tax amount (146 ) (1,647 ) Supplemental retirement plan Unrecognized net actuarial loss (652 ) (605 ) Unrecognized net prior service credit 311 395 (341 ) (210 ) Tax effect (47 ) (47 ) Net-of-tax amount (388 ) (257 ) Accumulated other comprehensive loss $ (534 ) $ (1,904 ) In 2020, the Company expects to recognize $83,000 in prior service credits and $45,000 in net actuarial losses as components of cost for the supplemental retirement plan. These amounts are included in accumulated other comprehensive loss at December 31, 2019. Prior service credits and net actuarial gains and losses are amortized to periodic pension cost over varying periods based on the plan participants to whom they relate. Segment reporting An operating segment is defined as a component of a business for which separate financial information is available that is evaluated regularly by the chief operating decision-maker in determining how to allocate resources and evaluate performance. The Company has two reporting business segments, namely, “Envision Bank” and “Envision Mortgage”. Management allocates indirect costs, such as IT, Marketing, Accounting and Administration, to each business segment in order to fully measure each segment’s results of operations. See Note 18 for disclosure of the Company’s segment information. Earnings (loss) per share Basic earnings (loss) per share represents income (loss) available to common stockholders divided by the weighted average of common shares outstanding during the period. Unvested restricted shares of common stock having dividend rights are treated as “participating securities” and, accordingly, are considered outstanding in computing basic earnings (loss) per share. Unallocated ESOP shares are not considered outstanding in computing earnings (loss) per share. Diluted earnings per share reflects additional common shares that would have been outstanding if dilutive potential shares had been issued. Stock options represent potential dilutive shares with the number of such shares computed using the treasury stock method. No options were included in the computation of earnings (loss) per share in 2019 and 2018 as their impact would be anti-dilutive. Business combinations We account for business combinations under the acquisition method of accounting. The application of this method of accounting requires the use of significant estimates and assumptions in the determination of the fair value of tangible and identified intangible assets acquired and liabilities assumed in order to properly allocate purchase price consideration between assets from those that are recorded as goodwill. Our estimates of the fair values of assets acquired and liabilities assumed are based upon assumptions that we believe to be reasonable, and whenever necessary, include assistance from independent third-party appraisal and valuation firms. Costs incurred to consummate a business combination are expensed as incurred. Recent accounting pronouncements On January 1, 2019, the Company early adopted Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers. In January 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-01, Financial Instruments In February 2016, FASB issued ASU 2016-02, Leases In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses In April 2017, the FASB issued ASU 2017-08 Receivables – Non-refundable Fees and Other Costs . In August 2018, the FASB issued ASU 2018-13 Fair Value Measurement – Changes to the Disclosure Requirements for Fair Value Measurement, . In December 2019, FASB issued ASU 2019-12, Income Taxes – Simplifying the Accounting for Income Taxes Reclassifications Certain reclassifications have been made to the 2018 consolidated financial statements in order to conform to the presentations used in the 2019 consolidated financial statements. Such reclassifications had no impact on net income (loss) as presented in such financial statements .

Securities Available for Sale

Securities Available for Sale	12 Months Ended
	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Securities Available for Sale	2 . SECURITIES AVAILABLE FOR SALE The amortized cost and fair value of securities available for sale, including gross unrealized gains and losses, are as follows: Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) December 31, 2019 U.S. Government-sponsored enterprises $ 4,000 $ 13 $ (1 ) $ 4,012 Corporate 1,513 15 — 1,528 Municipal 744 9 — 753 Residential mortgage-backed securities: U.S. Government-sponsored enterprises 35,238 458 (286 ) 35,410 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises 8,977 — (53 ) 8,924 U.S. Government-guaranteed 1,363 7 — 1,370 Collateralized mortgage obligations: U.S. Government-sponsored enterprises 1,395 23 — 1,418 U.S. Government-guaranteed 4,106 10 (28 ) 4,088 Total securities available for sale $ 57,336 $ 535 $ (368 ) $ 57,503 December 31, 2018 Debt securities: U.S. Government-sponsored enterprises $ 3,999 $ 13 $ (31 ) $ 3,981 Corporate 1,524 6 (18 ) 1,512 Municipal 1,489 18 — 1,507 Residential mortgage-backed securities: U.S. Government-sponsored enterprises 26,989 71 (754 ) 26,306 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises 9,094 — (487 ) 8,607 U.S. Government-guaranteed 1,796 — (33 ) 1,763 Collateralized mortgage obligations: U.S. Government-sponsored enterprises 1,642 — (17 ) 1,625 U.S. Government-guaranteed 4,839 2 (104 ) 4,737 Total debt securities 51,372 110 (1,444 ) 50,038 Mutual fund 518 — — 518 Total securities available for sale $ 51,890 $ 110 $ (1,444 ) $ 50,556 The amortized cost and fair value of debt securities by contractual maturity at December 31, 2019 are presented below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Fair Cost Value (In thousands) Within 1 year $ 4,501 $ 4,518 After 1 year through 5 years 1,512 1,522 After 5 years through 10 years 244 253 6,257 6,293 Mortgage-backed securities and collateralized mortgage obligations 51,079 51,210 $ 57,336 $ 57,503 Obligations of U.S. Government-sponsored enterprises consist primarily of securities issued by the Federal Home Loan Mortgage Corporation and the Federal National Mortgage Association. At December 31, 2019 and 2018, investment securities having a fair value of $2,013,000 and $2,010,000, respectively, were pledged as collateral for certain deposits and FHLBB borrowings. There were no individual holdings of investment securities at December 31, 2019 and 2018, other than holdings of the U.S. Government and its agencies, which exceeded 10% of the Company’s stockholders’ equity as of such dates. Information pertaining to securities with gross unrealized losses aggregated by investment category and length of time that individual securities have been in a continuous loss position follows: Less Over Twelve Months Gross Gross Unrealized Fair Unrealized Fair Losses Value Losses Value December 31, 2019 (In thousands) Debt securities: U.S. Government-sponsored enterprises $ — $ — $ (1 ) $ 1,999 Residential mortgage-backed securities: U.S. Government-sponsored enterprises (123 ) 11,256 (163 ) 9,632 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises (53 ) 8,924 — — Collateralized mortgage obligations: U.S. Government-guaranteed (15 ) 1,891 (13 ) 883 Total debt securities $ (191 ) $ 22,071 $ (177 ) $ 12,514 December 31, 2018 Debt securities: U.S. Government-sponsored enterprises $ — $ — $ (31 ) $ 1,969 Corporate (5 ) 497 (13 ) 506 Residential mortgage-backed securities: U.S. Government-sponsored enterprises (6 ) 7,038 (748 ) 12,981 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises — — (487 ) 8,607 U.S. Government-guaranteed — — (33 ) 1,763 Collateralized mortgage obligations: U.S. Government-sponsored enterprises — — (17 ) 1,625 U.S. Government-guaranteed — — (104 ) 3,879 Total debt securities $ (11 ) $ 7,535 $ (1,433 ) $ 31,330 At December 31, 2019, 26 debt securities have unrealized losses with aggregate depreciation of 1.05% from the Company’s amortized cost basis. The unrealized losses at December 31, 2019, which related primarily to mortgage-backed securities issued by U.S. government-sponsored enterprises, were primarily caused by changes in interest rates since their date of acquisition. The Company currently does not believe it is probable that it will be unable to collect all amounts due according to the contractual terms of these investments. Therefore, it is expected that the securities would not be settled at a price less than the par value of the investment. Because the Company does not intend to sell any debt securities and it is more likely than not that the Company will not be required to sell any debt securities before recovery of its amortized cost basis, it does not consider these investments to be other-than-temporarily impaired at December 31, 2019. For the year ended December 31, 2019, proceeds from the sale of a security amounted to $534,000, which resulted in a realized gain of $16,000. For the year ended December 31, 2018, proceeds from the sale of securities amounted to $8,958,000 which resulted in a realized gain of $49,000. In addition, losses of $33,000 and $27,000 were recognized upon prepayment of a commercial mortgage-backed security and an OTTI write-down of a mutual fund, respectively, in 2018.

Loans

Loans	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Loans	3 . LOANS A summary of the loan portfolio is as follows: December 31, 2019 2018 (In thousands) Mortgage loans on real estate: Residential: One-to four-family $ 244,711 $ 246,756 Home equity loans and lines of credit 41,669 43,545 Commercial 125,405 113,642 Construction 35,485 42,139 447,270 446,082 Commercial and industrial 9,093 21,285 Consumer 15,641 19,407 Total loans 472,004 486,774 Allowance for loan losses (4,280 ) (4,437 ) Net deferred loan costs and fees, and purchase premiums 1,407 1,509 $ 469,131 $ 483,846 The Company periodically transfers a portion of its originated commercial real estate loans to participating lenders. The amounts transferred have been accounted for as sales and are therefore not included in the Company’s accompanying consolidated balance sheets. The Company and participating lenders share ratably in any gains or losses that may result from a borrower’s lack of compliance with contractual terms of the loan. The Company continues to service the loans on behalf of the participating lenders and, as such, collects cash payments from the borrowers, remits payments (net of servicing fees) to participating lenders and disburses required escrow funds to relevant parties. At December 31, 2019 and 2018, the Company was servicing loans for participants aggregating $5,283,000 and $5,596,000, respectively. See Note 4 for information relating to the Company’s servicing of residential mortgage loans for others. The following tables present activity in the allowance for loan losses, by loan category, for the years ended December 31, 2019 and 2018 and allocation of the allowance to each category as of such dates: Second Residential Mortgages Commercial Commercial 1-4 Family and HELOC Real Estate Construction and Industrial Consumer Total (In thousands) Allowance for loan losses Balance at December 31, 2017 $ 854 $ 359 $ 1,620 $ 351 $ 335 $ 218 $ 3,737 Provision (credit) for loan losses 197 (67 ) 30 414 (70 ) 258 762 Loans charged-off — — (2 ) — — (119 ) (121 ) Recoveries 41 — — — — 18 59 Balance at December 31, 2018 1,092 292 1,648 765 265 375 4,437 Provision (credit) for loan losses (21 ) (3 ) 192 (73 ) (30 ) (65 ) — Loans charged-off — — — — — (192 ) (192 ) Recoveries 25 — — — — 10 35 Balance at December 31, 2019 $ 1,096 $ 289 $ 1,840 $ 692 $ 235 $ 128 $ 4,280 Second Residential Mortgages Commercial Commercial 1-4 Family and HELOC Real Estate Construction and Industrial Consumer Total December 31, 2019 Allowance for impaired loans $ 116 $ — $ — $ — $ — $ — $ 116 Allowance for non-impaired loans 980 289 1,840 692 235 128 4,164 Total allowance for loan losses $ 1,096 $ 289 $ 1,840 $ 692 $ 235 $ 128 $ 4,280 Impaired loans $ 5,640 $ 407 $ 46 $ — $ — $ — $ 6,093 Non-impaired loans 239,071 41,262 125,359 35,485 9,093 15,641 465,911 Total loans $ 244,711 $ 41,669 $ 125,405 $ 35,485 $ 9,093 $ 15,641 $ 472,004 December 31, 2018 Allowance for impaired loans $ 108 $ — $ — $ — $ — $ 174 $ 282 Allowance for non-impaired loans 984 292 1,648 765 265 201 4,155 Total allowance for loan losses $ 1,092 $ 292 $ 1,648 $ 765 $ 265 $ 375 $ 4,437 Impaired loans $ 6,291 $ 408 $ 52 $ — $ — $ 199 $ 6,950 Non-impaired loans 240,465 43,137 113,590 42,139 21,285 19,208 479,824 Total loans $ 246,756 $ 43,545 $ 113,642 $ 42,139 $ 21,285 $ 19,407 $ 486,774 The following table presents past due and non-accrual loans, by loan category, at December 31, 2019 and 2018: 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Past Due (1) Non-accrual Loans (In thousands) December 31, 2019 Residential one-to four-family $ 215 $ 587 $ — $ 802 $ 2,922 Home equity loans and lines of credit 188 244 — 432 336 Commercial real estate — — — — — Construction — — — — — Commercial and industrial — — — — — Consumer 76 11 — 87 — Total $ 479 $ 842 $ — $ 1,321 $ 3,258 December 31, 2018 Residential one-to four-family $ 655 $ 207 $ 635 $ 1,497 $ 2,474 Home equity loans and lines of credit 520 — — 520 407 Commercial real estate — — — — — Construction — — — — — Commercial and industrial — — — — — Consumer 25 4 — 29 149 Total $ 1,200 $ 211 $ 635 $ 2,046 $ 3,030 (1) Excludes non-accrual loans which are separately presented. Further information pertaining to impaired loans, which includes both non-accrual loans and troubled debt restructurings, follows: Recorded Investment Unpaid Principal Balance Related Allowance (In thousands) December 31, 2019 Impaired loans without a valuation allowance: Residential one-to four-family $ 3,322 $ 3,322 $ — Home equity loans and lines of credit 407 407 — Commercial real estate 46 46 — Total 3,775 3,775 — Impaired loans with a valuation allowance: Residential one-to four-family 2,318 2,318 116 Total impaired loans $ 6,093 $ 6,093 $ 116 December 31, 2018 Impaired loans without a valuation allowance: Residential one-to four-family $ 4,280 $ 4,280 $ — Home equity loans and lines of credit 408 408 — Commercial real estate 52 52 — Total 4,740 4,740 — Impaired loans with a valuation allowance: Residential one-to four-family 2,011 2,011 108 Consumer 199 199 174 Total 2,210 2,210 282 Total impaired loans $ 6,950 $ 6,950 $ 282 Information related to the average balances of impaired loans and the interest income recognized on such loans, follows: Average Interest Cash Basis Recorded Income Interest Investment Recognized Recognized (In thousands) Year Ended December 31, 2019 Residential one-to four-family $ 5,594 $ 236 $ 87 Home equity loans and lines of credit 424 11 10 Commercial real estate 132 4 — Consumer 35 1 — Total $ 6,185 $ 252 $ 97 Year Ended December 31, 2018 Residential one-to four-family $ 6,781 $ 210 $ 84 Home equity loans and lines of credit 420 36 36 Commercial real estate 244 15 — Consumer 50 2 — Total $ 7,495 $ 263 $ 120 No additional funds are committed to be advanced in connection with impaired loans. Troubled Debt Restructurings The Company periodically grants concessions to borrowers experiencing financial difficulties. The Company’s troubled debt restructurings consist primarily of interest rate concessions for periods of three months to thirty years for residential real estate loans, and for periods up to one year for commercial real estate loans. At December 31, 2019, the Company had eighteen residential real estate loans, one consumer loan and one commercial real estate loan aggregating $3,616,000, $44,000 and $46,000, respectively, which were subject to troubled debt restructuring agreements. At, December 31, 2018, the Company had seventeen residential real estate loans and one commercial real estate loan aggregating $3,341,000 and $52,000, respectively, which were subject to troubled debt restructuring agreements. As of December 31, 2019 and 2018, $3,706,000 and $3,393,000, respectively, in troubled debt restructurings were performing in accordance with the terms of the modified loan agreements. Included in such amounts are $1,557,000 and $366,000, respectively, that are being accounted for as non-accrual loans. For the year ended December 31, 2019 the Company entered into six loan modifications meeting the criteria of a troubled debt restructuring in which a loan term concession was granted to a borrower. For the year ended December 31, 2018, the Company entered into one loan modification meeting the criteria of a troubled debt restructuring. Management performs a discounted cash flow calculation to determine the amount of impairment reserve required on each of the troubled debt restructurings. Any reserve required is recorded as part of the allowance for loan losses. At December 31, 2019 and 2018 allowances of $116,000 and $282,000, respectively, related to troubled debt restructurings. During the years ended December 31, 2019 and 2018, there were no troubled debt restructurings that defaulted (over 30 days past due) within twelve months of the restructure date. No additional funds are committed to be advanced on loans being accounted for as troubled debt restructurings. Credit Quality Information The Company utilizes an eight-grade internal loan rating system for commercial real estate, construction and commercial loans, as follows: Loans rated 1 – 3A are considered “pass” rated loans with low to average risk. Loans rated 4 are considered “special mention.” These loans are starting to show signs of potential weakness and are being closely monitored by management. Loans rated 5 are considered “substandard” and are inadequately protected by the current net worth and paying capacity of the obligors and/or the collateral pledged. There is a distinct possibility that the Company will sustain some loss if the weakness is not corrected. Loans rated 6 are considered “doubtful” and have all the weaknesses inherent in those classified substandard with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, highly questionable and improbable. Loans rated 7 are considered uncollectible (“loss”) and of such little value that their continuance as loans is not warranted. On an annual basis, or more often if needed, the Company formally reviews the ratings on all commercial real estate, construction and commercial loans. Annually, the Company engages an independent third party to review a significant portion of loans within these segments. Management uses the results of these reviews as part of its annual review process. The following table presents the Company’s loans by risk rating at December 31, 2019 and 2018: December 31, 2019 December 31, 2018 Commercial Real Construction Commercial and Industrial Commercial Real Construction Commercial and Industrial (In thousands) Loans rated 1 - 3A $ 121,703 $ 35,485 $ 8,134 $ 113,642 $ 42,139 $ 21,285 Loans rated 4 3,702 — 206 — — — Loans rated 5 — — 753 — — — $ 125,405 $ 35,485 $ 9,093 $ 113,642 $ 42,139 $ 21,285 Residential mortgages, home equity loans and lines of credit, and consumer loans are monitored for credit quality based primarily on their payment status. When one of these loans becomes more than 90 days delinquent it is assigned an internal loan rating. At December 31, 2019, $2,925,000 in residential mortgages were rated as substandard and $1,293,000 in residential mortgages and $336,000 in home equity lines of credit were rated as special mention. At December 31, 2018, one consumer loan for $149,000 was rated as doubtful, $2,469,000 in residential mortgages and one consumer loan for $50,000 were rated as substandard and $936,000 in residential mortgages and $407,000 in home equity lines of credit were rated as special mention.

Loan Servicing

Loan Servicing	12 Months Ended
	Dec. 31, 2019
Transfers And Servicing [Abstract]
Loan Servicing	4 . LOAN SERVICING Mortgage loans serviced for others are not included in the accompanying consolidated balance sheets. The unpaid principal balances of mortgage loans serviced for others were $1,049,807,000 and $929,289,000 at December 31, 2019 and 2018, respectively. The following table summarizes the activity in the Company’s MSRs for the indicated periods: For the Years Ended December 31, 2019 2018 Mortgage servicing rights: (In thousands) Balance at beginning of year $ 7,786 $ 6,397 Additions through originations 2,979 2,380 Amortization (1,281 ) (983 ) Balance at end of year $ 9,484 $ 7,794 Valuation allowance: Balance at beginning of year $ 8 $ 90 Provision (credit) 920 (82 ) Balance at end of year $ 928 $ 8 Mortgage servicing rights, amortized cost $ 8,556 $ 7,786 Mortgage servicing rights, fair value $ 8,817 $ 8,554 At December 31, 2019 and 2018, the fair value of MSRs was determined using a discount rate of 12% and projected annual prepayment speeds ranging from 9% to 14% for 2019 and 7% to 35% for 2018. During the years ended December 31, 2019 and 2018, the Company increased (reduced) the valuation allowance for its MSRs by $920,000 and ($82,000), respectively. Such adjustments were due to changes in fair value caused by the impact of interest rate movements on actual and expected loan prepayments. Contractually specified servicing fees for the years ended December 31, 2019 and 2018 amounted to $2,585,000 and $2,165,000, respectively, and are included in mortgage servicing fees, net.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Premises and Equipment	5 . PREMISES AND EQUIPMENT A summary of the cost and accumulated depreciation and amortization of premises and equipment is as follows: December 31, Estimated 2019 2018 Useful Life (In thousands) (In years) Land and improvements $ 953 $ 1,025 Buildings and improvements 3,305 3,280 5 to 50 Leasehold improvements 2,231 2,136 3 to 10 Furniture and equipment 5,170 5,032 3 to 10 Construction-in-progress 82 84 11,741 11,557 Less accumulated depreciation and amortization (5,993 ) (5,189 ) $ 5,748 $ 6,368 Total depreciation and amortization expense for the years ended December 31, 2019 and 2018 amounted to $857,000 and $835,000, respectively. During 2017, the Company amended the lease for its Andover loan operations center relocating offices within an office complex. As part of this lease amendment, the landlord funded the cost of leasehold improvements which amounted to $646,000. These costs have been capitalized as part of premises and equipment and a tenant improvement allowance has been recorded as part of other liabilities in the accompanying consolidated balance sheet. Both the leasehold improvements and tenant improvement allowance are being amortized over the initial lease term of approximately five years. In July 2018, the Company entered into a sublease agreement for 27% of the space in its Andover location. This sublease commenced on October 1, 2018 and runs co-terminus with the Company’s lease which expires in March 2023. In October 2018, the Board of Directors approved a plan to consolidate mortgage banking operations in the Company’s North Attleboro loan operations center (see Note 20 for additional information). As part of this decision, certain mortgage banking employees not directly involved in the loan origination process remained at the Andover location. Based on an analysis of space needs for the remaining employees, the area not currently under sublease was subdivided resulting in approximately half of the total leased space in Andover becoming available for sublease. In connection with these actions, the Company recognized a fair value “cease use” liability of $565,000 based on estimated future cash flows which is included in the restructuring charge recorded in the fourth quarter of 2018. This space remains unoccupied and the Company adjusted the cease use liability at December 31, 2019 on the assumption that this space will continue to be unoccupied through the lease term which ends in March 2023. In addition to the cease use liability, the Company also recognized an impairment write-down of $168,000 for furniture and equipment which is no longer expected to be used in operations. This write-down is also included in the restructuring charge recorded in the fourth quarter of 2018. During 2018, the Company sold three branch buildings, two of which were replaced by newly constructed or leased locations. Two of these buildings were reclassified to assets held for sale in 2017. During 2018, these buildings were sold and a net gain of $215,000 was recognized. In December 2018, the Company sold its branch building in Boston for cash consideration of $5,000,000 and recognized a gain of $2,261,000. Earlier in 2018, this building experienced significant water damage resulting in an insurance claim. The Company recognized an insurance recovery of $90,000 for personal property damages which is included in other non-interest income. The insurance recovery for building damage, which was received in December 2018, is included in the gain on sale of the building.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2019
Deposits [Abstract]
Deposits	6 . DEPOSITS A summary of deposit balances, by type, is as follows: December 31, 2019 2018 (In thousands) Demand deposits $ 61,603 $ 64,229 NOW accounts 39,043 42,802 Money market deposits 71,530 60,843 Regular and other savings accounts 126,876 101,137 Brokered deposits 10,167 10,088 Total non-certificate accounts 309,219 279,099 Term certificates less than $250,000 85,425 99,491 Term certificates of $250,000 or more 21,707 8,048 Term certificates - brokered 80,691 50,492 Total certificate accounts 187,823 158,031 $ 497,042 $ 437,130 Included in brokered term certificates at December 31, 2019 are $15.3 million at a weighted average rate of 2.19% having call options. In January 2020, the Company exercised its right to call $11.8 million of these term certificates and in March 2020 exercised its right to call the remaining $3.5 million. A summary of term certificates, including brokered deposits, by maturity is as follows: December 31, 2019 December 31, 2018 Weighted Weighted Average Average Maturing during: Amount Rate Amount Rate (Dollars in thousands) 2019 $ — — % 89,167 1.68 % 2020 140,987 1.92 40,847 2.16 2021 18,840 1.88 12,785 2.16 2022 25,610 2.12 14,101 1.98 2023 1,743 1.28 1,131 1.38 2024 643 1.32 — — $ 187,823 1.94 % $ 158,031 1.87 %

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Borrowings	7 . BORROWINGS A summary of borrowings from the FHLBB at December 31, 2019 and 2018 is as follows: 2019 2018 Weighted Weighted Average Average Amount Rate Amount Rate (Dollars in thousands) Fixed-rate advances maturing: 2019 $ — — % $ 84,184 2.57 % 2020* 22,476 1.80 2,894 1.49 2021* 11,927 1.86 1,958 1.33 2022* 10,000 2.20 — — $ 44,403 1.91 % $ 89,036 2.50 % * Includes amortizing advances which require monthly principal and interest payments. Included in FHLBB borrowings at December 31, 2019 and 2018 are overnight advances and advances having a one-month maturity of $19.8 million and $82.7 million, respectively. Selected information for such short-term borrowings for the years presented is as follows (in 000’s): 2019 2018 Average daily balance $ 73,551 $ 63,552 Maximum outstanding at any month end 128,283 108,819 Advances from the FHLBB are secured by a blanket pledge agreement on the Bank’s qualified collateral, defined principally as 75% of the carrying value of pledged first mortgage loans on owner-occupied residential property and 65% on pledged commercial real estate loans. Available borrowing capacity at December 31, 2019 was $136.5 million. At December 31, 2019, the Bank was in compliance with the FHLBB collateral requirements. The Bank also has a $4,195,000 available line of credit with the FHLBB at an interest rate that adjusts daily. Borrowings under the line are limited to 2% of the Bank’s total assets. At December 31, 2019 and 2018, there were no advances outstanding. The Bank also has a $2,000,000 available line of credit with the Federal Reserve Bank of Boston and a $7,500,000 available line of credit with a correspondent bank. No advances were outstanding under either of these lines at December 31, 2019 and 2018.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	8 . INCOME TAXES Allocation of federal and state income taxes between current and deferred portions is as follows (in thousands): Years Ended December 31, 2019 2018 Current tax expense: Federal $ — $ — State 118 31 Total current tax expense 118 31 Deferred tax expense (benefit): Federal 723 (541 ) State 226 73 949 (468 ) Change in valuation allowance (949 ) 468 Total deferred tax expense (benefit) — — Total tax expense $ 118 $ 31 The reasons for the differences between the statutory federal income tax expense (benefit) and the actual tax expense are summarized as follows (in thousands): Years Ended December 31, 2019 2018 Statutory federal tax rate of 21% $ 745 $ (432 ) Increase (decrease) resulting from: State taxes, net of federal tax effect 272 83 Bank-owned life insurance (39 ) (46 ) Tax-exempt income (9 ) (25 ) Change in valuation allowance (949 ) 468 Other, net 98 (17 ) Total tax expense $ 118 $ 31 The Tax Cuts and Jobs Act of 2017 repealed the alternative minimum tax (“AMT”) and also provided that existing AMT credit carryforwards be refunded over a four-year period. During 2019, the Company received a refund of $231,000. At December 31, 2019, a tax receivable of $231,000 for the remaining balance of refundable AMT credits is included in other assets in the accompanying consolidated balance sheets. The components of the net deferred tax asset are as follows (in thousands): December 31, 2019 2018 Deferred tax assets: Federal $ 4,809 $ 5,134 State 1,066 1,134 5,875 6,268 Valuation allowance (2,297 ) (3,246 ) 3,578 3,022 Deferred tax liabilities: Federal (2,547 ) (2,189 ) State (1,031 ) (833 ) (3,578 ) (3,022 ) Net deferred tax asset $ — $ — The tax effects of items giving rise to deferred tax assets (liabilities) are as follows (in thousands): December 31, 2019 2018 Employee benefit plans $ 714 $ 825 Allowance for loan losses 1,203 1,247 Funded status of post-retirement benefits (47 ) (47 ) Securities available for sale (313 ) (313 ) Depreciation and amortization 279 249 Net deferred loan origination costs (350 ) (357 ) Mortgage servicing rights (2,366 ) (2,082 ) Net operating loss carryforward 2,517 2,864 Charitable contribution carryforward 619 700 Derivatives (377 ) (105 ) Stock-based compensation 185 121 Other, net 233 144 2,297 3,246 Valuation allowance on net deferred tax assets (2,297 ) (3,246 ) Net deferred tax asset $ — $ — At December 31, 2019, the Company has a federal net operating loss carryforward of $11,985,000, of which $2,981,000 expires on December 31, 2033, $406,000 expires on December 31, 2034, $1,542,000 expires on December 31, 2035, $501,000 expires on December 31, 2036, $2,871,000 expires on December 31, 2037 and $3,684,000 has no expiration. At December 31, 2019, the Company has a charitable contribution carryforward of $2,301,000 of which all but $77,000 expires on December 31, 2021. Since 2014, the Company has maintained a valuation allowance for all of its deferred tax assets based on a determination that it was more likely than not that such assets would not be realized. This determination was based on the Company’s net operating loss carryforward position, its current period operating results exclusive of non-recurring items and its expectations for the upcoming year. In performing subsequent assessments through 2018, management concluded that no significant changes in the key factors affecting the realizability of our deferred tax assets had occurred and that a valuation allowance for all deferred tax assets should be maintained. After incurring losses in four of the five previous years, the Company had net income of $3.4 million in 2019. In performing its assessment of the need for a valuation allowance as of December 31, 2019, management concluded that the improvement in operating results, while significant, would need to be sustained for an additional period to provide sufficient evidence that realizability of deferred tax assets was more likely than not to occur. As a result, the 100% valuation allowance for deferred tax assets was maintained at December 31, 2019. The federal income tax reserve for loan losses at the Company’s base year amounted to $2,033,000. If any portion of the reserve is used for purposes other than to absorb the losses for which it was established, approximately 150% of the amount actually used (limited to the amount of the reserve) would be subject to taxation in the fiscal year in which used. As the Company intends to use the reserve only to absorb loan losses, a deferred income tax liability of $571,000 has not been provided. The Company’s income tax returns are subject to review and examination by federal and state taxing authorities. The Company is currently open to audit under the applicable statutes of limitations by the Internal Revenue Service for the years ended December 31, 2016 through 2019. The years open to examination by state taxing authorities vary by jurisdiction; no years prior to 2016 are open.

On-Balance Sheet Derivative Ins

On-Balance Sheet Derivative Instruments and Hedging Activities	12 Months Ended
	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
On-Balance Sheet Derivative Instruments and Hedging Activities	9 . ON-BALANCE SHEET DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Derivative Loan Commitments Mortgage loan interest rate lock commitments qualify as derivative loan commitments if the loan that will result from exercise of the commitment will be held for sale upon funding. The Company enters into commitments to fund residential mortgage loans at specified rates and times in the future, with the intention that these loans will subsequently be sold in the secondary market or to other financial institutions. Outstanding derivative loan commitments expose the Company to the risk that the price of the loans arising from exercise of the loan commitment might decline from inception of the rate lock to funding of the loan due to an increase in mortgage interest rates. If interest rates increase, the value of these loan commitments decreases. Conversely, if interest rates decrease, the value of these loan commitments increases. The notional amount of derivative loan commitments was $89,925,000 and $36,852,000 at December 31, 2019 and 2018, respectively. The fair value of such commitments at December 31, 2019 and 2018 was an asset of $1,472,000 and $627,000, respectively, and is included in other assets in the accompanying consolidated balance sheets. During the years ended December 31, 2019 and 2018, the increase in aggregate fair value of $845,000 and $264,000, respectively, related to interest rate lock commitments was recognized and included in the net gain on loan origination and sales activities in the accompanying consolidated statements of operations. Forward Loan Sale Commitments The Company utilizes both “mandatory delivery” and “best efforts” forward loan sale commitments and, effective in the fourth quarter of 2018, TBA securities to hedge the financial impact of changes in interest rates on the value of loans that would result from the exercise of the derivative loan commitments. With a “mandatory delivery” contract, the Company commits to deliver a certain principal amount of mortgage loans to an investor at a specified price on or before a specified date. If the Company fails to deliver the amount of mortgages necessary to fulfill the commitment by the specified date, it may be obligated to pay a “pair-off” fee, based on then-current market prices, to the investor to compensate the investor in the event of a loss in value. With a “best efforts” contract, the Company commits to deliver an individual mortgage loan of a specified principal amount and quality to an investor if the loan to the underlying borrower closes. Generally, the price the investor will pay the seller for an individual loan is specified prior to the loan being funded (e.g., on the same day the lender commits to lend funds to a potential borrower). The Company expects that these forward loan sale commitments and TBA securities will experience changes in fair value that serve to substantially offset the change in fair value of derivative loan commitments the degree to which depends on the notional amount of such sale commitments. The aggregate notional amount of forward loan sale commitments and TBA securities was $85,401,000 and $42,021,000 at December 31, 2019 and 2018, respectively. The fair value of such commitments at December 31, 2019 and 2018 consisted of liabilities of $140,000 and $263,000, respectively, included in other liabilities in the consolidated balance sheets and assets of $11,000 and $10,000, respectively, included in other assets in the consolidated balance sheets. During the years ended December 31, 2019 and 2018, net reductions (increases) in the aggregate fair value liability of $124,000 and ($238,000), respectively, related to forward loan sale commitments and TBA securities were recognized and included in net gain on loan originations and sales activities in the accompanying consolidated statements of operations.

Minimum Regulatory Capital Requ

Minimum Regulatory Capital Requirements	12 Months Ended
	Dec. 31, 2019
Banking And Thrift [Abstract]
Minimum Regulatory Capital Requirements	1 0 . MINIMUM REGULATORY CAPITAL REQUIREMENTS The Bank is subject to various regulatory capital requirements administered by federal banking agencies. Capital adequacy guidelines and, additionally for banks, prompt corrective actions regulations, involve qualitative measures of assets, liabilities, and certain off-balance sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgement by regulators. Failure to meet capital requirements can initiate regulatory action. The final rules implementing Basel Committee on Banking Supervision’s capital guidelines for U.S. banks (Basel III rules) became effective for the Bank on January 1, 2015. Under BASEL III, community banking institutions must maintain a capital conservation buffer of common equity tier 1 capital in an amount greater than 2.5% of total risk-weighted assets to avoid being subject to limitations on capital distributions and discretionary bonuses. Quantitative measures established by regulation to ensure capital adequacy require the Bank to maintain minimum amounts and ratios (set forth in the following tables) of total, Tier 1 capital and common equity Tier 1 capital to risk weighted assets, and Tier 1 capital to average assets (all as defined). Management believes, as of December 31, 2019 and 2018, that the Bank met all capital adequacy requirements to which it is subject. As of December 31, 2019, the most recent notification from the FDIC categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well capitalized, the Bank must maintain minimum total risk-based, Tier 1 risk-based, common equity Tier 1 and Tier 1 leverage ratios as set forth in the following tables. There are no conditions or events since the notification that management believes have changed the Bank’s category. The Bank’s actual and minimum capital amounts and ratios, exclusive of the capital conservation buffer, are presented in the following table: Minimum To Be Well For Minimum Capitalized Under Capital Prompt Corrective Actual Adequacy Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) December 31, 2019 Total capital (to risk weighted assets) $ 76,652 16.7 % $ 36,637 8.0 % $ 45,796 10.0 % Tier 1 capital (to risk weighted assets) 72,372 15.8 27,478 6.0 36,637 8.0 Common equity Tier 1 capital (to risk weighted assets) 72,372 15.8 20,608 4.5 29,768 6.5 Tier 1 capital (to average assets) 72,372 11.3 25,627 4.0 32,033 5.0 December 31, 2018 Total capital (to risk weighted assets) 72,523 16.1 36,084 8.0 45,105 10.0 Tier 1 capital (to risk weighted assets) 68,086 15.1 27,063 6.0 36,084 8.0 Common equity Tier 1 capital (to risk weighted assets) 68,086 15.1 20,297 4.5 29,318 6.5 Tier 1 capital (to average assets) 68,086 10.9 25,056 4.0 31,320 5.0

Post-retirement Plans

Post-retirement Plans	12 Months Ended
	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Post-retirement Plans	1 1 . POST-RETIREMENT PLANS Supplemental retirement agreements The Company maintains supplemental retirement agreements with certain officers and directors (none of whom currently provide services to the Company) that provide for supplemental benefits commencing with retirement. The present value of future benefits payable is accrued over the terms of employment or anticipated term of each participating director’s position, as applicable, taking into consideration the vesting provisions in the agreements. At December 31, 2019 and 2018, the accrued benefits related to the agreements amounted to $507,000 and $549,000, respectively. Total expense, included in other non-interest expenses, related to these supplemental agreements amounted to $51,000 and $58,000 for the years ended December 31, 2019 and 2018, respectively. Supplemental retirement plan The Company has a master supplemental retirement plan (“Plan”) which covers certain officers and directors of the Company. In 2019 and 2018, the only active participants in the Plan were certain directors. Information pertaining to activity in the Plan follows: Years Ended December 31, 2019 2018 (In thousands) Change in plan assets: Fair value of plan assets at beginning of year $ — $ — Employer contributions 201 201 Benefits paid (201 ) (201 ) Fair value of plan assets at end of year — — Change in benefit obligation: Benefit obligation at beginning of year 1,561 1,724 Service cost 10 10 Interest cost 53 48 Actuarial (gain) loss 83 (20 ) Benefits paid (201 ) (201 ) Benefit obligation at end of year 1,506 1,561 Unfunded status and accrued supplemental pension cost at year end $ (1,506 ) $ (1,561 ) Accumulated benefit obligation at year end $ 1,506 $ 1,561 The assumptions used to determine the benefit obligation are as follows: December 31, 2019 2018 Discount rate 2.50 % 3.60 % Annual inflation factor 1.00 % 1.00 % Net periodic benefit cost, included in other non-interest expenses, attributable to the Plan for the years ended December 31, 2019 and 2018, consists of the following: 2019 2018 (In thousands) Service cost $ 10 $ 10 Interest cost 53 48 Amortization of net actuarial loss 36 41 Amortization of prior service credit (84 ) (89 ) $ 15 $ 10 The following assumptions were used to determine the net periodic benefit cost for the years ended December 31, 2019 and 2018: 2019 2018 Discount rate 3.60 % 2.90 % Annual inflation factor 1.00 % 1.00 % Estimated future benefit payments, which reflect expected future services, as appropriate, are as follows: Years Ending December 31, Amount (In thousands) 2020 $ 201 2021 201 2022 213 2023 345 2024 213 2025-2029 425 Endorsement split-dollar life insurance arrangements The Company is the sole owner of life insurance policies pertaining to certain of the Company’s current and former directors and executives. The Company has entered into agreements with these directors and executives whereby the Company will pay to the directors’ and executives’ estates or beneficiaries a portion of the death benefit that the Company will receive as beneficiary of such policies. Expense associated with this post-retirement benefit for the years ended December 31, 2019 and 2018 amounted to $19,000 and $16,000, respectively. At December 31, 2019 and 2018, the accrued benefits related to the split-dollar arrangements amounted to $451,000 and $432,000, respectively. 401(k) Plan The Company maintains a 401(k) Plan whereby each employee reaching the age of 21 automatically becomes a participant in the plan. Employees may contribute up to 15% of their compensation subject to certain limits based on federal tax laws. All employees who have worked for one year or 1,000 hours are eligible for an automatic employer contribution of 3% of employees’ compensation, which requires no vesting period. The Company also matches 50% of the first 2% of an eligible employee’s contributions, allowing for a total employer contribution of 4% of employees’ compensation. Matching contributions vest over a four year service period. In addition, a profit-sharing provision allows for an additional discretionary contribution by the Company upon approval of the Board of Directors. For the years ended December 31, 2019 and 2018, expense attributable to the 401(k) Plan amounted to $753,000 and $580,000, respectively.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	1 2 . STOCK-BASED COMPENSATION Under the Randolph Bancorp, Inc. 2017 Stock Option and Incentive Plan (the “Equity Plan”), the Company may grant options, restricted stock, restricted units or performance awards to its directors, officers and employees. Both incentive stock options and non-qualified stock options may be granted under the Equity Plan with 586,872 shares reserved for options. The exercise price of each option equals the market price of the Company’s stock on the date of the grant and the maximum term of each options is 10 years. The total number of shares reserved for restricted stock is 234,749. Options and awards generally vest ratably over three to five years. The fair value of shares awarded is based on the market price at the date of grant. Stock Options The fair value of each option grant is estimated on the date of the grant using the Black-Scholes option-pricing model with the following assumptions: • Volatility incorporates peer group volatility because the Company does not have a sufficient trading history. • Expected life represents the period of time that the option is expected to be outstanding, taking into account the contractual term, and the vesting period. • Expected dividend yield is based on the Company's history and expectation of dividend payouts. • The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for a period equivalent to the expected life of the option. The Company made the following grants of options to purchase shares of common stock during the years ended December 31, 2019 and 2018: 2019 2018 Options granted 57,252 27,000 Vesting period (years) 3 - 5 3 - 5 Expiration period (years) 10 10 Expected volatility 26.14% - 29.09% 29.09% - 29.87% Expected life (years) 6 - 6.5 6 - 6.5 Expected dividend yield — — Risk free interest rate 2.37% - 2.61% 2.68% - 2.77% Option fair value $2.99 - $5.83 $5.78 - $5.83 The following table presents the activity and certain other information related to stock option grants under the Equity Plan for the year ended December 31, 2019: Options Stock Option Grants Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Balance at January 1, 2019 312,705 $ 14.78 8.73 $ — Granted 57,252 14.93 Forfeited (6,500 ) 13.90 Expired (3,250 ) 14.66 Balance at December 31, 2019 360,207 $ 14.82 8.01 $ 1,017,708 Exercisable at December 31, 2019 120,704 $ 14.75 7.81 $ 349,852 Unrecognized compensation cost (inclusive of directors' options) $ 982,722 Weighted average remaining recognition period (years) 2.79 For the years ended December 31, 2019 and 2018, stock-based compensation expense applicable to stock options was $366,000 and $304,000, respectively. Restricted Stock Shares issued upon vesting may be either authorized but unissued shares or reacquired shares held by the Company. Any shares not issued because vesting requirements are not met will again be available for issuance under the plan. The fair market value of shares awarded, based on the market price at the date of grant, is recorded as unearned compensation and amortized over the applicable vesting period. Restricted stock awarded in 2017 and 2019 was at no cost to the awardee. The following table presents the activity and certain other information related to restricted stock awards under the Equity Plan for the year ended December 31, 2019: Restricted Stock Awards Weighted Average Grant Price Restricted stock awards at January 1, 2019 126,694 $ 14.66 Granted 33,335 15.07 Vested (31,668 ) 14.66 Forfeited (2,500 ) 15.07 Non-vested stock awards at December 31, 2019 125,861 $ 14.76 Unrecognized compensation cost $ 1,651,000 Weighted average remaining recognition period (years) 3.04 Total expense for the restricted stock awards was $553,000 and $493,000 for the years ended December 31, 2019 and 2018, respectively.

Employee Stock Ownership Plan

Employee Stock Ownership Plan	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Employee Stock Ownership Plan	1 3 . EMPLOYEE STOCK OWNERSHIP PLAN The Company maintains an Employee Stock Ownership Plan (“ESOP”), which is a tax-qualified retirement plan providing eligible employees the opportunity to own Company stock. The Company granted a loan to the ESOP for the purchase of 469,498 shares of its common stock at $10.00 per share. The loan is payable annually over 25 years with interest at the prime rate to be reset each January 1 st Shares are committed to be released on a monthly basis and allocated as of December 31 st

Share Repurchase Program

Share Repurchase Program	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Share Repurchase Program	1 4 . SHARE REPURCHASE PROGRAM In September 2017, the Company’s Board of Directors adopted a share repurchase program under which the Company may repurchase up to 10%, or 586,854 shares of its then outstanding common shares. Repurchases under the program may be made in open market or in privately negotiated transactions and pursuant to any trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities and Exchange Commission. Any repurchased shares will be held by the Company as authorized but unissued shares. The repurchase program may be suspended or terminated at any time without prior notice and is currently set to expire on September 14, 2020. As of December 31, 2019, the Company had repurchased 468,896 shares at a cost of $7,231,000 in connection with this program.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	15. EARNINGS (LOSS) PER SHARE Basic earnings (loss) per share represents net income (loss) divided by the weighted average of common shares outstanding during the period. Unvested restricted shares of common stock having dividend rights are treated as “participating securities” and, accordingly, are considered outstanding in computing basic earnings (loss) per share. Unallocated ESOP shares are not considered to be outstanding for purposes of computing earnings per share. None of the Company’s outstanding stock options were included in the computation of diluted earnings (loss) per share for the years ended December 31, 2019 and 2018, as their impact was anti-dilutive. The following table sets forth the calculation of the average number of shares outstanding used to calculate the basic and diluted earnings (loss) per share for the periods indicated: 2019 2018 Average number of common shares outstanding 5,787,385 5,994,373 Less: Average unallocated ESOP shares (403,768 ) (423,653 ) 5,383,617 5,570,720

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	1 6 . COMMITMENTS AND CONTINGENCIES In the normal course of business, there are outstanding commitments and contingencies which are not reflected in the accompanying consolidated financial statements. Lease commitments Pursuant to the terms of non-cancelable lease and sublease agreements in effect at December 31, 2019, future minimum rent commitments are as follows: Years Ending December 31, Leases Sub-lease Net (In thousands) 2020 $ 1,095 (89 ) $ 1,006 2021 878 (91 ) 787 2022 681 (94 ) 587 2023 228 (16 ) 212 2024 91 — 91 Thereafter 23 — 23 $ 2,996 $ (290 ) $ 2,706 The leases contain options to extend for periods of two to ten years. The cost of unexercised options periods is not included above. Total rent expense, net of sublease income, for the years ended December 31, 2019 and 2018 amounted to $887,000 and $992,000, respectively. Loan commitments The Company is a party to financial instruments with off-balance-sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit. These instruments involve, to varying degrees, elements of market, credit and interest rate risk which are not recognized in the consolidated financial statements. The Company’s exposure to credit loss is represented by the contractual amount of these commitments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance-sheet instruments. At December 31, 2019 and 2018, the following financial instruments were outstanding whose contract amounts represent credit risk: 2019 2018 (In thousands) Commitments to originate loans $ 117,086 $ 38,404 Unused lines and letters of credit 52,721 45,977 Unadvanced funds on construction loans 11,029 14,175 Overdraft lines of credit 8,178 8,475 Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. The commitments for lines of credit may expire without being drawn upon. Therefore, the total commitment amounts do not necessarily represent future cash requirements. The Company evaluates each customer’s creditworthiness on a case-by-case basis. The majority of these financial instruments are collateralized by real estate. Employment Arrangement and Change in Control Agreements The Company has entered into an employment arrangement with its President and Chief Executive Officer that provides for one year of salary continuation in the event his employment is terminated without cause or he resigns for good reason, subject to his providing a release of claims and complying with a non-solicitation and non-disclosure agreement. See Note 23 for additional information. The Company has also entered into change in control agreements with five members of senior management which provide that if, within two years of a change of control of the Company or the Bank, the executive is involuntarily terminated other than for cause, disability or death, or voluntarily resigns for good reason, the executive will be entitled to a lump-sum payment equal to two times salary plus bonus. Other contingencies The Company is not currently a party to any pending legal proceedings that it believes would have a material adverse effect on its financial condition, results of operations or cash flows.

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	1 7 . FAIR VALUE OF ASSETS AND LIABILITIES Determination of fair value The Company uses fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various assets and liabilities. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the asset or liability. The following methods and assumptions were used by the Company in estimating fair value disclosures: Cash and cash equivalents Certificates of deposit Securities Federal Home Loan Bank of Boston stock Loans held for sale Loans Mortgage servicing rights Deposit liabilities FHLBB advances Accrued interest On-balance-sheet derivatives Off-balance sheet credit-related instruments Assets and liabilities measured at fair value on a recurring basis Assets and liabilities measured at fair value on a recurring basis are summarized below. . Total Level 1 Level 2 Level 3 Fair December 31, 2019 (In thousands) Assets: Securities available for sale $ — $ 57,503 $ — $ 57,503 Portfolio loans (fair value option) 9,826 — 9,826 Loans held for sale (fair value option) — 62,792 — 62,792 Derivative loan commitments — 1,472 — 1,472 Forward loan sale commitments — 11 — 11 Liabilities: Forward loan sale commitments, including TBAs — 140 — 140 December 31, 2018 Assets: Securities available for sale: Debt securities $ — $ 50,038 $ — $ 50,038 Mutual fund — 518 — 518 Portfolio loans (fair value option) — 3,680 — 3,680 Loans held for sale (fair value option) — 38,474 — 38,474 Derivative loan commitments — 627 — 627 Forward loan sale commitments — 10 — 10 Liabilities: Forward loan sale commitments, including TBAs — 263 — 263 There were no transfers between levels for assets and liabilities recorded at fair value on a recurring basis during 2019 or 2018. Assets and liabilities measured at fair value on a non-recurring basis The Company may also be required, from time to time, to measure certain other assets on a non-recurring basis in accordance with U.S. generally accepted accounting principles. These adjustments to fair value usually result from application of lower-of-cost-or-market accounting or write-downs of individual assets and liabilities. The following table summarizes the fair value hierarchy used to determine each adjustment and the carrying value of the related assets and liabilities as of December 31, 2019 and 2018. The gains and losses represent the amounts recorded during 2019 and 2018 on the assets and liabilities held at year-end. There no liabilities recorded at fair value on a non-recurring basis as of December 31, 2019 and 2018. Year Ended December 31, 2019 December 31, 2019 Level 1 Level 2 Level 3 Total Assets: (In thousands) Collateral dependent impaired loans $ — $ — $ 2,250 $ — Mortgage servicing rights — 8,556 — (920 ) $ — $ 8,556 $ 2,250 $ (920 ) Year Ended December 31, 2018 December 31, 2018 Level 1 Level 2 Level 3 Total Gains (Losses) (In thousands) Collateral dependent impaired loans $ — $ — $ 1,352 $ — Mortgage servicing rights — 7,786 — 82 Foreclosed real estate — — 65 (36 ) $ — $ 7,786 $ 1,417 $ 46 Gains or losses applicable to impaired loans are based on the appraised value of the underlying collateral, discounted as necessary due to management’s estimates of changes in market conditions, less estimated selling costs, and are not recorded directly to current earnings but rather as a component in determining the allowance for loan losses. The Company utilizes an independent valuation from a third party which uses a discounted cash flow model to estimate the fair value of mortgage servicing rights. The model utilizes loan prepayment assumptions based on current market conditions and applies a discount rate based on indicated rates of return required by market participants. During the year ended December 31, 2018, the valuation allowance recognized in prior years due to partial impairment in certain strata of MSRs was reduced due to slower loan prepayment speeds and a reduction in the discount rate from 13% at December 31, 2017 to 12% at December 31, 2018. During the year ended December 31, 2019 the valuation allowance increased due to faster actual and projected loan prepayment speeds attributable to the decrease in interest rates on residential mortgage loans during the year. Summary of fair values of financial instruments The estimated fair values, and related carrying amounts, of the Company’s financial instruments are presented below. Certain financial instruments and all non-financial instruments are exempt from disclosure requirements. Accordingly, the aggregate fair value amounts presented herein do not represent the underlying fair value of the Company. This table excludes financial instruments for which the carrying amount approximates fair value. Financial assets for which the fair value approximates carrying value include cash and cash equivalents and accrued interest receivable. Financial liabilities for which the fair value approximates carrying value include mortgagor’s escrow accounts and accrued interest payable. December 31, 2019 Carrying Fair Amount Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Certificates of deposit $ 490 $ 492 $ — $ 492 $ — Securities available for sale 57,503 57,503 — 57,503 — Loans held for sale 62,792 62,792 — 62,792 — Loans, net 469,131 469,416 — — 469,416 Derivative assets 1,483 1,483 — 1,483 — Financial liabilities: Deposits $ 497,042 $ 496,979 $ — $ 496,979 $ — FHLBB advances 44,403 44,433 — 44,433 — Derivative liabilities 140 140 — 140 — December 31, 2018 Carrying Fair Amount Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Certificates of deposit $ 2,205 $ 2,196 $ — $ 2,196 $ — Securities available for sale 50,556 50,556 — 50,556 — Loans held for sale 38,474 38,474 — 38,474 — Loans, net 483,846 473,612 — — 473,612 Derivative assets 637 637 — 637 — Financial liabilities: Deposits $ 437,130 $ 435,964 $ — $ 435,964 $ — FHLBB advances 89,036 88,894 — 88,894 — Derivative liabilities 263 263 — 263 —

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Information	18. SEGMENT INFORMATION The Company reports its activities in one of two business segments, namely Envision Bank (“EB”) and Envision Mortgage (“EM”). EB operations primarily consist of accepting deposits from customers within the communities surrounding the Bank’s five full service branch offices and investing those funds in residential and commercial real estate loans, home equity lines of credit, construction loans, commercial and industrial loans, and consumer loans. EM’s operations primarily consist of the origination and sale of residential mortgage loans and the servicing of loans sold to government-sponsored entities. A portion of the loans originated by EM are held in the loan portfolio of EB. Segment information as of and for the year ended December 31, 2019, follows: For the Year Ended December 31, 2019 Envision Bank Envision Mortgage Consolidated Total (in thousands) Net interest income $ 15,985 $ 1,848 $ 17,833 Provision for loan losses — — — Net interest income after provision for loan losses 15,985 1,848 17,833 Non-interest income: Customer service fees 1,268 139 1,407 Gain on loan origination and sale activities, net (1) — 19,851 19,851 Mortgage servicing fees, net (363 ) 757 394 Other 596 366 962 Total non-interest income 1,501 21,113 22,614 Non-interest expenses: Salaries and employee benefits 7,065 17,831 24,896 Occupancy and equipment 1,527 1,256 2,783 Other non-interest expenses 4,789 3,482 8,271 Total non-interest expenses 13,381 22,569 35,950 Income before income taxes and elimination of inter-segment profit $ 4,105 $ 392 4,497 Elimination of inter-segment profit (951 ) Income before income taxes 3,546 Income tax expense 118 Net income $ 3,428 Total assets, December 31, 2019 $ 521,144 $ 109,860 $ 631,004 (1) Before elimination of inter-segment profit The information above was derived from the internal management reporting system used by management to measure performance of the segments. The Company’s internal transfer pricing arrangements determined by management primarily consist of the following: 1. EM’s cost of funds is based on the weighted average rate of overnight advances from the FHLBB for the period. 2. EM is credited with service released premiums and a sales premium totaling 1.50% for new loans transferred to EB’s loans held for investment, and a 1.00% fee for HELOC originations. This income for the year ended December 31, 2019 totaled $951,000. 3. Loan servicing fees are charged to EB by EM based on the balance of residential mortgage loans held in portfolio at a rate of 0.14% per annum and amounted to $363,000 for the year ended December 31, 2019. 4. Certain cost centers provide services to both business segments. The cost centers include Accounting, Marketing, IT and Administration. Costs which are common to both business segments are referred to as “indirect costs” and are allocated using relevant benchmarks, e.g. headcount, number of accounts, etc. Segment information as of and for the year ended December 31, 2018 follows: For the Year Ended December 31, 2018 Envision Bank Envision Mortgage Consolidated Total (in thousands) Net interest income $ 15,664 $ 1,032 $ 16,696 Provision for loan losses 762 — 762 Net interest income after provision for loan losses 14,902 1,032 15,934 Non-interest income: Customer service fees 1,344 120 1,464 Gain on loan origination and sale activities, net (1) — 8,859 8,859 Mortgage servicing fees, net (310 ) 1,574 1,264 Gain on sales of buildings 2,476 — 2,476 Other 520 420 940 Total non-interest income 4,030 10,973 15,003 Non-interest expenses: Salaries and employee benefits 6,793 12,972 19,765 Occupancy and equipment 1,507 1,366 2,873 Restructuring charge — 968 968 Other non-interest expenses 4,476 3,590 8,066 Total non-interest expenses 12,776 18,896 31,672 Income (loss) before income taxes and elimination of inter-segment profit $ 6,156 $ (6,891 ) (735 ) Elimination of inter-segment profit (1,320 ) Loss before income taxes (2,055 ) Income tax expense 31 Net loss $ (2,086 ) Total assets, December 31, 2018 $ 526,871 $ 87,469 $ 614,340 (1) Before elimination of inter-segment profit The information above was derived from the internal management reporting system used by management to measure performance of the segments. The Company’s internal transfer pricing arrangements determined by management primarily consist of the following: 1. EM’s cost of funds is based on the weighted average rate of overnight advances from the FHLBB for the period. 2. EM is credited with service released premiums and a sales premium totaling 1.50% for new loans transferred to EB’s loans held for investment, and a 1.00% fee for HELOC originations. This income for the year ended December 31, 2018 totaled $1,320,000. 3. Loan servicing fees are charged to EB by EM based on the balance of residential mortgage loans held in portfolio at a rate of 0.14% per annum and amounted to $310,000 for the year ended December 31, 2018. 4. Certain cost centers provide services to both business segments. The cost centers include Accounting, Marketing, IT and Administration. Costs which are common to both business segments are referred to as “indirect costs” and are allocated using relevant benchmarks, e.g. headcount, number of accounts, etc.

Other Non-Interest Expenses

Other Non-Interest Expenses	12 Months Ended
	Dec. 31, 2019
Other Income And Expenses [Abstract]
Other Non-Interest Expenses	1 9 . OTHER NON-INTEREST EXPENSES Included in other non-interest expenses in 2019 and 2018 are certain items exceeding 1% of the Company’s total interest and non-interest income as follows: 2019 2018 (In thousands) Software amortization, licenses and maintenance $ 1,017 $ 754 Card related expenses 459 470 Data communication and telephone 418 495 Directors fees, including stock-based compensation 586 613

Restructuring Charge

Restructuring Charge	12 Months Ended
	Dec. 31, 2019
Restructuring And Related Activities [Abstract]
Restructuring Charge	20 . RESTRUCTURING CHARGE During the fourth quarter of 2018, the Company finalized a plan to consolidate mortgage banking operations in the Company’s North Attleboro loan operations center. As a result, the Company eliminated fifteen administrative positions supporting the origination of residential mortgages in its Andover loan operations center and added eight similar positions in its North Attleboro location. Approximately twenty-five employees, including loan originators, remained in the Andover location. Terminated employees were given a severance package based on their length of service with the Company. In addition, retention bonuses were offered to certain employees. The total cost of severance payments and retention bonuses amounted to $235,000 and is included in the restructuring charges in the accompanying statement of operations. As more fully disclosed in Note 5, the Company vacated all but approximately 4,200 square feet of its remaining lease space in Andover and recorded a cease use fair value liability of $565,000 which is included in the restructuring charge in the fourth quarter of 2018. In addition to the cease use liability, the Company also recognized an impairment write-down of $168,000 for furniture and equipment which is no longer expected to be used in operations. This write-down is also included in the restructuring charge recorded in the fourth quarter of 2018.

Parent Company Condensed Financ

Parent Company Condensed Financial Statements	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Parent Company Condensed Financial Statements	21 . PARENT COMPANY CONDENSED FINANCIAL STATEMENTS Financial information as of December 31, 2019 and 2018 and for the years then ended pertaining to Randolph Bancorp, Inc. is as follows: BALANCE SHEETS December 31, December 31, 2019 2018 Assets Cash and due from bank $ 1,445 $ 6,850 Investment in Envision Bank 72,872 66,971 ESOP loan 4,162 4,266 Total assets $ 78,479 $ 78,087 Liabilities Accounts payable $ — $ 70 Due to Envision Bank 17 56 Total liabilities 17 126 Stockholders' Equity Common stock 56 60 Additional paid-in capital 51,127 55,608 Retained earnings 31,757 28,329 ESOP-Unearned compensation (3,944 ) (4,132 ) Accumulated other comprehensive loss, net of tax (534 ) (1,904 ) Total stockholders' equity 78,462 77,961 Total liabilities and stockholders' equity $ 78,479 $ 78,087 STATEMENTS OF OPERATIONS Years Ended December 31, 2019 2018 Interest income $ 235 $ 197 Operating expenses 194 197 Income before incomes taxes and equity in undistributed net income (loss) of Envision Bank 41 — Applicable income taxes 3 — Income before equity in undistributed net income (loss) of Envision Bank 38 — Equity in undistributed net income (loss) of Envision Bank 3,390 (2,086 ) Net income (loss) $ 3,428 $ (2,086 ) STATEMENTS OF CASH FLOWS Years Ended December 31, 2019 2018 Cash flows from operating activities: Net income (loss) $ 3,428 $ (2,086 ) Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities: Equity in undistributed net (income) loss of Envision Bank (3,390 ) 2,086 Change in intercompany receivable/payable (39 ) 197 Net cash provided by (used in) operating activities (1 ) 197 Cash flows from investing activities: Principal payments received on ESOP loan 104 112 Net cash provided by investing activities 104 112 Cash flows from financing activities: Stock repurchases (5,438 ) (1,716 ) Stock repurchase payable (70 ) 70 Net cash used in financing activities (5,508 ) (1,646 ) Net change in cash and due from bank (5,405 ) (1,337 ) Cash and due from bank at the beginning of year 6,850 8,187 Cash and due from bank at end of year $ 1,445 $ 6,850

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	22. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) First Quarter Second Quarter Third Quarter Fourth Quarter 2019 2018 2019 2018 2019 2018 2019 2018 (Dollars in thousands, except per share data) Interest and dividend income $ 6,016 $ 4,727 $ 6,454 $ 5,039 $ 6,541 $ 5,468 $ 6,219 $ 6,050 Interest expense 1,638 745 1,965 1,006 1,968 1,208 1,828 1,630 Net interest and dividend income 4,378 3,982 4,489 4,033 4,573 4,260 4,391 4,420 Provision (credit) for loan losses — 95 (144 ) (90 ) — 178 144 579 Gain on loan origination and sales activities, net 2,588 1,547 5,068 1,854 5,782 1,956 5,462 2,183 Other non-interest income 825 861 787 929 522 1,252 630 3,102 Total non-interest income 3,413 2,408 5,855 2,783 6,304 3,208 6,092 5,285 Restructuring charges — — — 92 — — — 875 Other non-interest expense 7,878 6,998 8,863 7,820 9,718 7,427 9,490 8,462 Total non-interest expense 7,878 6,998 8,863 7,912 9,718 7,427 9,490 9,337 Provision (benefit) for income taxes (36 ) 4 119 4 14 5 21 17 Net income (loss) $ (51 ) $ (707 ) $ 1,506 $ (1,010 ) $ 1,145 $ (142 ) $ 828 $ (228 ) Basic and diluted earnings (loss) per share $ (0.01 ) $ (0.13 ) $ 0.28 $ (0.18 ) $ 0.21 $ (0.03 ) $ 0.16 $ (0.04 ) Weighted average common shares (basic and diluted) 5,478,544 5,603,886 5,465,205 5,580,683 5,345,786 5,567,596 5,248,021 5,526,416 During the fourth quarter of 2019, the Company recognized an increase of $284,000 in the valuation allowance for MSRs which is included in other non-interest income. As disclosed in Note 20, the Company recognized a restructuring charge in the fourth quarter of 2018 associated with its mortgage banking operations. As disclosed in Note 5, the Company recognized a gain of $2,261,000 on the sale of its former Boston branch location in the fourth quarter of 2018 which is included in other non-interest income.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Event	23. SUBSEQUENT EVENT On January 29, 2020, the Company announced a management succession plan wherein its President and Chief Executive Officer and its Executive Vice President and Chief Financial Officer will retire from these roles effective April 1, 2020. In connection therewith the Company has entered into agreements with their successors that include customary provisions for executive management. The President and Chief Executive Officer will receive salary continuation for one year at his current base salary of $400,000 and transition pay of $200,000 payable over one year for his support of the management transition and agreement to the non-competition and non-solicitation provisions in his retirement agreement. Under the terms of their restricted stock and stock option agreements, all unvested stock and stock options will vest for both officers upon their retirement. During the quarter ending March 31, 2020, the Company estimates that it will recognize compensation expense of $1,350,000 associated with the provisions of these agreements.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations Envision Bank (the “Bank”) provides a variety of financial services to individuals and small businesses through its five branch offices in Massachusetts and twelve loan production offices and lending centers located throughout Massachusetts and Southern New Hampshire. The Bank’s primary deposit products are checking, savings and term certificate accounts and its primary lending products are residential and commercial mortgage loans. The Bank is also actively involved in the sale and servicing of residential mortgage loans in the secondary market. The Federal Deposit Insurance Corporation (“FDIC”) provides insurance coverage on all deposits up to $250,000 per depositor. As an FDIC insured institution, the Bank is subject to supervision, examination and regulation by the FDIC. Additionally, as a Massachusetts chartered savings bank, the Bank’s depositors are also insured by the Depositors Insurance Fund (“DIF”), a private industry-sponsored insurance company. The DIF insures bank deposits in excess of the FDIC insurance limits.
Basis of Presentation	Basis of Presentation The consolidated financial statements include the accounts of Randolph Bancorp, Inc. (a Massachusetts corporation) and its wholly-owned subsidiary, Envision Bank (together, the “Company”). The Bank has subsidiaries involved in owning investment securities and foreclosed real estate and a subsidiary which provides loan closing services. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of estimates In preparing consolidated financial statements in conformity with GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the consolidated balance sheet and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near term relate to the allowance for loan losses, mortgage servicing rights, deferred tax assets and fair value measurements.
Cash and Cash Equivalents	Cash and cash equivalents Cash equivalents include amounts due from banks, federal funds sold on a daily basis and interest-bearing deposits with original maturities of ninety days or less.
Certificates of Deposit	Certificates of deposit Certificates of deposit have original maturities ranging from one to five years and are carried at cost.
Fair Value Hierarchy	Fair value hierarchy The Company groups its assets and liabilities that are measured at fair value in three levels based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. Level 1 – Valuation is based on quoted prices in active markets for identical assets and liabilities. Valuations are obtained from readily available pricing sources. Level 2 – Valuation is based on observable inputs other than Level 1 prices, such as quoted prices for similar assets and liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets and liabilities. Level 3 – Valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities. Level 3 assets and liabilities include those for which the value is determined using unobservable inputs to pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. Transfers between levels are recognized at the end of a reporting period, if applicable.
Securities	Securities All securities are classified as available for sale and are recorded at fair value, with unrealized gains and losses excluded from earnings and reported in other comprehensive income/loss. Purchase premiums and discounts are recognized in interest income using the level yield method over the terms of the securities. Anticipated prepayments on mortgage-backed securities are used in applying this method. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. On a quarterly basis, the Company evaluates all securities with a decline in fair value below the amortized cost of the investment to determine whether or not the impairment is deemed to be other than temporary (“OTTI”). OTTI is required to be recognized: (1) if the Company intends to sell the security; (2) if it is “more likely than not” that the Company will be required to sell the security before recovery of its amortized cost basis; or (3) for debt securities, if the present value of expected cash flows is not sufficient to recover the entire amortized cost basis. For all impaired debt securities that the Company intends to sell, or more likely than not will be required to sell, the full amount of the decline in fair value is recognized as OTTI through earnings. For all other impaired debt securities, credit-related OTTI is recognized through earnings and non-credit related OTTI is recognized in other comprehensive income/loss, net of applicable taxes. Because the Company’s assessments are based on available factual information as well as subjective information, the determination as to whether an OTTI exists and, if so, the amount of impairment, is subjective and, therefore, the timing and amount of OTTI constitute material estimates that are subject to significant change.
Federal Home Loan Bank of Boston Stock	Federal Home Loan Bank of Boston stock The Bank, as a member of the Federal Home Loan Bank of Boston (“FHLBB”), is required to maintain an investment in capital stock of the FHLBB. Based on redemption provisions of the FHLBB, the stock has no quoted market value and is carried at cost. The Company periodically evaluates for impairment based on ultimate recovery of its cost basis in the FHLBB stock.
Loans Held for Sale and related derivatives	Loans held for sale and related derivatives The origination of residential mortgage loans is an integral part of the Company’s business. The Company generally sells its originations of such loans in the secondary market to either government-sponsored enterprises (“GSEs”) or other financial institutions. The servicing of loans sold to GSEs is generally retained while loans sold to other financial institutions are generally done on a servicing released basis. The Bank utilizes the fair value option pursuant to Accounting Standards Codification (“ASC”) 825, “Financial Instruments” for its residential mortgage loans being held for sale. Fair value is determined based on either commitments in effect from investors or prevailing market price and include the value of mortgage servicing rights. Gains and losses on the sales of loans are determined using the specific identification method. In determining the amount of the gain or loss the Company takes into consideration the direct costs of originating the loan. Also included in the net gain on loan origination and sale activities presented in the accompanying statements of operations are fair value adjustments for mortgage banking derivatives (interest rate lock commitments with borrowers, and forward loan sale commitments with investors for the delivery of mortgage loans to third party investors including To Be Announced securities (“TBAs”)) and loans held for sale.
Loans	Loans The Company grants residential real estate, commercial real estate, construction, commercial and consumer loans to customers. A substantial portion of the loan portfolio is represented by mortgage loans in Massachusetts and Rhode Island. The ability of the Company’s borrowers to honor their contracts is affected by real estate values and general economic conditions in these markets. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off are reported at their outstanding unpaid principal balances adjusted for charge-offs, the allowance for loan losses, and net deferred loan origination fees and costs and purchase premiums. Interest income is accrued on the unpaid principal balance. Certain direct loan origination costs and purchase premiums, net of origination fees, are deferred and recognized in interest income using the level yield method without anticipating prepayments. Interest is not accrued on loans which are ninety days or more past due, or when, in the judgment of management, the collectability of the principal or interest becomes doubtful. Past due status is based on contractual terms of the loan. Interest income previously accrued on such loans is reversed against current period earnings. Loans are returned to accrual status when all principal and interest amounts contractually due are brought current and future payments are reasonably assured. The Company periodically may agree to modify the contractual terms of loans. When a loan is modified and a concession is made to a borrower experiencing financial difficulty, the modification is considered a troubled debt restructuring (“TDR”). All TDRs are initially classified as impaired and placed on nonaccrual status. Generally, a nonaccrual loan that is restructured remains on nonaccrual for a period of six months to demonstrate that the borrower can meet the restructured terms. If the borrower’s ability to meet the revised terms is not reasonably assured, the loan remains on nonaccrual status.
Allowance for Loan Losses	Allowance for loan losses The allowance for loan losses is a valuation allowance for probable incurred credit losses. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses is evaluated on a regular basis and is based upon management’s periodic review of the collectibility of the loans in light of historical experience, the nature and volume of the loan portfolio, adverse situations that may affect the borrower’s ability to repay, estimated value of any underlying collateral and prevailing economic conditions. This evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as either additional information becomes available or circumstances change. The allowance for loan losses is allocated to loan types using both a formula-based approach applied to groups of loans (general component) and an analysis of certain individual loans for impairment (allocated component). General component The general component of the allowance for loan losses covers loans that are collectively evaluated for impairment and is based on historical loss experience adjusted for qualitative factors stratified by loan segments. Management uses a rolling average of historical losses based on a trailing 48 month time frame appropriate to capture relevant loss data for each loan segment. This historical loss factor is supplemented by the following qualitative factors: levels/trends in delinquencies; trends in volume and terms of loans; effects of changes in risk selection and underwriting standards and other changes in lending policies, procedures and practices; experience/ability/depth of lending management and staff; national and local economic trends and conditions, regulatory and legal factors; and risk rating concentrations. The qualitative factors are determined based on the various risk characteristics of each loan segment. Risk characteristics relevant to each portfolio segment are as follows: Residential one-to four-family real estate – The Company generally does not originate loans with a loan-to-value ratio greater than 80 percent. All loans in this segment are collateralized by one-to four-family owner, and non-owner-occupied, residential real estate and repayment is dependent on the credit quality of the individual borrower. The overall health of the economy, including unemployment rates and housing prices, will have an effect on the credit quality in this segment. Second mortgages and home equity lines of credit (HELOC) – Loans in this segment are primarily secured by second-position liens, and the Company may or may not also have a first-position lien. Regardless of which creditor is in first position, the Company does not originate loans with a combined loan-to-value ratio greater than 80 percent. All loans in this segment are collateralized by owner-occupied residential real estate and repayment is dependent on the credit quality of the individual borrower. The overall health of the economy, including unemployment rates and housing prices, will have an effect on the credit quality in this segment. Commercial real estate – Loans in this segment consist of owner-occupied and non-owner-occupied property primarily located in Massachusetts and Rhode Island. The underlying cash flows generated by the operating entities of owner-occupied real estate support the associated debt. Rental cash flows, for which management obtains periodic rent rolls, support the debt associated with non-owner-occupied real estate and can be negatively impacted by increased vacancy rates. Construction – Loans in this segment primarily include residential real estate development loans for which payment is derived from sale of the property. Credit risk is affected by cost overruns, time to sell at an adequate price, and market conditions. Commercial and Industrial – Loans in this segment are made to businesses and are generally secured by assets of the business. Repayment is expected from the cash flows of the business. A weakened economy, and resultant decreased consumer spending, would have an effect on the credit quality in this segment. Consumer – Loans in this segment primarily include personal unsecured loans, refinanced student loans and auto loans purchased from third party lenders. Repayment is dependent on the credit quality of the individual borrower. Allocated component The allocated component of the allowance for loan losses relates to loans that are individually classified as impaired. Residential real estate, commercial and industrial, commercial real estate and construction loans are evaluated for impairment on a loan-by-loan basis. Impairment is measured by either the present value of expected future cash flows discounted at the loan’s effective interest rate, or the fair value of the collateral if the loan is collateral dependent. An allowance is established when the discounted cash flows (or collateral value) of the impaired loan are lower than the carrying value of that loan. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, the Company does not generally identify individual consumer loans or second mortgages and HELOCs for impairment disclosures unless such loans are 90 days past due or are classified as a troubled debt restructuring. A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed.
Bank-owned Life Insurance	Bank-owned life insurance Bank-owned life insurance policies are reflected on the consolidated balance sheets at their cash surrender value net of charges or other amounts that are probable at settlement. Changes in the net cash surrender value of the policies, as well as insurance proceeds received, are reflected in non-interest income in the consolidated statements of operations and are not subject to income taxes, unless such policies are surrendered prior to the death of the insured individuals.
Mortgage Servicing Rights	Mortgage servicing rights The Company services mortgage loans for others. Mortgage servicing rights are recognized as separate assets at fair value when rights are acquired through purchase or through sale of financial assets (“MSRs”). Capitalized servicing rights are amortized into mortgage servicing income in proportion to, and over the period of, the estimated future net servicing income of the underlying financial assets. MSRs are evaluated for impairment based upon the fair value of the rights as compared to amortized cost. Impairment is determined by stratifying rights by predominant risk characteristics, such as interest rates and terms. Fair value is based on a valuation model that calculates the present value of estimated future net servicing income, using market-based assumptions. Impairment is recognized through a valuation allowance for an individual stratum, to the extent that fair value is less than the capitalized amount for the stratum. Changes in the valuation allowance, if any, are reported in mortgage servicing income.
Premises and Equipment	Premises and equipment Land is carried at cost. Buildings, equipment and leasehold improvements are stated at cost, less accumulated depreciation and amortization computed predominantly on the straight-line method over the estimated useful lives of the assets or the expected terms of the leases, if shorter. Expected terms include lease option periods to the extent that the exercise of such options is reasonably assured. Premises and equipment held for sale are stated at the lower of amortized cost or fair value less costs to sell.
Transfers of Financial Assets	Transfers of financial assets Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. During the normal course of business, the Company may transfer a portion of a financial asset, for example, a participation loan. In order to be eligible for sales treatment, all cash flows from the loan must be divided proportionately, the rights of each loan holder must have the same priority, the loan holders must have no recourse to the transferor other than standard representations and warranties, and no loan holder can have the right to pledge or exchange the entire loan. In certain cases, the Company may have an obligation to repurchase mortgage loans sold to third parties and to refund fees to the purchaser if a payment default or prepayment occurs, in each case within a prescribed time period not exceeding four months after the sale date, or in the case of a violation of its representations and warranties under the provisions of its loan sale agreements. The Company evaluates its obligations under these provisions and recognizes a liability for the fair value of its recourse obligations. At December 31, 2019 and 2018, the Company determined that its obligations in connection with the recourse provisions of its loan sale agreements were insignificant.
Foreclosed Real Estate	Foreclosed real estate Real estate acquired through, or in lieu of, loan foreclosure are held for sale and are initially recorded at fair value, less costs to sell, at the date of foreclosure, establishing a new cost basis. Subsequent to foreclosure, valuations are periodically performed by management and the assets are carried at the lower of carrying amount or fair value less costs to sell. Revenue and expenses from operations, changes in the valuation allowance and any direct write-downs are included in foreclosed real estate expense.
Supplemental Retirement Plans	Supplemental retirement plan The Company accounts for its supplemental retirement plan using an actuarial model that allocates cost over the service period of participants in the plan. The Company accounts for the over-funded or under-funded status of the plan as an asset or liability in its consolidated balance sheets and recognizes changes in the funded status in the year in which the changes occur through other comprehensive income/loss.
Employee Stock Ownership Plan	Employee Stock Ownership Plan Compensation expense for the Employee Stock Ownership Plan (“ESOP”) is computed based on the number of shares allocated to participants during the period multiplied by the average fair market value of the Company’s shares. This expense is recognized ratably throughout the year based on the expected allocation of shares for the year. Unearned compensation applicable to the ESOP is reflected as a reduction of stockholders’ equity. The difference between the average fair market value and cost of the shares allocated by the ESOP is recorded as an adjustment to additional paid-in capital.
Stock-Based Compensation	Stock-based compensation The fair value of restricted stock and stock options is determined on the date of grant and amortized to compensation expense with a corresponding increase to additional paid-in capital over the required service period, but in no event beyond the date of an employee’s or director’s date of termination. Forfeitures of unvested awards and grants are recorded as incurred.
Advertising Cost [Policy Text Block]	Advertising costs Advertising costs are expensed as incurred.
Income Taxes	Income taxes Deferred income tax assets and liabilities are determined using the liability (or balance sheet) method. Under this method, the net deferred tax asset or liability is determined based on the tax effects of the temporary differences between the book and tax basis of the various balance sheet assets and liabilities and gives current recognition to changes in tax rates and laws. A valuation allowance is established against deferred tax assets when, based upon available evidence including historical and projected taxable income, that some or all of the deferred tax assets will not be realized. A tax position is recognized as a benefit if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded. The Company does not have any uncertain tax positions at December 31, 2019 and 2018 which require accrual or disclosure. The Company records interest and penalties as part of income tax expense. No interest or penalties were recorded for the years ended December 31, 2019 and 2018.
Comprehensive Income (Loss)	Comprehensive income (loss) Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income (loss). Although certain changes in assets and liabilities are reported as a separate component of equity, such items, along with net income (loss), are components of comprehensive income (loss). The components of accumulated other comprehensive loss (“AOCI”), included in stockholders’ equity, are as follows: December 31, December 31, 2019 2018 (In thousands) Securities available for sale: Net unrealized gain (loss) $ 167 $ (1,334 ) Tax effect (313 ) (313 ) Net-of-tax amount (146 ) (1,647 ) Supplemental retirement plan Unrecognized net actuarial loss (652 ) (605 ) Unrecognized net prior service credit 311 395 (341 ) (210 ) Tax effect (47 ) (47 ) Net-of-tax amount (388 ) (257 ) Accumulated other comprehensive loss $ (534 ) $ (1,904 ) In 2020, the Company expects to recognize $83,000 in prior service credits and $45,000 in net actuarial losses as components of cost for the supplemental retirement plan. These amounts are included in accumulated other comprehensive loss at December 31, 2019. Prior service credits and net actuarial gains and losses are amortized to periodic pension cost over varying periods based on the plan participants to whom they relate.
Segment Reporting	Segment reporting An operating segment is defined as a component of a business for which separate financial information is available that is evaluated regularly by the chief operating decision-maker in determining how to allocate resources and evaluate performance. The Company has two reporting business segments, namely, “Envision Bank” and “Envision Mortgage”. Management allocates indirect costs, such as IT, Marketing, Accounting and Administration, to each business segment in order to fully measure each segment’s results of operations. See Note 18 for disclosure of the Company’s segment information.
Earnings (Loss) Per Share	Earnings (loss) per share Basic earnings (loss) per share represents income (loss) available to common stockholders divided by the weighted average of common shares outstanding during the period. Unvested restricted shares of common stock having dividend rights are treated as “participating securities” and, accordingly, are considered outstanding in computing basic earnings (loss) per share. Unallocated ESOP shares are not considered outstanding in computing earnings (loss) per share. Diluted earnings per share reflects additional common shares that would have been outstanding if dilutive potential shares had been issued. Stock options represent potential dilutive shares with the number of such shares computed using the treasury stock method. No options were included in the computation of earnings (loss) per share in 2019 and 2018 as their impact would be anti-dilutive.
Business Combinations	Business combinations We account for business combinations under the acquisition method of accounting. The application of this method of accounting requires the use of significant estimates and assumptions in the determination of the fair value of tangible and identified intangible assets acquired and liabilities assumed in order to properly allocate purchase price consideration between assets from those that are recorded as goodwill. Our estimates of the fair values of assets acquired and liabilities assumed are based upon assumptions that we believe to be reasonable, and whenever necessary, include assistance from independent third-party appraisal and valuation firms. Costs incurred to consummate a business combination are expensed as incurred.
Recent Accounting Pronouncements	Recent accounting pronouncements On January 1, 2019, the Company early adopted Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers. In January 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-01, Financial Instruments In February 2016, FASB issued ASU 2016-02, Leases In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses In April 2017, the FASB issued ASU 2017-08 Receivables – Non-refundable Fees and Other Costs . In August 2018, the FASB issued ASU 2018-13 Fair Value Measurement – Changes to the Disclosure Requirements for Fair Value Measurement, . In December 2019, FASB issued ASU 2019-12, Income Taxes – Simplifying the Accounting for Income Taxes
Reclassifications	Reclassifications Certain reclassifications have been made to the 2018 consolidated financial statements in order to conform to the presentations used in the 2019 consolidated financial statements. Such reclassifications had no impact on net income (loss) as presented in such financial statements .

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Components of Accumulated Other Comprehensive Loss (AOCI) and Related Tax Effects	The components of accumulated other comprehensive loss (“AOCI”), included in stockholders’ equity, are as follows: December 31, December 31, 2019 2018 (In thousands) Securities available for sale: Net unrealized gain (loss) $ 167 $ (1,334 ) Tax effect (313 ) (313 ) Net-of-tax amount (146 ) (1,647 ) Supplemental retirement plan Unrecognized net actuarial loss (652 ) (605 ) Unrecognized net prior service credit 311 395 (341 ) (210 ) Tax effect (47 ) (47 ) Net-of-tax amount (388 ) (257 ) Accumulated other comprehensive loss $ (534 ) $ (1,904 )

Securities Available for Sale (

Securities Available for Sale (Tables)	12 Months Ended
	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Schedule of Amortized Cost and Fair Value of Securities	The amortized cost and fair value of securities available for sale, including gross unrealized gains and losses, are as follows: Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value (In thousands) December 31, 2019 U.S. Government-sponsored enterprises $ 4,000 $ 13 $ (1 ) $ 4,012 Corporate 1,513 15 — 1,528 Municipal 744 9 — 753 Residential mortgage-backed securities: U.S. Government-sponsored enterprises 35,238 458 (286 ) 35,410 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises 8,977 — (53 ) 8,924 U.S. Government-guaranteed 1,363 7 — 1,370 Collateralized mortgage obligations: U.S. Government-sponsored enterprises 1,395 23 — 1,418 U.S. Government-guaranteed 4,106 10 (28 ) 4,088 Total securities available for sale $ 57,336 $ 535 $ (368 ) $ 57,503 December 31, 2018 Debt securities: U.S. Government-sponsored enterprises $ 3,999 $ 13 $ (31 ) $ 3,981 Corporate 1,524 6 (18 ) 1,512 Municipal 1,489 18 — 1,507 Residential mortgage-backed securities: U.S. Government-sponsored enterprises 26,989 71 (754 ) 26,306 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises 9,094 — (487 ) 8,607 U.S. Government-guaranteed 1,796 — (33 ) 1,763 Collateralized mortgage obligations: U.S. Government-sponsored enterprises 1,642 — (17 ) 1,625 U.S. Government-guaranteed 4,839 2 (104 ) 4,737 Total debt securities 51,372 110 (1,444 ) 50,038 Mutual fund 518 — — 518 Total securities available for sale $ 51,890 $ 110 $ (1,444 ) $ 50,556
Investments Classified by Contractual Maturity Date	The amortized cost and fair value of debt securities by contractual maturity at December 31, 2019 are presented below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Amortized Fair Cost Value (In thousands) Within 1 year $ 4,501 $ 4,518 After 1 year through 5 years 1,512 1,522 After 5 years through 10 years 244 253 6,257 6,293 Mortgage-backed securities and collateralized mortgage obligations 51,079 51,210 $ 57,336 $ 57,503
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	Information pertaining to securities with gross unrealized losses aggregated by investment category and length of time that individual securities have been in a continuous loss position follows: Less Over Twelve Months Gross Gross Unrealized Fair Unrealized Fair Losses Value Losses Value December 31, 2019 (In thousands) Debt securities: U.S. Government-sponsored enterprises $ — $ — $ (1 ) $ 1,999 Residential mortgage-backed securities: U.S. Government-sponsored enterprises (123 ) 11,256 (163 ) 9,632 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises (53 ) 8,924 — — Collateralized mortgage obligations: U.S. Government-guaranteed (15 ) 1,891 (13 ) 883 Total debt securities $ (191 ) $ 22,071 $ (177 ) $ 12,514 December 31, 2018 Debt securities: U.S. Government-sponsored enterprises $ — $ — $ (31 ) $ 1,969 Corporate (5 ) 497 (13 ) 506 Residential mortgage-backed securities: U.S. Government-sponsored enterprises (6 ) 7,038 (748 ) 12,981 Commercial mortgage-backed securities: U.S. Government-sponsored enterprises — — (487 ) 8,607 U.S. Government-guaranteed — — (33 ) 1,763 Collateralized mortgage obligations: U.S. Government-sponsored enterprises — — (17 ) 1,625 U.S. Government-guaranteed — — (104 ) 3,879 Total debt securities $ (11 ) $ 7,535 $ (1,433 ) $ 31,330

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Summary of Loan Portfolio	A summary of the loan portfolio is as follows: December 31, 2019 2018 (In thousands) Mortgage loans on real estate: Residential: One-to four-family $ 244,711 $ 246,756 Home equity loans and lines of credit 41,669 43,545 Commercial 125,405 113,642 Construction 35,485 42,139 447,270 446,082 Commercial and industrial 9,093 21,285 Consumer 15,641 19,407 Total loans 472,004 486,774 Allowance for loan losses (4,280 ) (4,437 ) Net deferred loan costs and fees, and purchase premiums 1,407 1,509 $ 469,131 $ 483,846
Summary of Activity in the Allowance for Loan Losses by Loan Category	The following tables present activity in the allowance for loan losses, by loan category, for the years ended December 31, 2019 and 2018 and allocation of the allowance to each category as of such dates: Second Residential Mortgages Commercial Commercial 1-4 Family and HELOC Real Estate Construction and Industrial Consumer Total (In thousands) Allowance for loan losses Balance at December 31, 2017 $ 854 $ 359 $ 1,620 $ 351 $ 335 $ 218 $ 3,737 Provision (credit) for loan losses 197 (67 ) 30 414 (70 ) 258 762 Loans charged-off — — (2 ) — — (119 ) (121 ) Recoveries 41 — — — — 18 59 Balance at December 31, 2018 1,092 292 1,648 765 265 375 4,437 Provision (credit) for loan losses (21 ) (3 ) 192 (73 ) (30 ) (65 ) — Loans charged-off — — — — — (192 ) (192 ) Recoveries 25 — — — — 10 35 Balance at December 31, 2019 $ 1,096 $ 289 $ 1,840 $ 692 $ 235 $ 128 $ 4,280
Summary of Additional Information Pertaining to the Allowance for Loan Losses	Second Residential Mortgages Commercial Commercial 1-4 Family and HELOC Real Estate Construction and Industrial Consumer Total December 31, 2019 Allowance for impaired loans $ 116 $ — $ — $ — $ — $ — $ 116 Allowance for non-impaired loans 980 289 1,840 692 235 128 4,164 Total allowance for loan losses $ 1,096 $ 289 $ 1,840 $ 692 $ 235 $ 128 $ 4,280 Impaired loans $ 5,640 $ 407 $ 46 $ — $ — $ — $ 6,093 Non-impaired loans 239,071 41,262 125,359 35,485 9,093 15,641 465,911 Total loans $ 244,711 $ 41,669 $ 125,405 $ 35,485 $ 9,093 $ 15,641 $ 472,004 December 31, 2018 Allowance for impaired loans $ 108 $ — $ — $ — $ — $ 174 $ 282 Allowance for non-impaired loans 984 292 1,648 765 265 201 4,155 Total allowance for loan losses $ 1,092 $ 292 $ 1,648 $ 765 $ 265 $ 375 $ 4,437 Impaired loans $ 6,291 $ 408 $ 52 $ — $ — $ 199 $ 6,950 Non-impaired loans 240,465 43,137 113,590 42,139 21,285 19,208 479,824 Total loans $ 246,756 $ 43,545 $ 113,642 $ 42,139 $ 21,285 $ 19,407 $ 486,774
Schedule of Past Due and Non-Accrual Loans by Loan Category	The following table presents past due and non-accrual loans, by loan category, at December 31, 2019 and 2018: 30 - 59 Days Past Due 60 - 89 Days Past Due 90 Days or More Past Due Total Past Due (1) Non-accrual Loans (In thousands) December 31, 2019 Residential one-to four-family $ 215 $ 587 $ — $ 802 $ 2,922 Home equity loans and lines of credit 188 244 — 432 336 Commercial real estate — — — — — Construction — — — — — Commercial and industrial — — — — — Consumer 76 11 — 87 — Total $ 479 $ 842 $ — $ 1,321 $ 3,258 December 31, 2018 Residential one-to four-family $ 655 $ 207 $ 635 $ 1,497 $ 2,474 Home equity loans and lines of credit 520 — — 520 407 Commercial real estate — — — — — Construction — — — — — Commercial and industrial — — — — — Consumer 25 4 — 29 149 Total $ 1,200 $ 211 $ 635 $ 2,046 $ 3,030
Summary of Impaired Loans and Information Related to Average Balances of Impaired Loans and Interest Income Recognized	Further information pertaining to impaired loans, which includes both non-accrual loans and troubled debt restructurings, follows: Recorded Investment Unpaid Principal Balance Related Allowance (In thousands) December 31, 2019 Impaired loans without a valuation allowance: Residential one-to four-family $ 3,322 $ 3,322 $ — Home equity loans and lines of credit 407 407 — Commercial real estate 46 46 — Total 3,775 3,775 — Impaired loans with a valuation allowance: Residential one-to four-family 2,318 2,318 116 Total impaired loans $ 6,093 $ 6,093 $ 116 December 31, 2018 Impaired loans without a valuation allowance: Residential one-to four-family $ 4,280 $ 4,280 $ — Home equity loans and lines of credit 408 408 — Commercial real estate 52 52 — Total 4,740 4,740 — Impaired loans with a valuation allowance: Residential one-to four-family 2,011 2,011 108 Consumer 199 199 174 Total 2,210 2,210 282 Total impaired loans $ 6,950 $ 6,950 $ 282 Information related to the average balances of impaired loans and the interest income recognized on such loans, follows: Average Interest Cash Basis Recorded Income Interest Investment Recognized Recognized (In thousands) Year Ended December 31, 2019 Residential one-to four-family $ 5,594 $ 236 $ 87 Home equity loans and lines of credit 424 11 10 Commercial real estate 132 4 — Consumer 35 1 — Total $ 6,185 $ 252 $ 97 Year Ended December 31, 2018 Residential one-to four-family $ 6,781 $ 210 $ 84 Home equity loans and lines of credit 420 36 36 Commercial real estate 244 15 — Consumer 50 2 — Total $ 7,495 $ 263 $ 120
Summary of Company's Loans by Risk Rating	The following table presents the Company’s loans by risk rating at December 31, 2019 and 2018: December 31, 2019 December 31, 2018 Commercial Real Construction Commercial and Industrial Commercial Real Construction Commercial and Industrial (In thousands) Loans rated 1 - 3A $ 121,703 $ 35,485 $ 8,134 $ 113,642 $ 42,139 $ 21,285 Loans rated 4 3,702 — 206 — — — Loans rated 5 — — 753 — — — $ 125,405 $ 35,485 $ 9,093 $ 113,642 $ 42,139 $ 21,285

Loan Servicing (Tables)

Loan Servicing (Tables)	12 Months Ended
	Dec. 31, 2019
Transfers And Servicing [Abstract]
Summary of Activity Relating to Mortgage Servicing Rights	The following table summarizes the activity in the Company’s MSRs for the indicated periods: For the Years Ended December 31, 2019 2018 Mortgage servicing rights: (In thousands) Balance at beginning of year $ 7,786 $ 6,397 Additions through originations 2,979 2,380 Amortization (1,281 ) (983 ) Balance at end of year $ 9,484 $ 7,794 Valuation allowance: Balance at beginning of year $ 8 $ 90 Provision (credit) 920 (82 ) Balance at end of year $ 928 $ 8 Mortgage servicing rights, amortized cost $ 8,556 $ 7,786 Mortgage servicing rights, fair value $ 8,817 $ 8,554

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Summary of Cost and Accumulated Depreciation and Amortization of Premises and Equipment	A summary of the cost and accumulated depreciation and amortization of premises and equipment is as follows: December 31, Estimated 2019 2018 Useful Life (In thousands) (In years) Land and improvements $ 953 $ 1,025 Buildings and improvements 3,305 3,280 5 to 50 Leasehold improvements 2,231 2,136 3 to 10 Furniture and equipment 5,170 5,032 3 to 10 Construction-in-progress 82 84 11,741 11,557 Less accumulated depreciation and amortization (5,993 ) (5,189 ) $ 5,748 $ 6,368

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2019
Deposits [Abstract]
Summary of Deposit Balances by Type	A summary of deposit balances, by type, is as follows: December 31, 2019 2018 (In thousands) Demand deposits $ 61,603 $ 64,229 NOW accounts 39,043 42,802 Money market deposits 71,530 60,843 Regular and other savings accounts 126,876 101,137 Brokered deposits 10,167 10,088 Total non-certificate accounts 309,219 279,099 Term certificates less than $250,000 85,425 99,491 Term certificates of $250,000 or more 21,707 8,048 Term certificates - brokered 80,691 50,492 Total certificate accounts 187,823 158,031 $ 497,042 $ 437,130
Summary of Term Certificates, Including Brokered Deposits, by Maturity	A summary of term certificates, including brokered deposits, by maturity is as follows: December 31, 2019 December 31, 2018 Weighted Weighted Average Average Maturing during: Amount Rate Amount Rate (Dollars in thousands) 2019 $ — — % 89,167 1.68 % 2020 140,987 1.92 40,847 2.16 2021 18,840 1.88 12,785 2.16 2022 25,610 2.12 14,101 1.98 2023 1,743 1.28 1,131 1.38 2024 643 1.32 — — $ 187,823 1.94 % $ 158,031 1.87 %

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Summary of Borrowings from FHLBB	A summary of borrowings from the FHLBB at December 31, 2019 and 2018 is as follows: 2019 2018 Weighted Weighted Average Average Amount Rate Amount Rate (Dollars in thousands) Fixed-rate advances maturing: 2019 $ — — % $ 84,184 2.57 % 2020* 22,476 1.80 2,894 1.49 2021* 11,927 1.86 1,958 1.33 2022* 10,000 2.20 — — $ 44,403 1.91 % $ 89,036 2.50 % * Includes amortizing advances which require monthly principal and interest payments.
Summary of Outstanding Balances of Short Term Borrowings from FHLBB	Included in FHLBB borrowings at December 31, 2019 and 2018 are overnight advances and advances having a one-month maturity of $19.8 million and $82.7 million, respectively. Selected information for such short-term borrowings for the years presented is as follows (in 000’s): 2019 2018 Average daily balance $ 73,551 $ 63,552 Maximum outstanding at any month end 128,283 108,819

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Allocation of Federal and State Income Taxes Between Current and Deferred Portions	Allocation of federal and state income taxes between current and deferred portions is as follows (in thousands): Years Ended December 31, 2019 2018 Current tax expense: Federal $ — $ — State 118 31 Total current tax expense 118 31 Deferred tax expense (benefit): Federal 723 (541 ) State 226 73 949 (468 ) Change in valuation allowance (949 ) 468 Total deferred tax expense (benefit) — — Total tax expense $ 118 $ 31
Summary of Differences Between Statutory Federal Income Tax Expense (Benefit) and Actual Tax Expense	The reasons for the differences between the statutory federal income tax expense (benefit) and the actual tax expense are summarized as follows (in thousands): Years Ended December 31, 2019 2018 Statutory federal tax rate of 21% $ 745 $ (432 ) Increase (decrease) resulting from: State taxes, net of federal tax effect 272 83 Bank-owned life insurance (39 ) (46 ) Tax-exempt income (9 ) (25 ) Change in valuation allowance (949 ) 468 Other, net 98 (17 ) Total tax expense $ 118 $ 31
Summary of Components of Net Deferred Tax Asset	The components of the net deferred tax asset are as follows (in thousands): December 31, 2019 2018 Deferred tax assets: Federal $ 4,809 $ 5,134 State 1,066 1,134 5,875 6,268 Valuation allowance (2,297 ) (3,246 ) 3,578 3,022 Deferred tax liabilities: Federal (2,547 ) (2,189 ) State (1,031 ) (833 ) (3,578 ) (3,022 ) Net deferred tax asset $ — $ —
Summary of Deferred Tax Assets (Liabilities)	The tax effects of items giving rise to deferred tax assets (liabilities) are as follows (in thousands): December 31, 2019 2018 Employee benefit plans $ 714 $ 825 Allowance for loan losses 1,203 1,247 Funded status of post-retirement benefits (47 ) (47 ) Securities available for sale (313 ) (313 ) Depreciation and amortization 279 249 Net deferred loan origination costs (350 ) (357 ) Mortgage servicing rights (2,366 ) (2,082 ) Net operating loss carryforward 2,517 2,864 Charitable contribution carryforward 619 700 Derivatives (377 ) (105 ) Stock-based compensation 185 121 Other, net 233 144 2,297 3,246 Valuation allowance on net deferred tax assets (2,297 ) (3,246 ) Net deferred tax asset $ — $ —

Minimum Regulatory Capital Re_2

Minimum Regulatory Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2019
Banking And Thrift [Abstract]
Summary of Actual and Minimum Capital Amounts and Ratios Exclusive of Capital Conservation Buffer	The Bank’s actual and minimum capital amounts and ratios, exclusive of the capital conservation buffer, are presented in the following table: Minimum To Be Well For Minimum Capitalized Under Capital Prompt Corrective Actual Adequacy Purposes Action Provisions Amount Ratio Amount Ratio Amount Ratio (Dollars in thousands) December 31, 2019 Total capital (to risk weighted assets) $ 76,652 16.7 % $ 36,637 8.0 % $ 45,796 10.0 % Tier 1 capital (to risk weighted assets) 72,372 15.8 27,478 6.0 36,637 8.0 Common equity Tier 1 capital (to risk weighted assets) 72,372 15.8 20,608 4.5 29,768 6.5 Tier 1 capital (to average assets) 72,372 11.3 25,627 4.0 32,033 5.0 December 31, 2018 Total capital (to risk weighted assets) 72,523 16.1 36,084 8.0 45,105 10.0 Tier 1 capital (to risk weighted assets) 68,086 15.1 27,063 6.0 36,084 8.0 Common equity Tier 1 capital (to risk weighted assets) 68,086 15.1 20,297 4.5 29,318 6.5 Tier 1 capital (to average assets) 68,086 10.9 25,056 4.0 31,320 5.0

Post-retirement Plans (Tables)

Post-retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Summary of Information Pertaining to Activity in Plan	The Company has a master supplemental retirement plan (“Plan”) which covers certain officers and directors of the Company. In 2019 and 2018, the only active participants in the Plan were certain directors. Information pertaining to activity in the Plan follows: Years Ended December 31, 2019 2018 (In thousands) Change in plan assets: Fair value of plan assets at beginning of year $ — $ — Employer contributions 201 201 Benefits paid (201 ) (201 ) Fair value of plan assets at end of year — — Change in benefit obligation: Benefit obligation at beginning of year 1,561 1,724 Service cost 10 10 Interest cost 53 48 Actuarial (gain) loss 83 (20 ) Benefits paid (201 ) (201 ) Benefit obligation at end of year 1,506 1,561 Unfunded status and accrued supplemental pension cost at year end $ (1,506 ) $ (1,561 ) Accumulated benefit obligation at year end $ 1,506 $ 1,561
Summary of Assumptions Used to Determine Benefit Obligation	The assumptions used to determine the benefit obligation are as follows: December 31, 2019 2018 Discount rate 2.50 % 3.60 % Annual inflation factor 1.00 % 1.00 % The following assumptions were used to determine the net periodic benefit cost for the years ended December 31, 2019 and 2018: 2019 2018 Discount rate 3.60 % 2.90 % Annual inflation factor 1.00 % 1.00 %
Summary of Net Periodic Benefit Cost Included in Salaries and Employee Benefits Expense	Net periodic benefit cost, included in other non-interest expenses, attributable to the Plan for the years ended December 31, 2019 and 2018, consists of the following: 2019 2018 (In thousands) Service cost $ 10 $ 10 Interest cost 53 48 Amortization of net actuarial loss 36 41 Amortization of prior service credit (84 ) (89 ) $ 15 $ 10
Summary of Estimated Future Benefit Payments Expected Future Services	Estimated future benefit payments, which reflect expected future services, as appropriate, are as follows: Years Ending December 31, Amount (In thousands) 2020 $ 201 2021 201 2022 213 2023 345 2024 213 2025-2029 425

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Grants of Options to Purchase Shares of Common Stock	The Company made the following grants of options to purchase shares of common stock during the years ended December 31, 2019 and 2018: 2019 2018 Options granted 57,252 27,000 Vesting period (years) 3 - 5 3 - 5 Expiration period (years) 10 10 Expected volatility 26.14% - 29.09% 29.09% - 29.87% Expected life (years) 6 - 6.5 6 - 6.5 Expected dividend yield — — Risk free interest rate 2.37% - 2.61% 2.68% - 2.77% Option fair value $2.99 - $5.83 $5.78 - $5.83
Summary of Activity and Certain Other Information Related to Stock Options Grants Under Equity Plan	The following table presents the activity and certain other information related to stock option grants under the Equity Plan for the year ended December 31, 2019: Options Stock Option Grants Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Balance at January 1, 2019 312,705 $ 14.78 8.73 $ — Granted 57,252 14.93 Forfeited (6,500 ) 13.90 Expired (3,250 ) 14.66 Balance at December 31, 2019 360,207 $ 14.82 8.01 $ 1,017,708 Exercisable at December 31, 2019 120,704 $ 14.75 7.81 $ 349,852 Unrecognized compensation cost (inclusive of directors' options) $ 982,722 Weighted average remaining recognition period (years) 2.79
Summary of Activity and Certain Other Information Related to Restricted Stock Awards Under Equity Plan	The following table presents the activity and certain other information related to restricted stock awards under the Equity Plan for the year ended December 31, 2019: Restricted Stock Awards Weighted Average Grant Price Restricted stock awards at January 1, 2019 126,694 $ 14.66 Granted 33,335 15.07 Vested (31,668 ) 14.66 Forfeited (2,500 ) 15.07 Non-vested stock awards at December 31, 2019 125,861 $ 14.76 Unrecognized compensation cost $ 1,651,000 Weighted average remaining recognition period (years) 3.04

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of Calculation of Average Number of Shares Outstanding Used to Calculate Basic and Diluted Earnings (Loss) Per Share	The following table sets forth the calculation of the average number of shares outstanding used to calculate the basic and diluted earnings (loss) per share for the periods indicated: 2019 2018 Average number of common shares outstanding 5,787,385 5,994,373 Less: Average unallocated ESOP shares (403,768 ) (423,653 ) 5,383,617 5,570,720

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rent Commitments	Pursuant to the terms of non-cancelable lease and sublease agreements in effect at December 31, 2019, future minimum rent commitments are as follows: Years Ending December 31, Leases Sub-lease Net (In thousands) 2020 $ 1,095 (89 ) $ 1,006 2021 878 (91 ) 787 2022 681 (94 ) 587 2023 228 (16 ) 212 2024 91 — 91 Thereafter 23 — 23 $ 2,996 $ (290 ) $ 2,706
Summary of Financial Instruments Outstanding Contract Amounts Represent Credit Risk	At December 31, 2019 and 2018, the following financial instruments were outstanding whose contract amounts represent credit risk: 2019 2018 (In thousands) Commitments to originate loans $ 117,086 $ 38,404 Unused lines and letters of credit 52,721 45,977 Unadvanced funds on construction loans 11,029 14,175 Overdraft lines of credit 8,178 8,475

Fair Value of Assets and Liab_2

Fair Value of Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	Assets and liabilities measured at fair value on a recurring basis are summarized below. . Total Level 1 Level 2 Level 3 Fair December 31, 2019 (In thousands) Assets: Securities available for sale $ — $ 57,503 $ — $ 57,503 Portfolio loans (fair value option) 9,826 — 9,826 Loans held for sale (fair value option) — 62,792 — 62,792 Derivative loan commitments — 1,472 — 1,472 Forward loan sale commitments — 11 — 11 Liabilities: Forward loan sale commitments, including TBAs — 140 — 140 December 31, 2018 Assets: Securities available for sale: Debt securities $ — $ 50,038 $ — $ 50,038 Mutual fund — 518 — 518 Portfolio loans (fair value option) — 3,680 — 3,680 Loans held for sale (fair value option) — 38,474 — 38,474 Derivative loan commitments — 627 — 627 Forward loan sale commitments — 10 — 10 Liabilities: Forward loan sale commitments, including TBAs — 263 — 263
Schedule of Assets Measured at Fair Value on a Non-Recurring Basis	The following table summarizes the fair value hierarchy used to determine each adjustment and the carrying value of the related assets and liabilities as of December 31, 2019 and 2018. The gains and losses represent the amounts recorded during 2019 and 2018 on the assets and liabilities held at year-end. There no liabilities recorded at fair value on a non-recurring basis as of December 31, 2019 and 2018. Year Ended December 31, 2019 December 31, 2019 Level 1 Level 2 Level 3 Total Assets: (In thousands) Collateral dependent impaired loans $ — $ — $ 2,250 $ — Mortgage servicing rights — 8,556 — (920 ) $ — $ 8,556 $ 2,250 $ (920 ) Year Ended December 31, 2018 December 31, 2018 Level 1 Level 2 Level 3 Total Gains (Losses) (In thousands) Collateral dependent impaired loans $ — $ — $ 1,352 $ — Mortgage servicing rights — 7,786 — 82 Foreclosed real estate — — 65 (36 ) $ — $ 7,786 $ 1,417 $ 46
Summary of Carrying Values, Estimated Fair Values and Placement in Fair Value Hierarchy of Company's Financial Instruments	The estimated fair values, and related carrying amounts, of the Company’s financial instruments are presented below. Certain financial instruments and all non-financial instruments are exempt from disclosure requirements. Accordingly, the aggregate fair value amounts presented herein do not represent the underlying fair value of the Company. This table excludes financial instruments for which the carrying amount approximates fair value. Financial assets for which the fair value approximates carrying value include cash and cash equivalents and accrued interest receivable. Financial liabilities for which the fair value approximates carrying value include mortgagor’s escrow accounts and accrued interest payable. December 31, 2019 Carrying Fair Amount Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Certificates of deposit $ 490 $ 492 $ — $ 492 $ — Securities available for sale 57,503 57,503 — 57,503 — Loans held for sale 62,792 62,792 — 62,792 — Loans, net 469,131 469,416 — — 469,416 Derivative assets 1,483 1,483 — 1,483 — Financial liabilities: Deposits $ 497,042 $ 496,979 $ — $ 496,979 $ — FHLBB advances 44,403 44,433 — 44,433 — Derivative liabilities 140 140 — 140 — December 31, 2018 Carrying Fair Amount Value Level 1 Level 2 Level 3 (In thousands) Financial assets: Certificates of deposit $ 2,205 $ 2,196 $ — $ 2,196 $ — Securities available for sale 50,556 50,556 — 50,556 — Loans held for sale 38,474 38,474 — 38,474 — Loans, net 483,846 473,612 — — 473,612 Derivative assets 637 637 — 637 — Financial liabilities: Deposits $ 437,130 $ 435,964 $ — $ 435,964 $ — FHLBB advances 89,036 88,894 — 88,894 — Derivative liabilities 263 263 — 263 —

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Summary of Segment Information	Segment information as of and for the year ended December 31, 2019, follows: For the Year Ended December 31, 2019 Envision Bank Envision Mortgage Consolidated Total (in thousands) Net interest income $ 15,985 $ 1,848 $ 17,833 Provision for loan losses — — — Net interest income after provision for loan losses 15,985 1,848 17,833 Non-interest income: Customer service fees 1,268 139 1,407 Gain on loan origination and sale activities, net (1) — 19,851 19,851 Mortgage servicing fees, net (363 ) 757 394 Other 596 366 962 Total non-interest income 1,501 21,113 22,614 Non-interest expenses: Salaries and employee benefits 7,065 17,831 24,896 Occupancy and equipment 1,527 1,256 2,783 Other non-interest expenses 4,789 3,482 8,271 Total non-interest expenses 13,381 22,569 35,950 Income before income taxes and elimination of inter-segment profit $ 4,105 $ 392 4,497 Elimination of inter-segment profit (951 ) Income before income taxes 3,546 Income tax expense 118 Net income $ 3,428 Total assets, December 31, 2019 $ 521,144 $ 109,860 $ 631,004 (1) Before elimination of inter-segment profit Segment information as of and for the year ended December 31, 2018 follows: For the Year Ended December 31, 2018 Envision Bank Envision Mortgage Consolidated Total (in thousands) Net interest income $ 15,664 $ 1,032 $ 16,696 Provision for loan losses 762 — 762 Net interest income after provision for loan losses 14,902 1,032 15,934 Non-interest income: Customer service fees 1,344 120 1,464 Gain on loan origination and sale activities, net (1) — 8,859 8,859 Mortgage servicing fees, net (310 ) 1,574 1,264 Gain on sales of buildings 2,476 — 2,476 Other 520 420 940 Total non-interest income 4,030 10,973 15,003 Non-interest expenses: Salaries and employee benefits 6,793 12,972 19,765 Occupancy and equipment 1,507 1,366 2,873 Restructuring charge — 968 968 Other non-interest expenses 4,476 3,590 8,066 Total non-interest expenses 12,776 18,896 31,672 Income (loss) before income taxes and elimination of inter-segment profit $ 6,156 $ (6,891 ) (735 ) Elimination of inter-segment profit (1,320 ) Loss before income taxes (2,055 ) Income tax expense 31 Net loss $ (2,086 ) Total assets, December 31, 2018 $ 526,871 $ 87,469 $ 614,340 (1) Before elimination of inter-segment profit

Other Non-Interest Expenses (Ta

Other Non-Interest Expenses (Tables)	12 Months Ended
	Dec. 31, 2019
Other Income And Expenses [Abstract]
Schedule of Company's Total Interest and Non-Interest Income Included in Other Non-Interest Expenses	Included in other non-interest expenses in 2019 and 2018 are certain items exceeding 1% of the Company’s total interest and non-interest income as follows: 2019 2018 (In thousands) Software amortization, licenses and maintenance $ 1,017 $ 754 Card related expenses 459 470 Data communication and telephone 418 495 Directors fees, including stock-based compensation 586 613

Parent Company Condensed Fina_2

Parent Company Condensed Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Balance Sheets	Financial information as of December 31, 2019 and 2018 and for the years then ended pertaining to Randolph Bancorp, Inc. is as follows: BALANCE SHEETS December 31, December 31, 2019 2018 Assets Cash and due from bank $ 1,445 $ 6,850 Investment in Envision Bank 72,872 66,971 ESOP loan 4,162 4,266 Total assets $ 78,479 $ 78,087 Liabilities Accounts payable $ — $ 70 Due to Envision Bank 17 56 Total liabilities 17 126 Stockholders' Equity Common stock 56 60 Additional paid-in capital 51,127 55,608 Retained earnings 31,757 28,329 ESOP-Unearned compensation (3,944 ) (4,132 ) Accumulated other comprehensive loss, net of tax (534 ) (1,904 ) Total stockholders' equity 78,462 77,961 Total liabilities and stockholders' equity $ 78,479 $ 78,087
Statements of Operations	Financial information as of December 31, 2019 and 2018 and for the years then ended pertaining to Randolph Bancorp, Inc. is as follows: STATEMENTS OF OPERATIONS Years Ended December 31, 2019 2018 Interest income $ 235 $ 197 Operating expenses 194 197 Income before incomes taxes and equity in undistributed net income (loss) of Envision Bank 41 — Applicable income taxes 3 — Income before equity in undistributed net income (loss) of Envision Bank 38 — Equity in undistributed net income (loss) of Envision Bank 3,390 (2,086 ) Net income (loss) $ 3,428 $ (2,086 )
Statements of Cash Flows	Financial information as of December 31, 2019 and 2018 and for the years then ended pertaining to Randolph Bancorp, Inc. is as follows: STATEMENTS OF CASH FLOWS Years Ended December 31, 2019 2018 Cash flows from operating activities: Net income (loss) $ 3,428 $ (2,086 ) Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities: Equity in undistributed net (income) loss of Envision Bank (3,390 ) 2,086 Change in intercompany receivable/payable (39 ) 197 Net cash provided by (used in) operating activities (1 ) 197 Cash flows from investing activities: Principal payments received on ESOP loan 104 112 Net cash provided by investing activities 104 112 Cash flows from financing activities: Stock repurchases (5,438 ) (1,716 ) Stock repurchase payable (70 ) 70 Net cash used in financing activities (5,508 ) (1,646 ) Net change in cash and due from bank (5,405 ) (1,337 ) Cash and due from bank at the beginning of year 6,850 8,187 Cash and due from bank at end of year $ 1,445 $ 6,850

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Summary of Selected Quarterly Financial Data	First Quarter Second Quarter Third Quarter Fourth Quarter 2019 2018 2019 2018 2019 2018 2019 2018 (Dollars in thousands, except per share data) Interest and dividend income $ 6,016 $ 4,727 $ 6,454 $ 5,039 $ 6,541 $ 5,468 $ 6,219 $ 6,050 Interest expense 1,638 745 1,965 1,006 1,968 1,208 1,828 1,630 Net interest and dividend income 4,378 3,982 4,489 4,033 4,573 4,260 4,391 4,420 Provision (credit) for loan losses — 95 (144 ) (90 ) — 178 144 579 Gain on loan origination and sales activities, net 2,588 1,547 5,068 1,854 5,782 1,956 5,462 2,183 Other non-interest income 825 861 787 929 522 1,252 630 3,102 Total non-interest income 3,413 2,408 5,855 2,783 6,304 3,208 6,092 5,285 Restructuring charges — — — 92 — — — 875 Other non-interest expense 7,878 6,998 8,863 7,820 9,718 7,427 9,490 8,462 Total non-interest expense 7,878 6,998 8,863 7,912 9,718 7,427 9,490 9,337 Provision (benefit) for income taxes (36 ) 4 119 4 14 5 21 17 Net income (loss) $ (51 ) $ (707 ) $ 1,506 $ (1,010 ) $ 1,145 $ (142 ) $ 828 $ (228 ) Basic and diluted earnings (loss) per share $ (0.01 ) $ (0.13 ) $ 0.28 $ (0.18 ) $ 0.21 $ (0.03 ) $ 0.16 $ (0.04 ) Weighted average common shares (basic and diluted) 5,478,544 5,603,886 5,465,205 5,580,683 5,345,786 5,567,596 5,248,021 5,526,416

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)Segmentshares	Dec. 31, 2018USD ($)shares
Summary Of Significant Accounting Policies [Line Items]
Cash equivalents maturity period	90 days
Time period to capture relevant loan loss data	48 months
Obligation to repurchase mortgage loans prescribed time period	4 months
Description of tax benefit	A tax position is recognized as a benefit if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur. The amount recognized is the largest amount of tax benefit greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.
Uncertain tax positions	$ 0	$ 0
Interest or penalties	$ 0	$ 0
Number of business segments | Segment	2
Anti-dilutive securities excluded from computation of earnings (loss) per share | shares	0	0
Supplemental Retirement Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Prior service credits	$ 83,000
Net actuarial losses	$ 45,000
Consumer Loans or Second Mortgages and HELOCs [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment disclosure requirement	Unless such loans are 90 days past due or are classified as a troubled debt restructuring.
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
FDIC insurance coverage limit	$ 250,000
Certificates of deposit maturity period	5 years
Maximum [Member] | Residential One-to-Four Family Real Estate Portfolio Segment [Member]
Summary Of Significant Accounting Policies [Line Items]
Loan-to-value ratio	80.00%
Maximum [Member] | Second Mortgages and Home Equity Lines of Credit Property Segment [Member]
Summary Of Significant Accounting Policies [Line Items]
Loan-to-value ratio	80.00%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Certificates of deposit maturity period	1 year
Percentage of tax benefit that likely of being realized on examination with taxing authority	50.00%

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Components of Accumulated Other Comprehensive Loss (AOCI) and Related Tax Effects (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Total other comprehensive income (loss)	$ 1,370	$ (737)
Accumulated other comprehensive loss	(534)	(1,904)
Accumulated Net Investment Gain (Loss) Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Net unrealized gain (loss)	167	(1,334)
Other comprehensive Loss, Tax effect	(313)	(313)
Total other comprehensive income (loss)	(146)	(1,647)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Net unrealized gain (loss)	(652)	(605)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Net unrealized gain (loss)	311	395
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Net unrealized gain (loss)	(341)	(210)
Other comprehensive Loss, Tax effect	(47)	(47)
Total other comprehensive income (loss)	$ (388)	$ (257)

Securities Available for Sale -

Securities Available for Sale - Schedule of Amortized Cost and Fair Value of Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 57,336	$ 51,890
Gross Unrealized Gains	535	110
Gross Unrealized Losses	(368)	(1,444)
Fair Value	57,503	50,556
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		51,372
Gross Unrealized Gains		110
Gross Unrealized Losses		(1,444)
Fair Value		50,038
Debt Securities [Member] | US Government-sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,000	3,999
Gross Unrealized Gains	13	13
Gross Unrealized Losses	(1)	(31)
Fair Value	4,012	3,981
Debt Securities [Member] | Corporate [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,513	1,524
Gross Unrealized Gains	15	6
Gross Unrealized Losses		(18)
Fair Value	1,528	1,512
Debt Securities [Member] | Municipal [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	744	1,489
Gross Unrealized Gains	9	18
Fair Value	753	1,507
Debt Securities [Member] | Residential Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	35,238	26,989
Gross Unrealized Gains	458	71
Gross Unrealized Losses	(286)	(754)
Fair Value	35,410	26,306
Debt Securities [Member] | Commercial Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,977	9,094
Gross Unrealized Losses	(53)	(487)
Fair Value	8,924	8,607
Debt Securities [Member] | Commercial Mortgage Backed Securities, U.S. Government-guaranteed [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,363	1,796
Gross Unrealized Gains	7
Gross Unrealized Losses		(33)
Fair Value	1,370	1,763
Debt Securities [Member] | Collateralized Mortgage Obligations, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,395	1,642
Gross Unrealized Gains	23
Gross Unrealized Losses		(17)
Fair Value	1,418	1,625
Debt Securities [Member] | Collateralized Mortgage Obligations, US Government Guaranteed [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,106	4,839
Gross Unrealized Gains	10	2
Gross Unrealized Losses	(28)	(104)
Fair Value	$ 4,088	4,737
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		518
Fair Value		$ 518

Securities Available for Sale_2

Securities Available for Sale - Investments Classified by Contractual Maturity Date (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Available-for-sale Securities, Debt Maturities, Amortized Cost
Within 1 year	$ 4,501
After 1 year through 5 years	1,512
After 5 years through 10 years	244
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis, Total	6,257
Mortgage-backed securities and collateralized mortgage obligations	51,079
Available-for-sale Debt Securities, Amortized Cost Basis, Total	57,336
Available-for-sale Securities, Debt Maturities, Fair Value
Within 1 year	4,518
After 1 year through 5 years	1,522
After 5 years through 10 years	253
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Fair Value Total	6,293
Mortgage-backed securities and collateralized mortgage obligations	51,210
Available-for-sale Securities, Debt Securities, Fair Value Total	$ 57,503

Securities Available for Sale_3

Securities Available for Sale - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)Debt_Security	Dec. 31, 2018USD ($)
Schedule of Available-for-sale Securities [Line Items]
Fair value of investment securities pledged as collateral	$ 2,013,000	$ 2,010,000
Number of debt securities with unrealized losses | Debt_Security	26
Unrealized losses debt securities aggregate depreciation percentage	1.05%
Proceeds from sales of available-for-sale securities	$ 534,000	8,958,000
Available-for-sale securities, gross realized gains	16,000	49,000
Prepayment of Commercial Mortgage-backed Security [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, gross realized losses		33,000
OTTI Write-down of Mutual Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, gross realized losses		27,000
Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities on equity	$ 0	$ 0

Securities Available for Sale_4

Securities Available for Sale - Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value (Detail) - Debt Securities [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	$ (191)	$ (11)
Less Than Twelve Months, Fair Value	22,071	7,535
Over Twelve Months, Gross Unrealized Losses	(177)	(1,433)
Over Twelve Months, Fair Value	12,514	31,330
US Government-sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Over Twelve Months, Gross Unrealized Losses	(1)	(31)
Over Twelve Months, Fair Value	1,999	1,969
Residential Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(123)	(6)
Less Than Twelve Months, Fair Value	11,256	7,038
Over Twelve Months, Gross Unrealized Losses	(163)	(748)
Over Twelve Months, Fair Value	9,632	12,981
Commercial Mortgage-backed Securities, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(53)
Less Than Twelve Months, Fair Value	8,924
Over Twelve Months, Gross Unrealized Losses		(487)
Over Twelve Months, Fair Value		8,607
Collateralized Mortgage Obligations, US Government Guaranteed [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses	(15)
Less Than Twelve Months, Fair Value	1,891
Over Twelve Months, Gross Unrealized Losses	(13)	(104)
Over Twelve Months, Fair Value	$ 883	3,879
Corporate [Member]
Schedule of Available-for-sale Securities [Line Items]
Less Than Twelve Months, Gross Unrealized Losses		(5)
Less Than Twelve Months, Fair Value		497
Over Twelve Months, Gross Unrealized Losses		(13)
Over Twelve Months, Fair Value		506
Commercial Mortgage Backed Securities, U.S. Government-guaranteed [Member]
Schedule of Available-for-sale Securities [Line Items]
Over Twelve Months, Gross Unrealized Losses		(33)
Over Twelve Months, Fair Value		1,763
Collateralized Mortgage Obligations, US Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Over Twelve Months, Gross Unrealized Losses		(17)
Over Twelve Months, Fair Value		$ 1,625

Loans - Summary of Loan Portfol

Loans - Summary of Loan Portfolio (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 472,004	$ 486,774
Allowance for loan losses	(4,280)	(4,437)
Net deferred loan costs and fees, and purchase premiums	1,407	1,509
Loans, net	469,131	483,846
Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	447,270	446,082
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	125,405	113,642
Commercial Real Estate Loans [Member] | Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	125,405	113,642
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	9,093	21,285
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	15,641	19,407
One-to-Four Family [Member] | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	244,711	246,756
One-to-Four Family [Member] | Residential Real Estate [Member] | Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	244,711	246,756
Home Equity Loans and Lines of Credit [Member] | Residential Real Estate [Member] | Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	41,669	43,545
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	35,485	42,139
Construction [Member] | Real Estate Sector [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 35,485	$ 42,139

Loans - Additional Information

Loans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)TDR	Dec. 31, 2018USD ($)TDR
Accounts, Notes, Loans and Financing Receivable [Line Items]
Servicing loans for participants	$ 5,283,000	$ 5,596,000
Impaired loans, additional funds committed	$ 0
Loans subject to troubled debt restructurings | TDR	6	1
Troubled debt restructuring amount	$ 3,706,000	$ 3,393,000
Allowances related to troubled debt restructurings	$ 116,000	282,000
Minimum past due days for loan rating	90 days
Total loans	$ 472,004,000	486,774,000
Consumer Loans [Member] | Doubtful [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		149,000
Consumer Loans [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		50,000
Residential Mortgage [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,925,000	2,469,000
Residential Mortgage [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	1,293,000	936,000
30 - 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired loans, additional funds committed	0
Troubled debt restructurings defaulted over 30 days past due	0	0
Non Accrual Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring amount	1,557,000	366,000
Home Equity Loans and Lines of Credit [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 336,000	$ 407,000
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans subject to troubled debt restructurings | TDR	18	17
Loans subject to troubled debt restructurings, amount	$ 3,616,000	$ 3,341,000
Residential Real Estate [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring, interest rate concession period	3 months
Residential Real Estate [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring, interest rate concession period	30 years
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans subject to troubled debt restructurings | TDR	1	1
Loans subject to troubled debt restructurings, amount	$ 46,000	$ 52,000
Total loans	125,405,000	113,642,000
Commercial Real Estate Loans [Member] | Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 3,702,000
Commercial Real Estate Loans [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructuring, interest rate concession period	1 year
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans subject to troubled debt restructurings | TDR	1
Loans subject to troubled debt restructurings, amount	$ 44,000
Total loans	$ 15,641,000	$ 19,407,000

Loans - Summary of Activity in

Loans - Summary of Activity in the Allowance for Loan Losses by Loan Category (Detail) - USD ($) $ in Thousands	3 Months Ended						12 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance						$ 3,737	$ 4,437	$ 3,737
Provision (credit) for loan losses	$ 144	$ (144)	$ 579	$ 178	$ (90)	95		762
Loans charged-off							(192)	(121)
Recoveries							35	59
Ending balance	4,280		4,437				4,280	4,437
Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance						1,620	1,648	1,620
Provision (credit) for loan losses							192	30
Loans charged-off								(2)
Ending balance	1,840		1,648				1,840	1,648
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance						335	265	335
Provision (credit) for loan losses							(30)	(70)
Ending balance	235		265				235	265
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance						218	375	218
Provision (credit) for loan losses							(65)	258
Loans charged-off							(192)	(119)
Recoveries							10	18
Ending balance	128		375				128	375
One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance						854	1,092	854
Provision (credit) for loan losses							(21)	197
Recoveries							25	41
Ending balance	1,096		1,092				1,096	1,092
Second Mortgages and HELOC [Member] | Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance						359	292	359
Provision (credit) for loan losses							(3)	(67)
Ending balance	289		292				289	292
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance						$ 351	765	351
Provision (credit) for loan losses							(73)	414
Ending balance	$ 692		$ 765				$ 692	$ 765

Loans - Summary of Additional I

Loans - Summary of Additional Information Pertaining to the Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for impaired loans	$ 116	$ 282
Allowance for non-impaired loans	4,164	4,155
Total allowance for loan losses	4,280	4,437	$ 3,737
Impaired loans	6,093	6,950
Non-impaired loans	465,911	479,824
Total loans	472,004	486,774
Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for non-impaired loans	1,840	1,648
Total allowance for loan losses	1,840	1,648	1,620
Impaired loans	46	52
Non-impaired loans	125,359	113,590
Total loans	125,405	113,642
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for non-impaired loans	235	265
Total allowance for loan losses	235	265	335
Non-impaired loans	9,093	21,285
Total loans	9,093	21,285
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for impaired loans		174
Allowance for non-impaired loans	128	201
Total allowance for loan losses	128	375	218
Impaired loans		199
Non-impaired loans	15,641	19,208
Total loans	15,641	19,407
One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for impaired loans	116	108
Allowance for non-impaired loans	980	984
Total allowance for loan losses	1,096	1,092	854
Impaired loans	5,640	6,291
Non-impaired loans	239,071	240,465
Total loans	244,711	246,756
Second Mortgages and HELOC [Member] | Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for non-impaired loans	289	292
Total allowance for loan losses	289	292	359
Impaired loans	407	408
Non-impaired loans	41,262	43,137
Total loans	41,669	43,545
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for non-impaired loans	692	765
Total allowance for loan losses	692	765	$ 351
Non-impaired loans	35,485	42,139
Total loans	$ 35,485	$ 42,139

Loans - Schedule of Past Due an

Loans - Schedule of Past Due and Non-Accrual Loans by Loan Category (Detail) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	$ 1,321	$ 2,046
Non-accrual Loans		3,258	3,030
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	87	29
Non-accrual Loans			149
One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	802	1,497
Non-accrual Loans		2,922	2,474
Home Equity Loans and Lines of Credit [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	[1]	432	520
Non-accrual Loans		336	407
30 - 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		479	1,200
30 - 59 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		76	25
30 - 59 Days Past Due [Member] | One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		215	655
30 - 59 Days Past Due [Member] | Home Equity Loans and Lines of Credit [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		188	520
60 - 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		842	211
60 - 89 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		11	4
60 - 89 Days Past Due [Member] | One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		587	207
60 - 89 Days Past Due [Member] | Home Equity Loans and Lines of Credit [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		$ 244
90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due			635
90 Days or More Past Due [Member] | One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due			$ 635
[1]	Excludes non-accrual loans which are separately presented.

Loans - Summary of Impaired Loa

Loans - Summary of Impaired Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Recorded Investment without a valuation allowance	$ 3,775	$ 4,740
Unpaid Principal Balance without a valuation allowance	3,775	4,740
Recorded Investment with a valuation allowance		2,210
Unpaid Principal Balance with a valuation allowance		2,210
Related Allowance, Total impaired loans	116	282
Recorded Investment, Total impaired loans	6,093	6,950
Unpaid Principal Balance, Total impaired loans	6,093	6,950
Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment without a valuation allowance	46	52
Unpaid Principal Balance without a valuation allowance	46	52
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment with a valuation allowance		199
Unpaid Principal Balance with a valuation allowance		199
Related Allowance, Total impaired loans		174
One-to-Four Family [Member] | Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment without a valuation allowance	3,322	4,280
Unpaid Principal Balance without a valuation allowance	3,322	4,280
Recorded Investment with a valuation allowance	2,318	2,011
Unpaid Principal Balance with a valuation allowance	2,318	2,011
Related Allowance, Total impaired loans	116	108
Home Equity Loans and Lines of Credit [Member] | Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded Investment without a valuation allowance	407	408
Unpaid Principal Balance without a valuation allowance	$ 407	$ 408

Loans - Summary of Information

Loans - Summary of Information Related to Average Balances of Impaired Loans and Interest Income Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 6,185	$ 7,495
Interest Income Recognized	252	263
Cash Basis Interest Recognized	97	120
Residential Real Estate [Member] | One-to-Four Family [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	5,594	6,781
Interest Income Recognized	236	210
Cash Basis Interest Recognized	87	84
Residential Real Estate [Member] | Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	424	420
Interest Income Recognized	11	36
Cash Basis Interest Recognized	10	36
Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	132	244
Interest Income Recognized	4	15
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	35	50
Interest Income Recognized	$ 1	$ 2

Loans - Summary of Company's Lo

Loans - Summary of Company's Loans by Risk Rating (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 472,004	$ 486,774
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	35,485	42,139
Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	125,405	113,642
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	9,093	21,285
Pass [Member] | Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	35,485	42,139
Pass [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	121,703	113,642
Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	8,134	$ 21,285
Special Mention [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	3,702
Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	206
Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 753

Loan Servicing - Additional Inf

Loan Servicing - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017
Servicing Assets At Amortized Value [Line Items]
Unpaid principal balances of residential mortgage loans serviced for others	$ 1,049,807,000	$ 929,289,000
Increase (reduced) the valuation allowance of mortgage servicing rights	920,000	(82,000)
Contractually specified servicing fees, net	$ 2,585,000	$ 2,165,000
Measurement Input, Discount Rate [Member]
Servicing Assets At Amortized Value [Line Items]
Discount rate	0.12	0.12	0.13
Measurement Input, Constant Prepayment Rate [Member] | Minimum [Member]
Servicing Assets At Amortized Value [Line Items]
Discount rate	0.09	0.07
Measurement Input, Constant Prepayment Rate [Member] | Maximum [Member]
Servicing Assets At Amortized Value [Line Items]
Discount rate	0.14	0.35

Loan Servicing - Summary of Act

Loan Servicing - Summary of Activity Relating to Mortgage Servicing Rights (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Mortgage servicing rights:
Balance at beginning of year	$ 7,786	$ 6,397
Additions through originations	2,979	2,380
Amortization	(1,281)	(983)
Balance at end of year	9,484	7,794
Valuation allowance:
Balance at beginning of year	8	90
Provision (credit)	920	(82)
Balance at end of year	928	8
Mortgage servicing rights, amortized cost	8,556	7,786
Mortgage servicing rights, fair value	$ 8,817	$ 8,554

Premises and Equipment - Summar

Premises and Equipment - Summary of Cost and Accumulated Depreciation and Amortization of Premises and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Land and improvements	$ 953	$ 1,025
Buildings and improvements	3,305	3,280
Leasehold improvements	2,231	2,136
Furniture and equipment	5,170	5,032
Construction-in-progress	82	84
Property plant and equipment, gross	11,741	11,557
Less accumulated depreciation and amortization	(5,993)	(5,189)
Property plant and equipment, net	$ 5,748	$ 6,368
Buildings and Improvements [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Life	5 years
Buildings and Improvements [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Life	50 years
Leasehold Improvements [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Life	3 years
Leasehold Improvements [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Life	10 years
Furniture and Equipment [Member] | Minimum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Life	3 years
Furniture and Equipment [Member] | Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Life	10 years

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Detail)	Jul. 31, 2018	Dec. 31, 2018USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)Office	Dec. 31, 2017USD ($)Building
Property Plant And Equipment [Line Items]
Depreciation and amortization expense			$ 857,000	$ 835,000
Leasehold improvements funded by landlord					$ 646,000
Leasehold improvements allowance amortized period					5 years
Tenant improvement allowance amortized period					5 years
Percentage of land occupied under sublease agreement	27.00%
Termination of lease	2023
Impairment write-down of assets held for sale				$ 166,000
Number of branches sold | Office				3
Number of branch office replaced | Office				2
Number of buildings reclassified to assets held for sale | Building					2
Gain (loss) on sale of building				$ 2,476,000
Branch Office, Other [Member]
Property Plant And Equipment [Line Items]
Gain (loss) on sale of building				215,000
Boston [Member] | Branch Office [Member]
Property Plant And Equipment [Line Items]
Gain (loss) on sale of building				2,261,000
Consideration received		$ 5,000,000		5,000,000
Boston [Member] | Branch Office [Member] | Insurance Recovery [Member]
Property Plant And Equipment [Line Items]
Insurance recovery for personal property				90,000
Consolidation of Mortgage Banking Operations [Member]
Property Plant And Equipment [Line Items]
Impairment write-down of assets held for sale		168,000
Consolidation of Mortgage Banking Operations [Member] | Restructuring Charges [Member] | Furniture and Equipment [Member]
Property Plant And Equipment [Line Items]
Impairment write-down of assets held for sale		168,000
Consolidation of Mortgage Banking Operations [Member] | Andover [Member]
Property Plant And Equipment [Line Items]
Fair value, Cease use liability		$ 565,000		$ 565,000

Deposits - Summary of Deposit B

Deposits - Summary of Deposit Balances by Type (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
Demand deposits	$ 61,603	$ 64,229
NOW accounts	39,043	42,802
Money market deposits	71,530	60,843
Regular and other savings accounts	126,876	101,137
Brokered deposits	10,167	10,088
Total non-certificate accounts	309,219	279,099
Term certificates less than $250,000	85,425	99,491
Term certificates of $250,000 or more	21,707	8,048
Term certificates - brokered	80,691	50,492
Total certificate accounts	187,823	158,031
Total deposits	$ 497,042	$ 437,130

Deposits - Additional Informati

Deposits - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended
	Mar. 31, 2020	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Term certificates - brokered			$ 80,691	$ 50,492
Weighted average rate, term certificate			1.94%	1.87%
Subsequent Event [Member]
Subsequent Event [Line Items]
Exercise of right to call option, term certificates	$ 3,500	$ 11,800
Call Option [Member]
Subsequent Event [Line Items]
Term certificates - brokered			$ 15,300
Weighted average rate, term certificate			2.19%

Deposits - Summary of Term Cert

Deposits - Summary of Term Certificates, Including Brokered Deposits, by Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Amount
2019		$ 89,167
2020	$ 140,987	40,847
2021	18,840	12,785
2022	25,610	14,101
2023	1,743	1,131
2024	643
Total certificate accounts	$ 187,823	$ 158,031
Weighted Average Rate
2019		1.68%
2020	1.92%	2.16%
2021	1.88%	2.16%
2022	2.12%	1.98%
2023	1.28%	1.38%
2024	1.32%
Total	1.94%	1.87%

Borrowings - Summary of Borrowi

Borrowings - Summary of Borrowings from FHLBB (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fixed-rate advances maturing:
2019		$ 84,184
2020	$ 22,476	2,894
2021	11,927	1,958
2022	10,000
Advances from FHLBB, Amount	$ 44,403	$ 89,036
Weighted Average Rate
2019		2.57%
2020	1.80%	1.49%
2021	1.86%	1.33%
2022	2.20%
Advances from FHLBB, Weighted Average Rate	1.91%	2.50%

Borrowings - Additional Informa

Borrowings - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Overnight advances of FHLBB borrowings	$ 19,800,000	$ 82,700,000
Federal Home Loan Bank advances	44,403,000	89,036,000
Correspondent Bank [Member]
Debt Instrument [Line Items]
Available borrowing capacity	7,500,000
Federal Home Loan Bank advances	$ 0	0
FHLBB [Member]
Debt Instrument [Line Items]
Percentage on carrying value of first mortgage loans pledged as collateral	75.00%
Available borrowing capacity		136,500,000
FHLBB [Member] | Commercial Real Estate Loans [Member]
Debt Instrument [Line Items]
Percentage on carrying value of first mortgage loans pledged as collateral	65.00%
FHLBB With Interest Rate Adjusts Daily [Member]
Debt Instrument [Line Items]
Available borrowing capacity	$ 4,195,000
Federal Home Loan Bank advances	$ 0	0
FHLBB With Interest Rate Adjusts Daily [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage on total assets for borrowings under line of credit	2.00%
Federal Reserve Bank of Boston [Member]
Debt Instrument [Line Items]
Available borrowing capacity	$ 2,000,000
Federal Home Loan Bank advances	$ 0	$ 0

Borrowings - Summary of Outstan

Borrowings - Summary of Outstanding Balances of Short Term Borrowings from FHLBB (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Federal Home Loan Bank Advances Activity For Year [Abstract]
Average daily balance	$ 73,551,000	$ 63,552,000
Maximum outstanding at any month end	$ 128,283,000	$ 108,819,000

Income Taxes - Allocation of Fe

Income Taxes - Allocation of Federal and State Income Taxes Between Current and Deferred Portions (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Current tax expense:
State									$ 118	$ 31
Total current tax expense									118	31
Deferred tax expense (benefit):
Federal									723	(541)
State									226	73
Total deferred federal and state tax expense (benefit)									949	(468)
Change in valuation allowance									(949)	468
Total tax expense	$ 21	$ 14	$ 119	$ (36)	$ 17	$ 5	$ 4	$ 4	$ 118	$ 31

Income Taxes - Summary of Diffe

Income Taxes - Summary of Differences Between Statutory Federal Income Tax Expense (Benefit) and Actual Tax Expense (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Tax Expense Benefit Continuing Operations Income Tax Reconciliation [Abstract]
Statutory federal tax rate of 21%									$ 745	$ (432)
Increase (decrease) resulting from:
State taxes, net of federal tax effect									272	83
Bank-owned life insurance									(39)	(46)
Tax-exempt income									(9)	(25)
Change in valuation allowance									(949)	468
Other, net									98	(17)
Total tax expense	$ 21	$ 14	$ 119	$ (36)	$ 17	$ 5	$ 4	$ 4	$ 118	$ 31

Income Taxes - Summary of Dif_2

Income Taxes - Summary of Differences Between Statutory Federal Income Tax Expense (Benefit) and Actual Tax Expense (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Statutory federal tax rate	21.00%	21.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Income Tax [Line Items]
Alternative minimum tax refundable period									4 years
Income tax refund received	$ 231,000								$ 231,000
Charitable contribution carryforward	$ 2,301,000								$ 2,301,000
Valuation allowance for deferred tax assets	100.00%								100.00%
Net income	$ 828,000	$ 1,145,000	$ 1,506,000	$ (51,000)	$ (228,000)	$ (142,000)	$ (1,010,000)	$ (707,000)	$ 3,428,000	$ (2,086,000)
Federal income tax reserve for loan losses	2,033,000								$ 2,033,000
Percentage of tax reserve for loan losses used for purpose other than to absorb losses subject to taxation									150.00%
Deferred income tax liability not been provided	571,000								$ 571,000
Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	11,985,000								11,985,000
Operating Loss Carryforwards Expires on December 31, 2033 [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	2,981,000								$ 2,981,000
Operating loss carryforward expiration date									Dec. 31, 2033
Operating Loss Carryforwards Expires on December 31, 2034 [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	406,000								$ 406,000
Operating loss carryforward expiration date									Dec. 31, 2034
Operating Loss Carryforward Expires on December 31, 2035 [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	1,542,000								$ 1,542,000
Operating loss carryforward expiration date									Dec. 31, 2035
Operating Loss Carryforward Expires on December 31, 2036 [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	501,000								$ 501,000
Operating loss carryforward expiration date									Dec. 31, 2036
Operating Loss Carryforward Expires on December 31, 2037 [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	2,871,000								$ 2,871,000
Operating loss carryforward expiration date									Dec. 31, 2037
Operating Loss Carryforward No Expiration [Member] | Federal [Member]
Income Tax [Line Items]
Net operating loss carryforward	3,684,000								$ 3,684,000
Deferred Tax Assets Charitable Contribution Carryforward Expires on December 31, 2021 [Member]
Income Tax [Line Items]
Charitable contribution carryforward	77,000								$ 77,000
Charitable contributions carryforward expiration years									Dec. 31, 2021
Other Assets [Member]
Income Tax [Line Items]
Income tax refund received	$ 231,000								$ 231,000

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Net Deferred Tax Asset (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Deferred tax assets, gross	$ 5,875	$ 6,268
Valuation allowance	(2,297)	(3,246)
Deferred tax assets, net	3,578	3,022
Deferred tax liabilities:
Deferred tax liabilities, gross	(3,578)	(3,022)
Federal [Member]
Deferred tax assets:
Deferred tax assets, gross	4,809	5,134
Deferred tax liabilities:
Deferred tax liabilities, gross	(2,547)	(2,189)
State [Member]
Deferred tax assets:
Deferred tax assets, gross	1,066	1,134
Deferred tax liabilities:
Deferred tax liabilities, gross	$ (1,031)	$ (833)

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Employee benefit plans	$ 714	$ 825
Allowance for loan losses	1,203	1,247
Funded status of post-retirement benefits	(47)	(47)
Securities available for sale	(313)	(313)
Depreciation and amortization	279	249
Net deferred loan origination costs	(350)	(357)
Mortgage servicing rights	(2,366)	(2,082)
Net operating loss carryforward	2,517	2,864
Charitable contribution carryforward	619	700
Derivatives	(377)	(105)
Stock-based compensation	185	121
Other, net	233	144
Deferred tax assets (liabilities) before valuation allowances	2,297	3,246
Valuation allowance on net deferred tax assets	$ (2,297)	$ (3,246)

On-Balance Sheet Derivative I_2

On-Balance Sheet Derivative Instruments and Hedging Activities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Derivative Loan Commitments [Member]
Derivative [Line Items]
Derivative, Notional amount	$ 89,925,000	$ 36,852,000
Derivative Loan Commitments [Member] | Net Gain on Sales of Mortgage Loans [Member]
Derivative [Line Items]
Increase (reductions) in aggregate fair value on derivatives, interest rate lock commitments	845,000	264,000
Undesignated Forward Loan Sale Commitments and TBA Securities [Member]
Derivative [Line Items]
Derivative, Notional amount	85,401,000	42,021,000
Undesignated Forward Loan Sale Commitments and TBA Securities [Member] | Net Gain on Sales of Mortgage Loans [Member]
Derivative [Line Items]
Increase (reductions) in aggregate fair value on derivatives, interest rate lock commitments	124,000	(238,000)
Other Assets [Member] | Derivative Loan Commitments [Member]
Derivative [Line Items]
Derivative fair value, Asset	1,472,000	627,000
Other Assets [Member] | Undesignated Forward Loan Sale Commitments and TBA Securities [Member]
Derivative [Line Items]
Derivative fair value, Asset	11,000	10,000
Other Liabilities [Member] | Undesignated Forward Loan Sale Commitments and TBA Securities [Member]
Derivative [Line Items]
Derivative fair value, Liability	$ 140,000	$ 263,000

Minimum Regulatory Capital Re_3

Minimum Regulatory Capital Requirements - Additional Information (Detail)	Dec. 31, 2019
Minimum [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Capital conservation buffer of common equity tier 1 capital to risk weighted assets ratio (as a percent)	2.50%

Minimum Regulatory Capital Re_4

Minimum Regulatory Capital Requirements - Summary of Actual and Minimum Capital Amounts and Ratios Exclusive of Capital Conservation Buffer (Detail) - Bank [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Total capital (to risk weighted assets), actual amount	$ 76,652	$ 72,523
Tier 1 capital (to risk weighted assets), actual amount	72,372	68,086
Common equity Tier 1 capital (to risk weighted assets), actual amount	72,372	68,086
Tier 1 capital (to average assets), actual amount	$ 72,372	$ 68,086
Total capital (to risk weighted assets), actual ratio	16.70%	16.10%
Tier 1 capital (to risk weighted assets), actual ratio	15.80%	15.10%
Common equity Tier 1 capital (to risk weighted assets), actual ratio	15.80%	15.10%
Tier 1 capital (to average assets), actual ratio	11.30%	10.90%
Total capital (to risk weighted assets), for minimum capital adequacy purposes amount	$ 36,637	$ 36,084
Tier 1 capital (to risk weighted assets), for minimum capital adequacy purposes amount	27,478	27,063
Common equity Tier 1 capital (to risk weighted assets), for minimum capital adequacy amount	20,608	20,297
Common equity Tier 1 capital (to risk weighted assets), for minimum capital adequacy amount	$ 25,627	$ 25,056
Total capital (to risk weighted assets), for minimum capital adequacy purposes ratio	8.00%	8.00%
Tier 1 capital (to risk weighted assets), for minimum capital adequacy purposes ratio	6.00%	6.00%
Common equity Tier 1 capital (to risk weighted assets), for minimum capital adequacy purposes ratio	4.50%	4.50%
Tier 1 capital (to average assets), for minimum capital adequacy purposes ratio	4.00%	4.00%
Total capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions amount	$ 45,796	$ 45,105
Tier 1 capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions amount	36,637	36,084
Common equity Tier 1 capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions amount	29,768	29,318
Tier 1 capital (to average assets), minimum to be well capitalized under prompt corrective action provisions amount	$ 32,033	$ 31,320
Total capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions ratio	10.00%	10.00%
Tier 1 capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions ratio	8.00%	8.00%
Common equity Tier 1 capital (to risk weighted assets), minimum to be well capitalized under prompt corrective action provisions ratio	6.50%	6.50%
Tier 1 capital (to average assets), minimum to be well capitalized under prompt corrective action provisions ratio	5.00%	5.00%

Post-Retirement Plans - Additio

Post-Retirement Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Other non-interest expense	$ 5,309,000	$ 5,069,000
Supplemental Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued benefits	507,000	549,000
Other non-interest expense	51,000	58,000
Endorsement Split-Dollar Life Insurance Arrangements [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued benefits	451,000	432,000
Post-retirement benefit expense	$ 19,000	16,000
401(k) Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Description of employees eligibility	The Company maintains a 401(k) Plan whereby each employee reaching the age of 21 automatically becomes a participant in the plan. Employees may contribute up to 15% of their compensation subject to certain limits based on federal tax laws. All employees who have worked for one year or 1,000 hours are eligible for an automatic employer contribution of 3% of employees’ compensation, which requires no vesting period.
Minimum age of employee to become participant	21 years
Maximum annual contributions per employee, percent	15.00%
Minimum number of year worked by employees	1 year
Minimum number of hours worked by employees	1000 hours
Employer contribution percentage on employees compensation	3.00%
Automatic employer matching contributions vesting period	0 years
Employer matching contribution, percent	50.00%
Employer match of eligible employees contributions percentage	2.00%
Employer matching contributions vesting period	4 years
Contribution expense	$ 753,000	$ 580,000
401(k) Plan [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contribution percentage on employees compensation	4.00%

Post-Retirement Plans - Summary

Post-Retirement Plans - Summary of Information Pertaining to Activity in Plan (Details) - Supplemental Retirement Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Change in plan assets:
Employer contributions	$ 201	$ 201
Benefits paid	(201)	(201)
Change in benefit obligation:
Benefit obligation at beginning of year	1,561	1,724
Service cost	10	10
Interest cost	53	48
Actuarial (gain) loss	83	(20)
Benefits paid	(201)	(201)
Benefit obligation at end of year	1,506	1,561
Unfunded status and accrued supplemental pension cost at year end	(1,506)	(1,561)
Accumulated benefit obligation at year end	$ 1,506	$ 1,561

Post-Retirement Plans - Summa_2

Post-Retirement Plans - Summary of Assumptions Used to Determine Benefit Obligation (Details) - Supplemental Retirement Plan [Member]	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.50%	3.60%
Annual inflation factor	1.00%	1.00%

Post-Retirement Plans - Summa_3

Post-Retirement Plans - Summary of Net Periodic Benefit Cost Included in Other Non-Interest Expenses Attributable to Plan (Details) - Supplemental Retirement Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 10	$ 10
Interest cost	53	48
Amortization of net actuarial loss	36	41
Amortization of prior service credit	(84)	(89)
Net periodic benefit cost	$ 15	$ 10

Post-Retirement Plans - Summa_4

Post-Retirement Plans - Summary of Assumptions Used to Determine Net Periodic Benefit Cost (Details) - Supplemental Retirement Plan [Member]	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.60%	2.90%
Annual inflation factor	1.00%	1.00%

Post-Retirement Plans - Summa_5

Post-Retirement Plans - Summary of Estimated Future Benefit Payments Expected Future Services (Details) - Supplemental Retirement Plan [Member] $ in Thousands	Dec. 31, 2018USD ($)
Defined Benefit Plan Disclosure [Line Items]
2020	$ 201
2021	201
2022	213
2023	345
2024	213
2025-2029	$ 425

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options term	10 years	10 years
Stock-based compensation expense	$ 366,000	$ 304,000
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 553,000	$ 493,000
Minimum [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options and awards vesting period	3 years	3 years
Maximum [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options and awards vesting period	5 years	5 years
Two Thousand Seventeen Stock Option and Incentive Plan [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance	586,872
Stock options term	10 years
Two Thousand Seventeen Stock Option and Incentive Plan [Member] | Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for issuance	234,749
Two Thousand Seventeen Stock Option and Incentive Plan [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options and awards vesting period	3 years
Two Thousand Seventeen Stock Option and Incentive Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options and awards vesting period	5 years

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Grants of Options to Purchase Shares of Common Stock (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options granted	57,252	27,000
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expiration period (years)	10 years	10 years
Expected volatility	26.14%	29.09%
Expected volatility	29.09%	29.87%
Risk free interest rate, minimum	2.37%	2.68%
Risk free interest rate, maximum	2.61%	2.77%
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option fair value	$ 2.99	$ 5.78
Minimum [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period (years)	3 years	3 years
Expected life (years)	6 years	6 years
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option fair value	$ 5.83	$ 5.83
Maximum [Member] | Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period (years)	5 years	5 years
Expected life (years)	6 years 6 months	6 years 6 months

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Activity and Certain Other Information Related to Stock Options Grants Under Equity Plan (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Stock Option Grants
Beginning Balance	312,705
Granted	57,252	27,000
Forfeited	(6,500)
Expired	(3,250)
Ending Balance	360,207	312,705
Exercisable at December 31, 2019	120,704
Unrecognized compensation cost (inclusive of directors' options)	$ 982,722
Weighted Average Exercise Price
Beginning Balance	$ 14.78
Granted	14.93
Forfeited	13.90
Expired	14.66
Ending Balance	14.82	$ 14.78
Exercisable at December 31, 2019	$ 14.75
Weighted Average Remaining Contractual Term and Aggregate Intrinsic Value
Weighted Average Remaining Contractual Term	8 years 3 days	8 years 8 months 23 days
Weighted Average Remaining Contractual Term, Exercisable	7 years 9 months 21 days
Aggregate Intrinsic Value, Outstanding		$ 0
Aggregate Intrinsic Value, Outstanding	$ 1,017,708
Aggregate Intrinsic Value, Exercisable	$ 349,852
Stock Options [Member]
Stock Option Grants
Weighted average remaining recognition period (years)	2 years 9 months 14 days

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Activity and Certain Other Information Related to Restricted Stock Awards Under Equity Plan (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares
Restricted Stock Awards
Beginning Balance | shares	126,694
Granted | shares	33,335
Vested | shares	(31,668)
Forfeited | shares	(2,500)
Ending Balance | shares	125,861
Unrecognized compensation cost | $	$ 1,651,000
Weighted Average Grant Price
Beginning Balance | $ / shares	$ 14.66
Granted | $ / shares	15.07
Vested | $ / shares	14.66
Forfeited | $ / shares	15.07
Ending Balance | $ / shares	$ 14.76
Restricted Stock [Member]
Restricted Stock Awards
Weighted average remaining recognition period (years)	3 years 14 days

Employee Stock Ownership Plan -

Employee Stock Ownership Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Employee Stock Ownership Plan E S O P Disclosures [Line Items]
Loan repaid term	25 years
Interest rate	5.50%	4.50%
Number of allocated shares	18,780
Annual allocation of shares, expiration year	2040
ESOP expense	$ 283,000	$ 301,000
Unallocated shares	394,378
Unallocated shares, value	$ 6,961,000
Common Stock [Member]
Employee Stock Ownership Plan E S O P Disclosures [Line Items]
Sale of stock, price per share	$ 10
The Randolph Savings Charitable Foundation, Inc. [Member]
Employee Stock Ownership Plan E S O P Disclosures [Line Items]
Sale of share in employee stock ownership plan	469,498

Share Repurchase Program - Addi

Share Repurchase Program - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2019	Dec. 31, 2018
Class Of Stock [Line Items]
Cost of shares repurchased		$ 5,438,000	$ 1,716,000
September 2017 Share Repurchase Program [Member]
Class Of Stock [Line Items]
Stock repurchase program percentage of outstanding shares repurchased	10.00%
Number of shares authorized to repurchase	586,854
Number of shares repurchased		468,896
Cost of shares repurchased		$ 7,231,000

Earnings (Loss) Per Share - Add

Earnings (Loss) Per Share - Additional Information (Detail) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Potentially dilutive common stock equivalents outstanding	0	0

Earnings (Loss) Per Share - Sch

Earnings (Loss) Per Share - Schedule of Calculation of Average Number of Shares Outstanding Used to Calculate Basic and Diluted Earnings (Loss) Per Share (Detail) - shares	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Average number of common shares outstanding									5,787,385	5,994,373
Less: Average unallocated ESOP shares									(403,768)	(423,653)
Average number of common shares outstanding (basic and diluted)	5,248,021	5,345,786	5,465,205	5,478,544	5,526,416	5,567,596	5,580,683	5,603,886	5,383,617	5,570,720

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Future Minimum Rent Commitments (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Operating Lease Liabilities Payments Due [Abstract]
2020	$ 1,095
2021	878
2022	681
2023	228
2024	91
Thereafter	23
Future minimum rent commitments, Leases	2,996
2020	(89)
2021	(91)
2022	(94)
2023	(16)
Future minimum rent commitments, Sub-leases	(290)
2020	1,006
2021	787
2022	587
2023	212
2024	91
Thereafter	23
Future minimum rent commitments, Net	$ 2,706

Commitments and Contingencies_2

Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)Member	Dec. 31, 2018USD ($)
Commitments And Contingencies [Line Items]
Rent expense | $	$ 887,000	$ 992,000
Salary continuation term of employment arrangement	1 year
Senior Management [Member]
Commitments And Contingencies [Line Items]
Number of members with change in control agreements | Member	5
Change in control agreement description of terms	The company provide that if, within two years of a change of control of the Company or the Bank, the executive in involuntarily terminated other than for cause, disability or death, or voluntarily resigns for good reason, the executive will be entitled to a lump-sum payment equal to two times salary plus bonus, except for one executive where the payment is equal to one times salary plus bonus.
Minimum [Member]
Commitments And Contingencies [Line Items]
Lease options to extend the period	2 years
Maximum [Member]
Commitments And Contingencies [Line Items]
Lease options to extend the period	10 years

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Financial Instruments Outstanding Contract Amounts Represent Credit Risk (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Commitments to Originate Loans [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	$ 117,086	$ 38,404
Unused Lines and Letters of Credit [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	52,721	45,977
Unadvanced Funds on Construction Loans [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	11,029	14,175
Overdraft Lines of Credit [Member]
Fair Value Off Balance Sheet Risks Disclosure Information [Line Items]
Financial instruments with off-balance-sheet risk	$ 8,178	$ 8,475

Fair Value of Assets and Liab_3

Fair Value of Assets and Liabilities - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	$ 57,503	$ 50,556
Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		50,038
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		518
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	57,503	50,556
Fair value, Loans held for sale	62,792	38,474
Derivative assets	1,483	637
Derivative liabilities	140	263
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	57,503
Fair value, Portfolio loans	9,826	3,680
Fair value, Loans held for sale	62,792	38,474
Fair Value, Measurements, Recurring [Member] | Derivative Loan Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,472	627
Fair Value, Measurements, Recurring [Member] | Forward Loan Sale Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	11	10
Fair Value, Measurements, Recurring [Member] | Forward Loan Sale Commitments, including TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	140	263
Fair Value, Measurements, Recurring [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		50,038
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		518
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	57,503
Fair value, Portfolio loans	9,826	3,680
Fair value, Loans held for sale	62,792	38,474
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Derivative Loan Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,472	627
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Forward Loan Sale Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	11	10
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Forward Loan Sale Commitments, including TBAs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	$ 140	263
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		50,038
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value		$ 518

Fair Value of Assets and Liab_4

Fair Value of Assets and Liabilities - Additional information (Detail)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, assets, level 1 to level 2 transfers, amount	$ 0	$ 0
Fair value, assets, level 2 to level 1 transfers, amount	0	0
Fair value, liabilities, level 1 to level 2 transfers, amount	0	0
Fair value, liabilities, level 2 to level 1 transfers, amount	$ 0	$ 0
Measurement Input, Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.12	0.12	0.13
Fair Value, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on nonrecurring basis	$ 0	$ 0

Fair Value of Assets and Liab_5

Fair Value of Assets and Liabilities - Schedule of Assets Measured at Fair Value on a Non-Recurring Basis (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights, fair value	$ 8,817	$ 8,554
Fair Value, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) on assets held, mortgage servicing rights	(920)	82
Gains (losses) on assets held, foreclosed real estate		(36)
Gains (Losses) on assets held	(920)	46
Fair Value, Nonrecurring | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights, fair value	8,556	7,786
Assets, Fair Value Disclosure	8,556	7,786
Fair Value, Nonrecurring | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Collateral dependent impaired loans	2,250	1,352
Fair value, Foreclosed real estate		65
Assets, Fair Value Disclosure	$ 2,250	$ 1,417

Fair Value of Assets and Liab_6

Fair Value of Assets and Liabilities - Summary of Carrying Values, Estimated Fair Values and Placement in Fair Value Hierarchy of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financial assets:
Securities available for sale	$ 57,503	$ 50,556
Level 2 [Member]
Financial assets:
Certificates of deposit	492	2,196
Securities available for sale	57,503	50,556
Loans held for sale	62,792	38,474
Derivative assets	1,483	637
Financial liabilities:
Deposits	496,979	435,964
FHLBB advances	44,433	88,894
Derivative liabilities	140	263
Level 3 [Member]
Financial assets:
Loans, net	469,416	473,612
Carrying Amount [Member]
Financial assets:
Certificates of deposit	490	2,205
Securities available for sale	57,503	50,556
Loans held for sale	62,792	38,474
Loans, net	469,131	483,846
Derivative assets	1,483	637
Financial liabilities:
Deposits	497,042	437,130
FHLBB advances	44,403	89,036
Derivative liabilities	140	263
Fair Value [Member]
Financial assets:
Certificates of deposit	492	2,196
Securities available for sale	57,503	50,556
Loans held for sale	62,792	38,474
Loans, net	469,416	473,612
Derivative assets	1,483	637
Financial liabilities:
Deposits	496,979	435,964
FHLBB advances	44,433	88,894
Derivative liabilities	$ 140	$ 263

Segment Information - Additiona

Segment Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)SegmentOffice	Dec. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Number of business segments | Segment	2
Number of branch offices | Office	5
Servicing fees amount	$ (394,000)	$ (1,264,000)
Envision Mortgage [Member]
Segment Reporting Information [Line Items]
Premium percentage for new loans	1.50%	1.50%
Premium income	$ 951,000	$ 1,320,000
Percentage of fees for HELOC	1.00%	1.00%
Servicing fees amount	$ (757,000)	$ (1,574,000)
Envision Bank [Member]
Segment Reporting Information [Line Items]
Percentage of loan servicing fees	0.14%	0.14%
Servicing fees amount	$ 363,000	$ 310,000

Segment Information - Summary o

Segment Information - Summary of Segment Information (Detail) - USD ($)		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net interest income		$ 4,391,000	$ 4,573,000	$ 4,489,000	$ 4,378,000	$ 4,420,000	$ 4,260,000	$ 4,033,000	$ 3,982,000	$ 17,833,000	$ 16,696,000
Provision for loan losses		144,000		(144,000)		579,000	178,000	(90,000)	95,000		762,000
Net interest income after provision for loan losses										17,833,000	15,934,000
Non-interest income:
Customer service fees										1,407,000	1,464,000
Gain on loan origination and sale activities, net	[1]									19,851,000	8,859,000
Mortgage servicing fees, net										394,000	1,264,000
Gain on sales of buildings											2,476,000
Other										962,000	940,000
Total non-interest income										22,614,000	15,003,000
Non-interest expenses:
Salaries and employee benefits										24,896,000	19,765,000
Occupancy and equipment										2,783,000	2,873,000
Restructuring charges						875,000		92,000			968,000
Other non-interest expenses										8,271,000	8,066,000
Total non-interest expenses		9,490,000	9,718,000	8,863,000	7,878,000	9,337,000	7,427,000	7,912,000	6,998,000	35,950,000	31,672,000
Income (loss) before income taxes and elimination of inter-segment profit										4,497,000	(735,000)
Elimination of inter-segment profit										(951,000)	(1,320,000)
Income (loss) before income taxes										3,546,000	(2,055,000)
Income tax expense		21,000	14,000	119,000	(36,000)	17,000	5,000	4,000	4,000	118,000	31,000
Net income (loss)		828,000	$ 1,145,000	$ 1,506,000	$ (51,000)	(228,000)	$ (142,000)	$ (1,010,000)	$ (707,000)	3,428,000	(2,086,000)
Total assets		631,004,000				614,340,000				631,004,000	614,340,000
Envision Bank [Member]
Segment Reporting Information [Line Items]
Net interest income										15,985,000	15,664,000
Provision for loan losses											762,000
Net interest income after provision for loan losses										15,985,000	14,902,000
Non-interest income:
Customer service fees										1,268,000	1,344,000
Mortgage servicing fees, net										(363,000)	(310,000)
Gain on sales of buildings											2,476,000
Other										596,000	520,000
Total non-interest income										1,501,000	4,030,000
Non-interest expenses:
Salaries and employee benefits										7,065,000	6,793,000
Occupancy and equipment										1,527,000	1,507,000
Other non-interest expenses										4,789,000	4,476,000
Total non-interest expenses										13,381,000	12,776,000
Income (loss) before income taxes and elimination of inter-segment profit										4,105,000	6,156,000
Total assets		521,144,000				526,871,000				521,144,000	526,871,000
Envision Mortgage [Member]
Segment Reporting Information [Line Items]
Net interest income										1,848,000	1,032,000
Net interest income after provision for loan losses										1,848,000	1,032,000
Non-interest income:
Customer service fees										139,000	120,000
Gain on loan origination and sale activities, net	[1]									19,851,000	8,859,000
Mortgage servicing fees, net										757,000	1,574,000
Other										366,000	420,000
Total non-interest income										21,113,000	10,973,000
Non-interest expenses:
Salaries and employee benefits										17,831,000	12,972,000
Occupancy and equipment										1,256,000	1,366,000
Restructuring charges											968,000
Other non-interest expenses										3,482,000	3,590,000
Total non-interest expenses										22,569,000	18,896,000
Income (loss) before income taxes and elimination of inter-segment profit										392,000	(6,891,000)
Total assets		$ 109,860,000				$ 87,469,000				$ 109,860,000	$ 87,469,000
[1]	Before elimination of inter-segment profit

Other Non-Interest Expenses - A

Other Non-Interest Expenses - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Other Income And Expenses [Abstract]
Percentage of certain items exceeding interest and non interest income	1.00%	1.00%

Other Non-Interest Expenses - S

Other Non-Interest Expenses - Schedule of Company's Total Interest and Non-Interest Income Included in Other Non-Interest Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Other Income And Expenses [Abstract]
Software amortization, licenses and maintenance	$ 1,017	$ 754
Card related expenses	459	470
Data communication and telephone	418	495
Directors fees, including stock-based compensation	$ 586	$ 613

Restructuring Charge - Addition

Restructuring Charge - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Dec. 31, 2018USD ($)ft²PositionEmployee	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Restructuring Cost And Reserve [Line Items]
Impairment write-down on furniture and equipment			$ 166,000
Consolidation of Mortgage Banking Operations [Member]
Restructuring Cost And Reserve [Line Items]
Impairment write-down on furniture and equipment	$ 168,000
Consolidation of Mortgage Banking Operations [Member] | Andover [Member]
Restructuring Cost And Reserve [Line Items]
Number of administrative positions eliminated | Position	15
Number of employees remained | Employee	25
Severance costs		$ 235,000
Remaining space available | ft²	4,200
Fair value, Cease use liability	$ 565,000		$ 565,000
Consolidation of Mortgage Banking Operations [Member] | North Attleboro [Member]
Restructuring Cost And Reserve [Line Items]
Number of administrative positions to be added | Position	8

Parent Company Condensed Fina_3

Parent Company Condensed Financial Statements - Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and due from banks	$ 4,371	$ 3,451
Total assets	631,004	614,340
Liabilities
Total liabilities	552,542	536,379
Stockholders' Equity:
Common stock	56	60
Additional paid-in capital	51,127	55,608
Retained earnings	31,757	28,329
ESOP-Unearned compensation	(3,944)	(4,132)
Accumulated other comprehensive loss, net of tax	(534)	(1,904)
Total stockholders' equity	78,462	77,961	$ 81,483
Total liabilities and stockholders' equity	631,004	614,340
Randolph Bancorp, Inc. and Predecessor Randolph Bancorp [Member]
Assets
Cash and due from banks	1,445	6,850
Investment in Envision Bank	72,872	66,971
ESOP loan	4,162	4,266
Total assets	78,479	78,087
Liabilities
Accounts payable		70
Due to Envision Bank	17	56
Total liabilities	17	126
Stockholders' Equity:
Common stock	56	60
Additional paid-in capital	51,127	55,608
Retained earnings	31,757	28,329
ESOP-Unearned compensation	(3,944)	(4,132)
Accumulated other comprehensive loss, net of tax	(534)	(1,904)
Total stockholders' equity	78,462	77,961
Total liabilities and stockholders' equity	$ 78,479	$ 78,087

Parent Company Condensed Fina_4

Parent Company Condensed Financial Statements - Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Condensed Income Statements Captions [Line Items]
Interest income	$ 6,219	$ 6,541	$ 6,454	$ 6,016	$ 6,050	$ 5,468	$ 5,039	$ 4,727	$ 25,231	$ 21,284
Income tax expense	21	14	119	(36)	17	5	4	4	118	31
Net income (loss)	$ 828	$ 1,145	$ 1,506	$ (51)	$ (228)	$ (142)	$ (1,010)	$ (707)	3,428	(2,086)
Randolph Bancorp, Inc. and Predecessor Randolph Bancorp [Member]
Condensed Income Statements Captions [Line Items]
Interest income									235	197
Operating expenses									194	197
Income before incomes taxes and equity in undistributed net income (loss) of Envision Bank									41
Income tax expense									3
Income before equity in undistributed net income (loss) of Envision Bank									38
Equity in undistributed net income (loss) of Envision Bank									3,390	(2,086)
Net income (loss)									$ 3,428	$ (2,086)

Parent Company Condensed Fina_5

Parent Company Condensed Financial Statements - Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ 3,428	$ (2,086)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Net cash used in operating activities	(16,475)	(11,291)
Cash flows from investing activities:
Net cash provided by (used in) investing activities	7,915	(73,365)
Cash flows from financing activities:
Stock repurchases	(5,438)	(1,716)
Net cash provided by financing activities	9,694	82,952
Net change in cash and cash equivalents	1,134	(1,704)
Cash and cash equivalents at beginning of year	7,118	8,822
Cash and cash equivalents at end of year	8,252	7,118
Randolph Bancorp, Inc. and Predecessor Randolph Bancorp [Member]
Cash flows from operating activities:
Net income (loss)	3,428	(2,086)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Equity in undistributed net (income) loss of Envision Bank	(3,390)	2,086
Change in intercompany receivable/payable	(39)	197
Net cash used in operating activities	(1)	197
Cash flows from investing activities:
Principal payments received on ESOP loan	104	112
Net cash provided by (used in) investing activities	104	112
Cash flows from financing activities:
Stock repurchases	(5,438)	(1,716)
Stock repurchase payable	(70)	70
Net cash provided by financing activities	(5,508)	(1,646)
Net change in cash and cash equivalents	(5,405)	(1,337)
Cash and cash equivalents at beginning of year	6,850	8,187
Cash and cash equivalents at end of year	$ 1,445	$ 6,850

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) - Summary of Selected Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Interest and dividend income	$ 6,219	$ 6,541	$ 6,454	$ 6,016	$ 6,050	$ 5,468	$ 5,039	$ 4,727	$ 25,231	$ 21,284
Interest expense	1,828	1,968	1,965	1,638	1,630	1,208	1,006	745	7,398	4,588
Net interest income	4,391	4,573	4,489	4,378	4,420	4,260	4,033	3,982	17,833	16,696
Provision (credit) for loan losses	144		(144)		579	178	(90)	95		762
Gain on loan origination and sales activities, net	5,462	5,782	5,068	2,588	2,183	1,956	1,854	1,547
Other non-interest income	630	522	787	825	3,102	1,252	929	861
Total non-interest income	6,092	6,304	5,855	3,413	5,285	3,208	2,783	2,408	21,663	13,683
Restructuring charges					875		92			968
Other non-interest expense	9,490	9,718	8,863	7,878	8,462	7,427	7,820	6,998
Total non-interest expenses	9,490	9,718	8,863	7,878	9,337	7,427	7,912	6,998	35,950	31,672
Provision (benefit) for income taxes	21	14	119	(36)	17	5	4	4	118	31
Net income (loss)	$ 828	$ 1,145	$ 1,506	$ (51)	$ (228)	$ (142)	$ (1,010)	$ (707)	$ 3,428	$ (2,086)
Basic and diluted earnings (loss) per share	$ 0.16	$ 0.21	$ 0.28	$ (0.01)	$ (0.04)	$ (0.03)	$ (0.18)	$ (0.13)	$ 0.64	$ (0.37)
Weighted average common shares (basic and diluted)	5,248,021	5,345,786	5,465,205	5,478,544	5,526,416	5,567,596	5,580,683	5,603,886	5,383,617	5,570,720

Selected Quarterly Financial _4

Selected Quarterly Financial Data (Unaudited) - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Effect Of Fourth Quarter Events [Line Items]
Increase of valuation allowance for mortgage servicing rights			$ 920,000	$ (82,000)
Boston Branch Location [Member]
Effect Of Fourth Quarter Events [Line Items]
Gain recognized on sale of former branch location		$ 2,261,000
Other Non Interest Income [Member]
Effect Of Fourth Quarter Events [Line Items]
Increase of valuation allowance for mortgage servicing rights	$ 284,000

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - USD ($)	Jan. 29, 2020	Mar. 31, 2020
Scenario Forecast [Member]
Subsequent Event [Line Items]
Recognize compensation expense		$ 1,350,000
President and Chief Executive Officer [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Current base salary	$ 400,000
Current base salary, period	1 year
Transition Salary payable	$ 200,000
Transition Salary payable, period	1 year