Postretirement Benefits Change in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Net actuarial (gain) loss	$ (1,972)	$ (894)
Amortization of net loss	(66)	(208)
Amortization of prior service credit	350	352
Deferred income taxes	(420)	(186)
Total recognized in accumulated other comprehensive income	$ (1,268)	$ (564)	$ 7

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Amount, before tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan.

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Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan.

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Amount, before tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.

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