Goodwill and Other Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 9.5	$ 10.0	$ 10.0
Gross carrying amount	156.2	193.7
Accumulated amortization	(59.9)	(64.0)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2020	8.0
2021	8.0
2022	8.0
2023	8.0
2024	8.0
Accumulated goodwill impairment	241.0	241.0	$ 241.0
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	76.8	93.4
Accumulated amortization	(29.7)	(31.9)
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	27.0	35.7
Accumulated amortization	(9.3)	(10.6)
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	52.4	64.6
Accumulated amortization	(20.9)	$ (21.5)
Cast Products
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Period Increase (Decrease)	(23.8)
Gross carrying amount	33.2
Accumulated amortization	(12.7)
Cast Products, Salem Oregon
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	4.3
Accumulated amortization	$ (1.0)

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of increase (decrease) in carrying value of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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