Segment Reporting	12 Months Ended
Segment Reporting	Dec. 31, 2025
Segment Reporting [Abstract]
Segment Reporting Disclosure	Segment Information The Company has one reportable operating segment, commercial banking. While our chief operating decision maker monitors revenue streams of various products and services, the identifiable segments’ operations are managed, and financial performance is evaluated on a company-wide basis. The commercial banking segment provides a broad array of financial products and services including commercial and consumer banking services, trust and wealth advisory services, and insurance to individual and business clients through most of its 78 banking center locations in 19 counties in Indiana and Michigan and Sarasota County in Florida. The accounting policies of the commercial banking segment are the same as those described in Note 1 of the Notes to Consolidated Financial Statements. The chief operating decision maker assesses performance for the commercial banking segment and decides how to allocate resources based on net income available to common shareholders which is also reported on the Consolidated Statements of Income as net income available to common shareholders. The measure of segment assets is reported on the Consolidated Statements of Financial Condition as total assets. The chief operating decision maker uses net income available to common shareholders to evaluate income generated from segment assets in deciding whether to reinvest profits into the commercial banking segment, pay dividends, or fund acquisitions. Net income available to common shareholders is also used by the chief operating decision maker to monitor budget versus actual results. Net income available to common shareholders as well as other common company-wide financial performance and credit quality metrics such as earnings per common share and net interest margin, among others, are used for competitive analysis by benchmarking to the Company’s competitors as well as used in assessing the performance of the segment and for establishing management’s compensation. See the Consolidated Statements of Financial Condition, the Consolidated Statements of Income, the Consolidated Statements of Comprehensive Income (Loss), the Consolidated Statements of Shareholders’ Equity, and the Consolidated Statements of Cash Flows. The Company’s chief operating decision maker is the Strategic Deployment Committee which includes the Executive Chairman of the Board, the President and Chief Executive Officer, the President of 1st Source Bank, the Chief Financial Officer, and several Group/Division Heads that report directly to the Chief Executive Officer or the President of 1st Source Bank.

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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+ Details

1ST SOURCE CORP 10-K