CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Statements of Income [Abstract]
Total net sales	$ 463.8	$ 464.7	$ 901.5	$ 896.0
Total cost of sales	351.8	348.8	679.8	666.6
Production margin	112.0	115.9	221.7	229.4
Marketing and administrative expenses	48.4	45.3	91.3	89.7
Research and development expenses	4.9	6.4	9.7	12.5
Acquisition related transaction and integration costs	0.0	1.0	0.0	1.4
Restructuring and other items, net	13.2	0.4	13.2	0.4
Income from operations	45.5	62.8	107.5	125.4
Interest expense, net	(10.9)	(11.5)	(22.3)	(22.2)
Other non-operating income (deductions), net	(2.4)	3.1	(3.8)	0.4
Total non-operating deductions, net	(13.3)	(8.4)	(26.1)	(21.8)
Income from operations before tax and equity in earnings	32.2	54.4	81.4	103.6
Provision for taxes on income	5.1	10.3	14.4	19.6
Equity in earnings of affiliates, net of tax	0.5	1.1	0.6	2.3
Consolidated net income	27.6	45.2	67.6	86.3
Less: Net income attributable to non-controlling interests	1.0	1.1	1.9	2.3
Net income attributable to Minerals Technologies Inc.	$ 26.6	$ 44.1	$ 65.7	$ 84.0
Basic:
Income from operations attributable to Minerals Technologies Inc. (in dollars per share)	$ 0.76	$ 1.25	$ 1.87	$ 2.37
Diluted:
Income from operations attributable to Minerals Technologies Inc. (in dollars per share)	0.75	1.24	1.86	2.36
Cash dividends declared per common share (in dollars per share)	$ 0.05	$ 0.05	$ 0.10	$ 0.10
Shares used in computation of earnings per share:
Basic (in shares)	35.2	35.3	35.2	35.4
Diluted (in shares)	35.3	35.6	35.3	35.6
Product [Member]
Statements of Income [Abstract]
Total net sales	$ 438.0	$ 445.0	$ 855.4	$ 857.2
Total cost of sales	334.0	335.3	648.0	640.3
Service [Member]
Statements of Income [Abstract]
Total net sales	25.8	19.7	46.1	38.8
Total cost of sales	$ 17.8	$ 13.5	$ 31.8	$ 26.3