Note 17 - Business Segments - Total Business Segments Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019
Total assets	$ 120,150	$ 119,330
Operating Segments [Member] | Grid [Member]
Total assets	32,169	31,075
Operating Segments [Member] | Wind [Member]
Total assets	11,416	8,167
Corporate, Non-Segment [Member]
Total assets	$ 76,565	$ 80,088