| Quarterly Financial Data - Additional Information (Detail) (USD $) In Millions, unless otherwise specified | 12 Months Ended | 1 Months Ended | 3 Months Ended | 1 Months Ended | 3 Months Ended | ||
|---|---|---|---|---|---|---|---|
| Dec. 31, 2011 | Dec. 31, 2010 | May 31, 2011
 Boa Vista Servicos S.A. | Apr. 30, 2010
 US Consumer Information Solutions
 APPRO Loan Origination Software | Jun. 30, 2010
 US Consumer Information Solutions
 APPRO Loan Origination Software | Jul. 31, 2010
 US Consumer Information Solutions
 Direct Marketing Services Division | Sep. 30, 2010
 US Consumer Information Solutions
 Direct Marketing Services Division | |
| Quarterly Financial Information [Line Items] | |||||||
| Percentage of interest acquired in Boa Vista Servicos S.A. ("BVS") | 15.00% | ||||||
| Proceeds received from divestitures | $ 2.5 | $ 181.7 | $ 72.0 | $ 72.0 | $ 117.0 | $ 117.0 | |
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- Details 
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- Definition Percentage of voting equity interests acquired in the business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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