Reconciliation of Total Business Segment Operating Income to Consolidated Income (Loss) Before Income Taxes (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating income	$ 61.2	$ 113.0	$ 204.6	$ 203.0
Interest expense	(7.8)	(12.5)	(25.0)	(51.7)
Other income (expense), net	(25.8)	16.6	(34.9)	(56.6)
Total income before income taxes	27.6	117.1	144.7	94.7
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating income	87.0	119.6	269.2	229.1
Corporate and Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other income (expense), net	$ (25.8)	$ (6.6)	$ (64.6)	$ (26.1)