Quarterly Results (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended						3 Months Ended																12 Months Ended						3 Months Ended																12 Months Ended						3 Months Ended																12 Months Ended						3 Months Ended																12 Months Ended						3 Months Ended																12 Months Ended						3 Months Ended																12 Months Ended						3 Months Ended																12 Months Ended						3 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009		Dec. 31, 2011 Scenario As Restated [Member]		Sep. 30, 2011 Scenario As Restated [Member]		Jun. 30, 2011 Scenario As Restated [Member]		Mar. 31, 2011 Scenario As Restated [Member]		Dec. 31, 2010 Scenario As Restated [Member]		Sep. 30, 2010 Scenario As Restated [Member]		Jun. 30, 2010 Scenario As Restated [Member]		Mar. 31, 2010 Scenario As Restated [Member]		Dec. 31, 2011 AMCOL Shareholders [Member]		Dec. 31, 2010 AMCOL Shareholders [Member]		Dec. 31, 2009 AMCOL Shareholders [Member]		Dec. 31, 2011 AMCOL Shareholders [Member] Scenario As Restated [Member]		Sep. 30, 2011 AMCOL Shareholders [Member] Scenario As Restated [Member]		Jun. 30, 2011 AMCOL Shareholders [Member] Scenario As Restated [Member]		Mar. 31, 2011 AMCOL Shareholders [Member] Scenario As Restated [Member]		Dec. 31, 2010 AMCOL Shareholders [Member] Scenario As Restated [Member]		Sep. 30, 2010 AMCOL Shareholders [Member] Scenario As Restated [Member]		Jun. 30, 2010 AMCOL Shareholders [Member] Scenario As Restated [Member]		Mar. 31, 2010 AMCOL Shareholders [Member] Scenario As Restated [Member]		Dec. 31, 2011 Minerals and Materials [Member]		Dec. 31, 2010 Minerals and Materials [Member]		Dec. 31, 2009 Minerals and Materials [Member]		Dec. 31, 2011 Minerals and Materials [Member] Scenario As Restated [Member]		Sep. 30, 2011 Minerals and Materials [Member] Scenario As Restated [Member]		Jun. 30, 2011 Minerals and Materials [Member] Scenario As Restated [Member]		Mar. 31, 2011 Minerals and Materials [Member] Scenario As Restated [Member]		Dec. 31, 2010 Minerals and Materials [Member] Scenario As Restated [Member]		Sep. 30, 2010 Minerals and Materials [Member] Scenario As Restated [Member]		Jun. 30, 2010 Minerals and Materials [Member] Scenario As Restated [Member]		Mar. 31, 2010 Minerals and Materials [Member] Scenario As Restated [Member]		Dec. 31, 2011 Environmental [Member]		Dec. 31, 2010 Environmental [Member]		Dec. 31, 2009 Environmental [Member]		Dec. 31, 2011 Environmental [Member] Scenario As Restated [Member]		Sep. 30, 2011 Environmental [Member] Scenario As Restated [Member]		Jun. 30, 2011 Environmental [Member] Scenario As Restated [Member]		Mar. 31, 2011 Environmental [Member] Scenario As Restated [Member]		Dec. 31, 2010 Environmental [Member] Scenario As Restated [Member]		Sep. 30, 2010 Environmental [Member] Scenario As Restated [Member]		Jun. 30, 2010 Environmental [Member] Scenario As Restated [Member]		Mar. 31, 2010 Environmental [Member] Scenario As Restated [Member]		Dec. 31, 2011 Oilfield Services [Member]		Dec. 31, 2010 Oilfield Services [Member]		Dec. 31, 2009 Oilfield Services [Member]		Dec. 31, 2011 Oilfield Services [Member] Scenario As Restated [Member]		Sep. 30, 2011 Oilfield Services [Member] Scenario As Restated [Member]		Jun. 30, 2011 Oilfield Services [Member] Scenario As Restated [Member]		Mar. 31, 2011 Oilfield Services [Member] Scenario As Restated [Member]		Dec. 31, 2010 Oilfield Services [Member] Scenario As Restated [Member]		Sep. 30, 2010 Oilfield Services [Member] Scenario As Restated [Member]		Jun. 30, 2010 Oilfield Services [Member] Scenario As Restated [Member]		Mar. 31, 2010 Oilfield Services [Member] Scenario As Restated [Member]		Dec. 31, 2011 Transportation [Member]		Dec. 31, 2010 Transportation [Member]		Dec. 31, 2009 Transportation [Member]		Dec. 31, 2011 Transportation [Member] Scenario As Restated [Member]		Sep. 30, 2011 Transportation [Member] Scenario As Restated [Member]		Jun. 30, 2011 Transportation [Member] Scenario As Restated [Member]		Mar. 31, 2011 Transportation [Member] Scenario As Restated [Member]		Dec. 31, 2010 Transportation [Member] Scenario As Restated [Member]		Sep. 30, 2010 Transportation [Member] Scenario As Restated [Member]		Jun. 30, 2010 Transportation [Member] Scenario As Restated [Member]		Mar. 31, 2010 Transportation [Member] Scenario As Restated [Member]		Dec. 31, 2011 Intersegment Sales/gross profit [Member]		Dec. 31, 2010 Intersegment Sales/gross profit [Member]		Dec. 31, 2009 Intersegment Sales/gross profit [Member]		Dec. 31, 2011 Intersegment Sales/gross profit [Member] Scenario As Restated [Member]		Sep. 30, 2011 Intersegment Sales/gross profit [Member] Scenario As Restated [Member]		Jun. 30, 2011 Intersegment Sales/gross profit [Member] Scenario As Restated [Member]		Mar. 31, 2011 Intersegment Sales/gross profit [Member] Scenario As Restated [Member]		Dec. 31, 2010 Intersegment Sales/gross profit [Member] Scenario As Restated [Member]		Sep. 30, 2010 Intersegment Sales/gross profit [Member] Scenario As Restated [Member]		Jun. 30, 2010 Intersegment Sales/gross profit [Member] Scenario As Restated [Member]		Mar. 31, 2010 Intersegment Sales/gross profit [Member] Scenario As Restated [Member]		Dec. 31, 2011 Corporate [Member]		Dec. 31, 2010 Corporate [Member]		Dec. 31, 2009 Corporate [Member]		Dec. 31, 2011 Corporate [Member] Scenario As Restated [Member]		Sep. 30, 2011 Corporate [Member] Scenario As Restated [Member]		Jun. 30, 2011 Corporate [Member] Scenario As Restated [Member]		Mar. 31, 2011 Corporate [Member] Scenario As Restated [Member]		Dec. 31, 2010 Corporate [Member] Scenario As Restated [Member]		Sep. 30, 2010 Corporate [Member] Scenario As Restated [Member]		Jun. 30, 2010 Corporate [Member] Scenario As Restated [Member]		Mar. 31, 2010 Corporate [Member] Scenario As Restated [Member]
Summary of Quarterly Results
Net sales	$ 943,796	[1]	$ 826,277	[1]	$ 687,485	[1]	$ 234,133	[1]	$ 247,917	[1]	$ 243,097	[1]	$ 218,649	[1]	$ 214,919	[1]	$ 225,059	[1]	$ 215,397	[1]	$ 170,902	[1]																							$ 476,700	[1]	$ 416,495	[1]	$ 336,272	[1]	$ 120,326	[1]	$ 122,209	[1]	$ 118,237	[1]	$ 115,928	[1]	$ 111,479	[1]	$ 107,038	[1]	$ 103,169	[1]	$ 94,809	[1]	$ 251,907	[1]	$ 225,544	[1]	$ 202,511	[1]	$ 54,394	[1]	$ 70,999	[1]	$ 74,831	[1]	$ 51,683	[1]	$ 53,382	[1]	$ 69,170	[1]	$ 64,522	[1]	$ 38,470	[1]	$ 194,735	[1]	$ 153,550	[1]	$ 119,821	[1]	$ 53,876	[1]	$ 50,175	[1]	$ 45,104	[1]	$ 45,580	[1]	$ 42,914	[1]	$ 40,774	[1]	$ 39,658	[1]	$ 30,204	[1]	$ 54,113	[1]	$ 52,225	[1]	$ 46,642	[1]	$ 11,782	[1]	$ 14,877	[1]	$ 14,780	[1]	$ 12,674	[1]	$ 12,238	[1]	$ 14,284	[1]	$ 13,583	[1]	$ 12,120	[1]	$ (33,659)	[1]	$ (21,537)	[1]	$ (17,761)	[1]	$ (6,245)	[1]	$ (10,343)	[1]	$ (9,855)	[1]	$ (7,216)	[1]	$ (5,094)	[1]	$ (6,207)	[1]	$ (5,535)	[1]	$ (4,701)	[1]
Gross profit	252,317	[1]	214,185	[1]	184,291	[1]	62,209	[1]	70,352	[1]	61,861	[1]	57,895	[1]	51,519	[1]	58,518	[1]	60,275	[1]	43,873	[1]																													30,730	[1]	31,555	[1]	26,156	[1]	28,090	[1]	22,217	[1]	24,105	[1]	26,629	[1]	23,169	[1]							14,597	[1]	21,845	[1]	22,210	[1]	15,273	[1]	16,428	[1]	21,258	[1]	20,318	[1]	11,363	[1]							15,348	[1]	15,377	[1]	11,733	[1]	13,499	[1]	11,545	[1]	11,525	[1]	11,785	[1]	8,014	[1]							1,323	[1]	1,775	[1]	1,640	[1]	1,403	[1]	1,365	[1]	1,630	[1]	1,543	[1]	1,327	[1]							211	[1]	(200)	[1]	122	[1]	(370)	[1]	(36)	[1]	0	[1]	0	[1]	0	[1]
Operating profit	86,086	[1]	69,012	[1]	49,344	[1]	20,383	[1]	25,815	[1]	20,905	[1]	18,983	[1]	11,342	[1]	22,832	[1]	23,722	[1]	11,116	[1]																							67,144	[1]	53,549	[1]	33,693	[1]	18,089	[1]	19,515	[1]	13,440	[1]	16,100	[1]	11,113	[1]	12,869	[1]	15,963	[1]	13,604	[1]	17,349	[1]	20,447	[1]	23,924	[1]	556	[1]	6,994	[1]	7,985	[1]	1,814	[1]	3,002	[1]	8,764	[1]	8,339	[1]	342	[1]	21,226	[1]	13,654	[1]	12,261	[1]	6,041	[1]	5,787	[1]	3,691	[1]	5,707	[1]	4,101	[1]	3,648	[1]	4,569	[1]	1,336	[1]	2,241	[1]	2,430	[1]	2,163	[1]	321	[1]	770	[1]	685	[1]	465	[1]	466	[1]	754	[1]	699	[1]	511	[1]																							(21,874)	[1]	(21,068)	[1]	(22,697)	[1]	(4,624)	[1]	(7,251)	[1]	(4,896)	[1]	(5,103)	[1]	(7,340)	[1]	(3,203)	[1]	(5,848)	[1]	(4,677)	[1]
Income (loss) from continuing operations	59,698	[1]	29,370	[1]	31,678	[1]	12,818	[1]	20,792	[1]	12,925	[1]	13,163	[1]	(10,436)	[1]	17,126	[1]	16,320	[1]	6,360	[1]
Income (loss) on discontinued operations	(1,162)	[1]	(887)	[1]	259	[1]	0	[1]	(1,267)	[1]	192	[1]	(87)	[1]	(96)	[1]	(132)	[1]	(140)	[1]	(519)	[1]
Net income (loss)	58,536	[1]	28,483	[1]	31,937	[1]	12,818	[1]	19,525	[1]	13,117	[1]	13,076	[1]	(10,532)	[1]	16,994	[1]	16,180	[1]	5,841	[1]	58,521	[1]	29,235	[1]	32,042	[1]
Net income (loss) attributable to noncontrolling interests	15	[1]	(752)	[1]	(105)	[1]	60	[1]	(6)	[1]	(32)	[1]	(7)	[1]	(239)	[1]	(155)	[1]	(4)	[1]	(354)	[1]
Net income (loss) attributable to AMCOL shareholders	$ 58,521	[1]	$ 29,235	[1]	$ 32,042	[1]																	$ 58,521	[1]					$ 12,758	[1]	$ 19,531	[1]	$ 13,149	[1]	$ 13,083	[1]	$ (10,293)	[1]	$ 17,149	[1]	$ 16,184	[1]	$ 6,195	[1]
Basic earnings per share attributable to AMCOL shareholders (in dollars per share)	$ 1.84	[1]	$ 0.94	[1]	$ 1.04	[1]																							$ 0.40	[1],[2]	$ 0.61	[1],[2]	$ 0.41	[1],[2]	$ 0.42	[1],[2]	$ (0.33)	[1],[2]	$ 0.55	[1],[2]	$ 0.52	[1],[2]	$ 0.20	[1],[2]
Diluted earnings per share attributable to AMCOL shareholders (in dollars per share)	$ 1.82	[1]	$ 0.93	[1]	$ 1.03	[1]																							$ 0.40	[1],[2]	$ 0.61	[1],[2]	$ 0.41	[1],[2]	$ 0.41	[1],[2]	$ (0.32)	[1],[2]	$ 0.54	[1],[2]	$ 0.51	[1],[2]	$ 0.20	[1],[2]

[1] Restated

[2] Earnings per share (EPS) for each quarter is computed using the weighted-average number of shares outstanding during the quarter, while EPS for the year is computed using the weighted-average number of shares outstanding during the year. Thus, the sum of the EPS for each of the four quarters may not equal the EPS for the year.