Note 9 - Retirement Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 27, 2020	Jun. 29, 2019
Service Cost Including Administration	$ 2,574	$ 2,288
Interest Cost	2,251	2,296
Expected Return on Plan Assets	(3,567)	(3,958)
Amortization of Prior Service Cost	23	30
Amortization of Net Loss	2,224	0
Net Periodic Benefit Cost	$ 3,505	$ 656