Correction of Errors in Previously Reported Financial Statements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Total/ Reduction In net income (loss)	$ 0.4	$ 0.5	$ (1.4)	$ (16.0)
Previously reported [Member]
Total/ Reduction In net income (loss)				(0.6)
Tax [Member]
Total/ Reduction In net income (loss)	0.3	1.5	(12.0)	0.1
Tax [Member] | Previously reported [Member]
Total/ Reduction In net income (loss)				(0.5)
Other [Member]
Total/ Reduction In net income (loss)	0.4	0.4	0.6	(0.7)
Other [Member] | Previously reported [Member]
Total/ Reduction In net income (loss)				(0.3)
Spain [Member]
Total/ Reduction In net income (loss)	(0.3)	(1.1)	(0.6)	(0.8)
South Africa [Member]
Total/ Reduction In net income (loss)		(0.5)		(0.3)
Malaysia [Member]
Total/ Reduction In net income (loss)		0.7	(0.4)
Dong Ming [Member]
Total/ Reduction In net income (loss)		(0.5)	0.2	0.1
Dong Ming [Member] | Previously reported [Member]
Total/ Reduction In net income (loss)				$ 0.2