CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statements of Income [Abstract]
Total net sales	$ 1,807.6	$ 1,675.7	$ 1,638.0
Total cost of sales	1,346.2	1,208.5	1,177.6
Production margin	461.4	467.2	460.4
Marketing and administrative expenses	178.6	180.7	176.4
Research and development expenses	22.7	23.7	23.8
Acquisition related transaction and integration costs	1.7	3.4	8.0
Restructuring and other items, net	2.5	15.0	28.3
Income from operations	255.9	244.4	223.9
Interest expense, net	(45.9)	(43.4)	(54.4)
Debt modification costs and fees	0.0	(3.9)	0.0
Non-cash pension settlement costs	(4.4)	0.0	0.0
Other non-operating income (deductions), net	(1.5)	(6.2)	0.8
Total non-operating deductions, net	(51.8)	(53.5)	(53.6)
Income from operations before tax and equity in earnings	204.1	190.9	170.3
Provision (benefit) for taxes on income	34.4	(6.6)	35.3
Equity in earnings of affiliates, net of tax	3.5	1.5	2.1
Consolidated net income	173.2	199.0	137.1
Less: Net income attributable to non-controlling interests	4.2	3.9	3.7
Net income attributable to Minerals Technologies Inc.	$ 169.0	$ 195.1	$ 133.4
Basic:
Income from operations attributable to Minerals Technologies Inc. (in dollars per share)	$ 4.79	$ 5.54	$ 3.82
Diluted:
Income from operations attributable to Minerals Technologies Inc. (in dollars per share)	4.75	5.48	3.79
Cash dividends declared per common share (in dollars per share)	$ 0.20	$ 0.20	$ 0.20
Shares used in computation of earnings per share:
Basic (in shares)	35.3	35.2	34.9
Diluted (in shares)	35.6	35.6	35.2
Product [Member]
Statements of Income [Abstract]
Total net sales	$ 1,729.3	$ 1,599.0	$ 1,552.1
Total cost of sales	1,293.3	1,158.5	1,117.7
Service [Member]
Statements of Income [Abstract]
Total net sales	78.3	76.7	85.9
Total cost of sales	$ 52.9	$ 50.0	$ 59.9