Wilson Bank Holding (WBHC) 10-K 8 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Mar. 08, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	WBHC
Entity Registrant Name	WILSON BANK HOLDING CO
Entity Central Index Key	885,275
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		10,720,815
Entity Public Float			$ 474,250,990.50

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Loans, net of allowance for loan losses of $27,174 and $23,909, respectively	$ 2,016,005,000	$ 1,727,253,000
Held-to-maturity, at amortized cost (market value $32,111)	0	32,480,000
Available-for-sale, at market (amortized cost $295,683 and $338,449, respectively)	285,252,000	332,716,000
Total securities	285,252,000	365,196,000
Loans held for sale	7,484,000	5,106,000
Interest bearing deposits	80,215,000	83,787,000
Federal funds sold	9,000,000	0
Restricted equity securities, at cost	3,012,000	3,012,000
Total earning assets	2,400,968,000	2,184,354,000
Cash and due from banks	9,976,000	11,731,000
Premises and equipment, net	58,363,000	54,215,000
Accrued interest receivable	6,724,000	6,266,000
Deferred income taxes	8,901,000	7,424,000
Other real estate	1,357,000	1,635,000
Bank owned life insurance	30,952,000	29,475,000
Goodwill	4,805,000	4,805,000
Other assets	21,636,000	17,128,000
Total assets	2,543,682,000	2,317,033,000
LIABILITIES AND STOCKHOLDERS’ EQUITY
Deposits	2,235,655,000	2,037,745,000
Securities sold under repurchase agreements	0	864,000
Accrued interest and other liabilities	12,360,000	10,694,000
Total liabilities	2,248,015,000	2,049,303,000
Stockholders’ equity:
Common stock, par value $2.00 per share, authorized 50,000,000 shares, 10,623,810 and 10,450,711 shares issued and outstanding, respectively	21,248,000	20,901,000
Additional paid-in capital	73,960,000	66,047,000
Retained earnings	208,164,000	185,017,000
Net unrealized losses on available-for-sale securities, net of taxes of $2,726 and $1,498, respectively	(7,705,000)	(4,235,000)
Total stockholders’ equity	295,667,000	267,730,000
COMMITMENTS AND CONTINGENCIES
Total liabilities and stockholders’ equity	$ 2,543,682,000	$ 2,317,033,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for loan losses	$ 27,174	$ 23,909
Held-to-maturity, market value		32,111
Amortized Cost	$ 295,683	$ 338,449
Common stock, par value (in dollars per share)	$ 2	$ 2
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	10,623,810	10,450,711
Common stock, shares outstanding	10,623,810	10,450,711
Net unrealized losses on available-for-sale securities, income taxes	$ 2,726	$ 1,498

Consolidated Statements of Earn

Consolidated Statements of Earnings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest income:
Interest and fees on loans	$ 94,917	$ 83,120	$ 77,024
Interest and dividends on securities:
Taxable securities	6,158	5,397	5,714
Exempt from Federal income taxes	1,020	1,208	1,191
Interest on loans held for sale	184	324	391
Interest on Federal funds sold	83	97	26
Interest on interest bearing deposits	979	723	278
Interest and dividends on restricted equity securities	184	151	122
Total interest income	103,525	91,020	84,746
Interest expense:
Interest on negotiable order of withdrawal accounts	1,823	1,308	1,371
Interest on money market accounts and other savings accounts	4,231	2,211	1,915
Interest on certificates of deposit and individual retirement accounts	7,944	5,353	4,978
Interest on securities sold under repurchase agreements	16	9	3
Interest on Federal funds purchased	4	8	17
Total interest expense	14,018	8,889	8,284
Net interest income before provision for loan losses	89,507	82,131	76,462
Provision for loan losses	4,298	1,681	379
Net interest income after provision for loan losses	85,209	80,450	76,083
Non-interest income	25,248	22,821	21,654
Non-interest expense	(69,080)	(60,391)	(57,263)
Earnings before income taxes	41,377	42,880	40,474
Income taxes	8,783	19,354	14,841
Net earnings	$ 32,594	$ 23,526	$ 25,633
Basic earnings per common share (in dollars per share)	$ 3.09	$ 2.26	$ 2.49
Diluted earnings per common share (in dollars per share)	$ 3.08	$ 2.26	$ 2.49
Weighted average common shares outstanding:
Basic (in shares)	10,564,172	10,407,211	10,279,332
Diluted (in shares)	10,572,221	10,412,536	10,284,328

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Earnings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 32,594	$ 23,526	$ 25,633
Other comprehensive earnings (losses), net of tax:
Net unrealized gains (losses) on available-for-sale securities arising during period, net of taxes of $1,398, $271, and $1,830, respectively	(3,950)	437	(2,948)
Reclassification adjustment for net losses (gains) included in net earnings, net of taxes of $170, $67, and $176, respectively	480	108	(284)
Other comprehensive earnings (losses)	(3,470)	545	(3,232)
Comprehensive earnings	$ 29,124	$ 24,071	$ 22,401

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Earnings (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Unrealized gains (losses) on available-for-sale securities arising during period, taxes	$ (1,398)	$ 271	$ (1,830)
Reclassification adjustment for net gains (losses) included in net earnings, taxes	$ (170)	$ (67)	$ 176

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Net Unrealized Gain (Loss) On Available-For-Sale Securities
Beginning balance at Dec. 31, 2015	$ 223,438	$ 15,304	$ 61,339	$ 147,646	$ (851)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends declared, per share	(5,756)			(5,756)
Issuance of shares of stock pursuant to dividend reinvestment plan	4,316	197	4,119
Issuance of shares of stock pursuant to exercise of stock options	152	10	142
Issuance of 2,564,091 shares of common stock pursuant to a 4 for 3 stock split	0	5,128	(5,128)
Share based compensation expense	69		69
Net change in fair value of available-for-sale securities during the year, net of taxes	(3,232)				(3,232)
Net earnings for the year	25,633			25,633
Ending balance at Dec. 31, 2016	244,620	20,639	60,541	167,523	(4,083)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends declared, per share	(6,729)			(6,729)
Issuance of shares of stock pursuant to dividend reinvestment plan	5,266	252	5,014
Issuance of shares of stock pursuant to exercise of stock options	152	10	142
Reclassification of deferred tax asset revaluation	0			697	(697)
Share based compensation expense	350		350
Net change in fair value of available-for-sale securities during the year, net of taxes	545				545
Net earnings for the year	23,526			23,526
Ending balance at Dec. 31, 2017	267,730	20,901	66,047	185,017	(4,235)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends declared, per share	(9,447)			(9,447)
Issuance of shares of stock pursuant to dividend reinvestment plan	7,470	324	7,146
Issuance of shares of stock pursuant to exercise of stock options	394	23	371
Share based compensation expense	396		396
Net change in fair value of available-for-sale securities during the year, net of taxes	(3,470)				(3,470)
Net earnings for the year	32,594			32,594
Ending balance at Dec. 31, 2018	$ 295,667	$ 21,248	$ 73,960	$ 208,164	$ (7,705)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares
Cash dividends declared, per shares (in dollars per share) | $ / shares	$ 0.90	$ 0.65	$ 0.56
Shares of stock pursuant to dividend reinvestment plan (in shares)	161,514	125,960	98,318
Shares of stock pursuant to exercise of stock options	11,585	5,078	5,120
Net change in fair value of available-for-sale securities, tax | $	$ 1,228	$ 338	$ (2,006)
Shares of stock pursuant to stock split (in shares)			2,564,091
Stock split, conversion ratio			1.3333

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Interest received	$ 105,318	$ 93,506	$ 86,641
Fees and other income received	20,503	17,876	16,029
Proceeds from sales of loans	131,321	149,775	160,816
Origination of loans held for sale	(129,060)	(135,835)	(161,114)
Interest paid	(12,565)	(8,612)	(8,278)
Cash paid to suppliers and employees	(64,186)	(57,643)	(53,454)
Income taxes paid	(10,558)	(16,400)	(13,837)
Net cash provided by operating activities	40,773	42,667	26,803
Cash flows from investing activities:
Purchase of available-for-sale securities	(9,118)	(96,180)	(181,285)
Proceeds from calls, maturities and paydowns of available-for-sale securities	36,955	38,839	102,596
Proceeds from sale of available-for-sale securities	35,093	35,555	90,007
Purchase of held-to-maturity securities	0	0	(11,479)
Proceeds from maturities and paydowns of held-to-maturity securities	4,651	3,859	2,742
Proceeds from sale of held-to-maturity securities	4,764	0	0
Loans made to customers, net of repayments	(293,655)	(61,826)	(223,950)
Purchase of bank owned life insurance and annuity contracts	(4,301)	0	(11,916)
Purchase of bank premises and equipment	(7,752)	(12,660)	(5,147)
Proceeds from sale of other assets	4	43	15
Proceeds from sale of other real estate	796	2,876	581
Net cash used in investing activities	(232,563)	(89,494)	(237,836)
Cash flows from financing activities:
Net increase in non-interest bearing, savings, NOW and money market deposit accounts	101,248	87,116	158,775
Net increase (decrease) in time deposits	96,662	8,494	(6,490)
Net increase (decrease) in securities sold under agreements to repurchase	(864)	128	(1,299)
Dividends paid	(9,447)	(6,729)	(5,756)
Proceeds from sale of common stock pursuant to dividend reinvestment	7,470	5,266	4,316
Proceeds from sale of common stock pursuant to exercise of stock options	394	152	152
Net cash provided by financing activities	195,463	94,427	149,698
Net increase (decrease) in cash and cash equivalents	3,673	47,600	(61,335)
Cash and cash equivalents at beginning of year	95,518	47,918	109,253
Cash and cash equivalents at end of year	99,191	95,518	47,918
Reconciliation of net earnings to net cash provided by operating activities:
Net earnings	32,594	23,526	25,633
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation, amortization and accretion	5,853	5,507	5,515
Provision for loan losses	4,298	1,681	379
Share-based compensation expense	1,237	692	69
Provision for deferred tax expense (benefit)	(248)	(607)	(164)
Revaluation of deferred tax assets due to change in tax rates	0	3,603	0
Loss (gain) on sales of other real estate, net	80	(6)	(52)
Loss on sales of other assets	3	15	1
Loss on sales of premises and equipment	2	0	73
Security loss (gain)	650	175	(460)
Decrease (increase) in loans held for sale	(2,378)	9,682	(4,653)
Increase (decrease) in taxes payable	(1,526)	(42)	1,168
Increase in other assets, bank owned life insurance and annuity contract earnings	(1,684)	(1,231)	(2,408)
Increase in accrued interest receivable	(458)	(162)	(860)
Increase in interest payable	1,453	277	6
Increase (decrease) in other liabilities	897	(443)	2,556
Total adjustments	8,179	19,141	1,170
Net cash provided by operating activities	40,773	42,667	26,803
Supplemental Schedule of Non-Cash Activities:
Change in fair value of securities available-for-sale, net of taxes of $1,228 in 2018, $338 in 2017, and $2,006 in 2016	(3,470)	545	(3,232)
Non-cash transfers from held-to-maturity to available-for-sale securities	22,800	0	0
Non-cash transfers from loans to other real estate	693	173	696
Non-cash transfers from other real estate to loans	95	195	1,050
Non-cash transfers from loans to other assets	$ 7	$ 2	$ 16

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Cash Flows [Abstract]
Unrealized loss in values of securities available-for-sale, net of taxes	$ (1,228)	$ 338	$ (2,006)

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies The accounting and reporting policies of Wilson Bank Holding Company (“the Company”) and Wilson Bank & Trust (“Wilson Bank”) are in accordance with accounting principles generally accepted in the United States of America (“U.S.”) and conform to general practices within the banking industry. The following is a brief summary of the significant policies. (a) Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary Wilson Bank. All significant intercompany accounts and transactions have been eliminated in consolidation. (b) Nature of Operations Wilson Bank operates under a state bank charter and provides full banking services. As a state-chartered bank that is not a member of the Federal Reserve, Wilson Bank is subject to regulations of the Tennessee Department of Financial Institutions and the Federal Deposit Insurance Corporation (“FDIC”). The areas served by Wilson Bank include Wilson County, DeKalb County, Rutherford County, Smith County, Trousdale County, Putnam County, Sumner County, Davidson County and Williamson County, Tennessee and surrounding counties in Middle Tennessee. Services are provided at the main office and twenty-eight branch locations. (c) Estimates In preparing consolidated financial statements in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”), management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near term relate to the determination of the allowance for loan losses, the valuation of deferred tax assets and other real estate, other-than-temporary impairments of securities, and the fair value of financial instruments. (d) Significant Group Concentrations of Credit Risk Most of the Company’s activities are with customers located within Middle Tennessee. The types of securities in which the Company invests are described in note 3. The types of lending in which the Company engages are described in note 2. The Company does not have any significant concentrations to any one industry or customer other than as disclosed in note 2. Residential 1-4 family, commercial real estate and construction mortgage loans, represented 22% , 34% and 25% and 23% , 38% and 22% of the loan portfolio at December 31, 2018 and 2017 , respectively. (e) Loans The Company grants mortgage, commercial and consumer loans to customers. A substantial portion of the loan portfolio is represented by mortgage loans throughout Middle Tennessee. The ability of the Company’s debtors to honor their contracts is dependent upon the real estate and general economic conditions in this area. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off generally are reported at their outstanding unpaid principal balances adjusted for unearned income, the allowance for loan losses, and any unamortized deferred fees or costs on originated loans, and premiums or discounts on purchased loans. Loan origination fees, net of certain direct origination costs, as well as premiums and discounts, are deferred and amortized on a straight line basis over the respective term of the loan. As part of its routine credit monitoring process, the Company performs regular credit reviews of the loan portfolio and loans receive risk ratings by the assigned credit officer, which are subject to validation by our independent loan review department. Risk ratings are categorized as pass, special mention, substandard or doubtful. The Company believes that its categories follow those outlined by Wilson Bank's primary federal regulator. Generally the accrual of interest on mortgage and commercial loans is discontinued at the time the loan is 90 days past due unless the credit is well-secured and in process of collection. Credit card loans and other personal loans are typically charged off no later than when they become 180 days past due. Past due status is based on contractual terms of the loan. In all cases, loans are placed on nonaccrual or charged-off at an earlier date if collection of principal or interest is considered doubtful. All interest accrued but not collected for loans that are placed on nonaccrual or charged off is reversed against interest income. The interest on these loans is accounted for on the cash-basis or cost-recovery method, until qualifying for return to accrual. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured. (f) Allowance for Loan Losses Management provides for loan losses by establishing an allowance. The allowance for loan losses is established as losses are estimated to have occurred through a provision for loan losses charged to earnings. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses is evaluated on a quarterly basis by management and is based upon management’s quarterly review of the collectibility of the loans in light of historical experience, the nature and volume of the loan portfolio, adverse situations that may affect the borrower’s ability to repay, estimated value of any underlying collateral and prevailing economic conditions. This evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available. In assessing the adequacy of the allowance, we also consider the results of our ongoing independent loan review process. We undertake this process both to ascertain whether there are loans in the portfolio whose credit quality has weakened over time and to assist in our overall evaluation of the risk characteristics of the entire loan portfolio. Our loan review process includes the judgment of management, independent loan reviewers, and reviews that may have been conducted by third-party reviewers. We incorporate relevant loan review results in the loan impairment determination. In addition, regulatory agencies, as an integral part of their examination process, will periodically review the Company’s allowance for loan losses and may require the Company to record adjustments to the allowance based on their judgment about information available to them at the time of their examinations. In addition to the independent loan review process, the aforementioned risk ratings are subject to continual review by loan officers to determine that the appropriate risk ratings are being utilized in our allowance for loan loss process. Each risk rating is also subject to review by our independent loan review department. Currently, our independent loan review department targets reviews of 100% of existing loan relationships with aggregate debt of $1.0 million and greater and new loans with aggregate debt of $500,000 and greater. In addition, our independent loan review department targets particular portfolio segments, loans assigned to a particular lending officer, and loans with four or more renewals. The allowance consists of allocated and general components. The allocated component relates to loans that are classified as impaired. For those loans that are individually classified as impaired, an allowance is established when the discounted cash flows (or collateral value or observable market price) of the impaired loan is lower than the carrying value of that loan. The general component covers nonclassified loans and is based on historical charge-off experience, historical loan loss factors, loss experience of various loan segments, and other adjustments based on management’s assessment of internal or external influences on credit quality that are not fully reflected in the historical loss or risk rating data. A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan by loan basis for commercial, mortgage and agricultural loans by either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s obtainable market price, or the fair value of the collateral if the loan is collateral dependent. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, the Company does not separately identify individual consumer loans for impairment disclosures, unless such loans are the subject of a restructuring agreement due to financial difficulties of the borrower. (g) Debt and Equity Securities Certain debt securities that management has the positive intent and ability to hold to maturity are classified as “held to maturity” and recorded at amortized cost. Trading securities are recorded at fair value with changes in fair value included in earnings. Securities not classified as held to maturity or trading, including equity securities with readily determinable fair values, are classified as “available for sale” and recorded at fair value based on available market prices, with unrealized gains and losses excluded from earnings and reported in other comprehensive income on an after-tax basis. Securities classified as “available for sale” are held for indefinite periods of time and may be sold in response to movements in market interest rates, changes in the maturity or mix of Company assets and liabilities or demand for liquidity. Purchase premiums and discounts are recognized in interest income using the interest method over the terms of the securities. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. Other-than-temporary Impairment —Impaired securities are assessed quarterly for the presence of other-than-temporary impairment (“OTTI”). A decline in the fair value of any available-for-sale or held-to-maturity security below cost that is deemed to be other-than-temporary results in a reduction in the carrying amount of the security. To determine whether OTTI has occurred, management considers factors such as (1) length of time and extent that fair value has been less than cost, (2) the financial condition and near term prospectus of the issuer, and (3) Wilson Bank’s ability and intent to hold the security for a period sufficient to allow for any anticipated recovery in fair value. If management deems a security to be OTTI, management reviews the present value of the future cash flows associated with the security. A shortfall of the present value of the cash flows expected to be collected in relation to the amortized cost basis is referred to as a credit loss. If a credit loss is identified, the credit loss is recognized as a charge to earnings and a new cost basis for the security is established. If management concludes that no credit loss exists and it is not “more-likely-than-not” that it will be required to sell the security before the recovery of the security’s cost basis, then the security is not deemed OTTI and the shortfall is recorded as a component of equity. No securities have been classified as trading securities or held-to-maturity securities at December 31, 2018 . (h) Federal Home Loan Bank Stock The Company, as a member of the Federal Home Loan Bank (“FHLB”) Cincinnati system, is required to maintain an investment in capital stock of the FHLB. Based on redemption provisions of the FHLB, the stock has no quoted market value and is carried at par value, which approximates its fair value. Management reviews the investment for impairment based on the ultimate recoverability of the cost basis in the FHLB stock. As of December 31, 2018 , this minimum required investment was valued at approximately $2.8 million. Stock redemptions are at the discretion of the FHLB. (i) Loans Held for Sale Mortgage loans held for sale are carried at fair value. The fair value of loans held for sale is determined using quoted prices for similar assets, adjusted for specific attributes of that loan. (j) Premises and Equipment Premises and equipment are stated at cost. Depreciation is computed primarily by the straight-line method over the estimated useful lives of the related assets. Gains or losses realized on items retired and otherwise disposed of are credited or charged to operations and cost and related accumulated depreciation are removed from the asset and accumulated depreciation accounts. Expenditures for major renovations and improvements of premises and equipment are capitalized and those for maintenance and repairs are charged to earnings as incurred. (k) Other Real Estate Assets acquired through, or in lieu of, loan foreclosure are held for sale and are initially recorded at fair value less the estimated cost to sell at the date the Company acquires the property, establishing a new cost basis. Subsequent to their acquisition by the Company, valuations of these assets are periodically performed by management, and the assets are carried at the lower of carrying amount or fair value less cost to sell. Revenue and expenses from operations and changes in the valuation allowance [i.e. any direct write-downs] are included within non-interest expense. (l) Intangible Assets The Financial Accounting Standards Board “FASB” Accounting Standards Codification “ASC” 350, Goodwill and Other Intangible Assets requires that management determine the allocation of intangible assets into identifiable groups at the date of acquisition and that appropriate amortization periods be established. Under the provisions of FASB ASC 350, goodwill is not to be amortized; rather, it is to be monitored for impairment and written down to the impairment value at the time impairment occurs. The Company has determined that no impairment loss needs to be recognized related to its goodwill. (m) Cash and Cash Equivalents For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks and Federal funds sold. Generally, Federal funds sold are purchased and sold for one day periods. Management makes deposits only with financial institutions it considers to be financially sound. (n) Long-Term Assets Premises and equipment, intangible assets, and other long-term assets are reviewed for impairment when events indicate their carrying amount may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value. (o) Securities Sold Under Agreements to Repurchase Substantially all repurchase agreement liabilities represent amounts advanced by various customers. Securities are pledged to cover these liabilities, which are not covered by Federal deposit insurance. (p) Income Taxes The Company accounts for Income Taxes in accordance with income tax accounting guidance (FASB ASC 740, Income Taxes ). The Company follows accounting guidance related to accounting for uncertainty in income taxes, which sets out a consistent framework to determine the appropriate level of tax reserves to maintain for uncertain tax positions. The income tax accounting guidance results in two components of income tax expense: current and deferred. Current income tax expense reflects taxes to be paid or refunded for the current period by applying the provisions of the enacted tax law to the taxable income. The Company determines deferred income taxes using the liability (or balance sheet) method. Under this method, the net deferred tax asset or liability is based on the tax effects of the differences between the book and tax bases of assets and liabilities, and enacted changes in tax rates and laws are recognized in the period in which they occur. Deferred income tax expense results from changes in deferred tax assets and liabilities between periods. Deferred tax assets are recognized if it is more likely than not, based on the technical merits, that the tax position will be realized or sustained upon examination. The term "more likely than not" means a likelihood of more than 50 percent . The terms "examined" and "upon examination" also include resolution of the related appeals or litigation processes, if any. A tax position that meets the more-likely-than-not recognition threshold is initially and subsequently measured as the largest amount of tax benefit that has a greater than 50 percent likelihood of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The determination of whether or not a tax position has met the more-likely-than-not recognition threshold considers the facts, circumstances, and information available at the reporting date and is subject to management’s judgment. Deferred tax assets are reduced by a valuation allowance if, based on the weight of evidence available, it is more likely than not that some portion or all of a deferred tax asset will not be realized. The Company recognizes interest and penalties on income taxes as a component of income tax expense. (q) Mortgage Banking Derivatives Commitments to fund mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of these mortgage loans are accounted for as free standing derivatives. The fair value of the interest rate lock is recorded at the time the commitment to fund the mortgage loan is executed and is adjusted for the expected exercise of the commitment before the loan is funded. Fair values of these mortgage derivatives are estimated based on changes in mortgage interest rates from the date the interest rate on the loan is locked. The Company enters into forward commitments for the future delivery of mortgage loans when interest rate locks are entered into, in order to hedge the change in interest rates resulting from its commitments to fund the loans. Changes in the fair values of these derivatives are included in net gains on sale of mortgage loans. (r) Equity-Based Incentives Stock compensation accounting guidance (FASB ASC 718, “ Compensation—Stock Compensation” ) requires that the compensation cost relating to share-based payment transactions be recognized in financial statements. That cost will be measured based on the grant date fair value of the equity or liability instruments issued. The stock compensation accounting guidance covers a wide range of share-based compensation arrangements including stock options, restricted share plans, performance-based awards, cash-settled stock appreciation rights (SARs), and employee share purchase plans. Because cash-settled SARs do not give the grantee the choice of receiving stock, all cash-settled SARs are accounted for as liabilities, not equity, as compensation is accrued over the requisite service period. The stock compensation accounting guidance requires that compensation cost for all stock awards be calculated and recognized over the employees’ service period, generally defined as the vesting period. For awards with graded-vesting, compensation cost is recognized on a straight-line basis over the requisite service period for the entire award. The Company uses the Black-Scholes option pricing model to estimate the fair value of stock options and cash-settled SARs. (s) Advertising Costs Advertising costs are expensed as incurred by the Company and totaled $2,552,000 , $2,326,000 and $2,310,000 for 2018 , 2017 and 2016 , respectively. (t) Earnings Per Share Basic earnings per share represents income available to common stockholders divided by the weighted-average number of common shares outstanding during the period. Diluted earnings per share reflects additional potential 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. Potential common shares that may be issued by the Company relate solely to outstanding stock options and are determined using the treasury stock method. (u) Fair Value of Financial Instruments Fair values of financial instruments are estimated using relevant market information and other assumptions, as more fully disclosed in Note 21 - Disclosures About Fair Value of Financial Instruments of the consolidated financial statements. Fair value estimates involve uncertainties and matters of significant judgment. Changes in assumptions or in market conditions could significantly affect the estimates. (v) Reclassification Certain reclassifications have been made to the 2017 and 2016 figures to conform to the presentation for 2018 . (w) Off-Balance-Sheet Financial Instruments In the ordinary course of business, Wilson Bank has entered into off-balance-sheet financial instruments consisting of commitments to extend credit, commitments under credit card arrangements, commercial letters of credit and standby letters of credit. Such financial instruments are recorded in the financial statements when they are funded or related fees are incurred or received. (x) Stock Split The Company paid a 4 for 3 stock split to stockholders on March 30, 2016. Each stockholder received four (4) shares of common stock for each three (3) shares owned with no allowance for fractional shares. Per share data and stock options included in these financial statements for periods prior to 2017 has been restated to give effect to the stock split. (y) Accounting Standard Updates Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 implements a common revenue standard that clarifies the principles for recognizing revenue. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve that core principle, an entity should apply the following steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract and (v) recognize revenue when (or as) the entity satisfies a performance obligation. Our revenue is primarily comprised of net interest income on financial assets and financial liabilities, which is explicitly excluded from the scope of ASU 2014-09. Because of this, our adoption of this Standard in the first quarter of 2018 did not have a significant impact on our financial statements. In February 2016, FASB issued ASU 2016-02, "Leases (Topic 842)." The amendments in this ASU are effective for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. As a result of the amendment, lessees will need to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). The liability will be equal to the present value of lease payments. The asset will be based on the liability, subject to adjustments, such as adjustments for initial direct costs. For income statement purposes, FASB retained a dual model, requiring leases to be classified as either operating or finance. Operating leases will result in straight-line expense (similar to current operating leases) while finance leases will result in a front-loaded expense pattern (similar to current capital leases). Classification will be based on criteria that are largely similar to those applied in current lease accounting, but without explicit bright lines. Based on preliminary estimates made by management, we expect to record a right-of-use asset and offsetting lease liability in the amount of $2.5 million during the first quarter of 2019. In June 2016, FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments." ASU 2016-13 requires 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 and requires enhanced disclosures related to the significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. In addition, ASU 2016-13 amends the accounting for credit losses on held-to-maturity debt securities and purchased financial assets with credit deterioration. ASU 2016-13 will be effective on January 1, 2020. We are currently evaluating the potential impact of ASU 2016-13 on our financial statements. We are also evaluating the sufficiency of current systems and data needed to comply with this ASU. While we are currently unable to reasonably estimate the impact of adopting ASU 2016-13, we expect that the impact of adoption will be significantly influenced by the composition, characteristics and quality of our loan and securities portfolios as well as the prevailing economic conditions and forecasts as of the adoption date. In August 2016, FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” ASU 2016-15 clarifies how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230. The update addresses eight specific cash flow issues including, but not limited to, proceeds from the settlement of bank-owned life insurance policies, with the objective of reducing the existing diversity in practice. ASU 2016-15 was effective on January 1, 2018 and did not have a significant impact on our financial statements. In January 2017, FASB issued ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment.” ASU 2017-04 eliminates Step 2 from the goodwill impairment test which required entities to compute the implied fair value of goodwill. Under ASU 2017-04, 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 should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. ASU 2017-04 will be effective for us on January 1, 2020, with early adoption permitted for interim or annual impairment tests beginning in 2017. ASU 2017-04 is not expected to have a significant impact on our financial statements. In March 2017, FASB issued ASU 2017-08, “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20) - Premium Amortization on Purchased Callable Debt Securities.” ASU 2017-08 provides guidance on the amortization period for certain purchased callable debt securities held at a premium. This update shortens the amortization period for the premium to the earliest call date. Under current generally accepted accounting principles, entities generally amortize the premium as an adjustment of yield over the contractual life of the instrument related to certain cash flow issues. ASU 2017-08 will be effective for us on January 1, 2019. We do not expect this update to have a significant impact on our financial statements. In February 2018, FASB issued ASU 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220) - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income." Under ASU 2018-02, entities may elect to reclassify certain income tax effects related to the change in the U.S. statutory federal income tax rate under the Tax Cuts and Jobs Act, which was enacted on December 22, 2017, from accumulated other comprehensive income to retained earnings. ASU 2018-02 also requires certain accounting policy disclosures. We elected to adopt the provisions of ASU 2018-02 for the year ended December 31, 2018 in advance of the required application date of January 1, 2019. See Note 10 - Income Taxes. In March 2018, FASB issued ASU 2018-05, "Income Taxes (Topic 740) - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin (SAB) No. 118. ASU 2018-05 amends the Accounting Standards Codification to incorporate various SEC paragraphs pursuant to the issuance of SAB 118. SAB 118 addresses the application of generally accepted accounting principles in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Cuts and Jobs Act. See Note 10 - Income Taxes. In August 2018, FASB issued ASU 2018-13, "Fair Value Measurement (Topic 820) - Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement." ASU 2018-13 modifies the disclosure requirements on fair value measurements in Topic 820. The amendments in this update remove disclosures that no longer are considered cost beneficial, modify/clarify the specific requirements of certain disclosures, and add disclosure requirements identified as relevant. ASU 2018-13 will be effective for us on January 1, 2020, with early adoption permitted, and is not expected to have a significant impact on our financial statements. Other than those previously discussed, there were no other recently issued accounting pronouncements that may materially impact the Company.

Loans and Allowance for Loan Lo

Loans and Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Loans and Allowance for Loan Losses	Loans and Allowance for Loan Losses The classification of loans at December 31, 2018 and 2017 is as follows: In Thousands 2018 2017 Mortgage loans on real estate: Residential 1-4 family $ 460,692 406,667 Multifamily 134,613 91,992 Commercial 701,055 661,223 Construction 518,245 392,039 Farmland 24,071 34,212 Second mortgages 11,197 8,952 Equity lines of credit 62,013 60,650 Total mortgage loans on real estate 1,911,886 1,655,735 Commercial loans 78,245 47,939 Agricultural loans 1,985 1,665 Consumer installment loans: Personal 45,072 40,155 Credit cards 3,687 3,385 Total consumer installment loans 48,759 43,540 Other loans 9,324 9,662 2,050,199 1,758,541 Net deferred loan fees (7,020 ) (7,379 ) Total loans 2,043,179 1,751,162 Less: Allowance for loan losses (27,174 ) (23,909 ) Loans, net $ 2,016,005 1,727,253 At December 31, 2018 , variable rate and fixed rate loans totaled $1,495,918,000 and $554,281,000 , respectively. At December 31, 2017 , variable rate and fixed rate loans totaled $1,252,794,000 and $505,747,000 , respectively. In the normal course of business, Wilson Bank has made loans at prevailing interest rates and terms to directors and executive officers of the Company and to their affiliates. The aggregate amount of these loans was $13,019,000 and $7,759,000 at December 31, 2018 and 2017 , respectively. None of these loans were restructured, charged-off or involved more than the normal risk of collectibility or presented other unfavorable features during the three years ended December 31, 2018 . An analysis of the activity with respect to such loans to related parties is as follows: In Thousands December 31, 2018 2017 Balance, January 1 $ 7,759 9,692 New loans and renewals during the year 17,278 15,299 Repayments (including loans paid by renewal) during the year (12,018 ) (17,232 ) Balance, December 31 $ 13,019 7,759 Risk characteristics relevant to each portfolio segment are as follows: Construction and land development: Loans for non-owner-occupied real estate construction or land development are generally repaid through cash flow related to the operation, sale or refinance of the property. The Company also finances construction loans for owner-occupied properties. A portion of the Company’s construction and land portfolio segment is comprised of loans secured by residential product types (residential land and single-family construction). With respect to construction loans to developers and builders that are secured by non-owner occupied properties that the Company may originate from time to time, the Company generally requires the borrower to have had an existing relationship with the Company and have a proven record of success. Construction and land development loans are underwritten utilizing independent appraisal reviews, sensitivity analysis of absorption and lease rates, market sales activity, and financial analysis of the developers and property owners. Construction loans are generally based upon estimates of costs and value associated with the complete project. These estimates may be inaccurate. Construction loans often involve the disbursement of substantial funds with repayment substantially dependent on the success of the ultimate project. Sources of repayment for these types of loans may be pre-committed permanent loans from approved long-term lenders, sales of developed property or an interim loan commitment from the Company until permanent financing is obtained. These loans are closely monitored by on-site inspections and are considered to have higher risks than other real estate loans due to their ultimate repayment being sensitive to interest rate changes, governmental regulation of real property, general economic conditions and the availability of long-term financing. 1-4 family residential real estate: Residential real estate loans represent loans to consumers or investors to finance a residence. These loans are typically financed on 15 to 30 year amortization terms, but generally with shorter maturities of 5 to 15 years . Many of these loans are extended to borrowers to finance their primary or secondary residence. Loans to an investor secured by a 1-4 family residence will be repaid from either the rental income from the property or from the sale of the property. This loan segment also includes closed-end home equity loans that are secured by a first or second mortgage on the borrower’s residence. This allows customers to borrow against the equity in their home. Loans in this portfolio segment are underwritten and approved based on a number of credit quality criteria including limits on maximum Loan-to-Value (LTV), minimum credit scores, and maximum debt to income. Real estate market values as of the time the loan is made directly affect the amount of credit extended and, in addition, changes in these residential property values impact the depth of potential losses in this portfolio segment. 1-4 family HELOC: This loan segment includes open-end home equity loans that are secured by a first or second mortgage on the borrower’s residence. This allows customers to borrow against the equity in their home utilizing a revolving line of credit. These loans are underwritten and approved based on a number of credit quality criteria including limits on maximum LTV, minimum credit scores, and maximum debt to income. Real estate market values as of the time the loan is made directly affect the amount of credit extended and, in addition, changes in these residential property values impact the depth of potential losses in this portfolio segment. Because of the revolving nature of these loans, as well as the fact that many represent second mortgages, this portfolio segment can contain more risk than the amortizing 1-4 family residential real estate loans. Multi-family and commercial real estate: Multi-family and commercial real estate loans are subject to underwriting standards and processes similar to commercial and industrial loans, in addition to those of real estate loans. These loans are viewed primarily as cash flow loans and secondarily as loans secured by real estate. Commercial real estate lending typically involves higher loan principal amounts and the repayment of these loans is generally largely dependent on the successful operation of the property securing the loan or the business conducted on the property securing the loan. Commercial real estate loans may be more adversely affected by conditions in the real estate markets or in the general economy. The properties securing the Company’s commercial real estate portfolio are diverse in terms of type. This diversity helps reduce the Company’s exposure to adverse economic events that affect any single market or industry. Management monitors and evaluates commercial real estate loans based on collateral, geography and risk grade criteria. The Company also utilizes third-party experts to provide insight and guidance about economic conditions and trends affecting the market areas it serves. In addition, management tracks the level of owner-occupied commercial real estate loans versus non-owner occupied loans. Non-owner occupied commercial real estate loans are loans secured by multifamily and commercial properties where the primary source of repayment is derived from rental income associated with the property (that is, loans for which 50 percent or more of the source of repayment comes from third party, nonaffiliated rental income) or the proceeds of the sale, refinancing, or permanent financing of the property. These loans are made to finance income-producing properties such as apartment buildings, office and industrial buildings, and retail properties. Owner-occupied commercial real estate loans are loans where the primary source of repayment is the cash flow from the ongoing operations and business activities conducted by the party, or affiliate of the party, who owns the property. Commercial and industrial: The commercial and industrial loan portfolio segment includes commercial and industrial loans to commercial customers for use in normal business operations to finance working capital needs, equipment purchases or other expansion projects. Collection risk in this portfolio is driven by the creditworthiness of underlying borrowers, particularly cash flow from customers’ business operations. Commercial and industrial loans are primarily made based on the identified cash flows of the borrower and secondarily on the underlying collateral provided by the borrower. The cash flows of borrowers, however, may not be as expected and the collateral securing these loans may fluctuate in value. Most commercial and industrial loans are secured by the assets being financed or other business assets such as accounts receivable or inventory and usually incorporates a personal guarantee; however, some short-term loans may be made on an unsecured basis. In the case of loans secured by accounts receivable, the availability of funds for the repayment of these loans may be substantially dependent on the ability of the borrower to collect amounts due from its customers. Consumer: The consumer loan portfolio segment includes non-real estate secured direct loans to consumers for household, family, and other personal expenditures. Consumer loans may be secured or unsecured and are usually structured with short or medium term maturities. These loans are underwritten and approved based on a number of consumer credit quality criteria including limits on maximum LTV on secured consumer loans, minimum credit scores, and maximum debt to income. Many traditional forms of consumer installment credit have standard monthly payments and fixed repayment schedules of one to five years. These loans are made with either fixed or variable interest rates that are based on specific indices. Installment loans fill a variety of needs, such as financing the purchase of an automobile, a boat, a recreational vehicle or other large personal items, or for consolidating debt. These loans may be unsecured or secured by an assignment of title, as in an automobile loan, or by money in a bank account. In addition to consumer installment loans, this portfolio segment also includes secured and unsecured personal lines of credit as well as overdraft protection lines. Loans in this portfolio segment are sensitive to unemployment and other key consumer economic measures. A loan is considered impaired, in accordance with the impairment accounting guidance (ASC 310), when based on current information and events, it is probable that the Company will be unable to collect all amounts due from the borrower in accordance with the contractual terms of the loan. Impaired loans include nonperforming loans but also include loans modified in troubled debt restructurings where concessions have been granted to borrowers experiencing financial difficulties. These concessions could include a reduction in the interest rate on the loan, payment extensions, forgiveness of principal, forbearance or other actions intended to maximize collection. Substantially all of the Company’s impaired loans are collateral dependent. The following tables, present the Company’s impaired loans at December 31, 2018 and 2017 : In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2018 With no related allowance recorded: Residential 1-4 family $ 1,196 1,795 — 1,862 42 Multifamily — — — — — Commercial real estate 317 316 — 320 16 Construction 690 686 — 822 42 Farmland — — — 233 — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 2,203 2,797 — 3,237 100 In Thousands Record Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2018 With allowance recorded: Residential 1-4 family $ 1,641 1,635 852 1,782 77 Multifamily — — — — — Commercial real estate 1,515 1,515 312 2,001 17 Construction — — — — — Farmland — — — — — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 3,156 3,150 1,164 3,783 94 In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2018 Total: Residential 1-4 family $ 2,837 3,430 852 3,644 119 Multifamily — — — — — Commercial real estate 1,832 1,831 312 2,321 33 Construction 690 686 — 822 42 Farmland — — — 233 — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 5,359 5,947 1,164 7,020 194 In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2017 With no related allowance recorded: Residential 1-4 family $ 2,314 2,322 — 742 103 Multifamily — — — — — Commercial real estate 893 889 — 902 39 Construction 1,185 1,182 — 1,354 64 Farmland — — — 26 — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 4,392 4,393 — 3,024 206 In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2017 With allowance recorded: Residential 1-4 family $ 409 581 136 461 29 Multifamily — — — — — Commercial real estate 2,157 2,157 291 2,894 17 Construction — — — — — Farmland — — — — — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 2,566 2,738 427 3,355 46 In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2017 Total: Residential 1-4 family $ 2,723 2,903 136 1,203 132 Multifamily — — — — — Commercial real estate 3,050 3,046 291 3,796 56 Construction 1,185 1,182 — 1,354 64 Farmland — — — 26 — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 6,958 7,131 427 6,379 252 The following tables present the Company’s nonaccrual loans, credit quality indicators and past due loans as of December 31, 2018 and 2017 . Loans on Nonaccrual Status In Thousands 2018 2017 Residential 1-4 family $ 948 — Multifamily — — Commercial real estate 1,102 1,729 Construction — — Farmland — 310 Second mortgages — — Equity lines of credit — — Commercial — — Agricultural, installment and other — 1 Total $ 2,050 2,040 The impact on net interest income for these loans was not material to the Company’s results of operations for the years ended December 31, 2018 , 2017 and 2016. Potential problem loans, which include nonperforming loans, amounted to approximately $12.0 million at December 31, 2018 compared to $16.2 million at December 31, 2017 . Potential problem loans represent those loans with a well defined weakness and where information about possible credit problems of borrowers has caused management to have serious doubts about the borrower’s ability to comply with present repayment terms. This definition is believed to be substantially consistent with the standards established by the FDIC, the Company’s primary federal regulator, for loans classified as special mention, substandard, or doubtful, excluding the impact of nonperforming loans. The following table presents our loan balances by primary loan classification and the amount classified within each risk rating category. Pass rated loans include all credits other than those included in special mention, substandard and doubtful which are defined as follows: • Special mention loans have potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or in the Company’s credit position at some future date. • Substandard loans are inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Assets so classified must have a well-defined weakness or weaknesses that jeopardize liquidation of the debt. Substandard loans are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. • Doubtful loans have all the characteristics of substandard loans with the added characteristics 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 loans on nonaccrual status. Credit Quality Indicators In Thousands Residential Multifamily Commercial Construction Farmland Second Equity Lines Commercial Agricultural, Total Credit Risk Profile by Internally Assigned Grade December 31, 2018 Pass $ 452,411 134,613 698,083 518,123 23,895 10,979 61,927 78,206 59,923 2,038,160 Special mention 3,949 — 1,690 64 112 179 — 39 78 6,111 Substandard 4,332 — 1,282 58 64 39 86 — 67 5,928 Doubtful — — — — — — — — — — Total $ 460,692 134,613 701,055 518,245 24,071 11,197 62,013 78,245 60,068 2,050,199 December 31, 2017 Pass $ 395,664 91,992 657,456 391,778 33,500 8,765 60,553 47,937 54,697 1,742,342 Special mention 5,677 — 646 84 125 43 41 2 77 6,695 Substandard 5,326 — 3,121 177 587 144 56 — 93 9,504 Doubtful — — — — — — — — — — Total $ 406,667 91,992 661,223 392,039 34,212 8,952 60,650 47,939 54,867 1,758,541 Age Analysis of Past Due Loans In Thousands 30-59 60-89 Nonaccrual Total Current Total Loans Recorded December 31, 2018 Residential 1-4 family $ 3,258 1,092 1,868 6,218 454,474 460,692 920 Multifamily — — — — 134,613 134,613 — Commercial real estate 312 109 1,174 1,595 699,460 701,055 72 Construction 1,567 26 32 1,625 516,620 518,245 32 Farmland 43 9 21 73 23,998 24,071 21 Second mortgages 333 — — 333 10,864 11,197 — Equity lines of credit 297 — 45 342 61,671 62,013 45 Commercial 93 — 24 117 78,128 78,245 24 Agricultural, installment and other 407 85 95 587 59,481 60,068 95 Total $ 6,310 1,321 3,259 10,890 2,039,309 2,050,199 1,209 December 31, 2017 Residential 1-4 family $ 3,631 524 673 4,828 401,839 406,667 673 Multifamily — — — — 91,992 91,992 — Commercial real estate — 83 1,729 1,812 659,411 661,223 — Construction 433 — 113 546 391,493 392,039 113 Farmland 112 — 310 422 33,790 34,212 — Second mortgages — — 2 2 8,950 8,952 2 Equity lines of credit — — 41 41 60,609 60,650 41 Commercial 2 137 — 139 47,800 47,939 — Agricultural, installment and other 432 57 149 638 54,229 54,867 148 Total $ 4,610 801 3,017 8,428 1,750,113 1,758,541 977 Transactions in the allowance for loan losses for the years ended December 31, 2018 and 2017 are summarized as follows: In Thousands Residential Multifamily Commercial Construction Farmland Second Equity Lines Commercial Agricultural, Total December 31, 2018 Allowance for loan losses: Beginning balance $ 5,156 1,011 9,267 6,094 487 94 723 401 676 23,909 Provision 1,568 470 436 921 (266 ) 24 7 218 920 4,298 Charge-offs (492 ) — — (19 ) — — — — (1,152 ) (1,663 ) Recoveries 65 — 50 88 — — 1 3 423 630 Ending balance $ 6,297 1,481 9,753 7,084 221 118 731 622 867 27,174 Ending balance individually evaluated for impairment $ 852 — 312 — — — — — — 1,164 Ending balance collectively evaluated for impairment $ 5,445 1,481 9,441 7,084 221 118 731 622 867 26,010 Loans: Ending balance $ 460,692 134,613 701,055 518,245 24,071 11,197 62,013 78,245 60,068 2,050,199 Ending balance individually evaluated for impairment $ 2,829 — 1,831 686 — — — — — 5,346 Ending balance collectively evaluated for impairment $ 457,863 134,613 699,224 517,559 24,071 11,197 62,013 78,245 60,068 2,044,853 In thousands Residential Multifamily Commercial Construction Farmland Second Equity Lines Commercial Agricultural, Total December 31, 2017 Allowance for loan losses: Beginning balance $ 4,571 839 9,541 5,387 658 112 675 386 562 22,731 Provision 675 172 (414 ) 586 (168 ) (10 ) 45 9 786 1,681 Charge-offs (118 ) — — — (3 ) (11 ) — — (1,090 ) (1,222 ) Recoveries 28 — 140 121 — 3 3 6 418 719 Ending balance $ 5,156 1,011 9,267 6,094 487 94 723 401 676 23,909 Ending balance individually evaluated for impairment $ 136 — 291 — — — — — — 427 Ending balance collectively evaluated for impairment $ 5,020 1,011 8,976 6,094 487 94 723 401 676 23,482 Loans: Ending balance $ 406,667 91,992 661,223 392,039 34,212 8,952 60,650 47,939 54,867 1,758,541 Ending balance individually evaluated for impairment $ 2,678 — 3,046 1,182 — — — — — 6,906 Ending balance collectively evaluated for impairment $ 403,989 91,992 658,177 390,857 34,212 8,952 60,650 47,939 54,867 1,751,635 The Company’s loan portfolio includes certain loans that have been modified in a troubled debt restructuring (TDR), where economic concessions have been granted to borrowers who have experienced or are expected to experience financial difficulties. The concessions typically result from the Company’s loss mitigation activities and could include reductions in the interest rate, payment extensions, forgiveness of principal, forbearance or other actions. Certain TDRs are classified as nonperforming at the time of restructure and may only be returned to performing status after considering the borrower’s sustained repayment performance for a reasonable period, generally six months. The following table summarizes the carrying balances of TDRs at December 31, 2018 and December 31, 2017 (dollars in thousands): 2018 2017 Performing TDRs $ 1,676 2,250 Nonperforming TDRs 816 1,834 Total TDRs $ 2,492 4,084 The following table outlines the amount of each TDR categorized by loan classification for the years ended December 31, 2018 and 2017 (dollars in thousands): December 31, 2018 December 31, 2017 Number Pre Post Number of Pre Post Residential 1-4 family 4 $ 448 $ 448 6 $ 610 $ 535 Multifamily — — — — — — Commercial real estate — — — — — — Construction — — — — — — Farmland — — — 1 86 86 Second mortgages — — — — — — Equity lines of credit — — — — — — Commercial — — — — — — Agricultural, installment and other 2 5 5 1 3 3 Total 6 $ 453 $ 453 8 $ 699 $ 624 As of December 31, 2018 , the Company did not have any loan previously classified as a TDR default within twelve months of the restructuring. As of December 31, 2017 , the Company had one loan totaling $103,000 previously classified as TDR default within twelve months of the restructuring. A default is defined as an occurrence which violates the terms of the receivable’s contract. As of December 31, 2018 and 2017 , the Company's recorded investment in consumer mortgage loans in the process of foreclosure amounted to $200,000 and $201,000 , respectively. The Company’s principal customers are primarily in the Middle Tennessee area with a concentration in Wilson County, Tennessee. Credit is extended to businesses and individuals and is evidenced by promissory notes. The terms and conditions of the loans including collateral vary depending upon the purpose of the credit and the borrower’s financial condition. In 2018 , 2017 and 2016 , the Company originated mortgage loans for sale into the secondary market of $129,060,000 , $135,835,000 and $161,114,000 , respectively. The fees and gain on sale of these loans totaled $4,639,000 , $4,258,000 and $4,355,000 in 2018 , 2017 and 2016 , respectively. The Company sells loans to third-party investors on a loan-by-loan basis and has not entered into any forward commitments with investors for future bulk sales. All of these loan sales transfer servicing rights to the buyer. In some instances, Wilson Bank sells loans that contain provisions which permit the buyer to seek recourse against Wilson Bank in certain circumstances. At December 31, 2018 and 2017 , total mortgage loans sold with recourse in the secondary market aggregated $94,801,000 and $105,308,000 , respectively. At December 31, 2018 , Wilson Bank has not been required to repurchase a significant amount of the mortgage loans originated by Wilson Bank and sold in the secondary market. Management expects no material losses to result from these recourse provisions.

Debt and Equity Securities

Debt and Equity Securities	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Debt and Equity Securities	Debt and Equity Securities Debt and equity securities have been classified in the consolidated balance sheet according to management’s intent. Debt and equity securities at December 31, 2018 consist of the following: Securities Available-For-Sale In Thousands Amortized Gross Gross Estimated Government-sponsored enterprises (GSEs) $ 71,446 — 2,979 68,467 Mortgage-backed securities 152,375 9 4,874 147,510 Asset-backed securities 22,534 10 844 21,700 Obligations of states and political subdivisions 49,328 22 1,775 47,575 $ 295,683 41 10,472 285,252 There were no debt and equity securities classified as held-to-maturity at December 31, 2018. During the year ended December 31, 2018 , the Company sold securities classified as held-to-maturity with a book value of $4,843,000 for a loss of $79,000 . Due to the sale, management determined the Company no longer had the intent to hold the remaining securities classified as held-to-maturity to their respective maturity dates and transferred the remaining book value of $22,800,000 to the available-for-sale classification. The Company’s classification of securities at December 31, 2017 was as follows: Securities Held-To-Maturity In Thousands Amortized Gross Gross Estimated Mortgage-backed securities $ 9,886 31 156 9,761 Obligations of states and political subdivisions 22,594 66 310 22,350 $ 32,480 97 466 32,111 Securities Available-For-Sale In Thousands Amortized Gross Gross Estimated Government-sponsored enterprises (GSEs) $ 74,690 4 1,714 72,980 Mortgage-backed securities 200,175 302 2,551 197,926 Asset-backed securities 26,387 — 789 25,598 Obligations of states and political subdivisions 37,197 7 992 36,212 $ 338,449 313 6,046 332,716 Included in mortgage-backed securities are collateralized mortgage obligations totaling $11,564,000 (fair value of $11,295,000 ) and $17,361,000 (fair value of $17,133,000 ) at December 31, 2018 and 2017 , respectively. The amortized cost and estimated market value of debt securities at December 31, 2018 , by contractual maturity, are shown below. Expected maturities will differ from contractual maturities of mortgage and asset-backed securities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. In Thousands Securities Available-For-Sale Amortized Cost Estimated Market Value Due in one year or less $ 2,230 2,234 Due after one year through five years 22,971 22,409 Due after five years through ten years 76,604 73,184 Due after ten years 18,969 18,215 120,774 116,042 Mortgage and asset-backed securities 174,909 169,210 $ 295,683 285,252 Results from sales of debt and equity securities are as follows: In Thousands 2018 2017 2016 Gross proceeds $ 39,857 35,555 90,007 Gross realized gains $ 102 76 716 Gross realized losses (752 ) (251 ) (256 ) Net realized gains (losses) $ (650 ) (175 ) 460 Securities carried on the balance sheet of approximately $260,562,000 (approximate market value of $251,549,000 ) and $213,154,000 (approximate market value of $209,575,000 ) were pledged to secure public deposits and for other purposes as required or permitted by law at December 31, 2018 and 2017 , respectively. Included in the securities above are $14,154,000 and $10,793,000 (approximate market value of $13,724,000 and $10,219,000 ) and $23,670,000 and $9,464,000 (approximate market value of $23,404,000 and $9,121,000 ) at December 31, 2018 and 2017 , respectively, in obligations of political subdivisions located within the State of Tennessee and Texas, respectively. Management purchases only obligations of such political subdivisions it considers to be financially sound. Securities that have rates that adjust prior to maturity totaled $32,864,000 (approximate market value of $32,217,000 ) and $53,248,000 (approximate market value of $53,040,000 ) at December 31, 2018 and 2017 , respectively. Temporarily Impaired Securities The following table shows the gross unrealized losses and fair value of the Company’s investments with unrealized losses that are not deemed to be other-than-temporarily impaired, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31, 2018 and 2017 . Available-for-sale and held-to-maturity securities that have been in a continuous unrealized loss position at December 31, 2018 and 2017 are as follows: In Thousands, Except Number of Securities Less than 12 Months 12 Months or More Total 2018 Fair Value Unrealized Number Fair Value Unrealized Number Fair Value Unrealized Available-for-Sale Securities: Debt securities: GSEs $ — $ — — $ 68,467 $ 2,979 28 $ 68,467 $ 2,979 Mortgage-backed securities 8,651 64 10 137,457 4,810 94 146,108 4,874 Asset-backed securities — — — 20,597 844 14 20,597 844 Obligations of states and political subdivisions 4,064 26 6 39,841 1,749 94 43,905 1,775 $ 12,715 $ 90 16 $ 266,362 $ 10,382 230 $ 279,077 $ 10,472 In Thousands, Except Number of Securities Less than 12 Months 12 Months or More Total 2017 Fair Value Unrealized Number Fair Value Unrealized Number Fair Value Unrealized Held-to-Maturity Securities: Debt securities: Mortgage-backed securities $ 3,316 $ 21 4 $ 5,206 $ 135 5 $ 8,522 $ 156 Obligations of states and political subdivisions 10,137 46 27 7,278 264 18 17,415 310 $ 13,453 $ 67 31 $ 12,484 $ 399 23 $ 25,937 $ 466 Available-for-Sale Securities: Debt securities: GSEs $ 16,099 $ 190 8 $ 55,726 $ 1,524 21 $ 71,825 $ 1,714 Mortgage-backed securities 92,180 769 43 81,434 1,782 54 173,614 2,551 Asset-backed securities 9,087 181 7 16,510 608 8 25,597 789 Obligations of states and political subdivisions 12,128 113 22 21,762 879 56 33,890 992 $ 129,494 $ 1,253 80 $ 175,432 $ 4,793 139 $ 304,926 $ 6,046 Declines in the fair value of available-for-sale securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses to the extent the impairment is related to credit losses. The amount of the impairment related to other factors is recognized in other comprehensive income. In estimating other-than-temporary impairment losses, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) the intent and our ability to retain our investment in the issuer for a period of time sufficient to allow for any anticipated recovery in cost. As of December 31, 2018, management does not have the intent to sell any of the securities classified as available-for-sale in the table above and believes that it is more likely than not that we will not have to sell any such securities before a recovery of cost. Any unrealized losses are largely due to increases in market interest rates over the yields available at the time the underlying securities were purchased. The fair value is expected to recover as the bonds approach their maturity date or repricing date or if market yields for such investments decline. Management does not believe any of the securities are impaired due to reasons of credit quality. Accordingly, as of December 31, 2018, management believes the impairments detailed in the table above are temporary and no impairment loss has been realized in our consolidated statements of earnings.

Restricted Equity Securities

Restricted Equity Securities	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Restricted Equity Securities	Restricted Equity Securities Restricted equity securities consists of stock of the FHLB of Cincinnati amounting to $3,012,000 at December 31, 2018 and 2017 . The stock can be sold back only at par or a value as determined by the issuing institution and only to the respective financial institution or to another member institution. These securities are recorded at cost.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment The detail of premises and equipment at December 31, 2018 and 2017 is as follows: In Thousands 2018 2017 Land $ 17,022 17,022 Buildings 44,921 31,686 Leasehold improvements 492 425 Furniture and equipment 12,600 12,521 Automobiles 343 353 Construction-in-progress 100 10,895 75,478 72,902 Less accumulated depreciation (17,115 ) (18,687 ) $ 58,363 54,215 During 2018 , 2017 and 2016 , payments of $2,633,000 , $5,934,000 and $1,361,000 , respectively, were made to an entity owned by a director for the construction of buildings and repair work on existing buildings. Depreciation expense was $3,602,000 , $2,859,000 and $2,760,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively.

Acquired Intangible Assets and

Acquired Intangible Assets and Goodwill	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Acquired Intangible Assets and Goodwill	Acquired Intangible Assets and Goodwill The Company's intangible assets result from the excess of purchase price over the applicable book value of the net assets acquired related to outside ownership of two previously 50% owned subsidiaries that the Company acquired 100% of in 2005. In Thousands 2018 2017 Goodwill: Balance at January 1, $ 4,805 4,805 Goodwill acquired during year — — Impairment loss — — Balance at December 31, $ 4,805 4,805

Deposits

Deposits	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Deposits	Deposits Deposits at December 31, 2018 and 2017 are summarized as follows: In Thousands 2018 2017 Demand deposits $ 254,157 239,559 Savings accounts 136,645 136,549 Negotiable order of withdrawal accounts 503,435 495,930 Money market demand accounts 727,654 648,606 Certificates of deposit $250,000 or greater 134,506 67,614 Other certificates of deposit 402,690 370,608 Individual retirement accounts $250,000 or greater 8,525 6,954 Other individual retirement accounts 68,043 71,925 $ 2,235,655 2,037,745 Principal maturities of certificates of deposit and individual retirement accounts at December 31, 2018 are as follows: (In Thousands) Maturity Total 2019 $ 290,385 2020 155,006 2021 89,620 2022 21,662 2023 50,328 Thereafter 6,763 $ 613,764 The aggregate amount of overdrafts reclassified as loans receivable was $496,000 and $531,000 at December 31, 2018 and 2017 , respectively. As of December 31, 2018 and 2017 , Wilson Bank was not required to maintain a cash balance with the Federal Reserve.

Securities Sold Under Repurchas

Securities Sold Under Repurchase Agreements	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Securities Sold Under Repurchase Agreements	Securities Sold Under Repurchase Agreements Securities sold under repurchase agreements was $864,000 at December 31, 2017 . There was no balance outstanding at December 31, 2018 . The maximum amounts of outstanding repurchase agreements at any month end during 2018 and 2017 were $6,831,000 and $1,843,000 , respectively. The average daily balance outstanding during 2018 and 2017 was $1,090,000 and $1,382,000 , respectively. The weighted-average interest rates on the outstanding balance at December 31, 2017 was 1.47% . The underlying securities are typically held by other financial institutions and are designated as pledged.

Non-Interest Income and Non-Int

Non-Interest Income and Non-Interest Expense	12 Months Ended
	Dec. 31, 2018
Other Income and Expenses [Abstract]
Non-Interest Income and Non-Interest Expense	Non-Interest Income and Non-Interest Expense The significant components of non-interest income and non-interest expense for the years ended December 31, 2018 , 2017 and 2016 are presented below: In Thousands 2018 2017 2016 Non-interest income: Service charges on deposits $ 6,799 $ 6,124 $ 5,769 Other fees and commissions 13,704 $ 11,752 $ 10,260 BOLI and annuity earnings 841 $ 871 $ 832 Security gains (losses), net (650 ) $ (175 ) $ 460 Fees and gains on sales of mortgage loans 4,639 $ 4,258 $ 4,355 Gain (loss) on sale of other real estate, net (80 ) $ 6 $ 52 Loss on sale of fixed assets, net (2 ) $ — $ (73 ) Loss on sale of other assets, net (3 ) $ (15 ) $ (1 ) $ 25,248 22,821 21,654 In Thousands 2018 2017 2016 Non-interest expense: Employee salaries and benefits $ 39,590 35,830 34,106 Equity-based compensation 1,237 692 104 Occupancy expenses 4,403 3,718 3,638 Furniture and equipment expenses 2,767 2,085 2,019 Data processing expenses 2,900 2,834 2,576 Advertising expenses 2,552 2,326 2,310 ATM & interchange fees 3,091 2,569 2,475 FDIC insurance 843 683 968 Directors’ fees 543 677 691 Other operating expenses 11,154 8,977 8,376 69,080 60,391 57,263

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes In December 2017, the Tax Cuts and Jobs Act was signed into law. As a result, the statutory corporate federal tax rate was lowered from 35% to 21%, effective January 1, 2018. In accordance with accounting principles generally accepted in the United States of America, the effect of rate changes are to be recorded as an adjustment to income in the year of enactment. As a result of the Tax Cuts and Jobs Act being signed into law, the Company revalued all deferred taxes to reflect the new statutory corporate tax rate resulting in a $3,603,000 charge to deferred tax expense in the fourth quarter of 2017. This charge included $697,000 related to unrealized losses on available-for-sale securities. Unrealized losses on available-for-sale securities are recognized as a component of equity as other comprehensive income. Management has elected to reclassify the $697,000 expense related to the available-for-sale rate change from retained earnings to other comprehensive income. The components of the net deferred tax asset are as follows: In Thousands 2018 2017 Deferred tax asset: Federal $ 9,046 7,222 State 2,739 2,068 11,785 9,290 Deferred tax liability: Federal (2,167 ) (1,402 ) State (717 ) (464 ) (2,884 ) (1,866 ) Net deferred tax asset $ 8,901 7,424 The tax effects of each type of significant item that gave rise to deferred tax assets (liabilities) are: In Thousands 2018 2017 Financial statement allowance for loan losses in excess of tax allowance $ 6,846 5,925 Excess of depreciation deducted for tax purposes over the amounts deducted in the financial statements (2,557 ) (1,539 ) Financial statement deduction for deferred compensation in excess of deduction for tax purposes 1,128 1,075 Writedown of other real estate not deductible for income tax purposes until sold 176 161 Financial statement income on FHLB stock dividends not recognized for tax purposes (327 ) (327 ) Unrealized loss on securities available-for-sale 2,726 1,498 Equity based compensation 469 178 Other items, net 440 453 Net deferred tax asset $ 8,901 7,424 The components of income tax expense (benefit) are summarized as follows: In Thousands Federal State Total 2018 Current $ 8,310 721 9,031 Deferred (136 ) (112 ) (248 ) Total $ 8,174 609 8,783 2017 Current $ 14,004 2,354 16,358 Deferred 3,205 (209 ) 2,996 Total $ 17,209 2,145 19,354 2016 Current $ 12,910 2,095 15,005 Deferred (136 ) (28 ) (164 ) Total $ 12,774 2,067 14,841 A reconciliation of actual income tax expense of $8,783,000 , $19,354,000 and $14,841,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively, to the “expected” tax expense (computed by applying the statutory rate of 21% for 2018 and 34% for 2017 and 2016 to earnings before income taxes) is as follows: In Thousands 2018 2017 2016 Computed “expected” tax expense $ 8,689 14,579 13,761 State income taxes, net of Federal income tax benefit 432 1,346 1,364 Tax exempt interest, net of interest expense exclusion (226 ) (415 ) (401 ) Federal income tax rate in excess of statutory rate related to taxable income over $10 million — 399 370 Earnings on cash surrender value of life insurance (177 ) (292 ) (283 ) Expenses not deductible for tax purposes 16 43 40 Equity based compensation expense (39 ) 16 35 Revaluation of federal deferred tax assets due to change in tax rates — 3,603 — Other 88 75 (45 ) $ 8,783 19,354 14,841 Total income tax expense for 2018 , 2017 and 2016 , includes $(170,000) , $(67,000) and $176,000 of expense (benefit) related to the realized gain and loss, respectively, on sale of securities. As of December 31, 2018 , 2017 and 2016 the Company has not accrued or recognized interest or penalties related to uncertain tax positions. It is the Company’s policy to recognize interest and/or penalties related to income tax matters in income tax expense. There were no unrecognized tax benefits at December 31, 2018 . Wilson Bank does not expect that unrecognized tax benefits will significantly increase or decrease within the next 12 months . Included in the balance at December 31, 2018 , were approximately $11.8 million of tax positions (deferred tax assets) for which the ultimate deductibility is highly certain but for which there is uncertainty about the timing of such deductibility. Because of the impact of deferred tax accounting, other than interest, the disallowance of the shorter deductibility period would not affect the annual effective tax rate but would accelerate the payment of cash to the taxing authority to an earlier period. The Company and Wilson Bank file income tax returns in the United States (“U.S.”), as well as in the State of Tennessee. The Company is no longer subject to U.S. federal or state income tax examinations by tax authorities for years before 2014. The Company’s Federal tax returns have been audited through December 31, 2005 with no changes.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	Commitments and Contingent Liabilities The Company is party to litigation and claims arising in the normal course of business. Management, after consultation with legal counsel, believes that the liabilities, if any, arising from such litigation and claims will not be material to the Company's consolidated financial position. Wilson Bank leases three branch facilities and land for certain branch facilities and automatic teller machine locations. Future minimum rental payments required under the terms of the noncancellable leases are as follows: Years Ending December 31, In Thousands 2019 $ 401 2020 399 2021 349 2022 180 2023 85 Thereafter 13 Total rent expense amounted to $362,000 , $215,000 and $204,000 , respectively, during the years ended December 31, 2018 , 2017 and 2016 . The Company has lines of credit with other financial institutions totaling $53,000,000 at December 31, 2018 and 2017 . At December 31, 2018 and 2017 , respectively, there was no balance outstanding under these lines of credit. The Company also has a Cash Management Advance ("CMA") Line of Credit agreement. The CMA is a component of the Company's Blanket Agreement for advances with the FHLB. The purpose of the CMA is to assist with short-term liquidity management. Under the terms of the CMA, the Company may borrow a maximum of $25,000,000 , selecting a variable rate of interest for up to 90 days or a fixed rate for a maximum of 30 days . There were no borrowings outstanding under the CMA at December 31, 2018 or December 31, 2017 .

Financial Instruments with Off-

Financial Instruments with Off-Balance-Sheet Risk	12 Months Ended
	Dec. 31, 2018
Investments, All Other Investments [Abstract]
Financial Instruments with Off-Balance-Sheet Risk	Financial Instruments with Off-Balance-Sheet Risk The Company is party to financial instruments with off-balance-sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments consist primarily of commitments to extend credit. These instruments involve, to varying degrees, elements of credit risk in excess of the amount recognized in the consolidated balance sheets. The contract or notional amounts of those instruments reflect the extent of involvement the Company has in particular classes of financial instruments. The Company's exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit is represented by the contractual notional amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance-sheet instruments. In Thousands Contract or 2018 2017 Financial instruments whose contract amounts represent credit risk: Unused commitments to extend credit $ 582,897 605,114 Standby letters of credit 80,165 69,156 Total $ 663,062 674,270 Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to be drawn upon, the total commitment amounts generally represent future cash requirements. The Company evaluates each customer's credit-worthiness on a case-by-case basis. The amount of collateral, if deemed necessary by the Company upon extension of credit, is based on management's credit evaluation of the counterparty. Collateral normally consists of real property. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a customer to a third party. Those guarantees are primarily issued to support public and private borrowing arrangements, including commercial paper, bond financing, and similar transactions. Most guarantees extend from one to two years. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. The fair value of standby letters of credit is estimated using the fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements, the likelihood of the counterparties drawing on such financial instruments and the present creditworthiness of such counterparties. Such commitments have been made on terms which are competitive in the markets in which the Company operates; thus, the fair value of standby letters of credit equals the carrying value for the purposes of this disclosure. The maximum potential amount of future payments that the Company could be required to make under the guarantees totaled $80.2 million at December 31, 2018.

Concentration of Credit Risk

Concentration of Credit Risk	12 Months Ended
	Dec. 31, 2018
Risks and Uncertainties [Abstract]
Concentration of Credit Risk	Concentration of Credit Risk Practically all of the Company’s loans, commitments, and commercial and standby letters of credit have been granted to customers in the Company’s market area. Practically all such customers are depositors of Wilson Bank. The concentrations of credit by type of loan are set forth in Note 2 - Loans and Allowance for Loan Losses. Interest bearing deposits totaling $80,215,000 were deposited with four commercial banks. Federal funds sold in the amount of $9,000,000 were deposited with one commercial bank.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit Plan Wilson Bank has in effect a 401(k) plan (the “401(k) Plan”) which covers eligible employees. To be eligible an employee must have obtained the age of 20.5 . The provisions of the 401(k) Plan provide for both employee and employer contributions. For the years ended December 31, 2018 , 2017 and 2016 , Wilson Bank contributed $2,383,000 , $2,145,000 and $2,006,000 , respectively, to the 401(k) Plan.

Dividend Reinvestment Plan

Dividend Reinvestment Plan	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Dividend Reinvestment Plan	Dividend Reinvestment Plan Under the terms of the Company’s dividend reinvestment plan (the “DRIP”) holders of common stock may elect to automatically reinvest cash dividends in additional shares of common stock. The Company may elect to sell original issue shares or to purchase shares in the open market for the account of participants. Original issue shares of 161,514 in 2018 , 125,960 in 2017 and 98,318 in 2016 were sold to participants under the terms of the DRIP.

Regulatory Matters and Restrict

Regulatory Matters and Restrictions on Dividends	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Regulatory Matters and Restrictions on Dividends	Regulatory Matters and Restrictions on Dividends The Company and Wilson Bank are subject to regulatory capital requirements administered by the FDIC, the Federal Reserve and the Tennessee Department of Financial Institutions. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Company’s and Wilson Bank’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and Wilson 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. Quantitative measures established by regulation to ensure capital adequacy require the Company and Wilson Bank to maintain minimum amounts and ratios (set forth in the following table) of total, Tier 1 and common equity Tier 1 capital (each as defined in the regulations) to risk-weighted assets (as defined) and of Tier 1 capital (as defined) to average assets (as defined). Management believes, as of December 31, 2018 and 2017 , that the Company and Wilson Bank meet all capital adequacy requirements to which they are subject. As of December 31, 2018 , the most recent notification from the FDIC categorized Wilson Bank as well capitalized under the regulatory framework for prompt corrective action. There are no conditions or events since the notification that management believes have changed Wilson Bank’s category. To be categorized as well capitalized for purposes of prompt corrective action regulations as of December 31, 2018 and 2017 , an institution must have maintained minimum capital ratios as set forth in the following tables and not have been subject to a written agreement, order or directive to maintain a higher capital level. The Company’s and Wilson Bank’s actual capital amounts and ratios as of December 31, 2018 and 2017 , are presented in the following tables: Actual Regulatory Minimum Capital Requirement with Basel III Capital Conservation Buffer Regulatory Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) December 31, 2018 Total capital to risk weighted assets: Consolidated $ 326,099 14.1 % $ 227,974 9.875 % $ 230,860 10.0 % Wilson Bank 323,852 14.0 227,915 9.875 230,800 10.0 Tier 1 capital to risk weighted assets: Consolidated 298,566 12.9 181,802 7.875 138,516 6.0 Wilson Bank 296,319 12.8 181,756 7.875 184,641 8.0 Common equity Tier 1 capital to risk weighted assets: Consolidated 298,566 12.9 147,173 6.375 N/A N/A Wilson Bank 296,319 12.8 147,136 6.375 150,021 6.5 Tier 1 capital to average assets: Consolidated 298,566 12.3 97,022 4.0 N/A N/A Wilson Bank 296,319 11.9 99,373 4.0 124,217 5.0 Actual Regulatory Minimum Capital Requirement with Basel III Capital Conservation Buffer Regulatory Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) December 31, 2017 Total capital to risk weighted assets: Consolidated $ 291,395 14.2 % $ 189,658 9.25 % $ 205,036 10.0 % Wilson Bank 289,824 14.1 189,618 9.25 204,992 10.0 Tier 1 capital to risk weighted assets: Consolidated 267,159 13.0 148,651 7.25 123,021 6.0 Wilson Bank 265,588 13.0 148,619 7.25 163,994 8.0 Common Equity Tier 1 capital to risk weighted assets: Consolidated 267,159 13.0 117,895 5.75 N/A N/A Wilson Bank 265,588 13.0 117,871 5.75 133,245 6.5 Tier 1 capital to average assets: Consolidated 267,159 11.9 90,110 4.0 N/A N/A Wilson Bank 265,588 11.5 92,062 4.0 115,078 5.0 In July 2013, the Federal banking regulators, in response to the Statutory Requirements of The Dodd-Frank Wall Street Reform and Consumer Protection Act, adopted new regulations implementing the Basel Capital Adequacy Accord (“Basel III”) and the related minimum capital ratios. The new capital requirements were effective beginning January 1, 2015 . The guidelines under Basel III established a 2.5% capital conservation buffer requirement that was phased in over four years beginning January 1, 2016 . The buffer is related to Risk Weighted Assets. In order to avoid limitations on capital distributions such as dividends and certain discretionary bonus payments to executive officers, a banking organization must maintain capital ratios above the minimum ratios including the buffer. The Basel III minimum requirements after giving effect to the buffer as of January 1, of each year presented are as follows: 2016 2017 2018 2019 Common Equity Tier I Ratio 5.125 % 5.75 % 6.375 % 7.0 % Tier I Capital to Risk Weighted Assets Ratio 6.625 % 7.25 % 7.875 % 8.5 % Total Capital to Risk Weighted Assets Ratio 8.625 % 9.25 % 9.875 % 10.5 % The requirements of Basel III also place additional restrictions on the inclusion of deferred tax assets and capitalized mortgage servicing rights as a percentage of Tier I Capital. In addition, the risk weights assigned to certain assets such as past due loans and certain real estate loans have been increased. The requirements of Basel III allow banks and bank holding companies with less than $250 billion in assets a one-time opportunity to opt-out of a requirement to include unrealized gains and losses in accumulated other comprehensive income in their capital calculation. The Company and Wilson Bank have opted out of this requirement. In 2018, the U.S. Congress passed, and the President signed into law, the Economic Growth, Regulatory Relief, and Consumer Protection Act of 2018 (the “Growth Act”). The Growth Act, among other things, requires the federal banking agencies to issue regulations allowing community bank organizations with total assets of less than $10.0 billion in assets and limited amounts of certain assets and off-balance sheet exposures to access a simpler capital regime focused on a bank’s Tier 1 leverage capital levels rather than risk-based capital levels that are the focus of the capital rules issued under the Dodd-Frank Act implementing Basel III. In November 2018, the federal banking agencies proposed regulations that would exempt a qualifying community bank and its holding company that have Tier 1 leverage ratios of greater than 9 percent from the risk-based capital requirements of the capital rules issued under the Dodd-Frank Act. A qualifying community banking organization and its holding company that have chosen the proposed framework would not be required to calculate the existing risk-based and leverage capital requirements. Such a bank would also be considered to have met the capital ratio requirements to be well capitalized for the agencies' prompt corrective action rules provided it has a community bank leverage ratio greater than 9 percent. The Growth Act also raised the eligibility for the small bank holding company policy statement to $3 billion of assets from $1 billion. The rules implementing these provisions of the Growth Act are not yet finalized and the Company has not yet made a determination regarding whether it will seek to take advantage of these new capital rules under the Growth Act.

Salary Deferral Plans

Salary Deferral Plans	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Salary Deferral Plans	Salary Deferral Plans The Company provides its executive officers certain non-qualified pension benefits through an Executive Salary Continuation Plan ("the Plan") and Supplemental Executive Retirement Plan (SERP) Agreements ("SERP Agreements"). The Plan and SERP agreements were established by the Board of Directors to reward executive management for past performance and to provide additional incentive to retain the service of executive management. The Plan and SERP Agreements generally provide executives with benefits of a portion of their salary beginning at retirement through life. As a result, the Company has accrued a liability for future obligations under the Plan and SERP Agreements. At December 31, 2018 and 2017 , the liability related to the Plan totaled $1,825,000 and $1,861,000 , respectively. At December 31, 2018 and 2017 the liability related to the SERP Agreements totaled $2,491,000 and $2,250,000 , respectively. The Company has purchased life insurance policies to provide the benefits related to the Plan, which at December 31, 2018 and 2017 had an aggregate cash surrender value of $4,540,000 and $3,791,000 , respectively, and an aggregate face value of insurance policies in force of $13,523,000 and $11,176,000 , respectively. The life insurance policies remain the sole property of the Company and are payable to the Company. The Company has also purchased bank owned life insurance policies on its executive officers. The insurance policies remain the sole property of the Company and are payable to the Company. The cash surrender value of the life insurance contracts totaled $26,412,000 and $25,684,000 and the face amount of the insurance policies in force approximated $61,202,000 and $61,239,000 at December 31, 2018 and 2017 , respectively. The Company has also purchased Flexible Premium Indexed Deferred Annuity Contracts (“Annuity Contracts”) to provide benefits related to the SERP Agreements. The Annuity Contracts remain the sole property of the Company and are payable to the Company. Included in other assets at December 31, 2018 and 2017 are the Annuity Contracts with an aggregate value of $14,558,000 and $10,816,000 , respectively.

Equity Incentive Plan

Equity Incentive Plan	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plan	Equity Incentive Plan In April 1999, the stockholders of the Company approved the Wilson Bank Holding Company 1999 Stock Option Plan (the “1999 Stock Option Plan”). The Stock Option Plan provided for the granting of stock options, and authorized the issuance of common stock upon the exercise of such options, for up to 200,000 shares of common stock, to officers and other key employees of the Company and its subsidiary. Furthermore, the Company and its subsidiary could reserve additional shares for issuance under the 1999 Stock Option Plan as needed in order that the aggregate number of shares that may be issued during the term of the 1999 Stock Option Plan is equal to five percent ( 5% ) of the shares of common stock then issued and outstanding. The 1999 Stock Option Plan terminated on April 13, 2009 , and no additional rewards may be issued under the 1999 Stock Option Plan. The awards granted under the 1999 Stock Option Plan prior to the plan's termination will remain outstanding until exercised or otherwise terminated. As of December 31, 2018, the Company had outstanding 2,133 options with a weighted average exercise price of $26.81 under the 1999 Stock Option Plan. In April 2009, the Company’s shareholders approved the Wilson Bank Holding Company 2009 Stock Option Plan (the “2009 Stock Option Plan”). The 2009 Stock Option Plan was effective as of April 14, 2009 and replaced the 1999 Stock Option Plan. Under the 2009 Stock Option Plan, awards may be in the form of options to acquire common stock of the Company. Subject to adjustment as provided by the terms of the 2009 Stock Option Plan, the maximum number of shares of common stock with respect to which awards may be granted under the 2009 Stock Option Plan is 100,000 shares. As of December 31, 2018 , the Company had outstanding 27,069 options with a weighted average exercise price of $31.78 and has available to grant 52,788 options to employees pursuant to the 2009 Stock Option Plan. Under the 2009 Stock Option Plan, stock option awards may be granted in the form of incentive stock options or nonstatutory stock options and are generally exercisable for up to ten years following the date such option awards are granted. Exercise prices of incentive stock options must be equal to or greater than 100% of the fair market value of the common stock on the grant date. During the second quarter of 2016, the Company’s shareholders approved the Wilson Bank Holding Company 2016 Equity Incentive Plan, which authorizes awards of up to 750,000 shares of common stock. The 2016 Equity Incentive Plan was approved by the Board of Directors and effective as of January 25, 2016 and approved by the Company’s shareholders on April 12, 2016. On September 26, 2016, the Board of Directors approved an amendment and restatement of the 2016 Equity Incentive Plan (as amended and restated the “2016 Equity Incentive Plan”) to make clear that directors who are not also employees of the Company may be awarded stock appreciation rights. The primary purpose of the 2016 Equity Incentive Plan is to promote the interest of the Company and its shareholders by, among other things, (i) attracting and retaining key officers, employees and directors of, and consultants to, the Company and its subsidiaries and affiliates, (ii) motivating those individuals by means of performance-related incentives to achieve long-range performance goals, (iii) enabling such individuals to participate in the long-term growth and financial success of the Company, (iv) encouraging ownership of stock in the Company by such individuals, and (v) linking their compensation to the long-term interests of the Company and its shareholders. Except for certain limitations, awards can be in the form of stock options (both incentive stock options and non-qualified stock options), stock appreciation rights, restricted shares and restricted share units, performance awards and other stock-based awards. As of December 31, 2018 , the Company has 485,104 shares remaining available for issuance under the 2016 Equity Incentive Plan. As of December 31, 2018, the Company had outstanding 128,220 options with a weighted average exercise price of $41.25 and 120,398 cash-settled stock appreciation rights with a weighted average grant price of $41.00 under the 2016 Equity Incentive Plan. The fair value of each stock option and cash-settled SAR grant is estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions used for grants in 2018 , 2017 and 2016 : 2018 2017 2016 Expected dividends 1.22 % 1.27 % 1.21 % Expected term (in years) 9.35 7.79 8.71 Expected stock price volatility 24 % 26 % 26 % Risk-free rate 2.83 % 2.23 % 2.02 % The expected stock price volatility is based on historical volatility adjusted for consideration of other relevant factors. The risk-free interest rates for periods within the contractual life of the awards are based on the U.S. Treasury yield curve in effect at the time of the grant. The dividend yield and forfeiture rate assumptions are based on the Company’s history and expectation of dividend payouts and forfeitures. A summary of the stock option and cash-settled SAR activity for 2018 , 2017 and 2016 is as follows: 2018 2017 2016 Shares Weighted Shares Weighted Shares Weighted Outstanding at beginning of year 285,780 $ 39.31 183,747 $ 38.09 49,895 $ 30.19 Granted 21,666 46.59 112,333 40.87 140,997 40.36 Exercised (22,460 ) 37.07 (5,078 ) 29.65 (5,545 ) 27.38 Forfeited or expired (7,166 ) 37.53 (5,222 ) 39.22 (1,600 ) 28.44 Outstanding at end of year 277,820 $ 40.11 285,780 $ 39.31 183,747 $ 38.09 Options and cash-settled SARs exercisable at year end 94,951 $ 39.14 42,256 $ 36.66 13,553 $ 29.29 The following table summarizes information about stock options and cash-settled SARs for the year ended December 31, 2018 : Options and Cash-Settled SARs Outstanding Options and Cash-Settled SARs Exercisable Range of Exercise Prices Number Weighted Weighted Number Weighted Weighted $22.00 - $32.00 16,388 $ 29.02 1.50 years 9,022 $ 28.74 1.32 years $32.01 - $47.75 261,432 $ 40.81 7.38 years 85,929 $ 40.23 6.12 years 277,820 94,951 Aggregate intrinsic value (in thousands) $ 2,679 $ 1,008 The weighted average fair value at the grant date of options and cash-settled SARs granted during the years 2018 , 2017 and 2016 was $14.41 , $12.59 and $11.29 , respectively. The total intrinsic value of options and cash-settled SARs exercised during the years 2018 , 2017 and 2016 was $200,000 , $62,000 and $65,000 , respectively. As of December 31, 2018 , there was $2,104,000 of total unrecognized cost related to non-vested share-based compensation arrangements granted under the Company’s equity incentive plans. The cost is expected to be recognized over a weighted-average period of 3.22 years .

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following is a summary of the components comprising basic and diluted earnings per share (“EPS”): In Thousands (except share data) 2018 2017 2016 Basic EPS Computation: Numerator - Earnings available to common stockholders $ 32,594 23,526 25,633 Denominator - Weighted average number of common shares outstanding 10,564,172 10,407,211 10,279,332 Basic earnings per common share $ 3.09 2.26 2.49 Diluted EPS Computation: Numerator - Earnings available to common stockholders $ 32,594 23,526 25,633 Denominator - Weighted average number of common shares outstanding 10,564,172 10,407,211 10,279,332 Dilutive effect of stock options 8,049 5,325 4,996 10,572,221 10,412,536 10,284,328 Diluted earnings per common share $ 3.08 2.26 2.49

Mortgage Banking Derivatives Mo

Mortgage Banking Derivatives Mortgage Banking Derivatives	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Mortgage Banking Derivatives	Mortgage Banking Derivatives Commitments to fund certain mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of mortgage loans to third party investors are considered derivatives. It is the Company's practice to enter into forward commitments for the future delivery of residential mortgage loans when interest rate lock commitments are entered into in order to economically hedge the effect of changes in interest rates resulting from its commitments to fund the loans. At year-end 2018, the Company had approximately $9,655,000 of interest rate lock commitments and approximately $11,750,000 of forward commitments for the future delivery of residential mortgage loans. The fair value of these mortgage banking derivatives was reflected by derivative asset and liability of $335,000 and $88,000 , respectively, at December 31, 2018. Changes in the fair values of these mortgage-banking derivatives are included in net gains on sale of loans. The net gains (losses) relating to free-standing derivative instruments used for risk management is summarized below (in thousands): In Thousands 2018 Forward contracts related to mortgage loans held for sale and interest rate contracts $ (88 ) Interest rate contracts for customers 335 The following table reflects the amount and fair value of mortgage banking derivatives included in the consolidated balance sheet as of December 31, 2018 (in thousands): In Thousands 2018 Notional Amount Fair Value Included in other assets (liabilities): Interest rate contracts for customers $ 9,655 335 Forward contracts related to mortgage loans held-for-sale 11,750 (88 )

Disclosures About Fair Value of

Disclosures About Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Disclosures About Fair Value of Financial Instruments	Disclosures About Fair Value of Financial Instruments Fair Value of Financial Instruments FASB ASC 820, Fair Value Measurements and Disclosures (“ASC 820”) , which defines fair value, establishes a framework for measuring fair value in U.S. GAAP and expands disclosures about fair value measurements. The definition of fair value focuses on the exit price, i.e., 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, not the entry price, i.e., the price that would be paid to acquire the asset or received to assume the liability at the measurement date. The statement emphasizes that fair value is a market-based measurement; not an entity-specific measurement. Therefore, the fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability. Valuation Hierarchy FASB ASC 820 establishes a three-level valuation hierarchy for disclosure of fair value measurements. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. The three levels are defined as follows: • Level 1 - inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets • Level 2 - inputs to the valuation methodology include all prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. • Level 3 - inputs to the valuation methodology that are unobservable and significant to the fair value measurement. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Following is a description of the valuation methodologies used for assets and liabilities measured at fair value, as well as the general classification of such assets and liabilities pursuant to the valuation hierarchy. Assets Securities available-for-sale - Where quoted prices are available for identical securities in an active market, securities are classified within Level 1 of the valuation hierarchy. Level 1 securities include highly liquid government securities and certain other financial products. If quoted market prices are not available, then fair values are estimated by using pricing models that use observable inputs or quoted prices of securities with similar characteristics and are classified within Level 2 of the valuation hierarchy. In certain cases where there is limited activity or less transparency around inputs to the valuation and more complex pricing models or discounted cash flows are used, securities are classified within Level 3 of the valuation hierarchy. From time to time, we will validate prices supplied by our third party vendor by comparison to prices obtained from third parties. Impaired loans - A loan is considered to be impaired when it is probable the Company will be unable to collect all principal and interest payments due in accordance with the contractual terms of the loan agreement. Impaired loans are measured based on the present value of expected payments using the loan’s original effective rate as the discount rate, the loan’s observable market price, or the fair value of the collateral less selling costs if the loan is collateral dependent. If the recorded investment in the impaired loan exceeds the measure of fair value, a valuation allowance may be established as a component of the allowance for loan losses or the expense is recognized as a charge-off. Impaired loans are classified within Level 3 of the hierarchy due to the unobservable inputs used in determining their fair value such as collateral values and the borrower’s underlying financial condition. Other real estate owned - Other real estate owned (“OREO”) represents real estate foreclosed upon by the Company through loan defaults by customers or acquired in lieu of foreclosure. Upon foreclosure, the property is recorded at the lower of cost or fair value, based on appraised value, less selling costs estimated as of the date acquired with any loss recognized as a charge-off through the allowance for loan losses. Additional OREO losses for subsequent valuation downward adjustments are determined on a specific property basis and are included as a component of noninterest expense along with holding costs. Any gains or losses realized at the time of disposal are also reflected in noninterest income or noninterest expense, as applicable. OREO is included in Level 3 of the valuation hierarchy due to the lack of observable market inputs into the determination of fair value. Appraisal values are property-specific and sensitive to the changes in the overall economic environment. Bank Owned Life Insurance - The cash surrender value of bank owned life insurance policies is carried at fair value. The Company uses financial information received from insurance carriers indicating the performance of the insurance policies and cash surrender values in determining the carrying value of life insurance. The Company reflects these assets within Level 3 of the valuation hierarchy due to the unobservable inputs included in the valuation of these items. The Company does not consider the fair values of these policies to be materially sensitive to changes in these unobservable inputs. Mortgage loans held for sale - Mortgage loans held for sale are carried at fair value. The fair value of mortgage loans held for sale is determined using quoted prices for similar assets, adjusted for specific attributes of that loan and mortgage loans held for sale are included in Level 2 of the valuation hierarchy. Derivatives - The fair values of derivatives are based on valuation models using observable market data as of the measurement date (Level 2). The following tables present the financial instruments carried at fair value as of December 31, 2018 and December 31, 2017 , by caption on the consolidated balance sheet and by FASB ASC 820 valuation hierarchy (as described above) (in thousands): Measured on a Recurring Basis Total Carrying Quoted Market Models with Models with December 31, 2018 Investment securities available-for-sale: U.S. Government sponsored enterprises $ 68,467 — 68,467 — Mortgage-backed securities 147,510 — 147,510 — Asset-backed securities 21,700 — 21,700 — State and municipal securities 47,575 — 47,575 — Total investment securities available-for-sale 285,252 — 285,252 — Mortgage loans held for sale 7,484 — 7,484 — Mortgage banking derivatives 335 — 335 — Bank owned life insurance 30,952 — — 30,952 Total assets $ 324,023 — 293,071 30,952 Mortgage banking derivatives $ 88 — 88 — Total liabilities $ 88 — 88 — Measured on a Recurring Basis Total Carrying Quoted Market Models with Models with December 31, 2017 Investment securities available-for-sale: U.S. Government sponsored enterprises $ 72,980 — 72,980 — Mortgage-backed securities 197,926 — 197,926 — Asset-backed securities 25,598 — 25,598 — State and municipal securities 36,212 — 36,212 — Total investment securities available-for-sale 332,716 — 332,716 — Mortgage loans held for sale 5,106 — 5,106 — Bank owned life insurance 29,475 — — 29,475 Total $ 367,297 — 337,822 29,475 Measured on a Non-Recurring Basis Total Carrying Quoted Market Models with Models with December 31, 2018 Other real estate owned $ 1,357 — — 1,357 Impaired loans, net (¹) 4,195 — — 4,195 Total $ 5,552 — — 5,552 December 31, 2017 Other real estate owned $ 1,635 — — 1,635 Impaired loans, net (¹) 6,531 — — 6,531 Total $ 8,166 — — 8,166 (¹) Amount is net of a valuation allowance of $1,164,000 at December 31, 2018 and $427,000 at December 31, 2017 as required by ASC 310, “Receivables.” The following table presents additional quantitative information about assets measured at fair value on a nonrecurring basis and for which we have utilized Level 3 inputs to determine fair value at December 31, 2018 and 2017 : Valuation Techniques ( 2 ) Significant Unobservable Inputs Range (Weighted Average) Impaired loans Appraisal Estimated costs to sell 10% Other real estate owned Appraisal Estimated costs to sell 10% ( 2 ) The fair value is generally determined through independent appraisals of the underlying collateral, which may include Level 3 inputs that are not identifiable, or by using the discounted cash flow method if the loan is not collateral dependent. In the case of its investment securities portfolio, the Company monitors the valuation technique utilized by various pricing agencies to ascertain when transfers between levels have been affected. The nature of the remaining assets and liabilities is such that transfers in and out of any level are expected to be rare. For the twelve months ended December 31, 2018 , there were no transfers between Levels 1, 2 or 3. The table below includes a rollforward of the balance sheet amounts for the year ended December 31, 2018 and 2017 (including the change in fair value) for financial instruments classified by the Company within Level 3 of the valuation hierarchy for assets and liabilities measured at fair value on a recurring basis. When a determination is made to classify a financial instrument within Level 3 of the valuation hierarchy, the determination is based upon the significance of the unobservable factors to the overall fair value measurement. However, since Level 3 financial instruments typically include, in addition to the unobservable or Level 3 components, observable components (that is, components that are actively quoted and can be validated to external sources), the gains and losses in the table below include changes in fair value due in part to observable factors that are part of the valuation methodology (in thousands): For the Year Ended December 31, 2018 2017 Other Other Other Other Fair value, January 1 $ 29,475 — $ 28,616 — Total realized gains included in income 841 — 859 — Change in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at December 31 — — — — Purchases, issuances and settlements, net 636 — — — Transfers out of Level 3 — — — — Fair value, December 31 $ 30,952 — $ 29,475 — Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at December 31 $ 841 — $ 859 — The following methods and assumptions were used by the Company in estimating its fair value disclosures for financial instruments that are not measured at fair value. In cases where quoted market prices are not available, fair values are based on estimates using discounted cash flow models. Those models are significantly affected by the assumptions used, including the discount rates, estimates of future cash flows and borrower creditworthiness. The fair value estimates presented herein are based on pertinent information available to management as of December 31, 2018 and December 31, 2017 . Such amounts have not been revalued for purposes of these consolidated financial statements since those dates and, therefore, current estimates of fair value may differ significantly from the amounts presented herein. Cash and cash equivalents - The carrying amounts of cash and short-term instruments approximate fair values and are classified as Level 1. Held-to-maturity securities - Estimated fair values for held-to-maturity investment securities are based on quoted market prices where available. If quoted market prices are not available, then fair values are estimated by using pricing models that use observable inputs or quoted prices of securities with similar characteristics. Loans - The fair value of our loan portfolio includes a credit risk factor in the determination of the fair value of our loans. This credit risk assumption is intended to approximate the fair value that a market participant would realize in a hypothetical orderly transaction. Fair values are estimated using discounted cash flow models, using current market interest rates offered for loans with similar terms to borrowers of similar credit quality. We believe current market rates capture a market participant's cost of funds, liquidity premium, capital charges, servicing charges and expectations of future rate movements. The values derived from the discounted cash flow approach for each of the above portfolios are then further discounted to incorporate credit risk to determine the exit price. Deposits and securities sold under agreements to repurchase - Fair values for deposits are estimated using discounted cash flow models, using current market interest rates offered on deposits with similar remaining maturities. Restricted equity securities - It is not practical to determine the fair value of Federal Home Loan Bank or Federal Reserve Bank stock due to restrictions placed on its transferability. Accrued interest receivable/payable - The carrying amounts of accrued interest approximate fair value resulting in a Level 1, Level 2 or Level 3 classification based on the asset/liability with which they are associated. Off-balance sheet instruments - Fair values for off-balance sheet, credit-related financial instruments are based on fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements and the counterparties' credit standing. The fair value of commitments is not material. The following table presents the carrying amounts, estimated fair value and placement in the fair value hierarchy of the Company’s financial instruments at December 31, 2018 and December 31, 2017 . This table excludes financial instruments for which the carrying amount approximates fair value. For short-term financial assets such as cash and cash equivalents, 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. (in Thousands) Carrying/ Estimated Quoted Market Models with Models with December 31, 2018 Financial assets: Cash and cash equivalents $ 99,191 99,191 99,191 — — Loans, net 2,016,005 2,017,272 — — 2,017,272 Restricted equity securities 3,012 NA NA NA NA Accrued interest receivable 6,724 6,724 3 1,362 5,359 Financial liabilities: Deposits 2,235,655 1,974,554 — — 1,974,554 Accrued interest payable 3,132 3,132 — — 3,132 December 31, 2017 Financial assets: Cash and cash equivalents $ 95,518 95,518 95,518 — — Securities held-to-maturity 32,480 32,111 — 32,111 — Loans, net 1,727,253 1,724,937 — — 1,724,937 Restricted equity securities 3,012 NA NA NA NA Accrued interest receivable 6,266 6,266 5 1,562 4,699 Financial liabilities: Deposits and securities sold under agreements to repurchase 2,038,609 1,812,011 — — 1,812,011 Accrued interest payable 1,679 1,679 — — 1,679 (¹) Estimated fair values are consistent with an exit-price concept. The assumptions used to estimate the fair values are intended to approximate those that a market-participant would realize in a hypothetical orderly transaction.

Wilson Bank Holding Company - P

Wilson Bank Holding Company - Parent Company Financial Information	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Wilson Bank Holding Company - Parent Company Financial Information	Wilson Bank Holding Company - Parent Company Financial Information WILSON BANK HOLDING COMPANY (Parent Company Only) Balance Sheets December 31, 2018 and 2017 Dollars In Thousands 2018 2017 ASSETS Cash $ 2,759 * 1,589 * Investment in wholly-owned commercial bank subsidiary 293,420 266,159 Deferred income taxes 469 178 Refundable income taxes 177 181 Total assets $ 296,825 268,107 LIABILITIES AND STOCKHOLDERS’ EQUITY Stock appreciation rights payable $ 1,158 377 Total liabilities 1,158 377 Stockholders’ equity: Common stock, par value $2.00 per share, authorized 50,000,000 shares, 10,623,810 and 10,450,711 shares issued and outstanding, respectively 21,248 20,901 Additional paid-in capital 73,960 66,047 Retained earnings 208,164 185,017 Net unrealized losses on available-for-sale securities, net of income taxes of $2,726 and $1,498, respectively (7,705 ) (4,235 ) Total stockholders’ equity 295,667 267,730 Total liabilities and stockholders’ equity $ 296,825 268,107 * Eliminated in consolidation. WILSON BANK HOLDING COMPANY (Parent Company Only) Statements of Earnings Three Years Ended December 31, 2018 Dollars In Thousands 2018 2017 2016 Income: Dividends from commercial bank subsidiary $ 3,000 1,500 1,500 Expenses: Directors’ fees 254 334 327 Other 1,351 805 194 1,605 1,139 521 Income before Federal income tax benefits and equity in undistributed earnings of commercial bank subsidiary 1,395 361 979 Federal income tax benefits 468 359 169 1,863 720 1,148 Equity in undistributed earnings of commercial bank subsidiary 30,731 * 22,806 * 24,485 * Net earnings $ 32,594 23,526 25,633 * Eliminated in consolidation. WILSON BANK HOLDING COMPANY (Parent Company Only) Statements of Cash Flows Three Years Ended December 31, 2018 Increase (Decrease) in Cash and Cash Equivalents Dollars In Thousands 2018 2017 2016 Cash flows from operating activities: Cash paid to suppliers and other $ (367 ) (447 ) (417 ) Tax benefits received 181 169 198 Net cash used in operating activities (186 ) (278 ) (219 ) Cash flows from investing activities: Dividends received from commercial bank subsidiary 3,000 1,500 1,500 Net cash provided by investing activities 3,000 1,500 1,500 Cash flows from financing activities: Payments made to stock appreciation rights holders (61 ) — — Dividends paid (9,447 ) (6,729 ) (5,756 ) Proceeds from sale of stock pursuant to dividend reinvestment plan 7,470 5,266 4,316 Proceeds from exercise of stock options 394 152 152 Net cash used in financing activities (1,644 ) (1,311 ) (1,288 ) Net increase (decrease) in cash and cash equivalents 1,170 (89 ) (7 ) Cash and cash equivalents at beginning of year 1,589 1,678 1,685 Cash and cash equivalents at end of year $ 2,759 1,589 1,678 WILSON BANK HOLDING COMPANY (Parent Company Only) Statements of Cash Flows, Continued Three Years Ended December 31, 2018 Increase (Decrease) in Cash and Cash Equivalents Dollars in Thousands 2018 2017 2016 Reconciliation of net earnings to net cash used in operating activities: Net earnings $ 32,594 23,526 25,633 Adjustments to reconcile net earnings to net cash used in operating activities: Equity in earnings of commercial bank subsidiary (33,731 ) (24,306 ) (25,985 ) Decrease (increase) in refundable income taxes 5 (12 ) 29 Increase in deferred taxes (291 ) (178 ) — Share based compensation expense 1,237 692 104 Total adjustments (32,780 ) (23,804 ) (25,852 ) Net cash used in operating activities $ (186 ) (278 ) (219 )

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	Quarterly Financial Data (Unaudited) Selected quarterly results of operations for the four quarters ended December 31 are as follows: (In Thousands, except per share data) 2018 2017 2016 Fourth Quarter Third Quarter Second Quarter First Quarter Fourth Quarter Third Quarter Second Quarter First Quarter Fourth Quarter Third Quarter Second Quarter First Quarter Interest income $ 27,585 26,298 25,548 24,094 $ 23,487 22,904 22,871 21,758 $ 22,078 21,454 20,877 20,337 Interest expense 4,606 3,656 3,097 2,659 2,439 2,332 2,094 2,024 1,990 2,077 2,106 2,111 Net interest income 22,979 22,642 22,451 21,435 21,048 20,572 20,777 19,734 20,088 19,377 18,771 18,226 Provision for loan losses 1,097 1,088 1,090 1,023 436 436 420 389 89 141 82 67 Earnings before income taxes 10,708 10,718 9,798 10,153 10,694 10,438 11,386 10,362 10,120 11,095 10,162 9,097 Net earnings 9,833 7,972 7,309 7,480 3,574 6,469 6,988 6,495 6,802 6,918 6,270 5,643 Basic earnings per common share 0.93 0.75 0.69 0.71 0.34 0.62 0.67 0.63 0.66 0.67 0.61 0.55 Diluted earnings per common share 0.92 0.75 0.69 0.71 0.34 0.62 0.67 0.63 0.66 0.67 0.61 0.55

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events ASC Topic 855, Subsequent Events , as amended by ASU No. 2010-90, establishes general standards of accounting for and disclosure of events that occur after the balance sheet date but before financial statements are issued. The Company evaluated all events or transactions that occurred after December 31, 2018 , through the date of the issued financial statements. During this period there were no material recognizable subsequent events that required recognition in the disclosures to the Company's December 31, 2018 financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary Wilson Bank. All significant intercompany accounts and transactions have been eliminated in consolidation.
Nature of Operations	Nature of Operations Wilson Bank operates under a state bank charter and provides full banking services. As a state-chartered bank that is not a member of the Federal Reserve, Wilson Bank is subject to regulations of the Tennessee Department of Financial Institutions and the Federal Deposit Insurance Corporation (“FDIC”). The areas served by Wilson Bank include Wilson County, DeKalb County, Rutherford County, Smith County, Trousdale County, Putnam County, Sumner County, Davidson County and Williamson County, Tennessee and surrounding counties in Middle Tennessee. Services are provided at the main office and twenty-eight branch locations.
Estimates	Estimates In preparing consolidated financial statements in conformity with accounting principles generally accepted in the United States (“U.S. GAAP”), management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near term relate to the determination of the allowance for loan losses, the valuation of deferred tax assets and other real estate, other-than-temporary impairments of securities, and the fair value of financial instruments.
Significant Group Concentrations of Credit Risk	Significant Group Concentrations of Credit Risk Most of the Company’s activities are with customers located within Middle Tennessee. The types of securities in which the Company invests are described in note 3. The types of lending in which the Company engages are described in note 2. The Company does not have any significant concentrations to any one industry or customer other than as disclosed in note 2.
Loans	Loans The Company grants mortgage, commercial and consumer loans to customers. A substantial portion of the loan portfolio is represented by mortgage loans throughout Middle Tennessee. The ability of the Company’s debtors to honor their contracts is dependent upon the real estate and general economic conditions in this area. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off generally are reported at their outstanding unpaid principal balances adjusted for unearned income, the allowance for loan losses, and any unamortized deferred fees or costs on originated loans, and premiums or discounts on purchased loans. Loan origination fees, net of certain direct origination costs, as well as premiums and discounts, are deferred and amortized on a straight line basis over the respective term of the loan. As part of its routine credit monitoring process, the Company performs regular credit reviews of the loan portfolio and loans receive risk ratings by the assigned credit officer, which are subject to validation by our independent loan review department. Risk ratings are categorized as pass, special mention, substandard or doubtful. The Company believes that its categories follow those outlined by Wilson Bank's primary federal regulator. Generally the accrual of interest on mortgage and commercial loans is discontinued at the time the loan is 90 days past due unless the credit is well-secured and in process of collection. Credit card loans and other personal loans are typically charged off no later than when they become 180 days past due. Past due status is based on contractual terms of the loan. In all cases, loans are placed on nonaccrual or charged-off at an earlier date if collection of principal or interest is considered doubtful. All interest accrued but not collected for loans that are placed on nonaccrual or charged off is reversed against interest income. The interest on these loans is accounted for on the cash-basis or cost-recovery method, until qualifying for return to accrual. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured.
Allowance for Loan Losses	Allowance for Loan Losses Management provides for loan losses by establishing an allowance. The allowance for loan losses is established as losses are estimated to have occurred through a provision for loan losses charged to earnings. Loan losses are charged against the allowance when management believes the uncollectibility of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. The allowance for loan losses is evaluated on a quarterly basis by management and is based upon management’s quarterly review of the collectibility of the loans in light of historical experience, the nature and volume of the loan portfolio, adverse situations that may affect the borrower’s ability to repay, estimated value of any underlying collateral and prevailing economic conditions. This evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available. In assessing the adequacy of the allowance, we also consider the results of our ongoing independent loan review process. We undertake this process both to ascertain whether there are loans in the portfolio whose credit quality has weakened over time and to assist in our overall evaluation of the risk characteristics of the entire loan portfolio. Our loan review process includes the judgment of management, independent loan reviewers, and reviews that may have been conducted by third-party reviewers. We incorporate relevant loan review results in the loan impairment determination. In addition, regulatory agencies, as an integral part of their examination process, will periodically review the Company’s allowance for loan losses and may require the Company to record adjustments to the allowance based on their judgment about information available to them at the time of their examinations. In addition to the independent loan review process, the aforementioned risk ratings are subject to continual review by loan officers to determine that the appropriate risk ratings are being utilized in our allowance for loan loss process. Each risk rating is also subject to review by our independent loan review department. Currently, our independent loan review department targets reviews of 100% of existing loan relationships with aggregate debt of $1.0 million and greater and new loans with aggregate debt of $500,000 and greater. In addition, our independent loan review department targets particular portfolio segments, loans assigned to a particular lending officer, and loans with four or more renewals. The allowance consists of allocated and general components. The allocated component relates to loans that are classified as impaired. For those loans that are individually classified as impaired, an allowance is established when the discounted cash flows (or collateral value or observable market price) of the impaired loan is lower than the carrying value of that loan. The general component covers nonclassified loans and is based on historical charge-off experience, historical loan loss factors, loss experience of various loan segments, and other adjustments based on management’s assessment of internal or external influences on credit quality that are not fully reflected in the historical loss or risk rating data. A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered by management in determining impairment include payment status, collateral value, and the probability of collecting scheduled principal and interest payments when due. Loans that experience insignificant payment delays and payment shortfalls generally are not classified as impaired. Management determines the significance of payment delays and payment shortfalls on a case-by-case basis, taking into consideration all of the circumstances surrounding the loan and the borrower, including the length of the delay, the reasons for the delay, the borrower’s prior payment record, and the amount of the shortfall in relation to the principal and interest owed. Impairment is measured on a loan by loan basis for commercial, mortgage and agricultural loans by either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s obtainable market price, or the fair value of the collateral if the loan is collateral dependent. Large groups of smaller balance homogeneous loans are collectively evaluated for impairment. Accordingly, the Company does not separately identify individual consumer loans for impairment disclosures, unless such loans are the subject of a restructuring agreement due to financial difficulties of the borrower.
Debt and Equity Securities	Debt and Equity Securities Certain debt securities that management has the positive intent and ability to hold to maturity are classified as “held to maturity” and recorded at amortized cost. Trading securities are recorded at fair value with changes in fair value included in earnings. Securities not classified as held to maturity or trading, including equity securities with readily determinable fair values, are classified as “available for sale” and recorded at fair value based on available market prices, with unrealized gains and losses excluded from earnings and reported in other comprehensive income on an after-tax basis. Securities classified as “available for sale” are held for indefinite periods of time and may be sold in response to movements in market interest rates, changes in the maturity or mix of Company assets and liabilities or demand for liquidity. Purchase premiums and discounts are recognized in interest income using the interest method over the terms of the securities. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. Other-than-temporary Impairment —Impaired securities are assessed quarterly for the presence of other-than-temporary impairment (“OTTI”). A decline in the fair value of any available-for-sale or held-to-maturity security below cost that is deemed to be other-than-temporary results in a reduction in the carrying amount of the security. To determine whether OTTI has occurred, management considers factors such as (1) length of time and extent that fair value has been less than cost, (2) the financial condition and near term prospectus of the issuer, and (3) Wilson Bank’s ability and intent to hold the security for a period sufficient to allow for any anticipated recovery in fair value. If management deems a security to be OTTI, management reviews the present value of the future cash flows associated with the security. A shortfall of the present value of the cash flows expected to be collected in relation to the amortized cost basis is referred to as a credit loss. If a credit loss is identified, the credit loss is recognized as a charge to earnings and a new cost basis for the security is established. If management concludes that no credit loss exists and it is not “more-likely-than-not” that it will be required to sell the security before the recovery of the security’s cost basis, then the security is not deemed OTTI and the shortfall is recorded as a component of equity. No securities have been classified as trading securities
Federal Home Loan Bank Stock	Federal Home Loan Bank Stock The Company, as a member of the Federal Home Loan Bank (“FHLB”) Cincinnati system, is required to maintain an investment in capital stock of the FHLB. Based on redemption provisions of the FHLB, the stock has no quoted market value and is carried at par value, which approximates its fair value. Management reviews the investment for impairment based on the ultimate recoverability of the cost basis in the FHLB stock. As of December 31, 2018 , this minimum required investment was valued at approximately $2.8 million. Stock redemptions are at the discretion of the FHLB.
Loans Held for Sale	Loans Held for Sale Mortgage loans held for sale are carried at fair value. The fair value of loans held for sale is determined using quoted prices for similar assets, adjusted for specific attributes of that loan.
Premises and Equipment	Premises and Equipment Premises and equipment are stated at cost. Depreciation is computed primarily by the straight-line method over the estimated useful lives of the related assets. Gains or losses realized on items retired and otherwise disposed of are credited or charged to operations and cost and related accumulated depreciation are removed from the asset and accumulated depreciation accounts. Expenditures for major renovations and improvements of premises and equipment are capitalized and those for maintenance and repairs are charged to earnings as incurred.
Other Real Estate	Other Real Estate Assets acquired through, or in lieu of, loan foreclosure are held for sale and are initially recorded at fair value less the estimated cost to sell at the date the Company acquires the property, establishing a new cost basis. Subsequent to their acquisition by the Company, valuations of these assets are periodically performed by management, and the assets are carried at the lower of carrying amount or fair value less cost to sell. Revenue and expenses from operations and changes in the valuation allowance [i.e. any direct write-downs] are included
Intangible Assets	Intangible Assets The Financial Accounting Standards Board “FASB” Accounting Standards Codification “ASC” 350, Goodwill and Other Intangible Assets requires that management determine the allocation of intangible assets into identifiable groups at the date of acquisition and that appropriate amortization periods be established. Under the provisions of FASB ASC 350, goodwill is not to be amortized; rather, it is to be monitored for impairment and written down to the impairment value at the time impairment occurs. The Company has determined that no impairment loss needs to be recognized related to its goodwill.
Cash and Cash Equivalents	Cash and Cash Equivalents For purposes of reporting cash flows, cash and cash equivalents include cash on hand, amounts due from banks and Federal funds sold. Generally, Federal funds sold are purchased and sold for one day periods. Management makes deposits only with financial institutions it considers to be financially sound.
Long-Term Assets	Long-Term Assets Premises and equipment, intangible assets, and other long-term assets are reviewed for impairment when events indicate their carrying amount may not be recoverable from future undiscounted cash flows. If impaired, the assets are recorded at fair value.
Securities Sold Under Agreements to Repurchase	Securities Sold Under Agreements to Repurchase Substantially all repurchase agreement liabilities represent amounts advanced by various customers. Securities are pledged to cover these liabilities, which are not covered by Federal deposit insurance.
Income Taxes	Income Taxes The Company accounts for Income Taxes in accordance with income tax accounting guidance (FASB ASC 740, Income Taxes ). The Company follows accounting guidance related to accounting for uncertainty in income taxes, which sets out a consistent framework to determine the appropriate level of tax reserves to maintain for uncertain tax positions. The income tax accounting guidance results in two components of income tax expense: current and deferred. Current income tax expense reflects taxes to be paid or refunded for the current period by applying the provisions of the enacted tax law to the taxable income. The Company determines deferred income taxes using the liability (or balance sheet) method. Under this method, the net deferred tax asset or liability is based on the tax effects of the differences between the book and tax bases of assets and liabilities, and enacted changes in tax rates and laws are recognized in the period in which they occur. Deferred income tax expense results from changes in deferred tax assets and liabilities between periods. Deferred tax assets are recognized if it is more likely than not, based on the technical merits, that the tax position will be realized or sustained upon examination. The term "more likely than not" means a likelihood of more than 50 percent . The terms "examined" and "upon examination" also include resolution of the related appeals or litigation processes, if any. A tax position that meets the more-likely-than-not recognition threshold is initially and subsequently measured as the largest amount of tax benefit that has a greater than 50 percent likelihood of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The determination of whether or not a tax position has met the more-likely-than-not recognition threshold considers the facts, circumstances, and information available at the reporting date and is subject to management’s judgment. Deferred tax assets are reduced by a valuation allowance if, based on the weight of evidence available, it is more likely than not that some portion or all of a deferred tax asset will not be realized. The Company recognizes interest and penalties on income taxes as a component of income tax expense.
Mortgage Banking Derivatives	Mortgage Banking Derivatives Commitments to fund mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of these mortgage loans are accounted for as free standing derivatives. The fair value of the interest rate lock is recorded at the time the commitment to fund the mortgage loan is executed and is adjusted for the expected exercise of the commitment before the loan is funded. Fair values of these mortgage derivatives are estimated based on changes in mortgage interest rates from the date the interest rate on the loan is locked. The Company enters into forward commitments for the future delivery of mortgage loans when interest rate locks are entered into, in order to hedge the change in interest rates resulting from its commitments to fund the loans. Changes in the fair values of these derivatives are included in net gains on sale of mortgage loans.
Equity-Based Incentives	Equity-Based Incentives Stock compensation accounting guidance (FASB ASC 718, “ Compensation—Stock Compensation” ) requires that the compensation cost relating to share-based payment transactions be recognized in financial statements. That cost will be measured based on the grant date fair value of the equity or liability instruments issued. The stock compensation accounting guidance covers a wide range of share-based compensation arrangements including stock options, restricted share plans, performance-based awards, cash-settled stock appreciation rights (SARs), and employee share purchase plans. Because cash-settled SARs do not give the grantee the choice of receiving stock, all cash-settled SARs are accounted for as liabilities, not equity, as compensation is accrued over the requisite service period. The stock compensation accounting guidance requires that compensation cost for all stock awards be calculated and recognized over the employees’ service period, generally defined as the vesting period. For awards with graded-vesting, compensation cost is recognized on a straight-line basis over the requisite service period for the entire award. The Company uses the Black-Scholes option pricing model to estimate the fair value of stock options and cash-settled SARs.
Advertising Costs	Advertising Costs Advertising costs are expensed as incurred by the Company
Earnings Per Share	Earnings Per Share Basic earnings per share represents income available to common stockholders divided by the weighted-average number of common shares outstanding during the period. Diluted earnings per share reflects additional potential 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. Potential common shares that may be issued by the Company relate solely to outstanding stock options and are determined using the treasury stock method.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair values of financial instruments are estimated using relevant market information and other assumptions, as more fully disclosed in Note 21 - Disclosures About Fair Value of Financial Instruments of the consolidated financial statements. Fair value estimates involve uncertainties and matters of significant judgment. Changes in assumptions or in market conditions could significantly affect the estimates.
Reclassifications	Reclassification Certain reclassifications have been made to the 2017 and 2016 figures to conform to the presentation for 2018 .
Off-Balance-Sheet Financial Instruments	Off-Balance-Sheet Financial Instruments In the ordinary course of business, Wilson Bank has entered into off-balance-sheet financial instruments consisting of commitments to extend credit, commitments under credit card arrangements, commercial letters of credit and standby letters of credit. Such financial instruments are recorded in the financial statements when they are funded or related fees are incurred or received.
Standards Accounting Updates	Accounting Standard Updates Accounting Standards Update (“ASU”) 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 implements a common revenue standard that clarifies the principles for recognizing revenue. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve that core principle, an entity should apply the following steps: (i) identify the contract(s) with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations in the contract and (v) recognize revenue when (or as) the entity satisfies a performance obligation. Our revenue is primarily comprised of net interest income on financial assets and financial liabilities, which is explicitly excluded from the scope of ASU 2014-09. Because of this, our adoption of this Standard in the first quarter of 2018 did not have a significant impact on our financial statements. In February 2016, FASB issued ASU 2016-02, "Leases (Topic 842)." The amendments in this ASU are effective for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. As a result of the amendment, lessees will need to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). The liability will be equal to the present value of lease payments. The asset will be based on the liability, subject to adjustments, such as adjustments for initial direct costs. For income statement purposes, FASB retained a dual model, requiring leases to be classified as either operating or finance. Operating leases will result in straight-line expense (similar to current operating leases) while finance leases will result in a front-loaded expense pattern (similar to current capital leases). Classification will be based on criteria that are largely similar to those applied in current lease accounting, but without explicit bright lines. Based on preliminary estimates made by management, we expect to record a right-of-use asset and offsetting lease liability in the amount of $2.5 million during the first quarter of 2019. In June 2016, FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments." ASU 2016-13 requires 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 and requires enhanced disclosures related to the significant estimates and judgments used in estimating credit losses, as well as the credit quality and underwriting standards of an organization’s portfolio. In addition, ASU 2016-13 amends the accounting for credit losses on held-to-maturity debt securities and purchased financial assets with credit deterioration. ASU 2016-13 will be effective on January 1, 2020. We are currently evaluating the potential impact of ASU 2016-13 on our financial statements. We are also evaluating the sufficiency of current systems and data needed to comply with this ASU. While we are currently unable to reasonably estimate the impact of adopting ASU 2016-13, we expect that the impact of adoption will be significantly influenced by the composition, characteristics and quality of our loan and securities portfolios as well as the prevailing economic conditions and forecasts as of the adoption date. In August 2016, FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” ASU 2016-15 clarifies how certain cash receipts and cash payments are presented and classified in the statement of cash flows under Topic 230. The update addresses eight specific cash flow issues including, but not limited to, proceeds from the settlement of bank-owned life insurance policies, with the objective of reducing the existing diversity in practice. ASU 2016-15 was effective on January 1, 2018 and did not have a significant impact on our financial statements. In January 2017, FASB issued ASU 2017-04, “Intangibles - Goodwill and Other (Topic 350) - Simplifying the Test for Goodwill Impairment.” ASU 2017-04 eliminates Step 2 from the goodwill impairment test which required entities to compute the implied fair value of goodwill. Under ASU 2017-04, 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 should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. ASU 2017-04 will be effective for us on January 1, 2020, with early adoption permitted for interim or annual impairment tests beginning in 2017. ASU 2017-04 is not expected to have a significant impact on our financial statements. In March 2017, FASB issued ASU 2017-08, “Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20) - Premium Amortization on Purchased Callable Debt Securities.” ASU 2017-08 provides guidance on the amortization period for certain purchased callable debt securities held at a premium. This update shortens the amortization period for the premium to the earliest call date. Under current generally accepted accounting principles, entities generally amortize the premium as an adjustment of yield over the contractual life of the instrument related to certain cash flow issues. ASU 2017-08 will be effective for us on January 1, 2019. We do not expect this update to have a significant impact on our financial statements. In February 2018, FASB issued ASU 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220) - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income." Under ASU 2018-02, entities may elect to reclassify certain income tax effects related to the change in the U.S. statutory federal income tax rate under the Tax Cuts and Jobs Act, which was enacted on December 22, 2017, from accumulated other comprehensive income to retained earnings. ASU 2018-02 also requires certain accounting policy disclosures. We elected to adopt the provisions of ASU 2018-02 for the year ended December 31, 2018 in advance of the required application date of January 1, 2019. See Note 10 - Income Taxes. In March 2018, FASB issued ASU 2018-05, "Income Taxes (Topic 740) - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin (SAB) No. 118. ASU 2018-05 amends the Accounting Standards Codification to incorporate various SEC paragraphs pursuant to the issuance of SAB 118. SAB 118 addresses the application of generally accepted accounting principles in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Cuts and Jobs Act. See Note 10 - Income Taxes. In August 2018, FASB issued ASU 2018-13, "Fair Value Measurement (Topic 820) - Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement." ASU 2018-13 modifies the disclosure requirements on fair value measurements in Topic 820. The amendments in this update remove disclosures that no longer are considered cost beneficial, modify/clarify the specific requirements of certain disclosures, and add disclosure requirements identified as relevant. ASU 2018-13 will be effective for us on January 1, 2020, with early adoption permitted, and is not expected to have a significant impact on our financial statements. Other than those previously discussed, there were no other recently issued accounting pronouncements that may materially impact the Company.
Fair Value of Financial Instruments	Fair Value of Financial Instruments FASB ASC 820, Fair Value Measurements and Disclosures (“ASC 820”) , which defines fair value, establishes a framework for measuring fair value in U.S. GAAP and expands disclosures about fair value measurements. The definition of fair value focuses on the exit price, i.e., 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, not the entry price, i.e., the price that would be paid to acquire the asset or received to assume the liability at the measurement date. The statement emphasizes that fair value is a market-based measurement; not an entity-specific measurement. Therefore, the fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability.

Loans and Allowance for Loan _2

Loans and Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Schedule of Details on Loans of Company	The classification of loans at December 31, 2018 and 2017 is as follows: In Thousands 2018 2017 Mortgage loans on real estate: Residential 1-4 family $ 460,692 406,667 Multifamily 134,613 91,992 Commercial 701,055 661,223 Construction 518,245 392,039 Farmland 24,071 34,212 Second mortgages 11,197 8,952 Equity lines of credit 62,013 60,650 Total mortgage loans on real estate 1,911,886 1,655,735 Commercial loans 78,245 47,939 Agricultural loans 1,985 1,665 Consumer installment loans: Personal 45,072 40,155 Credit cards 3,687 3,385 Total consumer installment loans 48,759 43,540 Other loans 9,324 9,662 2,050,199 1,758,541 Net deferred loan fees (7,020 ) (7,379 ) Total loans 2,043,179 1,751,162 Less: Allowance for loan losses (27,174 ) (23,909 ) Loans, net $ 2,016,005 1,727,253
Schedule of Loans and Leases Receivable Related Parties	An analysis of the activity with respect to such loans to related parties is as follows: In Thousands December 31, 2018 2017 Balance, January 1 $ 7,759 9,692 New loans and renewals during the year 17,278 15,299 Repayments (including loans paid by renewal) during the year (12,018 ) (17,232 ) Balance, December 31 $ 13,019 7,759
Company's Impaired Loans	The following tables, present the Company’s impaired loans at December 31, 2018 and 2017 : In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2018 With no related allowance recorded: Residential 1-4 family $ 1,196 1,795 — 1,862 42 Multifamily — — — — — Commercial real estate 317 316 — 320 16 Construction 690 686 — 822 42 Farmland — — — 233 — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 2,203 2,797 — 3,237 100 In Thousands Record Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2018 With allowance recorded: Residential 1-4 family $ 1,641 1,635 852 1,782 77 Multifamily — — — — — Commercial real estate 1,515 1,515 312 2,001 17 Construction — — — — — Farmland — — — — — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 3,156 3,150 1,164 3,783 94 In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2018 Total: Residential 1-4 family $ 2,837 3,430 852 3,644 119 Multifamily — — — — — Commercial real estate 1,832 1,831 312 2,321 33 Construction 690 686 — 822 42 Farmland — — — 233 — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 5,359 5,947 1,164 7,020 194 In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2017 With no related allowance recorded: Residential 1-4 family $ 2,314 2,322 — 742 103 Multifamily — — — — — Commercial real estate 893 889 — 902 39 Construction 1,185 1,182 — 1,354 64 Farmland — — — 26 — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 4,392 4,393 — 3,024 206 In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2017 With allowance recorded: Residential 1-4 family $ 409 581 136 461 29 Multifamily — — — — — Commercial real estate 2,157 2,157 291 2,894 17 Construction — — — — — Farmland — — — — — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 2,566 2,738 427 3,355 46 In Thousands Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Interest Income Recognized December 31, 2017 Total: Residential 1-4 family $ 2,723 2,903 136 1,203 132 Multifamily — — — — — Commercial real estate 3,050 3,046 291 3,796 56 Construction 1,185 1,182 — 1,354 64 Farmland — — — 26 — Second mortgages — — — — — Equity lines of credit — — — — — Commercial — — — — — Agricultural, installment and other — — — — — $ 6,958 7,131 427 6,379 252
Loans on Nonaccrual Status	The following tables present the Company’s nonaccrual loans, credit quality indicators and past due loans as of December 31, 2018 and 2017 . Loans on Nonaccrual Status In Thousands 2018 2017 Residential 1-4 family $ 948 — Multifamily — — Commercial real estate 1,102 1,729 Construction — — Farmland — 310 Second mortgages — — Equity lines of credit — — Commercial — — Agricultural, installment and other — 1 Total $ 2,050 2,040
Credit Quality Indicators	The following table presents our loan balances by primary loan classification and the amount classified within each risk rating category. Pass rated loans include all credits other than those included in special mention, substandard and doubtful which are defined as follows: • Special mention loans have potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or in the Company’s credit position at some future date. • Substandard loans are inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Assets so classified must have a well-defined weakness or weaknesses that jeopardize liquidation of the debt. Substandard loans are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. • Doubtful loans have all the characteristics of substandard loans with the added characteristics 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 loans on nonaccrual status. Credit Quality Indicators In Thousands Residential Multifamily Commercial Construction Farmland Second Equity Lines Commercial Agricultural, Total Credit Risk Profile by Internally Assigned Grade December 31, 2018 Pass $ 452,411 134,613 698,083 518,123 23,895 10,979 61,927 78,206 59,923 2,038,160 Special mention 3,949 — 1,690 64 112 179 — 39 78 6,111 Substandard 4,332 — 1,282 58 64 39 86 — 67 5,928 Doubtful — — — — — — — — — — Total $ 460,692 134,613 701,055 518,245 24,071 11,197 62,013 78,245 60,068 2,050,199 December 31, 2017 Pass $ 395,664 91,992 657,456 391,778 33,500 8,765 60,553 47,937 54,697 1,742,342 Special mention 5,677 — 646 84 125 43 41 2 77 6,695 Substandard 5,326 — 3,121 177 587 144 56 — 93 9,504 Doubtful — — — — — — — — — — Total $ 406,667 91,992 661,223 392,039 34,212 8,952 60,650 47,939 54,867 1,758,541
Age Analysis of Past Due Loans	Age Analysis of Past Due Loans In Thousands 30-59 60-89 Nonaccrual Total Current Total Loans Recorded December 31, 2018 Residential 1-4 family $ 3,258 1,092 1,868 6,218 454,474 460,692 920 Multifamily — — — — 134,613 134,613 — Commercial real estate 312 109 1,174 1,595 699,460 701,055 72 Construction 1,567 26 32 1,625 516,620 518,245 32 Farmland 43 9 21 73 23,998 24,071 21 Second mortgages 333 — — 333 10,864 11,197 — Equity lines of credit 297 — 45 342 61,671 62,013 45 Commercial 93 — 24 117 78,128 78,245 24 Agricultural, installment and other 407 85 95 587 59,481 60,068 95 Total $ 6,310 1,321 3,259 10,890 2,039,309 2,050,199 1,209 December 31, 2017 Residential 1-4 family $ 3,631 524 673 4,828 401,839 406,667 673 Multifamily — — — — 91,992 91,992 — Commercial real estate — 83 1,729 1,812 659,411 661,223 — Construction 433 — 113 546 391,493 392,039 113 Farmland 112 — 310 422 33,790 34,212 — Second mortgages — — 2 2 8,950 8,952 2 Equity lines of credit — — 41 41 60,609 60,650 41 Commercial 2 137 — 139 47,800 47,939 — Agricultural, installment and other 432 57 149 638 54,229 54,867 148 Total $ 4,610 801 3,017 8,428 1,750,113 1,758,541 977
Transactions in Allowance for Loan Losses	Transactions in the allowance for loan losses for the years ended December 31, 2018 and 2017 are summarized as follows: In Thousands Residential Multifamily Commercial Construction Farmland Second Equity Lines Commercial Agricultural, Total December 31, 2018 Allowance for loan losses: Beginning balance $ 5,156 1,011 9,267 6,094 487 94 723 401 676 23,909 Provision 1,568 470 436 921 (266 ) 24 7 218 920 4,298 Charge-offs (492 ) — — (19 ) — — — — (1,152 ) (1,663 ) Recoveries 65 — 50 88 — — 1 3 423 630 Ending balance $ 6,297 1,481 9,753 7,084 221 118 731 622 867 27,174 Ending balance individually evaluated for impairment $ 852 — 312 — — — — — — 1,164 Ending balance collectively evaluated for impairment $ 5,445 1,481 9,441 7,084 221 118 731 622 867 26,010 Loans: Ending balance $ 460,692 134,613 701,055 518,245 24,071 11,197 62,013 78,245 60,068 2,050,199 Ending balance individually evaluated for impairment $ 2,829 — 1,831 686 — — — — — 5,346 Ending balance collectively evaluated for impairment $ 457,863 134,613 699,224 517,559 24,071 11,197 62,013 78,245 60,068 2,044,853 In thousands Residential Multifamily Commercial Construction Farmland Second Equity Lines Commercial Agricultural, Total December 31, 2017 Allowance for loan losses: Beginning balance $ 4,571 839 9,541 5,387 658 112 675 386 562 22,731 Provision 675 172 (414 ) 586 (168 ) (10 ) 45 9 786 1,681 Charge-offs (118 ) — — — (3 ) (11 ) — — (1,090 ) (1,222 ) Recoveries 28 — 140 121 — 3 3 6 418 719 Ending balance $ 5,156 1,011 9,267 6,094 487 94 723 401 676 23,909 Ending balance individually evaluated for impairment $ 136 — 291 — — — — — — 427 Ending balance collectively evaluated for impairment $ 5,020 1,011 8,976 6,094 487 94 723 401 676 23,482 Loans: Ending balance $ 406,667 91,992 661,223 392,039 34,212 8,952 60,650 47,939 54,867 1,758,541 Ending balance individually evaluated for impairment $ 2,678 — 3,046 1,182 — — — — — 6,906 Ending balance collectively evaluated for impairment $ 403,989 91,992 658,177 390,857 34,212 8,952 60,650 47,939 54,867 1,751,635
Summary of Carrying Balances of TDRs	The following table summarizes the carrying balances of TDRs at December 31, 2018 and December 31, 2017 (dollars in thousands): 2018 2017 Performing TDRs $ 1,676 2,250 Nonperforming TDRs 816 1,834 Total TDRs $ 2,492 4,084
Troubled Debt Restructuring Categorized by Loan	The following table outlines the amount of each TDR categorized by loan classification for the years ended December 31, 2018 and 2017 (dollars in thousands): December 31, 2018 December 31, 2017 Number Pre Post Number of Pre Post Residential 1-4 family 4 $ 448 $ 448 6 $ 610 $ 535 Multifamily — — — — — — Commercial real estate — — — — — — Construction — — — — — — Farmland — — — 1 86 86 Second mortgages — — — — — — Equity lines of credit — — — — — — Commercial — — — — — — Agricultural, installment and other 2 5 5 1 3 3 Total 6 $ 453 $ 453 8 $ 699 $ 624

Debt and Equity Securities (Tab

Debt and Equity Securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of Debt and Equity Securities	The Company’s classification of securities at December 31, 2017 was as follows: Securities Held-To-Maturity In Thousands Amortized Gross Gross Estimated Mortgage-backed securities $ 9,886 31 156 9,761 Obligations of states and political subdivisions 22,594 66 310 22,350 $ 32,480 97 466 32,111 Securities Available-For-Sale In Thousands Amortized Gross Gross Estimated Government-sponsored enterprises (GSEs) $ 74,690 4 1,714 72,980 Mortgage-backed securities 200,175 302 2,551 197,926 Asset-backed securities 26,387 — 789 25,598 Obligations of states and political subdivisions 37,197 7 992 36,212 $ 338,449 313 6,046 332,716 Debt and equity securities have been classified in the consolidated balance sheet according to management’s intent. Debt and equity securities at December 31, 2018 consist of the following: Securities Available-For-Sale In Thousands Amortized Gross Gross Estimated Government-sponsored enterprises (GSEs) $ 71,446 — 2,979 68,467 Mortgage-backed securities 152,375 9 4,874 147,510 Asset-backed securities 22,534 10 844 21,700 Obligations of states and political subdivisions 49,328 22 1,775 47,575 $ 295,683 41 10,472 285,252
Maturity of Amortized Cost and Estimated Market Value of Debt Securities	Included in mortgage-backed securities are collateralized mortgage obligations totaling $11,564,000 (fair value of $11,295,000 ) and $17,361,000 (fair value of $17,133,000 ) at December 31, 2018 and 2017 , respectively. The amortized cost and estimated market value of debt securities at December 31, 2018 , by contractual maturity, are shown below. Expected maturities will differ from contractual maturities of mortgage and asset-backed securities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. In Thousands Securities Available-For-Sale Amortized Cost Estimated Market Value Due in one year or less $ 2,230 2,234 Due after one year through five years 22,971 22,409 Due after five years through ten years 76,604 73,184 Due after ten years 18,969 18,215 120,774 116,042 Mortgage and asset-backed securities 174,909 169,210 $ 295,683 285,252
Sales of Debt and Equity Securities	Results from sales of debt and equity securities are as follows: In Thousands 2018 2017 2016 Gross proceeds $ 39,857 35,555 90,007 Gross realized gains $ 102 76 716 Gross realized losses (752 ) (251 ) (256 ) Net realized gains (losses) $ (650 ) (175 ) 460
Gross Unrealized Losses and Fair Value of Company's Investments	Available-for-sale and held-to-maturity securities that have been in a continuous unrealized loss position at December 31, 2018 and 2017 are as follows: In Thousands, Except Number of Securities Less than 12 Months 12 Months or More Total 2018 Fair Value Unrealized Number Fair Value Unrealized Number Fair Value Unrealized Available-for-Sale Securities: Debt securities: GSEs $ — $ — — $ 68,467 $ 2,979 28 $ 68,467 $ 2,979 Mortgage-backed securities 8,651 64 10 137,457 4,810 94 146,108 4,874 Asset-backed securities — — — 20,597 844 14 20,597 844 Obligations of states and political subdivisions 4,064 26 6 39,841 1,749 94 43,905 1,775 $ 12,715 $ 90 16 $ 266,362 $ 10,382 230 $ 279,077 $ 10,472 In Thousands, Except Number of Securities Less than 12 Months 12 Months or More Total 2017 Fair Value Unrealized Number Fair Value Unrealized Number Fair Value Unrealized Held-to-Maturity Securities: Debt securities: Mortgage-backed securities $ 3,316 $ 21 4 $ 5,206 $ 135 5 $ 8,522 $ 156 Obligations of states and political subdivisions 10,137 46 27 7,278 264 18 17,415 310 $ 13,453 $ 67 31 $ 12,484 $ 399 23 $ 25,937 $ 466 Available-for-Sale Securities: Debt securities: GSEs $ 16,099 $ 190 8 $ 55,726 $ 1,524 21 $ 71,825 $ 1,714 Mortgage-backed securities 92,180 769 43 81,434 1,782 54 173,614 2,551 Asset-backed securities 9,087 181 7 16,510 608 8 25,597 789 Obligations of states and political subdivisions 12,128 113 22 21,762 879 56 33,890 992 $ 129,494 $ 1,253 80 $ 175,432 $ 4,793 139 $ 304,926 $ 6,046

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Detail of Premises and Equipment	The detail of premises and equipment at December 31, 2018 and 2017 is as follows: In Thousands 2018 2017 Land $ 17,022 17,022 Buildings 44,921 31,686 Leasehold improvements 492 425 Furniture and equipment 12,600 12,521 Automobiles 343 353 Construction-in-progress 100 10,895 75,478 72,902 Less accumulated depreciation (17,115 ) (18,687 ) $ 58,363 54,215

Acquired Intangible Assets an_2

Acquired Intangible Assets and Goodwill (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	The Company's intangible assets result from the excess of purchase price over the applicable book value of the net assets acquired related to outside ownership of two previously 50% owned subsidiaries that the Company acquired 100% of in 2005. In Thousands 2018 2017 Goodwill: Balance at January 1, $ 4,805 4,805 Goodwill acquired during year — — Impairment loss — — Balance at December 31, $ 4,805 4,805

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Deposits	Deposits at December 31, 2018 and 2017 are summarized as follows: In Thousands 2018 2017 Demand deposits $ 254,157 239,559 Savings accounts 136,645 136,549 Negotiable order of withdrawal accounts 503,435 495,930 Money market demand accounts 727,654 648,606 Certificates of deposit $250,000 or greater 134,506 67,614 Other certificates of deposit 402,690 370,608 Individual retirement accounts $250,000 or greater 8,525 6,954 Other individual retirement accounts 68,043 71,925 $ 2,235,655 2,037,745
Principal Maturities of Certificate of Deposit and Individual Retirement Accounts	Principal maturities of certificates of deposit and individual retirement accounts at December 31, 2018 are as follows: (In Thousands) Maturity Total 2019 $ 290,385 2020 155,006 2021 89,620 2022 21,662 2023 50,328 Thereafter 6,763 $ 613,764

Non-Interest Income and Non-I_2

Non-Interest Income and Non-Interest Expense (Tables)	12 Months Ended
	Dec. 31, 2018
Other Income and Expenses [Abstract]
Components of Non-Interest Income and Non-Interest Expense	The significant components of non-interest income and non-interest expense for the years ended December 31, 2018 , 2017 and 2016 are presented below: In Thousands 2018 2017 2016 Non-interest income: Service charges on deposits $ 6,799 $ 6,124 $ 5,769 Other fees and commissions 13,704 $ 11,752 $ 10,260 BOLI and annuity earnings 841 $ 871 $ 832 Security gains (losses), net (650 ) $ (175 ) $ 460 Fees and gains on sales of mortgage loans 4,639 $ 4,258 $ 4,355 Gain (loss) on sale of other real estate, net (80 ) $ 6 $ 52 Loss on sale of fixed assets, net (2 ) $ — $ (73 ) Loss on sale of other assets, net (3 ) $ (15 ) $ (1 ) $ 25,248 22,821 21,654 In Thousands 2018 2017 2016 Non-interest expense: Employee salaries and benefits $ 39,590 35,830 34,106 Equity-based compensation 1,237 692 104 Occupancy expenses 4,403 3,718 3,638 Furniture and equipment expenses 2,767 2,085 2,019 Data processing expenses 2,900 2,834 2,576 Advertising expenses 2,552 2,326 2,310 ATM & interchange fees 3,091 2,569 2,475 FDIC insurance 843 683 968 Directors’ fees 543 677 691 Other operating expenses 11,154 8,977 8,376 69,080 60,391 57,263

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Components of the Net Deferred Tax Asset	The components of the net deferred tax asset are as follows: In Thousands 2018 2017 Deferred tax asset: Federal $ 9,046 7,222 State 2,739 2,068 11,785 9,290 Deferred tax liability: Federal (2,167 ) (1,402 ) State (717 ) (464 ) (2,884 ) (1,866 ) Net deferred tax asset $ 8,901 7,424
Deferred Tax Assets (Liabilities) in Which Tax Effects of Significant Item that Gave Rise	The tax effects of each type of significant item that gave rise to deferred tax assets (liabilities) are: In Thousands 2018 2017 Financial statement allowance for loan losses in excess of tax allowance $ 6,846 5,925 Excess of depreciation deducted for tax purposes over the amounts deducted in the financial statements (2,557 ) (1,539 ) Financial statement deduction for deferred compensation in excess of deduction for tax purposes 1,128 1,075 Writedown of other real estate not deductible for income tax purposes until sold 176 161 Financial statement income on FHLB stock dividends not recognized for tax purposes (327 ) (327 ) Unrealized loss on securities available-for-sale 2,726 1,498 Equity based compensation 469 178 Other items, net 440 453 Net deferred tax asset $ 8,901 7,424
Summary of Components of Income Tax Expense (Benefit)	The components of income tax expense (benefit) are summarized as follows: In Thousands Federal State Total 2018 Current $ 8,310 721 9,031 Deferred (136 ) (112 ) (248 ) Total $ 8,174 609 8,783 2017 Current $ 14,004 2,354 16,358 Deferred 3,205 (209 ) 2,996 Total $ 17,209 2,145 19,354 2016 Current $ 12,910 2,095 15,005 Deferred (136 ) (28 ) (164 ) Total $ 12,774 2,067 14,841
Reconciliation of Actual Income Tax Expense to the Expected Tax Expense	A reconciliation of actual income tax expense of $8,783,000 , $19,354,000 and $14,841,000 for the years ended December 31, 2018 , 2017 and 2016 , respectively, to the “expected” tax expense (computed by applying the statutory rate of 21% for 2018 and 34% for 2017 and 2016 to earnings before income taxes) is as follows: In Thousands 2018 2017 2016 Computed “expected” tax expense $ 8,689 14,579 13,761 State income taxes, net of Federal income tax benefit 432 1,346 1,364 Tax exempt interest, net of interest expense exclusion (226 ) (415 ) (401 ) Federal income tax rate in excess of statutory rate related to taxable income over $10 million — 399 370 Earnings on cash surrender value of life insurance (177 ) (292 ) (283 ) Expenses not deductible for tax purposes 16 43 40 Equity based compensation expense (39 ) 16 35 Revaluation of federal deferred tax assets due to change in tax rates — 3,603 — Other 88 75 (45 ) $ 8,783 19,354 14,841

Commitments and Contingent Li_2

Commitments and Contingent Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Rental Payments Under Operating Leases	Wilson Bank leases three branch facilities and land for certain branch facilities and automatic teller machine locations. Future minimum rental payments required under the terms of the noncancellable leases are as follows: Years Ending December 31, In Thousands 2019 $ 401 2020 399 2021 349 2022 180 2023 85 Thereafter 13

Financial Instruments with Of_2

Financial Instruments with Off-Balance-Sheet Risk (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, All Other Investments [Abstract]
Financial Instruments Whose Contract Amounts Represent Credit Risk	In Thousands Contract or 2018 2017 Financial instruments whose contract amounts represent credit risk: Unused commitments to extend credit $ 582,897 605,114 Standby letters of credit 80,165 69,156 Total $ 663,062 674,270

Regulatory Matters and Restri_2

Regulatory Matters and Restrictions on Dividends (Tables)	12 Months Ended
	Dec. 31, 2018
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Summary of Actual Capital Amounts and Ratios, Regulatory Capital Ratios and Basel III Minimum Requirements	The Company’s and Wilson Bank’s actual capital amounts and ratios as of December 31, 2018 and 2017 , are presented in the following tables: Actual Regulatory Minimum Capital Requirement with Basel III Capital Conservation Buffer Regulatory Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) December 31, 2018 Total capital to risk weighted assets: Consolidated $ 326,099 14.1 % $ 227,974 9.875 % $ 230,860 10.0 % Wilson Bank 323,852 14.0 227,915 9.875 230,800 10.0 Tier 1 capital to risk weighted assets: Consolidated 298,566 12.9 181,802 7.875 138,516 6.0 Wilson Bank 296,319 12.8 181,756 7.875 184,641 8.0 Common equity Tier 1 capital to risk weighted assets: Consolidated 298,566 12.9 147,173 6.375 N/A N/A Wilson Bank 296,319 12.8 147,136 6.375 150,021 6.5 Tier 1 capital to average assets: Consolidated 298,566 12.3 97,022 4.0 N/A N/A Wilson Bank 296,319 11.9 99,373 4.0 124,217 5.0 Actual Regulatory Minimum Capital Requirement with Basel III Capital Conservation Buffer Regulatory Minimum To Be Well Capitalized Amount Ratio Amount Ratio Amount Ratio (dollars in thousands) December 31, 2017 Total capital to risk weighted assets: Consolidated $ 291,395 14.2 % $ 189,658 9.25 % $ 205,036 10.0 % Wilson Bank 289,824 14.1 189,618 9.25 204,992 10.0 Tier 1 capital to risk weighted assets: Consolidated 267,159 13.0 148,651 7.25 123,021 6.0 Wilson Bank 265,588 13.0 148,619 7.25 163,994 8.0 Common Equity Tier 1 capital to risk weighted assets: Consolidated 267,159 13.0 117,895 5.75 N/A N/A Wilson Bank 265,588 13.0 117,871 5.75 133,245 6.5 Tier 1 capital to average assets: Consolidated 267,159 11.9 90,110 4.0 N/A N/A Wilson Bank 265,588 11.5 92,062 4.0 115,078 5.0
Basel III Requirements
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Summary of Actual Capital Amounts and Ratios, Regulatory Capital Ratios and Basel III Minimum Requirements	The Basel III minimum requirements after giving effect to the buffer as of January 1, of each year presented are as follows: 2016 2017 2018 2019 Common Equity Tier I Ratio 5.125 % 5.75 % 6.375 % 7.0 % Tier I Capital to Risk Weighted Assets Ratio 6.625 % 7.25 % 7.875 % 8.5 % Total Capital to Risk Weighted Assets Ratio 8.625 % 9.25 % 9.875 % 10.5 %

Equity Incentive Plan (Tables)

Equity Incentive Plan (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Weighted-Average Black-Scholes Fair Value Assumptions	The fair value of each stock option and cash-settled SAR grant is estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions used for grants in 2018 , 2017 and 2016 : 2018 2017 2016 Expected dividends 1.22 % 1.27 % 1.21 % Expected term (in years) 9.35 7.79 8.71 Expected stock price volatility 24 % 26 % 26 % Risk-free rate 2.83 % 2.23 % 2.02 %
Summary of Stock Option Activity	A summary of the stock option and cash-settled SAR activity for 2018 , 2017 and 2016 is as follows: 2018 2017 2016 Shares Weighted Shares Weighted Shares Weighted Outstanding at beginning of year 285,780 $ 39.31 183,747 $ 38.09 49,895 $ 30.19 Granted 21,666 46.59 112,333 40.87 140,997 40.36 Exercised (22,460 ) 37.07 (5,078 ) 29.65 (5,545 ) 27.38 Forfeited or expired (7,166 ) 37.53 (5,222 ) 39.22 (1,600 ) 28.44 Outstanding at end of year 277,820 $ 40.11 285,780 $ 39.31 183,747 $ 38.09 Options and cash-settled SARs exercisable at year end 94,951 $ 39.14 42,256 $ 36.66 13,553 $ 29.29
Summary of Information about Stock Options	The following table summarizes information about stock options and cash-settled SARs for the year ended December 31, 2018 : Options and Cash-Settled SARs Outstanding Options and Cash-Settled SARs Exercisable Range of Exercise Prices Number Weighted Weighted Number Weighted Weighted $22.00 - $32.00 16,388 $ 29.02 1.50 years 9,022 $ 28.74 1.32 years $32.01 - $47.75 261,432 $ 40.81 7.38 years 85,929 $ 40.23 6.12 years 277,820 94,951 Aggregate intrinsic value (in thousands) $ 2,679 $ 1,008

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Summary of Components Comprising Basic and Diluted Earnings Per Share	The following is a summary of the components comprising basic and diluted earnings per share (“EPS”): In Thousands (except share data) 2018 2017 2016 Basic EPS Computation: Numerator - Earnings available to common stockholders $ 32,594 23,526 25,633 Denominator - Weighted average number of common shares outstanding 10,564,172 10,407,211 10,279,332 Basic earnings per common share $ 3.09 2.26 2.49 Diluted EPS Computation: Numerator - Earnings available to common stockholders $ 32,594 23,526 25,633 Denominator - Weighted average number of common shares outstanding 10,564,172 10,407,211 10,279,332 Dilutive effect of stock options 8,049 5,325 4,996 10,572,221 10,412,536 10,284,328 Diluted earnings per common share $ 3.08 2.26 2.49

Mortgage Banking Derivatives (T

Mortgage Banking Derivatives (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments, Gain (Loss)	The net gains (losses) relating to free-standing derivative instruments used for risk management is summarized below (in thousands): In Thousands 2018 Forward contracts related to mortgage loans held for sale and interest rate contracts $ (88 ) Interest rate contracts for customers 335
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table reflects the amount and fair value of mortgage banking derivatives included in the consolidated balance sheet as of December 31, 2018 (in thousands): In Thousands 2018 Notional Amount Fair Value Included in other assets (liabilities): Interest rate contracts for customers $ 9,655 335 Forward contracts related to mortgage loans held-for-sale 11,750 (88 )

Disclosures About Fair Value _2

Disclosures About Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present the financial instruments carried at fair value as of December 31, 2018 and December 31, 2017 , by caption on the consolidated balance sheet and by FASB ASC 820 valuation hierarchy (as described above) (in thousands): Measured on a Recurring Basis Total Carrying Quoted Market Models with Models with December 31, 2018 Investment securities available-for-sale: U.S. Government sponsored enterprises $ 68,467 — 68,467 — Mortgage-backed securities 147,510 — 147,510 — Asset-backed securities 21,700 — 21,700 — State and municipal securities 47,575 — 47,575 — Total investment securities available-for-sale 285,252 — 285,252 — Mortgage loans held for sale 7,484 — 7,484 — Mortgage banking derivatives 335 — 335 — Bank owned life insurance 30,952 — — 30,952 Total assets $ 324,023 — 293,071 30,952 Mortgage banking derivatives $ 88 — 88 — Total liabilities $ 88 — 88 — Measured on a Recurring Basis Total Carrying Quoted Market Models with Models with December 31, 2017 Investment securities available-for-sale: U.S. Government sponsored enterprises $ 72,980 — 72,980 — Mortgage-backed securities 197,926 — 197,926 — Asset-backed securities 25,598 — 25,598 — State and municipal securities 36,212 — 36,212 — Total investment securities available-for-sale 332,716 — 332,716 — Mortgage loans held for sale 5,106 — 5,106 — Bank owned life insurance 29,475 — — 29,475 Total $ 367,297 — 337,822 29,475
Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis	Measured on a Non-Recurring Basis Total Carrying Quoted Market Models with Models with December 31, 2018 Other real estate owned $ 1,357 — — 1,357 Impaired loans, net (¹) 4,195 — — 4,195 Total $ 5,552 — — 5,552 December 31, 2017 Other real estate owned $ 1,635 — — 1,635 Impaired loans, net (¹) 6,531 — — 6,531 Total $ 8,166 — — 8,166 (¹) Amount is net of a valuation allowance of $1,164,000 at December 31, 2018 and $427,000 at December 31, 2017 as required by ASC 310, “Receivables.”
Fair Value Inputs, Assets, Quantitative Information	The following table presents additional quantitative information about assets measured at fair value on a nonrecurring basis and for which we have utilized Level 3 inputs to determine fair value at December 31, 2018 and 2017 : Valuation Techniques ( 2 ) Significant Unobservable Inputs Range (Weighted Average) Impaired loans Appraisal Estimated costs to sell 10% Other real estate owned Appraisal Estimated costs to sell 10% ( 2 ) The fair value is generally determined through independent appraisals of the underlying collateral, which may include Level 3 inputs that are not identifiable, or by using the discounted cash flow method if the loan is not collateral dependent.
Changes in Fair Value Due to Observable Factors	The table below includes a rollforward of the balance sheet amounts for the year ended December 31, 2018 and 2017 (including the change in fair value) for financial instruments classified by the Company within Level 3 of the valuation hierarchy for assets and liabilities measured at fair value on a recurring basis. When a determination is made to classify a financial instrument within Level 3 of the valuation hierarchy, the determination is based upon the significance of the unobservable factors to the overall fair value measurement. However, since Level 3 financial instruments typically include, in addition to the unobservable or Level 3 components, observable components (that is, components that are actively quoted and can be validated to external sources), the gains and losses in the table below include changes in fair value due in part to observable factors that are part of the valuation methodology (in thousands): For the Year Ended December 31, 2018 2017 Other Other Other Other Fair value, January 1 $ 29,475 — $ 28,616 — Total realized gains included in income 841 — 859 — Change in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at December 31 — — — — Purchases, issuances and settlements, net 636 — — — Transfers out of Level 3 — — — — Fair value, December 31 $ 30,952 — $ 29,475 — Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at December 31 $ 841 — $ 859 —
Carrying Value and Estimated Fair Value of Financial Instruments	The following table presents the carrying amounts, estimated fair value and placement in the fair value hierarchy of the Company’s financial instruments at December 31, 2018 and December 31, 2017 . This table excludes financial instruments for which the carrying amount approximates fair value. For short-term financial assets such as cash and cash equivalents, 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. (in Thousands) Carrying/ Estimated Quoted Market Models with Models with December 31, 2018 Financial assets: Cash and cash equivalents $ 99,191 99,191 99,191 — — Loans, net 2,016,005 2,017,272 — — 2,017,272 Restricted equity securities 3,012 NA NA NA NA Accrued interest receivable 6,724 6,724 3 1,362 5,359 Financial liabilities: Deposits 2,235,655 1,974,554 — — 1,974,554 Accrued interest payable 3,132 3,132 — — 3,132 December 31, 2017 Financial assets: Cash and cash equivalents $ 95,518 95,518 95,518 — — Securities held-to-maturity 32,480 32,111 — 32,111 — Loans, net 1,727,253 1,724,937 — — 1,724,937 Restricted equity securities 3,012 NA NA NA NA Accrued interest receivable 6,266 6,266 5 1,562 4,699 Financial liabilities: Deposits and securities sold under agreements to repurchase 2,038,609 1,812,011 — — 1,812,011 Accrued interest payable 1,679 1,679 — — 1,679 (¹) Estimated fair values are consistent with an exit-price concept. The assumptions used to estimate the fair values are intended to approximate those that a market-participant would realize in a hypothetical orderly transaction.

Wilson Bank Holding Company -_2

Wilson Bank Holding Company - Parent Company Financial Information (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Balance Sheets - Parent Company Only	Balance Sheets December 31, 2018 and 2017 Dollars In Thousands 2018 2017 ASSETS Cash $ 2,759 * 1,589 * Investment in wholly-owned commercial bank subsidiary 293,420 266,159 Deferred income taxes 469 178 Refundable income taxes 177 181 Total assets $ 296,825 268,107 LIABILITIES AND STOCKHOLDERS’ EQUITY Stock appreciation rights payable $ 1,158 377 Total liabilities 1,158 377 Stockholders’ equity: Common stock, par value $2.00 per share, authorized 50,000,000 shares, 10,623,810 and 10,450,711 shares issued and outstanding, respectively 21,248 20,901 Additional paid-in capital 73,960 66,047 Retained earnings 208,164 185,017 Net unrealized losses on available-for-sale securities, net of income taxes of $2,726 and $1,498, respectively (7,705 ) (4,235 ) Total stockholders’ equity 295,667 267,730 Total liabilities and stockholders’ equity $ 296,825 268,107 * Eliminated in consolidation.
Statements of Earnings and Comprehensive Earnings - Parent Company Only	Statements of Earnings Three Years Ended December 31, 2018 Dollars In Thousands 2018 2017 2016 Income: Dividends from commercial bank subsidiary $ 3,000 1,500 1,500 Expenses: Directors’ fees 254 334 327 Other 1,351 805 194 1,605 1,139 521 Income before Federal income tax benefits and equity in undistributed earnings of commercial bank subsidiary 1,395 361 979 Federal income tax benefits 468 359 169 1,863 720 1,148 Equity in undistributed earnings of commercial bank subsidiary 30,731 * 22,806 * 24,485 * Net earnings $ 32,594 23,526 25,633 * Eliminated in consolidation
Statements of Cash Flows - Parent Company Only	Statements of Cash Flows Three Years Ended December 31, 2018 Increase (Decrease) in Cash and Cash Equivalents Dollars In Thousands 2018 2017 2016 Cash flows from operating activities: Cash paid to suppliers and other $ (367 ) (447 ) (417 ) Tax benefits received 181 169 198 Net cash used in operating activities (186 ) (278 ) (219 ) Cash flows from investing activities: Dividends received from commercial bank subsidiary 3,000 1,500 1,500 Net cash provided by investing activities 3,000 1,500 1,500 Cash flows from financing activities: Payments made to stock appreciation rights holders (61 ) — — Dividends paid (9,447 ) (6,729 ) (5,756 ) Proceeds from sale of stock pursuant to dividend reinvestment plan 7,470 5,266 4,316 Proceeds from exercise of stock options 394 152 152 Net cash used in financing activities (1,644 ) (1,311 ) (1,288 ) Net increase (decrease) in cash and cash equivalents 1,170 (89 ) (7 ) Cash and cash equivalents at beginning of year 1,589 1,678 1,685 Cash and cash equivalents at end of year $ 2,759 1,589 1,678 WILSON BANK HOLDING COMPANY (Parent Company Only) Statements of Cash Flows, Continued Three Years Ended December 31, 2018 Increase (Decrease) in Cash and Cash Equivalents Dollars in Thousands 2018 2017 2016 Reconciliation of net earnings to net cash used in operating activities: Net earnings $ 32,594 23,526 25,633 Adjustments to reconcile net earnings to net cash used in operating activities: Equity in earnings of commercial bank subsidiary (33,731 ) (24,306 ) (25,985 ) Decrease (increase) in refundable income taxes 5 (12 ) 29 Increase in deferred taxes (291 ) (178 ) — Share based compensation expense 1,237 692 104 Total adjustments (32,780 ) (23,804 ) (25,852 ) Net cash used in operating activities $ (186 ) (278 ) (219 )

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations for the Four Quarters	Selected quarterly results of operations for the four quarters ended December 31 are as follows: (In Thousands, except per share data) 2018 2017 2016 Fourth Quarter Third Quarter Second Quarter First Quarter Fourth Quarter Third Quarter Second Quarter First Quarter Fourth Quarter Third Quarter Second Quarter First Quarter Interest income $ 27,585 26,298 25,548 24,094 $ 23,487 22,904 22,871 21,758 $ 22,078 21,454 20,877 20,337 Interest expense 4,606 3,656 3,097 2,659 2,439 2,332 2,094 2,024 1,990 2,077 2,106 2,111 Net interest income 22,979 22,642 22,451 21,435 21,048 20,572 20,777 19,734 20,088 19,377 18,771 18,226 Provision for loan losses 1,097 1,088 1,090 1,023 436 436 420 389 89 141 82 67 Earnings before income taxes 10,708 10,718 9,798 10,153 10,694 10,438 11,386 10,362 10,120 11,095 10,162 9,097 Net earnings 9,833 7,972 7,309 7,480 3,574 6,469 6,988 6,495 6,802 6,918 6,270 5,643 Basic earnings per common share 0.93 0.75 0.69 0.71 0.34 0.62 0.67 0.63 0.66 0.67 0.61 0.55 Diluted earnings per common share 0.92 0.75 0.69 0.71 0.34 0.62 0.67 0.63 0.66 0.67 0.61 0.55

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Detail)	Mar. 30, 2016	Dec. 31, 2018USD ($)securityBranchloanComponent	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Mar. 31, 2019USD ($)
Significant Accounting Policies [Line Items]
Number of full service branches | Branch		28
Loan review target (as a percent)		100.00%
Existing loan review, Aggregate		$ 1,000,000
New loan review, Aggregate		$ 500,000
Number of loans renewed | loan		4
Securities classified as trading securities | security		0
Federal Home Loan Bank Stock minimum required investment		$ 2,800,000
Impairment loss recognized related to Goodwill		$ 0	$ 0
Federal fund maturity period		1 day
Number of components of income tax expense | Component		2
Deferred income tax benefit realizable (as a percent)		50.00%
Tax benefit (as a percent)		50.00%
Advertising costs Incurred		$ 2,552,000	$ 2,326,000	$ 2,310,000
Stock split, conversion ratio	1.3333			1.3333
Commercial
Significant Accounting Policies [Line Items]
Accruing loans past due period		90 days
Credit Card Loans and Other Personal Loans
Significant Accounting Policies [Line Items]
Accruing loans past due period		180 days
Real Estate Portfolio Segment | Residential 1-4 family
Significant Accounting Policies [Line Items]
Percentage of investment		22.00%	23.00%
Real Estate Portfolio Segment | Commercial
Significant Accounting Policies [Line Items]
Percentage of investment		34.00%	38.00%
Real Estate Portfolio Segment | Construction
Significant Accounting Policies [Line Items]
Percentage of investment		25.00%	22.00%
Forecast | Accounting Standards Update 2016-02
Significant Accounting Policies [Line Items]
Operating asset					$ 2,500,000
Lease, liability					$ 2,500,000

Loans and Allowance for Loan _3

Loans and Allowance for Loan Losses - Schedule of Details on Loans of Company (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	$ 2,050,199	$ 1,758,541
Net deferred loan fees	(7,020)	(7,379)
Total loans	2,043,179	1,751,162
Less: Allowance for loan losses	(27,174)	(23,909)	$ (22,731)
Loans, net	2,016,005	1,727,253
Real Estate Portfolio Segment
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,911,886	1,655,735
Real Estate Portfolio Segment | Residential 1-4 family
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	460,692	406,667
Less: Allowance for loan losses	(6,297)	(5,156)	(4,571)
Real Estate Portfolio Segment | Multifamily
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	134,613	91,992
Less: Allowance for loan losses	(1,481)	(1,011)	(839)
Real Estate Portfolio Segment | Commercial
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	701,055	661,223
Less: Allowance for loan losses	(9,753)	(9,267)	(9,541)
Real Estate Portfolio Segment | Construction
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	518,245	392,039
Less: Allowance for loan losses	(7,084)	(6,094)	(5,387)
Real Estate Portfolio Segment | Farmland
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	24,071	34,212
Less: Allowance for loan losses	(221)	(487)	(658)
Real Estate Portfolio Segment | Second mortgages
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	11,197	8,952
Less: Allowance for loan losses	(118)	(94)	(112)
Real Estate Portfolio Segment | Equity lines of credit
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	62,013	60,650
Less: Allowance for loan losses	(731)	(723)	$ (675)
Agricultural loans
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	1,985	1,665
Consumer installment loans | Personal
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	45,072	40,155
Consumer installment loans | Credit cards
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	3,687	3,385
Consumer installment loans | Consumer installment loans
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	48,759	43,540
Other loans
Loans and Leases Receivable Disclosure [Line Items]
Total Loans	$ 9,324	$ 9,662

Loans and Allowance for Loan _4

Loans and Allowance for Loan Losses - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)loan	Dec. 31, 2017USD ($)loan	Dec. 31, 2016USD ($)
Financing Receivable, Recorded Investment [Line Items]
Variable rate loans	$ 1,495,918	$ 1,252,794
Fixed rate loans	554,281	505,747
Prevailing interest rate loans	$ 13,019	$ 7,759	$ 9,692
Troubled debt restructuring number of loans | loan	0	1
Troubled debt restructurings subsequently default within twelve months		$ 103
Loans in secondary market	$ 129,060	135,835	161,114
Loans and leases receivable, consumer, mortgage	200	201
Gain on sale of loans in secondary market	4,639	4,258	$ 4,355
Loans sold with recourse	94,801	105,308
Nonperforming [Member]
Financing Receivable, Recorded Investment [Line Items]
Potential problem loans	$ 12,000	$ 16,200
Residential 1-4 family
Financing Receivable, Recorded Investment [Line Items]
Amortization term, lower range	15 years
Amortization term, upper range	30 years
Maturity period, lower range	5 years
Maturity period, upper range	15 years

Loans and Allowance for Loan _5

Loans and Allowance for Loan Losses - Schedule of Loans and Leases Receivable Related Parties (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance, January 1	$ 7,759	$ 9,692
New loans and renewals during the year	17,278	15,299
Repayments (including loans paid by renewal) during the year	(12,018)	(17,232)
Balance, December 31	$ 13,019	$ 7,759

Loans and Allowance for Loan _6

Loans and Allowance for Loan Losses - Company's Impaired Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	$ 3,156	$ 2,566
Unpaid Principal Balance	3,150	2,738
Related Allowance	1,164	427
Average Recorded Investment	3,783	3,355
Interest Income Recognized	94	46
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	2,203	4,392
Unpaid Principal Balance	2,797	4,393
Average Recorded Investment	3,237	3,024
Interest Income Recognized	100	206
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	5,359	6,958
Unpaid Principal Balance	5,947	7,131
Average Recorded Investment	7,020	6,379
Interest Income Recognized	194	252
Real Estate Portfolio Segment | Residential 1-4 family
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	1,641	409
Unpaid Principal Balance	1,635	581
Related Allowance	852	136
Average Recorded Investment	1,782	461
Interest Income Recognized	77	29
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	1,196	2,314
Unpaid Principal Balance	1,795	2,322
Average Recorded Investment	1,862	742
Interest Income Recognized	42	103
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	2,837	2,723
Unpaid Principal Balance	3,430	2,903
Average Recorded Investment	3,644	1,203
Interest Income Recognized	119	132
Real Estate Portfolio Segment | Multifamily
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Real Estate Portfolio Segment | Commercial
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	1,515	2,157
Unpaid Principal Balance	1,515	2,157
Related Allowance	312	291
Average Recorded Investment	2,001	2,894
Interest Income Recognized	17	17
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	317	893
Unpaid Principal Balance	316	889
Average Recorded Investment	320	902
Interest Income Recognized	16	39
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	1,832	3,050
Unpaid Principal Balance	1,831	3,046
Average Recorded Investment	2,321	3,796
Interest Income Recognized	33	56
Real Estate Portfolio Segment | Construction
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	690	1,185
Unpaid Principal Balance	686	1,182
Average Recorded Investment	822	1,354
Interest Income Recognized	42	64
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	690	1,185
Unpaid Principal Balance	686	1,182
Average Recorded Investment	822	1,354
Interest Income Recognized	42	64
Real Estate Portfolio Segment | Farmland
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	233	26
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	233	26
Interest Income Recognized	0	0
Real Estate Portfolio Segment | Second mortgages
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Real Estate Portfolio Segment | Equity lines of credit
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Commercial
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Agricultural, installment and other
Impaired Financing Receivable, Recorded Investment With Allowance [Abstract]
Record Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment Without Allowance [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	0	0
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Average Recorded Investment	0	0
Interest Income Recognized	$ 0	$ 0

Loans and Allowance for Loan _7

Loans and Allowance for Loan Losses - Loans on Nonaccrual Status (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	$ 2,050	$ 2,040
Real Estate Portfolio Segment | Residential 1-4 family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	948	0
Real Estate Portfolio Segment | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	0	0
Real Estate Portfolio Segment | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	1,102	1,729
Real Estate Portfolio Segment | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	0	0
Real Estate Portfolio Segment | Farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	0	310
Real Estate Portfolio Segment | Second mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	0	0
Real Estate Portfolio Segment | Equity lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	0	0
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	0	0
Agricultural, installment and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans on Nonaccrual Status, Total	$ 0	$ 1

Loans and Allowance for Loan _8

Loans and Allowance for Loan Losses - Credit Quality Indicators (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Credit Risk Profile by Internally Assigned Grade
Total Loans	$ 2,050,199	$ 1,758,541
Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	2,038,160	1,742,342
Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	6,111	6,695
Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	5,928	9,504
Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Real Estate Portfolio Segment
Credit Risk Profile by Internally Assigned Grade
Total Loans	1,911,886	1,655,735
Real Estate Portfolio Segment | Residential 1-4 family
Credit Risk Profile by Internally Assigned Grade
Total Loans	460,692	406,667
Real Estate Portfolio Segment | Residential 1-4 family | Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	452,411	395,664
Real Estate Portfolio Segment | Residential 1-4 family | Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	3,949	5,677
Real Estate Portfolio Segment | Residential 1-4 family | Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	4,332	5,326
Real Estate Portfolio Segment | Residential 1-4 family | Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Real Estate Portfolio Segment | Multifamily
Credit Risk Profile by Internally Assigned Grade
Total Loans	134,613	91,992
Real Estate Portfolio Segment | Multifamily | Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	134,613	91,992
Real Estate Portfolio Segment | Multifamily | Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Real Estate Portfolio Segment | Multifamily | Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Real Estate Portfolio Segment | Multifamily | Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Real Estate Portfolio Segment | Commercial
Credit Risk Profile by Internally Assigned Grade
Total Loans	701,055	661,223
Real Estate Portfolio Segment | Commercial | Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	698,083	657,456
Real Estate Portfolio Segment | Commercial | Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	1,690	646
Real Estate Portfolio Segment | Commercial | Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	1,282	3,121
Real Estate Portfolio Segment | Commercial | Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Real Estate Portfolio Segment | Construction
Credit Risk Profile by Internally Assigned Grade
Total Loans	518,245	392,039
Real Estate Portfolio Segment | Construction | Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	518,123	391,778
Real Estate Portfolio Segment | Construction | Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	64	84
Real Estate Portfolio Segment | Construction | Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	58	177
Real Estate Portfolio Segment | Construction | Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Real Estate Portfolio Segment | Farmland
Credit Risk Profile by Internally Assigned Grade
Total Loans	24,071	34,212
Real Estate Portfolio Segment | Farmland | Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	23,895	33,500
Real Estate Portfolio Segment | Farmland | Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	112	125
Real Estate Portfolio Segment | Farmland | Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	64	587
Real Estate Portfolio Segment | Farmland | Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Real Estate Portfolio Segment | Second mortgages
Credit Risk Profile by Internally Assigned Grade
Total Loans	11,197	8,952
Real Estate Portfolio Segment | Second mortgages | Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	10,979	8,765
Real Estate Portfolio Segment | Second mortgages | Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	179	43
Real Estate Portfolio Segment | Second mortgages | Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	39	144
Real Estate Portfolio Segment | Second mortgages | Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Real Estate Portfolio Segment | Equity lines of credit
Credit Risk Profile by Internally Assigned Grade
Total Loans	62,013	60,650
Real Estate Portfolio Segment | Equity lines of credit | Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	61,927	60,553
Real Estate Portfolio Segment | Equity lines of credit | Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	41
Real Estate Portfolio Segment | Equity lines of credit | Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	86	56
Real Estate Portfolio Segment | Equity lines of credit | Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Commercial
Credit Risk Profile by Internally Assigned Grade
Total Loans	78,245	47,939
Commercial | Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	78,206	47,937
Commercial | Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	39	2
Commercial | Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Commercial | Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	0	0
Agricultural, installment and other
Credit Risk Profile by Internally Assigned Grade
Total Loans	60,068	54,867
Agricultural, installment and other | Pass
Credit Risk Profile by Internally Assigned Grade
Total Loans	59,923	54,697
Agricultural, installment and other | Special mention
Credit Risk Profile by Internally Assigned Grade
Total Loans	78	77
Agricultural, installment and other | Substandard
Credit Risk Profile by Internally Assigned Grade
Total Loans	67	93
Agricultural, installment and other | Doubtful
Credit Risk Profile by Internally Assigned Grade
Total Loans	$ 0	$ 0

Loans and Allowance for Loan _9

Loans and Allowance for Loan Losses - Age Analysis of Past Due Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	$ 10,890	$ 8,428
Current	2,039,309	1,750,113
Total Loans	2,050,199	1,758,541
Recorded Investment Greater Than 90 Days and Accruing	1,209	977
30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	6,310	4,610
60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	1,321	801
Nonaccrual and Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	3,259	3,017
Real Estate Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	1,911,886	1,655,735
Real Estate Portfolio Segment | Residential 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	6,218	4,828
Current	454,474	401,839
Total Loans	460,692	406,667
Recorded Investment Greater Than 90 Days and Accruing	920	673
Real Estate Portfolio Segment | Multifamily
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	0	0
Current	134,613	91,992
Total Loans	134,613	91,992
Recorded Investment Greater Than 90 Days and Accruing	0	0
Real Estate Portfolio Segment | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	1,595	1,812
Current	699,460	659,411
Total Loans	701,055	661,223
Recorded Investment Greater Than 90 Days and Accruing	72	0
Real Estate Portfolio Segment | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	1,625	546
Current	516,620	391,493
Total Loans	518,245	392,039
Recorded Investment Greater Than 90 Days and Accruing	32	113
Real Estate Portfolio Segment | Farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	73	422
Current	23,998	33,790
Total Loans	24,071	34,212
Recorded Investment Greater Than 90 Days and Accruing	21	0
Real Estate Portfolio Segment | Second mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	333	2
Current	10,864	8,950
Total Loans	11,197	8,952
Recorded Investment Greater Than 90 Days and Accruing	0	2
Real Estate Portfolio Segment | Equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	342	41
Current	61,671	60,609
Total Loans	62,013	60,650
Recorded Investment Greater Than 90 Days and Accruing	45	41
Real Estate Portfolio Segment | 30-59 Days Past Due | Residential 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	3,258	3,631
Real Estate Portfolio Segment | 30-59 Days Past Due | Multifamily
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	0	0
Real Estate Portfolio Segment | 30-59 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	312	0
Real Estate Portfolio Segment | 30-59 Days Past Due | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	1,567	433
Real Estate Portfolio Segment | 30-59 Days Past Due | Farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	43	112
Real Estate Portfolio Segment | 30-59 Days Past Due | Second mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	333	0
Real Estate Portfolio Segment | 30-59 Days Past Due | Equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	297	0
Real Estate Portfolio Segment | 60-89 Days Past Due | Residential 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	1,092	524
Real Estate Portfolio Segment | 60-89 Days Past Due | Multifamily
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	0	0
Real Estate Portfolio Segment | 60-89 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	109	83
Real Estate Portfolio Segment | 60-89 Days Past Due | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	26	0
Real Estate Portfolio Segment | 60-89 Days Past Due | Farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	9	0
Real Estate Portfolio Segment | 60-89 Days Past Due | Second mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	0	0
Real Estate Portfolio Segment | 60-89 Days Past Due | Equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	0	0
Real Estate Portfolio Segment | Nonaccrual and Greater Than 90 Days | Residential 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	1,868	673
Real Estate Portfolio Segment | Nonaccrual and Greater Than 90 Days | Multifamily
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	0	0
Real Estate Portfolio Segment | Nonaccrual and Greater Than 90 Days | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	1,174	1,729
Real Estate Portfolio Segment | Nonaccrual and Greater Than 90 Days | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	32	113
Real Estate Portfolio Segment | Nonaccrual and Greater Than 90 Days | Farmland
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	21	310
Real Estate Portfolio Segment | Nonaccrual and Greater Than 90 Days | Second mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	0	2
Real Estate Portfolio Segment | Nonaccrual and Greater Than 90 Days | Equity lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	45	41
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	117	139
Current	78,128	47,800
Total Loans	78,245	47,939
Recorded Investment Greater Than 90 Days and Accruing	24	0
Commercial | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	93	2
Commercial | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	0	137
Commercial | Nonaccrual and Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	24	0
Agricultural, installment and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	587	638
Current	59,481	54,229
Total Loans	60,068	54,867
Recorded Investment Greater Than 90 Days and Accruing	95	148
Agricultural, installment and other | 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	407	432
Agricultural, installment and other | 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	85	57
Agricultural, installment and other | Nonaccrual and Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Nonaccrual and Past Due	$ 95	$ 149

Loans and Allowance for Loan_10

Loans and Allowance for Loan Losses - Transactions in Allowance for Loan Losses (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses	$ 1,097	$ 1,088	$ 1,090	$ 1,023	$ 436	$ 436	$ 420	$ 389	$ 89	$ 141	$ 82	$ 67	$ 4,298	$ 1,681
Allowance for loan losses:
Beginning balance				23,909				22,731					23,909	22,731
Charge-offs													(1,663)	(1,222)
Recoveries													630	719
Ending balance	27,174				23,909				22,731				27,174	23,909
Ending balance individually evaluated for impairment	1,164				427								1,164	427
Ending balance collectively evaluated for impairment	26,010				23,482								26,010	23,482
Loans:
Ending balance	2,050,199				1,758,541								2,050,199	1,758,541
Ending balance individually evaluated for impairment	5,346				6,906								5,346	6,906
Ending balance collectively evaluated for impairment	2,044,853				1,751,635								2,044,853	1,751,635
Real Estate Portfolio Segment
Loans:
Ending balance	1,911,886				1,655,735								1,911,886	1,655,735
Real Estate Portfolio Segment | Residential 1-4 family
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses													1,568	675
Allowance for loan losses:
Beginning balance				5,156				4,571					5,156	4,571
Charge-offs													(492)	(118)
Recoveries													65	28
Ending balance	6,297				5,156				4,571				6,297	5,156
Ending balance individually evaluated for impairment	852				136								852	136
Ending balance collectively evaluated for impairment	5,445				5,020								5,445	5,020
Loans:
Ending balance	460,692				406,667								460,692	406,667
Ending balance individually evaluated for impairment	2,829				2,678								2,829	2,678
Ending balance collectively evaluated for impairment	457,863				403,989								457,863	403,989
Real Estate Portfolio Segment | Multifamily
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses													470	172
Allowance for loan losses:
Beginning balance				1,011				839					1,011	839
Charge-offs													0	0
Recoveries													0	0
Ending balance	1,481				1,011				839				1,481	1,011
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	1,481				1,011								1,481	1,011
Loans:
Ending balance	134,613				91,992								134,613	91,992
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	134,613				91,992								134,613	91,992
Real Estate Portfolio Segment | Commercial
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses													436	(414)
Allowance for loan losses:
Beginning balance				9,267				9,541					9,267	9,541
Charge-offs													0	0
Recoveries													50	140
Ending balance	9,753				9,267				9,541				9,753	9,267
Ending balance individually evaluated for impairment	312				291								312	291
Ending balance collectively evaluated for impairment	9,441				8,976								9,441	8,976
Loans:
Ending balance	701,055				661,223								701,055	661,223
Ending balance individually evaluated for impairment	1,831				3,046								1,831	3,046
Ending balance collectively evaluated for impairment	699,224				658,177								699,224	658,177
Real Estate Portfolio Segment | Construction
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses													921	586
Allowance for loan losses:
Beginning balance				6,094				5,387					6,094	5,387
Charge-offs													(19)	0
Recoveries													88	121
Ending balance	7,084				6,094				5,387				7,084	6,094
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	7,084				6,094								7,084	6,094
Loans:
Ending balance	518,245				392,039								518,245	392,039
Ending balance individually evaluated for impairment	686				1,182								686	1,182
Ending balance collectively evaluated for impairment	517,559				390,857								517,559	390,857
Real Estate Portfolio Segment | Farmland
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses													(266)	(168)
Allowance for loan losses:
Beginning balance				487				658					487	658
Charge-offs													0	(3)
Recoveries													0	0
Ending balance	221				487				658				221	487
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	221				487								221	487
Loans:
Ending balance	24,071				34,212								24,071	34,212
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	24,071				34,212								24,071	34,212
Real Estate Portfolio Segment | Second mortgages
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses													24	(10)
Allowance for loan losses:
Beginning balance				94				112					94	112
Charge-offs													0	(11)
Recoveries													0	3
Ending balance	118				94				112				118	94
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	118				94								118	94
Loans:
Ending balance	11,197				8,952								11,197	8,952
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	11,197				8,952								11,197	8,952
Real Estate Portfolio Segment | Equity lines of credit
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses													7	45
Allowance for loan losses:
Beginning balance				723				675					723	675
Charge-offs													0	0
Recoveries													1	3
Ending balance	731				723				675				731	723
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	731				723								731	723
Loans:
Ending balance	62,013				60,650								62,013	60,650
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	62,013				60,650								62,013	60,650
Agricultural, installment and other
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses													920	786
Allowance for loan losses:
Beginning balance				676				562					676	562
Charge-offs													(1,152)	(1,090)
Recoveries													423	418
Ending balance	867				676				562				867	676
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	867				676								867	676
Loans:
Ending balance	60,068				54,867								60,068	54,867
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	60,068				54,867								60,068	54,867
Commercial
Noncancelable Obligations Future Minimum Payments Due [Line Items]
Provision for loan losses													218	9
Allowance for loan losses:
Beginning balance				$ 401				$ 386					401	386
Charge-offs													0	0
Recoveries													3	6
Ending balance	622				401				$ 386				622	401
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	622				401								622	401
Loans:
Ending balance	78,245				47,939								78,245	47,939
Ending balance individually evaluated for impairment	0				0								0	0
Ending balance collectively evaluated for impairment	$ 78,245				$ 47,939								$ 78,245	$ 47,939

Loans and Allowance for Loan_11

Loans and Allowance for Loan Losses - Summary of Carrying Balances of TDRs (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Total TDRS	$ 2,492	$ 4,084
Performing [Member]
Financing Receivable, Modifications [Line Items]
Total TDRS	1,676	2,250
Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Total TDRS	$ 816	$ 1,834

Loans and Allowance for Loan_12

Loans and Allowance for Loan Losses - Troubled Debt Restructuring Categorized by Loan (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)contract	Dec. 31, 2017USD ($)contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	6	8
Pre Modification Outstanding Recorded Investment	$ 453	$ 699
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 453	$ 624
Real Estate Portfolio Segment | Residential 1-4 family
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	4	6
Pre Modification Outstanding Recorded Investment	$ 448	$ 610
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 448	$ 535
Real Estate Portfolio Segment | Multifamily
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	0
Pre Modification Outstanding Recorded Investment	$ 0	$ 0
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 0	$ 0
Real Estate Portfolio Segment | Commercial
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	0
Pre Modification Outstanding Recorded Investment	$ 0	$ 0
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 0	$ 0
Real Estate Portfolio Segment | Construction
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	0
Pre Modification Outstanding Recorded Investment	$ 0	$ 0
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 0	$ 0
Real Estate Portfolio Segment | Farmland
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	1
Pre Modification Outstanding Recorded Investment	$ 0	$ 86
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 0	$ 86
Real Estate Portfolio Segment | Second mortgages
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	0
Pre Modification Outstanding Recorded Investment	$ 0	$ 0
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 0	$ 0
Real Estate Portfolio Segment | Equity lines of credit
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	0
Pre Modification Outstanding Recorded Investment	$ 0	$ 0
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 0	$ 0
Commercial
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	0	0
Pre Modification Outstanding Recorded Investment	$ 0	$ 0
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 0	$ 0
Agricultural, installment and other
Financing Receivable, Modifications [Line Items]
Number of Contracts | contract	2	1
Pre Modification Outstanding Recorded Investment	$ 5	$ 3
Post Modification Outstanding Recorded Investment, Net of Related Allowance	$ 5	$ 3

Debt and Equity Securities - Av

Debt and Equity Securities - Available-for-sale, Maturity, without Single Maturity Date (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Summary Of Debt And Equity Securities [Line Items]
Amortized Cost	$ 295,683	$ 338,449
Gross Unrealized Gains	41	313
Gross Unrealized Losses	10,472	6,046
Estimated Market Value	285,252	332,716
Government-sponsored enterprises (GSEs)
Summary Of Debt And Equity Securities [Line Items]
Amortized Cost	71,446	74,690
Gross Unrealized Gains	0	4
Gross Unrealized Losses	2,979	1,714
Estimated Market Value	68,467	72,980
Mortgage-backed securities
Summary Of Debt And Equity Securities [Line Items]
Amortized Cost	152,375	200,175
Gross Unrealized Gains	9	302
Gross Unrealized Losses	4,874	2,551
Estimated Market Value	147,510	197,926
Asset-backed securities
Summary Of Debt And Equity Securities [Line Items]
Amortized Cost	22,534	26,387
Gross Unrealized Gains	10	0
Gross Unrealized Losses	844	789
Estimated Market Value	21,700	25,598
Obligations of states and political subdivisions
Summary Of Debt And Equity Securities [Line Items]
Amortized Cost	49,328	37,197
Gross Unrealized Gains	22	7
Gross Unrealized Losses	1,775	992
Estimated Market Value	$ 47,575	$ 36,212

Debt and Equity Securities - Ad

Debt and Equity Securities - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Securities, Available-for-sale [Line Items]
Debt securities, held-to-maturity, sold, amount	$ 4,843
Debt securities, held-to-maturity, sold, realized loss	79
Non-cash transfers from held-to-maturity to available-for-sale securities	22,800	$ 0	$ 0
Collateralized mortgage obligations	11,564	17,361
Collateralized mortgage obligations, fair value	11,295	17,133
Securities pledged to secure public deposits	260,562	213,154
Market value of securities pledged to secure public deposits	251,549	209,575
Securities adjust prior to maturity	32,864	53,248
Market value of securities that have rates that adjust prior to maturity	32,217	53,040
Tennessee
Debt Securities, Available-for-sale [Line Items]
Securities in obligations of political subdivisions	14,154	23,670
Market value of securities in obligations of political subdivisions	13,724	23,404
Texas
Debt Securities, Available-for-sale [Line Items]
Securities in obligations of political subdivisions	10,793	9,464
Market value of securities in obligations of political subdivisions	$ 10,219	$ 9,121

Debt and Equity Securities - He

Debt and Equity Securities - Held-To-Maturity, Maturity, without Single Maturity Date (Details) $ in Thousands	Dec. 31, 2017USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 32,480
Gross Unrealized Gains	97
Gross Unrealized Losses	466
Estimated Market Value	32,111
Mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	9,886
Gross Unrealized Gains	31
Gross Unrealized Losses	156
Estimated Market Value	9,761
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	22,594
Gross Unrealized Gains	66
Gross Unrealized Losses	310
Estimated Market Value	$ 22,350

Debt and Equity Securities - Ma

Debt and Equity Securities - Maturity of Amortized Cost and Estimated Market Value of AFS (Detail) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amortized Cost
Due in one year or less	$ 2,230
Due after one year through five years	22,971
Due after five years through ten years	76,604
Due after ten years	18,969
Amortized Cost	120,774
Mortgage and asset-backed securities	174,909
Amortized Cost	295,683	$ 338,449
Estimated Market Value
Due in one year or less	2,234
Due after one year through five years	22,409
Due after five years through ten years	73,184
Due after ten years	18,215
Securities Available-For-Sale	116,042
Mortgage and asset-backed securities	169,210
Securities Available-For-Sale	$ 285,252

Debt and Equity Securities - Sa

Debt and Equity Securities - Sales of Debt and Equity Securities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Gross proceeds	$ 39,857	$ 35,555	$ 90,007
Gross realized gains	102	76	716
Gross realized losses	(752)	(251)	(256)
Net realized gains (losses)	$ (650)	$ (175)	$ 460

Debt and Equity Securities - Gr

Debt and Equity Securities - Gross Unrealized Losses and Fair Value of Company's Investments (Detail) $ in Thousands	Dec. 31, 2018USD ($)security	Dec. 31, 2017USD ($)security
Less than 12 Months
Fair Value		$ 13,453
Unrealized Losses		$ 67
Number of Securities Included | security		31
12 Months or More
Fair Value		$ 12,484
Unrealized Losses		$ 399
Number of Securities Included | security		23
Total
Fair Value		$ 25,937
Unrealized Losses		466
Less than 12 Months
Fair Value	$ 12,715	129,494
Unrealized Losses	$ 90	$ 1,253
Number of Securities Included | security	16	80
12 Months or More
Fair Value	$ 266,362	$ 175,432
Unrealized Losses	$ 10,382	$ 4,793
Number of Securities Included | security	230	139
Total
Fair Value	$ 279,077	$ 304,926
Unrealized Losses	10,472	6,046
GSEs
Less than 12 Months
Fair Value	0	16,099
Unrealized Losses	$ 0	$ 190
Number of Securities Included | security	0	8
12 Months or More
Fair Value	$ 68,467	$ 55,726
Unrealized Losses	$ 2,979	$ 1,524
Number of Securities Included | security	28	21
Total
Fair Value	$ 68,467	$ 71,825
Unrealized Losses	2,979	1,714
Mortgage-backed securities
Less than 12 Months
Fair Value		3,316
Unrealized Losses		$ 21
Number of Securities Included | security		4
12 Months or More
Fair Value		$ 5,206
Unrealized Losses		$ 135
Number of Securities Included | security		5
Total
Fair Value		$ 8,522
Unrealized Losses		156
Less than 12 Months
Fair Value	8,651	92,180
Unrealized Losses	$ 64	$ 769
Number of Securities Included | security	10	43
12 Months or More
Fair Value	$ 137,457	$ 81,434
Unrealized Losses	$ 4,810	$ 1,782
Number of Securities Included | security	94	54
Total
Fair Value	$ 146,108	$ 173,614
Unrealized Losses	4,874	2,551
Asset-backed securities
Less than 12 Months
Fair Value	0	9,087
Unrealized Losses	$ 0	$ 181
Number of Securities Included | security	0	7
12 Months or More
Fair Value	$ 20,597	$ 16,510
Unrealized Losses	$ 844	$ 608
Number of Securities Included | security	14	8
Total
Fair Value	$ 20,597	$ 25,597
Unrealized Losses	844	789
Obligations of states and political subdivisions
Less than 12 Months
Fair Value		10,137
Unrealized Losses		$ 46
Number of Securities Included | security		27
12 Months or More
Fair Value		$ 7,278
Unrealized Losses		$ 264
Number of Securities Included | security		18
Total
Fair Value		$ 17,415
Unrealized Losses		310
Less than 12 Months
Fair Value	4,064	12,128
Unrealized Losses	$ 26	$ 113
Number of Securities Included | security	6	22
12 Months or More
Fair Value	$ 39,841	$ 21,762
Unrealized Losses	$ 1,749	$ 879
Number of Securities Included | security	94	56
Total
Fair Value	$ 43,905	$ 33,890
Unrealized Losses	$ 1,775	$ 992

Restricted Equity Securities (D

Restricted Equity Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
FHLB
Marketable Securities [Line Items]
Restricted equity securities consists of stock of the Federal Home Loan Bank of Cincinnati	$ 3,012	$ 3,012

Premises and Equipment - Detail

Premises and Equipment - Detail of Premises and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 75,478	$ 72,902
Less accumulated depreciation	(17,115)	(18,687)
Premises and equipment, net	58,363	54,215
Land
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	17,022	17,022
Buildings
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	44,921	31,686
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	492	425
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	12,600	12,521
Automobiles
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	343	353
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 100	$ 10,895

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Construction of buildings and minor repair work	$ 2,633	$ 5,934	$ 1,361
Depreciation expense	$ 3,602	$ 2,859	$ 2,760

Acquired Intangible Assets an_3

Acquired Intangible Assets and Goodwill - Additional Information (Detail) - subsidiary	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2005
Goodwill and Intangible Assets Disclosure [Abstract]
Number of subsidiaries acquired	2
Intangible assets percentage of owned subsidiaries	50.00%
Ownership interests acquired (as a percent)		100.00%

Acquired Intangible Assets an_4

Acquired Intangible Assets and Goodwill - Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Balance at January 1,	$ 4,805	$ 4,805
Goodwill acquired during year	0	0
Impairment loss	0	0
Balance at December 31,	$ 4,805	$ 4,805

Deposits - Deposits (Detail)

Deposits - Deposits (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
Demand deposits	$ 254,157	$ 239,559
Savings accounts	136,645	136,549
Negotiable order of withdrawal accounts	503,435	495,930
Money market demand accounts	727,654	648,606
Certificates of deposit $250,000 or greater	134,506	67,614
Other certificates of deposit	402,690	370,608
Individual retirement accounts $250,000 or greater	8,525	6,954
Other individual retirement accounts	68,043	71,925
Deposits	$ 2,235,655	$ 2,037,745

Deposits - Principal Maturities

Deposits - Principal Maturities of Certificate of Deposit and Individual Retirement Accounts (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Banking and Thrift [Abstract]
2,019	$ 290,385
2,020	155,006
2,021	89,620
2,022	21,662
2,023	50,328
Thereafter	6,763
Time Deposits, Total	$ 613,764

Deposits - Additional Informati

Deposits - Additional Information (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
Overdrafts reclassified as loans receivable	$ 496,000	$ 531,000
Average required cash balance	$ 0	$ 0

Securities Sold Under Repurch_2

Securities Sold Under Repurchase Agreements (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Banking and Thrift [Abstract]
Securities sold under repurchase agreements	$ 0	$ 864,000
Maximum amounts of outstanding repurchase agreements	6,831,000	1,843,000
Average daily balance outstanding	$ 1,090,000	$ 1,382,000
Weighted average interest rate on outstanding balance (as a percent)		1.47%

Non-Interest Income and Non-I_3

Non-Interest Income and Non-Interest Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Non-interest income:
Service charges on deposits	$ 6,799	$ 6,124	$ 5,769
Other fees and commissions	13,704	11,752	10,260
BOLI and annuity earnings	841	871	832
Security gains (losses), net	(650)	(175)	460
Fees and gains on sales of mortgage loans	4,639	4,258	4,355
Gain (loss) on sale of other real estate, net	(80)	6	52
Loss on sale of fixed assets, net	(2)	0	(73)
Loss on sale of other assets, net	(3)	(15)	(1)
Non-interest income	25,248	22,821	21,654
Non-interest expense:
Employee salaries and benefits	39,590	35,830	34,106
Equity-based compensation	1,237	692	104
Occupancy expenses	4,403	3,718	3,638
Furniture and equipment expenses	2,767	2,085	2,019
Data processing expenses	2,900	2,834	2,576
Advertising expenses	2,552	2,326	2,310
ATM & interchange fees	3,091	2,569	2,475
FDIC insurance	843	683	968
Directors’ fees	543	677	691
Other operating expenses	11,154	8,977	8,376
Non-interest expense	$ 69,080	$ 60,391	$ 57,263

Income Taxes - Components of th

Income Taxes - Components of the Net Deferred Tax Asset (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Deferred Tax Assets And Liabilities [Line Items]
Deferred tax asset	$ 11,785	$ 9,290
Deferred tax liability	(2,884)	(1,866)
Net deferred tax asset	8,901	7,424
Federal
Schedule Of Deferred Tax Assets And Liabilities [Line Items]
Deferred tax asset	9,046	7,222
Deferred tax liability	(2,167)	(1,402)
State
Schedule Of Deferred Tax Assets And Liabilities [Line Items]
Deferred tax asset	2,739	2,068
Deferred tax liability	$ (717)	$ (464)

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets (Liabilities) in Which Tax Effects of Significant Item that Gave Rise (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Financial statement allowance for loan losses in excess of tax allowance	$ 6,846	$ 5,925
Excess of depreciation deducted for tax purposes over the amounts deducted in the financial statements	(2,557)	(1,539)
Financial statement deduction for deferred compensation in excess of deduction for tax purposes	1,128	1,075
Writedown of other real estate not deductible for income tax purposes until sold	176	161
Financial statement income on FHLB stock dividends not recognized for tax purposes	(327)	(327)
Unrealized loss on securities available-for-sale	2,726	1,498
Equity based compensation	469	178
Other items, net	440	453
Net deferred tax asset	$ 8,901	$ 7,424

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
Federal	$ 8,310	$ 14,004	$ 12,910
State	721	2,354	2,095
Total	9,031	16,358	15,005
Deferred
Federal	(136)	3,205	(136)
State	(112)	(209)	(28)
Total	(248)	2,996	(164)
Total
Federal	8,174	17,209	12,774
State	609	2,145	2,067
Total	$ 8,783	$ 19,354	$ 14,841

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Revaluation of deferred tax assets due to change in tax rates	$ 3,603,000	$ 0	$ 3,603,000	$ 0
Revaluation of deferred tax assets due to change in tax rates	697,000
Federal income tax benefits		$ 8,783,000	19,354,000	14,841,000
Statutory income tax rate (as a percent)		21.00%
Income tax expense related to the realized gain and loss, respectively, on sale of securities		$ (170,000)	(67,000)	176,000
Accrued or recognized interest or penalties related to uncertain tax positions	$ 0	0	$ 0	$ 0
Unrecognized tax benefits		$ 0
Period for change of unrecognized tax benefits		12 months
Deferred tax asset that we did not prevail on all uncertain tax position		$ 11,800,000

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Actual Income Tax Expense to the Expected Tax Expense (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Computed “expected” tax expense	$ 8,689,000	$ 14,579,000	$ 13,761,000
State income taxes, net of Federal income tax benefit	432,000	1,346,000	1,364,000
Tax exempt interest, net of interest expense exclusion	(226,000)	(415,000)	(401,000)
Federal income tax rate in excess of statutory rate related to taxable income over $10 million	0	399,000	370,000
Earnings on cash surrender value of life insurance	(177,000)	(292,000)	(283,000)
Expenses not deductible for tax purposes	16,000	43,000	40,000
Equity based compensation expense	(39,000)	16,000	35,000
Revaluation of federal deferred tax assets due to change in tax rates	0	3,603,000	0
Other	88,000	75,000	(45,000)
Total	8,783,000	$ 19,354,000	$ 14,841,000
Taxable income for which federal income tax rate in excess of statutory rate	$ 10,000,000

Commitments and Contingent Li_3

Commitments and Contingent Liabilities - Future Minimum Rental Payments under Operating Leases (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 401
2,020	399
2,021	349
2,022	180
2,023	85
Thereafter	$ 13

Commitments and Contingent Li_4

Commitments and Contingent Liabilities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 362,000	$ 215,000	$ 204,000
Debt Instrument [Line Items]
Line of credit with other financial institution	53,000,000	53,000,000
Balance outstanding under line of credit	0	0
Line of Credit [Member] | Cash Management Advance (CMA) [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 25,000,000
Borrowings under variable rate, period up to	90 days
Borrowings under fixed rate, period up to	30 days
Borrowings under CMA	$ 0	$ 0

Financial Instruments with Of_3

Financial Instruments with Off-Balance-Sheet Risk (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial instruments whose contract amounts represent credit risk
Financial instruments whose contract amounts represent credit risk	$ 663,062	$ 674,270
Unused Commitments to Extend Credit
Financial instruments whose contract amounts represent credit risk
Financial instruments whose contract amounts represent credit risk	582,897	605,114
Standby Letters of Credit
Financial instruments whose contract amounts represent credit risk
Financial instruments whose contract amounts represent credit risk	80,165	$ 69,156
Guarantor obligations, maximum exposure	$ 80,200

Concentration of Credit Risk (D

Concentration of Credit Risk (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)Bank	Dec. 31, 2017USD ($)
Risks and Uncertainties [Abstract]
Interest-bearing deposits in banks | $	$ 80,215
Interest bearing deposits deposited with banks, number or banks | Bank	4
Federal funds sold | $	$ 9,000	$ 0
Federal funds sold, number of banks | Bank	1

Employee Benefit Plan (Detail)

Employee Benefit Plan (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Minimum age limit of employee to be eligible for the plan	20 years 6 months
Employers contribution	$ 2,383	$ 2,145	$ 2,006

Dividend Reinvestment Plan (Det

Dividend Reinvestment Plan (Detail) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
Original issue shares under the terms of the dividend reinvestment plan (DRIP) (in shares)	161,514	125,960	98,318

Regulatory Matters and Restri_3

Regulatory Matters and Restrictions on Dividends - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
New capital requirement effective date	2,015
Capital conservation buffer ratio to be phased in over four years (as a percent)	2.50%
Capital conservation buffer phased in period	4 years
Capital conservation buffer beginning period	2,016
Basel III Requirements
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Unrealized gains and losses in accumulated other comprehensive income	$ 250,000,000,000

Regulatory Matters and Restri_4

Regulatory Matters and Restrictions on Dividends - Summary of Company's and Wilson Banks Actual Capital Amounts and Ratios (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Total capital to risk weighted assets:
Total capital to risk weighted assets actual amount	$ 326,099	$ 291,395
Total capital to risk weighted assets actual ratio (as a percent)	14.10%	14.20%
Total capital to risk weighted assets regulatory minimum capital requirement amount	$ 227,974	$ 189,658
Total capital to risk weighted assets regulatory minimum capital requirement ratio (as a percent)	9.875%	9.25%
Total capital to risk weighted assets regulatory minimum to be well capitalized amount	$ 230,860	$ 205,036
Total capital to risk weighted assets regulatory minimum to be well capitalized ratio (as a percent)	10.00%	10.00%
Tier 1 capital to risk weighted assets:
Tier 1 capital to risk weighted assets actual amount	$ 298,566	$ 267,159
Tier 1 capital to risk weighted assets actual ratio (as a percent)	12.90%	13.00%
Tier 1 capital to risk weighted assets regulatory minimum capital requirement amount	$ 181,802	$ 148,651
Tier 1 capital to risk weighted assets regulatory minimum capital requirement ratio (as a percent)	7.875%	7.25%
Tier 1 capital to risk weighted assets regulatory minimum to be well capitalized amount	$ 138,516	$ 123,021
Tier 1 capital to risk weighted assets regulatory minimum to be well capitalized ratio (as a percent)	6.00%	6.00%
Common equity Tier 1 capital to risk weighted assets:
Common equity Tier 1 capital to risk weighted assets actual amount	$ 298,566	$ 267,159
Common equity Tier 1 capital to risk weighted assets actual ratio (as a percent)	12.90%	13.00%
Common equity Tier 1 capital to risk weighted assets regulatory minimum capital requirement amount	$ 147,173	$ 117,895
Common equity Tier 1 capital to risk weighted assets regulatory minimum capital requirement ratio (as a percent)	6.375%	5.75%
Tier 1 capital to average assets:
Tier 1 capital to average assets actual amount	$ 298,566	$ 267,159
Tier 1 capital to average assets actual ratio (as a percent)	12.30%	11.90%
Tier 1 capital to average assets regulatory minimum capital requirement amount	$ 97,022	$ 90,110
Tier 1 capital to average assets regulatory minimum capital requirement ratio (as a percent)	4.00%	4.00%
Wilson Bank Holding Company
Total capital to risk weighted assets:
Total capital to risk weighted assets actual amount	$ 323,852	$ 289,824
Total capital to risk weighted assets actual ratio (as a percent)	14.00%	14.10%
Total capital to risk weighted assets regulatory minimum capital requirement amount	$ 227,915	$ 189,618
Total capital to risk weighted assets regulatory minimum capital requirement ratio (as a percent)	9.875%	9.25%
Total capital to risk weighted assets regulatory minimum to be well capitalized amount	$ 230,800	$ 204,992
Total capital to risk weighted assets regulatory minimum to be well capitalized ratio (as a percent)	10.00%	10.00%
Tier 1 capital to risk weighted assets:
Tier 1 capital to risk weighted assets actual amount	$ 296,319	$ 265,588
Tier 1 capital to risk weighted assets actual ratio (as a percent)	12.80%	13.00%
Tier 1 capital to risk weighted assets regulatory minimum capital requirement amount	$ 181,756	$ 148,619
Tier 1 capital to risk weighted assets regulatory minimum capital requirement ratio (as a percent)	7.875%	7.25%
Tier 1 capital to risk weighted assets regulatory minimum to be well capitalized amount	$ 184,641	$ 163,994
Tier 1 capital to risk weighted assets regulatory minimum to be well capitalized ratio (as a percent)	8.00%	8.00%
Common equity Tier 1 capital to risk weighted assets:
Common equity Tier 1 capital to risk weighted assets actual amount	$ 296,319	$ 265,588
Common equity Tier 1 capital to risk weighted assets actual ratio (as a percent)	12.80%	13.00%
Common equity Tier 1 capital to risk weighted assets regulatory minimum capital requirement amount	$ 147,136	$ 117,871
Common equity Tier 1 capital to risk weighted assets regulatory minimum capital requirement ratio (as a percent)	6.375%	5.75%
Common equity Tier 1 capital to risk weighted assets regulatory minimum to be well capitalized amount	$ 150,021	$ 133,245
Common equity Tier 1 capital to risk weighted assets regulatory minimum to be well capitalized ratio (as a percent)	6.50%	6.50%
Tier 1 capital to average assets:
Tier 1 capital to average assets actual amount	$ 296,319	$ 265,588
Tier 1 capital to average assets actual ratio (as a percent)	11.90%	11.50%
Tier 1 capital to average assets regulatory minimum capital requirement amount	$ 99,373	$ 92,062
Tier 1 capital to average assets regulatory minimum capital requirement ratio (as a percent)	4.00%	4.00%
Tier 1 capital to average assets regulatory minimum to be well capitalized amount	$ 124,217	$ 115,078
Tier 1 capital to average assets regulatory minimum to be well capitalized ratio (as a percent)	5.00%	5.00%

Regulatory Matters and Restri_5

Regulatory Matters and Restrictions on Dividends - Summary of Basel III Minimum Requirements After Giving Effect to the Buffer (Detail)	Dec. 31, 2018	Dec. 31, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Ratio (as a percent)	6.375%	5.75%
Tier 1 Capital to Risk Weighted Assets Ratio (as a percent)	7.875%	7.25%
Total Capital to Risk Weighted Assets Ratio (as a percent)	9.875%	9.25%
2,016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Ratio (as a percent)	5.125%
Tier 1 Capital to Risk Weighted Assets Ratio (as a percent)	6.625%
Total Capital to Risk Weighted Assets Ratio (as a percent)	8.625%
2,017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Ratio (as a percent)	5.75%
Tier 1 Capital to Risk Weighted Assets Ratio (as a percent)	7.25%
Total Capital to Risk Weighted Assets Ratio (as a percent)	9.25%
2,018
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Ratio (as a percent)	6.375%
Tier 1 Capital to Risk Weighted Assets Ratio (as a percent)	7.875%
Total Capital to Risk Weighted Assets Ratio (as a percent)	9.875%
2,019
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 Ratio (as a percent)	7.00%
Tier 1 Capital to Risk Weighted Assets Ratio (as a percent)	8.50%
Total Capital to Risk Weighted Assets Ratio (as a percent)	10.50%

Salary Deferral Plans (Detail)

Salary Deferral Plans (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Executive Salary Continuation Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Salary deferral compensation liability total	$ 1,825	$ 1,861
Cash surrender value of life insurance, carrying value	4,540	3,791
Face amount of the insurance policies in force	13,523	11,176
Supplemental Employee Retirement Plan Agreement
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Salary deferral compensation liability total	2,491	2,250
Cash surrender value of life insurance, carrying value	26,412	25,684
Face amount of the insurance policies in force	61,202	61,239
Flexible Indexed Annuity Contracts	$ 14,558	$ 10,816

Equity Incentive Plan - Additio

Equity Incentive Plan - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Apr. 14, 2009	Apr. 13, 2009	Apr. 30, 1999	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2016
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Percentage of common stock shares issued and outstanding			5.00%
Stock option expiration period				10 years
Percentage of the fair market value of the common stock on the grant date				100.00%
The weighted average fair value at the grant date of options granted (in dollars per share)				$ 14.41	$ 12.59	$ 11.29
The total intrinsic value of options exercised				$ 200	$ 62	$ 65
Total unrecognized cost related to non-vested share-based compensation arrangements granted under the Company's stock option plans				$ 2,104
Weighted-average period for recognition of unrecognized costs				3 years 2 months 19 days
1999 Stock Option Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares authorized			200,000
Stock Option Plan expiration date		Apr. 13, 2009
Option outstanding (in shares)				2,133
Outstanding weighted-average exercise price (in dollars per share)				$ 26.81
2009 Stock Option Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares authorized				100,000
Stock Option Plan effective date	Apr. 14, 2009
Option outstanding (in shares)				27,069
Outstanding weighted-average exercise price (in dollars per share)				$ 31.78
Shares remaining available for issuance (in shares)				52,788
2016 Equity Incentive Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares authorized							750,000
Option outstanding (in shares)				128,220
Outstanding weighted-average exercise price (in dollars per share)				$ 41.25
Shares remaining available for issuance (in shares)				485,104
Stock Appreciation Rights (SARs) [Member] | 2016 Equity Incentive Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number				120,398
Share-based Compensation Arrangement by Share-based Payment Award, Instruments Other Than Options, Exercisable, Weighted Average Exercise Price				$ 41

Equity Incentive Plan - Schedul

Equity Incentive Plan - Schedule of Weighted-Average Black-Scholes Fair Value Assumptions (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected dividends (as percent)	1.22%	1.27%	1.21%
Expected term	9 years 4 months 6 days	7 years 9 months 15 days	8 years 8 months 16 days
Expected volatility (as percent)	24.00%	26.00%	26.00%
Risk-free rate (as percent)	2.83%	2.23%	2.02%

Equity Incentive Plan - Summary

Equity Incentive Plan - Summary of Stock Option Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Exercised (in shares)	(11,585)	(5,078)	(5,120)
Stock Options and Stock Appreciation Rights
Shares
Option outstanding at beginning of year (in shares)	285,780	183,747	49,895
Granted (in shares)	21,666	112,333	140,997
Exercised (in shares)	(22,460)	(5,078)	(5,545)
Forfeited or expired (in shares)	(7,166)	(5,222)	(1,600)
Option outstanding at end of year (in shares)	277,820	285,780	183,747
Options exercisable at year end (in shares)	94,951	42,256	13,553
Weighted Average Exercise Price
Outstanding weighted-average exercise price at beginning of year (in dollars per share)	$ 39.31	$ 38.09	$ 30.19
Granted weighted-average exercise price (in dollars per shares)	46.59	40.87	40.36
Exercised weighted-average exercise price (in dollars per shares)	37.07	29.65	27.38
Forfeited or expired weighted-average exercise price (in dollars per shares)	37.53	39.22	28.44
Outstanding weighted-average exercise price at end of year (in dollars per shares)	40.11	39.31	38.09
Options exercisable weighted-average exercise price at year end (in dollars per shares)	$ 39.14	$ 36.66	$ 29.29

Equity Incentive Plan - Summa_2

Equity Incentive Plan - Summary of Information about Stock Options (Detail) - Stock Options and Stock Appreciation Rights $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of outstanding (in shares)	277,820
Options Outstanding, Aggregate intrinsic value | $	$ 2,679
Options Exercisable, Number exercisable (in shares)	94,951
Options Exercisable, Aggregate intrinsic value | $	$ 1,008
$22.00 - $32.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of outstanding (in shares)	16,388
Options Outstanding, Weighted average exercise price (in dollars per share) | $ / shares	$ 29.02
Options Outstanding, Weighted average remaining contractual term	1 year 6 months
Options Exercisable, Number exercisable (in shares)	9,022
Options Exercisable, Weighted average exercise price (in dollars per share) | $ / shares	$ 28.74
Options Exercisable, Weighted average remaining contractual term	1 year 3 months 26 days
$32.01 - $47.75
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of outstanding (in shares)	261,432
Options Outstanding, Weighted average exercise price (in dollars per share) | $ / shares	$ 40.81
Options Outstanding, Weighted average remaining contractual term	7 years 4 months 17 days
Options Exercisable, Number exercisable (in shares)	85,929
Options Exercisable, Weighted average exercise price (in dollars per share) | $ / shares	$ 40.23
Options Exercisable, Weighted average remaining contractual term	6 years 1 month 13 days

Equity Incentive Plan - Summa_3

Equity Incentive Plan - Summary of Information about Stock Options - Additional Information (Detail) - Stock Options and Stock Appreciation Rights	12 Months Ended
	Dec. 31, 2018$ / shares
$22.00 - $32.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower limit (in dollars per share)	$ 22
Exercise Price, Upper limit (in dollars per share)	32
$32.01 - $47.75
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price, Lower limit (in dollars per share)	32.01
Exercise Price, Upper limit (in dollars per share)	$ 47.75

Earnings Per Share (Detail)

Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Basic EPS Computation:
Numerator - Earnings available to common stockholders	$ 9,833	$ 7,972	$ 7,309	$ 7,480	$ 3,574	$ 6,469	$ 6,988	$ 6,495	$ 6,802	$ 6,918	$ 6,270	$ 5,643	$ 32,594	$ 23,526	$ 25,633
Denominator - Weighted average number of common shares outstanding													10,564,172	10,407,211	10,279,332
Basic earnings per common share (in dollars per share)	$ 0.93	$ 0.75	$ 0.69	$ 0.71	$ 0.34	$ 0.62	$ 0.67	$ 0.63	$ 0.66	$ 0.67	$ 0.61	$ 0.55	$ 3.09	$ 2.26	$ 2.49
Diluted EPS Computation:
Numerator - Earnings available to common stockholders													$ 32,594	$ 23,526	$ 25,633
Denominator - Weighted average number of common shares outstanding													10,564,172	10,407,211	10,279,332
Dilutive effect of stock options (in shares)													8,049	5,325	4,996
Weighted average number of shares outstanding-diluted													10,572,221	10,412,536	10,284,328
Diluted earnings per common share (in dollars per share)	$ 0.92	$ 0.75	$ 0.69	$ 0.71	$ 0.34	$ 0.62	$ 0.67	$ 0.63	$ 0.66	$ 0.67	$ 0.61	$ 0.55	$ 3.08	$ 2.26	$ 2.49

Mortgage Banking Derivatives -

Mortgage Banking Derivatives - Additional Information (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Interest rate contracts for customers
Derivative [Line Items]
Notional Amount	$ 9,655
Fair Value, Asset	335
Forward contracts related to mortgage loans held-for-sale
Derivative [Line Items]
Notional Amount	11,750
Fair Value, Liability	$ 88

Mortgage Banking Derivatives _2

Mortgage Banking Derivatives - Net gains (losses) relating to free-standing derivative instruments (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Forward contracts related to mortgage loans held-for-sale
Derivative [Line Items]
Gain (loss) on hedged item	$ (88)
Interest rate contracts for customers
Derivative [Line Items]
Gain (loss) on hedged item	$ 335

Mortgage Banking Derivatives _3

Mortgage Banking Derivatives - Amount and fair value of mortgage banking derivatives (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Interest rate contracts for customers
Derivative [Line Items]
Notional Amount	$ 9,655
Fair Value, Asset	335
Forward contracts related to mortgage loans held-for-sale
Derivative [Line Items]
Notional Amount	11,750
Fair Value, Liability	$ (88)

Disclosures About Fair Value _3

Disclosures About Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	$ 285,252	$ 332,716
Mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	147,510	197,926
Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	21,700	25,598
State and municipal securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	47,575	36,212
Reported Value Measurement | Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	285,252	332,716
Mortgage loans held for sale	7,484	5,106
Mortgage banking derivatives	335
Bank owned life insurance	30,952	29,475
Total	324,023	367,297
Mortgage banking derivatives	88
Total liabilities	88
Reported Value Measurement | Fair Value, Measurements, Recurring | U.S. Government sponsored enterprises
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	68,467	72,980
Reported Value Measurement | Fair Value, Measurements, Recurring | Mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	147,510	197,926
Reported Value Measurement | Fair Value, Measurements, Recurring | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	21,700	25,598
Reported Value Measurement | Fair Value, Measurements, Recurring | State and municipal securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	47,575	36,212
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Quoted Market Prices in an Active Market (Level 1)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	0	0
Mortgage loans held for sale	0	0
Mortgage banking derivatives	0
Bank owned life insurance	0	0
Total	0	0
Mortgage banking derivatives	0
Total liabilities	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Quoted Market Prices in an Active Market (Level 1) | U.S. Government sponsored enterprises
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	0	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Quoted Market Prices in an Active Market (Level 1) | Mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	0	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Quoted Market Prices in an Active Market (Level 1) | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	0	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Quoted Market Prices in an Active Market (Level 1) | State and municipal securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	0	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Observable Market Parameters (Level 2)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	285,252	332,716
Mortgage loans held for sale	7,484	5,106
Mortgage banking derivatives	335
Bank owned life insurance	0	0
Total	293,071	337,822
Mortgage banking derivatives	88
Total liabilities	88
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Observable Market Parameters (Level 2) | U.S. Government sponsored enterprises
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	68,467	72,980
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Observable Market Parameters (Level 2) | Mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	147,510	197,926
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Observable Market Parameters (Level 2) | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	21,700	25,598
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Observable Market Parameters (Level 2) | State and municipal securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	47,575	36,212
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Unobservable Market Parameters (Level 3)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	0	0
Mortgage loans held for sale	0	0
Mortgage banking derivatives	0
Bank owned life insurance	30,952	29,475
Total	30,952	29,475
Mortgage banking derivatives	0
Total liabilities	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Unobservable Market Parameters (Level 3) | U.S. Government sponsored enterprises
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	0	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Unobservable Market Parameters (Level 3) | Mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	0	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Unobservable Market Parameters (Level 3) | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	0	0
Estimate of Fair Value Measurement | Fair Value, Measurements, Recurring | Models with Significant Unobservable Market Parameters (Level 3) | State and municipal securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Estimated Market Value	$ 0	$ 0

Disclosures About Fair Value _4

Disclosures About Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis (Detail) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Reported Value Measurement
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Other real estate owned	$ 1,357	$ 1,635
Impaired loans, net	4,195	6,531
Total	5,552	8,166
Estimate of Fair Value Measurement | Quoted Market Prices in an Active Market (Level 1)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Other real estate owned	0	0
Impaired loans, net	0	0
Total	0	0
Estimate of Fair Value Measurement | Models with Significant Observable Market Parameters (Level 2)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Other real estate owned	0	0
Impaired loans, net	0	0
Total	0	0
Estimate of Fair Value Measurement | Models with Significant Unobservable Market Parameters (Level 3)
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Other real estate owned	1,357	1,635
Impaired loans, net	4,195	6,531
Total	$ 5,552	$ 8,166

Disclosures About Fair Value _5

Disclosures About Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Valuation allowance	$ 1,164	$ 427

Disclosures About Fair Value _6

Disclosures About Fair Value of Financial Instruments - Quantitative Unobservable Inputs (Details) - Fair Value, Measurements, Nonrecurring - Models with Significant Unobservable Market Parameters (Level 3) - Range (Weighted Average)	Dec. 31, 2018
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Impaired loans	0.10
Estimated costs to sell	0.10

Disclosures About Fair Value _7

Disclosures About Fair Value of Financial Instruments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018TransferStation
Fair Value Disclosures [Abstract]
Transfers between levels one, two and three	0

Disclosures About Fair Value _8

Disclosures About Fair Value of Financial Instruments - Changes in Fair Value Due to Observable Factors (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Other Assets
Other Assets
Fair value, January 1	$ 29,475	$ 28,616
Total realized gains included in income	841	859
Change in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at December 31	0	0
Purchases, issuances and settlements, net	636	0
Transfers out of Level 3	0	0
Fair value, December 31	30,952	29,475
Other Liabilities
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at December 31	841	859
Other Liabilities
Other Liabilities
Fair value, January 1	0	0
Total realized gains included in income	0	0
Change in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at December 31	0	0
Purchases, issuances and settlements, net	0	0
Transfers out of Level 3	0	0
Fair value, December 31	0	0
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at December 31	$ 0	$ 0

Disclosures About Fair Value _9

Disclosures About Fair Value of Financial Instruments - Carrying Value and Estimated Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial assets
Securities held-to-maturity		$ 32,111
Restricted equity securities, at cost	$ 3,012	3,012
Quoted Market Prices in an Active Market (Level 1)
Financial assets
Cash and cash equivalents	99,191	95,518
Securities held-to-maturity		0
Loans, net	0	0
Accrued interest receivable	3	5
Financial liabilities
Deposits and securities sold under agreements to repurchase	0	0
Accrued interest payable	0	0
Models with Significant Observable Market Parameters (Level 2)
Financial assets
Cash and cash equivalents	0	0
Securities held-to-maturity		32,111
Loans, net	0	0
Accrued interest receivable	1,362	1,562
Financial liabilities
Deposits and securities sold under agreements to repurchase	0	0
Accrued interest payable	0	0
Models with Significant Unobservable Market Parameters (Level 3)
Financial assets
Cash and cash equivalents	0	0
Securities held-to-maturity		0
Loans, net	2,017,272	1,724,937
Accrued interest receivable	5,359	4,699
Financial liabilities
Deposits and securities sold under agreements to repurchase	1,974,554	1,812,011
Accrued interest payable	3,132	1,679
Reported Value Measurement
Financial assets
Cash and cash equivalents	99,191	95,518
Securities held-to-maturity		32,480
Loans, net	2,016,005	1,727,253
Restricted equity securities, at cost	3,012	3,012
Accrued interest receivable	6,724	6,266
Financial liabilities
Deposits and securities sold under agreements to repurchase	2,235,655	2,038,609
Accrued interest payable	3,132	1,679
Estimate of Fair Value Measurement
Financial assets
Cash and cash equivalents	99,191	95,518
Securities held-to-maturity		32,111
Loans, net	2,017,272	1,724,937
Accrued interest receivable	6,724	6,266
Financial liabilities
Deposits and securities sold under agreements to repurchase	1,974,554	1,812,011
Accrued interest payable	$ 3,132	$ 1,679

Wilson Bank Holding Company -_3

Wilson Bank Holding Company - Parent Company Financial Information - Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Cash	$ 99,191	$ 95,518	$ 47,918	$ 109,253
Deferred income taxes	8,901	7,424
Total assets	2,543,682	2,317,033
LIABILITIES AND STOCKHOLDERS’ EQUITY
Total liabilities	2,248,015	2,049,303
Stockholders’ equity:
Common stock, par value $2.00 per share, authorized 50,000,000 shares, 10,623,810 and 10,450,711 shares issued and outstanding, respectively	21,248	20,901
Additional paid-in capital	73,960	66,047
Retained earnings	208,164	185,017
Net unrealized losses on available-for-sale securities, net of income taxes of $527 and $421, respectively	(7,705)	(4,235)
Total stockholders’ equity	295,667	267,730	244,620	223,438
Total liabilities and stockholders’ equity	2,543,682	2,317,033
Wilson Bank Holding Company
ASSETS
Cash	2,759	1,589	$ 1,678	$ 1,685
Investment in wholly-owned commercial bank subsidiary	293,420	266,159
Deferred income taxes	469	178
Refundable income taxes	177	181
Total assets	296,825	268,107
LIABILITIES AND STOCKHOLDERS’ EQUITY
Stock appreciation rights payable	1,158	377
Total liabilities	1,158	377
Stockholders’ equity:
Common stock, par value $2.00 per share, authorized 50,000,000 shares, 10,623,810 and 10,450,711 shares issued and outstanding, respectively	21,248	20,901
Additional paid-in capital	73,960	66,047
Retained earnings	208,164	185,017
Net unrealized losses on available-for-sale securities, net of income taxes of $527 and $421, respectively	(7,705)	(4,235)
Total stockholders’ equity	295,667	267,730
Total liabilities and stockholders’ equity	$ 296,825	$ 268,107

Wilson Bank Holding Company -_4

Wilson Bank Holding Company - Parent Company Financial Information - Balance Sheets, Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Parent Company Only Financial Information [Line Items]
Common stock, par value (in dollars per share)	$ 2	$ 2
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	10,623,810	10,450,711
Common stock, shares outstanding	10,623,810	10,450,711
Wilson Bank Holding Company
Parent Company Only Financial Information [Line Items]
Common stock, par value (in dollars per share)	$ 2	$ 2
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	10,623,810	10,450,711
Common stock, shares outstanding	10,623,810	10,450,711
Net unrealized losses on available-for-sale securities, income taxes	$ 2,726	$ 1,498

Wilson Bank Holding Company -_5

Wilson Bank Holding Company - Parent Company Financial Information - Statements of Earnings and Comprehensive Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Expenses:
Directors’ fees													$ 543	$ 677	$ 691
Non-interest expense													69,080	60,391	57,263
Federal income tax benefits													(8,783)	(19,354)	(14,841)
Net earnings	$ 9,833	$ 7,972	$ 7,309	$ 7,480	$ 3,574	$ 6,469	$ 6,988	$ 6,495	$ 6,802	$ 6,918	$ 6,270	$ 5,643	32,594	23,526	25,633
Wilson Bank Holding Company
Income:
Dividends from commercial bank subsidiary													3,000	1,500	1,500
Expenses:
Directors’ fees													254	334	327
Other													1,351	805	194
Non-interest expense													1,605	1,139	521
Income before Federal income tax benefits and equity in undistributed earnings of commercial bank subsidiary													1,395	361	979
Federal income tax benefits													468	359	169
Non-interest expense													1,863	720	1,148
Equity in undistributed earnings of commercial bank subsidiary													30,731	22,806	24,485
Net earnings													$ 32,594	$ 23,526	$ 25,633

Wilson Bank Holding Company -_6

Wilson Bank Holding Company - Parent Company Financial Information - Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Cash paid to suppliers and other													$ (64,186)	$ (57,643)	$ (53,454)
Net cash provided by operating activities													40,773	42,667	26,803
Cash flows from investing activities:
Net cash used in investing activities													(232,563)	(89,494)	(237,836)
Cash flows from financing activities:
Dividends paid													(9,447)	(6,729)	(5,756)
Proceeds from sale of stock pursuant to dividend reinvestment													7,470	5,266	4,316
Proceeds from exercise of stock options													394	152	152
Net cash provided by financing activities													195,463	94,427	149,698
Net increase (decrease) in cash and cash equivalents													3,673	47,600	(61,335)
Cash and cash equivalents at beginning of year				$ 95,518				$ 47,918				$ 109,253	95,518	47,918	109,253
Cash and cash equivalents at end of year	$ 99,191				$ 95,518				$ 47,918				99,191	95,518	47,918
Reconciliation of net earnings to net cash used in operating activities:
Net earnings	9,833	$ 7,972	$ 7,309	7,480	3,574	$ 6,469	$ 6,988	6,495	6,802	$ 6,918	$ 6,270	5,643	32,594	23,526	25,633
Adjustments to reconcile net earnings to net cash used in operating activities:
Decrease (increase) in refundable income taxes													(1,526)	(42)	1,168
Share-based compensation expense													1,237	692	69
Total adjustments													8,179	19,141	1,170
Net cash provided by operating activities													40,773	42,667	26,803
Wilson Bank Holding Company
Cash flows from operating activities:
Cash paid to suppliers and other													(367)	(447)	(417)
Tax benefits received													181	169	198
Net cash provided by operating activities													(186)	(278)	(219)
Cash flows from investing activities:
Dividends received from commercial bank subsidiary													3,000	1,500	1,500
Net cash used in investing activities													3,000	1,500	1,500
Cash flows from financing activities:
Payments made to stock appreciation rights holders													(61)	0	0
Dividends paid													(9,447)	(6,729)	(5,756)
Proceeds from sale of stock pursuant to dividend reinvestment													7,470	5,266	4,316
Proceeds from exercise of stock options													394	152	152
Net cash provided by financing activities													(1,644)	(1,311)	(1,288)
Net increase (decrease) in cash and cash equivalents													1,170	(89)	(7)
Cash and cash equivalents at beginning of year				$ 1,589				$ 1,678				$ 1,685	1,589	1,678	1,685
Cash and cash equivalents at end of year	$ 2,759				$ 1,589				$ 1,678				2,759	1,589	1,678
Reconciliation of net earnings to net cash used in operating activities:
Net earnings													32,594	23,526	25,633
Adjustments to reconcile net earnings to net cash used in operating activities:
Equity in earnings of commercial bank subsidiary													(33,731)	(24,306)	(25,985)
Decrease (increase) in refundable income taxes													5	(12)	29
Increase in deferred taxes													(291)	(178)	0
Share-based compensation expense													1,237	692	104
Total adjustments													(32,780)	(23,804)	(25,852)
Net cash provided by operating activities													$ (186)	$ (278)	$ (219)

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 27,585	$ 26,298	$ 25,548	$ 24,094	$ 23,487	$ 22,904	$ 22,871	$ 21,758	$ 22,078	$ 21,454	$ 20,877	$ 20,337	$ 103,525	$ 91,020	$ 84,746
Interest expense	4,606	3,656	3,097	2,659	2,439	2,332	2,094	2,024	1,990	2,077	2,106	2,111	14,018	8,889	8,284
Net interest income	22,979	22,642	22,451	21,435	21,048	20,572	20,777	19,734	20,088	19,377	18,771	18,226	89,507	82,131	76,462
Provision for loan losses	1,097	1,088	1,090	1,023	436	436	420	389	89	141	82	67	4,298	1,681
Earnings before income taxes	10,708	10,718	9,798	10,153	10,694	10,438	11,386	10,362	10,120	11,095	10,162	9,097	41,377	42,880	40,474
Net earnings	$ 9,833	$ 7,972	$ 7,309	$ 7,480	$ 3,574	$ 6,469	$ 6,988	$ 6,495	$ 6,802	$ 6,918	$ 6,270	$ 5,643	$ 32,594	$ 23,526	$ 25,633
Basic earnings per common share (in dollars per share)	$ 0.93	$ 0.75	$ 0.69	$ 0.71	$ 0.34	$ 0.62	$ 0.67	$ 0.63	$ 0.66	$ 0.67	$ 0.61	$ 0.55	$ 3.09	$ 2.26	$ 2.49
Diluted earnings per common share (in dollars per share)	$ 0.92	$ 0.75	$ 0.69	$ 0.71	$ 0.34	$ 0.62	$ 0.67	$ 0.63	$ 0.66	$ 0.67	$ 0.61	$ 0.55	$ 3.08	$ 2.26	$ 2.49