STOCK-BASED COMPENSATION - Schedule of Unamortized Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands |
6 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2026 |
Dec. 31, 2025 |
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| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | ||
| Unamortized stock-based compensation | $ 22,677 | $ 15,309 |
| Busey Awards | 2020 Equity Plan | ||
| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | ||
| Weighted average period over which expense is to be recognized | 2 years 1 month 6 days | 1 year 9 months 18 days |
| CrossFirst Awards | ||
| Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] | ||
| Weighted average period over which expense is to be recognized | 11 months | 1 year 2 months 12 days |
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- Definition Amount of cost not yet recognized for nonvested award under share-based payment arrangement. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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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/2003/role/disclosureRef
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