Property Plant and Equipment - Additional Information (Detail) (Property Plant and Equipment, USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Property Plant and Equipment
Component of Operating Other Cost and Expense [Line Items]
Depreciation of property, plant and equipment	$ 34.6	$ 35.6	$ 97.2	$ 107.6