Financial Instruments (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 M	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008 customer M lb
Derivative instruments
Percentage of projected intercompany purchases hedged by forward exchange contracts	50.00%
Period of projected intercompany purchase transactions (in months)	12
Notional amounts of foreign currency purchase contracts	$ 9.0
Nonmonetary notional amount of copper swaps (in pounds)				1,000,000
Period over which copper is to be delivered to one customer (in months)				12
Number of customers to whom the hedged item is to be delivered				1
Amount of Gain or (Loss) Recognized in Income on Derivatives
Income (loss) from derivatives recorded to other (income) expense in statement of operations	0.6	0.5	(0.8)
High end of range
Derivative instruments
Average volume of foreign currency contracts	15
Low end of range
Derivative instruments
Average volume of foreign currency contracts	$ 9