Derivative Financial Instruments And Commodity Hedging Activities (Summary Of Derivative Hedges Gains (Losses) Recognized In Statement Of Income) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion), Net of Tax	$ (0.1)	$ (0.2)	$ 0	$ 0
Amount of Gain or(Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	0	(0.3)	0	(2.1)
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0	0
Cash Flow Hedging | Natural Gas Forwards
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion), Net of Tax	0	(0.2)	0	0
Cash Flow Hedging | Natural Gas Forwards | Other Expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0	0
Cash Flow Hedging | Natural Gas Forwards | Manufacturing Cost Of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or(Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	0	(0.3)	0	(2.1)
Cash Flow Hedging | Foreign Exchange Forward
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion), Net of Tax	(0.1)	0	0	0
Amount of Gain or(Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	0	0	0	0
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	0	0	0	0
Net Investment Hedging | Cross Currency Interest Rate Contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative (Effective Portion), Net of Tax	8.4	(4.1)	4.4	(10.4)
Amount of Gain or(Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	0	0	0	0
Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing)	$ 0	$ 0	$ 0	$ 0