Intangible Assets and Goodwill (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2013	May 31, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life			4 years 10 months 24 days
Intangible assets, amortization expense	$ 300,000	$ 300,000	$ 600,000	$ 800,000
Goodwill impairment loss	0
Purchased Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible asset, amount	7,800,000		7,800,000
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible asset, amount	$ 200,000		$ 200,000