v2.4.0.8

Portfolio Loans Covered by Loss Share (Covered loans) - Summary of Activity in the FDIC Loss Share Receivable (Details) (USD $) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2013 | Sep. 30, 2013 | Sep. 30, 2012 | Dec. 31, 2012
PORTFOLIO LOANS COVERED BY LOSS SHARE [Abstract] |  |  |  |
FDIC loss share receivable | $ 40,054,000 | $ 40,054,000 |  | $ 61,475,000
Net cash proceeds received from FDIC loss share receivable |  | 9,654,000 | 85,173,000 |
FDIC Indemnification Asset, Period Increase (Decrease) |  | 1,880,000 |  |
FDIC Indemnification Asset, Accretion of Discount |  | (9,574,000) |  |
Loan impairment recapture |  | 2,205,000 |  |
Reductions for payments on Covered assets in excess of expected cash flows |  | (6,278,000) |  |
Amount of Estimated Clawback Liability | 1,400,000 | 1,400,000 |  |
Adjustment in FDIC clawback liability | $ 62,000 |  |  |

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- Definition Adjustment in FDIC clawback liability + References No definition available. + Details
Name: | efsc_AdjustmentInFdicClawbackLiability
Namespace Prefix: | efsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition Amount of estimated clawback liability + References No definition available. + Details
Name: | efsc_AmountOfEstimatedClawbackLiability
Namespace Prefix: | efsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition FDIC loss share receivable + References No definition available. + Details
Name: | efsc_FdicLossShareReceivable
Namespace Prefix: | efsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Loan impairment recapture + References No definition available. + Details
Name: | efsc_Loanimpairmentrecapture
Namespace Prefix: | efsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Definition Net cash proceeds received from FDIC loss share receivable + References No definition available. + Details
Name: | efsc_NetCashProceedsReceivedFromFdicLossShareReceivable
Namespace Prefix: | efsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Details
Name: | efsc_PortfolioLoansCoveredByLossShareAbstract
Namespace Prefix: | efsc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Reductions for payments on Covered assets in excess of expected cash flows + References No definition available. + Details
Name: | efsc_ReductionsforpaymentsonCoveredassetsinexcessofexpectedcashflows
Namespace Prefix: | efsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Definition Increases to the indemnification asset due to accretion of the loan discount relating to loss sharing agreements with the Federal Deposit Insurance Corporation (FDIC). + References No definition available. + Details
Name: | us-gaap_FDICIndemnificationAssetAccretionOfDiscount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition Change in carrying amount of the indemnification asset relating to loss sharing agreements with the Federal Deposit Insurance Corporation (FDIC). The change includes for example, but is not limited to, acquisitions, additional estimated losses, disposals, cash payments, accretion of discount and write-offs, net of recoveries. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration