Goodwill And Other Acquired Intangible Assets (Schedule Of Carrying Values Of Amortized Acquired Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2011	Nov. 30, 2010
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, intangible assets subject to amortization	$ 302,404	$ 274,382
Accumulated Amortization, intangible assets subject to amortization	(206,846)	(171,264)
Net Carrying Amount, intangible assets subject to amortization	95,558	103,118
In-process research and development, Gross Carrying Amount	1,700
Total intangible assets, Gross Carrying Amount	304,104	276,082
Total intangible assets, Net Carrying Amount	97,258	104,818
Developed Technologies [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, intangible assets subject to amortization	146,289	129,492
Accumulated Amortization, intangible assets subject to amortization	(102,034)	(85,589)
Net Carrying Amount, intangible assets subject to amortization	44,255	43,903
Customer Base [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, intangible assets subject to amortization	56,165	49,433
Accumulated Amortization, intangible assets subject to amortization	(37,376)	(31,606)
Net Carrying Amount, intangible assets subject to amortization	18,789	17,827
Patents/Core Technologies [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, intangible assets subject to amortization	27,922	27,628
Accumulated Amortization, intangible assets subject to amortization	(21,542)	(17,373)
Net Carrying Amount, intangible assets subject to amortization	6,380	10,255
Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, intangible assets subject to amortization	9,771	8,334
Accumulated Amortization, intangible assets subject to amortization	(7,077)	(6,103)
Net Carrying Amount, intangible assets subject to amortization	2,694	2,231
Non-Compete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
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]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, intangible assets subject to amortization	61,677	57,915
Accumulated Amortization, intangible assets subject to amortization	(38,237)	(29,052)
Net Carrying Amount, intangible assets subject to amortization	23,440	28,863
In-Process Research And Development [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
In-process research and development, Gross Carrying Amount	1,700	1,700
In-process research and development, Net Carrying Amount	$ 1,700	$ 1,700