Short-Term Investments (Tables)

12 Months Ended

Jul. 31, 2011

Short-term Investments [Abstract]

Summary of Short-Term Investments

			Gross		Gross
	Cost		Unrealized		Unrealized			Fair
	Basis		Gains		Losses			Value
	(In thousands)
As of July 31, 2011
Corporate bonds and notes	$	41,912	$	118	$	(10	)	$	42,020
U.S. government agency securities		40,824		33		(7	)		40,850
U.S. treasury bills		57,026		72		(5	)		57,093
Commercial paper		5,590		2		—			5,592
Certificates of deposit		7,618		12		—			7,630
Total short-term investments	$	152,970	$	237	$	(22	)	$	153,185

Cost Basis and Fair Value of Debt Securities by Contractual Maturity

			Gross		Gross
	Cost		Unrealized		Unrealized			Fair
	Basis		Gains		Losses			Value
	(In thousands)
As of July 31, 2010
Corporate bonds and notes	$	23,802	$	69	$	(4	)	$	23,867
U.S. government agency securities		80,683		78		(9	)		80,752
U.S. treasury bills		12,816		57		—			12,873
Commercial paper		4,495		—		—			4,495
Certificates of deposit		2,179		1		—			2,180
Total short-term investments	$	123,975	$	205	$	(13	)	$	124,167

The cost basis and fair value of debt securities by contractual maturity are presented below:

	Cost		Fair
	Basis		Value
	(In thousands)
As of July 31, 2011
One year or less	$	60,255	$	60,358
One to two years		92,715		92,827
Total short-term investments	$	152,970	$	153,185

	Cost		Fair
	Basis		Value
	(In thousands)
As of July 31, 2010
One year or less	$	93,597	$	93,700
One to two years		30,378		30,467
Total short-term investments	$	123,975	$	124,167

Fair value and gross unrealized losses of the Company's investments

	Less Than 12 Months
	Fair		Unrealized
	Value		Loss
	(In thousands)
As of July 31, 2011
Corporate bonds and notes	$	6,264	$	(10	)
U.S. government agency securities		11,576		(7	)
U.S. treasury bill		10,029		(5	)
	$	27,869	$	(22	)

	Less Than 12 Months
	Fair		Unrealized
	Value		Loss
	(In thousands)
As of July 31, 2010
Corporate bonds and notes	$	7,400	$	(4	)
U.S. government agency securities		15,245		(9	)
	$	22,645	$	(13	)

Fair value measurements of the Company's cash, cash equivalents and short-term investments

	Total		Level 1		Level 2
	(In thousands)
As of July 31, 2011
Corporate bonds and notes	$	42,020		—	$	42,020
U.S. government agency securities		40,850		—		40,850
U.S. treasury bills		57,093		—		57,093
Commercial paper		5,592		—		5,592
Money market funds		16,722		16,722		—
Total cash equivalents and short-term investments		162,277	$	16,722	$	145,555
Certificates of deposit		7,630
Cash deposits with third-party financial institutions		64,051
Total cash, cash equivalents and short-term investments	$	233,958

	Total		Level 1		Level 2
	(In thousands)
As of July 31, 2010
Corporate bonds and notes	$	23,867		—	$	23,867
U.S. government agency securities		80,752		—		80,752
U.S. treasury bills		12,873		—		12,873
Commercial paper		4,495		—		4,495
Money market funds		9,895		9,895		—
Total cash equivalents and short-term investments		131,882	$	9,895	$	121,987
Certificates of deposit		2,180
Cash deposits with third-party financial institutions		21,359
Total cash, cash equivalents and short-term investments	$	155,421