Note 8 - Commitments and Contingencies (Details Textual) - USD ($)			3 Months Ended
	Mar. 31, 2017	Sep. 02, 2016	Mar. 31, 2017
Operating Lease, Monthly Rent			$ 6,053
Operating Lease, Liability	$ 375,281		375,281
Mine Reclamation and Closing Liability, Noncurrent	4,800,000		$ 4,800,000
Construction of a Coal Preparation Plant, Coal Loadout and Associated Belting and Storage Facilities [Member]
Long-term Purchase Commitment, Amount		$ 27,800,000
Long-term Purchase Commitment, Unbilled Amount		11,800,000
Construction of a Railroad Spur [Member]
Long-term Purchase Commitment, Amount		$ 4,500,000
Long-term Purchase Commitment, Unbilled Amount	$ 1,000,000