v2.4.0.6

Fair Value Measurements - Estimate of the Fair Value of Financial Instruments Not Recorded at Fair Value on Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Financial Assets:
State tax credits held for sale	$ 20,053	$ 23,020
Fair Value, Level 1
Financial Assets:
Portfolio loans, net	0	0
State tax credits held for sale	0	0
Financial Liabilities:
Deposits	1,963,937	2,079,141
Subordinated debentures	0	0
Federal Home Loan Bank advances	0	0
Other borrowings	0	0
Fair Value, Level 2
Financial Assets:
Portfolio loans, net	0	0
State tax credits held for sale	0	0
Financial Liabilities:
Deposits	0	0
Subordinated debentures	65,760	65,840
Federal Home Loan Bank advances	88,482	89,301
Other borrowings	205,477	245,224
Fair Value, Level 3
Financial Assets:
Portfolio loans, net	2,224,976	2,266,834
State tax credits held for sale	40,850	43,802
Financial Liabilities:
Deposits	538,842	589,972
Subordinated debentures	0	0
Federal Home Loan Bank advances	0	0
Other borrowings	0	0
Estimated fair value
Financial Assets:
Portfolio loans, net	2,224,976	2,266,834
State tax credits held for sale	40,850	43,802
Financial Liabilities:
Deposits	2,502,779	2,669,113
Subordinated debentures	65,760	65,840
Federal Home Loan Bank advances	88,482	89,301
Other borrowings	$ 205,477	$ 245,224

X

- Definition

Loans And Leases Receivable Net Reported Amount Fair Value Disclosure

+ References

No definition available.

+ Details

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

X

- Definition

Other Borrowings Fair Value Disclosure

+ References

No definition available.

+ Details

Name:	efsc_OtherBorrowingsFairValueDisclosure
Namespace Prefix:	efsc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

State Tax Credits Held For Sale, Fair Value Disclosure

+ References

No definition available.

+ Details

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

X

- Details

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

X

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure. This item represents the aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits among others.

+ References

No definition available.

+ Details

Name:	us-gaap_DepositsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Amount of subordinated debt obligations (also known as subordinated loan, subordinated bond, subordinated debenture or junior debt) which has a priority ranking after other debts in a dissolution, measured at fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents an amount a bank borrows from the Federal Home Loan Bank [system] primarily to provide medium- and long-term sources of funding for its residential-mortgage and economic-development lending activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-DEP

-Paragraph 17

-IssueDate 2006-05-01

-Chapter 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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- Details

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Balance Type:	na
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