Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, foreign	$ 6.4
Operating loss carryforwards, state and local	15.5
Deferred tax assets
Net operating loss carryforwards	21.9	$ 18.4
Tax credit carryforwards	2.8	10.5
Pension and deferred compensation	25.6	27.2
Other	9.2	11.4
Valuation allowance	(15.9)	(16.0)
Total deferred tax assets	43.6	51.5
Deferred tax liabilities:
Accelerated depreciation	37.9	31.3
Tax on undistributed earnings of subsidiaries	6.3	6.6
Other	0.9	2.0
Total deferred tax liabilities	45.1	39.9
Net deferred tax (liability) asset	(1.5)	$ 11.6
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	226.9
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	49.4
Operating loss carryforwards, not subject to expiration	48.7
Year 2018 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	15.4
Year After 2018 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	211.5
Research Tax Credit Carryforward [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	2.0
Research Tax Credit Carryforward [Member] | Year 2022 [Member] | State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	0.5
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	$ 1.0