Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Continuing Operations
Net sales	$ 943,796	[1]	$ 826,277	[1]	$ 687,485	[1]
Cost of sales	691,479	[1]	612,092	[1]	503,194	[1]
Gross profit	252,317	[1]	214,185	[1]	184,291	[1]
Selling, general and administrative expenses	166,231	[1]	145,173	[1]	134,947	[1]
Operating profit	86,086	[1]	69,012	[1]	49,344	[1]
Other income (expense):
Interest expense, net	(11,070)	[1]	(9,584)	[1]	(11,994)	[1]
Other, net	233	[1]	1,241	[1]	(315)	[1]
Total other income (expense), net	(10,837)	[1]	(8,343)	[1]	(12,309)	[1]
Income before income taxes and income (loss) from affiliates and joint ventures	75,249	[1]	60,669	[1]	37,035	[1]
Income tax expense	20,786	[1]	20,302	[1]	5,363	[1]
Income before income (loss) from affiliates and joint ventures	54,463	[1]	40,367	[1]	31,672	[1]
Income (loss) from affiliates and joint ventures	5,235	[1]	(10,997)	[1]	6	[1]
Income (loss) from continuing operations	59,698	[1]	29,370	[1]	31,678	[1]
Discontinued Operations
Income (loss) on discontinued operations	(1,162)	[1]	(887)	[1]	259	[1]
Net income (loss)	58,536	[1]	28,483	[1]	31,937	[1]
Net income (loss) attributable to noncontrolling interests	15	[1]	(752)	[1]	(105)	[1]
Net income (loss) attributable to AMCOL shareholders	58,521	[1]	29,235	[1]	32,042	[1]
Basic earnings (loss) per share
Continuing operations (in dollars per share)	$ 1.88	[1]	$ 0.97	[1]	$ 1.03	[1]
Discontinued operations (in dollars per share)	$ (0.04)	[1]	$ (0.03)	[1]	$ 0.01	[1]
Net income (in dollars per share)	$ 1.84	[1]	$ 0.94	[1]	$ 1.04	[1]
Diluted earnings (loss) per share
Continuing operations (in dollars per share)	$ 1.86	[1]	$ 0.96	[1]	$ 1.02	[1]
Discontinued operations (in dollars per share)	$ (0.04)	[1]	$ (0.03)	[1]	$ 0.01	[1]
Net income (in dollars per share)	$ 1.82	[1]	$ 0.93	[1]	$ 1.03	[1]
Amounts attributable to AMCOL shareholders
Income from continuing operations, net of tax	59,683	[1]	30,122	[1]	31,783	[1]
Discontinued operations, net of tax	(1,162)	[1]	(887)	[1]	259	[1]
Net income	$ 58,521	[1]	$ 29,235	[1]	$ 32,042	[1]
Dividends declared per share (in dollars per share)	$ 0.72	[1]	$ 0.72	[1]	$ 0.72	[1]

[1] Restated