Earnings Per Share (EPS) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Dec. 31, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amounts attributable to MTI [Abstract]
Income from continuing operations attributable to MTI	$ 17.8	$ 30.3	$ 27.5	$ 36.0	$ 21.9	$ 37.6	$ 17.6	$ 16.3	$ 107.9	$ 90.3	$ 86.1
Income (loss) from discontinued operations attributable to MTI					0.1	0.2	1.8	0.0	0.0	2.1	(5.8)
Net income attributable to Minerals Technologies Inc. (MTI)	$ 17.0	$ 29.2	$ 26.6	$ 35.1	$ 21.3	$ 37.0	$ 18.5	$ 15.6	$ 107.9	$ 92.4	$ 80.3
Weighted average shares outstanding (in shares)									34,700,000	34,500,000	34,700,000
Earnings (Loss) per share attributable to MTI [Abstract]
Basic earnings per share from continuing operations attributable to MTI (in dollars per share)	$ 0.49	$ 0.84	$ 0.77	$ 1.01	$ 0.61	$ 1.07	$ 0.48	$ 0.45	$ 3.11	$ 2.62	$ 2.48
Basic loss per share from discontinued operations attributable to MTI (in dollars per share)	0	0	0	0	0.01	0	0.05	0	0	0.06	(0.17)
Basic earnings per share attributable to MTI (in dollars per share)	$ 0.49	$ 0.84	$ 0.77	$ 1.01	$ 0.62	$ 1.07	$ 0.53	$ 0.45	$ 3.11	$ 2.68	$ 2.31
Amounts attributable to MTI [Abstract]
Income from continuing operations attributable to MTI	$ 17.8	$ 30.3	$ 27.5	$ 36.0	$ 21.9	$ 37.6	$ 17.6	$ 16.3	$ 107.9	$ 90.3	$ 86.1
Income (loss) from discontinued operations attributable to MTI					0.1	0.2	1.8	0.0	0.0	2.1	(5.8)
Net income attributable to Minerals Technologies Inc. (MTI)	$ 17.0	$ 29.2	$ 26.6	$ 35.1	$ 21.3	$ 37.0	$ 18.5	$ 15.6	$ 107.9	$ 92.4	$ 80.3
Weighted average shares outstanding (in shares)									34,700,000	34,500,000	34,700,000
Dilutive effect of stock options and stock units (in shares)									300,000	300,000	300,000
Weighted average shares outstanding, adjusted (in shares)									35,000,000	34,800,000	35,000,000
Earnings (Loss) per share attributable to MTI [Abstract]
Diluted earnings per share from continuing operations attributable to MTI (in dollars per share)	$ 0.48	$ 0.83	$ 0.76	$ 1.01	$ 0.61	$ 1.06	$ 0.48	$ 0.45	$ 3.08	$ 2.59	$ 2.46
Diluted loss per share from discontinued operations attributable to MTI (in dollars per share)	0	0	0	0	0	0	0.05	0	0	0.06	(0.16)
Diluted earnings per share attributable to MTI (in dollars per share)	$ 0.48	$ 0.83	$ 0.76	$ 1.01	$ 0.61	$ 1.06	$ 0.53	$ 0.45	$ 3.08	$ 2.65	$ 2.30
Stock Options [Member]
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)									386,766	12,888	0