Employee Retirement Plans and Postretirement Benefits Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Multiemployer Plans, Plan Contributions	$ 7.9	$ 7.9	$ 7.7
Prescription Drug Benefit, Amount Paid	37.6	37.1	36.6
Defined Benefit Plan, Prescription Drug Benefit, Accumulated Postretirement Benefit Obligation, Decrease for Subsidy	$ 0.1	$ 0.3	$ 0.3