Accumulated Other Comprehensive Loss - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified to earnings from unrecognized net defined benefit plan costs component of accumulated other comprehensive loss	$ (2.8)
Amounts reclassified to earnings from the unrecognized net defined benefit plan costs, income tax benefit	1.1
Amount reclassified to earnings from the change in fair value of derivatives component of accumulated other comprehensive income	(1.5)
Amount reclassified to earnings from the change in fair value of derivatives component of accumulated other comprehensive income, income tax benefit	0.6
Foreign currency gains related to net investment hedges included in foreign currency translation component of accumulated other comprehensive loss	9.5
Foreign currency gains related to net investment hedges included in foreign currency translation component of accumulated other comprehensive loss, income tax provision	(3.6)
Interest and other debt expense | Interest Rate Swap Agreement
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount reclassified to earnings from the change in fair value of derivatives component of accumulated other comprehensive income	(1.4)
Cost of goods gold | Natural gas swap agreements
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount reclassified to earnings from the change in fair value of derivatives component of accumulated other comprehensive income	$ (0.1)