Quarterly report pursuant to Section 13 or 15(d)

Restricted Cash (Details Textual)

v2.4.0.8
Restricted Cash (Details Textual) (USD $)
In Millions, unless otherwise specified
Sep. 30, 2014
Restricted Cash and Cash Equivalents Items [Line Items]  
Reclamation bonding requirement $ 26.7
Certificate of deposit [Member] | Collectibility of Receivables [Member]
 
Restricted Cash and Cash Equivalents Items [Line Items]  
Restricted cash pledged as collateral 0.1
Money Market Funds [Member] | Surety Bond [Member]
 
Restricted Cash and Cash Equivalents Items [Line Items]  
Restricted cash pledged as collateral $ 6.0