STOCK-BASED COMPENSATION -Schedule of Shares Remaining Available For Issuance Under Busey’s Equity Compensation Plans (Details)	Mar. 31, 2026 shares
2020 Equity Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares Remaining Available for Issuance Pursuant to the Plan (in shares)	746,172
ESPP
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares Remaining Available for Issuance Pursuant to the Plan (in shares)	254,688

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.

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+ Details