Basis of Presentation and Changes in Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2025
Basis of Presentation and Changes in Significant Accounting Policies
Recent Accounting Pronouncements	Recent Accounting Pronouncements The following is a summary of recent accounting pronouncements that have impacted or could potentially affect the Company: ASU 2023-06 – On October 9, 2023, the FASB issued ASU 2023-06 “Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative.” The amendments in the ASU modify the disclosure or presentation requirements of a variety of topics in the codification. Certain of the amendments represent clarifications to, or technical corrections of, the current requirements. Each amendment in the ASU will only become effective if the SEC removes the related disclosure or presentation requirement from its existing regulations by June 30, 2027. The amendments in this ASU are not expected to have a material impact on the financial statements of the Company. ASU 2023-09 – On December 14, 2023, the FASB issued ASU 2023-09 “Income Taxes (Topic 740): Improvements to Income Tax Disclosures”. The amendments require that public business entities on an annual basis (1) disclose specific categories in the rate reconciliation, and (2) provide additional information for reconciling items that meet a quantitative threshold (if the effect of those reconciling items is equal to or greater than 5 percent of the amount computed by multiplying pretax income (or loss) by the applicable statutory income tax rate). The amendments require that all entities disclose on an annual basis the following information about income taxes paid: (1) The amount of income taxes paid (net of refunds received) disaggregated by federal (national), state, and foreign taxes, and (2) The amount of income taxes paid (net of refunds received) disaggregated by individual jurisdictions in which income taxes paid (net of refunds received) is equal to or greater than 5 percent of total income taxes paid (net of refunds received). The amendments also require that all entities disclose the following information: (1) Income (or loss) from continuing operations before income tax expense (or benefit) disaggregated between domestic and foreign, and (2) Income tax expense (or benefit) from continuing operations disaggregated by federal (national), state, and foreign. The ASU is effective for public business entities for annual periods beginning after December 15, 2024. Early adoption is permitted for annual financial statements that have not yet been issued or made available for issuance. The amendments should be applied on a prospective basis. Retrospective application is permitted. The Company is required to adopt the expanded disclosure requirements of this ASU in its annual financial statements as of December 31, 2025, and does not expect the amendments to have a material impact to the financial statements of the Company. ASU 2024-03 and ASU 2025-01 – On November 4, 2024, the FASB issued ASU 2024-03 “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses.” This ASU requires public companies to disclose, in the notes to financial statements, specified information about certain costs and expenses at each interim and annual reporting period. Specifically, they will be required to: (1) Disclose the amounts of (a) purchases of inventory; (b) employee compensation; (c) depreciation; (d) intangible asset amortization; and (e) depreciation, depletion, and amortization recognized as part of oil- and gas-producing activities (or other amounts of depletion expense) included in each relevant expense caption; (2) Include certain amounts that are already required to be disclosed under current generally accepted accounting principles (GAAP) in the same disclosure as the other disaggregation requirements; (3) Disclose a qualitative description of the amounts remaining in relevant expense captions that are not separately disaggregated quantitatively; and (4) Disclose the total amount of selling expenses and, in annual reporting periods, an entity’s definition of selling expenses. ASU 2024-03 is effective for public business entities for annual reporting periods beginning after December 15, 2026, and interim reporting periods within annual reporting periods beginning after December 15, 2027, which dates were clarified in ASU 2025-01, and is not expected to have a material impact on the financial statements of the Company. ASU 2025-03 – On May 12, 2025, the FASB issued ASU 2024-03 “Business Combinations (Topic 805) and Consolidation (Topic 810): Determining the Accounting Acquirer in the Acquisition of a Variable Interest Entity.” This ASU revises current guidance for determining the accounting acquirer for a transaction effected primarily by exchanging equity interests in which the legal acquiree is a variable interest entity that meets the definition of a business. The amendments require an entity to consider the same factors that are currently required for determining which entity is the accounting acquirer in other acquisition transactions. This ASU is effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods within those annual reporting periods. Early adoption is permitted in an interim or annual reporting period in which financial statements have not yet been issued (or made available for issuance). If an entity adopts ASU No. 2025-03 in an interim reporting period, it should adopt it as of the beginning of that interim reporting period or the beginning of the annual reporting period that includes that interim reporting period. An entity should apply ASU 2025-03 on a prospective basis to all business combinations that have an acquisition date that occurs on or after the date of initial application of ASU 2025-03. ASU 2025-03 is not expected to have a material impact on the financial statements of the Company.
Subsequent Events	Subsequent Events Dividends On July 15, 2025, our Board of Directors declared a cash dividend of $0.06 per share of common stock payable on August 4, 2025, to stockholders of record as of July 25, 2025; dividends of $3.2 million were paid to stockholders on August 4, 2025. Merger with Bancorp Financial, Inc. On July 1, 2025, the Company completed its previously announced merger with Bancorp Financial, pursuant to the agreement and plan of merger dated February 24, 2025. At the effective time of the merger, Bancorp Financial merged with and into the Company, with the Company continuing as the surviving corporation. Immediately following the merger, Evergreen Bank Group, an Illinois-chartered banking corporation and wholly owned subsidiary of Bancorp Financial, merged with and into Old Second National Bank (the “Bank”), a national banking association and wholly owned subsidiary of the Company, with the Bank continuing as the surviving bank. Under the terms of the merger agreement, each share of Bancorp Financial common stock outstanding immediately prior to the effective time was converted into the right to receive 2.5814 shares of Old Second common stock and $15.93 in cash, without interest, with cash paid in lieu of any fractional shares.

Basis of Presentation and Changes in Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2025

Basis of Presentation and Changes in Significant Accounting Policies

Recent Accounting Pronouncements

The following is a summary of recent accounting pronouncements that have impacted or could potentially affect the Company:

ASU 2023-06 – On October 9, 2023, the FASB issued ASU 2023-06 “Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative.” The amendments in the ASU modify the disclosure or presentation requirements of a variety of topics in the codification. Certain of the amendments represent clarifications to, or technical corrections of, the current requirements. Each amendment in the ASU will only become effective if the SEC removes the related disclosure or presentation requirement from its existing regulations by June 30, 2027. The amendments in this ASU are not expected to have a material impact on the financial statements of the Company.

ASU 2023-09 – On December 14, 2023, the FASB issued ASU 2023-09 “Income Taxes (Topic 740): Improvements to Income Tax Disclosures”. The amendments require that public business entities on an annual basis (1) disclose specific categories in the rate reconciliation, and (2) provide additional information for reconciling items that meet a quantitative threshold (if the effect of those reconciling items is equal to or greater than 5 percent of the amount computed by multiplying pretax income (or loss) by the applicable statutory income tax rate). The amendments require that all entities disclose on an annual basis the following information about income taxes paid: (1) The amount of income taxes paid (net of refunds received) disaggregated by federal (national), state, and foreign taxes, and (2) The amount of income taxes paid (net of refunds received) disaggregated by individual jurisdictions in which income taxes paid (net of refunds received) is equal to or greater than 5 percent of total income taxes paid (net of refunds received). The amendments also require that all entities disclose the following information: (1) Income (or loss) from continuing operations before income tax expense (or benefit) disaggregated between domestic and foreign, and (2) Income tax expense (or benefit) from continuing operations disaggregated by federal (national), state, and foreign. The ASU is effective for public business entities for annual periods beginning after December 15, 2024. Early adoption is permitted for annual financial statements that have not yet been issued or made available for issuance. The amendments should be applied on a prospective basis. Retrospective application is permitted. The Company is required to adopt the expanded disclosure requirements of this ASU in its annual financial statements as of December 31, 2025, and does not expect the amendments to have a material impact to the financial statements of the Company.

ASU 2024-03 and ASU 2025-01 – On November 4, 2024, the FASB issued ASU 2024-03 “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses.” This ASU requires public companies to disclose, in the notes to financial statements, specified information about certain costs and expenses at each interim and annual reporting period. Specifically, they will be required to: (1) Disclose the amounts of (a) purchases of inventory; (b) employee compensation; (c) depreciation; (d) intangible asset amortization; and (e) depreciation, depletion, and amortization recognized as part of oil- and gas-producing activities (or other amounts of depletion expense) included in each relevant expense caption; (2) Include certain amounts that are already required to be disclosed under current generally accepted accounting principles (GAAP) in the same disclosure as the other disaggregation requirements; (3) Disclose a qualitative description of the amounts remaining in relevant expense captions that are not separately disaggregated quantitatively; and (4) Disclose the total amount of selling expenses and, in annual reporting periods, an entity’s definition of selling expenses. ASU 2024-03 is effective for public business entities for annual reporting periods beginning after December 15, 2026, and interim reporting periods within annual reporting periods beginning after December 15, 2027, which dates were clarified in ASU 2025-01, and is not expected to have a material impact on the financial statements of the Company.

ASU 2025-03 – On May 12, 2025, the FASB issued ASU 2024-03 “Business Combinations (Topic 805) and Consolidation (Topic 810): Determining the Accounting Acquirer in the Acquisition of a Variable Interest Entity.” This ASU revises current guidance for determining the accounting acquirer for a transaction effected primarily by exchanging equity interests in which the legal acquiree is a variable interest entity that meets the definition of a business. The amendments require an entity to consider the same factors that are currently required for determining which entity is the accounting acquirer in other acquisition transactions. This ASU is effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods within those annual reporting periods. Early adoption is permitted in an interim or annual reporting period in which financial statements have not yet been issued (or made available for issuance). If an entity adopts ASU No. 2025-03 in an interim reporting period, it should adopt it as of the beginning of that interim reporting period or the beginning of the annual reporting period that includes that interim reporting period. An entity should apply ASU 2025-03 on a prospective basis to all business combinations that have an acquisition date that occurs on or after the date of initial application of ASU 2025-03. ASU 2025-03 is not expected to have a material impact on the financial statements of the Company.

Subsequent Events

Subsequent Events

Dividends

On July 15, 2025, our Board of Directors declared a cash dividend of $0.06 per share of common stock payable on August 4, 2025, to stockholders of record as of July 25, 2025; dividends of $3.2 million were paid to stockholders on August 4, 2025.

Merger with Bancorp Financial, Inc.

On July 1, 2025, the Company completed its previously announced merger with Bancorp Financial, pursuant to the agreement and plan of merger dated February 24, 2025. At the effective time of the merger, Bancorp Financial merged with and into the Company, with the Company continuing as the surviving corporation. Immediately following the merger, Evergreen Bank Group, an Illinois-chartered banking corporation and wholly owned subsidiary of Bancorp Financial, merged with and into Old Second National Bank (the “Bank”), a national banking association and wholly owned subsidiary of the Company, with the Bank continuing as the surviving bank. Under the terms of the merger agreement, each share of Bancorp Financial common stock outstanding immediately prior to the effective time was converted into the right to receive 2.5814 shares of Old Second common stock and $15.93 in cash, without interest, with cash paid in lieu of any fractional shares.