Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies Commitment and Contingencies (Details)

v3.6.0.2
Commitments and Contingencies Commitment and Contingencies (Details)
Aug. 31, 2016
ounce
Asahi Refining USA, Inc  
Long-term Purchase Commitment [Line Items]  
Operating leases, term of contract 1 year
Operating leases, renewal term 1 year
Lease fees, subject to adjustment 6 months
Supply Commitment | Asahi Refining USA, Inc  
Long-term Purchase Commitment [Line Items]  
Supply commitment, term 3 years
Supply commitment, renewal term 2 years
Price subject to adjustment, period 6 months
Silver Products | AM&ST Associates, LLC  
Long-term Purchase Commitment [Line Items]  
Purchase commitment, period 3 years
Purchase commitment, renewal term 2 years
Minimum quantity required (in ounces) 300,000
Price subject to adjustment, period 6 months
Guarantor Subsidiaries | Asahi Refining USA, Inc  
Long-term Purchase Commitment [Line Items]  
Agreement to lease (in ounces) 100,000