CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2012	Apr. 30, 2011
Net revenue:
Product	$ 115,094	$ 113,791	$ 351,290	$ 321,795
Engineering	6,176	3,380	14,270	16,451
Total net revenue	121,270	117,171	365,560	338,246
Cost of sales:
Product	71,613	69,714	218,549	199,366
Engineering	4,905	3,297	12,388	14,892
Total cost of sales	76,518	73,011	230,937	214,258
Gross profit	44,752	44,160	134,623	123,988
Operating expenses:
Research and product development	13,106	17,291	42,313	45,964
Selling and marketing	10,925	10,280	31,995	30,604
General and administrative	10,848	10,892	37,067	29,959
Restructuring				3,428
Total operating expenses	34,879	38,463	111,375	109,955
Income from operations	9,873	5,697	23,248	14,033
Other income (expense):
Interest income, net	98	137	367	543
Gain on sale of other investments			2,500
Other, net	325	(293)	822	(669)
Total other income (expense), net	423	(156)	3,689	(126)
Income from continuing operations before income taxes	10,296	5,541	26,937	13,907
Provision for (benefit from) income taxes	2,966	1,223	(4,034)	2,912
Income from continuing operations	7,330	4,318	30,971	10,995
Income from discontinued operations (net of income tax provision of $168)				289
Gain on disposal of discontinued operations (net of income tax provision of $505)				924
Net income	$ 7,330	$ 4,318	$ 30,971	$ 12,208
Basic net income per share:
Income from continuing operations	$ 0.60	$ 0.35	$ 2.48	$ 0.88
Income from discontinued operations, net of tax				$ 0.02
Gain on disposal of discontinued operations, net of tax				$ 0.07
Basic net income per share	$ 0.60	$ 0.35	$ 2.48	$ 0.97
Diluted net income per share:
Income from continuing operations	$ 0.59	$ 0.35	$ 2.45	$ 0.88
Income from discontinued operations, net of tax				$ 0.02
Gain on disposal of discontinued operations, net of tax				$ 0.07
Diluted net income per share	$ 0.59	$ 0.35	$ 2.45	$ 0.97
Weighted average shares outstanding:
Basic	12,227	12,381	12,470	12,526
Diluted	12,433	12,487	12,636	12,600