Quarterly Results (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended			3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2011 Performance Materials [Member]	Dec. 31, 2012 Construction Technologies [Member]	Mar. 31, 2012 Construction Technologies [Member]	Mar. 31, 2012 Corporate [Member]	Sep. 30, 2011 Belgian joint venture [Member] Performance Materials [Member]
Segment Reporting Information [Line Items]
Segment recorded expenses	$ (3.4)	$ 0.2	$ 1.3		$ 0.6	$ 1.8
Impairment of certain corporate information technology assets							0.7
Gain (loss) from sale of joint venture and affiliated entities								2.1
Recovery of mining costs				$ 1.5