Retirement Plans (Components Of Net Periodic Benefit Cost) (Details) $ in Thousands			3 Months Ended	4 Months Ended		12 Months Ended
		Dec. 31, 2019	Sep. 29, 2019 USD ($)	Jan. 19, 2020 USD ($) defined_benefit_plan healthcare_plan	Jan. 20, 2019 USD ($)	Sep. 29, 2019
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Number of sponsored defined benefit pension plans | defined_benefit_plan				2
Lump sum payments from Qualified Plan			$ 122,300
Number of postretirement health care plans | healthcare_plan				2
Defined Benefit Plan Disclosure [Line Items]
Pension settlement				$ (38,600)
Return on asset assumption (percent)		5.90%				5.80%
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost				5,076	$ 7,048
Expected return on plan assets				(6,656)	(8,104)
Pension settlement				38,606	0
Actuarial loss (gain)	[1]			1,672	1,219
Amortization of unrecognized prior service cost	[1]			26	35
Net periodic benefit cost				38,724	198
Postretirement Healthcare Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost				248	307
Actuarial loss (gain)	[1]			6	(49)
Net periodic benefit cost				$ 254	$ 258

[1] Amounts were reclassified from accumulated OCI into net earnings as a component of “Other pension and post-retirement expenses, net