Note 4 - Revenue From Contracts With Customers - Revenues Disaggregated (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues from external customers	$ 7,775	$ 6,261	$ 13,463	$ 11,720
Revenues from external customers	7,775	6,261	13,463	11,720
North America [Member]
Revenues from external customers	5,575	1,970	8,817	3,794
Revenues from external customers	5,575	1,970	8,817	3,794
Europe [Member]
Revenues from external customers	2,177	4,288	4,503	7,852
Revenues from external customers	2,177	4,288	4,503	7,852
Asia [Member]
Revenues from external customers	4	1	20	20
Revenues from external customers	4	1	20	20
Other Regions [Member]
Revenues from external customers	19	2	123	54
Revenues from external customers	19	2	123	54
Integrated Energy Infrastructure Solutions and Services Segment [Member]
Revenues from external customers	3,747	6,261	9,036	11,720
Revenues from external customers	3,747	6,261	9,036	11,720
Integrated Energy Infrastructure Solutions and Services Segment [Member] | North America [Member]
Revenues from external customers	1,547	1,970	4,390	3,794
Revenues from external customers	1,547	1,970	4,390	3,794
Integrated Energy Infrastructure Solutions and Services Segment [Member] | Europe [Member]
Revenues from external customers	2,177	4,288	4,503	7,852
Revenues from external customers	2,177	4,288	4,503	7,852
Integrated Energy Infrastructure Solutions and Services Segment [Member] | Asia [Member]
Revenues from external customers	4	1	20	20
Revenues from external customers	4	1	20	20
Integrated Energy Infrastructure Solutions and Services Segment [Member] | Other Regions [Member]
Revenues from external customers	19	2	123	54
Revenues from external customers	19	2	123	54
Electric Power and Solar Infrastructure Services Segment [Member]
Revenues from external customers	4,028		4,427
Revenues from external customers	4,028		4,427
Electric Power and Solar Infrastructure Services Segment [Member] | North America [Member]
Revenues from external customers	4,028		4,427
Revenues from external customers	4,028		4,427
Electric Power and Solar Infrastructure Services Segment [Member] | Europe [Member]
Revenues from external customers
Revenues from external customers
Electric Power and Solar Infrastructure Services Segment [Member] | Asia [Member]
Revenues from external customers
Revenues from external customers
Electric Power and Solar Infrastructure Services Segment [Member] | Other Regions [Member]
Revenues from external customers
Revenues from external customers
Transferred at Point in Time [Member]
Revenues from external customers	1,526	1,311	3,505	2,464
Revenues from external customers	1,526	1,311	3,505	2,464
Transferred at Point in Time [Member] | Integrated Energy Infrastructure Solutions and Services Segment [Member]
Revenues from external customers	1,526	1,311	3,505	2,464
Revenues from external customers	1,526	1,311	3,505	2,464
Transferred at Point in Time [Member] | Electric Power and Solar Infrastructure Services Segment [Member]
Revenues from external customers
Revenues from external customers
Transferred over Time [Member]
Revenues from external customers	6,249	4,950	9,958	9,256
Revenues from external customers	6,249	4,950	9,958	9,256
Transferred over Time [Member] | Integrated Energy Infrastructure Solutions and Services Segment [Member]
Revenues from external customers	2,221	4,950	5,531	9,256
Revenues from external customers	2,221	4,950	5,531	9,256
Transferred over Time [Member] | Electric Power and Solar Infrastructure Services Segment [Member]
Revenues from external customers	4,028		4,427
Revenues from external customers	$ 4,028		$ 4,427