Restructuring Reserves (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Assets held-for-sale, not part of disposal group, current	$ 3.5	$ 0.6
Melt Delivery and Control Systems [Member]
Restructuring Cost and Reserve [Line Items]
Assets held-for-sale, not part of disposal group, current	3.0
Other current liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Liability, severance-related actions	5.0		$ 2.6
Other expense, net [Member]
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 2.6