Fair Value Measurements and Risk (Details) In Millions, unless otherwise specified						3 Months Ended
	Jun. 30, 2013 country	Jun. 30, 2013 Recurring basis Total USD ($)	Dec. 31, 2012 Recurring basis Total USD ($)	Jun. 30, 2013 Recurring basis Significant Other Observable Inputs (Level 2) USD ($)	Dec. 31, 2012 Recurring basis Significant Other Observable Inputs (Level 2) USD ($)	Jun. 30, 2013 Fixed-rate natural gas swaps USD ($) MMBTU	Jun. 30, 2013 Fixed-rate aluminum swaps USD ($) lb	Jun. 30, 2013 Currency forward contracts EUR (€)
Items measured at Fair Value on a Recurring Basis
Maximum period of cash flow hedging						12 months	12 months
Nonmonetary Notional Amount of Price Risk Cash Flow Hedge Derivatives, Number of Units						1,700,000	2,400,000
Total contract value						$ 6.7	$ 2.2
Number of countries where company does business, greater than	40
Total notional amount related to the remaining outstanding currency forward contracts								194.5
Assets
Currency derivatives, assets		2.0	1.2	2.0	1.2
Commodity derivatives, assets		0	0.2	0	0.2
Total Assets		2.0	1.4	2.0	1.4
Liabilities
Currency derivatives, liabilities		1.2	5.1	1.2	5.1
Commodity derivatives, liabilities		0.7	0.4	0.7	0.4
Total Liabilities		$ 1.9	$ 5.5	$ 1.9	$ 5.5