CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Statements of Income [Abstract]
Total net sales	$ 437.7	$ 431.3
Total cost of sales	328.0	317.8
Production margin	109.7	113.5
Marketing and administrative expenses	42.9	44.4
Research and development expenses	4.8	6.1
Acquisition related transaction and integration costs	0.0	0.4
Income from operations	62.0	62.6
Interest expense, net	(11.4)	(10.7)
Other non-operating deductions, net	(1.4)	(2.7)
Total non-operating deductions, net	(12.8)	(13.4)
Income from operations before tax and equity in earnings	49.2	49.2
Provision for taxes on income	9.3	9.3
Equity in earnings of affiliates, net of tax	0.1	1.2
Consolidated net income	40.0	41.1
Less: Net income attributable to non-controlling interests	0.9	1.2
Net income attributable to Minerals Technologies Inc.	$ 39.1	$ 39.9
Basic:
Income from operations attributable to Minerals Technologies Inc. (in dollars per share)	$ 1.11	$ 1.13
Diluted:
Income from operations attributable to Minerals Technologies Inc. (in dollars per share)	1.11	1.12
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)	35.2	35.4
Diluted (in shares)	35.3	35.7
Product [Member]
Statements of Income [Abstract]
Total net sales	$ 417.4	$ 412.2
Total cost of sales	314.0	305.0
Service [Member]
Statements of Income [Abstract]
Total net sales	20.3	19.1
Total cost of sales	$ 14.0	$ 12.8