Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Continuing Operations
Net sales	$ 257.4	$ 243.1	$ 493.0	$ 461.7
Cost of sales	182.8	181.1	353.8	341.3
Gross profit	74.6	62.0	139.2	120.4
Selling, general and administrative expenses	43.6	41.0	86.9	80.1
Operating profit	31.0	21.0	52.3	40.3
Other income (expense):
Interest expense, net	(2.7)	(2.7)	(5.4)	(5.3)
Other, net	(0.5)	0.5	(2.7)	0.1
Total other income (expense), net	(3.2)	(2.2)	(8.1)	(5.2)
Income before income taxes and income (loss) from affiliates and joint ventures	27.8	18.8	44.2	35.1
Income tax expense	7.6	5.7	11.9	9.6
Income before income (loss) from affiliates and joint ventures	20.2	13.1	32.3	25.5
Income (loss) from affiliates and joint ventures	1.1	(0.1)	2.3	0.9
Income (loss) from continuing operations	21.3	13.0	34.6	26.4
Discontinued Operations
Income (loss) on discontinued operations		0.2		0.1
Net income (loss)	21.3	13.2	34.6	26.5
Net income (loss) attributable to noncontrolling interests	(0.3)		(0.2)
Net income (loss) attributable to AMCOL shareholders	21.6	13.2	34.8	26.5
Weighted average common shares outstanding	32.0	31.7	32.0	31.6
Weighted average common and common equivalent shares outstanding	32.3	32.2	32.3	32.1
Amounts attributable to AMCOL shareholders
Income from continuing operations, net of tax	21.6	13.0	34.8	26.4
Discontinued operations, net of tax		0.2		0.1
Net income	$ 21.6	$ 13.2	$ 34.8	$ 26.5
Basic earnings (loss) per share:
Continuing operations	$ 0.67	$ 0.41	$ 1.09	$ 0.84
Discontinued operations		$ 0.01
Net income	$ 0.67	$ 0.42	$ 1.09	$ 0.84
Diluted earnings (loss) per share:
Continuing operations	$ 0.67	$ 0.40	$ 1.08	$ 0.83
Discontinued operations		$ 0.01
Net income	$ 0.67	$ 0.41	$ 1.08	$ 0.83
Dividends declared per share	$ 0.18	$ 0.18	$ 0.36	$ 0.36