Quarterly report pursuant to Section 13 or 15(d)

SEGMENT INFORMATION (Operating Revenue and Operating Income by Operating Segment) (Detail)

v2.4.1.9
SEGMENT INFORMATION (Operating Revenue and Operating Income by Operating Segment) (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
segment
Mar. 31, 2014
Dec. 31, 2014
Segment Reporting Information [Line Items]      
Operating revenue $ 651.8us-gaap_SalesRevenueServicesNet $ 584.5us-gaap_SalesRevenueServicesNet  
Operating income 154.2us-gaap_OperatingIncomeLoss 151.9us-gaap_OperatingIncomeLoss  
Total assets 4,595.0us-gaap_Assets   4,674.2us-gaap_Assets
Number of reportable segments 4us-gaap_NumberOfReportableSegments    
U.S. Information Solutions      
Segment Reporting Information [Line Items]      
Operating revenue 298.7us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
261.2us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
 
Operating income 126.6us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
97.0us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
 
Total assets 1,972.9us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
  1,983.9us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_UnitedStatesConsumerInformationSolutionsMember
International      
Segment Reporting Information [Line Items]      
Operating revenue 138.8us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
140.8us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
 
Operating income 28.0us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
29.0us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
 
Total assets 918.7us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
  983.7us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_InternationalMember
Workforce Solutions      
Segment Reporting Information [Line Items]      
Operating revenue 148.7us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
119.7us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
 
Operating income 60.0us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
38.7us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
 
Total assets 1,285.5us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
  1,271.3us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_WorkforceMember
Personal Solutions      
Segment Reporting Information [Line Items]      
Operating revenue 65.6us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
62.8us-gaap_SalesRevenueServicesNet
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
 
Operating income 18.0us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
17.9us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
 
Total assets 119.3us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
  123.8us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_PersonalSolutionsMember
General Corporate      
Segment Reporting Information [Line Items]      
Operating income (78.4)us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_GeneralCorporateExpensesMember
(30.7)us-gaap_OperatingIncomeLoss
/ us-gaap_StatementBusinessSegmentsAxis
= efx_GeneralCorporateExpensesMember
 
Total assets $ 298.6us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_GeneralCorporateExpensesMember
  $ 311.5us-gaap_Assets
/ us-gaap_StatementBusinessSegmentsAxis
= efx_GeneralCorporateExpensesMember