CONSOLIDATED STATEMENTS OF INCOME (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CONSOLIDATED STATEMENTS OF INCOME
Net sales	$ 8,442.3	$ 8,134.7	$ 6,312.8
Costs and expenses:
Cost of sales (exclusive of depreciation and amortization shown below)	6,235.4	6,148.7	4,727.9
Warehouse, delivery, selling, general and administrative	1,396.2	1,280.1	1,103.6
Depreciation and amortization	151.5	133.1	120.6
Total costs and expenses	7,783.1	7,561.9	5,952.1
Operating income	659.2	572.8	360.7
Other income (expense):
Interest	(58.4)	(59.8)	(61.2)
Other income (expense), net	8.6	(1.4)	(3.0)
Income before income taxes	609.4	511.6	296.5
Income tax provision	201.1	162.4	98.6
Net income	408.3	349.2	197.9
Less: Net income attributable to noncontrolling interests	4.8	5.4	3.5
Net income attributable to Reliance	$ 403.5	$ 343.8	$ 194.4
Earnings per share:
Diluted earnings per common share attributable to Reliance shareholders (in dollars per share)	$ 5.33	$ 4.58	$ 2.61
Basic earnings per common share attributable to Reliance shareholders (in dollars per share)	$ 5.36	$ 4.60	$ 2.62
Cash dividends per share (in dollars per share)	$ 0.80	$ 0.48	$ 0.40