Earnings Per Share (EPS) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Sep. 30, 2012	Oct. 02, 2011
Basic EPS
Net income attributable to MTI	$ 18,630	$ 15,688	$ 56,377	$ 47,882
Weighted average shares outstanding	17,640,000	17,928,000	17,694,000	18,128,000
Basic earnings per share attributable to MTI	$ 1.06	$ 0.88	$ 3.19	$ 2.64
Diluted EPS
Net income attributable to MTI	$ 18,630	$ 15,688	$ 56,377	$ 47,882
Weighted average shares outstanding	17,640,000	17,928,000	17,694,000	18,128,000
Dilutive effect of stock options and stock units	100,000	100,000	100,000	100,000
Weighted average shares outstanding , adjusted	17,733,000	18,019,000	17,775,000	18,242,000
Diluted earnings per share attributable to MTI	$ 1.05	$ 0.87	$ 3.17	$ 2.62
Anti-dilutive options not included in the weighted average common shares outstanding calculation			113,000	603,869