Note 17 - Business Segments - Total Business Segments Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Total assets	$ 117,443	$ 119,330
Operating Segments [Member] | Grid [Member]
Total assets	34,479	31,075
Operating Segments [Member] | Wind [Member]
Total assets	12,474	8,167
Corporate, Non-Segment [Member]
Total assets	$ 70,490	$ 80,088