Revenue and Related Costs (Details) (USD $)	12 Months Ended			0 Months Ended	6 Months Ended
	Dec. 31, 2012 item	Dec. 31, 2011	Dec. 31, 2010	Jun. 30, 2010 Sumitomo	Jun. 30, 2010 Sumitomo	Jun. 30, 2010 Sumitomo ASML
Revenue and Related Costs
Number of customers to whom marketable products were sold	5
Number of dore and precipitate customers with whom the entity entered into an agreement for passing the title to purchasers after the product is received by the refinery	1
Inventory write down charged to cost of metals sold	$ 2,700,000	$ 3,800,000
Inventory write down charged to depreciation expense	800,000	600,000
Management service fees
Annual fee under the Management Agreement					11,400,000
Reimbursement for direct administrative expenses					5,400,000
Monthly management fee received to cover certain costs						450,000
Revenue related to the Management Agreement			11,216,000		6,200,000
Management service fees					5,400,000
Reimbursement for withholding taxes					800,000
Charges related to cost of services			2,566,000		2,500,000
Charges related to income taxes for the actual administrative costs and withholding taxes reimbursable under the Management Agreement					800,000
Termination fee received					4,300,000
Fee in lieu of performance of services					2,800,000
Required notice period					6 months
Termination payment					1,000,000
Performance bonus					500,000
Amount of return of prepaid administration fees used to partially offset termination fee proceeds					1,100,000
Net payment received				3,200,000	3,200,000
Additional revenue recognized as a result of the termination					4,900,000
Amount of reimbursed withholding taxes included in the additional revenue recognized as a result of termination					600,000
Additional revenue and minimal amounts to cost of services and income taxes related to certain final services completed under the agreement				$ 100,000