Goodwill Rollforward (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Goodwill [Roll Forward]
Beginning of period		$ 3,432	$ 0
Goodwill Acquired		526,204	3,432
Impairment	(289,900)	(289,894)	0	0
End of period	239,742	239,742	3,432	0
Chemicals and Oxides
Goodwill [Roll Forward]
Beginning of period		728	0
Goodwill Acquired		285,633	728
Impairment		(161,132)
End of period	125,229	125,229	728
Magnetic Materials and Alloys
Goodwill [Roll Forward]
Beginning of period		1,977	0
Goodwill Acquired		213,525	1,977
Impairment		(112,694)
End of period	102,808	102,808	1,977
Rare Metals
Goodwill [Roll Forward]
Beginning of period		727	0
Goodwill Acquired		27,046	727
Impairment		(16,068)
End of period	$ 11,705	$ 11,705	$ 727