Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 02, 2022	Oct. 03, 2021	Oct. 02, 2022	Oct. 03, 2021
Earnings per Share [Abstract]
Net income attributable to Minerals Technologies Inc.	$ 13.4	$ 41.4	$ 102.4	$ 123.2
Weighted average shares outstanding (in shares)	32,500,000	33,500,000	32,800,000	33,700,000
Dilutive effect of stock options and stock units (in shares)	100,000	300,000	100,000	200,000
Weighted average shares outstanding, adjusted (in shares)	32,600,000	33,800,000	32,900,000	33,900,000
Basic earnings per share attributable to Minerals Technologies Inc. (in dollars per share)	$ 0.41	$ 1.24	$ 3.12	$ 3.66
Diluted earnings per share attributable to Minerals Technologies Inc. (in dollars per share)	$ 0.41	$ 1.22	$ 3.11	$ 3.63
Stock Options [Member]
Earnings per Share [Abstract]
Options outstanding (in shares)	1,460,734	1,409,110	1,460,734	1,409,110
Anti-dilutive securities not included in computation of diluted earnings per share (in shares)	1,106,596	526,956	1,106,596	526,956