Earnings (Loss) per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Earnings (Loss) per Share [Abstract]
Net income (loss) attributable to Minerals Technologies Inc.	$ (19.2)	$ 13.4	$ 44.4	$ 102.4
Weighted average shares outstanding (in shares)	32,500,000	32,500,000	32,500,000	32,800,000
Dilutive effect of stock options and deferred restricted stock units (in shares)	0	100,000	100,000	100,000
Weighted average shares outstanding, adjusted (in shares)	32,500,000	32,600,000	32,600,000	32,900,000
Basic earnings (loss) per share attributable to Minerals Technologies Inc. (in dollars per share)	$ (0.59)	$ 0.41	$ 1.37	$ 3.12
Diluted earnings (loss) per share attributable to Minerals Technologies Inc. (in dollars per share)	$ (0.59)	$ 0.41	$ 1.36	$ 3.11
Stock Options [Member]
Earnings (Loss) per Share [Abstract]
Options outstanding (in shares)	1,604,217	1,460,734	1,604,217	1,460,734
Anti-dilutive securities not included in computation of diluted earnings per share (in shares)	1,285,619	1,106,596	1,285,619	1,106,596