Acquisitions - Summary of Unaudited Pro Forma Information (Detail) - Olympic Merger Agreement [Member] - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
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Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
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| Business Combination, Pro Forma Information [Line Items] | ||||
| Net sales | $ 2,006.2 | $ 1,665.3 | $ 3,823.3 | $ 3,293.3 |
| Net income (loss) attributable to Ryerson Holding Corporation | $ 29.0 | $ 3.9 | $ 20.1 | $ (27.1) |
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount, after tax, of pro forma income (loss) of combined entity as if acquisition date of business combination occurred as of beginning of period. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of pro forma revenue of combined entity as if acquisition date of business combination occurred as of beginning of period. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Details
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