CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Statements of Income [Abstract]
Total net sales	$ 417.5	$ 437.7
Total cost of sales	310.7	328.0
Production margin	106.8	109.7
Marketing and administrative expenses	43.4	42.9
Research and development expenses	5.1	4.8
Litigation expenses	0.6	0.0
Income from operations	57.7	62.0
Interest expense, net	(9.3)	(11.4)
Other non-operating income (deductions), net	0.6	(1.4)
Total non-operating deductions, net	(8.7)	(12.8)
Income from operations before tax and equity in earnings	49.0	49.2
Provision for taxes on income	9.7	9.3
Equity in earnings of affiliates, net of tax	0.3	0.1
Consolidated net income	39.6	40.0
Less: Net income attributable to non-controlling interests	1.0	0.9
Net income attributable to Minerals Technologies Inc.	$ 38.6	$ 39.1
Basic:
Income from operations attributable to Minerals Technologies Inc. (in dollars per share)	$ 1.12	$ 1.11
Diluted:
Income from operations attributable to Minerals Technologies Inc. (in dollars per share)	1.12	1.11
Cash dividends declared per common share (in dollars per share)	$ 0.05	$ 0.05
Shares used in computation of earnings per share:
Basic (in shares)	34.4	35.2
Diluted (in shares)	34.4	35.3
Product [Member]
Statements of Income [Abstract]
Total net sales	$ 392.3	$ 417.4
Total cost of sales	294.1	314.0
Service [Member]
Statements of Income [Abstract]
Total net sales	25.2	20.3
Total cost of sales	$ 16.6	$ 14.0