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, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating income	$ 24.0	$ 61.2	$ 63.6	$ 204.6
Interest expense	(2.4)	(7.8)	(7.7)	(25.0)
Other income (expense), net	1.9	(25.8)	11.1	(34.9)
Total income before income taxes	23.5	27.6	67.0	144.7
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total segment operating income	44.9	87.0	129.2	269.2
Corporate and Eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Other income (expense), net	$ (20.9)	$ (25.8)	$ (65.6)	$ (64.6)