Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2023	Jul. 03, 2022	Jul. 02, 2023	Jul. 03, 2022
Earnings Per Share [Abstract]
Net income attributable to Minerals Technologies Inc.	$ 26.6	$ 44.9	$ 63.6	$ 89.0
Weighted average shares outstanding (in shares)	32,500,000	32,800,000	32,500,000	33,000,000
Dilutive effect of stock options and deferred restricted stock units (in shares)	100,000	100,000	0	100,000
Weighted average shares outstanding, adjusted (in shares)	32,600,000	32,900,000	32,500,000	33,100,000
Basic earnings per share attributable to Minerals Technologies Inc. (in dollars per share)	$ 0.82	$ 1.37	$ 1.96	$ 2.7
Diluted earnings per share attributable to Minerals Technologies Inc. (in dollars per share)	$ 0.82	$ 1.36	$ 1.96	$ 2.69
Stock Options [Member]
Earnings per Share [Abstract]
Options outstanding (in shares)	1,607,833	1,524,368	1,607,833	1,524,368
Anti-dilutive securities not included in computation of diluted earnings per share (in shares)	1,289,235	728,322	1,289,235	728,322