Quarterly report pursuant to Section 13 or 15(d)

GOODWILL AND INTANGIBLE ASSETS (Changes in Amount of Goodwill) (Detail)

v2.4.1.9
GOODWILL AND INTANGIBLE ASSETS (Changes in Amount of Goodwill) (Detail) (USD $)
In Millions, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Goodwill [Line Items]  
Balance, December 31, 2014 $ 2,606.8us-gaap_Goodwill
Acquisitions 0us-gaap_GoodwillAcquiredDuringPeriod
Adjustments to initial purchase price allocation 0us-gaap_GoodwillPurchaseAccountingAdjustments
Foreign currency translation (19.4)us-gaap_GoodwillTranslationAdjustments
Tax benefits of stock options exercised 0efx_GoodwillTaxDeductionFromExerciseOfStockOptions
Balance, March 31, 2015 2,587.4us-gaap_Goodwill
U.S. Information Solutions  
Goodwill [Line Items]  
Balance, December 31, 2014 1,120.6us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
Acquisitions 0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
Adjustments to initial purchase price allocation 0us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
Foreign currency translation 0us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
Tax benefits of stock options exercised 0efx_GoodwillTaxDeductionFromExerciseOfStockOptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
Balance, March 31, 2015 1,120.6us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
International  
Goodwill [Line Items]  
Balance, December 31, 2014 487.0us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember 		[1]
Acquisitions 0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Adjustments to initial purchase price allocation 0us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Foreign currency translation (16.0)us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Tax benefits of stock options exercised 0efx_GoodwillTaxDeductionFromExerciseOfStockOptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Balance, March 31, 2015 471.0us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Workforce Solutions  
Goodwill [Line Items]  
Balance, December 31, 2014 907.6us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
Acquisitions 0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
Adjustments to initial purchase price allocation 0us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
Foreign currency translation 0us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
Tax benefits of stock options exercised 0efx_GoodwillTaxDeductionFromExerciseOfStockOptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
Balance, March 31, 2015 907.6us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
Personal Solutions  
Goodwill [Line Items]  
Balance, December 31, 2014 91.6us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember 		[1]
Acquisitions 0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
Adjustments to initial purchase price allocation 0us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
Foreign currency translation (3.4)us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
Tax benefits of stock options exercised 0efx_GoodwillTaxDeductionFromExerciseOfStockOptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
Balance, March 31, 2015 $ 88.2us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
[1] The December 31, 2014 balances have been recast to reflect the new organizational structure. As of December 31, 2014, the Personal Solutions goodwill includes $75.0 million of goodwill from the Europe reporting unit.