Note 1 - Summary of Significant Accounting Policies - Estimated Amortizable Lives of Intangible Assets (Details)	12 Months Ended
	Mar. 31, 2019
Computer Software, Intangible Asset [Member]
Intangible asset, useful life (Year)	3 years
Trade Names [Member]
Intangible asset, useful life (Year)	5 years
Certification Marks [Member]
Intangible asset, useful life (Year)	5 years
Noncompete Agreements [Member]
Intangible asset, useful life (Year)	5 years
Licensing Agreements [Member]
Intangible asset, useful life (Year)	5 years
Patents [Member]
Intangible asset, useful life (Year)	9 years
Customer Relationships [Member]
Intangible asset, useful life (Year)	10 years