Entity tax identification number Entity Tax Identification Number Participant rollovers EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Maximum Maximum [Member] Forfeited nonvested account, decrease from administrative expense EBP, Forfeited Nonvested Account, Decrease from Administrative Expense Legal Entity [Axis] Legal Entity [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] EBP, Description of Plan [Table] EBP, Description of Plan [Table] Mutual funds Mutual Fund [Member] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Fully Benefit-Responsive Investment Contract [Table] EBP, Fully Benefit-Responsive Investment Contract [Table] Total deductions EBP, Change in Net Asset Available for Benefit, Decrease Maximum borrowing, amount EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount FAIR VALUE MEASUREMENTS EBP, Investment, Fair Value and NAV [Text Block] EBP 002 EBP 002 [Member] EBP 002 Participant directed investments, at fair value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Money market account Money Market Funds [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Cash EBP, Cash [Member] EBP, Cash EBP, Investment, Fair Value and NAV [Abstract] Vesting percentage EBP, Employer Contribution Vesting Percentage Company contribution and/ or investment earning percentage vesting to the participant in Company Matching Contributions, Fixed Rate Contributions, Discretionary Profit-Sharing Contributions, Qualified Non-Elective Contributions, and Disability Contributions, upon completion of minimum service period or attainment of maximum vesting age EBP, Related Party and Party-in-Interest Transactions EBP, Related Party and Party-in-Interest Transactions [Table Text Block] ASSETS EBP, Asset [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] ADDITIONS TO NET ASSETS EBP, Change in Net Asset Available for Benefit, Increase [Abstract] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Table] Payment of Benefits EBP, Payment to Participant [Policy Text Block] Charles Schwab Bank EBP, Trustee [Member] Amendment Flag Amendment Flag Basis of Accounting EBP, Basis of Accounting [Policy Text Block] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] EBP, Description of Plan and Accounting Change [Abstract] Receivables: EBP, Receivable [Abstract] EBP, Investment, Fair Value and NAV EBP, Investment, Fair Value and NAV [Table Text Block] EBP, Contingency [Table] EBP, Contingency [Table] Maximum number of loans outstanding EBP, Note Receivable From Participant, Maximum Number Of Loans Outstanding EBP, Note Receivable From Participant, Maximum Number Of Loans Outstanding EBP, Contingency [Abstract] Investments [Domain] Investments [Domain] Use of Estimates and Assumptions EBP, Use of Estimate [Policy Text Block] EBP, Related Party and Party-in-Interest [Domain] EBP, Related Party and Party-in-Interest [Domain] Schedule H, Line 4i – Schedule of Assets (Held At End of Year) EBP, Schedule of Asset Held for Investment [Text Block] Cover [Abstract] Employers EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash Minimum Minimum [Member] EBP, Related Party and Party-in-Interest [Axis] EBP, Related Party and Party-in-Interest [Axis] Investment Type [Axis] Investment Type [Axis] Interest from notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution Concentration EBP, Concentration [Policy Text Block] EBP, Concentration Participants EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Next Two Percent Next Two Percent [Member] Next Two Percent Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment Interest and dividends on investments EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment EBP, Description of Plan [Line Items] EBP, Description of Plan [Line Items] Plan number EBP, Plan Number EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Line Items] PLAN DESCRIPTION EBP, Description of Plan [Text Block] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Employer Contribution, Rate [Axis] EBP, Employer Contribution, Rate [Axis] EBP, Employer Contribution, Rate Managed funds Managed Funds [Member] Managed Funds EBP, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Line Items] Common stock EBP, Employer, Common Stock [Member] EBP, Schedule of Asset Held for Investment [Abstract] EBP, Accounting Policy [Table] EBP, Accounting Policy [Table] Total additions EBP, Change in Net Asset Available for Benefit, Increase Allowance for credit loss EBP, Note Receivable from Participant, Allowance for Credit Loss First Three Percent First Three Percent [Member] First Three Percent Investment income: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] EBP, Employer Contribution, Rate [Domain] EBP, Employer Contribution, Rate [Domain] EBP, Employer Contribution, Rate [Domain] Investment, Identifier [Axis] Investment, Identifier [Axis] Administrative expenses EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Total EBP, Asset Held for Investment Vesting period EBP, Employer Contribution Vesting Service Period Minimum Vesting service period for company contribution and/ or investment earning to the participant in Company Matching Contributions, Fixed Rate Contributions, Discretionary Profit-Sharing Contributions, Qualified Non-Elective Contributions, and Disability Contributions. Risks and Uncertainties EBP, Risk and Uncertainty [Policy Text Block] Document Information [Line Items] Document Information [Line Items] Participant compensation matched, percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, Statement of Change in Net Asset Available for Benefit [Abstract] Level 2 Fair Value, Inputs, Level 2 [Member] EBP, Fully Benefit-Responsive Investment Contract [Line Items] EBP, Fully Benefit-Responsive Investment Contract [Line Items] NET ASSETS AVAILABLE FOR BENEFITS EBP, Net Asset Available for Benefit [Abstract] EBP, Net Asset Available for Benefit EBP, Tax Status [Table] EBP, Tax Status [Table] NET INCREASE EBP, Change in Net Asset Available for Benefit, Increase (Decrease) PARTY-IN-INTEREST TRANSACTIONS EBP, Related Party and Party-in-Interest Transactions [Text Block] EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Total receivables EBP, Receivable Employers’ contributions EBP, Employer Contribution, Receivable Benefits paid to participants EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant TOTAL INVESTMENTS EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] EBP, Statement of Net Asset Available for Benefit [Abstract] Involuntary cash-out limit EBP, Involuntary Cash-out Limit EBP, Involuntary Cash-out Limit Employer sharing contribution EBP, Employer Sharing Contribution Of Eligible Compensation EBP, Employer Sharing Contribution Of Eligible Compensation EBP, Accounting Policy [Line Items] EBP, Accounting Policy [Line Items] Participant compensation matched, minimum service period EBP, Requisite Service Period EBP, Requisite Service Period RECENT LEGISLATION EBP, Recent Legislation [Text Block] EBP, Recent Legislation First Busey Corporation EBP, Employer [Member] EBP, Employer EBP, Tax Status [Abstract] Stock fund EBP, Employer, Common Stock Fund [Member] Cash EBP, Noninterest-Bearing Cash Expenses EBP, Expense [Policy Text Block] Participant loan, current value EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Investment Valuation and Income Recognition EBP, Investment [Policy Text Block] Employees’ contributions EBP, Participant Contribution, Receivable Total Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Document Type Document Type PLAN TERMINATION EBP, Plan Termination [Text Block] Entity Central Index Key Entity Central Index Key Participant loan, interest rate EBP, Asset Held for Investment, Participant Loan, Interest Rate EBP, Tax Status [Line Items] EBP, Tax Status [Line Items] Primary residence, borrowing term EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term DEDUCTIONS FROM NET ASSETS EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Notes receivable from participants EBP, Note Receivable from Participant Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] SIGNIFICANT ACCOUNTING POLICIES EBP, Summary of Accounting Policy [Text Block] Entity Registrant Name Entity Registrant Name General loan, borrowing term EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term Subsequent Events EBP, Subsequent Event [Policy Text Block] INCOME TAX STATUS EBP, Tax Status [Text Block] Maximum borrowing, to total account, percentage EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage Percent of investment assets concentration EBP, Risk and Uncertainty, Concentration of Investment at Fair Value to Total Investments, Percentage EBP, Contingency [Line Items] EBP, Contingency [Line Items] Document Information [Table] Document Information [Table] Notes Receivable from Participants EBP, Note Receivable from Participant [Policy Text Block] Participant compensation matched, minimum service time EBP, Requisite Service Time EBP, Requisite Service Time Total investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Line Items] Level 3 Fair Value, Inputs, Level 3 [Member] Common stock and stock fund EBP, Employer, Common Stock And Stock Fund [Member] EBP, Employer, Common Stock And Stock Fund Net assets available for benefits Beginning of year End of year EBP, Net Asset Available for Benefit Entity [Domain] Entity [Domain] Participant compensation matched, minimum age EBP, Participant Minimum Age EBP, Participant Minimum Age Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Forfeited nonvested account EBP, Forfeited Nonvested Account Matching percentage EBP, Employer Contribution, Matching Percentage EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Line Items]