Commitments and Contingencies - Changes in Accrued Environmental Remediation and Related Costs (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Commitments And Contingent Liabilities [Line Items]
Balance at the beginning of the year	$ 50.2
Additions charged to expense, net	12.7
Payments, net	(2.8)
Changes in currency exchange rates	(0.1)
Balance at the end of period	60.0
Amounts recognized in our Condensed Consolidated Balance Sheet at the end of the period:
Current liabilities	6.4	7.6
Accrued environmental remediation and related costs	53.6	42.6
Total	$ 60.0