Long-Term Reclamation Liability and Retirement Obligation Asset (Reconciliation of Aggregate Retirement Liability) (Details) - USD ($)	9 Months Ended	12 Months Ended
Sep. 30, 2017	Dec. 31, 2016
Mine Reclamation and Closing Liability [Roll Forward]
Long-term reclamation liability — beginning of period	$ 7,353,346	$ 6,827,568
Additional obligations incurred	0	340,000
Accretion of reclamation liability	48,250	185,778
Long-term reclamation liability — end of period	$ 7,401,596	$ 7,353,346

Amount of a reclamation and mine closing liability that is associated with a legal obligation for the closure and reclamation of a mine including the removal of buildings, equipment, machinery and other physical remnants of mining, closure of tailings impoundments, leach pads and other mine features, and contouring, covering and revegetation of waste rock piles and other disturbed areas.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 5.Y.Q2)
-URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751

Name:	us-gaap_MineReclamationAndClosingLiabilityNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant