Annual report pursuant to Section 13 and 15(d)

ACQUISITIONS AND INVESTMENTS (Additional Information) (Detail)

v2.4.1.9
ACQUISITIONS AND INVESTMENTS (Additional Information) (Detail) (USD $)
In Millions, unless otherwise specified
 3 Months Ended 1 Months Ended 0 Months Ended 12 Months Ended
Mar. 31, 2014
acquisition
Dec. 31, 2013
acquisition
Dec. 31, 2012
Dec. 28, 2012
Dec. 31, 2012
Business Acquisition [Line Items]          
Business acquisition $ 338.8efx_BusinessAcquisitionsCostOfAcquiredEntityPurchasePrice        
Number of business acquisitions 2us-gaap_NumberOfBusinessesAcquired 2us-gaap_NumberOfBusinessesAcquired      
Unsecured Senior Notes          
Business Acquisition [Line Items]          
Debt, interest rate     3.30%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= efx_UnsecuredSeniorNotesMember 		  3.30%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= efx_UnsecuredSeniorNotesMember
Debt, maturity duration     10 years    
International Entity          
Business Acquisition [Line Items]          
Business acquisition   98.8efx_BusinessAcquisitionsCostOfAcquiredEntityPurchasePrice
/ us-gaap_BusinessAcquisitionAxis
= efx_InternationalEntityMember 		     
Computer Sciences Corporation          
Business Acquisition [Line Items]          
Business acquisition       1,000.0efx_BusinessAcquisitionsCostOfAcquiredEntityPurchasePrice
/ us-gaap_BusinessAcquisitionAxis
= efx_ComputerSciencesCorporationMember 		 
European and Latin American          
Business Acquisition [Line Items]          
Business acquisition         $ 16.5efx_BusinessAcquisitionsCostOfAcquiredEntityPurchasePrice
/ us-gaap_BusinessAcquisitionAxis
= efx_EuropeanAndLatinAmericanMember