CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jul. 03, 2016	Jul. 02, 2017	Jul. 03, 2016
CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) [Abstract]
Product sales	$ 396.2	$ 407.0	$ 782.5	$ 791.4
Service revenue	17.9	20.0	36.6	45.8
Total net sales	414.1	427.0	819.1	837.2
Cost of goods sold	282.7	291.2	561.7	568.8
Cost of service revenue	11.7	14.7	24.0	34.6
Total cost of sales	294.4	305.9	585.7	603.4
Production margin	119.7	121.1	233.4	233.8
Marketing and administrative expenses	44.1	45.1	88.5	91.8
Research and development expenses	6.1	6.1	11.9	12.0
Acquisition related transaction and integration costs	0.8	1.6	2.3	3.2
Restructuring and other changes, net	0.2	28.8	0.5	29.7
Income from operations	68.5	39.5	130.2	97.1
Interest expense, net	(10.2)	(13.9)	(22.0)	(28.0)
Debt modification costs and fees	0.0	0.0	(3.9)	0.0
Other non-operating income (deductions), net	(1.2)	0.6	(1.7)	2.3
Total non-operating deductions, net	(11.4)	(13.3)	(27.6)	(25.7)
Income from continuing operations before provision for taxes and equity in earnings	57.1	26.2	102.6	71.4
Provision for taxes on income	13.4	4.5	23.5	15.2
Equity in earnings of affiliates, net of tax	0.1	0.6	0.3	0.9
Consolidated net income	43.8	22.3	79.4	57.1
Less: Net income attributable to non-controlling interests	0.8	1.1	1.8	2.0
Net income attributable to Minerals Technologies Inc. (MTI)	$ 43.0	$ 21.2	$ 77.6	$ 55.1
Basic:
Income from continuing operations attributable to MTI (in dollars per share)	$ 1.23	$ 0.61	$ 2.21	$ 1.58
Diluted:
Income from continuing operations attributable to MTI (in dollars per share)	1.21	0.60	2.18	1.57
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)	35.1	34.8	35.1	34.8
Diluted (in shares)	35.6	35.1	35.6	35.0