Property, Plant and Mine Development – net - Capital Lease Obligations (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Future maturities of capital lease obligations
2015	$ 736
2016	900
Total payments due	1,636
Less amounts representing interest	(41)
Subtotal	1,595
Less current portion	(1,487)	$ (1,498)
Non-current portion	$ 108	$ 834

Amount of capital lease obligation due within one year or the normal operating cycle, if longer.

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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal, through the balance sheet date and due to be paid more than one year (or one operating cycle, if longer) after the balance sheet date.

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-Publisher FASB

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Amount of minimum lease payments for capital leases.

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Amount of minimum lease payments for capital leases due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount necessary to reduce net minimum lease payments to present value for capital leases.

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Amount of minimum lease payments for capital leases net of executory costs, which include amounts paid by the lessee to the lessor for insurance, maintenance and taxes.

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