Condensed Consolidating Guarantor Financial Statements (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Financial information of guarantor and non-guarantor subsidiaries and affiliates
Net sales	$ 1,090.6	$ 1,289.0	$ 2,212.2	$ 2,476.0
Cost of materials sold	906.6	1,125.1	1,837.4	2,155.4
Gross profit	184.0	163.9	374.8	320.6
Warehousing, delivery, selling, general and administrative	131.5	139.8	262.9	275.0
Restructuring and other charges		0.6		0.9
Impairment charge on fixed assets	0.9	2.5	0.9	2.5
Operating profit (loss)	51.6	21.0	111.0	42.2
Other income and (expense), net	0.8	(0.7)	0.5	5.0
Interest and other expense on debt	(19.8)	(20.4)	(39.1)	(40.1)
Intercompany transactions:
Income (loss) before income taxes	32.6	(0.1)	72.4	7.1
Provision for income taxes	3.2	7.7	5.9	6.5
Net income	29.4	(7.8)	66.5	0.6
Less: Net loss attributable to noncontrolling interest	(1.2)	(0.6)	(2.3)	(1.6)
Net income (loss) attributable to Ryerson Inc.	30.6	(7.2)	68.8	2.2
Comprehensive income (loss)	22.8	(8.0)	67.9	5.6
Less: Comprehensive loss attributable to noncontrolling interest	(1.7)	(0.3)	(2.7)	(1.1)
Comprehensive income (loss) attributable to Ryerson Inc.	24.5	(7.7)	70.6	6.7
Parent [Member]
Financial information of guarantor and non-guarantor subsidiaries and affiliates
Warehousing, delivery, selling, general and administrative	1.2	1.3	2.5	2.6
Operating profit (loss)	(1.2)	(1.3)	(2.5)	(2.6)
Other income and (expense), net			0.3
Interest and other expense on debt	(18.9)	(19.5)	(37.4)	(38.5)
Intercompany transactions:
Interest expense on intercompany loans	(13.0)	(9.2)	(24.6)	(21.6)
Income (loss) before income taxes	(33.1)	(30.0)	(64.2)	(62.7)
Provision for income taxes		0.9		(1.6)
Equity in earnings of subsidiaries	(63.7)	(23.7)	(133.0)	(63.3)
Net income	30.6	(7.2)	68.8	2.2
Net income (loss) attributable to Ryerson Inc.	30.6	(7.2)	68.8	2.2
Comprehensive income (loss)	24.5	(7.7)	70.6	6.7
Comprehensive income (loss) attributable to Ryerson Inc.	24.5	(7.7)	70.6	6.7
Guarantor [Member]
Financial information of guarantor and non-guarantor subsidiaries and affiliates
Net sales	945.2	1,118.4	1,928.2	2,135.8
Cost of materials sold	783.7	981.2	1,596.9	1,867.3
Gross profit	161.5	137.2	331.3	268.5
Warehousing, delivery, selling, general and administrative	109.4	118.4	220.1	230.8
Restructuring and other charges		0.6		0.9
Impairment charge on fixed assets	0.9	2.5	0.9	2.5
Operating profit (loss)	51.2	15.7	110.3	34.3
Other income and (expense), net	0.1	(0.5)	0.1	5.9
Interest and other expense on debt		(0.1)
Intercompany transactions:
Interest income on intercompany loans	13.0	9.2	24.6	21.6
Income (loss) before income taxes	64.3	24.3	135.0	61.8
Provision for income taxes	3.0	5.1	5.6	4.9
Equity in earnings of subsidiaries	(2.6)	(4.6)	(3.8)	(6.4)
Net income	63.9	23.8	133.2	63.3
Net income (loss) attributable to Ryerson Inc.	63.9	23.8	133.2	63.3
Comprehensive income (loss)	61.9	21.3	135.0	61.3
Comprehensive income (loss) attributable to Ryerson Inc.	61.9	21.3	135.0	61.3
Non-guarantor [Member]
Financial information of guarantor and non-guarantor subsidiaries and affiliates
Net sales	147.5	172.8	288.6	344.8
Cost of materials sold	125.0	146.1	245.1	292.7
Gross profit	22.5	26.7	43.5	52.1
Warehousing, delivery, selling, general and administrative	20.9	20.1	40.3	41.6
Operating profit (loss)	1.6	6.6	3.2	10.5
Other income and (expense), net	0.7	(0.2)	0.1	(0.9)
Interest and other expense on debt	(0.9)	(0.8)	(1.7)	(1.6)
Intercompany transactions:
Income (loss) before income taxes	1.4	5.6	1.6	8.0
Provision for income taxes	0.2	1.7	0.3	3.2
Net income	1.2	3.9	1.3	4.8
Less: Net loss attributable to noncontrolling interest	(1.2)	(0.6)	(2.3)	(1.6)
Net income (loss) attributable to Ryerson Inc.	2.4	4.5	3.6	6.4
Comprehensive income (loss)	(3.5)	6.1	0.6	11.5
Less: Comprehensive loss attributable to noncontrolling interest	(1.7)	(0.3)	(2.7)	(1.1)
Comprehensive income (loss) attributable to Ryerson Inc.	(1.8)	6.4	3.3	12.6
Eliminations [Member]
Financial information of guarantor and non-guarantor subsidiaries and affiliates
Net sales	(2.1)	(2.2)	(4.6)	(4.6)
Cost of materials sold	(2.1)	(2.2)	(4.6)	(4.6)
Intercompany transactions:
Interest expense on intercompany loans	13.0	9.2	24.6	21.6
Interest income on intercompany loans	(13.0)	(9.2)	(24.6)	(21.6)
Equity in earnings of subsidiaries	66.3	28.3	136.8	69.7
Net income	(66.3)	(28.3)	(136.8)	(69.7)
Net income (loss) attributable to Ryerson Inc.	(66.3)	(28.3)	(136.8)	(69.7)
Comprehensive income (loss)	(60.1)	(27.7)	(138.3)	(73.9)
Comprehensive income (loss) attributable to Ryerson Inc.	$ (60.1)	$ (27.7)	$ (138.3)	$ (73.9)