Consolidated Statements of Operations (USD $)	12 Months Ended
	Jul. 31, 2011		Jul. 31, 2010		Jul. 31, 2009
Condensed Consolidated Statements of Operations
Net sales	$ 612,379,000		$ 778,205,000		$ 586,372,000
Cost of sales	371,333,000		507,607,000		345,472,000
Gross profit	241,046,000		270,598,000		240,900,000
Expenses:
Selling, general and administrative	94,141,000		99,883,000		100,171,000
Research and development	43,516,000		46,192,000		50,010,000
Amortization of acquired in-process research and development	0		0		6,200,000
Amortization of intangibles	8,091,000		7,294,000		7,592,000
Impairment of goodwill	0		13,249,000		0
Merger termination fee, net	(12,500,000)		0		0
Total operating expenses	133,248,000		166,618,000		163,973,000
Operating income	107,798,000		103,980,000		76,927,000
Other expenses (income):
Interest expense	8,415,000		7,888,000		6,396,000
Interest income and other	(2,421,000)		(1,210,000)		(2,738,000)
Income before provision for income taxes	101,804,000		97,302,000		73,269,000
Provision for income taxes	33,909,000		36,672,000		25,744,000
Net income	$ 67,895,000		$ 60,630,000		$ 47,525,000
Net income per share:
Basic	$ 2.53		$ 2.14		$ 1.81
Diluted	$ 2.22	[1]	$ 1.91	[1]	$ 1.73	[1]
Weighted average number of common shares outstanding - basic	26,842,000		28,270,000		26,321,000
Weighted average number of common and common equivalent shares outstanding - diluted	32,623,000		34,074,000		29,793,000
Dividends declared per issued and outstanding common share as of the applicable dividend record date	$ 1		$ 0		$ 0

[1] * Income per share information for the full fiscal year may not equal the total of the quarters within the year.