Income Taxes (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 M	Sep. 30, 2011	Dec. 31, 2011
Income Taxes [Line Items]
Effective income tax rate	33.30%	44.60%	34.80%	40.50%
U.S. federal statutory rate			35.00%
Valuation allowance, deferred tax assets	$ 5.3		$ 5.3
Valuation allowance,tax expense			5.3
Uncertain tax positions	47.9		47.9		17.3
Offsetting tax benefits related to uncertain tax positions			32.6		2.9
Uncertain tax positions, net	15.3		15.3		14.4
Accrued interest and penalties on uncertain tax positions	4.0		4.0		3.6
Unrecognized tax positions increase decrease, months			12
CoreLogic [Member]
Income Taxes [Line Items]
Net payable related to tax matters prior to Separation	$ 41.0		$ 41.0		$ 35.4