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v3.22.4

Selected Quarterly Financial Data (Unaudited) - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Unusual Or Infrequent Item [Line Items] |  |  |
Net gain (loss) on sale of businesses | $ (134.2) | $ 0.0 | $ 0.0
Restructuring and other credits (charges) | (23.7) | 10.5 | (1,132.1)
Impairment of goodwill | 0.0 | 0.0 | (287.0)
Severance Costs |  |  | (60.5)
Termination benefits |  |  | (17.4)
Other Asset Impairment Charges | 0.0 | 0.0 | (1,041.5)
Other Postretirement Benefits |  |  |
Unusual Or Infrequent Item [Line Items] |  |  |
Termination benefits | $ 0.0 | $ 0.0 | $ (6.7)
Allegheny & Tsingshan Stainless |  |  |
Unusual Or Infrequent Item [Line Items] |  |  |
Equity method investment ownership percentage | 50.00% |  |
Tsingshan Group | Allegheny & Tsingshan Stainless |  |  |
Unusual Or Infrequent Item [Line Items] |  |  |
Equity method investment ownership percentage | 50.00% |  |

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- Definition Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=126905981&loc=d3e2443-110228 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230 + Details
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