Business Combinations (FerroKin and Pervasis) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 FerroKin	Dec. 31, 2011 FerroKin	Dec. 31, 2010 FerroKin	Apr. 02, 2012 FerroKin	Apr. 19, 2012 Pervasis
Business Acquisition [Line Items]
Percentage of voting interests acquired							100.00%
Acquisition-date fair value of consideration							$ 159.3	$ 26.1
Cash consideration paid							94.5	2.5
Fair value of contingent consideration payable							64.8	23.6
Maximum amount of contingent cash consideration							225.0	169.5
Post acquisition pre-tax losses included in consolidated statement of income				(19.1)	0	0
Integration and acquisition costs	25.2	13.7	8.0	12.1	0	0
Purchase Price Allocation
IPR&D							166.0	24.3
Net current liabilities assumed							6.6	0.2
Net non-current liabilities assumed (including deferred tax liabilities)							46.2
Goodwill				$ 46.1			$ 46.1	$ 2.0