Equifax Inc. Annual report pursuant to Section 13 and 15(d)

Debt Outstanding (Parenthetical) (Detail)	Dec. 31, 2011 Note, 4.25%, due in installments through May 2012	Dec. 31, 2010 Note, 4.25%, due in installments through May 2012	Dec. 31, 2011 Notes, 7.34%, due in installments through May 2014	Dec. 31, 2010 Notes, 7.34%, due in installments through May 2014	May 31, 2007 Notes, 7.34%, due in installments through May 2014	Dec. 31, 2011 Notes, 4.45%, due December 2014	Dec. 31, 2010 Notes, 4.45%, due December 2014	Nov. 04, 2009 Notes, 4.45%, due December 2014	Dec. 31, 2011 Notes, 6.30%, due July 2017	Dec. 31, 2010 Notes, 6.30%, due July 2017	Jun. 28, 2007 Notes, 6.30%, due July 2017	Dec. 31, 2011 Debentures, 6.90%, due July 2028	Dec. 31, 2010 Debentures, 6.90%, due July 2028	Dec. 31, 2011 Notes, 7.00%, due July 2037	Dec. 31, 2010 Notes, 7.00%, due July 2037	Jun. 28, 2007 Notes, 7.00%, due July 2037
Debt Instrument [Line Items]
Debt, interest rate	4.25%	4.25%	7.34%	7.34%	7.34%	4.45%	4.45%	4.45%	6.30%	6.30%	6.30%	6.90%	6.90%	7.00%	7.00%	7.00%
Debt, maturity date	2012-05	2012-05	2014-05	2014-05		2014-12	2014-12		2017-07	2017-07		2028-07	2028-07	2037-07	2037-07