Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Jul. 31, 2012		Jul. 31, 2011		Jul. 31, 2010
Net revenue:
Product	$ 494,675		$ 447,622		$ 393,765
Engineering	21,896		25,973		21,048
Total net revenue	516,571		473,595		414,813
Cost of sales:
Product	302,288		278,153		248,350
Engineering	21,099		22,479		18,566
Total cost of sales	323,387		300,632		266,916
Gross profit	193,184		172,963		147,897
Operating expenses:
Research and product development	57,230		63,125		49,150
Selling and marketing	44,238		41,413		36,793
General and administrative	51,753		40,623		39,944
Restructuring			7,066		690
Total operating expenses	153,221		152,227		126,577
Income from operations	39,963		20,736		21,320
Other income (expense):
Interest income, net	532		711		633
Gain on sale of other investments	2,500
Other, net	1,204		(515)		(486)
Total other income, net	4,236	[1]	196	[1]	147	[1]
Income from continuing operations before income taxes	44,199		20,932		21,467
Provision for income taxes	1,128		4,312		5,668
Income from continuing operations	43,071		16,620		15,799
Income (loss) from discontinued operations (net of income tax provision of $168 for fiscal year 2011 and an income tax benefit of $66 for fiscal year 2010.)			289		(244)
Gain on disposal of discontinued operations (net of income tax provision of $505)			924
Net income	$ 43,071		$ 17,833		$ 15,555
Basic net income (loss) per share:
Income from continuing operations	$ 3.51		$ 1.33		$ 1.26
Income (loss) from discontinued operations, net of tax			$ 0.02		$ (0.02)
Gain on disposal of discontinued operations, net of tax			$ 0.08
Basic net income per share	$ 3.51		$ 1.43		$ 1.24
Diluted net income (loss) per share:
Income from continuing operations	$ 3.42		$ 1.33		$ 1.25
Income (loss) from discontinued operations, net of tax			$ 0.02		$ (0.02)
Gain on disposal of discontinued operations, net of tax			$ 0.07
Diluted net income per share	$ 3.42		$ 1.42		$ 1.23
Weighted average shares outstanding:
Basic	12,265		12,491		12,584
Diluted	12,576		12,572		12,655

[1] Includes a gain of $2,500 from the sale of the Company's remaining interest in its China based affiliate received in fiscal year 2012. Includes net interest income of $532, $711, and $633 in fiscal years 2012, 2011, and 2010, respectively.