Earnings Per Share (EPS) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
Basic EPS
Income from continuing operations attributable to MTI	$ 21,900,000	$ 19,100,000	$ 63,400,000	$ 57,900,000
Loss from discontinued operations attributable to MTI	0	(500,000)	(5,700,000)	(1,500,000)
Net income attributable to MTI	21,864,000	18,630,000	57,741,000	56,377,000
Weighted average shares outstanding (in shares)	34,615,000	35,280,000	34,803,000	35,388,000
Basic earnings per share from continuing operations attributable to MTI (in dollars per share)	$ 0.63	$ 0.54	$ 1.82	$ 1.64
Basic loss per share from discontinued operations attributable to MTI (in dollars per share)	$ 0	$ (0.01)	$ (0.16)	$ (0.04)
Basic earnings per share attributable to MTI (in dollars per share)	$ 0.63	$ 0.53	$ 1.66	$ 1.60
Diluted EPS
Income from continuing operations attributable to MTI	21,900,000	19,100,000	63,400,000	57,900,000
Loss from discontinued operations attributable to MTI	0	(500,000)	(5,700,000)	(1,500,000)
Net income attributable to MTI	$ 21,864,000	$ 18,630,000	$ 57,741,000	$ 56,377,000
Weighted average shares outstanding (in shares)	34,615,000	35,280,000	34,803,000	35,388,000
Dilutive effect of stock options and stock units (in shares)	300,000	200,000	300,000	200,000
Weighted average shares outstanding , adjusted (in shares)	34,881,000	35,466,000	35,054,000	35,550,000
Diluted earnings per share from continuing operations attributable to MTI (in dollars per share)	$ 0.63	$ 0.54	$ 1.81	$ 1.63
Diluted loss per share from discontinued operations attributable to MTI (in dollars per share)	$ 0	$ (0.01)	$ (0.16)	$ (0.04)
Diluted earnings per share attributable to MTI (in dollars per share)	$ 0.63	$ 0.53	$ 1.65	$ 1.59
Anti-dilutive options not included in the weighted average common shares outstanding calculation			238,287	113,000