Pension Plan and Postretirement Health Care and Life Insurance Benefits (Details 1) - Postretirement Benefit Plans [Member] - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 12	$ 8	$ 24	$ 16
Interest cost	23	25	46	50
Amortization of prior service cost	1	1	2	2
Amortization of losses	(7)	(1)	(14)	(2)
Net periodic benefit cost	$ 29	$ 33	$ 58	$ 66

Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of net periodic benefit cost (credit) for defined benefit plan.

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- Definition

Amount of gain (loss) recognized in net periodic benefit (cost) credit from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk related to obligation and assets used to effect settlement.

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- Definition

Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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