Annual report pursuant to Section 13 and 15(d)

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Assets and Liabilities Measured at Fair Value on Recurring Basis) (Detail)

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Assets and Liabilities Measured at Fair Value on Recurring Basis) (Detail) (USD $)
In Millions, unless otherwise specified
Dec. 31, 2014
Fair Value  
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]  
Deferred Compensation Plan Assets $ 24.2efx_DeferredCompensationPlanAssetsFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember 		[1]
Deferred Compensation Plan Liability (24.2)efx_DeferredCompensationPlanLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember 		[1]
Total assets and liabilities 0us-gaap_FairValueNetAssetLiability
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
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 24.2efx_DeferredCompensationPlanAssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member 		[1]
Deferred Compensation Plan Liability 0efx_DeferredCompensationPlanLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member 		[1]
Total assets and liabilities 24.2us-gaap_FairValueNetAssetLiability
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
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 		[1]
Deferred Compensation Plan Liability (24.2)efx_DeferredCompensationPlanLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member 		[1]
Total assets and liabilities (24.2)us-gaap_FairValueNetAssetLiability
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
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 		[1]
Deferred Compensation Plan Liability 0efx_DeferredCompensationPlanLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member 		[1]
Total assets and liabilities $ 0us-gaap_FairValueNetAssetLiability
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
[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 plans. 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 participants investment selections and is valued at daily quoted market prices.