Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net sales	$ 5,675.3	$ 3,466.6	$ 4,501.6
Cost of materials sold	4,528.5	2,845.5	3,673.7
Gross profit	1,146.8	621.1	827.9
Warehousing, delivery, selling, general, and administrative	711.2	554.3	636.8
Gain on sale of assets	(109.6)		(20.6)
Gain on insurance settlement			(1.5)
Restructuring and other charges		2.2	2.4
Operating profit	545.2	64.6	210.8
Other income (expense):
Interest and other expense on debt	(51.0)	(76.4)	(93.2)
Pension settlement charges	(98.7)	(65.9)	(1.6)
Loss on retirement of debt	(5.5)	(17.7)	(0.2)
Other income and (expense), net	(0.9)	5.3	(0.6)
Income (loss) before income taxes	389.1	(90.1)	115.2
Provision (benefit) for income taxes	93.7	(24.8)	32.5
Net income (loss)	295.4	(65.3)	82.7
Less: Net income attributable to noncontrolling interest	1.1	0.5	0.3
Net income (loss) attributable to Ryerson Holding Corporation	$ 294.3	$ (65.8)	$ 82.4
Basic earnings (loss) per share	$ 7.67	$ (1.73)	$ 2.19
Diluted earnings (loss) per share	7.56	$ (1.73)	$ 2.17
Dividends declared per share	$ 0.165