Condensed Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Apr. 30, 2013		Apr. 30, 2012		Apr. 30, 2013		Apr. 30, 2012
Net revenue:
Product	$ 121,188		$ 115,094		$ 366,498		$ 351,290
Engineering	4,577		6,176		17,688		14,270
Total net revenue	125,765		121,270		384,186		365,560
Cost of sales:
Product	72,341		71,613		218,355		218,549
Engineering	4,284		4,905		16,206		12,388
Total cost of sales	76,625		76,518		234,561		230,937
Gross profit	49,140		44,752		149,625		134,623
Operating expenses:
Research and product development	16,127		13,106		46,324		42,313
Selling and marketing	13,540		10,925		37,062		31,995
General and administrative	12,265		10,848		37,793		37,067
Restructuring	496				496
Total operating expenses	42,428		34,879		121,675		111,375
Income from operations	6,712		9,873		27,950		23,248
Other income (expense):
Interest income, net	76		98		284		367
Gain on sale of other investments							2,500
Other, net	114		325		(1,402)		822
Total other income (expense), net	190	[1]	423	[1]	(1,118)	[1]	3,689	[1]
Income before income taxes	6,902		10,296		26,832		26,937
Provision for (benefit from) income taxes	1,678		2,966		7,418		(4,034)
Net income	$ 5,224		$ 7,330		$ 19,414		$ 30,971
Net income per common share:
Basic	$ 0.42		$ 0.60		$ 1.58		$ 2.48
Diluted	$ 0.41		$ 0.59		$ 1.54		$ 2.45
Weighted average shares outstanding:
Basic	12,305		12,227		12,300		12,470
Diluted	12,620		12,433		12,584		12,636
Dividends declared and paid per share:	$ 0.10		$ 0.10		$ 0.30		$ 0.30

[1] Includes a gain of $2,500 from the sale of our remaining interest in our China based affiliate received in the nine months ended April 30, 2012.