Quarterly report pursuant to Section 13 or 15(d)

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Items Measured at Fair Value on Recurring Basis) (Detail)

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Items Measured at Fair Value on Recurring Basis) (Detail) (Fair Value, Measurements, Recurring, USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]  
Deferred Compensation Plan Assets $ 24.1efx_DeferredCompensationPlanAssetsFairvalueDisclosure [1]
Deferred Compensation Plan Liability (24.1)efx_DeferredCompensationPlanLiabilitiesFairValueDisclosure [1]
Total 0efx_AssetsAndLiabilityFairValueDisclosure
Quoted Prices in Active Markets for Identical Assets (Level 1)  
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]  
Deferred Compensation Plan Assets 24.1efx_DeferredCompensationPlanAssetsFairvalueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember 		[1]
Deferred Compensation Plan Liability 0efx_DeferredCompensationPlanLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Total 24.1efx_AssetsAndLiabilityFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Significant Other Observable Inputs (Level 2)  
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]  
Deferred Compensation Plan Assets 0efx_DeferredCompensationPlanAssetsFairvalueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Deferred Compensation Plan Liability (24.1)efx_DeferredCompensationPlanLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember 		[1]
Total (24.1)efx_AssetsAndLiabilityFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Significant Unobservable Inputs (Level 3)  
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]  
Deferred Compensation Plan Assets 0efx_DeferredCompensationPlanAssetsFairvalueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Deferred Compensation Plan Liability 0efx_DeferredCompensationPlanLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Total $ 0efx_AssetsAndLiabilityFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
[1] We maintain deferred compensation plans that allow for certain management employees to defer the receipt of compensation (such as salary, incentive compensation and commissions) until a later date based on the terms of the plan. The liability representing benefits accrued for plan participants is valued at the quoted market prices of the participants’ investment elections. The asset consists of mutual funds reflective of the partcipants’ investment selections and is valued at daily quoted market prices.