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Business Segments (Details3) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | --- | ---
Segment Reporting Asset Reconciling Item [Line Items] |  |  |
Identifiable Assets | $ 5,501.8 | $ 5,185.4 | $ 5,170.0
Deferred taxes | 478.8 | 468.9 |
High Performance Materials & Components |  |  |
Segment Reporting Asset Reconciling Item [Line Items] |  |  |
Identifiable Assets | 2,765.4 | 2,662.3 | 2,744.3
Flat Rolled Products |  |  |
Segment Reporting Asset Reconciling Item [Line Items] |  |  |
Identifiable Assets | 2,225.7 | 2,218.4 | 2,056.4
Discontinued Operations [Member] |  |  |
Segment Reporting Asset Reconciling Item [Line Items] |  |  |
Identifiable Assets | 0.0 | 0.2 | 0.4
Corporate, Non-Segment [Member] |  |  |
Segment Reporting Asset Reconciling Item [Line Items] |  |  |
Deferred taxes | 8.7 | 7.6 | 12.1
Corporate: Cash and cash equivalents and other [Member] |  |  |
Segment Reporting Asset Reconciling Item [Line Items] |  |  |
Identifiable Assets | $ 502.0 | $ 296.9 | $ 356.8

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