Condensed Consolidated Statements of Income (unaudited) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Condensed Consolidated Statements of Income (unaudited)
Net sales	$ 227,041,000	$ 214,624,000	$ 747,554,000	$ 692,569,000
Cost of sales	177,598,000	168,224,000	581,234,000	529,495,000
Gross profit	49,443,000	46,400,000	166,320,000	163,074,000
Selling, general, administrative and engineering expenses	40,003,000	37,362,000	122,266,000	115,640,000
Asset impairment charge	0	0	0	2,170,000
Income from operations	9,440,000	9,038,000	44,054,000	45,264,000
Interest expense	152,000	46,000	242,000	140,000
Other income, net of expenses	856,000	264,000	2,333,000	1,037,000
Income before income taxes	10,144,000	9,256,000	46,145,000	46,161,000
Income taxes	3,244,000	1,492,000	16,558,000	14,134,000
Net income	6,900,000	7,764,000	29,587,000	32,027,000
Net income attributable to non-controlling interest	48,000	41,000	124,000	74,000
Net income attributable to controlling interest	$ 6,852,000	$ 7,723,000	$ 29,463,000	$ 31,953,000
Net income attributable to controlling interest:
Basic (in dollars per share)	$ 0.30	$ 0.34	$ 1.30	$ 1.42
Diluted (in dollars per share)	$ 0.30	$ 0.34	$ 1.28	$ 1.39
Weighted average number of common shares outstanding:
Basic (in shares)	22,691	22,599	22,675	22,580
Diluted (in shares)	23,053	23,007	23,049	22,973