Note 14 - Segments - Information on Business Segments (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Total revenues		$ 142	$ 192	$ 657	$ 5,005
Loss from operations		(14,712)	(6,103)	(43,612)	(19,336)
Interest expense		67	473	78	1,559
Depreciation and amortization		1,200	1,476	3,572	4,754
Acquisitions of plant, property and equipment:		33,115	106	52,965	1,404
Assets	[1]	675,355		675,355		$ 152,099
Operating Segments [Member] | UNITED STATES
Total revenues		49	12	282	3,853
Operating Segments [Member] | Non-US [Member]
Total revenues		93	180	375	1,152
Intersegment Eliminations [Member]
Assets	[2]	(162,914)		(162,914)		(131,971)
Gevo [Member] | Operating Segments [Member]
Total revenues		104	176	465	1,198
Loss from operations		(10,968)	(3,508)	(22,471)	(9,197)
Interest expense		67	465	67	1,546
Depreciation and amortization		112	53	214	159
Acquisitions of plant, property and equipment:		9,536	0	10,377	79
Assets		574,179		574,179		152,177
Agri-Energy [Member] | Operating Segments [Member]
Total revenues		38	16	192	3,807
Loss from operations		(3,473)	(2,272)	(12,629)	(9,440)
Interest expense		0	8	6	13
Depreciation and amortization		1,088	1,423	3,358	4,595
Acquisitions of plant, property and equipment:		3,154	106	5,062	1,325
Assets		144,552		144,552		131,893
Renewable Natural Gas [Member] | Operating Segments [Member]
Total revenues		0	0	0	0
Loss from operations		(218)	(323)	(286)	(699)
Interest expense		0	0	5	0
Depreciation and amortization		0	0	0	0
Acquisitions of plant, property and equipment:		14,450	0	31,551	0
Assets		112,594		112,594		0
Net-Zero [Member] | Operating Segments [Member]
Total revenues		0	0	0	0
Loss from operations		(53)	0	(8,226)	0
Interest expense		0	0	0	0
Depreciation and amortization		0	0	0	0
Acquisitions of plant, property and equipment:		5,975	$ 0	5,975	$ 0
Assets		$ 6,944		$ 6,944		$ 0

[1] All other significant non-cash items relate to the activities of Gevo.

[2] Intercompany sales of hydrocarbon during the nine months ended September 30, 2021 and for the year ended December 31, 2020 was $0 and $0.1 million, respectively.