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Goodwill Impairment - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | ---
Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019 | Mar. 31, 2020 | Dec. 31, 2019
Goodwill [Line Items] |  |  |  |  |  |
Goodwill | $ 236.4 |  | $ 236.4 |  |  | $ 525.8
Decrease of goodwill during period |  |  | (289.4) |  |  |
Impairment of goodwill | 287.0 | $ 0.0 | 287.0 | $ 0.0 |  |
Goodwill, foreign currency translation loss |  |  | 2.4 |  |  |
Accumulated goodwill impairment loss | 528.0 |  | 528.0 |  |  | $ 241.0
Forged Products |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Goodwill | 173.4 |  | 173.4 |  | $ 460.4 |
Reporting unit, percentage of fair value in excess of carrying amount |  |  |  |  |  | 30.00%
Specialty Materials |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |
Goodwill | $ 63.0 |  | $ 63.0 |  |  |

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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(10)(1)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=120320667&loc=SL49117168-202975 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266 + Details
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- Definition Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267 + Details
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