CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) [Abstract]
Net income (loss)	$ (18.1)	$ 14.6	$ 47.6	$ 105.0
Other comprehensive loss, net of tax:
Foreign currency translation adjustments	(22.1)	(52.0)	(38.2)	(111.5)
Pension and postretirement plan adjustments	0.4	0.9	1.3	4.3
Unrealized gains (losses) on derivative instruments	0.7	7.1	(1.2)	16.4
Total other comprehensive income (loss), net of tax	(21.0)	(44.0)	(38.1)	(90.8)
Total comprehensive income (loss) including non-controlling interests	(39.1)	(29.4)	9.5	14.2
Comprehensive income (loss) attributable to non-controlling interests	0.5	(0.1)	(0.8)	0.3
Comprehensive income (loss) attributable to Minerals Technologies Inc.	$ (38.6)	$ (29.5)	$ 8.7	$ 14.5