Discontinued Operations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash received from divestitures			$ 47.5	$ 2.5
Revenue from discontinued operations	0	23.9	9.3	63.3
Pretax income from discontinued operations		1.6		6.1
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