XML 119 R100.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Fair Value Measurements - Narrative (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 USD ($) security | Dec. 31, 2016 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
State tax credits, held for sale, including $400 and $3,585 carried at fair value, respectively | $ 43,468 | $ 38,071
State Tax Credits Held For Sale, Fair Value Disclosure | $ 400 |
State tax credit term | 10 years |
Years of tax credits generated | 10 years |
Recurring basis |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
State tax credits, held for sale, including $400 and $3,585 carried at fair value, respectively | $ 43,500 |
Recurring basis | Significant Unobservable Inputs (Level 3) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
State Tax Credits Held For Sale, Fair Value Disclosure | $ 400 | 3,585
Auction Rate Securities | Significant Unobservable Inputs (Level 3) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Number of available-for-sale securities | security | 0 |
Portion at Other than Fair Value, Fair Value Disclosure |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
State Tax Credits Held For Sale, Fair Value Disclosure | $ 43,100 |
Estimated fair value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
State Tax Credits Held For Sale, Fair Value Disclosure | 44,271 | 41,264
Estimated fair value | Recurring basis |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
State Tax Credits Held For Sale, Fair Value Disclosure | 400 | 3,585
State tax credits held for sale, at fair value | Recurring basis | Significant Unobservable Inputs (Level 3) |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Change in unrealized (losses) gains relating to assets still held at the reporting date | $ (885) | $ 575
Minimum | State tax credits held for sale, at fair value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Discount rate | 2.30% |
Maximum | State tax credits held for sale, at fair value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Discount rate | 4.82% |
LIBOR | Maximum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Discount rate basis spread on variable rate | 285.00% |
LIBOR | LIBOR Swap Curve |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Discount rate basis point spread | 2.05 |
Discount rate basis spread on variable rate | 205.00% | 205.00%
LIBOR | Minimum |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Discount rate basis spread on variable rate | 265.00% |
Prime Rate | State tax credits held for sale, at fair value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Discount rate basis spread on variable rate | 75.00% |

X
- Definition Available-for-sale Securities, Number of Positions + References No definition available. + Details
Name: | efsc_AvailableForSaleSecuritiesNumberOfPositions
Namespace Prefix: | efsc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair Value Measurement with Unobservable Inputs Reconciliation Recurring Basis Asset Change In Unrealized Relating To Assets Still Held At Reporting Date + References No definition available. + Details
Name: | efsc_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetChangeInUnrealizedRelatingToAssetsStillHeldAtReportingDate
Namespace Prefix: | efsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition State Tax Credit Fair Value Input Discount Rate Basis Point Spread + References No definition available. + Details
Name: | efsc_StateTaxCreditFairValueInputDiscountRateBasisPointSpread
Namespace Prefix: | efsc_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition State Tax Credit Term + References No definition available. + Details
Name: | efsc_StateTaxCreditTerm
Namespace Prefix: | efsc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition State tax credits, held for sale + References No definition available. + Details
Name: | efsc_StateTaxCreditsHeldForSale
Namespace Prefix: | efsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition State Tax Credits Held For Sale, Fair Value Disclosure + References No definition available. + Details
Name: | efsc_StateTaxCreditsHeldForSaleFairValueDisclosure
Namespace Prefix: | efsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Years of Tax Credits Generated + References No definition available. + Details
Name: | efsc_YearsOfTaxCreditsGenerated
Namespace Prefix: | efsc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage points added to the reference rate to compute the variable rate on the interest rate derivative. + References No definition available. + Details
Name: | us-gaap_DerivativeBasisSpreadOnVariableRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- 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 No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_AuctionRateSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_PortionAtOtherThanFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=efsc_StateTaxCreditsHeldForSaleMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=efsc_LiborSwapCurveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_PrimeRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |