Future Accounting Matters	12 Months Ended
Future Accounting Matters	Dec. 31, 2019
Accounting Changes and Error Corrections [Abstract]
Future Accounting Matters	Note 30 – Future Accounting Matters Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement The FASB has issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement . These amendments modify the disclosure requirements in Topic 820 as follows: Removals : the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy; the policy for timing of transfers between levels; and the valuation processes for Level 3 fair value measurements. Modifications : for investments in certain entities that calculate net asset value, an entity is required to disclose the timing of liquidation of an investee’s assets and the date when restrictions from redemption might lapse only if the investee has communicated the timing to the entity or announced the timing publicly; and the amendments clarify that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date. Additions : the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements held at the end of the reporting period; and the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The guidance is effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should all be applied prospectively for only the most recent interim or annual period presented in the initial year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted. An entity is permitted to early adopt any removed or modified disclosures upon issuance of ASU No. 2018-13 and delay adoption of the additional disclosures until their effective date. We are currently evaluating the impact of ASU 2018-13 and the impact on our accounting and disclosures. FASB ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment The FASB has issued ASU No. 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The new guidance is intended to simplify the subsequent measurement of goodwill by eliminating Step 2 from the goodwill impairment test. The annual, or interim, goodwill impairment test is performed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized 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. In addition, the income tax effects of tax deductible goodwill on the carrying amount of the reporting unit should be considered when measuring the goodwill impairment loss, if applicable. The amendments also eliminate the requirements for any reporting unit with a zero or negative carrying amount to perform Step 2 of the goodwill impairment test. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the qualitative impairment test is necessary. The amendments should be applied on a prospective basis. The nature of a reason for the change in accounting principle should be disclosed upon transition. The amendments in this update should be adopted for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted on testing dates after January 1, 2017. We are currently evaluating the impact of the new guidance on the consolidated financial statements, but it is not expected to have a material impact. FASB ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments The FASB has issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . The main objective of this amendment is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The amendment 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. Financial institutions and other organizations will now use forward-looking information to enhance their credit loss estimates. The amendment requires enhanced disclosures to help investors and other financial statement users better understand 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, the ASU amends the accounting for credit losses on available-for-sale debt securities and purchased financial assets with credit deterioration. The amendments in this update become effective for annual periods and interim periods within those annual periods beginning after December 15, 2019. Our Current Expected Credit Loss (“CECL”) task force has been meeting on a monthly basis, at a minimum, to review implementation matters related to the completeness and accuracy of historical data, model development and corporate governance documentation. Specifically regarding model development, the task force has analyzed results from parallel model runs for each portfolio segment and evaluated assumptions related to unfunded commitments, acquired performing loans, and economic and forecast factors. Our task force has also reviewed new corporate governance documentation, such as our new CECL Allowance for Credit Losses (“ACL”) policy, procedure manuals and internal control documentation. Horizon has completed data and model validation testing, determined qualitative adjustments, established additional supporting analytics, and developed related internal controls over model inputs (data and assumptions) and model operations. While the model is operational, approval of certain governance related matters, procedures and policies are being finalized. The final year-end estimate for CECL has not been determined and the required financial reporting disclosures are being completed for review. Internal controls over financial reporting specifically related to CECL have been designed and are being evaluated, however, all internal controls related to CECL implementation are not operational. The final step of completing the formal governance and approval process is in its final stages. We expect the one-time cumulative effect adjustment to the ACL will be between $16.2 million and $20.8 million upon adoption as of January 1, 2020. The majority of the increase is related to including our acquired loan portfolios in the model and the addition of using economic forecasts in estimating future losses. As we continue to evaluate and refine our CECL model during the first quarter of 2020, the estimated range of impact to the ACL as of January 1, 2020 could change.