CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 16.9	[1]	$ 24.1	[1],[2]
Accounts receivable, net	202.8	[1]	204.4	[1],[2]
Inventories	148.3	[1]	144.3	[1],[2]
Prepaid expenses	17.2	[1]	15.2	[1],[2]
Deferred income taxes	6.2	[1]	4.1	[1],[2]
Income taxes receivable	5.7	[1]	8.2	[1],[2]
Other	4.6	[1]	6.1	[1],[2]
Total current assets	401.7	[1]	406.4	[1],[2]
Property, plant, equipment, and mineral rights and reserves:
Land	12.5	[1]	12.1	[1],[2]
Mineral rights	55.0	[1]	52.5	[1],[2]
Depreciable assets	502.5	[1]	484.7	[1],[2]
Gross property, plant and equipment	570.0	[1]	549.3	[1],[2]
Less: accumulated depreciation and depletion	285.2	[1]	275.7	[1],[2]
Net property, plant and equipment	284.8	[1]	273.6	[1],[2]
Goodwill	70.2	[1]	69.5	[1],[2]
Intangible assets, net	37.2	[1]	36.9	[1],[2]
Investment in and advances to affiliates and joint ventures	27.1	[1]	26.4	[1],[2]
Available-for-sale securities	2.9	[1]	3.8	[1],[2]
Deferred income taxes	9.3	[1]	8.1	[1],[2]
Other assets	25.6	[1]	24.4	[1],[2]
Total noncurrent assets	457.1	[1]	442.7	[1],[2]
Total Assets	858.8	[1]	849.1	[1],[2]
Current liabilities:
Accounts payable	47.7	[1]	56.5	[1],[2]
Accrued income taxes	6.5	[1]	2.3	[1],[2]
Accrued liabilities	57.7	[1]	59.2	[1],[2]
Total current liabilities	111.9	[1]	118.0	[1],[2]
Noncurrent liabilities:
Long-term debt	250.7	[1]	260.7	[1],[2]
Pension liabilities	34.6	[1]	34.8	[1],[2]
Deferred compensation	9.5	[1]	8.9	[1],[2]
Deferred income taxes	14.8	[1]	12.7	[1],[2]
Other long-term liabilities	19.5	[1]	19.1	[1],[2]
Total noncurrent liabilities	329.1	[1]	336.2	[1],[2]
Shareholders' Equity:
Common stock	0.3	[1]	0.3	[1],[2]
Additional paid in capital	97.6	[1]	94.3	[1],[2]
Retained earnings	321.9	[1]	314.3	[1],[2]
Accumulated other comprehensive income (loss)	(4.7)	[1]	(14.7)	[1],[2]
Less: Treasury stock	(1.7)	[1]	(3.4)	[1],[2]
Total AMCOL shareholders' equity	413.4	[1]	390.8	[1],[2]
Noncontrolling interest	4.4	[1]	4.1	[1],[2]
Total equity	417.8	[1]	394.9	[1],[2]
Total Liabilities and Shareholders' Equity	$ 858.8	[1]	$ 849.1	[1],[2]

[1] Restated

[2] Condensed from audited financial statements.