CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 03, 2021	Sep. 27, 2020	Oct. 03, 2021	Sep. 27, 2020
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Consolidated net income	$ 42.4	$ 29.3	$ 126.4	$ 83.8
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(14.9)	6.6	(41.8)	(28.6)
Pension and postretirement plan adjustments	2.2	3.7	9.0	11.1
Unrealized gains (losses) on derivative instruments	2.6	(4.3)	6.5	(3.3)
Total other comprehensive income (loss), net of tax	(10.1)	6.0	(26.3)	(20.8)
Total comprehensive income including non-controlling interests	32.3	35.3	100.1	63.0
Comprehensive income attributable to non-controlling interests	(1.1)	(1.5)	(3.0)	(2.7)
Comprehensive income attributable to Minerals Technologies Inc.	$ 31.2	$ 33.8	$ 97.1	$ 60.3