Note 3 - Equipment and Leasehold Improvements, Net - Estimated Useful Lives (Details)	3 Months Ended
	Jun. 30, 2018
Equipment [Member] | Minimum [Member]
Estimated useful lives (Year)	3 years
Equipment [Member] | Maximum [Member]
Estimated useful lives (Year)	10 years
Furniture and Fixtures [Member] | Minimum [Member]
Estimated useful lives (Year)	3 years
Furniture and Fixtures [Member] | Maximum [Member]
Estimated useful lives (Year)	7 years
Leasehold Improvements [Member] | Minimum [Member]
Estimated useful lives (Year)	10 years
Leasehold Improvements [Member] | Maximum [Member]
Estimated useful lives (Year)	25 years