Income Taxes (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Income Tax Contingency [Line Items]
Provision for valuation allowance	$ 2.6	$ 1.1
Unrecognized tax benefits, interest on income taxes accrued	17.4	17.4
Unrecognized tax benefits, income tax penalties accrued	13.3	13.3
Unrecognized tax benefits relating to UTPs	81	81
No longer subject to examination for years prior to		2007
Statute of limitations to expire during next twelve months		2007,2008 and 2009
Potential change in unrecognized tax benefits is reasonably possible during next twelve months, amount of unrecorded benefit tax positions	34.4	34.4
Portion of reduction in unrecognized tax benefits during next twelve months that reduces the income tax provision		41
Potential change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit tax positions	26.5	26.5
Portion of reduction in unrecognized tax benefits during next three months that reduces the income tax provision		47
Increase in unrecognized tax benefits		10
Unrecognized tax benefits that would reduce the income tax provision	$ 64	$ 64