Summary Of Interest Expense (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Interest incurred	$ 271.1	$ 259.8	$ 233.3
Less: interest income	(15.2)	(13.6)	(9.1)
Less: interest capitalized as property, plant and equipment	(4.1)	(2.9)	(1.6)
Interest expense, net	$ 251.8	$ 243.3	$ 222.6