Pension Plans and Other Postretirement Benefits Multiemployer Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Multiemployer Plans [Line Items]
Multiemployer plan minimum level of funding for highest funding zone status	80.00%
Multiemployer plan, period contributions	$ 1.5	$ 1.5	$ 1.7
Minimum
Multiemployer Plans [Line Items]
Contributions to multiemployer plan, percentage of total contributions to plan	5.00%
Financial Improvement Plan | Selling, general and administrative expenses
Multiemployer Plans [Line Items]
Multiemployer plan, period contributions	$ 2.3	$ 3.3
Chemetall Surface Treatment
Multiemployer Plans [Line Items]
Multiemployer plan, period contributions			$ 1.3