Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	9 Months Ended
	Apr. 30, 2011	Apr. 30, 2010
Cash flows from operating activities
Net income (loss)	$ 2,503	$ (34,420)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	10,963	7,493
Provision for doubtful accounts	4	259
Write downs for excess and obsolete inventory	2,445	1,476
Stock-based compensation expense	45,828	26,765
Accretion of purchase discounts on short-term investments	997	482
Loss/ (gain) on disposal of fixed assets	(6)	19
Change in carrying value of contingent rights liability	(7,991)	0
Excess tax benefit associated with stock-based compensation	(15)	0
Changes in operating assets and liabilities:
Accounts receivable	(23,674)	1,523
Inventory	(7,211)	(9,123)
Prepaids and other	(873)	(1,147)
Deferred costs	(1,252)	(960)
Other assets	(426)	107
Accounts payable	(1,099)	4,145
Deferred revenue	6,451	6,555
Other current and noncurrent liabilities	8,009	12,493
Income taxes payable	138	(220)
Net cash provided by operating activities	34,791	15,447
Cash flows from investing activities
Purchases of short-term investments	(81,511)	(79,766)
Proceeds from sales of short-term investments	19,876	3,001
Proceeds from maturities of short-term investments	51,030	42,965
Purchases of property and equipment	(5,776)	(3,378)
Proceeds from sale of property and equipment	14	23
Cash paid in purchase acquisitions, net of cash acquired	(4,303)	0
Net cash used in investing activities	(20,670)	(37,155)
Cash flows from financing activities
Proceeds from issuance of common stock	31,856	9,957
Repurchases of unvested common stock	0	(36)
Excess tax benefit associated with stock-based compensation	15	0
Net cash provided by financing activities	31,871	9,921
Effect of exchange rate changes on cash and cash equivalents	(1)	(1)
Net increase (decrease) in cash and cash equivalents	45,991	(11,788)
Cash and cash equivalents, beginning of period	31,254	41,298
Cash and cash equivalents, end of period	77,245	29,510
Supplemental disclosure of cash flow information
Income taxes paid	781	768
Supplemental disclosure of non-cash investing and financing activities
Common stock issued for purchase acquisition	30,691	0
Contingent rights issued for purchase acquisition	$ 9,486	$ 0