Consolidated Statements of Operations (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net sales
Net sales of goods	$ 704.9	$ 709.3	$ 628.8
Service revenues	258.6	206.3	166.8
Freight revenues	22.1	28.2	30.7
Net sales	985.6	943.8	826.3
Cost of sales
Cost of goods sold	516.2	512.5	461.2
Cost of service revenues	180.8	157.0	126.0
Cost of freight revenues	17.5	22.0	24.9
Cost of sales	714.5	691.5	612.1
Gross profit	271.1	252.3	214.2
Selling, general and administrative expenses	173.0	166.2	145.2
Operating profit	98.1	86.1	69.0
Other income (expense):
Interest expense, net	(10.4)	(11.0)	(9.6)
Other, net	(3.4)	0.2	1.3
Total other income (expense), net	(13.8)	(10.8)	(8.3)
Income before income taxes and income (loss) from affiliates and joint ventures	84.3	75.3	60.7
Income tax expense	23.3	20.8	20.3
Income before income (loss) from affiliates and joint ventures	61.0	54.5	40.4
Income (loss) from affiliates and joint ventures	3.9	5.2	(11.0)
Income (loss) from continuing operations	64.9	59.7	29.4
Discontinued Operations
Income (loss) on discontinued operations	0	(1.2)	(0.9)
Net income (loss)	64.9	58.5	28.5
Net income (loss) attributable to noncontrolling interests	(0.2)	0	(0.7)
Net income (loss) attributable to AMCOL shareholders	65.1	58.5	29.2
Basic earnings (loss) per share
Continuing operations (in dollars per share)	$ 2.03	$ 1.89	$ 0.97
Discontinued operations (in dollars per share)	$ 0	$ (0.04)	$ (0.03)
Net income (in dollars per share)	$ 2.03	$ 1.85	$ 0.94
Diluted earnings (loss) per share
Continuing operations (in dollars per share)	$ 2.01	$ 1.86	$ 0.96
Discontinued operations (in dollars per share)	$ 0	$ (0.04)	$ (0.03)
Net income (in dollars per share)	$ 2.01	$ 1.82	$ 0.93
Amounts attributable to AMCOL shareholders
Income from continuing operations, net of tax	65.1	59.7	30.1
Discontinued operations, net of tax	0	(1.2)	(0.9)
Net income	$ 65.1	$ 58.5	$ 29.2
Dividends declared per share (in dollars per share)	$ 0.76	$ 0.72	$ 0.72