Landfill and Environmental Costs (Narrative) (Details) $ in Millions, ft³ in Billions		12 Months Ended
	Sep. 27, 2018 USD ($)	Dec. 31, 2018 USD ($) landfill ft³	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Environmental Exit Cost [Line Items]
Number of active solid waste landfills | landfill		190
Total available disposal capacity (billion in-place cubic feet) | ft³		137.7
Number of closed landfills | landfill		129
Net increase (decrease) in amortization expense		$ (13.2)	$ (0.1)	$ (6.5)
Fair value of assets that are legally restricted for final capping, closure and post-closure obligations		29.5	28.6
Aggregate potential remediation liability, amount higher than amount recorded		372.0
Payments for management and monitoring of remediation area		48.8	54.8	66.8
Remediation liability		540.2	$ 564.0	$ 602.9	$ 646.1
Estimated possible excess loss contingency		14.0
Bridgeton Closed Landfill
Environmental Exit Cost [Line Items]
Payments for management and monitoring of remediation area		16.2
Remediation liability		161.1
Expected remediation liability to be paid during the next 12 months		15.0
Estimated possible excess loss contingency		171.0
Insurance recoveries		$ 40.0
West Lake Landfill Superfund Site
Environmental Exit Cost [Line Items]
Anticipated remediation costs	$ 229.0
West Lake Landfill Superfund Site | Minimum
Environmental Exit Cost [Line Items]
Time period alloted for remediation	4 years
West Lake Landfill Superfund Site | Maximum
Environmental Exit Cost [Line Items]
Time period alloted for remediation	5 years