Intangible Assets and Goodwill (Schedule Of Intangible Assets) (Details) - USD ($) $ in Thousands	Feb. 28, 2018	Nov. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 239,843	$ 239,843
Accumulated Amortization	(154,086)	(144,949)
Net Book Value	85,757	94,894
Purchased technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	154,301	154,301
Accumulated Amortization	(94,043)	(88,224)
Net Book Value	60,258	66,077
Customer-related [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	67,802	67,802
Accumulated Amortization	(48,828)	(46,230)
Net Book Value	18,974	21,572
Trademarks and trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	17,740	17,740
Accumulated Amortization	(11,215)	(10,495)
Net Book Value	$ 6,525	$ 7,245