FSB Bancorp 10-K 30 Mar 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Mar. 26, 2020	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	FSB BANCORP, INC.
Entity Central Index Key	0001667939
Trading Symbol	FSBC
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding		1,940,661
Entity Public Float			$ 32.4
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 1,689	$ 1,581
Interest-earning demand deposits	6,244	4,710
Total Cash and Cash Equivalents	7,933	6,291
Securities available-for-sale, at fair value	18,126	18,331
Securities held-to-maturity, at amortized cost (fair value of 2019 $5,297; 2018 $6,030)	5,166	6,052
Investment in restricted stock, at cost	2,757	3,637
Loans held for sale	2,194	2,133
Loans, net of allowance for loan losses (2019 $1,641; 2018 $1,561)	274,508	281,741
Bank owned life insurance	3,877	3,819
Accrued interest receivable	807	876
Premises and equipment, net	2,439	2,731
Operating lease right-of-use assets	2,123
Foreclosed real estate	730
Other assets	2,650	2,658
Total Assets	323,310	328,269
Deposits:
Non-interest-bearing	12,886	10,947
Interest-bearing	222,674	211,668
Total Deposits	235,560	222,615
Short-term borrowings	1,000	13,750
Long-term borrowings	50,735	58,076
Official bank checks	519	863
Operating lease liabilities	2,322
Other liabilities	1,630	1,452
Total Liabilities	291,766	296,756
Commitments and Contingent Liabilities - see Note 12
Stockholders' Equity
Preferred stock - par value $0.01; 25,000,000 shares authorized, no shares issued and outstanding
Common stock, par value $0.01; 50,000,000 authorized shares; 1,940,661 shares issued and outstanding	19	19
Paid-in capital	16,081	15,746
Retained earnings	15,699	16,212
Accumulated other comprehensive loss	(9)	(183)
Unearned ESOP shares, at cost	(246)	(281)
Total Stockholders' Equity	31,544	31,513
Total Liabilities and Stockholders' Equity	$ 323,310	$ 328,269

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Consolidated Balance Sheets
Fair value securities held to maturity (in dollars)	$ 5,297	$ 6,030
Allowance for loan losses	$ 1,641	$ 1,561
Preferred stock - par value (in dollars per share)	$ 0.01
Preferred stock, shares authorized	25,000,000	25,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock - par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	1,940,661	1,940,661
Common stock, shares outstanding	1,940,661	1,940,661

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Interest and Dividend Income
Loans, including fees	$ 12,248	$ 11,827
Securities - taxable	483	415
Securities - tax exempt	102	105
Mortgage-backed securities	108	141
Other	106	52
Total Interest and Dividend Income	13,047	12,540
Interest Expense
Deposits	3,469	2,591
Short-term borrowings	133	215
Long-term borrowings	1,335	1,173
Total Interest Expense	4,937	3,979
Net Interest Income	8,110	8,561
Provision for Loan Losses	295	300
Net Interest Income after Provision for Loan Losses	7,815	8,261
Other Income
Increase in cash surrender value of bank owned life insurance	58	61
Realized gain on sale of loans	931	1,437
Mortgage fee income	612	743
Other	176	196
Total Other Income	1,937	2,717
Other Expense
Salaries and employee benefits	6,137	6,497
Occupancy	1,056	1,088
Data processing costs	467	426
Advertising	68	147
Equipment	543	542
Electronic banking	109	109
Directors' fees	218	205
Mortgage fees and taxes	243	422
FDIC premium expense	69	120
Audits and tax services	161	213
Professional services	295	214
Legal expense	362	166
Other	638	662
Total Other Expense	10,366	10,811
Income (Loss) before Income Taxes	(614)	167
Provision (Benefit) for Income Taxes	(101)	32
Net Income (Loss)	$ (513)	$ 135
Basic and Diluted Earnings (Loss) Per Common Share (in dollars per share)	$ (0.28)	$ 0.07
Service fees
Other Income
Other income including Service fees and Fee income	$ 141	$ 149
Insurance and securities commission income
Other Income
Other income including Service fees and Fee income	$ 19	$ 131

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statements of Comprehensive Income
Net Income (Loss)	$ (513)	$ 135
Other Comprehensive Income (Loss)
Change in unrealized holding gains (losses) on securities available-for-sale	220	(24)
Other Comprehensive Income (Loss), Before Tax	220	(24)
Income Tax Expense (Benefit) Related to Other Comprehensive Income (Loss)	46	(6)
Other Comprehensive Income (Loss), Net of Tax	174	(18)
Comprehensive Income (Loss)	(339)	117
Tax Expense (Benefit) Allocated to Each Component of Other Comprehensive Income (Loss)
Change in unrealized holding gains (losses) on securities available-for-sale	46	(6)
Income tax effect related to other comprehensive income (loss)	$ 46	$ (6)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Unearned ESOP Shares	Total
Balance at Dec. 31, 2017	$ 19	$ 15,441	$ 16,077	$ (165)	$ (316)	$ 31,056
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)			135			135
Other comprehensive income (loss), net				(18)		(18)
ESOP shares committed to be released		37			35	72
Stock based compensation		310				310
Effect of stock repurchase plan		(42)				(42)
Balance at Dec. 31, 2018	19	15,746	16,212	(183)	(281)	31,513
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)			(513)			(513)
Other comprehensive income (loss), net				174		174
ESOP shares committed to be released		31			35	66
Stock based compensation		304				304
Balance at Dec. 31, 2019	$ 19	$ 16,081	$ 15,699	$ (9)	$ (246)	$ 31,544

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash Flows from Operating Activities
Net income (loss)	$ (513,000)	$ 135,000
Adjustments to reconcile net income (loss) to net cash flows from operating activities:
Net amortization of premiums and accretion of discounts on investments	75,000	83,000
Gain on sale of loans	(931,000)	(1,437,000)
Proceeds from loans sold	42,723,000	62,069,000
Loans originated for sale	(41,853,000)	(59,995,000)
Amortization of net deferred loan origination costs	(11,000)	(37,000)
Depreciation and amortization	425,000	445,000
Provision for loan losses	295,000	300,000
Expense related to ESOP	66,000	72,000
Stock based compensation	304,000	310,000
Deferred income tax benefit	(210,000)	(135,000)
Earnings on investment in bank owned life insurance	(58,000)	(61,000)
Decrease (Increase) in accrued interest receivable	69,000	(52,000)
Decrease in other assets	8,000	42,000
Increase in other liabilities	541,000	334,000
Net Cash Flows From Operating Activities	930,000	2,073,000
Cash Flows from Investing Activities
Purchases of securities available-for-sale	(12,500,000)	(1,999,000)
Proceeds from maturities and calls of securities available-for-sale	11,065,000
Proceeds from principal paydowns on securities available-for-sale	1,808,000	1,901,000
Purchases of securities held-to-maturity		(517,000)
Proceeds from maturities and calls of securities held-to-maturity	815,000	835,000
Proceeds from principal paydowns on securities held-to-maturity	48,000	178,000
Net decrease (increase) in loans	6,219,000	(19,293,000)
Purchase of restricted stock	(414,000)	(1,477,000)
Redemption of restricted stock	1,294,000	1,110,000
Purchase of premises and equipment	(133,000)	(112,000)
Net Cash Flows From Investing Activities	8,202,000	(19,374,000)
Cash Flows from Financing Activities
Net increase in deposits	12,945,000	5,924,000
Proceeds from borrowings	22,146,000	67,300,000
Repayments on borrowings	(42,237,000)	(59,921,000)
Effect of stock repurchase plan		(42,000)
Net decrease in official bank checks	(344,000)	(66,000)
Net Cash Flows From Financing Activities	(7,490,000)	13,195,000
Change in Cash and Cash Equivalents	1,642,000	(4,106,000)
Cash and Cash Equivalents - Beginning	6,291,000	10,397,000
Cash and Cash Equivalents - Ending	7,933,000	6,291,000
Supplementary Cash Flows Information
Interest paid	4,994,000	3,905,000
Taxes paid		$ 38,000
Supplemental Noncash Disclosures
Transfers from loans to real estate owned	$ 730,000

Nature of Operations and Summar

Nature of Operations and Summary of Significant Accounting Policies (Imported)	12 Months Ended
	Dec. 31, 2019
Nature of Operations and Summary of Significant Accounting Policies
Nature of Operations and Summary of Significant Accounting Policies	Note 1 - Nature of Operations and Summary of Significant Accounting Policies Organization and Nature of Operations On March 2, 2016, the Boards of Directors of the FSB Community Bankshares, Inc. (“FSB Community”), FSB Community Bankshares, MHC (the “MHC”), and Fairport Savings Bank (the “Bank”) unanimously adopted a Plan of Conversion of the MHC pursuant to which the MHC undertook a “second-step” conversion and now no longer exists. The Bank reorganized from a two-tier mutual holding company structure to a fully public stock holding company structure effective July 13, 2016, and, as a result, is now the wholly-owned subsidiary of FSB Bancorp, Inc. (the “Company”). FSB Bancorp, Inc., the new stock holding company for the Bank, sold 1,034,649 shares of common stock at $10.00 per share, for gross offering proceeds of $10.3 million in its stock offering. Additionally, after accounting for conversion-related expenses of $1.4 million, which offset gross proceeds, the Company received $8.9 million in net proceeds. Concurrent with the completion of the conversion and reorganization, shares of common stock of FSB Community owned by public stockholders were exchanged for shares of the Company’s common stock so that the former public stockholders of FSB Community owned approximately the same percentage of the Company’s common stock as they owned of FSB Community’s common stock immediately prior to the conversion. Stockholders of FSB Community received 1.0884 shares of the Company’s common stock for each share of FSB Community’s stock they owned immediately prior to completion of the transaction. Cash in lieu of fractional shares was paid based on the offering price of $10.00 per share. As a result of the offering and the exchange of shares, the Company had 1,941,688 shares outstanding as of December 31, 2016. In accordance with Board of Governors of the Federal Reserve System regulations, at the time of the reorganization, the Company substantially restricted retained earnings by establishing a liquidation account. The liquidation account will be maintained for the benefit of eligible account holders who continue to maintain their accounts at the Bank after conversion. The Bank has established a parallel liquidation account to support the Company’s liquidation account in the event the Company does not have sufficient assets to fund its obligations under its liquidation account. The liquidation accounts will be reduced annually to the extent that eligible account holders have reduced their qualifying deposits. Subsequent increases will not restore an eligible account holder’s interest in the liquidation accounts. In the event of a complete liquidation of the Bank or the Company, each account holder will be entitled to receive a distribution in an amount proportionate to the adjusted qualifying account balances then held. The Bank may not pay dividends if those dividends would reduce equity capital below the required liquidation account amount. The Company provides a variety of financial services to individuals and corporate customers through its wholly-owned subsidiary, Fairport Savings Bank. The Bank’s operations are conducted in five branches located in Monroe County, New York. The Company and the Bank are subject to the regulations of certain regulatory authorities and undergo periodic examinations by those regulatory authorities. The Company’s principal business consists of originating one-to-four-family residential real estate mortgages, home equity loans and lines of credit and to a lesser extent, originations of commercial real estate, multi-family, construction, commercial and industrial, and other consumer loans. The Company has three mortgage origination offices located in Pittsford, New York; Watertown, New York; and Buffalo, New York. The Bank also provides non-deposit investment services to its customers through its wholly-owned subsidiary, Fairport Wealth Management. Prior to January 15, 2016, Fairport Wealth Management was known as Oakleaf Services Corporation. The results of operations of Fairport Wealth Management are not material to the consolidated financial statements. Basis of Consolidation The consolidated financial statements include the accounts of the Company, the Bank and Fairport Wealth Management. All significant intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expense during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant changes in the near term relate to the determination of the allowance for loan losses, deferred tax assets, and the estimation of fair values for accounting and disclosure purposes. The Company is subject to the regulations of various governmental agencies. The Company also undergoes periodic examinations by the regulatory agencies which may subject it to further changes with respect to asset valuations, amounts of required loss allowances, and operating restrictions resulting from the regulators’ judgments based on information available to them at the time of their examinations. Significant Group Concentrations of Credit Risk Most of the Company’s activities are with customers located within Monroe, Livingston, Ontario, Orleans, Wayne, Jefferson, Niagara, and Erie Counties, New York. Note 2 discusses the types of securities that the Company invests in. The concentration of credit by type of loan is set forth in Note 3. Although the Bank has a diversified loan portfolio, its debtors’ ability to honor their contracts is primarily dependent upon the real estate and general economic conditions in those areas. Cash and Cash Equivalents For purposes of the consolidated statement of cash flows, cash and cash equivalents include cash, balances due from banks and interest-earning demand deposits (with an original maturity of three months or less). Securities The Company classifies debt investing securities as either available-for-sale or held-to-maturity. The Company does not hold any securities considered to be trading. Available-for-sale securities are reported at fair value, with net unrealized gains and losses reflected as a separate component of stockholders’ equity, net of the applicable income tax effect. Held-to-maturity securities are those that the Company has the ability and intent to hold until maturity and are reported at amortized cost. Gains or losses on investment security transactions are based on the amortized cost of the specific securities sold. Premiums and discounts on securities are amortized and accreted into income using the interest method over the period to maturity. When the fair value of a held-to-maturity or available-for-sale security is less than its amortized cost basis, an assessment is made at the balance sheet date as to whether other-than-temporary impairment (“OTTI”) is present. The Company considers numerous factors when determining whether potential OTTI exists and the period over which the debt security is expected to recover. The principal factors considered are (1) the length of time and the extent to which the fair value has been less than amortized cost basis, (2) the financial condition of the issuer (and guarantor, if any) and adverse conditions specifically related to the security industry or geographic area, (3) failure of the issuer of the security to make scheduled interest or principal payments, (4) any changes to the rating of a security by a rating agency, and (5) the presence of credit enhancements, if any, including the guarantee of the federal government or any of its agencies. For debt securities, OTTI is considered to have occurred if (1) the Company intends to sell the security, (2) it is more likely than not the Company will be required to sell the security before recovery of its amortized cost basis, or (3) if the present value of expected cash flows is not sufficient to recover the entire amortized cost basis or carrying value. For debt securities, credit-related OTTI is recognized in earnings while noncredit-related OTTI on securities not expected to be sold is recognized in other comprehensive income (loss). Credit-related OTTI is measured as the difference between the present value of an impaired security’s expected cash flows and its amortized cost basis or carrying value. Noncredit-related OTTI is measured as the difference between the fair value of the security and its amortized cost, or carrying value, less any credit-related losses recognized. For securities classified as held-to-maturity, the amount of OTTI recognized in other comprehensive income (loss) is accreted to the credit-adjusted expected cash flow amounts of the securities over future periods. Investment securities are exposed to various risks such as interest rate, market and credit risks. Due to the level of risk associated with certain investment securities, it is at least reasonably possible that changes in the values of investment securities will occur in the near term and that such changes could materially affect the amounts reported in the accompanying consolidated financial statements. Restricted Stock Restricted equity securities are held as a long-term investment and value is determined based on the ultimate recoverability of the par value. Impairment of these investments is evaluated quarterly and is a matter of judgment that reflects management’s view of the issuer’s long-term performance, which includes factors such as the following: its operating performance; the severity and duration of declines in the fair value of its net assets related to its capital stock amount; its commitment to make payments required by law or regulation and the level of such payments in relation to its operating performance; and its liquidity and funding position. After evaluating these considerations, the Company concluded that the par value of these investments will be recovered and, as such, has not recognized any impairment on its holdings of restricted equity securities during the current year. The Company holds restricted stock from Federal Home Loan Bank and Atlantic Community Bankers Bank. No impairment charges were recorded related to the restricted stock during 2019 or 2018. Loans Held for Sale Mortgage loans held for sale in the secondary market are carried at the lower of amortized cost or fair value. Separate determinations of fair value for residential and commercial loans are made on an aggregate basis. Fair value is determined based solely on the effect of changes in secondary market interest rates and yield requirements from the commitment date to the date of the consolidated financial statements. Realized gains and losses on sales are computed using the specific identification method. Loan Servicing Rights The Company retains the servicing on a portion of conventional fixed-rate mortgage loans sold and receives a fee based on the principal balance outstanding. Loans serviced for others totaled $116,531,000 and $123,755,000 at December 31, 2019 and 2018, respectively. The Company also sells correspondent FHA, VA, and USDA mortgage loans, servicing released. Loan servicing rights are recorded at fair value when loans are sold with servicing rights retained. The fair value of the mortgage servicing rights (“MSRs”) is determined using a method which utilizes servicing income, discount rates, and prepayment speeds relative to the Bank’s portfolio for MSRs and are amortized over the life of the loan. MSRs amounted to $726,000 and $812,000 at December 31, 2019 and 2018, respectively, and are included in other assets on the consolidated balance sheets. In 2019, $30,000 was capitalized and $116,000 was amortized. In 2018, $5,000 was capitalized with $85,000 amortized. Loans Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off generally are reported at their outstanding unpaid principal balances adjusted for charge-offs, the allowance for loan losses, and net deferred origination fees and costs. Interest income is accrued on the unpaid principal balance. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the related loan yield using the interest method over the estimated life of the loan. The accrual of interest is generally discontinued when the contractual payment of principal or interest has become 90 days past due or management has serious doubts about further collectibility of principal or interest, even though the loan is currently performing. A loan may remain on accrual status if it is in the process of collection and is well secured. When a loan is placed on nonaccrual status, unpaid interest credited to income in the current year is reversed. Interest received on nonaccrual loans generally is either applied against principal or reported as interest income, according to management’s judgment as to the collectibility of principal. Generally, loans are restored to accrual status when the obligation is brought current, has performed in accordance with the contractual terms for a reasonable period of time and the ultimate collectibility of the total contractual principal and interest is no longer in doubt. Allowance for Loan Losses The allowance for loan losses (the “Allowance”) is established as losses are estimated to have occurred in the loan portfolio. The allowance for loan losses is recorded through a provision for loan losses charged to earnings. Loan losses are charged against the allowance when management believes the loan is uncollectable. 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 collectibility of the loans in light of historical experience, the nature and volume of the loan portfolio, adverse situations that may affect the borrower’s ability to repay, the 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. The allowance consists of specific, general and unallocated components. The specific component relates to loans that are deemed impaired and classified as either special mention, substandard, doubtful, or loss. For such loans that are also classified as impaired, an allowance is generally established when the collateral value of the impaired loan is lower than the carrying value of that loan. The general component covers non-classified loans and is based on historical loss experience adjusted for the following qualitative factors: effects of changes in lending policies; national and/or local economic trends and conditions; trends in volume and terms of loans; experience, ability, and depth of management; levels and trends of delinquencies, non-accruals and classified loans; quality of institutions loan review system; collateral value for collateral dependent loans; concentrations of credit; and competition, legal and regulatory requirements on level of estimated credit losses. 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 specific and general losses in the portfolio. A loan is considered impaired when, based on current information and events, it is probable that the Bank will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan-by-loan basis 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. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, the Company does not separately identify individual consumer and residential loans for impairment disclosures unless subject to a troubled debt restructuring. In addition, Federal regulatory agencies, as an integral part of their examination process, periodically review the Company’s allowance for loan losses and may require the Company to recognize additions to the allowance based on their judgments about information available to them at the time of their examination, which may not be currently available to management. Based on management’s comprehensive analysis of the loan portfolio, management believes the current level of the allowance for loan losses is adequate. Bank Owned Life Insurance The Company holds life insurance policies on a key executive. Bank owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement. Premises and Equipment Premises and equipment are stated at cost. Depreciation and amortization are computed on the straight-line basis over the shorter of the estimated useful lives or lease terms (in the case of leasehold improvements) of the related assets. Estimated useful lives are generally 20 to 30 years for premises and 3 to 10 years for furniture and equipment. Foreclosed Real Estate Real estate properties acquired through, or in lieu of, loan foreclosure are initially recorded at fair value less estimated selling costs at the date of foreclosure. Any write-downs based on the asset’s fair value at date of acquisition are charged to the allowance for loan losses. After foreclosure, property held for sale is carried at the lower of the new basis or fair value less any costs to sell. Costs of significant property improvements are capitalized, whereas costs relating to holding property are expensed. Valuations are periodically performed by management or third party valuation experts, and any subsequent write-downs are recorded as a charge to earnings, if necessary, to reduce the carrying value of the property to the lower of its cost or fair value less cost to sell. The Company had two foreclosed commercial real estate loans at December 31, 2019 and no foreclosed loans at December 31, 2018. At December 31, 2019 and 2018 the Company had one residential mortgage loan for $55,000 in the process of foreclosure. Income Taxes Income taxes are provided for the tax effects of certain transactions reported in the consolidated financial statements. Income taxes consist of taxes currently due plus deferred taxes related primarily to temporary differences between the financial reporting and income tax basis of the allowance for loan losses, premises and equipment, certain state tax credits, and deferred loan origination costs. The deferred tax assets and liabilities represent the future tax return consequences of the temporary differences, which will either be taxable or deductible when the assets and liabilities are recovered or settled. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion of the deferred tax assets will not be realized. Deferred tax assets and liabilities are reflected at income tax rates applicable to the period in which the deferred tax assets and liabilities are expected to be realized or settled. As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted through the provision for income taxes. Advertising Costs The Company follows the policy of charging the costs of advertising to expense as incurred. Off-Balance Sheet Financial Instruments In the ordinary course of business, the Company has entered into off-balance sheet financial instruments consisting of commitments to extend credit. Such financial instruments are recorded in the consolidated balance sheets when they are funded. Transfers of Financial Assets Transfers of financial assets are accounted for as sales, when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Comprehensive Income (Loss) Accounting principles generally require that recognized revenue, expenses, gains, and losses be included in earnings. Although certain changes in assets and liabilities, such as unrealized gains and losses on available-for-sale securities, 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 (loss). Accumulated other comprehensive income (loss) represents the sum of these items, with the exception of net income, as of the consolidated balance sheet date and is represented in the table below. As of December 31, 2019 2018 Accumulated Other Comprehensive Loss By Component: Unrealized losses on securities available-for-sale $ (12) $ (232) Tax effect 3 49 Net unrealized losses on securities available-for-sale (9) (183) Accumulated other comprehensive loss $ (9) $ (183) Earnings Per Common Share Basic earnings per common share is calculated by dividing net income available to common stockholders by the weighted-average number of common shares outstanding during the period. Diluted earnings per share is computed in a similar manner to that of basic earnings per share except that the weighted-average number of common shares outstanding is increased to reflect the assumed exercise and conversion of dilutive stock options and unvested restricted stock. In periods of loss, basic earnings per common share and diluted earnings per share are the same due to the fact that the inclusion of any of the dilutive shares will result in an anti-dilutive impact, driven by the loss. Net income available to common stockholders is net income of the Company. Unallocated common shares held by the ESOP are not included in the weighted average number of common shares outstanding for purposes of calculating earnings per common share until they are committed to be released. The following table sets forth the calculation of basic and diluted earnings per share. Year Ended December 31, (In thousands, except per share data) 2019 2018 Basic and Diluted Earnings (Loss) Per Common Share Net income (loss) available to common stockholders $ (513) $ 135 Weighted average basic common shares outstanding 1,859 1,851 Weighted average diluted common shares outstanding 1,859 1,853 Earnings (loss) per common share – basic and diluted $ (0.28) $ 0.07 Share Repurchases The Company announced on July 27, 2017 that the Board of Directors had adopted its first stock repurchase program. Under the repurchase program, the Company may repurchase up to 97,084 shares of its common stock, or approximately 5% of its then outstanding shares. The Company did not repurchase any shares in 2019. In 2018, the Company repurchased 2,592 shares at an average price of $16.38 per share. As of December 31, 2019, the Company had repurchased 72,127 shares at an average price of $15.31 per share. Stock-Based Compensation On September 27, 2017, the Board of Directors of the Company approved restricted stock and stock option grants to senior management and the directors of the Company, pursuant to the terms of the 2017 Equity Incentive Plan (the “Plan”). The Plan was approved previously by the Company’s stockholders on August 29, 2017. There were no stock options or shares of restricted stock granted to senior management or directors in 2019. An aggregate of 20,000 stock options and 8,400 shares of restricted stock were granted to senior management during the year ended December 31, 2018. The grants to senior management and directors vest over a five year period in equal annual installments, with the first installment vesting on the first anniversary date of the grant and succeeding installments on each anniversary thereafter, through 2023. New Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). This new guidance supersedes the lease requirements in Topic 840, Leases and was based on the principle that a lessee should recognize in the balance sheet a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. The accounting applied by a lessor was largely unchanged from that applied under the previous guidance. In addition, the guidance required an entity to separate the lease components from the nonlease components in a contract. The ASU required disclosures about the amount, timing, and judgments related to a reporting entity's accounting for leases and related cash flows. The standard was required to be applied to all leases in existence as of the date of adoption using a modified retrospective transition approach. This guidance was effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The Company adopted this ASU on January 1, 2019 and has recognized lease liabilities and right-of-use assets associated with these lease agreements. The new guidance required lessees to record a right-of-use asset and a lease liability for all leases with a term greater than 12 months. While the guidance required all leases to be recognized in the balance sheet, there continues to be a differentiation between finance leases and operating leases for purposes of income statement recognition and cash flow statement presentation. For finance leases, interest on the lease liability and amortization of the right-of-use asset will be recognized separately in the consolidated statement of income. Repayments of principal on those lease liabilities will be classified within financing activities and payments of interest on the lease liability will be classified within operating activities in the statement of cash flows. For operating leases, a single lease cost is recognized in the consolidated statement of income and allocated over the lease term, generally on a straight-line basis. All cash payments are presented within operating activities in the statement of cash flows. The accounting applied by lessors is largely unchanged from existing GAAP, however, the guidance eliminates the accounting model for leveraged leases for leases that commence after the effective date of the guidance. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326). This new guidance significantly changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. This ASU will replace the "incurred loss" model under existing guidance with an "expected loss" model for instruments measured at amortized cost, and require entities to record allowances for available-for-sale debt securities rather than reduce the carrying amount, as they do today under the other-than-temporary impairment model. This ASU also simplifies the accounting model for purchased credit-impaired debt securities and loans. This guidance requires adoption through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. This ASU was originally effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption was permitted for all companies as of fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Effective in November 2019, the FASB issued ASU No. 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates , which defers certain effective dates of the standards on credit losses (ASU No. 2016-13), hedging (ASU NO. 2017-12), and leases (ASU No. 2016-02). ASU No. 2016-13 is now required to be adopted by the Company effective January 1, 2023. In March 2017, the FASB issued an Update (ASU 2017-08) to its guidance on “Receivables – Nonrefundable Fees and Other Costs (Subtopic 310-20) related to premium amortization on purchased callable debt securities. The amendments in this update shortened the amortization period for certain callable debt securities held at a premium. Specifically, the amendments required the premium to be amortized to the earliest call date. The amendments did not require an accounting change for securities held at a discount; the discount continues to be amortized to maturity. For public companies, the amendments in this update were effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. An entity should apply the amendments in this update on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. Additionally, in the period of adoption, an entity should provide disclosure about a change in accounting principle. The adoption of this guidance did not have a material impact on our consolidated results of operations or financial position. In August 2018, the FASB has issued Accounting Standards Update (ASU) No. 2018-15, Intangibles—Goodwill and Other—Internal Use Software (Subtopic 350-40) : Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, a consensus of the FASB Emerging Issues Task Force, which amends the FASB ASC to provide guidance on accounting for costs of implementation activities performed in a cloud computing arrangement that is a service contract. In April 2015, the FASB issued ASU No. 2015-05, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer's Accounting for Fees Paid in a Cloud Computing Arrangement, which provided guidance to customers concerning whether a cloud computing arrangement (e.g., software, platform, or infrastructure offered as a service) includes a software license. Pursuant to that guidance, (1) if a cloud computing arrangement includes a software license, the software license element of the arrangement should be accounted for in a manner consistent with the acquisition of other software licenses, or (2) if the arrangement does not include a software license, then the arrangement should be accounted for as a service contract, with the fees associated with the hosting element (service) of the arrangement expensed as they are incurred. Following the issuance of ASU No. 2015-05, constituents requested that the FASB provide additional guidance on the accounting for costs of implementation activities performed in a cloud computing arrangement that is a service contract. Accordingly, because U.S. GAAP do not contain explicit guidance on accounting for such costs, and to address the resulting diversity in practice, the FASB has issued ASU No. 2018-15 to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop

Securities

Securities	12 Months Ended
	Dec. 31, 2019
Securities
Securities	Note 2 - Securities The amortized cost and estimated fair value of securities with gross unrealized gains and losses at December 31, 2019 and 2018 are as follows: Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value December 31, 2019: (In Thousands) Available-for-Sale: U.S. Government and agency obligations $ 14,043 $ 6 $ (14) $ 14,035 Mortgage-backed securities - residential 4,095 14 (18) 4,091 $ 18,138 $ 20 $ (32) $ 18,126 Held-to-Maturity: Mortgage-backed securities - residential $ 409 $ 3 $ — $ 412 State and municipal securities 4,757 128 — 4,885 $ 5,166 $ 131 $ — $ 5,297 December 31, 2018: Available-for-Sale: U.S. Government and agency obligations $ 12,610 $ 7 $ (162) $ 12,455 Mortgage-backed securities - residential 5,953 24 (101) 5,876 $ 18,563 $ 31 $ (263) $ 18,331 Held-to-Maturity: Mortgage-backed securities - residential $ 458 $ 6 $ (1) $ 463 State and municipal securities 5,594 29 (56) 5,567 $ 6,052 $ 35 $ (57) $ 6,030 Mortgage-backed securities consist of securities that are issued by Fannie Mae (“FNMA”), Freddie Mac (“FHLMC”), Ginnie Mae (“GNMA”), and are collateralized by residential mortgages. U.S. Government and agency obligations include notes and bonds with both fixed and variable rates. State and municipal securities consist of government obligations and revenue bonds. The amortized cost and estimated fair value by contractual maturity of debt securities at December 31, 2019 are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations. Available-for-Sale Held-to-Maturity Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value (In Thousands) Due in one year or less $ — $ — $ 746 $ 748 Due after one year through five years 9,043 9,041 2,517 2,554 Due after five years through ten years 5,000 4,994 1,494 1,583 Mortgage-backed securities - residential 4,095 4,091 409 412 $ 18,138 $ 18,126 $ 5,166 $ 5,297 There were no realized gains on sales of securities in 2019 or 2018. No securities were pledged to secure public deposits or for any other purpose required or permitted by law at December 31, 2019 and 2018. Management has reviewed its loan and mortgage-backed securities portfolios and determined that, to the best of its knowledge, little or no exposure exists to sub-prime or other high-risk residential mortgages. The Company is not in the practice of investing in, or originating, these types of investments or loans. The following table shows gross unrealized losses and fair value, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position, at December 31, 2019 and 2018: Less than 12 Months 12 Months or More Total Gross Gross Gross Fair Unrealized Fair Unrealized Fair Unrealized Value Losses Value Losses Value Losses (In Thousands) 2019: Available-for-Sale U.S. Government and agency obligations $ 2,993 $ 10 $ 2,536 $ 4 $ 5,529 $ 14 Mortgage-backed securities - residential (1) 131 — 3,065 18 3,196 18 $ 3,124 $ 10 $ 5,601 $ 22 $ 8,725 $ 32 2019: Held-to-Maturity Mortgage-backed securities - residential $ — $ — $ — $ — $ — $ — State and municipal Securities — — — — — — $ — $ — $ — $ — $ — $ — 2018: Available-for-Sale U.S. Government and agency obligations $ — $ — $ 9,445 $ 162 $ 9,445 $ 162 Mortgage-backed securities - residential (1) 203 — 3,749 101 3,952 101 $ 203 $ — $ 13,194 $ 263 $ 13,397 $ 263 2018: Held-to-Maturity Mortgage-backed securities - residential $ — $ — $ 165 $ 1 $ 165 $ 1 State and municipal Securities 1,039 4 3,021 52 4,060 56 $ 1,039 $ 4 $ 3,186 $ 53 $ 4,225 $ 57 (1) Aggregate unrealized loss position of these securities is less than $500. Management evaluates securities for other-than-temporary impairment at least on a quarterly basis, and more frequently when economic or market concerns warrant such evaluation. In 2019 and 2018, the Company did not record an other-than-temporary impairment charge. At December 31, 2019, one residential mortgage-backed security and two U.S. Government and agency obligations were in a continuous unrealized loss position for less than twelve months. At December 31, 2019, five residential mortgage-backed securities and two U.S. Government and agency obligations were in a continuous unrealized loss position for more than twelve months. The debt securities and residential mortgage-backed securities were issued by U.S. Government sponsored agencies. All are paying in accordance with their terms with no deferrals of interest or defaults. Because the decline in fair value is attributable to changes in interest rates, not credit quality, and because management does not intend to sell and will not be required to sell these securities prior to recovery or maturity, no declines are deemed to be other-than-temporary.

Loans and The Allowance for Loa

Loans and The Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2019
Loans and The Allowance for Loan Losses
Loans and The Allowance for Loan Losses	Note 3 – Loans and The Allowance for Loan Losses Net loans at December 31, 2019 and 2018 consist of the following: 2019 2018 (In Thousands) Real estate loans: Secured by one- to four-family residences $ 212,903 $ 221,602 Secured by multi-family residences 10,876 10,241 Construction 4,679 4,898 Commercial real estate 23,081 22,492 Home equity lines of credit 17,459 16,766 Commercial & industrial 7,133 7,290 Other loans 44 50 Total Loans 276,175 283,339 Net deferred loan origination fees (26) (37) Allowance for loan losses (1,641) (1,561) Net Loans $ 274,508 $ 281,741 To develop and document a systematic methodology for determining the allowance for loan losses, the Company has divided the loan portfolio into two portfolio segments, each with different risk characteristics but with similar methodologies for assessing risk. Each portfolio segment is broken down into loan classes where appropriate. Loan classes contain unique measurement attributes, risk characteristics, and methods for monitoring and assessing risk that are necessary to develop the allowance for loan losses. Unique characteristics such as borrower type, loan type, collateral type, and risk characteristics define each class. The following table illustrates the portfolio segments and classes for the Company’s loan portfolio: Portfolio Segment Class Real Estate Loans Secured by one- to four-family residences Secured by multi-family residences Construction Commercial real estate Home equity lines of credit Other Loans Commercial & industrial Other loans The Company’s primary lending activity is the origination of one- to four-family residential real estate mortgage loans. At December 31, 2019, $212.9 million, or 77.1%, of the total loan portfolio consisted of one- to four-family residential real estate mortgage loans compared to $221.6 million, or 78.2%, of the total loan portfolio at December 31, 2018. The Company offers home equity lines of credit, which are primarily secured by a second mortgage on one- to four-family residences. At December 31, 2019, home equity lines of credit totaled $17.5 million, or 6.3%, of total loans receivable compared to $16.8 million, or 5.9%, of total loans receivable at December 31, 2018. The underwriting standards for home equity lines of credit include a determination of the applicant’s credit history, an assessment of the applicant’s ability to meet existing obligations and payments on the proposed loan and the value of the collateral securing the loan. The combined loan-to-value ratio (first and second mortgage liens) for home equity lines of credit is generally limited to 90%. The Company originates home equity lines of credit without application fees or borrower-paid closing costs. Home equity lines of credit are offered with adjustable-rates of interest indexed to the prime rate, as reported in The Wall Street Journal . Multi-family residential loans generally are secured by rental properties. Multi-family real estate loans are offered with fixed and adjustable interest rates. Loans secured by multi-family real estate totaled $10.9 million, or 3.9%, of the total loan portfolio at December 31, 2019 compared to $10.2 million, or 3.6%, of the total loan portfolio at December 31, 2018. Multi-family real estate loans are originated for terms of up to 20 years. Adjustable-rate multi-family real estate loans are tied to the average yield on U.S. Treasury securities, subject to periodic and lifetime limitations on interest rate changes. Loans secured by multi-family real estate generally involve a greater degree of credit risk than one- to four-family residential mortgage loans and carry larger loan balances. This increased credit risk is a result of several factors, including the concentration of principal in a limited number of loans and borrowers, the effects of general economic conditions on income producing properties, and the increased difficulty of evaluating and monitoring these types of loans. Furthermore, the repayment of loans secured by multi-family real estate typically depends upon the successful operation of the real estate property securing the loans. If the cash flow from the project is reduced, the borrower’s ability to repay the loan may be impaired. The Company originates construction loans for the purchase of developed lots and for the construction of single-family residences. At December 31, 2019, construction loans totaled $4.7 million, or 1.7%, of total loans receivable compared to $4.9 million, or 1.7%, at December 31, 2018. At December 31, 2019, the additional unadvanced portion of these construction loans totaled $4.6 million compared to $4.4 million at December 31, 2018. Construction loans are offered to individuals for the construction of their personal residences by a qualified builder (construction/permanent loans). Before making a commitment to fund a construction loan, the Company requires an appraisal of the property by an independent licensed appraiser. The Company generally also reviews and inspects each property before disbursement of funds during the term of the construction loan. Construction financing generally involves greater credit risk than long-term financing on improved, owner-occupied real estate. Risk of loss on a construction loan depends largely upon the accuracy of the initial estimate of the value of the property at completion of construction compared to the estimated cost (including interest) of construction and other assumptions. If the estimate of construction cost proves to be inaccurate, the Company may be required to advance additional funds beyond the amount originally committed in order to protect the value of the property. Moreover, if the estimated value of the completed project proves to be inaccurate, the borrower may hold a property with a value that is insufficient to assure full repayment of the loan. Commercial real estate loans are secured by office buildings, mixed-use properties, places of worship and other commercial properties. Loans secured by commercial real estate totaled $23.1 million, or 8.3%, of the Company’s total loan portfolio at December 31, 2019 compared to $22.5 million, or 7.9%, of our total loan portfolio at December 31, 2018. The Company generally originates adjustable-rate commercial real estate loans with maximum terms of up to 15 years. The maximum loan-to-value ratio of commercial real estate loans is 80%. Loans secured by commercial real estate generally are larger than one- to four-family residential loans and involve greater credit risk. Commercial real estate loans often involve large loan balances to single borrowers or groups of related borrowers. Repayment of these loans depends to a large degree on the results of operations and management of the properties securing the loans or the businesses conducted on such property, and may be affected to a greater extent by adverse conditions in the real estate market or the economy in general. Accordingly, the nature of these loans makes them more difficult for management to monitor and evaluate. The commercial and industrial product set includes loans to individuals or businesses on an installment basis secured by vehicles, equipment or other durable goods for which the loans were made, loans for and secured by machinery and/or equipment for which a legitimate resale market exists, lines of credit to businesses and individuals, and unsecured loans to businesses and individuals on a short-term basis. At December 31, 2019, these loans totaled $7.1 million, or 2.6%, of the total loan portfolio compared to $7.3 million, or 2.6%, at December 31, 2018. These loans carry a higher risk than commercial real estate loans by the nature of the underlying collateral, which can be business assets such as equipment and accounts receivable. To reduce the risk, management also attempts to secure secondary collateral, such as real estate, and obtain personal guarantees of the borrowers. To further reduce risk and enhance liquidity, these loans generally carry variable rates of interest, repricing in five-year periods, and have a maturity of ten years or less. The Company is an approved SBA lender. SBA acts as a loan guarantor and these loans are generally for commercial business purposes versus real estate. The Company follows the Small Business Administration lending guidelines regarding eligibility, underwriting etc. as stated in SBA’s most current version of SOP 50 10 SBA’s Lender and Development Company Loan Program. The Company offers a variety of other loans secured by property other than real estate. At December 31, 2019, these other loans totaled $44,000, or 0.1%, of the total loan portfolio compared to other loans totaling $50,000, or 0.1%, of the total loan portfolio at December 31, 2018. These loans include automobile, passbook, overdraft protection and unsecured loans. Due to the relative immateriality of other loans, the Company’s risk associated with these loans is not considered significant. The following table sets forth the allowance for loan losses allocated by loan class and the activity in the allowance for loan losses for the years ending December 31, 2019 and 2018. The allowance for loan losses allocated to each class is not necessarily indicative of future losses in any particular class and does not restrict the use of the allowance to absorb losses in other classes. Secured by Secured by one-to-four multi-family Home equity At December 31, 2019 family residences residences Construction Commercial lines of credit Commercial Other/ (In thousands) real estate loans real estate loans real estate loans real estate loans real estate loans & industrial Unallocated Total Allowance for loan losses: Beginning Balance $ 866 $ 77 $ 24 $ 284 $ 103 $ 97 $ 110 $ 1,561 Charge-offs (1) — — (214) — — — (215) Recoveries — — — — — — — — Provisions (Credits) (77) 4 (1) 440 1 7 (79) 295 Ending balance $ 788 $ 81 $ 23 $ 510 $ 104 $ 104 $ 31 $ 1,641 Ending balance: related to loans individually evaluated for impairment — — — $ 154 — $ 10 — $ 164 Ending balance: related to loans collectively evaluated for impairment $ 788 $ 81 $ 23 $ 356 $ 104 $ 94 $ 31 $ 1,477 Loans receivables: Ending balance $ 212,903 $ 10,876 $ 4,679 $ 23,081 $ 17,459 $ 7,133 $ 44 $ 276,175 Ending balance: related to loans individually evaluated for impairment $ 55 — — $ 954 — $ 45 — $ 1,054 Ending balance: related to loans collectively evaluated for impairment $ 212,848 $ 10,876 $ 4,679 $ 22,127 $ 17,459 $ 7,088 $ 44 $ 275,121 Secured by Secured by one-to-four multi-family Home equity At December 31, 2018 family residences residences Construction Commercial lines of credit Commercial Other/ (In thousands) real estate loans real estate loans real estate loans real estate loans real estate loans & industrial Unallocated Total Allowance for loan losses: Beginning Balance $ 816 $ 80 $ 54 $ 148 $ 107 $ 47 $ 9 $ 1,261 Charge-offs — — — — — — — — Recoveries — — — — — — — — Provisions (Credits) 50 (3) (30) 136 (4) 50 101 300 Ending balance $ 866 $ 77 $ 24 $ 284 $ 103 $ 97 $ 110 $ 1,561 Ending balance: related to loans individually evaluated for impairment — — — — — — — — Ending balance: related to loans collectively evaluated for impairment $ 866 $ 77 $ 24 $ 284 $ 103 $ 97 $ 110 $ 1,561 Loans receivables: Ending balance $ 221,602 $ 10,241 $ 4,898 $ 22,492 $ 16,766 $ 7,290 $ 50 $ 283,339 Ending balance: related to loans individually evaluated for impairment — — — — — — — — Ending balance: related to loans individually evaluated for impairment $ 221,602 $ 10,241 $ 4,898 $ 22,492 $ 16,766 $ 7,290 $ 50 $ 283,339 The Company’s policies, consistent with regulatory guidelines, provide for the classification of loans that are considered to be of lesser quality as substandard, doubtful, or loss assets. An asset is considered substandard if it is inadequately protected by the current net worth and paying capacity of the obligor or of the collateral pledged, if any. Substandard assets include those assets characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Assets classified as doubtful have all of the weaknesses inherent in those classified as substandard with the added characteristic that the weaknesses present make collection or liquidation in full, on the basis of currently existing facts, conditions and values, highly questionable and improbable. Assets (or portions of assets) classified as loss are those considered uncollectible and of such little value that their continuance as assets is not warranted. Assets that do not expose the Company to risk sufficient to warrant classification in one of the aforementioned categories, but which possess potential weaknesses that deserve close attention, are required to be designated as special mention. When the Company classifies assets as pass a portion of the related general loss allowances is allocated to such assets as deemed prudent. The allowance for loan losses is the amount estimated by management as necessary to absorb credit losses incurred in the loan portfolio that are both probable and reasonably estimable at the consolidated balance sheet date. The Company’s determination as to the classification of its assets and the amount of its loss allowances are subject to review by its principal state regulator, the New York State Department of Financial Services, which can require that the Company establish additional loss allowances. The Company regularly reviews its asset portfolio to determine whether any assets require classification in accordance with applicable regulations. The following table summarizes impaired loans information by portfolio class as of and for the years ended December 31, 2019 and 2018: As of December 31, 2019 Interest Income Unpaid Average Recognized Recorded Principal Related Recorded on Cash (In thousands) Investment Balance Allowance Investment Basis Without an allowance recorded: Secured by one-to-four residences $ 55 $ 55 $ — $ 55 $ — With an allowance recorded: Commercial real estate $ 954 $ 954 $ 151 $ 961 $ 33 Commercial & industrial loans $ 45 $ 45 $ 10 $ 45 $ — Total loans $ 1,054 $ 1,054 $ 161 $ 1,061 $ 33 As of December 31, 2018 Interest Income Unpaid Average Recognized Recorded Principal Related Recorded on Cash (In thousands) Investment Balance Allowance Investment Basis Without an allowance recorded: Secured by one-to-four residences $ — $ — $ — $ — $ — With an allowance recorded: Commercial real estate $ — $ — $ — $ — $ — Commercial & industrial loans $ — $ — $ — $ — $ — Total loans $ — $ — $ — $ — $ — The commercial real estate loan that was considered impaired at December 31, 2019 was sold subsequent to year-end with no additional losses incurred by the Company. The following table presents the risk category of loans by class at December 31, 2019 and 2018: Special Pass Mention Substandard Doubtful Total (In Thousands) 2019 One- to four-family residential $ 210,194 $ 183 $ 2,526 $ — $ 212,903 Multi-family residential 10,876 — — — 10,876 Construction 4,679 — — — 4,679 Commercial real estate 18,772 3,355 954 — 23,081 Home equity lines of credit 17,280 14 165 — 17,459 Commercial & industrial 7,050 10 73 — 7,133 Other loans 39 - 5 — 44 Total $ 268,890 $ 3,562 $ 3,723 $ — $ 276,175 2018 One- to four-family residential $ 218,222 $ 494 $ 2,886 $ — $ 221,602 Multi-family residential 10,241 — — — 10,241 Construction 4,898 — — — 4,898 Commercial real estate 21,313 931 248 — 22,492 Home equity lines of credit 16,565 — 201 — 16,766 Commercial & industrial 7,245 — 45 — 7,290 Other loans 50 — — — 50 Total $ 278,534 $ 1,425 $ 3,380 $ — $ 283,339 Delinquent Loans . Loans are considered past due if the required principal and interest payments have not been received within thirty days of the payment due date. An age analysis of past due loans, segregated by portfolio segment and class of loans, as of December 31, 2019 and December 31, 2018, are detailed in the following table: 30‑59 Days 60‑89 Days 90 Days or Total Past Total Loans Past Due Past Due More Due Current Receivable (In thousands) 2019 Real estate loans: One- to four-family residential $ 82 $ — $ 55 $ 137 $ 212,766 $ 212,903 Multi-family residential — — — — 10,876 10,876 Construction — — — — 4,679 4,679 Commercial — — 954 954 22,127 23,081 Home equity lines of credit — 14 — 14 17,445 17,459 Commercial & industrial 16 21 45 82 7,051 7,133 Other loans — — 5 5 39 44 Total $ 98 $ 35 $ 1,059 $ 1,192 $ 274,983 $ 276,175 2018 Real estate loans: One- to four-family residential $ 227 $ 349 $ 55 $ 631 $ 220,971 $ 221,602 Multi-family residential — — — — 10,241 10,241 Construction — — — — 4,898 4,898 Commercial 248 — — 248 22,244 22,492 Home equity lines of credit 147 — — 147 16,619 16,766 Commercial & industrial — — 45 45 7,245 7,290 Other loans — — — — 50 50 Total $ 622 $ 349 $ 100 $ 1,071 $ 282,268 $ 283,339 Nonaccrual loans, segregated by class of loan, were as follows: December 31, December 31, (In thousands) 2019 2018 Residential mortgage loans: Secured by one-to-four family residences $ 55 $ 55 55 55 Commercial loans: Real estate 954 — Commercial and industrial loans 45 45 999 45 Total nonaccrual loans $ 1,054 $ 100 There were no loans that were past due 90 days or more and still accruing interest at December 31, 2019 and 2018. At December 31, 2019 and 2018, there were no troubled debt restructurings. Interest on non-accrual loans that would have been earned if loans were accruing interest was immaterial for 2019 and 2018. Management has reviewed its loan portfolio and determined that, to the best of its knowledge, no exposure exists to sub-prime or other high-risk residential mortgages. The Company is not in the practice of originating these types of loans. Foreclosed real estate at December 31, 2019 is summarized as follows (in thousands): Beginning balance $ — Commercial real estate loans transferred to real estate owned 944 Direct write-downs (214) End of year $ 730 Activity in the valuation allowance was as follows for the year ended December 31, 2019 (in thousands): Beginning balance $ 25 Provisions charged to expense 189 Direct write-downs (214) End of year $ — Expenses incurred during the year ended December 31, 2019 related to foreclosed assets include (in thousands): Operating expenses $ 27 At December 31, 2019, the balance of foreclosed real estate includes $0 of foreclosed residential real estate properties recorded as a result of obtaining physical possession of the property. The recorded investment of mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process is $55,000 at December 31, 2019 and 2018. The Company had no foreclosed real estate at December 31, 2018. Expenses related to foreclosed assets subsequent to December 31, 2019 totaled $28,000.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2019
Premises and Equipment
Premises and Equipment	Note 4 - Premises and Equipment Premises and equipment at December 31, 2019 and 2018 are summarized as follows: 2019 2018 (In Thousands) Premises $ 5,003 $ 5,003 Furniture and equipment 3,452 3,357 8,455 8,360 Accumulated depreciation and amortization (6,016) (5,629) $ 2,439 $ 2,731 Depreciation and amortization expense was $425,000 and $445,000 for the years ended December 31, 2019 and 2018, respectively. At December 31, 2019, the Company was obligated under non-cancelable operating leases for existing branches in Penfield, Irondequoit, Webster, and Perinton, New York and for four mortgage-origination offices in Watertown, Pittsford, Greece, and Buffalo, New York. Rent expense under leases totaled $456,000 during 2019 and $457,000 during 2018. The Company occupies certain banking and mortgage origination offices under noncancelable operating lease agreements which were not reflected on the consolidated balance sheet at December 31, 2018. Upon adoption of ASC Topic 842, Leases, on January 1, 2019, the Company recorded an asset of $2.3 million and a corresponding liability in the amount of $2.6 million on the consolidated balance sheets, as a result of recognizing operating lease right-of-use assets and operating lease liabilities on the consolidated balance sheets. The Company elected to adopt the transition relief under ASC Topic 842 using the modified retrospective transition method. All lease agreements are accounted for as operating leases. The Company has no unamortized initial direct costs related to the establishment of these lease agreements as of January 1, 2019. The Company has elected the available practical expedients and implemented internal controls and key system functionality to enable the preparation of financial information on adoption. Leases have remaining lease terms that vary from less than one year up to 12 years, some of which include options to extend the leases for various renewal periods. All options to renew are included in the current lease term when management believes it is reasonably certain that the renewal options will be exercised. The components of the lease expense are as follows: For the year ended December 31, (In thousands) 2019 Operating lease cost $ 387 Short-term lease cost 69 Total $ 456 Supplemental cash flow information related to leases was as follows: For the year ended December 31, (In thousands) 2019 Cash paid for amount included in the measurement of operating lease liabilities: Operating cash flows from operating leases $ 387 Supplemental consolidated balance sheet information related to leases was as follows: (In thousands, except lease term and discount rate) December 31, 2019 Operating Leases Operating lease right-of-use assets $ 2,123 Operating lease liabilities $ 2,322 Weighted Average Remaining Lease Term Operating Leases 8.6 years Weighted Average Discount Rate Operating Leases 3.52 % Maturities of operating lease liabilities were as follows: Year Ending December 31, (In thousands) 2020 $ 318 2021 312 2022 252 2023 194 2024 206 Thereafter 1,040 Total minimum lease payments $ 2,322

Deposits

Deposits	12 Months Ended
	Dec. 31, 2019
Deposits
Deposits	Note 5 - Deposits The components of deposits at December 31, 2019 and 2018 consist of the following: 2019 2018 (In Thousands) Non-interest bearing $ 12,886 $ 10,947 NOW accounts 30,950 28,376 Regular savings, tax escrow and demand clubs 25,500 27,478 Money market 33,392 31,880 Individual retirement accounts 6,774 6,477 Certificates of deposit 126,058 117,457 $ 235,560 $ 222,615 As of December 31, 2019, individual retirement accounts and certificates of deposit have scheduled maturities as follows (in thousands): 2020 $ 96,523 2021 32,296 2022 1,903 2023 905 2024 1,205 $ 132,832 The aggregate amount of time deposits, each with a minimum denomination of $250,000 was $20,430,000 and $18,032,000 at December 31, 2019 and 2018, respectively. Listing service deposits totaled $8,506,000 and $11,225,000 at December 31, 2019 and 2018, respectively. Under the Dodd-Frank Act, deposit insurance per account owner is $250,000. Interest expense on deposits for the years ended December 31, 2019 and 2018 is as follows: 2019 2018 (In Thousands) NOW accounts $ 88 $ 92 Regular savings and demand clubs 164 147 Money market 330 345 Individual retirement accounts 116 85 Certificates of deposit 2,771 1,922 $ 3,469 $ 2,591

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2019
Borrowings
Borrowings	Note 6 - Borrowings Borrowings consist of advances from the Federal Home Loan Bank of New York (FHLB). The following table sets forth the contractual maturities of borrowings with the FHLB as of December 31: Advance Maturity Current Date Date Rate 2019 2018 (In Thousands) 09/05/12 09/05/19 1.13 % $ — $ 246 12/19/12 12/19/19 1.20 % — 321 01/04/13 01/04/19 1.52 % — 1,000 01/22/13 01/22/19 1.44 % — 1,000 02/20/13 02/20/20 1.28 % 37 185 02/20/13 02/21/23 1.77 % 345 447 01/21/14 01/22/19 1.45 % — 34 03/20/14 03/20/19 1.50 % — 103 07/21/14 07/21/21 1.94 % 250 397 07/21/14 07/22/19 2.08 % — 500 08/21/14 08/21/19 2.12 % — 1,000 10/02/14 10/04/21 2.00 % 576 867 10/15/14 10/15/21 1.69 % 286 431 11/28/14 11/29/21 1.90 % 599 890 12/31/14 12/31/19 1.63 % — 224 01/14/15 01/14/20 1.73 % 1,500 1,500 01/21/15 01/21/20 1.79 % 500 500 01/21/15 01/21/21 1.97 % 500 500 04/13/15 04/13/20 1.74 % 1,000 1,000 05/20/15 05/20/20 1.52 % 103 308 05/20/15 05/20/22 1.91 % 372 517 06/25/15 06/25/20 1.65 % 121 326 10/29/15 10/29/20 1.51 % 378 784 10/29/15 10/29/20 1.90 % 1,000 1,000 01/27/16 01/27/21 1.92 % 1,000 1,000 01/27/16 01/27/23 1.87 % 469 611 02/12/16 02/13/23 1.66 % 479 621 02/12/16 02/13/23 2.04 % 500 500 10/28/16 10/28/20 1.57 % 1,000 1,000 11/04/16 11/04/21 1.72 % 2,000 2,000 11/17/16 11/17/21 2.13 % 1,000 1,000 11/17/16 11/17/21 1.78 % 411 611 11/17/16 11/17/23 2.07 % 589 729 11/28/16 11/29/19 1.78 % — 1,500 12/21/16 12/23/19 1.91 % — 1,000 01/04/17 01/04/19 1.62 % — 1,500 01/19/17 01/21/20 1.91 % 1,000 1,000 03/24/17 03/24/22 2.00 % 719 1,017 03/24/17 03/25/24 2.28 % 956 1,164 07/24/17 07/24/20 1.88 % 1,000 1,000 07/24/17 07/26/21 2.03 % 1,000 1,000 07/24/17 07/25/22 1.94 % 545 743 08/31/17 08/31/21 1.96 % 1,000 1,000 09/11/17 09/11/20 1.80 % 1,000 1,000 09/11/17 09/12/22 2.07 % 1,500 1,500 09/27/17 09/27/22 2.28 % 1,000 1,000 01/18/18 01/18/19 2.17 % - 1,500 01/24/18 01/24/20 2.42 % 1,500 1,500 02/09/18 02/09/22 2.78 % 2,500 2,500 03/21/18 03/21/23 3.13 % 1,500 1,500 04/04/18 04/04/23 3.00 % 2,000 2,000 05/22/18 05/23/22 3.22 % 1,500 1,500 05/29/18 05/31/22 2.97 % 2,000 2,000 05/29/18 05/30/23 3.01 % 1,500 1,500 06/28/18 06/28/23 3.13 % 1,000 1,000 06/28/18 06/28/24 3.25 % 2,000 2,000 07/23/18 07/23/24 3.34 % 1,000 1,000 08/20/18 08/20/20 2.93 % 2,000 2,000 08/31/18 02/28/19 2.56 % — 1,500 09/25/18 03/25/19 2.66 % — 2,000 09/27/18 09/27/21 3.24 % 1,500 1,500 10/18/18 04/18/19 2.76 % — 1,500 10/30/18 04/30/19 2.78 % — 1,500 11/23/18 05/23/19 2.82 % — 1,500 12/03/18 01/03/19 2.61 % — 3,750 12/20/18 06/20/19 2.81 % — 2,000 01/29/19 01/30/23 2.94 % 3,000 — 01/29/19 01/29/24 2.97 % 3,000 — 09/30/19 03/30/20 2.10 % 1,000 — $ 51,735 $ 71,826 Borrowings are secured by residential mortgages with a carrying amount of $194,868,000 at December 31, 2019 and the Company’s investment in FHLB stock. As of December 31, 2019, $111,948,000 was available for borrowings. At December 31, 2018, borrowings were secured by residential mortgages with a carrying amount of $201,922,000, and $94,106,000 was available for new borrowings. The following table sets forth the contractual maturities of all FHLB borrowings at December 31, 2019 (dollars in thousands): Contractual Weighted Maturity Average Rate 2020 $ 13,140 2.04 % 2021 10,121 2.11 2022 10,137 2.60 2023 11,381 2.78 2024 6,956 3.01 $ 51,735 2.46 % The Company also has a repurchase agreement with Raymond James providing an additional $10.0 million in liquidity collateralized by the Company’s U.S. Government and agency obligations. There were no advances outstanding under the repurchase agreement at December 31, 2019 and 2018. Securities are not pledged until the borrowing is initiated. In addition to the repurchase agreement with Raymond James, the Company also has an unsecured line of credit through Atlantic Community Bankers Bank which would provide an additional $5.0 million in liquidity. There were no draws or outstanding balances from the line of credit at December 31, 2019 and 2018.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Taxes
Income Taxes	Note 7 - Income Taxes The provision for (benefit from) income taxes for 2019 and 2018 consists of the following: 2019 2018 (In Thousands) Current Federal $ 106 $ 163 State 3 4 Deferred (210) (135) $ (101) $ 32 The Company’s effective tax rate was 16% and 19% in 2019 and 2018, respectively. The effective tax rate primarily reflects the impact of non-tax interest and dividends from tax exempt securities. Items that give rise to differences between income tax expense included in the consolidated statements of income and taxes computed by applying the statutory federal tax at a rate of 21% included the following (dollars in thousands): 2019 2018 % of Pre-tax % of Pre-tax Amount Income Amount Income Federal Tax at a Statutory rate $ (129) 21 % $ 35 21 % State taxes, net of Federal provision 422 (69) 14 9 Change in valuation allowance (419) 68 (11) (7) Nontaxable interest and dividend income (18) 3 (19) (11) Other items 43 (7) 13 7 Income tax provision $ (101) 16 % $ 32 19 % Deferred income tax assets and liabilities resulting from temporary differences are summarized as follows and are included in other assets at December 31, 2019 and at December 31, 2018 in the accompanying consolidated balance sheets: 2019 2018 (In Thousands) Deferred tax assets: Deferred loan origination fees $ 75 $ 94 Allowance for loan losses - Federal 485 408 State tax credits 180 825 Supplemental Executive Retirement Plan 221 216 Unrealized loss on securities available for sale 3 49 Net operating loss 639 477 Stock compensation 42 32 Depreciation 128 — Other 84 43 1,857 2,144 Valuation allowance (994) (1,413) Total deferred tax assets, net of valuation allowance 863 731 Deferred tax liabilities: Depreciation — (9) Mortgage servicing rights (190) (213) Total deferred tax liabilities (190) (222) Net deferred tax asset $ 673 $ 509 The Company has recorded a valuation allowance for mortgage recording tax credits incurred before 2015 as well as state tax deductions since anticipated levels of future state taxable income makes it more likely than not that all of these tax benefits will not be used. Beginning in 2015, the New York State Special Additional Mortgage Recording Tax Credit became a refundable credit, with the exception of residential mortgage loans originated in Erie County. To the extent that the credit exceeds the Company’s New York State tax liability, any remaining credit will be refunded to the Company. As a thrift institution, the Bank is subject to special provisions in the income tax laws regarding its allowable income tax bad debt deduction and related tax basis bad debt reserves. Deferred income tax liabilities are to be recognized with respect to any base-year reserves which are to become taxable (or "recaptured") in the foreseeable future. Under current income tax laws, the base-year reserves would be subject to recapture if the Company pays a cash dividend in excess of earnings and profits or liquidates. The Bank does not expect to take any actions in the foreseeable future that would require the recapture of any Federal reserves. As a result, a deferred tax liability has not been recognized with respect to the Federal base-year reserve of $1,518,000 at December 31, 2019 and 2018, because the Bank does not expect that this amount will become taxable in the foreseeable future. The unrecognized deferred tax liability with respect to the Federal base-year reserve was $319,000 at December 31, 2019 and 2018. It is more likely than not that this liability will never be incurred because, as noted above, the Bank does not expect to take any action in the future that would result in this liability being incurred. The Company’s Federal and New York State tax returns, constituting the returns of the major taxing jurisdictions, are subject to examination by the taxing authorities for 2016, 2017, and 2018 as prescribed by applicable statute. No waivers have been executed that would extend the period subject to examination beyond the period prescribed by statute.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2019
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Loss	Note 8 – Accumulated Other Comprehensive Loss Changes in the components of accumulated other comprehensive loss (“AOCI”), net of tax, for the periods indicated are summarized in the table below, in thousands. For the year ended December 31, 2019 Unrealized Losses on Available- (In thousands) for-Sale Securities Total Beginning balance $ (183) $ (183) Other comprehensive income 174 174 Ending balance $ (9) $ (9) For the year ended December 31, 2018 Unrealized Losses on Available- (In thousands) for-Sale Securities Total Beginning balance $ (165) $ (165) Other comprehensive loss (18) (18) Ending balance $ (183) $ (183)

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2019
Employee Benefit Plans
Employee Benefit Plans	Note 9 - Employee Benefit Plans The Bank has a 401(k) plan for all eligible employees. Employees are eligible for participation in the 401(k) Plan after one year of service and attaining age 19. The 401(k) Plan allows employees to contribute 1% to 100% of their annual salary subject to statutory limitations. Matching contributions made by the Bank are 100% of the first 6% of compensation that an employee contributes to the 401(k) Plan. In addition, the Bank may make a discretionary contribution as a percentage of each eligible employee’s annual base compensation including the value of ESOP shares allocated. Matching contributions to the 401(k) Plan amounted to $217,000 and $218,000 for the years ended December 31, 2019 and 2018, respectively. Discretionary contributions to the 401(k) Plan were $55,000 and $28,000 for the years ended December 31, 2019 and 2018, respectively. The Bank sponsors an Employee Stock Ownership Plan (ESOP) for eligible employees who have attained age 21 and completed one year of employment. The cost of shares not committed to be released is presented in the accompanying consolidated balance sheets as a reduction of stockholders’ equity. Allocations to individual accounts are based on participant compensation. As shares are committed to be released to participants, the Company reports compensation expense equal to the current market price of the shares and the shares become outstanding for earnings per share computations. The difference between the market price and the cost of shares committed to be released is recorded as an adjustment to additional paid-in-capital. Any dividends on allocated shares reduce retained earnings. Any dividends on unallocated ESOP shares reduce debt and accrued interest. In connection with establishing the ESOP in 2007, the ESOP borrowed $700,000 from FSB Community to purchase 69,972 common shares of FSB Community’s stock. The loan is being repaid in twenty equal annual installments through 2026. The loan bears interest at the Prime Rate. Shares are released to participants on a straight-line basis as the loan is repaid and totaled 3,808 shares for each of the years ended December 31, 2019 and December 31, 2018. Total expense for the ESOP was $66,000 and $72,000 for the years ended December 31, 2019 and 2018, respectively. At December 31, 2019, the Company had 26,655 unearned ESOP shares having an aggregate market value of $463,264. The Bank has a supplemental executive retirement plan (SERP) for two participants, one current executive and one retired executive. All benefits provided under the SERP are unfunded and, as these executives retire, the Company will make payments to participants. The Company has recorded $845,000 and $826,000 at December 31, 2019 and 2018 respectively, for the SERP in other liabilities. In 2019 and 2018, the expense under the SERP totaled $79,000 and $59,000, respectively. On September 27, 2017, the Board of Directors of the Company approved the grant of restricted stock awards to its Directors and executive officers under the 2017 Equity Incentive Plan that was approved at the special meeting of stockholders on August 29, 2017 when 77,668 shares were authorized for award. There were no restricted stock awards granted in 2019. On January 5, 2018 and July 2, 2018, a total of 8,400 restricted stock awards were granted to five executive officers of the Company with the fair value of the stock at $17.52 and $17.75, respectively. The awards vest ratably over five years (20% per year for each year of the participant’s service with the Company). Vesting will automatically accelerate in the event of a participant's death, disability, or involuntary termination following a change in control. A summary of the Company’s stock award activity for the years ended December 31, 2019 and 2018 is as follows: 2019 2018 Weighted Average Price Weighted Average Stock Awards Per Share Stock Awards Price Per Share Outstanding at beginning of year 71,100 $ 16.82 62,700 $ 16.72 Grants - — 8,400 17.57 Outstanding at year end 71,100 $ 16.82 71,100 $ 16.82 Vested shares at year end 29,408 $ 16.78 15,644 $ 16.72 Unvested shares at year end 41,692 $ 16.85 55,456 $ 16.85 Total outstanding shares at year end 71,100 71,100 The Bank also has a stock-based compensation plan which allows the Company to issue up to 194,168 stock options. There were no stock options granted in 2019. On January 5, 2018 and July 2, 2018, the Board of Directors granted a combined total of 20,000 options to buy stock under the plan at exercise prices of $17.52 and $17.75, the fair value of the stock as of January 5 th and July 2 nd , respectively. These options have a 10‑year term and are vested over a five-year period. Vesting will automatically accelerate in the event of a participant's death, disability, or involuntary termination following a change in control. A summary of the Company’s stock option activity and related information for its option plans for the years ended December 31, 2019 and 2018 is as follows: 2019 2018 Weighted Weighted Average Average Exercise Exercise Exercise Price Price Per Exercise Price Price Per Options Range Share Options Range Share Outstanding at beginning of year 172,080 $ 16.69-$17.75 $ 16.82 152,080 $ 16.69‑$16.72 $ 16.72 Grants — — — 20,000 $ 17.52‑$17.75 17.58 Exercised — — — — — — Outstanding at year end 172,080 $ 16.69-$17.75 $ 16.82 172,080 $ 16.69‑$17.75 $ 16.82 Exercisable at year end 64,832 $ 16.69-$17.75 $ 16.77 30,416 $ 16.69‑$16.72 $ 16.72 The Company uses the Black-Scholes option-pricing model to estimate fair value of stock-based awards. The following weighted average assumptions were used to value options granted during the years ended December 31, 2019 and 2018: 2019 2018 Risk-free interest rate — 2.41 % Volatility factor — 10.47 % Dividends — 0.00 % Weighted average expected life (years) — 5.00 Forfeiture rate — 0.00 % The Company calculates expected volatility for stock options by taking an average of historical volatility over the past five years and a computation of implied volatility. The computation of expected term was determined based on the contractual terms of the stock-based awards and vesting schedules. The interest rate for periods within the contractual life of the award is based on the U.S. Treasury yield in effect at the time of grant. Forfeiture rates are calculated by dividing unvested shares forfeited by beginning shares outstanding. The grants to senior management and directors vest over a five year period in equal annual installments, with the first installment vesting on the first anniversary date of the grant and succeeding installments on each anniversary thereafter, through 2023. Vesting will automatically accelerate in the event of a participant's death, disability, or involuntary termination following a change in control. The compensation expense of the awards is based on the fair value of the instruments on the date of grant. The Company recorded compensation expense in the amount of $304,000 and $310,000 for the years ended December 31, 2019 and 2018, respectively and is expected to record approximately $304,000 in 2020 and 2021, $238,000 in 2022, and $5,000 in 2023. The grant date fair value of all options granted during 2018 under the methods and assumptions described above was $55,000. The Company’s unrecognized compensation cost, net of estimated forfeitures, related to the non-vested share-based compensation arrangements granted under the plan is expected to be recognized over a weighted average period of approximately 2.80 years. The aggregate intrinsic value of options outstanding and exercisable at December 31, 2019 and 2018 were approximately $40,000 and $9,000, respectively. A summary of changes in the Company’s unvested options for the year is as follows: Weighted Average Unvested Options Options Grant Date Fair Value Unvested at January 1, 2019 141,664 $ 2.31 Granted — — Vested 34,416 2.30 Unvested at December 31, 2019 107,248 $ 2.31

Other Income

Other Income	12 Months Ended
	Dec. 31, 2019
Other Income
Other Income	Note 10: Other Income The Company has included the following table regarding the Company’s other income for 2019 and 2018. All of the Company’s revenue from contracts with customers in the scope of ASC 606 is recognized within Non-Interest Income. The following table presents the Company’s sources of Non-Interest Income for the twelve months ended December 31, 2019 and 2018. Items outside the scope of ASC 606 are noted as such. For the year ended For the year ended December 31, 2019 December 31, 2018 (In thousands) Service fees Deposit related fees $ 65 $ 66 Insufficient funds fee 76 83 Total service fees 141 149 Fee income Securities commission income 8 43 Insurance commission income 11 88 Total insurance and securities commission income 19 131 Card income Debit card interchange fee income 135 146 ATM fees 30 31 Total card income 165 177 Mortgage fee income and realized gain on sales of loans* Residential mortgage loan origination fees 229 324 Commercial loan fees 85 88 Loan servicing income 298 331 Realized gain on sales of residential mortgage loans 931 1,390 Realized gain on sale of SBA loan — 47 Total mortgage fee income and realized gain on sales of loans 1,543 2,180 Bank owned life insurance 58 61 Other miscellaneous income 11 19 Total non-interest income $ 1,937 $ 2,717 *Outside scope of ASC 606 The Company recognizes revenue as it is earned and noted no impact to its revenue recognition policies as a result of the adoption of ASU 2014‑09 on January 1, 2018. The following is a discussion of key revenues within the scope of the new revenue guidance: · Service fees – Revenue from fees on deposit accounts is earned through the presentation of an individual item for processing for insufficient funds fees or customer initiated activities or passage of time for deposit related fees. · Fee income – Fee income is earned through commissions on insurance and securities sales and earned at a point in time. · Card income – Card income consists of interchange fees from consumer debit card networks and other card related services. Interchange rates are set by the card networks. Interchange fees are based on purchase volumes and other factors and are recognized as transactions occur.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions
Related Party Transactions	Note 11 - Related Party Transactions Certain employees, executive officers and directors are engaged in transactions with the Bank in the ordinary course of business. It is the Bank’s policy that all related party transactions are conducted at “arms length” and all loans and commitments included in such transactions are made in the ordinary course of business, on substantially the same terms, including interest rates and collateral, as those prevailing at the time for comparable transactions with persons not related to the Bank and do not involve more than the normal risk of collectibility or present other unfavorable terms. As of December 31, 2019 and 2018, loans outstanding with related parties were $469,000 and $485,000, respectively. During 2019, there were new loans of $415,000, sales of $360,000 and repayments totaled $71,000.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2019
Commitments
Commitments	Note 12 - Commitments The Bank is a party to financial instruments with off-balance-sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. The Bank uses the same credit policies in making commitments and conditional obligations as it does for on-balance-sheet instruments. The Bank’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit is represented by the contractual amount of those instruments summarized as follows at December 31, 2019 and 2018: 2019 2018 (In Thousands) Commitments to extend credit: Commitments to grant loans $ 11,351 $ 5,578 Unadvanced portion of construction loans 4,601 4,439 Unfunded commitments under lines of credit 23,539 18,774 $ 39,491 $ 28,791 Commitments to grant loans at fixed-rates at December 31, 2019 totaled $5.9 million and had interest rates that ranged from 3.125% to 4.875% as compared to commitments to grant loans at fixed-rates at December 31, 2018 which totaled $3.1 million and had interest rates that ranged from 4.50% to 6.00%. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Bank had one commercial letter of credit for $16,000 at December 31, 2019 and three commercial letters of credit for $64,000 at December 31, 2018. The Bank evaluates each customer’s credit worthiness on a case-by-case basis. The amount and type of collateral obtained, if deemed necessary by the Bank upon extension of credit, varies and is based on management’s credit evaluation of the counterparty. In the ordinary course of business, the Bank sells residential mortgage loans to third parties and in certain limited situations, such as in the event of an early payment default, the Bank retains credit risk exposure on those residential mortgage loans and may be required to repurchase them or to indemnify guarantors for certain losses. The Bank may also be required to repurchase residential mortgage loans when representations and warranties made by the Bank in connection with those sales are breached. When a residential mortgage loan sold to an investor fails to perform according to its contractual terms, the investor will typically review the loan file to search for errors that may have been made in the process of originating the loan. If errors were discovered and it is determined that such errors constitute a breach of a representation or warranty made to the investor in connection with the Bank’s sale of the residential mortgage loan, the Bank will be required to either repurchase the loan or indemnify the investor for losses sustained. The bank has not been required to repurchase any residential mortgage loans or indemnify any investors for any such errors.

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2019
Regulatory Matters
Regulatory Matters	Note 13 - Regulatory Matters The Bank is subject to various regulatory capital requirements. Failure to meet minimum capital requirements can initiate certain mandatory, and possibly additional discretionary, actions by regulators that, if undertaken, could have a direct material effect on the Company’s consolidated financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Bank must meet specific guidelines that involve quantitative measures of the Bank’s assets, liabilities, and certain off-balance sheet items as calculated under regulatory accounting practices. The Bank’s capital amounts and classification are subject to qualitative judgments by the regulators about components, risk weightings, and other factors. Quantitative measures established by regulation to ensure capital adequacy require the Bank to maintain minimum amounts and ratios (set forth in the table below) of total, Tier 1 capital (as defined), and Common Equity Tier 1 capital (as defined in the regulations) to risk-weighted assets (as defined), and of Tier 1 to adjusted total assets (as defined). Management believes that, as of December 31, 2019 and 2018, the Bank met all capital adequacy requirements to which it was subject. As of December 31, 2019, the most recent notification categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well capitalized the Bank must maintain minimum total risk-based, Tier 1 risk-based, Common Equity Tier 1 risk-based, and Tier 1 leverage ratios as set forth in the following table. There are no conditions or events since that notification that management believes have changed the Bank’s status as well capitalized. The Bank’s actual capital amounts and ratios are presented in the table below. Minimum To Be "Well- Minimum Capitalized" Well-Capitalized For Capital Under Prompt With Buffer, Fully Actual Adequacy Purposes Corrective Provisions Phased in for 2019 (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Amount Ratio As of December 31, 2019 Total Core Capital (to Risk-Weighted Assets) $ 30,780 15.32 %  $16,075  8.0 %  $20,093  10.0 %  $21,098  10.5 % Tier 1 Capital (to Risk-Weighted Assets) 29,139 14.50  12,056  6.0  16,075  8.0  17,079  8.5 Tier 1 Common Equity (to Risk-Weighted Assets) 29,139 14.50  9,042  4.5  13,061  6.5  14,065  7.0 Tier 1 Capital (to Assets) 29,139 9.01  12,938  4.0  16,172  5.0  16,172  5.0 As of December 31, 2018: Total Core Capital (to Risk-Weighted Assets) $ 30,896 15.70 %  $14,927  8.0 %  $18,658  10.0 %  $20,665  10.5 % Tier 1 Capital (to Risk-Weighted Assets) 29,335 14.91  11,808  6.0  14,927  8.0  16,729  8.5 Tier 1 Common Equity (to Risk-Weighted Assets) 29,335 14.91  8,856  4.5  12,128  6.5  13,777  7.0 Tier 1 Capital (to Assets) 29,335 9.07  12,938  4.0  15,216  5.0  16,173  5.0 The FRB has issued a policy guidance regarding the payment of dividends by bank holding companies. In general, the FRB’s policies provide that dividends should be paid only out of current earnings and only if the prospective rate of earnings retention by the holding company appears consistent with the organization’s capital needs, asset quality and overall financial condition. FRB guidance provides for prior regulatory review of capital distributions in certain circumstances such as where the company’s net income for the past four quarters, net of dividends previously paid over that period, is insufficient to fully fund the dividend or the company’s overall rate of earnings retention is inconsistent with the company’s capital needs and overall financial condition. The ability of a holding company to pay dividends may be restricted if a subsidiary bank becomes undercapitalized. These regulatory policies could affect the ability of FSB Bancorp to pay dividends or otherwise engage in capital distributions.

Fair Value Measurement and Fair

Fair Value Measurement and Fair Values of Financial Instruments	12 Months Ended
	Dec. 31, 2019
Fair Value Measurement and Fair Values of Financial Instruments
Fair Value Measurement and Fair Values of Financial Instruments	Note 14 - Fair Value Measurement and Fair Values of Financial Instruments Management uses its best judgment in estimating the fair value of the Company’s assets and liabilities; however, there are inherent weaknesses in any estimation technique. Therefore, for substantially all assets and liabilities, the fair value estimates herein are not necessarily indicative of the amounts the Company could have realized in a sales transaction on the dates indicated. The estimated fair value amounts have been measured as of their respective year-ends and have not been re-evaluated or updated for purposes of these consolidated financial statements subsequent to those respective dates. As such, the estimated fair values of assets and liabilities subsequent to the respective reporting dates may be different than the amounts reported at each year-end. Accounting guidance establishes a fair value hierarchy that prioritizes the inputs to valuation methods used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are as follows: Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical unrestricted assets or liabilities. Level 2: Quoted prices in markets that are not active, or inputs that are observable either directly or indirectly, for substantially the full term of the asset or liability. Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e. supported with little or no market activity). An asset or liability’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. For financial assets measured at fair value on a recurring basis, the fair value measurements by level within the fair value hierarchy used are as follows at December 31: (In Thousands) Total Level 1 Level 2 Level 3 2019 U.S. Government and agency obligations $ 14,035 $ — $ 14,035 $ — Mortgage-backed securities - residential 4,091 — 4,091 — Total Available-for-Sale Securities $ 18,126 $ — $ 18,126 $ — 2018 Total Level 1 Level 2 Level 3 U.S. Government and agency obligations $ 12,455 $ — $ 12,455 $ — Mortgage-backed securities - residential 5,876 — 5,876 — Total Available-for-Sale Securities $ 18,331 $ — $ 18,331 $ — There were no securities transferred out of level 2 securities available-for-sale during the twelve months ended December 31, 2019 or 2018. The Company had the following assets measured at fair value on a nonrecurring basis as of December 31, 2019 and 2018: December 31, 2019 (In thousands) Level 1 Level 2 Level 3 Total Fair Value Impaired loans $ — $ 803 $ 90 $ 893 Loans held for sale $ — $ 2,194 $ — $ 2,194 Foreclosed real estate $ — $ — $ 730 $ 730 Total loans $ — $ 2,997 $ 820 $ 3,817 December 31, 2018 (In thousands ) Level 1 Level 2 Level 3 Total Fair Value Impaired loans $ — $ — $ — $ — Loans held for sale $ — $ 2,133 $ — $ 2,133 Foreclosed real estate $ — $ — $ — $ — Total loans $ — $ 2,133 $ — $ 2,133 The following table presents additional quantitative information about assets measured at fair value on a nonrecurring basis and for which Level 3 inputs were used to determine fair value at the indicated date: Quantitative Information about Level 3 Fair Value Measurements Valuation Range At December 31, 2019 Techniques Unobservable Input (Weighted Avg.) Impaired loans Appraisal of collateral Appraisal Adjustments % (Sales Approach) Costs to Sell 10.0% - 50.7% (41.7) % Foreclosed real estate Appraisal of collateral Appraisal Adjustments 25.0%-29.2% (26.6) % (Market Approach) Costs to Sell 6.7%-7.3% (6.9%) % There have been no transfers of assets into or out of any fair value measurement level during the year ended December 31, 2019. Required disclosures include fair value information about financial instruments, whether or not recognized in the consolidated balance sheets, for which it is practicable to estimate that value. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. In that regard, the fair value estimates cannot be substantiated by comparison to independent markets and, in many cases, could not be realized in immediate settlement of the instrument. Certain financial instruments and all non-financial instruments are excluded from the disclosure requirements. Accordingly, the aggregate fair value amounts presented do not represent the underlying value of the Company. Due to a wide range of valuation techniques and the degree of subjectivity used in making the estimates, comparisons between the Company’s disclosures and those of other companies may not be meaningful. The following methods and assumptions were used to estimate the fair values of certain of the Company’s assets and liabilities at December 31, 2019 and 2018. Cash, Due from Banks, and Interest-Earning Demand Deposits The carrying amounts of these assets approximate their fair values. Investment Securities The fair value of securities available-for-sale (carried at fair value) and held-to-maturity (carried at amortized cost) are determined by matrix pricing, which is a mathematical technique used widely in the industry to value debt securities without relying exclusively on quoted market prices for the specific securities but rather relying on the securities’ relationship to other benchmark quoted prices and is considered to be a Level 2 measurement. Investment in Restricted Stock The carrying value of restricted stock, which consists of Federal Home Loan Bank and Atlantic Community Bankers Bank, approximates its fair value based on the redemption provisions of the restricted stock, resulting in a Level 2 classification. Loans and Loans Held for Sale The fair values of loans held in portfolio are estimated using discounted cash flow analyses. The discount rate considers a market participant’s cost of funds, liquidity premiums, capital charges, servicing charges, and expectations of future rate movements (for variable rate loans), resulting in a Level 3 classification. Projected future cash flows are calculated based upon contractual maturity or call dates, projected repayments and prepayments of principal, and adjusted for potential defaulted loans. Mortgage loans held for sale in the secondary market are carried at the lower of cost or fair value, resulting in a Level 2 classification. Separate determinations of fair value for residential and commercial loans are made on an aggregate basis. Fair value is determined based solely on the effect of changes in secondary market interest rates and yield requirements from the commitment date to the date of the consolidated financial statements. Impaired Loans The fair value of impaired loans with specific allocations of the allowance for loan losses is generally based on recent real estate appraisals. These appraisals may utilize a single valuation approach or a combination of approaches including comparable sales and the income approach. Adjustments are routinely made in the appraisal process by the independent appraisers to adjust for differences between the comparable sales and income data available for similar loans and collateral underlying such loans. Non-real estate collateral may be valued using an appraisal, net book value per the borrower's financial statements, or aging reports, adjusted or discounted based on management's historical knowledge, changes in market conditions from the time of the valuation, and management's expertise and knowledge of the client and client's business, resulting in a Level 3 fair value classification. The one impaired loan, which was disposed of subsequent to year-end, was valued using prices at which the loan was sold, resulting in a Level 2 fair value classification. Impaired loans are evaluated on a quarterly basis for additional impairment and adjusted in accordance with the allowance policy. The Company had no unsecured impaired loans as of December 31, 2019 and 2018. Accrued Interest Receivable and Payable The carrying amount of accrued interest receivable and payable approximates fair value. Deposits The fair values disclosed for demand deposits (e.g., NOW accounts, non-interest checking, regular savings and certain types of money market accounts) are, by definition, equal to the amount payable on demand at the reporting date (i.e., their carrying amounts), resulting in a Level 1 classification. The carrying amounts for variable-rate certificates of deposit approximate their fair values at the reporting date, resulting in a Level 1 classification. Fair values for fixed-rate certificates of deposit are estimated using a discounted cash flow calculation that applies market interest rates currently being offered on certificates to a schedule of aggregated expected monthly maturities on time deposits, resulting in a Level 2 classification. Borrowings The fair values of FHLB long-term borrowings are estimated using discounted cash flow analyses, based on the quoted rates for new FHLB advances with similar credit risk characteristics, terms and remaining maturity, resulting in a Level 2 classification. Foreclosed Real Estate For each of the foreclosed real estate properties owned by the Bank during 2019, fair value was determined as either the highest price offered to the Bank for the property by a willing market participant or the appraisal value of the collateral less a discount factor. If there were changes to the conditions surrounding the property or management did not believe that a relied-upon offer was valid subsequent to the establishment of fair value, a new fair value was determined to be equal to or supported by the highest price from a current valid offer to the Bank. Fair value was discounted for estimated costs to sell as the Bank believed that each property would be sold with additional related costs. The carrying amounts and estimated fair values of the Company’s financial instruments at December 31, 2019 and 2018 are as follows: 2019 2018 Fair Value Carrying Fair Carrying Fair Hierarchy Amount Value Amount Value (In Thousands) Financial assets: Cash and due from banks $ 1,689 $ 1,689 $ 1,581 $ 1,581 Interest bearing demand deposits 6,244 6,244 4,710 4,710 Securities available for sale 18,126 18,126 18,331 18,331 Securities held to maturity 5,166 5,297 6,052 6,030 Investment in restricted stock 2,757 2,757 3,637 3,637 Loans held for sale 2,194 2,194 2,133 2,133 Loans, net 274,508 279,114 281,741 280,173 Foreclosed real estate 730 730 — — Accrued interest receivable 807 807 876 876 Financial liabilities: Demand deposits, savings, NOW and MMDA 102,728 102,728 98,681 98,681 Time deposits 132,832 132,972 123,934 124,182 Borrowings 51,735 52,348 71,826 71,086 Accrued interest payable 111 111 168 168

FSB Bancorp, Inc. (Parent Compa

FSB Bancorp, Inc. (Parent Company Only) Financial Information	12 Months Ended
	Dec. 31, 2019
FSB Bancorp, Inc. (Parent Company Only) Financial Information
FSB Bancorp, Inc. (Parent Company Only) Financial Information	Note 15 - FSB Bancorp, Inc. (Parent Company Only) Financial Information Balance Sheets December 31 2019 2018 (In Thousands) Assets Cash and cash equivalents $ 1,474 $ 1,570 Investment in banking subsidiary 29,796 29,661 ESOP loan receivable 297 331 Total Assets $ 31,567 $ 31,562 Liabilities and Stockholders’ Equity Total Liabilities $ 23 $ 49 Stockholders’ Equity 31,544 31,513 Total Liabilities and Stockholders’ Equity $ 31,567 $ 31,562 Statements of Income Year Ended December 31 2019 2018 (In Thousands) Interest Income $ 39 $ 36 Other Expense (447) (500) Equity in undistributed (loss) earnings of banking subsidiary (105) 599 Net (Loss) Income $ (513) $ 135 Statements of Cash Flows Year Ended December 31 2019 2018 (In Thousands) Cash flows from operating activities Net (loss) income $ (513) $ 135 Adjustments to reconcile net (loss) income to net cash flows from operating activities Equity in undistributed loss (earnings) of banking subsidiary 105 (599) Stock based compensation 304 310 Net (decrease) increase in other liabilities (26) 15 Net cash flows from operating activities (130) (139) Cash flows from investing activities Payments received on ESOP loan 34 34 Net cash flows from investing activities 34 34 Cash flows from financing activities Purchase of common stock — (42) Net cash flows from financing activities — (42) Net decrease in cash and cash equivalents (96) (147) Cash and cash equivalents - beginning 1,570 1,717 Cash and cash equivalents - ending $ 1,474 $ 1,570

Nature of Operations and Summ_2

Nature of Operations and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Nature of Operations and Summary of Significant Accounting Policies
Organization and Nature of Operations	Organization and Nature of Operations On March 2, 2016, the Boards of Directors of the FSB Community Bankshares, Inc. (“FSB Community”), FSB Community Bankshares, MHC (the “MHC”), and Fairport Savings Bank (the “Bank”) unanimously adopted a Plan of Conversion of the MHC pursuant to which the MHC undertook a “second-step” conversion and now no longer exists. The Bank reorganized from a two-tier mutual holding company structure to a fully public stock holding company structure effective July 13, 2016, and, as a result, is now the wholly-owned subsidiary of FSB Bancorp, Inc. (the “Company”). FSB Bancorp, Inc., the new stock holding company for the Bank, sold 1,034,649 shares of common stock at $10.00 per share, for gross offering proceeds of $10.3 million in its stock offering. Additionally, after accounting for conversion-related expenses of $1.4 million, which offset gross proceeds, the Company received $8.9 million in net proceeds. Concurrent with the completion of the conversion and reorganization, shares of common stock of FSB Community owned by public stockholders were exchanged for shares of the Company’s common stock so that the former public stockholders of FSB Community owned approximately the same percentage of the Company’s common stock as they owned of FSB Community’s common stock immediately prior to the conversion. Stockholders of FSB Community received 1.0884 shares of the Company’s common stock for each share of FSB Community’s stock they owned immediately prior to completion of the transaction. Cash in lieu of fractional shares was paid based on the offering price of $10.00 per share. As a result of the offering and the exchange of shares, the Company had 1,941,688 shares outstanding as of December 31, 2016. In accordance with Board of Governors of the Federal Reserve System regulations, at the time of the reorganization, the Company substantially restricted retained earnings by establishing a liquidation account. The liquidation account will be maintained for the benefit of eligible account holders who continue to maintain their accounts at the Bank after conversion. The Bank has established a parallel liquidation account to support the Company’s liquidation account in the event the Company does not have sufficient assets to fund its obligations under its liquidation account. The liquidation accounts will be reduced annually to the extent that eligible account holders have reduced their qualifying deposits. Subsequent increases will not restore an eligible account holder’s interest in the liquidation accounts. In the event of a complete liquidation of the Bank or the Company, each account holder will be entitled to receive a distribution in an amount proportionate to the adjusted qualifying account balances then held. The Bank may not pay dividends if those dividends would reduce equity capital below the required liquidation account amount. The Company provides a variety of financial services to individuals and corporate customers through its wholly-owned subsidiary, Fairport Savings Bank. The Bank’s operations are conducted in five branches located in Monroe County, New York. The Company and the Bank are subject to the regulations of certain regulatory authorities and undergo periodic examinations by those regulatory authorities. The Company’s principal business consists of originating one-to-four-family residential real estate mortgages, home equity loans and lines of credit and to a lesser extent, originations of commercial real estate, multi-family, construction, commercial and industrial, and other consumer loans. The Company has three mortgage origination offices located in Pittsford, New York; Watertown, New York; and Buffalo, New York. The Bank also provides non-deposit investment services to its customers through its wholly-owned subsidiary, Fairport Wealth Management. Prior to January 15, 2016, Fairport Wealth Management was known as Oakleaf Services Corporation. The results of operations of Fairport Wealth Management are not material to the consolidated financial statements.
Basis of Consolidation	Basis of Consolidation The consolidated financial statements include the accounts of the Company, the Bank and Fairport Wealth Management. All significant intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expense during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant changes in the near term relate to the determination of the allowance for loan losses, deferred tax assets, and the estimation of fair values for accounting and disclosure purposes. The Company is subject to the regulations of various governmental agencies. The Company also undergoes periodic examinations by the regulatory agencies which may subject it to further changes with respect to asset valuations, amounts of required loss allowances, and operating restrictions resulting from the regulators’ judgments based on information available to them at the time of their examinations.
Significant Group Concentrations of Credit Risk	Significant Group Concentrations of Credit Risk Most of the Company’s activities are with customers located within Monroe, Livingston, Ontario, Orleans, Wayne, Jefferson, Niagara, and Erie Counties, New York. Note 2 discusses the types of securities that the Company invests in. The concentration of credit by type of loan is set forth in Note 3. Although the Bank has a diversified loan portfolio, its debtors’ ability to honor their contracts is primarily dependent upon the real estate and general economic conditions in those areas.
Cash and Cash Equivalents	Cash and Cash Equivalents For purposes of the consolidated statement of cash flows, cash and cash equivalents include cash, balances due from banks and interest-earning demand deposits (with an original maturity of three months or less).
Securities	Securities The Company classifies debt investing securities as either available-for-sale or held-to-maturity. The Company does not hold any securities considered to be trading. Available-for-sale securities are reported at fair value, with net unrealized gains and losses reflected as a separate component of stockholders’ equity, net of the applicable income tax effect. Held-to-maturity securities are those that the Company has the ability and intent to hold until maturity and are reported at amortized cost. Gains or losses on investment security transactions are based on the amortized cost of the specific securities sold. Premiums and discounts on securities are amortized and accreted into income using the interest method over the period to maturity. When the fair value of a held-to-maturity or available-for-sale security is less than its amortized cost basis, an assessment is made at the balance sheet date as to whether other-than-temporary impairment (“OTTI”) is present. The Company considers numerous factors when determining whether potential OTTI exists and the period over which the debt security is expected to recover. The principal factors considered are (1) the length of time and the extent to which the fair value has been less than amortized cost basis, (2) the financial condition of the issuer (and guarantor, if any) and adverse conditions specifically related to the security industry or geographic area, (3) failure of the issuer of the security to make scheduled interest or principal payments, (4) any changes to the rating of a security by a rating agency, and (5) the presence of credit enhancements, if any, including the guarantee of the federal government or any of its agencies. For debt securities, OTTI is considered to have occurred if (1) the Company intends to sell the security, (2) it is more likely than not the Company will be required to sell the security before recovery of its amortized cost basis, or (3) if the present value of expected cash flows is not sufficient to recover the entire amortized cost basis or carrying value. For debt securities, credit-related OTTI is recognized in earnings while noncredit-related OTTI on securities not expected to be sold is recognized in other comprehensive income (loss). Credit-related OTTI is measured as the difference between the present value of an impaired security’s expected cash flows and its amortized cost basis or carrying value. Noncredit-related OTTI is measured as the difference between the fair value of the security and its amortized cost, or carrying value, less any credit-related losses recognized. For securities classified as held-to-maturity, the amount of OTTI recognized in other comprehensive income (loss) is accreted to the credit-adjusted expected cash flow amounts of the securities over future periods. Investment securities are exposed to various risks such as interest rate, market and credit risks. Due to the level of risk associated with certain investment securities, it is at least reasonably possible that changes in the values of investment securities will occur in the near term and that such changes could materially affect the amounts reported in the accompanying consolidated financial statements.
Restricted Stock	Restricted Stock Restricted equity securities are held as a long-term investment and value is determined based on the ultimate recoverability of the par value. Impairment of these investments is evaluated quarterly and is a matter of judgment that reflects management’s view of the issuer’s long-term performance, which includes factors such as the following: its operating performance; the severity and duration of declines in the fair value of its net assets related to its capital stock amount; its commitment to make payments required by law or regulation and the level of such payments in relation to its operating performance; and its liquidity and funding position. After evaluating these considerations, the Company concluded that the par value of these investments will be recovered and, as such, has not recognized any impairment on its holdings of restricted equity securities during the current year. The Company holds restricted stock from Federal Home Loan Bank and Atlantic Community Bankers Bank. No impairment charges were recorded related to the restricted stock during 2019 or 2018.
Loans Held for Sale	Loans Held for Sale Mortgage loans held for sale in the secondary market are carried at the lower of amortized cost or fair value. Separate determinations of fair value for residential and commercial loans are made on an aggregate basis. Fair value is determined based solely on the effect of changes in secondary market interest rates and yield requirements from the commitment date to the date of the consolidated financial statements. Realized gains and losses on sales are computed using the specific identification method.
Loan Servicing Rights	Loan Servicing Rights The Company retains the servicing on a portion of conventional fixed-rate mortgage loans sold and receives a fee based on the principal balance outstanding. Loans serviced for others totaled $116,531,000 and $123,755,000 at December 31, 2019 and 2018, respectively. The Company also sells correspondent FHA, VA, and USDA mortgage loans, servicing released. Loan servicing rights are recorded at fair value when loans are sold with servicing rights retained. The fair value of the mortgage servicing rights (“MSRs”) is determined using a method which utilizes servicing income, discount rates, and prepayment speeds relative to the Bank’s portfolio for MSRs and are amortized over the life of the loan. MSRs amounted to $726,000 and $812,000 at December 31, 2019 and 2018, respectively, and are included in other assets on the consolidated balance sheets. In 2019, $30,000 was capitalized and $116,000 was amortized. In 2018, $5,000 was capitalized with $85,000 amortized.
Loans	Loans Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off generally are reported at their outstanding unpaid principal balances adjusted for charge-offs, the allowance for loan losses, and net deferred origination fees and costs. Interest income is accrued on the unpaid principal balance. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the related loan yield using the interest method over the estimated life of the loan. The accrual of interest is generally discontinued when the contractual payment of principal or interest has become 90 days past due or management has serious doubts about further collectibility of principal or interest, even though the loan is currently performing. A loan may remain on accrual status if it is in the process of collection and is well secured. When a loan is placed on nonaccrual status, unpaid interest credited to income in the current year is reversed. Interest received on nonaccrual loans generally is either applied against principal or reported as interest income, according to management’s judgment as to the collectibility of principal. Generally, loans are restored to accrual status when the obligation is brought current, has performed in accordance with the contractual terms for a reasonable period of time and the ultimate collectibility of the total contractual principal and interest is no longer in doubt.
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses (the “Allowance”) is established as losses are estimated to have occurred in the loan portfolio. The allowance for loan losses is recorded through a provision for loan losses charged to earnings. Loan losses are charged against the allowance when management believes the loan is uncollectable. 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 collectibility of the loans in light of historical experience, the nature and volume of the loan portfolio, adverse situations that may affect the borrower’s ability to repay, the 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. The allowance consists of specific, general and unallocated components. The specific component relates to loans that are deemed impaired and classified as either special mention, substandard, doubtful, or loss. For such loans that are also classified as impaired, an allowance is generally established when the collateral value of the impaired loan is lower than the carrying value of that loan. The general component covers non-classified loans and is based on historical loss experience adjusted for the following qualitative factors: effects of changes in lending policies; national and/or local economic trends and conditions; trends in volume and terms of loans; experience, ability, and depth of management; levels and trends of delinquencies, non-accruals and classified loans; quality of institutions loan review system; collateral value for collateral dependent loans; concentrations of credit; and competition, legal and regulatory requirements on level of estimated credit losses. 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 specific and general losses in the portfolio. A loan is considered impaired when, based on current information and events, it is probable that the Bank will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan-by-loan basis 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. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, the Company does not separately identify individual consumer and residential loans for impairment disclosures unless subject to a troubled debt restructuring. In addition, Federal regulatory agencies, as an integral part of their examination process, periodically review the Company’s allowance for loan losses and may require the Company to recognize additions to the allowance based on their judgments about information available to them at the time of their examination, which may not be currently available to management. Based on management’s comprehensive analysis of the loan portfolio, management believes the current level of the allowance for loan losses is adequate.
Bank Owned Life Insurance	Bank Owned Life Insurance The Company holds life insurance policies on a key executive. Bank owned life insurance is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement.
Premises and Equipment	Premises and Equipment Premises and equipment are stated at cost. Depreciation and amortization are computed on the straight-line basis over the shorter of the estimated useful lives or lease terms (in the case of leasehold improvements) of the related assets. Estimated useful lives are generally 20 to 30 years for premises and 3 to 10 years for furniture and equipment.
Foreclosed Real Estate	Foreclosed Real Estate Real estate properties acquired through, or in lieu of, loan foreclosure are initially recorded at fair value less estimated selling costs at the date of foreclosure. Any write-downs based on the asset’s fair value at date of acquisition are charged to the allowance for loan losses. After foreclosure, property held for sale is carried at the lower of the new basis or fair value less any costs to sell. Costs of significant property improvements are capitalized, whereas costs relating to holding property are expensed. Valuations are periodically performed by management or third party valuation experts, and any subsequent write-downs are recorded as a charge to earnings, if necessary, to reduce the carrying value of the property to the lower of its cost or fair value less cost to sell. The Company had two foreclosed commercial real estate loans at December 31, 2019 and no foreclosed loans at December 31, 2018. At December 31, 2019 and 2018 the Company had one residential mortgage loan for $55,000 in the process of foreclosure
Income Taxes	Income Taxes Income taxes are provided for the tax effects of certain transactions reported in the consolidated financial statements. Income taxes consist of taxes currently due plus deferred taxes related primarily to temporary differences between the financial reporting and income tax basis of the allowance for loan losses, premises and equipment, certain state tax credits, and deferred loan origination costs. The deferred tax assets and liabilities represent the future tax return consequences of the temporary differences, which will either be taxable or deductible when the assets and liabilities are recovered or settled. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion of the deferred tax assets will not be realized. Deferred tax assets and liabilities are reflected at income tax rates applicable to the period in which the deferred tax assets and liabilities are expected to be realized or settled. As changes in tax laws or rates are enacted, deferred tax assets and liabilities are adjusted through the provision for income taxes.
Advertising Costs	Advertising Costs The Company follows the policy of charging the costs of advertising to expense as incurred.
Off-Balance Sheet Financial Instruments	Off-Balance Sheet Financial Instruments In the ordinary course of business, the Company has entered into off-balance sheet financial instruments consisting of commitments to extend credit. Such financial instruments are recorded in the consolidated balance sheets when they are funded.
Transfers of Financial Assets	Transfers of Financial Assets Transfers of financial assets are accounted for as sales, when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when (1) the assets have been isolated from the Company, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) the Company does not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Accounting principles generally require that recognized revenue, expenses, gains, and losses be included in earnings. Although certain changes in assets and liabilities, such as unrealized gains and losses on available-for-sale securities, 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 (loss). Accumulated other comprehensive income (loss) represents the sum of these items, with the exception of net income, as of the consolidated balance sheet date and is represented in the table below. As of December 31, 2019 2018 Accumulated Other Comprehensive Loss By Component: Unrealized losses on securities available-for-sale $ (12) $ (232) Tax effect 3 49 Net unrealized losses on securities available-for-sale (9) (183) Accumulated other comprehensive loss $ (9) $ (183)
Earnings Per Common Share	Earnings Per Common Share Basic earnings per common share is calculated by dividing net income available to common stockholders by the weighted-average number of common shares outstanding during the period. Diluted earnings per share is computed in a similar manner to that of basic earnings per share except that the weighted-average number of common shares outstanding is increased to reflect the assumed exercise and conversion of dilutive stock options and unvested restricted stock. In periods of loss, basic earnings per common share and diluted earnings per share are the same due to the fact that the inclusion of any of the dilutive shares will result in an anti-dilutive impact, driven by the loss. Net income available to common stockholders is net income of the Company. Unallocated common shares held by the ESOP are not included in the weighted average number of common shares outstanding for purposes of calculating earnings per common share until they are committed to be released. The following table sets forth the calculation of basic and diluted earnings per share. Year Ended December 31, (In thousands, except per share data) 2019 2018 Basic and Diluted Earnings (Loss) Per Common Share Net income (loss) available to common stockholders $ (513) $ 135 Weighted average basic common shares outstanding 1,859 1,851 Weighted average diluted common shares outstanding 1,859 1,853 Earnings (loss) per common share – basic and diluted $ (0.28) $ 0.07
Share Repurchases	Share Repurchases The Company announced on July 27, 2017 that the Board of Directors had adopted its first stock repurchase program. Under the repurchase program, the Company may repurchase up to 97,084 shares of its common stock, or approximately 5% of its then outstanding shares. The Company did not repurchase any shares in 2019. In 2018, the Company repurchased 2,592 shares at an average price of $16.38 per share. As of December 31, 2019, the Company had repurchased 72,127 shares at an average price of $15.31 per share.
Stock-Based Compensation	Stock-Based Compensation On September 27, 2017, the Board of Directors of the Company approved restricted stock and stock option grants to senior management and the directors of the Company, pursuant to the terms of the 2017 Equity Incentive Plan (the “Plan”). The Plan was approved previously by the Company’s stockholders on August 29, 2017. There were no stock options or shares of restricted stock granted to senior management or directors in 2019. An aggregate of 20,000 stock options and 8,400 shares of restricted stock were granted to senior management during the year ended December 31, 2018. The grants to senior management and directors vest over a five year period in equal annual installments, with the first installment vesting on the first anniversary date of the grant and succeeding installments on each anniversary thereafter, through 2023.
Subsequent Events	Subsequent Events Proposed Merger with Evans Bancorp, Inc. On December 19, 2019, FSB Bancorp and Evans entered into a merger agreement (the “Merger Agreement”) that provides that FSB Bancorp will merge with and into Evans, with Evans remaining as the surviving corporation in a multi-step merger transaction (the “Merger”). Following the Merger, Fairport Savings Bank will merge with and into Evans Bank, with Evans Bank remaining as the surviving bank (the “Bank Merger”). At the effective time of the Merger, each outstanding share of FSB Bancorp common stock will be converted into the right to receive, at the election of such holder, either (i) 0.4394 shares of Evans common stock, or (ii) $17.80 in cash, together with cash in lieu of fractional shares, if any. All such elections are subject to adjustment on a pro rata basis, so that approximately 50% of the aggregate merger consideration paid to FSB Bancorp stockholders will be the cash consideration and approximately 50% will be the stock consideration. The completion of the Merger is subject to customary closing conditions, including approval by FSB Bancorp’s stockholders and the receipt of regulatory approvals or waivers from the Board of Governors of the Federal Reserve System, the Office of the Comptroller of the Currency and the New York State Department of Financial Services. On March 18, 2020, the Office of the Comptroller of the Currency issued its approval for the Bank Merger. On March 20, 2020, the Federal Reserve Bank of New York issued its waiver for the Merger. COVID-19 The outbreak of Coronavirus Disease 2019 (“COVID-19”) could adversely impact a broad range of industries in which the Company’s customers operate and impair their ability to fulfill their obligations to the Company. The World Health Organization has declared Covid-19 to be a global pandemic indicating that almost all public commerce and related business activities must be, to varying degrees, curtailed with the goal of decreasing the rate of new infections. The spread of the outbreak will likely cause disruptions in the U.S. economy and is highly likely to disrupt banking and other financial activity in the areas in which the Company operates and could potentially create widespread business continuity issues for the Company. The Company’s business is dependent upon the willingness and ability of its employees and customers to conduct banking and other financial transactions. If the global response to contain COVID-19 escalates or is unsuccessful, the Company could experience a material adverse effect on its business, financial condition, results of operations and cash flows.

Nature of Operations and Summ_3

Nature of Operations and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Nature of Operations and Summary of Significant Accounting Policies
Schedule of comprehensive income (loss)	Accumulated other comprehensive income (loss) represents the sum of these items, with the exception of net income, as of the consolidated balance sheet date and is represented in the table below. As of December 31, 2019 2018 Accumulated Other Comprehensive Loss By Component: Unrealized losses on securities available-for-sale $ (12) $ (232) Tax effect 3 49 Net unrealized losses on securities available-for-sale (9) (183) Accumulated other comprehensive loss $ (9) $ (183)
Schedule of basic earnings per share	The following table sets forth the calculation of basic and diluted earnings per share. Year Ended December 31, (In thousands, except per share data) 2019 2018 Basic and Diluted Earnings (Loss) Per Common Share Net income (loss) available to common stockholders $ (513) $ 135 Weighted average basic common shares outstanding 1,859 1,851 Weighted average diluted common shares outstanding 1,859 1,853 Earnings (loss) per common share – basic and diluted $ (0.28) $ 0.07

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2019
Securities
Schedule of amortized cost and estimated fair value of securities	Gross Gross Amortized Unrealized Unrealized Fair Cost Gains Losses Value December 31, 2019: (In Thousands) Available-for-Sale: U.S. Government and agency obligations $ 14,043 $ 6 $ (14) $ 14,035 Mortgage-backed securities - residential 4,095 14 (18) 4,091 $ 18,138 $ 20 $ (32) $ 18,126 Held-to-Maturity: Mortgage-backed securities - residential $ 409 $ 3 $ — $ 412 State and municipal securities 4,757 128 — 4,885 $ 5,166 $ 131 $ — $ 5,297 December 31, 2018: Available-for-Sale: U.S. Government and agency obligations $ 12,610 $ 7 $ (162) $ 12,455 Mortgage-backed securities - residential 5,953 24 (101) 5,876 $ 18,563 $ 31 $ (263) $ 18,331 Held-to-Maturity: Mortgage-backed securities - residential $ 458 $ 6 $ (1) $ 463 State and municipal securities 5,594 29 (56) 5,567 $ 6,052 $ 35 $ (57) $ 6,030
Schedule of amortized cost and estimated fair value by contractual maturity of debt securities	Available-for-Sale Held-to-Maturity Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value (In Thousands) Due in one year or less $ — $ — $ 746 $ 748 Due after one year through five years 9,043 9,041 2,517 2,554 Due after five years through ten years 5,000 4,994 1,494 1,583 Mortgage-backed securities - residential 4,095 4,091 409 412 $ 18,138 $ 18,126 $ 5,166 $ 5,297
Schedule of continuous unrealized loss position for investment securities	Less than 12 Months 12 Months or More Total Gross Gross Gross Fair Unrealized Fair Unrealized Fair Unrealized Value Losses Value Losses Value Losses (In Thousands) 2019: Available-for-Sale U.S. Government and agency obligations $ 2,993 $ 10 $ 2,536 $ 4 $ 5,529 $ 14 Mortgage-backed securities - residential (1) 131 — 3,065 18 3,196 18 $ 3,124 $ 10 $ 5,601 $ 22 $ 8,725 $ 32 2019: Held-to-Maturity Mortgage-backed securities - residential $ — $ — $ — $ — $ — $ — State and municipal Securities — — — — — — $ — $ — $ — $ — $ — $ — 2018: Available-for-Sale U.S. Government and agency obligations $ — $ — $ 9,445 $ 162 $ 9,445 $ 162 Mortgage-backed securities - residential (1) 203 — 3,749 101 3,952 101 $ 203 $ — $ 13,194 $ 263 $ 13,397 $ 263 2018: Held-to-Maturity Mortgage-backed securities - residential $ — $ — $ 165 $ 1 $ 165 $ 1 State and municipal Securities 1,039 4 3,021 52 4,060 56 $ 1,039 $ 4 $ 3,186 $ 53 $ 4,225 $ 57

Loans and The Allowance for L_2

Loans and The Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2019
Loans and The Allowance for Loan Losses
Schedule of net loans	2019 2018 (In Thousands) Real estate loans: Secured by one- to four-family residences $ 212,903 $ 221,602 Secured by multi-family residences 10,876 10,241 Construction 4,679 4,898 Commercial real estate 23,081 22,492 Home equity lines of credit 17,459 16,766 Commercial & industrial 7,133 7,290 Other loans 44 50 Total Loans 276,175 283,339 Net deferred loan origination fees (26) (37) Allowance for loan losses (1,641) (1,561) Net Loans $ 274,508 $ 281,741
Schedule of loan portfolio of portfolio segments and classes	Portfolio Segment Class Real Estate Loans Secured by one- to four-family residences Secured by multi-family residences Construction Commercial real estate Home equity lines of credit Other Loans Commercial & industrial Other loans
Schedule of changes in the allowance for loan losses	Secured by Secured by one-to-four multi-family Home equity At December 31, 2019 family residences residences Construction Commercial lines of credit Commercial Other/ (In thousands) real estate loans real estate loans real estate loans real estate loans real estate loans & industrial Unallocated Total Allowance for loan losses: Beginning Balance $ 866 $ 77 $ 24 $ 284 $ 103 $ 97 $ 110 $ 1,561 Charge-offs (1) — — (214) — — — (215) Recoveries — — — — — — — — Provisions (Credits) (77) 4 (1) 440 1 7 (79) 295 Ending balance $ 788 $ 81 $ 23 $ 510 $ 104 $ 104 $ 31 $ 1,641 Ending balance: related to loans individually evaluated for impairment — — — $ 154 — $ 10 — $ 164 Ending balance: related to loans collectively evaluated for impairment $ 788 $ 81 $ 23 $ 356 $ 104 $ 94 $ 31 $ 1,477 Loans receivables: Ending balance $ 212,903 $ 10,876 $ 4,679 $ 23,081 $ 17,459 $ 7,133 $ 44 $ 276,175 Ending balance: related to loans individually evaluated for impairment $ 55 — — $ 954 — $ 45 — $ 1,054 Ending balance: related to loans collectively evaluated for impairment $ 212,848 $ 10,876 $ 4,679 $ 22,127 $ 17,459 $ 7,088 $ 44 $ 275,121 Secured by Secured by one-to-four multi-family Home equity At December 31, 2018 family residences residences Construction Commercial lines of credit Commercial Other/ (In thousands) real estate loans real estate loans real estate loans real estate loans real estate loans & industrial Unallocated Total Allowance for loan losses: Beginning Balance $ 816 $ 80 $ 54 $ 148 $ 107 $ 47 $ 9 $ 1,261 Charge-offs — — — — — — — — Recoveries — — — — — — — — Provisions (Credits) 50 (3) (30) 136 (4) 50 101 300 Ending balance $ 866 $ 77 $ 24 $ 284 $ 103 $ 97 $ 110 $ 1,561 Ending balance: related to loans individually evaluated for impairment — — — — — — — — Ending balance: related to loans collectively evaluated for impairment $ 866 $ 77 $ 24 $ 284 $ 103 $ 97 $ 110 $ 1,561 Loans receivables: Ending balance $ 221,602 $ 10,241 $ 4,898 $ 22,492 $ 16,766 $ 7,290 $ 50 $ 283,339 Ending balance: related to loans individually evaluated for impairment — — — — — — — — Ending balance: related to loans individually evaluated for impairment $ 221,602 $ 10,241 $ 4,898 $ 22,492 $ 16,766 $ 7,290 $ 50 $ 283,339
Schedule of impaired loans by portfolio segment	As of December 31, 2019 Interest Income Unpaid Average Recognized Recorded Principal Related Recorded on Cash (In thousands) Investment Balance Allowance Investment Basis Without an allowance recorded: Secured by one-to-four residences $ 55 $ 55 $ — $ 55 $ — With an allowance recorded: Commercial real estate $ 954 $ 954 $ 151 $ 961 $ 33 Commercial & industrial loans $ 45 $ 45 $ 10 $ 45 $ — Total loans $ 1,054 $ 1,054 $ 161 $ 1,061 $ 33 As of December 31, 2018 Interest Income Unpaid Average Recognized Recorded Principal Related Recorded on Cash (In thousands) Investment Balance Allowance Investment Basis Without an allowance recorded: Secured by one-to-four residences $ — $ — $ — $ — $ — With an allowance recorded: Commercial real estate $ — $ — $ — $ — $ — Commercial & industrial loans $ — $ — $ — $ — $ — Total loans $ — $ — $ — $ — $ —
Schedule of risk category of loans by class	Special Pass Mention Substandard Doubtful Total (In Thousands) 2019 One- to four-family residential $ 210,194 $ 183 $ 2,526 $ — $ 212,903 Multi-family residential 10,876 — — — 10,876 Construction 4,679 — — — 4,679 Commercial real estate 18,772 3,355 954 — 23,081 Home equity lines of credit 17,280 14 165 — 17,459 Commercial & industrial 7,050 10 73 — 7,133 Other loans 39 - 5 — 44 Total $ 268,890 $ 3,562 $ 3,723 $ — $ 276,175 2018 One- to four-family residential $ 218,222 $ 494 $ 2,886 $ — $ 221,602 Multi-family residential 10,241 — — — 10,241 Construction 4,898 — — — 4,898 Commercial real estate 21,313 931 248 — 22,492 Home equity lines of credit 16,565 — 201 — 16,766 Commercial & industrial 7,245 — 45 — 7,290 Other loans 50 — — — 50 Total $ 278,534 $ 1,425 $ 3,380 $ — $ 283,339
Schedule of age of the loan delinquencies by type and by amount past due	30‑59 Days 60‑89 Days 90 Days or Total Past Total Loans Past Due Past Due More Due Current Receivable (In thousands) 2019 Real estate loans: One- to four-family residential $ 82 $ — $ 55 $ 137 $ 212,766 $ 212,903 Multi-family residential — — — — 10,876 10,876 Construction — — — — 4,679 4,679 Commercial — — 954 954 22,127 23,081 Home equity lines of credit — 14 — 14 17,445 17,459 Commercial & industrial 16 21 45 82 7,051 7,133 Other loans — — 5 5 39 44 Total $ 98 $ 35 $ 1,059 $ 1,192 $ 274,983 $ 276,175 2018 Real estate loans: One- to four-family residential $ 227 $ 349 $ 55 $ 631 $ 220,971 $ 221,602 Multi-family residential — — — — 10,241 10,241 Construction — — — — 4,898 4,898 Commercial 248 — — 248 22,244 22,492 Home equity lines of credit 147 — — 147 16,619 16,766 Commercial & industrial — — 45 45 7,245 7,290 Other loans — — — — 50 50 Total $ 622 $ 349 $ 100 $ 1,071 $ 282,268 $ 283,339
Schedule of nonaccrual loans	December 31, December 31, (In thousands) 2019 2018 Residential mortgage loans: Secured by one-to-four family residences $ 55 $ 55 55 55 Commercial loans: Real estate 954 — Commercial and industrial loans 45 45 999 45 Total nonaccrual loans $ 1,054 $ 100
Schedule of foreclosed real estate	Beginning balance $ — Commercial real estate loans transferred to real estate owned 944 Direct write-downs (214) End of year $ 730
Schedule of real estate owned valuation allowance	Beginning balance $ 25 Provisions charged to expense 189 Direct write-downs (214) End of year $ —
Schedule of expenses on foreclosed assets	Operating expenses $ 27

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Premises and Equipment
Schedule of premises and equipment	2019 2018 (In Thousands) Premises $ 5,003 $ 5,003 Furniture and equipment 3,452 3,357 8,455 8,360 Accumulated depreciation and amortization (6,016) (5,629) $ 2,439 $ 2,731
Schedule of components of the lease expense	For the year ended December 31, (In thousands) 2019 Operating lease cost $ 387 Short-term lease cost 69 Total $ 456
Schedule of supplemental cash flow and balance sheet information related to leases	For the year ended December 31, (In thousands) 2019 Cash paid for amount included in the measurement of operating lease liabilities: Operating cash flows from operating leases $ 387 (In thousands, except lease term and discount rate) December 31, 2019 Operating Leases Operating lease right-of-use assets $ 2,123 Operating lease liabilities $ 2,322 Weighted Average Remaining Lease Term Operating Leases 8.6 years Weighted Average Discount Rate Operating Leases 3.52 %
Schedule of maturities of lease liabilities	Year Ending December 31, (In thousands) 2020 $ 318 2021 312 2022 252 2023 194 2024 206 Thereafter 1,040 Total minimum lease payments $ 2,322

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2019
Deposits
Schedule of components of deposits	2019 2018 (In Thousands) Non-interest bearing $ 12,886 $ 10,947 NOW accounts 30,950 28,376 Regular savings, tax escrow and demand clubs 25,500 27,478 Money market 33,392 31,880 Individual retirement accounts 6,774 6,477 Certificates of deposit 126,058 117,457 $ 235,560 $ 222,615
Schedule of individual retirement accounts and certificates of deposit have scheduled maturities	2020 $ 96,523 2021 32,296 2022 1,903 2023 905 2024 1,205 $ 132,832
Schedule of interest expense on deposits	2019 2018 (In Thousands) NOW accounts $ 88 $ 92 Regular savings and demand clubs 164 147 Money market 330 345 Individual retirement accounts 116 85 Certificates of deposit 2,771 1,922 $ 3,469 $ 2,591

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2019
Borrowings
Schedule of contractual maturities of borrowings	Advance Maturity Current Date Date Rate 2019 2018 (In Thousands) 09/05/12 09/05/19 1.13 % $ — $ 246 12/19/12 12/19/19 1.20 % — 321 01/04/13 01/04/19 1.52 % — 1,000 01/22/13 01/22/19 1.44 % — 1,000 02/20/13 02/20/20 1.28 % 37 185 02/20/13 02/21/23 1.77 % 345 447 01/21/14 01/22/19 1.45 % — 34 03/20/14 03/20/19 1.50 % — 103 07/21/14 07/21/21 1.94 % 250 397 07/21/14 07/22/19 2.08 % — 500 08/21/14 08/21/19 2.12 % — 1,000 10/02/14 10/04/21 2.00 % 576 867 10/15/14 10/15/21 1.69 % 286 431 11/28/14 11/29/21 1.90 % 599 890 12/31/14 12/31/19 1.63 % — 224 01/14/15 01/14/20 1.73 % 1,500 1,500 01/21/15 01/21/20 1.79 % 500 500 01/21/15 01/21/21 1.97 % 500 500 04/13/15 04/13/20 1.74 % 1,000 1,000 05/20/15 05/20/20 1.52 % 103 308 05/20/15 05/20/22 1.91 % 372 517 06/25/15 06/25/20 1.65 % 121 326 10/29/15 10/29/20 1.51 % 378 784 10/29/15 10/29/20 1.90 % 1,000 1,000 01/27/16 01/27/21 1.92 % 1,000 1,000 01/27/16 01/27/23 1.87 % 469 611 02/12/16 02/13/23 1.66 % 479 621 02/12/16 02/13/23 2.04 % 500 500 10/28/16 10/28/20 1.57 % 1,000 1,000 11/04/16 11/04/21 1.72 % 2,000 2,000 11/17/16 11/17/21 2.13 % 1,000 1,000 11/17/16 11/17/21 1.78 % 411 611 11/17/16 11/17/23 2.07 % 589 729 11/28/16 11/29/19 1.78 % — 1,500 12/21/16 12/23/19 1.91 % — 1,000 01/04/17 01/04/19 1.62 % — 1,500 01/19/17 01/21/20 1.91 % 1,000 1,000 03/24/17 03/24/22 2.00 % 719 1,017 03/24/17 03/25/24 2.28 % 956 1,164 07/24/17 07/24/20 1.88 % 1,000 1,000 07/24/17 07/26/21 2.03 % 1,000 1,000 07/24/17 07/25/22 1.94 % 545 743 08/31/17 08/31/21 1.96 % 1,000 1,000 09/11/17 09/11/20 1.80 % 1,000 1,000 09/11/17 09/12/22 2.07 % 1,500 1,500 09/27/17 09/27/22 2.28 % 1,000 1,000 01/18/18 01/18/19 2.17 % - 1,500 01/24/18 01/24/20 2.42 % 1,500 1,500 02/09/18 02/09/22 2.78 % 2,500 2,500 03/21/18 03/21/23 3.13 % 1,500 1,500 04/04/18 04/04/23 3.00 % 2,000 2,000 05/22/18 05/23/22 3.22 % 1,500 1,500 05/29/18 05/31/22 2.97 % 2,000 2,000 05/29/18 05/30/23 3.01 % 1,500 1,500 06/28/18 06/28/23 3.13 % 1,000 1,000 06/28/18 06/28/24 3.25 % 2,000 2,000 07/23/18 07/23/24 3.34 % 1,000 1,000 08/20/18 08/20/20 2.93 % 2,000 2,000 08/31/18 02/28/19 2.56 % — 1,500 09/25/18 03/25/19 2.66 % — 2,000 09/27/18 09/27/21 3.24 % 1,500 1,500 10/18/18 04/18/19 2.76 % — 1,500 10/30/18 04/30/19 2.78 % — 1,500 11/23/18 05/23/19 2.82 % — 1,500 12/03/18 01/03/19 2.61 % — 3,750 12/20/18 06/20/19 2.81 % — 2,000 01/29/19 01/30/23 2.94 % 3,000 — 01/29/19 01/29/24 2.97 % 3,000 — 09/30/19 03/30/20 2.10 % 1,000 — $ 51,735 $ 71,826
Schedule of contractual maturities of all FHLB borrowings	Contractual Weighted Maturity Average Rate 2020 $ 13,140 2.04 % 2021 10,121 2.11 2022 10,137 2.60 2023 11,381 2.78 2024 6,956 3.01 $ 51,735 2.46 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Taxes
Schedule of provision for income taxes	2019 2018 (In Thousands) Current Federal $ 106 $ 163 State 3 4 Deferred (210) (135) $ (101) $ 32
Schedule of differences between income tax expense to statutory federal tax at a rate	2019 2018 % of Pre-tax % of Pre-tax Amount Income Amount Income Federal Tax at a Statutory rate $ (129) 21 % $ 35 21 % State taxes, net of Federal provision 422 (69) 14 9 Change in valuation allowance (419) 68 (11) (7) Nontaxable interest and dividend income (18) 3 (19) (11) Other items 43 (7) 13 7 Income tax provision $ (101) 16 % $ 32 19 %
Schedule of deferred income tax assets and liabilities resulting from temporary differences	2019 2018 (In Thousands) Deferred tax assets: Deferred loan origination fees $ 75 $ 94 Allowance for loan losses - Federal 485 408 State tax credits 180 825 Supplemental Executive Retirement Plan 221 216 Unrealized loss on securities available for sale 3 49 Net operating loss 639 477 Stock compensation 42 32 Depreciation 128 — Other 84 43 1,857 2,144 Valuation allowance (994) (1,413) Total deferred tax assets, net of valuation allowance 863 731 Deferred tax liabilities: Depreciation — (9) Mortgage servicing rights (190) (213) Total deferred tax liabilities (190) (222) Net deferred tax asset $ 673 $ 509

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2019
Accumulated Other Comprehensive Loss
Schedule of accumulated other comprehensive income (loss)	For the year ended December 31, 2019 Unrealized Losses on Available- (In thousands) for-Sale Securities Total Beginning balance $ (183) $ (183) Other comprehensive income 174 174 Ending balance $ (9) $ (9) For the year ended December 31, 2018 Unrealized Losses on Available- (In thousands) for-Sale Securities Total Beginning balance $ (165) $ (165) Other comprehensive loss (18) (18) Ending balance $ (183) $ (183)

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Employee Benefit Plans
Schedule of stock option activity and related information for its option plans	2019 2018 Weighted Average Price Weighted Average Stock Awards Per Share Stock Awards Price Per Share Outstanding at beginning of year 71,100 $ 16.82 62,700 $ 16.72 Grants - — 8,400 17.57 Outstanding at year end 71,100 $ 16.82 71,100 $ 16.82 Vested shares at year end 29,408 $ 16.78 15,644 $ 16.72 Unvested shares at year end 41,692 $ 16.85 55,456 $ 16.85 Total outstanding shares at year end 71,100 71,100
Summary of stock option activity and option plans	2019 2018 Weighted Weighted Average Average Exercise Exercise Exercise Price Price Per Exercise Price Price Per Options Range Share Options Range Share Outstanding at beginning of year 172,080 $ 16.69-$17.75 $ 16.82 152,080 $ 16.69‑$16.72 $ 16.72 Grants — — — 20,000 $ 17.52‑$17.75 17.58 Exercised — — — — — — Outstanding at year end 172,080 $ 16.69-$17.75 $ 16.82 172,080 $ 16.69‑$17.75 $ 16.82 Exercisable at year end 64,832 $ 16.69-$17.75 $ 16.77 30,416 $ 16.69‑$16.72 $ 16.72
Schedule of estimate fair value of stock-based awards of weighted average assumptions	2019 2018 Risk-free interest rate — 2.41 % Volatility factor — 10.47 % Dividends — 0.00 % Weighted average expected life (years) — 5.00 Forfeiture rate — 0.00 %
Summary of changes in unvested shares	Weighted Average Unvested Options Options Grant Date Fair Value Unvested at January 1, 2019 141,664 $ 2.31 Granted — — Vested 34,416 2.30 Unvested at December 31, 2019 107,248 $ 2.31

Other Income (Tables)

Other Income (Tables)	12 Months Ended
	Dec. 31, 2019
Other Income
Schedule of non-interest income	For the year ended For the year ended December 31, 2019 December 31, 2018 (In thousands) Service fees Deposit related fees $ 65 $ 66 Insufficient funds fee 76 83 Total service fees 141 149 Fee income Securities commission income 8 43 Insurance commission income 11 88 Total insurance and securities commission income 19 131 Card income Debit card interchange fee income 135 146 ATM fees 30 31 Total card income 165 177 Mortgage fee income and realized gain on sales of loans* Residential mortgage loan origination fees 229 324 Commercial loan fees 85 88 Loan servicing income 298 331 Realized gain on sales of residential mortgage loans 931 1,390 Realized gain on sale of SBA loan — 47 Total mortgage fee income and realized gain on sales of loans 1,543 2,180 Bank owned life insurance 58 61 Other miscellaneous income 11 19 Total non-interest income $ 1,937 $ 2,717

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2019
Commitments
Schedule of nonperformance by the other party to the financial instrument for commitments	2019 2018 (In Thousands) Commitments to extend credit: Commitments to grant loans $ 11,351 $ 5,578 Unadvanced portion of construction loans 4,601 4,439 Unfunded commitments under lines of credit 23,539 18,774 $ 39,491 $ 28,791

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2019
Regulatory Matters
Schedule of capital amounts and ratios	Minimum To Be "Well- Minimum Capitalized" Well-Capitalized For Capital Under Prompt With Buffer, Fully Actual Adequacy Purposes Corrective Provisions Phased in for 2019 (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio Amount Ratio As of December 31, 2019 Total Core Capital (to Risk-Weighted Assets) $ 30,780 15.32 %  $16,075  8.0 %  $20,093  10.0 %  $21,098  10.5 % Tier 1 Capital (to Risk-Weighted Assets) 29,139 14.50  12,056  6.0  16,075  8.0  17,079  8.5 Tier 1 Common Equity (to Risk-Weighted Assets) 29,139 14.50  9,042  4.5  13,061  6.5  14,065  7.0 Tier 1 Capital (to Assets) 29,139 9.01  12,938  4.0  16,172  5.0  16,172  5.0 As of December 31, 2018: Total Core Capital (to Risk-Weighted Assets) $ 30,896 15.70 %  $14,927  8.0 %  $18,658  10.0 %  $20,665  10.5 % Tier 1 Capital (to Risk-Weighted Assets) 29,335 14.91  11,808  6.0  14,927  8.0  16,729  8.5 Tier 1 Common Equity (to Risk-Weighted Assets) 29,335 14.91  8,856  4.5  12,128  6.5  13,777  7.0 Tier 1 Capital (to Assets) 29,335 9.07  12,938  4.0  15,216  5.0  16,173  5.0

Fair Value Measurement and Fa_2

Fair Value Measurement and Fair Values of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Measurement and Fair Values of Financial Instruments
Schedule of assets measured at fair value on a recurring basis	(In Thousands) Total Level 1 Level 2 Level 3 2019 U.S. Government and agency obligations $ 14,035 $ — $ 14,035 $ — Mortgage-backed securities - residential 4,091 — 4,091 — Total Available-for-Sale Securities $ 18,126 $ — $ 18,126 $ — 2018 Total Level 1 Level 2 Level 3 U.S. Government and agency obligations $ 12,455 $ — $ 12,455 $ — Mortgage-backed securities - residential 5,876 — 5,876 — Total Available-for-Sale Securities $ 18,331 $ — $ 18,331 $ —
Fair Value Measurements, Nonrecurring [Table Text Block]	December 31, 2019 (In thousands) Level 1 Level 2 Level 3 Total Fair Value Impaired loans $ — $ 803 $ 90 $ 893 Loans held for sale $ — $ 2,194 $ — $ 2,194 Foreclosed real estate $ — $ — $ 730 $ 730 Total loans $ — $ 2,997 $ 820 $ 3,817 December 31, 2018 (In thousands ) Level 1 Level 2 Level 3 Total Fair Value Impaired loans $ — $ — $ — $ — Loans held for sale $ — $ 2,133 $ — $ 2,133 Foreclosed real estate $ — $ — $ — $ — Total loans $ — $ 2,133 $ — $ 2,133
Schedule of additional quantitative information of assets measured at fair value on a nonrecurring basis	Quantitative Information about Level 3 Fair Value Measurements Valuation Range At December 31, 2019 Techniques Unobservable Input (Weighted Avg.) Impaired loans Appraisal of collateral Appraisal Adjustments % (Sales Approach) Costs to Sell 10.0% - 50.7% (41.7) % Foreclosed real estate Appraisal of collateral Appraisal Adjustments 25.0%-29.2% (26.6) % (Market Approach) Costs to Sell 6.7%-7.3% (6.9%) %
Schedule of carrying amounts and estimated fair values of the financial instruments	2019 2018 Fair Value Carrying Fair Carrying Fair Hierarchy Amount Value Amount Value (In Thousands) Financial assets: Cash and due from banks $ 1,689 $ 1,689 $ 1,581 $ 1,581 Interest bearing demand deposits 6,244 6,244 4,710 4,710 Securities available for sale 18,126 18,126 18,331 18,331 Securities held to maturity 5,166 5,297 6,052 6,030 Investment in restricted stock 2,757 2,757 3,637 3,637 Loans held for sale 2,194 2,194 2,133 2,133 Loans, net 274,508 279,114 281,741 280,173 Foreclosed real estate 730 730 — — Accrued interest receivable 807 807 876 876 Financial liabilities: Demand deposits, savings, NOW and MMDA 102,728 102,728 98,681 98,681 Time deposits 132,832 132,972 123,934 124,182 Borrowings 51,735 52,348 71,826 71,086 Accrued interest payable 111 111 168 168

FSB Bancorp, Inc. (Parent Com_2

FSB Bancorp, Inc. (Parent Company Only) Financial Information (Tables)	12 Months Ended
	Dec. 31, 2019
FSB Bancorp, Inc. (Parent Company Only) Financial Information
Schedule of Balance Sheets	December 31 2019 2018 (In Thousands) Assets Cash and cash equivalents $ 1,474 $ 1,570 Investment in banking subsidiary 29,796 29,661 ESOP loan receivable 297 331 Total Assets $ 31,567 $ 31,562 Liabilities and Stockholders’ Equity Total Liabilities $ 23 $ 49 Stockholders’ Equity 31,544 31,513 Total Liabilities and Stockholders’ Equity $ 31,567 $ 31,562
Schedule of Statements of Income	Year Ended December 31 2019 2018 (In Thousands) Interest Income $ 39 $ 36 Other Expense (447) (500) Equity in undistributed (loss) earnings of banking subsidiary (105) 599 Net (Loss) Income $ (513) $ 135
Schedule of Statements of Cash Flows	Year Ended December 31 2019 2018 (In Thousands) Cash flows from operating activities Net (loss) income $ (513) $ 135 Adjustments to reconcile net (loss) income to net cash flows from operating activities Equity in undistributed loss (earnings) of banking subsidiary 105 (599) Stock based compensation 304 310 Net (decrease) increase in other liabilities (26) 15 Net cash flows from operating activities (130) (139) Cash flows from investing activities Payments received on ESOP loan 34 34 Net cash flows from investing activities 34 34 Cash flows from financing activities Purchase of common stock — (42) Net cash flows from financing activities — (42) Net decrease in cash and cash equivalents (96) (147) Cash and cash equivalents - beginning 1,570 1,717 Cash and cash equivalents - ending $ 1,474 $ 1,570

Nature of Operations and Summ_4

Nature of Operations and Summary of Significant Accounting Policies - Comprehensive income (loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Loss By Component:
Unrealized losses on securities available-for-sale	$ (12)	$ (232)
Tax effect	3	49
Net unrealized losses on securities available-for-sale	(9)	(183)	$ (165)
Accumulated other comprehensive loss	$ (9)	$ (183)	$ (165)

Nature of Operations and Summ_5

Nature of Operations and Summary of Significant Accounting Policies - Basic and diluted earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Basic and Diluted Earnings (Loss) Per Common Share
Net income (loss) available to common stockholders	$ (513)	$ 135
Weighted average basic common shares outstanding	1,859	1,851
Weighted average diluted common shares outstanding	1,859	1,853
Earnings (loss) per common share - basic and diluted (in dollars per share)	$ (0.28)	$ 0.07

Nature of Operations and Summ_6

Nature of Operations and Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2016
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Offering price (in dollars per share)		$ 16.38	$ 10
Number of shares issued to FSB Community			1.0884
Common stock, shares outstanding	1,940,661	1,940,661	1,941,688
Loan servicing rights	$ 116,531,000	$ 123,755,000
Proceeds from MSR	726,000	812,000
Capitalization of MSR	30,000	5,000
Amortization of MSR	116,000	85,000
Residential mortgage loan for foreclosure	$ 55,000	$ 55,000
Corporate federal income tax rat	21.00%	21.00%
Fairport Savings Bank [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of common stock issued	1,034,649
Offering price (in dollars per share)	$ 10
Proceeds from stock conversion and offering	$ 10,300
Conversion related expenses	1,400
Net proceeds from stock offering	$ 8,900

Nature of Operations and Summ_7

Nature of Operations and Summary of Significant Accounting Policies - Additional information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 27, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Depreciation Methods		Depreciation and amortization are computed on the straight-line basis over the shorter of the estimated useful lives or lease terms (in the case of leasehold improvements) of the related assets.
Repurchase of common stock	97,084		2,592
Percent of outstanding shares	5.00%
Average price (in dollars per share)			$ 16.38	$ 10
Total repurchase of common stock		72,127
Total average price (in dollars per share)		$ 15.31
Stock option
Property, Plant and Equipment [Line Items]
Stock granted		20,000
Restricted stock
Property, Plant and Equipment [Line Items]
Stock granted		8,400
Asset Impairment Charges		$ 0	$ 0
Minimum | Premises
Property, Plant and Equipment [Line Items]
Estimated Useful Lives		P20Y
Minimum | Furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Lives		P3Y
Maximum | Premises
Property, Plant and Equipment [Line Items]
Estimated Useful Lives		P30Y
Maximum | Furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Lives		P10Y

Nature of Operations and Summ_8

Nature of Operations and Summary of Significant Accounting Policies - Additional information (Details 2) $ in Thousands	Dec. 19, 2019$ / sharesshares	Jul. 02, 2018shares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options grants to senior management and directors		20,000	0
Number of foreclosed commercial real estate loans | $			2	0
Payment To Acquire Business Combination Per Share in Value	0.4394
Payment To acquire business combination per share in cash of fraction | $ / shares	$ 17.80
Business Combination , Percentage Of Business Consideration In Cash	50.00%
Business Combination, Percentage Of Business Consideration In Stock	50.00%
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted			0	8,400
Senior management | Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options grants to senior management and directors			0
Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted			0

Securities - Available for sale

Securities - Available for sale (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 18,138	$ 18,563
Gross Unrealized Gains	20	31
Gross Unrealized Losses	(32)	(263)
Fair Value	18,126	18,331
U.S. Government and agency obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	14,043	12,610
Gross Unrealized Gains	6	7
Gross Unrealized Losses	(14)	(162)
Fair Value	14,035	12,455
Mortgage-backed securities - residential
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,095	5,953
Gross Unrealized Gains	14	24
Gross Unrealized Losses	(18)	(101)
Fair Value	$ 4,091	$ 5,876

Securities - Held to maturity (

Securities - Held to maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 5,166	$ 6,052
Gross Unrealized Gains	131	35
Gross unrealized Losses	0	(57)
Fair Value	5,297	6,030
Mortgage-backed securities - residential
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	409	458
Gross Unrealized Gains	3	6
Gross unrealized Losses	0	(1)
Fair Value	412	463
State and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	4,757	5,594
Gross Unrealized Gains	128	29
Gross unrealized Losses	0	(56)
Fair Value	$ 4,885	$ 5,567

Securities - Contractual maturi

Securities - Contractual maturity of debt securities of AFS (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Available-for-Sale Amortized Cost
Due after one year through five years	$ 9,043
Due after five years through ten years	5,000
Totals	18,138	$ 18,563
Fair Value Available-for-Sale
Due after one year through five years	9,041
Due after five years through ten years	4,994
Totals	18,126	18,331
Mortgage-backed securities - residential
Available-for-Sale Amortized Cost
Totals	4,095	5,953
Fair Value Available-for-Sale
Totals	$ 4,091	$ 5,876

Securities - Contractual matu_2

Securities - Contractual maturity of debt securities of HTM (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Held-to-Maturity Amortized Cost
Due in one year or less	$ 746
Due after one year through five years	2,517
Due after five years through ten years	1,494
Securities - held-to-maturity	5,166	$ 6,052
Held-to-Maturity Fair Value
Due in one year or less	748
Due after one year through five years	2,554
Due after five years through ten years	1,583
Fair Value	5,297	6,030
Mortgage-backed securities - residential
Held-to-Maturity Amortized Cost
Securities - held-to-maturity	409	458
Held-to-Maturity Fair Value
Fair Value	$ 412	$ 463

Securities - Gross unrealized l

Securities - Gross unrealized loss position for investment securities - AFS (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Available-For-Sale Securities [Abstract]
Less than Twelve Months, fair value		$ 3,124	$ 203
Less than Twelve Months, unrealized losses		10	0
Twelve Months or More, fair value		5,601	13,194
Twelve Months or More, unrealized losses		22	263
Total Fair Value		8,725	13,397
Total Unrealized Losses		32	263
U.S. Government and agency obligations
Available-For-Sale Securities [Abstract]
Less than Twelve Months, fair value		2,993	0
Less than Twelve Months, unrealized losses		10	0
Twelve Months or More, fair value		2,536	9,445
Twelve Months or More, unrealized losses		4	162
Total Fair Value		5,529	9,445
Total Unrealized Losses		14	162
Mortgage-backed securities - residential
Available-For-Sale Securities [Abstract]
Less than Twelve Months, fair value	[1]	131	203
Less than Twelve Months, unrealized losses	[1]	0	0
Twelve Months or More, fair value	[1]	3,065	3,749
Twelve Months or More, unrealized losses	[1]	18	101
Total Fair Value	[1]	3,196	3,952
Total Unrealized Losses	[1]	$ 18	$ 101
[1]	Aggregate unrealized loss position of these securities is less than $500.

Securities - Gross unrealised l

Securities - Gross unrealised losses on investment securities - HTM (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Held-to-maturity Securities [Abstract]
Less than Twelve Months, Fair Value	$ 0	$ 1,039
Less than Twelve Months, Unrealized Losses	0	4
Twelve Months or More, Fair Value	0	3,186
Twelve Months or More, Unrealized Losses	0	53
Fair Value	0	4,225
Total Unrealized Losses	0	57
Mortgage-backed securities - residential
Held-to-maturity Securities [Abstract]
Less than Twelve Months, Fair Value	0	0
Less than Twelve Months, Unrealized Losses	0	0
Twelve Months or More, Fair Value	0	165
Twelve Months or More, Unrealized Losses	0	1
Fair Value	0	165
Total Unrealized Losses	0	1
State and political subdivisions
Held-to-maturity Securities [Abstract]
Less than Twelve Months, Fair Value	0	1,039
Less than Twelve Months, Unrealized Losses	0	4
Twelve Months or More, Fair Value	0	3,021
Twelve Months or More, Unrealized Losses	0	52
Fair Value	0	4,060
Total Unrealized Losses	$ 0	$ 56

Securities - Additional informa

Securities - Additional information (Details) $ in Thousands	12 Months Ended	24 Months Ended
	Dec. 31, 2019USD ($)security	Dec. 31, 2019USD ($)security	Dec. 31, 2018USD ($)
Schedule Of Available For Sale and Held To Maturity Securities [Line Items]
Aggregate unrealized loss position of the securities	$ 0	$ 0	$ 4,225
Realized gains on sales of securities	0	0
Securities pledged to secure public deposits	0	0
Maximum
Schedule Of Available For Sale and Held To Maturity Securities [Line Items]
Aggregate unrealized loss position of the securities	$ 500	$ 500	500
U.S. Government and agency obligations
Schedule Of Available For Sale and Held To Maturity Securities [Line Items]
Number of securities in unrealized loss position in for greater than twelve months | security	2	2
Mortgage-backed securities - residential
Schedule Of Available For Sale and Held To Maturity Securities [Line Items]
Number of securities in unrealized loss position in for less than twelve months | security	1	1
State and political subdivisions
Schedule Of Available For Sale and Held To Maturity Securities [Line Items]
Number of securities in unrealized loss position in for greater than twelve months | security	2	2
Aggregate unrealized loss position of the securities	$ 0	$ 0	4,060
Mortgage-backed securities - residential
Schedule Of Available For Sale and Held To Maturity Securities [Line Items]
Number of securities in unrealized loss position in for less than twelve months | security	5	5
Aggregate unrealized loss position of the securities	$ 0	$ 0	$ 165

Loans and The Allowance for L_3

Loans and The Allowance for Loan Losses - Major classifications of loans (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 276,175,000	$ 283,339,000
Net deferred loan origination costs	(26,000)	(37,000)
Less: Allowance for loan losses	(1,641,000)	(1,561,000)	$ (1,261,000)
Net Loans	274,508,000	281,741,000
Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	44,000	50,000
Real estate loans | Secured by one-to-four family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	212,903,000	221,602,000
Less: Allowance for loan losses	(788,000)	(866,000)	(816,000)
Real estate loans | Secured by multi-family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	10,876,000	10,241,000
Less: Allowance for loan losses	(81,000)	(77,000)	(80,000)
Real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	4,679,000	4,898,000
Less: Allowance for loan losses	(23,000)	(24,000)	(54,000)
Real estate loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	23,081,000	22,492,000
Less: Allowance for loan losses	(510,000)	(284,000)	(148,000)
Real estate loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	17,459,000	16,766,000
Less: Allowance for loan losses	(104,000)	(103,000)	(107,000)
Other Loan Portfolio Segment | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	7,133,000	7,290,000
Less: Allowance for loan losses	(104,000)	(97,000)	(47,000)
Other Loan Portfolio Segment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	44,000	50,000
Less: Allowance for loan losses	$ (31,000)	$ (110,000)	$ (9,000)

Loans and The Allowance for L_4

Loans and The Allowance for Loan Losses - Allowance for loan losses allocated by loan class and the activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Allowance for loan losses:
Beginning Balance	$ 1,561,000	$ 1,261,000
Charge-offs	215,000
Recoveries	0
Provisions (Credits)	295,000	300,000
Ending balance	1,641,000	1,561,000
Ending balance: related to loans individually evaluated for impairment	164,000
Ending balance: related to loans collectively evaluated for impairment	1,477,000	1,561,000
Loans receivables:
Ending balance	276,175,000	283,339,000
Ending balance: related to loans individually evaluated for impairment	1,054,000
Ending balance: related to loans collectively evaluated for impairment	275,121,000	283,339,000
Other loans
Loans receivables:
Ending balance	44,000	50,000
Real estate loans | Secured by one-to-four family residences
Allowance for loan losses:
Beginning Balance	866,000	816,000
Charge-offs	1,000
Recoveries	0
Provisions (Credits)	(77,000)	50,000
Ending balance	788,000	866,000
Ending balance: related to loans individually evaluated for impairment	0
Ending balance: related to loans collectively evaluated for impairment	788,000	866,000
Loans receivables:
Ending balance	212,903,000	221,602,000
Ending balance: related to loans individually evaluated for impairment	55,000
Ending balance: related to loans collectively evaluated for impairment	212,848,000	221,602,000
Real estate loans | Secured by multi-family residences
Allowance for loan losses:
Beginning Balance	77,000	80,000
Charge-offs	0
Recoveries	0
Provisions (Credits)	4,000	(3,000)
Ending balance	81,000	77,000
Ending balance: related to loans individually evaluated for impairment	0
Ending balance: related to loans collectively evaluated for impairment	81,000	77,000
Loans receivables:
Ending balance	10,876,000	10,241,000
Ending balance: related to loans individually evaluated for impairment	0
Ending balance: related to loans collectively evaluated for impairment	10,876,000	10,241,000
Real estate loans | Construction
Allowance for loan losses:
Beginning Balance	24,000	54,000
Charge-offs	0
Recoveries	0
Provisions (Credits)	(1,000)	(30,000)
Ending balance	23,000	24,000
Ending balance: related to loans individually evaluated for impairment	0
Ending balance: related to loans collectively evaluated for impairment	23,000	24,000
Loans receivables:
Ending balance	4,679,000	4,898,000
Ending balance: related to loans individually evaluated for impairment	0
Ending balance: related to loans collectively evaluated for impairment	4,679,000	4,898,000
Real estate loans | Commercial real estate
Allowance for loan losses:
Beginning Balance	284,000	148,000
Charge-offs	214,000
Recoveries	0
Provisions (Credits)	440,000	136,000
Ending balance	510,000	284,000
Ending balance: related to loans individually evaluated for impairment	154,000
Ending balance: related to loans collectively evaluated for impairment	356,000	284,000
Loans receivables:
Ending balance	23,081,000	22,492,000
Ending balance: related to loans individually evaluated for impairment	954,000
Ending balance: related to loans collectively evaluated for impairment	22,127,000	22,492,000
Real estate loans | Home equity lines of credit
Allowance for loan losses:
Beginning Balance	103,000	107,000
Charge-offs	0
Recoveries	0
Provisions (Credits)	1,000	(4,000)
Ending balance	104,000	103,000
Ending balance: related to loans individually evaluated for impairment	0
Ending balance: related to loans collectively evaluated for impairment	104,000	103,000
Loans receivables:
Ending balance	17,459,000	16,766,000
Ending balance: related to loans individually evaluated for impairment	0
Ending balance: related to loans collectively evaluated for impairment	17,459,000	16,766,000
Other Loan Portfolio Segment | Commercial and industrial loans
Allowance for loan losses:
Beginning Balance	97,000	47,000
Charge-offs	0
Recoveries	0
Provisions (Credits)	7,000	50,000
Ending balance	104,000	97,000
Ending balance: related to loans individually evaluated for impairment	10,000
Ending balance: related to loans collectively evaluated for impairment	94,000	97,000
Loans receivables:
Ending balance	7,133,000	7,290,000
Ending balance: related to loans individually evaluated for impairment	45,000
Ending balance: related to loans collectively evaluated for impairment	7,088,000	7,290,000
Other Loan Portfolio Segment | Other loans
Allowance for loan losses:
Beginning Balance	110,000	9,000
Charge-offs	0
Recoveries	0
Provisions (Credits)	(79,000)	101,000
Ending balance	31,000	110,000
Ending balance: related to loans individually evaluated for impairment	0
Ending balance: related to loans collectively evaluated for impairment	31,000	110,000
Loans receivables:
Ending balance	44,000	50,000
Ending balance: related to loans individually evaluated for impairment	0
Ending balance: related to loans collectively evaluated for impairment	$ 44,000	$ 50,000

Loans and The Allowance for L_5

Loans and The Allowance for Loan Losses - Impaired loans information by portfolio class (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Loans with specific valuation allowance
Impaired Financing Receivable, with Related Allowance, Recorded Investment	$ 1,054	$ 0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	1,054	0
Impaired Financing Receivable, Related Allowance	161	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,061	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	33	0
Secured by one-to-four family residences
Loans with specific valuation allowance
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	55	0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	55	0
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	55	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method		0
Commercial real estate
Loans with specific valuation allowance
Impaired Financing Receivable, with Related Allowance, Recorded Investment	954	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	954	0
Impaired Financing Receivable, Related Allowance	151	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	961	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	33	0
Commercial and industrial loans
Loans with specific valuation allowance
Impaired Financing Receivable, with Related Allowance, Recorded Investment	45	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	45	0
Impaired Financing Receivable, Related Allowance	10	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	$ 45	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method		$ 0

Loans and The Allowance for L_6

Loans and The Allowance for Loan Losses - Risk category of loans by class (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 276,175,000	$ 283,339,000
Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	268,890,000	278,534,000
Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	3,562,000	1,425,000
Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	3,723,000	3,380,000
Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	44,000	50,000
Real estate loans | Secured by one-to-four family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	212,903,000	221,602,000
Real estate loans | Secured by one-to-four family residences | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	210,194,000	218,222,000
Real estate loans | Secured by one-to-four family residences | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	183,000	494,000
Real estate loans | Secured by one-to-four family residences | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	2,526,000	2,886,000
Real estate loans | Secured by one-to-four family residences | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Real estate loans | Secured by multi-family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	10,876,000	10,241,000
Real estate loans | Secured by multi-family residences | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	10,876,000	10,241,000
Real estate loans | Secured by multi-family residences | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Real estate loans | Secured by multi-family residences | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Real estate loans | Secured by multi-family residences | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	4,679,000	4,898,000
Real estate loans | Construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	4,679,000	4,898,000
Real estate loans | Construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Real estate loans | Construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Real estate loans | Construction | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Real estate loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	23,081,000	22,492,000
Real estate loans | Commercial real estate | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	18,772,000	21,313,000
Real estate loans | Commercial real estate | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	3,355,000	931,000
Real estate loans | Commercial real estate | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	954,000	248,000
Real estate loans | Commercial real estate | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Real estate loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	17,459,000	16,766,000
Real estate loans | Home equity lines of credit | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	17,280,000	16,565,000
Real estate loans | Home equity lines of credit | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	14,000	0
Real estate loans | Home equity lines of credit | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	165,000	201,000
Real estate loans | Home equity lines of credit | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Other Loan Portfolio Segment | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	7,133,000	7,290,000
Other Loan Portfolio Segment | Commercial and industrial loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	7,050,000	7,245,000
Other Loan Portfolio Segment | Commercial and industrial loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	10,000	0
Other Loan Portfolio Segment | Commercial and industrial loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	73,000	45,000
Other Loan Portfolio Segment | Commercial and industrial loans | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Other Loan Portfolio Segment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	44,000	50,000
Other Loan Portfolio Segment | Other loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	39,000	50,000
Other Loan Portfolio Segment | Other loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	0	0
Other Loan Portfolio Segment | Other loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	5,000	0
Other Loan Portfolio Segment | Other loans | Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 0	$ 0

Loans and The Allowance for L_7

Loans and The Allowance for Loan Losses - Analysis of the age of the loan delinquencies by type and by amount past due (Details ) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,192,000	$ 1,071,000
Current	274,983,000	282,268,000
Loans	276,175,000	283,339,000
30-59 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	98,000	622,000
60-89 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	35,000	349,000
90 Days and Over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,059,000	100,000
Other loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	44,000	50,000
Real estate loans | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Current	4,679,000	4,898,000
Loans	4,679,000	4,898,000
Real estate loans | Construction | 30-59 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Real estate loans | Construction | 60-89 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Real estate loans | Construction | 90 Days and Over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Real estate loans | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	954,000	248,000
Current	22,127,000	22,244,000
Loans	23,081,000	22,492,000
Real estate loans | Commercial real estate | 30-59 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	248,000
Real estate loans | Commercial real estate | 60-89 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Real estate loans | Commercial real estate | 90 Days and Over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	954,000	0
Real estate loans | Home equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	14,000	147,000
Current	17,445,000	16,619,000
Loans	17,459,000	16,766,000
Real estate loans | Home equity lines of credit | 30-59 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	147,000
Real estate loans | Home equity lines of credit | 60-89 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	14,000	0
Real estate loans | Home equity lines of credit | 90 Days and Over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Real estate loans | Secured by multi-family residences
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Current	10,876,000	10,241,000
Loans	10,876,000	10,241,000
Real estate loans | Secured by multi-family residences | 30-59 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Real estate loans | Secured by multi-family residences | 60-89 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Real estate loans | Secured by multi-family residences | 90 Days and Over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Real estate loans | Secured by one-to-four family residences
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	137,000	631,000
Current	212,766,000	220,971,000
Loans	212,903,000	221,602,000
Real estate loans | Secured by one-to-four family residences | 30-59 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	82,000	227,000
Real estate loans | Secured by one-to-four family residences | 60-89 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	349,000
Real estate loans | Secured by one-to-four family residences | 90 Days and Over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	55,000	55,000
Other Loan Portfolio Segment | Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	82,000	45,000
Current	7,051,000	7,245,000
Loans	7,133,000	7,290,000
Other Loan Portfolio Segment | Commercial and industrial loans | 30-59 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	16,000	0
Other Loan Portfolio Segment | Commercial and industrial loans | 60-89 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	21,000	0
Other Loan Portfolio Segment | Commercial and industrial loans | 90 Days and Over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	45,000	45,000
Other Loan Portfolio Segment | Other loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,000	0
Current	39,000	50,000
Loans	44,000	50,000
Other Loan Portfolio Segment | Other loans | 30-59 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Other Loan Portfolio Segment | Other loans | 60-89 Days Past Due And Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Other Loan Portfolio Segment | Other loans | 90 Days and Over
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 5,000	$ 0

Loans and The Allowance for L_8

Loans and The Allowance for Loan Losses - Nonaccrual loans (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual loans	$ 1,054	$ 100
Residential mortgage loans | Secured by one-to-four family residences
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual loans	55	55
Commercial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual loans	999	45
Commercial loans | Real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual loans	954
Commercial loans | Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual loans	$ 45	$ 45

Loans and The Allowance for L_9

Loans and The Allowance for Loan Losses - Foreclosed real estate (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Loans and The Allowance for Loan Losses
Commercial real estate loans transferred to real estate owned	$ 944
Direct write-downs	(214)
End of year	$ 730

Loans and The Allowance for _10

Loans and The Allowance for Loan Losses - Activity in valuation allowance (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Loans and The Allowance for Loan Losses
Beginning balance	$ 25
Provisions charged to expense	189
Direct write-downs	$ (214)

Loans and The Allowance for _11

Loans and The Allowance for Loan Losses - Expenses related to foreclosed assets (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2019
Loans and The Allowance for Loan Losses
Operating expenses	$ 28,000	$ 27,000

Loans and The Allowance for _12

Loans and The Allowance for Loan Losses - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded Investment, nonaccrual status		$ 1,054,000	$ 100,000
Total loans		276,175,000	283,339,000
Mortgage Loans on Real Estate, Foreclosures		55,000	55,000
Fair value of mortgage servicing rights		116,531,000,000	123,755,000,000
Total Past Due		1,192,000	1,071,000
Foreclosed Real Estate Expense	$ 28,000	27,000
Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		44,000	50,000
Real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, recorded Investment, nonaccrual status		$ 0	0
Combine Loan to Value Ratio for Home Equity Lines of Credit Limited Percentage		90.00%
Real estate loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 17,459,000	$ 16,766,000
Percentage of portfolio loans		6.30%	5.90%
Combine Loan to Value Ratio for Home Equity Lines of Credit Limited Percentage		90.00%
Total Past Due		$ 14,000	$ 147,000
Real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 4,679,000	$ 4,898,000
Percentage of portfolio loans		1.70%	1.70%
Additional unadvanced portion of loans		$ 4,600,000	$ 4,400,000
Total Past Due		0	0
Real estate loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 23,081,000	$ 22,492,000
Percentage of portfolio loans		8.30%	7.90%
Maximum adjustable rate loans term		15 years
Maximum loan to value ratio		80.00%
Total Past Due		$ 954,000	$ 248,000
Real estate loans | Secured by one-to-four family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 212,903,000	$ 221,602,000
Percentage of portfolio loans		77.10%	78.20%
Total Past Due		$ 137,000	$ 631,000
Real estate loans | Secured by multi-family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 10,876,000	$ 10,241,000
Percentage of portfolio loans		3.90%	3.60%
Maximum adjustable rate loans term		20 years
Total Past Due		$ 0	$ 0
Other Loan Portfolio Segment | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 7,133,000	$ 7,290,000
Percentage of portfolio loans		2.60%	2.60%
Total Past Due		$ 82,000	$ 45,000
Other Loan Portfolio Segment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 44,000	$ 50,000
Percentage of portfolio loans		0.10%	0.10%
Total Past Due		$ 5,000	$ 0
Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		3,723,000	3,380,000
Substandard | Real estate loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		165,000	201,000
Substandard | Real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		0	0
Substandard | Real estate loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		954,000	248,000
Substandard | Real estate loans | Secured by one-to-four family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		2,526,000	2,886,000
Substandard | Real estate loans | Secured by multi-family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		0	0
Substandard | Other Loan Portfolio Segment | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		73,000	45,000
Substandard | Other Loan Portfolio Segment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		5,000	0
Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		3,562,000	1,425,000
Special Mention | Real estate loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		14,000	0
Special Mention | Real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		0	0
Special Mention | Real estate loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		3,355,000	931,000
Special Mention | Real estate loans | Secured by one-to-four family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		183,000	494,000
Special Mention | Real estate loans | Secured by multi-family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		0	0
Special Mention | Other Loan Portfolio Segment | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		10,000	0
Special Mention | Other Loan Portfolio Segment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		0	0
30-59 Days Past Due And Accruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		98,000	622,000
30-59 Days Past Due And Accruing | Real estate loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	147,000
30-59 Days Past Due And Accruing | Real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
30-59 Days Past Due And Accruing | Real estate loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	248,000
30-59 Days Past Due And Accruing | Real estate loans | Secured by one-to-four family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		82,000	227,000
30-59 Days Past Due And Accruing | Real estate loans | Secured by multi-family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
30-59 Days Past Due And Accruing | Other Loan Portfolio Segment | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		16,000	0
30-59 Days Past Due And Accruing | Other Loan Portfolio Segment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
60-89 Days Past Due And Accruing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		35,000	349,000
60-89 Days Past Due And Accruing | Real estate loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		14,000	0
60-89 Days Past Due And Accruing | Real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
60-89 Days Past Due And Accruing | Real estate loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
60-89 Days Past Due And Accruing | Real estate loans | Secured by one-to-four family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	349,000
60-89 Days Past Due And Accruing | Real estate loans | Secured by multi-family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
60-89 Days Past Due And Accruing | Other Loan Portfolio Segment | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		21,000	0
60-89 Days Past Due And Accruing | Other Loan Portfolio Segment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
90 Days and Over
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		1,059,000	100,000
90 Days and Over | Real estate loans | Home equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
90 Days and Over | Real estate loans | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
90 Days and Over | Real estate loans | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		954,000	0
90 Days and Over | Real estate loans | Secured by one-to-four family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		55,000	55,000
90 Days and Over | Real estate loans | Secured by multi-family residences
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		0	0
90 Days and Over | Other Loan Portfolio Segment | Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		45,000	45,000
90 Days and Over | Other Loan Portfolio Segment | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Past Due		$ 5,000	$ 0

Premises and Equipment - (Detai

Premises and Equipment - (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 8,455	$ 8,360
Accumulated depreciation and amortization	(6,016)	(5,629)
Premises and equipment, net	2,439	2,731
Premises
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	5,003	5,003
Furniture and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	$ 3,452	$ 3,357

Premises and Equipment - Compon

Premises and Equipment - Components of the lease expense (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Premises and Equipment
Operating lease cost	$ 387
Short-term lease cost	69
Lease, Cost, Total	$ 456

Premises and Equipment - Supple

Premises and Equipment - Supplemental cash flow information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Premises and Equipment
Operating cash flows from operating leases	$ 387

Premises and Equipment - Supp_2

Premises and Equipment - Supplemental consolidated balance sheet (Details) $ in Thousands	Dec. 31, 2019USD ($)
Premises and Equipment
Operating lease right-of-use assets	$ 2,123
Operating lease liabilities	$ 2,322
Operating Leases	8 years 7 months 6 days
Operating Leases	3.52%

Premises and Equipment - Operat

Premises and Equipment - Operating lease liabilities (Details) $ in Thousands	Dec. 31, 2019USD ($)
Premises and Equipment
2020	$ 318
2021	312
2022	252
2023	194
2024	206
Thereafter	1,040
Total minimum lease payments	$ 2,322

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets	$ 2,123,000
Operating lease liabilities include corresponding liability	2,322,000
Operating leases, rent expense, net	456,000	$ 457,000
Depreciation and amortization	$ 425,000	$ 445,000
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease right-of-use assets			$ 2,300,000
Operating lease liabilities include corresponding liability			$ 2,600,000
Description of operating lease option to extend	Leases have remaining lease terms that vary from less than one year up to 12 years, some of which include options to extend the leases for various renewal periods.
Accounting Standards Update 2016-02 | Minimum
Lessee, Lease, Description [Line Items]
Remaining lease terms	1 year
Accounting Standards Update 2016-02 | Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms	12 years

Deposits - Components of deposi

Deposits - Components of deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deposits
Non-interest bearing	$ 12,886	$ 10,947
NOW accounts	30,950	28,376
Regular savings, tax escrow and demand clubs	25,500	27,478
Money market	33,392	31,880
Individual retirement accounts	6,774	6,477
Certificates of deposit	126,058	117,457
Total Deposits	$ 235,560	$ 222,615

Deposits - Individual retiremen

Deposits - Individual retirement accounts and certificates of deposit (Details) $ in Thousands	Dec. 31, 2019USD ($)
Deposits
2020	$ 96,523
2021	32,296
2022	1,903
2023	905
2024	1,205
Time Deposits, Total	$ 132,832

Deposits - Interest expense on

Deposits - Interest expense on deposits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deposits
NOW accounts	$ 88	$ 92
Regular savings and demand clubs	164	147
Money market	330	345
Individual retirement accounts	116	85
Certificates of deposit	2,771	1,922
Deposits	$ 3,469	$ 2,591

Deposits - Additional Informati

Deposits - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deposits
Deposit insurance per account owner	$ 250,000
Time deposits, each with a minimum denomination of $250,000	20,430,000	$ 18,032,000
Listing service deposits	$ 8,506,000	$ 11,225,000

Borrowings (Details)

Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Federal Home Loan Bank, Advances [Line Items]
Contractual maturities of borrowings with the FHLB	$ 51,735	$ 71,826
Advance Date 9/5/2012
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	09/05/19
Current Rate	1.13%
Contractual maturities of borrowings with the FHLB	$ 0	246
Advance Date 12/19/2012
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	12/19/19
Current Rate	1.20%
Contractual maturities of borrowings with the FHLB	$ 0	321
Advance Date 1/4/2013
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/04/19
Current Rate	1.52%
Contractual maturities of borrowings with the FHLB	$ 0	1,000
Advance Date 01/22/2013
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/22/19
Current Rate	1.44%
Contractual maturities of borrowings with the FHLB	$ 0	1,000
Advance Date 2/20/2013
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	02/20/20
Current Rate	1.28%
Contractual maturities of borrowings with the FHLB	$ 37	185
Advance Date 2/20/2013
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	02/21/23
Current Rate	1.77%
Contractual maturities of borrowings with the FHLB	$ 345	447
Advance Date 1/21/2014
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/22/19
Current Rate	1.45%
Contractual maturities of borrowings with the FHLB	$ 0	34
Advance Date 3/20/2014
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	03/20/19
Current Rate	1.50%
Contractual maturities of borrowings with the FHLB	$ 0	103
Advance Date 7/21/2014
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	07/21/21
Current Rate	1.94%
Contractual maturities of borrowings with the FHLB	$ 250	397
Advance Date 7/21/2014
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	07/22/19
Current Rate	2.08%
Contractual maturities of borrowings with the FHLB	$ 0	500
Advance Date 8/21/2014
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	08/21/19
Current Rate	2.12%
Contractual maturities of borrowings with the FHLB	$ 0	1,000
Advance Date 10/02/2014
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	10/04/21
Current Rate	2.00%
Contractual maturities of borrowings with the FHLB	$ 576	867
Advance Date 10/15/2014
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	10/15/21
Current Rate	1.69%
Contractual maturities of borrowings with the FHLB	$ 286	431
Advance Date 11/28/2014
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	11/29/21
Current Rate	1.90%
Contractual maturities of borrowings with the FHLB	$ 599	890
Advance Date 12/31/2014
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	12/31/19
Current Rate	1.63%
Contractual maturities of borrowings with the FHLB	$ 0	224
Advance Date 1/14/2015
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/14/20
Current Rate	1.73%
Contractual maturities of borrowings with the FHLB	$ 1,500	1,500
Advance Date 1/21/2015
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/21/21
Current Rate	1.97%
Contractual maturities of borrowings with the FHLB	$ 500	500
Advance Date 1/21/2015
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/21/20
Current Rate	1.79%
Contractual maturities of borrowings with the FHLB	$ 500	500
Advance Date 4/13/2015
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	04/13/20
Current Rate	1.74%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 5/20/2015
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	05/20/20
Current Rate	1.52%
Contractual maturities of borrowings with the FHLB	$ 103	308
Advance Date 5/20/2015
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	05/20/22
Current Rate	1.91%
Contractual maturities of borrowings with the FHLB	$ 372	517
Advance Date 6/25/2015
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	06/25/20
Current Rate	1.65%
Contractual maturities of borrowings with the FHLB	$ 121	326
Advance Date 10/29/2015
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	10/29/20
Current Rate	1.51%
Contractual maturities of borrowings with the FHLB	$ 378	784
Advance Date 10/29/2015
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	10/29/20
Current Rate	1.90%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 1/27/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/27/21
Current Rate	1.92%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 1/27/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/27/23
Current Rate	1.87%
Contractual maturities of borrowings with the FHLB	$ 469	611
Advance Date 2/12/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	02/13/23
Current Rate	1.66%
Contractual maturities of borrowings with the FHLB	$ 479	621
Advance Date 2/12/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	02/13/23
Current Rate	2.04%
Contractual maturities of borrowings with the FHLB	$ 500	500
Advance Date 10/28/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	10/28/20
Current Rate	1.57%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 11/04/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	11/04/21
Current Rate	1.72%
Contractual maturities of borrowings with the FHLB	$ 2,000	2,000
Advance Date 11/17/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	11/17/21
Current Rate	2.13%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 11/17/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	11/17/21
Current Rate	1.78%
Contractual maturities of borrowings with the FHLB	$ 411	611
Advance Date 11/17/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	11/17/23
Current Rate	2.07%
Contractual maturities of borrowings with the FHLB	$ 589	729
Advance Date 11/28/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	11/29/19
Current Rate	1.78%
Contractual maturities of borrowings with the FHLB	$ 0	1,500
Advance Date 12/21/2016
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	12/23/19
Current Rate	1.91%
Contractual maturities of borrowings with the FHLB	$ 0	1,000
Advance Date 1/4/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/04/19
Current Rate	1.62%
Contractual maturities of borrowings with the FHLB	$ 0	1,500
Advance Date 1/19/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/21/20
Current Rate	1.91%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 3/24/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	03/24/22
Current Rate	2.00%
Contractual maturities of borrowings with the FHLB	$ 719	1,017
Advance Date 3/24/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	03/25/24
Current Rate	2.28%
Contractual maturities of borrowings with the FHLB	$ 956	1,164
Advance Date 7/24/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	07/24/20
Current Rate	1.88%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 7/24/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	07/26/21
Current Rate	2.03%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 7/24/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	07/25/22
Current Rate	1.94%
Contractual maturities of borrowings with the FHLB	$ 545	743
Advance Date 8/31/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	08/31/21
Current Rate	1.96%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 9/11/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	09/11/20
Current Rate	1.80%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 9/11/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	09/12/22
Current Rate	2.07%
Contractual maturities of borrowings with the FHLB	$ 1,500	1,500
Advance Date 9/27/2017
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	09/27/22
Current Rate	2.28%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 1/18/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/18/19
Current Rate	2.17%
Contractual maturities of borrowings with the FHLB	$ 0	1,500
Advance Date 1/24/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/24/20
Current Rate	2.42%
Contractual maturities of borrowings with the FHLB	$ 1,500	1,500
Advance Date 2/9/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	02/09/22
Current Rate	2.78%
Contractual maturities of borrowings with the FHLB	$ 2,500	2,500
Advance Date 3/21/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	03/21/23
Current Rate	3.13%
Contractual maturities of borrowings with the FHLB	$ 1,500	1,500
Advance Date 4/4/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	04/04/23
Current Rate	3.00%
Contractual maturities of borrowings with the FHLB	$ 2,000	2,000
Advance Date 5/22/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	05/23/22
Current Rate	3.22%
Contractual maturities of borrowings with the FHLB	$ 1,500	1,500
Advance Date 5/29/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	05/31/22
Current Rate	2.97%
Contractual maturities of borrowings with the FHLB	$ 2,000	2,000
Advance Date 5/29/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	05/30/23
Current Rate	3.01%
Contractual maturities of borrowings with the FHLB	$ 1,500	1,500
Advance Date 6/28/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	06/28/23
Current Rate	3.13%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 6/28/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	06/28/24
Current Rate	3.25%
Contractual maturities of borrowings with the FHLB	$ 2,000	2,000
Advance Date 7/23/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	07/23/24
Current Rate	3.34%
Contractual maturities of borrowings with the FHLB	$ 1,000	1,000
Advance Date 8/20/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	08/20/20
Current Rate	2.93%
Contractual maturities of borrowings with the FHLB	$ 2,000	2,000
Advance Date 8/31/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	02/28/19
Current Rate	2.56%
Contractual maturities of borrowings with the FHLB	$ 0	1,500
Advance Date 9/25/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	03/25/19
Current Rate	2.66%
Contractual maturities of borrowings with the FHLB	$ 0	2,000
Advance Date 9/27/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	09/27/21
Current Rate	3.24%
Contractual maturities of borrowings with the FHLB	$ 1,500	1,500
Advance Date 10/18/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	04/18/19
Current Rate	2.76%
Contractual maturities of borrowings with the FHLB	$ 0	1,500
Advance Date 10/30/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	04/30/19
Current Rate	2.78%
Contractual maturities of borrowings with the FHLB	$ 0	1,500
Advance Date 11/23/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	05/23/19
Current Rate	2.82%
Contractual maturities of borrowings with the FHLB	$ 0	1,500
Advance Date 12/3/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/03/19
Current Rate	2.61%
Contractual maturities of borrowings with the FHLB	$ 0	3,750
Advance Date 12/20/2018
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	06/20/19
Current Rate	2.81%
Contractual maturities of borrowings with the FHLB	$ 0	2,000
Advance Date 1/29/2019
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/30/23
Current Rate	2.94%
Contractual maturities of borrowings with the FHLB	$ 3,000	0
Advance Date 1/29/2019
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	01/29/24
Current Rate	2.97%
Contractual maturities of borrowings with the FHLB	$ 3,000	0
Advance Date 9/30/2019
Federal Home Loan Bank, Advances [Line Items]
Maturity Date	03/30/20
Current Rate	2.10%
Contractual maturities of borrowings with the FHLB	$ 1,000	$ 0

Borrowings - Contractual maturi

Borrowings - Contractual maturities of all FHLB borrowings (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Contractual Maturity
2020	$ 13,140
2021	10,121
2022	10,137
2023	11,381
2024	6,956
Total	$ 51,735	$ 71,826
Weighted Average Rate
2020	2.04%
2021	2.11%
2022	2.60%
2023	2.78%
2024	3.01%
Total	2.46%

Borrowings - Additional Informa

Borrowings - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Borrowings
Residential mortgages carrying amount	$ 194,868,000	$ 201,922,000
Residential mortgages available for borrowings	111,948,000	94,106,000
Repurchase agreement additional liquidity	10,000,000
Repurchase agreement additional liquidity of unsecured line of credit	5,000,000
Repurchase agreements	0	0
line of credit	$ 0	$ 0

Income Taxes - Provision for in

Income Taxes - Provision for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Current
Federal	$ 106	$ 163
State	3	4
Deferred	(210)	(135)
Income Tax Expense (Benefit), Total	$ (101)	$ 32

Income Taxes - Differences betw

Income Taxes - Differences between income tax expense to statutory federal tax at a rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Taxes
Federal Tax at a Statutory rate	$ (129)	$ 35
Federal Tax at a Statutory rate, % of Pre-tax Income	21.00%	21.00%
State taxes, net of Federal provision	$ 422	$ 14
State taxes, net of Federal provision, % of Pre-tax Income	(69.00%)	9.00%
Change in valuation allowance	$ (419)	$ (11)
Change in valuation allowance, % of Pre-tax Income	68.00%	(7.00%)
Nontaxable interest and dividend income	$ (18)	$ (19)
Nontaxable interest and dividend income, % of Pre-tax Income	3.00%	(11.00%)
Other items	$ 43	$ 13
Other items, % of Pre-tax Income	(7.00%)	7.00%
Income Tax Expense (Benefit), Total	$ (101)	$ 32
Income tax provision, % of Pre-tax Income	16.00%	19.00%

Income Taxes - Deferred income

Income Taxes - Deferred income tax assets and liabilities resulting from temporary differences (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Deferred loan origination fees	$ 75	$ 94
Allowance for loan losses - Federal	485	408
State tax credits	180	825
Supplemental Executive Retirement Plan	221	216
Unrealized loss on securities available for sale	3	49
Net operating loss	639	477
Stock compensation	42	32
Depreciation	128	0
Other	84	43
Total deferred tax assets, gross	1,857	2,144
Valuation allowance	(994)	(1,413)
Total deferred tax assets, net of valuation allowance	863	731
Deferred tax liabilities:
Depreciation	0	(9)
Mortgage servicing rights	(190)	(213)
Total deferred tax liabilities	(190)	(222)
Net deferred tax asset	$ 673	$ 509

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Taxes
Percentage of effective tax rate	21.00%	21.00%
Statutory federal income tax rate	16.00%	19.00%
Deferred tax liability not recognized with respect to Federal base year reserve	$ 1,518,000	$ 1,518,000
Deferred tax liability, unrecognized, federal base year reserve	$ 319,000	$ 319,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Unrealized Gains and Losses on Available-for-Sale Securities, Beginning balance	$ (183)	$ (165)
Unrealized Gains and Losses on Available-for-Sale Securities, Other comprehensive income (loss)	174	(18)
Unrealized Gains and Losses on Available-for-Sale Securities, Ending balance	(9)	(183)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(183)	(165)
Other comprehensive income (loss)	174	(18)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	$ (9)	$ (183)

Employee Benefit Plans - Stock

Employee Benefit Plans - Stock option activity and related information for its option plans (Details) - Restricted stock - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Stock Awards
Outstanding at beginning of year	71,100	62,700
Granted	0	8,400
Outstanding at year end	71,100	71,100
Weighted Average Price Per Share
Outstanding at beginning of year	$ 16.82	$ 16.72
Grants	0	17.57
Outstanding at year end	$ 16.82	$ 16.82
Stock Awards
Vested shares at year end			29,408	15,644
Unvested shares at year end			41,692	55,456
Total outstanding shares at year end	71,100	71,100	71,100	71,100
Vested shares at year end - Weighted Average Price Per Share			$ 16.78	$ 16.72
Unvested shares at year end - Weighted Average Price Per Share			$ 16.85	$ 16.85

Employee Benefit Plans - Stoc_2

Employee Benefit Plans - Stock option activity and option plans (Details) - $ / shares	6 Months Ended	12 Months Ended
	Jul. 02, 2018	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Beginning of Period [Abstract]
Stock options grants to senior management and directors	20,000	0
2017 Equity Incentive Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Beginning of Period [Abstract]
Outstanding at beginning of year		172,080	152,080
Stock options grants to senior management and directors		0	20,000
Exercised		0	0
Outstanding at year end		172,080	172,080
Exercisable at year end		64,832	30,416
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Outstanding at beginning of year		$ 16.82	$ 16.72
Grants		0	17.58
Exercised		0
Outstanding at year end		16.82	16.82
Exercisable at year end		16.77	16.72
2017 Equity Incentive Plan | Maximum | Exercise Price Range From 16.69 To 16.72 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range Upper Range Limit			16.72
2017 Equity Incentive Plan | Maximum | Exercise Price Range From 17.52 To 17.75 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range Upper Range Limit			17.75
2017 Equity Incentive Plan | Maximum | Exercise Price Range From 16.69 To 17.75 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range Upper Range Limit		17.75	17.75
2017 Equity Incentive Plan | Minimum | Exercise Price Range From 16.69 To 16.72 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range Lower Range Limit			16.69
2017 Equity Incentive Plan | Minimum | Exercise Price Range From 17.52 To 17.75 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range Lower Range Limit			17.52
2017 Equity Incentive Plan | Minimum | Exercise Price Range From 16.69 To 17.75 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range Lower Range Limit		$ 16.69	$ 16.69

Employee Benefit Plans - Estima

Employee Benefit Plans - Estimate fair value of stock-based awards of weighted average assumptions (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Employee Benefit Plans
Risk-free interest rate	0.00%	2.41%
Volatility factor	0.00%	10.47%
Dividends	0.00%	0.00%
Weighted average expected life (years)	0 years	5 years
Forfeiture rate	0.00%	0.00%

Employee Benefit Plans - Change

Employee Benefit Plans - Changes in unvested shares (Details) - $ / shares	6 Months Ended	12 Months Ended
	Jul. 02, 2018	Dec. 31, 2019
Unvested Shares
Unvested at January 1, 2019		141,664
Granted	20,000	0
Vested		34,416
Unvested at December 31, 2019		107,248
Weighted Average Grant Date Fair Value
Unvested at January 1, 2019		$ 2.31
Granted		0
Vested		2.30
Unvested at December 31, 2019		$ 2.31

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Details)	Jul. 02, 2018$ / shares	Jan. 05, 2018$ / shares	Jul. 02, 2018individualshares	Dec. 31, 2019USD ($)individual$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Aug. 29, 2017shares
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Description of defined contribution pension				Employees are eligible for participation in the 401(k) Plan after one year of service and attaining age 19. The 401(k) Plan allows employees to contribute 1% to 100% of their annual salary subject to statutory limitations. Matching contributions made by the Bank are 100% of the first 6% of compensation that an employee contributes to the 401(k) Plan.
Matching contributions made by the Bank				100.00%
Matching contributions made by employees | $				$ 217,000,000	$ 218,000,000
Discretionary contributions made | $				55,000,000	$ 28,000,000
ESOP borrowed to purchase shares | $				$ 700,000,000
Number of shares purchased				69,972
Employee stock ownership plan debt structure description				The loan is being repaid in twenty equal annual installments through 2026.
Total shares released to participants				3,808	3,808
Expense related to ESOP | $				$ 66,000	$ 72,000
Number of unearned ESOP shares | $				26,655,000
Aggregate market value of unearned ESOP shares. | $				$ 463,264,000
Stock options granted			20,000	0
Restricted stock
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Restricted stock granted				0	8,400
2017 Equity Incentive Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of shares authorized for award						77,668
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | $ / shares				$ 0	$ 17.58
Stock options granted				0	20,000
2017 Equity Incentive Plan | Restricted stock
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of external directors | individual			5
Grant vesting period				5 years
Percentage of share base payment award				20.00%
Restricted stock granted				0
2017 Equity Incentive Plan | Stock option
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Stock options granted				0
2017 Equity Incentive Plan | Executive Officer [Member] | Restricted stock
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of restricted stock awards granted			8,400
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | $ / shares	$ 17.75	$ 17.52
Supplemental executive retirement plan (SERP)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of executive under supplemental executive retirement plan (SERP) | individual				2
Contribution recorded under supplemental executive retirement plan (SERP) | $				$ 845,000,000	$ 826,000,000
Total expense under the SERP | $				$ 79,000,000	$ 59,000,000

Employee Benefit Plans - Addi_2

Employee Benefit Plans - Additional Information (Details 2) - USD ($) $ / shares in Units, $ in Thousands	Jul. 02, 2018	Jan. 05, 2018	Jul. 02, 2018	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Grants			20,000	0
Compensation expense				$ 304,000	$ 310,000
Expected compensation expense in 2020 and 2021				304,000
Expected compensation expense in 2022				238,000
Expected compensation expense in 2023				5,000
Aggregate intrinsic value of options exercisable				$ 40,000	9,000
Expected to be recognized over weighted average period				2 years 9 months 18 days
Grant date fair value of all options granted					$ 55,000
Stock - based compensation plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of shares authorized for options				194,168
Stock options exercise price	$ 17.75	$ 17.52
Term of option				10 years
Share based payment award, vesting period				5 years

Other income (Details)

Other income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Mortgage fee income and realized gain on sales of loans
Residential mortgage loan origination fees		$ 229	$ 324
Commercial loan fees		85	88
Loan servicing income	[1]	298	331
Realized gain on sales of residential mortgage loans	[1]	931	1,390
Realized gain on sale of SBA loan	[1]	0	47
Total mortgage fee income and realized gain on sales of loans		1,543	2,180
Bank Owned Life Insurance Income		58	61
Other miscellaneous income		11	19
Total non-interest income		1,937	2,717
Deposit related fees
Non Interest Income [Line Items]
Total insurance and securities commission income		65	66
Insufficient funds fee
Non Interest Income [Line Items]
Total insurance and securities commission income		76	83
Service fees
Non Interest Income [Line Items]
Total insurance and securities commission income		141	149
Securities commission income
Non Interest Income [Line Items]
Total insurance and securities commission income		8	43
Insurance commission income
Non Interest Income [Line Items]
Total insurance and securities commission income		11	88
Insurance and securities commission income
Non Interest Income [Line Items]
Total insurance and securities commission income		19	131
Debit card interchange fee income
Non Interest Income [Line Items]
Total insurance and securities commission income		135	146
ATM fees
Non Interest Income [Line Items]
Total insurance and securities commission income		30	31
Card income
Non Interest Income [Line Items]
Total insurance and securities commission income		$ 165	$ 177
[1]	Outside scope of ASC 606

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions
Loans outstanding with related parties	$ 469,000	$ 485,000
Amount of new loan	415,000
Proceeds of loan	360,000
Repayment of loans	$ 71,000

Commitments - Non-performance b

Commitments - Non-performance by the other party to the financial instrument for commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amount of financial instrument	$ 39,491	$ 28,791
Commitments to grant loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amount of financial instrument	11,351	5,578
Unadvanced portion of construction loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amount of financial instrument	4,601	4,439
Unfunded Commitments Under Lines Of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amount of financial instrument	$ 23,539	$ 18,774

Commitments - Additional Inform

Commitments - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)loan	Dec. 31, 2018USD ($)loan
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan amount	$ 5,900	$ 3,100
Number of commercial letters of credit | loan	1	3
Commercial letters of credit	$ 64,000	$ 16,000
Minimum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Interest rate during period	3.125%	4.50%
Maximum
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Interest rate during period	4.875%	6.00%

Regulatory Matters (Details)

Regulatory Matters (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Regulatory Matters
Total Core Capital (to Risk- Weighted Assets), Actual amount	$ 30,780	$ 30,896
Total Core Capital (to Risk- Weighted Assets), Actual ratio	15.32%	15.70%
Total Core Capital (to Risk- Weighted Assets), For capital adequacy purposes amount	$ 16,075	$ 14,927
Total Core Capital (to Risk- Weighted Assets), For capital adequacy purposes ratio	8.00%	8.00%
Total Core Capital (to Risk- Weighted Assets), To be well capitalized under prompt corrective action provisions amount	$ 20,093	$ 18,658
Total Core Capital (to Risk- Weighted Assets), To be well capitalized under prompt corrective action provisions ratio	10.00%	10.00%
Total Core Capital (to Risk- Weighted Assets), Well capitalized with buffer	$ 21,098	$ 20,665
Total Core Capital (to Risk- Weighted Assets), Well capitalized with buffer ratio	10.50%	10.50%
Tier 1 Capital (to Risk-Weighted Assets), Actual amount	$ 29,139	$ 29,335
Tier 1 Capital (to Risk-Weighted Assets), Actual ratio	14.50%	14.91%
Tier 1 Capital (to Risk-Weighted Assets), For capital adequacy purposes amount	$ 12,056	$ 11,808
Tier 1 Capital (to Risk-Weighted Assets), For capital adequacy purposes ratio	6.00%	6.00%
Tier 1 Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions amount	$ 16,075	$ 14,927
Tier 1 Capital (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions ratio	8.00%	8.00%
Tier 1 Capital (to Risk-Weighted Assets), Well capitalized with buffer	$ 17,079	$ 16,729
Tier 1 Capital (to Risk-Weighted Assets), Well capitalized with buffer ratio	8.50%	8.50%
Tier 1 Common Equity (to Risk-Weighted Assets), Actual amount	$ 29,139	$ 29,335
Tier 1 Common Equity (to Risk-Weighted Assets), Actual ratio	14.50%	14.91%
Tier 1 Common Equity (to Risk-Weighted Assets), For Capital Adequacy Purposes	$ 9,042	$ 8,856
Tier 1 Common Equity (to Risk-Weighted Assets), For capital adequacy purposes ratio	4.50%	4.50%
Tier 1 Common Equity (to Risk-Weighted Assets), To Be Well Capitalized Under Prompt Corrective Action Provisions	$ 13,061	$ 12,128
Tier 1 Common Equity (to Risk-Weighted Assets), To be well capitalized under prompt corrective action provisions ratio	6.50%	6.50%
Tier 1 Common Equity (to Risk-Weighted Assets), For well capitalized buffer	$ 14,065	$ 13,777
Tier 1 Common Equity (to Risk-Weighted Assets), For well capitalized buffer ratio	7.00%	7.00%
Tier 1 Capital (to Assets), Actual amount	$ 29,139	$ 29,335
Tier 1 Capital (to Assets), Actual ratio	9.01%	9.07%
Tier 1 Capital (to Assets), For adequacy purpose	$ 12,938	$ 12,938
Tier 1 Capital (to Assets), For adequacy purpose ratio	4.00%	4.00%
Tier 1 Capital (to Assets), To be well capitalized	$ 16,172	$ 15,216
Tier 1 Capital (to Assets), To well capitalized ratio	5.00%	5.00%
Tier 1 Capital (to Assets), To well capitalized with buffer	$ 16,172	$ 16,173
Tier 1 Capital (to Assets), To well capitalized with buffer ratio	5.00%	5.00%

Fair Value Measurement and Fa_3

Fair Value Measurement and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Available-for-Sale Portfolio
Securities available for sale	$ 18,126	$ 18,331
Mortgage-backed securities - residential
Available-for-Sale Portfolio
Securities available for sale	4,091	5,876
Fair Value, Measurements, Recurring
Available-for-Sale Portfolio
Securities available for sale	18,126	18,331
Fair Value, Measurements, Recurring | U.S. Government and agency obligations
Available-for-Sale Portfolio
Securities available for sale	14,035	12,455
Fair Value, Measurements, Recurring | Mortgage-backed securities - residential
Available-for-Sale Portfolio
Securities available for sale	4,091	5,876
Fair Value, Measurements, Recurring | Level 1
Available-for-Sale Portfolio
Securities available for sale	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. Government and agency obligations
Available-for-Sale Portfolio
Securities available for sale	0	0
Fair Value, Measurements, Recurring | Level 1 | Mortgage-backed securities - residential
Available-for-Sale Portfolio
Securities available for sale	0	0
Fair Value, Measurements, Recurring | Level 2
Available-for-Sale Portfolio
Securities available for sale	18,126	18,331
Fair Value, Measurements, Recurring | Level 2 | U.S. Government and agency obligations
Available-for-Sale Portfolio
Securities available for sale	14,035	12,455
Fair Value, Measurements, Recurring | Level 2 | Mortgage-backed securities - residential
Available-for-Sale Portfolio
Securities available for sale	4,091	5,876
Fair Value, Measurements, Recurring | Level 3
Available-for-Sale Portfolio
Securities available for sale	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. Government and agency obligations
Available-for-Sale Portfolio
Securities available for sale	0	0
Fair Value, Measurements, Recurring | Level 3 | Mortgage-backed securities - residential
Available-for-Sale Portfolio
Securities available for sale	0	0
Fair Value | Level 2
Available-for-Sale Portfolio
Securities available for sale	$ 18,126	$ 18,331

Fair Value Measurement and Fa_4

Fair Value Measurement and Fair Values of Financial Instruments - Fair value on a nonrecurring basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	$ 3,817	$ 2,133
Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	0
Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	2,997	2,133
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	820
Impaired loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	893
Impaired loans | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	0
Impaired loans | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	803
Impaired loans | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	90
Loans held for sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	2,194	2,133
Loans held for sale | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	0
Loans held for sale | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	2,194	$ 2,133
Loans held for sale | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	0
Foreclosed real estate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	730
Foreclosed real estate | Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	0
Foreclosed real estate | Level 2
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	0
Foreclosed real estate | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans	$ 730

Fair Value Measurement and Fa_5

Fair Value Measurement and Fair Values of Financial Instruments - Additional quantitative information (Details) - Level 3	Dec. 31, 2019
Impaired loans | Appraisal of collateral | Appraisal Adjustment
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	50
Impaired loans | Sales Approach | Cost to Sell | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	10
Impaired loans | Sales Approach | Cost to Sell | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	50.7
Impaired loans | Sales Approach | Cost to Sell | Weighted average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	41.7
Foreclosed real estate | Appraisal of collateral | Appraisal Adjustment | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	25
Foreclosed real estate | Appraisal of collateral | Appraisal Adjustment | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	29.2
Foreclosed real estate | Appraisal of collateral | Appraisal Adjustment | Weighted average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	26.6
Foreclosed real estate | Market Approach | Cost to Sell | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	6.7
Foreclosed real estate | Market Approach | Cost to Sell | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	7.3
Foreclosed real estate | Market Approach | Cost to Sell | Weighted average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loans	6.9

Fair Value Measurement and Fa_6

Fair Value Measurement and Fair Values of Financial Instruments - Carrying amounts and estimated fair values of the financial instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financial assets:
Interest bearing demand deposits	$ 6,244	$ 4,710
Securities available for sale	18,126	18,331
Securities held to maturity	5,166	6,052
Loans, net	3,817	2,133
Financial liabilities:
Time deposits	132,832
Level 1
Financial assets:
Loans, net	0
Level 2
Financial assets:
Loans, net	2,997	2,133
Level 3
Financial assets:
Loans, net	820
Carrying Amount | Level 1
Financial assets:
Cash and due from banks	1,689	1,581
Interest bearing demand deposits	6,244	4,710
Accrued interest receivable	807	876
Financial liabilities:
Demand Deposits, Savings, NOW and MMDA	102,728	98,681
Accrued interest payable	111	168
Carrying Amount | Level 2
Financial assets:
Securities available for sale	18,126	18,331
Securities held to maturity	5,166	6,052
Investment in restricted stock	2,757	3,637
Loans held for sale	2,194	2,133
Financial liabilities:
Time deposits	132,832	123,934
Borrowings	51,735	71,826
Carrying Amount | Level 3
Financial assets:
Loans, net	274,508	281,741
Foreclosed real estate	730	0
Fair Value | Level 1
Financial assets:
Cash and due from banks	1,689	1,581
Interest bearing demand deposits	6,244	4,710
Accrued interest receivable	807	876
Financial liabilities:
Demand Deposits, Savings, NOW and MMDA	102,728	98,681
Accrued interest payable	111	168
Fair Value | Level 2
Financial assets:
Securities available for sale	18,126	18,331
Securities held to maturity	5,297	6,030
Investment in restricted stock	2,757	3,637
Loans held for sale	2,194	2,133
Financial liabilities:
Time deposits	132,972	124,182
Borrowings	52,348	71,086
Fair Value | Level 3
Financial assets:
Loans, net	279,114	280,173
Foreclosed real estate	$ 730	$ 0

Fair Value Measurement and Fa_7

Fair Value Measurement and Fair Values of Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	24 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Measurement and Fair Values of Financial Instruments
Transfers of assets from level 1 to level 2	$ 0	$ 0
Transfers of assets from level 2 to level 1	0
Transfers of assets from and out of level 3	$ 0

FSB Bancorp, Inc. (Parent Com_3

FSB Bancorp, Inc. (Parent Company Only) (Schedule of Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 7,933	$ 6,291
Total Assets	323,310	328,269
Liabilities and Stockholders' Equity
Total Liabilities	291,766	296,756
Stockholders' Equity	31,544	31,513	$ 31,056
Total Liabilities and Stockholders' Equity	323,310	328,269
Parent Company [Member] | Reportable Legal Entities [Member]
Assets
Cash and cash equivalents	1,474	1,570
Investment in banking subsidiary	29,796	29,661
ESOP loan receivable	297	331
Total Assets	31,567	31,562
Liabilities and Stockholders' Equity
Total Liabilities	23	49
Stockholders' Equity	31,544	31,513
Total Liabilities and Stockholders' Equity	$ 31,567	$ 31,562

FSB Bancorp, Inc. (Parent Com_4

FSB Bancorp, Inc. (Parent Company Only) (Schedule of Statements of Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statements of Income
Interest Income	$ 12,248	$ 11,827
Net (Loss) Income	(513)	135
Parent Company [Member] | Reportable Legal Entities [Member]
Consolidated Statements of Income
Interest Income	39	36
Other Expense	(447)	(500)
Equity in undistributed (loss) earnings of banking subsidiary	(105)	599
Net (Loss) Income	$ (513)	$ 135

FSB Bancorp, Inc. (Parent Com_5

FSB Bancorp, Inc. (Parent Company Only) (Schedule of Statements of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net (Loss) Income	$ (513)	$ 135
Adjustments to reconcile net (loss) income to net cash flows from operating activities
Stock based compensation	304	310
Net (decrease) increase in other liabilities	541	334
Net cash flows from operating activities	930	2,073
Cash flows from investing activities
Net cash flows from investing activities	8,202	(19,374)
Cash flows from financing activities
Net cash flows from financing activities	(7,490)	13,195
Net decrease in cash and cash equivalents	1,642	(4,106)
Cash and Cash Equivalents - Beginning	6,291	10,397
Cash and Cash Equivalents - Ending	7,933	6,291
Parent Company [Member] | Reportable Legal Entities [Member]
Cash flows from operating activities
Net (Loss) Income	(513)	135
Adjustments to reconcile net (loss) income to net cash flows from operating activities
Equity in undistributed loss (earnings) of banking subsidiary	105	(599)
Stock based compensation	304	310
Net (decrease) increase in other liabilities	(26)	15
Net cash flows from operating activities	(130)	(139)
Cash flows from investing activities
Payments received on ESOP loan	34	34
Net cash flows from investing activities	34	34
Cash flows from financing activities
Purchase of common stock		(42)
Net cash flows from financing activities		(42)
Net decrease in cash and cash equivalents	(96)	(147)
Cash and Cash Equivalents - Beginning	1,570	1,717
Cash and Cash Equivalents - Ending	$ 1,474	$ 1,570