Note 2 - Revenue Recognition - Revenues By Major Customers (Details) - Customer Concentration Risk [Member] - Revenue Benchmark [Member]	3 Months Ended	9 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Wind [Member] \| Inox Wind Limited [Member]
Concentration risk percentage	10.00%	47.00%	11.00%	40.00%
Grid [Member] \| Department of Homeland Security [Member]
Concentration risk percentage	22.00%	10.00%	12.00%	10.00%
Grid [Member] \| Vestas WTG Mexico [Member]
Concentration risk percentage	25.00%	10.00%	10.00%	15.00%
Grid [Member] \| Fuji Bridex Pte Ltd [Member]
Concentration risk percentage	10.00%	17.00%	10.00%	10.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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