Note 4 - Fair Values of Financial Instruments - Schedule of Financial Assets and Liabilities (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Reported Value Measurement [Member]
Financial Assets:
Cash and cash equivalents	$ 9,263,356	$ 5,196,914
Accounts receivable	2,616,727	914,741
U. S. agency securities	19,859,952	45,289,747
Certificates of deposit		9,948,000
Total short-term investments	19,859,952	55,237,747
U. S. agency securities		5,199,077
Financial liabilities:
Accounts payable	(14,484,726)	(8,955,884)
Note payable		(500,000)
Note payable - Ramaco Coal, LLC		(10,629,275)
Estimate of Fair Value Measurement [Member]
Financial Assets:
Cash and cash equivalents	9,263,356	5,196,914
Accounts receivable	2,616,727	914,741
U. S. agency securities	19,844,499	45,245,318
Certificates of deposit		9,948,000
Total short-term investments	19,844,499	55,193,318
U. S. agency securities		5,190,640
Financial liabilities:
Accounts payable	(14,484,726)	(8,955,884)
Note payable		(500,000)
Note payable - Ramaco Coal, LLC		$ (10,629,275)