Note 1 - Significant Accounting Policies and Recent Accounting Pronouncements - Useful Life of Property, Plant, and Equipment (Details)	6 Months Ended
	Sep. 30, 2019
Furniture and Equipment [Member]
Useful life (Year)
Furniture and Equipment [Member] | Minimum [Member]
Useful life (Year)	5 years
Furniture and Equipment [Member] | Maximum [Member]
Useful life (Year)	7 years
Land and Land Improvements [Member]
Useful life (Year)	15 years
Land and Land Improvements [Member] | Minimum [Member]
Useful life (Year)
Land and Land Improvements [Member] | Maximum [Member]
Useful life (Year)