Nature of Operations Policy [Policy Text Block]

Nature of Operations

The Company, headquartered in Baton Rouge, Louisiana, provides full banking services, excluding trust services, through its wholly-owned banking subsidiary, Investar Bank, National Association (the “Bank”), a national bank, primarily to meet the needs of individuals and small to medium-sized businesses. The Company’s primary markets are in Louisiana, Texas and Alabama. At June 30, 2021, the Company operated 23 full service branches located in Louisiana, five full service branches located in Texas and six full service branches located in Alabama, and had 357 employees.

Use of Estimates, Policy [Policy Text Block]

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates, and such differences could be material.

Material estimates that are particularly susceptible to significant change relate to the determination of the allowance for loan losses. While management uses available information to recognize losses on loans, future additions to the allowance may be necessary based on changes in local economic conditions. In addition, regulatory agencies, as an integral part of their examination process, periodically review the Company’s allowance for loan losses. Such agencies may require the Company to recognize additions to the allowance based on their judgments about information available to them at the time of their examination. Because of these factors, it is reasonably possible that the allowance for loan losses may change materially in the near term. However, the amount of the change that is reasonably possible cannot be estimated.

Other estimates that are susceptible to significant change in the near term relate to the determination of other-than-temporary impairments of securities, and the fair value of financial instruments and goodwill.

The ongoing COVID-19 pandemic has made certain estimates more challenging, including those discussed above, as the pandemic is unprecedented in recent history, continues to evolve, and its future effects are impossible to predict with any certainty.

Marketable Securities, Policy [Policy Text Block]

Equity Securities

The Company is a member of the Federal Home Loan Bank (“FHLB”) system. Members of the FHLB are required to own a certain amount of stock based on the level of borrowings and other factors, and may invest in additional amounts. FHLB stock is carried at cost, is restricted as to redemption, and is periodically evaluated for impairment based on ultimate recovery of par value. Both cash and stock dividends are reported as income. Equity securities also include investments in our other correspondent banks including Independent Bankers Financial Corporation and First National Bankers Bank stock. These investments are carried at cost which approximates fair value. The balance of equity securities in our correspondent banks at June 30, 2021 and December 31, 2020 was $15.0 million and $14.9 million, respectively.

In addition, equity securities include marketable securities in corporate stocks and mutual funds. The estimated fair value of equity securities totaled $1.8 million and $1.7 million at June 30, 2021 and December 31, 2020, respectively.

Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]

Allowance for Loan Losses

The allowance for loan losses is estimated through a provision for loan losses charged to earnings. Loan losses are charged against the allowance when management believes the loan balance is uncollectible. Subsequent recoveries, if any, are credited to the allowance.

The allowance is an amount that management believes will be adequate to absorb probable losses inherent in the loan portfolio as of the balance sheet date based on evaluations of the collectability of loans and prior loan loss experience. The evaluations take into consideration such factors as changes in the nature and volume of the loan portfolio, overall portfolio quality, review of specific problem loans, and current economic conditions that may affect the borrower’s ability to pay. This evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available. Allowances for impaired loans are generally determined based on collateral values or the present value of estimated cash flows. Credits deemed uncollectible are charged to the allowance. Provisions for loan losses and recoveries on loans previously charged off are added to the allowance. Past due status is determined based on contractual terms.

The allowance consists of allocated and general components. The allocated component relates to loans that are classified as impaired. For loans that are 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 non-classified loans and is based on historical loss experience adjusted for qualitative factors. Based on management’s review and observations made through qualitative review, management may apply qualitative adjustments to determine loss estimates at a group and/or portfolio segment level as deemed appropriate. Management has an established methodology to determine the adequacy of the allowance for loan losses that assesses the risks and losses inherent in its portfolio and portfolio segments. The Company utilizes an internally developed model that requires judgment to determine the estimation method that fits the credit risk characteristics of the loans in its portfolio and portfolio segments. Qualitative and environmental factors that may not be directly reflected in quantitative estimates include: asset quality trends, changes in loan concentrations, new products and process changes, changes and pressures from competition, changes in lending policies and underwriting practices, trends in the nature and volume of the loan portfolio, changes in experience and depth of lending staff and management and national and regional economic trends. Changes in these factors are considered in determining changes in the allowance for loan losses. The impact of these factors on the Company’s qualitative assessment of the allowance for loan losses can change from period to period based on management’s assessment of the extent to which these factors are already reflected in historic loss rates. The uncertainty inherent in the estimation process is also considered in evaluating the allowance for loan losses.

In the ordinary course of business, the Bank enters into commitments to extend credit and standby letters of credit. Such financial instruments are recorded in the financial statements when they become payable. The credit risk associated with these commitments is evaluated in a manner similar to the allowance for loan losses. The reserve for unfunded lending commitments is included in accrued taxes and other liabilities in the consolidated balance sheet. At both June 30, 2021 and December 31, 2020 the reserve for unfunded loan commitments was $0.2 million.

Reclassification, Comparability Adjustment [Policy Text Block]

Reclassifications

Certain reclassifications have been made to the 2020 financial statements to be consistent with the 2021 presentation, if applicable.

New Accounting Pronouncements, Policy [Policy Text Block]

Accounting Standards Adopted in 2021

FASB ASC Topics 321, 323, and 815 “Investments—Equity Securities (Topic 321), Investments—Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815)” ASU No. 2020-01. ASU 2020-01 became effective for the Company on January 1, 2021. The ASU clarifies the interaction among ASC 321, ASC 323, and ASC 815 for equity securities, equity method investments, and certain financial instruments to acquire equity securities. It clarifies whether re-measurement of equity investments is appropriate when observable transactions cause the equity method to be triggered or discontinued. ASU 2020-01 also provides that certain forward contracts and purchased options to acquire equity securities will be measured under ASC 321 without an assessment of subsequent accounting upon settlement or exercise. The adoption of ASU 2020-01 did not have a material impact on the consolidated financial statements.

Accounting Pronouncements Not Yet Adopted

FASB ASC Topic 326 “Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments” Update No. 2016-13. The FASB issued ASU No. 2016-13 in June 2016. The ASU 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 available-for-sale debt securities and purchased financial assets with credit deterioration. We are currently evaluating the potential impact of ASU 2016-13 on our financial statements. In that regard, we have formed a cross-functional working group, under the direction of our Chief Financial Officer and our Chief Risk Officer. The working group is comprised of individuals from various functional areas including credit, risk management, finance and information technology. We have developed an implementation plan to include assessment of processes, portfolio segmentation, model development, system requirements and the identification of data and resource needs, among other things. We have also selected a third-party vendor solution to assist us in the application of ASU 2016-13.

The adoption of ASU 2016-13 is likely to result in an increase in the allowance for loan losses as a result of changing from an “incurred loss” model, which encompasses allowances for current known and inherent losses within the portfolio, to an “expected loss” model, which encompasses allowances for losses expected to be incurred over the life of the portfolio. Furthermore, ASU 2016-13 will necessitate that we establish an allowance for expected credit losses on debt securities. 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.

This amendment was originally effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. In July 2019, the FASB proposed changes that would delay the effective date for smaller reporting companies, as defined by the SEC, and other non-SEC reporting entities. In October 2019, the FASB voted in favor of finalizing its proposal to delay the effective date of this standard to fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. ASU 2016-13 will be effective for the Company on January 1, 2023. The Company expects to adopt the standard as soon as practicable, based upon progress on the implementation plan. Adoption prior to the revised effective date of January 1, 2023 is permitted by the ASU.

FASB ASC Topic 848 “Reference Rate Reform: Facilitation of the Effects of Reference Rate Reform on Financial Reporting” Update No. 2020-04. In March 2020, the FASB issued ASU 2020-04, which is intended to provide temporary optional expedients and exceptions to the GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens related to the expected market transition from the London Interbank Offered Rate (“LIBOR”) and other interbank offered rates to alternative reference rates. This guidance is effective beginning on March 12, 2020, and the Company may elect to apply the amendments prospectively through December 31, 2022. The Company is currently evaluating the provisions of the amendment and the impact on its future consolidated financial statements.