Note 7 - Retirement Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Dec. 30, 2017	Dec. 31, 2016
Service Cost	$ 1,981	$ 2,164	$ 5,944	$ 6,491
Interest Cost	1,985	1,919	5,956	5,756
Expected Return on Plan Assets	(3,673)	(2,978)	(10,640)	(8,934)
Amortization of Actuarial Loss		679		2,037
Amortization of Transition Asset	30	27	90	82
Net Periodic Benefit Cost	$ 323	$ 1,811	$ 1,350	$ 5,432