Pension Plan and Postretirement Health Care and Life Insurance Benefits (Details) - Pension Plan [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Components of net periodic benefit cost:
Service cost	$ 64	$ 58	$ 128	$ 116
Interest cost	221	226	442	452
Expected return on plan assets	(417)	(403)	(834)	(806)
Amortization of prior service cost	9	9	18	18
Amortization of losses	249	302	498	604
Net periodic benefit cost	$ 126	$ 192	$ 252	$ 384