Entity tax identification number Entity Tax Identification Number Rollovers EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Maximum Maximum [Member] 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] Pretax, maximum annual compensation to total compensation, percentage EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage 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] Minimum borrowing, amount EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount Total investments, at fair value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Level 1 Fair Value, Inputs, Level 1 [Member] Net asset value per unit (in dollars per share) EBP, Net Asset Value per Share or Unit EBP, Investment, Fair Value and NAV [Abstract] Assets: EBP, Asset [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] Additions: 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] Amendment Flag Amendment Flag Basis of Accounting EBP, Basis of Accounting [Policy Text Block] Safe Harbor Matching Contribution Safe Harbor Matching Contribution [Member] Safe Harbor Matching Contribution EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] Interest rate EBP, Investment, Interest Rate Number of units (in shares) EBP, Investment, Number of Shares EBP, Description of Plan and Accounting Change [Abstract] EBP, Investment, Fair Value and NAV EBP, Investment, Fair Value and NAV [Table Text Block] Market price (in dollars per share) EBP, Common Stock, Market Price Per Share EBP, Common Stock, Market Price Per Share EFSC common stock Common Stock [Member] Investments [Domain] Investments [Domain] Estimates and Assumptions EBP, Use of Estimate [Policy Text Block] Schedule H, Line 4i – Schedule of Assets (Held At End of Year) EBP, Schedule of Asset Held for Investment [Text Block] Cover [Abstract] Employer, net of forfeitures EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash Investment, purchased, number of shares (in shares) EBP, Investment, Purchased, Number of Shares Minimum Minimum [Member] EBP, Schedule of Reportable Transaction [Abstract] Interest income on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Investment Type [Axis] Investment Type [Axis] Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution Participants EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment Dividend and interest income 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] Description of Plan 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, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Line Items] EFSC 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 Investment activity: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Investment, Identifier [Axis] Investment, Identifier [Axis] Administrative expenses EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Employer Matching Contribution EBP, Employer Matching Contribution [Member] EBP, Employer Matching Contribution Risk and Uncertainties EBP, Risk and Uncertainty [Policy Text Block] Document Information [Line Items] Document Information [Line Items] Interest-bearing cash Interest-Bearing Deposits [Member] EBP 001 EBP 001 [Member] EBP 001 EBP, Statement of Change in Net Asset Available for Benefit [Abstract] Level 2 Fair Value, Inputs, Level 2 [Member] Investment sold, number of shares (in shares) EBP, Investment, Sold, Number of Shares Percentage of vested investments upon termination EBP, Plan Termination, Percentage Of Vested Investments Upon Termination EBP, Plan Termination, Percentage Of Vested Investments Upon Termination EBP, Employer Contribution, Type [Domain] EBP, Employer Contribution, Type [Domain] EBP, Employer Contribution, Type [Domain] EBP, Tax Status [Table] EBP, Tax Status [Table] Net increase EBP, Change in Net Asset Available for Benefit, Increase (Decrease) 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 Transactions with Related Parties and Parties-in-Interest 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] Automatic deferral rate EBP, Participant Contribution, Automatic, Deferral Rate Investments, at fair value: EBP, Investment, Fair Value [Abstract] Benefits paid to participants EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant 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. Current Value 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] Participant loans Participant Loans [Member] Participant Loans EBP, Statement of Net Asset Available for Benefit [Abstract] EBP, Accounting Policy [Line Items] EBP, Accounting Policy [Line Items] EBP, Tax Status [Abstract] EFSC common stock fund EBP, Employer, Common Stock Fund [Member] Basis spread on variable rate EBP, Participant Loan, Basis Spread On Variable Rate EBP, Participant Loan, Basis Spread On Variable Rate Noninterest-bearing cash EBP, Noninterest-Bearing Cash Benefits paid upon plan termination EBP, Payment Of Benefits Upon Termination EBP, Payment Of Benefits Upon Termination Investment Valuation and Income Recognition EBP, Investment [Policy Text Block] 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 Collective trust funds Common Collective Trust [Member] EBP, Tax Status [Line Items] EBP, Tax Status [Line Items] Deductions: EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Forfeited nonvested account, decrease from employer contribution EBP, Forfeited Nonvested Account, Decrease from Employer Contribution Notes receivable from participants EBP, Note Receivable from Participant Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Summary of Significant Accounting Policies EBP, Summary of Accounting Policy [Text Block] Entity Registrant Name Entity Registrant Name 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 Document Information [Table] Document Information [Table] Total investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Automatic deferral rate, annual increase EBP, Participant Contribution, Automatic, Annual Increase Deferral Rate Annual increase in percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) until the contribution reaches maximum threshold. 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] Fixed Rate Contribution EBP, Fixed Rate Contribution [Member] EBP, Fixed Rate Contribution Vesting percentage, second year EBP, Employer Contribution Vesting Percentage, Second Year EBP, Employer Contribution Vesting Percentage, Second Year Net assets available for benefits Net assets available for benefits at beginning of year Net assets available for benefits at end of year EBP, Net Asset Available for Benefit Entity [Domain] Entity [Domain] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] EBP, Employer Contribution, Type [Axis] EBP, Employer Contribution, Type [Axis] EBP, Employer Contribution, Type Forfeited nonvested account EBP, Forfeited Nonvested Account EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Table] Vesting percentage, first year EBP, Employer Contribution Vesting Percentage, First Year EBP, Employer Contribution Vesting Percentage, First Year EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Line Items]