First National (FXNC) 10-Q 7 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 07, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	FXNC
Entity Registrant Name	FIRST NATIONAL CORP /VA/
Entity Central Index Key	719,402
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		4,952,575

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	[1]
Assets
Cash and due from banks	$ 11,185	$ 11,358
Interest-bearing deposits in banks	58,092	28,628
Securities available for sale, at fair value	93,699	89,255
Securities held to maturity, at amortized cost	46,791	48,208
Restricted securities, at cost	1,590	1,570
Loans held for sale	68	438
Loans, net of allowance for loan losses	515,664	516,875
Other real estate owned, net of valuation allowance	0	326
Premises and equipment, net	19,833	19,891
Accrued interest receivable	1,869	1,916
Bank owned life insurance	13,711	13,967
Core deposit intangibles, net	799	930
Other assets	4,553	5,748
Total assets	767,854	739,110
Deposits:
Noninterest-bearing demand deposits	189,460	180,912
Savings and interest-bearing demand deposits	378,330	361,417
Time deposits	125,035	122,651
Total deposits	692,825	664,980
Subordinated debt	4,952	4,948
Junior subordinated debt	9,279	9,279
Accrued interest payable and other liabilities	1,105	1,749
Total liabilities	708,161	680,956
Shareholders’ Equity
Preferred stock, par value	0	0
Common stock, par value	6,191	6,182
Surplus	7,312	7,260
Retained earnings	48,109	45,670
Accumulated other comprehensive loss, net	(1,919)	(958)
Total shareholders’ equity	59,693	58,154
Total liabilities and shareholders’ equity	$ 767,854	$ 739,110
[1]	Derived from audited consolidated financial statements.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	[1]
Statement of Financial Position [Abstract]
Securities held to maturity, at fair value	$ 45,630	$ 47,702
Allowance for loan losses	5,272	5,326
Other real estate owned, valuation allowance	$ 0	$ 0
Preferred stock, par value (in usd per share)	$ 1.25	$ 1.25
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 1.25	$ 1.25
Common stock, shares authorized (in shares)	8,000,000	8,000,000
Common stock, shares issued (in shares)	4,952,575	4,945,702
Common stock, shares outstanding (in shares)	4,952,575	4,945,702
[1]	Derived from audited consolidated financial statements.

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest and Dividend Income
Interest and fees on loans	$ 6,305	$ 5,646
Interest on deposits in banks	160	61
Interest and dividends on securities:
Taxable interest	680	662
Tax-exempt interest	145	143
Dividends	22	20
Total interest and dividend income	7,312	6,532
Interest Expense
Interest on deposits	590	383
Interest on subordinated debt	89	89
Interest on junior subordinated debt	86	68
Total interest expense	765	540
Net interest income	6,547	5,992
Provision for loan losses	100	0
Net interest income after provision for loan losses	6,447	5,992
Noninterest Income
Service charges on deposit accounts	762	755
ATM and check card fees	519	501
Wealth management fees	407	347
Fees for other customer services	153	140
Income from bank owned life insurance	559	93
Net gains on sale of loans	9	33
Other operating income	224	72
Total noninterest income	2,633	1,941
Noninterest Expense
Salaries and employee benefits	3,383	3,242
Occupancy	400	367
Equipment	423	408
Marketing	109	136
Supplies	80	91
Legal and professional fees	191	197
ATM and check card expense	203	162
FDIC assessment	82	79
Bank franchise tax	115	104
Telecommunications expense	36	110
Data processing expense	162	150
Postage expense	61	61
Amortization expense	131	169
Other real estate owned (income) expense, net	(23)	2
Other operating expense	513	473
Total noninterest expense	5,866	5,751
Income before income taxes	3,214	2,182
Income tax expense	527	639
Net income	$ 2,687	$ 1,543
Earnings per common share
Basic (in usd per share)	$ 0.54	$ 0.31
Diluted (in usd per share)	$ 0.54	$ 0.31

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 2,687	$ 1,543
Other comprehensive (loss) income, net of tax,
Unrealized holding (losses) gains on available for sale securities, net of tax	(862)	381
Pension liability adjustment, net of tax	(99)	0
Total other comprehensive (loss) income	(961)	381
Total comprehensive income	$ 1,726	$ 1,924

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Unrealized holding gains on available for sale securities, tax	$ (229)	$ 196
Pension liability adjustment, tax	$ (27)	$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Cash Flows from Operating Activities
Net income	$ 2,687	$ 1,543
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of premises and equipment	345	351
Amortization of core deposit intangibles	131	169
Amortization of debt issuance costs	4	4
Origination of loans held for sale	(192)	(1,428)
Proceeds from sale of loans held for sale	571	1,798
Net gains on sales of loans held for sale	(9)	(33)
Provision for loan losses	100	0	$ 100
Net gains on sale of other real estate owned	(24)	0
Increase in cash value of bank owned life insurance	(91)	(85)
Accretion of discounts and amortization of premiums on securities, net	138	156
Accretion of premium on time deposits	(22)	(29)
Stock-based compensation	70	64
Excess tax benefits on stock-based compensation	(7)	(14)
Deferred income tax expense (benefit)	37	(102)
Changes in assets and liabilities:
Decrease (increase) in interest receivable	47	(7)
Decrease in other assets	1,394	168
(Decrease) increase in accrued expenses and other liabilities	(743)	280
Net cash provided by operating activities	4,436	2,835
Cash Flows from Investing Activities
Proceeds from maturities, calls, and principal payments of securities available for sale	3,052	3,370
Proceeds from maturities, calls, and principal payments of securities held to maturity	1,368	1,345
Purchases of securities available for sale	(8,676)	0
Net purchase of restricted securities	(20)	(22)
Purchase of premises and equipment	(287)	(275)
Proceeds from sale of other real estate owned	350	0
Proceeds from cash value of bank owned life insurance	347	0
Net decrease (increase) in loans	1,111	(11,573)
Net cash used in investing activities	(2,755)	(7,155)
Cash Flows from Financing Activities
Net increase in demand deposits and savings accounts	25,461	10,778
Net increase (decrease) in time deposits	2,406	(1,550)
Cash dividends paid on common stock, net of reinvestment	(233)	(161)
Repurchase of common stock	(24)	0
Net cash provided by financing activities	27,610	9,067
Increase in cash and cash equivalents	29,291	4,747
Cash and Cash Equivalents
Cash and cash equivalents, beginning of year	39,986	41,092	41,092
Cash and cash equivalents, end of year	69,277	45,839	$ 39,986
Cash payments for:
Interest	779	576
Supplemental Disclosures of Noncash Investing and Financing Activities
Unrealized (losses) gains on securities available for sale	(1,091)	577
Change in pension liability	(126)	0
Issuance of common stock, dividend reinvestment plan	$ 15	$ 12

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total		Preferred Stock	Common Stock	Surplus	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance at Dec. 31, 2016	$ 52,151		$ 0	$ 6,162	$ 7,093	$ 39,756	$ (860)
Net income	1,543					1,543
Other comprehensive income (loss)	381						381
Cash dividends on common stock	(173)					(173)
Stock-based compensation	64				64
Issuance of common stock, dividend reinvestment plan	12			1	11
Issuance of common stock, stock incentive plan	0			13	(13)
Ending Balance at Mar. 31, 2017	53,978		0	6,176	7,155	41,126	(479)
Beginning Balance at Dec. 31, 2017	58,154	[1]	0	6,182	7,260	45,670	(958)
Net income	2,687					2,687
Other comprehensive income (loss)	(961)						(961)
Cash dividends on common stock	(248)					(248)
Stock-based compensation	70				70
Issuance of common stock, dividend reinvestment plan	15			1	14
Issuance of common stock, stock incentive plan	0			9	(9)
Repurchase of common stock, stock incentive plan	(24)			(1)	(23)
Ending Balance at Mar. 31, 2018	$ 59,693		$ 0	$ 6,191	$ 7,312	$ 48,109	$ (1,919)
[1]	Derived from audited consolidated financial statements.

Consolidated Statements of Cha9

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Stockholders' Equity [Abstract]
Cash dividends on common stock, per share (in usd per share)	$ 0.05	$ 0.035
Issuance of common stock dividend reinvestment plan, shares (in shares)	851	827
Issuance of common stock incentive plan, shares (in shares)	7,339	10,536
Repurchase of common stock incentive plan, shares (in shares)	1,317

General

General	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
General	General The accompanying unaudited consolidated financial statements of First National Corporation (the Company) and its subsidiary, First Bank (the Bank), have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information. Accordingly, they do not include all of the information and footnotes required by GAAP. All significant intercompany balances and transactions have been eliminated. In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments and reclassifications of a normal and recurring nature considered necessary to present fairly the financial positions at March 31, 2018 and December 31, 2017 , the statements of income and comprehensive income for the three months ended March 31, 2018 and 2017 and the cash flows and changes in shareholders’ equity for the three months ended March 31, 2018 and 2017 . The statements should be read in conjunction with the consolidated financial statements and related notes included in the Annual Report on Form 10-K for the year ended December 31, 2017 . Operating results for the three months ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 . Adoption of ASU No. 2014-09, "Revenue from Contracts with Customers: Topic 606." On January 1, 2018, the Company adopted ASU No. 2014-09, "Revenue from Contracts with Customers: Topic 606." This ASU revised guidance for the recognition, measurement, and disclosure of revenue from contracts with customers. The original guidance was amended through subsequent accounting standard updates that resulted in technical corrections, improvements, and a one-year deferral of the effective date to January 1, 2018. The guidance, as amended, is applicable to all entities and replaces significant portions of existing industry and transaction-specific revenue recognition rules with a more principles-based recognition model. Most revenue associated with financial instruments, including interest income, loan origination fees, and credit card fees, is outside the scope of the guidance. Gains and losses on investment securities, derivatives, financial guarantees, and sales of financial instruments are similarly excluded from the scope. The guidance is applicable to noninterest revenue streams such as trust and asset management income, deposit related fees, interchange fees, and merchant income. The Company adopted this guidance via the modified retrospective approach, meaning the standard is applied only to the most current period presented in the financial statements with the cumulative effect of initially applying the standard recognized at the date of initial application. Since the guidance does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other GAAP, the new guidance did not have a material impact on revenue most closely associated with financial instruments, including interest income and expense. The Company completed its overall assessment of revenue streams and review of related contracts potentially affected by the ASU, including trust and asset management fees, deposit related fees, interchange fees, and merchant income. The Company also completed an evaluation of certain costs related to these revenue streams to determine whether such costs should be presented gross versus net. Based on these assessments, the Company concluded that ASU 2014-09 did not materially change the method in which the Company currently recognizes revenue for these revenue streams. Since there was no net income impact upon adoption of the new guidance, a cumulative effect adjustment to opening retained earnings was not deemed necessary. Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” Among other things, in the amendments in ASU 2016-02, lessees will be required to recognize the following for all leases (with the exception of short-term leases) at the commencement date: (1) A lease liability, which is a lessee‘s obligation to make lease payments arising from a lease, measured on a discounted basis; and (2) A right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. Under the new guidance, lessor accounting is largely unchanged. Certain targeted improvements were made to align, where necessary, lessor accounting with the lessee accounting model and Topic 606, Revenue from Contracts with Customers. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted upon issuance. Lessees (for capital and operating leases) and lessors (for sales-type, direct financing, and operating leases) must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. Lessees and lessors may not apply a full retrospective transition approach. The Company does not expect the adoption of ASU 2016-02 to have a material impact on its consolidated financial statements. The Company has analyzed its current lease commitments, along with reasonable assumptions to project lease activity in future periods, to measure the potential impact on net income and relevant capital and financial ratios. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The amendments in this ASU, among other things, require the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. Financial institutions and other organizations will now use forward-looking information to better inform their credit loss estimates. Many of the loss estimation techniques applied today will still be permitted, although the inputs to those techniques will change to reflect the full amount of expected credit losses. In addition, the ASU amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. The amendments in this ASU are effective for SEC filers for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The Company is currently assessing the impact that ASU 2016-13 will have on its consolidated financial statements. The Company has formed a committee to address the compliance requirements of this ASU and is currently in the process of analyzing gathered data, defining loan pools and segments, and selecting methods for applying the concepts included in this ASU. During 2018, the Company plans to test selected models, build policy and process documentation, and model the impact of the ASU on the capital and strategic plans. This guidance may result in material changes in the Company's accounting for credit losses of financial instruments. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment”. The amendments in this ASU simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Instead, under the amendments in this ASU, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. Public business entities that are U.S. Securities and Exchange Commission (SEC) filers should adopt the amendments in this ASU for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company does not expect the adoption of ASU 2017-04 to have a material impact on its consolidated financial statements. In March 2017, the FASB issued ASU No. 2017-08, “Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities.” The amendments in this ASU shorten the amortization period for certain callable debt securities purchased at a premium. Upon adoption of the standard, premiums on these qualifying callable debt securities will be amortized to the earliest call date. Discounts on purchased debt securities will continue to be accreted to maturity. The amendments are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. Upon transition, entities should apply the guidance on a modified retrospective basis, with a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption and provide the disclosures required for a change in accounting principle. The Company does not expect the adoption of ASU 2017-08 to have a material impact on its consolidated financial statements. In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities.” The amendments in this ASU modify the designation and measurement guidance for hedge accounting as well as provide for increased transparency regarding the presentation of economic results on both the financial statements and related footnotes. Certain aspects of hedge effectiveness assessments will also be simplified upon implementation of this update. The amendments are effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted, including adoption in any interim period. The Company is currently assessing the impact that ASU 2017-12 will have on its consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-03, “Technical Corrections and Improvements to Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments provide targeted improvements to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. Specifically, the amendments include clarifications related to: measurement elections, transition requirements, and adjustments associated with equity securities without readily determinable fair values; fair value measurement requirements for forward contracts and purchased options on equity securities; presentation requirements for hybrid financial liabilities for which the fair value option has been elected; and measurement requirements for liabilities denominated in a foreign currency for which the fair value option has been elected. The amendments are effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years beginning after June 15, 2018. Early adoption is permitted. The Company does not expect the adoption of ASU 2018-03 to have a material impact on its consolidated financial statements.

Securities

Securities	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Securities	Securities The Company invests in U.S. agency and mortgage-backed securities, obligations of state and political subdivisions, and corporate debt securities. Amortized costs and fair values of securities at March 31, 2018 and December 31, 2017 were as follows (in thousands): March 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value Securities available for sale: U.S. agency and mortgage-backed securities $ 81,309 $ 24 $ (2,225 ) $ 79,108 Obligations of states and political subdivisions 14,820 57 (286 ) 14,591 Total securities available for sale $ 96,129 $ 81 $ (2,511 ) $ 93,699 Securities held to maturity: U.S. agency and mortgage-backed securities $ 30,750 $ — $ (984 ) $ 29,766 Obligations of states and political subdivisions 14,541 18 (192 ) 14,367 Corporate debt securities 1,500 — (3 ) 1,497 Total securities held to maturity $ 46,791 $ 18 $ (1,179 ) $ 45,630 Total securities $ 142,920 $ 99 $ (3,690 ) $ 139,329 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value Securities available for sale: U.S. agency and mortgage-backed securities $ 76,074 $ 67 $ (1,337 ) $ 74,804 Obligations of states and political subdivisions 14,520 86 (155 ) 14,451 Total securities available for sale $ 90,594 $ 153 $ (1,492 ) $ 89,255 Securities held to maturity: U.S. agency and mortgage-backed securities $ 32,149 $ — $ (551 ) $ 31,598 Obligations of states and political subdivisions 14,559 74 (45 ) 14,588 Corporate debt securities 1,500 16 — 1,516 Total securities held to maturity $ 48,208 $ 90 $ (596 ) $ 47,702 Total securities $ 138,802 $ 243 $ (2,088 ) $ 136,957 At March 31, 2018 and December 31, 2017 , investments in an unrealized loss position that were temporarily impaired were as follows (in thousands): March 31, 2018 Less than 12 months 12 months or more Total Fair Value Unrealized (Loss) Fair Value Unrealized (Loss) Fair Value Unrealized (Loss) Securities available for sale: U.S. agency and mortgage-backed securities $ 47,868 $ (941 ) $ 29,121 $ (1,284 ) $ 76,989 $ (2,225 ) Obligations of states and political subdivisions 7,120 (149 ) 1,924 (137 ) 9,044 (286 ) Total securities available for sale $ 54,988 $ (1,090 ) $ 31,045 $ (1,421 ) $ 86,033 $ (2,511 ) Securities held to maturity: U.S. agency and mortgage-backed securities $ 17,269 $ (478 ) $ 12,497 $ (506 ) $ 29,766 $ (984 ) Obligations of states and political subdivisions 11,166 (192 ) — — 11,166 (192 ) Corporate debt securities 1,497 (3 ) — — 1,497 (3 ) Total securities held to maturity $ 29,932 $ (673 ) $ 12,497 $ (506 ) $ 42,429 $ (1,179 ) Total securities $ 84,920 $ (1,763 ) $ 43,542 $ (1,927 ) $ 128,462 $ (3,690 ) December 31, 2017 Less than 12 months 12 months or more Total Fair Value Unrealized (Loss) Fair Value Unrealized (Loss) Fair Value Unrealized (Loss) Securities available for sale: U.S. agency and mortgage-backed securities $ 29,963 $ (286 ) $ 30,362 $ (1,051 ) $ 60,325 $ (1,337 ) Obligations of states and political subdivisions 4,469 (53 ) 1,961 (102 ) 6,430 (155 ) Total securities available for sale $ 34,432 $ (339 ) $ 32,323 $ (1,153 ) $ 66,755 $ (1,492 ) Securities held to maturity: U.S. agency and mortgage-backed securities $ 18,301 $ (205 ) $ 13,297 $ (346 ) $ 31,598 $ (551 ) Obligations of states and political subdivisions 6,889 (45 ) — — 6,889 (45 ) Total securities held to maturity $ 25,190 $ (250 ) $ 13,297 $ (346 ) $ 38,487 $ (596 ) Total securities $ 59,622 $ (589 ) $ 45,620 $ (1,499 ) $ 105,242 $ (2,088 ) The tables above provide information about securities that have been in an unrealized loss position for less than twelve consecutive months and securities that have been in an unrealized loss position for twelve consecutive months or more. 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. Impairment is considered to be other-than-temporary if the Company (1) intends to sell the security, (2) more likely than not will be required to sell the security before recovering its cost, or (3) does not expect to recover the security’s entire amortized cost basis. Presently, the Company does not intend to sell any of these securities, does not expect to be required to sell these securities, and expects to recover the entire amortized cost of all the securities. At March 31, 2018 , there were eighty out of eighty-five U.S. agency and mortgage-backed securities, fifty-six out of eighty obligations of states and political subdivisions, and one corporate debt security in an unrealized loss position. One hundred percent of the Company’s investment portfolio is considered investment grade. The weighted-average re-pricing term of the portfolio was 5.0 years at March 31, 2018 . At December 31, 2017 , there were sixty-eight out of eighty-two U.S. agency and mortgage-backed securities and thirty-nine out of eighty obligations of states and political subdivisions in an unrealized loss position. One hundred percent of the Company’s investment portfolio was considered investment grade at December 31, 2017 . The weighted-average re-pricing term of the portfolio was 4.7 years at December 31, 2017 . The unrealized losses at March 31, 2018 in the U.S. agency and mortgage-backed securities portfolio, the obligations of states and political subdivisions portfolio, and the corporate debt securities portfolio were related to changes in market interest rates and not credit concerns of the issuers. The amortized cost and fair value of securities at March 31, 2018 by contractual maturity are shown below (in thousands). Expected maturities of mortgage-backed securities will differ from contractual maturities because borrowers may have the right to prepay obligations with or without call or prepayment penalties. Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 507 $ 514 $ — $ — Due after one year through five years 8,965 8,877 6,808 6,681 Due after five years through ten years 12,112 11,721 13,723 13,534 Due after ten years 74,545 72,587 26,260 25,415 $ 96,129 $ 93,699 $ 46,791 $ 45,630 Federal Home Loan Bank, Federal Reserve Bank and Community Bankers’ Bank stock are generally viewed as long-term investments and as restricted securities, which are carried at cost, because there is a minimal market for the stock. Therefore, when evaluating restricted securities for impairment, their value is based on the ultimate recoverability of the par value rather than by recognizing temporary declines in value. The Company does not consider these investments to be other-than-temporarily impaired at March 31, 2018 , and no impairment has been recognized. The composition of restricted securities at March 31, 2018 and December 31, 2017 was as follows (in thousands): March 31, December 31, Federal Home Loan Bank stock $ 665 $ 645 Federal Reserve Bank stock 875 875 Community Bankers’ Bank stock 50 50 $ 1,590 $ 1,570

Loans

Loans	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Loans	Loans Loans at March 31, 2018 and December 31, 2017 are summarized as follows (in thousands): March 31, December 31, Real estate loans: Construction and land development $ 33,941 $ 35,927 Secured by 1-4 family residential 208,338 208,177 Other real estate loans 222,352 222,256 Commercial and industrial loans 39,253 38,763 Consumer and other loans 17,052 17,078 Total loans $ 520,936 $ 522,201 Allowance for loan losses (5,272 ) (5,326 ) Loans, net $ 515,664 $ 516,875 Net deferred loan fees included in the above loan categories were $261 thousand and $301 thousand at March 31, 2018 and December 31, 2017 , respectively. Consumer and other loans included $222 thousand and $232 thousand of demand deposit overdrafts at March 31, 2018 and December 31, 2017 , respectively. Risk characteristics of each loan portfolio class that are considered by the Company include: • 1-4 family residential mortgage loans carry risks associated with the continued creditworthiness of the borrower and changes in the value of the collateral. • Real estate construction and land development loans carry risks that the project may not be finished according to schedule, the project may not be finished according to budget, and the value of the collateral may, at any point in time, be less than the principal amount of the loan. Construction loans also bear the risk that the general contractor, who may or may not be a loan customer, may be unable to finish the construction project as planned because of financial pressure or other factors unrelated to the project. • Other real estate loans carry risks associated with the successful operation of a business or a real estate project, in addition to other risks associated with the ownership of real estate, because repayment of these loans may be dependent upon the profitability and cash flows of the business or project. • Commercial and industrial loans carry risks associated with the successful operation of a business because repayment of these loans may be dependent upon the profitability and cash flows of the business. In addition, there is risk associated with the value of collateral other than real estate which may depreciate over time and cannot be appraised with as much reliability. • Consumer and other loans carry risk associated with the continued creditworthiness of the borrower and the value of the collateral, if any. These loans are typically either unsecured or secured by rapidly depreciating assets such as automobiles. They are also likely to be immediately and adversely affected by job loss, divorce, illness, personal bankruptcy, or other changes in circumstances. Consumer and other loans also include purchased consumer loans which could have been originated outside of the Company's market area. The following tables provide a summary of loan classes and an aging of past due loans as of March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 30-59 Days Past Due 60-89 Days Past Due > 90 Days Past Due Total Past Due Current Total Loans Non-accrual Loans 90 Days or More Past Due and Accruing Real estate loans: Construction and land development $ 45 $ 344 $ 512 $ 901 $ 33,040 $ 33,941 $ — $ 512 Secured by 1-4 family residential 873 397 302 1,572 206,766 208,338 300 99 Other real estate loans 268 384 162 814 221,538 222,352 382 162 Commercial and industrial 83 13 — 96 39,157 39,253 — — Consumer and other loans 144 51 — 195 16,857 17,052 — — Total $ 1,413 $ 1,189 $ 976 $ 3,578 $ 517,358 $ 520,936 $ 682 $ 773 December 31, 2017 30-59 Days Past Due 60-89 Days Past Due > 90 Days Past Due Total Past Due Current Total Loans Non-accrual Loans 90 Days or More Past Due and Accruing Real estate loans: Construction and land development $ 986 $ 30 $ 40 $ 1,056 $ 34,871 $ 35,927 $ 269 $ 40 Secured by 1-4 family residential 606 203 148 957 207,220 208,177 267 106 Other real estate loans 2,042 170 10 2,222 220,034 222,256 401 10 Commercial and industrial 184 25 — 209 38,554 38,763 — — Consumer and other loans 51 49 27 127 16,951 17,078 — 27 Total $ 3,869 $ 477 $ 225 $ 4,571 $ 517,630 $ 522,201 $ 937 $ 183 Credit Quality Indicators As part of the ongoing monitoring of the credit quality of the Company’s loan portfolio, management tracks certain credit quality indicators including trends related to the risk grading of specified classes of loans. The Company utilizes a risk grading matrix to assign a rating to each of its loans. The loan ratings are summarized into the following categories: pass, special mention, substandard, doubtful and loss. Pass rated loans include all risk rated credits other than those included in special mention, substandard or doubtful. Loans classified as loss are charged-off. Loan officers assign risk grades to loans at origination and as renewals arise. The Bank’s Credit Administration department reviews risk grades for accuracy on a quarterly basis and as credit issues arise. In addition, a certain amount of loans are reviewed each year through the Company’s internal and external loan review process. A description of the general characteristics of the loan grading categories is as follows: Pass – Loans classified as pass exhibit acceptable operating trends, balance sheet trends, and liquidity. Sufficient cash flow exists to service the loan. All obligations have been paid by the borrower as agreed. Special Mention – Loans classified as special mention have a potential weakness that deserves management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loan or the Bank’s credit position at some future date. Substandard – Loans classified as substandard are inadequately protected by the current net worth and payment capacity of the obligor or of the collateral pledged, if any. Loans so classified have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the Bank will sustain some loss if the deficiencies are not corrected. Doubtful – Loans classified as doubtful have all the weaknesses inherent in those classified as substandard, with the added characteristic that the weaknesses make collection or liquidation in full, on the basis of currently existing facts, conditions and values, highly questionable and improbable. The Company considers all doubtful loans to be impaired and places the loan on non-accrual status. Loss – Loans classified as loss are considered uncollectable and of such little value that their continuance as bankable assets is not warranted. The following tables provide an analysis of the credit risk profile of each loan class as of March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 Pass Special Mention Substandard Doubtful Total Real estate loans: Construction and land development $ 29,743 $ 2,448 $ 1,750 $ — $ 33,941 Secured by 1-4 family residential 204,456 1,908 1,974 — 208,338 Other real estate loans 215,723 962 5,667 — 222,352 Commercial and industrial 38,912 47 294 — 39,253 Consumer and other loans 17,052 — — — 17,052 Total $ 505,886 $ 5,365 $ 9,685 $ — $ 520,936 December 31, 2017 Pass Special Mention Substandard Doubtful Total Real estate loans: Construction and land development $ 31,553 $ 2,268 $ 2,106 $ — $ 35,927 Secured by 1-4 family residential 204,166 1,933 2,078 — 208,177 Other real estate loans 215,773 971 5,512 — 222,256 Commercial and industrial 38,606 53 104 — 38,763 Consumer and other loans 17,078 — — — 17,078 Total $ 507,176 $ 5,225 $ 9,800 $ — $ 522,201

Allowance for Loan Losses

Allowance for Loan Losses	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Allowance for Loan Losses	Allowance for Loan Losses The following tables present, as of March 31, 2018 , December 31, 2017 and March 31, 2017 , the total allowance for loan losses, the allowance by impairment methodology, and loans by impairment methodology (in thousands): March 31, 2018 Construction and Land Development Secured by 1-4 Family Residential Other Real Estate Commercial and Industrial Consumer and Other Loans Total Allowance for loan losses: Beginning Balance, December 31, 2017 $ 414 $ 775 $ 2,948 $ 418 $ 771 $ 5,326 Charge-offs — (2 ) — (8 ) (196 ) (206 ) Recoveries — 3 1 1 47 52 Provision for (recovery of) loan losses (18 ) 2 18 40 58 100 Ending Balance, March 31, 2018 $ 396 $ 778 $ 2,967 $ 451 $ 680 $ 5,272 Ending Balance: Individually evaluated for impairment — — — — — — Collectively evaluated for impairment 396 778 2,967 451 680 5,272 Loans: Ending Balance $ 33,941 $ 208,338 $ 222,352 $ 39,253 $ 17,052 $ 520,936 Individually evaluated for impairment 874 1,332 1,263 61 — 3,530 Collectively evaluated for impairment 33,067 207,006 221,089 39,192 17,052 517,406 December 31, 2017 Construction and Land Development Secured by 1-4 Family Residential Other Real Estate Commercial and Industrial Consumer and Other Loans Total Allowance for loan losses: Beginning Balance, December 31, 2016 $ 441 $ 1,019 $ 3,142 $ 380 $ 339 $ 5,321 Charge-offs — (126 ) — — (607 ) (733 ) Recoveries 11 302 50 10 265 638 Provision for (recovery of) loan losses (38 ) (420 ) (244 ) 28 774 100 Ending Balance, December 31, 2017 $ 414 $ 775 $ 2,948 $ 418 $ 771 $ 5,326 Ending Balance: Individually evaluated for impairment — — — — — — Collectively evaluated for impairment 414 775 2,948 418 771 5,326 Loans: Ending Balance $ 35,927 $ 208,177 $ 222,256 $ 38,763 $ 17,078 $ 522,201 Individually evaluated for impairment 1,150 1,307 1,289 65 — 3,811 Collectively evaluated for impairment 34,777 206,870 220,967 38,698 17,078 518,390 March 31, 2017 Construction and Land Development Secured by 1-4 Family Residential Other Real Estate Commercial and Industrial Consumer and Other Loans Total Allowance for loan losses: Beginning Balance, December 31, 2016 $ 441 $ 1,019 $ 3,142 $ 380 $ 339 $ 5,321 Charge-offs — — — — (106 ) (106 ) Recoveries 1 128 47 5 55 236 Provision for (recovery of) loan losses 39 (187 ) 78 (10 ) 80 — Ending Balance, March 31, 2017 $ 481 $ 960 $ 3,267 $ 375 $ 368 $ 5,451 Ending Balance: Individually evaluated for impairment — 31 — — — 31 Collectively evaluated for impairment 481 929 3,267 375 368 5,420 Loans: Ending Balance $ 36,024 $ 205,623 $ 216,591 $ 29,192 $ 10,340 $ 497,770 Individually evaluated for impairment 2,022 1,443 977 71 — 4,513 Collectively evaluated for impairment 34,002 204,180 215,614 29,121 10,340 493,257 Impaired loans and the related allowance at March 31, 2018 , December 31, 2017 and March 31, 2017 , were as follows (in thousands): March 31, 2018 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Interest Income Recognized Real estate loans: Construction and land development $ 992 $ 874 $ — $ 874 $ — $ 1,257 $ 13 Secured by 1-4 family 1,417 1,332 — 1,332 — 1,299 15 Other real estate loans 1,464 1,263 — 1,263 — 1,274 19 Commercial and industrial 74 61 — 61 — 64 1 Total $ 3,947 $ 3,530 $ — $ 3,530 $ — $ 3,894 $ 48 December 31, 2017 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Interest Income Recognized Real estate loans: Construction and land development $ 1,627 $ 1,150 $ — $ 1,150 $ — $ 1,814 $ 63 Secured by 1-4 family 1,387 1,307 — 1,307 — 1,637 64 Other real estate loans 1,483 1,289 — 1,289 — 1,137 95 Commercial and industrial 78 65 — 65 — 68 10 Total $ 4,575 $ 3,811 $ — $ 3,811 $ — $ 4,656 $ 232 March 31, 2017 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Interest Income Recognized Real estate loans: Construction and land development $ 2,455 $ 2,022 $ — $ 2,022 $ — $ 1,922 $ 13 Secured by 1-4 family 1,469 1,358 85 1,443 31 1,781 16 Other real estate loans 1,206 977 — 977 — 980 19 Commercial and industrial 89 71 — 71 — 73 1 Total $ 5,219 $ 4,428 $ 85 $ 4,513 $ 31 $ 4,756 $ 49 The “Recorded Investment” amounts in the table above represent the outstanding principal balance on each loan represented in the table. The “Unpaid Principal Balance” represents the outstanding principal balance on each loan represented in the table plus any amounts that have been charged off on each loan and/or payments that have been applied towards principal on non-accrual loans. Only loan classes with balances are included in the tables above. As of March 31, 2018 , loans classified as troubled debt restructurings (TDRs) and included in impaired loans in the disclosure above totaled $327 thousand . At March 31, 2018 , $278 thousand of the loans classified as TDRs were performing under the restructured terms and were not considered non-performing assets. There were $333 thousand in TDRs at December 31, 2017 , $282 thousand of which were performing under the restructured terms. Modified terms under TDRs may include rate reductions, extension of terms that are considered to be below market, conversion to interest only, and other actions intended to minimize the economic loss and to avoid foreclosure or repossession of the collateral. There were no loans modified under TDRs during the three month periods ended March 31, 2018 and 2017 . For the three months ended March 31, 2018 and 2017 , there were no troubled debt restructurings that subsequently defaulted within twelve months of the loan modification. Management defines default as over ninety days past due or the foreclosure and repossession of the collateral or charge-off of the loan during the twelve month period subsequent to the modification.

Other Real Estate Owned (OREO)

Other Real Estate Owned (OREO)	3 Months Ended
	Mar. 31, 2018
Real Estate [Abstract]
Other Real Estate Owned (OREO)	Other Real Estate Owned (OREO) Changes in the balance for OREO are as follows (in thousands): Three Months Ended Year Ended March 31, December 31, Balance at the beginning of year, gross $ 326 $ 250 Transfers in — 326 Charge-offs — — Sales proceeds (350 ) (441 ) Gain on disposition 24 191 Balance at the end of period, gross $ — $ 326 Less: valuation allowance — — Balance at the end of period, net $ — $ 326 There were no residential real estate properties included in the ending OREO balances above at March 31, 2018 and December 31, 2017 . The Bank did not have any consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings were in process as of March 31, 2018 . Net expenses applicable to OREO, other than the provision for losses, were $1 thousand and $2 thousand for the three months ended March 31, 2018 and 2017 , respectively and $5 thousand for the year ended December 31, 2017 .

Other Borrowings

Other Borrowings	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Other Borrowings	Other Borrowings The Bank had unused lines of credit totaling $131.5 million and $134.1 million available with non-affiliated banks at March 31, 2018 and December 31, 2017 , respectively. These amounts primarily consist of a blanket floating lien agreement with the Federal Home Loan Bank of Atlanta (FHLB) in which the Bank can borrow up to 19% of its total assets. The unused line of credit with FHLB totaled $79.9 million at March 31, 2018 . The Bank had collateral pledged on the borrowing line at March 31, 2018 and December 31, 2017 including real estate loans totaling $115.7 million and $117.7 million , respectively, and Federal Home Loan Bank stock with a book value of $665 thousand and $645 thousand , respectively. The Bank did not have borrowings from the FHLB at March 31, 2018 and December 31, 2017 .

Capital Requirements

Capital Requirements	3 Months Ended
	Mar. 31, 2018
Regulatory Capital Requirements [Abstract]
Capital Requirements	Capital Requirements The Bank is subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Bank’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Bank must meet specific capital guidelines that involve quantitative measures of their assets, liabilities, and certain off-balance-sheet items as calculated under regulatory accounting practices. The capital amounts and classification are also subject to qualitative judgments by the regulators about components, risk-weightings, and other factors. Prompt corrective action provisions are not applicable to bank holding companies. The final rules implementing the Basel Committee on Banking Supervision’s capital guidelines for U.S. banks (Basel III rules) became effective January 1, 2015, with full compliance of all the requirements being phased in over a multi-year schedule, and becoming fully phased in by January 1, 2019. As part of the new requirements, the common equity Tier 1 capital ratio is calculated and utilized in the assessment of capital for all institutions. The final rules also established a “capital conservation buffer” above the new regulatory minimum capital requirements. The capital conservation buffer is being phased-in over four years, which began on January 1, 2016. Quantitative measures established by regulation to ensure capital adequacy require the Bank to maintain minimum amounts and ratios (set forth in the following table) of total (as defined in the regulations), Tier 1 (as defined), and common equity Tier 1 capital (as defined) to risk-weighted assets (as defined), and of Tier 1 capital to average assets. Management believes, as of March 31, 2018 and December 31, 2017 , that the Bank met all capital adequacy requirements to which it is subject. As of March 31, 2018 , the most recent notification from the Federal Reserve Bank 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 risk-based capital and 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 category. A comparison of the capital of the Bank at March 31, 2018 and December 31, 2017 with the minimum regulatory guidelines were as follows (dollars in thousands): Actual Minimum Capital Requirement Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio March 31, 2018 Total Capital (to Risk-Weighted Assets) $ 69,435 13.52 % $ 41,075 8.00 % $ 51,344 10.00 % Tier 1 Capital (to Risk-Weighted Assets) $ 64,163 12.50 % $ 30,806 6.00 % $ 41,075 8.00 % Common Equity Tier 1 Capital (to Risk-Weighted Assets) $ 64,163 12.50 % $ 23,105 4.50 % $ 33,373 6.50 % Tier 1 Capital (to Average Assets) $ 64,163 8.55 % $ 30,014 4.00 % $ 37,517 5.00 % December 31, 2017 Total Capital (to Risk-Weighted Assets) $ 67,624 13.12 % $ 41,239 8.00 % $ 51,548 10.00 % Tier 1 Capital (to Risk-Weighted Assets) $ 62,298 12.09 % $ 30,929 6.00 % $ 41,239 8.00 % Common Equity Tier 1 Capital (to Risk-Weighted Assets) $ 62,298 12.09 % $ 23,197 4.50 % $ 33,506 6.50 % Tier 1 Capital (to Average Assets) $ 62,298 8.46 % $ 29,457 4.00 % $ 36,821 5.00 % In addition to the regulatory minimum risk-based capital amounts presented above, the Bank must maintain a capital conservation buffer as required by the Basel III final rules. The buffer began applying to the Bank on January 1, 2016, and is subject to phase-in from 2016 to 2019 in equal annual installments of 0.625% . Accordingly, the Bank was required to maintain a capital conservation buffer of 1.875% and 1.25% at March 31, 2018 and December 31, 2017 , respectively. Under the final rules, an institution is subject to limitations on paying dividends, engaging in share repurchases, and paying discretionary bonuses if its capital level falls below the buffer amount. As of March 31, 2018 and December 31, 2017 , the capital conservation buffer of the Bank was 5.52% and 5.12% , respectively.

Subordinated Debt

Subordinated Debt	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
Subordinated Debt	Subordinated Debt On October 30, 2015, the Company entered into a Subordinated Loan Agreement (the Agreement) pursuant to which the Company issued an interest only subordinated term note due 2025 in the aggregate principal amount of $5.0 million (the Note). The Note bears interest at a fixed rate of 6.75% per annum. The Note qualifies as Tier 2 capital for regulatory capital purposes and at March 31, 2018 , the total amount of subordinated debt issued was included in the Company’s Tier 2 capital. Unamortized debt issuance costs related to the Note were $48 thousand and $52 thousand at March 31, 2018 and December 31, 2017 , respectively. The Note has a maturity date of October 1, 2025. Subject to regulatory approval, the Company may prepay the Note, in part or in full, beginning on October 30, 2020. The Note is an unsecured, subordinated obligation of the Company and ranks junior in right of payment to the Company’s senior indebtedness and to the Company’s obligations to its general creditors. The Note ranks equally with all other unsecured subordinated debt, except any which by its terms is expressly stated to be subordinated to the Note. The Note ranks senior to all current and future junior subordinated debt obligations, preferred stock, and common stock of the Company. The Note is not convertible into common stock or preferred stock. The Agreement contains customary events of default such as the bankruptcy of the Company and the non-payment of principal or interest when due. The holder of the Note may accelerate the repayment of the Note only in the event of bankruptcy or similar proceedings and not for any other event of default.

Junior Subordinated Debt

Junior Subordinated Debt	3 Months Ended
	Mar. 31, 2018
Other Liabilities and Financial Instruments Subject to Mandatory Redemption [Abstract]
Junior Subordinated Debt	Junior Subordinated Debt On June 8, 2004, First National (VA) Statutory Trust II (Trust II), a wholly-owned subsidiary of the Company, was formed for the purpose of issuing redeemable capital securities, commonly known as trust preferred securities. On June 17, 2004, $5.0 million of trust preferred securities were issued through a pooled underwriting. The securities have a LIBOR-indexed floating rate of interest. The interest rate at March 31, 2018 and December 31, 2017 was 4.78% and 4.20% , respectively. The securities have a mandatory redemption date of June 17, 2034 , and were subject to varying call provisions that began September 17, 2009. The principal asset of Trust II is $5.2 million of the Company’s junior subordinated debt with maturities and interest rates comparable to the trust preferred securities. The Trust’s obligations under the trust preferred securities are fully and unconditionally guaranteed by the Company. The Company is current on its interest payments on the junior subordinated debt. On July 24, 2006, First National (VA) Statutory Trust III (Trust III), a wholly-owned subsidiary of the Company, was formed for the purpose of issuing redeemable capital securities. On July 31, 2006, $4.0 million of trust preferred securities were issued through a pooled underwriting. The securities have a LIBOR-indexed floating rate of interest. The interest rate at March 31, 2018 and December 31, 2017 was 3.29% and 2.94% , respectively. The securities have a mandatory redemption date of October 1, 2036 , and were subject to varying call provisions that began October 1, 2011. The principal asset of Trust III is $4.1 million of the Company’s junior subordinated debt with maturities and interest rates comparable to the trust preferred securities. The Trust’s obligations under the trust preferred securities are fully and unconditionally guaranteed by the Company. The Company is current on its interest payments on the junior subordinated debt. While these securities are debt obligations of the Company, they are included in capital for regulatory capital ratio calculations. Under present regulations, the junior subordinated debt may be included in Tier 1 capital for regulatory capital adequacy purposes as long as their amount does not exceed 25% of Tier 1 capital, including total junior subordinated debt. The portion of the junior subordinated debt not considered as Tier 1 capital, if any, may be included in Tier 2 capital. At March 31, 2018 and December 31, 2017 , the total amount of junior subordinated debt issued by the Trusts was included in the Company’s Tier 1 capital.

Benefit Plans

Benefit Plans	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
Benefit Plans	Benefit Plans The Bank had a noncontributory, defined benefit pension plan for all full-time employees over 21 years of age with at least one year of credited service and hired prior to May 1, 2011. Effective May 1, 2011, the plan was frozen to new participants. Only individuals employed on or before April 30, 2011 were eligible to become participants in the plan upon satisfaction of the eligibility requirements. Benefits were generally based upon years of service and average compensation for the five highest-paid consecutive years of service. The Bank’s funding practice was to make at least the minimum required annual contribution permitted by the Employee Retirement Income Security Act of 1974, as amended, and the Internal Revenue Code of 1986, as amended. On September 14, 2016, the defined benefit pension plan was amended to be terminated. Under the amendment, benefit accruals ceased as of November 30, 2016. The Internal Revenue Service approved the termination on October 16, 2017 and the Company distributed all plan assets on March 8, 2018. The funding status of the plan on March 8, 2018 was not significantly different from the funded status disclosed in Note 13 of the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . The benefit obligation and the fair value of assets did not change significantly prior to the distribution of plan assets. Pension plan assets remained in cash and equivalents through the distribution date. Components of the net periodic benefit cost of the plan for the three months ended March 31, 2018 and 2017 were as follows (in thousands): Three Months Ended March 31, March 31, Interest cost $ — $ 21 Expected return on plan assets — (9 ) Net periodic benefit cost $ — $ 12 The Company previously disclosed in its consolidated financial statements in its Annual Report on Form 10-K for the year ended December 31, 2017 , that it made a contribution of $205 thousand upon the final distribution of plan assets on March 8, 2018. The Company maintains a 401(k) plan and an employee stock ownership plan (ESOP) for eligible employees. On September 14, 2016, the ESOP was amended to freeze the plan to new participants and to cease all contributions, effective December 31, 2016. The amendment also directs matching contributions and certain other retirement contributions made by the Company to the 401(k) plan. The ESOP shall be maintained as a frozen plan and continue to be invested in Company stock and such other assets as permitted under the ESOP and Trust Agreement for the benefit of participants and their beneficiaries. See Note 13 of the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 for additional information about the Company’s benefit plans.

Earnings per Common Share

Earnings per Common Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings per Common Share	Earnings per Common Share Basic earnings per common share represents income available to common shareholders divided by the weighted-average number of common shares outstanding during the period. Diluted earnings per common share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued, as well as any adjustment to income that would result from the assumed issuance. The following table presents the computation of basic and diluted earnings per share for the three months ended March 31, 2018 and 2017 (dollars in thousands, except per share data): Three Months Ended March 31, 2018 March 31, 2017 (Numerator): Net income $ 2,687 $ 1,543 (Denominator): Weighted average shares outstanding – basic 4,949,112 4,935,421 Potentially dilutive common shares – restricted stock units 3,261 2,204 Weighted average shares outstanding – diluted 4,952,373 4,937,625 Income per common share Basic $ 0.54 $ 0.31 Diluted $ 0.54 $ 0.31

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company uses fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. In accordance with the “Fair Value Measurement and Disclosures” topic of FASB ASC, the fair value of a financial instrument is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. The fair value guidance provides a consistent definition of fair value, which focuses on exit price in an orderly transaction (that is, not a forced liquidation or distressed sale) between market participants at the measurement date under current market conditions. If there has been a significant decrease in the volume and level of activity for the asset or liability, a change in valuation technique or the use of multiple valuation techniques may be appropriate. In such instances, determining the price at which willing market participants would transact at the measurement date under current market conditions depends on the facts and circumstances and requires the use of significant judgment. The fair value is a reasonable point within the range that is most representative of fair value under current market conditions. Fair Value Hierarchy In accordance with this guidance, the Company groups its assets and liabilities generally measured at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. Level 1 - Valuation is based on quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. Level 1 assets and liabilities generally include debt and equity securities that are traded in an active exchange market. Valuations are obtained from readily available pricing sources for market transactions involving identical assets or liabilities. Level 2 - Valuation is based on inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. The valuation may be based on quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability. Level 3 - Valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which determination of fair value requires a significant management judgment or estimation. An instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The following describes the valuation techniques used by the Company to measure certain assets recorded at fair value on a recurring basis in the financial statements: Securities available for sale Securities available for sale are recorded at fair value on a recurring basis. Fair value measurement is based upon quoted market prices, when available (Level 1). If quoted market prices are not available, fair values are measured utilizing independent valuation techniques of identical or similar securities for which significant assumptions are derived primarily from or corroborated by observable market data. Third party vendors compile prices from various sources and may determine the fair value of identical or similar securities by using pricing models that consider observable market data (Level 2). The following tables present the balances of assets measured at fair value on a recurring basis as of March 31, 2018 and December 31, 2017 (in thousands). Fair Value Measurements at March 31, 2018 Description Balance as of March 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Securities available for sale U.S. agency and mortgage-backed securities $ 79,108 $ — $ 79,108 $ — Obligations of states and political subdivisions 14,591 — 14,591 — $ 93,699 $ — $ 93,699 $ — Fair Value Measurements at December 31, 2017 Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Securities available for sale U.S. agency and mortgage-backed securities $ 74,804 $ — $ 74,804 $ — Obligations of states and political subdivisions 14,451 — 14,451 — $ 89,255 $ — $ 89,255 $ — Certain assets are measured at fair value on a nonrecurring basis in accordance with GAAP. Adjustments to the fair value of these assets usually result from the application of lower-of-cost-or-market accounting or write-downs of individual assets. The following describes the valuation techniques used by the Company to measure certain assets recorded at fair value on a nonrecurring basis in the financial statements: Loans held for sale Loans held for sale are carried at the lower of cost or market value. These loans currently consist of one-to-four family residential loans originated for sale in the secondary market. Fair value is based on the price secondary markets are currently offering for similar loans using observable market data which is not materially different than cost due to the short duration between origination and sale (Level 2). As such, the Company records any fair value adjustments on a nonrecurring basis. No nonrecurring fair value adjustments were recorded on loans held for sale during the three months ended March 31, 2018 and the year ended December 31, 2017 . Impaired Loans Loans are designated as impaired when, in the judgment of management based on current information and events, it is probable that all amounts due according to the contractual terms of the loan agreements will not be collected. The measurement of loss associated with impaired loans can be based on the present value of expected future cash flows discounted at the loan’s effective interest rate, the observable market price of the loan, or the fair value of the collateral less estimated costs to sell. Collateral may be in the form of real estate or business assets including equipment, inventory, and accounts receivable. The vast majority of the Company’s collateral is real estate. The value of real estate collateral is determined utilizing a market valuation approach based on an appraisal conducted by an independent, licensed appraiser using observable market data (Level 2) within the last twelve months. However, if the collateral is a house or building in the process of construction or if an appraisal of the property is more than one year old and not solely based on observable market comparables or management determines the fair value of the collateral is further impaired below the appraised value, then a Level 3 valuation is considered to measure the fair value. The value of business equipment is based upon an outside appraisal, of one year or less, if deemed significant, or the net book value on the applicable business’s financial statements if not considered significant using observable market data. Likewise, values for inventory and accounts receivables collateral are based on financial statement balances or aging reports (Level 3). Impaired loans allocated to the allowance for loan losses are measured at fair value on a nonrecurring basis. Any fair value adjustments are recorded in the period incurred as provision for loan losses on the Consolidated Statements of Income. Other real estate owned Loans are transferred to other real estate owned when the collateral securing them is foreclosed on or acquired through a deed in lieu of foreclosure. The measurement of loss associated with other real estate owned is based on the appraisal documents and assessed the same way as impaired loans described above. Any fair value adjustments are recorded in the period incurred as other real estate owned (income) expense on the Consolidated Statements of Income. The Company did no t have any assets measured at fair value on a nonrecurring basis as of March 31, 2018. The following tables summarize the Company’s assets that were measured at fair value on a nonrecurring basis as of December 31, 2017 (dollars in thousands): Fair Value Measurements at December 31, 2017 Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other real estate owned $ 326 $ — $ — $ 326 Quantitative information about Level 3 Fair Value Measurements for December 31, 2017 Fair Value Valuation Technique Unobservable Input Range (Weighted-Average) Other real estate owned $ 326 Contract Price Selling cost 7 % Accounting guidance requires disclosure of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis. For short-term financial assets such as cash and short-term investments, the carrying amount is a reasonable estimate of fair value due to the relatively short time between the origination of the instrument and its expected realization. For non-marketable equity securities such as Federal Home Loan Bank, Federal Reserve Bank and Community Bankers’ Bank stock, the carrying amount is a reasonable estimate of fair value as these securities can only be redeemed or sold at their par value and only to the respective issuing government supported institution or to another member institution. Bank owned life insurance policies are carried at their cash surrender value, which approximates the fair value. The fair value of accrued interest receivable and payable are estimated to equal the carrying amount due to the short-term nature of these financial instruments. For financial liabilities such as noninterest-bearing demand, interest-bearing demand, and savings deposits, the carrying amount is a reasonable estimate of fair value due to these products having no stated maturity. The carrying values and estimated fair values of the Company’s financial instruments at March 31, 2018 and December 31, 2017 are as follows (in thousands): Fair Value Measurements at March 31, 2018 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets Level 1 Significant Other Observable Inputs Level 2 Significant Unobservable Inputs Level 3 Fair Value Financial Assets Cash and short-term investments $ 69,277 $ 69,277 $ — $ — $ 69,277 Securities available for sale 93,699 — 93,699 — 93,699 Securities held to maturity 46,791 — 44,133 1,497 45,630 Restricted securities 1,590 — 1,590 — 1,590 Loans held for sale 68 — 68 — 68 Loans, net (1) 515,664 — — 515,058 515,058 Bank owned life insurance 13,711 — 13,711 — 13,711 Accrued interest receivable 1,869 — 1,869 — 1,869 Financial Liabilities Deposits $ 692,825 $ — $ 567,790 $ 122,595 $ 690,385 Subordinated debt 4,952 — — 4,884 4,884 Junior subordinated debt 9,279 — — 9,357 9,357 Accrued interest payable 106 — 106 — 106 Fair Value Measurements at December 31, 2017 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets Level 1 Significant Other Observable Inputs Level 2 Significant Unobservable Inputs Level 3 Fair Value Financial Assets Cash and short-term investments $ 39,986 $ 39,986 $ — $ — $ 39,986 Securities available for sale 89,255 — 89,255 — 89,255 Securities held to maturity 48,208 — 46,186 1,516 47,702 Restricted securities 1,570 — 1,570 — 1,570 Loans held for sale 438 — 438 — 438 Loans, net (1) 516,875 — — 514,013 514,013 Bank owned life insurance 13,967 — 13,967 — 13,967 Accrued interest receivable 1,916 — 1,916 — 1,916 Financial Liabilities Deposits $ 664,980 $ — $ 542,329 $ 120,834 $ 663,163 Subordinated debt 4,948 — — 5,004 5,004 Junior subordinated debt 9,279 — — 9,653 9,653 Accrued interest payable 98 — 98 — 98 (1) In accordance with the prospective adoption of ASU No. 2016-01, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities," the fair value of loans as of March 31, 2018 was measured using an exit price notion. The fair value of loans as of December 31, 2017 was measured using an entry price notion. The Company assumes interest rate risk (the risk that general interest rate levels will change) as a result of its normal operations. As a result, the fair values of the Company’s financial instruments will change when interest rate levels change and that change may be either favorable or unfavorable to the Company. Management attempts to match maturities of assets and liabilities to the extent believed necessary to minimize interest rate risk. However, borrowers with fixed rate obligations are less likely to prepay in a rising rate environment and more likely to prepay in a falling rate environment. Conversely, depositors who are receiving fixed rates are more likely to withdraw funds before maturity in a rising rate environment and less likely to do so in a falling rate environment. Management monitors rates and maturities of assets and liabilities and attempts to minimize interest rate risk by adjusting terms of new loans and deposits and by investing in securities with terms that mitigate the Company’s overall interest rate risk.

Stock Compensation Plans

Stock Compensation Plans	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Compensation Plans	Stock Compensation Plans On May 13, 2014, the Company’s shareholders approved the First National Corporation 2014 Stock Incentive Plan, which makes available up to 240,000 shares of common stock for the granting of stock options, restricted stock awards, stock appreciation rights, and other stock-based awards. Awards are made at the discretion of the Board of Directors and compensation cost equal to the fair value of the award is recognized over the vesting period. Stock Awards Whenever the Company deems it appropriate to grant a stock award, the recipient receives a specified number of unrestricted shares of employer stock. Stock awards may be made by the Company at its discretion without cash consideration and may be granted as settlement of a performance-based compensation award. The Company did not have compensation expense related to stock awards for the three months ended March 31, 2018 . Compensation expense related to stock awards totaled $30 thousand for the three months ended March 31, 2017 . Restricted Stock Units Restricted stock units are an award of units that correspond in number and value to a specified number of shares of employer stock which the recipient receives according to a vesting plan and distribution schedule after achieving required performance milestones or upon remaining with the employer for a particular length of time. Each restricted stock unit that vests entitles the recipient to receive one share of common stock on a specified issuance date. In the first quarter of 2018 , 8,989 restricted stock units were granted to employees, with 2,999 units vesting immediately and 5,990 units subject to a two year vesting schedule with one half of the units vesting each year on the grant date anniversary. The recipient does not have any stockholder rights, including voting, dividend, or liquidation rights, with respect to the shares underlying awarded restricted stock units until vesting has occurred and the recipient becomes the record holder of those shares. The unvested restricted stock units will vest on the established schedule if the employees remain employed by the Company on future vesting dates. A summary of the activity for the Company’s restricted stock units for the period indicated is presented in the following table: Three Months Ended March 31, 2018 Shares Weighted Average Grant Date Fair Value Unvested, beginning of year 5,662 $ 11.76 Granted 8,989 18.50 Vested (7,339 ) 13.90 Forfeited (24 ) 15.20 Unvested, end of period 7,288 $ 17.91 At March 31, 2018 , based on restricted stock unit awards outstanding at that time, the total unrecognized pre-tax compensation expense related to unvested restricted stock unit awards was $121 thousand . This expense is expected to be recognized through 2020. Compensation expense related to restricted stock unit awards recognized for the three months ended March 31, 2018 and 2017 totaled $70 thousand and $34 thousand , respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Changes in each component of accumulated other comprehensive loss were as follows (in thousands): Net Unrealized Gains (Losses) on Securities Adjustments Related to Pension Benefits Accumulated Other Comprehensive Loss Balance at December 31, 2016 $ (860 ) $ — $ (860 ) Unrealized holding gains (net of tax, $196) 381 — 381 Change during period 381 — 381 Balance at March 31, 2017 $ (479 ) $ — $ (479 ) Balance at December 31, 2017 $ (1,057 ) $ 99 $ (958 ) Unrealized holding losses (net of tax, ($229)) (862 ) — (862 ) Pension liability adjustment (net of tax, ($27)) — (99 ) (99 ) Change during period (862 ) (99 ) (961 ) Balance at March 31, 2018 $ (1,919 ) $ — $ (1,919 ) The Company did not have any reclassifications from accumulated other comprehensive loss for the three month periods ended March 31, 2018 and 2017 .

General (Policies)

General (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Adoption of ASU No. 2014-09, "Revenue from Contracts with Customers: Topic 606." On January 1, 2018, the Company adopted ASU No. 2014-09, "Revenue from Contracts with Customers: Topic 606." This ASU revised guidance for the recognition, measurement, and disclosure of revenue from contracts with customers. The original guidance was amended through subsequent accounting standard updates that resulted in technical corrections, improvements, and a one-year deferral of the effective date to January 1, 2018. The guidance, as amended, is applicable to all entities and replaces significant portions of existing industry and transaction-specific revenue recognition rules with a more principles-based recognition model. Most revenue associated with financial instruments, including interest income, loan origination fees, and credit card fees, is outside the scope of the guidance. Gains and losses on investment securities, derivatives, financial guarantees, and sales of financial instruments are similarly excluded from the scope. The guidance is applicable to noninterest revenue streams such as trust and asset management income, deposit related fees, interchange fees, and merchant income. The Company adopted this guidance via the modified retrospective approach, meaning the standard is applied only to the most current period presented in the financial statements with the cumulative effect of initially applying the standard recognized at the date of initial application. Since the guidance does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other GAAP, the new guidance did not have a material impact on revenue most closely associated with financial instruments, including interest income and expense. The Company completed its overall assessment of revenue streams and review of related contracts potentially affected by the ASU, including trust and asset management fees, deposit related fees, interchange fees, and merchant income. The Company also completed an evaluation of certain costs related to these revenue streams to determine whether such costs should be presented gross versus net. Based on these assessments, the Company concluded that ASU 2014-09 did not materially change the method in which the Company currently recognizes revenue for these revenue streams. Since there was no net income impact upon adoption of the new guidance, a cumulative effect adjustment to opening retained earnings was not deemed necessary. Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” Among other things, in the amendments in ASU 2016-02, lessees will be required to recognize the following for all leases (with the exception of short-term leases) at the commencement date: (1) A lease liability, which is a lessee‘s obligation to make lease payments arising from a lease, measured on a discounted basis; and (2) A right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. Under the new guidance, lessor accounting is largely unchanged. Certain targeted improvements were made to align, where necessary, lessor accounting with the lessee accounting model and Topic 606, Revenue from Contracts with Customers. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early application is permitted upon issuance. Lessees (for capital and operating leases) and lessors (for sales-type, direct financing, and operating leases) must apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. Lessees and lessors may not apply a full retrospective transition approach. The Company does not expect the adoption of ASU 2016-02 to have a material impact on its consolidated financial statements. The Company has analyzed its current lease commitments, along with reasonable assumptions to project lease activity in future periods, to measure the potential impact on net income and relevant capital and financial ratios. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The amendments in this ASU, among other things, require the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. Financial institutions and other organizations will now use forward-looking information to better inform their credit loss estimates. Many of the loss estimation techniques applied today will still be permitted, although the inputs to those techniques will change to reflect the full amount of expected credit losses. In addition, the ASU amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. The amendments in this ASU are effective for SEC filers for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The Company is currently assessing the impact that ASU 2016-13 will have on its consolidated financial statements. The Company has formed a committee to address the compliance requirements of this ASU and is currently in the process of analyzing gathered data, defining loan pools and segments, and selecting methods for applying the concepts included in this ASU. During 2018, the Company plans to test selected models, build policy and process documentation, and model the impact of the ASU on the capital and strategic plans. This guidance may result in material changes in the Company's accounting for credit losses of financial instruments. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment”. The amendments in this ASU simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. Instead, under the amendments in this ASU, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. Public business entities that are U.S. Securities and Exchange Commission (SEC) filers should adopt the amendments in this ASU for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Company does not expect the adoption of ASU 2017-04 to have a material impact on its consolidated financial statements. In March 2017, the FASB issued ASU No. 2017-08, “Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20), Premium Amortization on Purchased Callable Debt Securities.” The amendments in this ASU shorten the amortization period for certain callable debt securities purchased at a premium. Upon adoption of the standard, premiums on these qualifying callable debt securities will be amortized to the earliest call date. Discounts on purchased debt securities will continue to be accreted to maturity. The amendments are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. Upon transition, entities should apply the guidance on a modified retrospective basis, with a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption and provide the disclosures required for a change in accounting principle. The Company does not expect the adoption of ASU 2017-08 to have a material impact on its consolidated financial statements. In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities.” The amendments in this ASU modify the designation and measurement guidance for hedge accounting as well as provide for increased transparency regarding the presentation of economic results on both the financial statements and related footnotes. Certain aspects of hedge effectiveness assessments will also be simplified upon implementation of this update. The amendments are effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted, including adoption in any interim period. The Company is currently assessing the impact that ASU 2017-12 will have on its consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-03, “Technical Corrections and Improvements to Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities.” The amendments provide targeted improvements to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. Specifically, the amendments include clarifications related to: measurement elections, transition requirements, and adjustments associated with equity securities without readily determinable fair values; fair value measurement requirements for forward contracts and purchased options on equity securities; presentation requirements for hybrid financial liabilities for which the fair value option has been elected; and measurement requirements for liabilities denominated in a foreign currency for which the fair value option has been elected. The amendments are effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years beginning after June 15, 2018. Early adoption is permitted. The Company does not expect the adoption of ASU 2018-03 to have a material impact on its consolidated financial statements.
Fair Value Measurement and Disclosures	The Company uses fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. In accordance with the “Fair Value Measurement and Disclosures” topic of FASB ASC, the fair value of a financial instrument is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company’s various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument.

Securities (Tables)

Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Costs and Fair Values of Securities	Amortized costs and fair values of securities at March 31, 2018 and December 31, 2017 were as follows (in thousands): March 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value Securities available for sale: U.S. agency and mortgage-backed securities $ 81,309 $ 24 $ (2,225 ) $ 79,108 Obligations of states and political subdivisions 14,820 57 (286 ) 14,591 Total securities available for sale $ 96,129 $ 81 $ (2,511 ) $ 93,699 Securities held to maturity: U.S. agency and mortgage-backed securities $ 30,750 $ — $ (984 ) $ 29,766 Obligations of states and political subdivisions 14,541 18 (192 ) 14,367 Corporate debt securities 1,500 — (3 ) 1,497 Total securities held to maturity $ 46,791 $ 18 $ (1,179 ) $ 45,630 Total securities $ 142,920 $ 99 $ (3,690 ) $ 139,329 December 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized (Losses) Fair Value Securities available for sale: U.S. agency and mortgage-backed securities $ 76,074 $ 67 $ (1,337 ) $ 74,804 Obligations of states and political subdivisions 14,520 86 (155 ) 14,451 Total securities available for sale $ 90,594 $ 153 $ (1,492 ) $ 89,255 Securities held to maturity: U.S. agency and mortgage-backed securities $ 32,149 $ — $ (551 ) $ 31,598 Obligations of states and political subdivisions 14,559 74 (45 ) 14,588 Corporate debt securities 1,500 16 — 1,516 Total securities held to maturity $ 48,208 $ 90 $ (596 ) $ 47,702 Total securities $ 138,802 $ 243 $ (2,088 ) $ 136,957
Summary of Investments in an Unrealized Loss Position that were Temporarily Impaired	At March 31, 2018 and December 31, 2017 , investments in an unrealized loss position that were temporarily impaired were as follows (in thousands): March 31, 2018 Less than 12 months 12 months or more Total Fair Value Unrealized (Loss) Fair Value Unrealized (Loss) Fair Value Unrealized (Loss) Securities available for sale: U.S. agency and mortgage-backed securities $ 47,868 $ (941 ) $ 29,121 $ (1,284 ) $ 76,989 $ (2,225 ) Obligations of states and political subdivisions 7,120 (149 ) 1,924 (137 ) 9,044 (286 ) Total securities available for sale $ 54,988 $ (1,090 ) $ 31,045 $ (1,421 ) $ 86,033 $ (2,511 ) Securities held to maturity: U.S. agency and mortgage-backed securities $ 17,269 $ (478 ) $ 12,497 $ (506 ) $ 29,766 $ (984 ) Obligations of states and political subdivisions 11,166 (192 ) — — 11,166 (192 ) Corporate debt securities 1,497 (3 ) — — 1,497 (3 ) Total securities held to maturity $ 29,932 $ (673 ) $ 12,497 $ (506 ) $ 42,429 $ (1,179 ) Total securities $ 84,920 $ (1,763 ) $ 43,542 $ (1,927 ) $ 128,462 $ (3,690 ) December 31, 2017 Less than 12 months 12 months or more Total Fair Value Unrealized (Loss) Fair Value Unrealized (Loss) Fair Value Unrealized (Loss) Securities available for sale: U.S. agency and mortgage-backed securities $ 29,963 $ (286 ) $ 30,362 $ (1,051 ) $ 60,325 $ (1,337 ) Obligations of states and political subdivisions 4,469 (53 ) 1,961 (102 ) 6,430 (155 ) Total securities available for sale $ 34,432 $ (339 ) $ 32,323 $ (1,153 ) $ 66,755 $ (1,492 ) Securities held to maturity: U.S. agency and mortgage-backed securities $ 18,301 $ (205 ) $ 13,297 $ (346 ) $ 31,598 $ (551 ) Obligations of states and political subdivisions 6,889 (45 ) — — 6,889 (45 ) Total securities held to maturity $ 25,190 $ (250 ) $ 13,297 $ (346 ) $ 38,487 $ (596 ) Total securities $ 59,622 $ (589 ) $ 45,620 $ (1,499 ) $ 105,242 $ (2,088 )
Amortized Cost and Fair Value of Securities	The amortized cost and fair value of securities at March 31, 2018 by contractual maturity are shown below (in thousands). Expected maturities of mortgage-backed securities will differ from contractual maturities because borrowers may have the right to prepay obligations with or without call or prepayment penalties. Available for Sale Held to Maturity Amortized Cost Fair Value Amortized Cost Fair Value Due within one year $ 507 $ 514 $ — $ — Due after one year through five years 8,965 8,877 6,808 6,681 Due after five years through ten years 12,112 11,721 13,723 13,534 Due after ten years 74,545 72,587 26,260 25,415 $ 96,129 $ 93,699 $ 46,791 $ 45,630
Composition of Restricted Securities	The composition of restricted securities at March 31, 2018 and December 31, 2017 was as follows (in thousands): March 31, December 31, Federal Home Loan Bank stock $ 665 $ 645 Federal Reserve Bank stock 875 875 Community Bankers’ Bank stock 50 50 $ 1,590 $ 1,570

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Summary of Loans	Loans at March 31, 2018 and December 31, 2017 are summarized as follows (in thousands): March 31, December 31, Real estate loans: Construction and land development $ 33,941 $ 35,927 Secured by 1-4 family residential 208,338 208,177 Other real estate loans 222,352 222,256 Commercial and industrial loans 39,253 38,763 Consumer and other loans 17,052 17,078 Total loans $ 520,936 $ 522,201 Allowance for loan losses (5,272 ) (5,326 ) Loans, net $ 515,664 $ 516,875
Summary of Loan Classes and an Aging of Past Due Loans	The following tables provide a summary of loan classes and an aging of past due loans as of March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 30-59 Days Past Due 60-89 Days Past Due > 90 Days Past Due Total Past Due Current Total Loans Non-accrual Loans 90 Days or More Past Due and Accruing Real estate loans: Construction and land development $ 45 $ 344 $ 512 $ 901 $ 33,040 $ 33,941 $ — $ 512 Secured by 1-4 family residential 873 397 302 1,572 206,766 208,338 300 99 Other real estate loans 268 384 162 814 221,538 222,352 382 162 Commercial and industrial 83 13 — 96 39,157 39,253 — — Consumer and other loans 144 51 — 195 16,857 17,052 — — Total $ 1,413 $ 1,189 $ 976 $ 3,578 $ 517,358 $ 520,936 $ 682 $ 773 December 31, 2017 30-59 Days Past Due 60-89 Days Past Due > 90 Days Past Due Total Past Due Current Total Loans Non-accrual Loans 90 Days or More Past Due and Accruing Real estate loans: Construction and land development $ 986 $ 30 $ 40 $ 1,056 $ 34,871 $ 35,927 $ 269 $ 40 Secured by 1-4 family residential 606 203 148 957 207,220 208,177 267 106 Other real estate loans 2,042 170 10 2,222 220,034 222,256 401 10 Commercial and industrial 184 25 — 209 38,554 38,763 — — Consumer and other loans 51 49 27 127 16,951 17,078 — 27 Total $ 3,869 $ 477 $ 225 $ 4,571 $ 517,630 $ 522,201 $ 937 $ 183
Analysis of the Credit Risk Profile of Each Loan Class	The following tables provide an analysis of the credit risk profile of each loan class as of March 31, 2018 and December 31, 2017 (in thousands): March 31, 2018 Pass Special Mention Substandard Doubtful Total Real estate loans: Construction and land development $ 29,743 $ 2,448 $ 1,750 $ — $ 33,941 Secured by 1-4 family residential 204,456 1,908 1,974 — 208,338 Other real estate loans 215,723 962 5,667 — 222,352 Commercial and industrial 38,912 47 294 — 39,253 Consumer and other loans 17,052 — — — 17,052 Total $ 505,886 $ 5,365 $ 9,685 $ — $ 520,936 December 31, 2017 Pass Special Mention Substandard Doubtful Total Real estate loans: Construction and land development $ 31,553 $ 2,268 $ 2,106 $ — $ 35,927 Secured by 1-4 family residential 204,166 1,933 2,078 — 208,177 Other real estate loans 215,773 971 5,512 — 222,256 Commercial and industrial 38,606 53 104 — 38,763 Consumer and other loans 17,078 — — — 17,078 Total $ 507,176 $ 5,225 $ 9,800 $ — $ 522,201

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Allowance by Impairment Methodology and Loans by Impairment Methodology	The following tables present, as of March 31, 2018 , December 31, 2017 and March 31, 2017 , the total allowance for loan losses, the allowance by impairment methodology, and loans by impairment methodology (in thousands): March 31, 2018 Construction and Land Development Secured by 1-4 Family Residential Other Real Estate Commercial and Industrial Consumer and Other Loans Total Allowance for loan losses: Beginning Balance, December 31, 2017 $ 414 $ 775 $ 2,948 $ 418 $ 771 $ 5,326 Charge-offs — (2 ) — (8 ) (196 ) (206 ) Recoveries — 3 1 1 47 52 Provision for (recovery of) loan losses (18 ) 2 18 40 58 100 Ending Balance, March 31, 2018 $ 396 $ 778 $ 2,967 $ 451 $ 680 $ 5,272 Ending Balance: Individually evaluated for impairment — — — — — — Collectively evaluated for impairment 396 778 2,967 451 680 5,272 Loans: Ending Balance $ 33,941 $ 208,338 $ 222,352 $ 39,253 $ 17,052 $ 520,936 Individually evaluated for impairment 874 1,332 1,263 61 — 3,530 Collectively evaluated for impairment 33,067 207,006 221,089 39,192 17,052 517,406 December 31, 2017 Construction and Land Development Secured by 1-4 Family Residential Other Real Estate Commercial and Industrial Consumer and Other Loans Total Allowance for loan losses: Beginning Balance, December 31, 2016 $ 441 $ 1,019 $ 3,142 $ 380 $ 339 $ 5,321 Charge-offs — (126 ) — — (607 ) (733 ) Recoveries 11 302 50 10 265 638 Provision for (recovery of) loan losses (38 ) (420 ) (244 ) 28 774 100 Ending Balance, December 31, 2017 $ 414 $ 775 $ 2,948 $ 418 $ 771 $ 5,326 Ending Balance: Individually evaluated for impairment — — — — — — Collectively evaluated for impairment 414 775 2,948 418 771 5,326 Loans: Ending Balance $ 35,927 $ 208,177 $ 222,256 $ 38,763 $ 17,078 $ 522,201 Individually evaluated for impairment 1,150 1,307 1,289 65 — 3,811 Collectively evaluated for impairment 34,777 206,870 220,967 38,698 17,078 518,390 March 31, 2017 Construction and Land Development Secured by 1-4 Family Residential Other Real Estate Commercial and Industrial Consumer and Other Loans Total Allowance for loan losses: Beginning Balance, December 31, 2016 $ 441 $ 1,019 $ 3,142 $ 380 $ 339 $ 5,321 Charge-offs — — — — (106 ) (106 ) Recoveries 1 128 47 5 55 236 Provision for (recovery of) loan losses 39 (187 ) 78 (10 ) 80 — Ending Balance, March 31, 2017 $ 481 $ 960 $ 3,267 $ 375 $ 368 $ 5,451 Ending Balance: Individually evaluated for impairment — 31 — — — 31 Collectively evaluated for impairment 481 929 3,267 375 368 5,420 Loans: Ending Balance $ 36,024 $ 205,623 $ 216,591 $ 29,192 $ 10,340 $ 497,770 Individually evaluated for impairment 2,022 1,443 977 71 — 4,513 Collectively evaluated for impairment 34,002 204,180 215,614 29,121 10,340 493,257
Impaired Loans and Related Allowance	Impaired loans and the related allowance at March 31, 2018 , December 31, 2017 and March 31, 2017 , were as follows (in thousands): March 31, 2018 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Interest Income Recognized Real estate loans: Construction and land development $ 992 $ 874 $ — $ 874 $ — $ 1,257 $ 13 Secured by 1-4 family 1,417 1,332 — 1,332 — 1,299 15 Other real estate loans 1,464 1,263 — 1,263 — 1,274 19 Commercial and industrial 74 61 — 61 — 64 1 Total $ 3,947 $ 3,530 $ — $ 3,530 $ — $ 3,894 $ 48 December 31, 2017 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Interest Income Recognized Real estate loans: Construction and land development $ 1,627 $ 1,150 $ — $ 1,150 $ — $ 1,814 $ 63 Secured by 1-4 family 1,387 1,307 — 1,307 — 1,637 64 Other real estate loans 1,483 1,289 — 1,289 — 1,137 95 Commercial and industrial 78 65 — 65 — 68 10 Total $ 4,575 $ 3,811 $ — $ 3,811 $ — $ 4,656 $ 232 March 31, 2017 Unpaid Principal Balance Recorded Investment with No Allowance Recorded Investment with Allowance Total Recorded Investment Related Allowance Average Recorded Investment Interest Income Recognized Real estate loans: Construction and land development $ 2,455 $ 2,022 $ — $ 2,022 $ — $ 1,922 $ 13 Secured by 1-4 family 1,469 1,358 85 1,443 31 1,781 16 Other real estate loans 1,206 977 — 977 — 980 19 Commercial and industrial 89 71 — 71 — 73 1 Total $ 5,219 $ 4,428 $ 85 $ 4,513 $ 31 $ 4,756 $ 49

Other Real Estate Owned (OREO)

Other Real Estate Owned (OREO) (Tables)	3 Months Ended
	Mar. 31, 2018
Real Estate [Abstract]
Summary of Changes in the Balance for OREO	Changes in the balance for OREO are as follows (in thousands): Three Months Ended Year Ended March 31, December 31, Balance at the beginning of year, gross $ 326 $ 250 Transfers in — 326 Charge-offs — — Sales proceeds (350 ) (441 ) Gain on disposition 24 191 Balance at the end of period, gross $ — $ 326 Less: valuation allowance — — Balance at the end of period, net $ — $ 326

Capital Requirements (Tables)

Capital Requirements (Tables)	3 Months Ended
	Mar. 31, 2018
Regulatory Capital Requirements [Abstract]
Comparison of Capital of Company and Bank with Minimum Regulatory Guidelines	A comparison of the capital of the Bank at March 31, 2018 and December 31, 2017 with the minimum regulatory guidelines were as follows (dollars in thousands): Actual Minimum Capital Requirement Minimum To Be Well Capitalized Under Prompt Corrective Action Provisions Amount Ratio Amount Ratio Amount Ratio March 31, 2018 Total Capital (to Risk-Weighted Assets) $ 69,435 13.52 % $ 41,075 8.00 % $ 51,344 10.00 % Tier 1 Capital (to Risk-Weighted Assets) $ 64,163 12.50 % $ 30,806 6.00 % $ 41,075 8.00 % Common Equity Tier 1 Capital (to Risk-Weighted Assets) $ 64,163 12.50 % $ 23,105 4.50 % $ 33,373 6.50 % Tier 1 Capital (to Average Assets) $ 64,163 8.55 % $ 30,014 4.00 % $ 37,517 5.00 % December 31, 2017 Total Capital (to Risk-Weighted Assets) $ 67,624 13.12 % $ 41,239 8.00 % $ 51,548 10.00 % Tier 1 Capital (to Risk-Weighted Assets) $ 62,298 12.09 % $ 30,929 6.00 % $ 41,239 8.00 % Common Equity Tier 1 Capital (to Risk-Weighted Assets) $ 62,298 12.09 % $ 23,197 4.50 % $ 33,506 6.50 % Tier 1 Capital (to Average Assets) $ 62,298 8.46 % $ 29,457 4.00 % $ 36,821 5.00 %

Benefit Plans (Tables)

Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost	Components of the net periodic benefit cost of the plan for the three months ended March 31, 2018 and 2017 were as follows (in thousands): Three Months Ended March 31, March 31, Interest cost $ — $ 21 Expected return on plan assets — (9 ) Net periodic benefit cost $ — $ 12

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table presents the computation of basic and diluted earnings per share for the three months ended March 31, 2018 and 2017 (dollars in thousands, except per share data): Three Months Ended March 31, 2018 March 31, 2017 (Numerator): Net income $ 2,687 $ 1,543 (Denominator): Weighted average shares outstanding – basic 4,949,112 4,935,421 Potentially dilutive common shares – restricted stock units 3,261 2,204 Weighted average shares outstanding – diluted 4,952,373 4,937,625 Income per common share Basic $ 0.54 $ 0.31 Diluted $ 0.54 $ 0.31

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Balances of Assets Measured at Fair Value on a Recurring Basis	The following tables present the balances of assets measured at fair value on a recurring basis as of March 31, 2018 and December 31, 2017 (in thousands). Fair Value Measurements at March 31, 2018 Description Balance as of March 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Securities available for sale U.S. agency and mortgage-backed securities $ 79,108 $ — $ 79,108 $ — Obligations of states and political subdivisions 14,591 — 14,591 — $ 93,699 $ — $ 93,699 $ — Fair Value Measurements at December 31, 2017 Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Securities available for sale U.S. agency and mortgage-backed securities $ 74,804 $ — $ 74,804 $ — Obligations of states and political subdivisions 14,451 — 14,451 — $ 89,255 $ — $ 89,255 $ —
Summary of Assets Measured at Fair Value on a Nonrecurring Basis	The following tables summarize the Company’s assets that were measured at fair value on a nonrecurring basis as of December 31, 2017 (dollars in thousands): Fair Value Measurements at December 31, 2017 Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Other real estate owned $ 326 $ — $ — $ 326
Quantitative Information about Level 3 Fair Value Measurements	Quantitative information about Level 3 Fair Value Measurements for December 31, 2017 Fair Value Valuation Technique Unobservable Input Range (Weighted-Average) Other real estate owned $ 326 Contract Price Selling cost 7 %
Carrying Values and Estimated Fair Values of Company's Financial Instruments	The carrying values and estimated fair values of the Company’s financial instruments at March 31, 2018 and December 31, 2017 are as follows (in thousands): Fair Value Measurements at March 31, 2018 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets Level 1 Significant Other Observable Inputs Level 2 Significant Unobservable Inputs Level 3 Fair Value Financial Assets Cash and short-term investments $ 69,277 $ 69,277 $ — $ — $ 69,277 Securities available for sale 93,699 — 93,699 — 93,699 Securities held to maturity 46,791 — 44,133 1,497 45,630 Restricted securities 1,590 — 1,590 — 1,590 Loans held for sale 68 — 68 — 68 Loans, net (1) 515,664 — — 515,058 515,058 Bank owned life insurance 13,711 — 13,711 — 13,711 Accrued interest receivable 1,869 — 1,869 — 1,869 Financial Liabilities Deposits $ 692,825 $ — $ 567,790 $ 122,595 $ 690,385 Subordinated debt 4,952 — — 4,884 4,884 Junior subordinated debt 9,279 — — 9,357 9,357 Accrued interest payable 106 — 106 — 106 Fair Value Measurements at December 31, 2017 Using Carrying Amount Quoted Prices in Active Markets for Identical Assets Level 1 Significant Other Observable Inputs Level 2 Significant Unobservable Inputs Level 3 Fair Value Financial Assets Cash and short-term investments $ 39,986 $ 39,986 $ — $ — $ 39,986 Securities available for sale 89,255 — 89,255 — 89,255 Securities held to maturity 48,208 — 46,186 1,516 47,702 Restricted securities 1,570 — 1,570 — 1,570 Loans held for sale 438 — 438 — 438 Loans, net (1) 516,875 — — 514,013 514,013 Bank owned life insurance 13,967 — 13,967 — 13,967 Accrued interest receivable 1,916 — 1,916 — 1,916 Financial Liabilities Deposits $ 664,980 $ — $ 542,329 $ 120,834 $ 663,163 Subordinated debt 4,948 — — 5,004 5,004 Junior subordinated debt 9,279 — — 9,653 9,653 Accrued interest payable 98 — 98 — 98 (1) In accordance with the prospective adoption of ASU No. 2016-01, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities," the fair value of loans as of March 31, 2018 was measured using an exit price notion. The fair value of loans as of December 31, 2017 was measured using an entry price notion.

Stock Compensation Plans (Table

Stock Compensation Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Restricted Stock Units	A summary of the activity for the Company’s restricted stock units for the period indicated is presented in the following table: Three Months Ended March 31, 2018 Shares Weighted Average Grant Date Fair Value Unvested, beginning of year 5,662 $ 11.76 Granted 8,989 18.50 Vested (7,339 ) 13.90 Forfeited (24 ) 15.20 Unvested, end of period 7,288 $ 17.91

Accumulated Other Comprehensi34

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Schedule of Changes in Component of Accumulated Other Comprehensive Loss	Changes in each component of accumulated other comprehensive loss were as follows (in thousands): Net Unrealized Gains (Losses) on Securities Adjustments Related to Pension Benefits Accumulated Other Comprehensive Loss Balance at December 31, 2016 $ (860 ) $ — $ (860 ) Unrealized holding gains (net of tax, $196) 381 — 381 Change during period 381 — 381 Balance at March 31, 2017 $ (479 ) $ — $ (479 ) Balance at December 31, 2017 $ (1,057 ) $ 99 $ (958 ) Unrealized holding losses (net of tax, ($229)) (862 ) — (862 ) Pension liability adjustment (net of tax, ($27)) — (99 ) (99 ) Change during period (862 ) (99 ) (961 ) Balance at March 31, 2018 $ (1,919 ) $ — $ (1,919 )

Securities - Summary of Amortiz

Securities - Summary of Amortized Costs and Fair Values of Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Securities available for sale:
Amortized Cost	$ 96,129	$ 90,594
Gross Unrealized Gains	81	153
Gross Unrealized (Losses)	(2,511)	(1,492)
Fair Value	93,699	89,255
Securities held to maturity:
Amortized Cost	46,791	48,208
Gross Unrealized Gains	18	90
Gross Unrealized (Losses)	(1,179)	(596)
Fair Value	45,630	47,702	[1]
Total securities, Amortized cost	142,920	138,802
Total securities, Gross unrealized gains	99	243
Total securities, Gross unrealized (losses)	(3,690)	(2,088)
Total securities, Fair value	139,329	136,957
U.S. agency and mortgage-backed securities
Securities available for sale:
Amortized Cost	81,309	76,074
Gross Unrealized Gains	24	67
Gross Unrealized (Losses)	(2,225)	(1,337)
Fair Value	79,108	74,804
Securities held to maturity:
Amortized Cost	30,750	32,149
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	(984)	(551)
Fair Value	29,766	31,598
Obligations of states and political subdivisions
Securities available for sale:
Amortized Cost	14,820	14,520
Gross Unrealized Gains	57	86
Gross Unrealized (Losses)	(286)	(155)
Fair Value	14,591	14,451
Securities held to maturity:
Amortized Cost	14,541	14,559
Gross Unrealized Gains	18	74
Gross Unrealized (Losses)	(192)	(45)
Fair Value	14,367	14,588
Corporate debt securities
Securities held to maturity:
Amortized Cost	1,500	1,500
Gross Unrealized Gains	0	16
Gross Unrealized (Losses)	(3)	0
Fair Value	$ 1,497	$ 1,516
[1]	Derived from audited consolidated financial statements.

Securities - Summary of Investm

Securities - Summary of Investments in an Unrealized Loss Position that were Temporarily Impaired (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Securities available for sale:
Less than 12 months - Fair value	$ 54,988	$ 34,432
Less than 12 months - Unrealized (loss)	(1,090)	(339)
12 months or more - Fair value	31,045	32,323
12 months or more - Unrealized (loss)	(1,421)	(1,153)
Fair Value	86,033	66,755
Unrealized (Loss)	(2,511)	(1,492)
Securities held to maturity:
Less than 12 months - Fair value	29,932	25,190
Less than 12 months - Unrealized (loss)	(673)	(250)
12 months or more - Fair value	12,497	13,297
12 months or more - Unrealized (loss)	(506)	(346)
Fair Value	42,429	38,487
Unrealized (Loss)	(1,179)	(596)
Total securities, Less than 12 months - Fair value	84,920	59,622
Total securities, Less than 12 months - Unrealized (loss)	(1,763)	(589)
Total securities, 12 months or more - Fair value	43,542	45,620
Total securities, 12 months or more - Unrealized (loss)	(1,927)	(1,499)
Total securities, Total fair value	128,462	105,242
Total unrealized (loss)	(3,690)	(2,088)
U.S. agency and mortgage-backed securities
Securities available for sale:
Less than 12 months - Fair value	47,868	29,963
Less than 12 months - Unrealized (loss)	(941)	(286)
12 months or more - Fair value	29,121	30,362
12 months or more - Unrealized (loss)	(1,284)	(1,051)
Fair Value	76,989	60,325
Unrealized (Loss)	(2,225)	(1,337)
Securities held to maturity:
Less than 12 months - Fair value	17,269	18,301
Less than 12 months - Unrealized (loss)	(478)	(205)
12 months or more - Fair value	12,497	13,297
12 months or more - Unrealized (loss)	(506)	(346)
Fair Value	29,766	31,598
Unrealized (Loss)	(984)	(551)
Obligations of states and political subdivisions
Securities available for sale:
Less than 12 months - Fair value	7,120	4,469
Less than 12 months - Unrealized (loss)	(149)	(53)
12 months or more - Fair value	1,924	1,961
12 months or more - Unrealized (loss)	(137)	(102)
Fair Value	9,044	6,430
Unrealized (Loss)	(286)	(155)
Securities held to maturity:
Less than 12 months - Fair value	11,166	6,889
Less than 12 months - Unrealized (loss)	(192)	(45)
12 months or more - Fair value	0	0
12 months or more - Unrealized (loss)	0	0
Fair Value	11,166	6,889
Unrealized (Loss)	(192)	$ (45)
Corporate debt securities
Securities held to maturity:
Less than 12 months - Fair value	1,497
Less than 12 months - Unrealized (loss)	(3)
12 months or more - Fair value	0
12 months or more - Unrealized (loss)	0
Fair Value	1,497
Unrealized (Loss)	$ (3)

Securities - Additional Informa

Securities - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2018USD ($)Security	Dec. 31, 2017Security
Schedule of Available-for-sale Securities [Line Items]
Percentage of investment portfolio	100.00%	100.00%
Weighted-average period of re-pricing of portfolio	5 years	4 years 8 months 12 days
Impairment recognized | $	$ 0
U.S. agency and mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Number of securities in an unrealized loss position	80	68
Total number of securities	85	82
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Number of securities in an unrealized loss position	56	39
Total number of securities	80	80
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Number of securities in an unrealized loss position	1

Securities - Amortized Cost and

Securities - Amortized Cost and Fair Value of Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	[1]
Amortized Cost
Due within one year	$ 507
Due after one year through five years	8,965
Due after five years through ten years	12,112
Due after ten years	74,545
Amortized Cost	96,129
Fair Value
Due within one year	514
Due after one year through five years	8,877
Due after five years through ten years	11,721
Due after ten years	72,587
Fair Value	93,699	$ 89,255
Amortized Cost
Due within one year	0
Due after one year through five years	6,808
Due after five years through ten years	13,723
Due after ten years	26,260
Amortized Cost	46,791	48,208
Fair Value
Due within one year	0
Due after one year through five years	6,681
Due after five years through ten years	13,534
Due after ten years	25,415
Fair Value	$ 45,630	$ 47,702
[1]	Derived from audited consolidated financial statements.

Securities - Composition of Res

Securities - Composition of Restricted Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Federal Home Loan Bank stock	$ 665	$ 645
Federal Reserve Bank stock	875	875
Community Bankers’ Bank stock	50	50
Total restricted securities	$ 1,590	$ 1,570	[1]
[1]	Derived from audited consolidated financial statements.

Loans - Summary of Loans (Detai

Loans - Summary of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017		Mar. 31, 2017	Dec. 31, 2016
Real estate loans:
Loans	$ 520,936	$ 522,201		$ 497,770
Allowance for loan losses	(5,272)	(5,326)	[1]	(5,451)	$ (5,321)
Loans, net	515,664	516,875	[1]
Real estate loans | Construction and land development
Real estate loans:
Loans	33,941	35,927		36,024
Allowance for loan losses	(396)	(414)		(481)	(441)
Real estate loans | Secured by 1-4 family residential
Real estate loans:
Loans	208,338	208,177		205,623
Allowance for loan losses	(778)	(775)		(960)	(1,019)
Real estate loans | Other real estate loans
Real estate loans:
Loans	222,352	222,256		216,591
Allowance for loan losses	(2,967)	(2,948)		(3,267)	(3,142)
Commercial and industrial loans
Real estate loans:
Loans	39,253	38,763		29,192
Allowance for loan losses	(451)	(418)		(375)	(380)
Consumer and other loans
Real estate loans:
Loans	17,052	17,078		10,340
Allowance for loan losses	$ (680)	$ (771)		$ (368)	$ (339)
[1]	Derived from audited consolidated financial statements.

Loans - Additional Information

Loans - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Net deferred loan fees and costs	$ 261	$ 301
Total Loans	520,936	522,201	$ 497,770
Consumer and other loans
Financing Receivable, Recorded Investment [Line Items]
Total Loans	17,052	17,078	$ 10,340
Consumer and other loans | Demand deposit overdrafts
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 222	$ 232

Loans - Summary of Loan Classes

Loans - Summary of Loan Classes and an Aging of Past Due Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 3,578	$ 4,571
Current	517,358	517,630
Total Loans	520,936	522,201	$ 497,770
Non-accrual Loans	682	937
90 Days or More Past Due and Accruing	773	183
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,413	3,869
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,189	477
90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	976	225
Real estate loans | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	901	1,056
Current	33,040	34,871
Total Loans	33,941	35,927	36,024
Non-accrual Loans	0	269
90 Days or More Past Due and Accruing	512	40
Real estate loans | Secured by 1-4 family residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,572	957
Current	206,766	207,220
Total Loans	208,338	208,177	205,623
Non-accrual Loans	300	267
90 Days or More Past Due and Accruing	99	106
Real estate loans | Other real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	814	2,222
Current	221,538	220,034
Total Loans	222,352	222,256	216,591
Non-accrual Loans	382	401
90 Days or More Past Due and Accruing	162	10
Real estate loans | 30-59 Days Past Due | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	45	986
Real estate loans | 30-59 Days Past Due | Secured by 1-4 family residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	873	606
Real estate loans | 30-59 Days Past Due | Other real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	268	2,042
Real estate loans | 60-89 Days Past Due | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	344	30
Real estate loans | 60-89 Days Past Due | Secured by 1-4 family residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	397	203
Real estate loans | 60-89 Days Past Due | Other real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	384	170
Real estate loans | 90 Days Past Due | Construction and land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	512	40
Real estate loans | 90 Days Past Due | Secured by 1-4 family residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	302	148
Real estate loans | 90 Days Past Due | Other real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	162	10
Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	96	209
Current	39,157	38,554
Total Loans	39,253	38,763	29,192
Non-accrual Loans	0	0
90 Days or More Past Due and Accruing	0	0
Commercial and industrial loans | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	83	184
Commercial and industrial loans | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	13	25
Commercial and industrial loans | 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Consumer and other loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	195	127
Current	16,857	16,951
Total Loans	17,052	17,078	$ 10,340
Non-accrual Loans	0	0
90 Days or More Past Due and Accruing	0	27
Consumer and other loans | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	144	51
Consumer and other loans | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	51	49
Consumer and other loans | 90 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 0	$ 27

Loans - Analysis of the Credit

Loans - Analysis of the Credit Risk Profile of Each Loan Class (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 520,936	$ 522,201	$ 497,770
Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	505,886	507,176
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	5,365	5,225
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	9,685	9,800
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Real estate loans | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	33,941	35,927	36,024
Real estate loans | Secured by 1-4 family residential
Financing Receivable, Recorded Investment [Line Items]
Total Loans	208,338	208,177	205,623
Real estate loans | Other real estate loans
Financing Receivable, Recorded Investment [Line Items]
Total Loans	222,352	222,256	216,591
Real estate loans | Pass | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	29,743	31,553
Real estate loans | Pass | Secured by 1-4 family residential
Financing Receivable, Recorded Investment [Line Items]
Total Loans	204,456	204,166
Real estate loans | Pass | Other real estate loans
Financing Receivable, Recorded Investment [Line Items]
Total Loans	215,723	215,773
Real estate loans | Special Mention | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	2,448	2,268
Real estate loans | Special Mention | Secured by 1-4 family residential
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,908	1,933
Real estate loans | Special Mention | Other real estate loans
Financing Receivable, Recorded Investment [Line Items]
Total Loans	962	971
Real estate loans | Substandard | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,750	2,106
Real estate loans | Substandard | Secured by 1-4 family residential
Financing Receivable, Recorded Investment [Line Items]
Total Loans	1,974	2,078
Real estate loans | Substandard | Other real estate loans
Financing Receivable, Recorded Investment [Line Items]
Total Loans	5,667	5,512
Real estate loans | Doubtful | Construction and land development
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Real estate loans | Doubtful | Secured by 1-4 family residential
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Real estate loans | Doubtful | Other real estate loans
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Commercial and industrial loans
Financing Receivable, Recorded Investment [Line Items]
Total Loans	39,253	38,763	29,192
Commercial and industrial loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	38,912	38,606
Commercial and industrial loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	47	53
Commercial and industrial loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	294	104
Commercial and industrial loans | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Consumer and other loans
Financing Receivable, Recorded Investment [Line Items]
Total Loans	17,052	17,078	$ 10,340
Consumer and other loans | Pass
Financing Receivable, Recorded Investment [Line Items]
Total Loans	17,052	17,078
Consumer and other loans | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Consumer and other loans | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total Loans	0	0
Consumer and other loans | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total Loans	$ 0	$ 0

Allowance for Loan Losses - All

Allowance for Loan Losses - Allowance by Impairment Methodology and Loans by Impairment Methodology (Detail) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2018		Mar. 31, 2017	Dec. 31, 2017
Allowance for loan losses:
Beginning Balance	$ 5,326	[1]	$ 5,321	$ 5,321
Charge-offs	(206)		(106)	(733)
Recoveries	52		236	638
Provision for (recovery of) loan losses	100		0	100
Ending Balance	5,272		5,451	5,326	[1]
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	0		31	0
Allowance for loan losses, Collectively evaluated for impairment	5,272		5,420	5,326
Loans:
Total Loans	520,936		497,770	522,201
Losses, Individually evaluated for impairment	3,530		4,513	3,811
Losses, Collectively evaluated for impairment	517,406		493,257	518,390
Real estate loans | Construction and Land Development
Allowance for loan losses:
Beginning Balance	414		441	441
Charge-offs	0		0	0
Recoveries	0		1	11
Provision for (recovery of) loan losses	(18)		39	(38)
Ending Balance	396		481	414
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	0		0	0
Allowance for loan losses, Collectively evaluated for impairment	396		481	414
Loans:
Total Loans	33,941		36,024	35,927
Losses, Individually evaluated for impairment	874		2,022	1,150
Losses, Collectively evaluated for impairment	33,067		34,002	34,777
Real estate loans | Secured by 1-4 Family Residential
Allowance for loan losses:
Beginning Balance	775		1,019	1,019
Charge-offs	(2)		0	(126)
Recoveries	3		128	302
Provision for (recovery of) loan losses	2		(187)	(420)
Ending Balance	778		960	775
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	0		31	0
Allowance for loan losses, Collectively evaluated for impairment	778		929	775
Loans:
Total Loans	208,338		205,623	208,177
Losses, Individually evaluated for impairment	1,332		1,443	1,307
Losses, Collectively evaluated for impairment	207,006		204,180	206,870
Real estate loans | Other Real Estate
Allowance for loan losses:
Beginning Balance	2,948		3,142	3,142
Charge-offs	0		0	0
Recoveries	1		47	50
Provision for (recovery of) loan losses	18		78	(244)
Ending Balance	2,967		3,267	2,948
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	0		0	0
Allowance for loan losses, Collectively evaluated for impairment	2,967		3,267	2,948
Loans:
Total Loans	222,352		216,591	222,256
Losses, Individually evaluated for impairment	1,263		977	1,289
Losses, Collectively evaluated for impairment	221,089		215,614	220,967
Commercial and industrial loans
Allowance for loan losses:
Beginning Balance	418		380	380
Charge-offs	(8)		0	0
Recoveries	1		5	10
Provision for (recovery of) loan losses	40		(10)	28
Ending Balance	451		375	418
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	0		0	0
Allowance for loan losses, Collectively evaluated for impairment	451		375	418
Loans:
Total Loans	39,253		29,192	38,763
Losses, Individually evaluated for impairment	61		71	65
Losses, Collectively evaluated for impairment	39,192		29,121	38,698
Consumer and other loans
Allowance for loan losses:
Beginning Balance	771		339	339
Charge-offs	(196)		(106)	(607)
Recoveries	47		55	265
Provision for (recovery of) loan losses	58		80	774
Ending Balance	680		368	771
Ending Balance:
Allowance for loan losses, Individually evaluated for impairment	0		0	0
Allowance for loan losses, Collectively evaluated for impairment	680		368	771
Loans:
Total Loans	17,052		10,340	17,078
Losses, Individually evaluated for impairment	0		0	0
Losses, Collectively evaluated for impairment	$ 17,052		$ 10,340	$ 17,078
[1]	Derived from audited consolidated financial statements.

Allowance for Loan Losses - Imp

Allowance for Loan Losses - Impaired Loans and Related Allowance (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	$ 3,947	$ 5,219	$ 4,575
Recorded Investment with No Allowance	3,530	4,428	3,811
Recorded Investment with Allowance	0	85	0
Total Recorded Investment	3,530	4,513	3,811
Related Allowance	0	31	0
Average Recorded Investment	3,894	4,756	4,656
Interest Income Recognized	48	49	232
Real estate loans | Construction and Land Development
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	992	2,455	1,627
Recorded Investment with No Allowance	874	2,022	1,150
Recorded Investment with Allowance	0	0	0
Total Recorded Investment	874	2,022	1,150
Related Allowance	0	0	0
Average Recorded Investment	1,257	1,922	1,814
Interest Income Recognized	13	13	63
Real estate loans | Secured by 1-4 Family Residential
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	1,417	1,469	1,387
Recorded Investment with No Allowance	1,332	1,358	1,307
Recorded Investment with Allowance	0	85	0
Total Recorded Investment	1,332	1,443	1,307
Related Allowance	0	31	0
Average Recorded Investment	1,299	1,781	1,637
Interest Income Recognized	15	16	64
Real estate loans | Other real estate loans
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	1,464	1,206	1,483
Recorded Investment with No Allowance	1,263	977	1,289
Recorded Investment with Allowance	0	0	0
Total Recorded Investment	1,263	977	1,289
Related Allowance	0	0	0
Average Recorded Investment	1,274	980	1,137
Interest Income Recognized	19	19	95
Commercial and industrial loans
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	74	89	78
Recorded Investment with No Allowance	61	71	65
Recorded Investment with Allowance	0	0	0
Total Recorded Investment	61	71	65
Related Allowance	0	0	0
Average Recorded Investment	64	73	68
Interest Income Recognized	$ 1	$ 1	$ 10

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018USD ($)Contract	Mar. 31, 2017USD ($)Contract	Dec. 31, 2017USD ($)
Allowance For Loan Losses [Line Items]
TDRs performing under the restructured terms	$ 327,000		$ 333,000
Loans modified under TDRs | Contract	0	0
Troubled debt restructuring loan subsequent default	$ 0	$ 0
Troubled debt restructuring loan subsequent default period	90 days
Performing financing receivable
Allowance For Loan Losses [Line Items]
TDRs performing under the restructured terms	$ 278,000		$ 282,000

Other Real Estate Owned (OREO47

Other Real Estate Owned (OREO) - Summary of Changes in the Balance for OREO (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Real Estate [Abstract]
Balance at the beginning of year, gross	$ 326	$ 250
Transfers in	0	326
Charge-offs	0	0
Sales proceeds	(350)	(441)
Gain on disposition	24	191
Balance at the end of period, gross	0	326
Less: valuation allowance	0	0
Balance at the end of period, net	$ 0	$ 326	[1]
[1]	Derived from audited consolidated financial statements.

Other Real Estate Owned (OREO48

Other Real Estate Owned (OREO) - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Other Real Estate [Line Items]
Residential real estate carrying amount included in OREO	$ 0		$ 326,000	$ 250,000
Net expenses applicable to other real estate owned	1,000	$ 2,000	5,000
Residential real estate properties
Other Real Estate [Line Items]
Residential real estate carrying amount included in OREO	0		$ 0
Mortgage loans foreclosed	$ 0

Other Borrowings - Additional I

Other Borrowings - Additional Information (Detail) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unused lines of credit	$ 131,500,000	$ 134,100,000
Blanket floating lien agreement	19.00%
Collateral pledged on borrowings including real estate loans	$ 115,700,000	117,700,000
FHLB stock book value	665,000	645,000
Borrowings from FHLB	0	$ 0
FHLB
Debt Instrument [Line Items]
Unused lines of credit	$ 79,900,000

Capital Requirements - Addition

Capital Requirements - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018	Jan. 01, 2019	Jan. 01, 2018	Dec. 31, 2017	Jan. 01, 2017	Jan. 01, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital conservation buffer period	4 years
Capital conservation buffer percentage	1.875%		0.625%	1.25%	0.625%	0.625%
Capital conservation buffer percentage maintained at bank	5.52%			5.12%
Scenario, Forecast
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital conservation buffer percentage		0.625%

Capital Requirements - Comparis

Capital Requirements - Comparison of Capital of Company and Bank with Minimum Regulatory Guidelines (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Regulatory Capital Requirements [Abstract]
Actual amount total capital (to risk weighted assets)	$ 69,435	$ 67,624
Actual ratio total capital (to risk weighted assets)	13.52%	13.12%
Minimum capital requirement amount total capital (to risk weighted assets)	$ 41,075	$ 41,239
Minimum capital requirement ratio total capital (to risk weighted assets)	8.00%	8.00%
Minimum to be well capitalized under prompt corrective action provisions amount total capital (to risk weighted assets)	$ 51,344	$ 51,548
Minimum to be well capitalized under prompt corrective action provisions ratio total capital (to risk weighted assets)	10.00%	10.00%
Actual amount Tier 1 capital (to risk weighted assets)	$ 64,163	$ 62,298
Actual ratio Tier 1 capital (to risk weighted assets)	12.50%	12.09%
Minimum capital requirement amount Tier 1 capital (to risk weighted assets)	$ 30,806	$ 30,929
Minimum capital requirement ratio Tier 1 capital (to risk weighted assets)	6.00%	6.00%
Minimum to be well capitalized under prompt corrective action provisions amount Tier 1 capital (to risk weighted assets)	$ 41,075	$ 41,239
Minimum to be well capitalized under prompt corrective action provisions ratio Tier 1 capital (to risk weighted assets)	8.00%	8.00%
Actual amount common equity Tier 1 capital (to risk weighted assets)	$ 64,163	$ 62,298
Actual ratio common equity Tier 1 capital (to risk weighted assets)	12.50%	12.09%
Minimum capital requirement amount common equity Tier 1 capital (to risk weighted assets)	$ 23,105	$ 23,197
Minimum capital requirement ratio common equity Tier 1 capital (to risk weighted assets)	4.50%	4.50%
Minimum to be well capitalized under prompt corrective action provisions amount common equity Tier 1 capital (to risk weighted assets)	$ 33,373	$ 33,506
Minimum to be well capitalized under prompt corrective action provisions ratio common equity Tier 1 capital (to risk weighted assets)	6.50%	6.50%
Actual amount Tier 1 capital (to average assets)	$ 64,163	$ 62,298
Actual ratio Tier 1 capital (to average assets)	8.55%	8.46%
Minimum capital requirement amount Tier 1 capital (to average assets)	$ 30,014	$ 29,457
Minimum capital requirement ratio Tier 1 capital (to average assets)	4.00%	4.00%
Minimum to be well capitalized under prompt corrective action provisions amount Tier 1 capital (to average assets)	$ 37,517	$ 36,821
Minimum to be well capitalized under prompt corrective action provisions ratio Tier 1 capital (to average assets)	5.00%	5.00%

Subordinated Debt - Additional

Subordinated Debt - Additional Information (Detail) - 6.75% fixed interest subordinate term note - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Oct. 30, 2015
Subordinated Borrowing [Line Items]
Aggregate principal amount			$ 5,000,000
Fixed interest rate			6.75%
Unamortized debt issuance costs	$ 48,000	$ 52,000

Junior Subordinated Debt - Addi

Junior Subordinated Debt - Additional Information (Detail) - USD ($) $ in Millions	Jul. 31, 2006	Jun. 17, 2004	Mar. 31, 2018	Dec. 31, 2017
First National (VA) Statutory Trust II
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Issuance of trust preferred securities		$ 5
LIBOR-indexed floating rate of interest			4.78%	4.20%
Junior subordinated debt			$ 5.2
First National (VA) Statutory Trust III
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Issuance of trust preferred securities	$ 4
LIBOR-indexed floating rate of interest			3.29%	2.94%
Junior subordinated debt			$ 4.1
Maximum capital required for capital adequacy			25.00%

Benefit Plans - Additional Info

Benefit Plans - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 08, 2018	Mar. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Minimum eligibility for full-time employees, age		21 years
Number of highest-paid consecutive years for benefits		5 years
Amount contributed to pension plan	$ 205
Minimum
Defined Benefit Plan Disclosure [Line Items]
Period of service credit by employee		1 year

Benefit Plans - Components of N

Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Retirement Benefits [Abstract]
Interest cost	$ 0	$ 21
Expected return on plan assets	0	(9)
Net periodic benefit cost	$ 0	$ 12

Earnings per Common Share - Com

Earnings per Common Share - Computation of Basic and Diluted Earnings per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Numerator [Abstract]
Net income	$ 2,687	$ 1,543
Denominator [Abstract]
Weighted average shares outstanding – basic (in shares)	4,949,112	4,935,421
Potentially dilutive common shares – restricted stock units (in shares)	3,261	2,204
Weighted average shares outstanding – diluted (in shares)	4,952,373	4,937,625
Basic (in usd per share)	$ 0.54	$ 0.31
Diluted (in usd per share)	$ 0.54	$ 0.31

Fair Value Measurements - Balan

Fair Value Measurements - Balances of Assets Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 93,699	$ 89,255	[1]
Recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	93,699	89,255
Recurring basis | U.S. agency and mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	79,108	74,804
Recurring basis | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	14,591	14,451
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. agency and mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	93,699	89,255
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. agency and mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	79,108	74,804
Recurring basis | Significant Other Observable Inputs (Level 2) | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	14,591	14,451
Recurring basis | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. agency and mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Obligations of states and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 0	$ 0
[1]	Derived from audited consolidated financial statements.

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Loans held for sale | Nonrecurring basis
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non recurring fair value adjustments on loans held for sale	$ 0	$ 0
Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Period under consideration for valuation of real estate collateral	12 months
Period under consideration for valuation of business equipment	1 year
Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Period under consideration for valuation of house or building in the process of construction	1 year

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assets Measured at Fair Value on a Nonrecurring Basis (Detail) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	$ 0	$ 326,000	[1]
Nonrecurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	$ 0	326,000
Nonrecurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned		0
Nonrecurring basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned		0
Nonrecurring basis | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned		$ 326,000
[1]	Derived from audited consolidated financial statements.

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information about Level 3 Fair Value Measurements (Detail) - Nonrecurring basis - Significant Unobservable Inputs (Level 3) - Other real estate owned $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 326
Range (Weighted-Average)	7.00%

Fair Value Measurements - Carry

Fair Value Measurements - Carrying Values and Estimated Fair Values of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financial Assets
Securities available for sale, at fair value	$ 93,699	$ 89,255	[1]
Securities held to maturity	46,791	48,208	[1]
Restricted securities	1,590	1,570	[1]
Bank owned life insurance	13,711	13,967	[1]
Accrued interest receivable	1,869	1,916	[1]
Carrying Amount
Financial Assets
Cash and short-term investments	69,277	39,986
Securities available for sale, at fair value	93,699	89,255
Securities held to maturity	46,791	48,208
Restricted securities	1,590	1,570
Loans held for sale	68	438
Loans, net	515,664	516,875
Bank owned life insurance	13,711	13,967
Accrued interest receivable	1,869	1,916
Financial Liabilities
Deposits	692,825	664,980
Subordinated debt	4,952	4,948
Junior subordinated debt	9,279	9,279
Accrued interest payable	106	98
Fair Value
Financial Assets
Cash and short-term investments	69,277	39,986
Securities available for sale, at fair value	93,699	89,255
Securities held to maturity	45,630	47,702
Restricted securities	1,590	1,570
Loans held for sale	68	438
Loans, net	515,058	514,013
Bank owned life insurance	13,711	13,967
Accrued interest receivable	1,869	1,916
Financial Liabilities
Deposits	690,385	663,163
Subordinated debt	4,884	5,004
Junior subordinated debt	9,357	9,653
Accrued interest payable	106	98
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value
Financial Assets
Cash and short-term investments	69,277	39,986
Securities available for sale, at fair value	0	0
Securities held to maturity	0	0
Restricted securities	0	0
Loans held for sale	0	0
Loans, net	0	0
Bank owned life insurance	0	0
Accrued interest receivable	0	0
Financial Liabilities
Deposits	0	0
Subordinated debt	0	0
Junior subordinated debt	0	0
Accrued interest payable	0	0
Significant Other Observable Inputs (Level 2) | Fair Value
Financial Assets
Cash and short-term investments	0	0
Securities available for sale, at fair value	93,699	89,255
Securities held to maturity	44,133	46,186
Restricted securities	1,590	1,570
Loans held for sale	68	438
Loans, net	0	0
Bank owned life insurance	13,711	13,967
Accrued interest receivable	1,869	1,916
Financial Liabilities
Deposits	567,790	542,329
Subordinated debt	0	0
Junior subordinated debt	0	0
Accrued interest payable	106	98
Significant Unobservable Inputs (Level 3) | Fair Value
Financial Assets
Cash and short-term investments	0	0
Securities available for sale, at fair value	0	0
Securities held to maturity	1,497	1,516
Restricted securities	0	0
Loans held for sale	0	0
Loans, net	515,058	514,013
Bank owned life insurance	0	0
Accrued interest receivable	0	0
Financial Liabilities
Deposits	122,595	120,834
Subordinated debt	4,884	5,004
Junior subordinated debt	9,357	9,653
Accrued interest payable	$ 0	$ 0
[1]	Derived from audited consolidated financial statements.

Stock Compensation Plans - Addi

Stock Compensation Plans - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	May 13, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense related to stock awards	$ 0	$ 30,000
Stock-based compensation	$ 70,000	64,000
2014 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares)				240,000
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, granted (in shares)	8,989
Restricted stock units, vested (in shares)	7,339
Restricted stock units, nonvested (in shares)	7,288		5,662
Vesting period	2 years
Total unrecognized pre-tax compensation expense related to unvested restricted stock unit awards	$ 121,000
Stock-based compensation	$ 70,000	$ 34,000
Restricted stock units | Vesting immediately
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, vested (in shares)	2,999
Restricted stock units | Vesting within one year
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of units vesting	50.00%
Restricted stock units | Vesting within two years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, nonvested (in shares)	5,990
Percentage of units vesting	50.00%

Stock Compensation Plans - Summ

Stock Compensation Plans - Summary of Restricted Stock Units (Detail) - Restricted stock units	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning of year (in shares) | shares	5,662
Granted (in shares) | shares	8,989
Vested (in shares) | shares	(7,339)
Forfeited (in shares) | shares	(24)
Unvested, end of period (in shares) | shares	7,288
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Unvested, beginning of year (in usd per share) | $ / shares	$ 11.76
Granted (in usd per share) | $ / shares	18.50
Vested (in usd per share) | $ / shares	13.90
Forfeited (in usd per share) | $ / shares	15.20
Unvested, end of period (in usd per share) | $ / shares	$ 17.91

Accumulated Other Comprehensi64

Accumulated Other Comprehensive Loss - Schedule of Changes in Component of Accumulated Other Comprehensive Loss (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018		Mar. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 58,154,000	[1]	$ 52,151,000
Unrealized holding (losses) gains, net of tax	(862,000)		381,000
Pension liability adjustment, net of tax	(99,000)		0
Change during period	(961,000)		381,000
Ending Balance	59,693,000		53,978,000
Unrealized holding gains, tax	(229,000)		196,000
Pension liability adjustment, tax	(27,000)		0
Reclassification from AOCI current period, net of tax	0		0
Net Unrealized Gains (Losses) on Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(1,057,000)		(860,000)
Unrealized holding (losses) gains, net of tax	(862,000)		381,000
Pension liability adjustment, net of tax	0
Change during period	(862,000)		381,000
Ending Balance	(1,919,000)		(479,000)
Adjustments Related to Pension Benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	99,000		0
Unrealized holding (losses) gains, net of tax	0		0
Pension liability adjustment, net of tax	(99,000)
Change during period	(99,000)		0
Ending Balance	0		0
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(958,000)		(860,000)
Unrealized holding (losses) gains, net of tax	(862,000)		381,000
Pension liability adjustment, net of tax	(99,000)
Change during period	(961,000)		381,000
Ending Balance	$ (1,919,000)		$ (479,000)
[1]	Derived from audited consolidated financial statements.