CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Sep. 30, 2012	Oct. 02, 2011
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Net sales	$ 250,346	$ 262,192	$ 761,453	$ 793,111
Cost of goods sold	195,347	209,282	595,175	633,585
Production margin	54,999	52,910	166,278	159,526
Marketing and administrative expenses	22,046	22,553	66,784	69,392
Research and development expenses	5,105	4,723	15,178	14,489
Restructuring and other costs	0	240	0	470
Income from operations	27,848	25,394	84,316	75,175
Non-operating income (deductions), net	(650)	(1,663)	(2,016)	(3,299)
Income from continuing operations before provision for taxes	27,198	23,731	82,300	71,876
Provision for taxes on income	8,015	7,387	24,270	21,686
Consolidated net income	19,183	16,344	58,030	50,190
Less: Net income attributable to non-controlling interests	553	656	1,653	2,308
Net income attribute to Minerals Technologies Inc. (MTI)	$ 18,630	$ 15,688	$ 56,377	$ 47,882
Earnings per share:
Basic	$ 1.06	$ 0.88	$ 3.19	$ 2.64
Diluted	$ 1.05	$ 0.87	$ 3.17	$ 2.62
Cash dividends declared per common share	$ 0.05	$ 0.05	$ 0.15	$ 0.15
Shares used in computation of earnings per share:
Basic	17,640	17,928	17,694	18,128
Diluted	17,733	18,019	17,775	18,242