Accounts Payable and Other Accrued Liabilities (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Accounts Payable and Other Accrued Liabilities
Accounts payable and accruals	$ 2,056,000	$ 4,098,000
Accrued employee compensation and benefits	3,415,000	2,134,000
Accounts payable and other accrued liabilities	5,471,000	6,232,000
Accrued vacation payable	300,000	100,000
Accrued severance payments	2,000,000
Withholding taxes and benefits payable	1,100,000	2,000,000
Corporate administrative activities
Accounts Payable and Other Accrued Liabilities
Accounts payable and accruals	300,000	700,000
Exploration
Accounts Payable and Other Accrued Liabilities
Accounts payable and accruals	100,000	400,000
Velardena Operations
Accounts Payable and Other Accrued Liabilities
Accounts payable and accruals	1,700,000	3,000,000
Accrued employee compensation and benefits	$ 2,200,000	$ 1,700,000