Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jul. 02, 2023	Jun. 30, 2024	Jul. 02, 2023
Earnings per Share [Abstract]
Net income attributable to Minerals Technologies Inc.	$ 19.7	$ 26.6	$ 66.4	$ 63.6
Weighted average shares outstanding (in shares)	32,200,000	32,500,000	32,300,000	32,500,000
Dilutive effect of stock options and deferred restricted stock units (in shares)	200,000	100,000	100,000	0
Weighted average shares outstanding, adjusted (in shares)	32,400,000	32,600,000	32,400,000	32,500,000
Basic earnings per share attributable to Minerals Technologies Inc. (in dollars per share)	$ 0.61	$ 0.82	$ 2.06	$ 1.96
Diluted earnings per share attributable to Minerals Technologies Inc. (in dollars per share)	$ 0.61	$ 0.82	$ 2.05	$ 1.96
Stock Options [Member]
Earnings Per Share [Abstract]
Options outstanding (in shares)	1,482,563	1,607,833	1,482,563	1,607,833
Anti-dilutive securities not included in computation of diluted earnings per share (in shares)	196,471	1,289,235	196,471	1,289,235