Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Aug. 31, 2012	Aug. 31, 2011
Cash flows from operating activities:
Net income	$ 11,419	$ 47,454
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property and equipment	6,990	6,569
Amortization of acquired intangibles and other	18,379	18,064
Stock-based compensation	21,504	18,755
Asset impairment	875	0
Deferred income taxes	888	(3,768)
Tax benefit from stock plans	563	5,945
Excess tax benefit from stock plans	(1,338)	(3,998)
Allowances for accounts receivable	774
Changes in operating assets and liabilities:
Accounts receivable	30,250	40,255
Other assets	(5,412)	4,244
Accounts payable and accrued liabilities	4,201	(27,240)
Income taxes payable and uncertain tax positions	(2,760)	11,093
Deferred revenue	(10,619)	755
Net cash flows from operating activities	75,714	118,128
Cash flows from investing activities:
Purchases of investments	(27,924)	(105,125)
Sales and maturities of investments	70,185	50,435
Redemptions at par by issuers of auction rate securities	2,925	6,300
Purchases of property and equipment	(6,606)	(13,956)
Increase in other noncurrent assets	247	(814)
Net cash flows from investing activities	38,827	(63,160)
Cash flows from financing activities:
Proceeds from stock-based compensation plans	24,284	41,496
Purchases of common stock related to withholding taxes from the issuance of restricted stock units	(2,681)	(1,720)
Repurchases of common stock	0	(134,892)
Excess tax benefit from stock plans	1,338	3,998
Payment of long-term debt	(357)	(276)
Payment of issuance costs for revolving line of credit	0	752
Net cash flows from financing activities	22,584	(92,146)
Effect of exchange rate changes on cash	(3,822)	8,388
Net increase (decrease) in cash and equivalents	133,303	(28,790)
Cash and cash equivalents, beginning of period	161,095	286,559
Cash and cash equivalents, end of period	294,398	257,769
Supplemental disclosure:
Cash paid for income taxes, net of refunds of $632 in 2012 and $8,441 in 2011	$ 13,912	$ 7,696