Note 8 - Retirement Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 29, 2019	Jun. 30, 2018
Service Cost	$ 2,288	$ 2,442
Interest Cost	2,296	2,243
Expected Return on Plan Assets	(3,958)	(3,596)
Amortization of Prior Service Cost	30	30
Amortization of Net Loss		303
Net Periodic Benefit Cost	$ 656	$ 1,422