CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) [Abstract]
Consolidated net income	$ 14.9	$ 27.6	$ 54.5	$ 67.6
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	7.9	(18.7)	(35.2)	(19.1)
Pension and postretirement plan adjustments	5.3	1.7	7.4	3.3
Unrealized gains (losses) on derivative instruments	(0.8)	(3.3)	1.0	(2.1)
Total other comprehensive income (loss), net of tax	12.4	(20.3)	(26.8)	(17.9)
Total comprehensive income including non-controlling interests	27.3	7.3	27.7	49.7
Comprehensive income attributable to non-controlling interests	(1.5)	(0.8)	(1.2)	(2.2)
Comprehensive income attributable to Minerals Technologies Inc.	$ 25.8	$ 6.5	$ 26.5	$ 47.5