Pension and Postretirement Benefits Net Periodic Income and Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	$ 1,213	$ 1,157
Interest Cost on Projected Benefit Obligation	8,660	9,930
Expected Return on Plan Assets	(12,820)	(13,582)
Amortization of Prior Service Cost (Credit)	19	45
Amortization of Actuarial Loss	3,987	2,910
Net Periodic Expense (Income)	1,059	460
Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	21	26
Interest Cost on Projected Benefit Obligation	451	583
Expected Return on Plan Assets	0	0
Amortization of Prior Service Cost (Credit)	0	(182)
Amortization of Actuarial Loss	752	790
Net Periodic Expense (Income)	$ 1,224	$ 1,217