CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) [Abstract]
Net sales	$ 547.8	$ 541.9	$ 1,645.4	$ 1,617.9
Cost of goods sold	414.7	423.6	1,263.6	1,250.6
Production margin	133.1	118.3	381.8	367.3
Marketing and administrative expenses	50.9	46.0	155.0	143.6
Research and development expenses	5.2	5.1	16.1	15.2
Restructuring and other items, net	0.3	0.0	6.9	0.0
Impairment of assets	71.7	0.0	71.7	0.0
Acquisition-related expenses	0.0	0.5	0.3	4.7
Litigation expenses	12.9	31.1	26.8	32.6
Income (loss) from operations	(7.9)	35.6	105.0	171.2
Interest expense, net	(15.3)	(11.0)	(44.0)	(31.2)
Debt extinguishment expenses	0.0	(6.9)	0.0	(6.9)
Non-cash pension settlement charge	0.0	(0.2)	0.0	(1.7)
Other non-operating income (deductions), net	0.6	(0.4)	(1.9)	(2.0)
Total non-operating deductions, net	(14.7)	(18.5)	(45.9)	(41.8)
Income (loss) before tax and equity in earnings	(22.6)	17.1	59.1	129.4
Provision (benefit) for taxes on income	(3.5)	3.2	14.5	25.8
Equity in earnings of affiliates, net of tax	1.0	0.7	3.0	1.4
Net income (loss)	(18.1)	14.6	47.6	105.0
Less: Net income attributable to non-controlling interests	1.1	1.2	3.2	2.6
Net income (loss) attributable to Minerals Technologies Inc.	$ (19.2)	$ 13.4	$ 44.4	$ 102.4
Earnings (loss) per share:
Basic net income (loss) per share attributable to Minerals Technologies Inc. (in dollars per share)	$ (0.59)	$ 0.41	$ 1.37	$ 3.12
Diluted net income (loss) per share attributable to Minerals Technologies Inc. (in dollars per share)	(0.59)	0.41	1.36	3.11
Cash dividends declared per common share (in dollars per share)	$ 0.05	$ 0.05	$ 0.15	$ 0.15
Shares used in computation of earnings per share:
Basic (in shares)	32.5	32.5	32.5	32.8
Diluted (in shares)	32.5	32.6	32.6	32.9