Note 9 - Pension Plans - Net Periodic Pension Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Service cost	$ 25	$ 26	$ 51	$ 52
Interest cost on projected benefit obligation	371	467	739	940
Expected return on plan assets	(442)	(494)	(880)	(991)
Recognized actuarial loss	45	18	$ 90	36
Net periodic pension expense	$ (1)	$ 17		$ 37