Intangible Assets and Goodwill (Schedule Of Intangible Assets) (Details) - USD ($) $ in Thousands	Aug. 31, 2017	Nov. 30, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 237,428	$ 192,628
Accumulated Amortization	(135,651)	(111,801)
Net Book Value	101,777	80,827
Purchased technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	151,886	109,886
Accumulated Amortization	(82,245)	(68,116)
Net Book Value	69,641	41,770
Customer-related [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	67,802	67,602
Accumulated Amortization	(43,632)	(35,852)
Net Book Value	24,170	31,750
Trademarks and trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	17,740	15,140
Accumulated Amortization	(9,774)	(7,833)
Net Book Value	$ 7,966	$ 7,307