Quarterly report pursuant to Section 13 or 15(d)

DEBT - Additional Information (Detail)

DEBT - Additional Information (Detail) (USD $)
3 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]    
Credit facility borrowing capacity 750,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity  
Line of credit facility, potential maximum borrowing capacity 1,000,000,000efx_LineOfCreditFacilityPotentialMaximumBorrowingCapacity  
Long-term Debt 1,525,000,000us-gaap_LongTermDebt 1,527,900,000us-gaap_LongTermDebt
Line of credit facility, available for borrowing 373,500,000us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity  
Commercial paper notes 750,000,000efx_CommercialPaperMaximumBorrowingCapacity  
Commercial Paper Notes Outstanding 375,000,000efx_CommercialPaperNotesOutstanding  
Debt Instrument [Line Items]    
Commercial paper, maturity date 1 day  
Debt Instrument [Line Items]    
Commercial paper, maturity date 90 days  
Letter of Credit    
Debt Instrument [Line Items]    
Long-term Debt 1,500,000us-gaap_LongTermDebt
/ us-gaap_CreditFacilityAxis
= us-gaap_LetterOfCreditMember
Revolving Credit Facility    
Debt Instrument [Line Items]    
Line of Credit Facility, Expiration Date Dec. 31, 2017  
Long-term Line of Credit 0us-gaap_LineOfCredit
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember