Annual report pursuant to Section 13 and 15(d)

COMMITMENTS AND CONTINGENCIES (Additional Information) (Detail)

v2.4.1.9
COMMITMENTS AND CONTINGENCIES (Additional Information) (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Commitments and Contingencies Disclosure [Line Items]      
Rental expense for operating leases $ 22.6us-gaap_OperatingLeasesRentExpenseNet $ 24.2us-gaap_OperatingLeasesRentExpenseNet $ 21.5us-gaap_OperatingLeasesRentExpenseNet
Cash paid for data processing, outsourcing services and other agreements 50us-gaap_ProfessionalAndContractServicesExpense 60us-gaap_ProfessionalAndContractServicesExpense 70us-gaap_ProfessionalAndContractServicesExpense
Severance benefit term
In the event of a qualifying termination, the executive will become entitled to continuation of group health, dental, vision, life, disability, 401(k) and similar benefits for three years, as well as a lump sum severance payment, all of which differs by executive. 
   
Potential Percentage Of Stock Acquired With Change In Control
any person acquires 20% or more of our voting stock
   
Qualifying termination, continuation of benefits for executives 3 years    
Qualifying termination, continuation of benefits for executives, automatic renewal 3 years    
Conditional payment for unrecognized severance benefit for key executives 56.5efx_ConditionalSeverancePayments    
Assumed tax on expected payment for unrecognized severance benefit for key executives 31.8efx_UnrecognizedTaxBenefitsUncertainAmounts    
Conditional payout percentage of target award 100.00%efx_ConditionalSharePayoutPercentage    
Guarantees      
Commitments and Contingencies Disclosure [Line Items]      
Performance bonds and standby letters of credit remaining maturity date one year or less.    
Data Processing, Outsourcing Services And Other Agreements | Minimum      
Commitments and Contingencies Disclosure [Line Items]      
Service agreements expiration year 2015    
Estimated aggregate minimum contractual obligation 40efx_NonCancelableContractualObligations
/ us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis
= efx_DataProcessingOutsourcingServicesAndOtherAgreementsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
   
Data Processing, Outsourcing Services And Other Agreements | Maximum      
Commitments and Contingencies Disclosure [Line Items]      
Service agreements expiration year 2023    
Estimated aggregate minimum contractual obligation 60efx_NonCancelableContractualObligations
/ us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis
= efx_DataProcessingOutsourcingServicesAndOtherAgreementsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
   
IBM Operations Support Services Agreement      
Commitments and Contingencies Disclosure [Line Items]      
Service Agreements Expiration Term     2 years
Service agreements expiration date     Dec. 31, 2016
IBM Operations Support Services Agreement | Minimum      
Commitments and Contingencies Disclosure [Line Items]      
Expected future year's minimum contractual obligation 15efx_ContractualCommitmentsFutureMinimumPaymentsDue
/ us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis
= efx_IbmOperationsSupportServicesAgreementMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
   
IBM Operations Support Services Agreement | Maximum      
Commitments and Contingencies Disclosure [Line Items]      
Expected future year's minimum contractual obligation $ 25efx_ContractualCommitmentsFutureMinimumPaymentsDue
/ us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis
= efx_IbmOperationsSupportServicesAgreementMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember