Condensed Consolidated Statements of Income (unaudited) (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Condensed Consolidated Statements of Operations [Abstract]
Net sales	$ 247,756	$ 209,249	$ 477,945	$ 402,704
Cost of sales	185,785	162,571	361,271	309,884
Gross profit	61,971	46,678	116,674	92,820
Selling, general, administrative and engineering expenses	38,789	30,824	78,278	63,542
Asset impairment charge	2,170	0	2,170	0
Income from operations	21,012	15,854	36,226	29,278
Interest expense	58	135	94	259
Other income, net of expenses	366	122	773	610
Income before income taxes	21,320	15,841	36,905	29,629
Income taxes	7,215	5,511	12,642	10,467
Net income	14,105	10,330	24,263	19,162
Net income attributable to non-controlling interest	19	22	33	60
Net income attributable to controlling interest	$ 14,086	$ 10,308	$ 24,230	$ 19,102
Net income attributable to controlling interest:
Basic	$ 0.62	$ 0.46	$ 1.07	$ 0.85
Diluted	$ 0.61	$ 0.45	$ 1.06	$ 0.84
Weighted average number of common shares outstanding:
Basic	22,576,222	22,507,078	22,571,192	22,490,431
Diluted	22,991,917	22,832,785	22,955,707	22,800,223