Note 14 - Segments - Information on Business Segments (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Total revenues		$ 93	$ 3,825
Loss from operations		(9,878)	(7,976)
Interest expense		5	545
Depreciation and amortization		1,149	1,649
Acquisitions of plant, property and equipment:		5,432	801
Assets	[1]	608,728		$ 152,099
Operating Segments [Member] | UNITED STATES
Total revenues		93	3,750
Operating Segments [Member] | Non-US [Member]
Total revenues			75
Intersegment Eliminations [Member]
Assets	[2]	(129,487)		(131,971)
Gevo [Member] | Operating Segments [Member]
Total revenues		13	125
Loss from operations		(5,104)	(2,881)
Interest expense			543
Depreciation and amortization		56	56
Acquisitions of plant, property and equipment:		253	10
Assets		595,834		152,177
Agri-Energy [Member] | Operating Segments [Member]
Total revenues		80	3,700
Loss from operations		(2,047)	(4,939)
Interest expense			2
Depreciation and amortization		1,093	1,593
Acquisitions of plant, property and equipment:		10	791
Assets		129,523		131,893
Renewable Natural Gas [Member] | Operating Segments [Member]
Total revenues
Loss from operations		(68)	(156)
Interest expense		5
Depreciation and amortization
Acquisitions of plant, property and equipment:		5,169
Assets		12,748
Net-Zero [Member] | Operating Segments [Member]
Total revenues
Loss from operations		(2,659)
Interest expense
Depreciation and amortization
Acquisitions of plant, property and equipment:
Assets		$ 110

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

[2] Includes no intercompany sales during the three months ended March 31, 2021 and $0.1 million for the year ended December 31, 2020 for hydrocarbon sales.