Annual report pursuant to Section 13 and 15(d)

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

v2.4.1.9
GOODWILL AND OTHER INTANGIBLE ASSETS (Changes in Amount of Goodwill) (Detail) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Goodwill [Roll Forward]    
Beginning Balance $ 2,395.1us-gaap_Goodwill [1] $ 2,290.4us-gaap_Goodwill [1]
Acquisitions 240.2us-gaap_GoodwillAcquiredDuringPeriod 55.3us-gaap_GoodwillAcquiredDuringPeriod
Adjustments to initial purchase price allocation 2.1us-gaap_GoodwillPurchaseAccountingAdjustments 87.8us-gaap_GoodwillPurchaseAccountingAdjustments
Foreign currency translation (30.5)us-gaap_GoodwillTranslationAdjustments (8.0)us-gaap_GoodwillTranslationAdjustments
Tax benefits of options exercised (0.1)efx_Goodwilltaxdeductionfromexerciseofstockoptions (0.2)efx_Goodwilltaxdeductionfromexerciseofstockoptions
Businesses sold   (30.2)us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
Ending Balance 2,606.8us-gaap_Goodwill 2,395.1us-gaap_Goodwill [1]
U.S. Information Solutions    
Goodwill [Roll Forward]    
Beginning Balance 1,054.2us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember 		[1] 969.4us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember 		[1]
Acquisitions 66.4us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember 		0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember
Adjustments to initial purchase price allocation 0us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember 		87.5us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember
Foreign currency translation 0us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember 		0us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember
Tax benefits of options exercised 0efx_Goodwilltaxdeductionfromexerciseofstockoptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember 		0efx_Goodwilltaxdeductionfromexerciseofstockoptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember
Businesses sold   (2.7)us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember
Ending Balance 1,120.6us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember 		1,054.2us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_USConsumerInformationSolutionsMember 		[1]
International    
Goodwill [Roll Forward]    
Beginning Balance 416.5us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember 		[1] 385.2us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember 		[1]
Acquisitions 173.8us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember 		40.8us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Adjustments to initial purchase price allocation 2.1us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember 		(0.1)us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Foreign currency translation (30.5)us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember 		(8.0)us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Tax benefits of options exercised 0efx_Goodwilltaxdeductionfromexerciseofstockoptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember 		0efx_Goodwilltaxdeductionfromexerciseofstockoptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Businesses sold   (1.4)us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Ending Balance 561.9us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember 		416.5us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember 		[1]
Workforce Solutions    
Goodwill [Roll Forward]    
Beginning Balance 907.7us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember 		934.0us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember
Acquisitions 0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember 		0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember
Adjustments to initial purchase price allocation 0us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember 		0us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember
Foreign currency translation 0us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember 		0us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember
Tax benefits of options exercised (0.1)efx_Goodwilltaxdeductionfromexerciseofstockoptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember 		(0.2)efx_Goodwilltaxdeductionfromexerciseofstockoptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember
Businesses sold   (26.1)us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember
Ending Balance 907.6us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember 		907.7us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_TALXMember
North America Personal Solutions    
Goodwill [Roll Forward]    
Beginning Balance 16.7us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember 		1.8us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember
Acquisitions 0us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember 		14.5us-gaap_GoodwillAcquiredDuringPeriod
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember
Adjustments to initial purchase price allocation 0us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember 		0.4us-gaap_GoodwillPurchaseAccountingAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember
Foreign currency translation 0us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember 		0us-gaap_GoodwillTranslationAdjustments
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember
Tax benefits of options exercised 0efx_Goodwilltaxdeductionfromexerciseofstockoptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember 		0efx_Goodwilltaxdeductionfromexerciseofstockoptions
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember
Businesses sold   0us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember
Ending Balance $ 16.7us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember 		$ 16.7us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_NorthAmericaPersonalSolutionsMember
[1] The December 31, 2013 and 2012 balances have been recast to reflect the new organizational structure. As of December 31, 2013, the USIS and International goodwill include $21.7 million and $15.5 million of goodwill, respectively, from the legacy NACS segment. As of December 31, 2012, the USIS and International goodwill include $21.7 million and $15.9 million of goodwill, respectively, from the legacy NACS segment