DiscontinuedOperations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received from divestitures	$ 43.7	$ 0
Revenue from discontinued operations	9.3	16.7
Pretax income from discontinued operations	1.5	0.8
Gain on divestitures	18.4
Income tax benefit from disposals	18.1
Discontinued Operation Income Loss From Discontinued Operation Income Tax Benefit Current	14.3
Us Consumer Information Solutions [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received from divestitures	47.5
Talent Management Services [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow Receivable From Sale Of Business	$ 3.5