v3.26.1
Segment Information - Summary of Segment Revenue, Significant Expenses Regularly Reviewed By CODM, and Other Segment Items (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting Information [Line Items]            
Net sales $ 2,006.2   $ 1,169.3   $ 3,572.7 $ 2,305.0
Selling general and administrative expense 320.3   201.8   585.5 403.9
Depreciation and amortization expense         55.1 38.6
Interest and other expense on debt 14.3   9.8   26.0 19.3
Income (loss) before income taxes 22.0   (6.3)   35.2 (13.2)
Provision (benefit) for income taxes 6.0   (8.4)   14.2 (10.0)
Net income (loss) 16.0 $ 5.0 2.1 $ (5.3) 21.0 (3.2)
Less: Net income attributable to noncontrolling interest 0.5   0.2   1.0 0.5
Net income (loss) attributable to Ryerson Holding Corporation 15.5   1.9   20.0 (3.7)
Operating Segments [Member]            
Segment Reporting Information [Line Items]            
Net sales 2,006.2   1,169.3   3,572.7 2,305.0
Cost of materials sold, excluding LIFO expense [1] 1,634.0   946.7   2,901.7 1,871.2
LIFO expense [1] 17.0   13.2   27.0 20.0
Delivery expense [1] 60.6   31.7   102.3 61.8
Compensation and benefits expense [1] 156.2   92.9   287.3 189.5
Selling general and administrative expense [1] 22.3   19.1   41.2 36.8
Operating expense - fixed [1] 20.0   18.7   40.3 38.7
Operating expense - variable [1] 26.3   15.3   47.0 30.3
Reorganization expense and one-time items [1],[2] 2.3   5.0   6.0 9.0
Depreciation and amortization expense [1] 31.7   19.4   55.1 38.6
Interest and other expense on debt 14.3   9.8   26.0 19.3
Other segment items [3] (0.5)   3.8   3.6 3.0
Income (loss) before income taxes 22.0   (6.3)   35.2 (13.2)
Provision (benefit) for income taxes 6.0   (8.4)   14.2 (10.0)
Net income (loss) 16.0   2.1   21.0 (3.2)
Less: Net income attributable to noncontrolling interest 0.5   0.2   1.0 0.5
Net income (loss) attributable to Ryerson Holding Corporation $ 15.5   $ 1.9   $ 20.0 $ (3.7)
[1] The significant expense categories and amounts align with the information that is regularly provided to the CODM.
[2] Reorganization expense and one-time items is used by management to capture excess costs associated with one-time events or with implementing significant Company projects or changes and allows the CODM to assess performance without the impact of these items. It is not a GAAP financial measure. Expenses excluding reorganization expense and one-time items should not be used as a substitute for total expenses reported on our Condensed Consolidated Statements of Comprehensive Income (Loss).
[3] Other segment items include merger expenses, foreign exchange gain and loss, pension settlement gains, impairment charges on assets, discounts on accounts receivable factoring, and pension and postretirement benefit costs other than service costs.