Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, foreign	$ 2.5
Operating loss carryforwards, state and local	17.2
Deferred tax assets
Net operating loss carryforwards	19.7	$ 15.4
Tax credit carryforwards	13.7	27.9
Restructuring and impairment charges	0.1	2.9
Pension and deferred compensation	28.3	46.4
Other	14.3	19.5
Valuation allowance	(20.9)	(18.7)
Total deferred tax assets	55.2	93.4
Deferred tax liabilities:
Accelerated depreciation	26.3	30.3
Tax on undistributed foreign earnings	9.8	0.0
Other	3.8	6.1
Total deferred tax liabilities	39.9	36.4
Net deferred tax asset	15.3	$ 57.0
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	258.4
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	17.5
Operating loss carryforwards, not subject to expiration	14.0
Year 2018 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	11.4
Year After 2018 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	247.0
Year 2020 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	0.9
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	3.0
Research Tax Credit Carryforward [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	6.9
Research Tax Credit Carryforward [Member] | Year 2035 [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	1.5
Research Tax Credit Carryforward [Member] | Year 2036 [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	1.8
Research Tax Credit Carryforward [Member] | Year 2037 [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	1.8
Research Tax Credit Carryforward [Member] | Year 2038 [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	1.8
Research Tax Credit Carryforward [Member] | Year 2021 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	0.2
Research Tax Credit Carryforward [Member] | Year 2022 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	0.8
Research Tax Credit Carryforward [Member] | Year 2023 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	0.5
Research Tax Credit Carryforward [Member] | Year After 2023 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	$ 1.5