Income Taxes (Components of Deferred Tax Assets (Liabilities)) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss and other tax carryforwards	$ 125.1	$ 125.1
Interest limitation	73.7	47.1
Pension and workers compensation benefits	43.1	46.0
Accrued compensation	16.1	16.6
Accrued liabilities	11.1	14.1
Goodwill and intangible assets	17.4	11.4
Allowance for doubtful accounts	5.5	6.4
Other	8.0	7.3
Total deferred tax assets	300.0	274.0
Valuation allowance	(107.1)	(115.2)
Net deferred tax assets	192.9	158.8
Deferred tax liabilities:
Property, plant and equipment	(130.6)	(153.8)
Other	(3.9)	(9.7)
Total deferred tax liabilities	(134.5)	(163.5)
Net deferred tax assets (liabilities)		(4.7)
Net deferred tax assets (liabilities)	58.4
Valuation allowance	107.1	115.2
Domestic Tax Authority
Deferred tax assets:
Valuation allowance	(4.5)
Deferred tax liabilities:
Net operating loss carryforwards	32.8
Capital loss carryforwards	18.3
Tax credit carryforward	2.1
Valuation allowance	4.5
Domestic Tax Authority | Expires in 2021
Deferred tax liabilities:
Capital loss carryforwards	1.1
Domestic Tax Authority | Expires in 2022
Deferred tax liabilities:
Capital loss carryforwards	17.2
Foreign Tax Authority
Deferred tax assets:
Valuation allowance	(47.0)
Deferred tax liabilities:
Net operating loss carryforwards	81.1
Net operating loss carryforwards, not subject to expiration	29.1
Tax credit carryforward	28.4
Valuation allowance	47.0
State and Local Jurisdiction
Deferred tax assets:
Valuation allowance	(55.6)
Deferred tax liabilities:
Net operating loss carryforwards	522.3
Capital loss carryforwards	9.0
Tax credit carryforward	43.9
Tax credit carryforward, not subject to expiration	32.1
Valuation allowance	55.6
State and Local Jurisdiction | Expires in 2021
Deferred tax liabilities:
Capital loss carryforwards	0.5
State and Local Jurisdiction | Expires in 2022
Deferred tax liabilities:
Capital loss carryforwards	8.5
Deferred Income Taxes
Deferred tax liabilities:
Net deferred tax assets (liabilities)	(2.8)	(32.1)
Other Noncurrent Assets
Deferred tax liabilities:
Net deferred tax assets (liabilities)	$ 61.2	$ 27.4