Contingencies (Details)		1 Months Ended		6 Months Ended
	Jun. 30, 2018 Party	Nov. 30, 2019 USD ($)	Mar. 31, 2016 Party mi	Jun. 27, 2020 USD ($) contaminant	Dec. 28, 2019 USD ($)
Loss Contingencies [Line Items]
Area of land | mi			8.3
Estimate of possible loss				$ 1,380,000,000
Number of parties | Party	100		100
Number of contaminants | contaminant				8
Loss related to litigation settlement		$ 600,000
Range of possible loss				$ 100,000
Insurance Environmental and Litigation Matters [Member]
Loss Contingencies [Line Items]
Reserves for insurance, environmental and litigation contingencies				67,500,000	$ 70,500,000
Insurance settlements receivable				26,200,000	$ 26,200,000
Settled Litigation [Member]
Loss Contingencies [Line Items]
Number of parties | Party	20
Pending Litigation [Member]
Loss Contingencies [Line Items]
Estimate of possible loss				$ 165,000,000
Number of parties | Party	40
Plant, One [Member]
Loss Contingencies [Line Items]
Loss related to litigation settlement		300,000
Plant, Two [Member]
Loss Contingencies [Line Items]
Loss related to litigation settlement		$ 300,000