Note 6 - Commitments and Contingencies (Details) $ in Millions	6 Months Ended
Jun. 30, 2019 USD ($)
COMMITMENTS AND CONTINGENCIES
Asset Retirement Obligation	$ 13.2
Reclamation bonding requirements	12.8
Take-or-pay Purchase Commitments
COMMITMENTS AND CONTINGENCIES
Commitments	$ 2.3

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
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-Subparagraph (c)
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(17))
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
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- Definition

Adjustment of the mine reclamation or mine shutdown liability account that is made when estimates of future costs are changed.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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