Note 10 - Pension Plans - Net Periodic Pension Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Service cost	$ 28	$ 25	$ 56	$ 51
Interest cost on projected benefit obligation	326	371	678	739
Expected return on plan assets	(296)	(442)	(619)	(880)
Recognized actuarial loss	44	45	92	90
Net periodic pension expense	$ 102	$ (1)	$ 207