Note 2 - Leases (Details Textual) $ in Thousands	3 Months Ended	9 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Operating Lease, Payments	$ 2,019	$ 6,110
Operating Lease, Weighted Average Remaining Lease Term	4 years 7 months 6 days	4 years 7 months 6 days
Operating Lease, Weighted Average Discount Rate, Percent	3.25%	3.25%
Minimum [Member]
Lessee, Operating Lease, Term of Contract	1 year	1 year
Maximum [Member]
Lessee, Operating Lease, Term of Contract	15 years	15 years