Accounts Payable and Other Accrued Liabilities (Details) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Accounts Payable and Other Accrued Liabilities
Accounts payable and accruals	$ 2,808,000	$ 5,172,000
Accrued employee compensation and benefits	3,226,000	2,898,000
Accounts payable and other accrued liabilities	6,034,000	8,070,000
Accrued vacation payable	200,000	300,000
Withholding taxes and benefits payable	3,000,000	2,600,000
Corporate administrative activities
Accounts Payable and Other Accrued Liabilities
Accounts payable and accruals	700,000	800,000
Exploration
Accounts Payable and Other Accrued Liabilities
Accounts payable and accruals	100,000	600,000
Velardena Operations
Accounts Payable and Other Accrued Liabilities
Accounts payable and accruals	2,000,000	3,000,000
Withholding taxes and benefits payable	1,800,000	2,100,000
El Quevar project
Accounts Payable and Other Accrued Liabilities
Accounts payable and accruals		$ 800,000