Loans - Recorded Investment in Nonperforming Loans by Category (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	$ 12,344,705	$ 11,800,338
Non-Covered Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccrual loans	87,173	81,180
Loans over 90 days past due and still accruing interest	97	1,629
Nonperforming loans	87,270	82,809
Loans, including unearned loan fees	12,347,329	11,801,093
Nonaccrual loans with no allowance	52,961	54,511
Non-Covered Loans \| CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	48,914	40,311
Non-Covered Loans \| Residential Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	910	8,574
Non-Covered Loans \| Blanket Lien
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	8,659	3,391
Non-Covered Loans \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	156	15,644
Non-Covered Loans \| C&I
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccrual loans	32,950	26,359
Loans over 90 days past due and still accruing interest	88	1,620
Nonperforming loans	33,038	27,979
Loans, including unearned loan fees	5,472,681	5,236,473
Nonaccrual loans with no allowance	10,153	14,800
Non-Covered Loans \| C&I \| CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	8,750	0
Non-Covered Loans \| C&I \| Residential Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	5	19
Non-Covered Loans \| C&I \| Blanket Lien
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	8,659	3,391
Non-Covered Loans \| C&I \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	156	15,644
Non-Covered Loans \| Commercial - investor owned
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccrual loans	25,573	36,988
Loans over 90 days past due and still accruing interest	0	0
Nonperforming loans	25,573	36,988
Loans, including unearned loan fees	3,237,616	2,986,906
Nonaccrual loans with no allowance	24,590	23,685
Non-Covered Loans \| Commercial - investor owned \| CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	23,695	35,701
Non-Covered Loans \| Commercial - investor owned \| Residential Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0	0
Non-Covered Loans \| Commercial - investor owned \| Blanket Lien
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0	0
Non-Covered Loans \| Commercial - investor owned \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0	0
Non-Covered Loans \| Commercial - owner occupied
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccrual loans	25,705	9,338
Loans over 90 days past due and still accruing interest	0	0
Nonperforming loans	25,705	9,338
Loans, including unearned loan fees	2,482,819	2,460,761
Nonaccrual loans with no allowance	15,869	7,927
Non-Covered Loans \| Commercial - owner occupied \| CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	15,096	4,610
Non-Covered Loans \| Commercial - owner occupied \| Residential Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0	456
Non-Covered Loans \| Commercial - owner occupied \| Blanket Lien
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0	0
Non-Covered Loans \| Commercial - owner occupied \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0	0
Non-Covered Loans \| Construction and land development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccrual loans	1,729	155
Loans over 90 days past due and still accruing interest	0	0
Nonperforming loans	1,729	155
Loans, including unearned loan fees	747,202	689,357
Nonaccrual loans with no allowance	1,373	0
Non-Covered Loans \| Construction and land development \| CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	1,373
Non-Covered Loans \| Construction and land development \| Residential Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0
Non-Covered Loans \| Construction and land development \| Blanket Lien
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0
Non-Covered Loans \| Construction and land development \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0
Non-Covered Loans \| Residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccrual loans	1,216	8,340
Loans over 90 days past due and still accruing interest	0	0
Nonperforming loans	1,216	8,340
Loans, including unearned loan fees	356,507	367,127
Nonaccrual loans with no allowance	976	8,099
Non-Covered Loans \| Residential \| CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0	0
Non-Covered Loans \| Residential \| Residential Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	905	8,099
Non-Covered Loans \| Residential \| Blanket Lien
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0	0
Non-Covered Loans \| Residential \| Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Loans, including unearned loan fees	0	0
Non-Covered Loans \| Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Nonaccrual loans	0	0
Loans over 90 days past due and still accruing interest	9	9
Nonperforming loans	9	9
Loans, including unearned loan fees	50,504	60,469
Nonaccrual loans with no allowance	$ 0	$ 0

Financing Receivable, Excluding Accrued Interest, Nonperforming

No definition available.

Name:	efsc_FinancingReceivableExcludingAccruedInterestNonperforming
Namespace Prefix:	efsc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, of financing receivable 90 days or more past due and still accruing. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterest90DaysOrMorePastDueStillAccruing
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-5

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-34

Reference 3: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-33

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amortized cost of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

Name:	us-gaap_FinancingReceivableNonaccrualNoAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	efsc_LoansByMajorCategoryAxis=efsc_NoncoveredLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=efsc_BlanketLienMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CollateralAxis=efsc_OtherCollateralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=efsc_CommercialAndIndustrialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=efsc_CommercialRealEstateInvestorOwnedFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=efsc_CommercialRealEstateOwnerOccupiedFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=efsc_ConstructionAndLandDevelopmentFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=efsc_ResidentialRealEstateFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=efsc_ConsumerAndOtherPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: