Quarterly report pursuant to Section 13 or 15(d)

GOODWILL AND INTANGIBLE ASSETS - Additional Information (Detail)

v2.4.1.9
GOODWILL AND INTANGIBLE ASSETS - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Line Items]      
Goodwill $ 2,587.4us-gaap_Goodwill   $ 2,606.8us-gaap_Goodwill
Amortization expense related to purchased intangible assets 31.3us-gaap_AmortizationOfIntangibleAssets 32.7us-gaap_AmortizationOfIntangibleAssets  
International      
Goodwill and Intangible Assets Disclosure [Line Items]      
Goodwill 471.0us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
  487.0us-gaap_Goodwill
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
[1]
International | Personal Solutions      
Goodwill and Intangible Assets Disclosure [Line Items]      
Goodwill     $ 75.0us-gaap_Goodwill
/ efx_LegacyNacsAxis
= efx_PersonalSolutionsMember
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
[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.