Note 10 - Gevo Development (Details Textual) - Gevo Development [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Capital Contribution to Subsidiaries	$ 0.5	$ 3.0	$ 1.8	$ 6.2
Equity Ownership of Wholly Owned Subsidiary			100.00%