Related-Party Transactions (Details) (USD $)	12 Months Ended					12 Months Ended			6 Months Ended		7 Months Ended			1 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Traxys North America LLC and affiliates	Dec. 31, 2012 Traxys North America LLC and affiliates	Dec. 31, 2011 Traxys North America LLC and affiliates Lanthanum oxide	Dec. 31, 2011 Traxys North America LLC and affiliates Tantalum Metal	Dec. 31, 2012 Traxys North America LLC and affiliates Tantalum Metal	Jun. 11, 2012 Neo Material Technologies, Inc. neodymium/praseodymium	Jun. 11, 2012 Neo Material Technologies, Inc. Rare earth metals	Dec. 31, 2012 TMT Compounds	Dec. 31, 2012 TMT Neo Powders	Dec. 31, 2012 Keli Metals	Jun. 30, 2012 Ingal Stade Gallium Metal
Related Party Transactions
Principal payments made	$ 0	$ 3,150,000	$ 1,107,000	$ 3,100,000
Outstanding amount of short-term borrowing payable to related party		870,000		900,000
Outstanding amount of trade accounts payable related to sales made to related party but not remitted				2,800,000
Purchases made from related party						6,200,000					2,800,000		32,600,000	3,300,000
Related party receivables				200,000	0		2,100,000	0
Sales to related party							$ 3,200,000		$ 4,300,000	$ 1,600,000		$ 1,600,000