Earnings Per Share (EPS) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013
Basic EPS [Abstract]
Income from continuing operations attributable to MTI	$ 16.7	$ 22.1	$ 32.3	$ 41.6
Income (loss) from discontinued operations attributable to MTI	1.8	(5.0)	1.8	(5.7)
Net income attributable to Minerals Technologies Inc. (MTI)	18.5	17.1	34.1	35.9
Weighted average shares outstanding (in shares)	34,500,000	34,800,000	34,500,000	34,900,000
Basic earnings per share from continuing operations attributable to MTI (in dollars per share)	$ 0.48	$ 0.63	$ 0.94	$ 1.19
Basic earnings (loss) per share from discontinued operations attributable to MTI (in dollars per share)	$ 0.05	$ (0.14)	$ 0.05	$ (0.16)
Basic earnings per share attributable to MTI (in dollars per share)	$ 0.53	$ 0.49	$ 0.99	$ 1.03
Diluted EPS [Abstract]
Income from continuing operations attributable to MTI	16.7	22.1	32.3	41.6
Income (loss) from discontinued operations attributable to MTI	1.8	(5.0)	1.8	(5.7)
Net income attributable to Minerals Technologies Inc. (MTI)	$ 18.5	$ 17.1	$ 34.1	$ 35.9
Weighted average shares outstanding (in shares)	34,500,000	34,800,000	34,500,000	34,900,000
Dilutive effect of stock options and stock units (in shares)	300,000	200,000	200,000	200,000
Weighted average shares outstanding, adjusted (in shares)	34,800,000	35,000,000	34,700,000	35,100,000
Diluted earnings per share from continuing operations attributable to MTI (in dollars per share)	$ 0.48	$ 0.63	$ 0.93	$ 1.18
Diluted earnings (loss) per share from discontinued operations attributable to MTI (in dollars per share)	$ 0.05	$ (0.14)	$ 0.05	$ (0.16)
Diluted earnings per share attributable to MTI (in dollars per share)	$ 0.53	$ 0.49	$ 0.98	$ 1.02
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities not included in the weighted average commons shares outstanding calculation (in shares)	173,068	239,770	173,068	239,770