Melrose Bancorp (MELR) 10-K 16 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Mar. 16, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	MELR
Entity Registrant Name	MELROSE BANCORP, INC.
Entity Central Index Key	1,600,890
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		2,600,743
Entity Public Float			$ 46.6

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Cash and due from banks	$ 8,903	$ 11,715
Money market funds	3,963	2,077
Federal funds sold	4,737
Cash and cash equivalents	17,603	13,792
Investments in available-for-sale securities, at fair value	26,496	31,831
Federal Home Loan Bank stock, at cost	1,800	964
Loans, net of allowance for loan losses of $1,134 at December 31, 2017 and $890 at December 31, 2016	251,317	213,165
Premises and equipment, net	1,993	1,248
Co-operative Central Bank deposit	886	881
Bank-owned life insurance	6,090	5,874
Accrued interest receivable	702	572
Deferred tax asset, net	364	120
Other assets	275	199
Total assets	307,526	268,646
Deposits:
Noninterest-bearing	16,180	17,586
Interest-bearing	216,741	197,180
Total deposits	232,921	214,766
Federal Home Loan Bank advances	29,000	10,000
Other liabilities	612	576
Total liabilities	262,533	225,342
Stockholders' equity:
Common stock, par value $0.01 per share, authorized 15,000,000 shares; issued 2,600,743 shares at December 31, 2017 and 2,602,079 at December 31, 2016	26	26
Additional paid-in-capital	23,496	23,292
Retained earnings	23,674	21,912
Unearned compensation - ESOP (196,184 shares unallocated at December 31, 2017 and 203,728 shares at December 31, 2016)	(1,961)	(2,037)
Unearned compensation - restricted stock	(451)	(585)
Accumulated other comprehensive income	209	696
Total stockholders' equity	44,993	43,304
Total liabilities and stockholders' equity	$ 307,526	$ 268,646

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowance for loan losses	$ 1,134	$ 890
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	15,000,000	15,000,000
Common stock, shares issued	2,600,743	2,602,079
ESOP number of shares unallocated	196,184	203,728

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Interest and dividend income:
Interest and fees on loans	$ 8,168	$ 6,551
Interest and dividends on securities:
Taxable	534	740
Tax-exempt	69	59
Other interest	170	55
Total interest and dividend income	8,941	7,405
Interest expense:
Interest on deposits	1,853	1,618
Interest on Federal Home Loan Bank advances	330	22
Total interest expense	2,183	1,640
Net interest and dividend income	6,758	5,765
Provision for loan losses	245	310
Net interest and dividend income, after (benefit)/provision for loan losses	6,513	5,455
Noninterest income:
Fees and service charges	88	76
Gain on sales of available-for-sale securities, net	1,385	1,004
Income on bank-owned life insurance	162	141
Other income	8	14
Total noninterest income	1,643	1,235
Noninterest expense:
Salaries and employee benefits	3,240	2,772
Occupancy expense	375	300
Equipment expense	45	37
Data processing expense	400	370
Advertising expense	193	146
Printing and supplies	48	39
FDIC assessment	65	116
Audits and examinations	201	212
Other professional services	320	328
Other expense	223	152
Total noninterest expense	5,110	4,472
Loss before undistributed income of subsidiary and income tax expense (benefit)	3,046	2,218
Income tax expense	1,242	796
Net income	$ 1,804	$ 1,422
Weighted average common shares outstanding:
Basic	2,367,424	2,426,687
Diluted	2,372,297	2,427,498
Earnings per share:
Basic	$ 0.76	$ 0.59
Diluted	$ 0.76	$ 0.59

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 1,804	$ 1,422
Other comprehensive loss, net of tax:
Net unrealized holding gain on available-for-sale securities	478	285
Reclassification adjustment for net realized gains included in net income	(1,385)	(1,004)
Other comprehensive loss before income tax effect	(907)	(719)
Income tax benefit	378	269
Other comprehensive loss, net of tax	(529)	(450)
Comprehensive income	$ 1,275	$ 972

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in-Capital [Member]	Retained Earnings [Member]	Unearned Compensation - ESOP [Member]	Unearned Compensation - RSA [Member]	Accumulated Other Comprehensive Income [Member]
Beginning balance at Dec. 31, 2015	$ 45,545	$ 28	$ 25,994	$ 20,490	$ (2,113)		$ 1,146
Beginning balance, shares at Dec. 31, 2015		2,787,579
Net income	1,422			1,422
Other comprehensive loss, net of tax	(450)						(450)
Restricted stock awarded			670			$ (670)
Restricted stock awarded, shares		44,300
Restricted stock award expense	85					85
Stock option expense	106		106
Buyback of common stock	$ (3,520)	$ (2)	(3,518)
Buyback of common stock, shares	(229,800)	(229,800)
Common stock held by ESOP committed to be allocated	$ 116		40		76
Ending balance at Dec. 31, 2016	43,304	$ 26	23,292	21,912	(2,037)	(585)	696
Ending balance, shares at Dec. 31, 2016		2,602,079
Net income	1,804			1,804
Other comprehensive loss, net of tax	(529)						(529)
Shares repurchased for tax withholdings on stock-based compensation	(22)		(22)
Shares repurchased for tax withholdings on stock-based compensation, shares		(1,336)
Restricted stock award expense	134					134
Stock option expense	$ 166		166
Buyback of common stock, shares	(1,336)
Common stock held by ESOP committed to be allocated	$ 136		60		76
Reclassification adjustment for stranded accumulated other comprehensive income due to tax rate change	42			(42)			42
Ending balance at Dec. 31, 2017	$ 44,993	$ 26	$ 23,496	$ 23,674	$ (1,961)	$ (451)	$ 209
Ending balance, shares at Dec. 31, 2017		2,600,743

Consolidated Statements of Cha7

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Common stock held by ESOP committed to be allocated, shares	7,544	7,546

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 1,804	$ 1,422
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of securities, net of accretion	144	37
Gain on sales of available-for-sale securities, net	(1,385)	(1,004)
Provision for loan losses	245	310
Change in net deferred loan costs	(3)	77
Change in unamortized premiums	(113)	(372)
Depreciation	187	85
Increase in accrued interest receivable	(130)	(132)
Increase in other assets	(76)	(4)
Increase in other liabilities	36	17
Deferred tax expense	134	71
Income on bank-owned life insurance	(162)	(141)
ESOP expense	136	116
Stock-based compensation expense	300	191
Net cash provided by operating activities	1,117	673
Cash flows from investing activities:
Purchases of available-for-sale securities	(4,214)	(4,991)
Proceeds from sales of available-for-sale securities	4,498	9,321
Proceeds from maturities and calls of available-for-sale securities	5,385	9,230
Purchases of Federal Home Loan Bank stock	(836)	(527)
Increase in Cooperative Central Bank deposit	(5)
Loan originations and principal collections, net	(18,785)	(18,286)
Loans purchased	(19,496)	(34,591)
Capital expenditures	(932)	(107)
Premiums paid on bank-owned life insurance	(54)	(503)
Net cash (used in) provided by investing activities	(34,439)	(40,454)
Cash flows from financing activities:
Net increase in demand deposits, NOW and savings accounts	5,640	3,969
Net increase in time deposits	12,515	26,270
Proceeds from Federal Home Loan Bank advances	19,000	10,000
Shares repurchased for tax withholdings on stock-based compensation	(22)
Repurchase of Melrose Bancorp, Inc. common stock		(3,520)
Net cash provided by financing activities	37,133	36,719
Net increase (decrease) in cash and cash equivalents	3,811	(3,062)
Cash and cash equivalents at beginning of the year	13,792	16,854
Cash and cash equivalents at end of the year	17,603	13,792
Supplemental disclosures:
Interest paid	2,184	1,634
Income taxes paid	1,181	$ 644
Reclassification adjustment for stranded accumulated other comprehensive income due to tax rate change	$ 42

Nature of Operations

Nature of Operations	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	NOTE 1 – NATURE OF OPERATIONS Melrose Cooperative Bank (the “Bank”) is a state chartered co-operative On October 21, 2014, in accordance with a Plan of Conversion (Conversion), Melrose Cooperative Bank completed a mutual-to-stock As set forth above, in connection with the Conversion, the Bank established and funded the Melrose Cooperative Bank Foundation (Foundation) with 106,170 shares of the Company’s common stock, plus a cash contribution of $300,000. This contribution resulted in recognition of expense of $1,362,000 in the year ended December 31, 2014 based on the $10 per share offering price, plus $300,000 of cash. The Foundation supports charitable causes and community development activities in the Bank’s area of operations. Also, in connection with the Conversion, the Bank established an employee stock ownership plan (ESOP), which purchased 226,366 shares of the Company’s common stock at a price of $10 per share. The Bank, at the time of the Conversion, established a Liquidation Account in an amount equal to the net worth of the Bank as of the date of the latest consolidated statement of financial condition contained in the final prospectus distributed in connection with the Conversion. The function of the Liquidation Account is to establish a priority on liquidation. The Liquidation Account will be maintained by the Company for the benefit of the eligible account holders who continue to maintain deposit accounts with the Bank following the conversion. Each eligible account holder shall, with respect to each deposit account, hold a related inchoate interest in a portion of the Liquidation Account balance, in relation to each deposit account balance at the eligibility record date, or to such balance as it may be subsequently reduced, as hereinafter provided. The initial Liquidation Account balance shall not be increased, and shall be subject to downward adjustment to the extent of any downward adjustment of any subaccount balance of any eligible account holder in accordance with the Regulations of the Division of Banks of the Commonwealth of Massachusetts. In the unlikely event of a complete liquidation of the Bank (and only in such event), following all liquidation payments to creditors (including those to depositors to the extent of their deposit accounts) each eligible account holder shall be entitled to receive a liquidating distribution from the Liquidation Account, in the amount of the then-adjusted subaccount balances for his or her deposit accounts then held, before any liquidating distribution may be made to any holder of the Bank’s capital stock.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 2 – SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The accounting and reporting policies of the Company and its subsidiary conform to accounting principles generally accepted in the United States of America (GAAP) and predominant practices within the banking industry. The consolidated financial statements were prepared using the accrual basis of accounting. The significant accounting policies are summarized below to assist the reader in better understanding the consolidated financial statements and other data contained herein. BASIS OF PRESENTATION: The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary the Bank, and the Bank’s wholly-owned subsidiary, MCBSC, Inc., which is used to hold investment securities. All significant intercompany accounts and transactions have been eliminated in the consolidation. USE OF ESTIMATES: In preparing consolidated financial statements in conformity with accounting principles generally accepted in the United States of America, 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. The material estimate that is particularly susceptible to significant change in the near-term relates to the determination of the allowance for loan losses. RECLASSIFICATIONS: Certain amounts in the prior year have been reclassified to be consistent with the current year’s presentation. CASH AND CASH EQUIVALENTS: For purposes of reporting cash flows, cash and cash equivalents include cash, amounts due from banks, money market funds and federal funds sold. SECURITIES: Investments in debt securities are adjusted for amortization of premiums and accretion of discounts computed so as to approximate the interest method. Gains or losses on sales of investment securities are computed on a specific identification basis. The Company classifies all debt and equity securities as available-for-sale. Available-for-sale For any debt security with a fair value less than its amortized cost basis, the Company will determine whether it has the intent to sell the debt security or whether it is more likely than not it will be required to sell the debt security before the recovery of its amortized cost basis. If either condition is met, the Company will recognize a full impairment charge to earnings. For all other debt securities that are considered other-than-temporarily impaired and do not meet either condition, the credit loss portion of impairment will be recognized in earnings as realized losses. The other-than-temporary impairment related to all other factors will be recorded in other comprehensive loss. Declines in marketable equity securities below their cost that are deemed other-than-temporary are reflected in earnings as realized losses. FEDERAL HOME LOAN BANK STOCK: As a member of the Federal Home Loan Bank of Boston, the Company is required to invest in $100 par value stock of the FHLB. The FHLB capital structure mandates that members must own stock as determined by their Total Stock Investment Requirement which is the sum of a member’s Membership Stock Investment Requirement and Activity-Based Stock Investment Requirement. Management evaluates the Company’s investment in FHLB stock for other-than-temporary impairment at least on a quarterly basis and more frequently when economic or market conditions warrant such evaluation. Based on its most recent analysis of the FHLB as of December 31, 2017, management deems its investment in FHLB stock to be not other-than-temporarily impaired. LOANS: Loans receivable that management has the intent and ability to hold until maturity or payoff are reported at their outstanding principal balances adjusted for amounts due to borrowers on outstanding home equity lines of credit, commercial lines of credit and construction loans, any charge-offs, the allowance for loan losses and any deferred fees or costs on originated loans, or unamortized premiums or discounts on purchased loans. Loan origination and commitment fees and certain direct origination costs are deferred, and the net amount amortized as an adjustment of the related loan’s yield. The Company is amortizing these amounts over the expected lives of the related loans. Residential real estate loans are generally placed on nonaccrual when reaching 90 days past due or are in the process of foreclosure. All closed-end Cash receipts of interest income on impaired loans are credited to principal to the extent necessary to eliminate doubt as to the collectability of the net carrying amount of the loan. Some or all of the cash receipts of interest income on impaired loans are recognized as interest income if the remaining net carrying amount of the loan is deemed to be fully collectible. When recognition of interest income on an impaired loan on a cash basis is appropriate, the amount of income that is recognized is limited to that which would have been accrued on the net carrying amount of the loan at the contractual interest rate. Any cash interest payments received in excess of the limit and not applied to reduce the net carrying amount of the loan are recorded as recoveries of charge-offs until the charge-offs are fully recovered. ALLOWANCE FOR LOAN LOSSES: The allowance for loan losses is established as losses are estimated to have occurred through a provision for loan losses charged to earnings. Loan losses are charged against the allowance when management believes the uncollectability 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 by management and is based upon management’s periodic review of the collectability 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 more information becomes available. General Component: The general component of the allowance for loan losses is based on historical loss experience adjusted for qualitative factors stratified by the following loan segments: one- 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: One- loan-to-value loan-to-value Commercial real estate: Loans in this segment are primarily income-producing properties throughout Massachusetts. The underlying cash flows generated by the properties are adversely impacted by a downturn in the economy as evidenced by increased vacancy rates, which in turn, will have an effect on the credit quality in this segment. Loans in this segment also include loans secured by multifamily dwellings. Management periodically obtains rent rolls and continually monitors the cash flows of these loans. Construction: Loans in this segment primarily include speculative 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. Consumer: Loans in this segment are generally secured and repayment is dependent on the credit quality of the individual borrower. Loans in this segment include auto loans and other consumer loans. Allocated Component: The allocated component relates to loans that are classified as impaired. Impairment is measured on a loan by loan basis for commercial real estate and construction loans 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 is 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 separately identify individual consumer and one- 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 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. Unallocated Component: An unallocated component is maintained to cover uncertainties that could affect management’s estimate of probable losses. The unallocated component of the allowance reflects the margin of imprecision inherent in the underlying assumptions used in the methodologies for estimating allocated and general reserves in the portfolio. PREMISES AND EQUIPMENT: Land is carried at cost. Buildings and equipment are stated at cost, less accumulated depreciation and amortization. Cost and related allowances for depreciation and amortization of premises and equipment retired or otherwise disposed of are removed from the respective accounts with any gain or loss included in income or expense. Depreciation and amortization are calculated principally on the straight-line method over the estimated useful lives of the assets. Estimated lives are 15 to 30 years for buildings and 3 to 10 years for furniture and equipment. Premises and equipment are periodically evaluated for impairment when events or changes in circumstances indicate the carrying amount may not be recoverable. Impairment exists when the expected undiscounted future cash flows of premises and equipment are less than its carrying amount. In that event, the Company records a loss for the difference between the carrying amount and the fair value of the asset based on quoted market prices, if applicable, or a discounted cash flow analysis. BANK-OWNED LIFE INSURANCE: The Company has purchased insurance policies on the lives of certain directors, executive officers and employees. Bank-owned life insurance policies are reflected on the consolidated balance sheets at cash surrender value. Changes in net cash surrender value of the policies, as well as insurance proceeds received, are reflected in non-interest ADVERTISING: The Company directly expenses costs associated with advertising as they are incurred. INCOME TAXES: The Company recognizes income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are established for the temporary differences between the accounting basis and the tax basis of the Company’s assets and liabilities at enacted tax rates expected to be in effect when the amounts related to such temporary differences are realized or settled. EMPLOYEE STOCK OWNERSHIP PLAN: Compensation expense for the Employee Stock Ownership Plan (“ESOP”) is recorded at an amount equal to the shares allocated by the ESOP multiplied by the average fair value of the shares during the period. Unearned compensation applicable to the ESOP is reflected as a reduction of stockholders’ equity in the consolidated balance sheets. The difference between the average fair value and the cost of shares allocated by the ESOP is recorded as an adjustment to additional paid-in STOCK-BASED COMPENSATION: The Company recognizes stock-based compensation based on the grant-date fair value of the award. Forfeitures will be recognized when they occur. The Company values share-based stock option awards granted using the Black-Scholes option-pricing model. The Company recognizes compensation expense for its awards on a straight-line basis over the requisite service period for the entire award (straight-line attribution method), ensuring that the amount of compensation cost recognized at any date at least equals the portion of the grant-date fair value of the award that is vested at that time. EARNINGS PER SHARE (EPS): When presented, basic EPS is computed by dividing income available to common stockholders by the weighted-average number of common shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the entity. For the purposes of computing diluted EPS, the treasury stock method is used. Unallocated ESOP shares and unearned shares of restricted stock are not deemed outstanding for earnings per share calculations. The calculation of basic and diluted EPS is presented below. Year Ended Year Ended (Dollars in thousands, except earnings per share) Net income $ 1,804 $ 1,422 Basic Common Shares: Weighted average common shares outstanding 2,601,223 2,660,521 Weighted average shares – unearned restricted stock (33,843 ) (26,333 ) Weighted average unallocated ESOP shares (199,956 ) (207,501 ) Basic weighted average shares outstanding 2,367,424 2,426,687 Diluted effect of unvested stock options — — Dilutive effect of unvested restricted stock awards 4,873 811 Diluted weighted average shares outstanding 2,372,297 2,427,498 Basic earnings per share $ 0.76 $ 0.59 Diluted earnings per share (1) $ 0.76 $ 0.59 (1) Options to purchase 224,200 shares, representing all outstanding options, were not included in the computation of diluted earnings per share for the years ended December 31, 2017 and 2016 because the effect is anti-dilutive. FAIR VALUES OF FINANCIAL INSTRUMENTS: Accounting Standards Codification (ASC) 825, “Financial Instruments,” requires that the Company disclose the estimated fair value for its financial instruments. Fair value methods and assumptions used by the Company in estimating its fair value disclosures are as follows: Cash and cash equivalents: The carrying amounts reported in the consolidated balance sheets for cash and cash equivalents approximate those assets’ fair values. Securities: Fair values for securities are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments. Loans receivable: For variable-rate loans that reprice frequently and with no significant change in credit risk, fair values are based on carrying values. The fair values for other loans are estimated using discounted cash flow analyses, using interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. Accrued interest receivable: The carrying amount of accrued interest receivable approximates its fair value. Deposit liabilities: The fair values disclosed for demand deposits (e.g., interest and non-interest Federal Home Loan Bank advances: The fair values of FHLB advances are estimated using discounted cash flow analyses based on the current incremental borrowing rates for similar types of borrowing arrangements. RECENT ACCOUNTING PRONOUNCEMENTS: As an “emerging growth company,” as defined in Title 1 of Jumpstart Our Business Startups (JOBS) Act, the Company has elected to use the extended transition period to delay adoption of new or reissued accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. Accordingly, the consolidated financial statements may not be comparable to the financial statements of public companies that comply with such new or revised accounting standards. As of December 31, 2017, there is no significant difference in the comparability of the financial statements as a result of this extended transition period. The extended transition period for an emerging growth company is five years, and the Company’s emerging growth status will end on December 31, 2019. In May 2014 and August 2015, respectively, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update ASU 2014-09 2015-14, 2014-09 2015-14 2014-09 2014-09, non-interest Form 10-Q. In January 2016, the FASB issued ASU 2016-01, 825-10): 1. Require equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. However, the entity may choose to measure equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same manner. 2. Simplify the impairment assessment of equity investments without determinable fair values by requiring a qualitative assessment to identify impairment. When a qualitative assessment indicates that impairment exists, an entity is required to measure the investment at fair value. 3. Eliminate the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet. 4. Require public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes. 5. Require an entity to present separately in other comprehensive income the portion of the total change in fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. 6. Require separate presentation of financial assets and financial liabilities by measurement category and form of financial assets (that is, securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements. 7. Clarify that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale Under the extended transition period for an emerging growth company, the amendments in this Update are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption of item 5 above is permitted as of the beginning of fiscal years or interim periods for which financial statements have not been issued. Early adoption of all other amendments in this ASU is not permitted. The Company is currently evaluating the amendments of ASU No. 2016-01 In February 2016, the FASB issued ASU 2016-02, In March 2016, the FASB issued ASU No. 2016-09, paid-in-capital No. 2016-09 In June 2016, the FASB issued ASU No. 2016-13, available-for-sale No. 2016-13 In March 2017, the FASB issued ASU 2017-08, No. 2017-08 No. 2017-08 In February 2018, the FASB issued ASU 2018-02, 2018-02 2018-02

Investments in Available-For-Sa

Investments in Available-For-Sale Securities	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investments in Available-For-Sale Securities	NOTE 3 – INVESTMENTS IN AVAILABLE-FOR-SALE Debt and equity securities have been classified in the consolidated balance sheets according to management’s intent. The amortized cost basis of securities and their approximate fair values are as follows as of December 31: Amortized Gross Gross Fair (In Thousands) December 31, 2017: U.S. Government and federal agency obligations $ 5,390 $ — $ 65 $ 5,325 Debt securities issued by states of the United States and political subdivisions of the states 2,898 12 29 2,881 Corporate bonds and notes 11,364 7 77 11,294 Preferred stock 3,000 13 — 3,013 Mortgage-backed securities 1,495 — 47 1,448 Marketable equity securities 2,046 490 1 2,535 $ 26,193 $ 522 $ 219 $ 26,496 December 31, 2016: U.S. Government and federal agency obligations $ 5,819 $ — $ 131 $ 5,688 Debt securities issued by states of the United States and political subdivisions of the states 2,695 2 41 2,656 Corporate bonds and notes 12,537 17 61 12,493 Preferred stock 3,000 20 82 2,938 Mortgage-backed securities 1,498 — 66 1,432 Marketable equity securities 5,072 1,557 5 6,624 $ 30,621 $ 1,596 $ 386 $ 31,831 The scheduled maturities of debt securities as of December 31, 2017 are as follows: Fair (In Thousands) Due within one year $ 3,496 Due after one year through five years 12,038 Due after five years through ten years 2,390 Due after ten years 2,077 Mortgage-backed securities 1,448 Asset-backed securities 1,509 $ 22,958 Not included in the maturity table above is preferred stock with no stated maturity of $1.0 million at December 31, 2017. There were no securities of issuers whose aggregate carrying amount exceeded 10% of stockholders’ equity at December 31, 2017. During the year ended December 31, 2017, proceeds from the sales of available-for-sale available-for-sale The Company had no pledged securities as of December 31, 2017 and December 31, 2016. The aggregate fair value and unrealized losses of securities that have been in a continuous unrealized loss position for less than twelve months and for twelve months or more, and are not other-than-temporarily impaired, are as follows as of December 31: Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized (In Thousands) December 31, 2017 U.S. Government and federal agency obligations $ 2,855 $ 20 $ 2,470 $ 45 $ 5,325 $ 65 Debt securities issued by states of the United States and political subdivisions of the states 991 6 535 23 1,526 29 Corporate bonds and notes 4,467 24 3,946 53 8,413 77 Mortgage-backed securities 453 6 995 41 1,448 47 Marketable equity securities 485 1 — — 485 1 Total temporarily impaired securities $ 9,251 $ 57 $ 7,946 $ 162 $ 17,197 $ 219 December 31, 2016 U.S. Government and federal agency obligations $ 4,359 $ 59 $ 1,328 $ 72 $ 5,687 $ 131 Debt securities issued by states of the United States and political subdivisions of the states 1,760 28 245 13 2,005 41 Corporate bonds and notes 5,784 61 — — 5,784 61 Preferred stock 1,918 82 — — 1,918 82 Mortgage-backed securities 370 8 1,062 58 1,432 66 Marketable equity securities 2,235 5 — — 2,235 5 Total temporarily impaired securities $ 16,426 $ 243 $ 2,635 $ 143 $ 19,061 $ 386 The Company conducts periodic reviews of investment securities with unrealized losses to evaluate whether the impairment is other-than-temporary. The Company’s review for impairment generally includes a determination of the cause, severity and duration of the impairment; and an analysis of both positive and negative evidence available. The Company also determines if it has the ability and intent to hold the investment for a period of time sufficient to allow for anticipated recovery to cost basis. Based on the Company’s recent review of securities in the investment portfolio, management deemed securities with unrealized losses as of December 31, 2017 to be temporarily impaired and has the ability and intent to hold these securities until recovery to cost basis occurs. A summary of this review is as follows. Unrealized losses on U.S. Government and federal agency obligations amounted to $65,000 and consisted of eleven securities; seven of which had unrealized losses that were each individually less than 2% of amortized cost basis, and four of which had unrealized losses between 2% and 5% of amortized cost basis. Unrealized losses on municipal bonds amounted to $29,000 and consisted of four securities; three of which had unrealized losses that were each individually less than 3% of amortized cost basis, and one of which had an unrealized loss of 6% of amortized cost basis. Unrealized losses on corporate bonds and notes amounted to $77,000 and consisted of sixteen securities, eleven of which had unrealized losses that were 1% or less of amortized cost basis, and five of which had unrealized losses that were each individually between 1% and 4%. Unrealized losses on mortgage-backed securities amounted to $47,000 and consisted of five securities; all with unrealized losses from 2% to 7% of amortized cost basis. Unrealized losses on marketable equity securities amounted to $1,000 and consisted of one equity security with an unrealized loss of 0.2% of amortized cost basis. The unrealized losses on all of these debt securities were primarily due to changes in interest rates. The unrealized loss on equity securities was primarily due to market fluctuations. In regard to corporate debt, the Company also considers the issuer’s current financial condition and its ability to make future scheduled interest and principal payments on a timely basis in assessing other-than-temporary impairment. During 2017 and 2016, there were there were no available-for-sale

Loans

Loans	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Loans	NOTE 4 – LOANS Loans consisted of the following: December 31, December 31, (In Thousands) Real estate loans: One-to four-family residential $ 189,763 $ 168,111 Home equity loans and lines of credit 11,585 10,720 Commercial 34,686 23,011 Construction 15,853 11,738 Consumer loans 44 71 Total loans 251,931 213,651 Allowance for loan losses (1,134 ) (890 ) Deferred loan costs, net 35 32 Unamortized premiums 485 372 Net loans $ 251,317 $ 213,165 Certain directors and executive officers of the Company and companies in which they have significant ownership interest were customers of the Bank during the year ended December 31, 2017. Total loans to such persons and their companies amounted to $2,274,000 and $2,455,000 as of December 31, 2017 and December 31, 2016, respectively. During the year ended December 31, 2017, there was one new loan disbursement of $439,000, $13,000 of advances were made, principal payments totaled $138,000, and loan payoffs totaled $495,000. December 31, 2016, there was one new loan disbursement of $500,000, $122,000 of advances were made, principal payments totaled $150,000, and loan payoffs totaled $382,000. The following tables set forth information on the allowance for loan losses at and for the years ended December 31, 2017 and 2016: Real Estate: One- to four-family Home Equity Loans Commercial Construction Consumer Unallocated Total (In Thousands) Year ended December 31, 2017 Allowance for loan losses: Beginning balance $ 418 $ 49 $ 276 $ 117 $ 1 $ 29 $ 890 Charge offs — — — — (1 ) — (1 ) Recoveries — — — — — — — Provision (benefit) 63 3 196 (10 ) 1 (8 ) 245 Ending balance $ 481 $ 52 $ 472 $ 107 $ 1 $ 21 $ 1,134 At December 31, 2017 Allowance for loan losses: Ending Balance: Individually evaluated for impairment $ 8 $ — $ — $ — $ — $ — $ 8 Ending balance: Collectively evaluated for impairment 473 52 472 107 1 21 1,126 Total allowance for loan losses ending balance $ 481 $ 52 $ 472 $ 107 $ 1 $ 21 $ 1,134 Loans: Ending balance: Individually evaluated for impairment $ 100 $ — $ — $ — $ — $ — $ 100 Ending balance: Collectively evaluated for impairment 189,663 11,585 34,686 15,853 44 — 251,831 Total loans ending balance $ 189,763 $ 11,585 $ 34,686 $ 15,853 $ 44 $ — $ 251,931 Real Estate: One- to four-family Home Equity Loans Commercial Construction Consumer Unallocated Total (In Thousands) Year ended December 31, 2016 Allowance for loan losses: Beginning balance $ 331 $ 49 $ 150 $ 40 $ 1 $ 9 $ 580 Charge offs — — — — — — — Recoveries — — — — — — — Provision 87 — 126 77 — 20 310 Ending balance $ 418 $ 49 $ 276 $ 117 $ 1 $ 29 $ 890 At December 31, 2016 Ending Balance: Individually evaluated for impairment $ — $ — $ — $ — $ — $ — $ — Ending balance: Collectively evaluated for impairment 418 49 276 117 1 29 890 Total allowance for loan losses ending balance $ 418 $ 49 $ 276 $ 117 $ 1 $ 29 $ 890 Loans: Ending balance: Individually evaluated for impairment $ — $ — $ — $ — $ — $ — $ — Ending balance: Collectively evaluated for impairment 168,111 10,720 23,011 11,738 71 — 213,651 Total loans ending balance $ 168,111 $ 10,720 $ 23,011 $ 11,738 $ 71 $ — $ 213,651 The following tables set forth information regarding nonaccrual loans and past-due 30 – 59 60 – 89 90 Days or Total Past Total Total 90 Days or More Non- (In Thousands) At December 31, 2107 Real estate loans: One-to four-family residential $ 295 $ 177 $ — $ 472 $ 189,291 $ 189,763 $ — $ 189 Home equity loans and lines of credit 189 — — 189 11,396 11,585 — — Commercial — — — — 34,686 34,686 — — Construction — — — — 15,853 15,853 — — Consumer loans — — — — 44 44 — — Total $ 484 $ 177 $ — $ 661 $ 251,270 $ 251,931 $ — $ 189 At December 31, 2016 Real estate loans: One-to four-family residential $ 518 $ 9 $ — $ 527 $ 167,584 $ 168,111 $ — $ 9 Home equity loans and lines of credit — — — — 10,720 10,720 — — Commercial — — — — 23,011 23,011 — — Construction — — — — 11,738 11,738 — — Consumer loans — — — — 71 71 — — Total $ 518 $ 9 $ — $ 527 $ 213,124 $ 213,651 $ — $ 9 As of and during the year ended December 31, 2017 there was one, one- 310-10-35. 310-10-35. During the year ended December 31, 2017 the same impaired one, one- During the year ended December 31, 2017 and 2016, there were no troubled debt restructure loans that subsequently defaulted within 12 months of modification. In addition, there are no commitments to lend additional funds for loans modified as a troubled debt restructure. At December 31, 2017, there were no consumer mortgage loans collateralized by residential real estate property in the process of foreclosure. As of December 31, 2017, the Bank had no foreclosed real estate owned. At December 31, 2016, there was one consumer mortgage loan collateralized by residential real estate property in the process of foreclosure with a recorded investment of $321,000. As of December 31, 2016, the Bank had no foreclosed real estate owned. Credit Quality Information The Company has established an 11 point internal loan rating system for commercial real estate and construction loans. For residential real estate and consumer loans, the Company initially assesses credit quality based upon the borrower’s ability to pay and subsequently monitors these loans based on the borrower’s ability to pay. The risk rating system will assist the Company in better understanding the risk inherent in each loan. The loan ratings are as follows: Loans rated 1: Secured by cash collateral or highly liquid diversified marketable securities. Loans rated 2 – 3: Strongest quality loans in the portfolio not secured by cash. Defined by consistent, solid profits, strong cash flow and are well secured. Very little vulnerability to changing economic conditions and compare favorably to their industry. Loans rated 4 – 5: These loans are pass rated. Borrower will show average to strong cash flow, strong to adequate collateral coverage, and will have a generally sound balance sheet. Inclusive in the 5 rating are all open and closed – end residential and retail loans which are paying as agreed. Loans rated 6: Loans with above average risk but still considered pass. Generally this rating is reserved for projects currently under construction or borrowers with modest cash flow, although still meeting all loan covenants. Loans rated 6W: Contain all the risks of a 6 rated credit but have an inherent weakness that requires close monitoring. This rating also generally includes open and closed-end Loans rated 7: Considered special mention. Potential weaknesses which warrant management’s close attention. If weaknesses are uncorrected, repayment prospects may be weakened. This is typically a transitional rating. Loans rated 8: Considered substandard. There is a likelihood of loss if the deficiencies are not corrected. Generally, open and closed – end retail loans, as well as automotive and other consumer loans past 90 cumulative days from the contractual due date should be classified as an 8. Loans rated 9: Borrower has a pronounced weakness and all current information indicates collection or liquidation of all debts in full is improbable and highly questionable. Loans rated 10: Uncollectable and a loss will be taken. Open and closed – end loans secured by residential real estate that are beyond 180 days past due will be assessed for value and any outstanding loan balance in excess of said value, less cost to sell, will be classified as a 10. On an annual basis, or more often if needed, the Company formally reviews the ratings on all commercial real estate and construction loans over $350,000. As of December 31, 2017, there were no one- one- one- As of December 31, 2016, one-

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Premises and Equipment	NOTE 5 – PREMISES AND EQUIPMENT The following is a summary of premises and equipment as of December 31: December 31, December 31, 2017 2016 (In Thousands) Land $ 393 $ 393 Building 2,070 1,840 Construction in process 641 — Furniture and equipment 553 549 Data processing equipment 360 303 4,017 3,085 Accumulated depreciation (2,024 ) (1,837 ) $ 1,993 $ 1,248

Deposits

Deposits	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Deposits	NOTE 6 – DEPOSITS The aggregate amount of time deposit amounts in denominations that meet or exceed the Federal Deposit Insurance Corporation (FDIC) insurance limit of $250,000 as of December 31, 2017 and 2016 amounted to $27,781,000 and $23,434,000, respectively. For time deposits as of December 31, 2017 the scheduled maturities for each of the following years ended December 31 are as follows: (In Thousands) 2018 $ 102,073 2019 12,664 2020 1,638 2021 8,208 2022 1,537 $ 126,120 Deposits from related parties held by the Bank as of December 31, 2017 and 2016 amounted to $3,603,000 and $3,782,000, respectively.

Federal Home Loan Bank Advances

Federal Home Loan Bank Advances	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Federal Home Loan Bank Advances	NOTE 7 – FEDERAL HOME LOAN BANK ADVANCES Advances consist of funds borrowed from the Federal Home Loan Bank of Bank (FHLB). Maturities of advances from the FHLB for the years ending after December 31, 2017 are summarized as follows (in thousands): 2018 $ 10,000 2019 19,000 $ 29,000 Borrowings from the FHLB are secured by a blanket lien on qualified collateral, consisting primarily of loans with first mortgages secured by one-to-four Co-Operative At December 31, 2017, the interest rates on FHLB advances ranged from 1.42% to 2.37%. At December 31, 2017, the weighted-average interest rate on FHLB advances was 1.78%. At December 31, 2016, the interest rates on FHLB advances ranged from 1.42% to 1.48%. At December 31, 2016, the weighted-average interest rate on FHLB advances was 1.45%.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 8 – INCOME TAXES The components of income tax expense are as follows for the years ended December 31: Years Ended 2017 2016 (In Thousands) Current: Federal $ 857 $ 543 State 251 182 1,108 725 Deferred: Federal (12 ) 80 Change in federal tax rate 181 — State (11 ) (9 ) Change in valuation allowance (24 ) — 134 71 Total income tax expense $ 1,242 $ 796 The reasons for the differences between the statutory federal income tax rate and the effective tax rates are summarized as follows for the years ended December 31: Years Ended December 31, 2017 2016 % of Income % of Income Federal income tax at statutory rate 34.0 % 34.0 % State tax, net of federal tax benefit 5.2 5.2 Change in valuation allowance (0.8 ) 0.0 Change in tax rate 5.9 0.0 Dividends received deduction (0.5 ) (1.3 ) Bank-owned life insurance (1.8 ) (2.2 ) Solar credits (2.3 ) (0.0 ) Stock compensation 1.1 1.1 Tax exempt income (1.0 ) (1.3 ) ESOP 0.7 0.6 Other 0.3 (0.3 ) Effective tax rates 40.8 % 35.9 % The Company had gross deferred tax assets and gross deferred tax liabilities as follows as of December 31: December 31, 2017 2016 (In Thousands) Deferred tax assets: Allowance for loan losses $ 319 $ 356 Deferred compensation 83 83 Security writedowns 5 27 ESOP 16 12 Stock based compensation 47 47 Accrued expenses 31 13 Contribution to Melrose Cooperative Bank Foundation 204 406 Gross deferred tax assets 705 944 Valuation allowance (66 ) (90 ) Gross deferred tax assets, net of valuation allowance 639 854 Deferred tax liabilities: Accelerated depreciation (181 ) (220 ) Net unrealized holding gain on available-for-sale securities (94 ) (514 ) Gross deferred tax liabilities (275 ) (734 ) Net deferred tax asset $ 364 $ 120 In connection with its initial public offering, the Company donated common stock and cash in the amount of $1,362,000 to the Melrose Cooperative Bank Foundation. As of December 31, 2017, the Company had a remaining gross deferred tax asset of $204,000. A valuation allowance of $66,000 has been established against the deferred tax assets related to the uncertain utilization of the charitable contribution carryforward created primarily by the donation to the Foundation. The judgment applied by management considers the likelihood that sufficient taxable income will be realized within the carryforward period in light of its tax planning strategies and changes in market conditions. The charitable contribution carryforward of $769,000 at December 31, 2017 expires in 2019 and the related tax benefit, net of the valuation allowance, included in net deferred tax assets is $138,000. It is the Company’s policy to provide for uncertain tax positions and the related interest and penalties based upon management’s assessment of whether a tax benefit is more likely than not to be sustained upon examination by tax authorities. As of December 31, 2017 and 2016, there were no material uncertain tax positions related to federal and state income tax matters. The Company is currently open to audit under the statute of limitations by the Internal Revenue Service and state taxing authorities for the years ended December 31, 2014 through December 31, 2017. Interest and penalties, if any, are recorded as income tax expense. On December 22, 2017, the U.S. government enacted the Tax Cuts and Jobs Act (TCJA), a comprehensive tax legislation which, among other things, reduced the federal income tax rate for C corporations to 21% effective January 1, 2018. The TCJA makes broad and complex changes to the Internal Revenue Code which will impact the Company, including reduction of the corporate income tax rate as well as introduction of business-related exclusions, deductions and credits. The effects of the TCJA have been recorded in the fourth quarter 2017. As a result of the reduction of the Company’s corporate income tax rate from 34% to 21% under the TCJA, the Company revalued its net deferred tax asset at December 31, 2017 and recognized an $181,000 tax expense.

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Benefit Plans	NOTE 9 – BENEFIT PLANS 401(k) Savings Plan The Company participates in a 401(k) savings plan through Pentegra. Eligible employees may contribute up to 100% of their salary, subject to IRS limitations, which can be matched up to 5% by the Company on a dollar for dollar basis. The Company’s expense under this 401(k) plan was $82,000 and $80,000 for the years ended December 31, 2017 and 2016, respectively. Supplemental Executive Retirement Benefits Effective January 1, 2014, the Company established a Supplemental Executive Retirement Plan (SERP Plan). Under the SERP Plan, on a yearly basis, the Company shall credit the participant’s SERP account with the annual contribution specified in the participant’s participation agreement, based on a fixed percent of each participant’s annual salary. The SERP account is an unfunded liability due to each participant and is accruing interest. For the plan years ended December 31, 2017 and 2016, the related liability amounted to $294,000 and $208,000, respectively, and is included in other liabilities. Participants vest in full upon attaining five years of service from the date of participation, or attainment of benefit age, or following a change in control. For each of the years ended December 31, 2017 and 2016, expense recognized under the plan for these benefits was $86,000 and $70,000, respectively. Employee Stock Ownership Plan The Company has adopted a tax-qualified The ESOP funded its stock purchase through a loan from the Company equal to 100% of the aggregate purchase price of the common stock. The ESOP trustee will repay the loan principally through the Bank’s contributions to the ESOP and, possibly, dividends paid on common stock held by the plan over the loan term of 29.2 years. The trustee holds the shares purchased in a loan suspense account and will release the shares from the suspense account on a pro rata basis as it repays the loan. The trustee will allocate the shares released among active participants on the basis of each active participant’s proportional share of compensation compared to all active participants for the plan year. Participants vest in their benefit at a rate of 20% per year and will be fully vested upon completion of five years of credited service. Generally, participants will receive distributions from the ESOP upon separation from service. The trustee will reallocate any unvested shares of common stock forfeited by participants upon their separation from service among the remaining participants in the plan. Eligible employees who were employed with the Bank shall receive credit for vesting purposes for each year of continuous employment prior to adoption of the ESOP. The Company records compensation expense for the ESOP at an amount equal to the shares allocated by the ESOP multiplied by the average fair market value of shares during the period. At December 31, 2017, the remaining principal balance on the ESOP debt was $2,019,000 and the number of shares held by the ESOP was 226,366. Total compensation expense recognized in connection with the ESOP was $136,000 and $116,000 for the years ended December 31, 2017 and 2016, respectively. The remaining principal balance on the ESOP debt as of December 31, 2017 is payable as follows: Years Ending December 31, Amount (In Thousands) 2018 $ 51 2019 52 2020 54 2021 56 2022 58 Thereafter 1,748 $ 2,019 Shares held by the ESOP are as follows as of December 31: 2017 2016 Allocated 30,182 22,638 Unallocated 196,184 203,728 Shares held by ESOP 226,366 226,366 The fair value of unallocated ESOP shares was $3,924,000 at December 31, 2017. 2015 Equity Incentive Plan Melrose Bancorp, Inc. adopted the Melrose Bancorp, Inc. 2015 Equity Incentive Plan (the “2015 Equity Incentive Plan”) to provide directors, officers, and employees of the Company and Melrose Cooperative Bank with additional incentives to promote growth and performance of the Company and Melrose Cooperative Bank. The 2015 Equity Incentive Plan authorizes the issuance or delivery to participants of up to 396,140 shares of Melrose Bancorp, Inc. common stock pursuant to grants of incentive and non-statutory On May 12, 2016, the Company issued 44,300 shares of common stock restricted stock awards. The restricted stock award expense is based on $15.13 per share price on the date of grant, and shares vest over 5 years commencing one year from the grant date. The total expense recognized in connection with the restricted stock awards was $134,000 and $85,000, for the years ended December 31, 2017 and 2016, respectively, and the recognized tax benefit was $54,000 and $34,000, respectively. On May 12, 2016, the Company granted 224,200 stock options. The stock options have an exercise price of $15.13 per share, and vest ratably over 5 years commencing one year from the date of the grant. The stock option expense is equal to the number of options expected to vest each year times the grant date fair value of the shares as determined using the Black-Scholes option pricing model. The Company completed an analysis of seven peer banks to determine the expected volatility of 20.24%. The exercise price used in the pricing model was $15.13, the closing price of the stock on the grant date. The expected life was estimated to be 6.5 years and the 7 year treasury rate of 1.54% was used as the annual risk free interest rate. Using these variables, the estimated fair value is $3.71 per share. The aggregate intrinsic value is $1.1 million as of December 31, 2017. The total expense recognized in connection with the stock options was $166,000 and $106,000 for the years ended December 31, 2017 and 2016, respectively, and the recognized tax benefit was $18,000 and $13,000, respectively. No options have been exercised or forfeited to date. At December 31, 2017, the unrecognized share based compensation expense related to the 35,440 unvested restricted stock awards amounted to $451,000. The unrecognized expense will be recognized over a weighted average period of 3.3 years. At December 31, 2017, 44,840 of the 224,200 stock options outstanding are exercisable, and the remaining contractual life is 8.3 years. The unrecognized expense related to the unvested options is $559,000, and will be recognized over a weighted average period of 3.3 years. Other Agreements The Company has entered into employment agreements and change in control agreements with certain executive officers which provide the executive officers with severance payments based on salary, and the continuation of other benefits, upon a change in control as defined in the agreements.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2017
Investments, All Other Investments [Abstract]
Financial Instruments	NOTE 10 – FINANCIAL INSTRUMENTS The Company is party to financial instruments with off-balance un-advanced The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for loan commitments is represented by the contractual amounts of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance Commitments to originate loans are agreements to lend to a customer provided 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 Company evaluates each customer’s creditworthiness on a case-by-case Financial instrument liabilities with off-balance December 31, December 31, 2017 2016 (In Thousands) Commitments to originate loans $ 2,401 $ 7,864 Unused lines of credit 17,611 13,742 Due to borrowers on unadvanced construction loans 2,320 3,852 $ 22,332 $ 25,458

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 11 – FAIR VALUE MEASUREMENTS ASC 820-10, contract-by-contract In accordance with ASC 820-10, Level 1 – Valuations for assets and liabilities traded in active exchange markets, such as the New York Stock Exchange. Level 1 also includes U.S. Treasury, other U.S. Government and agency mortgage-backed securities that are traded by dealers or brokers in active markets. Valuations are obtained from readily available pricing sources for market transactions involving identical assets or liabilities. Level 2 – Valuations for assets and liabilities traded in less active dealer or broker markets. Valuations are obtained from third party pricing services for identical or comparable assets or liabilities. Level 3 – Valuations for assets and liabilities that are derived from other methodologies, including option pricing models, discounted cash flow models and similar techniques, are not based on market exchange, dealer, or broker traded transactions. Level 3 valuations incorporate certain assumptions and projections in determining the fair value assigned to such assets and liabilities. A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. A description of the valuation methodologies used for instruments measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below. These valuation methodologies were applied to all of the Company’s financial assets and financial liabilities carried at fair value for December 31, 2017 and December 31, 2016. The Company did not have any significant transfers of assets between levels 1 and 2 of the fair value hierarchy during the years ended December 31, 2017 and 2016. The Company’s marketable equity securities and preferred stocks are generally classified within level 1 of the fair value hierarchy because they are valued using quoted market prices. The Company’s investment in debt securities available-for-sale Level 3 is for positions that are not traded in active markets or are subject to transfer restrictions, valuations are adjusted to reflect illiquidity and/or non-transferability, The Company’s impaired loans, if any, are reported at the fair value of the underlying collateral if repayment is expected solely from the collateral. Collateral values are estimated using level 2 inputs based upon appraisals of similar properties obtained from a third party. For level 3 inputs, fair value is based upon management estimates of the value of the underlying collateral or the present value of the expected cash flows. The following summarizes assets measured at fair value on a recurring basis as of December 31: Fair Value Measurements at Reporting Date Using: Total Quoted Prices in Significant Significant (In Thousands) December 31, 2017: U.S. Government and federal agency obligations $ 5,325 $ — $ 5,325 $ — Debt securities issued by states of the United States and political subdivisions of the states 2,881 — 2,881 — Corporate bonds and notes 11,294 — 11,294 — Preferred stock 3,013 3,013 — — Mortgage-backed securities 1,448 — 1,448 — Marketable equity securities 2,535 2,535 — — Totals $ 26,496 $ 5,548 $ 20,948 $ — December 31, 2016: U.S. Government and federal agency obligations $ 5,688 $ — $ 5,688 $ — Debt securities issued by states of the United States and political subdivisions of the states 2,656 — 2,656 — Corporate bonds and notes 12,493 — 12,493 — Preferred stock 2,938 2,938 — — Mortgage-backed securities 1,432 — 1,432 — Marketable equity securities 6,624 6,624 — — Totals $ 31,831 $ 9,562 $ 22,269 $ — Under certain circumstances the Company makes adjustments to fair value for its assets and liabilities although they are not measured at fair value on an ongoing basis. At December 31, 2017 and 2016, there were no financial instruments carried on the consolidated balance sheet for which a nonrecurring change in fair value has been recorded. The estimated fair values of the Company’s financial instruments, all of which are held or issued for purposes other than trading, are as follows: December 31, 2017 Carrying Fair Value Level 1 Level 2 Level 3 Total (In Thousands) Financial assets: Cash and cash equivalents $ 17,603 $ 17,603 $ — $ — $ 17,603 Available-for-sale securities 26,496 5,548 20,948 — 26,496 Federal Home Loan Bank stock 1,800 1,800 — — 1,800 Loans, net 251,317 — — 252,792 252,792 Co-operative Central Bank deposit 886 886 — — 886 Accrued interest receivable 702 702 — — 702 Financial liabilities: Deposits 232,921 — 232,899 — 232,899 FHLB advances 29,000 — 28,660 — 28,660 December 31, 2016 Carrying Fair Value Level 1 Level 2 Level 3 Total (In Thousands) Financial assets: Cash and cash equivalents $ 13,792 $ 13,792 $ — $ — $ 13,792 Available-for-sale securities 31,831 9,562 22,269 — 31,831 Federal Home Loan Bank stock 964 964 — — 964 Loans, net 213,165 — — 213,582 213,582 Co-operative Central Bank deposit 881 881 — — 881 Accrued interest receivable 572 572 — — 572 Financial liabilities: Deposits 214,766 — 215,443 — 215,443 FHLB advances 10,000 — 9,930 — 9,930 The carrying amounts of financial instruments shown in the above table are included in the consolidated balance sheets under the indicated captions. Accounting policies related to financial instruments are described in Note 2.

Other Comprehensive Loss

Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Other Comprehensive Loss	NOTE 12 – OTHER COMPREHENSIVE LOSS Accounting principles generally require that recognized revenue, expenses, gains and losses be included in net income. Although certain changes in assets and liabilities are reported as a separate component of the stockholders’ equity section of the consolidated balance sheets, such items, along with net income, are components of comprehensive income. The components of other comprehensive loss included in stockholders’ equity are as follows: Years Ended 2017 2016 (In thousands) Net unrealized holding gain on available-for-sale securities $ 478 $ 285 Reclassification adjustment for net realized gains included in net income (1) (1,385 ) (1,004 ) Other comprehensive loss before income tax effect (907 ) (719 ) Income tax benefit 378 269 Other comprehensive loss, net of tax $ (529 ) $ (450 ) (1) Reclassification adjustments include net realized securities gains and losses. Realized gains and losses have been reclassified out of accumulated other comprehensive income and affect certain captions in the consolidated statements of income as follows: pre-tax available-for-sale available-for-sale Accumulated other comprehensive income as of December 31, 2017 and 2016 consists of net unrealized holding gains on available-for-sale

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Regulatory Matters	NOTE 13 – REGULATORY MATTERS The Bank is subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Bank’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Bank must meet specific capital guidelines that involve quantitative measures of the Bank’s assets, liabilities and certain off-balance Effective January 1, 2015, (with a phase-in Management believes, as of December 31, 2017, that the Bank meets all capital adequacy requirements to which it is subject. As of December 31, 2017, 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 Common Equity Tier 1 risked-based, total risk-based, Tier 1 risk-based and Tier 1 leverage capital ratios as set forth in the following table. There were no conditions or events since that notification that management believes have changed the Bank’s category. The Bank’s actual capital amounts and ratios are also presented in the table. Actual For Capital To Be Well Amount Ratio Amount Ratio Amount Ratio (Dollars In Thousands) As of December 31, 2017: Total Capital (to Risk Weighted Assets) $ 37,141 19.80 % $ 15,007 8.0 % $ 18,759 10.0 % Tier 1 Capital (to Risk Weighted Assets) 35,786 19.08 11,255 6.0 15,007 8.0 Common Equity Tier 1 Capital (to Risk Weighted Assets) 35,786 19.08 8,441 4.5 12,193 6.5 Tier 1 Capital (to Average Assets) 35,786 12.59 11,373 4.0 14,216 5.0 As of December 31, 2016: Total Capital (to Risk Weighted Assets) $ 35,236 21.09 % $ 13,368 8.0 % $ 16,710 10.0 % Tier 1 Capital (to Risk Weighted Assets) 33,648 20.14 10,026 6.0 13,368 8.0 Common Equity Tier 1 Capital (to Risk Weighted Assets) 33,648 20.14 7,519 4.5 10,861 6.5 Tier 1 Capital (to Average Assets) 33,648 13.58 9,909 4.0 12,386 5.0

Common Stock Repurchases

Common Stock Repurchases	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Common Stock Repurchases	NOTE 14 – COMMON STOCK REPURCHASES From time to time, our board of directors authorizes stock repurchase plans. In general, stock repurchase plans allow us to proactively manage our capital position and return excess capital to shareholders. Shares purchased under such plans also provide us with shares of common stock necessary to satisfy obligations related to stock compensation awards. On September 14, 2017, the board of directors of the Company authorized an increase in the number of shares that may be repurchased pursuant to the Company’s stock repurchase plan that was previously announced on November 12, 2015. Under the expanded repurchase plan, the Company is authorized to repurchase an additional 130,037 shares, representing approximately 5.0% of the Company’s issued and outstanding shares of common stock as of September 14, 2017. At that date, the Company had 11,200 shares remaining to be purchased under its previously announced share repurchase plan of 283,000. The actual amount and timing of future share repurchases, if any, will depend on market conditions, applicable SEC rules and various other factors. During the twelve months ended December 31, 2017, 1,336 shares of common stock were repurchased, as a result of the first annual installment of the stock awards vesting. This stock transaction was not part of the Company’s stock repurchase plan; the Company was required to purchase these shares for the payment of income taxes withheld on unvested restricted stock awards. In 2016, 229,800 shares of common stock were repurchased at an average cost of $15.32.

Significant Group Concentration

Significant Group Concentrations of Credit Risk	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Significant Group Concentrations of Credit Risk	NOTE 15 – SIGNIFICANT GROUP CONCENTRATIONS OF CREDIT RISK Most of the Bank’s business activity is with customers located within the Commonwealth of Massachusetts. There are no concentrations of credit to borrowers that have similar economic characteristics. The majority of the Bank’s loan portfolio is comprised of loans collateralized by real estate located in the Commonwealth of Massachusetts.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	NOTE 16 – SUBSEQUENT EVENTS On January 17, 2018, the Board of Directors of Melrose Bancorp, Inc. (the “Company”) declared a special cash dividend on the Company’s common stock of $0.34 per share. The dividend was paid on February 14, 2018 to stockholders of record as of January 29, 2018.

Condensed Parent Company Only F

Condensed Parent Company Only Financial Statements	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Parent Company Only Financial Statements	NOTE 17 – CONDENSED PARENT COMPANY ONLY FINANCIAL STATEMENTS MELROSE BANCORP, INC. PARENT COMPANY ONLY BALANCE SHEETS (In Thousands) December 31, 2017 2016 Assets Non-interest bearing deposit in the Bank $ 1,998 $ 1,881 Money market funds 1,363 1,558 Cash and cash equivalents 3,361 3,439 Investments in available-for-sale securities (at fair value) 3,233 2,980 Investment in subsidiary, Melrose Cooperative Bank 35,997 34,399 Loan receivable ESOP 2,019 2,070 Accrued interest receivable 11 5 Deferred tax assets 203 388 Other assets 286 147 Total assets $ 45,110 $ 43,428 Liabilities and Stockholders’ Equity Other liabilities $ 117 $ 124 Stockholders’ equity 44,993 43,304 Total liabilities and stockholders’ equity $ 45,110 $ 43,428 MELROSE BANCORP, INC. PARENT COMPANY ONLY STATEMENTS OF INCOME (In Thousands) For the year ended For the year ended Interest and dividend income: Interest on ESOP loan $ 67 $ 69 Interest and dividends on securities 49 71 Total interest and dividend income 116 140 Noninterest expense: Salaries and employee benefits 300 191 Other expenses — 1 Total noninterest expense 300 192 Loss before undistributed income of subsidiary and income tax expense (benefit) (184 ) (52 ) Undistributed income of subsidiary 2,004 1,472 Income before income taxes 1,820 1,420 Income tax expense (benefit) 16 (2 ) Net income $ 1,804 $ 1,422 MELROSE BANCORP, INC. PARENT COMPANY ONLY STATEMENTS OF CASH FLOWS (In Thousands) For the year ended For the year ended Cash flows from operating activities: Net income $ 1,804 $ 1,422 Adjustments to reconcile net income to net cash provided by operating activities: Amortization of securities, net of accretion 62 31 Increase in accrued interest receivable (6 ) (1 ) Deferred tax expense 175 29 Increase in other assets (139 ) (36 ) (Decrease) increase in other liabilities (7 ) 124 Stock based compensation expense 300 191 Equity in undistributed earnings of subsidiary (2,004 ) (1,472 ) Net cash provided by operating activities 185 288 Cash flows from investing activities: Purchases of available-for-sale securities (898 ) — Proceeds from maturities of available-for-sale securities 606 810 Repayment of principal on ESOP loan 51 46 Net cash (used in) provided by investing activities (241 ) 856 Cash flows from financing activities: Payment of income taxes for shares withheld in stock based award activity (22 ) — Cash paid for stock repurchases — (3,520 ) Net cash used in financing activities (22 ) (3,520 ) Net decrease in cash and cash equivalents (78 ) (2,376 ) Cash and cash equivalents at beginning of year 3,439 5,815 Cash and cash equivalents at end of year $ 3,361 $ 3,439

Quarterly Data (Unaudited)

Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Data (Unaudited)	NOTE 18 – QUARTERLY DATA (UNAUDITED) Year Ended December 31, 2017 First Second Third Fourth (Dollars in thousands, except share data) Interest and dividend income $ 2,044 $ 2,195 $ 2,348 $ 2,354 Interest expense 467 499 591 626 Net interest and dividend income 1,577 1,696 1,757 1,728 (Benefit)/provision for loan losses (20 ) 111 3 151 Net interest and dividend income, after (benefit)/provision for loan losses 1,596 1,585 1,754 1,578 Total noninterest income 507 393 494 249 Total noninterest expense 1,240 1,277 1,317 1,276 Income before income taxes 863 701 931 551 Provision for income taxes 337 280 300 325 Net income $ 526 $ 421 $ 631 $ 226 Earnings per share: Basic $ 0.22 $ 0.18 $ 0.27 $ 0.09 Diluted $ 0.22 $ 0.18 $ 0.27 $ 0.09 Year Ended December 31, 2016 First Second Third Fourth (Dollars in thousands, except share data) Interest and dividend income $ 1,695 $ 1,769 $ 1,911 $ 2,030 Interest expense 361 395 429 455 Net interest and dividend income 1,334 1,374 1,482 1,575 Provision for loan losses 60 103 117 30 Net interest and dividend income, after provision for loan losses 1,274 1,271 1,365 1,545 Total noninterest income 45 336 325 529 Total noninterest expense 1,039 1,194 1,082 1,157 Income before income taxes 280 413 608 917 Provision for income taxes 87 138 222 349 Net income $ 193 $ 275 $ 386 $ 568 Earnings per share: Basic $ 0.08 $ 0.11 $ 0.16 $ 0.24 Diluted $ 0.08 $ 0.11 $ 0.16 $ 0.24

Summary of Significant Accoun27

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION: The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary the Bank, and the Bank’s wholly-owned subsidiary, MCBSC, Inc., which is used to hold investment securities. All significant intercompany accounts and transactions have been eliminated in the consolidation.
USE OF ESTIMATES	USE OF ESTIMATES: In preparing consolidated financial statements in conformity with accounting principles generally accepted in the United States of America, 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. The material estimate that is particularly susceptible to significant change in the near-term relates to the determination of the allowance for loan losses.
RECLASSIFICATIONS	RECLASSIFICATIONS: Certain amounts in the prior year have been reclassified to be consistent with the current year’s presentation.
CASH AND CASH EQUIVALENTS	CASH AND CASH EQUIVALENTS: For purposes of reporting cash flows, cash and cash equivalents include cash, amounts due from banks, money market funds and federal funds sold.
SECURITIES	SECURITIES: Investments in debt securities are adjusted for amortization of premiums and accretion of discounts computed so as to approximate the interest method. Gains or losses on sales of investment securities are computed on a specific identification basis. The Company classifies all debt and equity securities as available-for-sale. Available-for-sale For any debt security with a fair value less than its amortized cost basis, the Company will determine whether it has the intent to sell the debt security or whether it is more likely than not it will be required to sell the debt security before the recovery of its amortized cost basis. If either condition is met, the Company will recognize a full impairment charge to earnings. For all other debt securities that are considered other-than-temporarily impaired and do not meet either condition, the credit loss portion of impairment will be recognized in earnings as realized losses. The other-than-temporary impairment related to all other factors will be recorded in other comprehensive loss. Declines in marketable equity securities below their cost that are deemed other-than-temporary are reflected in earnings as realized losses.
FEDERAL HOME LOAN BANK STOCK	FEDERAL HOME LOAN BANK STOCK: As a member of the Federal Home Loan Bank of Boston, the Company is required to invest in $100 par value stock of the FHLB. The FHLB capital structure mandates that members must own stock as determined by their Total Stock Investment Requirement which is the sum of a member’s Membership Stock Investment Requirement and Activity-Based Stock Investment Requirement. Management evaluates the Company’s investment in FHLB stock for other-than-temporary impairment at least on a quarterly basis and more frequently when economic or market conditions warrant such evaluation. Based on its most recent analysis of the FHLB as of December 31, 2017, management deems its investment in FHLB stock to be not other-than-temporarily impaired.
LOANS	LOANS: Loans receivable that management has the intent and ability to hold until maturity or payoff are reported at their outstanding principal balances adjusted for amounts due to borrowers on outstanding home equity lines of credit, commercial lines of credit and construction loans, any charge-offs, the allowance for loan losses and any deferred fees or costs on originated loans, or unamortized premiums or discounts on purchased loans. Loan origination and commitment fees and certain direct origination costs are deferred, and the net amount amortized as an adjustment of the related loan’s yield. The Company is amortizing these amounts over the expected lives of the related loans. Residential real estate loans are generally placed on nonaccrual when reaching 90 days past due or are in the process of foreclosure. All closed-end Cash receipts of interest income on impaired loans are credited to principal to the extent necessary to eliminate doubt as to the collectability of the net carrying amount of the loan. Some or all of the cash receipts of interest income on impaired loans are recognized as interest income if the remaining net carrying amount of the loan is deemed to be fully collectible. When recognition of interest income on an impaired loan on a cash basis is appropriate, the amount of income that is recognized is limited to that which would have been accrued on the net carrying amount of the loan at the contractual interest rate. Any cash interest payments received in excess of the limit and not applied to reduce the net carrying amount of the loan are recorded as recoveries of charge-offs until the charge-offs are fully recovered.
ALLOWANCE FOR LOAN LOSSES	ALLOWANCE FOR LOAN LOSSES: The allowance for loan losses is established as losses are estimated to have occurred through a provision for loan losses charged to earnings. Loan losses are charged against the allowance when management believes the uncollectability 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 by management and is based upon management’s periodic review of the collectability 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 more information becomes available. General Component: The general component of the allowance for loan losses is based on historical loss experience adjusted for qualitative factors stratified by the following loan segments: one- 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: One- loan-to-value loan-to-value Commercial real estate: Loans in this segment are primarily income-producing properties throughout Massachusetts. The underlying cash flows generated by the properties are adversely impacted by a downturn in the economy as evidenced by increased vacancy rates, which in turn, will have an effect on the credit quality in this segment. Loans in this segment also include loans secured by multifamily dwellings. Management periodically obtains rent rolls and continually monitors the cash flows of these loans. Construction: Loans in this segment primarily include speculative 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. Consumer: Loans in this segment are generally secured and repayment is dependent on the credit quality of the individual borrower. Loans in this segment include auto loans and other consumer loans. Allocated Component: The allocated component relates to loans that are classified as impaired. Impairment is measured on a loan by loan basis for commercial real estate and construction loans 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 is 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 separately identify individual consumer and one- 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 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. Unallocated Component: An unallocated component is maintained to cover uncertainties that could affect management’s estimate of probable losses. The unallocated component of the allowance reflects the margin of imprecision inherent in the underlying assumptions used in the methodologies for estimating allocated and general reserves in the portfolio.
PREMISES AND EQUIPMENT	PREMISES AND EQUIPMENT: Land is carried at cost. Buildings and equipment are stated at cost, less accumulated depreciation and amortization. Cost and related allowances for depreciation and amortization of premises and equipment retired or otherwise disposed of are removed from the respective accounts with any gain or loss included in income or expense. Depreciation and amortization are calculated principally on the straight-line method over the estimated useful lives of the assets. Estimated lives are 15 to 30 years for buildings and 3 to 10 years for furniture and equipment. Premises and equipment are periodically evaluated for impairment when events or changes in circumstances indicate the carrying amount may not be recoverable. Impairment exists when the expected undiscounted future cash flows of premises and equipment are less than its carrying amount. In that event, the Company records a loss for the difference between the carrying amount and the fair value of the asset based on quoted market prices, if applicable, or a discounted cash flow analysis.
BANK-OWNED LIFE INSURANCE	BANK-OWNED LIFE INSURANCE: The Company has purchased insurance policies on the lives of certain directors, executive officers and employees. Bank-owned life insurance policies are reflected on the consolidated balance sheets at cash surrender value. Changes in net cash surrender value of the policies, as well as insurance proceeds received, are reflected in non-interest
ADVERTISING	ADVERTISING: The Company directly expenses costs associated with advertising as they are incurred.
INCOME TAXES	INCOME TAXES: The Company recognizes income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are established for the temporary differences between the accounting basis and the tax basis of the Company’s assets and liabilities at enacted tax rates expected to be in effect when the amounts related to such temporary differences are realized or settled.
EMPLOYEE STOCK OWNERSHIP PLAN	EMPLOYEE STOCK OWNERSHIP PLAN: Compensation expense for the Employee Stock Ownership Plan (“ESOP”) is recorded at an amount equal to the shares allocated by the ESOP multiplied by the average fair value of the shares during the period. Unearned compensation applicable to the ESOP is reflected as a reduction of stockholders’ equity in the consolidated balance sheets. The difference between the average fair value and the cost of shares allocated by the ESOP is recorded as an adjustment to additional paid-in
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION: The Company recognizes stock-based compensation based on the grant-date fair value of the award. Forfeitures will be recognized when they occur. The Company values share-based stock option awards granted using the Black-Scholes option-pricing model. The Company recognizes compensation expense for its awards on a straight-line basis over the requisite service period for the entire award (straight-line attribution method), ensuring that the amount of compensation cost recognized at any date at least equals the portion of the grant-date fair value of the award that is vested at that time.
EARNINGS PER SHARE (EPS)	EARNINGS PER SHARE (EPS): When presented, basic EPS is computed by dividing income available to common stockholders by the weighted-average number of common shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in the earnings of the entity. For the purposes of computing diluted EPS, the treasury stock method is used. Unallocated ESOP shares and unearned shares of restricted stock are not deemed outstanding for earnings per share calculations. The calculation of basic and diluted EPS is presented below. Year Ended Year Ended (Dollars in thousands, except earnings per share) Net income $ 1,804 $ 1,422 Basic Common Shares: Weighted average common shares outstanding 2,601,223 2,660,521 Weighted average shares – unearned restricted stock (33,843 ) (26,333 ) Weighted average unallocated ESOP shares (199,956 ) (207,501 ) Basic weighted average shares outstanding 2,367,424 2,426,687 Diluted effect of unvested stock options — — Dilutive effect of unvested restricted stock awards 4,873 811 Diluted weighted average shares outstanding 2,372,297 2,427,498 Basic earnings per share $ 0.76 $ 0.59 Diluted earnings per share (1) $ 0.76 $ 0.59 (1) Options to purchase 224,200 shares, representing all outstanding options, were not included in the computation of diluted earnings per share for the years ended December 31, 2017 and 2016 because the effect is anti-dilutive.
FAIR VALUES OF FINANCIAL INSTRUMENTS	FAIR VALUES OF FINANCIAL INSTRUMENTS: Accounting Standards Codification (ASC) 825, “Financial Instruments,” requires that the Company disclose the estimated fair value for its financial instruments. Fair value methods and assumptions used by the Company in estimating its fair value disclosures are as follows: Cash and cash equivalents: The carrying amounts reported in the consolidated balance sheets for cash and cash equivalents approximate those assets’ fair values. Securities: Fair values for securities are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments. Loans receivable: For variable-rate loans that reprice frequently and with no significant change in credit risk, fair values are based on carrying values. The fair values for other loans are estimated using discounted cash flow analyses, using interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. Accrued interest receivable: The carrying amount of accrued interest receivable approximates its fair value. Deposit liabilities: The fair values disclosed for demand deposits (e.g., interest and non-interest Federal Home Loan Bank advances: The fair values of FHLB advances are estimated using discounted cash flow analyses based on the current incremental borrowing rates for similar types of borrowing arrangements.
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS: As an “emerging growth company,” as defined in Title 1 of Jumpstart Our Business Startups (JOBS) Act, the Company has elected to use the extended transition period to delay adoption of new or reissued accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. Accordingly, the consolidated financial statements may not be comparable to the financial statements of public companies that comply with such new or revised accounting standards. As of December 31, 2017, there is no significant difference in the comparability of the financial statements as a result of this extended transition period. The extended transition period for an emerging growth company is five years, and the Company’s emerging growth status will end on December 31, 2019. In May 2014 and August 2015, respectively, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update ASU 2014-09 2015-14, 2014-09 2015-14 2014-09 2014-09, non-interest Form 10-Q. In January 2016, the FASB issued ASU 2016-01, 825-10): 1. Require equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of the investee) to be measured at fair value with changes in fair value recognized in net income. However, the entity may choose to measure equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same manner. 2. Simplify the impairment assessment of equity investments without determinable fair values by requiring a qualitative assessment to identify impairment. When a qualitative assessment indicates that impairment exists, an entity is required to measure the investment at fair value. 3. Eliminate the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet. 4. Require public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes. 5. Require an entity to present separately in other comprehensive income the portion of the total change in fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments. 6. Require separate presentation of financial assets and financial liabilities by measurement category and form of financial assets (that is, securities or loans and receivables) on the balance sheet or the accompanying notes to the financial statements. 7. Clarify that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale Under the extended transition period for an emerging growth company, the amendments in this Update are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption of item 5 above is permitted as of the beginning of fiscal years or interim periods for which financial statements have not been issued. Early adoption of all other amendments in this ASU is not permitted. The Company is currently evaluating the amendments of ASU No. 2016-01 In February 2016, the FASB issued ASU 2016-02, In March 2016, the FASB issued ASU No. 2016-09, paid-in-capital No. 2016-09 In June 2016, the FASB issued ASU No. 2016-13, available-for-sale No. 2016-13 In March 2017, the FASB issued ASU 2017-08, No. 2017-08 No. 2017-08 In February 2018, the FASB issued ASU 2018-02, 2018-02 2018-02

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Calculation of Basic and Diluted EPS	The calculation of basic and diluted EPS is presented below. Year Ended Year Ended (Dollars in thousands, except earnings per share) Net income $ 1,804 $ 1,422 Basic Common Shares: Weighted average common shares outstanding 2,601,223 2,660,521 Weighted average shares – unearned restricted stock (33,843 ) (26,333 ) Weighted average unallocated ESOP shares (199,956 ) (207,501 ) Basic weighted average shares outstanding 2,367,424 2,426,687 Diluted effect of unvested stock options — — Dilutive effect of unvested restricted stock awards 4,873 811 Diluted weighted average shares outstanding 2,372,297 2,427,498 Basic earnings per share $ 0.76 $ 0.59 Diluted earnings per share (1) $ 0.76 $ 0.59 (1) Options to purchase 224,200 shares, representing all outstanding options, were not included in the computation of diluted earnings per share for the years ended December 31, 2017 and 2016 because the effect is anti-dilutive.

Investments in Available-For-29

Investments in Available-For-Sale Securities (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investments in Available-For-Sale Securities	The amortized cost basis of securities and their approximate fair values are as follows as of December 31: Amortized Gross Gross Fair (In Thousands) December 31, 2017: U.S. Government and federal agency obligations $ 5,390 $ — $ 65 $ 5,325 Debt securities issued by states of the United States and political subdivisions of the states 2,898 12 29 2,881 Corporate bonds and notes 11,364 7 77 11,294 Preferred stock 3,000 13 — 3,013 Mortgage-backed securities 1,495 — 47 1,448 Marketable equity securities 2,046 490 1 2,535 $ 26,193 $ 522 $ 219 $ 26,496 December 31, 2016: U.S. Government and federal agency obligations $ 5,819 $ — $ 131 $ 5,688 Debt securities issued by states of the United States and political subdivisions of the states 2,695 2 41 2,656 Corporate bonds and notes 12,537 17 61 12,493 Preferred stock 3,000 20 82 2,938 Mortgage-backed securities 1,498 — 66 1,432 Marketable equity securities 5,072 1,557 5 6,624 $ 30,621 $ 1,596 $ 386 $ 31,831
Scheduled Maturities of Debt Securities	The scheduled maturities of debt securities as of December 31, 2017 are as follows: Fair (In Thousands) Due within one year $ 3,496 Due after one year through five years 12,038 Due after five years through ten years 2,390 Due after ten years 2,077 Mortgage-backed securities 1,448 Asset-backed securities 1,509 $ 22,958
Aggregate Fair Value and Unrealized Losses of Securities in Continuous Unrealized Loss Position	The aggregate fair value and unrealized losses of securities that have been in a continuous unrealized loss position for less than twelve months and for twelve months or more, and are not other-than-temporarily impaired, are as follows as of December 31: Less than 12 months 12 months or longer Total Fair Unrealized Fair Unrealized Fair Unrealized (In Thousands) December 31, 2017 U.S. Government and federal agency obligations $ 2,855 $ 20 $ 2,470 $ 45 $ 5,325 $ 65 Debt securities issued by states of the United States and political subdivisions of the states 991 6 535 23 1,526 29 Corporate bonds and notes 4,467 24 3,946 53 8,413 77 Mortgage-backed securities 453 6 995 41 1,448 47 Marketable equity securities 485 1 — — 485 1 Total temporarily impaired securities $ 9,251 $ 57 $ 7,946 $ 162 $ 17,197 $ 219 December 31, 2016 U.S. Government and federal agency obligations $ 4,359 $ 59 $ 1,328 $ 72 $ 5,687 $ 131 Debt securities issued by states of the United States and political subdivisions of the states 1,760 28 245 13 2,005 41 Corporate bonds and notes 5,784 61 — — 5,784 61 Preferred stock 1,918 82 — — 1,918 82 Mortgage-backed securities 370 8 1,062 58 1,432 66 Marketable equity securities 2,235 5 — — 2,235 5 Total temporarily impaired securities $ 16,426 $ 243 $ 2,635 $ 143 $ 19,061 $ 386

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Summary of Loans	Loans consisted of the following: December 31, December 31, (In Thousands) Real estate loans: One-to four-family residential $ 189,763 $ 168,111 Home equity loans and lines of credit 11,585 10,720 Commercial 34,686 23,011 Construction 15,853 11,738 Consumer loans 44 71 Total loans 251,931 213,651 Allowance for loan losses (1,134 ) (890 ) Deferred loan costs, net 35 32 Unamortized premiums 485 372 Net loans $ 251,317 $ 213,165
Information Regarding Nonaccrual Loans and Past-due Loans	The following tables set forth information on the allowance for loan losses at and for the years ended December 31, 2017 and 2016: Real Estate: One- to four-family Home Equity Loans Commercial Construction Consumer Unallocated Total (In Thousands) Year ended December 31, 2017 Allowance for loan losses: Beginning balance $ 418 $ 49 $ 276 $ 117 $ 1 $ 29 $ 890 Charge offs — — — — (1 ) — (1 ) Recoveries — — — — — — — Provision (benefit) 63 3 196 (10 ) 1 (8 ) 245 Ending balance $ 481 $ 52 $ 472 $ 107 $ 1 $ 21 $ 1,134 At December 31, 2017 Allowance for loan losses: Ending Balance: Individually evaluated for impairment $ 8 $ — $ — $ — $ — $ — $ 8 Ending balance: Collectively evaluated for impairment 473 52 472 107 1 21 1,126 Total allowance for loan losses ending balance $ 481 $ 52 $ 472 $ 107 $ 1 $ 21 $ 1,134 Loans: Ending balance: Individually evaluated for impairment $ 100 $ — $ — $ — $ — $ — $ 100 Ending balance: Collectively evaluated for impairment 189,663 11,585 34,686 15,853 44 — 251,831 Total loans ending balance $ 189,763 $ 11,585 $ 34,686 $ 15,853 $ 44 $ — $ 251,931 Real Estate: One- to four-family Home Equity Loans Commercial Construction Consumer Unallocated Total (In Thousands) Year ended December 31, 2016 Allowance for loan losses: Beginning balance $ 331 $ 49 $ 150 $ 40 $ 1 $ 9 $ 580 Charge offs — — — — — — — Recoveries — — — — — — — Provision 87 — 126 77 — 20 310 Ending balance $ 418 $ 49 $ 276 $ 117 $ 1 $ 29 $ 890 At December 31, 2016 Ending Balance: Individually evaluated for impairment $ — $ — $ — $ — $ — $ — $ — Ending balance: Collectively evaluated for impairment 418 49 276 117 1 29 890 Total allowance for loan losses ending balance $ 418 $ 49 $ 276 $ 117 $ 1 $ 29 $ 890 Loans: Ending balance: Individually evaluated for impairment $ — $ — $ — $ — $ — $ — $ — Ending balance: Collectively evaluated for impairment 168,111 10,720 23,011 11,738 71 — 213,651 Total loans ending balance $ 168,111 $ 10,720 $ 23,011 $ 11,738 $ 71 $ — $ 213,651
Summary of Changes in Allowance for Loan Losses	The following tables set forth information regarding nonaccrual loans and past-due 30 – 59 60 – 89 90 Days or Total Past Total Total 90 Days or More Non- (In Thousands) At December 31, 2107 Real estate loans: One-to four-family residential $ 295 $ 177 $ — $ 472 $ 189,291 $ 189,763 $ — $ 189 Home equity loans and lines of credit 189 — — 189 11,396 11,585 — — Commercial — — — — 34,686 34,686 — — Construction — — — — 15,853 15,853 — — Consumer loans — — — — 44 44 — — Total $ 484 $ 177 $ — $ 661 $ 251,270 $ 251,931 $ — $ 189 At December 31, 2016 Real estate loans: One-to four-family residential $ 518 $ 9 $ — $ 527 $ 167,584 $ 168,111 $ — $ 9 Home equity loans and lines of credit — — — — 10,720 10,720 — — Commercial — — — — 23,011 23,011 — — Construction — — — — 11,738 11,738 — — Consumer loans — — — — 71 71 — — Total $ 518 $ 9 $ — $ 527 $ 213,124 $ 213,651 $ — $ 9

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Summary of Premises and Equipment	The following is a summary of premises and equipment as of December 31: December 31, December 31, 2017 2016 (In Thousands) Land $ 393 $ 393 Building 2,070 1,840 Construction in process 641 — Furniture and equipment 553 549 Data processing equipment 360 303 4,017 3,085 Accumulated depreciation (2,024 ) (1,837 ) $ 1,993 $ 1,248

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Scheduled Maturities of Time Deposits	For time deposits as of December 31, 2017 the scheduled maturities for each of the following years ended December 31 are as follows: (In Thousands) 2018 $ 102,073 2019 12,664 2020 1,638 2021 8,208 2022 1,537 $ 126,120

Federal Home Loan Bank Advanc33

Federal Home Loan Bank Advances (Tables)	12 Months Ended
	Dec. 31, 2017
Federal Home Loan Banks [Abstract]
Maturities of advances from the FHLB	Maturities of advances from the FHLB for the years ending after December 31, 2017 are summarized as follows (in thousands): 2018 $ 10,000 2019 19,000 $ 29,000

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Components of Income Tax Expense	The components of income tax expense are as follows for the years ended December 31: Years Ended 2017 2016 (In Thousands) Current: Federal $ 857 $ 543 State 251 182 1,108 725 Deferred: Federal (12 ) 80 Change in federal tax rate 181 — State (11 ) (9 ) Change in valuation allowance (24 ) — 134 71 Total income tax expense $ 1,242 $ 796
Summary of Differences Between the Statutory Federal Income Tax Rate and the Effective Tax Rates	The reasons for the differences between the statutory federal income tax rate and the effective tax rates are summarized as follows for the years ended December 31: Years Ended December 31, 2017 2016 % of Income % of Income Federal income tax at statutory rate 34.0 % 34.0 % State tax, net of federal tax benefit 5.2 5.2 Change in valuation allowance (0.8 ) 0.0 Change in tax rate 5.9 0.0 Dividends received deduction (0.5 ) (1.3 ) Bank-owned life insurance (1.8 ) (2.2 ) Solar credits (2.3 ) (0.0 ) Stock compensation 1.1 1.1 Tax exempt income (1.0 ) (1.3 ) ESOP 0.7 0.6 Other 0.3 (0.3 ) Effective tax rates 40.8 % 35.9 %
Deferred Tax Assets and Liabilities	The Company had gross deferred tax assets and gross deferred tax liabilities as follows as of December 31: December 31, 2017 2016 (In Thousands) Deferred tax assets: Allowance for loan losses $ 319 $ 356 Deferred compensation 83 83 Security writedowns 5 27 ESOP 16 12 Stock based compensation 47 47 Accrued expenses 31 13 Contribution to Melrose Cooperative Bank Foundation 204 406 Gross deferred tax assets 705 944 Valuation allowance (66 ) (90 ) Gross deferred tax assets, net of valuation allowance 639 854 Deferred tax liabilities: Accelerated depreciation (181 ) (220 ) Net unrealized holding gain on available-for-sale securities (94 ) (514 ) Gross deferred tax liabilities (275 ) (734 ) Net deferred tax asset $ 364 $ 120

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Schedule of Principal Balance on ESOP Debt	The remaining principal balance on the ESOP debt as of December 31, 2017 is payable as follows: Years Ending December 31, Amount (In Thousands) 2018 $ 51 2019 52 2020 54 2021 56 2022 58 Thereafter 1,748 $ 2,019
Schedule of Shares Held by ESOP	Shares held by the ESOP are as follows as of December 31: 2017 2016 Allocated 30,182 22,638 Unallocated 196,184 203,728 Shares held by ESOP 226,366 226,366

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, All Other Investments [Abstract]
Summary of Financial Instrument Liabilities with off-Balance Sheet Credit Risk	Financial instrument liabilities with off-balance December 31, December 31, 2017 2016 (In Thousands) Commitments to originate loans $ 2,401 $ 7,864 Unused lines of credit 17,611 13,742 Due to borrowers on unadvanced construction loans 2,320 3,852 $ 22,332 $ 25,458

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Summary of Assets Measured at Fair Value on Recurring Basis	The following summarizes assets measured at fair value on a recurring basis as of December 31: Fair Value Measurements at Reporting Date Using: Total Quoted Prices in Significant Significant (In Thousands) December 31, 2017: U.S. Government and federal agency obligations $ 5,325 $ — $ 5,325 $ — Debt securities issued by states of the United States and political subdivisions of the states 2,881 — 2,881 — Corporate bonds and notes 11,294 — 11,294 — Preferred stock 3,013 3,013 — — Mortgage-backed securities 1,448 — 1,448 — Marketable equity securities 2,535 2,535 — — Totals $ 26,496 $ 5,548 $ 20,948 $ — December 31, 2016: U.S. Government and federal agency obligations $ 5,688 $ — $ 5,688 $ — Debt securities issued by states of the United States and political subdivisions of the states 2,656 — 2,656 — Corporate bonds and notes 12,493 — 12,493 — Preferred stock 2,938 2,938 — — Mortgage-backed securities 1,432 — 1,432 — Marketable equity securities 6,624 6,624 — — Totals $ 31,831 $ 9,562 $ 22,269 $ —
Summary of Estimated Fair Values of Bank's Financial Instruments	The estimated fair values of the Company’s financial instruments, all of which are held or issued for purposes other than trading, are as follows: December 31, 2017 Carrying Fair Value Level 1 Level 2 Level 3 Total (In Thousands) Financial assets: Cash and cash equivalents $ 17,603 $ 17,603 $ — $ — $ 17,603 Available-for-sale securities 26,496 5,548 20,948 — 26,496 Federal Home Loan Bank stock 1,800 1,800 — — 1,800 Loans, net 251,317 — — 252,792 252,792 Co-operative Central Bank deposit 886 886 — — 886 Accrued interest receivable 702 702 — — 702 Financial liabilities: Deposits 232,921 — 232,899 — 232,899 FHLB advances 29,000 — 28,660 — 28,660 December 31, 2016 Carrying Fair Value Level 1 Level 2 Level 3 Total (In Thousands) Financial assets: Cash and cash equivalents $ 13,792 $ 13,792 $ — $ — $ 13,792 Available-for-sale securities 31,831 9,562 22,269 — 31,831 Federal Home Loan Bank stock 964 964 — — 964 Loans, net 213,165 — — 213,582 213,582 Co-operative Central Bank deposit 881 881 — — 881 Accrued interest receivable 572 572 — — 572 Financial liabilities: Deposits 214,766 — 215,443 — 215,443 FHLB advances 10,000 — 9,930 — 9,930

Other Comprehensive Loss (Table

Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Components of Other Comprehensive Loss Included in Stockholders' Equity	The components of other comprehensive loss included in stockholders’ equity are as follows: Years Ended 2017 2016 (In thousands) Net unrealized holding gain on available-for-sale securities $ 478 $ 285 Reclassification adjustment for net realized gains included in net income (1) (1,385 ) (1,004 ) Other comprehensive loss before income tax effect (907 ) (719 ) Income tax benefit 378 269 Other comprehensive loss, net of tax $ (529 ) $ (450 ) (1) Reclassification adjustments include net realized securities gains and losses. Realized gains and losses have been reclassified out of accumulated other comprehensive income and affect certain captions in the consolidated statements of income as follows: pre-tax available-for-sale available-for-sale

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2017
Banking and Thrift [Abstract]
Summary of Actual Capital Amounts and Ratios	The Bank’s actual capital amounts and ratios are also presented in the table. Actual For Capital To Be Well Amount Ratio Amount Ratio Amount Ratio (Dollars In Thousands) As of December 31, 2017: Total Capital (to Risk Weighted Assets) $ 37,141 19.80 % $ 15,007 8.0 % $ 18,759 10.0 % Tier 1 Capital (to Risk Weighted Assets) 35,786 19.08 11,255 6.0 15,007 8.0 Common Equity Tier 1 Capital (to Risk Weighted Assets) 35,786 19.08 8,441 4.5 12,193 6.5 Tier 1 Capital (to Average Assets) 35,786 12.59 11,373 4.0 14,216 5.0 As of December 31, 2016: Total Capital (to Risk Weighted Assets) $ 35,236 21.09 % $ 13,368 8.0 % $ 16,710 10.0 % Tier 1 Capital (to Risk Weighted Assets) 33,648 20.14 10,026 6.0 13,368 8.0 Common Equity Tier 1 Capital (to Risk Weighted Assets) 33,648 20.14 7,519 4.5 10,861 6.5 Tier 1 Capital (to Average Assets) 33,648 13.58 9,909 4.0 12,386 5.0

Condensed Parent Company Only40

Condensed Parent Company Only Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Summary of Balance Sheets	BALANCE SHEETS (In Thousands) December 31, 2017 2016 Assets Non-interest bearing deposit in the Bank $ 1,998 $ 1,881 Money market funds 1,363 1,558 Cash and cash equivalents 3,361 3,439 Investments in available-for-sale securities (at fair value) 3,233 2,980 Investment in subsidiary, Melrose Cooperative Bank 35,997 34,399 Loan receivable ESOP 2,019 2,070 Accrued interest receivable 11 5 Deferred tax assets 203 388 Other assets 286 147 Total assets $ 45,110 $ 43,428 Liabilities and Stockholders’ Equity Other liabilities $ 117 $ 124 Stockholders’ equity 44,993 43,304 Total liabilities and stockholders’ equity $ 45,110 $ 43,428
Summary of Statements of Income	STATEMENTS OF INCOME (In Thousands) For the year ended For the year ended Interest and dividend income: Interest on ESOP loan $ 67 $ 69 Interest and dividends on securities 49 71 Total interest and dividend income 116 140 Noninterest expense: Salaries and employee benefits 300 191 Other expenses — 1 Total noninterest expense 300 192 Loss before undistributed income of subsidiary and income tax expense (benefit) (184 ) (52 ) Undistributed income of subsidiary 2,004 1,472 Income before income taxes 1,820 1,420 Income tax expense (benefit) 16 (2 ) Net income $ 1,804 $ 1,422
Summary of Statements of Cash Flows	STATEMENTS OF CASH FLOWS (In Thousands) For the year ended For the year ended Cash flows from operating activities: Net income $ 1,804 $ 1,422 Adjustments to reconcile net income to net cash provided by operating activities: Amortization of securities, net of accretion 62 31 Increase in accrued interest receivable (6 ) (1 ) Deferred tax expense 175 29 Increase in other assets (139 ) (36 ) (Decrease) increase in other liabilities (7 ) 124 Stock based compensation expense 300 191 Equity in undistributed earnings of subsidiary (2,004 ) (1,472 ) Net cash provided by operating activities 185 288 Cash flows from investing activities: Purchases of available-for-sale securities (898 ) — Proceeds from maturities of available-for-sale securities 606 810 Repayment of principal on ESOP loan 51 46 Net cash (used in) provided by investing activities (241 ) 856 Cash flows from financing activities: Payment of income taxes for shares withheld in stock based award activity (22 ) — Cash paid for stock repurchases — (3,520 ) Net cash used in financing activities (22 ) (3,520 ) Net decrease in cash and cash equivalents (78 ) (2,376 ) Cash and cash equivalents at beginning of year 3,439 5,815 Cash and cash equivalents at end of year $ 3,361 $ 3,439

Quarterly Data (Unaudited) (Tab

Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Year Ended December 31, 2017 First Second Third Fourth (Dollars in thousands, except share data) Interest and dividend income $ 2,044 $ 2,195 $ 2,348 $ 2,354 Interest expense 467 499 591 626 Net interest and dividend income 1,577 1,696 1,757 1,728 (Benefit)/provision for loan losses (20 ) 111 3 151 Net interest and dividend income, after (benefit)/provision for loan losses 1,596 1,585 1,754 1,578 Total noninterest income 507 393 494 249 Total noninterest expense 1,240 1,277 1,317 1,276 Income before income taxes 863 701 931 551 Provision for income taxes 337 280 300 325 Net income $ 526 $ 421 $ 631 $ 226 Earnings per share: Basic $ 0.22 $ 0.18 $ 0.27 $ 0.09 Diluted $ 0.22 $ 0.18 $ 0.27 $ 0.09 Year Ended December 31, 2016 First Second Third Fourth (Dollars in thousands, except share data) Interest and dividend income $ 1,695 $ 1,769 $ 1,911 $ 2,030 Interest expense 361 395 429 455 Net interest and dividend income 1,334 1,374 1,482 1,575 Provision for loan losses 60 103 117 30 Net interest and dividend income, after provision for loan losses 1,274 1,271 1,365 1,545 Total noninterest income 45 336 325 529 Total noninterest expense 1,039 1,194 1,082 1,157 Income before income taxes 280 413 608 917 Provision for income taxes 87 138 222 349 Net income $ 193 $ 275 $ 386 $ 568 Earnings per share: Basic $ 0.08 $ 0.11 $ 0.16 $ 0.24 Diluted $ 0.08 $ 0.11 $ 0.16 $ 0.24

Nature of Operations - Addition

Nature of Operations - Additional Information (Detail)	Oct. 21, 2014USD ($)$ / sharesshares	Dec. 31, 2017USD ($)Officeshares	Dec. 31, 2014USD ($)
Nature Of Operations [Line Items]
Entity incorporation date		Feb. 1, 2014
Aggregate issuance of common stock | shares	2,829,579
Common stock , price per share | $ / shares	$ 10
Net proceeds from the stock offering	$ 25,518,000
Stock offering costs	$ 1,716,000
Cash funded to charitable foundation			$ 300,000
Expenses recognized			$ 1,362,000
Shares purchased under employee stock ownership plan | shares		226,366
Melrose Cooperative Bank Foundation [Member]
Nature Of Operations [Line Items]
Common stock, shares sold | shares	106,170
Expenses recognized		$ 1,362,000
Melrose Cooperative Bank [Member]
Nature Of Operations [Line Items]
Aggregate issuance of common stock | shares	2,723,409
Massachusetts [Member]
Nature Of Operations [Line Items]
Melrose Cooperative Bank (Number of banking office) | Office		1

Summary of Significant Accoun43

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Significant Accounting Policies [Line Items]
Par value stock		$ 0.01	$ 0.01
Allowance for loan losses adjustments		$ 0	$ 0
Company tax rate		34.00%	34.00%
Reclassified from accumulated other comprehensive income to retained earnings		$ 42,000
Scenario, Plan [Member]
Significant Accounting Policies [Line Items]
Company tax rate	21.00%
Retained Earnings [Member]
Significant Accounting Policies [Line Items]
Reclassified from accumulated other comprehensive income to retained earnings		(42,000)
Accumulated Other Comprehensive Income [Member]
Significant Accounting Policies [Line Items]
Reclassified from accumulated other comprehensive income to retained earnings		$ 42,000
Building [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives		15 years
Building [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives		30 years
Furniture and Equipment [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives		3 years
Furniture and Equipment [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful lives		10 years
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Percentage of loan-to-value ratio		80.00%
Federal Home Loan Bank of Boston [Member]
Significant Accounting Policies [Line Items]
Par value stock		$ 100

Summary of Significant Accoun44

Summary of Significant Accounting Policies - Summary of Calculation of Basic and Diluted EPS (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 226	$ 631	$ 421	$ 526	$ 568	$ 386	$ 275	$ 193	$ 1,804	$ 1,422
Basic Common Shares:
Weighted average common shares outstanding									2,601,223	2,660,521
Weighted average shares - unearned restricted stock									(33,843)	(26,333)
Weighted average unallocated ESOP shares									(199,956)	(207,501)
Basic weighted average shares outstanding									2,367,424	2,426,687
Diluted weighted average shares outstanding									2,372,297	2,427,498
Basic earnings per share	$ 0.09	$ 0.27	$ 0.18	$ 0.22	$ 0.24	$ 0.16	$ 0.11	$ 0.08	$ 0.76	$ 0.59
Diluted earnings per share	$ 0.09	$ 0.27	$ 0.18	$ 0.22	$ 0.24	$ 0.16	$ 0.11	$ 0.08	$ 0.76	$ 0.59
Unvested Stock Options [Member]
Basic Common Shares:
Diluted effect of unvested stock									0
Unvested Restricted Stock Awards [Member]
Basic Common Shares:
Diluted effect of unvested stock									4,873	811

Summary of Significant Accoun45

Summary of Significant Accounting Policies - Summary of Calculation of Basic and Diluted EPS (Parenthetical) (Detail) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Anti-dilutive securities excluded from computation of diluted earnings	224,200	224,200

Investments in Available-For-46

Investments in Available-For-Sale Securities - Amortized Cost Basis of Securities and Their Approximate Fair Values (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	$ 26,193	$ 30,621
Gross Unrealized Gains	522	1,596
Gross Unrealized Losses	219	386
Fair Value	26,496	31,831
U.S. Government and Federal Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	5,390	5,819
Gross Unrealized Losses	65	131
Fair Value	5,325	5,688
Debt Securities Issued by States of the United States and Political Subdivisions of the States [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	2,898	2,695
Gross Unrealized Gains	12	2
Gross Unrealized Losses	29	41
Fair Value	2,881	2,656
Corporate Bonds and Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	11,364	12,537
Gross Unrealized Gains	7	17
Gross Unrealized Losses	77	61
Fair Value	11,294	12,493
Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	3,000	3,000
Gross Unrealized Gains	13	20
Gross Unrealized Losses		82
Fair Value	3,013	2,938
Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	1,495	1,498
Gross Unrealized Losses	47	66
Fair Value	1,448	1,432
Marketable Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	2,046	5,072
Gross Unrealized Gains	490	1,557
Gross Unrealized Losses	1	5
Fair Value	$ 2,535	$ 6,624

Investments in Available-For-47

Investments in Available-For-Sale Securities - Scheduled Maturities of Debt Securities (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Schedule of Available-for-sale Securities [Line Items]
Due within one year	$ 3,496
Due after one year through five years	12,038
Due after five years through ten years	2,390
Due after ten years	2,077
Debt security, fair value	22,958
Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt securities	1,448
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt securities	$ 1,509

Investments in Available-For-48

Investments in Available-For-Sale Securities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)Securitiesshares	Dec. 31, 2016USD ($)Securities
Schedule of Available-for-sale Securities [Line Items]
Number of securities with aggregate carrying value exceeding 10% of stockholders' equity | shares	0
Proceeds from sales of available-for-sale securities | $	$ 4,498,000	$ 9,321,000
Gain on sales of available-for-sale securities, net | $	1,385,000	1,004,000
Tax expense applicable to net realized gain | $	490,000	359,000
Pledged securities | $	$ 0	$ 0
Number of marketable securities that were declared other than temporarily impaired	0	0
Corporate Bonds And Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses | $	$ 77,000
Unrealized losses, securities	16
Corporate Bonds And Notes [Member] | Debt Security Four [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, securities	5
Corporate Bonds And Notes [Member] | Debt Security Four [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of unrealized losses of debt securities with amortized cost	1.00%
Corporate Bonds And Notes [Member] | Debt Security Four [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of unrealized losses of debt securities with amortized cost	4.00%
Corporate Bonds And Notes [Member] | Debt Security Seven [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, securities	11
Corporate Bonds And Notes [Member] | Debt Security Seven [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of unrealized losses of debt securities with amortized cost	1.00%
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses | $	$ 29,000
Unrealized losses, securities	4
Municipal Bonds [Member] | Debt Security One [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, securities	1
Percentage of unrealized losses of debt securities with amortized cost	6.00%
Municipal Bonds [Member] | Debt Security Three [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, securities	3
Municipal Bonds [Member] | Debt Security Three [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of unrealized losses of debt securities with amortized cost	3.00%
Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Preferred stock, no stated maturity | $	$ 1,000,000
U.S. Government and Federal Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses | $	$ 65,000
Unrealized losses, securities	11
U.S. Government and Federal Agency Obligations [Member] | Debt Security Four [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, securities	4
U.S. Government and Federal Agency Obligations [Member] | Debt Security Four [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of unrealized losses of debt securities with amortized cost	2.00%
U.S. Government and Federal Agency Obligations [Member] | Debt Security Four [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of unrealized losses of debt securities with amortized cost	5.00%
U.S. Government and Federal Agency Obligations [Member] | Debt Security Seven [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, securities	7
U.S. Government and Federal Agency Obligations [Member] | Debt Security Seven [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of unrealized losses of debt securities with amortized cost	2.00%
Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses | $	$ 47,000
Unrealized losses, securities	5
Mortgage-backed Securities [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of unrealized losses of debt securities with amortized cost	2.00%
Mortgage-backed Securities [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage of unrealized losses of debt securities with amortized cost	7.00%
Marketable Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses, securities	1
Percentage of unrealized losses of debt securities with amortized cost	0.20%
Unrealized losses | $	$ 1,000

Investments in Available-For-49

Investments in Available-For-Sale Securities - Aggregate Fair Value and Unrealized Losses of Securities in Continuous Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	$ 9,251	$ 16,426
Less than 12 Months Unrealized Losses	57	243
12 Months or Longer Fair Value	7,946	2,635
12 Months or Longer Unrealized Losses	162	143
Total Fair Value	17,197	19,061
Total Unrealized Losses	219	386
U.S. Government and Federal Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	2,855	4,359
Less than 12 Months Unrealized Losses	20	59
12 Months or Longer Fair Value	2,470	1,328
12 Months or Longer Unrealized Losses	45	72
Total Fair Value	5,325	5,687
Total Unrealized Losses	65	131
Debt Securities Issued by States of the United States and Political Subdivisions of the States [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	991	1,760
Less than 12 Months Unrealized Losses	6	28
12 Months or Longer Fair Value	535	245
12 Months or Longer Unrealized Losses	23	13
Total Fair Value	1,526	2,005
Total Unrealized Losses	29	41
Corporate Bonds and Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	4,467	5,784
Less than 12 Months Unrealized Losses	24	61
12 Months or Longer Fair Value	3,946
12 Months or Longer Unrealized Losses	53
Total Fair Value	8,413	5,784
Total Unrealized Losses	77	61
Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value		1,918
Less than 12 Months Unrealized Losses		82
Total Fair Value		1,918
Total Unrealized Losses		82
Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	453	370
Less than 12 Months Unrealized Losses	6	8
12 Months or Longer Fair Value	995	1,062
12 Months or Longer Unrealized Losses	41	58
Total Fair Value	1,448	1,432
Total Unrealized Losses	47	66
Marketable Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	485	2,235
Less than 12 Months Unrealized Losses	1	5
Total Fair Value	485	2,235
Total Unrealized Losses	$ 1	$ 5

Loans - Summary of Loans (Detai

Loans - Summary of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	$ 251,931	$ 213,651
Allowance for loan losses	(1,134)	(890)	$ (580)
Deferred loan costs, net	35	32
Unamortized premiums	485	372
Net loans	251,317	213,165
One- to Four- Family Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	189,763	168,111
Allowance for loan losses	(481)	(418)	(331)
Home Equity Loans and Lines of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	11,585	10,720
Allowance for loan losses	(52)	(49)	(49)
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	34,686	23,011
Allowance for loan losses	(472)	(276)	(150)
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	15,853	11,738
Allowance for loan losses	(107)	(117)	(40)
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable	44	71
Allowance for loan losses	$ (1)	$ (1)	$ (1)

Loans - Additional Information

Loans - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)SecurityLoan	Dec. 31, 2016USD ($)SecurityLoan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total amount of loans	$ 2,274,000	$ 2,455,000
Loan disbursement	$ 439,000	$ 500,000
Number of loan disbursement	1	1
Loans advance	$ 13,000	$ 122,000
Principal payment	138,000	150,000
Troubled debt restructured loan	0	0
Amount of loan in foreclosed	$ 0	$ 0
Number of consumer mortgage loans in foreclosure process | SecurityLoan	0	1
Amount of consumer mortgage loan in foreclosure process		$ 321,000
Credit quality information requirement description	On an annual basis, or more often if needed, the Company formally reviews the ratings on all commercial real estate and construction loans over $350,000.
One Four Family Residential Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired loan	$ 100,000	0
Number of Impaired loan	1
Troubled debt restructured loan, unpaid principal balance	$ 100,000
Loan specific reserve	8,000
Troubled debt restructured loan		0
One- to Four- Family Residential [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality		$ 287,000
One- to Four- Family Residential [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Risk Rating 6 W [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	$ 472,000
Number of loans | SecurityLoan	3
One- to Four- Family Residential [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	0
One- to Four- Family Residential [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Risk Rate 7 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	$ 99,000
Commercial Real Estate and Construction Loans Portfolio [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans acquired with deteriorated credit quality	$ 350,000

Loans - Summary of Changes in A

Loans - Summary of Changes in Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Allowance For Loan Losses [Line Items]
Beginning balance	$ 890	$ 580
Charge offs	(1)
Recoveries	0	0
Provision (benefit)	245	310
Ending balance	1,134	890
Individually evaluated for impairment	8
Collectively evaluated for impairment	1,126	890
Total allowance for loan losses ending balance	1,134	890
Individually evaluated for impairment	100
Collectively evaluated for impairment	251,831	213,651
Total	251,931	213,651
One- to Four- Family Residential [Member]
Schedule Of Allowance For Loan Losses [Line Items]
Beginning balance	418	331
Recoveries	0	0
Provision (benefit)	63	87
Ending balance	481	418
Individually evaluated for impairment	8
Collectively evaluated for impairment	473	418
Total allowance for loan losses ending balance	481	418
Individually evaluated for impairment	100
Collectively evaluated for impairment	189,663	168,111
Total	189,763	168,111
Home Equity Loans and Lines of Credit [Member]
Schedule Of Allowance For Loan Losses [Line Items]
Beginning balance	49	49
Recoveries	0	0
Provision (benefit)	3
Ending balance	52	49
Collectively evaluated for impairment	52	49
Total allowance for loan losses ending balance	52	49
Collectively evaluated for impairment	11,585	10,720
Total	11,585	10,720
Commercial [Member]
Schedule Of Allowance For Loan Losses [Line Items]
Beginning balance	276	150
Recoveries	0	0
Provision (benefit)	196	126
Ending balance	472	276
Collectively evaluated for impairment	472	276
Total allowance for loan losses ending balance	472	276
Collectively evaluated for impairment	34,686	23,011
Total	34,686	23,011
Construction Loans [Member]
Schedule Of Allowance For Loan Losses [Line Items]
Beginning balance	117	40
Recoveries	0	0
Provision (benefit)	(10)	77
Ending balance	107	117
Collectively evaluated for impairment	107	117
Total allowance for loan losses ending balance	107	117
Collectively evaluated for impairment	15,853	11,738
Total	15,853	11,738
Consumer Loans [Member]
Schedule Of Allowance For Loan Losses [Line Items]
Beginning balance	1	1
Charge offs	(1)
Recoveries	0	0
Provision (benefit)	1
Ending balance	1	1
Collectively evaluated for impairment	1	1
Total allowance for loan losses ending balance	1	1
Collectively evaluated for impairment	44	71
Total	44	71
Unallocated [Member]
Schedule Of Allowance For Loan Losses [Line Items]
Beginning balance	29	9
Recoveries	0	0
Provision (benefit)	(8)	20
Ending balance	21	29
Collectively evaluated for impairment	21	29
Total allowance for loan losses ending balance	$ 21	$ 29

Loans - Information Regarding N

Loans - Information Regarding Nonaccrual Loans and Past-due Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 661	$ 527
Total Current	251,270	213,124
Total	251,931	213,651
90 Days Or More Past Due and Accruing	0	0
Non-Accrual	189	9
30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	484	518
60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	177	9
One- to Four- Family Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	472	527
Total Current	189,291	167,584
Total	189,763	168,111
90 Days Or More Past Due and Accruing	0	0
Non-Accrual	189	9
One- to Four- Family Residential [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	295	518
One- to Four- Family Residential [Member] | 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	177	9
Home Equity Loans and Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	189
Total Current	11,396	10,720
Total	11,585	10,720
90 Days Or More Past Due and Accruing	0	0
Home Equity Loans and Lines of Credit [Member] | 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	189
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Current	34,686	23,011
Total	34,686	23,011
90 Days Or More Past Due and Accruing	0	0
Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Current	15,853	11,738
Total	15,853	11,738
90 Days Or More Past Due and Accruing	0	0
Consumer Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Current	44	71
Total	44	71
90 Days Or More Past Due and Accruing	$ 0	$ 0

Premises and Equipment - Summar

Premises and Equipment - Summary of Premises and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 4,017	$ 3,085
Accumulated depreciation	(2,024)	(1,837)
Premises and equipment, net	1,993	1,248
Land [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	393	393
Building [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	2,070	1,840
Construction in Process [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	641
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	553	549
Data Processing Equipment [Member]
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 360	$ 303

Deposits - Additional Informati

Deposits - Additional Information (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
FDIC insurance limit	$ 250,000	$ 250,000
Aggregate amount of time deposit	27,781,000	23,434,000
Deposits from related parties held by bank	$ 3,603,000	$ 3,782,000

Deposits - Scheduled Maturities

Deposits - Scheduled Maturities of Time Deposits (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Banking and Thrift [Abstract]
2,018	$ 102,073
2,019	12,664
2,020	1,638
2,021	8,208
2,022	1,537
Total	$ 126,120

Federal Home Loan Bank Advanc57

Federal Home Loan Bank Advances - Maturities of Advances from the FHLB (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Banks [Abstract]
2,018	$ 10,000
2,019	19,000
Total	$ 29,000	$ 10,000

Federal Home Loan Bank Advanc58

Federal Home Loan Bank Advances - Additional Information (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
FHLB Borrowings	$ 29,000,000	$ 10,000,000
Cooperative Central Bank [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Maximum borrowing capacity	5,000,000
Federal Home Loan Bank of Boston [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal Home Loan Bank, remaining maximum borrowing capacity	81,700,000
FHLB Borrowings	$ 29,000,000
Weighted-average interest rate on FHLB advances	1.78%	1.45%
Federal Home Loan Bank of Boston [Member] | Minimum [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest rates on FHLB advances	1.42%	1.42%
Federal Home Loan Bank of Boston [Member] | Maximum [Member]
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest rates on FHLB advances	2.37%	1.48%

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal									$ 857	$ 543
State									251	182
Current Income Tax Expense (Benefit)									1,108	725
Deferred:
Federal									(12)	80
Change in federal tax rate									181
State									(11)	(9)
Change in valuation allowance									(24)
Deferred Income Tax Expense (Benefit)									134	71
Total income tax expense	$ 325	$ 300	$ 280	$ 337	$ 349	$ 222	$ 138	$ 87	$ 1,242	$ 796

Income Taxes - Summary of Diffe

Income Taxes - Summary of Differences Between the Statutory Federal Income Tax Rate and the Effective Tax Rates (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal income tax at statutory rate	34.00%	34.00%
State tax, net of federal tax benefit	5.20%	5.20%
Change in valuation allowance	(0.80%)	0.00%
Change in tax rate	5.90%	0.00%
Dividends received deduction	(0.50%)	(1.30%)
Bank-owned life insurance	(1.80%)	(2.20%)
Solar credits	(2.30%)	(0.00%)
Stock compensation	1.10%	1.10%
Tax exempt income	(1.00%)	(1.30%)
ESOP	0.70%	0.60%
Other	0.30%	(0.30%)
Effective tax rates	40.80%	35.90%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Allowance for loan losses	$ 319	$ 356
Deferred compensation	83	83
Security writedowns	5	27
ESOP	16	12
Stock based compensation	47	47
Accrued expenses	31	13
Contribution to Melrose Cooperative Bank Foundation	204	406
Gross deferred tax assets	705	944
Valuation allowance	(66)	(90)
Gross deferred tax assets, net of valuation allowance	639	854
Deferred tax liabilities:
Accelerated depreciation	(181)	(220)
Net unrealized holding gain on available-for-sale securities	(94)	(514)
Gross deferred tax liabilities	(275)	(734)
Net deferred tax asset	$ 364	$ 120

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Income Taxes [Line Items]
Valuation allowance against deferred tax		$ 66,000	$ 90,000
Gross deferred tax asset		204,000	406,000
Contribution to Melrose Cooperative Bank Foundation				$ 1,362,000
Income tax charitable contribution carry forward		769,000
Liability for uncertain tax positions		$ 0	$ 0
Federal income tax rate		34.00%	34.00%
Deferred income tax expense recognized		$ 181,000
Scenario, Plan [Member]
Income Taxes [Line Items]
Federal income tax rate	21.00%
Melrose Bancorp, Inc. [Member]
Income Taxes [Line Items]
Valuation allowance against deferred tax		138,000
Melrose Cooperative Bank Foundation [Member]
Income Taxes [Line Items]
Valuation allowance against deferred tax		66,000
Gross deferred tax asset		204,000
Contribution to Melrose Cooperative Bank Foundation		$ 1,362,000

Benefit Plans - 401(k) Savings

Benefit Plans - 401(k) Savings Plan - Additional Information (Detail) - Pentegra Plan [Member] - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Employees contribution to benefit plan	100.00%
Employer's expense under 401(k) plan	$ 82,000	$ 80,000
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Matching contribution by employer	5.00%

Benefit Plans - Supplemental Ex

Benefit Plans - Supplemental Executive Retirement Benefits - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Employee vesting period	5 years
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Liability for retirement benefit plans	$ 294,000	$ 208,000
Employee vesting period	5 years
Expense recognized for benefit plan	$ 86,000	$ 70,000

Benefit Plans - Employee Stock

Benefit Plans - Employee Stock Ownership Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Common stock purchased by ESOP	226,366	226,366
Common stock purchased by ESOP, per share	$ 10
Percentage of aggregate purchase price of common stock	100.00%
Loan repayment period	29 years 2 months 12 days
Defined contribution plan, vesting percentage per year	20.00%
Employee vesting period	5 years
Loans receivable ESOP	$ 2,019,000
Compensation expense recognized	136,000	$ 116,000
Fair value of unallocated ESOP shares	$ 3,924,000

Benefit Plans - Schedule of Pri

Benefit Plans - Schedule of Principal Balance on ESOP Debt (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Retirement Benefits [Abstract]
2,018	$ 51
2,019	52
2,020	54
2,021	56
2,022	58
Thereafter	1,748
Loans receivable ESOP	$ 2,019

Benefit Plans - Schedule of Sha

Benefit Plans - Schedule of Shares Held by ESOP (Detail) - shares	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Allocated	30,182	22,638
Unallocated	196,184	203,728
Shares held by ESOP	226,366	226,366

Benefit Plans - 2015 Equity Inc

Benefit Plans - 2015 Equity Incentive Plan - Additional Information (Detail) - 2015 Equity Incentive Plan [Member] - USD ($)	May 12, 2016	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Number of shares authorized under plan		396,140
Employee Stock Option [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of shares authorized under plan		282,957
Stock-based compensation expense, related tax benefits		$ 18,000	$ 13,000
Number of shares granted	224,200
Stock options granted, exercise price	$ 15.13
Weighted average remaining years to vest	5 years
Expected volatility	20.24%
Stock options granted, fair value	$ 15.13
Expected option life	6 years 6 months
Period of U.S. Treasury rate	7 years
Annual risk free interest rate	1.54%
Estimated fair value of award determined by Black-Scholes option pricing model	$ 3.71
Aggregate intrinsic value		1,100,000
Stock option expense		$ 166,000	106,000
Options exercised/forfeited		0
Unrecognized compensation costs, weighted-average recognition period		3 years 3 months 19 days
Number of shares outstanding		224,200
Number of shares exercisable		44,840
Weighted average remaining contractual terms, Exercisable		8 years 3 months 19 days
Unrecognized compensation costs		$ 559,000
Restricted Stock Awards and Restricted Stock Units [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of shares authorized under plan		113,183
Restricted Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of shares awarded	44,300
Weighted-average grant-date fair values of options granted per share	$ 15.13
Award vesting period	5 years
Minimum vesting period from date of grant	1 year
Stock-based compensation expense		$ 134,000	85,000
Stock-based compensation expense, related tax benefits		$ 54,000	$ 34,000
Number of unvested restricted stock awarded		35,440
Unrecognized share based compensation expense		$ 451,000
Unrecognized compensation costs, weighted-average recognition period		3 years 3 months 19 days

Financial Instruments - Summary

Financial Instruments - Summary of Financial Instrument Liabilities with off-Balance Sheet Credit Risk (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instrument liabilities with off-balance sheet credit risk	$ 22,332	$ 25,458
Commitments to Originate Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instrument liabilities with off-balance sheet credit risk	2,401	7,864
Unused Lines of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instrument liabilities with off-balance sheet credit risk	17,611	13,742
Due to Borrowers on Unadvanced Construction Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instrument liabilities with off-balance sheet credit risk	$ 2,320	$ 3,852

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	$ 26,496	$ 31,831
U.S. Government and Federal Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	5,325	5,688
Debt Securities Issued by States of the United States and Political Subdivisions of the States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	2,881	2,656
Corporate Bonds and Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	11,294	12,493
Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	3,013	2,938
Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	1,448	1,432
Marketable Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	2,535	6,624
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	5,548	9,562
Level 1 [Member] | Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	3,013	2,938
Level 1 [Member] | Marketable Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	2,535	6,624
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	20,948	22,269
Level 2 [Member] | U.S. Government and Federal Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	5,325	5,688
Level 2 [Member] | Debt Securities Issued by States of the United States and Political Subdivisions of the States [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	2,881	2,656
Level 2 [Member] | Corporate Bonds and Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	11,294	12,493
Level 2 [Member] | Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value on a recurring basis	$ 1,448	$ 1,432

Fair Value Measurements - Sum71

Fair Value Measurements - Summary of Estimated Fair Values of Bank's Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financial assets:
Available-for-sale securities	$ 26,496	$ 31,831
Federal Home Loan Bank stock	1,800	964
Co-operative Central Bank deposit	886	881
Accrued interest receivable	702	572
Carrying Amount [Member]
Financial assets:
Cash and cash equivalents	17,603	13,792
Available-for-sale securities	26,496	31,831
Federal Home Loan Bank stock	1,800	964
Loans, net	251,317	213,165
Co-operative Central Bank deposit	886	881
Accrued interest receivable	702	572
Financial liabilities:
Deposits	232,921	214,766
FHLB advances	29,000	10,000
Estimate of Fair Value Measurement [Member]
Financial assets:
Cash and cash equivalents	17,603	13,792
Available-for-sale securities	26,496	31,831
Federal Home Loan Bank stock	1,800	964
Loans, net	252,792	213,582
Co-operative Central Bank deposit	886	881
Accrued interest receivable	702	572
Financial liabilities:
Deposits	232,899	215,443
FHLB advances	28,660	9,930
Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Financial assets:
Cash and cash equivalents	17,603	13,792
Available-for-sale securities	5,548	9,562
Federal Home Loan Bank stock	1,800	964
Co-operative Central Bank deposit	886	881
Accrued interest receivable	702	572
Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Financial assets:
Available-for-sale securities	20,948	22,269
Financial liabilities:
Deposits	232,899	215,443
FHLB advances	28,660	9,930
Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Financial assets:
Loans, net	$ 252,792	$ 213,582

Other Comprehensive Loss - Comp

Other Comprehensive Loss - Components of Other Comprehensive Loss Included in Stockholders' Equity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Net unrealized holding gain on available-for-sale securities	$ 478	$ 285
Reclassification adjustment for net realized gains included in net income	(1,385)	(1,004)
Other comprehensive loss before income tax effect	(907)	(719)
Income tax benefit	378	269
Other comprehensive loss, net of tax	$ (529)	$ (450)

Other Comprehensive Loss - Co73

Other Comprehensive Loss - Components of Other Comprehensive Loss Included in Stockholders' Equity (Parenthetical) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification adjustment for net realized gains in net income	$ 1,385,000	$ 1,004,000
Reclassified Out of Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification adjustment for net realized gains in net income	1,400,000	1,000,000
Tax benefit, included in income tax expense	$ 490,000	$ 359,000

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier 1 capital, minimum capital requirement ratio	4.50%	4.50%
Tier 1 capital to risk weighted assets, minimum capital requirement ratio	6.00%	6.00%
Tier 1 leverage ratio, minimum capital requirement ratio	4.00%	4.00%
Common equity tier 1 capital, minimum to be well capitalized ratio	6.50%	6.50%
Total capital to risk weighted assets, minimum to be well capitalized ratio	10.00%	10.00%
Tier 1 capital to risk weighted assets, minimum to be well capitalized ratio	8.00%	8.00%
Tier 1 leverage ratio, minimum to be well capitalized ratio	5.00%	5.00%
Tier 1 capital to risk-weighted assets capital conservation buffer above the required capital ratios Annual Increase	0.625%
Tier 1 capital to risk-weighted assets capital conservation buffer above the required capital ratios that phases in beginning January 1, 2016	0.625%
Tier 1 capital to risk-weighted assets capital conservation buffer above the required capital ratios Annual fully phased in effective January 1, 2019	2.50%
Maximum [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Phase in period term	4 years
Minimum [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Phase in period term	2 years
Capital Regulations [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier 1 capital, minimum capital requirement ratio	4.50%
Total capital to risk weighted assets, minimum capital requirement ratio	8.00%
Tier 1 capital to risk weighted assets, minimum capital requirement ratio	6.00%
Tier 1 leverage ratio, minimum capital requirement ratio	4.00%
Common equity tier 1 capital, minimum to be well capitalized ratio	6.50%
Total capital to risk weighted assets, minimum to be well capitalized ratio	10.00%
Tier 1 capital to risk weighted assets, minimum to be well capitalized ratio	8.00%
Tier 1 leverage ratio, minimum to be well capitalized ratio	5.00%

Regulatory Matters - Summary of

Regulatory Matters - Summary of Actual Capital Amounts and Ratios (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument Fair Value Carrying Value [Abstract]
Total Capital (to Risk Weighted Assets), Actual	$ 37,141	$ 35,236
Tier 1 Capital (to Risk Weighted Assets), Actual	35,786	33,648
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual	35,786	33,648
Tier 1 Capital (to Average Assets), Actual	$ 35,786	$ 33,648
Total Capital (to Risk Weighted Assets), Actual Ratio	19.80%	21.09%
Tier 1 Capital (to Risk Weighted Assets), Actual Ratio	19.08%	20.14%
Common Equity Tier 1 Capital (to Risk Weighted Assets), Actual Ratio	19.08%	20.14%
Tier 1 Capital (to Average Assets), Actual Ratio	12.59%	13.58%
Total Capital (to Risk Weighted Assets), For Capital Adequacy purpose Amount	$ 15,007	$ 13,368
Tier 1 Capital (to Risk Weighted Assets) For Capital Adequacy purpose Amount	11,255	10,026
Common Equity Tier 1 Capital (to Risk Weighted Assets) For Capital Adequacy purpose Amount	8,441	7,519
Tier 1 Capital (to Average Assets) For Capital Adequacy purpose Amount	$ 11,373	$ 9,909
Total Capital (to Risk Weighted Assets), For Capital Adequacy purpose Ratio	8.00%	8.00%
Tier 1 Capital (to Risk Weighted Assets) For Capital Adequacy purpose Ratio	6.00%	6.00%
Common Equity Tier 1 Capital (to Risk Weighted Assets), For Capital Adequacy purpose Ratio	4.50%	4.50%
Tier 1 Capital (to Average Assets) For Capital Adequacy purpose Ratio	4.00%	4.00%
Total Capital (to Risk Weighted Assets), Capitalized Under Prompt Corrective Action Provisions Amount	$ 18,759	$ 16,710
Tier 1 Capital (to Risk Weighted Assets), Capitalized Under Prompt Corrective Action Provisions Amount	15,007	13,368
Common Equity Tier 1 Capital (to Risk Weighted Assets), Capitalized Under Prompt Corrective Action Provisions Amount	12,193	10,861
Tier 1 Capital (to Average Assets), Capitalized Under Prompt Corrective Action Provisions Amount	$ 14,216	$ 12,386
Total Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	10.00%	10.00%
Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	8.00%	8.00%
Common Equity Tier 1 Capital (to Risk Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	6.50%	6.50%
Tier 1 Capital (to Average Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	5.00%	5.00%

Common Stock Repurchases - Addi

Common Stock Repurchases - Additional Information (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 14, 2017
Equity, Class of Treasury Stock [Line Items]
Additional number of shares authorized for repurchase			130,037
Additional number of shares authorized for repurchase, percentage			5.00%
Remaining number of shares authorized to be repurchased			11,200
Total number of shares repurchased	1,336	229,800
Average cost of shares repurchased		$ 15.32
Maximum [Member]
Equity, Class of Treasury Stock [Line Items]
Number of shares authorized to be repurchased	283,000

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - Subsequent Event [Member]	Jan. 17, 2018$ / shares
Common stock dividend declared, cash	$ 0.34
Dividend payable declared date	Jan. 17, 2018
Dividend payable recored date	Jan. 29, 2018
Dividend payable date	Feb. 14, 2018

Condensed Parent Company Only78

Condensed Parent Company Only Financial Statements - Summary of Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Non-interest bearing deposit in the Bank	$ 8,903	$ 11,715
Money market funds	3,963	2,077
Investments in available-for-sale securities (at fair value)	26,496	31,831
Loan receivable ESOP	2,019
Accrued interest receivable	702	572
Deferred tax assets	639	854
Other assets	275	199
Total assets	307,526	268,646
Liabilities and Stockholders' Equity
Other liabilities	612	576
Stockholders' equity	44,993	43,304	$ 45,545
Total liabilities and stockholders' equity	307,526	268,646
Parent Company [Member]
Assets
Non-interest bearing deposit in the Bank	1,998	1,881
Money market funds	1,363	1,558
Cash and cash equivalents	3,361	3,439	$ 5,815
Investments in available-for-sale securities (at fair value)	3,233	2,980
Investment in subsidiary, Melrose Cooperative Bank	35,997	34,399
Loan receivable ESOP	2,019	2,070
Accrued interest receivable	11	5
Deferred tax assets	203	388
Other assets	286	147
Total assets	45,110	43,428
Liabilities and Stockholders' Equity
Other liabilities	117	124
Stockholders' equity	44,993	43,304
Total liabilities and stockholders' equity	$ 45,110	$ 43,428

Condensed Parent Company Only79

Condensed Parent Company Only Financial Statements - Summary of Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Interest and dividend income:
Total interest and dividend income	$ 2,354	$ 2,348	$ 2,195	$ 2,044	$ 2,030	$ 1,911	$ 1,769	$ 1,695	$ 8,941	$ 7,405
Noninterest expense:
Salaries and employee benefits									3,240	2,772
Other expenses									223	152
Total noninterest expense	1,276	1,317	1,277	1,240	1,157	1,082	1,194	1,039	5,110	4,472
Loss before undistributed income of subsidiary and income tax expense (benefit)									3,046	2,218
Income before income taxes	551	931	701	863	917	608	413	280
Income tax expense (benefit)	325	300	280	337	349	222	138	87	1,242	796
Net income	$ 226	$ 631	$ 421	$ 526	$ 568	$ 386	$ 275	$ 193	1,804	1,422
Parent Company [Member]
Interest and dividend income:
Interest on ESOP loan									67	69
Interest and dividends on securities									49	71
Total interest and dividend income									116	140
Noninterest expense:
Salaries and employee benefits									300	191
Other expenses										1
Total noninterest expense									300	192
Loss before undistributed income of subsidiary and income tax expense (benefit)									(184)	(52)
Undistributed income of subsidiary									2,004	1,472
Income before income taxes									1,820	1,420
Income tax expense (benefit)									16	(2)
Net income									$ 1,804	$ 1,422

Condensed Parent Company Only80

Condensed Parent Company Only Financial Statements - Summary of Statements of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 226	$ 631	$ 421	$ 526	$ 568	$ 386	$ 275	$ 193	$ 1,804	$ 1,422
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of securities, net of accretion									144	37
Increase in accrued interest receivable									(130)	(132)
Deferred tax expense									134	71
Increase in other assets									(76)	(4)
(Decrease) increase in other liabilities									36	17
Stock based compensation expense									300	191
Net cash provided by operating activities									1,117	673
Cash flows from investing activities:
Purchases of available-for-sale securities									(4,214)	(4,991)
Proceeds from maturities of available-for-sale securities									5,385	9,230
Net cash (used in) provided by investing activities									(34,439)	(40,454)
Cash flows from financing activities:
Payment of income taxes for shares withheld in stock based award activity									(22)
Cash paid for stock repurchases										(3,520)
Net cash provided by financing activities									37,133	36,719
Parent Company [Member]
Cash flows from operating activities:
Net income									1,804	1,422
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of securities, net of accretion									62	31
Increase in accrued interest receivable									(6)	(1)
Deferred tax expense									175	29
Increase in other assets									(139)	(36)
(Decrease) increase in other liabilities									(7)	124
Stock based compensation expense									300	191
Equity in undistributed earnings of subsidiary									(2,004)	(1,472)
Net cash provided by operating activities									185	288
Cash flows from investing activities:
Purchases of available-for-sale securities									(898)
Proceeds from maturities of available-for-sale securities									606	810
Repayment of principal on ESOP loan									51	46
Net cash (used in) provided by investing activities									(241)	856
Cash flows from financing activities:
Payment of income taxes for shares withheld in stock based award activity									(22)
Cash paid for stock repurchases										(3,520)
Net cash provided by financing activities									(22)	(3,520)
Net decrease in cash and cash equivalents									(78)	(2,376)
Cash and cash equivalents at beginning of year				$ 3,439				$ 5,815	3,439	5,815
Cash and cash equivalents at end of year	$ 3,361				$ 3,439				$ 3,361	$ 3,439

Quarterly Data - Summary of Qua

Quarterly Data - Summary of Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Interest and dividend income	$ 2,354	$ 2,348	$ 2,195	$ 2,044	$ 2,030	$ 1,911	$ 1,769	$ 1,695	$ 8,941	$ 7,405
Interest expense	626	591	499	467	455	429	395	361	2,183	1,640
Net interest and dividend income	1,728	1,757	1,696	1,577	1,575	1,482	1,374	1,334	6,758	5,765
(Benefit)/provision for loan losses	151	3	111	(20)	30	117	103	60
Net interest and dividend income, after (benefit)/provision for loan losses	1,578	1,754	1,585	1,596	1,545	1,365	1,271	1,274	6,513	5,455
Total noninterest income	249	494	393	507	529	325	336	45	1,643	1,235
Total noninterest expense	1,276	1,317	1,277	1,240	1,157	1,082	1,194	1,039	5,110	4,472
Income before income taxes	551	931	701	863	917	608	413	280
Provision for income taxes	325	300	280	337	349	222	138	87	1,242	796
Net income	$ 226	$ 631	$ 421	$ 526	$ 568	$ 386	$ 275	$ 193	$ 1,804	$ 1,422
Earnings per share:
Basic	$ 0.09	$ 0.27	$ 0.18	$ 0.22	$ 0.24	$ 0.16	$ 0.11	$ 0.08	$ 0.76	$ 0.59
Diluted	$ 0.09	$ 0.27	$ 0.18	$ 0.22	$ 0.24	$ 0.16	$ 0.11	$ 0.08	$ 0.76	$ 0.59