Goodwill And Acquired Intangible Assets (Carrying Value Of Intangible Assets By Major Class) (Details) (USD $) In Thousands	Aug. 31, 2011	Nov. 30, 2010
Gross carrying amount, intangible assets subject to amortization	$ 291,829	$ 274,382
Accumulated amortization, intangible assets subject to amortization	(206,353)	(171,264)
Net carrying amount, intangible assets subject to amortization	85,476	103,118
In-process research and development, gross carrying amount	1,700	1,700
In-process research and development, net carrying amount	1,700	1,700
Total intangible assets net, gross carrying amount	293,529	276,082
Total intangible assets net, accumulated amortization	(206,353)	(171,264)
Total intangible assets net, net carrying amount	87,176	104,818
Developed Technologies [Member]
Gross carrying amount, intangible assets subject to amortization	136,404	129,492
Accumulated amortization, intangible assets subject to amortization	(102,360)	(85,589)
Net carrying amount, intangible assets subject to amortization	34,044	43,903
Customer Base [Member]
Gross carrying amount, intangible assets subject to amortization	56,225	49,433
Accumulated amortization, intangible assets subject to amortization	(37,368)	(31,606)
Net carrying amount, intangible assets subject to amortization	18,857	17,827
Patents/Core Technologies [Member]
Gross carrying amount, intangible assets subject to amortization	28,837	27,628
Accumulated amortization, intangible assets subject to amortization	(21,650)	(17,373)
Net carrying amount, intangible assets subject to amortization	7,187	10,255
Trademarks [Member]
Gross carrying amount, intangible assets subject to amortization	9,120	8,334
Accumulated amortization, intangible assets subject to amortization	(7,022)	(6,103)
Net carrying amount, intangible assets subject to amortization	2,098	2,231
Non-compete Agreements [Member]
Gross carrying amount, intangible assets subject to amortization	580	1,580
Accumulated amortization, intangible assets subject to amortization	(580)	(1,541)
Net carrying amount, intangible assets subject to amortization		39
Maintenance Agreements [Member]
Gross carrying amount, intangible assets subject to amortization	60,663	57,915
Accumulated amortization, intangible assets subject to amortization	(37,373)	(29,052)
Net carrying amount, intangible assets subject to amortization	$ 23,290	$ 28,863