Note 16 - New Accounting Pronouncements (Details)	9 Months Ended
Dec. 31, 2018 USD ($)
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Extended Product Warranty Description	terms generally ranging from 5 to 7 years
Extended Product Warranty Accrual	$ 366,374
Recognition of Deferred Revenue	$ 33,255

Amount as of the balance sheet date of the aggregate extended product warranty liability. Does not include the ending balance for the standard product warranty liability.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)(1),(c)(5)
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

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Balance Type:	credit
Period Type:	instant

- Definition

Describes the nature of the extended product warranties, which generally require additional fees to be paid by the buyer, and other guarantee contracts excluded from the initial recognition and initial measurement requirements. Does not include disclosures for standard product warranties, which typically have substantially shorter periods of time or provide less coverage, or both.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248

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- References

No definition available.

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- Definition

The amount of previously reported deferred or unearned revenue that was recognized as revenue during the period. For cash flows, this element primarily pertains to amortization of deferred credits on long-term arrangements. As a noncash item, it is deducted from net income when calculating cash provided by or used in operations using the indirect method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

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