Income Tax Status (Details) - Community Financial System, Inc. 401(k) Employee Stock Ownership Plan |
12 Months Ended |
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Dec. 31, 2025 | |
| Income Tax Status | |
| Determination letter obtained | true |
| Determination letter date | Jan. 01, 2026 |
| Tax qualification status | us-gaap:QualifiedPlanMember |
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- Definition Date of tax determination letter for employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), in YYYY-MM-DD format. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Indicates (true false) whether tax determination letter was obtained by employer of participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Indicates tax qualification status of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Details
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