Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 23,698	$ 27,262
Accounts receivable:
Trade	191,167	178,473
Other	15,667	15,495
Inventories	146,582	107,515
Prepaid expenses	15,715	12,581
Deferred income taxes	5,918	5,553
Income tax receivable	6,866	8,474
Other	6,655	6,211
Total current assets	412,268	361,564
Property, plant, equipment, and mineral rights and reserves:
Land	13,881	11,591
Mineral rights	41,861	51,435
Depreciable assets	482,338	454,351
Gross property, plant and equipment	538,080	517,377
Less: accumulated depreciation and depletion	275,503	256,889
Net property, plant and equipment	262,577	260,488
Goodwill	69,509	70,909
Intangible assets	36,610	42,590
Investment in and advances to affiliates and joint ventures	26,407	19,056
Available-for-sale securities	3,802	14,168
Deferred income taxes	7,783	7,570
Other assets	23,746	22,748
Total noncurrent assets	430,434	437,529
Total Assets	842,702	799,093
Current liabilities:
Accounts payable	56,451	53,167
Accrued income taxes	2,679	4,104
Accrued liabilities	58,950	55,204
Total current liabilities	118,080	112,475
Noncurrent liabilities:
Long-term debt	260,670	236,171
Pension liabilities	34,840	21,338
Deferred compensation	8,927	8,686
Other long-term liabilities	19,965	19,987
Total noncurrent liabilities	324,402	286,182
Equity:
Common stock, par value $.01 per share, 100,000,000 shares authorized; 32,015,771 shares issued in 2011 and 2010	320	320
Additional paid in capital	94,529	95,074
Retained earnings	319,538	283,189
Accumulated other comprehensive income (loss)	(14,968)	28,936
Stockholders' equity before treasury stock	399,419	407,519
Less: Treasury stock (286,802 and 768,946 shares in 2011 and 2010, respectively)	3,426	8,945
Total AMCOL shareholders' equity	395,993	398,574
Noncontrolling interest	4,227	1,862
Total equity	400,220	400,436
Total Liabilities and Shareholders' Equity	$ 842,702	$ 799,093