CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2024	Oct. 01, 2023	Sep. 29, 2024	Oct. 01, 2023
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) [Abstract]
Net sales	$ 524.7	$ 547.8	$ 1,600.4	$ 1,645.4
Cost of goods sold	389.5	414.7	1,185.4	1,263.6
Production margin	135.2	133.1	415.0	381.8
Marketing and administrative expenses	50.1	50.9	156.4	155.0
Research and development expenses	5.9	5.2	17.3	16.1
Provision for credit losses	0.0	0.0	30.0	0.0
Restructuring and other items, net	0.0	0.3	0.0	6.9
Impairment of assets	0.0	71.7	0.0	71.7
Acquisition-related expenses	0.0	0.0	0.0	0.3
Litigation expenses	2.6	12.9	8.9	26.8
Income (loss) from operations	76.6	(7.9)	202.4	105.0
Interest expense, net	(14.0)	(15.3)	(43.8)	(44.0)
Other non-operating income (deductions), net	(3.1)	0.6	(4.4)	(1.9)
Total non-operating deductions, net	(17.1)	(14.7)	(48.2)	(45.9)
Income (loss) before tax and equity in earnings	59.5	(22.6)	154.2	59.1
Provision (benefit) for taxes on income	13.7	(3.5)	43.2	14.5
Equity in earnings of affiliates, net of tax	1.9	1.0	5.2	3.0
Net income (loss)	47.7	(18.1)	116.2	47.6
Less: Net income attributable to non-controlling interests	1.0	1.1	3.1	3.2
Net income (loss) attributable to Minerals Technologies Inc.	$ 46.7	$ (19.2)	$ 113.1	$ 44.4
Earnings (loss) per share:
Basic net income (loss) attributable to Minerals Technologies Inc. (in dollars per share)	$ 1.45	$ (0.59)	$ 3.51	$ 1.37
Diluted net income (loss) attributable to Minerals Technologies Inc. (in dollars per share)	1.45	(0.59)	3.49	1.36
Cash dividends declared per common share (in dollars per share)	$ 0.1	$ 0.05	$ 0.3	$ 0.15
Shares used in computation of earnings per share:
Basic (in shares)	32.1	32.5	32.2	32.5
Diluted (in shares)	32.3	32.5	32.4	32.6