Plant Turnaround Costs (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Net capitalized turnaround costs:
Balance at the beginning of the period	$ 54.8	$ 66.8
Additions	29.2	5.9
Depreciation	(22.1)	(21.0)
Effect of exchange rate changes	0.4	(0.6)
Balance at the end of the period	$ 62.3	$ 51.1