Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 01, 2017	Dec. 31, 2012
Site Contingency [Line Items]
Litigation Settlement, Amount		$ 110,000
Environmental Costs Recovered	$ 37,000
Huntsville Site [Member]
Site Contingency [Line Items]
Environmental Remediation Expense To Date	5,500
Additional Expected Project Expenditures Low Estimate	3,000
Additional Expected Project Expenditures High Estimate	4,000
Huntsville Site [Member] | Investigation Report [Member]
Site Contingency [Line Items]
Additional Expected Project Expenditures Low Estimate	300
Additional Expected Project Expenditures High Estimate	600
Norco Site [Member] | Remediation, Project Management, Regulatory Oversight, and Investigative and Feasability Studies [Member]
Site Contingency [Line Items]
Environmental Remediation Expense To Date	54,500
Additional Expected Project Expenditures Low Estimate	20,600
Additional Expected Project Expenditures High Estimate	$ 31,300