Earnings Per Share (EPS) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Earnings Per Share (EPS) [Abstract]
Net income attributable to MTI	$ 41.9	$ 41.7	$ 125.9	$ 119.3
Weighted average shares outstanding (in shares)	35,300,000	35,300,000	35,300,000	35,100,000
Dilutive effect of stock options and stock units (in shares)	300,000	300,000	300,000	500,000
Weighted average shares outstanding, adjusted (in shares)	35,600,000	35,600,000	35,600,000	35,600,000
Basic earnings per share attributable to MTI (in dollars per share)	$ 1.19	$ 1.18	$ 3.57	$ 3.40
Diluted earnings per share attributable to MTI (in dollars per share)	$ 1.18	$ 1.17	$ 3.54	$ 3.35
Stock Options [Member]
Antidilutive Securities Excluded from Earnings Per Share Calculation [Abstract]
Anti-dilutive securities not included in the weighted average commons shares outstanding calculation (in shares)	352,625	184,569	352,625	184,569