CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Continuing Operations
Net sales	$ 262.8	$ 257.4	$ 499.5	$ 492.9
Cost of sales	190.8	182.7	364.4	353.5
Gross profit	72.0	74.7	135.1	139.4
Selling, general and administrative expenses	47.0	43.6	93.8	86.9
Operating profit	25.0	31.1	41.3	52.5
Other income (expense):
Interest expense, net	(2.5)	(2.7)	(5.0)	(5.4)
Other, net	(0.5)	(0.6)	(1.2)	(2.7)
Total other income (expense), net	(3.0)	(3.3)	(6.2)	(8.1)
Income before income taxes and income (loss) from affiliates and joint ventures	22.0	27.8	35.1	44.4
Income tax expense	6.3	7.6	9.9	12.0
Income before income (loss) from affiliates and joint ventures	15.7	20.2	25.2	32.4
Income (loss) from affiliates and joint ventures	0.9	1.1	1.8	2.4
Income from continuing operations	16.6	21.3	27.0	34.8
Net income (loss) attributable to noncontrolling interests	0.1	(0.3)	0	(0.2)
Net income (loss) attributable to AMCOL shareholders	$ 16.5	$ 21.6	$ 27.0	$ 35.0
Weighted average common shares outstanding (in shares)	32,425,798	32,035,503	32,402,571	32,005,514
Weighted average common and common equivalent shares outstanding (in shares)	32,703,232	32,333,505	32,681,932	32,310,556
Earnings per share attributable to AMCOL shareholders:
Basic earnings per share (in dollars per share)	$ 0.51	$ 0.67	$ 0.83	$ 0.42
Diluted earnings per share (in dollars per share)	$ 0.51	$ 0.67	$ 0.83	$ 0.41
Dividends declared per share (in dollars per share)	$ 0.20	$ 0.18	$ 0.40	$ 0.18