Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net sales	$ 603,446	$ 555,487	$ 526,544
Cost of sales	332,642	311,349	341,645
Gross profit	270,804	244,138	184,899
Operating expenses:
Research and development and other engineering	25,886	21,110	18,756
Selling	73,568	63,293	58,790
General and administrative	95,820	79,788	75,063
Impairment of goodwill	1,282	6,292
Loss (gain) on sale of assets	191	(4,769)	794
Total operating expenses	196,747	165,714	153,403
Income from operations	74,057	78,424	31,496
Income (loss) in equity method investment, before tax	4,389	(535)	(194)
Interest income	913	492	542
Interest expense	(573)	(344)	(367)
Income from continuing operations before taxes	78,786	78,037	31,477
Provision for income taxes from continuing operations	27,886	33,239	17,356
Income from continuing operations, net of tax	50,900	44,798	14,121
Loss from discontinued operations, net of tax		(16,212)	(1,904)
Net income	$ 50,900	$ 28,586	$ 12,217
Basic
Continuing operations (in dollars per share)	$ 1.04	$ 0.91	$ 0.29
Discontinued operations (in dollars per share)		$ (0.33)	$ (0.04)
Net income (in dollars per share)	$ 1.04	$ 0.58	$ 0.25
Diluted
Continuing operations (in dollars per share)	$ 1.04	$ 0.90	$ 0.29
Discontinued operations (in dollars per share)		$ (0.33)	$ (0.04)
Net income (in dollars per share)	$ 1.04	$ 0.58	$ 0.25
Weighted average number of shares outstanding
Basic (in shares)	48,974	49,498	49,135
Diluted (in shares)	49,023	49,612	49,256