| COMMITMENTS AND CONTINGENCIES - Additional Information (Detail) In Millions, unless otherwise specified | 1 Months Ended | 12 Months Ended | 12 Months Ended | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| May 31, 2011
 USD ($) | May 31, 2011
 CAD | Dec. 31, 2011
 USD ($) | Dec. 31, 2010
 USD ($) | Dec. 31, 2009
 USD ($) | Dec. 31, 2011
 Guarantees | Dec. 31, 2011
 Maximum
 USD ($) | Dec. 31, 2011
 Data Processing, Outsourcing Services And Other Agreements
 Minimum
 USD ($) | Dec. 31, 2011
 Data Processing, Outsourcing Services And Other Agreements
 Maximum
 USD ($) | Dec. 31, 2011
 Agreement With Computer Sciences Corporation | Dec. 31, 2011
 Agreement With Computer Sciences Corporation
 Open Option Contracts | Dec. 31, 2011
 Agreement With Computer Sciences Corporation
 Minimum
 USD ($) | Dec. 31, 2011
 Agreement With Computer Sciences Corporation
 Maximum
 USD ($) | |
| Commitments and Contingencies Disclosure [Line Items] | |||||||||||||
| Rental expense for operating leases | $ 22.0 | $ 20.5 | $ 20.9 | ||||||||||
| Service agreements expiration year | 2012 | 2018 | |||||||||||
| Estimated aggregate minimum contractual obligation | 55 | 70 | |||||||||||
| Expected future year's minimum contractual obligation | 20 | 30 | |||||||||||
| Service agreements expiration date | Dec. 31, 2014 | Dec. 31, 2016 | Jul. 31, 2018 | ||||||||||
| Agreement renewable period | 10 years | ||||||||||||
| Service agreements expiration period | 3 years | ||||||||||||
| Cash paid for data processing, outsourcing services and other agreements | 79.7 | 61.1 | 87.3 | ||||||||||
| CSC option to sell its credit reporting business, option expiration year | 2013 | ||||||||||||
| Option to buy CSC credit reporting business exercise expected payment period | The option exercise price will be determined by a third-party appraisal process and would be due in cash within 180 days after the exercise of the option. | ||||||||||||
| Estimate option exercise price | 650 | 750 | |||||||||||
| 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. | ||||||||||||
| Qualifying termination, continuation of benefits for executives | 3 years | ||||||||||||
| Qualifying termination, continuation of benefits for executives, automatic renewal | 3 years | ||||||||||||
| Expected payment for unrecognized severance benefit for key executives | 46.1 | ||||||||||||
| Assumed tax on expected payment for unrecognized severance benefit for key executives | 19.3 | ||||||||||||
| Performance bonds and standby letters of credit remaining maturity date | one year or less | ||||||||||||
| Tax settlements with CRA | 1.1 | 1.1 | |||||||||||
| Net refund of deposit and accrued interest received related to tax matters with CRA | $ 9.9 | 9.7 | |||||||||||
| Tax examination years | In 2003, the Canada Revenue Agency, or CRA, issued Notices of Reassessment, asserting that Acrofax, Inc., a wholly-owned Canadian subsidiary of Equifax, was liable for additional tax for the 1995 through 2000 tax years, related to certain intercompany capital contributions and loans. | In 2003, the Canada Revenue Agency, or CRA, issued Notices of Reassessment, asserting that Acrofax, Inc., a wholly-owned Canadian subsidiary of Equifax, was liable for additional tax for the 1995 through 2000 tax years, related to certain intercompany capital contributions and loans. | |||||||||||